ACTIVE LEARNING PROCESS

1. ACTIVE LEARNING PROCESS Branch: Electronics & Communication Guided By : Prof. C O Yadav Prepared By : BINI MOL THOMAS 13BEECG069 VISHAL SALVI 13BEECG067 HARSHAL M.H 13BEECG064

2. Boilers

3. Objectives 1. Describe the theory, construction, and applications of boilers 2. Describe the common type of boilers 3. Explain how to assess the performance and efficiency of a boiler 4. Describe methods to improve boiler efficiency 5.List energy efficiency opportunities

4. Objectives • Introduction – Purpose? • Type of boilers • Boiler Assessment • Energy efficiency opportunities

5. Introduction What is a Boiler? • Vessel that heats water to become hot water or steam • At atmospheric pressure water volume increases 1,600 times • Hot water or steam used to transfer heat to a process

6. Introduction STEAM TO PROCESS VENT EXHAUST GAS STACK DEAERATOR PUMPS ECO-NOMI-ZER Thermal Equipment/ Boilers BOILER VENT BURNER WATER SOURCE BLOW DOWN SEPARATOR FUEL BRINE CHEMICAL FEED SOFTENERS Figure: Schematic overview of a boiler room

7. Types of Boilers What Type of Boilers Are There? • Fire Tube Boiler • Water Tube Boiler • Packaged Boiler • Fluidized Bed (FBC) Boiler • Stoker Fired Boiler • Pulverized Fuel Boiler • Waste Heat Boiler Thermal Equipment/ Boilers

8. Type of Boilers 1. Fire Tube Boiler • Relatively small steam capacities (12,000 kg/hour) • Low to medium steam pressures (18 kg/cm2) • Operates with oil, gas or solid fuels Thermal Equipment/ Boilers (Light Rail Transit Association)

11. Type of Boilers 2. Water Tube Boiler • Used for high steam demand and pressure requirements • Capacity range of 4,500 – 120,000 kg/hour • Combustion efficiency enhanced by induced draft provisions • Lower tolerance for water quality and needs water treatment plant Thermal Equipment/ Boilers (Your Dictionary.com)

12. To Chimney Oil Burner Type of Boilers 3. Packaged Boiler • Comes in complete package • Features • High heat transfer • Faster evaporation • Good convective heat transfer • Good combustion efficiency • High thermal efficiency • Classified based on number of passes Thermal Equipment/ Boilers (BIB Cochran, 2003)

13. Type of Boilers 4. Fluidized Bed Combustion (FBC) Boiler • Particles (e.g. sand) are suspended in high velocity air stream: bubbling fluidized bed • Combustion at 840° – 950° C • Fuels: coal, washery rejects, rice husk, bagasse and agricultural wastes • Benefits: compactness, fuel flexibility, higher combustion efficiency, reduced SOx & NOx Thermal Equipment/ Boilers

14. Type of Boilers • 5. Stoke Fired Boilers • a) Spreader stokers • Coal is first burnt in suspension then in coal bed • Flexibility to meet load fluctuations • Favored in many industrial applications Thermal Equipment/ Boilers

15. Type of Boilers 5. Stoke Fired Boilers b) Chain-grate or traveling-grate stoker • Coal is burnt on moving steel grate • Coal gate controls coal feeding rate • Uniform coal size for complete combustion Thermal Equipment/ Boilers (University of Missouri, 2004)

16. Type of Boilers 6. Pulverized Fuel Boiler • Pulverized coal powder blown with combustion air into boiler through burner nozzles Thermal Equipment/ Boilers • Combustion temperature at 1300 -1700 °C • Benefits: varying coal quality coal, quick response to load changes and high pre-heat air temperatures Tangential firing

17. Independence Steam Electric Station - Newark, AR Operation: Unit 1 - January 1983/Unit 2 - December 1984 Fuel: Low-sulfur coal mined near Gillette, Wyoming Capability: 1,678 megawatts

18. Type of Boilers 7. Waste Heat Boiler • Used when waste heat available at medium/high temp • Auxiliary fuel burners used if steam demand is more than the waste heat can generate • Used in heat recovery from exhaust gases from gas turbines and diesel engines Thermal Equipment/ Boilers Agriculture and Agri-Food Canada, 2001

19. Assessment of a Boiler 1. Boiler performance • Causes of poor boiler performance • Poor combustion • Heat transfer surface fouling • Poor operation and maintenance • Deteriorating fuel and water quality • Heat balance: identify heat losses • Boiler efficiency: determine deviation from best efficiency Thermal Equipment/ Boilers

20. FUEL INPUT Stochiometric Excess Air Un burnt Stack Gas STEAM OUTPUT Convection & Radiation Blow Down Ash and Un-burnt parts of Fuel in Ash Assessment of a Boiler Heat Balance An energy flow diagram describes geographically how energy is transformed from fuel into useful energy, heat and losses Thermal Equipment/ Boilers

21. Assessment of a Boiler Heat Balance Balancing total energy entering a boiler against the energy that leaves the boiler in different forms 12.7 % Thermal Equipment/ Boilers Heat loss due to dry flue gas BOILER 8.1 % Heat loss due to steam in fuel gas 1.7 % 100.0 % Heat loss due to moisture in fuel 0.3 % Fuel Heat loss due to moisture in air 2.4 % Heat loss due to unburnts in residue 1.0 % Heat loss due to radiation & other unaccounted loss 73.8 % 73.8 % Heat in Steam

22. Assessment of a Boiler Heat Balance Goal: improve energy efficiency by reducing avoidable losses • Avoidable losses include: • Stack gas losses (excess air, stack gas temperature) • Losses by unburnt fuel • Blow down losses • Condensate losses • Convection and radiation Thermal Equipment/ Boilers

23. Assessment of a Boiler 1. Boiler Efficiency Thermal efficiency: % of (heat) energy input that is effectively useful in the generated steam Thermal Equipment/ Boilers

24. THANK YOU....