| Solid oxide fuel cells(SOFCs)are ceramic-based cells that operate at high temperatures.Unlike conventional power generation technologies,SOFCs convert chemical energy from fuel directly into electricity,eliminating the need for an intermediate process.SOFC applications are very wide,in addition to hydrogen energy,SOFC can also directly use a variety of carbon-based fuels,and has a high conversion efficiency.As a result,SOFCs are receiving increasing attention from academia and industry.SOFC reactors typically operate at temperatures above 700℃,making it a difficult task to maintain a low level of air tightness in flat-panel fuel cell reactors.This paper aims to reduce the leakage rate of SOFC reactor.The main research contents are as follows:(1)In order to obtain better sealing performance,based on labyrinth sealing structure widely used in rotary machinery,this paper studies and designs a connection with labyrinth sealing structure based on glass sealing,which can be used in sealing plate electric reactor.Based on finite element analysis,the contact stress model of sealing interface is established.The contact stress of two labyrinth seals and traditional plane seals is simulated under different working temperature and load pressure.(2)The hydrogen leakage rate was then estimated based on Hertz contact mechanics and seepage theory.The results show that the labyrinth seal can obtain a larger sealing interface width,and at the same time produce a larger contact stress.Under the same sealing section width and load pressure,the leakage rate of labyrinth seal is reduced from 0.00277 sccm/cm to 0.00053 sccm/cm,which is reduced by 80.9%.(3)The test was verified on the air tightness test bench.Based on the above leakage rate prediction model,parametric modeling of tooth height,tooth width and tooth number in two labyrinth seal structures was carried out to conduct a comparative study of leakage rate,analyze the influence of tooth height,tooth width and tooth number on the leakage rate and find the labyrinth seal structure size with the minimum leakage rate.(4)Finally,a simulation model for studying the bond strength of the sealing interface was established in ABAQUS using the cohesiveness model theory,and the comparison of the bond strength of the glass connector interface between the labyrinth seal structure and the plane seal structure proposed in this paper was simulated and analyzed at working temperature.The results show that although the labyrinth seal structure is slightly more complex than the traditional plane seal structure,the damage degree of the glass-connector bond interface is not higher than that of the plane seal at working temperature.Finally,the influence of the mechanical properties of connectors and glass on the tightness and mechanical properties of glass is studied based on the control variable method. |
