Performance analysis of a hot water supply system with a CO2 heat pump by numerical simulation: (1st report, modeling and analysis of heat pump)

Abstract

Heat pumps using CO2 as a natural refrigerant have been developed and are expected to contribute to energy saving in hot water supply. In residential applications, CO2 heat pumps are used in combination with hot water storage tanks. The objective of this series of papers is to analyze the overall performance of a hot water supply system composed of a CO2 heat pump and a hot water storage tank by numerical simulation. In the 1st report, a simulation model of a CO2 heat pump is created based on thermodynamic equations and measured data for an existing CO2 heat pump. In addition, the performance of a CO2 heat pump is clarified in relation to the air temperature as well as the inlet and outlet water temperatures.