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Q2) The gas turbine plant shown in fig Q2 uses two stage compression with inter-cooling. Each compressor has the same pressure ratio and intercooling may be considered perfect.

Air enters the Low Pressure Compressor at a temperature of 20℃ and mass flow rate of 120 .

The air fuel ratio is 75 : 1 and 74.1 MW of heat energy is supplied in the Combustion Chamber.

The isentropic efficiency of each compressor is 80% and that of the turbine is 88%.

The overall pressure ratio of the plant is 12 : 1.

(a) Calculate EACH of the following:

(i) the compressor power; (4)

(ii) the turbine inlet temperature; (3)

(iii) the net power output of the plant. (5)

(b) Sketch the cycle on a temperature – specific entropy diagram showing the temperatures. (4)

Note:

For the air ɣ = 1.4, C_p = 1.005kJkgK

For the gas ɣ = 1.33, C_p = 1.11kJkgK