Study on Flow Pattern Evolution in Outlet Heat Removal Pipe of Open Natural Circulation System
-
摘要: 开式自然循环系统作为新型非能动余排系统最终热阱排放回路，其安全稳定运行对于事故工况下堆芯余热安全导出至关重要，本研究通过可视化实验方法观察了开式自然循环系统出口排热管内流型演化特性，发现随着加热功率增加，开式自然循环逐步建立，该系统出口排热管内依次出现单相流、间歇性汽泡流、弥散泡状流、弹状流和间歇喷射流5种典型流型，分析了出口排热管内流型与系统稳定运行之间的关系，发现了开式自然循环系统剧烈振荡的根源，为提高开式自然循环系统流动稳定性提供了参考。Abstract: As the ultimate heat sink discharge loop of the new passive residual heat removal system, the safe and stable operation of the open natural circulation system is very important for removing the residual heat of the reactor core under accident conditions. In this paper, the flow pattern evolution in the outlet heat removal pipe of the open natural circulation system is observed by visual experiment. It was found that with the increase of heating power, the open natural circulation is gradually established. There are five typical flow patterns in the heat removal pipe at the outlet of the system: single-phase flow, intermittent bubble flow, dispersed bubble flow, slug flow and intermittent jet flow. The relationship between the flow pattern in the outlet heat removal pipe and the stable operation of the system is analyzed, and the source of the violent oscillation of the open natural circulation system is found, which provides reference for improving the flow stability of the open natural circulation system.
-
Key words:
- Open natural circulation /
- Two-phase flow pattern /
- Flow oscillation
-
图 3 开式自然循环系统运行特性
Figure 3. Operation Characteristic of the Open Natural Circulation System
-
[1] 房玉良,曹夏昕,倪嵩,等. 低压自然循环系统流动闪蒸过程流型研究[J]. 原子能科学技术,2019, 53(11): 2162-2168. doi: 10.7538/yzk.2018.youxian.0852 [2] ARITOMI M, CHIANG J H, MORI M. Fundamental studies on safety-related thermo-hydraulics of natural circulation boiling parallel channel flow systems under startup conditions (mechanism of geysering in parallel channels)[J]. Nuclear Safety, 1992, 33(2): 170-182. [3] HSIEH C C, WANG S B, PAN C. Dynamic visualization of two-phase flow patterns in a natural circulation loop[J]. International Journal of Multiphase Flow, 1997, 23(6): 1147-1169. doi: 10.1016/S0301-9322(97)00026-8 [4] 徐锡斌,徐济鋆,黄海涛,等. 低压下两相自然循环流动不稳定性的实验研究(Ⅰ)机理探索[J]. 核科学与工程,1996, 16(2): 104-113. [5] MANTHEY R, SCHUSTER C, LIPPMANN W, et al. Effect of throttling on the two-phase flow stability in an open natural circulation system[J]. Heat and Mass Transfer, 2020, 56(1): 37-52. doi: 10.1007/s00231-019-02679-x [6] 郭雪晴,孙中宁,王建军. 开式自然循环系统启动特性实验研究[J]. 核技术,2014, 37(4): 69-74. [7] 郭雪晴,孙中宁,张东洋. 细长自然循环系统流动不稳定性实验研究[J]. 原子能科学技术,2014, 48(2): 267-270. doi: 10.7538/yzk.2014.48.02.0267 [8] HOU X F, SUN Z N, FAN G M, et al. Experimental and analytical investigation on the flow characteristics in an open natural circulation system[J]. Applied Thermal Engineering, 2017, 124: 673-687. doi: 10.1016/j.applthermaleng.2017.05.201 -
下载:
图(4)
计量
- 文章访问数: 328
- HTML全文浏览量: 72
- PDF下载量: 29
- 被引次数: 0
