Fire and explosion risk assessment for large-scale oil export terminal

Now in Russian Federation and other countries large-scale oil terminals (volume of one tank exceeds 100 000 m³, total volume of tanks exceeds 300 000 m³) are designed and constructed. Therefore fire safety of such objects becomes a very important task, solution of which is hardly possible without detail fire risk assessment. This study is aimed to a solution of this problem. Potential, individual and social risks were calculated. The potential risk was defined as a frequency of occurrence of hazardous factors of fires and explosions in a given point of space (the so-called risk contours). The individual risk was defined as a frequency of injuring a given person by hazardous factors of fires and explosions. Time of presence of this person in hazardous zones (near the hazardous installation) is taken into account during calculations of the individual risk. Social risk was defined as a dependence of frequency of injuring a given number of people by hazardous factors of fires and explosions on this number. In practice the social risk is usually determined on injuring not less than 10 people.

The oil terminal under consideration includes the following main parts: crude oil storage consisting of three tanks of volume 100 000 m³ each, input crude oil pipeline of diameter 0.6 m, crude oil pumps, output crude oil pipeline of diameter 0.8 m, auxiliary buildings and facilities. The following main scenarios of tank fires have been considered: rim seal fire, pool fire on a surface of a floating roof, pool fire on a total cross-section surface of the tank, pool fire in a dyke, explosions in closed or semiclosed volumes. Fires and explosions in other parts of the terminal are also taken into account. Effects of escalation of accidents are considered.

Risk contours have been calculated both for the territory of the terminal and for the neighbouring space. The potential risk for the storage zone is near 10⁻⁴–10⁻⁵ year⁻¹, and at a distance 500 m from the terminal the potential risk values do not exceed 10⁻⁶ year⁻¹. The values of the individual risk for various categories of workers are in the range of 10⁻⁵–10⁻⁶ year⁻¹. Because of low number of the workers on the terminal and large distances to towns and villages the social risk value is negligible. These risk values are consistent with practice of the best oil companies, and fire hazard level of the terminal can be accepted as tolerable.     

Floating roof storage tank boilover

Storage tanks are important facilities for the major hazard installations (MHIs) to store large quantity of crude oil. There is several fire types can occur with large diameter open top floating roof storage tanks. Boilover is considered one of the most dangerous fires in large-scale oil tank. The world has witnessed many incidents due to boilover in floating roof storage tank. Boilover problem has been studied in experiments and by models to understand how to control the boilover phenomena. An experimental study has been carried out in Jebel Dhanna (JD) terminal area by Abu Dhabi Company for Onshore Oil Operations (ADCO) with support of Resource Protection International (RPI) consultant. 2.4 m diameter and 4.5 m diameters pans have been used to study the characteristics of the large oil-tank fires (i) to gain more knowledge of the boilover phenomenon of crude oil (ii) verify if the crude oil stored by ADCO would boilover (ii) estimation of rate of hot-zone growth and the period needed from ignition to boilover (iii) estimation of radiant heat and consequences of boilover. This paper presents an overview on the floating roof storage tank boilover. The paper also presents briefly boilover experimental research study carried out by ADCO.     

石油储罐油气蒸发损耗的成因、危害及对策

油气蒸发威胁安全,蒸发的油蒸气易引发爆炸,从而导致油罐爆炸着火。油蒸气是气相烃类,属有毒物品,漂浮地面易致人窒息。油蒸气还易形成光化学烟雾的二次污染物。由于油蒸气的蒸发损耗,全世界每年散失于大气中的油气约为１×１０８吨,折合人民币２４００亿元。因其所蒸发的都是油料中的最轻组分且油气蒸发还严重影响成品油质量。笔者分析了油气蒸发损耗的危害、产生原因及各种影响因素,并提出了降低油气蒸发损耗的对策     

大型原油商业储备油库火灾危险性数值模拟分析

石油储备油库多向大型化、复杂化方向发展,发生事故时扑救非常困难。为了深入探讨巨型油罐火灾发展趋势与规律、事故危害后果,结合宁夏惠安堡原油商业储备油库这一工程实例,采用基于大涡模拟的FDS模型作为模拟计算平台,对巨型油罐火灾的燃烧过程进行数值模拟计算。通过分析计算,得到烟气分布、温度分布、热辐射强度分布等火灾过程参数的变化趋势,以及在有风和无风状态下着火罐对相邻油罐的影响,探讨现行建设工程消防技术标准就储罐防火间距、火灾时对邻近罐体冷却设计要求运用于巨型储油罐时的消防安全状况,为巨型储油罐消防安全科学合理设计提供理论依据。     

原油油气职业卫生标准研究

我国目前尚未制订原油油气卫生标准,多数引用溶剂汽油卫生标准,研究表明原油油气毒性较溶剂汽油大,为保障油运装卸作业人员的健康,科学地监测与控制油气污染,确定合理的作业环境,制订原油油气卫生标准是十分必要的。该研究通过色-质联用分析,表明原油蒸气成份大多为C9以下烷烃、环烷烃及少量的芳香烃。采用大、小鼠为对象的急性毒性实验研究,获得大庆、胜利、渤海3种原油油气的LC50分别为49.54g/m3、77.54g/m3、417.50g/m3;亚慢性毒性实验研究表明,原油油气对动物神经系统的影响较为突出。现场劳动卫生学调查统计表明油轮、油码头作业人员,除了在装船、装罐作业状态下受到较大油气浓度危害外,大部分时间处于100mg/m3以下油气浓度环境,但长期从事油运装卸作业,表现出一定的健康异常,其主要症状是神衰症候群发生率明显增高,植物神经功能障碍,血象异常,其次为心率、心电图的改变等。根据上述研究结果,该研究认为原油装卸贮运作业场所原油油气时间加权平均容许浓度确定为100mg/m3(以总烃计)较为适宜。     

原油储罐基础沉降在线监测与安全性研究

为满足我国各地原油储备及周转需要，油田企业建设有大型原油储罐。部分储罐随着服役年数的增加，出现由于储罐地基的不均匀沉降而导致的罐壁变形，进而浮盘不能自由升降的现象。通过对储罐基础实测沉降数据建立储罐有限元模型，由计算结果分析研究基础沉降储罐的结构响应，并提出该储罐的安全运行液位，可为使用年限较久的储罐的安全评估提供一定的指导。     

含硫油品储罐自燃着火原因的研究

简述了储罐中硫化亚铁形成的过程和硫化亚铁引发储罐自燃的机理,并模拟储罐中硫化亚铁的形成过程,对其进行氧化实验,证明储罐腐蚀产物一硫化亚铁氧化放热是引发储罐着火的原因之一。     

原油储罐区可燃气体探测器布置优化方案研究

为有效预警原油储备区储罐气体泄漏,制定气体探测器布置优化方案,以某大型原油站库为例,基于CFD法和FLACS软件模拟原油泄漏及可燃蒸汽云溢散分布,通过分析蒸汽云扩散规律,实现全方位气体探测器优化布置.结果表明:原油储罐区探测器分别布置在区块21-2、6-1、31-1、40-2,且每个罐组总计布置16处;优化设置方案可满...     

Model experiment on the dynamic process of oil leakage from the double hull tanker

This paper presents an experimental investigation on oil leakage from the double hull tanker (DHT). It is designed to explore the dynamic process of oil leakage from bottom-rupture hole of DHT. The experimental test shows the leakage resistance mechanism of ballast tank space. The behavior of oil leakage from damaged DHT and dynamic features of flow in the overall process are demonstrated from experimental results. The overall process of oil leakage is divided into free-leakage and resistance-leakage stage according to the corresponding power to study the dynamic features of oil-water flow inside or outside the tank. The corresponding dominated factors of oil leakage in different stage are also pointed out, and the unsteady Bernoulli’s equation is used to verify experimental results. Meanwhile, viscous effect in leakage process is discussed and the importance of hydrodynamic features associated with the mechanism of oil leakage is explored from experimental results.     

大型原油储罐泄漏隔堤池火灾后果研究

为了研究储罐大孔泄漏后可能产生的隔堤局部面状液池火灾,以10万立方大型原油储罐为例,采用计算流体力学软件FLUENT和火灾模拟软件FDS计算储罐在真实泄漏场景下的液池区域,模拟发生隔堤池火的分布特征及对临罐热辐射影响。研究结果表明:储罐原油泄漏后将在隔堤内形成相对稳定面积的液池,在储罐不同方位处泄漏形成的液池面积与储罐壁距雨水收集槽长度相关;储罐正下方的隔堤池火对储罐造成的热辐射极大;风对临罐受到的池火热辐射强度影响明显,指向罐组中心方向的来风对临罐热辐射强度影响较大。     

铁路运输含硫原油过程中H_2S挥发规律模拟试验研究

以塔河12区含硫原油为研究对象,通过模拟铁路运输原油工况,研究罐内原油中H_2S挥发规律.结果表明,铁路运输过程中原油里H_2S析出浓度与时间的关系近似为6次多项式,并建证了H_2S浓度随时间变化的曲线方程;对影响罐内原油中H_2S挥发的2个主要因素罐内原油温度和罐车振动强度进行了分析.结果表明,罐内原油温度是原油中H_2S挥发的主要影响因素,升高罐内原油温度可以明显增加H_2S的挥发浓度.加大罐车振动强度对原油中H_2S挥发有促进作用,但不明显.     

FeS引发储油罐着火温度动态变化曲线的研究

储油罐着火事故被推测是由硫腐蚀产生的FeS氧化引起的。笔者阐述了储罐中FeS形成的原因 ,并采用自然发火绝热测试系统对FeS自然氧化进行 1 9h的跟踪实验 ,观察FeS绝热氧化过程中温度动态变化特性。实验发现 ,FeS氧化由诱导氧化期、中速氧化期和加速氧化期 3个阶段组成。诱导氧化期是积蓄能量 ,激发FeS活性的过程 ,试样温度基本未发生变化 ;中速氧化期是FeS试样表面的分子活性被激发 ,与FeS试样表面吸附的氧气发生氧化反应的过程 ,温度增加较慢 ;加速氧化期是FeS分子内部的活性被激活并进行氧化反应的过程 ,温度迅速升高。结果证明 :随着反应的进行 ,温度随反应时间变化的幅度越来越大 ,氧化反应的反应热不能及时散开而急剧地积累 ,温度急剧地升高 ,将引起油品自燃。此外 ,通过X衍射图和氧化升温曲线证明 ,水是影响FeS氧化的重要因素。     

海底管道泄漏原油扩散漂移规律数值模拟

针对浅海输油管道泄漏原油扩散漂移问题,依据计算流体动力学理论,采用VOF模型和k－ε湍流模型来模拟多相流动,采用速度边界造波法和阻尼消波法来模拟波浪,建立洋流波浪环境下海底管道原油泄漏扩散漂移模型,对不同海洋环境、原油密度和泄漏量工况下的原油扩散漂移行为进行模拟,预测水下原油扩散上升路径、上浮到水面时间、溢油扩散范围以及水面溢油漂移速率等关键数据。研究结果表明:相对于静水、洋流和波浪等单一环境条件,在洋流波浪环境下泄漏原油的水下扩散范围更广、扩散上升速率更小、水面原油漂移速率更大;海洋环境对原油在水面的漂移速率影响较大,泄漏速率对原油的水下上升扩散速率影响较大;原油密度主要影响水下原油上升扩散过程,对水面原油漂移过程影响较小。     

Impact of leakage location and downwind storage tank on the gas dispersion in a typical chemical tank storage area

Toxic gas leakage in a tank area can have catastrophic consequences. Storage tank leakage location (particularly for high leakage) and downwind storage tanks potentially influence gas diffusion in tank areas. In this study, we developed a numerical and experimental method to investigate the impact of a high leakage location and downwind storage tank on gas diffusion based on three (1.05H, 0.90H, and 0.77H, H was the tank height, 22m) leakage field experiments on the leeward side of storage tank, which have been not conducted before. The experiments revealed an unexpected phenomenon: the maximum ground concentration first decreased and then increased with increasing leakage height. The simulations illustrated that the differences in micrometeorological conditions caused the maximum ground concentration of gas emitted from the roof to be higher than that emitted from the tank wall near the storage tank height. The downwind storage tank 1) had little influence on the entire diffusion direction but altered the local diffusion pattern; 2) reduced the maximum ground concentration (∼18.7%) and the distance from the emission source (approximately a storage tank diameter); and 3) had strong influences on the concentration, velocity, turbulence, and pressure on the leeward side. The concentration negatively correlated with the velocity, pressure, and turbulence in the middle of the two storage tanks on wind centerline. Our results can improve understanding of gas dispersion in tank areas and provide references for mitigating loss and protecting lives during emergency response processes.     

三元组分图在储罐退役惰性化过程设计中的应用

储罐退役之前,一般要进行惰化处理,以降低可燃气体浓度,避免形成爆炸性混合气体。根据三元组分图,可以方便、直观地设计惰化施工的方案,包括惰化操作的程序设计和危险气体控制目标浓度的确定。本文从理论上研究了在储罐退役惰性化过程设计时,如何用三元组分图表示爆炸极限、最小含氧浓度以及在储罐稀释惰性化过程中气体组成的变化轨迹。提出了两套惰化设计方案,在分析比较的基础上,确定了储罐退役惰化时的最安全实施方案。     

Microwave-assisted preparation of two-dimensional amphiphilic nanoplate herding surfactants for offshore oil spill treatment

Oil spills are the uncontrolled release of liquid hydrocarbon by ruptured pipelines and tanker hulls, or blowouts and leaks from offshore storage facilities and drilling rigs, either by faulty human behaviors or inevitable natural aging processes. Spills cause disastrous environmental and economic consequences, with the effects of marine habitat damage for lasting decades, necessitating a critical need for efficient oil spill mitigation and leakage treatment. In this study, we develop a two-dimensional (2D) amphiphilic nanoplate as the herding surfactant for retracting spilled oil offshore on the seawater surface with various temperature and saline concentrations. Applying 2D nanoplate herding surfactant causes areas of thin oil slick floating on water to largely shrink and form a thick bulk layer. This transformation lays the foundation for the next-step oil treatment and recovery. Microwave-assisted synthesis method was used to fabricate the surface-modified zirconium phosphate (ZrP) nanoplates as the oil herder, which has an amphiphilic characteristic, containing both hydrophilic and hydrophobic properties. The 2D nanoplate surfactants decrease the air-water surface tension to facilitate the oil herding process efficiently. Using this herding procedure, we propose a biocompatible, high herding efficiency and cost-effective 2D herding surfactant fabrication method and offer a new direction for oil treatment in the offshore process safety field.     

输油管道监控系统设计与开发

管道输送具有运输量大、运费低、能耗少、损耗率低、投资少等优点,已成为原油或油品销售及运输的重要方式之一.管道或输油库一旦发生泄漏或火灾等事故,会造成输送停止、油损失、污染周边环境等严重后果.通过分析输油管道的工艺特点及危险因素,设计了输油管道临控系统的整体结构及各监控终端的硬件结构,研究了输油管道泄漏的综合分析技术方法,详细讨论了系统的信息采集、自动化控制、动态监控、状态分析、信息融合、基于GIS的输油管道管理等功能的开发内容及方法.     

Fuzzy fault tree analysis for fire and explosion of crude oil tanks

Crude oil tank fire and explosion (COTFE) is the most frequent type of accident in petroleum refineries, oil terminals or storage which often results in human fatality, environment pollution and economic loss. In this paper, with fault tree qualitative analysis technique, various potential causes of the COTFE are identified and a COTFE fault tree is constructed. Conventional fault tree quantitative analysis calculates the occurrence probability of the COTFE using exact probability data of the basic events. However, it is often very difficult to obtain corresponding precise data and information in advance due to insufficient data, changing environment or new components. Fuzzy set theory has been proven to be effective on such uncertain problems. Hence, this article investigates a hybrid approach of fuzzy set theory and fault tree analysis to quantify the COTFE fault tree in fuzzy environment and evaluate the COTFE occurrence probability. Further, importance analysis for the COTFE fault tree, including the Fussell–Vesely importance measure of basic events and the cut sets importance measure, is performed to help identifying the weak links of the crude oil tank system that will provide the most cost-effective mitigation. Also, a case study and analysis is provided to testify the proposed method.     

光催化和吸收组合工艺净化丙酮气体的研究

为了获得"光催化"与"吸收"联合净化VOCs气体的最佳组合工艺,首先以泡沫陶瓷为载体,羧甲基纤维素钠为黏结剂,采用浸渍-黏结法制得TiO2/泡沫陶瓷光催化材料,然后在自制的VOCs气体净化系统中,选择水溶性的丙酮气体为代表性VOCs气体,以水为吸收剂,考察了"光催化"与"吸收"不同组合工艺对丙酮气体的净化性能,并借助GC/MS和LC/MS手段对尾气和吸收液中的产物相进行分析测定。结果表明,纳米TiO2在泡沫陶瓷上的平均负载率为3.5%,且主要集中负载于陶瓷孔隙附近。不同组合工艺对丙酮气体的净化效率由高到低依次为"光催化+吸收""吸收+光催化""吸收""光催化",其中在"光催化+吸收"最佳工艺条件(液气比为5 L/m3、停留时间为6 s、光照强度为60W)下,丙酮气体的最高去除率达93.7%以上。气相和液相产物分析结果表明,丙酮气体经"光催化"处理后会产生O3和CH3COOH中间产物,但CH3COOH的产生量很少,在以"光催化"为末端工序的尾气中难以测出,而在以"吸收"为末端工序的循环吸收液中反而能检出。在此基础上,给出了"光催化+吸收"净化工艺的反应机理方程。研究得出,"光催化+吸收"工艺组合不仅可实现丙酮气体的高效净化,而且可避免"光催化"末端工序带来的O3和CH3COOH二次污染问题。     

基于VR技术的大型储罐火灾爆炸仿真软件设计

为了研究大型储罐事故后果的严重性，针对大型储罐火灾爆炸试验难以实施的情况，以虚拟现实技术为研究手段，重现大型储罐火灾和爆炸事故过程；通过对储罐火灾和爆炸事故进行理论分析，优选出大型储罐火灾爆炸事故后果数学模型；基于某商业原油储备库布置，利用3Ds Max软件对库区进行建模，结合Qt界面编写技术和OSG粒子效果技术进行交互式设计，划分火灾和爆炸2大仿真模块，设计各模块下属基本功能，形成1套基于真实场景的大型储罐火灾爆炸事故后果三维仿真模拟软件。研究结果表明:基于VR技术的大型储罐火灾爆炸仿真软件具有较强的沉浸感和交互性等特点，能够实时仿真大型储罐火灾爆炸事故动态演变过程，降低大型储罐火灾爆炸试验成本，同时为制定事故应急预案和应急处置措施提供科学参考。