Simulation And Risk Analysis On Hydrogen Releases Of Hydrogen Refueling Station And Hydrogen Vehicle

With the environment pollution and energy shortage becoming more serious,hydrogen is gaining more attention as a clean and high efficient energy,hydrogen energy industry develop rapidly.At the same time,hydrogen safety is the key question to its extended application.Hydrogen accident can be divided in to jet fire,vapor cloud explosion,flash fire,leakage and dispersion.The study of hydrogen accident scenario and accident consequences are of great significance for the improvement of hydrogen safety standards.In this paper,CFD is used to simulate the hydrogen release accident.The main research contents are as follows:(1)The numerical model of jet fire,flash fire and diffusion of CFD was validated with former experiment results.The simulation are in good agreement with the experiment data.(2)Jet fire and flash fire from hydrogen storage tank failure were simulated and the effect of leak diameter and storage pressure on the fatality probability was clarified.For jet fire,there is a linear relationship between fatality probability and distance at far field.For flash fire,there is a linear relationship between safety distance and leak diameter while the leak diameter is no more than 50 mm and there is a power function relationship between safety distance and leak diameter while the leak diameter is more than 50 mm.Several empirical equations were determined to estimate the fatality probability,which provided a reliable foundation for the risk assessment of hydrogen refueling station.(3)The accident scenario of hydrogen storage tank was analyzed and event data model was built.The accident scenario was simulated and the effects of storage pressure on the safety distance were investigated.This paper provided a suitable safety distance for the hydrogen refueling station.(4)The accident scenario of HFCV was analyzed and the accident consequence of jet fire was compared to that of vapor cloud explosion.For jet fire,thermal damage criteria is more suitable than heat flux criteria.For vapor cloud explosion,over-pressure&impulse criteria is more suitable than over-pressure criteria.(5)The unignited blowdown release of HFCV was simulated and the effect of ventilation skylight and inducing fan on the diffusion of hydrogen was compared.The effect of ventilation skylight is significantly higher than the effect of inducing fan.This paper provided a reference for the build of garage ventilation system.