High Boiler Pressure Chapter 2323232.pptx

Unit II: High Pressure Boilers

1. Unit II: High Pressure Boilers

2. 03 Unit II: High Pressure Boilers TOPICS COVERED IN PREVIOUS LECTURE (04):- 2.3 Construction and principle of working of :- 2. Benson Boiler, 3. Loeffler Boiler 4. Schmidt- Hartmann Boiler TOPICS TO BE COVERED IN THIS LECTURE (04):- 2.3 Construction and principle of working of :- Velox Boiler Ramsin Boiler www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

3. 04 Unit II: High Pressure Boilers 2.3.5 : VELOX BOILER : DIAGRAM & BASICS Types of boiler: Forced circulation, High Pressure boiler, Water tube boiler Steam Generating Capacity: 100 tones/hour Pressure: 84 bar Temp.: 540°C www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

4. 05 Unit II: High Pressure Boilers 2.3.5 : VELOX BOILER : DIAGRAM & COMPONENTS Various part of boiler: Evaporator Drum Feed Pump Gas Turbine Air Compressor Super Heater Combustion Chamber Fuel Tank Steam Separator www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

5. 07 Unit II: High Pressure Boilers 2.3.5 : VELOX BOILER : CONSTRUCTION In Velox boiler, pressurized combustion is used so axial flow compressor is used which is run by gas turbine. The combustion chamber and evaporating tubes are arranged in such a way that the hot products from combustion chamber are directly passed to annulus of evaporating tubes. Steam separator is arranged tangential to evaporating tubes. Hot flue gases are used for running gas turbine , for economizer and for super heater . www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

6. 08 Unit II: High Pressure Boilers 2.3.5 : VELOX BOILER : WORKING The air is compressed by air compressor driven by gas a turbine driven. This compressed air passes from the combustion chamber , where more heat release by the fuel which increase the velocity of the flue gases up to sound velocity. From the bottom of combustion chamber, this flue gases pass from the fire tubes . These fire tubes surrounded by the evaporator water tubes. The water from the economizer passes from the evaporator tube force by a circulating pump. This water passes 15 – 20 time from the evaporator tube at very high speed. Due to this high speed circulation, heat is transfer from the gases to the water at very high rate. The mixture of water and steam is formed which further passes from the water and steam separator. www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

7. 09 Unit II: High Pressure Boilers 2.3.5 : VELOX BOILER : WORKING The steam from the steam separator passes to the super heater and further for process work. The remaining water in the steam separator again passes from the evaporator tube. The flue gases from the fire tubes send to the super heater tubes, where it increases the steam temperature. The gas from the super heater sends to the turbine where it rotates the gas turbine and then passes from the economizer. www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

8. 10 Unit II: High Pressure Boilers 2.3.5 : VELOX BOILER : PATH OF FLOW www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

9. 11 Unit II: High Pressure Boilers 2.3.5 : VELOX BOILER : ADVANTAGES This boiler has high heat transfer rate . It has great flexibility . It is Compact in design. It is easy to control . It is fully automatic . It has great thermal efficiency of about 90 – 95% www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

10. 12 Unit II: High Pressure Boilers 2.3.5 : VELOX BOILER : DISADVANTAGES It can only operate on liquid or gaseous fuels. The size of the Velox boiler is limited, hence the capacity is low. www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

11. 13 Unit II: High Pressure Boilers 2.3.6 : RAMSIN BOILER : DIAGRAM & BASICS Types of boiler: Forced circulation, High Pressure boiler, Water tube boiler Also called ‘Once through boiler’ Pressure: 221 bar www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

12. 14 Unit II: High Pressure Boilers 2.3.6 : RAMSIN BOILER : DIAGRAM & WORKING It is a supercritical boiler. It is very similar to Benson boiler, except that evaporator section spiral tube instead if straight tubes . Its water circuit is shown in Figure. The boiler consists of inclined evaporator coil arranged in spiral 40 such coils is paralleled around the furnace. Water is forced into the economizer by a feed water pump where it is heated and then it enters in spiral evaporator tube where water flashes to steam. Steam generated in evaporator, flows into headers and then convection super heater. The superheated steam is utilized for power generation. www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

13. 16 Unit II: High Pressure Boilers 2.3.6 : RAMSIN BOILER : ADVANTAGES This boiler has high heat transfer rate . It has high thermal efficiency. Corrosion and erosion problem are minimized . It is adaptable to load fluctuations. www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik

14. 16 Unit II: High Pressure Boilers 2.3.6 : RAMSIN BOILER : DISADVANTAGES It is costly due to increased requirement for steel for heat transfer surface, pump and feed water piping. Generation of steam using forced circulation, high and supercritical pressure. www.sandipfoundation.org Mechanical Engineering Department, Sandip Polytechnic, Nashik