高性能微通道换热器内凹形多孔微通道成形机理及性能研究

Microchannel heat sink shows its wide application potentials in the areas of microelectric, optoelectronic and aerospace devices. According to the design and manufacture limit of the current high-performance microchannel heat sink, this project developed novel reentrant porous microchannel structures with multi-scale rough surface in order to enhance the microscale heat transfer. It was fabricated via the sintering and transfer pattering method with the aid of a micro Ω-shaped convex graphite mould. The main research contents were as follows: digital characterization method of the reentrant porous microchannels as well as its multi-scale rough surface topography, and optimal design of the microchannel geometry; the fabrication mechanisms of porous microchannels by sintering copper powder and transfer pattering were studied, and the effects of fabrication parameters on the formation of porous microchannels are assessed. The control method for the formation of multi-scale rough surface is also explored. Besides, we also investigate the heat and mass transfer performance, as well as the heat transfer and fluid flow dynamics in the reentrant porous microchannels in order to establish the theoretical model and reveal the mechanism of enhanced boiling heat transfer. The above researches are expected to provide a new way for the design and fabrication of high-performance microchannel heat sink, which can extend the research of microchannel heat sinks from solid microchannels to porous microchannel. This project will introduce a system of design and manufacture method and theory of high-performance microchannel heat sink, which will promote the thermal management technologies for high heat-flux devices.

微通道换热器在微电子、光电、航空等领域应用前景广泛。针对高性能微通道换热器受制于微通道结构设计与制造的现状，项目以电火花线切割加工的特殊“Ω”形石墨微凸台为模板，利用烧结转印技术加工出具有多尺度粗糙表面形貌的内凹形多孔微通道结构，显著强化微通道换热器传热性能。项目研究该多孔微通道的数字化表征方法，进行结构优化设计；研究铜粉颗粒烧结转印制备内凹形多孔微通道的成形机理，揭示多因素协同作用下加工参数对多孔微通道及其表面形貌的影响规律，探索多尺度粗糙形貌的生成控制；分析多孔微通道换热器宏观传热传质性能规律和微观热流体动力学过程机理，建立传热传质过程模型，揭示其强化沸腾传热内在机制。项目研究为高性能微通道换热器的设计与制造提供崭新的思路，实现由传热实体微通道向多孔微通道的拓展，形成一套完整的高性能微通道换热器设计、制造理论体系及加工方法，推动我国高热流密度热控制技术的进步。

微通道换热器是解决微电子、光电、化工、航空航天等领域散热难题的理想选择. 针对高性能微通道换热器受制于微通道结构设计与制造的现状，项目以电火花线切割加工的特殊“Ω”形石墨微凸台为模板，利用烧结转印技术加工出具有多尺度粗糙表面形貌的内凹形多孔微通道结构，显著强化微通道换热器传热性能。项目在内凹形微通道结构优化设计、多孔微通道烧结转印加工方法与成形机理、多孔微通道结构关键物性参数表征、内凹形多孔微通道散热器微尺度传热传质性能等方面取得了一系列研究成果：实现了内凹形微通道结构的优化设计，并提出新颖交错内凹形微通道结构的设计；开发出内凹形多孔微通道烧结转印加工成形技术，提供了新的微通道加工方法，实现了微通道换热器从传统的硅、金属等实体基体向多孔基体的有效拓展，并揭示了多孔微通道烧结转印成形机理；系统表征了多孔微通道结构的粗糙表面形貌、孔径分布、力学、润湿、导热等关键性能参数，完善了多孔微通道结构相关物性数据；证实了内凹形多孔微通道在降低沸腾起始点壁面过热度、强化沸腾传热、抑制两相流动非稳定性、提高壁面温度均匀性等方面的显著优势，揭示了其强化传热传质的内在机制，阐明了多场耦合作用下微尺度传热传质机理，实现多孔微通道换热器的性能优化。上述研究成果为高效微通道散热器的进一步应用推广提供了重要的技术与理论基础，为电子、光电、航空航天等产品突破热失效瓶颈、提升性能提供了有力的技术支撑，对于提高我国在微通道换热器的制造技术和理论研究水平具有非常重要的意义。.相关研究成果在包括精密制造、传热、节能等领域顶级期刊在内的国际SCI刊物上发表论文15篇，其中一区1 篇，二区Top Journal 7 篇，并获得欧洲科学与艺术学院院士、中国科学院院士、多个国际传热学最高奖获得者、ASME Fellow等国际国内权威专家的广泛引用和正面评价。授权发明专利4项，获邀担任ASME第5届微纳传热传质会议分会场主席。