11-61E A two-stage compression refrigeration system with an adiabatic liquid-vapor separation unit like that in Fig. P11-60 ( uses refrigerant-134a as the working fluid. The system operates the evaporator at 60 psia., the condenser at 300 psia, and the separator at 120 psia. The compressors use 25 kW of power. Determine the rate of cooling provided by the evaporator and the COP of this cycle. The refrigerant is saturated liquid at the inlet of each expansion valve and saturated vapor at the inlet of each compressor, and the compressors are isentropic. Condenser Compressor Separator Compressor rit6 Evaporator

11-61E A two-stage compression refrigeration system with an adiabatic liquid-vapor separation unit like that in Fig. P11-60 ( uses refrigerant-134a as the working fluid. The system operates the evaporator at 60 psia., the condenser at 300 psia, and the separator at 120 psia. The compressors use 25 kW of power. Determine the rate of cooling provided by the evaporator and the COP of this cycle. The refrigerant is saturated liquid at the inlet of each expansion valve and saturated vapor at the inlet of each compressor, and the compressors are isentropic. Condenser Compressor Separator Compressor rit6 Evaporator

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...

See similar textbooks

Similar questions

When a standard-efficiency air-cooled condenser is used, the condensing refrigerant will normally be higher in temperature than the entering air temperature.
What are the approximate temperature ranges tor low-, medium-, and high-temperature refrigeration applications?
How will oversizing the buffer tank on a water-to-water heat pump system affect the run time of the system?
Define flash gas, and explain how it applies to the net refrigeration effect of the refrigeration cycle.
Consider a two-stage compression refrigeration system operating between the pressure limits of 0.8 and 0.14 MPa. The working fluid is refrigerant-134a. The refrigerant leaves the condenser as a saturated liquid and is throttled to a flash chamber operating at 0.4 MPa. Part of the refrigerant evaporates during this flashing process, and this vapor is mixed with the refrigerant leaving the low-pressure compressor. The mixture is then compressed to the condenser pressure by the high-pressure compressor. The liquid in the flash chamber is throttled to the evaporator pressure, and it cools the refrigerated space as it vaporizes in the evaporator. Assuming the refrigerant leaves the evaporator as saturated vapor and both compressors are isentropic, determine (a)the fraction of the refrigerant that evaporates as it is throttled to the flash chamber, (b)the amount of heat removed from the refrigerated space and the compressor work per unit mass of refrigerant flowing through the condenser,…
Q1.2 Consider a two-stage compression refrigeration system operating between the pressure limits of 0.8and0.14 MPa(see Fig. Q 2). The working fluid isrefrigerant -134a. The refrigerant leaves thecondenser as a saturated liquid and is throttled to aflash chamberoperating at0.4 MPa. Part ofthe refrigerant evaporates during this flashing process, and this vapour is mixed with the refrigerantleaving the low-pressure compressor. The mixture is then compressed to the condenser pressure bythe high-pressure compressor. The liquid in the flash chamber is throttled to the evaporator pressure,and it cools the refrigerated space as it vaporizes in the evaporator. Assuming the refrigerant leavesthe evaporator as saturated vapor and both compressors are isentropic, determine(a) the coefficient of performance (COP).Re-draw the schematic diagram and sketch the cycle accurately on a T-s diagram with the propertyvalues labelled at all state points.
Consider a two-stage compression refrigeration system operating between the pressure limits of 1.2 MPa and 0.16 MPa. The working fluid is refrigerant-134a. The refrigerant leaves the condenser as a saturated liquid and is throttled to a flash chamber operating at 0.7 MPa. Part of the refrigerant evaporates and the remainder is mixed with the refrigerant leaving the low-pressure compressor. The mixture is then compressed to the condenser pressure by the high-pressure compressor. The liquid in the flash chamber is throttled to the evaporator pressure, and it cools the refrigerated space as It vaporizes in the evaporator. Assume that the refrigerant leaves the evaporator as saturated vapor and both compressors are isentropic. a) i) Determine the amount of heat removed from the refrigerated space ii) Determine the compressor work per unit mass of refrigerant flowing through the condenser b) Determine the coefficient of performance
Consider a two-stage compression refrigeration system operating between the pressure limits of 1.2 MPa and 0.16 MPa. The working fluid is refrigerant-134a. The refrigerant leaves the condenser as a saturated liquid and is throttled to a flash chamber operating at 0.7 MPa. Part of the refrigerant evaporates and the remainder is mixed with the refrigerant leaving the low-pressure compressor. The mixture is then compressed to the condenser pressure by the high-pressure compressor. The liquid in the flash chamber is throttled to the evaporator pressure, and it cools the refrigerated space as It vaporizes in the evaporator. Assume that the refrigerant leaves the evaporator as saturated vapor and both compressors are isentropic. a) Draw the 'T-S' Diagram and state the assumptions b) Determine the fraction of the refrigerant that evaporates as it is throttled to the flash chamber (x_e).
Q1 Consider a two-stage compression refrigeration system operating between the pressure limits of 0.8and0.14 MPa(see Fig. Q 2). The working fluid isrefrigerant -134a. The refrigerant leaves thecondenser as a saturated liquid and is throttled to aflash chamberoperating at0.4 MPa. Part ofthe refrigerant evaporates during this flashing process, and this vapour is mixed with the refrigerantleaving the low-pressure compressor. The mixture is then compressed to the condenser pressure bythe high-pressure compressor. The liquid in the flash chamber is throttled to the evaporator pressure,and it cools the refrigerated space as it vaporizes in the evaporator. Assuming the refrigerant leavesthe evaporator as saturated vapor and both compressors are isentropic, determine(a) the fraction of the refrigerant that evaporates as it is throttled to the flash chamber,(b) the amount of heat removed from the refrigerated space and the compressor work per unit massof refrigerant flowing through the…
A two-stage compression refrigeration system operates with refrigerant-134a between the pressure limits of 1.4 MPa and 0.10 MPa. The refrigerant leaves the condenser as a saturated liquid and is throttled to a flash chamber operating at 0.6 MPa. he flash chamber is maintained at the same pressure as the low pressure discharge which is 0.6 Mpa. The vapor in the flash chamber is then compressed to the condenser pressure by the high-pressure compressor, and the liquid is throttled to the evaporator pressure. Assume the refrigerant leaves the evaporator as saturated vapor and both compressors are isentropic. Consider a mass flow rate of 0.19 kg/s through the condenser. (Take the required values from saturated refrigerant-134a tables.) Determine the fraction of the refrigerant that evaporates as it is throttled to the flash chamber. (You must provide an answer before moving to the next part.) The fraction of the refrigerant that evaporates as it is throttled to the flash chamber is…
A two-stage compression refrigeration system operates with refrigerant-134a between the pressure limits of 1.4 MPa and 0.10 MPa. The refrigerant leaves the condenser as a saturated liquid and is throttled to a flash chamber operating at 0.6 MPa. he flash chamber is maintained at the same pressure as the low pressure discharge which is 0.6 Mpa. The vapor in the flash chamber is then compressed to the condenser pressure by the high-pressure compressor, and the liquid is throttled to the evaporator pressure. Assume the refrigerant leaves the evaporator as saturated vapor and both compressors are isentropic. Consider a mass flow rate of 0.19 kg/s through the condenser. (Take the required values from saturated refrigerant-134a tables.) Determine the coefficient of performance. The coefficient of performance is ______.
1. Consider a two-stage cascade refrigeration system operating between the pressure limits of 1.2 MPa and 200 kPa with refrigerant-134a as the working fluid.Heat rejection from the lower to the upper cycle takes place in a countercurrent adiabatic heat exchanger where the pressures in the upper and lower cycles are 0.4 and 0.5 MPa, respectively. In both cycles the refrigerant is a saturated liquid at the condenser outlet and a saturated vapor at the compressor inlet, and the isentropic efficiency of the compressor is 80 percent.The mass flow rate of the refrigerant in the lower cycle is 0.15 kg/s.Determine the following:a) the mass flow of the refrigerant through the upper cycle,b) the rate of removal from the refrigerated space andc) the COP of this refrigerator.d) Draw the T-s graph of the complete system and the diagram with all the components and processes of both cycles, indicate all the states in both cases (1, 2, 3….)