Vapour Power cycle

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A SEMINAR ON “VAPOUR POWER CYCLE”:

A SEMINAR ON “ VAPOUR POWER CYCLE ” Submitted by:- Vishwnath Kumar Mech.Engg.,7 th Sem Reg. No.:0701224251 M.I.T.S Engg.College. Rayagada(Orissa)

Contents:

Contents Introduction of vapour power cycle Rankine cycle The Influence of Steam Property Reheat cycle Regenerative cycle Binary-Vapour cycle Conclusion

Introduction:

Introduction Vapour power cycles are external combustion systems in which the working fluid is alternately vapourised and condensed. Water/steam is easily available, is cheap, is chemically stable and physiologically harmless. Due to its use as working substance in vapour power cycle. Why Vapour Power Cycle ??? Thermodynamic Consideration Largest irreversibility-non-isothermal heat transfer Historical Development Compress liquid, let vapor to expand

9-1 The Rankine Cycle:

9-1 The Rankine Cycle 9-1-1. Vapor Carnot cycle T s 1 2 3 4 There are some problems: Compressor turbine

Slide 6:

Boiler Turbine Compressor (pump) Heat exchanger 4 1 2 3 Q out Q in W out W in

There are four processes in the Rankine cycle, each changing the state of the working fluid. These states are identified by number in the diagram below :

There are four processes in the Rankine cycle, each changing the state of the working fluid. These states are identified by number in the diagram below .

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Process 1-2 : The working fluid is pumped from low to high pressure, as the fluid is a liquid at this stage the pump requires little input energy Process 2-3 : The high pressure liquid enters a boiler where it is heated at constant pressure by an external heat source to become a dry saturated vapor.

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Process 3-4 : The dry saturated vapor expands through a turbine , generating power. This decreases the temperature and pressure of the vapor, and some condensation may occur. Process 4-1 : The wet vapor then enters a condenser where it is condensed at a constant pressure and temperature to become a saturated liquid . The pressure and temperature of the condenser is fixed by the temperature of the cooling coils as the fluid is undergoing a phase-change

9-2 The Influence of Steam Property:

9-2 The Influence of Steam Property 9-2-1. Exhaust Pressure To decrease the exhaust pressure can increase the efficiency of Rankine cycle. But the dryness fraction will increase too. This can lead some damage to steam turbine

Slide 12:

9-2-2. Inlet temperature decreasing the inlet temperature can increase the efficiency of Rankine cycle. But this increase depends on boiler material

Slide 13:

9-2-3. Inlet pressure increasing the inlet pressure can increase the efficiency of Rankine cycle greatly. But this increase also depends on boiler material

9-3 Reheat Cycle:

Boiler condenser Feed water pump Steam turbine 9-3-1 Equipments of Reheat Cycle Reheater 9-3 Reheat Cycle

Slide 15:

T-s diagram The optimal way of increasing the boiler pressure but not increase the moisture content in the exiting vapor is to reheat the vapor after it exits from a first-stage turbine and redirect this reheated vapor into a second turbine.

Slide 16:

Analysis of Reheat Cycle 1—2 Isentropic Pumping. 2 –3 Constant (High)pressure Heat addition. 3 –4 Isentropic expansion in HP turbine. 4—5 Constant (Low) Pressure Reheating. 5 – 6 Isentropic expansion in LP turbine. 6 – 1 Constant pressure condensation.

Regenerative Cycle:

Regenerative Cycle Ideal Regenerative Cycle

Slide 18:

9-4-2 Regenerative Cycle boiler condenser Feed water pump Steam turbine Feed water heater Steam drainage pump 1 2 3 4 5 6 a

Slide 19:

T s 1 2 3 4 5 6 The feed water is heated by steam bleeding out from steam turbine. The average temperature of heat absorption process increases then .

Slide 20:

boiler condenser Feed water pump Steam turbine Feed water heater drainage pump 1 2 3 4 5 7 a 6 b

Slide 21:

T s 1 2 3 4 5 6 7 The more stages of bleeding steam, the higher efficiency the cycle has

Slide 22:

9-4-2 The efficiency of regenerative Cycle As to a two stages regenerative cycle,the properties: p 1 , t 1 , p a , p b , p 2 are available. If neglect the pump work, the T-s diagram should be as following. T s 1 2 3 4 5 a b 6

Slide 23:

9-5-2 Binary-vapor Cycle

Conclusion:

Conclusion At last I want to conclude that after doing this seminar I learned a lot of things about “ Vapour Power Cycle ”

Slide 25:

The End of This Chapter Thank you