多孔微槽道复合结构的强化沸腾传热性能

摘要

In the investigation, a porous micro-channel composite structure was designed and prepared .First, the copper particles were sintered together with the base at high temperatures to form a porous layer structure of certain thickness.Then, a micro-channel structure of certain depth was made on the porous layer through wire-electrode cutting.The micro-channel structure is not only able to increase the surface area of sintered porous layer when boiling but also provide steam channels to ensure the steam to escape when resistance becomes less , thus helping bubbles go out easily .Meanwhile , when liquid is boiling violently , micro-channels can provide gas-liquid two-phase channels , thus separating gas with liquid .Finally, the influence of such key parameters as micro-channel number , micro-channel angle and micro-channel width and depth on the boiling heat-transfer performance were analyzed .Experimental results indicate that the more the micro-channel numbers and the larger the micro-channel depth are , the more contact area of gas-liquid interface will bring about better enhanced boiling heat-transfer effect .%设计了一种多孔微槽道复合结构，首先在高温条件下通过烧结将颗粒状铜粉与基体紧密结合在一起，形成具有一定厚度的多孔层结构；再利用线切割在多孔层上加工出具有一定深度的微槽道结构。微槽道结构不仅增加了沸腾时烧结多孔层的表面积，还提供蒸汽通道来保证蒸汽在较小阻力情况下逸出，从而利于气泡脱离；同时在液体剧烈沸腾时可以提供气液两相通道，从而分离气液相对流动。文中还分析了多孔微槽道复合结构关键参数（微槽道数目、微槽道角度、槽宽和槽深等）对沸腾传热效果的影响。实验结果表明，微槽道数目越多，微槽道深度越大，气液界面接触面积越大，强化沸腾传热效果越明显。