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Unformatted text preview: cycle COP? 3. (11.129) A small heat pump unit is used to heat water for a hot-water supply. Assume that the unit uses R-22 and operates on the ideal refrigeration cycle. The evaporator temperature is 15 C, and the condenser temperature is 60 C. If the amount of hot water needed is 0.1 kg/s, determine the amount of energy saved by using the heat pump instead of directly heating the water from 15 to 60 C. 4. (11.133) In an actual refrigeration cycle using R-12 as the working fluid, the refrigerant flow rate is 0.05 kg/s. Vapor enters the compressor at 150 kPa and -10 C and leaves at 1.2 MPa and 75 C. The power input to the nonadiabatic compressor is measured and found to be 2.4 kW. The refrigerator enters the expansion valve at 1.15 MPa and 40 C and leaves the evaporator at 175 kPa and -15 C. Determine the entropy generation in the compression process, the refrigeration capacity, and the coefficient of performance for this cycle....
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This note was uploaded on 09/05/2011 for the course EML 4304C taught by Professor Abbitt during the Summer '09 term at University of Florida.
- Summer '09