Question

In: Mechanical Engineering

An air conditioner using R134a as the working fluid operates on an ideal vapour compression system...

  1. An air conditioner using R134a as the working fluid operates on an ideal vapour compression system between 0.3 and 0.8 MPa. If the specified capacity for air conditioning is 20 kW. What would be its capacity for food freezing for which the evaporator temperature -20oC. Show the cycle on a PH diagram and explain the effect of the changes to the compressor and condenser respectively.

Solutions

Expert Solution


Related Solutions

An air conditioner using refrigerant-134a as the working fluid and operating on the ideal vapor-compression refrigeration...
An air conditioner using refrigerant-134a as the working fluid and operating on the ideal vapor-compression refrigeration cycle is to maintain a space at 30°C while operating its condenser at 1000 kPa. Determine the COP of the system when a temperature difference of 2°C is allowed for the transfer of heat in the evaporator. (Take the required values from saturated refrigerant-134a tables.) The COP of the system is ?
An ideal vapor compression refrigeration cycle with R134a as the working fluid operates between the pressure...
An ideal vapor compression refrigeration cycle with R134a as the working fluid operates between the pressure limits of 200 kPa and 1200 kPa. Determine a) the mass fraction of the refrigerant that is in the liquid phase at the inlet of the evaporator, and b) the amount of heat transfer (in kJ/kg) to the refrigerant in the evaporator (??).
a refrigerator uses refrigerant 134a as a working fluid and operates on the vapour -compression refrigiration...
a refrigerator uses refrigerant 134a as a working fluid and operates on the vapour -compression refrigiration cycle.the evaporator is maintained at -100C and the refrigirant is a dry saturated vapour as it leaves the evaporator. the compressor has an efficiency of 80%.the conditions at the outlet of the condensor are 300C and 9 bar. 1-if the mass flow rate of the refrigerant is 0,08kg/s workout the rate of heat removal from the refrigerant space.the power input to the cpmpressor and...
An ideal diesel engine uses air as the working fluid and operates with a thermal efficiency...
An ideal diesel engine uses air as the working fluid and operates with a thermal efficiency ?th =0.5 with a rate of heat addition Qin=120 kW. The temperature at the beginning and the end of the addition heat (combustion) are respectively: T2=900 K and T3=2100 K. Assume constant specific heats (Cp and Cv). The air properties at a room temperature T1=293.0 K are: Cp=1.005 kJ/kg.K, Cv=0.718KJ/kg.K, the gas constant of air is R=0.287 kJ/kg.K and the ratio of specific heats...
An ideal vapor compression refrigeration cycle using r134a as the refrigerant is being used to cool...
An ideal vapor compression refrigeration cycle using r134a as the refrigerant is being used to cool a house. It provides 3 refrigeration tons ≈ 10.5kW of cooling (heat removal from the house air). The refrigerant in the evaporator operates at 400kPa while in the condenser it is at 1000kPa. Treat the surroundings as a thermal reservoir at 33◦C and the air in the house as a thermal reservoir at 19◦C. All reservoirs are at 100kPa. 1. What is the COPr...
An ideal vapour refrigeration cycle uses RF-134a as the working fluid and consists of the following...
An ideal vapour refrigeration cycle uses RF-134a as the working fluid and consists of the following steps: (i)        Saturated vapour at 20 psia is compressed adiabatically and reversibly to a pressure of 120 psia. [The compressor] (ii)       The vapour is cooled and condensed at constant pressure, leaving the condenser as a saturated liquid. [The condenser] (iii)      The saturated liquid is expanded through a throttling valve to a pressure of 20 psia. [The throttling valve] (iv)      The liquid-vapour mixture leaving the...
An Otto Cycle has air operating as the working fluid. The air begins the compression process...
An Otto Cycle has air operating as the working fluid. The air begins the compression process at 90 kPa and 40oC. During the heat addition process, the maximum temperature of the air (T3) is 2000oC. The compression ratio of the cycle is 9.2. Treating this as a “Hot Air Standard Cycle”, determine the temperature and pressure at the end of each process, the net work per kg of air produced in the cycle, the thermal efficiency of the cycle, and...
An ideal diesel engine has a compression ratio of 20 and uses air as the working...
An ideal diesel engine has a compression ratio of 20 and uses air as the working fluid. The state of air at the beginning of the compression process is 95 kPa and 200C. If the maximum temperature in the cycle is not to exceed 2200 K, Determine: a) The thermal efficiency, and b) The mean effective pressure, and Assume constant specific heats for air at room temperature.
An ideal diesel engine has a compression ratio of 20 and uses air as the working...
An ideal diesel engine has a compression ratio of 20 and uses air as the working fluid. The state of air at the beginning of the compressor process is 100 kpa and 27 C. The maximum temperature in the cycle is 2200 K and the cutoff ratio is 1.2 Determine the following: The internal energies at the beginning and the end of the compression The enthalpy before and end of the combustion The internal energy before and end of the...
An ideal Otto engine has a compression ratio of 10 and uses air as the working...
An ideal Otto engine has a compression ratio of 10 and uses air as the working fluid. The state of air at the beginning of the compression process is 100 kPa and 27 0C. The maximum temperature in the cycle is 2100K. (R=0.287 for air) (using variable specific heat) Draw the P-v diagram of the Otto cycle Determine the specific internal energies at the beginning and the end of the compression, Determine the specific internal energies before and after the...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT