I have been given two questions to solve, the first of the two I solved which is: 'Consider an idea gas turbine cycle with stages of compression and two stages of expansion. The pressure ratio across each stage of the compressor and turbine is 3. The air enters each stage of the compressor at 300 K and each stage of the turbine at 1200 K. The cycle has a net power output of 110kW. Find the mass flow rate of the air that passes through the engine.' I solved this as follows: 1. pressure ratio at state 1 = 1.386 2. pressure ratio at state 2 = 4.158 3. the enthalpy at state 2 = 411.27 KJ/kg and state 4 = 1277.79 KJ/kg 4. pressure ratio at state 5 = 238 5. pressure ratio at state 6 = 79.33 6. work input into the compressor = 221.14 KJ/kg 7. work output of the turbine = 662.86 KJ/kg 8. net work done by the gas turbine = 440.72 KJ/kg 9. mass flow rate = 0.25 kg/s The part I need help in is the follow up question to the one i solved above which is as follows: 'Reconsider the previous problem but now equipped with a regenerator with effectiveness of 75% and isentropic efficiency of the compressor being 86% and that of turbine is 90%. Find a) the ratio of the power consumed by the compressor and that produce by the turbine, b) the thermal efficiency of the cycle without regenerator, c) the thermal efficiency of the cycle with the regenerator.
I have been given two questions to solve, the first of the two I solved which is:
'Consider an idea gas turbine cycle with stages of compression and two stages of expansion. The
pressure ratio across each stage of the compressor and turbine is 3. The air enters each stage of the
compressor at 300 K and each stage of the turbine at 1200 K. The cycle has a net power output of
110kW. Find the mass flow rate of the air that passes through the engine.'
I solved this as follows:
1. pressure ratio at state 1 = 1.386
2. pressure ratio at state 2 = 4.158
3. the enthalpy at state 2 = 411.27 KJ/kg and state 4 = 1277.79 KJ/kg
4. pressure ratio at state 5 = 238
5. pressure ratio at state 6 = 79.33
6. work input into the compressor = 221.14 KJ/kg
7. work output of the turbine = 662.86 KJ/kg
8. net work done by the gas turbine = 440.72 KJ/kg
9. mass flow rate = 0.25 kg/s
The part I need help in is the follow up question to the one i solved above which is as follows:
'Reconsider the previous problem but now equipped with a regenerator with effectiveness of 75% and
isentropic efficiency of the compressor being 86% and that of turbine is 90%. Find a) the ratio of
the power consumed by the compressor and that produce by the turbine, b) the thermal efficiency
of the cycle without regenerator, c) the thermal efficiency of the cycle with the regenerator.'
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