氢气浓度对泄爆特性影响的实验研究

发布时间：2018-03-17 11:38

本文选题：单泄爆口泄爆　切入点：氢气　出处：《安徽理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：氢气(H2)是世界上目前已经知道的密度最小的气体,也是相对分子质量最小的物质,氢气的质量只有空气的1/14。在常温常压条件下,氢气是一种非常容易燃烧、爆炸的气体,并且无臭无味、无色透明。氢气燃烧后生成水,所以氢气作为燃料具有清洁环保、对环境无任何污染的优点,而且其反应后的转换利用效率很高,生成的水还可以用来作为制备氢气的原料,在未来很有可能成为与电能同样重要的人类不可或缺的二次能源。在常温下,氢气的化学性质非常稳定,很难与其它物质发生化学反应。但是在外界条件发生改变时(如加热、点燃、使用催化剂等),情况就不同了。氢气是爆炸极限范围相当宽的一种气体,当空气中氢气气体的体积分数在4%-75%范围内时,遇到火源,即可立刻引起燃烧或爆炸。因此,在日常生活中,一旦对氢气使用或者储存不当,极易导致火灾和爆炸事故的发生,而一旦发生事故,其后果不堪设想。所以研究氢气的泄爆特性及规律对氢气的安全储存和运输意义重大。本实验使用单泄爆口泄爆容器作为泄爆容器,利用高速相机、纹影系统、压力传感器对氢气-空气预混气体的单口泄爆进行研究,分析了氢气-空气当量比的不同对泄爆过程泄爆容器内部压力、泄爆口处压力变化规律、破膜时间及破膜后外部火焰进行了研究,得到如下结论： (1)氢气-空气预混气体在各个当量比下,当量比对泄爆容器的内部压力及其峰值的变化具有很大程度的影响,且存在一个临界当量比1.6。在临界当量比下,泄爆容器内部压力峰值达到最大值。当量比小于1.6时,随当量比的增大,内部峰值压力逐渐增大,到当量比为1.6时达到最大值；当量比大于1.6时,随当量比的进一步增大,峰值压力开始变小。 (2)当量比对破膜时间也有很大影响。同样存在一个临界当量比1.6,在此当量比下,破膜时间最短Tmin=.7.4ms。当量比小于1.6时,随当量比变大,破膜时间逐渐缩短；当量比大于1.6时,破膜时间逐渐变长。 (3)当量比对氢气-空气预混气体泄爆口处的压力变化有显著的影响,在当量比为1.6时泄爆口处的压力上升速率最快,处于1.6两边的当量比下速率都有所减小。 (4)当量比对泄爆口破膜后外部火焰的发展会产生很大的影响。随当量比增大,外部火焰最大长度逐渐变长,直至当量比增大到4.0时,外部火焰最大长度达到最大值为dmin=1.64m,随当量比的进一步增加,最大火焰长度逐渐缩短。
[Abstract]:Hydrogen gas (H2) is the smallest density in the world already know, is the smallest relative molecular mass, the hydrogen air quality is only 1/14. under normal temperature and pressure conditions, hydrogen is a very flammable, explosive gas, and odorless, colorless and transparent. The hydrogen generated after the combustion of water. So hydrogen as a fuel with clean environmental protection, has the advantages of no pollution to the environment, and its conversion after reaction efficiency is very high, the water can also be used as raw materials to prepare hydrogen, in the future is likely to become the two energy and electric energy as an important human indispensable. At room temperature, chemical the nature of hydrogen is very stable, it is difficult to react with other substances. But in the external conditions changed (such as heating, lighting, use of catalyst etc.), the situation is different. The explosion limits of hydrogen is quite A gas wide, when the volume fraction of hydrogen gas in the air in the range of 4%-75%, encountered fire, can immediately cause a fire or explosion. Therefore, in daily life, once the hydrogen use or improper storage, extremely easy to cause fire and explosion accidents, but once the accident, the consequences be unbearable to contemplate. So the study of hydrogen explosion characteristics and law of hydrogen storage and transportation safety of great significance.
This experiment using a single vent vent venting container as the container, using high-speed camera, schlieren system, single pressure sensor mixed gas of hydrogen - air pre venting research, analysis of hydrogen air equivalence ratio on the venting process of venting pressure inside the container, the vent variation at the pressure, the rupture time after rupture of membranes and external flame were studied. The conclusions are obtained as follows:
(1) hydrogen air premixed gas in each equivalence ratio, to a great extent changes the internal pressure and equivalence ratio on the discharge peak explosion vessel, and there is a critical equivalence ratio of 1.6. in critical equivalence ratio, the internal pressure vessel explosion peak reaches the maximum value. When the volume ratio is less than 1.6. With the increase of equivalence ratio, the internal pressure is gradually increased to the peak, the equivalent ratio of 1.6 reached the maximum; the equivalent ratio is greater than 1.6, further increases with the equivalence ratio, the peak pressure decreases.
(2) equivalence ratio also has a great influence on the breaking time. There is also a critical equivalence ratio of 1.6. Under the equivalence ratio, the breaking time is the shortest and the Tmin=.7.4ms. equivalence ratio is less than 1.6. When the equivalence ratio is bigger, the breaking time decreases. When the equivalence ratio is greater than 1.6, the time of breaking the film becomes longer.
(3) equivalence ratio has a significant impact on the pressure change of the hydrogen air premixed gas venting orifice. When the equivalence ratio is 1.6, the pressure rise rate at the vent is the fastest, and the rate at the 1.6 sides of the equivalence ratio decreases.
(4) the development of equivalence ratio on the vent after rupture of membranes outside the flame will have a huge impact. As the equivalence ratio increases, the maximum length of external flame becomes longer, until the equivalence ratio increases to 4, the maximum length of external flame reaches the maximum value of dmin=1.64m, with further increase of the equivalence ratio, the maximum flame length is shortened gradually.

【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ116.2

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