• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>International Journal of Heat and Mass Transfer >Gradient wick channels for enhanced flow boiling HTC and delayed CHF
【24h】

Gradient wick channels for enhanced flow boiling HTC and delayed CHF

机译：用于增强流沸腾HTC和延迟CHF的梯度芯频道

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Liquid supply to wick structures of flow boiling surfaces is fundamentally restricted by the capillary limit at which the pressure drop of the wicked liquid surpasses texture-amplified capillary forces. Gradient wick structures partially decouple permeability and capillary pressure, thereby delaying the capillary limit. In this study, gradient wick channels facilitating out-of-plane liquid delivery are introduced to postpone the capillary limit and thus enhance the two-phase flow boiling heat transfer coefficient (HTC) and delay critical heat flux (CHF). Here, the permeability of the gradient wick channels is augmented by large-pore-size meshes employed near the bulk fluid while capillary pressure is maximized by small-pore-size meshes utilized near the hot boiling surface. This combination of wick structures enables to preferentially guide the cooling liquid, deionized water, from the far-field cold liquid toward the bottom hot substrate. The spatial distribution of individual gradient wick channels promotes separate liquid-vapor pathways, thus facilitating the vapor escape process. Experiments conducted here reveal that the flow boiling performance metrics of the proposed heat sink leveraging the gradient wick channels outperform those of the homogenous wick channels and solid fin channels. The proposed heat sink demonstrates a strong liquid mass flux dependency due to a combination of convective boiling and amplified wickability effects. The enhanced convective boiling could be related to surface roughness, a high number of active nude-ation sites, and a large surface area available through tortuous passages of wick channels. At higher mass flow rates, effective capillary pressure available for out-of-plane wicking action also increases, thereby further boosting the wickability effect and associated heat transfer processes. This could meaningfully delay the CHF. In fact, the CHF limit was not observed on the gradient wick channel surfaces in the mass flux and wall superheat range studied. The experimental results indicated a maximum heat flux of 870 W/cm2 with a gradient wick channel heat sink, a 60% improvement compared with a plain copper surface. Furthermore, a maximum HTC of 1000 kW/m2-K at a wall superheat of 3 °C was observed, a three-fold enhancement compared with that of the plain surface. The proposed gradient wick channel topology offers new pathways for designing innovative surface technologies with high heat removal capabilities, thereby potentially improving the energy economy in myriad modern energy applications.
机译：液体供应到芯沸点的芯沸点结构基本上受到毛细管限制的毛细管限制，储存液体的压降超过纹理扩增的毛细力。梯度芯结构部分地脱渗透性和毛细管压力，从而延迟毛细管极限。在该研究中，引入了促进外平面液体输送的梯度芯通道，以推迟毛细管限制，从而提高两相流沸腾传热系数（HTC）和延迟临界热通量（CHF）。这里，梯度芯通道的渗透率通过在散装液附近使用的大孔径网来增强，而毛细管压力通过在热沸点附近使用的小孔径网最大化。这种芯结构的这种组合使得能够优先引导冷却液，去离子水，从远场冷液朝向底部热基材。各个梯度芯通道的空间分布促进了单独的液态蒸气途径，从而促进蒸汽逃逸过程。这里进行的实验表明，所提出的散热器的流沸腾性能度量利用梯度芯通道的散热槽优异地呈现同源芯通道和实心翅片通道的散热器。所提出的散热器由于对流沸腾和扩增的变形效应的组合而表现出强烈的液体质量通量依赖性。增强的对流沸腾可能与表面粗糙度，大量有源裸色地点以及可通过芯灯道的曲折通道提供的大表面积有关。在较高的质量流速下，可用于外平面芯吸作用的有效毛细管压力也增加，从而进一步提高了变形效果和相关的传热过程。这可以有意义地延迟CHF。事实上，在研究的梯度芯和壁过热范围内未观察到CHF限制。实验结果表明，870W / cm2的最大热通量，梯度芯沟道散热器，与普通铜表面相比，改善了60％。此外，观察到3°C的壁过热的最大HTC为3°C的过热，与平原表面相比的三倍增强。所提出的梯度灯芯通道拓扑提供了用于设计具有高散热能力的创新表面技术的新途径，从而潜在地改善了无数现代能源应用中的能源经济。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号