A vapor-compression refrigeration system circulates R-134a at a rate (m) of 10 kg/min. The refrigerant enters the compressor at - 10oC, 1.2 bar and exits at 7 bar. The isentropic efficiency of the adiabatic compressor is 68%. There are no significant pressure drops as the refrigerant flows through the condenser and evaporator. The refrigerant leaves the condenser at 7 bar and 24oC. A temperature difference of 5oC is maintained for effective heat exchange between the refrigerant and its surroundings at the evaporator and condenser. The atmospheric conditions are 100 kPa and 25oC.
(a) Perform an energy inventory on a rate (kW) basis for the entire cycle complete with an energy flow diagram. Determine
(b) The energetic efficiency
(c) COP of the system.
(d) Identify the device with the highest rate of energy destruction.