Problem 6.30:
Design a vapor compression refrigeration unit using R290 as the refrigerant. The unit must be capable of pumping 1.5 refrigeration tons of heat at -25 °C. The condenser will be operated using water at 25 °C. Determine the flow rate of the refrigerant and the coefficient of performance assuming the compressor to operate with 80% efficiency. Additional information: One standard refrigeration ton is 12,000 BTU/h (3,517 W).
Problem 6.31:
The process shown in Figure 6-19 is part of a chiller unit that uses water as the refrigerant. The following data are available: stream 1 is a vapor-liquid mixture at 0.5 bar; stream 5 is saturated vapor at 5 °C; stream 6 is at 500 °C; stream 7 is at 100 °C. Calculate the following on the basis of 1 kg/s of water in stream 1:
