DieselShip's Online Content Library

Q3. A three -stage reciprocating air compressor onboard a tanker. The compressor is perfectly intercooled and has a clearance ratio of 3.5%. The air properties at induction are 1 bar and 20℃ and the compressor delivers 25m³/min at these conditions

The discharge pressure of the compressor is 15. 50 bar. The stage pressure ratios are equal. And the index of compression and expansion is 1. 34 for all stages.

a) Sketch the p-v diagram of the compression (4)

b) Calculate EACH of the following:

(i) calculate the indicated power of the compression. (8)

(ii) the volumetric efficiency. (4)

Note: For Air c_p = 1005 J/kgK, c_v = 718 J/kgK