基于贝叶斯网络的粉尘爆炸多米诺效应分析

粉尘爆炸机理的复杂性及引起粉尘爆炸因素的多样性使得粉尘爆炸成为学者们研究的热点课题,目前研究成果集中在不同种类粉尘的爆炸特性、粉尘爆炸机理、预防和减轻粉尘爆炸的安全措施及粉尘爆炸定量风险分析等方面,但在建立粉尘爆炸相关模型及风险评价方面的研究较少。本文在剖析粉尘爆炸机理的基础上结合多米诺效应原理建立了粉尘爆炸多米诺效应计算模型,该模型在计算出初始粉尘爆炸事故的条件概率后,利用贝叶斯网络灵活的特性和自动推理引擎,可以计算出潜在多米诺效应传播的途径。通过实例应用该模型的计算结果,可以得出发生粉尘爆炸多米诺效应的概率变化情况及粉尘爆炸事故最可能发生的传播途径,为粉尘爆炸事故的预防控制及风险评价提供了方向。     

浅析粉尘爆炸事故的预防和处置

易、可燃气体化学爆炸的事故比较常见,容易引起人们的重视。可燃粉尘因爆炸所需的浓度和能量较大,一般不易发生化学爆炸,容易滋生人们麻痹大意心理,忽略了其爆炸危险性和危害性。文章从国内外粉尘爆炸事故案例出发,分析粉尘爆炸的成因及事故处置注意事项,提高人们对粉尘爆炸危险性、危害性的认识,提高对粉尘爆炸事故的预防和处置能力。     

粉尘爆炸的研究进展

粉尘爆炸作为一种典型的事故类型,对人类的生产生活危害性极大。论述了粉尘爆炸的定义、机理及特点,影响粉尘爆炸的特性参数如环境温度、点火能量、最低爆炸限度、粒径和质量浓度等。并对目前国内粉尘爆炸的防爆措施研究现状进行概括,最后就粉尘爆炸防护措施方面存在的问题提出几点建议。     

铝粉尘爆炸典型案例分析及安全对策

介绍了铝粉的理化性质和火灾危险性,通过铝粉尘爆炸典型事故案例,分析了铝粉粉尘爆炸的事故特点,铝粉粉尘爆炸的事故原因,探讨了预防铝粉粉尘爆炸的主要技术措施和铝粉粉尘事故发生后一般处置手段和注意事项。     

粉尘爆炸的研究进展

粉尘爆炸作为一种典型的事故类型,对人类的生产生活危害性极大。论述了粉尘爆炸的定义、机理及特点,影响粉尘爆炸的特性参数如环境温度、点火能量、最低爆炸限度、粒径和质量浓度等。并对目前国内粉尘爆炸的防爆措施研究现状进行概括,最后就粉尘爆炸防护措施方面存在的问题提出几点建议。     

对粉尘爆炸影响因素及防护措施的初步探讨

详细分析了粉尘爆炸的条件、机理、特点及影响因素,重点总结、归纳了抑制爆炸的诸如粉尘性质、助燃剂浓度、点火源、环境温度、可燃性气体及惰性物质等重要影响因素,并分类介绍了粉尘爆炸的预防性防范措施和四种粉尘爆炸的结构性防范措施,以期指导安全生产。     

镜片树脂粉尘爆炸案例分析及防范措施应用研究

针对某树脂镜片厂发生的粉尘爆炸事故,运用粉尘爆炸原理分析原因,归纳出此种爆炸的特点;提出了防范措施:采用湿法除尘和切削工艺可降低粉尘浓度;控制磨头等点火源,可减少粉尘爆炸的几率;对除尘设备进行泄爆和抑爆设计,可减轻粉尘爆炸的损失。案例分析对树脂镜片生产企业防范粉尘爆炸事故具有实践指导意义。     

粉尘爆炸的背因与防止措施的思考

通过分析近年来频繁发生的重大粉尘爆炸事故的原因,发现这些事故的深层次背因均源自对粉尘爆炸危险认知上的盲区和不作为有关。不了解粉尘爆炸的危险与信息,是当前粉尘爆炸的共同背因;在危险分析和事故统计的基础上,指出适时整改和安全教育是改变粉尘爆炸事故趋势的主要手段。     

浅谈粉尘爆炸实验装置的主体部分设计

在对管道内粉尘爆炸的特性理论研究的基础上,设计了一套80mm×80mm、长5m的长方体可燃粉尘爆炸实验管道,其为粉尘爆炸实验装置的主体部分。粉尘爆炸实验装置的主体部分包括管道进气口、空气压缩机、实验管道主体部分(点火区,观察区,灭火区)、传感器、管道出气口、送风机,扬尘喷管、燃爆测定系统控制仪、可燃粉尘质量、速度传感器、动态数据采集分析仪和爆炸的点火装置。对粉尘爆炸实验装置的主体部分的设计有利于研究可燃粉尘在管道中的爆燃转爆轰(DDT)过程、压力变化过程等,也有利于可燃粉尘在管道中的爆炸研究。     

浅谈粉尘爆炸事故的预防

在工业生产过程中,粉尘爆炸事故时有发生.给人们生命和财产造成严重的损害.本文从国内外粉尘爆炸事故案例出发,分析粉尘爆炸的形成的原因及事故预防措施,提高人们对粉尘爆炸危险性、危害性的认识.     

燃料空气炸药爆炸地面振动的幅值特征研究

对燃料空气炸药爆炸（FAE）爆炸时所引起的地面振动幅值特征提出了研究，在相同的装药量和场地条件下，进行了FAE与TNT炸药爆炸地震效应的对比实验，得到了地面是竖向振动的时间历史记录结果。分析表明，FAE爆炸所产生的地震效应具有更高的峰值强度，所得到的研究结果对认识FAE爆炸力学效应具有一定的指导价值。     

基于ARAMIS体系的爆炸风险评价法及其应用

根据ARAMIS体系,提出针对爆炸事故的定量风险评估方法。采用蝴蝶结分析法(bow-tie法)定性分析事故原因及计算爆炸事故发生的概率,基于TNO多能法计算远场爆炸超压,计算超压严重度和装置脆弱度,确定爆炸风险值并绘制爆炸风险图。对某液化天然气罐区进行了实例计算,结果表明:基于ARAMIS体系的爆炸风险评估法的评价结果是合理的,且具有较好的应用前景。     

Flammability of Vapor–Gas Mixtures C2F4, SO3, and C2F4OSO2

Flammability limits and conditions of flegmatization of vapor–gas mixtures by helium and perfluoropropane are determined. For most mixtures, the maximum pressure of explosion and the maximum growth rate of pressure in explosion are determined. Addition of sulfuric anhydride to tetrafluoroethylene significantly decreases the minimum energy of flammability as compared to pure tetrafluoroethylene but weakly affects the maximum pressure of explosion and pressure growth rate in explosion. It is found that pure vapors of tetrafluoroethanesultone present an explosive hazard, but its mixtures with sulfuric anhydride are most dangerous.     

Study on concentration distribution of radical groups of gasoline-air explosion in long-narrow confined space based on OH-PLIF

To measure the key free radicals of the gasoline-air explosion in long-narrow confined space accurately, which is important to the accurate analysis of the explosion flow field and the flame propagation, an experimental study on the gasoline-air mixture explosion in a long-narrow confined space is designed based on the planar laser induced fluorescence system (PLIF),and the experiments in different conditions of the gasoline-air explosion in long-narrow confined space are carried out. The concentration distributions of the OH radical of those are obtained. The results of experiments show that the concentration of OH radical rises and then descends among the gasoline concentrations of 1.1%—2.4%(volume fraction); the concentration of OH radical rises steadily along with the development of flame propagation, which means the explosion is strengthen; the distributions of the OH radical are different in different explosion stages, which means the combustion reaction area in different explosion stages differs a lot; there is a "isolation belt" between the flame and the wall, which is the result of the slowing of the flame propagation caused by the concentration increase of unburned gasoline. The main innovation is to solve the transient measurement of free radical distribution in unsteady premixed combustion by designing the timing control subsystem.     

基于OH-PLIF的狭长受限空间油气爆炸中间基团浓度分布研究

为了精确测量狭长受限空间油气爆炸过程中的关键自由基团,从而实现对其爆炸流场、火焰传播的精确分析,基于先进的平面激光诱导荧光测量技术（PLIF）,设计构建了油气爆炸PLIF测量系统,开展了不同工况下狭长受限空间汽油-空气混合气爆炸实验研究,获得了该爆炸中间基团OH基的浓度分布。实验结果表明,1.1%~2.4%（体积分数）油气浓度之间,OH基浓度先增大后减小;随火焰的传播发展,OH基浓度不断变大,表明爆炸不断强化;爆燃不同时期OH基分布情况不同,表明不同爆燃阶段的燃烧反应区域有较大差异;爆燃前期火焰与壁面之间有“隔离带”,是由未燃气浓度增大导致火焰传播变慢的结果。主要创新点在于通过设计时序控制子系统,解决了非稳态预混燃烧中自由基分布瞬态测量。     

Heat of explosion of commercial and brisant high explosives

Methods for determining the heat of explosion of high explosives (HEs) with ideal and nonideal processes of explosive decomposition are considered. It is shown that the heat of explosion is of significance for estimating the efficiency of commercial HEs and is used in the energetic characterization of the working capacity. The heat of explosion of brisant HEs is only part of the blast heat of explosion and is the heat content of gaseous detonation products during their isentropic expansion from the initial state to a certain expansion ratio (determined by experimental conditions). The heat of explosion can be obtained by thermodynamic calculations based on physically justified equations of state for fluids (gaseous detonation products in the chemical-reaction zone of the detonation wave in the supercritical state) and condensed nanocarbon phases (nanographite, nanodiamond, and liquid carbon). Experimental and calculated values of the heat of explosion are given. The thermodynamic calculation is inapplicable to commercial HEs because of the nonideal nature of their detonation. The heat of explosion of commercial HEs can be calculated using the Hess law. The heat of explosion of brisant HEs is not a measure of power. The power of HEs is characterized by the propellant performance. It is shown that even detonation velocity cannot be a measure of the power of HEs. The power and detonation parameters of brisant HEs are determined by the energy release density in unit volume of the chemical-reaction zone of the detonation wave and by the rate of energy release from the shock front rather than by the heat of explosion, which cannot be considered a universal characteristic. __________ Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 2, pp. 100–107, March–April, 2007.     

Estimation of the Fireball Size in an Ethyne–Air Cloud Explosion

A gas explosion accident is often followed by a serious fire. In order to effectively prevent fire induced by a gas explosion accident, it is necessary to have some knowledge of the related explosion processes. The subject of the present study is to examine deflagration behaviors beyond the original cloud of the ethyne–air mixture and the fireball size in an ethyne–air explosion by means of numerical simulations. The explosion overpressure, flow velocity, and reaction rate distribution in an ethyne–air explosion are obtained. The peak explosion overpressure is found to reach its maximum beyond the original cloud for ethyne–air mixtures with ethyne concentrations greater than 13% (by volume). The explosion pressures beyond the original cloud may be higher than those within the cloud for these ethyne–air mixtures. The ratio of the combustion range to that of the original cloud is 1.4–2.7 in the radial direction on the ground and 1.5–4.0 along the axis of symmetry perpendicular to the ground.     

连通容器气体爆炸流场的CFD模拟

跟单个容器或管道相比,连通容器内气体爆炸会导致较高的爆炸压力和压力上升速率,以至于很多装置或设备不能承受而造成人员伤亡和财产损失。连通容器内气体爆炸强度增加主要是跟气体流动与燃烧过程有关,研究该类气体爆炸机理就必须从爆炸流场着手。本文利用大型计算流体动力学软件FLUENT对气体爆炸流场进行了数值模拟,获得了气体爆炸流场中温度、压力、速度、密度和燃烧速率随时间的变化规律,模拟结果能够比较清晰地反映出气体爆炸的整个过程。研究表明,连通容器中气体燃烧和流动引起未燃气体的压缩和湍流以及湍流诱导的喷射燃烧是系统中气体爆炸强度增加的主要原因,而管道在湍流诱导的喷射火焰中扮演非常重要的角色。     

定容体系中氮气影响瓦斯爆炸反应的动力学模拟

为考察惰性气体(N2)对瓦斯爆炸过程的影响,建立了受限空间(定容弹)中瓦斯爆炸反应的计算模型,化学反应采用详细反应机理(包括53种组分、325个反应). 结果显示,影响瓦斯爆炸及爆炸后部分致灾性气体生成的关键反应步有R32, R53, R98, R155, R156, R158, R161, R170,瓦斯爆炸会产生瞬间高温和高压,爆炸持续时间仅为0.0001 s左右;惰性气体(N2)对瓦斯爆炸有抑制作用,混合气中N2浓度越大,瓦斯引爆时间越延迟,且随N2浓度增长,爆炸强度也越弱(充入10%, 15%, 20% N2,爆炸时间分别延迟0.0009, 0.0013, 0.0019 s,爆炸后压力以约5.065 kPa递减,爆炸温度以约35 K递减);在混合气体中充注N2能在一定程度上抑制CO, CO2, NO, NO2等有害气体的生成,含N2量增加抑制作用更明显.     

泄压条件下管道内瓦斯爆炸传播的氮气阻爆

矿井瓦斯爆炸发生后,采用灭火剂进行阻爆,将有助于从根本上消除爆炸的灾难性后果。本文在爆炸管道上设置双喷头,探索喷出N₂来实现阻爆和熄灭火焰。对于四周保持密闭的平直管道,采用不同压力将氮气喷出,但均未能阻止爆炸火焰沿管道的传播。在管道下表面设置开口进行泄压后,可以观测到爆炸过程中大量的高温气团和预混气从该开口流出,并在开口外继续发生反应。结合侧向泄压,当双喷头中左喷头（第二喷头）不喷N₂时,右喷头（第一喷头）所喷N₂在各个压力下也仍未能实现阻爆。但当左喷头（第二个喷头）压力在0.1 MPa及以上时,均能实现阻爆。并且双喷头所喷N₂压力越大,爆炸火焰被阻止和熄灭的位置越靠前。通过侧向泄压使管道内的反应变弱是有利于阻爆的第一个主要原因。侧向泄压使管道内爆炸火焰的传播速度下降,从而喷出更多氮气并获得更长的时间来对预混气进行充分稀释,这是实现阻爆和熄灭火焰的第二个主要原因。