POWER PLANT ENGINEERING_ MET81_U1_vapour power cycle_ppt
0 likes119 views
This document provides an overview of a Power Plant Engineering course taught by Prof. R. Thirumavalavan at Acharia College of Engineering Technology. The document outlines the course syllabus which includes topics like the Rankine cycle, regenerative cycles, reheat cycles and binary vapor power cycles. It also provides context on India's energy scenario and discusses different steam generators and boiler accessories used in thermal power plants.
POWER PLANT ENGINEERING_ MET81_U1_vapour power cycle_ppt
- 1. PROF R.THIRUMAVALAVAN, Professor & Head ACHARIYA COLLEGE OF ENGINEERING TECHNOLOGY MET81 POWER PLANT ENGINEERING UNIT-I INSTRUCTOR Prof. R. Thirumavalavan , Professor & Head DEPARTMENT OF MECHANICAL ENGINEERING
- 2. PROF R.THIRUMAVALAVAN, Professor & Head SYLLABUS Unit – I Power Scenario in India- Vapour power cycles - Rankine Cycle Reheat cycle – Regenerative cycle – Reheat – regenerative cycle. Binary vapour cycle. Steam generators – modern high pressure generators- Accessories: Boiler Feed Pump, feed water heaters/ economiser, air-preheaters, Superheaters.
- 3. PROF R.THIRUMAVALAVAN, Professor & Head INDIAN CONTEXT OF ENERGY Economic growth in India, being dependent on the power sector, has necessitated an enormous growth in electricity demand over the last two decades. In 1947, the total power generation capacity was only 1360 MW, and by 1991 it grew to 65,000 MW, of which 69% (45,000 MW) was generated in thermal plants. The Hydro developments, as stated are not so environmentally benign as was earlier believed.
- 4. PROF R.THIRUMAVALAVAN, Professor & Head INDIAN CONTEXT OF ENERGY They can cause conflict over usage of lands and the damage to ecology. The total Indian hydro-potential, as assessed by the Central Electricity Authority, is 84,000 MW. The installed capacity is 18,443 MW (March, 1991) compared to 200 KW in 1897 (Darjeeling) and 508 MW at the time of independence Most of the turbomachinery have been indigenously produced by the Bharat Heavy Electricals Ltd., the largest unit being 165 MW. However, the pace of hydro development has considerably slowed down recently for many reasons. Tentatively, in the order of 26,000 MW of hydro capacity would be added by 2002 during the 9five-year plan, as envisaged.
- 5. PROF R.THIRUMAVALAVAN, Professor & Head INDIAN CONTEXT OF ENERGY Nuclear power promotion has all but ceased in many areas of the world as a consequence of growing public concern regarding safety and regulatory hurdles. Nonetheless, in India, there appears to be a comparatively energetic nuclear programme . Presently, in India, about 2.3% of generating capacity is nuclear based. This corresponds to about 1500 MW of the installed capacity comprising 8 units. An additional 1320 MW is under construction, based on 220 MW units, and should be on line by 1997.
- 6. PROF R.THIRUMAVALAVAN, Professor & Head INDIAN CONTEXT OF ENERGY According to the development plan, the total installed capacity by 2002 will be 5700 MW, including the first Indian 500 MW PHWR unit in Rajasthan. It is anticipated that following on the tail of the natural uranium fuelled reactor programme, a fast breeder programme using plutonium will be established, followed by a thorium based programme, thereby taking advantage of a large indigenous resource of thorium.
- 7. PROF R.THIRUMAVALAVAN, Professor & Head INDIAN CONTEXT OF ENERGY
- 8. PROF R.THIRUMAVALAVAN, Professor & Head COAL PRODUCTION
- 9. PROF R.THIRUMAVALAVAN, Professor & Head Natural gas production
- 10. PROF R.THIRUMAVALAVAN, Professor & Head Solar Energy
- 11. PROF R.THIRUMAVALAVAN, Professor & Head RANKINE CYCLE Rankine cycle is the theoretical cycle on which the steam turbine works. The line diagram of the plant working on the cycle is shown in fig. The Rankine cycle has the following processes.
- 12. PROF R.THIRUMAVALAVAN, Professor & Head RANKINE CYCLE Processes: 1 -2 Reversible adiabatic expansion in the turbine. 2-3 Constant pressure heat transfer in the condenser. 3- 4 Reversible adiabatic pumping process in the feed pump. 4-1 Constant pressure heat transfer in the boiler.
- 13. PROF R.THIRUMAVALAVAN, Professor & Head RANKINE CYCLE To analyze the cycle we take 1 kg of fluid and applying steady flow energy equation to boiler, turbine, condenser and pump: 1. Boiler (as constant volume) h1 = Q1+hf4 Q1 = h1 – hf4 Where Q1= Heat supplied in boiler. 2. For turbine (as constant volume) h1 = WT + h2 WT = h1 - h2 Where, WT = Turbine work
- 14. PROF R.THIRUMAVALAVAN, Professor & Head RANKINE CYCLE 3. For condenser h2 = Q2 + hf3 Q2 = h2 – hf3 Where, Q2 = Heat rejection in condenser 4. For pump Hf3 + Wp = hf4 Wp = hf4 – hf3 Wp = V3 (p1 – p2) Where, Wp = Pump work, and V in m3/kg P in bar
- 15. PROF R.THIRUMAVALAVAN, Professor & Head Reheating of steam Types of reheating: Flue gas reheating Live steam reheating Combined flue gas and live steam reheating
- 16. PROF R.THIRUMAVALAVAN, Professor & Head Flue gas reheating: In this, the flue gas out from the boiler is used to heat the steam. The reheater is always placed behind the high-pressure super – heater. The steam can be reheated to initial throttle temperature and reheating normally employs the counter flow heat exchanger.
- 17. PROF R.THIRUMAVALAVAN, Professor & Head Live-steam reheating In this process, the high-pressure steam from the boiler is used for reheating the steam coming out from H.P. turbine in a specially designed heat exchanger.
- 18. PROF R.THIRUMAVALAVAN, Professor & Head Combined gas and live steam reheater: In the combined heating system, the disadvantage that the steam cannot be reheated to its initial throttle temperature and the live steam reheating is eliminated. The steam coming out from the H.P. turbine is first passed through the live steam reheater and then to gas reheater. It is clearly shown in the fig.
- 19. PROF R.THIRUMAVALAVAN, Professor & Head Rankine cycle with reheating
- 20. PROF R.THIRUMAVALAVAN, Professor & Head Regenerative Cycle: In the Rankine cycle, it is observed that the condensate which is coming out has very low temperature and it mixes with hot water boiler. This results in decrease of cycle efficiency. To avoid this, the condensate coming out is heated with the help of steam in a reversible manner. The temperature of steam and water is same at any section. This type of heating is known as regenerative heating. Fig. shows a layout of a condensing steam power plant in which a surface condenser is used to condense all the steam that is not extracted for feed water heating. The boiler is equipped with a super heater and turbine is double extracting type. The conditions of steam bled for each heater are so selected that the temperature of saturated steam will be 4 to 10˚C higher than the final condensate temperature.
- 21. PROF R.THIRUMAVALAVAN, Professor & Head Rankine cycle with regeneration
- 22. PROF R.THIRUMAVALAVAN, Professor & Head Efficiency of system Work done by the turbine Work required for pump Heat addition Heat rejection
- 23. PROF R.THIRUMAVALAVAN, Professor & Head Advantages and Disadvantage of regenerative cycle Advantages of regenerative cycle: 1.The thermal stresses set up in the boiler are minimized. 2.The heating process in the boiler tends to become reversible. 3.Heat rate is reduced. 4.A small size condenser is required. Disadvantages: 1.Due to addition of heaters, greater maintenance is required. 2.The plant becomes more complicated. 3.Large capacity boiler is required
- 24. PROF R.THIRUMAVALAVAN, Professor & Head Combined Reheat-Regenerative Cycle Reheat-Regenerative cycle is used in actual thermal power plant with high steam pressure to increase the overall efficiency of the cycle. The figure is shown the Reheat-Regenerative cycle. The thermal efficiency of the reheat-regenerative cycle is higher than only reheat or only regenerative cycle.
- 25. PROF R.THIRUMAVALAVAN, Professor & Head Combined Reheat-Regenerative Cycle
- 26. PROF R.THIRUMAVALAVAN, Professor & Head Binary vapour power cycle It is one type of combined cycles in which usually two working fluids mercury and water are used to improve the overall thermal efficiency of the power plant. For getting the best performance of vapour power cycle, the working fluid should have the following characteristics. 1. High enthalpy of vaporization.2.Good heat transfer characteristics. 3. High critical temperature with a low corresponding saturation temperature. 4. High condenser temperature. 5. Freezing temperature should be below room temperature
- 27. PROF R.THIRUMAVALAVAN, Professor & Head Binary vapour power cycle
- 28. PROF R.THIRUMAVALAVAN, Professor & Head Topping cycle
- 29. PROF R.THIRUMAVALAVAN, Professor & Head Combined cycle
- 30. PROF R.THIRUMAVALAVAN, Professor & Head T-S of combined cycle
- 31. PROF R.THIRUMAVALAVAN, Professor & Head Topping cycle The topping cycle really is the only economic cycle of the two. The main heat source generates high-enthalpy steam and electricity. Low-enthalpy steam is taken from an intermediate turbine stage or the turbine exhaust for process requirements. If the steam is taken from the turbine exhaust, this is called a back pressure turbine.
- 32. PROF R.THIRUMAVALAVAN, Professor & Head Bottoming Cycle In a bottoming cycle, the primary fuel produces high temperature thermal energy and the heat rejected from the process is used to generate power through a recovery boiler and a turbine generator
- 33. PROF R.THIRUMAVALAVAN, Professor & Head BOILERS Steam boiler or simply a boiler is basically a closed vessel into which water is heated until the water is converted into steam at required pressure. This is most basic definition of boiler. 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.
- 34. PROF R.THIRUMAVALAVAN, Professor & Head La-Mont Boiler
- 35. PROF R.THIRUMAVALAVAN, Professor & Head Benson Boiler
- 36. PROF R.THIRUMAVALAVAN, Professor & Head Loeffler boiler
- 37. PROF R.THIRUMAVALAVAN, Professor & Head Economizer
- 38. PROF R.THIRUMAVALAVAN, Professor & Head Boiler Accessories: The boilers are equipped with some more components other than mountings. They are installed to increase the efficiency of the boiler plants or help in proper working of the boiler unit. These components are known as boiler accessories. A modern boiler has the following accessories attached to it. 1.Economizer, 2.Air pre-heater, 3.Super heater, 4.Injector, 5.Feed pump, 6.Stem separator, 7.Steam trap etc.
- 39. PROF R.THIRUMAVALAVAN, Professor & Head Air Preheater
- 40. PROF R.THIRUMAVALAVAN, Professor & Head SUPER HEATER Super heat (radiant and convective)
- 41. PROF R.THIRUMAVALAVAN, Professor & Head Steam injector
- 42. PROF R.THIRUMAVALAVAN, Professor & Head Feed pump
- 43. PROF R.THIRUMAVALAVAN, Professor & Head Steam Separator
- 44. PROF R.THIRUMAVALAVAN, Professor & Head Ball float steam trap