Modification of Method of Interpreting Thermal Response Test of Borehole Heat Exchanger

Abstract

Prior to complex designing borehole heat exchangers thermal reaction tests are recommended. Proper interpretation of the obtained results reveals the actual values of effective thermal conductivity factor of the drilled profile and thermal resistance of the heat exchanger, typical of the rock mass-borehole system. A theoretical model of heat exchange in a heat exchanger has been analyzed in the paper. On an example of selected industrial tests the results of the so far interpretation TRT were compared with those obtained by a novel method, accounting for the results of heat balance in the rock mass-borehole relation. The presented analysis was aimed at optimizing the thermal reaction tests of borehole heat exchangers in view of minimization of time of the tests and so their cost.