Experimental study of the thermal conductivity of sand with different moisture content

The experimental study concerns the variation of the thermal conductivity of sand with the change of moisture content, which is the basis for ground source heat pump system design. The study examines the thermal conductivity variation of 5 sand samples and the comparison of empirical curves and fitting curves of eight mixtures. The result shows that: for all the sand samples, the thermal conductivity increases with the increase of the moisture content, while the size of the sand samples has little effect of the thermal conductivity. At low moisture content (ω<15%), the fitting curves of eight mixtures are in good agreement with the empirical curves.