Q2. Consider a 300 kJ/min refrigeration system that operates on an ideal vapor-compression refrigeration cycle with refrigerant-134a as the working fluid. The refrigerant enters the compressor as saturated vapor at 140 kPa and is compressed to 800 kPa. Show the cycle on a T-s diagram with respect to saturation lines and determine (a) the quality of the refrigerant at the end of the throttling process, (b) the coefficient of performance, and (c) the power input to the compressor. Solve this question using both tables and P-h chart

Q2. Consider a 300 kJ/min refrigeration system that operates on an ideal vapor-compression refrigeration cycle with refrigerant-134a as the working fluid. The refrigerant enters the compressor as saturated vapor at 140 kPa and is compressed to 800 kPa. Show the cycle on a T-s diagram with respect to saturation lines and determine (a) the quality of the refrigerant at the end of the throttling process, (b) the coefficient of performance, and (c) the power input to the compressor. Solve this question using both tables and P-h chart

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

Chapter28: Special Refrigeration Applications

Section: Chapter Questions

Problem 15RQ: Why is two-stage compression popular for extra-low-temperature refrigeration systems?

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Condensers in these refrigerators are all_______cooled.
a) A freezer working on an ideal vapour-compression refrigeration cycle uses refrigerant R- 134a with a mass flow rate of 0.10 kg/s. The refrigerant leaves the evaporator as saturated vapour at a temperature of -8 °C. It leaves the condenser as saturated liquid at a pressure of 0.8 MPa. Determine the power required to drive the compressor. Note that the thermodynamic properties of R-134a are attached at the end of the paper. 0.8 MPa A Figure Q4 b) A freezer wall is made of a composite material with a thickness of 20 mm and a conductivity of 0.03 W/m-K. Air temperatures inside and outside the freezer are -6 °C and 20 °C, respectively. The convection coefficient is 2 W/m² K on both the inner and outer surfaces of the freezer wall. Determine the heat flux through the freezer wall. -8 C
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you design a custom refrigeration system using 1,1,2-tetrafluoroethane (R-134a) as refrigerant.You design your ideal compression-based refrigeration cycle to operate between 2 bar and 9 bar. Before enteringthe ideal butterfly valve (delta H = 0), the refrigerant is a saturated liquid. Before entering the compressor, therefrigerant is saturated vapor. In fact, in isentropic operation, the refrigerant which leaves the compressor is alsosaturated vapor. The operation of the compressor and the evaporator is isobaric. Assuming a mass flow rate of1.5 kg / s, determine the compressor efficiency required to achieve a coefficient of performance of 6.96. Whatis ?? ̇ et ?? ̇ to this performance.
A vapor-compression refrigeration system circulates R-134a at a rate (m_dot) of 10 kg/min . The refrigerant enters the compressor at -10 ∘C∘C, 1.2 bar and exits at 7 bar. The isentropic compressor efficiency is 68%. There are no significant pressure drops as the refrigerant flows through the condenser and evaporator. The refrigerant leaves the condenser at 7 bar and 24 ∘C. Ignore the heat transfer between the compressor and its surroundings. (Figure 1) Part A. Determine the coefficient of performance (COPR) Part B. Determine the refrigerating capacity Part C. a. Determine the irreversibility rates of the compressor for an ambient temperature of 20 ∘C b. Determine the irreversibility rates of the expansion valve for an ambient temperature of 20 ∘C
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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
Q1: A gas refrigeration system using air as the working fluid has a pressure ratio of 5 (see Fig. Q 1). Air enters the compressor at 0°C. The high-pressure air is cooled to C 35o by rejecting heat to the surroundings. The refrigerant leaves the turbine at C 80o and enters the refrigerated space where it absorbs heat before entering the regenerator. The mass flow rate of air is kg/s 4. 0 . Assuming isentropic efficiencies of 8 .0 for the compressor and 85 .0 for the turbine and variable specific heats. Draw accurately the cycle on a T-s diagram with properly labelled property values. Determine (a) the effectiveness of the regenerator, (b) the rate of heat removal from the refrigerated space, (c) the COP of the cycle. Also, determine (d) the refrigeration load and the COP if this system operated on the simple gas refrigeration cycle. Use the same compressor inlet temperature as given, the same turbine inlet temperature as calculated, and the same compressor and turbine efficiencies.…
can u explaine fast please
A two-stage refrigeration system operates with ammonia refrigerant flowing at the rate of 15 kg/min through the evaporator. The saturation temperature in the condenser and evaporator units have been noted to be 40⁰C and - 15⁰C respectively. If the system has intercooling by liquid refrigerant at 4.25 bar, determine (a) The capacity and COP of the system. (b) How will these parameters be affected if the compression is carried out in a single stage unit ; the operating temperature limits remaining the same? Use the p-h chart and property tables for saturated ammonia refrigerant
can u explaine fast please
can u explaine fast please