An ideal refrigeration cycle uses ammonia as the working fluid. The refrigerant enters the compressor at 120'

Question:

An ideal refrigeration cycle uses ammonia as the working fluid. The refrigerant enters the compressor at 120' kPa and the throttle at 1200 kPa. If it produces 12 tons of refrigeration, calculate:
(i) The power input to the compressor
(ii) The heat rejection from the condenser
(iii) The coefficient of performance for the system
(iv) The volume rate of flow entering the compressor