昆明和北京两幢建筑物表面热力效应的观测对比

Thermal Effects of Architecture Surface in Kunming and Beijing

利用昆明、北京两座城市内建筑物为研究对象,对其不同朝向外墙壁面、屋顶面表面温度及壁面近旁气温进行了观测,分析了建筑物外墙壁面表面温度及其近旁气温的垂直分布以及壁面、屋顶对周围大气的热力效应特征,并对两座城市内建筑物的热力状况进行了比较分析。研究表明:建筑物表面温度受太阳辐射的影响要比近旁气温大得多,一般说来,壁面昼间是热源,夜间是热汇;受研究对象所在的大区域气候、人类活动等影响,建筑物外表面的热力效应有许多异同;建筑物屋顶面与近旁空气间的平均热通量基本为正值,呈现较强的热源效应,其热力效应强度与太阳辐射呈现正相关;城市建筑物的外表面(壁面、屋顶面)已成为城市区域内有别于城市地面,且对城市立体气候的形成具有不可忽视影响的热力作用面。

Urban architecture and the urban heat island intensity is extremely closely related. The buildings＇ outside surface exhibits unique thermal energy characteristic because it absorbs the solar radiation and thermal energy from people＇s daily life influences buildings. The atmospheric thermal energy condition around buildings is affected inevitably, then the urban climate is affected. The observational data of buildings＇ external walls＇ surface temperature, rooftop surface temperature and the air temperature near the buildings＇ external surfaces in three different cities of Kunming, Beijing utilized. The vertical distribution rule of buildings＇ external surface temperature and air temperature near the buildings＇ external surfaces, the thermal effect features of the wall, and the rooftop between the nearby atmosphere are analyzed. The comparative analysis on two cities buildings thermal conditions is conducted. The following preliminary conclusions are drawn. In the same area, buildings＇ external walls＇ surface temperature and the air temperature near the buildings＇ external surfaces are different respectively from different directions, seasons, and heights. The influence of solar radiation on buildings＇ external walls surface temperature is greater than on the air temperature near the buildings＇ external surfaces. Generally speaking, the wall＇s surface is a heat source in daytime, and a heat sink at night. In different areas, there are many similarities and many differences in the thermal energy affect on buildings＇ external walls. The heat flux of the buildings＇ external walls basically is positive in daytime, is negative at night, and there is an extreme small value just before sunrise in Kunming. While in summer of Beijing, the heat flux of the buildings＇ external walls is basically negative in daytime and positive at night. This indicates that the influence of climate and people＇s activity is great to the thermal energy effect on the urban buildings＇ external walls in different cities. The average heat fluxes between the buildings＇ rooftop and its nearby air are basically positive in different areas and seasons. Buildings＇ rooftop displays the strong heat source effect. The thermal energy effect intensity and the solar radiation show a positive correlation. In summary, the urban building external surfaces （external wall surfaces, the surface of rooftop） are different from the ground in the urban region, and is noticeably influential thermal active surface in the formation of urban climate.