Arefrigerator uses refrigerant-134a as the working fluid and operates on the ideal vaporcompression refrigeration cycle except for the compression process. the refrigerant enters the evaporator at 120 kpa with a quality of 30 percent and leaves the compressor at 60°c. if the compressor consumes 450 w of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the cop of the refrigerator.

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.