Today a Thermal Response Test (TRT) was completed on the GeoKoax Borehole at the Druids Glen site. The purpose of the Thermal Response Test is to determine the ground thermal properties, in particular the thermal conductivity. This is essential for the sizing of heat collectors and for predicting performance.
The TRT rig is a small vehicle towed trailer consisting of heaters, pumps and sensors. Heated water is injected into the flow side of the collector, and the return temperature is recorded. As this test is run over several days, the return temperature will elevate and eventually plateau as it reaches a steady state. The heating profile can be examined mathematically and a value for thermal conductivity derived. The test has been completed as of this post, but this value has not yet been calculated. Careful insulation of the rig is needed to ensure minimal losses above ground. The ideal situation is that the only heat losses should be the losses to the rock surrounding the borehole.
TRT tests are generally run for several days, with 72 hours being the norm. A 6kW and 3kW heater are inside the rig, this often necessitates a generator for power if the site is not electrified. The test at druids glen was completed without incident for 72 hours with application of 6kW heat .