基于瞬态平面热源法,利用HOTDISK仪器对不同条件(环境温度、材料密度及材料厚度)下高聚物导热系数的变化规律进行测试研究.采用熵值法对影响高聚物导热系数的因素进行权重分析,并与传统隔热材料进行对比,验证高聚物材料的隔热性能.结果表明:高聚物导热系数随环境温度呈先增大后减小的变化趋势,存在上升段(-40~10℃,20~90℃)、平缓段(10~20℃)及下降段(>90℃);高聚物导热系数随材料密度的增大而增大,在环境温度较高时,存在材料密度增大而导热系数减小的现象;高聚物导热系数与材料厚度无关.在影响高聚物导热系数的因素中,环境温度的影响最大,材料密度次之,材料厚度最小.高聚物材料具有优良的隔热性能,可作为高地温隧道的隔热材料.

The frequency of high geo-temperature phenomenon gets higher, with the increase in the long anddeep-buried tunnels of the new construction in China. Setting low thermal conductivity materials as thermalinsulation layer has become one of effective target methods. However, the existing materials on heat transferperformance cannot satisfy the needs. As a kind of material, which could be used in tunnel heat insulation, thethermal conductivity of non-water reacted two-component polymer has rarely reported in detail. The project isbased on the technique of transient plane source, the variation of the thermal conductivity of polymers underdifferent conditions ( ambient temperature,density and thickness )are tested and studied by HOTDISKinstrument. The factors of weight distribution are affecting the thermal conductivity of polymers, which areanalyzed by entropy method and comparison with traditional thermal insulation materials to verify the thermalinsulation performance of polymer. The study reveals that the thermal conductivity of polymer firstly increases,and then decreases with temperatures. There are two rising sections ( -40~10 ℃, 20~90 ℃) , one flat section( 10 ~ 20 ℃) and one descending section ( >90 ℃) . The thermal conductivity of polymer increases with theincrease of density. There is a phenomenon, which the density increases and the thermal conductivity decreasesat high temperature. The thermal conductivity of polymer is independent of thickness. Among the factors affectingthe thermal conductivity of polymer, the temperature has the greatest influence, the density is the second, andthe thickness is the smallest. Polymer has excellent thermal insulation properties and can be popularized andapplied as a thermal insulation material for high geo-temperature tunnels.