220. A twin cylinder ammonia compressor with volume displacement of 14,726 cm3

operates at

300 rpm. Condenser and evaporator pressure are 1200 kPa and 227 kPa respectively. Specific

volume of refrigerant at the entrance of compressor is 528.26 L/kg. Compression process is

polytropic with n = 1.20 and clearance factor of compressor is 2 percent. Determine the

horsepower required.

A. 60 hp B. 70 hp C. 80 hp D. 90 hp