3. A refrigeration system utilizing refrigerant R134a as the working fluid is engineering data are provided for your convenience: i. The system is operated to maintain the refrigerated space at -30°C ii. The inlet state of the compressor is 60 kPa and -34°C while gaining a net heat of 0.450 kW (Qin) from the surrounding iii. The exit temperature and pressure of the compressor are 65°C and 1.2 MPa iv. The cooling water enters and exits the condenser at 18°C and 26°C with a mass flow rate of 0.25kg/s v. The exit temperature of the condenser is 42°C vi. The h₁ = 230.04 kJ/kg, h2 = 295.18 kJ/kg, h3=111.28 = h4 vii. The water inlet and outlet enthalpy to cool the condenser are hw1,18°c = 75.47 kJ/kg and hw2,26°C 108.94 kJ/kg etermine (a) the actual enthalpy at state 2 with aid of interpolation, (b) the enthalpy at state 4, (c) the ality of the refrigerant at the evaporator inlet and the enthalpy at state 4, (d) the mass flow rate of the frigerant, (e) the waste heat transferred from the refrigerant, the compressor power input, and the Frigeration load of the thermal system using an energy balance, and (f) the COP of the refrigerator.

3. A refrigeration system utilizing refrigerant R134a as the working fluid is engineering data are provided for your convenience: i. The system is operated to maintain the refrigerated space at -30°C ii. The inlet state of the compressor is 60 kPa and -34°C while gaining a net heat of 0.450 kW (Qin) from the surrounding iii. The exit temperature and pressure of the compressor are 65°C and 1.2 MPa iv. The cooling water enters and exits the condenser at 18°C and 26°C with a mass flow rate of 0.25kg/s v. The exit temperature of the condenser is 42°C vi. The h₁ = 230.04 kJ/kg, h2 = 295.18 kJ/kg, h3=111.28 = h4 vii. The water inlet and outlet enthalpy to cool the condenser are hw1,18°c = 75.47 kJ/kg and hw2,26°C 108.94 kJ/kg etermine (a) the actual enthalpy at state 2 with aid of interpolation, (b) the enthalpy at state 4, (c) the ality of the refrigerant at the evaporator inlet and the enthalpy at state 4, (d) the mass flow rate of the frigerant, (e) the waste heat transferred from the refrigerant, the compressor power input, and the Frigeration load of the thermal system using an energy balance, and (f) the COP of the refrigerator.

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

Chapter22: Condensers

Section: Chapter Questions

Problem 7RQ: When a standard-efficiency air-cooled condenser is used, the condensing refrigerant will normally be...

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