Perform an air-standard-cycle analysis of a gas-turbine engine that employs regeneration (i.e., some of the energy in the hot exhaust stream is transferred to the air between the compressor and the “combustor”).

A. Sketch the regenerative cycle using T–s coordinates and label the state points.

B. From your analysis, derive a formula for the ideal cycle efficiency expressed in terms of temperatures.

C. Use your result from part B to calculate the thermal efficiency for an ideal cycle in which the air enters at 300 K,  regenerator preheats the air from 75 K, and the pressure ratio is 12.5. The turbine inlet temperature is 1050 K.

D. Compare your result from part C with the thermal efficiency calculated in Problem 9.63. Discuss.

Problem 9.63

Consider a gas-turbine engine operating with 30 kg/s of air entering at 300 K and a pressure ratio of 12.5. Using an ideal air-standard cycle as a model of this engine, determine the ideal thermal efficiency and the net shaft power delivered to the load. Assume the turbine inlet temperature is 1050 k.

Transcribed Image Text:

Lout 4' wwwwww 2' 2 Compressor Regenerator Oin 3 4 Turbine Wshaft