A ordinary vapor-compression refrigeration using R-134A operates with a condenser tem- perature of -45°C and an evaporator a -10°C. The compressor is 80% efficient. (a) Determine the amount of cooling per kg of R-134A circulated (b) Determine the amount of heat rejected per kg of R-134A circulated (c) Determine the amount of work required per kg of R-134A circulated, and the COP

A ordinary vapor-compression refrigeration using R-134A operates with a condenser tem- perature of -45°C and an evaporator a -10°C. The compressor is 80% efficient. (a) Determine the amount of cooling per kg of R-134A circulated (b) Determine the amount of heat rejected per kg of R-134A circulated (c) Determine the amount of work required per kg of R-134A circulated, and the COP

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 2RQ: The operating condition for the single compressor in a household refrigerator is the lowest box...

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A refrigeration system operates on an ideal vapor compression using R-12 with an evaporator temperature of -30 C and a condenser exit temperature of 49.30C and requires 74.6 kW motor to drive the compressor. What is the capacity of the refrigerator in tons of refrigeration? Enthalpy at the condenser ,entrance = 382KJ/Kg, exit = 248.15KJ/Kg, at evaporator entrance= 248.15kJ/kg, exit =338.14kJ/kg.
1. A refrigeration system operates on an ideal vapor compression using R-12 with an evaporator temperature of -30°C and condenser exit temperature of 49 30 °C and requires 74.6 kW motor to drive the compressor. What is the capacity of the refrigerator in tons of refrigeration? Enthalpy at condenser entrance = 382 kJ/kg, exit = 248.15 kJ/kg, at evaporator entrance 248.15 KJ/kg, exit = 338.14 kJ/kg.
A compressor serves two evaporators, one providing 5 tons of cooling at -20 degree F and the other, 10 tons of cooling at 10F. The system is a vapor-compression refrigeration system using R-12 with the condenser pressure at 200 psia. Assume saturated conditions leaving the condenser and evaporators and isentropic compression. Determine (a) the refrigerant flow through each evaporator, (b) the R-12 state entering the compressor, and (c) the compressor power.
Avapour compression refrigeration system using refrigerant F-12 is employed to produce 8640 kg of ice per day. The condensing and evaporating temperature of refrigerant are 48°C and -20°C respectively. Saturated liquid leaves the condenser and saturated vapour leaves the evaporator. Compression is isentropic, water at 35 C is used to form the ice. The temperature of ice should be-8°C. Heat flow into the orme tank from surroundings may be taken as 10% of total heat absorbed from water to form ice. Determine the power required to drive the compressor. Take specific heat of ice = 2,26 kJ/kg-K. Latent heat of Ice= 335 kJ/kg. Specific heat of water = 4.2 kJ/kg-K.
A standard vapor compression system produces 20 tons of refrigeration using R134a while operating between a condenser temperature of 45 deg-C and an evaporator temperature of -25 deg-C. Determine the refrigerating effect per unit of refrigerant, circulation rate in kg/s, power supplied, COP, heat rejected in kW, the volume flow rate in L/s, and temperature at the compressor discharge.
A standard vapor compression system produces 20 tons of refrigeration using r-12 while operating between a condenser temperature of 45 deg-C and an evaporator temperature of -25 deg-C. Determine the refrigerating effect per unit of refrigerant, circulation rate in kg/s, power supplied, COP, heat rejected in kW, the volume flow rate in L/s, and temperature at the compressor discharge. Please answer completely.
In an ideal vapour-compression refrigeration cycle, refrigerant R-12 enters the compressor as a saturated vapour at −18 degree C and leaves the condenser as a saturated liquid at 25 degree C. The mass flow rate of the refrigerant is 0.5 kg/s, and the pressure drop in the evaporator and the condenser are negligible. Calculate: a) the refrigeration effect (rate of refrigeration or heat transfer rate in the evaporator) b)power consumed by the compressor c)the coefficient of performance of the refrigerator) d)qualityof the refrigerant after the expansion valve e)heat transfer rate in the condenser
A vapor-compression refrigeration system, using ammonia (R-717) as the refrigerant, is operating with an evaporator temperature of -5°C and condenser temperature of 40°C. It is desired to determine the influence of raising the *6.5 evaporator temperature to 5°C while holding condenser temperature at 40°C. Calculate the percent changes in a. Refrigeration effect per kg refrigerant flow iate b. С.О.P. c. Heat of compression d. Theoretical power requirements e. Rate of heat rejected at the condenser, anticipated due to raising the evaporator temperature