纳米级别铝粉粉尘爆炸的实验研究

以3种不同粒径的纳米铝粉为研究对象,采用20L球形爆炸测试装置对纳米铝粉的爆炸特性进行了实验研究.通过对实验过程中纳米铝粉的爆炸过程和爆炸特性数据的分析,得出纳米铝粉的爆炸规律.纳米铝粉的最大爆炸压力和最大压力上升速率受粉尘浓度的影响.当粉尘浓度在0.50kg/m3以下时,爆炸压力随粉尘浓度的增加而有较明显的增大,并逐渐趋向最大值,并在一定范围内趋于稳定;当浓度超过1.25kg/m3以后,最大爆炸压力随粉尘浓度的增加而减小.最大压力上升速率随粉尘浓度的变化与最大爆炸压力随粉尘浓度变化的规律相似.     

TNT粉尘爆炸压力发展过程研究

在２０Ｌ球形粉尘爆炸装置中，对ＴＮＴ粉尘爆炸压力发展过程进行了研究，主要讨论了浓度、粒度对其最大爆炸压力及最大压力上升速率的影响，同时，理论建模对不同粒度，浓度、湍流等情况下压力发展进行了研究，发现与实验基本吻合。     

烟煤粉爆炸特性实验研究

为了评估和控制煤矿、发电厂等煤粉爆炸的危害,利用20 L球形爆炸装置的标准测试方法测试了烟煤粉的爆炸特性.重点讨论了煤粉粒径、粉尘浓度、点火能量对最大爆炸压力、最大爆压上升速率、爆炸指数、爆炸下限的影响.煤粉越细,其爆炸下限越低,爆炸烈度越大,但煤粉细到75 μm以下后,这种变化趋势趋缓;在所测浓度范围内(小于700 g/m~3),最大爆压、最大压力上升速率和爆炸指数均随煤粉浓度增大而增大;爆炸烈度随点火能增大而迅速增强,点火能小于1 kJ时各煤样在不同浓度的爆炸都很微弱.研究结果对理解煤粉爆炸危险性、控制煤粉爆炸危害以及进行内在安全设计有重要参考价值.     

受限空间内气体爆炸惰化泄爆实验研究

为研究惰化条件下受限空间内部混合气体爆炸及泄爆过程中的压力变化规律,对侧面带有泄爆口的球形容器在不同惰性气体浓度条件下密闭爆炸及泄爆过程进行了实验研究.结果表明:容器内初始压力越大,气体爆炸压力及压力上升速率越大,且容器内压力峰值与初压呈线性增加;密闭爆炸时惰性气体占甲烷-空气混合气体的比重越高,容器内的最大压力越低,压力上升速率越小,从点火到达最大压力所用的时间越长,容器内的最大压力与惰性气体的体积分数呈近似线性关系;泄爆与惰化联合作用对容器内的压力峰值及压力上升速率影响都较显著,破膜之前压力缓慢上升,破膜之后快速下降;当惰性气体的浓度达到临界体积分数10%时,泄爆膜一打开,容器内的压力立即下降,使非平衡泄爆转化为平衡泄爆.     

管道条件下超细煤粉尘的爆炸特性研究

研究了4种不同粒径的超细煤粉尘在管道条件下的爆炸过程和爆炸特性.研究了超细煤粉尘爆炸前后工业成分及物理状态的变化;研究了煤粉尘的浓度和粒径对超细煤粉尘在管道条件下的最大爆炸压力及最大爆炸压力上升速率的影响规律.研究表明,随着煤粉尘粒径的减小,爆炸后产生的灰分减少,而最大爆炸压力越大,最大爆炸压力上升速率也越大.     

TNT 粉尘爆炸压力发展过程研究

在２０Ｌ球形粉尘爆炸装置中，对ＴＮＴ粉尘爆炸压力发展过程进行了研究，主要讨论了浓度、粒度对其最大爆炸压力（ｐｍ）及最大压力上升速率（（ｄｐ／ｄｔ）ｍ）的影响；同时，理论建模对不同粒度、浓度、湍流度等情况下压力发展进行了研究，发现与实验基本吻合．     

TNT粉尘爆炸物性研究

本文就ＴＮＴ粉尘在二种粒度范围１６０－２００目、２００目以上和不同温度的情况，对其最小点火能量和爆炸下限进行了较全面的测试，并针对延迟时间、电极间隙、贮能电容、放电电阻、环境湿度、喷气压力和粉尘浓度等试验条件对粉尘爆炸特性的影响进行了讨论，而且对易挥发性炸药粉尘的爆炸机理做了初步证明。     

TNT粉尘爆炸特性研究

本文就ＴＮＴ粉尘在二种粒度范围１６０～２００目、２００目以上和不同温度的情况，对其最小点火能量和爆炸下限进行了较全面的测试，并针对延迟时间、电极间隙、贮能电容、放电电阻、环境湿度、喷气压力和粉尘浓度等试验条件对粉尘爆炸特性的影响进行了讨论，而且对易挥发性炸药粉尘的爆炸机理做了初步证明。     

煤尘粒径对瓦斯煤尘爆炸的影响研究

煤尘的粒径大小和质量浓度对煤尘的燃烧爆炸存在重要的影响.为研究分析大颗粒煤尘对瓦斯煤尘爆炸产生的影响,在煤尘质量浓度相同的基础上,从参与爆炸的主体煤尘中选取粒径为75μm的大颗粒,分别与粒径为15,25,35μm的小颗粒进行混合爆炸并同时改变大颗粒煤尘的质量百分比,通过有限元软件Fluent,应用连续相、颗粒相计算方法对爆炸过程进行数值模拟,对最大爆炸压力和火焰传播速度进行了分析.结果表明:在大小颗粒混合的复合爆炸中,最大爆炸压力一直处于一个范围之间;总质量一定,最大爆炸压力、火焰传播速度随着大颗粒煤尘质量百分比的增大而呈现下降趋势,并且混合煤尘中小颗粒粒径越小,最大爆炸压力、火焰传播速度越大.     

水平管道内甲烷-煤尘混合爆炸压力的研究

为研究水平管道内甲烷-煤尘混合爆炸对压力的影响,防控煤矿瓦斯爆炸的发生,利用自制的水平管道式气体-粉尘爆炸测试装置研究了不同甲烷-煤尘配比浓度、煤尘粒度下,爆炸压力的变化.结果表明:随着甲烷和煤尘配比浓度的增加,最大爆炸压力先增大后减小,当甲烷-煤尘配比浓度为5%甲烷、400 g/m3煤尘浓度时爆炸压力达到最大;各甲烷-煤尘配比浓度所对应的最大爆炸压力不同,最大爆炸压力的增幅与降幅有显著的差异,最大分别为42%和52%;煤尘粒径与爆炸压力之间呈线性减小关系,在43~125μm范围内,煤尘粒径越大,爆炸压力越小.     

煤粉—惰性介质混合体系爆炸特性实验研究

为深入认识煤粉—惰性介质混合体系爆炸行为,在Siwek 20 L球形爆炸测试系统内研究了煤粉—惰性介质混合体系的爆炸威力(最大爆炸压力、最大升压速率、燃烧持续时间)、敏感度(爆炸上、下限)和惰性介质的抑爆效力,并重点考察了点火能量、煤粉热值、惰性介质组分、煤粉浓度、煤/惰性介质混合比等因素的影响。结果表明,添加惰性介质能显著降低煤粉爆炸威力,其抑爆效力随点火能量增加而下降,并由此建议采用5～10 kJ点火能量考察惰化效应;煤粉热值增加可显著提高混合体系的爆炸威力;就惰化效应而言,湿分的抑爆效力优于磷酸二氢铵和碳酸钙,而磷酸二氢铵的抑爆效力又优于碳酸钙,其中煤粉完全惰化所需惰化剂量与煤尘浓度密切相关,在200～400 g/m3处有最大值,为"最危险浓度";增加惰性介质添加量可降低爆炸上限,提高爆炸下限,有效压缩煤粉尘可爆浓度范围。研究结果对深入理解粉尘爆炸规律、优化惰化标准,完善测试方法有参考价值。     

半封闭受限空间煤尘与瓦斯耦合爆炸研究

煤尘参与的瓦斯爆炸事故具有很强的破坏性和伤害性,是煤矿的重大事故之一.用一端开口的半封闭管道爆炸实验装置,通过改变瓦斯与煤尘耦合爆炸浓度及点火条件,揭示受限空间瓦斯与煤尘耦合爆炸的规律.实验结果表明,封闭下的耦合体爆炸火焰传播速度较开口状态达到极值快,但极值点距点火位置较近,开口爆炸火焰传播距离是积聚耦合体长度的2倍左右;瓦斯参与的煤尘爆炸,爆炸相对强度随瓦斯浓度的增加而增加,传播距离更远;理论推导瓦斯与煤尘耦合爆炸超压传播距离与爆炸能量的平方根成正比,与巷道断面积的平方根成反比,研究结果为防治瓦斯爆炸、事故勘验以及阻隔爆装置的研制提供了可靠的实验数据.     

Simulation Analysis of Indoor Gas Explosion Damage

The influence factors and process of indoor gas explosion are studied with AutoReaGas explosion simula-tor. The result shows that venting pressure has great influence on the indoor gas explosion damage. The higher the venting pressure is, the more serious the hazard consequence will be. The ignition location has also evident ef-fect on the gas explosion damage. The explosion static overpressure would not cause major injury to person and se-rious damage to structure in the case of low venting pressure (lower than 2 kPa). The high temperature combus-tion after the explosion is the major factor to person injury in indoor gas explosion accidents.     

长持时爆炸冲击波产生方法

不同持时的爆炸冲击波对建筑结构及防护工程的作用显著不同，在试验或数值模拟中常需要得到长持时爆炸冲击波，延长爆炸冲击波正压作用时间是研究长持时爆炸荷载下结构响应的难点。在AUTODYN中建立长筒爆室小当量炸药多点延时起爆模型，分析爆炸冲击波在长筒爆室中的传播规律，研究管道长度、延时起爆时差、起爆顺序对冲击波波形的影响。结果表明：距离增加，超压峰值减小、正压持续时间增加；根据炸药量和爆室长度合理地选择起爆时差可以获得波形丰满且连续衰减的超压时程曲线；爆室底部起爆、合理控制延时间隔，可以形成类似于大当量远距离爆炸下产生的连续衰减的长持时冲击波。分别给出100、200 ms爆炸持时起爆方案，为长持时爆炸模拟装置的设计提供技术支持。     

Numerical simulation for explosion wave propagation of combustible mixture gas

A two-dimensional multi-material code was indigenously developed to investigate the effects of duct boundary conditions and ignition positions on the propagation law of explosion wave for hydrogen and methane-based combustible mixture gas. In the code,Young’s technique was employed to track the interface between the explosion products and air,and combustible function model was adopted to simulate ignition process. The code was employed to study explosion flow field inside and outside the duct and to obtain peak pressures in different boundary conditions and ignition positions. Numerical results suggest that during the propagation in a duct,for point initiation,the curvature of spherical wave front gradually decreases and evolves into plane wave. Due to the multiple reflections on the duct wall,multi-peak values appear on pressure—time curve,and peak pressure strongly relies on the duct boundary conditions and ignition position. When explosive wave reaches the exit of the duct,explosion products expand outward and forms shock wave in air. Multiple rarefaction waves also occur and propagate upstream along the duct to decrease the pressure in the duct. The results are in agreement with one-dimensional isentropic gas flow theory of the explosion products,and indicate that the ignition model and multi-material interface treatment method are feasible.     

Experimental and Numerical Study on the Gas Explosion in Urban Regulator Station

Regulator station is an important part in the urban gas transmission and distribution system. Once gas explosion occurs, the real explosion process and consequences of methane gas explosion in the regulator station were not revealed systematically. In this study, a full-scale experiment was carried out to simulate the regulator station explosion process, and some numerical simulations with a commercial CFD software called FLACS were conducted to analyze the effect of ignition and vent conditions on the blast overpressure and flame propagation. The experimental results demonstrated that the peak overpressure increased as the distance from the vent increased within a certain distance. And the maximum overpressure appeared 3 m away from the door, which was about 36.6 kPa. It was found that the pressure-time rising curves obtained from the simulation are basically the same as the ones from the experiment, however, the time of reaching the peak pressure was much shorter. The numerical simulation results show that the peak overpressures show an increase trend as the ignition height decreased and the vent relief pressure increased. It indicates that the damage and peak overpressure of gas explosion could be well predicted by FLACS in different styles of regulator station. In addition, the results help us to understand the internal mechanism and development process of gas explosion better. It also offers technical support for the safety protection of the urban regulator station.     

Investigation on extremal and critical characteristics of ignition time for H_2/O_2 combustion system and their applications

The L,H and C curves in P-T phase are proposed to describe the minimal,maximal and critical char-acteristics of ignition time of H2/O2 combustion system,respectively.The features of H2/O2(Air) com-bustion system,including explosion or not as well as the time delay to achieve its explosion status,can be well shown by explosion limits and these proposed curves.These curves can be described by 1.2k1=ks[Ms],(k11/k10+1)k1=ks[Ms],and 2k1=ks[Ms],respectively,which provide a physical explanation for these curves an...     

抑爆器缓冲器的平衡压力试验研究

抑爆器是工业、仓储等常用的重要安全设备。缓冲器作为自产气式抑爆器的动力源,其平衡压力影响着腔内推进剂的燃烧速度,推进剂的燃烧速度决定了抑爆器喷粉效果,从而决定了抑爆器的抑爆能力。为了有效控制缓冲器的平衡压力,通过实验测试,对测试结果拟合得出计算平衡压力的半经验公式。在设计缓冲器时可以通过该半经验公式计算缓冲器的平衡压力。     

Investigation on extremal and critical characteristics of ignition time for H<Subscript>2</Subscript>/O<Subscript>2</Subscript> combustion system and their applications

The L, H and C curves in P-T phase are proposed to describe the minimal, maximal and critical characteristics of ignition time of H₂/O₂ combustion system, respectively. The features of H₂/O₂(Air) combustion system, including explosion or not as well as the time delay to achieve its explosion status, can be well shown by explosion limits and these proposed curves. These curves can be described by 1.2k ₁=k _s [M_s], (k ₁₁/k ₁₀+1)k ₁=k _s [M_s], and 2k ₁=k _s [M_s], respectively, which provide a physical explanation for these curves and give another way to establish them. Based on the contour of ignition time, the Z-type explosion limits can be explained by thermal explosion theory. Furthermore, the ignition distance of supersonic combustion is predicted according to the ignition time obtained in a Semenov system, which is very reasonable.