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Q3. A single-acting, TWO stage reciprocating air compressor is designed for minimum

work with perfect intercooling, and the LP cylinder has a volumetric efficiency of 91%.

The compressor delivers 4.8 kg/min of air from an initial condition of 1.0135 bar and 8℃.

In EACH stage the clearance volume is 5% of the respective swept volume, and the index for all compressions and expansions is n = 1.25.

The speed of rotation is 360 r/min.

(a) Sketch the cycle on a pressure-volume diagram. (2)

(b) Determine EACH of the following:

(i) the delivery pressure; (5)

(ii) the power; (5)

(iii) the volume induced per cycle. (4)

Note: For air C_V = 0.718 kJ/kgK and C_P= 1.005 kJ/kgK