A counter flow heat exchanger operates in a stable state, ignoring kinetic and potential effects. Liquid water enters at 15°C and leaves at 23°C, neglecting the change in pressure on the liquid side. On the other side, the refrigerant R-134a enters at 12 bar, 90°C and 150 kg/h, and the outlet condition is 12 bar, 28°C. The heat from the outer surface of the heat exchanger will be neglected. a) Determine the mass flow rate of the liquid water flow in kg/h. b) Determine the entropy production of the heat exchanger in kW/K

A counter flow heat exchanger operates in a stable state, ignoring kinetic and potential effects. Liquid water enters at 15°C and leaves at 23°C, neglecting the change in pressure on the liquid side. On the other side, the refrigerant R-134a enters at 12 bar, 90°C and 150 kg/h, and the outlet condition is 12 bar, 28°C. The heat from the outer surface of the heat exchanger will be neglected. a) Determine the mass flow rate of the liquid water flow in kg/h. b) Determine the entropy production of the heat exchanger in kW/K

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

Chapter45: Domestic Refrigerators And Freezers

Section: Chapter Questions

Problem 12RQ: Refrigerators currently being manufactured in the United States are using______as their refrigerant.

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A counter flow heat exchanger operates in a stable state, ignoring kinetic and potential effects. Liquid water enters at 15°C and leaves at 23°C, neglecting the change in pressure on the liquid side. On the other side, the refrigerant R-134a enters at 12 bar, 90°C and 150 kg/h, and the outlet condition is 12 bar, 28°C. The heat from the outer surface of the heat exchanger will be neglected. a) Determine the mass flow rate of the liquid water flow in kg/h. b) Determine the entropy production of the heat exchanger in kW/K.(THERMODYNAMICS)
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A well-insulated, thin-walled, counterflow heat exchanger is to be used to cool oil (cp = 2.20 kJ/kg.oC) from 150 to 40oC at a rate of 2 kg/s with water (cp = 4.18 kJ/kg.oC) that enters at 22oC at a rate of 1.5 kg/s. The diameter of the tube is 2.5 cm, and its length is 6 m. Determine (a) the rate of heat transfer and (b) the rate of exergy destruction in the heat exchanger.
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