XPS保温板导热系数的不确定度分析

Uncertainty Analysis of Thermal Conductivity of XPS

XPS保温板具有高热阻、低吸水率、抗压强度高、阻燃效果好等优点,被广泛应用于各个领域尤其是建筑领域。导热性能是XPS板等绝热材料重要的性能参数,准确测定导热系数值有助于更好地选取和应用材料。利用防护热板法对XPS保温板的导热系数进行测定,分析了引入不确定度的因素,并通过《测量不确定度评定与表示》标准提供的方法(GUM法)对不确定度分量、合成不确定度和扩展不确定度进行测定和分析,计算出XPS板的导热系数和不确定度。结果显示,温度均匀性、热电偶的精度以及参比板精度对导热系数的不确定度影响较大,并针对设备改进和日常实验提出建议。

Extruded polystyrene(XPS) has the advantages of high thermal resistance, low water absorption, high compressive strength, good flame retardant effect. It is widely used in various fields, especially in the construction field. Thermal conductivity is an important performance parameter of isothermal insulation material such as XPS. The accurate determination of thermal conductivity is helpful for better selection and application of materials. The thermal conductivity of XPS is measured by the method of protective hot plate, and the factors introducing uncertainty are analyzed. The uncertainty component, synthetic uncertainty and extended uncertainty are measured and analyzed by the GUM method which presented in the standard of Evaluation and Expression of Uncertainty in Measurement, and the thermal conductivity and uncertainty of XPS are calculated. The results show that temperature uniformity, precision of thermocouple and precision of reference plate have great influence on the uncertainty of thermal conductivity.