Performance comparisons of the glass evacuated tube solar collectors of different absorber tubes

진공관형 태양열 집열기의 흡수관 형상 변화에 따른 성능 비교

The thermal performance of glass evacuated tube solar collectors are numerically and experimentally investigated. Four different shapes of solar collectors are considered and the performances of these solar collectors are compared. Dealing with a single collector tube, the effects of not only the shapes of the absorber tube but also the incidence angle of solar irradiation (beam irradiation) on thermal performance of the collector are studied. However, the solar irradiation consists of the beam irradiation as well as the diffuse irradiation. Also, the interference of solar irradiation and heat transfer interaction between the tubes exist in an actual solar collector, These effects are considered in this study experimentally and numerically. The accuracy of the numerical model is verified by the experimental results. The result shows that the thermal performance of the absorber used a plate fin and U-tube is the best.