Analysis of the effect of thermosyphon force on Thermal performance of a flat solar collector

Abstract

In a solar thermosyphon system, the reduction in energy-carrying fluid density causes fluid to move. In this study, to investigate the effect of thermosyphon properties on the thermal performance of a solar flat collector, a composite system including: a solar flat collector and a thermosyphon suction section is considered and the thermal performance results of this system are examined in two cases. In the first case, the air enters the collector with zero temperature celsius and increases the temperature by ten degrees and twenty degrees and thirty degrees Celsius. In the second case, the air enters the collector with a temperature of twenty-seven degrees selsius and this is the increase in temperatures. . In both cases, the height of the thermosyphon suction section (installed on the output of the flat solar collector varies from one meter to six meters. The results show that in both of the above cases, the presence of a thermosyphon suction section can increase the mass flow rate of air passing through the solar collector by two and a half times. Increasing air mass discharge reduces the temperature of the sun's absorbing surface, as well as reducing the collector's heat loss, thereby increasing the system's thermal efficiency. In addition, the results show that the use of this composite solar system, for the preheating of the air required for ventilation, can lead to the highest possible thermal efficiency for the solar flat collector.