An ideal brayton refrigeration cycle has a compressor pressure ratio of 7. at the compressor inlet, the pressure and temperature of the entering air are 22 lbf/in2 and 450ºr, respectively. the temperature at the inlet of the turbine is 680ºr. for a refrigerating capacity of 13.5 tons, determine
(a) the mass flow rate of the refrigerant, in lb/min.
(b) the net power input, in btu/min
(c) the coefficient of performance.