三元乙丙橡胶防热材料传热试验方法与温度数值计算

Heat transfer experiment method and temperature numerical calculation of EPDM insulating material

三元乙丙橡胶(EPDM)由于具有导热系数低的特点,在测量其背面温度时会产生比较大的测量误差。为减少测量误差,在热电偶测温端与被测表面之间增加具有高热导率的金属片作为集热片,对加与不加集热片、集热片选取不同材料(铜片和铝片),以及同厚度不同直径与同直径不同厚度分别进行了试验研究和瞬态传热数值计算,分析了集热片材料与尺寸对温度测量准确性及动态响应的影响。计算结果与试验结果吻合较好,表明铝片比铜片响应稍快,但强度没有铜片高,从而选用铜片;直径大与厚度小的铜片比直径小与厚度大的铜片响应快。

Due to low heat conductivity of EPDM, there exists great error when measuring the back-wall temperature. In order to eliminate measurement error, the metal chip with high heat conductivity are put between the point of the measuring temperature and the back-wall of thermocouple. The action of the collector chip under different conditions was experimentally investigated, and transient heat transfer was numerically calculated, such as with or without the collector chip, the collector chip with different material （copper and aluminium） ,the collector chip with the same thickness and different diameter,the collector with different thickness and the same diameter, and so on. The effects of material and dimension of the collector chip on accuracy and dynamic response of temperature measurement were analyzed. The calculation results agree well with experimental results. Although the dynamic response of aluminium chip is faster than that of copper chip, the copper chip was chosen due to its higher strength. The dynamic response of copper chip with bigger diameter and smaller thickness is faster.