基于Logistic回归的燃气管网风险因素重要度分析方法研究*

为确定燃气管网风险评估的关键风险因素,以A省各地市燃气管网为研究对象,基于燃气专家经验确定燃气管线风险等级,提出基于Logistic回归的燃气管网风险因素重要度分析方法。采用样本增强及随机抽样的方式,选取400个均衡样本作为管网评估数据输入,通过因子分析方法对其进行降维,得到3个公共因子并作为一级指标反向构建燃气管网风险评估指标体系;利用有序多分类Logistic回归方法,根据回归系数绝对值大小对风险因素进行重要度排序。研究结果表明:外界环境对燃气管网风险的贡献程度相对较高,管道自身因素和巡检养护次之。研究结果可为城市燃气风险防控提供理论依据和方法参考。     

浅析废烟气脱硝催化剂环境管理

随着"十二五"期间国家对氮氧化物排放的控制越来越严格,选择性催化还原(SCR)烟气脱硝技术被广泛应用于火电厂的脱硝工程。本文介绍我国目前废烟气脱硝催化剂的产生情况、存在的环境风险以及发达国家的管理经验,从而提出我国将废烟气脱硝催化剂纳入危险废物管理,推行危险废物经营许可证制度,加强产生和经营单位的日常监督管理,从而促进行业的健康可持续发展。     

Dynamic risk assessment for underground gas storage facilities based on Bayesian network

Loss of the underground gas storage process can have significant effects, and risk analysis is critical for maintaining the integrity of the underground gas storage process and reducing potential accidents. This paper focuses on the dynamic risk assessment method for the underground gas storage process. First, the underground gas storage process data is combined to create a database, and the fault tree of the underground gas storage facility is built by identifying the risk factors of the underground gas storage facility and mapping them into a Bayesian network. To eliminate the subjectivity in the process of determining the failure probability level of basic events, fuzzy numbers are introduced to determine the prior probability of the Bayesian network. Then, causal and diagnostic reasoning is performed on the Bayesian network to determine the failure level of the underground gas storage facilities. Based on the rate of change of prior and posterior probabilities, sensitivity and impact analysis are combined to determine the significant risk factors and possible failure paths. In addition, the time factor is introduced to build a dynamic Bayesian network to perform dynamic assessment and analysis of underground gas storage facilities. Finally, the dynamic risk assessment method is applied to underground gas storage facilities in depleted oil and gas reservoirs. A dynamic risk evaluation model for underground gas storage facilities is built to simulate and validate the dynamic risk evaluation method based on the Bayesian network. The results show that the proposed method has practical value for improving underground gas storage process safety.     

江苏省300MW以上燃煤电厂汞排放现状分析

基于2012年江苏省10家典型燃煤电厂相关数据,分析了影响烟气中汞(Hg)排放浓度的因素。其中电厂负荷、烟气净化设施、燃烧炉类型等会直接影响烟气中Hg的排放浓度,而原煤中Hg的含量与烟气中Hg的浓度没有直接的关系。通过模型对江苏省现有300 MW以上燃煤电厂Hg排放量进行了估算,2012年Hg排放总量约为7.307 t。通过反距权重插值进行分析,发现在区域分布上江苏省整体呈现出南部高于北部的趋势。     

气相色谱法测定废水中6种挥发性脂肪酸含量

挥发性脂肪酸(VFA)是厌氧消化过程的重要中间产物,在反应器运行中,出水VFA用作重要的控制指标。通过色谱条件探索将各种脂肪酸分离,同时研究了水样酸碱度,吸附等对测定的影响,进一步优化了废水中挥发性脂肪酸的测定。方法的检出限在0.99~1.77 mg/L,回收率在90.9%~102.7%之间,相对标准差(n=5)在1.3%~3.8%之间。     

Fenton试剂氧化法在工业废水处理中的应用研究

Fenton试剂的氧化能力强,反应过程短,降解效果好,本文中介绍了Fenton试剂的特点,并且通过实验得出几种无机离子对Fenton试剂氧化处理工业废水的影响。     

气相色谱法测定水中的三氯乙醛

建立了一种用气相色谱法测定水体中三氯乙醛的方法。水样先以石油醚萃取,除去高沸点化合物,加入氯化钠破乳,然后再用石油醚—乙醚混合溶剂(V/V=2:1)萃取3次,萃取液经色谱柱分离,用电子捕获检测器检测。最低检出浓度可达0.008 mg/L,线性关系良好(相关系数γ=0.992~0.998),一般共存物质不干扰测定。     

硫黄联合装置停工密闭吹扫的实现

介绍了中国石化济南分公司硫黄回收联合装置安全环保停工的过程,在硫黄回收联合装置停工前,研究讨论各装置停工密闭吹扫的流程及方法,并确定各装置停工吹扫的顺序、注意事项和前期准备工作。在各装置停工吹扫过程中,严格按照停工方案,采取了分装置吹扫,该装置吹扫完毕后立即加盲板隔离,最后放火炬公用系统采取倒吹扫,实现了装置停工密闭吹扫,达到了各装置停工酸性气系统吹扫不放火炬的要求。     

普光气田含硫污水尾气处理工艺应用与优化

针对中国石化普光气田产出水属于典型的含硫污水,密闭处理系统中产生大量高含硫尾气,论述了尾气处理工艺中存在的问题,优化了单一的生物除硫、活性炭吸附工艺,增加了一级碱洗、氧化除硫工艺,实现尾气达标排放。     

液液萃取-气相色谱法测定地表水中17种有机氯农药研究

建立了二氯甲烷液液萃取-气相色谱法同时测定地表水中17种有机氯农药的方法。标准曲线线性良好,17种化合物的相关系数R2均大于0.999。当取样量为200 mL时,方法检出限在0.015μg/L~0.062μg/L之间。以超纯水样品进行基质加标实验,重复测定6次的相对标准偏差为1.2%~6.2%,平均加标回收率为72.8%~93.5%。方法简单快捷,精密度良好,准确性高,适用于地表水中痕量有机氯农药的测定。