O. The vapor compression cycle 1-2-3-4-1 operates at evaporating temperature of 270K and condensing temperature of 326 K, as shown in the p-h diagram below, where the subcooling and superheating are 1918612 尔 5K, respectively. The compressor efficiency h. = 0.8, the refrigerant is R-134a, and the refrigeration 1918612 19186124 1918612 amount is 10 kW. Determine the required mass flow rate, the heat rejection by the condenser, and the system 1918612 1918612 СР. 1918612 1918612 1918612 19186124 3 326K S=const 2 特米尔 270K 191861242 特米尔 191861242 特米尔 191861242 Pressure

O. The vapor compression cycle 1-2-3-4-1 operates at evaporating temperature of 270K and condensing temperature of 326 K, as shown in the p-h diagram below, where the subcooling and superheating are 1918612 尔 5K, respectively. The compressor efficiency h. = 0.8, the refrigerant is R-134a, and the refrigeration 1918612 19186124 1918612 amount is 10 kW. Determine the required mass flow rate, the heat rejection by the condenser, and the system 1918612 1918612 СР. 1918612 1918612 1918612 19186124 3 326K S=const 2 特米尔 270K 191861242 特米尔 191861242 特米尔 191861242 Pressure

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?

See similar textbooks

Similar questions

Refrigerators currently being manufactured in the United States are using______as their refrigerant.
For the NH3/H2O cycle the following relationship give the solution flow rate per unit refrigeration rate: WFS_A * X - WFS_G(X-1) = 1 whereWFS_A = mass fraction of NH3 in solution form the absorberWFS_G = mass fraction of NH3 in solution from the generator X-1 =mass of solution from the generator per unit mass of refrigerant flowFor large systems, a reasonable pressure drop between the evaporator and absorber is 1.5 psiConsider a large NH3/H2O plant operating per the schematic below: Known/given:i. Refrigeration load = 500 tonsii. Evaporator temperature (state point 10) = 41.1 Fiii. Evaporator pressure (state point 10) = 75 psiaiv. Absorber pressure (state point 11) = 73.5 psia (per rule of thumb above regarding pressure drop between the evaporator and absorber)v. Strong aqua solution temperature (state point 3) = 105 Fvi. Condenser temperature (state point 8) = 100 Fvii. Condenser and tower pressure (state point 7) = 211.9 psiaviii. Concentration split, WFS_G - WFS_A =6% by weight…
Air enters the compressor of an ideal Brayton refrigeration cycle at 100 kPa, 270 K. The compressor pressure ratio is 3 and the temperature at the turbine inlet is 310 K. Determine:d).the coefficient of performance of a Carnot refrigeration cycle operating between thermal reservoirs at TC 270 K and TH 310 K, respectively. The above Brayton refrigeration cycle is modified by introducing a regenerative heat exchanger. In the modified cycle, the compressed air enters the regenerative heat exchanger at 310 K and is cooled to 280 K before entering the turbine. Determine for the modified cycle:(e).the lowest temperature, in K.f).the net work input per unit mass of air flow, in kJ / kg.
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 closed-cycle gas turbine plant consists of a compressor, a heat exchanger, a heater, a two-stage turbine with reheater, and a cooler. The maximum and minimum pressures and temperature in the cycle are 30 bar and 570oC, and 7.5 bar and 15oC. The pressure in the reheater is 15 bar. Sketch the layout of the plant and indicate pressures and temperaturesbetween the components if (a) the heat exchanger is used, (b) the heat exchanger by-passed.Calculate the ideal cycle efficiencies and work ratios in both cases. The gas used in the circuit is helium, which has a molar mass of 4 kg/kmol and cp=1.5 R
Air enters the compressor of an ideal gas refrigeration cycle at 12°C and 50 kPa and the turbine at 47°C and 250 kPa. The mass flow rate of air through the cycle is 0.08 kg/s. Assuming variable specific heats for air, determine (a) the rate of refrigeration, (b) the net power input, and (c) the coefficient of performance.
A 105 x 205 mm reciprocating R134a compressor operates with a suction pressure of 0.2928 MPa and a condenserpressure of 1.2 MPa. The cycle frequency is 23 cps. The evaporator load is 12.8 tons. The mechanical efficiency ofcompressor is 75%. The clearance volume of compressor is 5% (a) Draw the ph Diagram and Refrigeration System Diagram(b) enthalpy and temperature of superheated vapor (show interpolation)(c) mass of flash vapor entering evaporator, kg vapor/kg refrigerant(d) mass of refrigerant recirculated, kg/s(e) condenser load, kW(f) volume capacity of isentropic compressor at suction, L/s(g) volume displacement of compressor, L/s(h) actual volumetric efficiency, %(i) clearance volumetric efficiency(j) power requirement of isentropic compressor, kW(k) coefficient of performance(l) brake power output of electric motor, kW to drive isentropic compressor(m) power requirement of polytropic compressor, kW for compression efficiency of 80%
Refrigerant R12 is used in a vapour compression cycle. The saturated vapour entersthe compressor at -18.8°C, and subsequently leaves at 75°C and 10 bar. Thesaturated liquid leaving the condenser is at 10 bar. The resulting stream is throttledand evaporated before being fed back to the compressor. a) Determine the coefficient of performance of the refrigerator. Take the specific enthalpy,h, at 10 bar and 36 K of superheat to be 163.7 kJ/kgb) Obtain the isentropic efficiency of the compressor. Take the specific entropy, s, at 10bar to be 1.188 kJ/kg
A simple vapor compression cycle develops 15 tons of refrigeration using ammonia as refrigerant and operating at condensing temperature of 24 C and evaporating temperature of -18C and assuming compression are isentropic and that the gas leaving the condenser is saturated, find the power per ton. Properties of Ammonia: h1=hf = 312.87 kJ/kg h2= 1665 kJ/kg At -18C hg = 1439.94 kJ/kg
Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.22 MPa and 27 C at a rate of 0.07 kg/s, and it leaves at 1.2 MPa and 73°C. The refrigerant is cooled in the condenser to 44°C and 1.16 MPa, and t is throttied to 0.21 MPa. 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 (a) the rate of heat removal from the refrigerated space and the power input to the compressor, (b) the isentropic efficiency of the compressor, and (c) the COP of the refrigerator.
Please help!!!! Refrigerant 22 enters the compressor of an ideal vapor-compression refrigeration system as saturated vapor at -30°C with a volumetric flow rate of 10 m3/min. The refrigerant leaves the condenser at 19°C, 9 bar. Determine: (a) the magnitude of the compressor power, in kW. (b) the refrigerating capacity, in tons. (c) the coefficient of performance. (d) the rate of entropy production for the cycle, in kW/K. Answer for part (a): 52 kW Answer for part (b): 59 tons Answer for part (c): 3.98 Please answer part also d! That's the part I also need. Thank you!
Refrigerant 134a is the working fluid in a vapor compression heat pump that provides 35 kW heat to a dwelling. Saturated vapor enters the compressor at 1.6 bar, and saturated liquid exits the condenser, which operates at 8 bars. Isentropic efficiency of the compressor is 75%. The pressure drops across the condenser and evaporator can be neglected. Kinetic and potential energy changes are negligible. a) Determine the compressor power, in kW b) Determine the coefficient of performance (COP) c) Draw the processes in a T-s diagram