摘要
对平板式固体氧化物燃料电池(SOFC)的压缩密封结构的泄漏特性进行定量研究。为模拟粗糙泄漏通道的复杂形貌,采用粗糙表面数值重构技术来构建不同气体泄漏通道;考虑流动通道尺度细微、边界复杂,应用格子Boltzmann方法(LBM)对气体流动特性进行数值分析,建立包括粗糙表面几何特性参数在内的泄漏率计算模型;通过单粗糙峰微观接触力学分析,建立泄漏通道结构特征参数随应力变化的定量关系式,并分析各种因素对封接气密性的影响。结果表明:压缩密封结构的主要影响因素为粗糙表面形貌、密封材料机械力学特性、密封流体物性以及密封结构工作状态;表面粗糙度越大,温度越高,泄漏率越低;压缩密封过程中材料变形较小,对泄漏率的影响也较小;不同介质的热物理性质差异会引起泄漏率的不同。将提出的模型应用于某SOFC密封结构的泄漏率预测,计算结果与实验测量结果吻合良好,验证了模型的准确性。
The leakage characteristics of planar solid oxide fuel cell(SOFC)compressive seals were studied quantitatively.In order to simulate the complex morphology of the rough leaky channel,a rough surface numerical reconstruction technique was used to construct different gas leak channels.By considering the minute size and complex boundaries,the gas flow characteristics were numerically analyzed by using the Lattice Boltzmann method(LBM),and the leakage rate calculation model including the geometric parameters of the rough surface was established.Based on the micro-contact mechanics analysis of single rough peak,the quantitative relationship between structural characteristic parameters of leakage passage and stress was established,and the effects of various factors on sealing tightness were analyzed.The results show that the main influencing factors of compressive seal structure are rough surface morphology,mechanical properties of sealing material,physical properties of sealing fluid and working state of sealing structure.The leakage rate will decrease with increasing temperature and surface roughness.The material has slight deformation in the process of compression sealing,which ghas small influence on leakage rate.The difference of thermophysical properties of different media will lead to the difference of leakage rate.The model was applied to the leakage rate prediction of a SOFC seal structure.The calculated results are in good agreement with the experimental results,which proves the accuracy of the model.
作者
许国良
杜阳
朱一萍
孙佳伟
师春雨
黄晓明
XU Guoliang;DU Yang;ZHU Yiping;SUN Jiawei;SHI Chunyu;HUANG Xiaoming(School of Energy and Power Engineering,Huazhong University of Science and Technology,Wuhan Hubei 430074,China)
出处
《润滑与密封》
CAS
CSCD
北大核心
2019年第4期1-7,共7页
Lubrication Engineering
基金
国家自然科学基金项目(51576077)
作者简介
许国良(1968—),男,博士,教授,研究方向为流动与传热、稳定燃烧、新能源技术.E-mail:duyang@hust.edu.cn;通信作者:黄晓明(1976—),女,博士,副教授,研究方向为流体传热传质理论及电子器件散热技术.E-mail:xmhuang@hust.edu.cn.
