多级复合芯结构的强化沸腾传热研究

采用固相烧结技术制备了均匀多孔层、复合16芯和复合32芯三种多孔结构，并且建立了池沸腾传热测试系统来研究不同芯数量、粒径与结构高度对多孔结构沸腾传热性能的影响。实验结果表明，在测试范围内复合层高1 mm的多孔复合32芯结构传热性能较强，临界热通量(CHF)最高为386 W/cm²，传热系数最高达到9.5 W/(cm²·K)。同时利用高速摄影观察气泡行为来研究强化沸腾传热机理。可视化数据表明，相比于光滑表面，在高热通量下多孔复合表面上气泡周期更短，脱离更快，气泡的离开带来了更多的液体补充，进而不断提升传热性能，获得更高的CHF值。

Research on enhanced boiling heat transfer of multilevel composite wick structure

Three kinds of porous structures, uniform porous layer, composite 16-core and composite 32-core were prepared by solid-phase sintering technology, and a pool boiling heat transfer test system was established to study the boiling heat transfer performance of the porous structure with different number of cores, particle size and structure height impact. The experimental results show that the porous composite 32-core structure with a composite layer height of 1 mm has strong heat transfer performance within the test range, with a maximum critical heat flux of 386 W/cm² and a heat transfer coefficient of up to 9.5 W/(cm²·K). At the same time, high-speed photography is used to observe bubble behavior to study the mechanism of enhancing boiling heat transfer. Visual data shows that compared with light surfaces, the bubble cycle on the porous composite surface is shorter and the separation is faster under high heat flux. The leaving of the bubbles brings more liquid replenishment, which in turn continuously improves the heat transfer performance and achieves higher critical heat flux.