Modeling Of High Pressure Hydrogen Releases In Confined Spaces

In recent years,with the continuous improvement of China’s energy consumption level,environmental pollution problem has become increasingly serious.As a new energy source with high efficiency and no pollution,hydrogen energy is gradually being valued by people.hydrogen fuel cell vehicles and hydrogen refueling stations as hydrogen fuel cell vehicle infrastructure are important development directions for hydrogen energy applications.Since hydrogen is a flammable and explosive gas,high-pressure hydrogen storage equipment in hydrogen fuel cell vehicles and hydrogen refueling stations is highly likely to cause a burning or explosion accident.The study of high-pressure hydrogen in confined space releases is a prerequisite for the promotion of hydrogen fuel cell vehicles and hydrogen refueling stations.In this paper,CFD is used to simulate the release accident of high-pressure hydrogen in a confined space such as a garage and a hydrogen refueling station.The main research contents are as follows:(1)The high-pressure hydrogen leak in the confined space was simulated based on the real garage size and high-pressure hydrogen storage tank release speed.The effects of obstacles,different leak locations and different vent layouts on the hydrogen concentration distribution in the space and the pressure peak during the release process were investigated.(2)The process of hydrogen diffusion to the outside after the end of the leak was simulated,and the influence of the vent on the diffusion of hydrogen to the external environment was clarified.Then combined with the simulation results of the initial leak period,this paper provides a suitable vent layout for the hydrogen fuel cell vehicle garage.(3)A three-dimensional model of the design of a hydrogen refueling station with a hydrogenation capacity of 100 kg per day was built.The hydrogen refueling station referenced the NFPA fire protection design specification during the design process.The process of generating,flowing and dissipating the flammable gas cloud after the high-pressure hydrogen release of different equipment in the hydrogen refueling station was simulated.(4)Exploring the effects of release environment complexity,ambient wind speed and other factors on the flow and dissipation of flammable gas clouds.This paper also pointing out the advantages and disadvantages of establishing a wall around the hydrogen storage area.The results can provide guidance for the design of hydrogen fuel cell vehicle garages in the future.It can also provide reference for high-pressure hydrogen leak research in hydrogen refueling stations or provide data support for quantitative risk assessment of hydrogen refueling stations.