外界环境对材料导热系数的影响研究探讨

Discussion on the influence of environment on thermal conductivity

随着绿色建筑概念的提出,建筑屋面材料的保温隔热性对于节约能源消耗具有重要的意义。由于保温隔热性能由材料的导热系数直接体现,因此分别考虑环境温度、湿度、应力及光照对导热系数的影响。通过已有文献试验得出:不同材料的导热系数会随着温度的变化呈现出三种不同的变化:正相关、负相关和无关;非吸湿性的材料的导热系数与湿度无关,但吸湿性的材料的导热系数与湿度呈正相关;材料导热系数与应力呈正相关关系,但这种变化较小几乎可以忽略;光照对材料导热性能不会产生直接影响,但会影响材料的老化。考虑这四种不同环境的影响,可以为今后屋面保温隔热性能提升有着较大的意义。

With the concept of green building proposed,building roofing material insulation and heat preservation for energy consumption is of great significance.Because the thermal insulation performance is directly reflected by the thermal conductivity of materials,the influence of environmental temperature,humidity,stress and illumination on thermal conductivity is considered respectively.Through the literature tests show that the thermal conductivity of different materials with change in temperature showing three different changes:positive correlation,negative correlation and independent;thermal conductivity and humidity non hygroscopic material has nothing to do,but the thermal conductivity and moisture absorbent material was positively related;thermal conductivity of materials and stress positively related,but this variation is almost negligible;light has a direct effect on the thermal conductivity of the material will not,but will affect the material aging.Considering the influence of these four different environments,it is of great significance for the improvement of roof insulation performance.