Survey-based analysis on the diffusion of evacuation advisory warnings during regional evacuations for accidents that release toxic vapors: A case study

This paper analyzes the diffusion of evacuation advisory warnings during regional evacuations for accidents that release toxic vapors. Investigations results on the propagation of evacuation advisory warnings in the ‘4.16’ chlorine release and the explosion accident at Chongqing Tianyuan Chemical Factory in China, and a comparison analysis of the evacuation notification process of six typical leakage accidents are presented in this paper. After conducting the evacuation notification investigation on the ‘4.16’ accident, in which 401 valid questionnaires were collected from people who should have evacuated during the accident, the methods and channels of the evacuation notification, the notification efficiency, and the actual response efficiency of the recipients after the issuing of the evacuation advisory warnings were analyzed. A comparison analysis of the evacuation notification process is performed by analyzing six typical leakage accidents, and basic principles of evacuation notification for a regional evacuation for toxic vapor release accidents are proposed.     

LEACHATE LEAKAGE FROM LANDFILLS WITH MODERN LINER SYSTEMS1

ABSTRACT: Recent technological advances have led to a new generation of landfill liner systems that are highly effective at intercepting and removing leachate. Many of the modern liner systems are so effective that they allow very little or no leakage. Indeed, the amount of leakage through those liners is so minimal that, although it can be theoretically predicted, it cannot be measured with the available monitoring well technology. In addition to being highly effective, some modern liner systems are constructed with two liner layers separated by a drainage medium that detects and removes any leakage through the top liner. These significant improvements in liner system technology have led to the questioning of the necessity for the currently required high number of monitoring wells. Reduction of the number of the monitoring wells and/or of the frequency of sampling would result in substantial cost savings. The present study reports the results of a research project conducted at eleven municipal landfills with modern liner technology throughout the State of Florida. Through actual field data and computer modeling, it was found that the liner systems standards applied in the State of Florida are very effective at preventing any groundwater contamination. Thus, the present monitoring well regulations are too conservative.     

The Social Meaning of Carbon Dioxide Emission Trading Institutional Capacity Building for a Green Market in Costa Rica

Forests offer good possibilities for the sequestration of carbon dioxide. This service can be commodified by the introduction of carbon (dioxide) credits, which can be traded on a carbon market. The premise of this paper is that the traditional economic view on the construction of these carbon markets is a too simplistic one, particularly, because it neglects the social meaning of a carbon market for developing countries. From their viewpoint as suppliers of carbon credits such a market has a broader meaning. It must be seen as a social mechanism for improving both the living conditions of local people and a more encompassing improvement of the environment than climate as such. What initially might be labelled as a carbon market might better be understood as a more encompassing 'green market'. The agreement between Costa Rica and Norway, officially known as the Reforestation Conservation Activities Implemented Jointly Project (RFCAIJP) represents a clear example of a green market. In this paper, we study the development, characteristics and benefits of that market, asking the question what lessons can be learned from this first practical experiences. More specifically we focus on the conditions that have made this type of agreement successful.     

Has EU ETS caused carbon leakage in the EU carbon-intensive industries?A study from the perspective of bilateral trade

Reducing carbon leakage is one of the important reasons that was put forward by the EU for their border adjustment tax proposal.However,there are not many empirical evidences supporting significant carbon leakage in the EU carbonintensive industries.This paper applied the structural breakpoint test for the time series of import and export of cement,aluminum,and steel between EU and China.No significant structural changes were detected in the import and export of cement and aluminum.However,there proved to be two breakpoints,i.e.,2003 and 2008,in the import and export of steel,in which at the second point the overall level of steel import increased.Furthermore,Granger causality test was applied to the carbon price from European Climate Exchange and the import and export of steel.It was found that the carbon price was the Granger cause for the changes of steel import,but not the Granger cause for the export.The results of the study showed that the impacts of EU ETS on the EU carbon-intensive industries were limited.Among the three industries,partial evidence of carbon leakage was only found in the steel industry.Therefore,reducing carbon leakage could not serve as a convincing justification for border adjustment tax.     

“U+L”型通风综采工作面采空区漏风特性研究

为了掌握“U+L”型通风综采工作面采空区的漏风规律,以某矿综采工作面为试验地点,先采用Fluent软件对综采工作面采空区的漏风流场进行了数值模拟,后结合数值模拟结果制定了综采工作面示踪气体SF6的测漏风技术方案,并现场实测了“U+L”型综采工作面采空区的漏风风流分布特征.数值模拟结果与现场实测结果十分吻合.结果表明:1)“U+L”型综采工作面全程向采空区漏风,漏风汇至滞后联络巷后经专用排瓦斯巷排出;2)“U+L”型综采工作面漏风量随联络巷距离工作面距离增大而逐渐降低;3)“U+L”型综采工作面漏风量沿工作面倾向方向(从进风至回风)呈逐渐减少趋势.     

受限空间泄漏孔径对气体扩散影响的模拟研究

室内天然气意外泄漏后极易引起火灾爆炸事故,为避免或减少其事故的发生,得到泄漏后气体扩散规律及爆炸危险浓度分布状况,利用Fluent软件对某12m×7m厂房在不同泄漏孔径下泄漏扩散情况进行了数值模拟.分析风速为1 m/s时,泄漏孔径对甲烷气体扩散的影响,并将燃气管道泄漏速率的模拟结果与理论预测值进行对比分析.结果表明:所建立的数学模型和设置参数是合理的;在不同泄漏孔径下,监测受限空间内5个不同点气体分布状况,得出在风速和壁面的影响下,排气扇附近相对较危险,窗户下方相对较安全.     

危险性重气介质在隧道内泄漏扩散数值模拟

采用CFD软件Fluent对隧道内运载危险性重气(氯气)的槽罐车在行驶过程中发生小孔泄漏导致的氯气扩散进行了数值模拟,得到危险性重气质量浓度随时间和空间的变化规律,分析了泄漏源位置改变产生的不同释放方式以及车体不同行驶速度对危险性重气泄漏扩散的影响。研究结果表明,在相同条件下,车子的速度越大,氯气泄漏产生的危害性越小;泄漏孔位于车体后部比顶部更危险,产生危害更大;泄漏后不同时刻隧道内危险距离及造成损失不同,对泄漏危险距离进行了分析和确定,得出了不同条件下的死亡半径和重伤半径。研究结果可为隧道内有害重气介质泄漏扩散引发的事故的预防和控制提供借鉴。     

埋地成品油管道泄漏强度模型与试验验证

针对泄漏事故频发的埋地成品油管道,搭建埋地成品油管道泄漏试验平台,以柴油为输送介质开展试验。通过试验获得,管道泄漏量及泄漏强度随输油压力和泄漏孔面积增大而逐步增加,在输油压力较小时,泄漏孔位置对管道泄漏量及泄漏强度有影响,但随着输油压力的逐步增加,泄漏孔位置对泄漏量及泄漏强度的影响逐渐减小。同时根据伯努利方程推导得出埋地成品油管道泄漏强度模型,将试验参数代入模型,对比模型计算值与试验数据,结果表明,计算结果与试验数据吻合良好,验证了模型的正确性,可用于指导埋地成品油管道泄漏事故的定量风险评价及处理。     

山谷地区埋地天然气管道泄漏三维数值模拟

针对山谷地区埋地天然气泄漏问题,建立三维泄漏模型,将管道模型建立于土壤下,给出山谷地区风随海拔高度变化边界条件,在此基础上对山谷地区高含硫天然气泄漏问题进行六组模拟。结果表明:六组工况下硫化氢的危险区域全部大于甲烷的危险区域,突显出天然气泄漏问题中硫化氢的危害性之大。风速对危险范围的影响很大,在山谷地形条件下危险范围大小与风速大小成反比,且风速越大,危险范围越小。三个泄漏口方向中漏口斜向上45°时空气中泄漏气体的总质量分数最大,扩散的范围最大,但部分范围内并未达到泄漏气体的危险浓度,危险范围比实际扩散范围要小,漏口斜向下45°时危险区域是最大的,漏口水平介于中间。     

气体管道中阀门内漏声发射信号特性研究

针对石化企业气体阀门内漏在线诊断问题,设计并建立气体截止阀内漏检测实验装置,根据声发射技术理论与实验相结合研究截止阀内漏特性,对比不同压差下信号参数分布规律。结果表明,阀门泄漏率与信号振幅和平均信号电平ASL均呈指数分布,与能量和均方根AERMS呈对数分布,并拟合了泄漏率与AERMS的函数关系式。因此,可以综合各对应关系对阀门是否泄漏进行检测,并利用泄漏率与AERMS的函数关系式定量估算阀门泄漏率。