Fig. 3From: Temperature sensor module for groundwater flow detection around borehole heat exchangersSchematic top view of the fine discretized part of the 2D model with the double U-tube BHE in the middle. The property zones are color-coded and differ in heat conductivity, heat capacity, porosity and permeability (see Table 2 for the values). The two inlet tubes (I and II) are shown in orange and light blue, and the two outlet tubes (III and IV) in light green and greenBack to article page