


A simple refrigerator comprises an evaporator, compressor, condenser and throttle valve (refer Figure 1 below). The...
2. MULTIPLE EVAPORATOR/ EXPANSION VALVE A refrigeration installation using Freon 12, comprises one compressor, one condenser and three evaporators of 10 tonnes, 20 tonnes, and 30 tonnes capacities maintained at 10 C, 5 C and -10 C respectively. The system comprises multiple expansion valves and back pressure check valves. The condenser pressure is 9.609 bar (saturation temp. 40 C). The vapours leaving the evaporator are dry saturated. The liquid refrigerant is sub-cooled by 10 C in the condenser sub-cooler. Assume...
A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at by The refrigerant enters the condenser at compressor consumes 3.3 kW of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (e) the COP, and (d) the g waste heat to cooling water that enters the condenser at 18°C at a rate of 0.25 kg/s and leaves at 26°C. 1.2 MPa and 50°C and leaves at the same...
Consider a two-stage cascade refrigeration system operating between the pressure limits of 1 MPa and 180 kPa with refrigerant-134a as the working fluid. The refrigerant leaves the condenser as a saturated liquid and is throttled to a flash chamber operating at 0.4 MPa. Part of the refrigerant evaporates during this flashing process, and this vapor is mixed with the refrigerant leaving the low-pressure compressor. The mixture is then compressed to the condenser pressure by the high-pressure compressor. The liquid in...
A refrigeration system with a flash chamber operates with R134a between the pressure limits of 1.0 and 0.1 MPa. The refrigerant leaves the condenser as saturated liquid and is throttled to a flash chamber operating at 0.5 MPa. The refrigerant leaving the low-pressure compressor at 0.5 MPa is also routed to the flash chamber. The vapor in the flash chamber is then compressed to the condenser pressure by the high-pressure compressor, and the liquidis throttled to the evaporator pressure. Assume...
refrigerator, as shown in FIGURE P 3 with the corresponding T-s diagram, uses refrigerant R-134a as the working fluid and operates on the ideal vapour-compression refrigeration cycle except for the compression process. The refrigerant enters the evaporator at 120 kPa with a quality of 34.026 percent and leaves the compressor at 70 0C. If the compressor consumes 0.45 kW of power, Determine: (a) The mass flow rate of the refrigerant, in kg/s, correct to 6 dp. (b) The condenser pressure,...
A two-stage cascade refrigeration system operates between the pressure limits of 1.4MPa and 200 kPa with refrigerant-134a. The fluid leaves the condenser as a saturated liquid and is throttled to a flash chamber operating at 0.50 MPa. Part of the refrigerant evaporates in the flashing process, and this vapor is mixed with the refrigerant leaving the low-pressurin compressor. The liguid in the flash chamber iS throttled to the evaporator pressure and cools the refrigerated space. The mass flow rate of...
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...
1) A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -30°C by rejecting its waste heat to cooling water that enters the condenser at 16 °C at a rate of 0.25 kg/s and leaves at 26°C. The refrigerant enters the condenser at 1.2 MPa and 65°C and leaves at 42°C. The inlet state of the compressor is 60 kPa and -34°C and the compressor is estimated to gain a net heat of...
Pressure limits in a two-stage cooling system are 0.9 MPa and
250kPa. Refrigerant condenser
comes out as saturated liquid and works at 700kPa pressure
reduced to the pressure of the evaporation chamber. Meanwhile, some
of the refrigerant evaporates and is mixed with the fluid from the
low pressure compressor. The mixture is then
It is compressed to condenser pressure with high pressure
compressor. The liquid in the evaporation chamber is reduced to
evaporator pressure and draws heat from the cooled...
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...