3D打印铜多孔结构池沸腾传热实验研究

Experimental investigation of pool boiling heat transfer of copper porous structures fabricated via 3D printing

采用SLM(选择性激光熔化)技术制备铜多孔结构试样,以去离子水为工质,实验研究SLM工艺参数和多孔结构形式对所制备样品毛细性能及池沸腾传热性能的影响。结果表明:增大激光扫描间距显著提升水在多孔结构内的毛细上升速度和最大上升高度。相比小扫描间距参数制备的试样,大扫描间距试样的毛细上升最大高度提升约29.6%。同时,随着扫描间距的增加,大扫描间距试样的临界热流密度F_(CH)和传热系数C_(HT)均增大。与光滑表面相比,柱状和栅格状结构试样的F_(CH)和C_(HT)明显提升,柱状结构具有更优的传热性能,其F_(CH)和C_(HT)分别增至233.5 W/cm^(2)和12 W/(cm^(2)·K),提升103%和106.9%。这些提升是由于柱状结构的骨架内存在更多的气化核心密度,同时还可以有效改善气液流动,促进液体回流。

SLM(selective laser melting)technology was employed to fabricate copper porous structure samples,and deionized water was used as the working fluid.The effects of SLM process parameters and porous structure configurations on capillary performance and pool boiling heat transfer characteristics of the fabricated samples were investigated.The results show that increasing the laser scan spacing significantly enhances the capillary rise speed and maximum capillary rise height within the porous structure.Compared with samples prepared by smaller scan spacing parameters,the maximum capillary rise height of samples produced with larger scan spacing increases by approximately 29.6%.Additionally,with the augmentation of scan spacing,the critical heat fluxF_(CH)and heat transfer coefficientC_(HT)of samples with larger scan spacing both increase.When compared to smooth surfaces,samples with pillar and lattice structures demonstrate notable improvements inF_(CH)andC_(HT).Particularly,the pillar structure exhibites superior heat transfer performance,withF_(CH)andC_(HT)increasing to 233.5 W/cm^(2)and 12 W/(cm^(2)·K),respectively,marking enhancements of 103%and 106.9%.These enhancements can be attributed to the higher density of nucleation sites within the skeletal framework of the pillar structure,which also effectively improves gas-liquid flow and promotes liquid reflux.