三维矩形截面通道内不同流速下的过冷流动沸腾数值探究  

Numerical Investigation of Subcooled Flow Boiling at Different Flow Velocities in a 3D Rectangular Cross-Section Channel

作　　者：靳姝琦 陈宇杰 凌空 陶文铨[1] JIN Shuqi;CHEN Yujie;LING Kong;TAO Wenquan(Key Laboratory of Thermal Fluid Science and Engineering of MOE,Xi’an Jiaotong University,Xi’an 710049,China;Beijing Institute of Petrochemical Technology,Beijing 102617,China;Xi’an Shufeng Technological Information Co.,Ltd.,Xi’an 710049,China)

机构地区：[1]西安交通大学热流科学与工程教育部重点实验室,西安710049 [2]北京石油化工学院,北京102617 [3]西安数峰信息科技有限责任公司,西安710049

出　　处：《西安交通大学学报》2025年第5期54-63,共10页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金创新群体项目(51721004)。

摘　　要：为探究微液层蒸发对于过冷流动沸腾的贡献,基于适用于方管内流动沸腾的微液层模型,考虑流固耦合传热和动态接触角的影响,采用界面捕捉方法(VOSET)对基本的三维矩形截面通道单元内过冷流动沸腾过程中壁面上附着的单气泡生长情况展开数值探究,讨论了不同入口流速下通道内单气泡生长演变的流型和壁面过热度的变化,并对其微液层分布、蒸发量和传热性能作以定量分析,以增加对微小通道沸腾传热的理解和认识,为完整流程的流动沸腾传热研究奠定基础。计算结果表明:初始气泡随着加热和流动的影响沿着壁面生长滑动,体积膨胀直至气泡直径与通道截面尺寸相当后形成延长气泡,最终流出通道,气泡与壁面之间的微液层蒸发作用为气泡的生长和传热贡献了很大的作用,尤其在形成延长气泡后,蒸发热流占比最高可达近80%,直接影响着局部壁面过热度和对流传热系数的大小;增大流速后,同一时刻气泡生长的更快,但气泡在通道内的停留时间缩短,使得微液层蒸发发挥作用的时间缩短,总体上的平均对流传热系数随流速增加而减小。To investigate the contribution of microlayer evaporation to subcooled flow boiling,a numerical study is conducted based on a microlayer mathematical model suitable for flow boiling in square tubes.In this study,the effects of fluid-solid conjugate heat transfer and dynamic contact angles are considered,and the interface capturing method(VOSET)is employed to capture interfaces.The focus is on the growth of a single attached bubble on the wall during the process of subcooled flow boiling within a basic three-dimensional rectangular cross-section channel unit.The flow pattern evolution and wall superheat degree change during the growth and evolution of a single bubble in the channel under different flow velocity are discussed,and the distribution of microlayer,evaporation capacity and heat transfer performance are quantitatively analyzed,which enhances the understanding and knowledge of boiling heat transfer in microchannels,laying the foundation for research on flow boiling heat transfer in complete processes.The results show that the initial bubble grows and slides along the wall under the influence of heating and flow,expanding in volume until its diameter becomes comparable to the cross-sectional size of the channel,then an extended bubble is formed,and it flows out of channel.The evaporation of the microlayer between the bubble and the wall contributes greatly to the bubble growth and heat transfer.Especially after the formation of an elongated bubble,the evaporation heat flux can account for nearly 80%of the total,directly affecting the local wall superheat and convective heat transfer coefficient.With the increase of flow velocity,the bubble grows faster,but their residence time in the channel is shortened,thereby reducing the duration during which microlayer evaporation can play a significant role.On the whole,the average heat transfer coefficient decreases with the increase of inlet velocity.

关 键 词：流动沸腾传热 界面捕捉方法 微液层模型 

分 类 号：TK124[动力工程及工程热物理—工程热物理]