Design and simulation of a heat pump for simultaneous heating and cooling using HFC or CO2 as a working fluid.
Résumé
This article presents the design of a Heat Pump for Simultaneous heating and cooling (HPS) of hotels, luxury dwellings and smaller office buildings. It realizes simultaneously space heating and space cooling. It also preheats hot water for domestic use. The ambient air is used as a balancing source. During winter, some energy recovered by subcooling of the refrigerant is stored in the cold water tank. This energy is used to run a defrosting system and to improve the annual energy efficiency. Two refrigerants have been studied: R407C and CO2. HFCs provide interesting performances, but new regulations on F-gases have led us to study low-GWP refrigerants. CO2 seems to be a refrigerant which adapts well to the operation of the HPS. It enables direct DHW production and improves the defrosting system. Simulation results show that despite the 20% lower performance using CO2, it offers good working conditions to the HPS.