[关键词]
[摘要]
窄通道具有结构紧凑、传热效率高等优点。随着科技发展,窄通道已经成为强化换热的常用结构形式之一,被广泛应用于各种换热设备。由于窄通道内间隙内气泡的尺寸受限,气泡在发展过程中会受到挤压而发生变形,带走大量的潜热,引起汽液界面的扰动,换热性能较常规通道有很大区别。本文综述了窄通道内的主要流型及转变准则;介绍了几何与工况参数变化对窄通道内换热效果影响的传热实验研究;分析了窄通道中传热机理以及两相摩擦压降机理,并对关联式进行了总结与评述;对窄通道内强化换热的机理与进一步强化换热的方法进行归纳总结;结合目前实验与理论研究总结了现存问题,为窄通道内流动沸腾强化换热的进一步研究提供了参考。
[Key word]
[Abstract]
The narrow channels have the advantages of compact structure and high heat transfer efficiency. With the development of technology, narrow channels have become one of the common structures to enhance heat exchange and are widely used in various heat exchange equipment. Due to the restriction of vapor bubble size caused by narrow channel gap, the vapor bubble will be deformed caused by squeezing during the development process, taking away a large amount of latent heat and causing disturbance at the vaporliquid interface. The heat transfer performance is very different from that of conventional channels. In this paper, the main flow patterns and transformation criteria in narrow channels are reviewed; the experimental study on the effects of geometry and operating parameters on heat transfer in narrow channels is introduced; the heat transfer mechanism and the twophase friction pressure drop mechanism in narrow channels are analyzed, and the correlations are summarized and commented; the mechanism of enhancd heat transfer in narrow channels and methods for further enhanced heat transfer are summarized; the existing problems are proposed in relation to the current experimental and theoretical studies, providing a reference for further research on enhanced heat transfer by flow boiling in narrow channels.
[中图分类号]
TK124
[基金项目]
上海市动力工程多相流动与传热重点实验室研究项目(2019KJFZ201)