恒热流边界摆动射流冲击冷却的换热特性研究  

Research on heat transfer characteristics of oscillating jet impinging cooling with constant heat flux boundary

作　　者：颜健[1] 田勇 谢欣旖 彭佑多[1] YAN Jian;TIAN Yong;XIE Xinyi;PENG Youduo(School of Mechanical Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学机电工程学院,湖南湘潭411201

出　　处：《热科学与技术》2024年第6期603-611,共9页Journal of Thermal Science and Technology

基　　金：湖南省自然科学基金资助项目(2020JJ5189,2019JJ40085);湖南省教育厅科学研究资助项目(19C0794)

摘　　要：针对均匀热流边界下聚光光伏电池的高效均匀冷却问题,基于动态化冷却思想,提出了一种新颖的摆动射流冲击冷却方式实现动态均匀控温。考虑到摆动射流冲击冷却的流动换热复杂性,仅从二维数值模型开展初步探索,详细分析了摆动频率f、雷诺数Re、靶面长度与狭缝宽度之比L_(T)/D、冲击间距与靶面长度之比H/L_(T)与最大摆动角α等关键参数对靶面努塞尔数分布与换热均匀性的影响,初步掌握了摆动射流冲击冷却特性。结果表明:靶面的周期时间努塞尔数Nu_(t)随着摆动频率f的增加而逐渐降低,而其换热均匀性则呈相反变化趋势;Nu_(t)随雷诺数的增大而线性增加,最优Re=12 000时靶面平均Nu_(t)可达31.90,同时换热非均匀因子只有0.059,表现为优异的均匀冷却效果;随着最大摆动角α的增加,靶面Nu_(t)呈现为先降低后增加再降低的复杂非线性变化,而射流刚好扫到靶面的端点位置时并非最优换热效果;靶面上最大努塞尔数Nu的位置和数值均随时间变化,在射流与靶面垂直时Nu值最大,而在倾斜射流冲击时Nu略有下降,相对传统射流冲击冷却,摆动射流冲击冷却更具有灵活性和动态适应性,能有效提升靶面的换热均匀性。Aiming at the problem of efficient and uniform cooling of concentrating photovoltaic cells under the uniform heat flow boundary,a novel oscillating jet impingement cooling method is proposed based on dynamic cooling idea to realize dynamic uniform temperature control.Considering the complexity of flow and heat transfer in oscillating jet impingement cooling,a two-dimensional numerical model is built.The effects of key parameters such as the oscillating frequency f,Reynolds number Re,the ratio of target surface length to slot width L_(T)/D,the ratio of impact spacing to target surface length H/L_(T),and the maximum swing angleαon the distribution of the Nusselt number of the target surface and the uniformity of heat transfer are investigated.The results show that the periodic time Nu_(t) of the target surface gradually decreases with the increase of the oscillating frequency f but finally tends to be stable,while the heat transfer uniformity shows the opposite trend.Nu_(t) increases linearly with the increase of Reynolds number.When the optimal Re=12000,the average Nu_(t) on the target surface can reach 31.90,and the heat transfer non-uniformity factor C_(Nu) is only 0.059,showing an excellent uniform cooling effect.With the increase of the maximum oscillating angleα,the target surface Nu_(t) presents a complex nonlinear change that first decreases,then increases,and then decreases,while the jet is not the optimal heat transfer effect when it can just sweep to the endpoint position of the target surface.Both the position and value of the maximum Nusselt number Nuon the target surface change with time.When the jet is perpendicular to the target surface,the Nu value is the largest,while the inclined jet impacts Nu decreases slightly.Compared with the traditional jet impingement cooling,the oscillating jet impingement cooling is more flexible and dynamic adaptability,effectively improving the uniformity of heat transfer.

关 键 词：聚光光伏系统 光伏电池组件 摆动射流冲击冷却 努塞尔数 换热均匀性 

分 类 号：TK519[动力工程及工程热物理—热能工程]