In a pneumatic tool pressing machine, the compressed air is required at 8 bar. This compressed air is supplied by a reciprocating compressor, in which the air is compressed at the rate of 4 m³/min at 1 bar 27°C following polytrophic compression with n=1.2. With the Two stage compressor used water cooled intercooler, the perfect intercooling occurs at optimum intercooler pressure. Compare the work input required of (i) if the same compression occurs in single stage (ii) Perfect intercooling (iii) with imperfect intercooling up to 30°C at the optimum intercooling pressure. Take, $C_p$ = 1.0032 kJ/kg K and R = 0.287 kJ/kg K.
