413 POWER PLANT ENGINEERING PART-A 1. Define Power. Power is the rate at which energy is used (or) Energy/time. 2. What are the types of fuels? Solid fuel Liquid fuel Gaseous fuel (Any one among the above types) 3. Define calorific values and fuels. The heat energy liberated by the complete oxidation of unit mass is called calorific value. A substance which on burning with oxygen in the atmospheric air. 4. Define Tariff. The rate of charge per kilowatt hour of the energy supplied to the customer. 5. State the function of pulveriser. The pulverisers are the equipments which are used to powdered coal. 6. What is the function of surface condenser? It receives the exhaust steam from turbine and condense it. 7. What are the types of cooling tower? Atmospheric cooling tower. Natural draught cooling tower. Forced draught cooling tower. (Any one among the above types) 8. What is a Draught? It is the difference between absolute gas pressure and ambient atmospheric pressure. 9. State any two applications of hydro power plant. Higher utilisation factor,higher capacity factor. 10. What is the function of surge tank? The surge tank controls the water when the load on the turbine decreases and supplies water when load on turbine increases. 11. Mention any two safety measures in hydro power station. Screens, fish pass, sand traps. 12. Give the classification of hydraulic turbines. Impulse turbine, Reaction turbine. 13. What is the function of inter cooling? The heat supply and work ratio are increased. 14. State any two advantages of diesel engine power plant. Design and layout simple. It occupies less space. Located at any place. No stand by losses. (Any two among above advantages) 15. What is reheating? Increase the turbine output and reduce thermal efficiency.
16. What are the methods of cooling in a diesel power plant? Air cooling and water cooling. 17. What is geothermal energy? Thermal energy contained in the interior of the earth. 18. Define fission. It is the process of splitting the nucleus of an atom. 19. List the types of reactors. Fast reactor, slow reactor.pwr, BWR. 20. How is nuclear waste disposed off? Dilution, sealed container, underground burial. Part-B 21. (A) Compare various types of fuels. S.No SOLID FUEL (4 marks) LIQUID FUEL (4 marks) GAS FUEL (4 marks) 1 No risk of fire Higher calorific value Directly used in IC engine 2 Transportation cost is less Better economy in handling Free from solid and liquid impurities 3 Consumption is less Better control of consumption Complete combustion with minimum air supply. 4 Ash produce. No ashes No ashes 5 Less efficiency. More efficiency Highly inflammable. 6 Low cost Higher cost. Large storage is required. NOTE: each section contain 4 marks. Any other Comparison also acceptable minimum four points required. (B)i) Write a note on selection of coal. o High calorific value. o Physical properties. o Grind ability of coal. o Size and grade of coal. o Good burning characteristics. o High weather ability. NOTE: each point contain 1 marks. Any other points also acceptable. (B)ii) Write briefly about economics of power generation. o Cost of fuel and transportation. o Cost of transmitting energy. o Selection of equipment. o Increase the efficiency of plant. o Reliability. o The type of load to be taken by the plant. NOTE: each point contain 1 marks. Any other points also acceptable. 22. (A) (1) Explain Coal and ash circuit. Coal handling equipments. Coal burnt temperature 1500-2000. Ash collected & ash pit. Ash is taken to dump site. Outdoor storage and covered storage. In plant handling,weighing,feed coal into furnace. NOTE: Above each section containing one mark
(2) What are the advantages of steam turbines over the steam engine. High thermal efficiency. High speed and high range of speed. High overload capacity. Reduced cost of lubrication. Less floor space is required. Simple mechanism. Greater capacity is possible. NOTE: each point contain 1 marks. Any other points also acceptable. (B) With a neat sketch, explain the layout of steam power plant Diagram------------- 7marks Super heated steam is used to rotate the turbine blades. Rotation of turbine blade is used to rotate generator coupled to that turbine.--- 1 marks Coal and Ash circuit.----- 1 marks Coal handling. Heat 1500 to 2000 degree Celsius required for combustion. After combustion ash is collected and send to dumpsite using ash ghandling circuit Air and flue gas Circuit..----- 1 marks Atmospheric air is heated by Air pre heater. This hot air entered into boiler and used for combustion. After combustion this flue gases are send to economiser and pre heater. Finally this flue gases are sent out using chimney Feed water and steam circuit..----- 1 marks The outlet steam from boiler is loss its heat and pressure. This steam is
convert into water using condenser. This condensed water is used in boiler again and cooling water circuit. Cooling water circuit..----- 1 marks Condensed steam is recycled and used for cooling. 23. (A) Explain the construction and working of hydro electric power plant. Diagram------------- 6 marks Explanation--------- 6marks Water reservoir. Dam. Surgetank. Penstock. Draft tube. Tail race. Generator and transformer. (B) (1) Write the function of draft tube and explain any one draft tube with neat sketch... It is a mechanical pipe or concrete tunnel.---1marks Related explanation.-----2marks Diagram of straight conical or elbow type..---3marks (2) State site selection procedure for hydroelectric power plant.. o Availability of water. o Storage facility. o Head of water. o Load centre distance. o Accessibility to site.
o Structure of land NOTE: Each contain ONE Marks. 24. (A) Explain component of diesel engine power plant with a layout. Diagram------------- 6marks Explanation---------- 6marks Fuel system. Air intake system. Exhaust system. Cooling system. Lubrication system. Starting system. NOTE: Above each section containing one mark (B) 1) Write the advantages and disadvantages of diesel engine power plant. MERITS : Simple design and installation. ( 3 marks) Space requirement is less. Easy lubrication. Less capital cost. DEMERITS: High operating cost. ( 3 marks) More noise during operations. Low life of plants. Cost of diesel is high.
2) Compare open and closed cycle gas power plant. S.NO OPEN CYCLE (3 marks) CLOSED CYCLE (3 marks) 1 Less initial investment More initial investment 2 Difficult in starting Easy starting. 3 High thermal stress Low thermal stress 4 No pre cooler Need pre cooler 5 No coolant Need coolant 6 High response to load variation Low response to load variation NOTE: Above each section contain minimum 3 points. 25. (A) Explain briefly working of nuclear power plant with their elements. Diagram------------- 7marks Explanation---------- 5marks Nuclear reactor. Boiler. Turbine. condenser. Feed pump. NOTE: Above each section containing one mark (B) Explain biogas plant with a sketch and write its advantages and disadvantages. Diagram------------- 5marks
Explanation---------- 5marks Biogas plant converts cattle dung and other organic matter into inflammable gas called biogas. There are two popular types.i)floating drum ii) fixed dome. There is a steel dome for gas collection which floats over the slurry. A partition wall is provided in the digester to improve circulation. Advantages & Disadvantages----- 2MARKS Prepared by P.LOGESH (37563002), LECTURER/EEE, JAYARAM POLYTECHNIC COLLEGE, THURAIYUR, TRICHY. Mob no : 7708194060