A closed-cycle gas-turbine power plant is used to provide power for a remote exper- imental station....

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A closed-cycle gas-turbine power plant is used to provide power for a remote exper- imental station. The schematic for such a power plant is shown below. Component performance factors for this power plant are as follows: compressor efficiency of 0.8, turbine efficiency of 0.82, and regenerator effectiveness, €, (T3 — T2)/(T5 – T2) = 0.85. QR Reactor Compressor Wc 2 Bypass valve Precooler 8 Op 6 7 Regenerator Ta 5 3 10 5 Turbine Figure 4: Gas turbine power plant. The system has two operating cases. The first one is with the bypass valve closed and the system produces a maximum net output power. In the second operating case, the bypass valve is open and the system is self sustaining, producing no net output power. In both cases the compressor pressure ratio is 2.5 and inlet conditions are 550 kPa and 15°C, while the turbine pressure ratio is 2 and the inlet conditions are 1.2 MPa and 650°C. The working fluid in the system is nitrogen, which may be assumed to be an ideal gas with constant specific heats. R = 296.8 J/kg-K and y= 1.4. (a) For the case with no bypass flow, assume the net output power is 500 kW and determine the nitrogen mass flow rate, the reactor heat transfer rate, the precooler heat rejection rate, the compressor power input, the turbine power output, and the cycle efficiency. For the self-sustaint case, use the same compressor flow rate as in the previous part to determine the bypass and turbine flow rate, reactor heat transfer rate, the precooler heat rejection rate, the compressor power input, and the turbine power output. (c) For the same compressor and turbine inlet conditions, what is the efficiency for no bypass flow if the regenerator were eliminated (bigger reactor and precooler)? Justify your answer. W₂ A closed-cycle gas-turbine power plant is used to provide power for a remote exper- imental station. The schematic for such a power plant is shown below. Component performance factors for this power plant are as follows: compressor efficiency of 0.8, turbine efficiency of 0.82, and regenerator effectiveness, €, (T3 — T2)/(T5 – T2) = 0.85. QR Reactor Compressor Wc 2 Bypass valve Precooler 8 Op 6 7 Regenerator Ta 5 3 10 5 Turbine Figure 4: Gas turbine power plant. The system has two operating cases. The first one is with the bypass valve closed and the system produces a maximum net output power. In the second operating case, the bypass valve is open and the system is self sustaining, producing no net output power. In both cases the compressor pressure ratio is 2.5 and inlet conditions are 550 kPa and 15°C, while the turbine pressure ratio is 2 and the inlet conditions are 1.2 MPa and 650°C. The working fluid in the system is nitrogen, which may be assumed to be an ideal gas with constant specific heats. R = 296.8 J/kg-K and y= 1.4. (a) For the case with no bypass flow, assume the net output power is 500 kW and determine the nitrogen mass flow rate, the reactor heat transfer rate, the precooler heat rejection rate, the compressor power input, the turbine power output, and the cycle efficiency. For the self-sustaint case, use the same compressor flow rate as in the previous part to determine the bypass and turbine flow rate, reactor heat transfer rate, the precooler heat rejection rate, the compressor power input, and the turbine power output. (c) For the same compressor and turbine inlet conditions, what is the efficiency for no bypass flow if the regenerator were eliminated (bigger reactor and precooler)? Justify your answer. W₂

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Part a No Bypass Flow Nitrogen Mass Flow Rate Using the net output power and the enthalpy difference between turbine and precooler outlet m Wnet h4 h5 500 kW h4 h5 Need enthalpy values at point 4 and ... View the full answer