The figure shows a two-stage, vapor-compression refrigeration system with two evaporators and a direct contact heat exchanger. Saturated vapor ammonia from evaporator 1 enters compressor 1 at 12 Ibf/in? and exits the compressor at 66 lbf/in?. Evaporator 2 operates at 66 Ibf/in?, with saturated vapor exiting at state 8. The condenser pressure is 200 lbf/in?, and saturated liquid refrigerant exits the condenser. Each compressor stage has an isentropic efficiency of 80%. The refrigeration capacity of each evaporator is shown on the figure. Čout Condenser Compressor 2 Expansion valve - 6 Direct Evaporator contact heat exchanger Qin2 = 10 tons Expansion valve Compressor 1 - 7 Evaporator Om1 =5 tons

The figure shows a two-stage, vapor-compression refrigeration system with two evaporators and a direct contact heat exchanger. Saturated vapor ammonia from evaporator 1 enters compressor 1 at 12 Ibf/in? and exits the compressor at 66 lbf/in?. Evaporator 2 operates at 66 Ibf/in?, with saturated vapor exiting at state 8. The condenser pressure is 200 lbf/in?, and saturated liquid refrigerant exits the condenser. Each compressor stage has an isentropic efficiency of 80%. The refrigeration capacity of each evaporator is shown on the figure. Čout Condenser Compressor 2 Expansion valve - 6 Direct Evaporator contact heat exchanger Qin2 = 10 tons Expansion valve Compressor 1 - 7 Evaporator Om1 =5 tons

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter28: Special Refrigeration Applications

Section: Chapter Questions

Problem 15RQ: Why is two-stage compression popular for extra-low-temperature refrigeration systems?

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