An R-12 standard refrigeration cycle operates at an evaporating pressure of 386 kPa and a condensing pressure of 1009 kPa. Show the effects of decreasing the vaporizing pressure to 270 kPa on the following: For a unit mass, (a) refrigerating effect, (b) COP, and (c) work. For a refrigerating capacity of 1 kW, (d) power, (e) mass flow rate

An R-12 standard refrigeration cycle operates at an evaporating pressure of 386 kPa and a condensing pressure of 1009 kPa. Show the effects of decreasing the vaporizing pressure to 270 kPa on the following: For a unit mass, (a) refrigerating effect, (b) COP, and (c) work. For a refrigerating capacity of 1 kW, (d) power, (e) mass flow rate

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?
Condensers in these refrigerators are all_______cooled.
When a standard-efficiency air-cooled condenser is used, the condensing refrigerant will normally be higher in temperature than the entering air temperature.
Why is truck refrigeration designed to provide low- and medium-temperature refrigeration?
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 using refrigerant 12 is to have a refrigerating capacity of 80 kW. The cycle is a standard vapor-compression cycle in which the evaporating temperature is -15°C and the condensing temperature 30°C. At the entrance to the evaporator, what is the fraction of vapor in the mixture expressed on a mass basis? 0.97 0.29 0.92 0.27
3. When subcooling the liquid refrigerant:a. the refrigerating effect per unit mass increases. b. the mass rate of flow per unit capacity decreases. c. the volume flow rate per unit capacity decreases. d. the work of compression per unit mass remain the same. e. the COP increases. f. the theoretical power per unit capacity decreases. A simple saturated refrigeration cycle for R-12 system operates at an evaporating temperature of - 5oC and condensing temperature of 40oC. Show the effect from a to f if the liquid refrigerant is subcooled to 30 oC.
A Freon 12 vapour compression system operating at a condenser temperature of 45oC and an evaporator temperature of 5oC develops 10 tons of refrigeration. Using the p-h diagram for Freon 12, determine. (a) the discharge temperature and mass flow rate of the refrigerant circulated. (b) the theoritical piston displacement of the compressor and piston displacement per ton of refrigeration, (c) the theoritical horsepower of the compressor and horsepower per ton of refrigeration, (d) the heat rejected in the condensor, (e) the carnot COP and the actual COP of the cycle
An R-12 refrigeration system using a single compressor serves three evaporators of 50, 30 and 20 tons capacity in parallel to each other with an evaporating temperatures of 0 C(hg = 351.447 KJ/kg), -5 C(hg = 349.321 KJ/kg) and -10 C(hg = 347.134 KJ/kg), respectively. If the condenser is maintained at 40 C(hf = 238.535 KJ/kg), compute the COP of the system. Enthalpy at the end of compression is at 378 KJ/kg.
The values of a vapor compression refrigeration cycle were given below. Calculate the values ofrefrigerant flow rate, refrigeration capacity, and the COP of the system.T1= Evaporator water outlet = 10 °CT2= Evaporator water inlet = 16 °CT3= Condenser water inlet = 16 °CT4= Condenser water outlet = 22°CCooling water flow rate = 1.5 L/minHeating water flow rate = 1.5 L/minEnthalpy of R134a in evaporator outlet = 305 kj/kg,Enthalpy of R134a in evaporator inlet =115 kj/kgEnthalpy of R134a in condenser inlet =327 kj/kg
A standard vapor compression system produces 20 tons of refrigeration using r-12 while operating between a condenser temperature of 45 deg-C and an evaporator temperature of -25 deg-C. Determine the refrigerating effect per unit of refrigerant, circulation rate in kg/s, power supplied, COP, heat rejected in kW, the volume flow rate in L/s, and temperature at the compressor discharge. Please answer completely.
In a CO2 refrigerating plant, the specific enthalpy of the refrigerant as it leaves in the condenser is 135 kJ/kg and as it leaves the evaporator it is 320 kJ/kg. If the mass flow of the refrigerant is 5 kg/min, calculate the refrigerating effect per hour.