Experimental Study On The Airtightness Of SOFC Stack Glass Seal

With the continuous reduction of non renewable energy,the energy crisis is approaching,and the environmental pollution problem is becoming increasingly serious.All countries are exploring a clean,environmentally friendly,and efficient energy conversion technology.Based on this goal,fuel cell technology emerged,and solid oxide fuel cell(SOFC)is a type of fuel cell.Compared to other types of fuel cells,SOFC has higher efficiency and is more environmentally friendly.The research focus in this field is on flat panel structured SOFCs.During the development of flat panel SOFCs,the sealing problem of battery stacks has become a bottleneck in their development,and therefore has become the focus of research by various SOFC teams.In the high-temperature environment where SOFCs operate,exploring suitable sealing materials,optimizing sealing structures,and improving sealing performance are the key points.This article conducts research and analysis based on experiments in the direction of SOFC stack sealing.The main research contents of this article are as follows:(1)Firstly,an airtightness testing platform suitable for the existing stack structure was built,including the design of the overall framework structure,the flow design of hardware devices,and the upper computer interface design based on Labview program control.Select and purchase various instruments and meters(pressure gauges,flow meters,solenoid valves,etc.),and assemble the gas circuit panel.Conduct pressure maintaining test on the built test bench to ensure good sealing performance of the test bench.(2)Determine the test method of the experiment,first of all,different sealing materials(hot aluminum 866,hot stone 866 plus glass and phlogopite sheet plus glass)leakage test,in which phlogopite plus glass material under a load of 0.05MPa,3KPa ventilation pressure,the leakage rate of 810℃ is 0.0969sccm/cm;Then,the sealing test of the touch reactor was carried out by pure glass,and the sealing performance of different sealing widths and maze surfaces of the plane was explored,and the experimental results showed that the large compressive stress on the surface could reduce the leakage,and the increase of the sealing width was conducive to improving the sealing performance,and the leakage rate of the 15mm sealing width reached 0.0089sccm/cm when the ventilation pressure was 2KPa and the load pressure was 0.1 MPa;However,the compressive load has little effect on the labyrinth seal,the load pressure increases from 0.06MPa to 0.1 MPa,and the leakage rate changes within 0.005 sccm/cm.(3)Based on the influence of plane sealing width on glass sealing,the stress simulation analysis was conducted using existing structural models and ABAQUS software.Firstly,the problem of mismatch between the thermal expansion coefficient of the glass material and the connector assembly at high temperatures was analyzed,which led to the phenomenon of stress concentration of the seal due to thermal stress.In addition,negative contact stress occurs on the surface around the fuel side of the seal.Through stress simulation of seal models with different seal widths,it is found that increasing the seal width can appropriately reduce the occurrence of stress concentration and negative stress phenomena.