Performance of a gas engine driven heat pump for hot water supply systems

The present work aimed at evaluating the experimental performance of a gas engine heat pump for hot water supply. In order to achieve this objective, a test facility was developed and experiments were performed over a wide range of ambient air temperature (10.9–25.3 °C), condenser water inlet temperature (33–49 °C) and at two engine speeds (1300 and 1750 rpm). Performance characteristics of the gas engine heat pump were characterized by water outlet temperatures, total heating capacity and primary energy ratio. The reported results revealed that hot water outlet temperature between 35 and 70 °C can be obtained over the considered range of the operating parameters. Also, total heating capacity and gas engine heat recovery decrease by 9.3 and 27.7%, respectively, while gas engine energy consumption increases by 17.5% when the condenser water inlet temperature changes from 33 to 49 °C. Total heating capacity, gas engine heat recovery and gas engine energy consumption at ambient air temperature of 25.3 °C are higher than those at ambient air temperature of 10.9 °C by about 10.9, 6.3 and 1.5% respectively. Moreover, system primary energy ratio decreases by 15.3% when the engine speed changes from 1300 to 1750 rpm.

► Nowadays, GEHP has been paid more attention due to its advantage of reducing the energy consumption in the heating process.
► Experiments have been performed over a wide range of operating conditions to evaluate performance of the GEHP used for hot water supply.
► As the condenser water inlet temperature changes from 33 °C to 49 °C recovered gas engine heat decreases by 27.7%.
► Primary energy ratio of the GEHP increases by 5.6% when the ambient air temperature varies from 10.9 °C to 25.3 °C.
► Total heating capacity increases by 39.4% while primary energy ratio decreases by 15.3% as engine speed increases from 1300 to 1750 rpm.