5. A refrigerator with tetrafluoroethane as refrigerant operates with an evaporation temperature of 247.15 K (-26°C) and a condensation temperature of 300.15 K (27°C). Saturated liquid refrigerant from the condenser flows through an expansion valve into the evaporator, from which it emerges as saturated vapor. (a) For a cooling rate of 5.275 kW, what is the circulation rate of the refrigerant? (b) By how much would the circulation rate be reduced if the throttle valve were replaced by a turbine in which the refrigerant expands isentropically? (c) Suppose the cycle of (a) is modified by the inclusion of a countercurrent heat exchanger between the condenser and the throttle valve in which heat is transferred to vapor returning from the evaporator. If liquid from the condenser enters the exchanger at 300.15 K (27°C) and if vapor from the evaporator enters the exchanger at 247.15 K (-26°C) and leaves at 294.15 K (21°C), what is the circulation rate of the refrigerant?

5. A refrigerator with tetrafluoroethane as refrigerant operates with an evaporation temperature of 247.15 K (-26°C) and a condensation temperature of 300.15 K (27°C). Saturated liquid refrigerant from the condenser flows through an expansion valve into the evaporator, from which it emerges as saturated vapor. (a) For a cooling rate of 5.275 kW, what is the circulation rate of the refrigerant? (b) By how much would the circulation rate be reduced if the throttle valve were replaced by a turbine in which the refrigerant expands isentropically? (c) Suppose the cycle of (a) is modified by the inclusion of a countercurrent heat exchanger between the condenser and the throttle valve in which heat is transferred to vapor returning from the evaporator. If liquid from the condenser enters the exchanger at 300.15 K (27°C) and if vapor from the evaporator enters the exchanger at 247.15 K (-26°C) and leaves at 294.15 K (21°C), what is the circulation rate of the refrigerant?

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

Chapter41: Troubleshooting

Section: Chapter Questions

Problem 8RQ: When the outside ambient air temperature is 90F, the temperature of the condensing refrigerant in a...

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