DieselShip's Online Content Library

Q3. (a) Sketch the p-V diagram for a two-stage reciprocating air compressor, indicating the area(s) which represent the work saved by intercooling.

(b) In a two-stage reciprocating air compressor, the L.P suction pressure is 0.95 bar and the H.P delivery pressure is 11 bar. The L.P suction temperature is 303 K. The index of compression and expansion is 1.3. Intercooling is perfect, and the stage pressures are in geometric progression.

Determine EACH of the following

(i) The indicated work per kg of air

(ii) The heat removed in the intercooler per kg of air

(iii) The work saved per kg of air by intercooling

(iv) The isothermal efficiencies with and without intercooling.

Note: For air, R = 0.287 kJ/kg K and C_P = 1.005 kJ/kg K.