High Pressure and efficient Boilers for High Pressure and efficient Boilers for
Cogeneration applicationsCogeneration applications
•
What is CO-GENERATION?
• This is a combined / integrated System of
production of Electrical power and useful heat by
sequential use of energy from a common fuel source
generally bagasse).
• To generate surplus power
For Best Utilization of resources
. To have Independency in power and steam
The Major advantage of Co- Gen The Major advantage of Co- Gen
power is ;-power is ;-
•A-Most techno- commercial viable Projects with short pay back.
•B-Cost of power production is very cheap compare to that of
• purchase power.
•C-Dependability and reliability with quality of power.
•D-Quick return on investments.
•E-Restore ecological imbalance.
•F-Ability to use Bio-Mass and organic matters like wood, grass and
agro wastes and also municipal wastes.
•G-Availability of power between Nov. to May when Hydel power availability
less.
•H-provides ecmomical and timely solution of Power problems.
CO-GENERATION in SUGAR MILLS
How Cogeneration Saves Energy
BOILER
ALTERNATORTURBINE
TO
PROCESS
TO PROCESS
Fuel
Air
TO
POWER
SUPPLY
CONDENSER
TO COOLING
TOWER
COGENERATION PLANT LAYOUT
Feed water
PRDS
•Better Power Quality
•Improved Reliability and run ability
•Lower Energy Costs
•Reduction CO2 in the environment
•Conserve Natural Resources
•Support Grid Infrastructure
–Fewer T&D Constraints
–Defer Costly Grid Upgrades
–Price Stability
Benefits of cogeneration
Steps for conservationSteps for conservation
1.Government of India enforced the 1.Government of India enforced the
energy conservation act 2001 with effect energy conservation act 2001 with effect
from 1.3.2002.from 1.3.2002.
2.The initial phase of 5 years would be 2.The initial phase of 5 years would be
implementation of the act . implementation of the act .
3.The act provides mainly for efficient use 3.The act provides mainly for efficient use
of energy and its conservation.of energy and its conservation.
4.Industry using 4.Industry using
Mandatory Requirement of ActMandatory Requirement of Act
•Those unit having connected load of 5000 KWh
are called as ‘ Designated Energy Consumer’.
•As per the act it is mandatory for all designated
Energy Consumers to get Energy Audit
conducted by an Accredited Energy Auditor. And
to designate or appoint an Energy Manager.
Energy Saving potential areas in sugar industries
1.Convertion from low Pressure to HP
Boilers
2.Steam Boilers (Reducing moisture percentage
in Bagasse)
3.Crushing section
4.Evaporator section
FEASIBILITY STUDY (TYPICAL STEPS)
Energy auditing
Technical Analysis
Inception
Implementation Planning
Financing
Operation and maintenance
CASE STUDIESCASE STUDIES
•A-IMPROVEMENT PROJECT By
•I-BY RETROFITTING
•II- -RENOVATION &TECHNOLOGICAL
UPGRADATION
•B-INITIATING NEW PROJECTS
RETROFITTINGRETROFITTING
•Replacement of old 18/21Kgs/cm to HP >100bars
boilers
•A-Provision of Better control system.
•B-Efficiency improvement by Automation
•C-Reduction of unaccountable losses by
• providing dust extraction system
•D-Reduction of Boiler & TG down time &
• efficiency improvement by water & steam
• quality control
Case StudiesCase Studies
•Introducing New HP Boiler without affecting
Present Existing System
2002-03 2001-02 2000-01 1999-00 1998-99 Max Min Diff
%
Saving
scope
SL
NO.PARTICULARS UOM Actual Actual Actual Actual Actual
1Cane Crushed MT 729598 736838 646051 700916 736663
2No. of Crop Days 173 191 159 165 188
3Crushing Rate/22 hours MT 4162.95 3951 4194.98 4385.11 4230.29
4Crushing Rate/24 hours MT 4541.39 4311.12 4576.34 4783.32 4614.77
5Crop Day Average MT 4217.33 3857 4063.22 4247.98 3918.42
6Recovery % 9.51 9.11 9.758 9.23 8.187
7Bagasse Moisture % 50.66 50.56 50.11 50.4 51.3 51.3 50.11 1.19 2.32
8Steam % Cane % 48.76 50.71 48.75 49.45 49.74
9Power / Ton of Cane KWH 24.68 25.46 25.18 25.8 24.68 1.08 4.19
DOWN TIME ANALYSIS
Rs
51.57
lakhs
per
season
10No Cane Hrs-Mts 6.-00 57-50 142-15 154-55 204-10
11Mechanical Hrs-Mts 64-35 59-30 4.-30 24-55 180-45 181 4.5 176 97.5
12Electrical Hrs-Mts 11.-10 53-55 4.-00 24-25 70-00 70 4 66 94.3
13General Cleaning Hrs-Mts 97-10 97-15 109-25 110-25 51-05 110 51.08 59.3 53.7
14Lost % on Available Hours % 7.06 10.3 11.23 8.96 11.9 11.9 7.06 4.84 40.7
Comparison of performance during various seasns from 1998 to 2002
SL
NO
PARTICULAR UOM 2002-03 2000-01 1994-95 Max Min %saving scope
% Recovery during 2002-03
8.05
8.84
10.06
10.6510.14
8.75
6.68
0
2
4
6
8
10
12
Dec Jan Feb Mar Apl May Jun
R
e
c
o
v
e
r
y
%bagasse moisture
27.5328.8229.0629.4230.1930.7531.63
0
5
10
15
20
25
30
35
Dec JanFebMar AplMay Jun
Dec Jan Feb Mar Apl May Jun
%
b
a
g
a
s
s
e
m
o
is
t
u
r
e
Column 7
29
28.6
28.2
27.8
27.4
power consumption per ton of cane
crushed
23.6123.6123.27
24.6925.1325.57
34.3
0
5
10
15
20
25
30
35
40
DecJanFebMarAplMayJun
p
o
w
e
r
c
o
n
s
u
m
e
d
p
e
r
t
o
n
o
f
c
a
n
e
BY Technological Up gradationBY Technological Up gradation
•A-Replacement of old low pressure Boilers to
High pressure to get the benefits
improved cycle efficiency.
•B-Providing Topping up TG Set to optimize
expenses on Electrical system.
• C-Better environments by Providing
• Emission monitoring.
Acquire Best Available Technology in Acquire Best Available Technology in
New ProjectsNew Projects
•A-Select Most modern and reliable
• equipments
•B-Design Tailor make System.
•C-Select Flexible System for Better
utilization of resources and Better economy.
T
G
ComparisonComparison
Prevailing SystemPrevailing System Proposed SystemProposed System
Multi fuel Boiler
105ata, 525º C, 88%
T
o
p
p
i
n
g
u
p
T
G
s
e
t1
8
.
6
M
W
,
6
1
t
p
h
T
G
GEC Turbine
SIEMENS Turbine
C
C
11 KV BUS
9
.
7
4
M
W
,
7
0
t
p
h
T
G
1
8
.
6
M
W
,
6
1
t
p
h
T
G
C
C
GEC Turbine
SIEMENS Turbine
6
7
a
t
a
&
4
8
5
º
C
4
2
a
t
a
&
4
0
0
º
C
Actual Thermal Efficiency of existing power plant Actual Thermal Efficiency of existing power plant
on dateon date
Heat value of KPC boiler ≈ 767 Kcal/kg (from steam table)
(at 43.4 ata and 400ºC)
Then net heat value of KPC boiler ≈ 767 – 105 ≈ 662 Kcal/kg.
Thermal efficiency of KPC boiler = η
th
= (Net heat value * Total Steam generation) / (CV of
the bagasse * total bagasse consumption)
η
th
= (662 * 122759) / (2277 * 61672)
= 57.99% ≈ 58% ( against 69% of design)
Heat value of TBW boiler = 807.7 Kcal/kg (From steam table)
(at 67 ata and 485ºC)
Then net heat value of TBW boiler ≈ 807.7 – 105 ≈ 702.7 Kcal/kg
GCV of coal = (CV of coal * total coal consumption) / Total fuel consumption
= (5500 * 4622) / 56213 = 452.22 Kcal/kg
GCV of Bagasse = (CV of bagasse * total bagasse consumption) / Total fuel consumption
= (2277 * 51591) / 56213 = 2089.77 Kcal/kg
Then net GCV = 452.22 + 2089.77 = 2542 Kcal/kg
Then net heat gain = heat gain * steam required for cane * efficiency of Topping TG set
= 13.8 * 125*10
3
* 0.9
= 1552.5 Kcal/kg
Total power generation = 1552.5/860 = 1.8 MW
Transfer rate = 1800 * 24 * 330 * 1.96 = 2.79 crore.
Thermal efficiency of TBW boiler = η
th
= (Net heat value * Total Steam generation) /
(Net GCV * total fuel consumption)
= (702.7 * 129399) * 100 / (2542 * 56213)
η
th
= 63% (against 71.75% of design)
Average thermal efficiency of KPC & TBW boiler = (58+63) / 2 = 60.5%
Expected direct efficiency of multifuel boiler = 84%
Then fuel saving = 84 – 60.5 = 23.5%
Cost of fuel saving = Actual cane crushed * % of fuel caned * % fuel save
for 02-03 = 729598 * 0.3 * 0.235
= Rs. 51436.65
Then total saving of bagasse = 51437 * 500
= Rs. 2,57,815
= 2.57 crore
Net gain in power = 2.79 crore
Net gain in fuel save = 2.57 crore
Then total gain = 2.79+2.57 = 5.36 crore
Heat value of AFBC boiler = 821.5 Kcal/kg (from steam table)
(at 515º C and 105 kg/cm
2
)
Then net heat gain = 821.5 – 807.7
= 13.8 Kcal/kg
From data
Budgeted cane crushed/year = 775000 M.T
Actual cane crushed/year = 72598.401 M.T
No. of crop days = 170 days
% Steam required for cane = 48%
% of bagasse in cane = 30%
Then steam required for cane/hr. = (budgeted cane crushed * %steam reqd. for cane) /
(No. of days * 24)
= (775000 * 0.48) / (170*24)
= 91.176 tph
≈ 100 tph
For maximum efficiency
steam required for cane/hr = 100/0.80 = 125 tph
The Major advantage of Co- Gen The Major advantage of Co- Gen
power is ;-power is ;-
•A-Most techno- commercial viable Projects with short pay back.
•B-Cost of power production is very cheap compare to that of purchase
power.
•C-Dependability and reliability with quality of power.
•D-Quick return on investments.
•E-Restore ecological imbalance.
•F-Ability to use Bio-Mass and organic matters like wood, grass and agro
and
• municipal wastes.
•G-Availability of power between Nov. to May when Hydel power availability
• less.
•
Continue---
•H-provides ecmomical and timeluy solution of Power problems.
STEPS FOR SAVINGSSTEPS FOR SAVINGS
•!-Saving of Bagasse by adopting high technology HP Boilers
•2-Reduction of moisture in bagasse 50 to 45% by improving Milling
Technique.
•3-Reduction in Process steam consumptions in evaporator and Prime
movers
• BLTFF evaporators
•4- Reduction in live s team consumption by using multi stage reaction
Turbines.
•5- Reduction in over consumptions of power TCH using new technique of
•
• Variable drives and high efficient auxiliaries.
•6-improve crushing rate by having quality power