Characteristic Analysis on Distribution of Void Fraction during Stable Flow Flashing Process under Low Pressure

Zhang Yongfa; Du Keyue; Cao Xiaxin; Fang Yuliang; Liu Xiaoya; Jiang Lizhi

doi:10.13832/j.jnpe.2021.06.0012

Volume 42 Issue 6

Dec. 2021

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Zhang Yongfa, Du Keyue, Cao Xiaxin, Fang Yuliang, Liu Xiaoya, Jiang Lizhi. Characteristic Analysis on Distribution of Void Fraction during Stable Flow Flashing Process under Low Pressure[J]. Nuclear Power Engineering, 2021, 42(6): 12-16. doi: 10.13832/j.jnpe.2021.06.0012

Citation:

Zhang Yongfa, Du Keyue, Cao Xiaxin, Fang Yuliang, Liu Xiaoya, Jiang Lizhi. Characteristic Analysis on Distribution of Void Fraction during Stable Flow Flashing Process under Low Pressure[J]. Nuclear Power Engineering, 2021, 42(6): 12-16. doi: 10.13832/j.jnpe.2021.06.0012

Citation:

Zhang Yongfa, Du Keyue, Cao Xiaxin, Fang Yuliang, Liu Xiaoya, Jiang Lizhi. Characteristic Analysis on Distribution of Void Fraction during Stable Flow Flashing Process under Low Pressure[J]. Nuclear Power Engineering, 2021, 42(6): 12-16. doi: 10.13832/j.jnpe.2021.06.0012

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Characteristic Analysis on Distribution of Void Fraction during Stable Flow Flashing Process under Low Pressure

doi: 10.13832/j.jnpe.2021.06.0012

1.
College of Nuclear Science and Technology, Naval University of Engineering, Wuhan, 430033, China
2.
College of Nuclear Science and Technology, Harbin Engineering University, Harbin, 150001, China

Received Date: 2020-11-11
Rev Recd Date: 2021-01-07
Publish Date: 2021-12-09

Abstract

Abstract

Taking the flashing phenomenon in the low pressure natural circulation system as the research object, the change law of void fraction in the stage of stable two-phase natural circulation flow driven by flashing is analyzed. Through the analysis, the following law is found that the inlet fluid temperature of the rising section and the liquid level height of the water tank will cause the flow to affect the flashing vaporization process, which makes the radial and axial distribution of the void fraction different. Through the analysis, it is concluded that the main factor affecting the vaporization process is the fluid superheat degree. It is known that reducing the fluid degree of subcooling at the inlet of the rising section, the flashing starting point will move down, and the flashing two-phase section will become longer. Along with the continuous flashing vaporization, the fluid degree of subcooling decreases gradually, the axial void fraction distribution increases rapidly first and then gradually slows down, and the radial void fraction changes from “wall peak” type to “nuclear peak” type. Then, based on the change of local fluid degree of subcooling, fitting gives the calculation formula of axial void fraction under different cases. By comparing with the experimental data, it is found that the fitting is good, and the relative error is within ±15%.
- Low pressure,
- Natural circulation,
- Flashing,
- Void fraction,
- Superheat degree

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References(13)

References

[1]	邢继. 华龙一号能动与非能动相结合的先进压水堆核电厂[M]. 北京: 中国原子能出版社, 2016: 21.
[2]	宋代勇,赵斌,袁霞,等. “华龙一号”能动与非能动相结合的安全系统设计[J]. 中国核电,2017(4): 468-471.
[3]	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[J]. 核科学与工程,1996, 16(2): 104-113.
[4]	郭予飞,苏光辉,喻真烷,等. 低压低含汽率工况下两相自然循环流动不稳定的实验研究[J]. 核科学与工程,1999, 19(2): 137-141.
[5]	姜胜耀,张佑,吴莘馨. 自然循环静态流量漂移诱发动态流量振荡研究[J]. 清华大学学报(自然科学版),2000, 40(2): 17-32.
[6]	JIANG S Y, WU X X, WU S R. Experimental study on flashing concerned Instability in a natural circulation system at nuclear heating reactor conditions[J]. Kerntechnik, 1997, 62(1): 56-62.
[7]	VAN B, DE K, MANERA A, et al. Analytical modeling of flashing-induced instabilities in a natural circulation cooled boiling water reactor[J]. Nuclear Engineering and Design, 2002(215): 87-98. doi: 10.1016/S0029-5493(02)00043-2
[8]	MANERA A, ROHDE U, PRASSER H M, et al. Modeling of flashing-induced instabilities in the start-up phase of natural-circulation BWRs using the two-phase flow code FLOCAL[J]. Nuclear Engineering and Design, 2005(235): 1517-1535. doi: 10.1016/j.nucengdes.2005.01.008
[9]	MANERA A. Experimental and analytical investigations on flashing-induced instabilities in natural circulation two-phase systems[D]. Nederland : Delft University of Technology, 2003.
[10]	FURUYA M, INADA F, VAN D H. Flashing-induced density wave oscillations in a natural circulation BWR-mechanism of instability and stability map[J]. Nuclear Engineering and Design, 2005(235): 1557-1569. doi: 10.1016/j.nucengdes.2005.01.006
[11]	MANERA A, PRASSER H M, LUCAS D, et al. Three-dimensional flow pattern visualization and bubble size distributions in stationary and transient upward flashing flow[J]. International Journal of Multiphase Flow, 2006, 32(8): 996-1016. doi: 10.1016/j.ijmultiphaseflow.2006.03.005
[12]	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[J]. 原子能科学技术,2019, 53(11): 2162-2168.
[13]	杜可越. 流动闪蒸过程中的汽相分布规律研究[D]. 哈尔滨: 哈尔滨工程大学, 2019: 6.