样品尺寸对有效导热系数测量值影响的相关性研究

Correlation Study on the Effect of Sample Size on the Measured Value of Effective Thermal Conductivity

在工程实践中,样品的尺寸对保温材料有效导热系数的检测有极大影响。以XPS保温板和蒸压加气混凝土砌块为例,采用防护热板法研究了样品的规格尺寸对保温材料有效导热系数实测值的影响,探究了非标准尺寸保温材料的有效导热系数检测方法,结果表明:尺寸规格、拼接材料的导热系数、空气填充量均影响试验检测结果,选择不同导热系数的拼接材料拼接试验样品时,拼接材料导热系数远小于试验样品的导热系数,测得实验结果误差最小;拼接材料导热系数与试验样品的导热系数相近时,选择环形拼接测得实验结果误差最小。在可允许条件下,应用同种材料选择环形拼接,但不宜用不同材料拼接,以免误导工程试验。

In engineering practice,the sample size has a great influence on the detection of effective thermal conductivity of thermal insulation materials.Taking XPS insulation board and autoclaved aerated concrete block as examples,this paper studies the influence of the size of the sample on the measured value of the effective thermal conductivity of the insulation material by using the protective hot plate method,and explores the detection method of the effective thermal conductivity of the insulation material(non-standard size).The results show that the size,the thermal conductivity of the splicing material and the amount of air filling all affect the test results,When the splicing materials with different thermal conductivity are selected to splice the test samples,the thermal conductivity of the splicing materials is far less than that of the test samples,and the error of the test results is the smallest;When the thermal conductivity of the splicing material is close to that of the test sample,the annular splicing is selected to minimize the error of the experimental results.Under allowable conditions,ring splicing shall be selected with the same material,but it is not suitable to use different materials for splicing,so as to avoid misleading the engineering test.