平板型太阳能集热器热损失随海拔高度变化规律研究

Study on heat loss of flat plate solar collector varying with altitude

受到高原地区气压低、空气密度小、大气透明度高等特殊环境影响,平板太阳能集热器表面对流和辐射热损失发生一定变化,这对集热器在高原地区的实际应用产生一定影响.该研究通过对平板太阳能集热器传热过程进行分析,考虑不同海拔高度下对流及辐射换热机制,选取了位于不同海拔的典型城市,对平板太阳能集热器的对流、辐射和总热损失进行数值模拟分析.结果表明:随海拔高度升高,平板集热器的对流热损失系数减小,辐射热损失系数增大;而由于对流和辐射热损失系数的变化程度不同,总热损失系数随海拔高度先减小而后增大,最大变化约在10%.研究为不同海拔高度平板集热器热利用提供计算依据.

Due to the special environmental impacts of low air pressure,low air density and high atmospheric transparency in plateau area,the convective and radiative heat loss of flat plate solar collectors change to some extent,which has a certain impact on the practical application of collectors in plateau area.In this study,by analyzing the heat transfer process of flat plate solar collector and considering the convective and radiative heat transfer mechanism at different altitudes,typical cities at different altitudes are selected to simulate the convective,radiative and total heat loss of flat panel solar collector.The results show that with the increase of altitude,the convective heat loss coefficient of the flat plate collector decreases,and the radiation heat loss coefficient increases.However,due to the different variation degrees of convection and radiation heat loss coefficients,the total heat loss coefficient decreases first and then increases with the altitude,and the maximum change is about 10%.The study provides calculation basis for heat utilization of flat plate collectors at different altitudes.