Thermal energy system comprising geothermal borehole heat exchangers and a heat pump

摘要

A thermal energy system comprises a first thermal system having a heating and/or cooling demand, a closed loop geothermal energy system 6 comprising a plurality of borehole heat exchangers 42, and an intermediate heat pump 32 thermally connected between the first thermal system and the geothermal energy system. The thermal connection between the first thermal system and the geothermal energy system, via the intermediate heat pump, can be controlled to provide a heat source or a heat sink for the first thermal system. In particular, the first thermal system is a refrigeration system 2 including at least one condenser 16, where the closed loop geothermal energy system provides cooling for the condenser(s) of the refrigeration system. In a further aspect, the intermediate heat pump is selectively and alternately thermally connected to first or second groups of the borehole heat exchangers in a succession of alternating cycles so that in one cycle the first group constitutes the heat sink and in a successive cycle the second group constitutes the heat sink. Preferably, each borehole heat exchanger comprises an elongate tube having a closed bottom end with first and second adjacent elongate conduits interconnected at the bottom end.