基于镜像热源原理测定固体材料热物性的方法及应用

基于平行热线法结合镜像热源原理，提出了一种新的固体材料热物性参数测算模型，在热线法测试原理的基础上，以试样绝热边界为界线，设与真实热源对称位置处存在虚拟镜像热源，以此消除绝热边界造成的热积聚效应影响，测试时可不需再限制实验时间和试样厚度. 当相邻时刻材料的热物性参数计算结果大于判别准则时，引入镜像热源对计算温度进行修正. 为防止修正过程所用热物性参数对实验初期计算值的依赖，模型对实测温度进行两次修正. 以石棉板为研究对象，理论分析结合计算结果表明，两次修正结果不同，但差异不大，且第二次修正后各组热物性参数计算结果更稳定. 对石棉板、大理石、硼硅玻璃、硅砖等4种材料的薄板和厚板进行了热物性测定，结果与文献值较吻合，最大误差均小于5%，验证了本测定方法适用于薄板和厚板试样，有效提升了热线法测定精度，扩大了应用范围.

Measurement method and application of thermophysical properties of solid materials based on enantiomorphous heat-source principle

Based on the parallel hot-wire method and the principle of enantiomorphous heat-source, a new model for measuring the thermophysical parameters of solid materials was proposed. On the basis of the principle of hotline test, the existence of virtual mirror heat-source at the symmetrical position of the real heat-source was taken as the boundary of the adiabatic boundary of the specimen, so as to eliminate the influence of the heat accumulation effect caused by the adiabatic boundary. Therefore, the test can no longer limit the experimental time and sample thickness. When the calculation results of the thermal physical parameters in the adjacent time were greater than that of the criteria proposed, the mirror heat-source was introduced to correct the calculated temperature. In order to avoid the dependence of the thermal physical parameters on the calculated value at the initial stage of the experiment, the measured temperature was corrected by the model two times. Asbestos as the research object, through the theoretical analysis combined with numerical calculation, shows that there was a difference between the two correction results, but the difference was not large and the second correction of the thermophysical parameters of the calculation results more stable. The thermal property test applied to the asbestos board, marble, borosilicate glass, silica brick and other 4 kinds of thin and thick material. The results showed that it was consistent with the measured values of other methods in the literature, and the maximum error was less than 5%. This test method was validated for the thin plate samples and thick plate samples, effectively improving the hot wire method test accuracy and expanding the scope of application.