油氢合建站储氢瓶组氢气泄漏扩散行为研究

Research on hydrogen dispersion behavior induced by storage cylinder group failure in oil-hydrogen refueling station

为探究油氢合建站储氢瓶组阀体面板失效后引发的氢气泄漏事故及氢气扩散行为的影响因素,根据真实场景构建等比例数值模型,针对不同泄漏源和环境风力条件下的氢气泄漏扩散过程进行了模拟研究,从事故后果角度提出了不同事故场景下的应急处置方式。结果表明,当储氢瓶组发生小孔泄漏时,氢气运动沿中心线形成欠膨胀射流,在泄漏源周围形成氢气云团高浓度分布。随着泄漏口孔径增大,短时间内氢气扩散在距离泄漏源较远区域形成具备爆炸性的混合气云团。氢气泄漏方向的改变直接影响其扩散行为的变化,促使氢气/空气混合气云团分布区域呈现显著差异。对于水平泄漏模式下的氢气扩散行为要着重考虑站内装置和设备的阻挡作用,而竖直向下的泄漏模式会造成范围更广的高浓度氢气聚集。随着环境风力的增强和站内布局复杂化,泄漏氢气在局部区域浓度升高,沿下风向水平范围的扩散半径增大,而在竖向空间的扩散高度下降,爆炸性混合气云呈现朝下风向区域移动的趋势。

This work aims to investigate the hydrogen leakage and dispersion process caused by the valve panel failure from the storage cylinder group in a new type of oil-hydrogen refueling station,and clearly understand the effects of different influencing factors on the hydrogen dispersion behavior.In this work,a full-scale model of an oil-hydrogen refueling station was built based on real scenarios,and numerical simulations were carried out in a CFD-based simulator tool.Compared with various numerical scenarios,hydrogen dispersion behaviors were discussed under different leakage sources and ambient wind conditions.Meanwhile,the emergency treatment plans with different accidental scenarios from accident consequences were proposed in this work accordingly.The current results indicate that the leaked hydrogen movement generates an under-expanded jet along the center line and forms a high-concentration distribution of explosive hydrogen cloud around the leakage source when a small rupture occurs in the hydrogen storage cylinder group.With the increasing rupture sizes,the hydrogen dispersion forms a hydrogen/air mixture cloud in a region far away from the hydrogen storage cylinder group within a short time.The changes in leakage directions in the hydrogen storage cylinder group immediately affected the characteristic variations of hydrogen dispersion behavior,which suggests the distribution region of the hydrogen/air mixture cloud has changed significantly.The hydrogen dispersion process in the horizontal orientation mainly considers the obstacles of devices and equipment in the oil-hydrogen refueling station,while the vertical downward dispersion mode leads to a wider range of high-concentration hydrogen dispersion distribution.With the enhancement of ambient wind and layout complexity of oil-hydrogen refueling stations,the concentration of hydrogen dispersion in local areas rises.As a result,the hydrogen dispersion radius of the horizontal area with the downwind increases,while hydrogen dispersion height in the vertical area decreases,and the hydrogen/air mixture cloud tends to move towards the downwind area of the oil-hydrogen refueling station.