Measurements and Design Calculations for a Deep Coaxial Borehole Heat Exchanger in Aachen, Germany

Figure 9

The used 2D cylinder grid (radius 99.5 m and depth 2973.5 m) with the different material property zones of the borehole heat exchanger (1) conducting cement, (2) insulating cementation, (3) normal cement, (4) inner pipe, (5) steel casings, (6) water, and (7) surrounding rocks.