稳态平板法测量导热系数的若干影响因素分析

Analysis on the influencing factor of stable flat measuring method for thermal conductivity measurement

研究发现,热源温度和环境温度等因素通过试样的侧面散热影响平板稳态法测量导热系数的精度,散热铜板的上下表面散热功率不一致也将影响导热系数测量的准确性.用大空间自然对流理论对实验数据处理公式修正后,可有效减小侧面散热对测量的影响.在设计实验时应首先获得散热铜板的散热功率曲线,选择合适的散热铜板温度,而后通过综合考虑试样厚度和热源温度以控制传热温差,使测量时散热铜板温度处于最佳温度附近.

The main factors that affect the veracity of steady-state method measuring thermal conductivity are heat resource temperature, ambient temperature, sample thickness and sample thermal conductivity. The cooling rate of cooling plate is different on upper surface and below surface is another important factor. The natural convection empirical formula is used to improve the data processing, the effect of elimination of heat from the side of sample is reduced. It is important to design the experiment to keep the temperature of cooling plate in an appropriate range, and the cooling rate of cooling plate is uniform anywhere at such temperature.