CIESC Journal ›› 2019, Vol. 70 ›› Issue (11): 4231-4237.DOI: 10.11949/0438-1157.20190407

• Fluid dynamics and transport phenomena • Previous Articles     Next Articles

Experimental research on reverse flow phenomenon in natural circulation with equal height difference under low flow rate

Jianchuang SUN1(),Xiaxin CAO1,Xu RAN2,Zhuohua ZHANG2,Zhengpeng MI2,Ming DING1()   

  1. 1. Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001, Heilongjiang, China
    2. Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China, Chengdu 610213, Sichuan, China
  • Received:2019-04-18 Revised:2019-08-02 Online:2019-11-05 Published:2019-11-05
  • Contact: Ming DING

低流量下等高差自然循环系统倒流现象实验研究

孙建闯1(),曹夏昕1,冉旭2,张卓华2,米争鹏2,丁铭1()   

  1. 1. 哈尔滨工程大学核安全与仿真技术国防重点实验室,黑龙江 哈尔滨 150001
    2. 中国核动力研究设计院核反应堆系统设计技术重点实验室,四川 成都 610213
  • 通讯作者: 丁铭
  • 作者简介:孙建闯(1993—),男,博士研究生,sunjianchuang@hrbeu.edu.cn
  • 基金资助:
    国家自然科学基金项目(11605033)

Abstract:

Natural circulation systems are widely used in nuclear power plants due to their inherent safety. Natural circulation system with equal height different is a special system, because its heating section and water tank are connected by upper and lower horizontal loops. However, the phenomenon that the water in water tank reversely flows to the upper horizontal loop will be occurred in this kind of natural circulation system under low flow rate conditions. The studies of this phenomenon are not common. The reverse flow characteristics of upper horizontal loop is researched by visualization experiments. The results show that the reverse flow length in the upper horizontal loop decreases with the increase of flow rate, and increases with the increase of temperature difference between the outlet fluid of heater and the reverse flow fluid form water tank. It is found that the reverse flow in the upper horizontal loop is mainly affected by the inertia force of the hot water and the buoyancy force formed by the hot water and the reverse flow fluid. In addition, the reverse flow phenomenon in the upper horizontal loop can be judged by Richardson number.

Key words: flow, heat conduction, hydrodynamics, equal height difference natural circulation, visualization, reverse flow phenomenon, Richardson number

摘要:

自然循环系统由于具有固有安全性而被广泛应用于核电站中。等高差自然循环系统是一种特殊的系统,其加热段与水箱之间是通过上下水平段连接。在低流量条件下,这类自然循环系统会发生水箱冷水倒流至上水平段的现象,目前对该现象的研究并不常见。对等高度差自然循环系统的上水平段倒流特性进行了可视化实验研究。实验结果表明,上水平段倒流长度随流量的增加而减小,随着加热段出口流体与倒流流体温差的增大而增加。研究发现,上水平段倒流现象主要受加热段出口流体惯性力和与倒流流体形成的浮升力共同影响,并且倒流现象的发生可以通过Richardson数来判定。

关键词: 流动, 热传导, 流体动力学, 等高差自然循环, 可视化, 倒流现象, Richardson数

CLC Number: