氢安全研究现状及面临的挑战

氢能具有储运便捷、来源多样、洁净环保等突出优点,许多国家把发展氢能作为重要的能源战略。氢安全是氢能大规模商业化应用的重要保障。在分析国内外氢安全领域近年来最新研究进展的基础上,依次从氢泄漏与扩散、氢燃烧与爆炸、氢与金属材料相容性及氢风险评价等方面,系统总结了国内外氢安全研究面临的挑战,并对我国氢安全的发展提出了建议。

Research status-in-situ and key challenges in hydrogen safety

The present paper is aimed at summarizing the research status-in-situ and the key challenges of the hydrogen safety in the hydrogen leakage and diffusion,the hydrogen combustion and explosion,the hydrogen and metallic material compatibility,in addition to the related hydrogen risk assessment. At the same time,the paper has also brought about some suggestions for hydrogen safety measures perfection at home in China so as to confine the hydrogen leakage into a properly controlled sphere.Thus,as a matter of fact,we have also traced and examined the effects of the hydrogen storage pressure,the diameter and the ventilation size,as well as the pressure relief device( PRD) on the pressure peak through experiments. In spite of this,there remain still lots of difficulties to be overcome through study of the complex physical properties of the liquid hydrogen by establishing and verifying the liquid hydrogen leakage model. The combustion regularity of hydrogen in the confined or semi-confined spaces,such as the garage,the tunnels and hydrogen refueling stations,should still be paid great attention,too. Besides,much attention has also been paid to the research of the mechanism of the flame acceleration( FA) and the deflagration-to-detonation transition( DDT) in the confined spaces by the scholars around the world today. Hence,the results of the above research prove that the interaction among the flame,the dominant shock wave and the reflected shock wave should be taken as the main factor to promote the said DDT. What is more,when the material is operated in a hydrogen environment for too long,it may also cause deterioration of the mechanical properties,known as the hydrogen environment embrittlement( HE). Actually,quite a few of tests we can conduct to make out the HE susceptibility of the metallic materials,including the slow strain rate tensile test,the fatigue life test,the fatigue crack growth test and the fracture toughness test. All the above said widely accepted testing methods can be adopted directly to confine the sample under the highpressure hydrogen environment. However,since there is no internationally uniformed hydrogen and material compatibility testing standard for the time being,it wouldn’t be conducive to the sharing of the material testing data under the high-pressure hydrogen environment among the countries. All the above said risk assessments have become more and more urgent with the commercial application of the hydrogen refueling stations( HRS) and the hydrogen fuel cell vehicles( HFCV). Such risk assessment methods may include the fast risk ranking( FRR) and the quantitative risk assessment( QRA),the latter of which can not only be used for scientific evaluation of the risk of an accident,but also for the directly application to the formulation of the hydrogen safety distance standards. Besides,some researchers have also been carrying out the QRA studies to the hydrogen leakage accidents in different scenarios,to result in the corresponding QRA methods,though the development of QRA is inseparable from the support of the said software. Therefore,at present,SNL has launched a toolkit,HyRAM,specifically for the hydrogen risk assessment,though the effective data on the hydrogen system structure failure and leakage frequency remain under great need for further proof and rectification.