土壤热参数确定方法比较与修正

土壤热参数是分析研究土壤热传递的基本参数,寻求确定热参数简单方法是研究的热点问题.该文利用自行研制的土壤热特性试验系统,测定了4种质地土壤热特性,计算了不同质地土壤在不同含水率、不同容重情况下的热扩散率,进一步推导出不同情况下的导热率,并与Campbell经验公式计算的导热率进行比较,发现计算值与实测值相差较大,并对Campbell经验公式进行修正,同时对修正经验公式进行分析、检验,并讨论此经验公式的适用范围.结果显示在体积含水率小于20%的时候,修正经验公式可以用于计算导热率.

Modification and comparison of methods for determining soil thermal parameters

Soil thermal parameters are essential parameters in analyzing thermal transfer, and many researches have been focused on finding the simple and accurate estimation method of the thermal transfer parameters. The thermal transfer experiments for four texture soils were conducted through the self-developed experimental system. Thermal diffusivity of four texture soils with different water content and bulk density was calculated. Thermal conductivity was induced by the calculated thermal diffusivity and compared with that calculated by Campbell empirical method. The results show that significant differences exit between thermal conductivity calculated by the two methods. Campbell empirical method was modified according to the experimental results. The modified equation was analyzed, verified and its application scope was discussed. The results show that the modified equation can be used to calculate thermal conductivity in the condition that volumetric water content is less than 20%.