Experimental Study On Light-heat Performance Of Solar Collector In Hohhot

According to the related theory of solar radiation and in view of several existing solar radiation models, the solar radiation on horizontal plane or on inclined plane on different conditions was calculated and analyzed by using the software of MATLAB. The values calculated by HOTTEL model are better agree with that calculated by the ASHRAE model in spring and summer, but the values calculated by HOTTEL model are very different to that calculated by the ASHRAE model in autumn and winter. The values of solar radiation in the district of Hohhot calculated by both the HOTTEL model and the ASHRAE model are better agreement with the measured values in spring and summer. But the values calculated by the HOTTEL model are better than that calculated by ASHRAE model in autumn and winter, the error of the HOTTEL model is less than 5%, it is suitable for computation and design of solar project. The HOTTEL model can not only forecast local solar radiation but also offer references to adjacent district's solar radiation.Based on the background of treating bitter salt water in the west of China and producing ultra pure water, the membrane distillation system powered by solar is proposed. In order to using the all-glass evacuated tubes which is a high efficiency heat absorbing element in solar powered membrane distillation system and at the same time to overcome the shortcoming of it, the glass evacuated solar collector tube with an inserted heat pipe is adopted in this paper, which integrates all-glass evacuated tubes with heat pipe technology. The characteristic structure of this collector tube and all-glass evacuated collector tubes is introduced. in the comparisons of daily average efficiency, instantaneous efficiency in different solar radiation, different tilt angle and different weather conditions, average heat loss coefficient by experiment. The results show that the daily average efficiency of this collector tube is higher than all-glass evacuated solar collector tube's, average heat loss coefficient is lower than all-glass evacuated solar collector tube's, and instantaneous efficiency is higher than all-glass evacuated solar collector tube's, their instantaneous efficiency have the same trend. In practice, this collector tube has small heat capacity, start up quickly and appropriate anti-freezing capability. It can ensure the solar membrane distillation system running pressure-resistant, safely and steady. These research work has laid the experimental foundation for the heating system, optimized design and the experimental study of solar powered membrane distillation system.