The comparison between two high-temperature heat-pumps for the production of sanitary water

Abstract

High-temperature heat-pumps are devices that exploit low-temperature heat sources for the production of hot water at high temperatures. This paper presents a comparison between two high temperature heat-pumps for the production of hot sanitary water of temperatures between 65 °C and 85 °C. A high-temperature heat-pump that uses ammonia as a refrigerant and transcritical heat-pump that uses carbon dioxide as a refrigerant were compared in terms of coefficient of performance. Theoretical calculations were based on the REFPROP property method within Aspen Plus software. The simulations showed that the ammonia high-temperature heat-pump outperforms the transcritical heat-pump in terms of coefficient of performance within the evaporation temperature range between -20 °C and 20 °C.