Hydro-Thermal Properties of the Unsaturated Soil
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In this paper, 10 approaches were initially used to predict the thermal conductivity (k) of different soils. The comparison showed that three principal parameters indicating sand content (xs), dry density (ρdry), and degree of saturation (Sr) influenced highly the soil thermal conductivity. Moreover, 3 approaches for the volumetric heat capacity (Cv) of soil were used to predict the experimental data from the literature. The result showed that the classical approaches can induce the errors because of the non-consideration of the mineral and water content. This insufficiency was solved by proposing a new model. Finally, the most compatible approaches for the thermal properties were implemented into a 2D subsurface model using finite element method (FEM). The variation of suction (s), thermal conductivity (k) and temperature (T) with time and space was then investigated in the numerical simulation model under the influence of seasonal suction and temperature on the top boundary.
KeywordsSoil Volumetric Heat Capacity Sand Content Thermal Response Test (TRT) Residual Volumetric Water Content Hydrothermal Transfer
This work is supported by the China Scholarship Council (CSC).
- Ball, D.A., Fischer, R.D., Hodgett, D.L.: Design methods for ground-source heat pumps. ASHRAE Trans. 89(2B), 416–440 (1983)Google Scholar
- de Vries, D.A.: Thermal properties of soil. In: van Wijk, W.R. (ed.) Physics of Plant Environment, pp. 210–235. New Holland, Amsterdam (1963)Google Scholar
- Johansen, O.: Thermal conductivity of soils, PhD Thesis, Trondheim, Norway, ADA 044002 (1975)Google Scholar
- Kersten, M.: Thermal properties of soils. Eng. Exp. Stat. 52 (1949)Google Scholar
- Richards, L.A.: Capillary conduction of liquids through porous mediums. J. Appl. Phys. 1, 318–333 (1931)Google Scholar
- Sakashita, H., Kumada, T.: Heat transfer model for predicting thermal conductivity of highly compacted bentonite. J. Japan At. Soc. 40, 235–240 (1998)Google Scholar
- Tang, A.M., Cui, Y.-J., Le, T.T.: A study on the thermal conductivity of compacted bentonites. 41(3–4), 181–189 (2008)Google Scholar