A refrigerator operating on the vapor-compression refrigeration cycle using refrigerant-134a as the refrigerant is considered. The temperatures of the cooled space and the ambient air are at 10°F and 80°F, respectively. R-134a enters the compressor at 20 psia as a saturated vapor and leaves at 140 psia and 160°F. The refrigerant leaves the condenser as a saturated liquid. The rate of cooling provided by the system is 45,000 Btu/h. Determine (a) the mass flow rate of R-134a and the COP, (b) the exergy destruction in each component of the cycle and the second-law efficiency of the compressor, and (c) the second-law efficiency of the cycle and the total exergy destruction in the cycle.