CIESC Journal ›› 2022, Vol. 73 ›› Issue (7): 2962-2970.DOI: 10.11949/0438-1157.20220178

• Fluid dynamics and transport phenomena • Previous Articles     Next Articles

Mechanism model of critical heat flux in narrow rectangular channel based on flow oscillations

Meiyue YAN1(),Jian DENG2,Liangming PAN1(),Zaiyong MA1,Xiang LI1,Jiewen DENG1,Qingche HE1   

  1. 1.Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China
    2.Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China, Chengdu 610041, Sichuan, China
  • Received:2022-02-07 Revised:2022-04-18 Online:2022-08-01 Published:2022-07-05
  • Contact: Liangming PAN

基于流量振荡的窄矩形通道内临界热通量机理模型

闫美月1(),邓坚2,潘良明1(),马在勇1,李想1,邓杰文1,何清澈1   

  1. 1.重庆大学低品位能源利用技术及系统教育部重点实验室,重庆 400044
    2.中国核动力研究设计院反应堆系统设计技术;重点实验室,四川 成都 610041
  • 通讯作者: 潘良明
  • 作者简介:闫美月(1993—),女,博士研究生, yanmeiyue@cqu.edu.cn
  • 基金资助:
    国家重点研发计划项目(02120023710003);重庆市研究生科研创新项目(CYB21023)

Abstract:

The maximum operating power of the device is limited by the critical heat flux (CHF), however, the flow oscillation can cause premature critical heat flux (called PM-CHF) and reduce the stable operating range. In order to study the critical heat flux in a narrow rectangular channel under flow oscillation conditions, this paper conducted experiments to visualize the boiling crisis in a narrow rectangular channel under vertical upward flow condition with deionized water as the working medium, with mass flux range of 350—2000 kg/(m2·s), narrow gap size range of 1—5 mm, and system pressure range of 1—4 MPa. The results show that CHF increases linearly with increasing mass flow rate in the narrow rectangular channel. The flow oscillation occurs when the mass flux is small, and the oscillation period is about 0.1 s. The flow oscillation leads to the early onset of boiling crisis, during which the flow pattern is slug-churn flow. Based on the flow oscillation and the bubble dynamics characteristics in the narrow rectangular channel, the theoretical analysis and derivation are carried out from the perspective of flow oscillation. In results, a PM-CHF mechanism model is established, and the error is within 30%.

Key words: narrow rectangular channel, PM-CHF, two-phase flow, flow regime, bubble

摘要:

设备最大运行功率受临界热通量(CHF)限制,而流量振荡会导致沸腾危机早发,此时的临界热通量称为PM-CHF。为了研究流量振荡条件下窄矩形通道内的临界热通量,进行单侧加热窄矩形通道内竖直向上流动条件下沸腾危机可视化实验,实验工质为去离子水,质量流速范围为350~2000 kg/(m2·s),窄缝宽度范围为1~5 mm,系统压力范围为1~4 MPa。结果显示,在窄矩形通道中CHF随质量流速的增加而线性增加。当流速较小时会发生流量振荡,振荡周期约为0.1 s。流量振荡继而导致沸腾危机早发,其流型表现为弹状流-搅混流。此外,针对本实验观察到的流量振荡和窄矩形通道内气泡动力学特性,从流量振荡的角度进行理论分析与推导,建立窄矩形通道内由于流动失稳引起的PM-CHF机理模型,预测误差在30%以内。

关键词: 窄矩形通道, PM-CHF, 两相流, 流域, 气泡

CLC Number: