schematic diagram of a va- por-compression refrigeration system with two evapora- tors using Refrigerant 134a as...

   

Transcribed Image Text:

schematic diagram of a va- por-compression refrigeration system with two evapora- tors using Refrigerant 134a as the working fluid. This arrangement is used to achieve refrigeration at two differ- ent temperatures with a single compressor and a single condenser. The low-temperature evaporator operates at -18°C with saturated vapor at its exit and has a refrigerat- ing capacity of 3 tons. The higher-temperature evaporator produces saturated vapor at 3.2 bar at its exit and has a refrigerating capacity of 2 tons. Compression is isentropic to the condenser pressure of 10 bar. There are no signifi- cant pressure drops in the flows through the condenser and the two evaporators, and the refrigerant leaves the condenser as saturated liquid at 10 bar. Calculate (a) the mass flow rate of refrigerant through each evapo- rator, in kg/min. Condenser Compressor Expansion valve 4 Evaporator Expansion valve Ona =2 tons Expansion valve Evaporator =3 tons 3.2 bar=320kPa 10bar= 1Mpa Determine: 1. T,H in the states 1,2,3,4,5,6,7,8 2. Mass Flow Rate on each Evaporator 3. Qout 4. Wc 5. COP schematic diagram of a va- por-compression refrigeration system with two evapora- tors using Refrigerant 134a as the working fluid. This arrangement is used to achieve refrigeration at two differ- ent temperatures with a single compressor and a single condenser. The low-temperature evaporator operates at -18°C with saturated vapor at its exit and has a refrigerat- ing capacity of 3 tons. The higher-temperature evaporator produces saturated vapor at 3.2 bar at its exit and has a refrigerating capacity of 2 tons. Compression is isentropic to the condenser pressure of 10 bar. There are no signifi- cant pressure drops in the flows through the condenser and the two evaporators, and the refrigerant leaves the condenser as saturated liquid at 10 bar. Calculate (a) the mass flow rate of refrigerant through each evapo- rator, in kg/min. Condenser Compressor Expansion valve 4 Evaporator Expansion valve Ona =2 tons Expansion valve Evaporator =3 tons 3.2 bar=320kPa 10bar= 1Mpa Determine: 1. T,H in the states 1,2,3,4,5,6,7,8 2. Mass Flow Rate on each Evaporator 3. Qout 4. Wc 5. COP