某石化企业粉体料仓爆燃事故原因分析

本文以某企业HDPE料仓的一次爆燃事故为案例,通过分析事故的成因,提供了调查料仓事故的思路及整改方案的确定方法.     

几种碳氢燃料与空气混合物相对爆轰敏感度的测定

利用矩形激波管测定了几种碳氢燃料（丁烷，石脑油，ＪＣ５，戊烯，已烯）直接起爆时形成爆轰所需的临界起爆能，并以化学当量比的乙炔氧气混合物直接起爆形成爆轰的临界起爆能为基准，定义了一个无量纲常数Ｄｈ。再利用这个常数，比较了这几种燃料的相对爆轰敏感度。     

Deflagration to detonation transition in a vapour cloud explosion in open but congested space: Large scale test

The paper reviews large scale experiments with various fuels in air where successful deflagration to detonation transition (DDT) took place. This includes a recent experiment disclosed in the Buncefield R&D program, where DDT developed in the propane/air mixture. The DDT occurred in branches of deciduous trees in a premixed stagnant mixture. An internal R&D investigation programme was initiated to better understand the phenomena. A large scale experiment in an open space with ethane air mixture is presented in the paper. The premixed mixture was ignited at the edge of the congested three-dimensional rigs which consisted of vertical and horizontal pipes. After ignition, the flame accelerated in the congestion and transitioned to detonation at the end of congestion. Stable detonation propagated through the remaining open and uncongested space.The flame acceleration process leading to DDT is scale dependent. It also depends on many parameters leading to a large investigation array and, significant cost. However, such R&D efforts aimed toward a safer plant design, i.e. the prevention of occurrence of a major accident, are a small fraction of a real accident cost.     

矿井瓦斯煤尘爆炸传播数值模拟研究

基于连续相、燃烧、颗粒相数理方程建立瓦斯煤尘爆炸传播数理模型,并应用连续相、颗粒相计算方法,依据大型巷道瓦斯爆炸、瓦斯煤尘爆炸传播实验数据,借助普遍应用的流场模拟平台,成功开发瓦斯、煤尘爆炸数值模拟系统。该系统可有效地模拟煤矿瓦斯、煤尘的爆炸事故过程,对瓦斯爆炸的爆燃转爆轰、煤尘是否参与爆炸、爆炸冲击传播速度、衰减规律以及爆炸灾害的波及范围都能进行较准确的模拟。     

无起爆药雷管内管装药密度对燃烧转爆轰的影响研究

起爆药雷管生产中产生大量有毒废水,且其运输、贮存存在安全隐患。为克服这些困难,笔者自行制备无起爆药雷管。采用圆筒式金属内管中装填超细PETN(季戊四醇四硝酸酯),作为起爆元件,代替起爆药部分,研究装药密度对内管燃烧转爆轰(DDT)的影响。研究结果表明,在内管壁厚1～2 mm,内径Φ4.0 mm,长25 mm,装压密度为0.8～1.14 g/cm3的范围内,内管能可靠实现燃烧转爆轰。     

约束空间可燃气体燃烧爆轰特性的数值研究

在可燃气体的输送、贮存、加工和使用过程中,容易发生可燃气体的燃烧和爆炸事故。文中基于有限体积方法,采用五阶WENO格式进行左右状态量的重构后,利用ROE格式进行空间离散,自行开发程序对甲烷氧气的气相爆轰波传播过程进行了数值研究。计算结果表明:在CH4质量分数为10%的混合气体中,高温高压气团可诱导气相发生爆轰,爆轰波以2133.3 m/s的速度传播。在带有障碍物的约束空间内,文中分析了障碍物不同高度、不同间距条件下爆轰波传播时波的绕射、马赫反射等现象,给出障碍物表面压力随时间变化历程和冲量值,揭示波与障碍物的相互作用机理以及由此引发流场的变化规律,为有效地控制可燃气体的燃烧速率、防治爆炸灾害的发生提供理论依据。     

建构筑物周边爆破施工安全控制距离及分析方法研究

为研究在居民区附近开展大面积爆破施工的安全可行性以及安全控制距离标准,采用数值模拟方法,分析了地铁车辆段爆破施工对周边高压线及居民楼的影响,根据分析结果,给出了安全控制距离及关键控制指标,说明采用数值模拟的方法适用于类似工况的可行性。另外,研究发现,在居民楼附近进行地铁车辆段爆破施工风险较高,建议在距建构筑物100 m范围内采用静态爆破或机械开挖的方式进行施工。     

炸药爆轰气体产物中无机组份的离子色谱分析方法研究

采用超纯水、Na2CO3-NaHCO3NaOH3种不同的吸收液吸收爆轰气体产物、离子色谱进行样品分离、外标法定量,建立了爆轰气体产物中HF、HCl、HCN无机污染物的离子色谱分析方法。研究表明,炸药爆轰气体中合有一定量的HF、HCl和少量的HCN,选择3．2mmol／LNa2C03与1．0mmol／LNaHCO3混合溶液作为爆轰产物中无机组份的吸收液,吸收效率均值太于90％;离子色谱分析方法的相对标准偏差（RSD）小于5．0％,相关系数达到0．9990以上;进样量为100μL时,HF、HCl、HCN的检测限分别为0．04mg／m^3、0．03mg／m^3、0．05mg／m^3。该方法灵敏度高,回收率好,且样品预处理简单。     

爆炸形成过程中火焰加速的试验研究

为预防和控制工业爆炸事故,并为脉冲爆轰发动机的研究提供理论指导,分析火焰加速导致的燃烧转爆轰过程的影响因素。采用爆轰管探讨障碍物的阻塞比、混合物的组成、初始压力和点火能等4个因素对爆炸性气体火焰速度和爆轰压力的影响规律。试验结果表明:障碍物的存在能大大提高火焰速度和爆轰压力;爆轰压力随管内障碍物阻塞比的增大先变大后减小,并在阻塞比为0.498,燃料种类为天然气,化学当量比为1时达到最大;爆轰压力还随混合气体初始压力的增大和点火能的提高而增大。选择适宜的条件可大大提高火焰加速速率,促进燃烧向爆轰过程转变。     

Influence of physical properties of ammonium nitrate on the detonation behaviour of ANFO

In order to obtain a better understanding of the non-ideal detonation behaviour of ammonium nitrate based explosives, detonation velocities of ANFO (ammonium nitrate and fuel oil) prepared with different kinds of ammonium nitrate (AN) were measured in steel tubes. In this series of test six kinds of AN were used and the influence of the pore diameter, the pore volume and the particle diameter of the AN particle on the detonation velocity of ANFO was investigated.

It was found that the pore diameter and the pore volume had a strong influence on the detonation velocities of ANFO. In the case of ANFO samples which were prepared with AN that had the same pore diameter and the pore volume, when tested the highest detonation velocity (3.85 km/s) was observed when the smallest particle diameter (<0.85 mm) was used. This value corresponded to 75% of the ideal detonation velocity, which was theoretically predicted by the CHEETAH code with the JCZ3-EOS.

The 12 months aging showed the change of the detonation velocities of ANFO and the reaction of ANFO was influenced both by the physical and the chemical properties of AN particles and oil during the storage period.