Effect of Evaporator Load on Heat Pump Operating Parameters and Performance

This work investigates the impact of varying the evaporator load on the performance and parameter characteristics of a heat pump. A series of experiments have been done on a vapor compression cycle heat pump which is run with R134a. The evaporator in this system is a coil submerged in a water/glycol bath accommodated in a thermally insulated steel container. The load of the evaporator is changed through a heater in this bath with a capacity of 1.8 kW. The glycol bath is mixed through an electric stirrer. The results showed that system pressures and temperatures generally increase and then decrease after a certain heat load has been imposed. The same trend is for COP of the refrigeration system; hence there is an optimum load point to which the COP increases to a maximum and then starts to decline. This optimum point corresponds to the best efficiency of the system.