Investigation On Control Of Temperature Rise In Fast Filling Of High Pressure Hydrogen And Diffusion Due To Its Leakage

Due to the scarcity of fossil fuels and environment problems,hydrogen is likely to be one of the most important carriers of energy due to its renewable and no polluting product.The most popular and most highly developed storage method for hydrogen refueling station and fuel cell vehicles is high pressure hydrogen storage due to its technical simplicity and low cost.Safe and reliable transportation and storage of hydrogen for hydrogen energy is one of the key issues which are needed to be resolved.There is a certain degree of risk for high-pressure hydrogen storage in the practical application.Therefore,safe and reliable high pressure storage of hydrogen is needed to be gotten hold of.This paper aimed at research on temperature rise in hydrogen fast filling process for composite hydrogen storage cylinders,high-pressure hydrogen leakage and diffusion funded by the National Basic Research Program(863) of China "technology and equipment of high-pressure hydrogen storage vessels"(Project No: 2006AA05Z143),the National Hi-Tech Research and Development Program(973) of China "New high-density on-board hydrogen storage system and its theoretical safety prediction research"(Project No:2007CB209706),and the U.S.Department of Transportation,Office of the Secretary "Safety issues related to transport and storage of hydrogen in northern climates"(Grant No.DTOS59-06-G-00048),and main contents and research results were as follows:(1) Establish a theoretical analysis model for temperature rise in hydrogen fast filling process for composite hydrogen storage cylinders based on theoretical analysis.The temperature rise in adiabatic filling process for the cylinder was analyzed with the model and the settled temperature rise was obtained,that is,the maximum value of temperature rise in practical filling process was found out.Based on this model,the effect of the initial temperature and initial pressure in the storage cylinder on the temperature rise was obtained.Establish a numerical model for temperature rise in hydrogen fast filling process for composite hydrogen storage cylinders based on real gas state equation.The model was an accurate and visually displayed model to forecast the temperature rise in the fast filling process under different filling parameters. (2) First carried out the experimental study on temperature rise in the hydrogen fast filling process for hydrogen storage cylinders in China.Testing platform for temperature rise in fast filling process was build and much experimental data was obtained.Based on the testing platform,the unsteady flow in fast filling process for hydrogen storage cylinder had been studied.And the changing regularity of pressure in the cylinder and storage tank,temperature in the cylinder,mass filling rate in filling process was obtained.Furthermore,the effect of initial temperature in the cylinder, mass filling rate on the temperature rise was found out with the testing platform.(3) Based on the simulation results and experimental data,an equation for temperature rise calculation of 35MPa 150L storage cylinder was put forward.Furthermore,an equation for fulfill rate calculation of the cylinder was obtained.The limited mass filling rate in different filling pare meters was obtained.Furthermore,the control method for temperature rise was brought out.It could be implemented by controlling the temperature of hydrogen before into the cylinder and mass filling rate.The settled pressure for mass requirement with various filling parameters was obtained.(4) Establish a numerical calculation model for analysis of leakage and diffusion of high-pressure hydrogen and natural gas due to pipeline or storage tank failure basing Reliableκ-εturbulent model.The effect of leakage position,diameter of leakage hole,ambient temperature,ambient wind velocity and obstacle on the diffusion of hydrogen due to storage tank failure was also obtained.And corresponding law was found out.Also the different diffusion properties of hydrogen to natural gas were obtained.The simulation results show that the natural gas is more danger than hydrogen.The rationality of safety distance for hydrogen storage tanks was analyzed. The corresponding results could provide reference for dealing with emergency in high pressure gaseous hydrogen occasions such as in hydrogen refueling stations.