Consider a two-stage cascade refrigeration system in Figure 3.1 operating between the pressure limits of F MPa and 200 kPa with refrigerant R-134a as the working fluid. Heat rejection from the lower cycle to the upper cycle takes place in adiabatic heat exchanger where the pressure in the upper and lower cycles are 0.5 and 0.4 MPa, respectively. In both cycles, the refrigerant is a saturated liquid at the condenser exit and a saturated vapor at the compressor inlet, and the isentropic efficiency of the compressor is G %. If the mass flow rate of the refrigerant through the lower cycle is 'H kg/s, answer the following questions: (a) Draw the T-s diagram for this refrigeration cycle (b) The mass flow rate of the refrigerant through the upper cycle (c) The coefficient of performance (COP) of this refrigerator

Consider a two-stage cascade refrigeration system in Figure 3.1 operating between the pressure limits of F MPa and 200 kPa with refrigerant R-134a as the working fluid. Heat rejection from the lower cycle to the upper cycle takes place in adiabatic heat exchanger where the pressure in the upper and lower cycles are 0.5 and 0.4 MPa, respectively. In both cycles, the refrigerant is a saturated liquid at the condenser exit and a saturated vapor at the compressor inlet, and the isentropic efficiency of the compressor is G %. If the mass flow rate of the refrigerant through the lower cycle is 'H kg/s, answer the following questions: (a) Draw the T-s diagram for this refrigeration cycle (b) The mass flow rate of the refrigerant through the upper cycle (c) The coefficient of performance (COP) of this refrigerator

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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Refrigerators currently being manufactured in the United States are using______as their refrigerant.
The operating condition for the single compressor in a household refrigerator is the lowest box temperature, which is typically A. 0F B. -20F C. 20F D. 40F
Condensers in these refrigerators are all_______cooled.
Referring to Problem 1.74, how many kilograms of ice can a 3-ton refrigeration unit produce in a 24-h period? The heat of fusion of water is 330 kJ/kg.
A refrigeration system operated on an ideal vapor-compression using R-12 with a vaporizing temperature of -10 degrees Celsius and a condensing temperature of 30 degrees Celsius, it requires 15 hp to drive the motor of the compressor. Find the ff: Enthalpies at each point of the cycle in kJ/kg Refrigerating Capacity in TOR • Mass of the Refrigerant in kg/s Percent Quality in the mixture Heat Rejected in kW Coefficient of Performance • Schematic and P-h Diagram
please answers fasterrr An ice-making machine in Restoran Syed operates on the vapor-compression refrigeration cycle. Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.13MPa and a °C at a rate of 0.13kg/s, and it leaves at 0.7 MPa and b °C. The refrigerantis cooled in the condenser to c°C and dMPa, and it is throttled to 0.14MPa. Disregarding any heat transfer and pressure drops in the connecting lines between the components, show the cycle on a T-s diagram with respect to saturation lines, and determine;i.the rate of heat removal from the refrigerated space,ii.the power input to the compressor, iii.the isentropic efficiency of the compressor, and iv.the COP of the refrigerator.v.if the compressor has no irreversibility, how about the COP?vi.Justify the difference between ideal and actual cycles. a= -8 b= 49 c= 25 d= 670
Step: Evaluate the performance of Refrigerator 2.Refrigerator 2 is a refrigerator that operates as an ideal vapor refrigeration cycle, and uses theSame refrigerant and evaporation and condensing temperatures as Refrigerator 1.In Cooler 2, the working fluid must be admitted by the compressor only in the form of vaporsaturated, and must leave the compressor in the form of superheated steam with enthalpy equal to 1640 kJ/kg.Differently from Refrigerator 1, the cycle operates with an expansion valve (isenthalpic process).For this 2nd step, you must determine the following design parameters:a) The rate of cooling and the rate of heat rejection in the condenser.b) The power of the compressor;c) The COP of the cycle.For the energy balance, make the following considerations:- Permanent regime;- Variation of kinetic and potential energy are negligible;- Compressor and expansion valve operate adiabatically;- Evaporation and condensation steps do not involve work. Please, make it typeable,…
E Expert Q&A Show the heat pump that operates on the ideal vapor-compression refrigeration cycle, with refrigerant-134a as the working fluid, on T-s diagram as in Figure (1). T House Он 1.4 MPa Win 320 kPa 4 step: 2 of 8 For the given ideal vapor-compression refrigeration cycle, with refrigerant-134a as the working fluid,specific entropy, specific enthalpy, pressure, and specific volumeat state are $i, ", , and Virespectively. Also, the saturated liquid state is denoted by the subscript f, the saturated vapor is denoted by the subscript g, and the properties at latent stage are denoted by the subscript fg. th step: 3 of 8 (a) Use â€œsaturated refrigerant-134a 00 00 Tools 88 Home Courses 2.
(a) Figure 3 shows a refrigeration system using Refrigerant-134a as the refrigerant has a compressor that consumes 800 W of power when operational. The refrigerant enters the evaporator at 100 kPa as saturated mixture of quality 25% and leaves the condenser the same pressure as at a temperature of -26°C. Determine the rate of heat rejected (Q.) at the condenser and the COP of the refrigerator. The mass flow rate of the refrigerant is 0.005 kg/s. condenser expansion compressor valve evaporator Figure 3: Refrigeration system (b) After graduation, you decided to work overseas to experience living in a country with four seasons. Your neighbour, knowing that you are an engineer asked your help to install a heat pump system for his house. He wanted to always maintain the temperature in his house at 24°C during winter. In that area during winters, average outside temperature is -3°C. He also has an underground water well with average water temperature of 10°C during winter. You estimated that…
1.A vapor-compression refrigeration system, using R-134a, is being used to keep a food storage room under desired cold temperature. At steady state conditions, the evaporator temperature is 0°C, and the condenser temperature is 48°C. The cooling load on the refrigeration system is 8 tons of refrigeration. Calculate the refrigerant flow rate, the compressor power if the compressor efficiency is 78%, and C.O.P.
2. An ideal refrigeration cycle that has a condenser temperature of 25°C and an evaporator temperature of -25°C. Compute for the work input to the compressor, heat absorbed by the evaporator from the cold space, heat released to the hot space, and the COP of this refrigerator for the working fluid R-410a. Equations: Efficiency of a turbine: W,(actual) H2.actual – H1 W,(isentropic) H2.isentropic - H, Efficiency of a compressor: W,(isentropic) H2isentropic – H1 = W,(actual) H2actual – H1 Rankine cycle efficiency: Wnet_ |Wturbinel - |Wpump| Qboiler COP of a refrigerator: Q¿(heat absorbed from cold space) B Wc(work input to the compressor) Thermodynamic tables: Water Van Ness – Page 681 Sonntag – Page 776 R-134a Sonntag – Page 810
Refrigerant 22 is the working fluid in a Carnot vapor refrigeration cycle for which the evaporator temperature is -30°C. Saturated vapor enters the condenser at 36°C, and saturated liquid exits at the same temperature. The mass flow rate of refrigerant is 10 kg/min. Determine the rate of heat transfer to the refrigerant passing through the evaporator, in kW,