Heat pump system with a thermal store comprising a phase change material

摘要

A heat pump system 10 comprises a heat pump 12 having an evaporator 22 to be arranged in heat exchange with a heat source 16 and a condenser 24 to be arranged in heat exchange with a target fluid. The heat pump is configurable between a heating mode of operation, in which heat is transferred from the heat source to heat the target fluid, and a defrosting mode of operation, in which heat is transferred from the target fluid to heat the evaporator to remove frost formed on it. The heat pump system further comprises a thermal store 34 which includes a phase change material 36 configured to be heated when the heat pump is in a heating mode of operation. When the heat pump is switched to a defrosting mode of operation, heat is transferred from the target fluid to heat the evaporator, and the thermal store provides heat to re-heat the target fluid. In a further aspect, an air source heat pump utilising a reversed cycle defrosting system to defrost an air cooler is disclosed, where a thermal store is used to re-heat flowing water cooled as a result of the reversed cycle defrost.