Modified Brayton cycle is to be analyzed using the air-standard assumption with constant specific heats at a temperature of 300K. Air flows through the Brayton cycle with a mass flow rate of 400 kg/s and enters the first compressor with a pressure of 100kPa and a density of 1.2 kg/m3.
It is then compressed to 800kPa in the first of two compressors with an isentropic efficiency of 85%. After this compression, the air is cooled at constant pressure where it is now found to have a volumetric flow rate of 57.4 m3/s when it enters the second compressor. The second compressor has an isentropic efficiency of 85% as well and the air leaves this stage of the cycle at a pressure of 2.5 MPa.
The cycle has a regenerator with an effectiveness of 75% which heats the air to a temperature of 600K after leaving the final compressor. The air enters the first turbine which has an isentropic efficiency of 90% at a temperature of 1200K after which it expands to a pressure of 700 kPa. The second and last turbine stage has an isentropic efficiency of 80%.
Determine:
a) Sketch the cycle on a T-S diagram and clearly label all your states
b) The temperature of the air leaving the last turbine
c) The net power production of the cycle
d) The thermal efficiency of the cycle