A refrigerator that operates on the ideal vapor-compression cycle with refrigerant-134a is to maintain the refrigerated space at -12°C while rejecting heat to the environment at 28°C. What are the reasonable evaporator and condenser pressures? (Take the required values from saturated refrigerant-134a tables.) The recommended evaporator pressure is MPa, and the condenser pressure is ________________MPa

A refrigerator that operates on the ideal vapor-compression cycle with refrigerant-134a is to maintain the refrigerated space at -12°C while rejecting heat to the environment at 28°C. What are the reasonable evaporator and condenser pressures? (Take the required values from saturated refrigerant-134a tables.) The recommended evaporator pressure is MPa, and the condenser pressure is ________________MPa

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

What are the approximate temperature ranges tor low-, medium-, and high-temperature refrigeration applications?
When a standard-efficiency air-cooled condenser is used, the condensing refrigerant will normally be higher in temperature than the entering air temperature.
The defrost cycle in a domestic refrigerator may be terminated by two methods: ___and___.
Problem 1 (Using thermodynamic tables)A large refrigeration plant is to be maintained at -12 C. It requires refrigeration at a rate of 120 kW.The condenser of the plant is to be cooled by liquid water, which experiences a temperature rise of 10 C as it flows over the coils of the condenser. Assuming the plant operates on the ideal vapor-compression cycle using refrigerant- 134a between the pressure limits of 100 and 700 kPa, determine (a) the mass flow rate of the refrigerant, (b) the power input to the compressor, and (c) the mass flow rate of the cooling water
. A steady-flow Carnot refrigeration cycle uses refrigerant-134a as the working fluid. The refrigerant changes from saturated vapor to saturated liquid at 608C in the condenser as it rejects heat. The evaporator pressure is 140 kPa. Show the cycle on a T-s diagram relative to saturation lines, and determine (a) the coefficient of performance, (b) the amount of heat absorbed from the refrigerated space, and (c) the net work input.
Why is the throttling valve not replaced by an isentropic turbine in the ideal vapor-compression refrigeration cycle?
A vapor-compression refrigeration cycle with refrigerant-134a as the working fluid operates between pressure limits of 240 and 1600 kPa. The isentropic efficiency of the compressor is 78%. Determine (a) the heat absorption in the evaporator, (b) the heat rejection in the condenser, (c) the work input, and (d) the COP
Consider a two-stage cascade refrigeration system operating between the pressure limits of 0.8 and 0.14 MPa. Each stage operates on the ideal vapor-compression refrigeration cycle with refrigerant-134a as the working fluid. Heat rejection from the lower cycle to the upper cycle takes place in an adiabatic counter-flow heat exchanger where both streams enter at about 0.4 MPa. If the mass flow rate of the refrigerant through the upper cycle is 0.24 kg/s, determine (a) the mass flow rate of the refrigerant through the lower cycle, (b) the rate of heat removal from the refrigerated space and the power input to the compressor, (c) the coefficient of performance of this cascade refrigerator, and (d) the intermediate pressure of the cascade cycle. For full credit, accurately, neatly draw the cascade system on an electronic PDF p-h diagram. Please only solve part d. If possible, show the ph diagram
A vapor-compression refrigeration cycle with refrigerant-134a as the working fluid operates between pressure limits of 240 and 1600 kPa. The isentropic efficiency of the compressor is 78%. The refrigerant is superheated by 5.4 °C at the compressor inlet and subcooled by 5.9 °C at the exit of the condenser. Determine (a) the heat absorption in the evaporator, (b) the heat rejection in the condenser, (c) the work input, and (d) the COP. (e) Also determine all parameters if the cycle operated on the ideal vapor-compression refrigeration cycle between the same pressure limits.
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….)
Consider a two-stage cascade refrigeration system operating between the pressure limits of 0.8 and 0.14 MPa. Each stage operates on the ideal vapor-compression refrigeration cycle with refrigerant-134a as the working fluid. Heat rejection from the lower cycle to the upper cycle takes place in an adiabatic counterflow heat exchanger where both streams enter at about 0.4 MPa. If the mass flow rate of the Refrigerant through the upper circle is 0.24 kg/s, determine (a)the mass flow rate of the refrigerant through the lower cycle, (b)the rate of heat removal from the refrigerated space and the power input to the compressor, and (c)the coefficient of performance of this cascade refrigerator. Answers: (a) 0.195 kg/s, (b) 34.2 kW, 7.63 kW, (c) 4.49
A R-134A vapor refrigeration cycle cycle operates at an evaporator temperature of 20 Celsius and a condensing temperature of 35 Celsius. Determine the coefficient performance for. Ideal saturation cycle. Wet compression with saturated vapor leaving the compressor . Suction to the compressor is superheated by 7 degrees Celsius. Using this table https://www.docdroid.net/VkxK8WH/refrigerant-134a-pdf