Multi-parameters optimization design of downward jet solar air collector with corrugated absorber plate structure

In a solar air collector, there is a strong coupling between the flow field and the temperature field, where any change in flow boundary conditions or airflow channel parameters impacts the flow structure, temperature distribution , and heat transfer efficiency. Building on this heat transfer mechanism, this paper introduces a novel solar air collector that integrates a downward impulse jet with a corrugated absorber plate . The flow and heat transfer performance of the collector are analyzed under various flow conditions by varying parameters, such as jet hole spacing along the flow direction, spanwise spacing, sine wave amplitude, and ripple period. Based on the univariate research results, considering the influence of the interaction between different parameters on the comprehensive performance of solar air collectors, the response surface methodology is adopted to optimize the main parameters and the optimal combination of parameters has been obtained, they are X/D = 1.77, Y/D = 2.19, A = 1 mm, which corresponds to the maximum THPP value of 6.06. Compared with the collector structures with multi-arc convex ribs on the absorber plate and multiple V-arranged bumps on the absorber plate in references, the average improvement of the comprehensive heat transfer coefficient of the proposed solar air collector in this study are 20.84 % and 32.67 %, respectively. In addition, the effects of Re and air inlet temperature on the heat collection efficiency were studied. When Re changes from 6000 to 18,000, the heat collection efficiency gradually decreases with the increasing Re , and the average heat collection efficiency of the optimized structure is 39.4 % higher than that of the traditional flat plate. When the inlet temperature increases from 280 K to 300 K, the air outlet temperature decreases by 1.2 K, and the heat collection efficiency decreases by 5.6 %. It is concluded that the air inlet temperature has a great influence on the heat collection efficiency. The novel solar air collector structure proposed in this study, which integrates a downward jet mode with corrugated absorber plate, achieves a significant enhancement in heat transfer capacity and minimal increase in pressure drop. This design holds substantial scientific research value and engineering significance for efficiently harnessing solar energy, reducing fossil fuel consumption, and promoting environmental protection.