对天然气水合物预防管理保障安全生产的研究

为了保障陆上气田冬季天然气安全生产,防止因天然气水合物导致安全事故,采用鱼骨图法对陆上气田天然气水合物产生的原因进行系统分析。分析显示,导致天然气水合物产生的根本原因,出现在天然气产能建设和日常生产管理各环节,以及单井、输气管道和集气站各生产场所,为防止天然气水合物产生,针对原因采用5W1H法进行管理,从而达到对冬季天然气生产主要安全风险进行有效控制的目标。     

Resilience-based optimal firefighting to prevent domino effects in process plants

Domino effects triggered by fire can cause extremely severe damages to the chemical and process plants. In the need of a more effective prevention of fire domino effects, the present study focuses on firefighting which has received less attention compared to passive and active fire protection systems. Considering both the vulnerability and recoverability phases during fire domino effects, we have introduced a methodology for optimal identification of firefighting strategies so as to increase the resiliency of process plants in dealing with fire escalation scenarios. The area above the resilience curve (AARC), which is equal to the accumulation of loss of resilience over time, was considered as the metric to identify the optimal firefighting strategies. In other words, the strategy leading to the lowest AARC can be selected as the optimal strategy from a resiliency perspective.     

Developing a risk-based maintenance model for a Natural Gas Regulating and Metering Station using Bayesian Network

During the last decades, the vital role of maintenance activities in industries including natural gas distribution system has cleared up progressively. High costs may induce to reduced maintenance and, in turn, lead to a lower availability and high risk of undesired events. Therefore, a probabilistic model, based on an acceptable level of risk, is required to avoid under and over estimation of maintenance time interval. This paper presents an advanced Risk-based Maintenance (RBM) methodology to optimize maintenance time schedule. Bayesian Network (BN) is applied to model the risk and the associated uncertainty. The developed method can assist the asset managers to work out the exact maintenance time for each component according to the risk level. To demonstrate and discuss the applicability of the methodology, a case study of Natural Gas Reduction and Measuring Station in Italy is considered. Results prove that the most critical components are the calculator and pilots, while the most reliable one is the odorization. Furthermore, the pressure and temperature gauge (PTG), the remote control system (RCS) and the meter are predicted as the components that require less time to transit from minor risk to catastrophic risk.     

An integrated model for vent area design of hydrocarbon-air mixture explosion inside cubic enclosures with obstacles

This study aims to develop an integrated model - NFPA-68-BRANN model, which can be used to calculate the vent areas of cubic enclosures with obstacles. Seven experiments regarding vented explosion inside the obstructed enclosure are reviewed and applied to check the accuracy of two existing standards, i.e. the NFPA-68 2018 and the BS EN 14994:2007. Accordingly, the parameters to describe the flame development in the NFPA-68 2018 are amended by adopting the Bauwens model. Bayesian Regularization Artificial Neuron Network (BRANN) model presenting the non-linear relationship between the turbulent flame enhancement factor X and its affecting factors is subsequently developed. Eventually, the NFPA-68-BRANN model is generated by incorporating the BRANN model into the modified NFAP-68 2018. The accuracy of the NFPA-68-BRANN model is validated by using a series of the New Baker Test data.     

改进的模糊层次分析法在采动滑坡稳定性影响因素评价中的应用

采动滑坡是山区煤矿开采沉陷诱发的最为严重的一种非连续滑动破坏形式。为了对采动滑坡的稳定性进行评价,在常规层次分析法求解权重的基础上,通过对判断矩阵构造过程的改进避免了一致性检验,建立了改进的模糊层次分析模型,并以马桑湾滑坡为例,在分析采动滑坡稳定性主要影响因素的基础上,建立了采动滑坡稳定性影响因素评价指标递阶层次结构,应用改进的模糊层次分析法对该采动滑坡稳定性影响因素进行了重要性排序,其排序结果与现场实际相符合,证明了该方法的可行性。该研究结果对采动滑坡预防和治理具有重要的工程意义。     

基于贝叶斯方法的竖井中性面模型参数不确定性研究

随着高层建筑越来越多,其发生火灾的风险也越来越大,火灾烟气是导致火势蔓延和人员伤亡的主要原因,因此高层建筑防排烟设计问题可谓重中之重。建筑中性面的性质决定了其在防排烟设计中的关键地位,通过对建筑中性面位置的研究来优化建筑防排烟设计,减少火灾烟气对人和建筑的危害具有重要的意义。在前人工作的基础上,利用场模拟的方法得到样本值,并引入贝叶斯概率方法量化模型参数的不确定性,分析了竖井结构单一参数的不确定性对中性面位置分布的影响。旨在为火灾安全工程设计和竖井模型实验台设计,以及建筑竖向通道防排烟设计提供一定的参考。     

基于逻辑树和贝叶斯网络的海洋平台火灾概率分析

火灾概率分析是海洋平台火灾定量风险评估的重要组成部分,考虑到传统事故树和事件树方法存在一定的局限性,提出了基于逻辑树和贝叶斯网络的火灾概率分析模型。首先采用数理统计方法对墨西哥湾地区2 837起火灾事故进行统计分析,依据事故情况构建逻辑树,然后将逻辑树转化为贝叶斯网络,根据历史数据确定贝叶斯网络各节点的先验概率和条件概率。结果表明:海洋平台火灾事故是设备、人因和组织管理多因素耦合作用的结果;基于贝叶斯网络模型得到海洋平台火灾概率约为1.0×10~(-5),为海洋平台火灾定量风险评估提供了基础数据;由贝叶斯网络模型分析得出,人因操作失误与缺乏作业安全分析的后验概率分别达到0.471和0.119,表明人因组织因素对海洋平台火灾事故具有重要影响。     

多孔黏土异构材料对气态萘的吸附

以膨润土为基质,添加表面活性剂和助表面活性剂,制备了多孔黏土异构材料(PCHs),采用SEM和BET技术进行了表征,并将其用于气态萘的吸附。考察了吸附效果的影响因素,并探讨了吸附机理。表征结果显示,PCHs具有较大的比表面积,孔径分布均匀,兼具微孔和中孔结构。实验结果表明:当吸附温度为30℃、初始萘质量浓度为560 mg/m3、相对湿度为0时,PCHs对萘的平衡吸附量达370 mg/g,远高于膨润土和有机膨润土;吸附为放热过程,温度越高平衡吸附量越低;平衡吸附量随初始萘质量浓度的增加呈非线性增长;水蒸气的存在导致萘的平衡吸附量减小;萘在PCHs上的吸附机理主要为表面物理吸附和有机质的分配作用。     

池火灾评价法在环氧乙烷罐区的应用研究

以某石油化工厂区为工程应用背景,通过对环氧乙烷储罐区计算模型的建立,应用池火灾评价法对环氧乙烷储罐发生池火灾的热辐射伤害区域进行了定量计算,得出环氧乙烷罐区发生池火灾的各级影响半径和造成的伤害程度。结果表明,只有当人员撤离罐区67.35 m范围外方可避免受到热辐射伤害。从环氧乙烷罐区的整体安全性出发,提出了具体的防护措施和建议,为企业的安全管理工作提供参考依据。     

结合流程图与ISM的区域管制运行风险分析

为保障区域管制系统运行的安全,采用流程图法从管制员、设备、环境、管理四方面识别各运行环节潜在的风险,并建立风险因素集合。运用解释结构模型(ISM),对风险因素间的关系进行推理和计算,最终形成一个五级递阶结构解释模型,将风险因素之间原本模糊不清的关系转化为直观的具有层次分明的结构。通过对解释结构模型的分析找出了影响区域管制运行安全的直接因素、间接因素以及深层次的因素,并提出了相应的风险控制措施。