摘要
为研究热流密度对LNG空温式翅片管内两相流流型及翅片管换热特性的影响,文中建立单根空温式翅片管管内外耦合传热模型,采用分段线性界面构造(PLIC)几何重建法构建气液界面,采用VOSET方法追踪管内两相区的流型,获得不同热流密度下管内两相区流型并与文献实验结果对比验证,分析流型转换边界及各流型形成机理。结果表明:随着热流密度从10^(4)W/m^(2)增加到3×10^(4)W/m^(2),LNG翅片管内两相区及相对应的流型出现位置提前;高热流密度下出现液束环状流与气膜塞状流,过渡流型缩短,气相区占比从58.3%增长至68.75%;由于LNG表面张力较小,弹-搅转换边界向高气相动量流速方向移动;随管径的减小,泡-弹转换边界向折合气速增大的方向移动,同时随热流密度的增大,泡-弹转换边界的移动提前。
The coupling model for the heat transfer inside and outside the LNG air-based finned tube was developed in order to investigate the effects of heat flux on the two-phase flow pattern and heat transfer performance of the tube.The bubble boundary was established by the PLIC method,and the flow patterns in the vapor-liquid region in the tube was captured by the VOSET method.The flow patterns under different heat fluxes obtained by the model were in comparison with the experimental results reported in the literature to verify the model.The trends of transition boundary between different flow patterns and the formation mechanisms were analyzed.The results show that the two-phase region of LNG and the corresponding flow patterns in the tube appear earlier with the heat flux increasing from 10^(4) W/m^(2) to 3×10^(4) W/m^(2).There is the liquid jet annular flow and the gas film plug flow for the higher heat flux,and the length of the transition flow to that of the two-phase region ratio significantly decreases and the proportion of the vapor-phase zone in the tube rises from 58.3%to 68.75%.The transition boundary between the slug flow and the agitation flow tends to move towards high vapor-phase momentum velocity due to the small surface tension of LNG,and bubble-bullet transition boundary tends to move towards high vapor-phase velocity due to reduction of pipe diameter.An earlier movement of the bubble-bullet transition boundary happens with the increase in heat flux.
作者
时国华
蒋可
周文博
赵岳天
SHI Guo-hua;JIANG Ke;ZHOU Wen-bo;ZHAO Yue-tian(School of Energy Power and Mechanical Engineering,North China Electric Power University,Baoding 071003,Hebei Province,China;China Electronic System Engineering No.2 Construction Co.,Ltd.,Wuxi 214151,Jiangsu Province,China)
出处
《化学工程》
CAS
CSCD
北大核心
2023年第5期45-51,共7页
Chemical Engineering(China)
基金
河北省重点研发计划项目(21374501D)。
关键词
LNG
两相流
热流密度
流固耦合
流型
LNG
two-phase flow
heat flux
fluid-structure coupling
flow patterns
