室外人体受地面热辐射的理论计算模型

Theoretical Calculation Model of Ground Thermal Radiation to Human Body in Outdoor Space

室外地面热辐射包括地表面本身发射辐射和反射辐射,是影响人体室外热感觉的重要因素。本文首先通过合理的基本假设,认为地面辐射符合兰贝特余弦定律,将室外人体等效为一柱体——"人体柱",然后建立"人体柱"受地面热辐射的物理数学模型,通过对物理数学模型进行理论分析,获得了室外人体受地面热辐射量的理论计算关系式。该关系式表明:在地面性质一定的条件下,人体受地面热辐射随离人体距离的增加而迅速减少,离人体距离8 m范围内的辐射占人体受到地面总辐射的90%左右。所得结论对于确定室外人体受地面热辐射量具有重要的理论意义,对于室外地表绿化和水体设置具有参考价值和指导作用。

The ground thermal radiation includes emitted radiation and reflected radiation, which plays an important role in outdoor thermal environment. In this paper, the reasonable assumptions were firstly proposed, in detail, the ground thermal radiation agrees with Lambert cosine law and the outdoor human body could be equivalent to a ＂human cylinder＂, and then the mathematical model to describe the ground thermal radiation to a human body was derived, Based on the theoretical analysis, the formula for calculating the ground thermal radiation to a human body was obtained. The formula indicated that the quantity of ground thermal radiation to a human body would decrease quickly with the distance increasing between the two objects, and the ground thermal radiation within 8.0 m from the human body dominated about 90% of the total quantity. The conclusions drawn in this paper would be useful for determining the ground thermal radiation quantity to the human body, and would be helpful to improve the design of afforestation and landscaping.