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In: Mechanical Engineering

An ideal vapor-compression refrigeration cycle is modified to include a counterflow heat exchanger, as shown in...

An ideal vapor-compression refrigeration cycle is modified to include a counterflow heat exchanger, as shown in the figure below. Ammonia leaves the evaporator as saturated vapor at 1 bar and is heated at constant pressure to 5°C before entering the compressor. Following isentropic compression to 18 bar, the refrigerant passes through the condenser, exiting at 40°C, 18 bar. The liquid then passes through the heat exchanger, entering the expansion valve at 18 bar.



If the mass flow rate of refrigerant is 16 kg/min, determine:

(a) the refrigeration capacity, in tons of refrigeration.

(b) the compressor power input, in kW.

(c) the coefficient of performance.

(d) the rate of entropy production in the compressor, in kW/K.

(e) the rate of exergy destruction in the compressor, in kW.

Let T0 = 20°C

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