Performance analysis of solar air collector with trapezoidal surface geometry using CFD simulation

Nowadays, with the developing technology, the reduction of fossil fuel consumption and the increasing tendency towards renewable energy sources, studies on the research and use of solar energy systems are increasing. In addition to water heating systems with solar energy, which is a known technique, studies are still being carried out on solar air collectors to be used in preheating processes in areas such as drying, space heating in buildings, humidification or greenhouse cultivation. In this study, absorber plate collectors with trapezoidal geometries of different sizes are experimentally and numerically investigated to improve the performance of solar air collectors. For different operating parameters, flow analyses were performed numerically using Solidworks Flow Simulation program. Two collectors with flat and 45o angle trapezoidal absorber plates were experimentally tested and compared with CFD analysis results of the same collectors. The tests and analyses were carried out for six different mass flow rates ranging from 0.01-0.1 kg/s for flow air and solar irradiance values of 600, 800 and 1000 W/m2. The maximum deviation between CFD analyses and experimental results was 8%. The agreement of the three-dimensional numerical analysis results with the experimental results confirms the numerical analysis model used to solve the problem. As a result of the study, the highest thermal efficiency for 1000 W/m2 irradiation and 0.01 kg/s mass flow rate was found to be 80% for e/Dh = 0.45 and P/e = 8 for M2 collector. It is concluded that the most suitable collector is the M2 model with a 45o trapezoidal angle absorber plate.