A refrigeration unit using refrigerant R-134a rejects heat at 40 C and absorbs heat at -40 C. Assuming the following:
- the expansion valve operates isenthalpically
- • the refrigerant leaving the evaporator coil is saturated vapor
- • the refrigerant leaving the condenser is saturated liquid.
Using the diagram below, the circulation rate (lb/min) of the refrigerant required for a 4 ton cooling system is most nearly: