Journal of the Korean Solar Energy Society ISSN:1598-6411(Print) 2508-3562(Online) 한국태양에너지학회 논문집

Conventionally, solar thermal systems in South Korea have primarily focused on domestic hot water supply and partial space heating. However, with the recent expansion of applications to include industrial process heat and space heating in greenhouses with seasonal heat storage, there is an increasing requirement for developing highly efficient solar collectors that can operate effectively throughout the year. A solar thermal collector absorbs incoming solar radiation, converts it into thermal energy, and then transfers the energy to a heat-transfer fluid. The entire process should be optimized to minimize energy loss and ensure economic efficiency. A flat plate collector with single glazing is highly efficient at low temperatures and high solar intensities, whereas an evacuated tube collector is relatively efficient at high temperatures and low solar intensities. Therefore, in this study, we proposed a flat plate collector with double glazing that exhibited excellent thermal performance under all operating conditions. We validated the thermal performance through theoretical analysis and empirical experiments. In the theoretical analysis, we presented an analytical model for the comprehensive modeling of the flat plate collector and examined its thermal performance based on key design parameters, such as solar transmittance, emissivity, and gas fill. The thermal performance was confirmed, and an optimal design solution was derived. Furthermore, to validate the accuracy of our analysis, we conducted thermal performance testing on an optimized flat plate collector with double glazing, according to the specifications outlined in KS B 8295. The results showed a correlation between the simulation and experimental results.