不同保温形式墙体温度场数值模拟与分析

Temperature fields of external walls of different thermal insulation placements

基于有限差分方法,建立了考虑太阳辐射和环境温度变化的建筑外墙实时温度场数值计算模型.利用该模型,计算了北京地区典型内外保温墙体的温度场.计算结果表明,建筑外墙温度分布受太阳辐射影响显著,影响程度与季节、朝向密切相关.墙体保温后外表面温度升高明显;保温层内温度变化剧烈,其中外保温比内保温保温层温度变化幅度更大.外保温墙体结构层温度均在零度以上,而内保温墙体结构层温度有时处于零度以下且承受正负循环.外保温墙体外防护层一年四季温度变化明显,年温度变化可达67℃.

Numeric temperature field models for external walls with thermal insulation layers were developed based on the finite differential method, in which solar radiation and environmental temperature were taken into account. By applying the model, the temperature field of an externally or internally insulated wall in typical seasons in Beijing was calculated and analyzed. In the calculation, the different effects of either inner or outer thermal insulation layers were taken into account. The calculations showed that the influence of solar radiation on the temperature field of external walls was significant and the degree of influence depended on wall positions and seasons. The structural layer＇s temperature range increased significantly when there was inner thermal insulation, compared to the range of an externally insulated wall. The temperature of the structural layer in an externally insulated wall remained above 0℃, while internally insulated walls sometimes went below 0℃, undergoing positive and negative cycling. The temperature of the outer protection layer of the externally insulated wall obviously changed in the four seasons, with an annual highest temperature of 67℃.