含水量对谷物热传导性能的影响

Influence of Water Content on the Thermal Conductivity Performance of Grain

[目的]提高谷物导热系数的测量精度。[方法]采用热线法分别测定4种不同含水率小麦、高粱、水稻、玉米的导热系数,并考察4种谷物含水率与其导热系数的关系。[结果]含水率对4种谷物热传导性能的影响规律基本一致,即各种谷物的导热系数均随含水率的升高而升高;在谷物含水率从5%～20%的变化过程中,小麦、高粱、水稻、玉米的导热系数分别提高了0.072、0.035、0.022、0.027W/(M.K);4种谷物中,小麦含水率的变化对其导热性能的影响最大。[结论]采用热线法测定谷物导热系数具有简单、快捷、易操作等优点,该方法同样适用于测定其他颗粒材料的导热系数。

[Objective] The aim was to enhance the measuring precision of coefficient of thermal conductivity of grain.[Method] The coefficients of thermal conductivity of wheat,sorghum,rice and corn with 4 different water contents were measured by using hot line method and the relationships between water content and coefficient of thermal conductivity in 4 kinds of grains were investigated.[Result] The influence laws of water content on thermal conductivity performance of 4 kinds of grains were basically identical.The coefficients of thermal conductivity in various grains were increased along with increase of water content;while the water content in grains varied from 5% to 20%,the coefficients of thermal conductivity of wheat,sorghum,rice and corn were enhanced for 0.072,0.035,0.022 and 0.027 W/（M·K）resp.Among the 4 grains,the change of water content in wheat had maximum influence on its thermal conductivity performance.[Conclusion] The measuring of coefficients of thermal conductivity of grains by using hot line method had advantages of simple,rapid and easy to operate.This method was also suitable for measuring the coefficients of thermal conductivity of other particle materials.