power required to drive the compressor assuming overall efficiency of the drive as 90%.

Question

An air compressor has eight stages of equal pressure ratio 1.35. The flow rate through the compressor and its overall efficiency are 50 kg/s and 82 percent respectively. If the condition of air at entry are 1.0 bar and 40⁰C, determine:

1. the state of air at the compressor exit,
2. polytropic or small stage efficiency,
3. efficiency of each stage,
4. power required to drive the compressor assuming overall efficiency of the drive as 90%.

take C_P = 1.005 kJ/kg K and g = 1.4