A study on the structure of Solar/Photovoltaic Hybrid system for the purpose of preventing overheat and improving the system performance

Abstract

In countries, such as Korea, where climate change is clear due to the four seasons, some of the collected energy must be released in the summer season, and these measures for heat dissipation fail to be very effective, thus causing system overload and defects frequently. In this study, we devised an overheating prevention system for the solar hot water and heating system using the variation of the shadow caused by the solar altitude angle that changes every hour, and for this purpose, a solar power generation module was placed over the solar collector. By using simulations, the system was designed in such a way that direct sunlight would be naturally blocked from reaching the solar collector due to the high solar altitude in the summer and that 100% of direct sunlight could reach the collector due to the low solar altitude in the winter. It was confirmed that the designed conditions were also satisfied in the actual test bed. In order to predict the performance of the system through simulations, the temperature of the solar thermal storage tank was calculated every hour after modifying the energy equation used in a previous study, and as a result of determining whether the system is overheated afterwards, it is expected that the degree of system overheating can be reduced. The shading did not affect the system efficiency in the season in which an actual heating and hot water load was needed.