Question

In: Other

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 throttling valve is heated at constant pressure until it is 100% saturated vapour. [The evaporator]

The flow rate of refrigerant in this cycle is 0.1 kg s^-1. For this cycle do the following:

(a) Plot the cycle on the attached P-h chart for RF-134a.

(b) Calculate the power input to the compressor in kW.

(c) Calculate the heat transferred to the environment in the condenser in kW.

(d) Calculate the coefficient of performance (as a refrigerator) for the cycle. (5marks)

Total = 20 marks

Note: Use the attached P-H chart for R-134a as your data source.

1 kg = 2.21 lbm

1 J = 9.48*10^-4 Btu

1 bar = 10⁵ Pa = 14.5 psia

Expert Solution

Amanda K answered 5 months ago

An ideal refrigeration cycle utilizes R-134a as a working fluid. If the fluid enters the compressor...

An ideal refrigeration cycle utilizes R-134a as a working fluid. If the fluid enters the compressor as saturated vapor at 6 C and enters a throttling valve as a saturated liquid at 1.2MPa. Assuming the mass flow rate of fluid is 1 kg/sec. 1. The heat received by the fluid (kJ) is 2. The heat received by the surroundings (kJ) is 3. The power input to the compressor (kJ) is 4. The coefficient of performance is

Consider a vapour compression refrigeration cycle that uses R-134a as refrigerant. The R-134a enter

Consider a vapour compression refrigeration cycle that uses R-134a as refrigerant. The R-134a enters the compressor as a saturated vapour at 200 kPa, and exits the condenser as a saturated liquid at 900 kPa. The rate of refrigeration of the cycle is to be 6.0 tons of refrigeration (1 ton of refrigeration = 3.517 kW). The compressor isentropic efficiency is 80%. Determine: a) The temperature of evaporation and condensation of the refrigerant; b) Mass flow of the refrigerant R-134a, in ...

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...

A steady-flow Carnot refrigeration cycle uses refrigerant-134a as the working fluid. The refrigerant changes from saturated...

A steady-flow Carnot refrigeration cycle uses refrigerant-134a as the working fluid. The refrigerant changes from saturated vapor to saturated liquid at 40 C in the condenser as it rejects heat. The evaporator pressure is 120 kPa. Determine: (a) the amount of heat absorbed from the refrigerated space; qL = _______________ kJ/kg (b) the net work input; and wnet = ______________ kJ/kg (c) the coefficient of performance of the system. COP = _____________

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 ?

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 10 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. (c) the coefficient of performance.

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 gas refrigeration cycle with a pressure ratio of 4.3 uses helium as the working fluid....

A gas refrigeration cycle with a pressure ratio of 4.3 uses helium as the working fluid. The temperature of the helium is 26°C at the compressor inlet and 50°C at the turbine inlet. Assuming isentropic efficiencies of 87 percent for both the turbine and the compressor, determine (a) the minimum temperature in the cycle, (b) the coefficient of performance, and (c) the mass flow rate of the helium for a refrigeration rate of 20 kW. ans a)198.76 b)0.574 c)0.0564. Can...

A gas refrigeration cycle with a pressure ratio of 4 uses helium as the working fluid....

A gas refrigeration cycle with a pressure ratio of 4 uses helium as the working fluid. The temperature of the helium is -6°C at the compressor inlet and 50°C at the turbine inlet. Assume isentropic efficiencies of 88 percent for both the turbine and the compressor. (Given: The properties of helium are cp= 5.1926 kJ/kg·K and k = 1.667.) FIND: a. The minimum temperature of the cycle. b. The coefficient of performance. c. the mass flow rate of the helium.

An ideal Rankine Cycle with reheat uses water as the working fluid with a flow rate...

An ideal Rankine Cycle with reheat uses water as the working fluid with a flow rate of 0.15 kg/s. At the inlet of the turbine (state 1) the water is a superheated vapor at 475ºC and 11 MPa. The pressure at the exit of the first stage of the turbine is 0.9 MPa. The reheat temperature (state 3) is also 475ºC. The condenser pressure is 8 kPa, and the water exits as a saturated liquid Find: (a) The heat addition to...