Question

R-134a enters the compressor of a refrigerator as superheated vapour at 0.14 MPa, -10 °C at...

R-134a enters the compressor of a refrigerator as superheated vapour at 0.14 MPa, -10 °C at a rate of 0.12 kg/s, and it leaves at 0.7 MPa and 50 °C.
The refrigerant is cooled in the condenser to 24 °C and 0.65 MPa, and it is throttled to 0.15 MPa.
Disregard 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
(a) the rate of heat removal from the refrigerated space and the power input to the compressor,
(b) the isentropic efficiency of the compressor
(c) the COP of the refrigerator

A company claims they can raise the COP of the refrigerator to 4.8 by reducing heat transfer and pressure drops in the compressor only.
(d) Show if it is possible by calculation

Homework Answers

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Regarding a Vapor-Compression cycle: A refrigerant (HCFC-22) enters the compressor of a refrigerator as a superheated...
Regarding a Vapor-Compression cycle: A refrigerant (HCFC-22) enters the compressor of a refrigerator as a superheated vapor at .14MPa and -20 degrees Celsius at a rate of .05 kg/s and leaves at .8 MPa and 50 degrees Celsius. The refrigerant is cooled in the condenser to 26 degrees Celsius and .72MPa and is then throttled down to .15 MPa. Determine the rate of heat removal from the refrigerated space and the power input to the compressor and the Coefficient of...
A commercial refrigerator with refrigerant R-134a as the working fluid is used to keep the refrigerated...
A commercial refrigerator with refrigerant R-134a as the working fluid is used to keep the refrigerated space at -30 C by rejecting its waste heat to cooling water that enters the condenser at 18 C at a rate of 0.25 kg/s and leaves at 26 C. The refrigerant enters the condenser at 1.2 MPa and 65 C and leaves at 42 C. The inlet state of the compressor is 60 kPa and -34 C and the compressor is estimated to...
Consider a commercial refrigerator which operates on the refrigeration cycle. R- 134a is used as the...
Consider a commercial refrigerator which operates on the refrigeration cycle. R- 134a is used as the working uid and the refrigerated space is kept at -25oC by rejecting its waste heat to cooling water that enters the condenser at room temperature, that is 20oC, at a rate of 0.1 kg/s and leaves at 40oC. The refrigerant enters the condenser at 1.2 MPa and 70oC and leaves at 40oC. The inlet state of the compressor is saturated vapor at 100 kPa...
A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space...
A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at −30°C by rejecting its waste heat to cooling water that enters the condenser at 18°C at a rate of 0.32 kg/s and leaves at 26°C. The refrigerant enters the condenser at 1.2 MPa and 65°C and leaves at 42°C. The inlet state of the compressor is 60 kPa and −34°C and the compressor is estimated to gain a net heat of 460 W...
Consider a single-stage refrigeration system operating between the pressure limits of 1.4 MPa and 160 kPa...
Consider a single-stage refrigeration system operating between the pressure limits of 1.4 MPa and 160 kPa with refrigerant R134a as the working fluid. The refrigerant is a saturated liquid at the condenser exit and a saturated vapor at the compressor inlet. The isentropic efficiency for the compressor is 80 percent. If the mass flow rate of the refrigerant through the cycle is 0.11 kg/s determine (a) the rate of heat removal from the refrigerated space, and (b) the coefficient of...
- a vapour-compression air-conditioning cycle where the compressor has an isentropic efficiency of 75%. Refrigerant (R12)...
- a vapour-compression air-conditioning cycle where the compressor has an isentropic efficiency of 75%. Refrigerant (R12) is used as the working fluid with a mass now rate of 0.04kg/s. saturated vapour eaters the compressor at 0.5 MPa and leaves to the condenser at 1.2IMPa. The air-conditioner cools down the station to 26°C through an evaporator, and rejects heat to the 34°C ambient through a condenser. (a) Sketch and label the schematic of the air-conditioning cycle and its T-S and P-h...
A cooling plant adopted a two-stage cascade refrigeration system to meet the required cooling load. In...
A cooling plant adopted a two-stage cascade refrigeration system to meet the required cooling load. In both upper and lower cycles, the refrigerant leaves condenser as saturated liquid and enters compressor as saturated vapor. The isentropic efficiency of the upper cycle compressor is 80 %, while the lower cycle compressor is 70% efficient. The pressure limits of the upper and lower cycles are 1 MPa and 0.2 MPa with refrigerant-134a, respectively. Heat rejection from the lower cycle to the upper...
Refrigerant 134a is the working fluid in a vapor-compression heat pump system with a heating capacity...
Refrigerant 134a is the working fluid in a vapor-compression heat pump system with a heating capacity of 60,000 Btu/h. The condenser operates at 240 lbf/in.2, and the evaporator temperature is 0°F. The refrigerant is a saturated vapor at the evaporator exit and a liquid at 110°F at the condenser exit. Pressure drops in the flows through the evaporator and condenser are negligible. The compression process is adiabatic, and the temperature at the compressor exit is 180°F. Determine (a) the mass...
A condenser is essentially a type of heat exchanger that is used to remove heat from...
A condenser is essentially a type of heat exchanger that is used to remove heat from a vapor and convert it to liquid. The picture below shows a condenser that is used in a commercial refrigerator with refrigerant-134a as the working fluid. Water enters the condenser at 18ºC at a rate of 0.25 kg/s and leaves at 26ºC. The refrigerant enters the condenser at 1.2 MPa and 50ºC and leaves at the same pressure but at T=41.3ºC. a) Find the...
A vapor-compression refrigeration cycle operates at steady state with Refrigerant 134a as the working fluid. Saturated...
A vapor-compression refrigeration cycle operates at steady state with Refrigerant 134a as the working fluid. Saturated vapor enters the compressor at 2 bar, and saturated liquid exits the condenser at 8 bar. The isentropic compressor efficiency is 80%. The mass flow rate of refrigerant is 7 kg/min. Determine: (a) the compressor power, in kW, (b) the refrigeration capacity, in tons, (1 ton = 3.5168 kW) and, (c) the coefficient of performance, (d) rate of entropy production in kW/K, for the...