use of the electrical analogy to model heat transfer within the borehole and thermal response factors (short and long time … discretized only within the borehole domain, with two nodes for the fluid and two additional nodes for the grouting material …, achieving good RMSE values, which were smaller than 0.15 °C for water outlet temperature and borehole surface mean temperature. …

(MIR-TRT). For comparison, a second MIR-TRT was performed without pumping of groundwater. The required borehole length was … borehole length with increasing heat input rate during the MIR-TRT without pumping of groundwater due to buoyancy …Convection is shown in earlier studies to improve the thermal contact between heat exchanger and borehole wall in water …