
A fridge uses R-134a in its compression cycle. The R-134a enters the valve at 80F° in...
An ideal vapor-compression refrigeration cycle that uses refrigerant R-134a as its working fluid maintains a condenser at 800 kPa and the evaporator at -12C. (a) Determine this system's COP and the amount of power required to service a 150kW cooling load. (b) Determine the P,T, h, S and exergy of R-134a at all four states of the entire cycle. Assume the ambient temperature to be 25C.
Problem I: Not applicable for 2017 Problem II: In an R-134a vapor-compression home heat pump, R-134A enters the compressor (75% isentropic efficiency) as a saturated vapor at 200 kPa and leaves at 800 kPa. The refrigerant goes through a constant pressure condenser and leaves as a saturated liquid. The refrigerant then goes through an adiabatic expansion valve enters the evaporator as a liquid-vapor mixture. The mass flow rate of refrigerant is 0.1 kg/s. and Cod A. Write the equation for...
3) A vapor-compression refrigerator uses refrigerant-134a. Superheated vapor enters the compressor at 100 kPa and -20° C, and exits at 1 MPa and 60° C. The refrigerant is cooled to 35° C in the condenser and then expands back to 100 kPa through an expansion valve. Neglect pressure losses within the condenser and evaporator. The refrigerant flow rate is 0.10 kg/s. Calculate the following a) the rate of heat removal from the cooled space, in kw, b) the rate of...
An ideal vapor-compression refrigeration cycle with R-134a as the working fluid has an evaporator temperature of-15 °C and a condenser pressure of 12 bar. Saturated vapor enters the compressor, and saturated liquid exits the condenser. The mass flow rate of the refrigerant is 3.5 kg/min. Draw and label the cycle on a T-s diagram. What is the coefficient of performance? Ans. 2.98 What is the refrigerating capacity in tons? a. b. c.
A vapor-compression heat pump system uses Refrigerant R-134a as the working fluid. The refrigerant enters the compressor at 2.0bar, -5degC and with a mass-flow rate of 26g/s. Compression is adiabatic to 11.6bar, 60degC and the refrigerant exits the condenser 8degC sub-cooled. a) Draw a P-h chart to visualise the refrigeration cycle and display known data. b) Determine the power input to the compressor in kW c) Determine the heating capacity of the system in kW d) Determine the coefficient of...
An ideal vapor-compression heat pump cycle using R-134a is used to heat a house. The inside temperature is 22 ℃; the outside temperature is 0 ℃ Saturated vapor at 2.2 bar enters the compressor, and saturated liquid leaves the condenser at 3 ba. The mass ow rate is 0.2 kg/s. Detemine: a the power iput to the compressor (in kw) b. the coefficient of performance c. the coefficient of performance if the system were used as a refrigeration cycle d....
A vapor compression refrigeration cycle utilizes R-134a as the working fluid. The refrigerant flow rate is 50 g/s. Vapor at 150 kPa and -10 0C enters the compressor and leaves at 1.2 MPa and 75 0C. The power input to the non-adiabatic compressor is measured and found to be 2.4 kW. The refrigerant enters the expansion valve at 1.15 MPa and 40 0C and leaves the evaporator at 160 kPa and -15 0C. Determine the entropy generation in the compression...
Refrigerant 134a is the working fluid in an ideal vapor-compression
refrigeration cycle. Saturated vapor enters the compressor at h =
400 J/kg and saturated liquid leaves the condenser at h= 242 J/kg.
If the mass flow rate of the refrigerant is 0.08 kg/s, and
superheated vapor exits the compressor at h = 420 J/kg, pression
work will be equal to 1.6 kW
inch-h) 6.08(420 - 6oo) = 1.6
An ideal vapor-compression refrigerant cycle operates at steady state with Refrigerant 134a as the working fluid. Saturated vapor enters the compressor at -10°C, and saturated liquid leaves the condenser at 28°C. The mass flow rate of refrigerant is 5 kg/min. Determine (a) The compressor power, in kW (b) The refrigerating capacity, in tons. (c) The coefficient of performance. Sketch the system on a T-s diagram with full label. A vapor-compression heat pump with a heating capacity of 500 kJ/min is...
Condenser Compressor An ideal vapor-compression refrigeration cycle is modified to include a counter-flow heat exchanger as shown. Refrigerant 134a leaves the evaporator as saturated vapor at 0.10 MPa and is heated at constant pressure to 20°C before entering the compressor. Following isentropic compression to 1.4 MPa, the refrigerant passes through the condenser and exits at 45°C and 1.4 MPa. The liquid then passes through the heat exchanger and enters the expansion valve at 1.4 MPa. The mass flow rate of...