The capacity of a propane vapor-compression refrigeration systemis 8 tons. Saturated vapor at 0°F enters the compressor, andsuperheated vapor leaves at 120°F, 180 lbf/in.2 Heattransfer from the compressor to its surroundings occurs at a rateof 3.5 Btu per lb of refrigerant passing through the compressor.Liquid refrigerant enters the expansion valve at 85°F, 180lbf/in.2 The condenser is water-cooled, with waterentering at 65°F and leaving at 80°F with a negligible change inpressure. Determine
| (a) the compressor power input, inBtu/min |
| (b) the mass flow rate of cooling waterthrough the condenser, in lb/min |
| (c) the coefficient of performance |
Round answers to 3 significant digits.
