Stress Assessment And Fatigue Analysis Of Hydrogen Storage Tank For Hydrogen Fuel Cell Ship During Charging Process

In recent years,with the problem of environmental degradation and energy depletion becoming more and more obvious,the new energy system has become one of the hotspots of world scholars,and one of the most ideal fossil energy alternatives is hydrogen energy.At present,the realization of large-scale hydrogen fuel cell also provides convenience for the research and development of hydrogen fuel cell ship.As an efficient and clean new energy,hydrogen also has such dangerous characteristics as flammable and explosive.Once the leakage occurs,it is easy to produce explosion,which also brings great challenges to the transportation,storage and safe use of hydrogen.As the carrier of hydrogen storage,hydrogen storage tank must have high stability and durability.Therefore,the stress assessment and life prediction of hydrogen storage tanks are particularly important.In this paper,based on ANSYS WORKBENCH platform,the working process of a hydrogen storage tank for a hydrogen fuel cell ship was studied by using the fluid-solid coupling method.The boundary conditions of the hydrogen storage tank under the influence of the internal heat flow field in the inflation process are obtained,and the stress analysis and strength verification of the hydrogen storage tank are carried out.Finally,the life prediction of hydrogen storage tank is carried out based on the stress-fatigue method.The research results are as follows :(1)The influence of different mass inlets on the velocity of fluid,temperature,pressure,density,inflation time,heat exchange rate and other parameters of the pressure vessel is analyzed,and the internal pressure and temperature field during the startup of the pressure vessel are obtained.(2)Based on the third strength theory,the stress linearization evaluation of the hydrogen storage tank was carried out.Combined with the flow field analysis,the distribution and causes of the stress in the working process of the hydrogen storage tank were explained.By comparison,the stress types that played a major role in the working process of the hydrogen storage tank were obtained.The stress values at the end of the startup process under different inflation rates were compared and the mechanism was explained.(3)Based on the stress fatigue and Miner linear damage theory,the stress fatigue analysis of the hydrogen storage tank was carried out.The S-N curve of the material was corrected according to the material type and the processing characteristics of the hydrogen storage tank.Combined with the finite element analysis,the service life of the dangerous part of the hydrogen storage tank reached 22 years.(4)Considering the influence of ship rocking load on hydrogen storage tank,the stress distribution of hydrogen storage tank with and without internal pressure under rocking load is analyzed,and the safety evaluation of hydrogen storage tank under this working condition is carried out,which proves the safety of hydrogen storage tank used in ships.