Research on thermal performance and pressure loss of a new perforated-folded baffle solar air collector

Abstract

In order to further improve the heat collection performance of solar air heaters and reduce internal pressure. This study establishes a collector with perforated baffle based on baffled collector. The model was simulated using CFD software. Fit and analyze the efficiency of the collector with the hole-opened rate (the ratio of the opening area to the baffle area). The results show that compared with non-perforated baffle collectors, perforated baffle collectors have lower pressure loss, higher collection efficiency, lower heat dissipation coefficient of about 37.58%, and higher heat transfer coefficient of about 10.51%. When the hole height is 30 mm, the hole diameter is 80 mm, and the hole-opened rate is 0.24, the coupling between heat collection efficiency and pressure loss is the best, which is 64.11% and 4.32 Pa, respectively. The heat collection efficiency decreases with the increase of porosity, and the fitting degree R 2 = 0.98. The deviation of fitting curve (between turbulence intensity and hole-opened rate) is less than 10%. Nusselt number increases gradually with the increase of Reynolds number. Fitting correlation between Nusselt number and Reynolds number, and fitting degree is 0.9985. Perforated-folded baffle collector provides theoretical basis for improving the solar thermal utilization rate.