Distributed thermal response tests on pipe-in-pipe borehole heat exchangers

Borehole Thermal Energy Storage systems typically use U-pipe Borehole Heat Exchangers (BHE) having borehole thermal resistances of at least 0.06Km/W. Obviously, there is room for improvement in the U-pipe design to decrease these values. Additionally, there is a need for methods of getting more detailed knowledge about the performance of BHEs. Performing Distributed Thermal Response Tests (DTRT) on new proposed designs helps to fill this gap, as the ground thermal conductivity and thermal resistances in a BHE can be determined at many instances in the borehole thanks to distributed temperature measurements along the depth.