可燃液体燃料云雾形成和爆炸问题研究

发布时间：2018-07-17 17:24

【摘要】：可燃液体燃料是民用工业以及国防工业重要材料,其爆炸安全性研究是安全科学领域重要研究问题。可燃液体燃料云雾形成涉及诸多瞬态变量,且对云雾爆炸过程产生直接影响,使得云雾爆炸问题的研究更具有复杂性。本文以揭示可燃液体燃料云雾爆炸规律为目的,建立了云雾形成和多元变量测量的新方法,构建了云雾形成和爆炸实验系统;结合当前实际需要,开展了可燃液体燃料云雾爆炸极限和爆炸发展过程的研究,取得了如下主要创新成果。基于多相流理论及气动雾化原理,提出了二次脉动雾化方法,即一次气动力对液体产生两次脉动作用。该方法使液体形成液膜后进一步碎裂成细小液滴,同时形成大喷雾张角,改善了液体雾化效果和均匀性,实现了与20L球形爆炸空间结构的瞬态匹配。建立了云雾形成和爆炸多元变量测量方法,主要包括:相同粒径条件下不同浓度的测量方法,云雾中气相浓度和液相浓度的测量方法,云雾均匀性测量方法等。最后基于云雾形成方法和多元变量测量方法,构建了20L球型云雾形成和爆炸实验系统,实现了云雾粒径、浓度、爆压、爆温、火焰、湍流强度等系统参数瞬态测量。运用20L球型云雾形成和爆炸实验系统,得到了在不同粒径、不同点火能量下乙醚和正癸烷云雾的爆炸极限,同时分析了相同粒径条件下5种可燃液体(环氧丙烷、乙醚、正戊烷、正辛烷、正癸烷)云雾爆炸下限的区别,揭示了可燃液体云雾爆炸极限的特征规律。同时获得了不同粒径下乙醚和正癸烷云雾的爆炸参数(超压峰值、温度峰值、最大压力上升速率和最大温度上升速率以及最小点火能量)、不同浓度下乙醚云雾火焰传播延迟时间和火焰传播过程,并通过实验和分析计算得到了不同粒径条件下乙醚云雾最大有效燃烧速度,从而揭示了可燃液体燃料云雾爆炸发展过程的特征规律。本文建立了可燃液体云雾形成和爆炸研究新型实验系统,获得了典型可燃液体燃料云雾爆炸极限和爆炸发展过程特征规律,对预防和控制可燃液体燃料爆炸事故发生具有指导意义,同时丰富了可燃液体云雾形成和爆炸理论基础。
[Abstract]:Flammable liquid fuel is an important material in civil industry and national defense industry, and its explosion safety is an important problem in the field of safety science. The formation of flammable liquid fuel cloud involves many transient variables and has a direct impact on the process of cloud and fog explosion, which makes the study of cloud and fog explosion more complicated. In order to reveal the explosion law of flammable liquid fuel cloud and fog, a new method of cloud formation and multivariate variable measurement is established in this paper, and the experimental system of cloud formation and explosion is constructed. The explosion limit and explosion development process of combustible liquid fuel are studied. Based on the theory of multiphase flow and the principle of pneumatic atomization, a method of secondary pulsating atomization is proposed, that is, the primary aerodynamic force produces two pulsating effects on the liquid. By this method, the liquid is further broken into small droplets after forming liquid film, and a large spray angle is formed, which improves the atomization effect and uniformity of the liquid, and achieves the transient matching with the 20L spherical explosion space structure. The multivariate variable measurement methods of cloud formation and explosion were established, including the measurement methods of different concentrations under the same particle size condition, the measurement methods of gas phase concentration and liquid phase concentration in cloud and fog, the measurement method of cloud and fog uniformity, etc. Finally, based on the cloud formation method and multivariate variable measurement method, a 20L spherical cloud formation and explosion experiment system is constructed. The system parameters such as particle size, concentration, explosion pressure, explosion temperature, flame, turbulence intensity and other system parameters are measured. The explosion limits of ether and decane cloud fog with different particle size and different ignition energy were obtained by using the 20L spherical cloud formation and explosion test system. At the same time, five kinds of flammable liquids (propylene oxide, ether) were analyzed under the same particle size. The difference of the lower limit of cloud explosion of n-pentane, n-octane and n-decane reveals the characteristic law of cloud explosion limit of combustible liquid. At the same time, the explosion parameters (peak overpressure, peak temperature) of ether and decane cloud under different particle sizes were obtained. Maximum pressure rise rate, maximum temperature rise rate and minimum ignition energy), flame propagation delay time and flame propagation process of ether cloud and fog at different concentrations, The maximum effective combustion rate of ether cloud under different particle size conditions is obtained by experiments and analysis, thus revealing the characteristics of the development process of flammable liquid fuel cloud fog explosion. In this paper, a new experimental system for the formation and explosion of combustible liquid cloud and mist is established, and the explosion limit and the characteristics of explosion process of typical combustible liquid fuel are obtained. It is of guiding significance to prevent and control explosion accidents of combustible liquid fuel and enrich the theoretical basis of cloud formation and explosion of combustible liquid.
【学位授予单位】：北京理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：X932

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