The effect of closed cycle of air flow circulation on the thermal performance of solar air collector

This experimental study aims to investigate the effect of the closed cycle of air circulation on the thermal performance of the solar air collector with attached fins in the site of Laghouat in Algeria, under climatic conditions. Our experimental procedure includes two types of cycles: open cycle and closed cycle. For each cycle, we have considered two tilt angle: 0 and 30 degree. Moreover, the solar collector is oriented in a southerly direction with a definite angle of inclination. The flow rate used in experiment is equal to 0.0129402 m3/s. Then, by comparing the experimental and theoretical results, we observe that the maximum temperature difference between the outlet and inlet air for the open cycle (27 °C, at 14h30) is higher than that of the close cycle (17 °C, at 14h00). The maximum efficiencies obtained for the open cycle for the both configurations were η (30 degrees) = 25.29 % and η (0 degree) = 35.71 % at 4 pm. These values are higher than those of the maximum efficiencies of the closed cycle with η (30 degrees) = 7.86 % at 4 pm and η (0  degree) = 13.31% at 12h00, respectively