建设用地土壤中11种半挥发性有机物的测定

利用快速溶剂萃取-气相色谱-质谱法对建设用地土壤中11种半挥发性有机物(SVOCS)进行分析,并优化了萃取溶剂、温度和循环次数.经测定,标准曲线的相关系数(R2)>0.990,相对标准偏差(RSD)为1.7％ ～14％,加标回收率为65.0％ ～86.4％,方法检出限为0.01～0.06 mg/kg.结果表明,方法的精...     

Residual bending capacity for pipelines with corrosion defects

Residual bending capacity for corroded pipelines in the presence of axial force and internal pressure can be determined analytically assuming a full plastic failure mode for the pipeline. In this paper, a set of closed-form analytical solutions for residual bending capacity are developed for pipelines with idealized corrosion geometries, namely, constant-depth, elliptical, and parabolic corrosions. It is shown that pipelines with idealized elliptical or parabolic corrosion yield higher bending resistance than that of constant-depth, with the difference between elliptical or parabolic corrosion particularly significant for the case of deep and wide corrosion. It is further pointed out that the simplification of the actual corrosion geometry by constant-depth, as commonly assumed in current code assessment of corroded pipelines, will inevitably underestimate the residual strength of the pipe, especially for the case of deep and wide corrosion. Finally, the experimentally measured bending moment is adopted to validate the proposed analytical solutions in this paper.     

Comparing tools of varying complexity for calculating the gas dispersion

When handling flammable and/or toxic liquids or gases, the gas dispersion following a release of substance is a scenario to be considered in the risk assessment to determine the lower flammability distance (LFD) and toxicity thresholds. In this work a comparison of different gas dispersion tools of varying complexity ranging from a simple Gaussian model over a boundary layer model (BLM) and a Lagrangian model to CFD (in this case ANSYS CFX v14) is presented. The BLM covers the special case of liquid releases with formation of a pool. It does not only solve the gas dispersion but also calculates the evaporating mass flow out of the pool. The simulation values are compared to each other and to experimental data resulting mainly from our own open air experiments covering the near field and carried out on the Test Site Technical Safety of BAM (BAM-TTS) for different release types (pool evaporation, gas release) and topologies. Other validation data were taken from literature and cover large scale experiments in the range of several 100 m.     

Development of a theoretical framework for the evaluation of risk connected to accidental oxygen releases

A short-cut methodology for a fast estimation of hazards from oxygen releases and the evaluation of safety distances is presented. Starting from a historical survey on accidents involving oxygen releases and consequent scenarios, the approach includes analytical models for the quantification of incremental hazards due to oxygen releases, in non-obstructed areas, both for continuous and nearly instantaneous scenarios, adopting a simple Gaussian dispersion model. An example of the application of the model in a real case-study and relevant quantitative results are presented.     

青岛输油管道泄漏爆炸事故分析与整改建议

分析了青岛输油管道泄漏爆炸事故发生的原因：城市输油管网规划布置不合理;安全监管责任不落实,检查管道状况不到位;泄漏后的应急处置不当,未及时疏散周边群众等。对照美国油气管线的管理体系和历次事故分析经验与整改过程,指出我国油气管线运营管理和安全事故处理方面存在的问题,并提出整改的建议。     

城市油气管道泄漏爆炸重大案例应急管理对比研究

青岛东黄输油管道泄漏爆炸特别重大事故,引起公众对城市油气管道安全的普遍关注。近年来,城市油气管道事故频繁发生,反映出我国在城市地下管道安全管理方面存在较大问题。基于国内外管道相似事故调研,选取墨西哥瓜达拉哈拉管道泄漏爆炸事故和青岛东黄输油管道泄漏爆炸事故进行对比分析。基于事故致因理论,探究事故发展模式,建立事故链模型。结合应急管理思想,从预警预控、应急处置、评估恢复角度分析事故应急管理过程的共性失误。最后,针对应急管理各阶段共性失误提出防范措施,对提高类似事故的应急管理能力具有一定的参考意义     

聚乙烯燃气管道的全面检验

由于聚乙烯管道材质的特殊性,其损伤机理和失效模式与钢质管道有很大的不同,寻找一种有效的埋地PE管道检验方法是大家关心的问题。本文通过聚乙烯燃气管道全面检验的实践,在常规检验项目的基础上,介绍了新的资料审查方法和开挖割样的原则,提出了通过割样检验来评估埋地PE管道材质性能变化情况及原始焊口安装质量的观点;最后,针对最不利条件下的组合载荷,介绍了管壁截面稳定性校核的方法。这些方法及建议,对同行有一定的参考和借鉴意义。     

地下天然气储气井的现状与前景

储气井是一种压力容器,也是地下压力容器的典型代表。由于开发储气井的理念来源于油气井,因此储气井具有常规压力容器所不具备的特性并存在很多先天不足。文章针对储气井的现状,剖析了储气井在材料、设计、制造、检验检测等各环节存在的问题,并对储气井的健康发展提出了改进建议。     

采空塌陷区埋地输气管道的变形及受力分析

针对采空塌陷对输气管道的潜在威胁,采用管道－土壤相互作用（PSI）单元,结合三向土弹簧非线性模型,建立采空塌陷区埋地输气管道的有限元计算模型,分析了不同管径、壁厚和内压影响下管道的变形和受力规律,并确定最大变形和最大受力的位置。结果表明:适当增加壁厚和减少内压能有效提高管道的安全性;最大Von-Mises应力和最大竖向应变位置均在内边缘塌陷区且靠近中间塌陷区;最大轴向应力和最大轴向应变位置均位于中间塌陷区两侧。所得结果对埋地输气管道穿越采空区的安全防护具有一定参考价值。     

岩鹰山隧道内天然气管道泄漏规律及通风方案研究

采用经典流体力学理论,以及计算流体力学（CFD）等方法相结合,对中缅油气 管线上具有代表性的岩鹰山隧道进行研究。用Fluent软件对岩鹰山隧道天然气管道泄漏 进行仿真模拟,利用Fluent模拟结果与泄漏源计算结果相结合,经过理论分析与数据拟 合,提出泄漏天然气充满隧道的时间计算模型,通过不同边界条件下隧道内天然气泄漏 扩散规律的模拟结果对时间模型进行验算并修正。利用计算流体力学（CFD）方法,研 究岩鹰山隧道在发生天然气泄漏事故后,单风机通风方案的效率,得出隧道通风优化方 案,方案内容包括最佳送风方式、布设水平位置、布设高度、布设间距。根据通风方案 计算结果对风机型号选取、以及隧道洞门设计提出了建议。