大型液化天然气储罐内液体内分层和翻滚影响因素分析

液化天然气（LNG）的储存温度和组分的变化都会引发诸多问题,如分层、翻滚、蒸发等。基于双扩散理论和黏性流体方程,建立了紊流态LNG分层和翻滚演变的数学模型。模型的模拟计算结果可以直观地看到LNG分层和翻滚演变过程。模拟结果表明,LNG的分层是产生翻滚现象的根本原因,储罐内LNG受热后的热边界层的流动是产生翻滚的直接原因,利用紊流态LNG分层与翻滚演变模型对影响LNG分层、产生翻滚的各种因素进行了分析,得出当漏热强度超过30 W·m^-2后,改变漏热强度,对翻滚现象的产生时间影响不大;当储罐的充满率均为70%时,储罐的容积越大,储罐内的LNG分层发生翻滚的时间越长。为预防LNG储罐发生翻滚的各种措施提供了理论依据。     

液化天然气储罐火灾爆炸事故后果模拟分析

对液化天然气储罐的主要危险性及其特点进行分析,采用数学模型,对其主要危险事故类型：蒸气云爆炸（VCE）和沸腾液体扩展蒸气爆炸（BLEVE）进行后果模拟分析,估算事故的后果严重程度。     

分析液化天然气储运的安全性

液化天然气具有易燃易爆的特性,如果发生燃烧爆炸,不仅会造成巨大的经济损失,还会对人的生命造成威胁,所以对于液化天然气的储存和运输要格外的小心,要确保其安全性,避免因为储运的问题而造成事故发生。下文就是对液化天然气储运的安全性进行的探讨。     

天然气的液化工艺和储运安全性

液化天然气即LNG,主要成分是甲烷,具有无色无味无毒且无腐蚀性的特性,众所周知,在甲烷完全燃烧后生成产物为二氧化碳与水。在已知能源中,它是地球上最干净的化石能源。在改革开放不断实践过程中,天然气的低成本高热值以及环保性受到了我国能源利用领域的青睐。在能源市场中,相较于煤矿等能源,天然气的影响力正不断扩大,在各个能源领域的利用率与日俱增。因此,对于天然气液化工艺以及储运工作有了更高的要求。     

液化天然气储运技术

随着化工行业规模的扩大,对液化天然气运输的需求也在持续增加,有效防控液化天然气储运风险,确保液化天然气运输过程的安全性变得尤为关键。精准的液化天然气运输风险评估是正确认识危化学运输风险的前提,能够更好地控制运输风险。立足于此,本文深入探讨了液化天然气公路运输的隐患,并论述了液化天然气储运风险管控现状。     

大型液化天然气储罐的发展状况

随着液化天然气的需求量日益增加,它的储存运输问题也得到了越来越大的重视。液化天然气储罐是储存液化天然气的一种重要设备。主要简介了液化天然气的优点,液化天然气储罐的分类,国内外现状,以及建造时可能遇到的问题,并简单总结了液化天然气储罐的发展趋势。     

液化天然气储运的安全技术及管理

完整的液化天然气（LNG）工业链系主要包括销售、储运、开采、气化等一系列环节,其中LNG 供气站、LNG 运输和液化站是三个主要的接点,尤其是液化天然气储运极为重要。本文首先阐述了液化天然气的常见储运方式,其次,深入探讨了液化天然气储运的安全技术,具有一定的参考价值。     

大型液化天然气储罐的发展浅谈

本文从大型液化天然气储罐的简介入手,重点探讨了国内外大型液化天然气储罐的发展现状及其发展趋势。     

超低温储罐液化天然气储罐的应用和技术安全

经济发展和科技进步改变了人们的生活状况,液化天然气已在人们的生活和工业生产中得到了广泛的应用。因此,在超低温储罐液化天然气中,如何提升储罐的应用和技术安全研究被逐渐提上日程,成为亟须解决的首要问题。本文基于储罐结构的设计,从满足储罐的材质要求到便于液化天然气固定和安装应用技术进行阐述,为实现液化天然气行业的稳健发展,保障其在储存和安装中的安全性要求,更好地服务国民经济提供了可行性借鉴。     

关于液化天然气的储罐安全技术的分析

天然气作为一种新型能源,有着易燃、易爆等特性。为此,液化天然气应用过程中尤其重视安全生储存。当前,我国液化天然气应用技术仍然处于发展阶段,摸索中应十分重视储罐安全技术研究与探索工作。为了有效保证液化天燃气储存安全,本文结合液化天然气特性、储罐技术环节及储罐构成扼要分析了储罐安全技术要点,为储罐安全提供保障。     

Simulation and economic evaluation of natural gas hydrates [NGH] as an alternative to liquefied natural gas [LNG]

Despite the fact that relatively little is known about the ultimate resource potential of natural gas hydrates, it is certain that gas hydrates are a vast storehouse of natural gas and significant technical challenges need to be met before this enormous resource can be considered an economically producible reserve. In this theoretical study, a simulation scheme was suggested to produce NGH in an industrial scale using pure water as a carrier and seawater as a cooling source. Parametric study was carried out and rigorous design calculations for different operating parameters were investigated. Further more and economical evaluation was done taken data of locally produced LNG as a comparison. Production rates, storage and transportation from production region to consumer's ends were investigated. Results obtained suggested that NGH with little consideration can be a good alternative for fuel gas carrier.     

LNG接收站及其工艺发展现状

液化天然气(LNG)作为一种清洁能源在国际能源贸易中占有重要地位,而接收站是LNG的重要基础设施,对于促进LNG贸易具有关键作用。总结国内外LNG接收站发展及现状,比较LNG接收站的两种主要处理工艺及流程,分析现有LNG接收站工艺中能耗偏高、操作困难等问题及相关优化方案,并对我国LNG接收站技术研究中需要关注的几个方面提出建议。     

液化天然气罐区爆炸危险性分析

通过对液化天然气罐区火灾爆炸危险因素分析,并对罐区进行了重大危险源辨识。采用蒸汽云爆炸伤害数学模型对罐区爆炸后果进行预测,并提出相应安全对策措施。     

Application of inverse methods based algorithms to Liquefied Natural Gas (LNG) storage management

Liquefied Natural Gas is one of the major fossil fuels used throughout the world and is to gain even more of the market share being the cleanest burning fossil fuel and also due to its availability. In addition, now it becomes crucial to improve the existing LNG storage models to support safe and economic managing of LNG storage sites. In this article two inverse methods are compared. First one, being the previously developed optimization method for the real-time inverse problem, is analyzed and its main characteristics are identified. Next, an alternative method is being proposed, based on normal equations applied to nonlinear parameter estimation, dealing with the main limitations of the previous approach. Both methods significantly improve the accuracy of LNG storage models and credibility of predictions, by making use of the available measurements from the tank's gauges and processing them with the developed algorithms.     

冷库利用LNG冷能的工艺设计

介绍LNG冷能应用于冷库的工艺流程,并对工艺流程进行了优化。初步探讨了改变换热器结构形式、管线设置对冷能利用效果的影响。项目正式投产运行后的结果表明LNG冷能利用效果明显,每年可节省相关电费约25万元。     

LNG泄漏扩散影响因素模拟研究

为了研究液化天然气(LNG)泄漏扩散规律,用PHAST软件对某150 m~3 LNG储罐的泄漏扩散过程进行了模拟,分析了LNG储罐泄漏口径、环境风速及环境温度对LNG泄漏扩散过程产生的影响。模拟结果表明,50 mm泄漏口径、100 mm泄漏口径和灾难性破裂时天然气的扩散距离分别为160、296、365 m,泄漏口径越大,气云扩散范围越广;环境风速在1.5、5和8 m/s情况下,天然气扩散距离达到245、162、146 m,环境风速越大,气云扩散距离越小;环境温度在283和298 K的情况下,天然气云扩散距离为222和245 m,环境温度越高,气云扩散距离越大。     

Statistical Analysis of Contributors to Chemical Process Accidents

A database study of accident contributors in the chemical process industry (CPI) was carried out. All 364 CPI‐related accidents available in the Failure Knowledge Database were analyzed to identify the main and the subcontributors of the accidents. The accident contributors were ranked in accordance with their frequency and importance in accident prevention. The most common accident contributors were the human and organizational aspects in operation (19 % of contributors), contamination (11 %), flow‐related issues (11 %), and heat transfer (10 %). In the main contributor analysis, the same classes of contributors were also the most frequent causes of accidents. A four‐quadrant analysis identified the most important contributors to be focused on in accident prevention: contamination, flow‐related and heat transfer categories. The relationships between the contributors were also studied using an interconnection matrix, which revealed three functional groups of accident contributors. Their relationships were illustrated through an interconnection diagram.     

大型LNG储罐液固耦合模态分析

利用ADIAN软件中的Lanczos特征值算法,以山东青岛市董家口一座16万m3大型预应力混凝土储罐为研究对象,考虑液固耦合效应,对LNG储罐内外罐进行模态分析,比较了考虑液固耦合的理论计算结果与有限元计算的结果,证明了ADINA计算的正确性及有效性。对比分析外罐对內罐液固耦合和液体晃动的影响。得出液固耦合作用下,配筋方式及预应力钢筋间距对大型LNG混凝土外罐的梁式振动频率的影响;外罐自振频率跟泄露液体深度的曲线关系;对于LNG储罐的优化设计提供了设计依据,对地震作用下储罐的动态分析提供数据,为研究LNG储罐的抗震设计具有明显的指导性意义。     

Design of an Intermediate Fluid Vaporizer for Liquefied Natural Gas

The intermediate fluid vaporizer (IFV) owns various advantages over other types of liquefied natural gas (LNG) vaporizers. Research findings related to the design of an IFV, including configurational variations, selection of candidate working fluids, one‐dimensional steady‐state thermal model, computational fluid dynamics (CFD) model for thermal dynamic analysis, and cold energy recovery have been reviewed. Further updates to the current one‐dimensional thermal model are needed. A three‐dimensional unsteady CFD model should be established for the instantaneous flow and heat transfer analysis. Integrating the LNG regasification and cold energy recovery will bring more complexity in process design, optimization, and operation.     

LNG槽车瞬态泄漏特性及事故后果研究

我国每年危化品道路运输量占总货运量的30%以上,运输安全事故发生率居高不下。通过构建槽车泄漏事故,针对液相泄漏经典模型对于瞬态研究的局限性,结合罐内气体状态方程和复合积分法改进泄漏模型,研究了卧罐泄漏速率与时间耦合关系。结果表明,泄漏速率随时间推移呈二阶指数衰减关系,利用泄漏速率函数与时间叠加修正高斯模型,将修正后的关系运用到火灾爆炸事故后果计算中,得出泄漏最远距离为37.5 m,喷射火和沸腾液体扩展蒸汽爆炸(Boiling Liquid Expand Vapor Explosion, BLEVE)分别造成15和298 m内人员致死率达37%,蒸气云爆炸15 m内人员致死率为1%。利用Fluent和Aloha模型验证了模型精度,可为危险液体储罐泄漏定量风险评价和突发事件事前预判提供理论依据。