在对常功率平面热源法基本原理深入分析的基础上,根据其在第:二类边界条件下半无限大物体一维导热的数学模型,研制一套低导热系数材料的热物性测量装置,并结合相关文献通过数值计算获得高斯误差补函数一次积分较为精确的解。设计的测试系统采用数据采集卡DUT5000,利用VB编程技术对温度进行实时采集及处理,测定8种耐火砖和陶瓷纤维的导热系数和导温系数。研究结果表明,本研究所设计的测试系统所得导热系数和导温系数与文献中的结果相对误差不超过6%,具有结构简单、操作方便、测试时间短、精度较高等特点。
Based on the principle of constant heat rate source method and one-dimensional conduction mathematic model for semi-infinite object built under the second boundary condition, a set of device for measuring materials with low thermal conductivity was developed and precise analytical solution was obtained by numeric calculation in related references. The DUT5000 data acquisition card and VB software were used to conduct real-time data acquisition and data processing. The thermal diffusivity and thermal conductivity of eight kinds of firebricks and ceramic fibers were tested. The results show that the relative errors between experimental results and results from references are evaluated to be within 6%. The testing system has the characteristic of simple structure, easy operation, short testing time and high precision.