Modelling of a borehole heat exchanger using a finite element with multiple degrees of freedom

► We propose a new finite element model for a borehole heat exchanger. ► We use multiple degrees of freedom to determine more accurate results. ► A significant shortening of calculation time in relation to the Ansys fully 3D model. ► The MDF model has good accuracy and the possibility of practical application. ► Better accuracy at the beginning of the heat flow process for the MDF model.