一种低密度莫来石高温导热系数计算模型的建立及验证

Development and Verification of Calculation Models for Thermal Conductivity of a Low-Density Mullite under High Temperature Condition

采用防护热板法测试了一种低密度莫来石在150～500℃的导热系数,分析了测试温度、压力、试样厚度、设定温差等测试参数对测试结果的影响,在此基础上拟合得到了3组该低密度莫来石导热系数的计算模型,并根据实际测试结果对3组计算模型分别进行了验证。结果表明:该低密度莫来石试样的导热系数随测试温度的升高而升高,温度-压力、温度-温差的计算模型在所选温度范围内的相对偏差小于5%,温度-厚度的计算模型在所选温度范围内的相对偏差小于10%。

The thermal conductivities of a low-density mullite were tested by guarded hot plate method at temperature of 150-500 ℃.The influence of test parameters such as testing temperature,pressure,specimen thickness and temperature difference on the test results were analyzed.On this basis,three groups of calculation models of thermal conductivity of the low-density mullite were obtained.According to the actual test results,these three groups of calculation models were verified respectively.The results show that the thermal conductivity of the low-density mullite specimen increased with the increase of test temperature.The relative deviations of temperaturepressure and temperature-temperature difference calculation models were less than 5%in the selected temperature range,and the relative deviation of temperature-thickness calculation model was less than 10% in the selected temperature range.