A vapor compression system using ammonia as the refrigerant has two evaporators and a flash intercooler as shown in Fig. 3.6(a). Refrigerant flows at the rate of 0.375 kgsí1 through the...

A vapor compression system using ammonia as the refrigerant has two evaporators and a flash intercooler as shown in Fig. 3.6(a). Refrigerant flows at the rate of 0.375 kgsí1 through the low-temperature evaporator at í30°C. The refrigerant flow rate through the hightemperature evaporator at í4°C is 0.225 kgsí1 . The liquid leaving the two evaporates is in a saturated state. The liquid in the flash tank is at í4°C. Dry saturated vapor enters the low-pressure compressor and the highpressure compressor at í30°C and í4°C respectively. The liquid entering the expansion valve EV-2 is subcooled to 20°C. The condensing temperature is 40°C. Calculate (i) the heat absorption rates in the two evaporators, (ii) the work input to the two compressors, and (ii) the COP of the cycle.