Study On Quantitative Analysis Of Gas Leakage And Diffusion Of High Pressure Hydrogen Storage Containers In Hydrogen Refueling Station

Hydrogen energy is well known as its diverse sources,clean and low-carbon,flexible and efficient,and wide-ranging applications.However,sufficient safety and reliability is a crucial prerequisite for the development and utilization of hydrogen energy.With the vigorous development of hydrogen fuel cell vehicles in various countries,hydrogen refueling station as an infrastructure for supporting hydrogen energy has emerged.This master thesis used hydrogen refueling station as the analysis object to conduct qualitative and quantitative safety assessments,and quantitatively calculated the leakage accidents of high-pressure hydrogen storage containers in hydrogen refueling station,aiming to provide references for accident prevention and dynamic monitoring.By identifying harmful factors and adhering to the principle of considering top events with high risks,domestic hydrogen refueling station was turned into the main target,the fault tree qualitative risk assessment and the Dow Chemical Index quantitative safety risk assessment were carried out at the meantime.Based on the fault tree,a total of 38 basic events 6 minimum diameter sets were obtained,and the structural importance of the basic events in terms of hydrogen leakage was the most important.According to Dow Chemical Index analysis,the damage coefficient of the hydrogen refueling station unit was 0.70,the fire and explosion hazard index was 96.81,and the safety measure compensation coefficient was 0.48.After the safety measure compensation,the fire and explosion hazard index dropped to 46.47,and the safety risk rating was changed from "Medium" to "Minimum",which showed that after safety measures,the risk of accidents at hydrogen refueling station could be greatly reduced.Then the thesis calculated the consequences of two typical accidents which were jet fire and vapor cloud explosion.The exposure distance of 37.98m was derived from the jet fire incident flux value,and the consequences of the vapor cloud explosion accident were calculated by the TNT equivalent method.The exposure radius was 38.76m from the explosion energy.According to the calculation results,the recommended reserved distance was given.In addition,the thesis also established a high-pressure hydrogen storage vessel leakage model and used FLUENT software for simulation analysis.Six simulation experiments were carried out with wind speed,leakage aperture,and leakage location as variables.It was concluded that turbulence areas were easily formed at low altitudes,and there was also hazardous in the upwind area.As the ambient wind speed increased,the hydrogen cloud diffusion rate increased.When the wind speed increased or the aperture expanded,the hazardous area at the initial stage of leakage expanded,and the same as the concentration of hydrogen leakage.For vertical hydrogen storage containers,compared with the top leakage,the side bottom leakage was more hazardous to the personnel dangerous area.The thesis summarized the results of safety risk assessment,accident consequence calculation and simulation experiment.From the perspective of reducing the possibility of accidents,11 safety measures were given in 2 categories,and 4 safety measures were given from the perspective of reducing accident hazards.A total of 15 safety measures and recommendations had been put forward for hydrogen refueling station.