氢气的爆炸极限抑制研究

发布时间：2018-03-01 02:14

本文关键词： 氢气爆炸极限惰性气体卤代烷烃爆炸特性抑制　出处：《山东建筑大学》2017年硕士论文　论文类型：学位论文

【摘要】：目前最常用作浮空器充装气体的是氦气,但氦气的制取困难且价格昂贵,而氢气的制取则容易很多且价格仅为氦气的约八分之一,此外氢气还具有更小的密度,所以氢气自然而然地成为了替代氦气作为浮空器充装气体的理想选择。但阻碍氢气大规模使用的原因是氢气的易燃、易爆特性,氢气的最小点火能很低(约0.02m J)且爆炸极限范围很大(4%~75%),因此想要用氢气替代氦气则必须要对氢气的爆炸极限进行抑制。本文通过对影响氢气爆炸极限的主要因素进行分析后,确定采用添加抑制剂的方式对氢气爆炸极限进行抑制,并通过理论研究不同物质对氢气的爆炸抑制机理提出可行的抑制剂方案,然后搭建可燃气体爆炸极限测试实验台对氢气添加各种抑制剂之后的爆炸极限进行测定,分析实验数据并根据实验结果指导氢气的安全应用,同时推荐在控制浮力损失情况下抑制效果最好的抑制剂。不同物质对于氢气爆炸抑制的机理大致包括物理热力学抑制和化学反应动力学抑制两方面,惰性气体以前者为主,不可燃卤代烷烃和可燃不饱和烃气体则以后者为主。本文最终考虑将三种惰性气体(He、N_2和CO_2)、四种不可燃卤代烷烃(CHF_3、CHClF_2、CH_2FCF_3和C_2HF_5)和两者混合形成的二元混合物作为氢气的抑制剂备选方案。实验结果显示,在三种惰性气体抑制剂中,CO_2相对于He和N_2对氢气具有更好的抑爆效果,其主要原因是由于CO_2具有较大的比热容。而不可燃卤代烷烃对氢气爆炸极限抑制作用明显强于惰性气体。二元混合抑制剂对氢气的抑爆效果则与两种组分的浓度配比有关。通过对实验结果的分族讨论,发现在不可燃卤代烷烃中碳原子数量相同的情况下,不同卤代烷烃对氢气爆炸极限的抑制效果跟其与氢气燃烧链式反应活化中心的化学反应速率直接相关。此外,本文还通过根据合适的计算方法对两种不可燃抑制剂与氢气的三元混合气体的爆炸极限取得精度良好的估算值。由于氢气是最轻的气体,添加抑制剂则必然带来浮力的损失,关键如何在控制浮力损失的前提下获得尽可能好的抑爆效果。通过对文中提出的各种抑制剂在极限掺混比例下加入氢气后的爆炸极限的比较分析,发现CHF_3对氢气的抑爆效果是最好的抑制剂,在控制氢气抑爆后浮力损失不超过20%的情况下,其加入氢气后的混合气体爆炸极限范围可以缩小至5.39%~58.12%。
[Abstract]:At present, helium is the most commonly used gas for floating air, but helium is difficult and expensive to produce, while hydrogen is much easier to produce and costs only about 1/8 of helium. In addition, hydrogen has a smaller density. So hydrogen has naturally become an ideal alternative to helium as a gas to fill a floating air tank. But the reason why hydrogen is being used on a large scale is because of its flammable and explosive properties. The minimum ignition energy of hydrogen is very low (about 0.02m J) and the explosion limit range is very large. Therefore, in order to replace helium gas with hydrogen, the explosion limit of hydrogen must be restrained. The method of adding inhibitors to suppress the explosion limit of hydrogen was determined, and a feasible inhibitor scheme was put forward through the theoretical study on the mechanism of explosion inhibition of different substances to hydrogen. Then the explosion limit of the combustible gas after adding various inhibitors was measured by building a test bench, the experimental data were analyzed and the safe application of hydrogen was guided according to the experimental results. At the same time, it is recommended that the best inhibitor can control the loss of buoyancy. The mechanism of hydrogen explosion inhibition by different substances includes two aspects: physical thermodynamic inhibition and chemical reaction kinetic inhibition, and the inert gas is the main inert gas. The latter is the main source of non-combustible halogenated hydrocarbons and combustible unsaturated hydrocarbon gases. This paper finally considers using the binary mixture of three inert gases, HeN _ 2 and CO _ 2, four nonflammable halogenated alkanes, CHF _ 3C _ HClF _ 2C _ (C _ HClF _ 2F _ 2C _ C _ 3 and C _ 2HF _ 5) and a binary mixture of the two as the suppression of hydrogen. Preparation options. Experimental results show that, Among the three inert gas inhibitors, Cost2 has a better explosion suppression effect on hydrogen than he and NST2. The main reason is that CO_2 has a large specific heat capacity, while the incombustible halogenated hydrocarbon has a stronger inhibition effect on the limit of hydrogen explosion than that of inert gas. The inhibitory effect of binary mixture inhibitor on hydrogen is similar to the concentration of two components. Ratio related. Through the experimental results of the group discussion, It is found that when the number of carbon atoms in noncombustible halogenated hydrocarbons is the same, the inhibition effect of different halogenated hydrocarbons on the explosion limit of hydrogen is directly related to the reaction rate of the hydrogen combustion chain reaction activation center. The explosion limit of two kinds of incombustible inhibitor and hydrogen mixture gas is estimated with good precision according to the appropriate calculation method. Since hydrogen is the lightest gas, adding inhibitor will inevitably bring about loss of buoyancy. The key is how to obtain the best explosion suppression effect under the premise of controlling the buoyancy loss. It is found that CHF_3 is the best inhibitor of hydrogen. When the buoyancy loss of hydrogen is not more than 20%, the limit range of explosion of mixed gas can be reduced to 5.39% and 58.12%.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X932

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