An ice-making machine operates on the ideal vapor-compression cycle, using Refrigerant-134a. The refrigerant enters the compressor as saturated vapor at 160 kPa and leaves the condenser as saturated liquid at 700 kPa. Water enters the ice-making machine at 150 C and leaves as ice at -50 °C. For an ice production rate of 12 kg/h, where 384 kJ of heat needs to be removed from each kilogram of water at 150 °C to turn into ice at -50 °C, determine the power input to the ice machine.

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.