激光脉冲法测量硬硅钙石绝热材料热扩散率

本文采用非线性参数估计方法来确定硬硅钙石型微孔硅酸钙绝热材料的热扩散率.首先将绝热材料夹在两个金属片之间制成夹层结构试样,采用激光脉冲法测量试样背面温升;然后通过理论温升曲线与实验测得的温升曲线的拟合,来估计绝热材料的热扩散率.采用非线性参数估计可同时估计出热扩散率、散热系数以及试样吸收的能量.通过实验确定出进行热扩散率测量的绝热材料最佳厚度为1.6～1.9mm;由试样厚度精度和接触热阻所引起的测量误差在5.8%以内.

Thermal diffusivity measurements on xonotlite insulation materials by the laser-flash method

A nonlinear parameter estimation method was adopted to determine the thermal diffusivity of a xonotlite-type calcium silicate insulation material. The measurements were performed with a laser-flash apparatus by rear-face detection of the temperature response of the three-layered sample,where the insulating material was sandwiched between two iron slices. The thermal diffusivity was evaluated by fitting the theoretical curve with the recorded temperature-time one. The nonlinear parameter estimation technique can simultaneously estimate the thermal conductivity,heat transfer coefficient and absorbed energy. Based on experimental results,the optimal thickness range of the insulation material in the sample was suggested from 1.6 to 1.9?mm. The effect of thickness and contact resistance on measurement uncertainty was estimated within 5.8%.