A Numerical Study of the Solar Air Heater Performance Using Artificial Spherical Obstacles

Solar air heaters (SAH) are required to adhere to specific standards regarding thermal efficiency and minimal internal pressure loss.We addressed the issue of significant pressure loss in SAH across five cases, designated "A" to "E", by developing an innovative SAH featuring spherical baffles (SP).We utilized computational fluid dynamics (CFD) to model the solar air heater (SAH) with solar panels (SPs), concentrating on key parameters such as heat-collecting efficiency and pressure loss magnitude.In another case, Case "E" SPs demonstrated superior performance compared to the baffle regarding heat collecting efficiency and pressure loss, as indicated by the data.An SP can improve the thermal efficiency of an SAH.The simulation of wavelengths for SPs in instance "E" at 400 mm demonstrated optimal heat collection by the SAH, achieving an efficiency of 80.65%.The investigation concentrated on the wave height of the SPs to measure wavelength.The SAH exhibited a minimum pressure loss of 19.86 Pa, a maximum heat-collecting efficiency of 60.68 percent, and a wave height of 40 mm.Higher Reynolds numbers (Re) at the air inlet were associated with improved collection efficiency and reduced internal pressure loss, whereas lower outlet temperatures corresponded with lower Re values.An accuracy of 0.897 was observed in the fitting curve for pressure loss when analyzing the imported Reynolds number and pressure loss.This study not only establishes a theoretical foundation for winter air heating but also has significant practical implications.