水平布置方式下抛物槽式集热器辐照量分析

Analysis of solar irradiance received by horizontal parabolic trough collectors

采用适用于中等纬度的Hottel晴天太阳辐射模型,对地处北纬41.34°,水平布置方式下的抛物槽式集热器夏季和冬季的辐照量进行了计算。计算结果表明：水平南北布置的抛物槽式集热器在夏季接收的太阳辐射较多,月辐照量可达1 GJ/m2,而冬季接收的太阳辐射较少,月辐照量为0.3～0.45 GJ/m2,且冬至日辐照量仅为夏至日辐照量的1/4左右;水平东西布置的抛物槽式集热器夏季月辐照量在0.75 GJ/m2左右,而冬季月辐照量为0.5 GJ/m2左右,冬至日辐照量可达夏至日辐照量的1/2以上。由此可见,在北纬41.34°地区应用抛物槽式集热器时,如考虑在夏季使用,应采用水平南北布置方式;若考虑在冬季使用,则应采用水平东西布置方式。

Solar irradiance received by parabolic trough collectors（PTCs） which were fixed horizontally in a place of latitude 41.34 °in summer and winter were investigated with Hottel model that estimates clear sky solar radiation in mid latitude area. The results show that PTCs in horizontal N-S orientation absorb much more solar energy in summer, whose monthly irradiation received is up to 1 GJ/m2; but absorb less solar energy in winter, whose monthly irradiation received is about0.3～0.45 GJ/m2, and the energy falling on the collector surface at the winter solstice can only be a quarter of that at the summer solstice. On the contrary, PTCs in horizontal E-W orientation absorb about 0.75 GJ/m2per month in summer, and about 0.5 GJ/m2per month in winter, the energy falling on the collector surface at the winter solstice can be more than a half of that at the summer solstice. As a result, PTCs in horizontal N-S orientation mode are suitable in an area of latitude 41.34 °when they are mainly used in summer, while PTCs in horizontal E-W orientation mode can be applied when they are mainly used in winter.