
In this system, the liquid refrigerant expands in the first expansion valve to the flash chamber...
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...
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 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...
2.39 An industrial plant has available a 4 cylinder, 3 in. bore by 4 in. stroke, 800 rpm, single-acting compressor for use with R-134a. Proposed operating conditions for the compres- sor are 100°F condensing temperature and 40°F evaporating temperature. It is estimated that the refrigerant will enter the expansion valve as a saturated liquid, that vapor will leave the evaporator at a temperature of 45°F, and that vapor will enter the compressor at a temperature of 55°F. Assume a compres-...
In a vapor-compression refrigeration cycle, ammonia exits the
evaporator as saturated vapor at -22 °C. There are
irreversibilities in the compressor. The refrigerant enters the
condenser at 16 bar and 160 °C, and saturated liquid exits at 16
bar. There is no significant heat transfer between the compressor
and its surroundings, and the refrigerant passes through the
evaporator with a negligible change in pressure.
Calculate the coefficient of performance, b, and the isentropic
compressor efficiency, defined as:
2s Condenser Expansion...
A two-stage compression refrigeration system with an adiabatic liquid-vapor separation unit uses refrigerant-134a as working fluid. The system operates the evaporator at 0.4 MPa, the condenser at 1.6 MPa, and the separator at 0.8 MPa. The compressors use 25 kW of power. Given that the refrigerant is saturated liquid at the inlet of each expansion valve and saturated vapor at the inlet of each compressor, and the compressors are isentropic: (0) show the process on a T-s diagram; ) calculate...
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...
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...
A Refrigeration System Using R-134A In a refrigeration system, the refrigerant R-134A begins as saturated vapor at -15°(State 1). It then goes through a reversible adiabatic compressor to reach State 2. After flowing through the condenser (a heat exchanger), the refrigerant exits as saturated liquid at 70°C (State 3). It is then throttled by going through an expansion valve, to reach State 4. It finishes the cycle by going through another heat exchanger (the evaporator), to return to State 1....
Q1/ Figure 1 shows a refrigeration system of multi evaporators and single compressor using R407C as refrigerant. The evaporators provide cooling capacity of 10 and 20 TR at temperatures of -10 °C and 10 °C respectively. The system provided with multi ex valves (the multi expansion valve advantage is that the refrigerant that enters the low temperature evaporator expansion valve is saturated liquid and the flash gas is removed at poirnt 4). The condenser temperature is 50 °C. Calculate the...