高原山地城市重气泄漏扩散的示踪实验研究

为分析高原山区城市(个旧市)重气泄漏扩散规律,进行了重气泄漏扩散环境风洞实验。实验表明,重气浓度主要集中于近地层,测点的重气浓度随风速增大先增大后减小,存在一个危险风速,通过曲线拟合所得危险风速值与风洞实验所得危险风速值相近。在该风速下,重气浓度达到最大,且粘滞系数也最大,结果表明,粘滞系数越大越不利于重气的扩散。     

某油田大型联合站多排放源VOCs扩散的数值模拟

油田联合站是油田的重要组成部分,存在油气(VOCs)排放的可能,有必要对其扩散规律进行研究,以制定相关污染防控及安全措施。以某典型联合站为例,建立1:1的实际模型,结合现场调研测试和数值模拟,重点分析了联合站正常工况下多排放源的VOCs扩散机理及储罐裂缝处VOCs泄漏扩散的叠加效应。结果表明：在风速影响下,罐间和背风侧由于出现绕流和回流,容易达到爆炸极限;在重力和涡流的作用下,联合站内的背风侧会出现VOCs聚集,但叠加效应不明显;当储罐发生罐壁破损时,在事故罐后方出现正压区,在涡流和强气流的影响下,叠加后的VOCs浓度会明显增强,并呈点射状向下风向扩散,油气爆炸危险区域加速扩展。本研究成果可为联合站设计、运行管理及制定安全环保措施提供参考。     

废水液滴在低温烟气中的蒸发特性数值研究

建立了液滴在低温低速烟气中运动和蒸发的数学模型,数值研究了液滴在不同的烟气速度和烟气温度环境中的蒸发特性,获得了液滴速度、温度和直径随时间的变化规律,以及烟气速度和温度对液滴蒸发特性的影响。计算结果表明：气相速度越大,液滴初速度对液滴运动速度的影响越小,液滴速度越容易达到烟气速度。对于初始直径和速度一定的液滴,气液初始相对速度越大,液滴达到临界蒸发温度所需的时间越短,完全蒸发时间也越短。在文中研究的烟气速度范围内,整体上气相速度的改变对液滴完全蒸发时间的影响很小。气相温度的改变对液滴达到临界蒸发温度的时间以及完全蒸发时间的影响很大。烟气从较高温度和较低温度分别下降相同幅度的温度时,液滴在烟气中的完全蒸发时间按不同的倍数在增加,烟气温度越低,液滴完全蒸发时间增加的越多。对于文中研究的液滴,无量纲完全蒸发时间随烟气温度变化呈指数递减规律。     

加油站油气扩散与回收效果的数值分析

加油站排放出的油气是有毒有害的气体。目前控制油品蒸发损耗的有效方法是采用油气回收系统。基于湍流模式理论,采用FLUENT软件,模拟加油站在使用油气回收系统前后空气中油气浓度分布情况及风对油气扩散的影响,得到油气浓度等值面图、直线及点上浓度变化曲线图。模拟结果表明,实施油气回收,其大气净化率可高达95％以上,因此明显减小加油站火灾隐患及环境污染,并可减少经济损失及节约加油站占地面积。另外,风对油气扩散稀释有明显的影响,如距排放口下风侧5 m处,相对于风速１ m/s,风速为5、8 m/s时的大气净化率分别为54％、71％。虽然无法降低油气排放总量,但是随着风速的增加大气净化率随之变大,可以减少油气浓度值过高造成的危害。     

基于流固耦合的滤袋振动的数值模拟

滤袋是决定袋式除尘器除尘效率的关键元件,由于是柔性的悬挂结构,相邻的滤袋在气流作用下可能会发生相互碰撞,引起严重的破袋事故。针对该问题采用流固耦合方法,对袋式除尘器流场引起柔性滤袋的振动进行了数值模拟。分别以3个大小不同的进口风速模拟了滤袋的振动规律,得到了滤袋底部一点的位移图和轨迹图,结果表明,进口速度越大,滤袋的位移越大。所以有效地控制进口风速和提高内部气流速度的均匀性,可以减少滤袋的破袋事故,对节约更换滤袋的费用,有很大的经济效益。     

浮盘和气窗位置对内浮顶罐正己烷蒸发损耗的影响

在环境保护日趋严格和受到重视的大环境下,内浮顶罐的蒸发损耗机理和减排降耗规律尚有进一步研究的空间。使用自制的1 000 m3内浮顶罐缩比模型,研究了不同气窗和浮盘位置对罐内气体空间气流分布、罐内风速、储液蒸气浓度以及损耗速率的影响。结果表明:罐壁通气孔储罐和罐顶边缘通气孔储罐的气孔流向均呈现两进两出的特点;壁面通气孔储罐内风速大于顶盖边缘通气孔储罐,而浓度小于后者;浮盘位置越高,蒸发损耗速率越大,顶孔罐相比于壁孔罐的减排效果就越明显,其原因是贯穿整个壁孔罐内气体空间的大旋涡对边圈密封处的影响造成的。通过分析,建议将罐壁通气孔改造成罐顶边缘通气孔,建议在API内浮顶罐损耗公式的修订中考虑气窗和浮盘位置的影响。     

蒸汽相变作用下不可溶PM_(10)增长性能的数值模拟

目前,对颗粒凝结增长性能的数值模拟均忽略了其碰撞效应。为了对其进行补充,在相关研究的基础上,将颗粒群平衡模型(population balance module,PBM)与欧拉多相流模型进行耦合,通过用户自定义函数(user-defined function,UDF)同时引入碰撞团聚核函数和凝结增长速率函数,采用数值模拟,分析了初始蒸汽饱和度、停留时间、初始颗粒数浓度和初始粒径对不可溶PM_(10)凝结增长性能的影响。模拟结果表明,初始蒸汽饱和度越大,颗粒凝结增长后的最终粒径越大;在一定范围内,延长停留时间,能够促进颗粒的凝结增长;初始颗粒数浓度的增大不利于颗粒的凝结增长;初始粒径越小,颗粒凝结增长性能越好,相变凝结的效果越明显。上述模拟结果与实验结果一致。     

二氧化碳水合物储气特性的实验研究

利用二氧化碳水合物小型实验装置分别在恒容和恒压条件下,研究了机械搅拌对二氧化碳气体溶解的影响以及温度与水-气比对二氧化碳水合物形成和储气密度的影响。通过实验结果发现,机械搅拌对二氧化碳的溶解有非常明显的促进作用,可以在3 min内完成溶解过程,促进溶解作用好于添加剂SDS。研究还发现,反应温度越低,二氧化碳水合物的生成速率越快,总的储气量越大,而水-气比越大,储气密度越小。在实验压力3 MPa、反应温度273.55 K的条件下,1体积的水生成水合物后可储存157体积的二氧化碳。     

混凝土尘抑尘剂配方研制及其性能表征

针对建筑工地扬尘控制需求,研究了适用于混凝土尘的抑尘剂。以高温抗蒸发性、抗研磨性、渗透性作为指标,研究了以吸湿剂、凝并剂和表面活性剂为组成的抑尘剂配方,并对其抑制混凝土尘性能进行了表征。结果表明:(1)混凝土尘粒径越小,越难被润湿。200目混凝土尘粒径均一;Ca含量最多,其次是Si,质量分数占11.10%;真密度为6.41g/cm3。(2)抑尘剂最优配方为25%(质量分数,下同)CaCl2、0.15%蔗糖、0.10%吐温-20。(3)10d后喷洒抑尘剂溶液的混凝土尘含湿量仍能达到10%,具有很好的吸湿放湿性。持续14m/s风速1h后,混凝土尘的损失率为2.23%(质量分数),具有良好的抗风蚀性能。     

UV-Vis/Fe(Ⅲ)/H2O2体系对水中雌酮的光降解

以250W照明金属卤化物灯为光源,研究了水中雌酮（E1）在UV-Vis／Fe（Ⅲ）／H2O2体系中的光降解;考查了初始pH、Fe（Ⅲ）、H2O2、E1初始浓度对E1光降解的影响。结果表明,UV-Vis／Fe（Ⅲ）／H2O2体系能有效地光降解E1,在[Fe（Ⅲ）30-20．8μmol／L、[H2O2]0=1664μmol／L、pH=3．0时,光照160min,18．5btmol／L E1的光降解率可达98．4%;在pH3．0～8．0范围内,pH初始值越小,E1降解率越大,反应初始速率越大;实验条件下,Fe（Ⅲ）、H2O2初始浓度越大,E1降解率越大,反应初始速率越大;E1初始浓度越低,E1降解率越大,反应初始速率越小。pH=3．0,实验浓度范围内的表观动力学方程为：dCE1／dt=0．00093[H2O2]^0.47[Fe（Ⅲ）]^0.62[E1]0.24;Fe（Ⅲ）是影响反应速率的主要浓度因素。     

14C-dimethoate residues in olive oil during oil processing

An olive tree was treated twice in the field with 14C-dimethoate (237.7 muCi, 2.4 g) and 14C residues were determined in the olive fruits at harvest. The fruits were crushed and pressed to extract the crude oil, then refined by neutralization, bleaching and deodorization. The crude oil contained 14.1% of the total 14C in the olive fruits. Neutralization resulted in a reduction of 14C by about 50% of the total 14C residues in oil. Bleaching and deodorization processes further reduced the 14C residues and the refined oil contained 31.6% (which corresponds to 4.4% of 14C residues of the total 14C in olive fruits) of the total 14C in the crude oil. Industrially extracted crude oil was fortified with 14C-dimethoate at 1.8 mg kg-1 (0.02 muCi) level and subjected to the same refining process. A sharp decrease in the amount of 14C was observed by neutralization and the amount of 14C remaining in the refined oil was about 7.3% of the total 14C in the crude fortified oil. The data suggest that the 14C residues in the aged and the fortified oil amples were not of the same nature. The terminal 14C residue in the refined oil obtained from the field experiment did not contain dimethoate and/or its oxon.     

生物柴油促进原油污染砂粒释放油

对4种生物柴油促进原油污染砂粒释放油的效果进行了研究,并探讨了菜籽生物柴油投加量和砂粒粒径对促进效果的影响。结果表明,菜籽生物柴油的促进效果最好,8 h释放量达到73%,废油脂生物柴油的效果最差,仅为52%;生物柴油的促进效果随着投加量的增大而升高,当投加量超过海水体积的5%时促进效果不再明显增加;在生物柴油作用下,小粒径砂粒上原油的释放效果优于大粒径砂粒。     

海洋石油工程新型溢油监测系统的研究

随着海洋石油的开采力度的加大,海上平台溢油事故也不断发生。在对传统监测方式的不足和海上溢油监测技术未来发展的趋势进行了综合考虑之后,开发了一套基于紫外诱导荧光探测技术的溢油监测系统。监测系统主要由检测终端、数据采集及异常报警系统和计算机处理及显示终端3个子模块组成,可以实现对海上平台潜在油污染源头信息的实时收集、传输、预警等功能。     

14C‐dimethoate residues in olive oil during oil processing

Abstract

An olive tree was treated twice in the field with ¹⁴C‐dimethoate (237.7 (μCi, 2.4 g) and ¹⁴C residues were determined in the olive fruits at harvest. The fruits were crushed and pressed to extract the crude oil, then refined by neutralization, bleaching and deodorization. The crude oil contained 14.1% of the total ¹⁴C in the olive fruits. Neutralization resulted in a reduction of ¹⁴C by about 50% of the total ¹⁴C residues in oil. Bleaching and deodorization processes further reduced the ¹⁴C residues and the refined oil contained 31.6% (which corresponds to 4.4% of ^I4C residues of the total ¹⁴C in olive fruits) of the total ¹⁴C in the crude oil. Industrially extracted crude oil was fortified with ¹⁴C‐dimethoate at 1.8 mg kg^‐1 (0.02 μCi) level and subjected to the same refining process. A sharp decrease in the amount of ¹⁴C was observed by neutralization and the amount of ¹⁴C remaining in the refined oil was about 7.3% of the total ^l4C in the crude fortified oil. The data suggest that the ¹⁴C residues in the aged and the fortified oil amples were not of the same nature. The terminal ¹⁴C residue in the refined oil obtained from the field experiment did not contain dimethoate and/or its oxon.     

落地油泥土壤性质对超声除油效果的影响

落地油泥是油田产生的一类危险固体废弃物,其无害化处理是目前各大油田所面临的重大挑战之一。为了深入认识超声处理过程中油泥土壤性质与超声处理除油效果之间的关系,以不同油田典型落地油泥为研究对象,超声处理后对其土壤残留含油量、土壤颗粒级配、土壤化学组成等进行分析。结果表明:油泥中土壤颗粒粒径较大的大庆、大港落地油泥经超声处理后的除油效果均在60%以上,而土壤颗粒粒径较小的冀东落地油泥超声除油率仅为11%;同时,超声除油效果较好的大庆、大港落地油泥中的钙氧化物含量较低(分别为4.84%和5.94%),而超声除油效果差的冀东落地油泥中的钙氧化物含量较高(11.57%)。进一步的模拟实验结果表明,钙氧化物含量高的土壤对原油的吸附量大、吸附强度高、超声除油效果差,而钙氧化物含量低的土壤吸附量小、吸附强度低、超声除油效果好。以上结果可为油田落地油泥超声处理技术的开发及规模化应用提供指导。     

油田含油污泥超声脱油的研究

在油田含油污泥的热洗处理中引入超声辐照处理技术,研究考察了超声脱油技术中超声强度,超声辐照时间,含油污泥预热温度,清洗液用量和清洗液回用4个试验操作条件对污泥脱油的影响,认为在优化条件（超声发生器输出电压175 V,辐照时间15 min,预热温度55 ℃,清洗液和含油污泥以质量比8∶1）下,超声脱油技术可以把污泥的干基油含量由0.35 g/g降低到0.14 g/g,同时也证明清洗液可以反复使用。根据简单的经济核算,处理1 t含油污泥可以产出66元的效益。研究表明,使用超声处理可以有效地提高含油污泥的污油脱除效率,明显降低污泥清洗的操作温度。     

Emissions tradeoffs among alternative marine fuels: total fuel cycle analysis of residual oil, marine gas oil, and marine diesel oil

Worldwide concerns about sulfur oxide (SOx) emissions from ships are motivating the replacement of marine residual oil (RO) with cleaner, lower-sulfur fuels, such as marine gas oil (MGO) and marine diesel oil (MDO). Vessel operators can use MGO and MDO directly or blended with RO to achieve environmental and economic objectives. Although expected to be much cleaner in terms of criteria pollutants, these fuels require additional energy in the upstream stages of the fuel cycle (i.e., fuel processing and refining), and thus raise questions about the net impacts on greenhouse gas emissions (primarily carbon dioxide [CO2]) because of production and use. This paper applies the Total Energy and Environmental Analysis for Marine Systems (TEAMS) model to conduct a total fuel cycle analysis of RO, MGO, MDO, and associated blends for a typical container ship. MGO and MDO blends achieve significant (70-85%) SOx emissions reductions compared with RO across a range of fuel quality and refining efficiency assumptions. We estimate CO2 increases of less than 1% using best estimates of fuel quality and refinery efficiency parameters and demonstrate how these results vary based on parameter assumptions. Our analysis suggests that product refining efficiency influences the CO2 tradeoff more than differences in the physical and energy parameters of the alternative fuels, suggesting that modest increases in CO2 could be offset by efficiency improvements at some refineries. Our results help resolve conflicting estimates of greenhouse gas tradeoffs associated with fuel switching and other emissions control policies.     

糎T] "7.16"大连新港石油管道爆炸事故中的热红外溢油监测

利用有效的监测手段、降低溢油事故的风险是海洋环境保护和社会经济节约的关键问题。"7.16"事故中使用3.0～5.0μm红外热像仪作为机载监测的一种手段,对事故海域进行常规监测,识别海面油膜,利用热红外油膜厚度模式分析油膜的相对厚度,并且结合其他遥感数据,在GIS系统中绘制每日的事故海域溢油分布图,为清污指挥部门提供决策依据。     

Pyrolysis-GC-MS analysis of crude and heavy fuel oil asphaltenes for application in oil fingerprinting

A Pyrolysis – Gas Chromatography – Mass Spectrometry (Py-GC-MS) method was developed for the analysis and profiling of crude and heavy fuel oil asphaltenes, for application in oil fingerprinting. Asphaltenes were precipitated from ten geographically different oils using n-pentane, and analysed by Py-GC-MS. Alkane profiles and sulphur/aromatic profiles were used to compare the oils, and to correctly differentiate oils from different geographical regions. Py-GC-MS could not differentiate a weathered oil sample and a fresh oil sample from the same source. The results of this study support the findings from a previously developed FTIR method for asphaltene profiling.