含盐土导热系数的试验研究

An Experimental Research on the Thermal Conductivity Coefficient of Saline Soil

室内试验表明,含盐土的导热系数与其含盐成分(盐类)及含量有很大的关系.同类土在含水量和干容重相同时,在同一正温条件下粘土和砂土的导热系数是随氯化钠盐含量的增加而增大,随硫酸钠盐含量的增加而减小;在同一负温条件下,无论何种土和含何种盐其导热系数均随含盐量的增加而减小,含盐砂土和含硫酸钠盐土减小幅度显著.硫酸钠盐土在含盐量相同时,导热系数在负温区随温度升高而减小,在正温区随温度升高而增大;硫酸钠盐土在含盐量和温度相同时,其导热系数随含水量的增加而增大.

It is found by indoor experiments that the thermal conductivity of saline soil has very close relation with salt component (salts) and salt content. At the same water content and the same dry bulk density of the same type of soil, for the same temperature above 0 ℃, the thermal conductivity coefficient of clay and sand soil increases with the enhancing sodium chloride salt content, but decreases with the enhancing sodium sulphate content. While for the same temperature below 0 ℃, whenever soils and salts, the thermal conductivity coefficient always decreases with increasing salt content, especially, the saline sand soil and the sodium sulphate soil decreases obviously. Under the same salt content, the thermal conductivity coefficient of sodium sulphate soil decreases with temperature when the temperature is under 0 ℃, and the thermal conductivity coefficient of sodium sulphate soil increases with temperature when the temperature is above 0 ℃. For the same salt content and temperature, the thermal conductivity coefficient of sodium sulphate soil increases with enhancing water content.