Question

In: Mechanical Engineering

Consider the combined power cycle for which Qin=Qin1 ,Qout=Qout2 and Wcycle=Wcycle1 + Wcycle2. Derive an expression...

Consider the combined power cycle for which Qin=Qin1 ,Qout=Qout2 and Wcycle=Wcycle1 + Wcycle2. Derive an expression for the thermal efficiency ? of the combined power cycle in terms of ?1 and ?2.

Prove that ? > ?1 and ? > ?2. In plain English, you are being asked to prove that the combined power cycle is more efficient than each of the two cycles alone [Hint: Starting from the expression for ? derived in part (ii), each of the two proofs requires exactly one additional step and no more.]

Solutions

Expert Solution


Related Solutions

Consider a combined gas-steam power cycle. The topping cycle is a simple Brayton cycle that has...
Consider a combined gas-steam power cycle. The topping cycle is a simple Brayton cycle that has a pressure ratio of 7. Air enters the compressor at 15 ºC at a rate of 10 kg/s and the gas turbine at 950 ºC. The bottoming cycle is a reheat Rankine cycle between the pressure limits of 6 MPa and 10 kPa. Steam is heated in a heat exchanger at a rate of 1.15 kg/s by the exhaust gases leaving the gas turbine,...
Consider a combined gas-steam power cycle. The topping cycle is a simple Brayton cycle that has...
Consider a combined gas-steam power cycle. The topping cycle is a simple Brayton cycle that has a pressure ratio of 7. Air enters the compressor at 15 ºC at a rate of 10 kg/s and the gas turbine at 950 ºC. The bottoming cycle is a reheat Rankine cycle between the pressure limits of 6 MPa and 10 kPa. Steam is heated in a heat exchanger at a rate of 1.15 kg/s by the exhaust gases leaving the gas turbine,...
Derive an expression for the power going into the braking system when a car is decelerated...
Derive an expression for the power going into the braking system when a car is decelerated from a speed u to a standstill with constant deceleration a (Remember using v = u-at = 0, where a is the magnitude of the deceleration) on a level road. Include the force required to overcome aerodynamic drag (1 ??2???) and rolling 2 friction (μmg). (2) Hence, derive an expression to allow the energy dissipated during the deceleration period to be calculated. (3) The...
Explain briefly the difference between a conventional power plant and a combined cycle power plant with...
Explain briefly the difference between a conventional power plant and a combined cycle power plant with the aid of neat diagrams.
Working from first principles, derive an expression for the efficiency of an Otto Cycle engine in...
Working from first principles, derive an expression for the efficiency of an Otto Cycle engine in terms of compression ratio. Sketch the P-V diagram for this cycle and annotate it using the same station numbers used in your derivation. State why the efficiency must be less than that of the Carnot Cycle.
A combined cycle power system uses a simple gas-turbine Brayton cycle in conjunction with a simple...
A combined cycle power system uses a simple gas-turbine Brayton cycle in conjunction with a simple Rankine cycle to produce a total power of 100 MW. In such configuration, the exhaust stream from the gas turbine is used as the heat source for the steam power cycle in a heat exchanger as shown in the figure. The following data are known for the gas-turbine cycle. Atmospheric air enters the compressor at 100 kPa and 20oC, the compressor pressure ratio is...
Prob.1) Consider a combined gas and steam power plant that has a net power output of...
Prob.1) Consider a combined gas and steam power plant that has a net power output of 450 MW. The pressure ratio of the gas turbine cycle is 14. Air enters the compressor at 300 K and the turbine at 1 400 K. The combustion gases leaving the gas turbine are used to heat the steam to 8 MPa. up to 400 ° C in a heat exchanger. The combustion gases exit the heat exchanger at 460 K. An open feedwater...
Derive the expression for the time averaged heating in the metal in which AC current of...
Derive the expression for the time averaged heating in the metal in which AC current of frequency ω flows – use the expression for the AC conductivity and P= ⋅EJ relation for instant power
Consider a steam power plant operating on a simple ideal Rankine cycle in which the steam...
Consider a steam power plant operating on a simple ideal Rankine cycle in which the steam enters the turbine at 3 MPa and 350C and is condensed in the condenser at 75 kPa. Determine the thermal efficiency of this cycle and sketch an appropriately labeled T-s diagram. Also compare this thermal efficiency to that a Carnot heat engine operating between these same two limits. The change in enthalpy across the pump = work done by the pump: h2-h1= v1(P2– P1)
jhmjhhjjhbus 5 is a Combined Cycle Gas Turbine (CCGT) power plant beside the sea , built...
jhmjhhjjhbus 5 is a Combined Cycle Gas Turbine (CCGT) power plant beside the sea , built on a vast area next to a rural/ village setting. The fishing vil lage houses a community of about 1300 people who live on a day- to -day simple livelihood. Discuss the positive and negative impac t of the power plant on the environment and culture of this community. Generator bus 5 is a Combined Cycle Gas Turbine (CCGT) power plant beside the sea...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT