爆炸气体（蒸气）最大试验安全间隙的试验方法研究

对可燃气体（或蒸气）最大试验安全间隙值的测定方法进行了研究,设计了一套测定可燃气体（或蒸气）与空气混合物爆炸的最大试验安全间隙值的装置,用其所测数据与ＩＥＣ标准中的推荐数据具有较好的可比性,为爆炸性气体（或蒸气）的分级、分组以及隔爆型电气设备的设计提供了理论依据。     

爆炸气体(蒸气)最大试验安全间隙的试验方法研究

对可燃气体(或蒸气)最大试验安全间隙值的测定方法进行了研究,设计了一套测定可燃气体(或蒸气)与空气混合物混合爆炸的最大试验安全间隙值的装置,用其所测数据与IEC标准中的推荐数据具有较好的可比性,为爆炸性气体(或蒸气)的分级、分组以及隔爆型电气设备的设计提供了理论依据。     

隔爆水幕对瓦斯爆炸传播规律影响的试验研究

为研究自制隔爆水幕抑制瓦斯爆炸的有效性,采用大直径瓦斯爆炸试验管道系统,在不同瓦斯浓度和不同水幕流量条件下进行瓦斯爆炸试验,利用数据采集系统测量瓦斯爆炸特性参数并对其变化规律和隔爆效果进行分析。结果表明:瓦斯浓度9.5%时经过隔爆水幕抑制作用,瓦斯爆炸压力峰值由64 kPa下降到39 kPa,衰减了39%;温度峰值由969 K下降到498 K,衰减了49%;速度最大值由136 m/s下降到73 m/s,衰减了15%。虽然隔爆水幕对不同浓度瓦斯产生的爆炸起到良好的抑制效果,但隔爆之后的传播规律依然受到瓦斯浓度影响。隔爆水幕对瓦斯爆炸的抑制效果取决于喷水流量的大小,随着流量的增加,水幕的隔爆效果增强,喷头最佳的工作流量为16.4 L/min。     

化工防爆电气设备安全管理水平提升策略

为有效提升企业防爆电气设备的管理水平,本文通过对防爆电气设备事故案例解析,提出相应的安全管理策略,希望对化工防爆电气设备产生事故预防起到参考借鉴作用。     

最大熵试验法在炸药机加工艺安全管理中的应用

由于炸药高能量、一定条件下能发生化学爆炸的特点,其机械加工过程承受的摩擦、挤压、冲击和加热等,对机加过程的安全有着重要的影响。为确保炸药机加过程的安全,本文基于最大熵试验法,对改变炸药机加线速度的安全可靠性进行了评估试验。评估结果表明:在设计的目标值以及试验次数状态下进行炸药切削是安全的。最大熵试验法能够为炸药安全切削试验设计提供理论依据,对炸药机加工艺参数的变更管理具有指导意义。     

安全管理学及其试验设计研究

针对目前国内安全管理学教学中普遍存在的问题,运用文献分析、印证,问卷调查等方法,以事故致因"2-4"模型为理论依据,将安全管理学教学内容定位在行为安全学领域,构建以事故预防的行为控制为主线的教学内容,明确了课程内容,形成独立的课程体系。为了让学生更好地掌握课程内容、并学会运用事故致因"2-4"模型分析事故原因及利用行为控制方法预防事故,在全国各高校中率先创新,开设"事故案例的综合原因分析及预防对策制定"试验课程,设计试验内容,并设计出事故案例分析表、"分子结构式样"小球模型等两种实用型试验用具。通过试验,学生可以拼接出事故案例的现代事故致因链立体模型,从行为控制角度制定事故预防对策,实现了对整个课程知识的综合掌握。     

飞行安全技术影响因素及其作用机制研究

为通过管控飞行安全技术的影响因素提高飞行员飞行技术水平,从信息感知、信息处理、判断决策和反应行动4个方面分析了影响飞行安全技术的因素,并对影响作用做出假设。采用问卷调查获取数据,并应用结构方程模型定量分析各因素对飞行安全技术的作用。研究结果表明:判断决策相关因素、信息处理相关因素、反应行动相关因素、信息感知相关因素对飞行安全技术的影响程度依次递减;平衡觉、运动觉、视觉、震动觉、听觉通过作用于飞行员的信息感知进而影响飞行安全技术且影响程度依次递减;飞行经验、注意、理论知识、记忆通过作用于飞行员的信息处理进而影响飞行安全技术且影响程度依次递减;空间定向、风险感知、逻辑推理、快速运算通过作用于飞行员的判断决策进而影响飞行安全技术且影响程度依次递减;动作协调性、动作准确性、动作及时性通过作用于飞行员的反应行动进而影响飞行安全技术且影响程度依次递减。     

贫燃条件下氢气比例对甲烷/氢气预混气火焰传播的影响

为探究贫燃条件下氢气对甲烷/氢气混合气体火焰传播和传爆能力的影响,测定了甲烷/氢气混合气体的最大试验安全间隙(MESG),在安装波纹板阻火器的DN80管道试验装置上开展火焰传播试验。结果表明：在贫燃条件下,火焰速度受Ф和当量比的控制,当Ф增大时,当量比为主导因素,火焰速度降低;随Ф增加,混合气体的整体活性增大且在Ф小于25%时,火焰传播速度曲线变化相似,在Ф大于30%时,火焰传播速度曲线稳定性较弱,MESG快速下降,临界阻火速度降低,火焰无法在阻火器内淬熄,IIA类爆燃阻火器无法满足阻火需求。     

Effects of significant damage of flame gap surfaces in flameproof electrical apparatus on flame gap efficiency

Electrical apparatus for use in the presence of explosive gas atmospheres has to be specially designed to prevent the apparatus from igniting the gas. Flameproof design is one of several options, and one requirement is then that any holes and slits in the enclosure wall be designed to prevent a possible gas explosion inside the enclosure from being transmitted to an explosive gas cloud outside it. Current standards (IEC) require that joint surfaces have a surface roughness of <6.3 μm. Any damaged joint surface has be restored to this quality. The present investigation has demonstrated that flame gap surfaces in flameproof electrical apparatuses can suffer considerable mechanical and corrosive damage before the flame gaps no longer function satisfactorily. In some cases very significant mechanical surface damage in fact improves the gap performance. This indicates that current high costs of repairing and replacing flameproof electrical apparatus in process plants offshore and onshore can be reduced considerably without any increase of the explosion risk.     

The influence of inert gas on limiting experimental safe gap of fuel-air mixtures at various initial pressures

The Maximum Experimental Safe Gap (MESG) is an important criterion to assess the propagation of flames through small gaps. This safety-related parameter is used to classify the flammable gases and vapors in explosion groups, which are fundamental to constructional explosion protection. It is used both, for the safe design of flameproof encapsulated devices as well as for selecting flame arresters appropriate to the individual application. The MESG of a fuel is determined experimentally according to the standard ISO/IEC 80079-20-1:2017 at normal conditions (20 °C, 1.0 bar) with air as oxidizing gas. The aim of this work is to investigate the effect of inert gas addition on the MESG in order to assess the effectiveness of inertization in constructional explosion protection. The term limiting experimental safe gap (S_G) is used for the result of these measurements. The fuel-air mixtures (fuels: hydrogen, ethylene, propene, methane) used as representatives for the explosion groups in flame arrester testing were chosen and diluted with inert gas (nitrogen, carbon dioxide) before testing. The dependence of the limiting experimental safe gap on the total initial pressure, amount and nature of inert additive is discussed. The initial pressure was varied up to 2.0 bar to include increased pressure conditions used in flame arrester testing. Apart from the well-known reciprocal dependence on the initial pressure, the added inert gas results in an exponential increase of S_G. This effect depends on the inertizing potential of the gas and is therefore different with nitrogen and carbon dioxide. The ranking of the fuels is the same as with MESG. As a result, various mixtures of the same limiting experimental safe gap can now be chosen and tested with an individual flame arrester to prove the concept of a constant and device-related limiting safe gap. The work was funded by BG-RCI in Heidelberg (PTB grant number 37056).