Modeling Thermal Interference Between Shallow Geothermal Boreholes Using TRNSYS: Application to the Q-Thermie-Uniovi Boreholes (Asturias, Spain)

This study presents the implementation of a new Type for TRNSYS based on the integral exponential function, which is fundamental in subsurface heat transfer modeling. This function can be expressed as a series expansion, and the developed Type enables the representation of multiple terms in this expansion. To validate its accuracy, the model’s results are compared with experimental data from two geothermal boreholes located in Asturias, Spain: Q-Thermie-Uniovi 1 and Q-Thermie-Uniovi 2. These boreholes, spaced 7.3 m apart and each 48 m deep, were used in a thermal response test, where Q-Thermie-Uniovi 1 underwent thermal injection while temperature measurements were recorded in Q-Thermie-Uniovi 2 over a period of three months. This study evaluates how the number of terms in the series expansion influences the model’s accuracy and demonstrates that the newly developed Type effectively replicates experimental data. This work provides a robust tool for optimizing the design of geothermal systems and enhancing the understanding of subsurface heat transfer dynamics.