A vapor-compression refregeration (i.e. reverse Rankine) system circulates Refrigerant 134a at a rate of 6kg/min. The refrigerant enters the compressor at -10 degrees Celcius, 1.4 bar (v_1=.14549m^3/kg, u_1 = 223.03kj/kg, h_1 = 243.4Kj/kg, s_1 = .9606kJ/kg.k), and exits at 7 bar. The isentropic compressor efficiency is 67%. There are no appreciable pressure drops as the refrigerant flows through the condensor and evaporator. The refrigerant leaves the condenser at 7 bar, 24 degrees Celcius (v_3=.000827m^3/kg, u_3 = 82.37kj/kg, h_3 = 82.9Kj/kg, s_3 = .3113kJ/kg.k),
Find:
(a) the coefficient of performance
(b) the refrigerating capacity, in tons (1 ton = 211kJ/min)