螺旋管式直流蒸汽发生器多并联通道两相流动不稳定性研究  

Two-phase flow instability in multi-parallel channels of helical-coiled once-through steam generator

作　　者：钱冠华 赵亚楠 王旭 于涛[1,2] QIAN Guanhua;ZHAO Ya'nan;WANG Xu;YU Tao(School of Nuclear Science and Technology,University of South China,Hengyang 421001,China;Key Lab of Advanced Nuclear Energy Design and Safety,Ministry of Education,Hengyang 421001,China;China Nuclear Engineering Consulting Co.,Ltd.,Beijing 100032,China)

机构地区：[1]南华大学核科学技术学院,衡阳421001 [2]先进核能技术设计与安全教育部重点实验室,衡阳421001 [3]中核工程咨询有限公司,北京100032

出　　处：《核技术》2025年第2期153-162,共10页Nuclear Techniques

基　　金：国家自然科学基金(No.12205142);湖南省自然科学基金(No.2023JJ40526)资助。

摘　　要：螺旋管式直流蒸汽发生器结构紧凑,传热能力强,适用于铅冷快堆等第四代反应堆。两相流的不稳定性可能导致传热管束的机械振动和热疲劳加重,从而对蒸汽发生器的安全运行构成严重威胁。采用RELAP5/MOD3.4程序对14根螺旋传热管的螺旋管式直流蒸汽发生器的二次侧进行了建模,并基于时域方法研究了启动过程中的振荡行为以及参数对系统稳定性的影响。结果表明:二次侧流体的压力、质量流量和温度在加热段呈现(n-2,2)模式的密度波振荡,并叠加有流型转变不稳定性。此外,增加入口节流度和系统压力、减少出口节流都有利于提高螺旋管式直流蒸汽发生器的系统稳定性。[Background]The helical-coiled once-through steam generator(H-OTSG)has the advantages of compact structure and strong heat transfer ability,which is appropriate for lead-cooled fast reactor(LFR).The two-phase flow instability may cause mechanical vibration and thermal fatigue of heat transfer tube bundles,posing a serious threat to the safe operation of steam generators.[Purpose]This study aims to explore the oscillation modes and influencing laws of two-phase flow instability of H-OTSG,providing reference for industrial design.[Methods]Firstly,RELAP5/MOD3.4 code was applied to modelling the helical-coiled once-through steam generator with 14 parallel heat exchange tubes.The primary working fluid of H-OTSG was liquid lead bismuth eutectic(LBE)and the secondary fluid was water.Then,the oscillation behavior during start-up was studied based on time-domain method and the oscillation characteristics and the parameter sensitivity of the stable boundary were analyzed.The limit cycles of the oscillation in each channel were shown on the pressure-drop vs.flow-rate plane.Finally,the influence of structural parameters on system stability were explored,so did that of operating parameters such as the pressure,flow rate,and temperature of the secondary fluid.[Results]The results indicate that the operating parameters exhibit density wave oscillations at the heating section in a(n-2,2)pattern,with superimposed flow pattern transition instability.The smaller the flow amplitude,the shorter and thinner the corresponding limit cycle,and the closer to the circle.In the same channel,as the driving force increases,the flow amplitude gradually decreases,and the limit cycle also gradually shrinks.In addition,as the inlet throttling has been increased from 1100 to 1700,the duration of oscillation shortened from approximately 6000 s to less than 1000 s,and the amplitude decreased by nearly 30%.With the increase of the outlet throttling from 0 to 200,the duration of oscillation has been lengthened from less than 5400 s to approximately 18

关 键 词：螺旋管式直流蒸汽发生器 多并联通道 两相流 流动不稳定性 时域分析 

分 类 号：TL331[核科学技术—核技术及应用]