Influence of Different Heat Loads and Durations on the Field Thermal Response Test

Geothermal energy exhibits considerable development potential in space heating. Shallow geothermal stored the soil form of low-grade is mainly extracted via ground source heat pump (GSHP) system. GSHP systems use subsoil as a source, typically involving vertical borehole exchanger (BHE) to extract from formation. Accurate measurement thermal properties formation very important for design BHEs. At present, most common and effective method measure conductivity field response test (TRT). However, conditions (heat load, time) during can impact results. Therefore, this study, with depth 130 m was evaluated field. The TRT module distributed (DTRT) based on optical fiber temperature sensor (DOFTS) technology were used monitor different working real-time. In tests, evolution time determined. Based results under loads times, influence analyzed described. A constant zone located at 25 50 m, an increasing gradient 3 °C/100 m. showed that load slightly influenced initial stage test, significantly increased 0 12 h. After reaching quasi-stable state, characteristics recovery after studied. decreased, which could shorten recover temperature. provide basis optimization conditions.