First step towards development of Distributed thermal response test using heating cables

Abstract: A Distributed Thermal Response Test is a method to determine ground properties such as thermal conductivity. Knowing the thermal properties of the ground is essential for designing and installing ground source heat pump and BTES systems. Knowing more accurate thermal properties can increase the efficiency of heat pumps by up to 20%, thus, contributing to energy efficiency and ultimately to sustainable development. This study introduces a convenient method for thermal response tests using heating cables as the single heat source. Once this new method is developed, it will make the implementation of DTRT techniques more versatile and inexpensive compared to the conventional DTRT, and it will create incentive for more investments in geothermal heat pump systems. This project is experimental in nature, hence, different equipment were tested and analyzed in order to find those that best suit this application. Several equipment such as certain types of heating cables have been tested and proven to be not optimal and some others, such as the selected power regulator, have resulted to be more adequate. The overall design initially proposed at the beginning of this study has been analyzed, modified and improved, and recommendations are given for future development. In conclusion, many obstacles have been overcome from the development process of DTRT with heating cables. A functional DTRT unit that uses heating cables has been built, however, it remains a challenge to improve the design in order to make it suitable for all potential borehole depths and various test requirements.