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Q8.A single acting, three stage reciprocating compressors, is designed for minimum work with perfect intercooling. It delivers 8 kg/mi of air from initial conditions of 1.15 bar and 25℃ and has a volumetric efficiency of 0.88 at a speed of 360 rev/min.

The clearance volume in each stage is 5 % of the respective swept volume.

Compression and expansion pressures take place according to the law pV^1.25 = constant.

(a) Calculate EACH of the following:

(i) The stage delivery pressure; (5)

(ii) The indicated power; (3)

(iii) The total heat removed in the intercoolers. (4)

(b) Sketch the cycle on a pressure- Volume diagram, indicating the stage pressures. (4)

Note :for air R = 287 J⁄(kg K)  ,C_p= 1005  J⁄(kg K)