A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -30°C by rejecting its waste heat to cooling water that enters the condenser at 18°C at a rate of 0.29 kg/s and leaves at 26°C. The refrigerant enters the condenser at 1.2 MPa and 65°C and leaves at 42°C. The inlet state of the compressor is 60 kPa and -34°C and the compressor is estimated to gain a net heat of 430 W from the surroundings. The heat exchanger loses no heat to the environment. Water 26°C 1 18°C 1.2 MPa 42°C 65°C (2 Condenser It im W. Expansion valve Evaporator Compressor | 60 kPa -34°C Determine the quality of the refrigerant at the evaporator inlet. (Take the required values from saturated efrigerant-134a tables.) You must provide an answer before moving on to the next part.) he quality of the refrigerant at the evaporator inlet is|

A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -30°C by rejecting its waste heat to cooling water that enters the condenser at 18°C at a rate of 0.29 kg/s and leaves at 26°C. The refrigerant enters the condenser at 1.2 MPa and 65°C and leaves at 42°C. The inlet state of the compressor is 60 kPa and -34°C and the compressor is estimated to gain a net heat of 430 W from the surroundings. The heat exchanger loses no heat to the environment. Water 26°C 1 18°C 1.2 MPa 42°C 65°C (2 Condenser It im W. Expansion valve Evaporator Compressor | 60 kPa -34°C Determine the quality of the refrigerant at the evaporator inlet. (Take the required values from saturated efrigerant-134a tables.) You must provide an answer before moving on to the next part.) he quality of the refrigerant at the evaporator inlet is|

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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3. A refrigerator uses refrigerant-134a as the working fluid and operates on the ideal vapor- compression refrigeration cycle except for the compression process. The refrigerant enters the evaporator at 120 kPa with a quality of 34 percent and leaves the compressor at 70°C. If the compressor consumes 450 W of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the COP of the refrigerator. Answers: (a) 0.00644 kg/s, (b) 800 kPa, (c) 2.03 |↓ Condenser Expansion valve 120 kPa x=0.34 Evaporator M Warm environment 70°C Compressor Cold environment
Consider an actual vapor-compression refrigeration cycle. R-134a enters the compressor as superheated vapor at 0.18 MPa and -10°C at a rate of 0.055 kg/s, and it leaves at 1.2 MPa and 60°C. The refrigerant is cooled in the condenser to 42°C and 1.15 MPa, and it is throttled to 0.22 MPa. Determine the rate of heat addition to the evaporator, in kW.
es A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -35°C by rejecting waste heat to cooling water that enters the condenser at 18°C at a rate of 0.35 kg/s and leaves at 26°C. The refrigerant enters the condenser at 1.2 MPa and 50°C and leaves at the same pressure subcooled by 5°C. The compressor consumes 3.3 kW of power. Use data from the tables. 26°C 1.2 MPa 50 subcooled fo Expansion valve Condenser Evaporator 000 QL Water 18°C 1.2 MPa 50°C Compressor kW. W in Determine the refrigeration load. The refrigeration load is (You must provide an answer before moving to the next part.) 27
Refrigerant 134-a enters the condenser of a residential heat pump at 80O0kPa and 35°C at a rate of 0.018kg/s and leaves at 800kPa as a saturated liquid. (Refer to Figure 4). If the compressor consumes 1.2kW of power, determine: (a) the COP of the heat pump (b) the rate of heat absorption from the outside air. 800 kPa Он Saturated 800 kPa liquid 35°C Condenser ´Expansion valve Win Compressor Evaporator Figure 4
Refrigerant -134a enters the compressor of a refrigerator as superheated vapour at 0.10 MPa and -10 oC with a mass flow rate of 0.21 kg/s, and it leaves at a pressure of 1 MPa. The refrigerant enters the condenser at 1 MPa and leaves as a saturated liquid, and then throttled back to 0.10 MPa. The isentropic efficiency of the compressor is 88 percent. Disregard any heat transfer and pressure drops in the connecting lines between the components. 2.1 Show the cycle on the T-s diagram with respect to saturation lines. Determine: 2.2 the refrigeration capacity, 2.3 the power input to the compressor, 2.4 the refrigerant temperature at the compressor exit, and 2.5 the coefficient of performance.
Thermodynamics
1) Refrigerant-134a enters the condenser at 200 kPa and 10°C and it leaves at 200 kPa with a quality of 45 percent in a heat pump. The load of heat pump is 700 W and COP of the heat pump is 3.5, determine a- The rate of heat gains from the environment ( b- The minimum compressor work c- The mass flow rate of the refrigerant
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A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -30°C by rejecting waste heat to cooling water that enters the condenser at 20°C at a rate of 0.25 kg/s and leaves at 28°C. The refrigerant enters the condenser at 1.2 MPa and 50°C and leaves at the same pressure subcooled by 5°C. If the Talking PIYATIDA TENURUK compressor consumes 3.7 kW of power, determine (a) the mass flow rate of the refrigerant (b) the refrigeration load (c) the COP (d) the minimum power input to the compressor for the same refrigeration load
A refrigerator using fluid-134a as a work fluid is used to keep the cooling medium at -25 oC. The refrigerator releases the waste heat, which enters the condenser at 18 oC with a flow of 0.30 kg / s and from the condenser at 26 oC to the cooling water. The refrigerant enters the condensate at a pressure of 1.2 MPa and 50 oC, and leaves the condenser at 40 oC at the same pressure. Find a) the mass flow rate of the refrigerant, b) the power consumed by the compressor, c) the COP value, and d) the minimum power that the compressor will consume for the same cooling load.They watch the specific heat of water as ?? = 4.22 ?? / ???.