A New Estimate of Sand and Grout Thermal Properties in the Sandbox Experiment for Accurate Validations of Borehole Simulation Codes

Ground-coupled heat pumps usually employ fields of borehole exchangers (BHEs), which must be designed by suitable models. In order to validate a BHE model, it is advisable compare the computation results with experimental data. A well-known data set was provided Beier et al. (Geothermics 2011, 40) through laboratory model called “sandbox”. Several authors proposed estimates thermal properties sandbox grout and sand. this paper, we present new estimate those properties, obtained means 2D finite-element simulations that consider all details setup, including thin aluminum pipe at boundary. Our show measured temperatures in fluid sand can reproduced very accurately considering conductivities 0.863 W/(mK) for 3.22 sand, volumetric capacities 4.6 MJ/(m3K) 3.07 slightly enhanced capacity water contained BHE. The are validated comparison an analytical solution 3D simulations.