A household refrigerator operates with cold- andhot-temperature reservoirs et
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- Refrigerators currently being manufactured in the United States are using______as their refrigerant.arrow_forwardWelded ______sealed compressors are normally used in household refrigerators.arrow_forwardA typical 200-m2 house can be cooled adequately by a 3.5-ton air conditioner whose COP is 4.0. Determine the rate of heat gain of the house when the air conditioner is running continuously to maintain a constant temperature in the house.arrow_forward
- A 55 kW refrigeration load is to be carried by an air refrigeration system with a discharge pressure of 1370 kPa and a refrigerator pressure of 345 kPa. Compression and expansion processes are polytropic with n-1.37. The pressure at the start of the expansion is 1344 kPa and the temperature is 32°C. Air temperature leaving the refrigerator is 0°C and entering the compressor is 5°C. Clearance for both compressor and expander is 5%. Determine the (b)The net work loadarrow_forwardA four cylinder, single acting R-12 compressor 35 cm x 40 cm runs at 1000 r.p.m. The compressor clearance factor is 0.04 and the law of compression pV1.1=C. the operating pressures for the vapour compression refrigeration system are: 8.47 bar (350C) and 1.004bar (-300C). The refrigerant temperatures are: entering the compressor -200C, leaving the compressor 500C; entering the condenser 450C, leaving the condenser 250C, entering the expansion valve 300C and leaving the evaporator dry saturated. Assuming that heat removed in the compressor is 26 kJ/sec. calculate: The refrigerating capacity, The compressor power COP, Mass of condensing cooling water assuming the rise in temperature to be 100 Tabulate energy balance for 1 kg of refrigerantarrow_forward:(a) A four cylinder, single acting R-12 compressor 35 cm x 40 cm runs at 1000 r.p.m. The compressor clearance factor is 0.04 and the law of compression pV1.1=C. the operating pressures for the vapour compression refrigeration system are: 8.47 bar (350C) and 1.004bar (-300C). The refrigerant temperatures are: entering the compressor -200C, leaving the compressor 500C; entering the condenser 450C, leaving the condenser 250C, entering the expansion valve 300C and leaving the evaporator dry saturated. Assuming that heat removed in the compressor is 26 kJ/sec. calculate: Mass of condensing cooling water assuming the rise in temperature to be 100 Tabulate energy balance for 1 kg of refrigerantarrow_forward
- A commercial refrigerator using R-134a as a refrigerant is used to keep the cooled environment at -35 C. The refrigerator releases the waste heat to the cooling water that enters the condenser at 18 C at 0.25 kg / s and leaves the condenser at 26 C. The refrigerant enters the condenser at a pressure of 1.2 MPa and a temperature of 50 ° C, and leaves the condenser at the same pressure, supercooled at 5 ° C. Since the compressor consumes 3.3 kW of power, a) Mass flow rate of the refrigerant, b) Cooling load and COP value c) Calculate the minimum power consumed by the compressor for the same cooling load.arrow_forwardA two stage cascade refrigeration system uses R-12 in the high pressure loop with a condenser temperature of 300C and -100C in the cascade condenser, and R-22 in the low pressure loop with a temperature in the cascade condenser of 00C and an evaporator temperature of -30 0C. The refrigeration load is 28 tons. Given : h6 = 366 kJ/kg; h2= 421 kJ/kg Determine: 1) the mass flow rate in the low pressure loop in kg/s 2) mass flow rate in the high pressure loop, in kg/s 3) total power requirement in KW 4.) COP 5.) heat rejected in the condenser, KW 6.) amount of cooling water needed for a temp rise of 140C. in kg/s 7.) amount of ice (kg)for a 10 hrs operation if the initial temp of water is 31 0C to ice at -80C. Answe in kg.arrow_forwardA two stage cascade refrigeration system uses R-12 in the high pressure loop with a condenser temperature of 300C and -100C in the cascade condenser, and R-22 in the low pressure loop with a temperature in the cascade condenser of 00C and an evaporator temperature of -30 0C. The refrigeration load is 24 tons. Given : h6 = 368 kJ/kg; h2= 420 kJ/kg Determine: 1) the mass flow rate in the low pressure loop in kg/s 2) mass flow rate in the high pressure loop, in kg/s 3) total power requirement in KWarrow_forward
- In a 112 TR R-22 flooded chiller, the water inlet temperature is 11.67°C. The mass flow rate of water to be chilled is 18.93 kg/s. The evaporating temperature of the refrigerant is 2.8°C. The copper tubes used are 1.27 cm OD and 1.12 cm ID. There are two parallel circuits and eight passes forwater. The refrigerant-side heat-transfer coefficient is given by Rohsenow’s correlation. Calculatethe overall heat-transfer surface area of the chiller.SPECIAL DIRECTION : STEP BY STEP SOLUTION AND HOW TO GET ho properly find or Calculatethe overall heat-transfer surface area of the chiller.arrow_forwardThe heat removal rate from a refrigerated space and the power input to the compressor are 8.5kW and 1.7 respectively. The coefficient of performance of the refrigerantarrow_forwardA 55 kW refrigeration load is to be carried by an air refrigeration system with a discharge pressure of 1370 kPa and a refrigerator pressure of 345 kPa. Compression and expansion processes are polytropic with n-1.37. The pressure at the start of the expansion is 1344 kPa and the temperature is 32°C. Air temperature leaving the refrigerator is 0°C and entering the compressor is 5°C. Clearance for both compressor and expander is 5%. Determine the COP.arrow_forward
- Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning