Question: A 4500 KW gas turbine generating set operates with two compressors stages
0

the overall pressure ratio is 9:1. A high pressure turbine is used to drive the compressor, and a low pressure turbine is 625ºC and the gases are reheated to 625ºC after expansion in the first turbine. The exhaust gases leaving the low pressure turbine are passed through a heat exchanger to heat air leaving the high pressure stage compressor. The compressor have equal pressure ratios and inter-cooling is completed between the stages. The air inlet temperature to the unit is 20 ºC The isentropic efficiency of each compressor stage is 0.8 and the isentropic efficiency of each turbine stage is 0.85, the heat exchanger thermal ratio is 0.8. A mechanical efficiency of 95 % can be assumed for both the power shaft and compressor turbine shaft.

Neglecting all pressure losses and change of kinetic energy, calculate:

i) The thermal efficiency

ii) Work ratio of the plant

iii) The mass flow in Kg/s

iv) Neglect the mass of the fuel and assume the following Cp = 1.005 KJ/KgK, and ϒ= 1.4

Subject : Thermal and Fluid Power Engineering

Topic : Gas Turbine

Difficulty : High

tfpe(66) • 370 views
 written 20 months ago by ashusarode90 • 30