基于离子风冷却的LED集成系统耦合建模及性能优化研究

Thermal management of high-power light-emitting diode (LED) has become one of the bottlenecks in the semiconductor lighting industry. The electrohydrodynamic (EHD) enhancement of heat transfer is expected to meet the cooling requirements of high-power LED due to their advantages such as small electrodes and easy integrating with LED chip. But there exists some key issues that must be solved, including the local high heat flux caused by the current congestion effects near the electrodes, cooling problems of the LED chip with shaped substrate and the high-power LED chip array. Based on the methods of experimental measurement, theoretical analysis and numerical simulation, this project will investigate the mechanism of EHD enhancement of heat transfer, improve the mathematical models for EHD air pump, develop the integrated modeling technology for EHD-LED integrated system, establish the multi-parameter optimization approach for the EHD-LED integrated systems to optimize the integrated system structure, and achieve the overall performance enhancement of EHD-LED integrated system ultimately. Besides, it will also conduct related experiments for mechanism verification of EHD enhancement of heat transfer, test the overall performance of EHD-LED integrated system, as well as accumulate the basic experimental data. This project can promote the cross-disciplinary for engineering thermal physics and other disciplines, and also can provide a valuable theoretical guidance and technical reserves for the thermal management of next generation of high-power LED.

大功率发光二极管（LED）热管理问题已经成为制约半导体照明产业和技术发展的瓶颈之一。电流体动力学（EHD）离子风强化传热具有电极体积小、易和LED芯片集成等特点，有望解决大功率LED的散热需求。但目前存在单芯片电极附近电流拥塞效应带来的局部高热流散热、异形衬底LED芯片散热及大功率LED芯片阵列散热等关键问题亟待解决。本项目拟采用实验测量、理论分析和数值模拟的研究方法，开展EHD增强换热机理研究，完善现有EHD空气泵数学模型，发展EHD-LED集成系统的一体化建模技术，建立EHD-LED集成系统的多参数反问题优化方法，对集成系统进行多参数同时优化，实现由内到外、由微观到宏观、由局部到整体的全面性能提升；开展相关EHD机理验证实验和EHD-LED集成系统整体性能测试实验，积累基础实验数据。本课题可促进工程热物理学科与其它学科的交叉，也将为下一代大功率LED热管理提供可行的理论依据及技术储备。

电流体动力效应（EHD）强化换热以其能耗低、体积小、易集成、无噪音等诸多优点成为颇具前景的主动强化换热技术。虽然国内外已对其进行了广泛研究，但因机理复杂，长期以来研究以实验居多，对其强化换热机理认识不深，特别是微通道中EHD效应引发的新现象、新机理尤其缺乏，不能有效指导微通道内强化换热设计。签于此，本项目以LED的热管理应用为切入点，利用CFD方法发展了EHD多物理耦合模型，揭示了微通道中的强化换热机理，并通过新的电极组态设计及敏感参数优化，使换热效果显著增强，主要研究成果包括：.（1）建立了微通道内EHD多物理场耦合模型，模型与实验结果吻合良好。提出了电极组态的设计准则：电极置于通道前端更有利于强化换热；增大电极间距可削弱电极间的能量耗散从而使换热强化；大电极间距以电极远离入口为代价，必须兼顾横向位置和电极间距。.（2）基于电场激发的不同旋涡形态、强度及涡间相互作用机制，提出了电极间“势垒效应”的新概念。发现换热贡献在射流强度和射流数目间存在竞争，并据此提出了通过调控电极组态可实现EHD换热节能设计的策略。.（3）发现了双壁换热负载通道内“额外体积力”是控制通道内换热特性的决定性因素。提出了通道内被动涡应被主动涡替代的设计思想，此设计可消除电极间的“势垒效应”。和无EHD时相比，改进的电极组态可使上壁面换热强度提高166.4%，下壁面提高242.7%。.本项目按照预定研究计划执行，进展顺利，未进行调整，已完成相关研究内容。依托本项目，共发表国际期刊论文3篇，其中SCI检索论文3篇，EI检索论文3篇，详见附表，所列成果全部标注本项目资助；参加国内基金进展学术交流会一次；作为副导师，协助指导培养的研究生中一名并已毕业。