DieselShip's Online Content Library

Q3. In an open gas turbine cycle, 4.5 kg/s of air is induced into a rotary compressor at a pressure and temperature of 1 bar and 18℃ respectively.

It is compressed through a pressure ratio of 5:1 with an isentropic efficiency of 0.85.

The hot gases leave the combustion chamber and enter the turbine at a temperature of 810℃, expanding to the initial pressure with an isentropic efficiency 0.88.

The mass flow rate of fuel may be ignored.

(a) Sketch the cycle on a Temperature-specific entropy diagram. (4)

(b) Calculate EACH of the following:

(i) the net power output of the cycle; (6)

(ii) the work ratio; (2)

(iii) the thermal efficiency. (4)

Note:  for air and the hot gas γ = 1.4 and C_p = 1.006 kJ/kgK