Modelling and experimental validation of a novel co-axial spiral borehole heat exchanger

Abstract

In order to optimize the operation of a ground source heat pump (GSHP) system, the development of dynamic models that integrate all the system components is a key factor. Particularly, the modelling of the ground source heat exchanger and its coupling to the heat pump operation becomes important. Usually, this kind of systems present an on/off operation, which makes it necessary to have an accurate prediction of both the short and long thermal response of the borehole heat exchanger (BHE). In this context, the novel B2G dynamic model was developed and experimentally validated in previous works for a single U-loop BHE. This work presents the adaptation and experimental validation of the B2G dynamic model to a novel co-axial spiral BHE configuration designed in the framework of a HORIZON 2020 European Project, GEOT€CH (Geothermal Technology for €conomic Cooling and Heating). The results show that the B2G approach applied to this specific configuration produces a model that can accurately predict the behavior of the BHE.