矩形窄缝通道内泡状流—弹状流流型转变准则研究  

Transition Criterion of Bubbly-slug Flow Pattern in Rectangular Narrow Channel

作　　者：韩晋玉 何雯 赵陈儒 薄涵亮 HAN Jinyu;HE Wen;ZHAO Chenru;BO Hanliang(Institute of Nuclear and New Energy Technology,Collaborative Innovation Center for Advanced Nuclear Energy Technology,Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学核能与新能源技术研究院,先进核能技术协同创新中心,先进反应堆工程与安全教育部重点实验室,北京100084

出　　处：《原子能科学技术》2022年第12期2524-2532,共9页Atomic Energy Science and Technology

基　　金：中核集团“青年英才”项目。

摘　　要：在两相流系统中,流型影响系统的摩擦阻力和传热等特性,准确判定不同流型对于两相流的计算具有重要意义。对于窄缝通道内的气液两相流动,特别是矩形窄缝通道内流型转变准则,已有学者进行了一定的实验研究,但由于实验装置及工况的限制,目前尚缺乏统一且适用性较广的流型转变准则,已有的基于矩形通道的流型判定准则适用性也有待于进一步评估。本文以空气-水为工质,对竖直矩形窄缝通道内泡状流-弹状流流型转变准则进行分析研究,基于1 168个流型实验数据,采用分界成功率对已有转变准则对于实验数据的适用性进行定量综合评价,并针对流型转变原理开展理论分析,引入无量纲数约束因子Co,建立考虑工质物性和流道尺寸、精度更高、适用范围更广的窄缝通道内泡状流-弹状流流型转变准则。本文结论可为反应堆换热元件和紧凑式换热器设计计算提供依据。In the two-phase flow system, the flow pattern affects the frictional resistance and heat transfer characteristics of the system. Accurate identification of different flow patterns is of great significance to the calculation of two-phase flow. For the gas-liquid flow in narrow channels, especially the flow pattern and flow pattern transition criterion in rectangular narrow channels, some researchers have done some experimental studies. For the study of flow pattern in narrow rectangular channels, the classification of flow patterns is basically consistent with that in conventional rectangular channels, including bubbly flow, slug flow, churn flow and annular flow. However, the performance of existing flow pattern transition criteria for two-phase flow in narrow rectangular channels still needs further and comprehensive assessments. In this paper, a parameter representing the success rate of boundary separation of bubbly-slug flow transition was introduced to quantitatively evaluate the performances of five typical bubbly-slug flow transition criteria and experimental data reported by 10 previous researchers, covering channel sizes ranging from 0.6 mm to 3.0 mm. Results show that the success rate of boundary separation of the Jones & Zuber criterion, Taitel criterion, Mishima-Ishii criterion and Xu criterion in predicting the experimental data varies from 61.86% to 98.10%. The variation mainly attributes to the assumption of constant critical void fraction in these criterions, since analyzing shows that the critical void fraction of flow pattern transition is related to the channel geometry. Although the Hibiki-Mishima criterion considers the effect of channel size on the critical void fraction, the bubbly diameter(D) is also needed in this model, which is difficult to obtain. The influence of channel size on the flow transition was quantitatively analyzed based on a dimensionless parameter of confinement number(Co). Finally, the flow pattern transition function(f(k)) was correlated with Co, and a new flow pattern

关 键 词：矩形通道 窄缝 两相流 流型转变 

分 类 号：TL375.5[核科学技术—核技术及应用]