Simulation of a top-heat-type thermosyphon-based flow stabilization system

Addressing the problem of global warming requires reducing greenhouse gas emissions; thus, considerable efforts are being made to effectively utilize renewable energy. Currently, the conversion efficiency of photovoltaic (PV) panels is approximately 20%, whereas the conversion efficiency of the solar collector exceeds 40%. Therefore, generating hot water with a solar collector is more efficient and cost-effective than using PV panels. Under these circumstances, the effectiveness of a control system in top-heat-type thermosyphon systems to convert the intermittent flow of the circulating working fluid to continuous flow has been established through both indoor and outdoor testing. In this study, a model of the experimental setup involving the top-heat-type thermosyphon is developed, and numerical simulation is performed to investigate the effects of circulating working fluid pressure and pipe friction on intermittent flow. Moreover, the simulation results are compared with those of the experiment with pressure changes. According to the findings, intermittent flow occurs when there is large pipe friction and high pressure. These results attest to the efficacy of the proposed working fluid stabilizing technique. (C) 2022 The Author(s). Published by Elsevier Ltd.