Thermal power plant summer training report on Rswm ldt. report tpp.
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About This Presentation
thermal power plant summer training report
Slide Content
THERMAL POWER PLANT
A
Practical Training Report
Submitted in partial fulfillment of the requirements for the award of
the degree of
BACHELOR OF TECHNOLOGY
SUBMITTED TO
RAJASTHAN TECHNICAL UNIVERSITY, KOTA
SUBMITTED BY
Ashutosh Mishra
September,2016
PACIFIC COLLEGE OF ENGINEERING, UDAIPUR, RAJASTHAN
A
Practical Training Report
Submitted in partial fulfillment of the requirements for the award of
the degree of
BACHELOR OF TECHNOLOGY
SUBMITTED TO
RAJASTHAN TECHNICAL UNIVERSITY, KOTA
SUBMITTED BY
Ashutosh Mishra
September,2016
PACIFIC COLLEGE OF ENGINEERING, UDAIPUR, RAJASTHAN
i
DECLARATION
I Ashutosh Mishra hereby declare that; I have successfully completed my Practical/Summer
Training from RSWM Ltd., Banswara on Thermal Power Plant during 06-06-2016 to 06-08-
2016.
Signature of the Student
(H.O.D. of Electrical Engg.) Training advisor
DECLARATION
I Ashutosh Mishra hereby declare that; I have successfully completed my Practical/Summer
Training from RSWM Ltd., Banswara on Thermal Power Plant during 06-06-2016 to 06-08-
2016.
Signature of the Student
(H.O.D. of Electrical Engg.) Training advisor
ii
ACKNOWLEDGEMENT
First and foremost, I would like to express my deep sense of gratitude to Mr.Virendra Singh
Kumawat because of them I get the approval of vocational Training in RSWM LTD.
Thermal Power Plant and also I would like to thank to Asst. Ex. Engg.Mr.Abhishek
Sharma and Asst. Engg. Mr. Shiv Shankar Das who helped me during the project.
I enjoyed the amazing work experience of Power Plant maintenance and working style and
positive attitude of Mr. Amit Vaishnav and Mr.Abhishek Sharma in my heart, for their
careful and precious guidance which was extremely valuable for my study work theoretically
and practical knowledge.
I would like to thanks Director of the Institute Mr. Piyush, Principal of the Institute, Prof.
Gajendra Purohit, for include 60days vocational training in our B Tech. curriculum
program.
Especially, I would like to thanks to the Head ofElectrical DepartmentProf. Raju Swamiand
all my faculty members for their support during the project preparation.
Signature of Student
Ashutosh Mishra
ACKNOWLEDGEMENT
First and foremost, I would like to express my deep sense of gratitude to Mr.Virendra Singh
Kumawat because of them I get the approval of vocational Training in RSWM LTD.
Thermal Power Plant and also I would like to thank to Asst. Ex. Engg.Mr.Abhishek
Sharma and Asst. Engg. Mr. Shiv Shankar Das who helped me during the project.
I enjoyed the amazing work experience of Power Plant maintenance and working style and
positive attitude of Mr. Amit Vaishnav and Mr.Abhishek Sharma in my heart, for their
careful and precious guidance which was extremely valuable for my study work theoretically
and practical knowledge.
I would like to thanks Director of the Institute Mr. Piyush, Principal of the Institute, Prof.
Gajendra Purohit, for include 60days vocational training in our B Tech. curriculum
program.
Especially, I would like to thanks to the Head ofElectrical DepartmentProf. Raju Swamiand
all my faculty members for their support during the project preparation.
Signature of Student
Ashutosh Mishra
iii
ABSTRACT
A thermal power plant generated electrical energy but energy not are generated it only
converted one form to other form. Thermal power station is a power plant in which the prime
mover is steam driven. Water is heated, turns into steam and spins a steam which either
drives an electrical generator or does some other work, like ship propulsion. After it passes
through the turbine, the steam is condensed in a condenser and recycled to where it was
heated; this is known as a Rankine cycle. The greatest variation in the design of thermal
power stations is due to the different fuel sources. Some prefer to use the term energy
Centre because such facilities convert forms of heat energy into electrical power
geothermal, solar thermal electric, and waste incineration plants, as well as many natural gas
power plants are thermal.Power plants burning coal, oil or natural gas are often referred to
collectively as fossil-fuel power plants. Some biomass-fuelled thermal power plants have
appeared also.
Commercial electric utility power stations are most usually constructed on a very large scale
and designed for continuous operation. Electric power plants typically use three-phase or
individual-phase electrical generators to produce alternating current (AC) electric power at a
frequency of 50 Hz or 60 Hz (hertz, which is an AC sine wave per second) depending on its
location in the world.
ABSTRACT
A thermal power plant generated electrical energy but energy not are generated it only
converted one form to other form. Thermal power station is a power plant in which the prime
mover is steam driven. Water is heated, turns into steam and spins a steam which either
drives an electrical generator or does some other work, like ship propulsion. After it passes
through the turbine, the steam is condensed in a condenser and recycled to where it was
heated; this is known as a Rankine cycle. The greatest variation in the design of thermal
power stations is due to the different fuel sources. Some prefer to use the term energy
Centre because such facilities convert forms of heat energy into electrical power
geothermal, solar thermal electric, and waste incineration plants, as well as many natural gas
power plants are thermal.Power plants burning coal, oil or natural gas are often referred to
collectively as fossil-fuel power plants. Some biomass-fuelled thermal power plants have
appeared also.
Commercial electric utility power stations are most usually constructed on a very large scale
and designed for continuous operation. Electric power plants typically use three-phase or
individual-phase electrical generators to produce alternating current (AC) electric power at a
frequency of 50 Hz or 60 Hz (hertz, which is an AC sine wave per second) depending on its
location in the world.
iv
List of Content
Chapter Page No.
Declaration i
Acknowledgement ii
Abstract iii
List of Contents iv
List of Tables vii
List of Figures viii
1. Introduction of Company 1
2. Introduction of thermal power station 3
2.1 History 5
2.2 Efficiency 5
2.3 RSWM Ltd. Thermal power plant 7
3. General idea and basic layout of thermal power plant 9
3.1 Introduction 9
3.2 Division of RSWM TPP 9
4. Description of various component of power plant 11
4.1 Cooling tower 11
4.2 Cooling water pump 11
4.3 Electrical power transmission 11
4.4 Transformer 12
4.5 Steam turbine 14
4.6 Surface condenser 16
4.7 Control valves 16
4.8 Deaerator 17
4.9 Water heater 17
4.10 Coal 18
4.11 Pulverizer 18
4.12 Steam drum 18
4.13 Boiler 18
List of Content
Chapter Page No.
Declaration i
Acknowledgement ii
Abstract iii
List of Contents iv
List of Tables vii
List of Figures viii
1. Introduction of Company 1
2. Introduction of thermal power station 3
2.1 History 5
2.2 Efficiency 5
2.3 RSWM Ltd. Thermal power plant 7
3. General idea and basic layout of thermal power plant 9
3.1 Introduction 9
3.2 Division of RSWM TPP 9
4. Description of various component of power plant 11
4.1 Cooling tower 11
4.2 Cooling water pump 11
4.3 Electrical power transmission 11
4.4 Transformer 12
4.5 Steam turbine 14
4.6 Surface condenser 16
4.7 Control valves 16
4.8 Deaerator 17
4.9 Water heater 17
4.10 Coal 18
4.11 Pulverizer 18
4.12 Steam drum 18
4.13 Boiler 18
v
Chapter Page No.
4.14 Superheater 18
4.15 Centrifugal fans(ID & FD fans) 19
4.16 Economizer 20
4.17 Air preheater 20
4.18 Electrostatic precipitator 21
4.19 Flue gas stack 21
5. Coal handling plant 22
5.1 Coal handling plant equipment 22
5.2 Types of coal used in RSWM Ltd. 23
5.3 Rating of impector crusher 23
5.4 Conveying system 24
5.5 Magnetic separator 25
6. Water treatment plant 26
6.1 Introduction 26
6.2 Parts of water treatment plant 26
6.3 Condensate system 28
6.4 Air extraction system 29
6.5 Low pressure heater 30
6.6 Gland cooler 30
6.7 Dearator 30
7. Boiler 31
7.1 Definition of boiler 31
7.2 Working principle of boiler 31
7.3 Types of boiler 32
7.4 Advantage of water tube boiler 32
7.5 Working principle of water tube boiler 32
7.6 Types of water tube boiler 33
8. Steam turbine 34
8.1 Introduction 34
8.2 Principle of operation of steam turbine 34
8.3 Description of 23 MW steam turbine 35
8.4 Feed water and steam cycle 36
Chapter Page No.
4.14 Superheater 18
4.15 Centrifugal fans(ID & FD fans) 19
4.16 Economizer 20
4.17 Air preheater 20
4.18 Electrostatic precipitator 21
4.19 Flue gas stack 21
5. Coal handling plant 22
5.1 Coal handling plant equipment 22
5.2 Types of coal used in RSWM Ltd. 23
5.3 Rating of impector crusher 23
5.4 Conveying system 24
5.5 Magnetic separator 25
6. Water treatment plant 26
6.1 Introduction 26
6.2 Parts of water treatment plant 26
6.3 Condensate system 28
6.4 Air extraction system 29
6.5 Low pressure heater 30
6.6 Gland cooler 30
6.7 Dearator 30
7. Boiler 31
7.1 Definition of boiler 31
7.2 Working principle of boiler 31
7.3 Types of boiler 32
7.4 Advantage of water tube boiler 32
7.5 Working principle of water tube boiler 32
7.6 Types of water tube boiler 33
8. Steam turbine 34
8.1 Introduction 34
8.2 Principle of operation of steam turbine 34
8.3 Description of 23 MW steam turbine 35
8.4 Feed water and steam cycle 36
vi
Chapter Page No.
9. Generator 37
9.1 Introduction 37
9.2 Stator 38
9.3 Terminal bushing 39
9.4 Bearings 39
9.5 Hydrogen cooler 40
9.6 Rotor 40
10. Rating of various equipment 42
10.1 Induction motor 42
10.2 Rating of ACW motor 43
10.3 Rating of DM plant HMDC pump motor 43
10.4 Circuit breaker 43
11. Switch yard component of plant 48
11.1 Potential transformer 48
11.2 Current transformer 48
11.3 Lightning arrester 49
11.4 Isolator 49
12. Ash handling plant 51
12.1 Introduction 51
12.2 Chimney 53
12.3 Controller 54
12.4 High voltage rectifier transmission 54
12.5 Electrostatic precipitator 54
12.6 Fans 54
13. Cooling and excitation system 57
13.1 Cooling towers 57
13.2 Excitation system 57
13.3 Static excitation system 58
13.4 General arrangement 58
13.5 Operation 59
14. Conclusion 60
15. Reference 61
Chapter Page No.
9. Generator 37
9.1 Introduction 37
9.2 Stator 38
9.3 Terminal bushing 39
9.4 Bearings 39
9.5 Hydrogen cooler 40
9.6 Rotor 40
10. Rating of various equipment 42
10.1 Induction motor 42
10.2 Rating of ACW motor 43
10.3 Rating of DM plant HMDC pump motor 43
10.4 Circuit breaker 43
11. Switch yard component of plant 48
11.1 Potential transformer 48
11.2 Current transformer 48
11.3 Lightning arrester 49
11.4 Isolator 49
12. Ash handling plant 51
12.1 Introduction 51
12.2 Chimney 53
12.3 Controller 54
12.4 High voltage rectifier transmission 54
12.5 Electrostatic precipitator 54
12.6 Fans 54
13. Cooling and excitation system 57
13.1 Cooling towers 57
13.2 Excitation system 57
13.3 Static excitation system 58
13.4 General arrangement 58
13.5 Operation 59
14. Conclusion 60
15. Reference 61
vii
List of Table
Table Page no.
10.1 Technical data of ACW motor 43
10.2 Technical data of DM plant HMDC motor pump 43
10.3 Technical data of vacuum circuit breaker of STG incomer-2 46
10.4 Technical data of air circuit breaker incomer-1 47
List of Table
Table Page no.
10.1 Technical data of ACW motor 43
10.2 Technical data of DM plant HMDC motor pump 43
10.3 Technical data of vacuum circuit breaker of STG incomer-2 46
10.4 Technical data of air circuit breaker incomer-1 47
viii
List of Figure
Figure Page no.
1.1 RSWM Ltd., Banswara 1
2.1 Typical coal fired thermal power plant 4
2.2 Block diagram of thermal power plant 6
2.3 Block diagram of RSWM plant 8
3.1 Layout of power plant 9
4.1 Electric power transmission 11
4.2 Transformer 13
4.3 Steam turbine 14
4.4 Arrangement of steam turbine 15
4.5 Centrifugal fan 19
4.6 Air preheater 20
5.1 Block diagram of coal handling plant 24
6.1 Systematic diagram of water treatment plant 26
6.2 Block diagram of Demineralization plant 28
7.1 Boiler 31
7.2 Water tube boiler conceptual diagram 33
8.1 Overview of steam turbine 34
9.1 Generator 37
List of Figure
Figure Page no.
1.1 RSWM Ltd., Banswara 1
2.1 Typical coal fired thermal power plant 4
2.2 Block diagram of thermal power plant 6
2.3 Block diagram of RSWM plant 8
3.1 Layout of power plant 9
4.1 Electric power transmission 11
4.2 Transformer 13
4.3 Steam turbine 14
4.4 Arrangement of steam turbine 15
4.5 Centrifugal fan 19
4.6 Air preheater 20
5.1 Block diagram of coal handling plant 24
6.1 Systematic diagram of water treatment plant 26
6.2 Block diagram of Demineralization plant 28
7.1 Boiler 31
7.2 Water tube boiler conceptual diagram 33
8.1 Overview of steam turbine 34
9.1 Generator 37
ix
Figure Page no.
10.1 Induction motor 42
11.1 Potential transformer 48
11.2 Current transformer 49
11.3 Isolator 49
12.1 Overview of ash handling plant 51
Figure Page no.
10.1 Induction motor 42
11.1 Potential transformer 48
11.2 Current transformer 49
11.3 Isolator 49
12.1 Overview of ash handling plant 51
1
CHAPTER - 1
Introduction of company
Fig. 1.1 RSWM LIMITED, BANSWARA
RSWM Limited, the flagship Company of the LNJ Bhilwara Group, is one of the largest
textile manufacturers in the country, primarily producing the best quality of yarns like
synthetic, blended, mélange, cotton, specialty yarns and the value added - suiting and denim
fabrics.Established in 1961, RSWM is an IS/ISO 9001:2001 and SA-8000:2008 accredited
Company, which moved from strength to strength and today, the largest manufacturer and
exporter of synthetic spun yarns from India. RSWM has built one of the most impressive
textile manufacturing infrastructures in the country: 8 state-of-the-art manufacturing plants;
4,10,000 spindles; 190 looms; 1,20,000 MTA yarn capacity; 30 MMA fabric capacities,
including denim fabric. The Company also owns a fabric process house at Mordi (Rajasthan).
RSWM is self-reliant in captive power generation of 46 MW that feeds to its integrated units
spread across the state of Rajasthan, located at Kharigram, Banswara, Mordi, Mandpam,
Rishabhdev and Ringas. The main competitive strength of the Company is its innovative
product range that includes specialty, functional and technical yarns and fabrics. The
Company recently has shifted its focus to produce more and more eco-friendly and natural
textiles in order to meet the emerging needs of the market.
RSWM exports its range of yarn and fabric to over 73 countries worldwide.
CHAPTER - 1
Introduction of company
Fig. 1.1 RSWM LIMITED, BANSWARA
RSWM Limited, the flagship Company of the LNJ Bhilwara Group, is one of the largest
textile manufacturers in the country, primarily producing the best quality of yarns like
synthetic, blended, mélange, cotton, specialty yarns and the value added - suiting and denim
fabrics.Established in 1961, RSWM is an IS/ISO 9001:2001 and SA-8000:2008 accredited
Company, which moved from strength to strength and today, the largest manufacturer and
exporter of synthetic spun yarns from India. RSWM has built one of the most impressive
textile manufacturing infrastructures in the country: 8 state-of-the-art manufacturing plants;
4,10,000 spindles; 190 looms; 1,20,000 MTA yarn capacity; 30 MMA fabric capacities,
including denim fabric. The Company also owns a fabric process house at Mordi (Rajasthan).
RSWM is self-reliant in captive power generation of 46 MW that feeds to its integrated units
spread across the state of Rajasthan, located at Kharigram, Banswara, Mordi, Mandpam,
Rishabhdev and Ringas. The main competitive strength of the Company is its innovative
product range that includes specialty, functional and technical yarns and fabrics. The
Company recently has shifted its focus to produce more and more eco-friendly and natural
textiles in order to meet the emerging needs of the market.
RSWM exports its range of yarn and fabric to over 73 countries worldwide.
2
The Company holds the prestigious ‘Golden Trading House’ status and, has received Export
Awards from the Synthetic and Rayon Textiles Export Promotion Council for several years.
The Company is a recipient of the “Rajiv Gandhi National Quality Award” received twice
from the Bureau of Indian Standards and many more quality certifications.
One of the leading brand from RSWM, `MayurSuitings’, enjoys high brand equity in its
target segment in the country.
The Company holds the prestigious ‘Golden Trading House’ status and, has received Export
Awards from the Synthetic and Rayon Textiles Export Promotion Council for several years.
The Company is a recipient of the “Rajiv Gandhi National Quality Award” received twice
from the Bureau of Indian Standards and many more quality certifications.
One of the leading brand from RSWM, `MayurSuitings’, enjoys high brand equity in its
target segment in the country.
3
CHAPTER - 2
Introduction of thermal power station
A thermal power plant generated electrical energy but energy not are generated it only
converted one form to other form.Thermal power station is a power plant in which the prime
mover is steam driven. Water is heated, turns into steam and spins a steam which either
drives an electrical generator or does some other work, like ship propulsion. After it passes
through the turbine, the steam is condensed in a condenser and recycled to where it was
heated; this is known as a Rankine cycle. The greatest variation in the design of thermal
power stations is due to the different fuel sources. Some prefer to use the term energy
Centre because such facilities convert forms of heat energy into electrical power
geothermal, solar thermal electric, and waste incineration plants, as well as many natural gas
power plants are thermal. Natural gas is frequently combusted in gas turbines as well
as boilers. The waste heat from a gas turbine can be used to raise steam, in a combined
cycle plant that improves overall efficiency. Power plants burning coal, oil or natural gas are
often referred to collectively as fossil-fuel power plants. Some biomass-fuelled thermal
power plants have appeared also. Non-nuclear thermal power plants, particularly fossil-
fuelled plants, which do not use cogeneration, are sometimes referred to asconventional
power plants.
Commercial electric utility power stations are most usually constructed on a very large scale
and designed for continuous operation. Electric power plants typically use three-phase or
individual-phase electrical generators to produce alternating current (AC) electric power at a
frequency of 50 Hz or 60 Hz (hertz, which is an AC sine wave per second) depending on its
location in the world. Other large companies or institutions may have their own usually
smaller power plants to supply heating or electricity to their facilities, especially if heat or
steam is created anyway for other purposes. In some industrial, large institutional facilities, or
other populated areas, there are combined heat and power (CHP) plants, often called
cogeneration plants, which produce both power and heat for facility or district heating or
industrial applications. AC electrical power can be stepped up to very high voltages for long
distance transmission with minimal loss of power. Steam and hot water lose energy when
piped over substantial distance, so carrying heat energy by steam or hot water is often only
worthwhile within a local area or facility, such as steam distribution for a ship or industrial
facility or hot water distribution in a local municipal.
CHAPTER - 2
Introduction of thermal power station
A thermal power plant generated electrical energy but energy not are generated it only
converted one form to other form.Thermal power station is a power plant in which the prime
mover is steam driven. Water is heated, turns into steam and spins a steam which either
drives an electrical generator or does some other work, like ship propulsion. After it passes
through the turbine, the steam is condensed in a condenser and recycled to where it was
heated; this is known as a Rankine cycle. The greatest variation in the design of thermal
power stations is due to the different fuel sources. Some prefer to use the term energy
Centre because such facilities convert forms of heat energy into electrical power
geothermal, solar thermal electric, and waste incineration plants, as well as many natural gas
power plants are thermal. Natural gas is frequently combusted in gas turbines as well
as boilers. The waste heat from a gas turbine can be used to raise steam, in a combined
cycle plant that improves overall efficiency. Power plants burning coal, oil or natural gas are
often referred to collectively as fossil-fuel power plants. Some biomass-fuelled thermal
power plants have appeared also. Non-nuclear thermal power plants, particularly fossil-
fuelled plants, which do not use cogeneration, are sometimes referred to asconventional
power plants.
Commercial electric utility power stations are most usually constructed on a very large scale
and designed for continuous operation. Electric power plants typically use three-phase or
individual-phase electrical generators to produce alternating current (AC) electric power at a
frequency of 50 Hz or 60 Hz (hertz, which is an AC sine wave per second) depending on its
location in the world. Other large companies or institutions may have their own usually
smaller power plants to supply heating or electricity to their facilities, especially if heat or
steam is created anyway for other purposes. In some industrial, large institutional facilities, or
other populated areas, there are combined heat and power (CHP) plants, often called
cogeneration plants, which produce both power and heat for facility or district heating or
industrial applications. AC electrical power can be stepped up to very high voltages for long
distance transmission with minimal loss of power. Steam and hot water lose energy when
piped over substantial distance, so carrying heat energy by steam or hot water is often only
worthwhile within a local area or facility, such as steam distribution for a ship or industrial
facility or hot water distribution in a local municipal.
4
Fig 2.1 Diagram of a typical coal-fired thermal power station
1. Cooling Tower 2.Cooling Water Pump
3. Transmission line (3-phase) 4. Step-up transformer (3-phase)
5. Electrical generator (3-phase) 6. Low pressure steam turbine
7. Condensate pumps 8. Surface condenser
9. Intermediate pressure steam turbine 10. Steam governor valve
11. High pressure steam turbine 12. Deaerator
13. Feed water heater 14. Coal conveyor
15. Coal hopper 16. Coal pulverizer
17. Boiler steam drums 18. Bottom ash hopper
19. Super heater 20. Forced draught (draft) fan
21. Reheater 22. Combustion air intake
23. Economizer 24. Air preheater
Fig 2.1 Diagram of a typical coal-fired thermal power station
1. Cooling Tower 2.Cooling Water Pump
3. Transmission line (3-phase) 4. Step-up transformer (3-phase)
5. Electrical generator (3-phase) 6. Low pressure steam turbine
7. Condensate pumps 8. Surface condenser
9. Intermediate pressure steam turbine 10. Steam governor valve
11. High pressure steam turbine 12. Deaerator
13. Feed water heater 14. Coal conveyor
15. Coal hopper 16. Coal pulverizer
17. Boiler steam drums 18. Bottom ash hopper
19. Super heater 20. Forced draught (draft) fan
21. Reheater 22. Combustion air intake
23. Economizer 24. Air preheater
5
25. Precipitator 26. Induced draught (draft) fan
27. Flue gas stack
2.1. History:-
The initially developed reciprocating steam engine has been used to produce mechanical
power since the 18th Century, with notable improvements being made by James Watt. When
the first commercially developed central electrical power stations were established in 1882 at
Pearl Street Station in New York and Hebron Viaduct power station in London, reciprocating
steam engines were used. The development of the steam turbine in 1884 provided larger and
more efficient machine designs for central generating stations. By 1892 the turbine was
considered a better alternative to reciprocating engines turbines offered higher speeds, more
compact machinery, and stable speed regulation allowing for parallel synchronous operation
of generators on a common bus. After about 1905, turbines entirely replaced reciprocating
engines in large central power stations.
The largest reciprocating engine-generator sets ever built were completed in 1901 for the
Manhattan Elevated Railway. Each of seventeen units weighed about 500 tons and was rated
6000 kilowatts; a contemporary turbine-set of similar rating would have weighed about 20%
as much.
2.2. Efficiency:-
A Rankine cycle with a two-stage steam turbine and a single feed water heater.
The energy efficiency of a conventional thermal power station, considered salable energy
produced as a percent of the heating value of the fuel consumed, is typically 33% to 48%.As
with all heat engines, their efficiency is limited, and governed by the laws of
thermodynamics. By comparison, most hydropower stations in the United States are about 90
percent efficient in converting the energy of falling water into electricity.
The energy of a thermal not utilized in power production must leave the plant in the form of
heat to the environment. This waste heat can go through a condenser and be disposed of with
cooling water or in cooling towers. If the waste heat is instead utilized for district heating, it
is called co-generation. Important classes of thermal power station are associated with
25. Precipitator 26. Induced draught (draft) fan
27. Flue gas stack
2.1. History:-
The initially developed reciprocating steam engine has been used to produce mechanical
power since the 18th Century, with notable improvements being made by James Watt. When
the first commercially developed central electrical power stations were established in 1882 at
Pearl Street Station in New York and Hebron Viaduct power station in London, reciprocating
steam engines were used. The development of the steam turbine in 1884 provided larger and
more efficient machine designs for central generating stations. By 1892 the turbine was
considered a better alternative to reciprocating engines turbines offered higher speeds, more
compact machinery, and stable speed regulation allowing for parallel synchronous operation
of generators on a common bus. After about 1905, turbines entirely replaced reciprocating
engines in large central power stations.
The largest reciprocating engine-generator sets ever built were completed in 1901 for the
Manhattan Elevated Railway. Each of seventeen units weighed about 500 tons and was rated
6000 kilowatts; a contemporary turbine-set of similar rating would have weighed about 20%
as much.
2.2. Efficiency:-
A Rankine cycle with a two-stage steam turbine and a single feed water heater.
The energy efficiency of a conventional thermal power station, considered salable energy
produced as a percent of the heating value of the fuel consumed, is typically 33% to 48%.As
with all heat engines, their efficiency is limited, and governed by the laws of
thermodynamics. By comparison, most hydropower stations in the United States are about 90
percent efficient in converting the energy of falling water into electricity.
The energy of a thermal not utilized in power production must leave the plant in the form of
heat to the environment. This waste heat can go through a condenser and be disposed of with
cooling water or in cooling towers. If the waste heat is instead utilized for district heating, it
is called co-generation. Important classes of thermal power station are associated with
6
desalination facilities; these are typically found in desert countries with large supplies of
natural gas and in these plants, freshwater production and electricity are equally important co-
products.
The Carnot efficiency dictates that higher efficiencies can be attained by increasing the
temperature of the steam. Sub-critical fossil fuel power plants can achieve 36–40%
efficiency. Super critical designs have efficiencies in the low to mid 40% range, with new
"ultra-critical" designs using pressures of 4400 psi (30.3 MPa.) and multiple stage reheat
reaching about 48% efficiency. Above the critical point for water of 705 °F (374 °C) and
3212 psi (22.06 MPa.), there is no phase transition from water to steam, but only a gradual
decrease in density.
Current nuclear power plants must operate below the temperatures and pressures that coal-
fired plants do, since the pressurized vessel is very large and contains the entire bundle of
nuclear fuel rods. The size of the reactor limits the pressure that can be reached. This, in turn,
limits their thermodynamic efficiency to 30–32%. Someadvanced reactor designs being
studied, such as the Very high temperature reactor, Advanced gas-cooled reactor and Super
critical water reactor, would operate at temperatures and pressures similar to current coal
plants, producing comparable thermodynamic efficiency.
Fig 2.2 Block diagram of Thermal Power Plant
desalination facilities; these are typically found in desert countries with large supplies of
natural gas and in these plants, freshwater production and electricity are equally important co-
products.
The Carnot efficiency dictates that higher efficiencies can be attained by increasing the
temperature of the steam. Sub-critical fossil fuel power plants can achieve 36–40%
efficiency. Super critical designs have efficiencies in the low to mid 40% range, with new
"ultra-critical" designs using pressures of 4400 psi (30.3 MPa.) and multiple stage reheat
reaching about 48% efficiency. Above the critical point for water of 705 °F (374 °C) and
3212 psi (22.06 MPa.), there is no phase transition from water to steam, but only a gradual
decrease in density.
Current nuclear power plants must operate below the temperatures and pressures that coal-
fired plants do, since the pressurized vessel is very large and contains the entire bundle of
nuclear fuel rods. The size of the reactor limits the pressure that can be reached. This, in turn,
limits their thermodynamic efficiency to 30–32%. Someadvanced reactor designs being
studied, such as the Very high temperature reactor, Advanced gas-cooled reactor and Super
critical water reactor, would operate at temperatures and pressures similar to current coal
plants, producing comparable thermodynamic efficiency.
Fig 2.2 Block diagram of Thermal Power Plant
7
2.3. RSWM(Rajasthan spinning & weaving mills) limited power plant: -
The RSWM limited power plant to generate the electricity in 46MW. In this plant use the two
units 23MW, 23MW the total power generated 46MW and send the energy mayor plant,
denim plant, and Lodha village. Plant generated every day 100000$ electricity.
Every power plant has three main functions:-
1. Generation:-
How the power generated?
Which method we used for moving turbine?
In RSWM thermal power plant the power generated by steam turbine and this steam is
produced by coal.
Transmission:-
How much power is transmit?
How will the switchyard design?
In this plant 11kv generated and transmit in 132kv by step up transformer and there
are 2 transformers in switchyard because there are two units.
Distribution:-
Where power transmit?
How many feeders?
There is only one feeder i.e. Lodha and some power they used in plant.
2.3. RSWM(Rajasthan spinning & weaving mills) limited power plant: -
The RSWM limited power plant to generate the electricity in 46MW. In this plant use the two
units 23MW, 23MW the total power generated 46MW and send the energy mayor plant,
denim plant, and Lodha village. Plant generated every day 100000$ electricity.
Every power plant has three main functions:-
1. Generation:-
How the power generated?
Which method we used for moving turbine?
In RSWM thermal power plant the power generated by steam turbine and this steam is
produced by coal.
Transmission:-
How much power is transmit?
How will the switchyard design?
In this plant 11kv generated and transmit in 132kv by step up transformer and there
are 2 transformers in switchyard because there are two units.
Distribution:-
Where power transmit?
How many feeders?
There is only one feeder i.e. Lodha and some power they used in plant.
8
Fig. 2.3 Block diagram of RSWM plant
I.D FAN
APH.
ECOM.
BOILER
TURBIN
E
CAND.
ACC F.
F.DFAN
DEATER
PA FAN
G.B.
BFP
GENER.
VCB
BUNKER
CHP PL.
ESP
DCF
CHY.
Fig. 2.3 Block diagram of RSWM plant
I.D FAN
APH.
ECOM.
BOILER
TURBIN
E
CAND.
ACC F.
F.DFAN
DEATER
PA FAN
G.B.
BFP
GENER.
VCB
BUNKER
CHP PL.
ESP
DCF
CHY.
9
CHAPTER - 3
General idea and basic layout
3.1 Introduction:-
A control system of station basically works on Rankin Cycle. Steam is produced in
Boiler is exported in prime mover and is condensed in condenser to be fed into the boiler
again. In practice of good number of modifications are affected so as to have heat economy
and to increase the thermal efficiency of plant.
Fig 3.1 Layout of Power Plant
3.2 Division of RSWM TPP:-
The RSWM Thermal Power Plant is divided into four main circuits:
Fuel and Ash Circuit.
Air and Gas Circuit.
Water and steam Circuit
Cooling Water Circuit.
CHAPTER - 3
General idea and basic layout
3.1 Introduction:-
A control system of station basically works on Rankin Cycle. Steam is produced in
Boiler is exported in prime mover and is condensed in condenser to be fed into the boiler
again. In practice of good number of modifications are affected so as to have heat economy
and to increase the thermal efficiency of plant.
Fig 3.1 Layout of Power Plant
3.2 Division of RSWM TPP:-
The RSWM Thermal Power Plant is divided into four main circuits:
Fuel and Ash Circuit.
Air and Gas Circuit.
Water and steam Circuit
Cooling Water Circuit.
10
3.2.1 Fuel & Ash Circuit:-
Fuel from the storage is fed to the boiler through fuel handlingDevice. The fuel used
in RSWM thermal power plant is coal, which on combustion in the boiler produced the ash.
The quantity of ash produced is approximately 35-40% of coal used. This ash is collected at
the back of the boiler and removed to ash storage tank through ash disposal equipment.
3.2.2 Air and Gas Circuit:-
Air from the atmosphere is supplied to the combustion chamber ofBoiler through the
action of forced draft fan and induced draft fan. The flue gas gases are first pass around the
boiler tubes and super-heated tubes in the furnace, next through dust collector (ESP) & then
economizer. Finally, they are exhausted to the atmosphere through fans.
3.2.3 Feed Water and Steam Circuit:-
The condensate leaving the condenser is first heated in low pressure (LP) heaters
through extracted steam from the lower pressure extraction of the turbine. Then its goes to de
aerator where extra air and non-condensable gases are removed from the hot water to avoid
pitting / oxidation. From de aerator it goes to boiler feed pump which increases the pressure
of the water. From the BFP it passes through the high pressure heaters. A small part of water
and steam is lost while passing through different components therefore water is added in hot
well.This water is called the makeup water. Thereafter, feed water enters into the boiler drum
through economizer. In boiler tubes water circulates because of density difference in lower
and higher temperature section of the boiler. The wet steam passes through superheated.
From superheated it goes into the HP turbine after expanding in the HP turbine. The low
pressure steam calledthe cold reheat steam (CRH) goes to the Reheater (boiler). From
Reheater it goes to IP turbine and then to the LP turbine and then exhausted through the
condenser into hot well.
3.2.4 Cooling Water Circuit:-
A large quantity of cooling water is required to condense the steam in condenser and
marinating low pressure in it. The water is drawn from reservoir and after use it is drained
into the river.
3.2.1 Fuel & Ash Circuit:-
Fuel from the storage is fed to the boiler through fuel handlingDevice. The fuel used
in RSWM thermal power plant is coal, which on combustion in the boiler produced the ash.
The quantity of ash produced is approximately 35-40% of coal used. This ash is collected at
the back of the boiler and removed to ash storage tank through ash disposal equipment.
3.2.2 Air and Gas Circuit:-
Air from the atmosphere is supplied to the combustion chamber ofBoiler through the
action of forced draft fan and induced draft fan. The flue gas gases are first pass around the
boiler tubes and super-heated tubes in the furnace, next through dust collector (ESP) & then
economizer. Finally, they are exhausted to the atmosphere through fans.
3.2.3 Feed Water and Steam Circuit:-
The condensate leaving the condenser is first heated in low pressure (LP) heaters
through extracted steam from the lower pressure extraction of the turbine. Then its goes to de
aerator where extra air and non-condensable gases are removed from the hot water to avoid
pitting / oxidation. From de aerator it goes to boiler feed pump which increases the pressure
of the water. From the BFP it passes through the high pressure heaters. A small part of water
and steam is lost while passing through different components therefore water is added in hot
well.This water is called the makeup water. Thereafter, feed water enters into the boiler drum
through economizer. In boiler tubes water circulates because of density difference in lower
and higher temperature section of the boiler. The wet steam passes through superheated.
From superheated it goes into the HP turbine after expanding in the HP turbine. The low
pressure steam calledthe cold reheat steam (CRH) goes to the Reheater (boiler). From
Reheater it goes to IP turbine and then to the LP turbine and then exhausted through the
condenser into hot well.
3.2.4 Cooling Water Circuit:-
A large quantity of cooling water is required to condense the steam in condenser and
marinating low pressure in it. The water is drawn from reservoir and after use it is drained
into the river.
11
CHAPTER - 4
Description of various component of power plant
4.1. Cooling tower: -
Cooling towers are heat removal devices used to transfer process waste heat to
the atmosphere. Cooling towers may either use the evaporation of water to remove process
heat and cool the working fluid to near the wet-bulb air temperature or rely solely on air to
cool the working fluid to near the dry-bulb air temperature. Common applications include
cooling the circulating water used in oil refineries, chemical plants, power stations and
building cooling. The towers vary in size from small roof-top units to very large hyperboloid
structures (as in Image 1) that can be up to 200 meters tall and 100 meters in diameter, or
rectangular structures (as in Image 2) that can be over 40 meters tall and 80 meters long.
Smaller towers are normally factory-built, while larger ones are constructed on site. They are
often associated with nuclear power plants in popular culture.
4.2. Cooling water pump: -
This pump is used in cooling water circulation. These pumps are run with the help of
induction motor.
4.3 Electric power transmissions: -
Fig 4.1 Electric Power Transmission
CHAPTER - 4
Description of various component of power plant
4.1. Cooling tower: -
Cooling towers are heat removal devices used to transfer process waste heat to
the atmosphere. Cooling towers may either use the evaporation of water to remove process
heat and cool the working fluid to near the wet-bulb air temperature or rely solely on air to
cool the working fluid to near the dry-bulb air temperature. Common applications include
cooling the circulating water used in oil refineries, chemical plants, power stations and
building cooling. The towers vary in size from small roof-top units to very large hyperboloid
structures (as in Image 1) that can be up to 200 meters tall and 100 meters in diameter, or
rectangular structures (as in Image 2) that can be over 40 meters tall and 80 meters long.
Smaller towers are normally factory-built, while larger ones are constructed on site. They are
often associated with nuclear power plants in popular culture.
4.2. Cooling water pump: -
This pump is used in cooling water circulation. These pumps are run with the help of
induction motor.
4.3 Electric power transmissions: -
Fig 4.1 Electric Power Transmission
12
Electric power transmission or "high voltage electric transmission" is the bulk transfer
of electrical energy, from generating plants to substations located near to population centers
and other plants like mayor plant ,denim plant . This is distinct from the local wiring between
high voltage substations and customers, which is typically referred to as distribution. And
transmitted 132kv line in Lodha village.
Transmission lines, when interconnected with each other, become high voltage transmission
networks. Historically, transmission and distribution lines were owned by the same company,
but over the last decade or so many countries have introduced market reforms that have led to
the separation of the electricity transmission business from the distribution business.
Transmission lines mostly use three phase alternating current (AC), although single phase AC
is sometimes used in railway electrification systems. High-voltage direct current (HVDC)
technology is used only for very long distances (typically greater than 400 miles, or 600 km);
undersea cables (typically longer than 30 miles, or 50 km); or for connecting two AC
networks that are not synchronized.
Electricity is transmitted at high voltages (110 kV or above) to reduce the energy lost in long
distance transmission. Power is usually transmitted through overhead power lines.
Underground power transmission has a significantly higher cost and greater operational
limitations but is sometimes used in urban areas or sensitive locations.
A key limitation in the distribution of electricity is that, with minor exceptions, electrical
energy cannot be stored, and therefore it must be generated as it is needed. A sophisticated
system of control is therefore required to ensure electric generation very closely matches the
demand. If supply and demand are not in balance, generation plants and transmission
equipment can shut down which, in the worst cases, can lead to a major regional blackout.
Much analysis is done by transmission companies to determine the maximum reliable
capacity of each line which is mostly less than its physical or thermal limit, to ensure spare
capacity is available should there be any such failure in another part of the network
4.4. Transformer: -
A transformer is a device that transfers electrical energy from one circuit to another
through inductively coupled conductors—the transformer's coils. A varying current in the
first or primary winding creates a varying magnetic flux in the transformer's core, and thus a
varying magnetic field through the secondary winding. This varying magnetic field induces a
Electric power transmission or "high voltage electric transmission" is the bulk transfer
of electrical energy, from generating plants to substations located near to population centers
and other plants like mayor plant ,denim plant . This is distinct from the local wiring between
high voltage substations and customers, which is typically referred to as distribution. And
transmitted 132kv line in Lodha village.
Transmission lines, when interconnected with each other, become high voltage transmission
networks. Historically, transmission and distribution lines were owned by the same company,
but over the last decade or so many countries have introduced market reforms that have led to
the separation of the electricity transmission business from the distribution business.
Transmission lines mostly use three phase alternating current (AC), although single phase AC
is sometimes used in railway electrification systems. High-voltage direct current (HVDC)
technology is used only for very long distances (typically greater than 400 miles, or 600 km);
undersea cables (typically longer than 30 miles, or 50 km); or for connecting two AC
networks that are not synchronized.
Electricity is transmitted at high voltages (110 kV or above) to reduce the energy lost in long
distance transmission. Power is usually transmitted through overhead power lines.
Underground power transmission has a significantly higher cost and greater operational
limitations but is sometimes used in urban areas or sensitive locations.
A key limitation in the distribution of electricity is that, with minor exceptions, electrical
energy cannot be stored, and therefore it must be generated as it is needed. A sophisticated
system of control is therefore required to ensure electric generation very closely matches the
demand. If supply and demand are not in balance, generation plants and transmission
equipment can shut down which, in the worst cases, can lead to a major regional blackout.
Much analysis is done by transmission companies to determine the maximum reliable
capacity of each line which is mostly less than its physical or thermal limit, to ensure spare
capacity is available should there be any such failure in another part of the network
4.4. Transformer: -
A transformer is a device that transfers electrical energy from one circuit to another
through inductively coupled conductors—the transformer's coils. A varying current in the
first or primary winding creates a varying magnetic flux in the transformer's core, and thus a
varying magnetic field through the secondary winding. This varying magnetic field induces a
13
varying electromotive force (EMF) or "voltage" in the secondary winding. This effect is
called mutual induction.
Fig. 4.2 Transformer
In this plant use 11to 132kv step up transformer .the plant generated 11kv electricity and use
step up transformer step up in 132kv and send according to load and requirement .If a load is
connected to the secondary, an electric current will flow in the secondary winding and
electrical energy will be transferred from the primary circuit through the transformer to the
load. In an ideal transformer, the induced voltage in the secondary winding (VS) is in
proportion to the primary voltage (VP), and is given by the ratio of the number of turns in the
secondary (NS) to the number of turns in the primary (NP) as follows:
By appropriate selection of the ratio of turns, a transformer thus allows an alternating current
(AC) voltage to be "stepped up" by making NSgreater than NP, or "stepped down" by
making NS less than NP.
In the vast majority of transformers, the windings are coils wound around a ferromagnetic
core, air-core transformers being a notable exception.
Transformers range in size from a thumbnail-sized coupling transformer hidden inside a
stage microphone to huge units weighing hundreds of tons used to interconnect portions
of power grids. All operate with the same basic principles, although the range of designs is
wide. While new technologies have eliminated the need for transformers in some electronic
circuits, transformers are still found in nearly all electronic devices designed for household
varying electromotive force (EMF) or "voltage" in the secondary winding. This effect is
called mutual induction.
Fig. 4.2 Transformer
In this plant use 11to 132kv step up transformer .the plant generated 11kv electricity and use
step up transformer step up in 132kv and send according to load and requirement .If a load is
connected to the secondary, an electric current will flow in the secondary winding and
electrical energy will be transferred from the primary circuit through the transformer to the
load. In an ideal transformer, the induced voltage in the secondary winding (VS) is in
proportion to the primary voltage (VP), and is given by the ratio of the number of turns in the
secondary (NS) to the number of turns in the primary (NP) as follows:
By appropriate selection of the ratio of turns, a transformer thus allows an alternating current
(AC) voltage to be "stepped up" by making NSgreater than NP, or "stepped down" by
making NS less than NP.
In the vast majority of transformers, the windings are coils wound around a ferromagnetic
core, air-core transformers being a notable exception.
Transformers range in size from a thumbnail-sized coupling transformer hidden inside a
stage microphone to huge units weighing hundreds of tons used to interconnect portions
of power grids. All operate with the same basic principles, although the range of designs is
wide. While new technologies have eliminated the need for transformers in some electronic
circuits, transformers are still found in nearly all electronic devices designed for household
14
("mains") voltage. Transformers are essential for high voltage power transmission, which
makes long distance transmission economically practical
4.5. Steam turbine: -
Fig. 4.3 Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam,
and converts it into rotary motion.
It has almost completely replaced the reciprocating piston steam engine primarily because of
its greater thermal efficiency and higher power-to-weight ratio. Because the turbine
generates rotary motion, it is particularly suited to be used to drive an electrical generator –
about 80% of all electricity generation in the world is by use of steam turbines. The steam
turbine has two type one reaction type and one impulse type turbine. In this plant impulse-
reaction type combination type turbine are used . steam turbine is a form of heat engine that
derives much of its improvement in thermodynamic efficiency through the use of multiple
stages in the expansion of the steam, which results in a closer approach to the ideal reversible
process. The turbine is main part of steam plant boiler’s pipes direct connected to high
presser to turbine by using nozzle .the nozzle through the steam with high presser to turbine
wings and turbine are moving at high speed. The turbine has three parts one main turbine one
switch gear box and generator .when steam send to turbine by nozzle the turbine wings are
rotated at high speed at 7700rpm and turbine drive connected to switch box. The switch box
one type of gear box to control the speed of turbine 7700 to1500rpm and switch gear pipe
("mains") voltage. Transformers are essential for high voltage power transmission, which
makes long distance transmission economically practical
4.5. Steam turbine: -
Fig. 4.3 Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam,
and converts it into rotary motion.
It has almost completely replaced the reciprocating piston steam engine primarily because of
its greater thermal efficiency and higher power-to-weight ratio. Because the turbine
generates rotary motion, it is particularly suited to be used to drive an electrical generator –
about 80% of all electricity generation in the world is by use of steam turbines. The steam
turbine has two type one reaction type and one impulse type turbine. In this plant impulse-
reaction type combination type turbine are used . steam turbine is a form of heat engine that
derives much of its improvement in thermodynamic efficiency through the use of multiple
stages in the expansion of the steam, which results in a closer approach to the ideal reversible
process. The turbine is main part of steam plant boiler’s pipes direct connected to high
presser to turbine by using nozzle .the nozzle through the steam with high presser to turbine
wings and turbine are moving at high speed. The turbine has three parts one main turbine one
switch gear box and generator .when steam send to turbine by nozzle the turbine wings are
rotated at high speed at 7700rpm and turbine drive connected to switch box. The switch box
one type of gear box to control the speed of turbine 7700 to1500rpm and switch gear pipe
15
connected to directed to generator rotor and rotor also rotated at speed at 1500rpm and when
rotor moving a magnet the cut flux and induced the emf and generated the energy.
First boiler converted water to steam and steam flow to turbine by using pipe to high presser
and turbine’s wings are rotated at high speed at 7700 rpm but generator not rotated at
7700rpm speed so control the speed use the one gear box. The gear box connect to turbine
shaft in gear box use two type to gear one big and one small, small gear connect to turbine
shaft and big gear connect to generator shaft .the gear box convert the speed 7700 to 1500
rpm and connect to generator shaft and generator rotated at 1500rpm speed and generated the
energy and energy send to transmission line and other use.
Fig. 4.4Arrangement of Steam Turbine
Rating of switch gear box: -
Power in KW - 23600kw.
Speed in input (min-1) - 7700rpm.
Speed in output (min-1) - 1500rpm.
Oil required - 171 L/min.
Oil presser in bar - 20 bars.
Rating of exciter: -
Type - EAP11/16-15/6.
Voltage - 220v.
Current - 3.94A.
connected to directed to generator rotor and rotor also rotated at speed at 1500rpm and when
rotor moving a magnet the cut flux and induced the emf and generated the energy.
First boiler converted water to steam and steam flow to turbine by using pipe to high presser
and turbine’s wings are rotated at high speed at 7700 rpm but generator not rotated at
7700rpm speed so control the speed use the one gear box. The gear box connect to turbine
shaft in gear box use two type to gear one big and one small, small gear connect to turbine
shaft and big gear connect to generator shaft .the gear box convert the speed 7700 to 1500
rpm and connect to generator shaft and generator rotated at 1500rpm speed and generated the
energy and energy send to transmission line and other use.
Fig. 4.4Arrangement of Steam Turbine
Rating of switch gear box: -
Power in KW - 23600kw.
Speed in input (min-1) - 7700rpm.
Speed in output (min-1) - 1500rpm.
Oil required - 171 L/min.
Oil presser in bar - 20 bars.
Rating of exciter: -
Type - EAP11/16-15/6.
Voltage - 220v.
Current - 3.94A.
16
Frequency - 75 Hz.
Phase - 3 phase induction motor.
Speed in rpm - 1500 rpm.
4.6. Surface condenser: -
Surface condenser is the commonly used term for a water-cooled shell and tube heat
exchanger installed on the exhaust steam from a steam turbine in thermal power stations.
These condensers are heat exchangers which convert steam from its gaseous to its liquid state
at a pressure below atmospheric pressure. Where cooling water is in short supply, an air-
cooled condenser is often used. An air-cooled condenser is however significantly more
expensive and cannot achieve as low a steam turbine exhaust pressure as a surface condenser.
Surface condensers are also used in applications and industries other than the condensing of
steam turbine exhaust in power plants.
In thermal power plants, the primary purpose of a surface condenser is to condense the
exhaust steam from a steam turbine to obtain maximum efficiency and also to convert the
turbine exhaust steam into pure water (referred to as steam condensate) so that it may be
reused in the steam generator or boiler as boiler feed water.ACC type condenser is used in
mordi plant.
4.7. Control valves: -
Control valves are valves used to control conditions such as flow, pressure, temperature,
and liquid level by fully or partially opening or closing in response to signals received from
controllers that compare a "set point" to a "process variable" whose value is provided
by sensors that monitor changes in such conditions.
The opening or closing of control valves is done by means
of electrical, hydraulic or pneumatic systems. Positioners are used to control the opening or
closing of the actuator based on Electric, or Pneumatic Signals. These control signals,
traditionally based on 3-15psi (0.2-1.0bar), more common now are 4-20mA signals for
industry, 0-10V for HVAC systems, & the introduction of "Smart" systems, HART, Field bus
Foundation, &Profibus being the more common protocols.
Frequency - 75 Hz.
Phase - 3 phase induction motor.
Speed in rpm - 1500 rpm.
4.6. Surface condenser: -
Surface condenser is the commonly used term for a water-cooled shell and tube heat
exchanger installed on the exhaust steam from a steam turbine in thermal power stations.
These condensers are heat exchangers which convert steam from its gaseous to its liquid state
at a pressure below atmospheric pressure. Where cooling water is in short supply, an air-
cooled condenser is often used. An air-cooled condenser is however significantly more
expensive and cannot achieve as low a steam turbine exhaust pressure as a surface condenser.
Surface condensers are also used in applications and industries other than the condensing of
steam turbine exhaust in power plants.
In thermal power plants, the primary purpose of a surface condenser is to condense the
exhaust steam from a steam turbine to obtain maximum efficiency and also to convert the
turbine exhaust steam into pure water (referred to as steam condensate) so that it may be
reused in the steam generator or boiler as boiler feed water.ACC type condenser is used in
mordi plant.
4.7. Control valves: -
Control valves are valves used to control conditions such as flow, pressure, temperature,
and liquid level by fully or partially opening or closing in response to signals received from
controllers that compare a "set point" to a "process variable" whose value is provided
by sensors that monitor changes in such conditions.
The opening or closing of control valves is done by means
of electrical, hydraulic or pneumatic systems. Positioners are used to control the opening or
closing of the actuator based on Electric, or Pneumatic Signals. These control signals,
traditionally based on 3-15psi (0.2-1.0bar), more common now are 4-20mA signals for
industry, 0-10V for HVAC systems, & the introduction of "Smart" systems, HART, Field bus
Foundation, &Profibus being the more common protocols.
17
The most common and versatile types of control valves are sliding-stem globe and angle
valves. Their popularity derives from rugged construction and the many options available that
make them suitable for a variety of process applications, including severe service.
4.8. Deaerator: -
A deaerator is a device that is widely used for the removal of air and other
dissolved gases from the feed water to steam-generating boilers. In particular,
dissolved oxygen in boiler feed waters will cause serious corrosion damage in steam systems
by attaching to the walls of metal piping and other metallic equipment and
Forming oxides (rust). Water also combines with any dissolved carbon dioxide to
form carbonic acid that causes further corrosion. Most deaerators are designed to remove
oxygen down to levels of 7 ppb by weight (0.0005 cm³/L) or less.
There are two basic types of deaerators, the tray-type and the spray-type:
The tray-type (also called the cascade-type) includes a vertical domed deaeration section
mounted on top of a horizontal cylindrical vessel which serves as the deaerated boiler
feed water storage tank.
The spray-type consists only of a horizontal (or vertical) cylindrical vessel which serves
as both the deaeration section and the boiler feed water storage tank.
4.9. Feedwater heater: -
A feedwater heater is a power plant component used to pre-heat water delivered to
a steam generating boiler. Preheating the feedwater reduces the irreversibility’s involved in
steam generation and therefore improves the thermodynamic efficiency of the system. This
reduces plant operating costs and also helps to avoid thermal to the boiler metal when the
feed water is introduced back into the steam cycle. Many of the locomotive systems
are ACFI type.
In a steam power plant (usually modeled as a modified Rankine cycle), feed water heaters
allow the feed water to be brought up to the saturation temperature very gradually. This
minimizes the inevitable irreversibility associated with heat transfer to the working fluid
The most common and versatile types of control valves are sliding-stem globe and angle
valves. Their popularity derives from rugged construction and the many options available that
make them suitable for a variety of process applications, including severe service.
4.8. Deaerator: -
A deaerator is a device that is widely used for the removal of air and other
dissolved gases from the feed water to steam-generating boilers. In particular,
dissolved oxygen in boiler feed waters will cause serious corrosion damage in steam systems
by attaching to the walls of metal piping and other metallic equipment and
Forming oxides (rust). Water also combines with any dissolved carbon dioxide to
form carbonic acid that causes further corrosion. Most deaerators are designed to remove
oxygen down to levels of 7 ppb by weight (0.0005 cm³/L) or less.
There are two basic types of deaerators, the tray-type and the spray-type:
The tray-type (also called the cascade-type) includes a vertical domed deaeration section
mounted on top of a horizontal cylindrical vessel which serves as the deaerated boiler
feed water storage tank.
The spray-type consists only of a horizontal (or vertical) cylindrical vessel which serves
as both the deaeration section and the boiler feed water storage tank.
4.9. Feedwater heater: -
A feedwater heater is a power plant component used to pre-heat water delivered to
a steam generating boiler. Preheating the feedwater reduces the irreversibility’s involved in
steam generation and therefore improves the thermodynamic efficiency of the system. This
reduces plant operating costs and also helps to avoid thermal to the boiler metal when the
feed water is introduced back into the steam cycle. Many of the locomotive systems
are ACFI type.
In a steam power plant (usually modeled as a modified Rankine cycle), feed water heaters
allow the feed water to be brought up to the saturation temperature very gradually. This
minimizes the inevitable irreversibility associated with heat transfer to the working fluid
18
(water). See the article on the Second Law of Thermodynamics for a further discussion of
such irreversibility.
4.10. Coal: -
Coal is a readily combustible black or brownish-black sedimentary rock normally occurring
in rock strata in layers or veins called coal beds. The harder forms, such as anthracite coal,
can be regarded as metamorphic rock because of later exposure to elevated temperature and
pressure. Coal is composed primarily of carbon along with variable quantities of other
elements, chiefly sulphur, hydrogen, oxygen and nitrogen.
4.11. Pulverizer: -
A pulverizer is a mechanical device for the grinding of many different types of materials. For
example, they are used to pulverize coal for combustion in the steam-generating furnaces of
fossil fuel power plants.
4.12. Steam drum: -
A steam drum is a standard feature of a water-tube boiler. It is a reservoir of water/steam at
the top end of the water tubes. The drum stores the steam generated in the water tubes and
acts as a phase-separator for the steam/water mixture. The difference in densities between hot
and cold water helps in the accumulation of the "hotter"-water/and saturated-steam into the
steam-drum.
4.13. Boilers: -
A boiler is a closed vessel in which water under pressure is converted into steam. It is one of
the major components of a thermal power plant. A boiler is always designed to absorb
maximum amount of heat released in the process of combustion.
4.14. Superheater: -
A superheater is a device used to convert saturated steam or wet steam into dry steam used
for power generation or processes. There are three types of superheaters namely: radiant,
convection, and separately fired. A superheater can vary in size from a few tens of feet to
several hundred feet (a few meters or some hundred meters).
A radiant superheater is placed directly in the combustion chamber.
(water). See the article on the Second Law of Thermodynamics for a further discussion of
such irreversibility.
4.10. Coal: -
Coal is a readily combustible black or brownish-black sedimentary rock normally occurring
in rock strata in layers or veins called coal beds. The harder forms, such as anthracite coal,
can be regarded as metamorphic rock because of later exposure to elevated temperature and
pressure. Coal is composed primarily of carbon along with variable quantities of other
elements, chiefly sulphur, hydrogen, oxygen and nitrogen.
4.11. Pulverizer: -
A pulverizer is a mechanical device for the grinding of many different types of materials. For
example, they are used to pulverize coal for combustion in the steam-generating furnaces of
fossil fuel power plants.
4.12. Steam drum: -
A steam drum is a standard feature of a water-tube boiler. It is a reservoir of water/steam at
the top end of the water tubes. The drum stores the steam generated in the water tubes and
acts as a phase-separator for the steam/water mixture. The difference in densities between hot
and cold water helps in the accumulation of the "hotter"-water/and saturated-steam into the
steam-drum.
4.13. Boilers: -
A boiler is a closed vessel in which water under pressure is converted into steam. It is one of
the major components of a thermal power plant. A boiler is always designed to absorb
maximum amount of heat released in the process of combustion.
4.14. Superheater: -
A superheater is a device used to convert saturated steam or wet steam into dry steam used
for power generation or processes. There are three types of superheaters namely: radiant,
convection, and separately fired. A superheater can vary in size from a few tens of feet to
several hundred feet (a few meters or some hundred meters).
A radiant superheater is placed directly in the combustion chamber.
19
A convection superheater is located in the path of the hot gases.
A separately fired superheater, as its name implies, is totally separated from the boiler.
A superheater is a device in a steam engine, when considering locomotives, that heats the
steam generated by the boiler again, increasing its thermal energy and decreasing the
likelihood that it will condense inside the engine . Superheaters increase the efficiency of the
steam engine, and were widely adopted. Steam which has been superheated is logically
known as superheated steam; non-superheated steam is called saturated steam or wet steam.
Superheaters were applied to steam locomotives in quantity from the early 20th century, to
most steam vehicles, and to stationary steam engines. This equipment is still an integral part
of power generating stations throughout the world.
4.15. Centrifugal fan (ID fan and FD fan): -
A centrifugal fan (also squirrel-cage fan, as it looks like a hamster wheel) is a mechanical
device for moving air or gases. It has a fan wheel composed of a number of fan blades,
or ribs, mounted around a hub. As shown in Figure 1, the hub turns on a driveshaft that
passes through the fan housing. The gas enters from the side of the fan wheel, turns 90
degrees and accelerates due to centrifugal as it flows over the fan blades and exits the fan
housing.
[1]
Centrifugal fans can generate pressure rises in the gas stream. Accordingly, they are well-
suited for industrial processes and air pollution control systems. They are also common in
central heating/cooling systems.
Fig 4.5Centrifugal Fan
A convection superheater is located in the path of the hot gases.
A separately fired superheater, as its name implies, is totally separated from the boiler.
A superheater is a device in a steam engine, when considering locomotives, that heats the
steam generated by the boiler again, increasing its thermal energy and decreasing the
likelihood that it will condense inside the engine . Superheaters increase the efficiency of the
steam engine, and were widely adopted. Steam which has been superheated is logically
known as superheated steam; non-superheated steam is called saturated steam or wet steam.
Superheaters were applied to steam locomotives in quantity from the early 20th century, to
most steam vehicles, and to stationary steam engines. This equipment is still an integral part
of power generating stations throughout the world.
4.15. Centrifugal fan (ID fan and FD fan): -
A centrifugal fan (also squirrel-cage fan, as it looks like a hamster wheel) is a mechanical
device for moving air or gases. It has a fan wheel composed of a number of fan blades,
or ribs, mounted around a hub. As shown in Figure 1, the hub turns on a driveshaft that
passes through the fan housing. The gas enters from the side of the fan wheel, turns 90
degrees and accelerates due to centrifugal as it flows over the fan blades and exits the fan
housing.
[1]
Centrifugal fans can generate pressure rises in the gas stream. Accordingly, they are well-
suited for industrial processes and air pollution control systems. They are also common in
central heating/cooling systems.
Fig 4.5Centrifugal Fan
20
4.16. Economizer: -
Economizers are mechanical devices intended to reduce energy consumption, or to perform another
useful function like preheating a fluid. The term economizer is used for other purposes as
well. Boiler, power plant, and heating, ventilating, and air-conditioning (HVAC) uses are discussed in
this article. In simple terms, an economizer is a heat exchanger. In economizer water flow inside in
zigzag pipe and surrounded flow to high temp. Sludge gases so the gas heat transfer the heat into
water and water is heated at 100’c.to use the economizer to increase the efficiency of boiler.
4.17. Air preheater: -
An air preheater (APH) is a general term to describe any device designed to heat air before
another process (for example, combustion in a boiler) with the primary objective of
increasing the thermal efficiency of the process. They may be used alone or to replace
a recuperative heat system or to replace a steam coil.
In particular, this article describes the combustion air preheaters used in large boilers found
in stations producing electric power from e.g. fossil fuels, biomasses or waste.
The purpose of the air preheater is to recover the heat from the boiler flue gas which
increases the thermal efficiency of the boiler by reducing the useful heat lost in the flue gas.
As a consequence, the flue gases are also sent to the flue gas stack (or chimney) at a lower
temperature, allowing simplified design of the ducting and the flue gas stack. It also allows
control over the temperature of gases leaving the stack (to meet emissions regulations, for
example).
Fig. 4.6Air Preheater
4.16. Economizer: -
Economizers are mechanical devices intended to reduce energy consumption, or to perform another
useful function like preheating a fluid. The term economizer is used for other purposes as
well. Boiler, power plant, and heating, ventilating, and air-conditioning (HVAC) uses are discussed in
this article. In simple terms, an economizer is a heat exchanger. In economizer water flow inside in
zigzag pipe and surrounded flow to high temp. Sludge gases so the gas heat transfer the heat into
water and water is heated at 100’c.to use the economizer to increase the efficiency of boiler.
4.17. Air preheater: -
An air preheater (APH) is a general term to describe any device designed to heat air before
another process (for example, combustion in a boiler) with the primary objective of
increasing the thermal efficiency of the process. They may be used alone or to replace
a recuperative heat system or to replace a steam coil.
In particular, this article describes the combustion air preheaters used in large boilers found
in stations producing electric power from e.g. fossil fuels, biomasses or waste.
The purpose of the air preheater is to recover the heat from the boiler flue gas which
increases the thermal efficiency of the boiler by reducing the useful heat lost in the flue gas.
As a consequence, the flue gases are also sent to the flue gas stack (or chimney) at a lower
temperature, allowing simplified design of the ducting and the flue gas stack. It also allows
control over the temperature of gases leaving the stack (to meet emissions regulations, for
example).
Fig. 4.6Air Preheater
21
4.18. Electrostatic precipitator: -
An electrostatic precipitator (ESP),or electrostatic air cleaner is a particulate collection device
that removes particles from a flowing gas (such as air) using the force of an induced
electrostatic. Electrostatic precipitators are highly efficient filtration devices that minimally
impede the flow of gases through the device, and can easily remove fine particulate matter
such as dust and smoke from the air stream. In contrast to wet scrubbers which apply energy
directly to the flowing fluid medium, an ESP applies energy only to the particulate matter
being collected and therefore is very efficient in its consumption of energy (in the form of
electricity).in other word .in combustion processes generated the some gases and in gases
dissolved some ash particles so use the ESP the gas through the ESP chamber. The ESP
separated ash to gas and ash send to ash chamber and gas send to chimney.
4.19. Flue gas stack: -
A flue gas stack is a type of chimney, a vertical pipe, channel or similar structure through
which combustion product gases called flue gases are exhausted to the outside air. Flue gases
are produced when coal, oil, natural gas, wood or any other fuel is combusted in an
industrial furnace, a power steam-generating boiler, or other large combustion device. Flue
gas is usually composed of carbon dioxide (CO2) andwatervapour as well as nitrogen and
excess oxygen remaining from the intake combustion air. It also contains a small percentage
of pollutants such as particulate matter, carbon monoxide, nitrogen oxides and sulfur oxides.
The flue gas stacks are often quite tall, up to 400 meters (1300 feet) or more, so as to disperse
the exhaust pollutants over a greater area and thereby reduce the concentration of the
pollutants to the levels required by governmental environmental policy and environmental
regulation.
When the flue gases are exhausted from stoves, ovens, fireplaces, or other small sources
within residential abodes, restaurants, hotels, or other public buildings and small commercial
enterprises, their flue gas stacks are referred to as chimneys.
4.18. Electrostatic precipitator: -
An electrostatic precipitator (ESP),or electrostatic air cleaner is a particulate collection device
that removes particles from a flowing gas (such as air) using the force of an induced
electrostatic. Electrostatic precipitators are highly efficient filtration devices that minimally
impede the flow of gases through the device, and can easily remove fine particulate matter
such as dust and smoke from the air stream. In contrast to wet scrubbers which apply energy
directly to the flowing fluid medium, an ESP applies energy only to the particulate matter
being collected and therefore is very efficient in its consumption of energy (in the form of
electricity).in other word .in combustion processes generated the some gases and in gases
dissolved some ash particles so use the ESP the gas through the ESP chamber. The ESP
separated ash to gas and ash send to ash chamber and gas send to chimney.
4.19. Flue gas stack: -
A flue gas stack is a type of chimney, a vertical pipe, channel or similar structure through
which combustion product gases called flue gases are exhausted to the outside air. Flue gases
are produced when coal, oil, natural gas, wood or any other fuel is combusted in an
industrial furnace, a power steam-generating boiler, or other large combustion device. Flue
gas is usually composed of carbon dioxide (CO2) andwatervapour as well as nitrogen and
excess oxygen remaining from the intake combustion air. It also contains a small percentage
of pollutants such as particulate matter, carbon monoxide, nitrogen oxides and sulfur oxides.
The flue gas stacks are often quite tall, up to 400 meters (1300 feet) or more, so as to disperse
the exhaust pollutants over a greater area and thereby reduce the concentration of the
pollutants to the levels required by governmental environmental policy and environmental
regulation.
When the flue gases are exhausted from stoves, ovens, fireplaces, or other small sources
within residential abodes, restaurants, hotels, or other public buildings and small commercial
enterprises, their flue gas stacks are referred to as chimneys.
22
CHAPTER - 5
Coal handling plant
A coal handling plant is a facility that washes coal of soil and rock, preparing it for transport.
FRIGATE coal handling plant can handle coal from its receipt to storage, reclamation,
preparation until the final point of use in steel or thermal power plant. Depending on the end
use of coal, the CHP facility processes coal to the correct size, making it suitable for coke
ovens, boiler, etc. FRIGATE extends its expertise to the mine face to integrate all aspects of
the supply chain. A typical CHP project would entail one or many of the following
equipment's:
5.1. Coal handling plant equipment: -
Railway Wagon unloading (by wagon tipplers or thru track hopers).
Dumper unloading thru underground bottom hoppers or elevated hoppers.
Ship unloaders / loaders
Paddle Feeders
Apron Feeders
Scrapper Chain Conveyors
Vibratory Feeders
Lump Breakers
Long distance Belt Conveyors
Elevated Conveyor Galleries
Transfer/Junction Towers
Shuttle Conveyor
Bifurcating Chutes/Flap Gates
Crushing & Screening Circuits
Stacking & Reclaiming Circuits
Underground / over ground / Elevated Storages
Rapid Unloading Systems
Pipe Conveyors
High Angle Conveyors
En-masse Conveyors
CHAPTER - 5
Coal handling plant
A coal handling plant is a facility that washes coal of soil and rock, preparing it for transport.
FRIGATE coal handling plant can handle coal from its receipt to storage, reclamation,
preparation until the final point of use in steel or thermal power plant. Depending on the end
use of coal, the CHP facility processes coal to the correct size, making it suitable for coke
ovens, boiler, etc. FRIGATE extends its expertise to the mine face to integrate all aspects of
the supply chain. A typical CHP project would entail one or many of the following
equipment's:
5.1. Coal handling plant equipment: -
Railway Wagon unloading (by wagon tipplers or thru track hopers).
Dumper unloading thru underground bottom hoppers or elevated hoppers.
Ship unloaders / loaders
Paddle Feeders
Apron Feeders
Scrapper Chain Conveyors
Vibratory Feeders
Lump Breakers
Long distance Belt Conveyors
Elevated Conveyor Galleries
Transfer/Junction Towers
Shuttle Conveyor
Bifurcating Chutes/Flap Gates
Crushing & Screening Circuits
Stacking & Reclaiming Circuits
Underground / over ground / Elevated Storages
Rapid Unloading Systems
Pipe Conveyors
High Angle Conveyors
En-masse Conveyors
23
Classifier circuits
Allied environment Control Systems
All related Power, Control &Instrumentation
5.2. Types of coal used in RSWM thermal power plant: -
Coal is another raw material for thermal power plant. There are three types of coal used in
this power plant.
a. Indian coal- it purchase from chattisghar state.
b. Imported coal- this coal is imported from Indonesia.
c. Petcock coal.
In mordi plant three type of coals are used one Indian coal , second important coal and third
petcock type coal according to requirement the coal are use the coal is main part of plant in
this plant required more tune coal every day then use the coal storage plant and we cannot
direct handle the coal storage to boiler because boiler temperature is very high so use one
automatic process is known as coal handling process in process first coal size is very big so
use the hopper crush the coal at 110 to 150mm size . the 150mm size coal send to next stage
magnetic separator by using belts in coal dissolved some magnetic parts so use magnetic
separator separate the magnetic part to coal and coal send next stage . now coal size is big
and high efficiency to reduce the size of coal by using crusher in this plant use to impector
type crusher use the crusher crush the coal at 4-6 mm size and send to scanner to scan the
coal in scanner use the small size hole at below 6mm size then pass the below 6mm size
coal and send next stage and up to high 6 mm size coal again send to hopper .and below 6
mm size coal send to coal to boiler to combustion. Coal begins as layers of plant matter
accumulate at the bottom of a body of water. For the process to continue the plant matter
must be protected from biodegradation and oxidization, usually by mud or acidic water.
5.3. RATING OF IMPECTOR CRUSHER : -
Motor - 3 phase induction motor
Speed in rpm - 1490 rpm
Voltage of crusher - 415v
Classifier circuits
Allied environment Control Systems
All related Power, Control &Instrumentation
5.2. Types of coal used in RSWM thermal power plant: -
Coal is another raw material for thermal power plant. There are three types of coal used in
this power plant.
a. Indian coal- it purchase from chattisghar state.
b. Imported coal- this coal is imported from Indonesia.
c. Petcock coal.
In mordi plant three type of coals are used one Indian coal , second important coal and third
petcock type coal according to requirement the coal are use the coal is main part of plant in
this plant required more tune coal every day then use the coal storage plant and we cannot
direct handle the coal storage to boiler because boiler temperature is very high so use one
automatic process is known as coal handling process in process first coal size is very big so
use the hopper crush the coal at 110 to 150mm size . the 150mm size coal send to next stage
magnetic separator by using belts in coal dissolved some magnetic parts so use magnetic
separator separate the magnetic part to coal and coal send next stage . now coal size is big
and high efficiency to reduce the size of coal by using crusher in this plant use to impector
type crusher use the crusher crush the coal at 4-6 mm size and send to scanner to scan the
coal in scanner use the small size hole at below 6mm size then pass the below 6mm size
coal and send next stage and up to high 6 mm size coal again send to hopper .and below 6
mm size coal send to coal to boiler to combustion. Coal begins as layers of plant matter
accumulate at the bottom of a body of water. For the process to continue the plant matter
must be protected from biodegradation and oxidization, usually by mud or acidic water.
5.3. RATING OF IMPECTOR CRUSHER : -
Motor - 3 phase induction motor
Speed in rpm - 1490 rpm
Voltage of crusher - 415v
24
Current of crusher - 331A
P.F. - .89
Frequency - 50Hz
Ambient temp. - 45’C
Efficiency - 94.6%
Connection - delta
Size - 1200*1800
Type - non reversible
Fig. 5.1 Block Diagram of Coal Handling Plant (C.H.P)
5.4. CONVEYING SYSTEM:-
5.4.1 Stacker Reclaimer:-
The stacker re-claimer unit can stack the material on to the pipe or reclaim the stack
filed material and fed on to the main line conveyor. While stacking material is being
fed from the main line conveyor via tripler unit and vibrating feeder on the
intermediate conveyor which feds the boom conveyor of the stacker cum reclaimer.
During reclaiming the material discharged on to the boom conveyor by the bucket
Current of crusher - 331A
P.F. - .89
Frequency - 50Hz
Ambient temp. - 45’C
Efficiency - 94.6%
Connection - delta
Size - 1200*1800
Type - non reversible
Fig. 5.1 Block Diagram of Coal Handling Plant (C.H.P)
5.4. CONVEYING SYSTEM:-
5.4.1 Stacker Reclaimer:-
The stacker re-claimer unit can stack the material on to the pipe or reclaim the stack
filed material and fed on to the main line conveyor. While stacking material is being
fed from the main line conveyor via tripler unit and vibrating feeder on the
intermediate conveyor which feds the boom conveyor of the stacker cum reclaimer.
During reclaiming the material discharged on to the boom conveyor by the bucket
25
fitted to the bucket wheel body and boom conveyor feeds the material on the main
line conveyor running in the reverse direction.
5.5. MAGNATIC SEPARATOR: -
Magnetic separator is used in the coal handling plant to remove the metal content in
the coal. With the help of magnetic separator the other particle such as bolt, ferrous
material are mixed with coal is removing by its magnetic property.
5.5.1. Magnetic separator rating:-
Motor – three phase induction motor.
Output – 30 Kw.
Speed – 1475 RPM.
Voltage – 415 +/- 10%.
Current – 50.40 A.
Frequency – 50 Hz.
% efficiency – 92 %.
Wdg. Temp. – 45° C.
Connection – delta (∆)
fitted to the bucket wheel body and boom conveyor feeds the material on the main
line conveyor running in the reverse direction.
5.5. MAGNATIC SEPARATOR: -
Magnetic separator is used in the coal handling plant to remove the metal content in
the coal. With the help of magnetic separator the other particle such as bolt, ferrous
material are mixed with coal is removing by its magnetic property.
5.5.1. Magnetic separator rating:-
Motor – three phase induction motor.
Output – 30 Kw.
Speed – 1475 RPM.
Voltage – 415 +/- 10%.
Current – 50.40 A.
Frequency – 50 Hz.
% efficiency – 92 %.
Wdg. Temp. – 45° C.
Connection – delta (∆)
26
CHAPTER - 6
WATER TREATMENT PLANT
6.1. INTRODUCTION:-
The principal problem in high-pressure boiler is to control corrosion and steam quality.
Internal corrosion costs power station cores of rupees in repair without strict control
impurities in steam also form deposit over turbine blades and nozzles. The impurities present
in water solid materials are: Un-dissolved and suspended solid minerals, Dissolved salts and
minerals, Dissolved Gases and other minerals (oil, acid etc.)Turbidity Sediment, Silica, Micro
Biological, Sodium & Potassium Salt, Dissolved SaltsMinerals. Gas (Oxygen, Carbon-Di-
Oxide).
Fig. 6.1 Systematic Diagram ofWater Treatment Plant
6.2. Parts of water treatment plant:-
6.2.1. Demineralization plant:-
Water is the raw material for the thermal power plant. In thermal power plant weevaporate
water to steam and by use of steam turbine we get work.
CHAPTER - 6
WATER TREATMENT PLANT
6.1. INTRODUCTION:-
The principal problem in high-pressure boiler is to control corrosion and steam quality.
Internal corrosion costs power station cores of rupees in repair without strict control
impurities in steam also form deposit over turbine blades and nozzles. The impurities present
in water solid materials are: Un-dissolved and suspended solid minerals, Dissolved salts and
minerals, Dissolved Gases and other minerals (oil, acid etc.)Turbidity Sediment, Silica, Micro
Biological, Sodium & Potassium Salt, Dissolved SaltsMinerals. Gas (Oxygen, Carbon-Di-
Oxide).
Fig. 6.1 Systematic Diagram ofWater Treatment Plant
6.2. Parts of water treatment plant:-
6.2.1. Demineralization plant:-
Water is the raw material for the thermal power plant. In thermal power plant weevaporate
water to steam and by use of steam turbine we get work.
27
The basic properties of water before entering the boiler are:-
It must be alkaline.(pH= 9.8 to 10.2)
Hardness must be nail.
TDS must be less than 100 PPM.
Dissolve gases which causes corrosion must be removed.
Water should be odorless.
Conductivity must be less than 200 micro s/cm.
Silica contents must be less than 3 PPM.
In D.M. plant we induce these properties in raw water which taken from a river at
“CHANDU JI KA GADA” village about 3 km from the RSWM power plant. First of all this
raw water is taken in raw water tank, then this water is pumped into settling tank where
chlorine,alum& lime are added in water for removal of bacteria, for sedimentation and for
removal hardness respectively. Then this water is taken into filtration tank & mud of settling
tank is thrown to the found.
Now this water is taken to the filtration tank where a greasy chemical is added to combine
small particles which settle down due to gravity. In the filtration tank an agitator is rotated in
a circular wire mash screen. Raw water coming from settling tank comes in this section and
filtered water comes out of wire mash and impurities remains there.
This filtered water is taken to the storage tank where the turbidity in the water is
approximately 3-3 PPM. From storage tank water is pumped into dual media filter (DMF)
section. This DMF section contents sand+ anthracite carbons. By which turbidity is reduced
up to 1 PPM & odor is removed from water. Then this water is pumped into cat ion exchange
resin, wherepositively charged impurities are removed & this resin is recharged by HCl. Now
this water is taken in degasifier tank where CO2 is removed. In degasifier tank air is blown
through incoming water which removes CO. Then this water is pumped in strong base anion
(SBA) tank where positively charged impurities are removed & it is recharged by NaOH.
Now this water is taken into mix bed unit where remaining impurities are removed by anion
&cation resin & this water is stored in storage tank from where water is pumped to dearator.
The basic properties of water before entering the boiler are:-
It must be alkaline.(pH= 9.8 to 10.2)
Hardness must be nail.
TDS must be less than 100 PPM.
Dissolve gases which causes corrosion must be removed.
Water should be odorless.
Conductivity must be less than 200 micro s/cm.
Silica contents must be less than 3 PPM.
In D.M. plant we induce these properties in raw water which taken from a river at
“CHANDU JI KA GADA” village about 3 km from the RSWM power plant. First of all this
raw water is taken in raw water tank, then this water is pumped into settling tank where
chlorine,alum& lime are added in water for removal of bacteria, for sedimentation and for
removal hardness respectively. Then this water is taken into filtration tank & mud of settling
tank is thrown to the found.
Now this water is taken to the filtration tank where a greasy chemical is added to combine
small particles which settle down due to gravity. In the filtration tank an agitator is rotated in
a circular wire mash screen. Raw water coming from settling tank comes in this section and
filtered water comes out of wire mash and impurities remains there.
This filtered water is taken to the storage tank where the turbidity in the water is
approximately 3-3 PPM. From storage tank water is pumped into dual media filter (DMF)
section. This DMF section contents sand+ anthracite carbons. By which turbidity is reduced
up to 1 PPM & odor is removed from water. Then this water is pumped into cat ion exchange
resin, wherepositively charged impurities are removed & this resin is recharged by HCl. Now
this water is taken in degasifier tank where CO2 is removed. In degasifier tank air is blown
through incoming water which removes CO. Then this water is pumped in strong base anion
(SBA) tank where positively charged impurities are removed & it is recharged by NaOH.
Now this water is taken into mix bed unit where remaining impurities are removed by anion
&cation resin & this water is stored in storage tank from where water is pumped to dearator.
28
Fig. 6.2. Block diagram of DM plant
HRSCC-high rate solid content clarifier chamber
S.A.C-solid acidic cat ion
S.B.A-solid basic am ion
C.W.S.T. - ACW makeup water pump
6.2.2. BCWpump house:-
Filter water after demineralization is used for bearing cooling from BCW pump house after
passing through strainer and heat exchanger it enter at 30-32° C and leave exchanger quantity
is stored in sumps of BCW Pump House. From here the water is pumped to CW pump By
TWS (Traveling water screens) pumps are run by motors of 90 KW and has a capacity of 240
Cum/hr/pump at pressure of 5 kg/cm
2
.
BCW here stand for water used for cooling oil the bearing. In CW pump house water is
discharged from nozzle and impinged for traveling water screens for cleaning it.
6.3. Condensate system:-
A typical condensate system consists of the following
6.3.1.Condenser:-
The functions of condenser are to provide lowest economic heat rejection temperature for the
steam. Thus saving on steam required per unit of electricity. Also convert exhaust steam to
water for reuse thus saving on feed water requirement. Duration of makeup water introduce
in the condenser. And to from a convenient point for introducing makes up water.
Fig. 6.2. Block diagram of DM plant
HRSCC-high rate solid content clarifier chamber
S.A.C-solid acidic cat ion
S.B.A-solid basic am ion
C.W.S.T. - ACW makeup water pump
6.2.2. BCWpump house:-
Filter water after demineralization is used for bearing cooling from BCW pump house after
passing through strainer and heat exchanger it enter at 30-32° C and leave exchanger quantity
is stored in sumps of BCW Pump House. From here the water is pumped to CW pump By
TWS (Traveling water screens) pumps are run by motors of 90 KW and has a capacity of 240
Cum/hr/pump at pressure of 5 kg/cm
2
.
BCW here stand for water used for cooling oil the bearing. In CW pump house water is
discharged from nozzle and impinged for traveling water screens for cleaning it.
6.3. Condensate system:-
A typical condensate system consists of the following
6.3.1.Condenser:-
The functions of condenser are to provide lowest economic heat rejection temperature for the
steam. Thus saving on steam required per unit of electricity. Also convert exhaust steam to
water for reuse thus saving on feed water requirement. Duration of makeup water introduce
in the condenser. And to from a convenient point for introducing makes up water.
29
6.3.2. Types of condenser:-
6.3.2.1. Direct contact type (jet condenser): -
In this type condensation of steam takes place by directly mixing exhaust steam and cooling
water. Requirement of cooling water is much less here compare to surface type. But cooling
water quality should be equal to condensate quality.
6.3.2.2. Surface condenser:-
This type is generally used for modern steam turbine installation. Condensations of exhaust
steam takes place on the outer surface of the tubes, which are cooled by water flowing inside
them.
6.3.2.3.Condensate extraction pumps:-
Condensate extraction pumps are normally multistage, vertical, centrifugal pumps. They are
generally required to operate on minimum net positive suction head (NPSH). The condensate
pumps operate on few inches of suction submergence. A van line connects the hot well, from
where the condensate pumps the suction with the condenser. No. of stages in the pump is
determined by the discharges pressure required for the condensate cycle. In 120 MW unit.
Three condensate pumps, each having 50% capacity, are provided for pumping the
condensate to desecrater. Condensate water is also used for:
Sealing of glands of valves operating under vacuum.
Temperature control of LP by pass steam.
Falling siphons of main ejectors and 15 meter symphony of drain expander.
Operation of group protection device for by passing HP heaters.
6.4 Air extraction system:-
Air extraction system is needed to extract air and other non-condensable gasesfrom the
condenser for maintaining vacuum. Amount of air to be extracted from condenser during start
up is quite large land the extraction should be done as rapidly as possible so as to allow the
turbine to be started.
To guard against excessive water vapour extraction along with air, the space beneath the air
extraction baffles has been provided with its own cooling tubes in order to condense as much
water vapour as possible and thus preventing its removal from condenser.
6.3.2. Types of condenser:-
6.3.2.1. Direct contact type (jet condenser): -
In this type condensation of steam takes place by directly mixing exhaust steam and cooling
water. Requirement of cooling water is much less here compare to surface type. But cooling
water quality should be equal to condensate quality.
6.3.2.2. Surface condenser:-
This type is generally used for modern steam turbine installation. Condensations of exhaust
steam takes place on the outer surface of the tubes, which are cooled by water flowing inside
them.
6.3.2.3.Condensate extraction pumps:-
Condensate extraction pumps are normally multistage, vertical, centrifugal pumps. They are
generally required to operate on minimum net positive suction head (NPSH). The condensate
pumps operate on few inches of suction submergence. A van line connects the hot well, from
where the condensate pumps the suction with the condenser. No. of stages in the pump is
determined by the discharges pressure required for the condensate cycle. In 120 MW unit.
Three condensate pumps, each having 50% capacity, are provided for pumping the
condensate to desecrater. Condensate water is also used for:
Sealing of glands of valves operating under vacuum.
Temperature control of LP by pass steam.
Falling siphons of main ejectors and 15 meter symphony of drain expander.
Operation of group protection device for by passing HP heaters.
6.4 Air extraction system:-
Air extraction system is needed to extract air and other non-condensable gasesfrom the
condenser for maintaining vacuum. Amount of air to be extracted from condenser during start
up is quite large land the extraction should be done as rapidly as possible so as to allow the
turbine to be started.
To guard against excessive water vapour extraction along with air, the space beneath the air
extraction baffles has been provided with its own cooling tubes in order to condense as much
water vapour as possible and thus preventing its removal from condenser.
30
6.5 Low pressure heater: -
The heater is of horizontal surface type consisting of two halves, each half has been located
inside the upper part of each condenser. The two halves have been installed in parallel. The
steam to both is supplied from the same extraction point.
6.6 Gland cooler:-
Gland cooler has been designed to condensate the leaks off steam from intermediate
chambers of land earthling of HP & IP turbines.
The construction of this cooler is identical with low pressure heater No. 2, 3 & 4. The main
condensate flows through the tubes in four paths before leaving the cooler.
The deal off steam enters the shell through a pipe and flow over the tube nest.The
participation wall installed in the tube system lead to zigzag flow of steam over the tube nest.
6.7 Dearator: -
The pressure of certain gases like Oxygen, carbon dioxide and ammonia dissolved in water is
harmful because of their corrosive attack on metals, particularly at elevated, temperature.
Thus in modern high pressure boiler, to prevent internal corrosion, the feed water should be
free as far as practicable of all dissolved gases specially oxygen.
6.5 Low pressure heater: -
The heater is of horizontal surface type consisting of two halves, each half has been located
inside the upper part of each condenser. The two halves have been installed in parallel. The
steam to both is supplied from the same extraction point.
6.6 Gland cooler:-
Gland cooler has been designed to condensate the leaks off steam from intermediate
chambers of land earthling of HP & IP turbines.
The construction of this cooler is identical with low pressure heater No. 2, 3 & 4. The main
condensate flows through the tubes in four paths before leaving the cooler.
The deal off steam enters the shell through a pipe and flow over the tube nest.The
participation wall installed in the tube system lead to zigzag flow of steam over the tube nest.
6.7 Dearator: -
The pressure of certain gases like Oxygen, carbon dioxide and ammonia dissolved in water is
harmful because of their corrosive attack on metals, particularly at elevated, temperature.
Thus in modern high pressure boiler, to prevent internal corrosion, the feed water should be
free as far as practicable of all dissolved gases specially oxygen.
31
CHAPTER - 7
Boiler
Fig. 7.1 Boiler
7.1 Definition of boiler: -
A boiler (or steam generator) is a closed vessel in which water, underPressure is converted
into steam. It is one of the major components of a thermal power plant. A boiler is always
designed to absorb maximum amount of heat released in process of combustion. This is
transferred to the boiler by all the three modes of heat transfer i.e. conduction, convection and
radiation.
7.2 Working principle of boiler: -
The basic working principle of boiler is very simple and easy to understand. The boiler is
essentially aclosed vessel inside which water is stored. Fuel (generally coal) is bunt in a
furnace and hot gasses are produced. These hot gasses come in contact with water vessel
where the heat of these hot gases transfer to the water and consequently steam is produced in
the boiler. Then this steam is piped to the turbine of thermal power plant. There are many
different types of boiler utilized for different purposes like running a production unit,
sanitizing some area, sterilizing equipment, to warm up the surroundings etc.
CHAPTER - 7
Boiler
Fig. 7.1 Boiler
7.1 Definition of boiler: -
A boiler (or steam generator) is a closed vessel in which water, underPressure is converted
into steam. It is one of the major components of a thermal power plant. A boiler is always
designed to absorb maximum amount of heat released in process of combustion. This is
transferred to the boiler by all the three modes of heat transfer i.e. conduction, convection and
radiation.
7.2 Working principle of boiler: -
The basic working principle of boiler is very simple and easy to understand. The boiler is
essentially aclosed vessel inside which water is stored. Fuel (generally coal) is bunt in a
furnace and hot gasses are produced. These hot gasses come in contact with water vessel
where the heat of these hot gases transfer to the water and consequently steam is produced in
the boiler. Then this steam is piped to the turbine of thermal power plant. There are many
different types of boiler utilized for different purposes like running a production unit,
sanitizing some area, sterilizing equipment, to warm up the surroundings etc.
32
7.3 Types of boiler: -
There are mainly two types of boiler – water tube boiler and fire tube boiler.
In fire tube boiler, there are numbers of tubes through which hot gases are passed and water
surrounds these tubes.Water tube boiler is reverse of the fire tube boiler in water tube boiler
the water is heated inside tubes and hot gasses surround these tubes.
A water tube boiler is such kind of boiler where the water is heated inside tubes and the hot
gasses surround them. This is the basic definition of water tube boiler. Actually this boiler is
just opposite of fire tube boiler where hot gasses are passed through tubes which are
surrounded by water.
7.4Advantagesofwater tube boiler: -
There are many advantages of water tube boiler due to which these types of boiler are
essentially used in large thermal power station.
1) Larger heating surface can be achieved by using more numbers of water tubes.
2) Due to convectional flow, movement of water is much faster than that of fire tube boiler;
hence rate of heat transfer is high which results into higher efficiency.
3) Very high pressure in order of 140 kg/cm
2
can be obtained smoothly.
7.5 Working principle of Water Tube Boiler: -
The working principle of water tube boiler is very interesting and simple.
It consists of mainly tow drums, one is upper drum called steam drum other is lower drum
called mud drum. These upper drum and lower drum are connected with two tubes namely
down-comer and riser tubes as shown in the picture. Water in the lower drum and in the riser
connected to it, is heated and steam is produced in them which comes to the upper drums
naturally. In the upper drum the steam is separated from water naturally and stored above the
water surface. The colder water is fed from feed water inlet at upper drum and as this water is
heavier than the hotter water of lower drum and that in the riser, the colder water push the
hotter water upwards through the riser. So there is one convectional flow of water in the
7.3 Types of boiler: -
There are mainly two types of boiler – water tube boiler and fire tube boiler.
In fire tube boiler, there are numbers of tubes through which hot gases are passed and water
surrounds these tubes.Water tube boiler is reverse of the fire tube boiler in water tube boiler
the water is heated inside tubes and hot gasses surround these tubes.
A water tube boiler is such kind of boiler where the water is heated inside tubes and the hot
gasses surround them. This is the basic definition of water tube boiler. Actually this boiler is
just opposite of fire tube boiler where hot gasses are passed through tubes which are
surrounded by water.
7.4Advantagesofwater tube boiler: -
There are many advantages of water tube boiler due to which these types of boiler are
essentially used in large thermal power station.
1) Larger heating surface can be achieved by using more numbers of water tubes.
2) Due to convectional flow, movement of water is much faster than that of fire tube boiler;
hence rate of heat transfer is high which results into higher efficiency.
3) Very high pressure in order of 140 kg/cm
2
can be obtained smoothly.
7.5 Working principle of Water Tube Boiler: -
The working principle of water tube boiler is very interesting and simple.
It consists of mainly tow drums, one is upper drum called steam drum other is lower drum
called mud drum. These upper drum and lower drum are connected with two tubes namely
down-comer and riser tubes as shown in the picture. Water in the lower drum and in the riser
connected to it, is heated and steam is produced in them which comes to the upper drums
naturally. In the upper drum the steam is separated from water naturally and stored above the
water surface. The colder water is fed from feed water inlet at upper drum and as this water is
heavier than the hotter water of lower drum and that in the riser, the colder water push the
hotter water upwards through the riser. So there is one convectional flow of water in the
33
boiler system. More steam is produced the pressure of the closed system increases which
obstructs this convectional flow of water and hence rate production of steam becomes slower
proportionately. Again if the steam is taken trough steam outlet, the pressure inside the
system falls and consequently the convectional flow of water becomes faster which result in
faster steam production rate. In this way the water tube boiler can control its own pressure.
Hence this type of boiler is referred as self-controlled machine.
7.6 Types of Water Tube Boiler: -
There are many types of water tube boiler. They can be sub-categorized in three types
namely: -
1) Horizontal Straight Tube Boiler
2) Bent Tube Boiler
3) Cyclone Fired Boiler
Fig. 7.2 Water Tube boiler- Conceptual Diagram
boiler system. More steam is produced the pressure of the closed system increases which
obstructs this convectional flow of water and hence rate production of steam becomes slower
proportionately. Again if the steam is taken trough steam outlet, the pressure inside the
system falls and consequently the convectional flow of water becomes faster which result in
faster steam production rate. In this way the water tube boiler can control its own pressure.
Hence this type of boiler is referred as self-controlled machine.
7.6 Types of Water Tube Boiler: -
There are many types of water tube boiler. They can be sub-categorized in three types
namely: -
1) Horizontal Straight Tube Boiler
2) Bent Tube Boiler
3) Cyclone Fired Boiler
Fig. 7.2 Water Tube boiler- Conceptual Diagram
34
CHAPTER - 8
Steam turbine
8.1 INTRODUCTION
Turbine is a machine in which a shaft is rotated steadily by impact or reaction of current or
stream of working substance (steam,air, water, gases etc.) upon blades of a wheel. It converts
the potential or kinetic energy of the working substance into mechanical power by virtue of
dynamic action of working substance. When the working substance is steam it is called the
steam turbine.
8.2 Principle of operation of steam turbine: -
Fig 8.1 Overview of steam turbine
Working of the steam turbine depends wholly upon the dynamic action of Steam. The steam
is caused to fall in pressure in a passage of nozzle due to this fall in pressure a certain amount
of heat energy is converted into mechanical kinetic energy and the steam is set moving with a
greater velocity. The rapidly moving particles of steam, enter the moving part of the turbine
and here suffer a change in direction of motion which gives rose to change of momentum and
therefore to a force. This constitutes the driving force of the machine. The processor of
expansion and direction changing may occur once or a number of times in succession and
may be carried out with difference of detail. The passage of steam through moving part of
the commonly called the blade, may take place in such a manner that the pressure at the outlet
side of the blade is equal to that at the inlet inside. Such a turbine is broadly termed as
impulse turbine.
TURBINE SECTION
CHAPTER - 8
Steam turbine
8.1 INTRODUCTION
Turbine is a machine in which a shaft is rotated steadily by impact or reaction of current or
stream of working substance (steam,air, water, gases etc.) upon blades of a wheel. It converts
the potential or kinetic energy of the working substance into mechanical power by virtue of
dynamic action of working substance. When the working substance is steam it is called the
steam turbine.
8.2 Principle of operation of steam turbine: -
Fig 8.1 Overview of steam turbine
Working of the steam turbine depends wholly upon the dynamic action of Steam. The steam
is caused to fall in pressure in a passage of nozzle due to this fall in pressure a certain amount
of heat energy is converted into mechanical kinetic energy and the steam is set moving with a
greater velocity. The rapidly moving particles of steam, enter the moving part of the turbine
and here suffer a change in direction of motion which gives rose to change of momentum and
therefore to a force. This constitutes the driving force of the machine. The processor of
expansion and direction changing may occur once or a number of times in succession and
may be carried out with difference of detail. The passage of steam through moving part of
the commonly called the blade, may take place in such a manner that the pressure at the outlet
side of the blade is equal to that at the inlet inside. Such a turbine is broadly termed as
impulse turbine.
TURBINE SECTION
35
8.3 Description of 23 MW steam turbine: -
8.3.1 Steam flow: -
23 MW steam turbine is a tandem compound machine with HP, IP & LP parts. The HP part is
single flow cylinder and IP & LP parts are double flow cylinders. The individual turbine
rotors and generator rotor are rigidly coupled. The HP cylinder has a throttle control. Main
steam is admitted before blending by two combined main stop and control valves. The HP
turbine exhaust (CRH) leading to reheated have to swing check valves that prevent back flow
of hot steam from reheated, into HP turbine. The steam coming from reheated called HRH is
passed to turbine via two combined stop and control valves. The IP turbine exhausts directly
goes to LP turbine by cross ground pipes.
8.3.2 HP turbine: -
The HP casing is a barrel type casing without axial joint. Because of its rotation symmetry
the barrel type casing remain constant in shape and leak proof during quick change in
temperature. The inner casing is cylinder in shape as horizontal joint flange are relieved by
higher pressure arising outside and this can kept small. Due to this reason barrel type casing
are especially suitable for quick start up and loading.
The HP turbine consists of 25 reaction stages. The moving and stationary blades are inserted
into appropriately shapes into inner casing and the shaft to reduce leakage losses at blade tips.
8.3.3 IP turbine: -
The IP part of turbine is of double flow construction. The casing of IP turbine is split
horizontally and is of double shell construction. The double flow inner casing is supported
kinematically in the outer casing. The steam from HP turbine after reheating enters the inner
casing from above and below through two inlet nozzles. The Centreflow compensates the
axial thrust and prevents steam inlet temperature affecting brackets, bearing etc.
8.3.4 LP turbine: -
The casing of double flow type LP turbine is of three shell design. The shells are axially split
and have rigidly welded construction. The outer casing consists of the front and rear walls,
the lateral longitudinal support bearing and upper part. The outer casing is supported by the
ends of longitudinal beams on the base plates of foundation. The double flow inner casing
consists of outer shell and inner shell.
8.3 Description of 23 MW steam turbine: -
8.3.1 Steam flow: -
23 MW steam turbine is a tandem compound machine with HP, IP & LP parts. The HP part is
single flow cylinder and IP & LP parts are double flow cylinders. The individual turbine
rotors and generator rotor are rigidly coupled. The HP cylinder has a throttle control. Main
steam is admitted before blending by two combined main stop and control valves. The HP
turbine exhaust (CRH) leading to reheated have to swing check valves that prevent back flow
of hot steam from reheated, into HP turbine. The steam coming from reheated called HRH is
passed to turbine via two combined stop and control valves. The IP turbine exhausts directly
goes to LP turbine by cross ground pipes.
8.3.2 HP turbine: -
The HP casing is a barrel type casing without axial joint. Because of its rotation symmetry
the barrel type casing remain constant in shape and leak proof during quick change in
temperature. The inner casing is cylinder in shape as horizontal joint flange are relieved by
higher pressure arising outside and this can kept small. Due to this reason barrel type casing
are especially suitable for quick start up and loading.
The HP turbine consists of 25 reaction stages. The moving and stationary blades are inserted
into appropriately shapes into inner casing and the shaft to reduce leakage losses at blade tips.
8.3.3 IP turbine: -
The IP part of turbine is of double flow construction. The casing of IP turbine is split
horizontally and is of double shell construction. The double flow inner casing is supported
kinematically in the outer casing. The steam from HP turbine after reheating enters the inner
casing from above and below through two inlet nozzles. The Centreflow compensates the
axial thrust and prevents steam inlet temperature affecting brackets, bearing etc.
8.3.4 LP turbine: -
The casing of double flow type LP turbine is of three shell design. The shells are axially split
and have rigidly welded construction. The outer casing consists of the front and rear walls,
the lateral longitudinal support bearing and upper part. The outer casing is supported by the
ends of longitudinal beams on the base plates of foundation. The double flow inner casing
consists of outer shell and inner shell.
36
The inner shell is attached to outer shell with provision of free thermal movement. Steam
admitted to LP turbine from IP turbine flows into the inner casing from both sides through
steam inlet nozzles.
8.4Feed water and steam cycle: -
The condensate leaving the condenser is first heated in low pressure (LP) heaters through
extracted steam from the lower pressure extraction of the turbine. Then its goes to dearator
where extra air and non-condensable gases are removed from the hot water to avoid pitting /
oxidation. From dearator it goes to boiler feed pump which increases the pressure of the
water. From the BFP it passes through the high pressure heaters. A small part of water and
steam is lost while passing through different components therefore water is added in hot well.
This water is called the makeup water. Thereafter, feed water enters into the boiler drum
through economizer. In boiler tubes water circulates because of density difference in lower
and higher temperature section of the boiler. The wet steam passes through superheated.
From superheated it goes into the HP turbine after expanding in the HP turbine. The low
pressure steam called the cold reheat steam (CRH) goes to the Reheater (boiler). From
Reheater it goes to IP turbine and then to the LP turbine and then exhausted through the
condenser into hot well.
The inner shell is attached to outer shell with provision of free thermal movement. Steam
admitted to LP turbine from IP turbine flows into the inner casing from both sides through
steam inlet nozzles.
8.4Feed water and steam cycle: -
The condensate leaving the condenser is first heated in low pressure (LP) heaters through
extracted steam from the lower pressure extraction of the turbine. Then its goes to dearator
where extra air and non-condensable gases are removed from the hot water to avoid pitting /
oxidation. From dearator it goes to boiler feed pump which increases the pressure of the
water. From the BFP it passes through the high pressure heaters. A small part of water and
steam is lost while passing through different components therefore water is added in hot well.
This water is called the makeup water. Thereafter, feed water enters into the boiler drum
through economizer. In boiler tubes water circulates because of density difference in lower
and higher temperature section of the boiler. The wet steam passes through superheated.
From superheated it goes into the HP turbine after expanding in the HP turbine. The low
pressure steam called the cold reheat steam (CRH) goes to the Reheater (boiler). From
Reheater it goes to IP turbine and then to the LP turbine and then exhausted through the
condenser into hot well.
37
CHAPTER - 9
Generator
Fig. 9.1 Generator
9.1 Introduction: -
TURBO GENERATOR manufactured by BHEL and incorporated with most modern design
concepts and constructional features, which ensures reliability, with constructional &
operational economy. The generator stator is a tight construction, supporting & enclosing the
stator windings, core and hydrogen coolers. Cooling medium hydrogen is contained within
frame & circulated by fans mounted at either ends of rotor. The generator is driven by
directly coupled steam turbine at a speed of 1500 rpm Temperature detectors and other
devices installed or connected within the machine; permit the windings, teeth core &
hydrogen temperature, pressure & purity in machine under the conditions. The auxiliary
equipment’s supplied with the machine suppresses and enables the control of hydrogen
pressure and purity, shaft sealing lubricating oils. There is a provision for cooling water in
order to maintain a constant temperature of coolant (hydrogen) which controls the
temperature of windings.
CHAPTER - 9
Generator
Fig. 9.1 Generator
9.1 Introduction: -
TURBO GENERATOR manufactured by BHEL and incorporated with most modern design
concepts and constructional features, which ensures reliability, with constructional &
operational economy. The generator stator is a tight construction, supporting & enclosing the
stator windings, core and hydrogen coolers. Cooling medium hydrogen is contained within
frame & circulated by fans mounted at either ends of rotor. The generator is driven by
directly coupled steam turbine at a speed of 1500 rpm Temperature detectors and other
devices installed or connected within the machine; permit the windings, teeth core &
hydrogen temperature, pressure & purity in machine under the conditions. The auxiliary
equipment’s supplied with the machine suppresses and enables the control of hydrogen
pressure and purity, shaft sealing lubricating oils. There is a provision for cooling water in
order to maintain a constant temperature of coolant (hydrogen) which controls the
temperature of windings.
38
9.2 Stator: -
9.2.1 Stator frame: -
The stator frame of welded steel frame construction, which gives sufficient & necessary
rigidity to minimize the vibrations and to withstand the thermal gas pressure. Heavy end
shields enclose the ends of frame and form mounting of generator bearings and radial shaft
seals. Ribs subdivide the frame and axial members to form duct from which the cooling gas
to & fro radial ducts in the core and is re-circulated through internally mounted coolers. All
the gas ducts are designed so as to secure the balanced flow of hydrogen to all parts of the
core. The stator constructed in a single piece houses the core and windings. The horizontally
mounted watercooled gas coolers being so arranged that it may be cleaned on the water side
without opening the machine to atmosphere. All welded joints exposed to hydrogen are
specially made to prevent leakage. The complete frame is subjected to hydraulic test at a
pressure of 7 ATA.
9.2.2 Stator core: -
It is built up of special sheet laminations and whose assembly is supported by a special guide
base. The method of construction ensures that the core is firmly supported at a large number
of points on its periphery. The laminations of high quality silicon steel which combines high
permeability with low hysteresis and eddy current losses. After stamping each lamination is
varnished on both sides with two coats. The segment of insulating material is inserted at
frequent intervals to provide additional insulation. The laminations are stamped out with
accurately fine combination of ties. Laminations are assembled on guide base of group
separated by radial ducts to provide ventilation passage. The ventilation ducts are disposed so
as to distribute the gas evenly over the core & in particularly to give adequate supports to the
teeth. At frequent intervals during stacking the assembled laminations are passed together in
powerful hydraulic press to ensure tight core which is finally kept between heavy clamping
plates which are non-magnetic steel. Use of non-magnetic steel reduces considerably by
heating of end iron clamping.
9.2.3 Stator bars: -
Stator bars are manufactured as half bars. Each stator half coil is composed of double glass
cover and bars of copper transposed in straight portion of “Robill Method” so that each strip
occupies every radial portion in the bar. For an equal length along the bar. They are made in
strips to reduce skin effect. The winding overhead is in volute shape. The overhung portion of
9.2 Stator: -
9.2.1 Stator frame: -
The stator frame of welded steel frame construction, which gives sufficient & necessary
rigidity to minimize the vibrations and to withstand the thermal gas pressure. Heavy end
shields enclose the ends of frame and form mounting of generator bearings and radial shaft
seals. Ribs subdivide the frame and axial members to form duct from which the cooling gas
to & fro radial ducts in the core and is re-circulated through internally mounted coolers. All
the gas ducts are designed so as to secure the balanced flow of hydrogen to all parts of the
core. The stator constructed in a single piece houses the core and windings. The horizontally
mounted watercooled gas coolers being so arranged that it may be cleaned on the water side
without opening the machine to atmosphere. All welded joints exposed to hydrogen are
specially made to prevent leakage. The complete frame is subjected to hydraulic test at a
pressure of 7 ATA.
9.2.2 Stator core: -
It is built up of special sheet laminations and whose assembly is supported by a special guide
base. The method of construction ensures that the core is firmly supported at a large number
of points on its periphery. The laminations of high quality silicon steel which combines high
permeability with low hysteresis and eddy current losses. After stamping each lamination is
varnished on both sides with two coats. The segment of insulating material is inserted at
frequent intervals to provide additional insulation. The laminations are stamped out with
accurately fine combination of ties. Laminations are assembled on guide base of group
separated by radial ducts to provide ventilation passage. The ventilation ducts are disposed so
as to distribute the gas evenly over the core & in particularly to give adequate supports to the
teeth. At frequent intervals during stacking the assembled laminations are passed together in
powerful hydraulic press to ensure tight core which is finally kept between heavy clamping
plates which are non-magnetic steel. Use of non-magnetic steel reduces considerably by
heating of end iron clamping.
9.2.3 Stator bars: -
Stator bars are manufactured as half bars. Each stator half coil is composed of double glass
cover and bars of copper transposed in straight portion of “Robill Method” so that each strip
occupies every radial portion in the bar. For an equal length along the bar. They are made in
strips to reduce skin effect. The winding overhead is in volute shape. The overhung portion of
39
the bar is divided into four quadrants & insulated. The arrangement reduces additional losses
due to damping currents which otherwise be present due to self-induced non-uniform flux
distribution in the coil slots. The main distribution for the bar consists of resin rich mica
loosed thermosetting epoxy. This has excellent mechanical and electrical properties & does
not require any impregnation.
9.2.4 Stator windings: -
Stator windings are double star layers, lap wound, three phase, and short pitch type. The top
& bottom are brazed and insulated at either end to form turns. Several such turns form a
phase. Phases are connected to form a double star winding. The end of winding form
involutes shape ends, inclined towards machine axis by 20
o
, thus form a basket winding with
total induced conical angle of 40
’
. Due to these stray load losses in the stator ends to zero.
9.3 Terminal bushings: -
Six output leads (3 long, 3 short) have been brought out of the coming on the exciter side.
External connections are to be made to the three shorter terminals, which are phase terminals.
The large terminals are of neutral & current transformer is inserted. The conductor of
Generator terminal bushing having hollow copper tubes with Copper brazed at the ends to
avoid leakage of hydrogen. Hollow portions enable bushings to be hydrogen cooled. Ends of
bushings are Silver-plated; middle portion of the bushing is adequately insulated & has a
circular flange for bolting the stator casing. Gaskets are provided between the Flange of
terminal bushings and castings to make it absolutely gas tight.
9.4 Bearings: -
Generator bearings have electrical seats of consists of steel bodies with removable steel
pads.The bearings are formed for forced lubrication of oil at a pressure of 2-3 ATM from the
samepump that supplies oils to the turbine, bearings & governing gears. There is a provision
to ensure & measure the rotor bearing temperature by inserting a resistance thermometer in
the oil pockets.
9.4.1 Ventilation system: -
The machine is designed with ventilation system having 2 ATM rated hydrogen pressure.
Two axial fans mounted on either side of the rotor to ensure circulation of hydrogen. The
stator is designed for radial ventilation by stem. The end stator core packets & core clamping
& plates are intensively cooled by Hydrogen through special ventilation system.
the bar is divided into four quadrants & insulated. The arrangement reduces additional losses
due to damping currents which otherwise be present due to self-induced non-uniform flux
distribution in the coil slots. The main distribution for the bar consists of resin rich mica
loosed thermosetting epoxy. This has excellent mechanical and electrical properties & does
not require any impregnation.
9.2.4 Stator windings: -
Stator windings are double star layers, lap wound, three phase, and short pitch type. The top
& bottom are brazed and insulated at either end to form turns. Several such turns form a
phase. Phases are connected to form a double star winding. The end of winding form
involutes shape ends, inclined towards machine axis by 20
o
, thus form a basket winding with
total induced conical angle of 40
’
. Due to these stray load losses in the stator ends to zero.
9.3 Terminal bushings: -
Six output leads (3 long, 3 short) have been brought out of the coming on the exciter side.
External connections are to be made to the three shorter terminals, which are phase terminals.
The large terminals are of neutral & current transformer is inserted. The conductor of
Generator terminal bushing having hollow copper tubes with Copper brazed at the ends to
avoid leakage of hydrogen. Hollow portions enable bushings to be hydrogen cooled. Ends of
bushings are Silver-plated; middle portion of the bushing is adequately insulated & has a
circular flange for bolting the stator casing. Gaskets are provided between the Flange of
terminal bushings and castings to make it absolutely gas tight.
9.4 Bearings: -
Generator bearings have electrical seats of consists of steel bodies with removable steel
pads.The bearings are formed for forced lubrication of oil at a pressure of 2-3 ATM from the
samepump that supplies oils to the turbine, bearings & governing gears. There is a provision
to ensure & measure the rotor bearing temperature by inserting a resistance thermometer in
the oil pockets.
9.4.1 Ventilation system: -
The machine is designed with ventilation system having 2 ATM rated hydrogen pressure.
Two axial fans mounted on either side of the rotor to ensure circulation of hydrogen. The
stator is designed for radial ventilation by stem. The end stator core packets & core clamping
& plates are intensively cooled by Hydrogen through special ventilation system.
40
9.4.2 MEASUREMENT OF BEARING TEMPERATURE
Two RTDs are provided in the shelves of Turbo-Generator for measurement of signalization
of the bearing metal cap. All the terminals of RTDs are brought out to a common terminal
board located on the stator frame.
9.5 Hydrogen coolers: -
Three Hydrogen Coolers each comprising of two individual units is mounted inside the stator
frame. The inlet and outlet of cooling water from both of machine i.e. from non-driving side
as well as turbine side.
9.6 Rotor: -
Rotor shaft consists of single piece alloy steel forging of high mechanical and magnetic
properties performance test includes
Tensile test on specimen piece.
Surface examination.
Sulphur priest tests.
Magnetic crack detection.
Visual examination of bore.
Ultrasonic examination.
9.6.1 Vibration of rotor: -
The fully brazed rotor is dynamically balanced and subject to 120 % over speed test at the
work balancing tunnel so as to ensure reliable operation.
9.6.2 Rotor windings: -
Rotor winding is of direct coil type and consists of parallel strips of very high conductivity
Silver Bearing Copper, bent on edge to form coil. The coils are placed in impregnated glass,
laminated short shells; using glass strips inter turn insulation and will be brazed at the end to
form continuous winding.
9.4.2 MEASUREMENT OF BEARING TEMPERATURE
Two RTDs are provided in the shelves of Turbo-Generator for measurement of signalization
of the bearing metal cap. All the terminals of RTDs are brought out to a common terminal
board located on the stator frame.
9.5 Hydrogen coolers: -
Three Hydrogen Coolers each comprising of two individual units is mounted inside the stator
frame. The inlet and outlet of cooling water from both of machine i.e. from non-driving side
as well as turbine side.
9.6 Rotor: -
Rotor shaft consists of single piece alloy steel forging of high mechanical and magnetic
properties performance test includes
Tensile test on specimen piece.
Surface examination.
Sulphur priest tests.
Magnetic crack detection.
Visual examination of bore.
Ultrasonic examination.
9.6.1 Vibration of rotor: -
The fully brazed rotor is dynamically balanced and subject to 120 % over speed test at the
work balancing tunnel so as to ensure reliable operation.
9.6.2 Rotor windings: -
Rotor winding is of direct coil type and consists of parallel strips of very high conductivity
Silver Bearing Copper, bent on edge to form coil. The coils are placed in impregnated glass,
laminated short shells; using glass strips inter turn insulation and will be brazed at the end to
form continuous winding.
41
9.6.3 Bearings: -
The bearings are self-aligned & consist of slip steel shells linked with special bearing metal
having very low coefficient of friction. The bore is machined on an elliptical shape so as to
increase the mechanical stability of the rotor. The bearings are pressure lubricated from the
turbine oil supply.
9.6.4 Slip rings: -
The slip rings are made of forged steel. They are located at either side of Generator Shaft.
The slip ring towards the exciter side is given +ve polarity initially. They have helical
grooves and skewed holes in the body for cooling purpose by air.
9.6.5 Bush gear assembly: -
Generator bushes are made from the various compositions of natural graphite and binding
material. They have a low coefficient of friction and are self-lubricating. The brushes are
provided with a double flexible copper or pigtails.
9.6.3 Bearings: -
The bearings are self-aligned & consist of slip steel shells linked with special bearing metal
having very low coefficient of friction. The bore is machined on an elliptical shape so as to
increase the mechanical stability of the rotor. The bearings are pressure lubricated from the
turbine oil supply.
9.6.4 Slip rings: -
The slip rings are made of forged steel. They are located at either side of Generator Shaft.
The slip ring towards the exciter side is given +ve polarity initially. They have helical
grooves and skewed holes in the body for cooling purpose by air.
9.6.5 Bush gear assembly: -
Generator bushes are made from the various compositions of natural graphite and binding
material. They have a low coefficient of friction and are self-lubricating. The brushes are
provided with a double flexible copper or pigtails.
42
CHAPTER- 10
Rating ofvarious equipment
10.1 Induction motor: -
Fig. 10.1-Induction motor
An induction motor or asynchronous motor is a type of alternating current motor where
power is supplied to the rotor by means of electromagnetic induction.
An electric motor converts electrical power to mechanical power in its rotor (rotating part).
There are several ways to supply power to the rotor. In a DC motor this power is supplied to
the armature directly from a DC source, while in an induction motor this power is induced in
the rotating device. An induction motor is sometimes called a rotating transformer because
the stator (stationary part) is essentially the primary side of the transformer and the rotor
(rotating part) is the secondary side. Unlike the normal transformer which changes the current
by using time varying flux, induction motors use rotating magnetic fields to transform the
voltage. The primary side's current creates an electromagnetic field which interacts with the
secondary side's electromagnetic field to produce a resultant torque, thereby transforming the
electrical energy into mechanical energy. Induction motors are widely used, especially poly-
phase induction motors, which are frequently used in industrial drives.
CHAPTER- 10
Rating ofvarious equipment
10.1 Induction motor: -
Fig. 10.1-Induction motor
An induction motor or asynchronous motor is a type of alternating current motor where
power is supplied to the rotor by means of electromagnetic induction.
An electric motor converts electrical power to mechanical power in its rotor (rotating part).
There are several ways to supply power to the rotor. In a DC motor this power is supplied to
the armature directly from a DC source, while in an induction motor this power is induced in
the rotating device. An induction motor is sometimes called a rotating transformer because
the stator (stationary part) is essentially the primary side of the transformer and the rotor
(rotating part) is the secondary side. Unlike the normal transformer which changes the current
by using time varying flux, induction motors use rotating magnetic fields to transform the
voltage. The primary side's current creates an electromagnetic field which interacts with the
secondary side's electromagnetic field to produce a resultant torque, thereby transforming the
electrical energy into mechanical energy. Induction motors are widely used, especially poly-
phase induction motors, which are frequently used in industrial drives.
43
Induction motors are now the preferred choice for industrial motors due to their rugged
construction, absence of brushes (which are required in most DC motors).
10.2. Rating of ACW motor: -
Table No.-10.1 TECHNICAL DATA OF ACW MOTOR
10.3. Rating of DM plant HMDC pump motor: -
Table No. 10.2 TECHNICAL DATA OF DM PLANT HMDC PUMP MOTOR
10.4. Circuit breaker: -
A circuit breaker is an automatically-operated electrical switch designed to protect an
electrical circuit from damage caused by overload or short circuit. Its basic function is to
detect a fault condition and, by interrupting continuity, to immediately discontinue electrical
flow. Unlike a fuse, which operates once and then has to be replaced, a circuit breaker can be
reset (either manually or automatically) to resume normal operation. Circuit breakers are
made in varying sizes, from small devices that protect an individual household appliance up
to large switchgear designed to protect high voltage circuits feeding an entire city.
10.4.1. Types of circuit breaker: -
Many different classifications of circuit breakers can be made, based on their features such as
voltage class, construction type, interrupting type, and structural features.
10.4.1.1. Low voltage circuit breakers: -
Low voltage (less than 1000 VAC) types are common in domestic, commercial and industrial
application, include:
Induction motors are now the preferred choice for industrial motors due to their rugged
construction, absence of brushes (which are required in most DC motors).
10.2. Rating of ACW motor: -
Table No.-10.1 TECHNICAL DATA OF ACW MOTOR
10.3. Rating of DM plant HMDC pump motor: -
Table No. 10.2 TECHNICAL DATA OF DM PLANT HMDC PUMP MOTOR
10.4. Circuit breaker: -
A circuit breaker is an automatically-operated electrical switch designed to protect an
electrical circuit from damage caused by overload or short circuit. Its basic function is to
detect a fault condition and, by interrupting continuity, to immediately discontinue electrical
flow. Unlike a fuse, which operates once and then has to be replaced, a circuit breaker can be
reset (either manually or automatically) to resume normal operation. Circuit breakers are
made in varying sizes, from small devices that protect an individual household appliance up
to large switchgear designed to protect high voltage circuits feeding an entire city.
10.4.1. Types of circuit breaker: -
Many different classifications of circuit breakers can be made, based on their features such as
voltage class, construction type, interrupting type, and structural features.
10.4.1.1. Low voltage circuit breakers: -
Low voltage (less than 1000 VAC) types are common in domestic, commercial and industrial
application, include:
44
MCB (Miniature Circuit Breaker)—rated current not more than 100 A. Trip
characteristics normally not adjustable. Thermal or thermal-magnetic operation.
Breakers illustrated above are in this category.
MCCB (Molded Case Circuit Breaker)—rated current up to 2500 A. Thermal or
thermal-magnetic operation. Trip current may be adjustable in larger ratings.
Low voltage power circuit breakers can be mounted in multi-tiers in LV switchboards
or switchgear cabinets.
The 10 ampere DIN rail-mounted thermal-magnetic miniature circuit breaker is the most
common style in modern domestic consumer units and commercial electrical distribution
boards throughout Europe. The design includes the following components:
1. Actuator lever - used to manually trip and reset the circuit breaker. Also indicates the status
of the circuit breaker (On or Off/tripped). Most breakers are designed so they can still trip
even if the lever is held or locked in the "on" position. This is sometimes referred to as "free
trip" or "positive trip" operation.
2. Actuator mechanism - forces the contacts together or apart.
3. Contacts - Allow current when touching and break the current when moved apart.
4. Terminals
5. Bimetallic strip
6. Calibration screw - allows the manufacturer to precisely adjust the trip current of the
device after assembly.
7. Solenoid
8. Arc divider/extinguisher
9. Magnetic circuit breaker
Magnetic circuit breakers use a solenoid (electromagnet) that’s pulling force increases with
the current. Certain designs utilize electromagnetic forces in addition to those of the solenoid.
MCB (Miniature Circuit Breaker)—rated current not more than 100 A. Trip
characteristics normally not adjustable. Thermal or thermal-magnetic operation.
Breakers illustrated above are in this category.
MCCB (Molded Case Circuit Breaker)—rated current up to 2500 A. Thermal or
thermal-magnetic operation. Trip current may be adjustable in larger ratings.
Low voltage power circuit breakers can be mounted in multi-tiers in LV switchboards
or switchgear cabinets.
The 10 ampere DIN rail-mounted thermal-magnetic miniature circuit breaker is the most
common style in modern domestic consumer units and commercial electrical distribution
boards throughout Europe. The design includes the following components:
1. Actuator lever - used to manually trip and reset the circuit breaker. Also indicates the status
of the circuit breaker (On or Off/tripped). Most breakers are designed so they can still trip
even if the lever is held or locked in the "on" position. This is sometimes referred to as "free
trip" or "positive trip" operation.
2. Actuator mechanism - forces the contacts together or apart.
3. Contacts - Allow current when touching and break the current when moved apart.
4. Terminals
5. Bimetallic strip
6. Calibration screw - allows the manufacturer to precisely adjust the trip current of the
device after assembly.
7. Solenoid
8. Arc divider/extinguisher
9. Magnetic circuit breaker
Magnetic circuit breakers use a solenoid (electromagnet) that’s pulling force increases with
the current. Certain designs utilize electromagnetic forces in addition to those of the solenoid.
45
The circuit breaker contacts are held closed by a latch. As the current in the solenoid
increases beyond the rating of the circuit breaker, the solenoid's pull releases the latch which
then allows the contacts to open by spring action. Some types of magnetic breakers
incorporate a hydraulic time delay feature using a viscous fluid. The core is restrained by a
spring until the current exceeds the breaker rating. During an overload, the speed of the
solenoid motion is restricted by the fluid. The delay permits brief current surges beyond
normal running current for motor starting, energizing equipment, etc. Short circuit currents
provide sufficient solenoid force to release the latch regardless of core position thus
bypassing the delay feature. Ambient temperature affects the time delay but does not affect
the current rating of a magnetic breaker.
10.4.1.2. Thermal magnetic circuit breaker: -
Thermal magnetic circuit breakers, which are the type found in most distribution boards,
incorporate both techniques with the electromagnet responding instantaneously to large
surges in current (short circuits) and the bimetallic strip responding to less extreme but
longer-term over-current conditions.
10.4.1.3. Common trip breakers: -
Three pole common trip breaker for supplying a three-phase device. This breaker has a 2 A
rating
When supplying a branch circuit with more than one live conductor, each live conductor must
be protected by a breaker pole. To ensure that all live conductors are interrupted when any
pole trips, a "common trip" breaker must be used. These may either contain two or three
tripping mechanisms within one case, or for small breakers, may externally tie the poles
together via their operating handles. Two pole common trip breakers are common on 120/240
volt systems where 240 volt loads (including major appliances or further distribution boards)
span the two live wires.
Three-pole common trip breakers are typically used to supply three-phase electric power to
large motors or further distribution boards.
Two and four pole breakers are used when there is a need to disconnect the neutral wire, to be
sure that no current can flow back through the neutral wire from other loads connected to the
same network when people need to touch the wires for maintenance. Separate circuit breakers
must never be used for disconnecting live and neutral, because if the neutral gets
disconnected while the live conductor stays connected, a dangerous condition arises: the
circuit will appear de-energized (appliances will not work), but wires will stay live and RCDs
The circuit breaker contacts are held closed by a latch. As the current in the solenoid
increases beyond the rating of the circuit breaker, the solenoid's pull releases the latch which
then allows the contacts to open by spring action. Some types of magnetic breakers
incorporate a hydraulic time delay feature using a viscous fluid. The core is restrained by a
spring until the current exceeds the breaker rating. During an overload, the speed of the
solenoid motion is restricted by the fluid. The delay permits brief current surges beyond
normal running current for motor starting, energizing equipment, etc. Short circuit currents
provide sufficient solenoid force to release the latch regardless of core position thus
bypassing the delay feature. Ambient temperature affects the time delay but does not affect
the current rating of a magnetic breaker.
10.4.1.2. Thermal magnetic circuit breaker: -
Thermal magnetic circuit breakers, which are the type found in most distribution boards,
incorporate both techniques with the electromagnet responding instantaneously to large
surges in current (short circuits) and the bimetallic strip responding to less extreme but
longer-term over-current conditions.
10.4.1.3. Common trip breakers: -
Three pole common trip breaker for supplying a three-phase device. This breaker has a 2 A
rating
When supplying a branch circuit with more than one live conductor, each live conductor must
be protected by a breaker pole. To ensure that all live conductors are interrupted when any
pole trips, a "common trip" breaker must be used. These may either contain two or three
tripping mechanisms within one case, or for small breakers, may externally tie the poles
together via their operating handles. Two pole common trip breakers are common on 120/240
volt systems where 240 volt loads (including major appliances or further distribution boards)
span the two live wires.
Three-pole common trip breakers are typically used to supply three-phase electric power to
large motors or further distribution boards.
Two and four pole breakers are used when there is a need to disconnect the neutral wire, to be
sure that no current can flow back through the neutral wire from other loads connected to the
same network when people need to touch the wires for maintenance. Separate circuit breakers
must never be used for disconnecting live and neutral, because if the neutral gets
disconnected while the live conductor stays connected, a dangerous condition arises: the
circuit will appear de-energized (appliances will not work), but wires will stay live and RCDs
46
will not trip if someone touches the live wire (because RCDs need power to trip). This is why
only common trip breakers must be used when switching of the neutral wire is needed.
10.4.1.4. Medium-voltage circuit breakers: -
Medium-voltage circuit breakers rated between 1 and 72 kV may be assembled into metal-
enclosed switchgear line ups for indoor use, or may be individual components installed
outdoors in a substation. Air-break circuit breakers replaced oil-filled units for indoor
applications, but are now themselves being replaced by vacuum circuit breakers (up to about
35 kV). Like the high voltage circuit breakers described below, these are also operated by
current sensing protective relays operated through current transformers. The characteristics of
MV breakers are given by international standards such as IEC 62271. Medium-voltage circuit
breakers nearly always use separate current sensors and protection relays, instead of relying
on built-in thermal or magnetic overcurrent sensors.
Medium-voltage circuit breakers can be classified by the medium used to extinguish the arc:
10.4.1.4.1 Vacuum circuit breaker: -
with rated current up to 3000 A, these breakers interrupt the current by creating and
extinguishing the arc in a vacuum container. These are generally applied for voltages up to
about 35,000 V, which corresponds roughly to the medium-voltage range of power systems.
Vacuum circuit breakers tend to have longer life expectancies between overhaul than do air
circuit breakers.
Rating of vacuum circuit breaker of STG incomer -2
Table No.- 10.3 Technical data of vacuum circuit breaker of STG incomer -2
10.4 .1.4.2.AIR CIRCUIT BREAKER
Rated current up to 10,000 A. Trip characteristics are often fully adjustable including
configurable trip thresholds and delays.Usually electronically controlled, though some
will not trip if someone touches the live wire (because RCDs need power to trip). This is why
only common trip breakers must be used when switching of the neutral wire is needed.
10.4.1.4. Medium-voltage circuit breakers: -
Medium-voltage circuit breakers rated between 1 and 72 kV may be assembled into metal-
enclosed switchgear line ups for indoor use, or may be individual components installed
outdoors in a substation. Air-break circuit breakers replaced oil-filled units for indoor
applications, but are now themselves being replaced by vacuum circuit breakers (up to about
35 kV). Like the high voltage circuit breakers described below, these are also operated by
current sensing protective relays operated through current transformers. The characteristics of
MV breakers are given by international standards such as IEC 62271. Medium-voltage circuit
breakers nearly always use separate current sensors and protection relays, instead of relying
on built-in thermal or magnetic overcurrent sensors.
Medium-voltage circuit breakers can be classified by the medium used to extinguish the arc:
10.4.1.4.1 Vacuum circuit breaker: -
with rated current up to 3000 A, these breakers interrupt the current by creating and
extinguishing the arc in a vacuum container. These are generally applied for voltages up to
about 35,000 V, which corresponds roughly to the medium-voltage range of power systems.
Vacuum circuit breakers tend to have longer life expectancies between overhaul than do air
circuit breakers.
Rating of vacuum circuit breaker of STG incomer -2
Table No.- 10.3 Technical data of vacuum circuit breaker of STG incomer -2
10.4 .1.4.2.AIR CIRCUIT BREAKER
Rated current up to 10,000 A. Trip characteristics are often fully adjustable including
configurable trip thresholds and delays.Usually electronically controlled, though some
47
models are microprocessor controlled via an integral electronic trip unit.Often used for main
power distribution in large industrial plant, where the breakers are arranged in draw-out
enclosures for ease of maintenance.
Rating of air circuit breaker of Incomer -1
Table no.-10.4 Technical data of air circuit breaker of incomer -1
.
models are microprocessor controlled via an integral electronic trip unit.Often used for main
power distribution in large industrial plant, where the breakers are arranged in draw-out
enclosures for ease of maintenance.
Rating of air circuit breaker of Incomer -1
Table no.-10.4 Technical data of air circuit breaker of incomer -1
.
48
CHAPTER-11
Switch yard component of plant
11.1. Potential transformer: -
Potential Transformer is designed for monitoring single-phase and three-phase power line
voltages in power metering applications.
The primary terminals can be connected either in line-to-line or in line-to-neutral
configuration. Fused transformer models are designated by a suffix of "F" for one fuse or
"FF" for two fuses.
A Potential Transformer is a special type of transformer that allows meters to take readings
from electrical service connections with higher voltage (potential) than the meter is normally
capable of handling without at potential transformer.
Fig. 11.1- Potential transformer
11.2. Current transformer: -
In electrical engineering, a current transformer (CT) is used for measurement of electric
currents. Current transformers, together with voltage transformers (VT) (potential
transformers (PT)), are known as instrument transformers. When current in a circuit is too
high to directly apply to measuring instruments, a current transformer produces a reduced
current accurately proportional to the current in the circuit, which can be conveniently
connected to measuring and recording instruments. A current transformer also isolates the
CHAPTER-11
Switch yard component of plant
11.1. Potential transformer: -
Potential Transformer is designed for monitoring single-phase and three-phase power line
voltages in power metering applications.
The primary terminals can be connected either in line-to-line or in line-to-neutral
configuration. Fused transformer models are designated by a suffix of "F" for one fuse or
"FF" for two fuses.
A Potential Transformer is a special type of transformer that allows meters to take readings
from electrical service connections with higher voltage (potential) than the meter is normally
capable of handling without at potential transformer.
Fig. 11.1- Potential transformer
11.2. Current transformer: -
In electrical engineering, a current transformer (CT) is used for measurement of electric
currents. Current transformers, together with voltage transformers (VT) (potential
transformers (PT)), are known as instrument transformers. When current in a circuit is too
high to directly apply to measuring instruments, a current transformer produces a reduced
current accurately proportional to the current in the circuit, which can be conveniently
connected to measuring and recording instruments. A current transformer also isolates the
49
measuring instruments from what may be very high voltage in the monitored circuit. Current
transformers are commonly used in metering and protective relays in the electrical power
industry.
.
Fig. 11.2- Current transformer.
11.3. Lightning arrester: -
A lightning arrester is a device used on electrical Power systems to protect the insulation on
the system from the damaging effect of lightning. Metal Oxide Varsities (MOVs) have been
used for power system protection since the mid-1970s. The typical lightning arrester also
known as surge arrester has a high voltage terminal and a ground terminal. When a lightning
surge or switching surge travels down the power system to the arrester, the current from the
surge is diverted around the protected insulation in most cases to earth.
11.4. Isolator: -
Fig. 11.3- Isolator
In electrical engineering, a disconnect or isolator switch is used to make sure that an electrical
circuit can be completely de-energized for service or maintenance. Such switches are often
found in electrical distribution and industrial applications where machinery must have its
source of driving power removed for adjustment or repair. High-voltage isolation switches
are used in electrical substations to allow isolation of apparatus such as circuit breakers and
transformers, and transmission lines, for maintenance. Isolating switches are commonly fitted
measuring instruments from what may be very high voltage in the monitored circuit. Current
transformers are commonly used in metering and protective relays in the electrical power
industry.
.
Fig. 11.2- Current transformer.
11.3. Lightning arrester: -
A lightning arrester is a device used on electrical Power systems to protect the insulation on
the system from the damaging effect of lightning. Metal Oxide Varsities (MOVs) have been
used for power system protection since the mid-1970s. The typical lightning arrester also
known as surge arrester has a high voltage terminal and a ground terminal. When a lightning
surge or switching surge travels down the power system to the arrester, the current from the
surge is diverted around the protected insulation in most cases to earth.
11.4. Isolator: -
Fig. 11.3- Isolator
In electrical engineering, a disconnect or isolator switch is used to make sure that an electrical
circuit can be completely de-energized for service or maintenance. Such switches are often
found in electrical distribution and industrial applications where machinery must have its
source of driving power removed for adjustment or repair. High-voltage isolation switches
are used in electrical substations to allow isolation of apparatus such as circuit breakers and
transformers, and transmission lines, for maintenance. Isolating switches are commonly fitted
50
to domestic extractor fans when used in bathrooms in the UK. Often the isolation switch is
not intended for normal control of the circuit and is only used for isolation.
Isolator switches have provisions for a padlock so that inadvertent operation is not possible
(see: Lock and tag). In high voltage or complex systems, these padlocks may be part of a
trapped-key interlock system to ensure proper sequence of operation. In some designs the
isolator switch has the additional ability to earth the isolated circuit thereby providing
additional safety. Such an arrangement would apply to circuits which inter-connect power
distribution systems where both end of the circuit need to be isolated.
The major difference between an isolator and a circuit breaker is that an isolator is an off-load
device intended to be opened only after current has been interrupted by some other control
device. Safety regulations of the utility must prevent any attempt to open the disconnect or
while it supplies a circuit.
to domestic extractor fans when used in bathrooms in the UK. Often the isolation switch is
not intended for normal control of the circuit and is only used for isolation.
Isolator switches have provisions for a padlock so that inadvertent operation is not possible
(see: Lock and tag). In high voltage or complex systems, these padlocks may be part of a
trapped-key interlock system to ensure proper sequence of operation. In some designs the
isolator switch has the additional ability to earth the isolated circuit thereby providing
additional safety. Such an arrangement would apply to circuits which inter-connect power
distribution systems where both end of the circuit need to be isolated.
The major difference between an isolator and a circuit breaker is that an isolator is an off-load
device intended to be opened only after current has been interrupted by some other control
device. Safety regulations of the utility must prevent any attempt to open the disconnect or
while it supplies a circuit.
51
CHAPTER - 12
Ash handling plant
12.1.Introduction: -
This plant can be divided into three sub plants:-
1) Fuel and Ash plant.
2) Air and Gas Plant.
3) Ash disposal and collection plant.
Fig. 12.1 Overview of Ash Handling Plant
12.1.1 Fuel and ash plant: -
Coal is used as the main combustion material in RSWM POWER PLANT in order to get an
efficient utilization of coal. It is pulverized in coal mills. The pulverization also increases the
overall efficiency and flexibility of the boiler. However for initial type lighting up and to
withstand and static load oil burners are also used. Ash produced as a result of combustion of
coal is collected and removed by ash handling system.
Ash handling plant at RSWM POWER PLANT consists of especially designed bottom ash
and fly ash hopper located below furnace and fly ash in ESP economize and air preheated
hopper.
Fuel & ash cycle: -
Fuel from the storage is fed to the boiler through fuel handling device. The fuel used in
RSWM POWER PLANT is coal, which on combustion in the boiler produced the ash. The
CHAPTER - 12
Ash handling plant
12.1.Introduction: -
This plant can be divided into three sub plants:-
1) Fuel and Ash plant.
2) Air and Gas Plant.
3) Ash disposal and collection plant.
Fig. 12.1 Overview of Ash Handling Plant
12.1.1 Fuel and ash plant: -
Coal is used as the main combustion material in RSWM POWER PLANT in order to get an
efficient utilization of coal. It is pulverized in coal mills. The pulverization also increases the
overall efficiency and flexibility of the boiler. However for initial type lighting up and to
withstand and static load oil burners are also used. Ash produced as a result of combustion of
coal is collected and removed by ash handling system.
Ash handling plant at RSWM POWER PLANT consists of especially designed bottom ash
and fly ash hopper located below furnace and fly ash in ESP economize and air preheated
hopper.
Fuel & ash cycle: -
Fuel from the storage is fed to the boiler through fuel handling device. The fuel used in
RSWM POWER PLANT is coal, which on combustion in the boiler produced the ash. The
52
quantity of ash produced is approximately 35-40% of coal used. This ash is collected at the
back of the boiler and removed to ash storage tank through ash disposal equipment.
12.1.2Air and gas plant: -
Air from the atmosphere is supplied to the combustion chamber of boiler through the action
of FD fan & ID fan. In RSWM TPP there are 2 FD & 2 ID fans available for draft system.
The air before being supplied by the boiler passes through preheater where it is heated by
heat of fuel gases. The preheater causes improved and intensified combustion. In RSWM
POWER PLANT regenerative type preheater are used. The fuel gases formed due to
combustion of fuels passed round the boiler &superheater tubes the superheating of system
rises the temp of steam above the saturation temp. To extract the heat of fuel gases, they are
made to pass through reheaters, air preheaters and economizer. In reheater the fuel gases
raises the tempof steam of plant. It has extracted energy from high turbine with increasing no.
of steps of reheater the efficiency of cycle also increases. In economizer the heat of fuel gases
raises the temp of feed water finally it is exhausted through chimney.
12.1.3Air and gas cycle: -
Air from the atmosphere is supplied to the combustion chamber of Boiler through the action
of forced draft fan and induced draft fan. The flue gas gases are first pass around the boiler
tubes and super-heated tubes in the furnace, next through dust collector (ESP) & then
economizer. Finally, they are exhausted to the atmosphere through fans.
12.1.4Ash disposal and dust collection plant: -
RSWM POWER PLANT has dry bottom furnace. Ash handling plant consisting of especially
designed bottom and fly ash system for two system generators. The system for both units is
identical & following description applies to both the units the water completed the bottom ash
hopper receives the bottom ash from the furnace where it is stored an discharged through the
lurker grinders and ejectors for transfer through the transport lines one in every eight hours to
the slurry drum which is common for all the units. The bottom ash system is capable of ash
disposing off in one hour. Dry free flying ash collected in the total of 2 fly ash hopper which
is handled by two independent fly ash systems. The ash is removed from fly ash hopper in the
dry.
quantity of ash produced is approximately 35-40% of coal used. This ash is collected at the
back of the boiler and removed to ash storage tank through ash disposal equipment.
12.1.2Air and gas plant: -
Air from the atmosphere is supplied to the combustion chamber of boiler through the action
of FD fan & ID fan. In RSWM TPP there are 2 FD & 2 ID fans available for draft system.
The air before being supplied by the boiler passes through preheater where it is heated by
heat of fuel gases. The preheater causes improved and intensified combustion. In RSWM
POWER PLANT regenerative type preheater are used. The fuel gases formed due to
combustion of fuels passed round the boiler &superheater tubes the superheating of system
rises the temp of steam above the saturation temp. To extract the heat of fuel gases, they are
made to pass through reheaters, air preheaters and economizer. In reheater the fuel gases
raises the tempof steam of plant. It has extracted energy from high turbine with increasing no.
of steps of reheater the efficiency of cycle also increases. In economizer the heat of fuel gases
raises the temp of feed water finally it is exhausted through chimney.
12.1.3Air and gas cycle: -
Air from the atmosphere is supplied to the combustion chamber of Boiler through the action
of forced draft fan and induced draft fan. The flue gas gases are first pass around the boiler
tubes and super-heated tubes in the furnace, next through dust collector (ESP) & then
economizer. Finally, they are exhausted to the atmosphere through fans.
12.1.4Ash disposal and dust collection plant: -
RSWM POWER PLANT has dry bottom furnace. Ash handling plant consisting of especially
designed bottom and fly ash system for two system generators. The system for both units is
identical & following description applies to both the units the water completed the bottom ash
hopper receives the bottom ash from the furnace where it is stored an discharged through the
lurker grinders and ejectors for transfer through the transport lines one in every eight hours to
the slurry drum which is common for all the units. The bottom ash system is capable of ash
disposing off in one hour. Dry free flying ash collected in the total of 2 fly ash hopper which
is handled by two independent fly ash systems. The ash is removed from fly ash hopper in the
dry.
53
Combustion: -
The secondary air combustion is preheated by means of regenerative preheaters, and then
forced inside the furnace for combustion of fuel providing required oxygen for it.
Combustion igniters: -
Air needed for combustion igniters causes from passage having direct connecting with the
discharge duct of FD fans. A booster is used to boot the air pressure to the full level required
to assure positive supply to igniter.
Converging and drying of pulverized coal: -
Primary air is supplied by the primary air fans, primary air is preheated with the help of
preheater until desired limit so that the coal, which is to be carried off-desired doesn’t form
duster i.e. pulverized coal remains dry dampers contract the mixing partition of hot & cold
primary air.
Sealing: -
Hot air shut off gate and dampers control the proportion of cold air to be mixed with hot air
carrying dust small portion of air from air carrying dust to be pulverize is taken off and
boosted up by booster to the pressure required to sealing the pipelines connected to the
pulverize.
Gas flow: -
Path of fuel gases moving upward inside the abstracted by superheaters, economizers and air
preheaters waste going of fuel gases is used heating the primary and secondary air.
12.2 Chimney: -
The purpose of the chimney is to exit the exhaust gases sufficiently high to avoid misname to
the surrounding people so a high chimney has been made to concrete and steel at RSWM TPP
since concrete is strong is compression and weak in tension so vertically steel rods are used to
reinforce the concrete in order to resist the tensile strength resulting from wind pressure
horizontal wings of steel are used to take up stress.
There are two steps for size of chimney first finding max. value of the fuel gases, will
discharge by the boiler when operating at max. Ratting generally dia. of chimney should be
8-9% of height of the chimney to produce given draught abstaining by using the air out side
of some volume.
Combustion: -
The secondary air combustion is preheated by means of regenerative preheaters, and then
forced inside the furnace for combustion of fuel providing required oxygen for it.
Combustion igniters: -
Air needed for combustion igniters causes from passage having direct connecting with the
discharge duct of FD fans. A booster is used to boot the air pressure to the full level required
to assure positive supply to igniter.
Converging and drying of pulverized coal: -
Primary air is supplied by the primary air fans, primary air is preheated with the help of
preheater until desired limit so that the coal, which is to be carried off-desired doesn’t form
duster i.e. pulverized coal remains dry dampers contract the mixing partition of hot & cold
primary air.
Sealing: -
Hot air shut off gate and dampers control the proportion of cold air to be mixed with hot air
carrying dust small portion of air from air carrying dust to be pulverize is taken off and
boosted up by booster to the pressure required to sealing the pipelines connected to the
pulverize.
Gas flow: -
Path of fuel gases moving upward inside the abstracted by superheaters, economizers and air
preheaters waste going of fuel gases is used heating the primary and secondary air.
12.2 Chimney: -
The purpose of the chimney is to exit the exhaust gases sufficiently high to avoid misname to
the surrounding people so a high chimney has been made to concrete and steel at RSWM TPP
since concrete is strong is compression and weak in tension so vertically steel rods are used to
reinforce the concrete in order to resist the tensile strength resulting from wind pressure
horizontal wings of steel are used to take up stress.
There are two steps for size of chimney first finding max. value of the fuel gases, will
discharge by the boiler when operating at max. Ratting generally dia. of chimney should be
8-9% of height of the chimney to produce given draught abstaining by using the air out side
of some volume.
54
12.3 Controller: -
Now a day microprocessor based intelligent controllers are used to regulate the power fed to
the HVR. The controls the firing/ignition angle of the thrusters connected in parallel mode.
Input out waves of the controller and HVR are also shown above, which clearly indicates that
average power fed to ESP field can be controlled by variation of the firing angle of thrusters.
12.4 High voltage rectifier transformer: -
HVR receives the regulated supply from controller. It steps up to high voltage rectifier. The
DC supply is fed to ESP field through its negative bushing. The positive bushing so
connected to earth through small resistance, which forms a current, feedback circuit. A very
high resistance column is also connected with negative bushing. It forms the voltage feedback
circuit.
12.5 Electrostatic precipitator: -
Mechanical precipitations consist of number of primary cells having vanes to impart the ash
particles & course ash particles fall into the primary hoppers.
The ESP, consists of a large in which have No. of collecting electrodes. In it dust particles are
charged and stick to the electrodes.
ESP field: -
The field consists of emitting and collecting electrodes structure, which are totally isolated
from each other and hanging with the top roof of field. The emitting is also isolated from the
roof through the support insulators, which are supporting the emitting electrode frame works,
and also the supply to these electrodes is fed through support insulators. The collecting
electrodes are of the shape of flat plates. By several similar plates which the emitting
electrodes are of the shape of spring. Strong on the emitting framework with the help of
hooks in both the ends.
12.6 Fans: -
A fan can be defined as a volumetric machine, which like pumps moves quantities of air or
gas from one place to another. In doing this it overcomes resistance to flow by supplying the
fluid will the energy necessary for contained motion. The following fans are used in boiler
house:
12.3 Controller: -
Now a day microprocessor based intelligent controllers are used to regulate the power fed to
the HVR. The controls the firing/ignition angle of the thrusters connected in parallel mode.
Input out waves of the controller and HVR are also shown above, which clearly indicates that
average power fed to ESP field can be controlled by variation of the firing angle of thrusters.
12.4 High voltage rectifier transformer: -
HVR receives the regulated supply from controller. It steps up to high voltage rectifier. The
DC supply is fed to ESP field through its negative bushing. The positive bushing so
connected to earth through small resistance, which forms a current, feedback circuit. A very
high resistance column is also connected with negative bushing. It forms the voltage feedback
circuit.
12.5 Electrostatic precipitator: -
Mechanical precipitations consist of number of primary cells having vanes to impart the ash
particles & course ash particles fall into the primary hoppers.
The ESP, consists of a large in which have No. of collecting electrodes. In it dust particles are
charged and stick to the electrodes.
ESP field: -
The field consists of emitting and collecting electrodes structure, which are totally isolated
from each other and hanging with the top roof of field. The emitting is also isolated from the
roof through the support insulators, which are supporting the emitting electrode frame works,
and also the supply to these electrodes is fed through support insulators. The collecting
electrodes are of the shape of flat plates. By several similar plates which the emitting
electrodes are of the shape of spring. Strong on the emitting framework with the help of
hooks in both the ends.
12.6 Fans: -
A fan can be defined as a volumetric machine, which like pumps moves quantities of air or
gas from one place to another. In doing this it overcomes resistance to flow by supplying the
fluid will the energy necessary for contained motion. The following fans are used in boiler
house:
55
Forced draft fan (FD fan): -
To take air from the atmosphere at ambient temperature to supply all the combustion air can
either be sized to overcome all the boiler loss or just put the air in the furnace; Speed varies
between 600 to 1500 rpm.
Rating of FD fan:-
Motor - three phase squirrel cage I.M.
Type - M2BA35ML A-4.
Duty - S1
Amb. Temp. - 50°C.
Efficiency - 96.30 %.
Voltage - 415 ± 10%.
Connection - delta (∆)
Frequency - 50 Hz ± 5%.
Output - 300 kW.
Hp - 400 Hp.
Speed - 1486 rpm.
Current - 500 A.
Induced draft fan (ID fan): -
Used only in balanced draft units to suck the gases out of the furnace and through them into
the stack. Handles fly ash laden gases at temperature of 125 to 200 degree centigrade Speed
seldom exceeds 1000 rpm.
Rating of ID fan:-
Motor - 3-Ø squirrel cage I.M.
Efficiency - 94.9 %.
Voltage - 415 ± 10 %.
Connection - delta (∆).
Frequency - 50 Hz ± 5 %.
Output - 132 kW.
Hp - 180 Hp.
Speed - 987 rpm.
Current - 229 A.
Forced draft fan (FD fan): -
To take air from the atmosphere at ambient temperature to supply all the combustion air can
either be sized to overcome all the boiler loss or just put the air in the furnace; Speed varies
between 600 to 1500 rpm.
Rating of FD fan:-
Motor - three phase squirrel cage I.M.
Type - M2BA35ML A-4.
Duty - S1
Amb. Temp. - 50°C.
Efficiency - 96.30 %.
Voltage - 415 ± 10%.
Connection - delta (∆)
Frequency - 50 Hz ± 5%.
Output - 300 kW.
Hp - 400 Hp.
Speed - 1486 rpm.
Current - 500 A.
Induced draft fan (ID fan): -
Used only in balanced draft units to suck the gases out of the furnace and through them into
the stack. Handles fly ash laden gases at temperature of 125 to 200 degree centigrade Speed
seldom exceeds 1000 rpm.
Rating of ID fan:-
Motor - 3-Ø squirrel cage I.M.
Efficiency - 94.9 %.
Voltage - 415 ± 10 %.
Connection - delta (∆).
Frequency - 50 Hz ± 5 %.
Output - 132 kW.
Hp - 180 Hp.
Speed - 987 rpm.
Current - 229 A.
56
Primary air fan (PA fan) or exhauster fan: -
Used for pulverized system. Primary air has got two-function viz. drying the coal and
transportation into the furnace. Usually sized for 1500 rpm due to high pressure.
Rating of pa fan:-
Motor - 3-Ø squirrel cage I.M.
Type - HX/280 SMB4.
Duty - S1.
Amb. Temp. - 50°C.
Efficiency - 93.8%.
Voltage - 415 ± 5%.
Connection - delta (∆).
Frequency - 50 Hz ± 5%.
Output - 75 kW.
Hp - 100 Hp.
Speed - 1475 rpm.
Current - 132.5 Amps.
Primary air fan (PA fan) or exhauster fan: -
Used for pulverized system. Primary air has got two-function viz. drying the coal and
transportation into the furnace. Usually sized for 1500 rpm due to high pressure.
Rating of pa fan:-
Motor - 3-Ø squirrel cage I.M.
Type - HX/280 SMB4.
Duty - S1.
Amb. Temp. - 50°C.
Efficiency - 93.8%.
Voltage - 415 ± 5%.
Connection - delta (∆).
Frequency - 50 Hz ± 5%.
Output - 75 kW.
Hp - 100 Hp.
Speed - 1475 rpm.
Current - 132.5 Amps.
57
CHAPTER 13
Cooling & excitation system
13.1.Cooling towers: -
A cooling tower is a steel or concrete hyperbolic structure having a reservoir at the bottom for
storage of cooled water. Warm water is led to the top. Air flows from the bottom to the top.
The water drops falling from the top come in contact with air, lose heat to the air & get
cooled. Eliminators are provided at the top to prevent escape of water particles with air. Such
a tower is known as wet cooling tower. In such system the loss of water due to evaporation is
about 1%. Another 2% of the water circulated is used in purging the system of dissolved salts
i.e. salts concentrated in the system due to continuous recirculation. Therefore, the total
quantity of makeup water is about 3% of the quantity circulated in the system. Generally this
make up water is obtained from and the purge is returned to the nearby river. Air can be
circulated in a wet cooling tower by natural draft or forced draft or induced draft. The height
of the cooling tower may be about 150m.
Cooling water cycle: -
A large quantity of cooling water is required to condense the steam in condenser and
marinating low pressure in it. The water is drawn from reservoir and after use it is drained
into the river.
13.2. Excitation system: -
The electric power Generators requires direct current excited magnets for its field system.
The excitation system must be reliable, stable in operation and must response quickly to
excitation current requirements. When excitation system response is controlled by fast acting
regulators, it is chiefly dependent on exciter. Exciter supply is given from transformer and
then rectified.
13.2.1. Function of excitation system: -
The main function of excitation system is to supply required excitation current at rated load
condition of turbo Generator. It should be able to adjust the field current of the Generator,
CHAPTER 13
Cooling & excitation system
13.1.Cooling towers: -
A cooling tower is a steel or concrete hyperbolic structure having a reservoir at the bottom for
storage of cooled water. Warm water is led to the top. Air flows from the bottom to the top.
The water drops falling from the top come in contact with air, lose heat to the air & get
cooled. Eliminators are provided at the top to prevent escape of water particles with air. Such
a tower is known as wet cooling tower. In such system the loss of water due to evaporation is
about 1%. Another 2% of the water circulated is used in purging the system of dissolved salts
i.e. salts concentrated in the system due to continuous recirculation. Therefore, the total
quantity of makeup water is about 3% of the quantity circulated in the system. Generally this
make up water is obtained from and the purge is returned to the nearby river. Air can be
circulated in a wet cooling tower by natural draft or forced draft or induced draft. The height
of the cooling tower may be about 150m.
Cooling water cycle: -
A large quantity of cooling water is required to condense the steam in condenser and
marinating low pressure in it. The water is drawn from reservoir and after use it is drained
into the river.
13.2. Excitation system: -
The electric power Generators requires direct current excited magnets for its field system.
The excitation system must be reliable, stable in operation and must response quickly to
excitation current requirements. When excitation system response is controlled by fast acting
regulators, it is chiefly dependent on exciter. Exciter supply is given from transformer and
then rectified.
13.2.1. Function of excitation system: -
The main function of excitation system is to supply required excitation current at rated load
condition of turbo Generator. It should be able to adjust the field current of the Generator,
58
either by normal controller automatic control so that for all operation & between no load and
rated load. The terminal voltage of the system machine is maintained at its value.
11.2.2 Types of excitation system: -
There has been continuing reach among the design and the use alike from improving the
excitation system performance. The ultimate is to achieve stability; accuracy etc. the modern
excitation system adopted presently on BHEL makes turbo-generator I. Conventional DC
excitation system, Brushes excitation system.
13.3. Static excitation system: -
In RSWM TPP static excitation system is provided it mainly consists of the following:-
Rectifier transformer.
Nos. of thyristor converters.
An automatic voltage regulator (AVR).
Field suppression equipment.
Field flashing equipment.
13.4. General arrangement: -
In the excitation system the power required for excitation of Generation are tapped from 11
KV bus ducts through a step down rectifier transformer. After rectification in thermistor,
converter, the DC power is fed to the Generator field winding through a field breaker. The
AVR control the o/p from thyristor converter by adjusting the firing angle depending upon
Generator voltages.
13.4.1 Rectifier transformer: -
This transformer steps down the bus voltage 11 KV to 640KV and has a rating of 1360 KVA.
It is dry type. It is provided with current relays and two temperature sensors.
13.4.2 Thyristor convertor: -
The thyristor panel and are intended for controlled rectification of AC Input power. 6
Thyristor converter are connected in parallel each rates for continuous current o/p of 20 % of
either by normal controller automatic control so that for all operation & between no load and
rated load. The terminal voltage of the system machine is maintained at its value.
11.2.2 Types of excitation system: -
There has been continuing reach among the design and the use alike from improving the
excitation system performance. The ultimate is to achieve stability; accuracy etc. the modern
excitation system adopted presently on BHEL makes turbo-generator I. Conventional DC
excitation system, Brushes excitation system.
13.3. Static excitation system: -
In RSWM TPP static excitation system is provided it mainly consists of the following:-
Rectifier transformer.
Nos. of thyristor converters.
An automatic voltage regulator (AVR).
Field suppression equipment.
Field flashing equipment.
13.4. General arrangement: -
In the excitation system the power required for excitation of Generation are tapped from 11
KV bus ducts through a step down rectifier transformer. After rectification in thermistor,
converter, the DC power is fed to the Generator field winding through a field breaker. The
AVR control the o/p from thyristor converter by adjusting the firing angle depending upon
Generator voltages.
13.4.1 Rectifier transformer: -
This transformer steps down the bus voltage 11 KV to 640KV and has a rating of 1360 KVA.
It is dry type. It is provided with current relays and two temperature sensors.
13.4.2 Thyristor convertor: -
The thyristor panel and are intended for controlled rectification of AC Input power. 6
Thyristor converter are connected in parallel each rates for continuous current o/p of 20 % of
59
the rated capacity i.e. 20 % reserve. Each thyristor converter consists of 6 thyristor connected
in 3-3, full wave, 6-pulse bridge from and they are cooled by fans provided with a fuse for
protection against short circuit.
13.4.3 Automatic voltage controls: -
The AVR is transistorized thyristor controlled equipment with very fast response. The AVR
is also having provision of stator and rotor currents limits and load angle limits for optimum
utilization of lagging and leading reactive capacities of generator.
13.4.4 Field suppression equipment: -
The field equipment consists of a field breaker with discharge resistors. The field breakers
have 4 main breaking contacts and two discharge contacts, which close before main contact
break.
13.5 Operation: -
After bringing the speed to operation speed say 3000 rpm, the voltage is slowly built up with
the help of excitation system. This action is taken for synchronizing the Generator.
Synchronizing: -
For synchronizing the Generator to the grid system 5 condition of equality have to be
satisfied.
These are
(I) Voltage
(II) Frequency
(III) Phase displacement
(IV) Phase sequence
(V) Wave form and phase sequence
Of the Generator are determined at the design of each connection
SYNCHRONIZING of the generator.
the rated capacity i.e. 20 % reserve. Each thyristor converter consists of 6 thyristor connected
in 3-3, full wave, 6-pulse bridge from and they are cooled by fans provided with a fuse for
protection against short circuit.
13.4.3 Automatic voltage controls: -
The AVR is transistorized thyristor controlled equipment with very fast response. The AVR
is also having provision of stator and rotor currents limits and load angle limits for optimum
utilization of lagging and leading reactive capacities of generator.
13.4.4 Field suppression equipment: -
The field equipment consists of a field breaker with discharge resistors. The field breakers
have 4 main breaking contacts and two discharge contacts, which close before main contact
break.
13.5 Operation: -
After bringing the speed to operation speed say 3000 rpm, the voltage is slowly built up with
the help of excitation system. This action is taken for synchronizing the Generator.
Synchronizing: -
For synchronizing the Generator to the grid system 5 condition of equality have to be
satisfied.
These are
(I) Voltage
(II) Frequency
(III) Phase displacement
(IV) Phase sequence
(V) Wave form and phase sequence
Of the Generator are determined at the design of each connection
SYNCHRONIZING of the generator.
60
14. Conclusion
It was a great experience to be there in RSWM for my practical training. During training
period, I certainly learnt a lot about every aspect of this field, right from the working
environment to the technical details of various equipment and process. Every industry
functions with the help of every branch individual whether mechanical, electrical, and
chemical etc.
I got a glimpse of working procedure of a company & an industry.
At last I want to say that my practical training at RSWM has broadened my knowledge &
widened my thinking as professional.
Overall my internship has been a success. I was able to gain practical skills, work in a
fantastic environment & make connections that will last a lifetime. I could not be more
thankful.
To conclude I would say that it actually showed the practical side of what I have learnt in my
curriculum. Also, it has helped to enhance my sense of professionalism and team work.
14. Conclusion
It was a great experience to be there in RSWM for my practical training. During training
period, I certainly learnt a lot about every aspect of this field, right from the working
environment to the technical details of various equipment and process. Every industry
functions with the help of every branch individual whether mechanical, electrical, and
chemical etc.
I got a glimpse of working procedure of a company & an industry.
At last I want to say that my practical training at RSWM has broadened my knowledge &
widened my thinking as professional.
Overall my internship has been a success. I was able to gain practical skills, work in a
fantastic environment & make connections that will last a lifetime. I could not be more
thankful.
To conclude I would say that it actually showed the practical side of what I have learnt in my
curriculum. Also, it has helped to enhance my sense of professionalism and team work.
61
15.References
www.rswm.in
www.fortum.com
Steam & gas Turbines and Power Plant Engineering, Dr. R. Yadav
Fluid Mechanics, R.K. Bansal
slideshare.net
Wikipedia.org
15.References
www.rswm.in
www.fortum.com
Steam & gas Turbines and Power Plant Engineering, Dr. R. Yadav
Fluid Mechanics, R.K. Bansal
slideshare.net
Wikipedia.org
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