Analytical Modeling of Grout Heat Storage Effects in Thermal Response Tests: Toward Faster and More Reliable Parameter Estimation
Hsiang-Wen Wang, Ying-Fan Lin, Chia-Hao Chang, Bo-Tsen Wang, Hikari Fujii, Yu-Feng Forrest Lin, Kuo-Hsin Yang, Jui-Pin Tsai · Case Studies in Thermal Engineering · 2026
DOI 10.1016/j.csite.2026.107695When does grout heat storage matter in a thermal response test?
The paper asks how a borehole grout's heat capacity changes early-time temperature responses and the timing of reliable thermal-property estimation.
A borehole heat exchanger with a composite cylindrical source
A thermal response test in a 54 m borehole, with grout storage represented at the inner boundary and radial heat transfer through the surrounding ground.
Retain grout capacity in the analytical boundary condition
The composite cylindrical source formulation keeps grout volumetric heat capacity in a dynamic inner boundary condition and compares it with ILS and ICSS treatments.
Early and late parts of the test carry different information
The reported comparison gives RMSE values of 0.12 degrees C for CCS, 0.16 degrees C for ILS, and 0.25 degrees C for ICSS; grout capacity matters earlier, while ground conductivity becomes more influential later.
Animated research summary
The animation explains the paper's physical and mathematical logic. Conceptual curves are not presented as new field observations.