射流式太阳能空气集热器性能的数值模拟研究  

Numerical simulation study for impinging jet solar air heater

作　　者：龙艳萍[1] LONG Yanping(Department of Mechanical and Electrical Engineering,Jinan Engineering Polytechnic,Jinan 250200,China)

机构地区：[1]济南工程职业技术学院机电工程学院,山东济南250200

出　　处：《区域供热》2024年第4期119-126,共8页District Heating

基　　金：山东省教育发展研究微课题(FC068);济南工程职业技术学院重点科研项目(GHK21J01)。

摘　　要：为了提高太阳能空气集热器的性能,建立了射流太阳能空气集热器的数学模型,并分析了空气射流对太阳能空气集热器性能的影响。结果表明:在太阳能空气集热器内设置折流板形成射流流动,不仅可以增加集热板近壁面处的流动速度,还能减小垂直于空气流动方向的速度梯度。射流流动优化了流道内的速度分布,从而有效提高了空气与集热板的对流传热系数。与普通太阳能空气集热器相比,射流太阳能空气集热器的集热效率明显更高。当入口速度从0.5 m/s增加到3.0 m/s时,两者集热效率的差距从5.01%增加到15.38%。然而,射流太阳能空气集热器的压力损失较大,因此其有效效率随空气流量的增加呈现先增加后减小的趋势。在入口速度为2.5 m/s时,有效效率达到了极值63.75%,比普通太阳能空气集热器提高了11.21%。综上所述,利用折流板形成射流能显著提高太阳能空气集热器的集热效率与有效效率。In order to enhance the performance of solar air heaters,this study establishes a mathematical model for air jet solar air heaters and analyzes the influence of air jets on the performance of solar air heaters.The results indicate that by incorporating baffle plates inside the solar air heater to induce jet flow,not only the flow velocity near the wall of the absorber plate can be increased,but also the velocity gradient perpendicular to the direction of airflow can be reduced.The jet flow optimizes the velocity distribution within the duct,thereby effectively improving the convective heat transfer coefficient between the air and the absorber plate.Compared to conventional solar air heaters,air jet solar air heaters exhibit significantly higher thermal efficiency.When the inlet velocity increases from 0.5 m/s to 3.0 m/s,the difference in thermal efficiency between the two types increases from 5.01%to 15.38%.However,air jet solar air heaters suffer from relatively high pressure losses,resulting in a declining trend in effective efficiency as the air flow rate increases.At an inlet velocity of 2.5 m/s,the effective collection efficiency of jet solar air heater reaches a maximum efficiency of 63.75%,representing an improvement of 11.21%compared to conventional solar air heaters.To sum up,the use of baffles to form air jets could significantly improve the heat collection efficiency of solar air heaters.

关 键 词：射流 太阳能空气集热器 集热效率 压力损失 

分 类 号：TK513.1[动力工程及工程热物理—热能工程]