The air is compressed to a final pressure of 0.7 MPa. The intermediate pressure is ideal and cooling is perfect. The compression index in both the stages is 1.25 and the compressor runs at 600 r.p.m Neglect clearance. Determine:

1. Intermediate pressure
2. Total volume of each cylinder
3. Power required to drive the compressor
4. Rate of heat rejection in the intercooler

Given:

Two stage single acting reciprocating comp $V_1=0.2 m^3/s, T_1=16^o, P_1=0.1M,P_a=1 ×10^5 Pa$

$P_3=0.7mPa=7×10^5 Pa,n=1.25 , N=600 rpm$

To Find:$P_2= ?,V_{LP}=?,V_{HP}=?,Power,Q_(\frac{i}{c})$

Solution:

Assume optimum intermediate pressure

$P_2=\sqrt(P_1.P_3 )=\sqrt(0.1 ×0.7)$

=$0.264 MPa=2.64×10^5 Pa$

$V_{LP}=V_1=0.2 m^3/s$

$V_{LP}=V_1=\frac{0.2 ×60}{600}=0.02 m^3$

PV=mRT

$\frac{PV}{RT}=m →constant$

$\frac{P_1 V_1}{RT_1}=\frac{P_2 V_5}{RT_5}$

$\frac{1 ×10^5 ×0.02}{287 …