18 May 2017

P.1.7.2 Storage and hot and cold water in a thermocline for Space heating/cooling and domestic hot water

Water thermoclines with heat pumps are used to store hot water for space heating (SH) and domestic hot water (DHW) needed for districts during winter time. The heat pump (HP) in the circuit, allows to discharge the thermocline up to a water temperature of 5°C (increase energy storage capacity). In summertime energy is needed to produce both domestic hot water and space cooling (SC). Usually these productions are separated. The thermal architecture proposed has as an objective to take fluid at medium temperature in the thermocline, heating up one part of this water in the heat pump condenser (going back on the top of the thermocline) and cooling down the other part of this water in the heat pump evaporator (going back on the bottom of the thermocline). A calculation of the annual energy consumption has been done for an application case with this technical solution compared to classical ones. Then the Return On Investment (ROI) of this technical solution has been carried out in order to identify the technical opportunity. It appears that for districts needing space cooling in summer time this solution has a very good ROI compared to usual solutions. Next step planned is to build a demonstrator to confirm the potential identified by this first theoretical study.