A refrigerator uses refrigerant-134a as the working fluid and operates on the vapor-compression refrigeration cycle. The evaporator and condenser pressures are 100 kPa and 1400 kPa, respectively. The isentropic efficiency of the compressor is 88 percent. The refrigerant enters the compressor at a rate of 0.022 kg/s superheated by 26.37°C and leaves the condenser subcooled by 4.4°C.

NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. 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 18°C at a rate of 0.28 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 420 W from the surroundings. The heat exchanger loses no heat to the environment. 26°C 42°C Expansion valve 4 Condenser ↓ Evaporator Water 18°C QL 1.2 MPa 65°C Qin W in Compressor 60 kPa -34°C Determine the quality of the refrigerant at the evaporator inlet. (Take the required values from saturated refrigerant-134a tables.) (You must provide an answer before moving on to the next part.) The quality of the refrigerant at the evaporator inlet is

In a vapor-compression refrigeration cycle, 9 kg/min of ammonia exits the evaporator as saturated vapor at-12°C. The refrigerant enters the condenser at 16 bar and 140C, 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. Determine the refrigerating capacity, in kW. kW %3D Determine the power input to the compressor, in kW. kW %3D

Required information NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. 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 18°C at a rate of 0.29 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 430 W from the surroundings. The heat exchanger loses no heat to the environment. 26°C 42°C ↓ Condenser 3 Expansion valve Water 18°C Evaporator QL (2) 1.2 MPa 65°C lin Win Compressor 60 kPa -34°C Determine the COP of the refrigerator. (You must provide an answer before moving on to the next part.) The COP of the refrigerator is

An ammonia-water absorption refrigeration cycle is used to keep a space at -5 C when the ambient temperature is 20 C. Pure ammonia enters the condenser at 20 bar and 60 C at a rate of 0.02 kg/s. Ammonia leaves the condenser as a saturated liquid and is expanded to 2 bar. Ammonia leaves the evaporator as a saturated vapor. Heat is supplied to the generator by geothermal liquid water that enters at 100 C at a rate of 0.25 kg/s and leaves at 70 C.  Determine (a) the cooling capacity (in TR) and (b) COP of the system. The enthalpies of ammonia at various states of the system are: condenser inlet h2 = 1510 kJ/kg, evaporator inlet h4 = 418 kJ/kg, evaporator exit h1 = 1420 kJ/kg. Take the specific heat of geothermal water to be 4.18 kJ/kg-K