Thermal energy storage as a way to improve transcritical CO2 heat pump performance by means of heat recovery cycles

Electrification of the heating sector is a major target energy transition towards more sustainable, efficient, and less polluted future. Heat pumps are considered suitable than electrical heaters or fossil-fueled boilers; however, common refrigerants cause ozone layer depletion, which exacerbates greenhouse effect. Natural refrigerants, such as CO2, perform comparably even better hydrofluorocarbons while minimizing negative aspects. This study presents model water-heater CO2 transcritical heat pump in configuration that increases overall coefficient performance (COP) by introducing thermal storage (TES). The thermodynamic cycle was divided into two separate phases. After TES (charging), warm water used fluid evaporator to increase evaporation temperature pressure reduced work compressor. As decreased progressively, discharge cycles improved total COP. case focuses on dairy processes suggests straightforward cheaper method improve efficiency current processes, ejector-expansion systems double compression.