辐射散热器表面发射率对室内平均辐射温度分布的影响

Influence of radiator surface emissivity on distribution of indoor mean radiant temperature

分析了采用微元球体代替Fanger图算法求解人体对环境的角系数的可行性。推导了当环境中存在发射率较小的表面时平均辐射温度的计算公式。分别分析了设计工况下和散热器表面温度变化时表面发射率对室内平均辐射温度分布的影响。结果表明,散热器表面发射率越大,散热器附近平均辐射温度越高;散热器表面温度越高,表面发射率对平均辐射温度分布的影响越大。辐射散热器表面发射率应作为室内平均辐射温度计算和供暖设计的参数之一。

Analyses the feasibility of an alternative algorithm, which uses infinitesimal sphere formula calculating the view factor of human on the environment instead of Fanger＇s graphic method. Deduces a formula calculating mean radiant temperature in the environment with the surfaces whose emissivity is less. Analyses the influences of surface emissivity on distribution of indoor mean radiant temperature under the design condition and at different surface temperatures separately. The results show that the greater the surface emissivity of radiator is, the higher mean radiant temperature near radiator is. The higher the surface temperature of radiator is, the larger the influence of surface emissivity on the distribution of mean radiant temperature is. The surface emissivity should be considered as an important parameter for both the calculation of indoor mean radiant temperature and the heating design.