3m直径煤油池火灾火焰特性的数值研究

为了预测油池火灾的火焰特性,采用CFD模拟技术开展静风状态下3 m直径煤油液池的火灾场景模拟,探讨火焰温度、火焰羽流速度、辐射热通量、燃烧产物质量分数等油池火焰特性参数随高度的变化关系;并结合火焰形态分布,提出一种4区域模型,即将湍流扩散火焰划分为油气混合燃烧区、燃烧火焰区、烟尘区和热烟气区来分析燃烧气流在不同高度的实际物理化学特性。此外,通过经验公式和CFD模拟2种方法分别计算出3 m直径煤油池火灾的火焰高度、火焰表面的辐射通量及热辐射破坏半径,并对计算结果进行比较分析,结果表明:2种方法可互相补充完善,有助于池火灾的热辐射危害性评估。     

水平井油基钻井液气侵溶解气膨胀运移规律研究

天然气进入井筒并溶解于油基钻井液会对钻井安全产生潜在威胁,溶解气随钻井液运移到井口附近突然发生析出 并膨胀,使气侵早期监测及预警的难度显著增加。为了降低井喷发生概率和钻井作业风险,针对水平井油基钻井液溶解 气运移规律进行了研究。采用气液两相流模型,模拟了不同初始气侵速率情况下甲烷溶解气和游离气随钻井液在水平段 和垂直段的运移过程,得到环空中钻井液的流速变化、甲烷析出过程、井筒环空气液两相流流型变化、泥浆池增量随时 间变化和截面含气率沿程分布等规律。模拟结果表明,油基钻井液发生气侵时的初始进气率存在临界值;在小气侵速率 情况下,侵入环空的甲烷将以溶解气的形式运移到井口,在井口分离释放,对钻井安全构成的威胁较小;而当气侵量超 过临界值时,在环空上部发生气体分离,分离点迅速下移,如不及时控制,在极短时间内便可演化为井喷,危险性极大 。     

流域污染负荷水质响应的时空数值源解析方法研究

以目前广泛应用的环境流体动力学模型EFDC为平台,构建时空数值源解析方法,理论上可以得到任意时刻任意空间点位污染物的来源构成.其原理是考虑水质模型的微分方程,直接对每个污染负荷再微分,从而将原来1个微分方程变为关于每个污染源的微分方程组,然后联立以EFDC的水动力模型求解,得到每个源对每个时空点的贡献.概化的抚仙湖模型作为数值案例用以验证方法.时空数值源解析的结果与传统扰动方法的结果几乎重合,验证了时空数值源解析方法的正确性.另一方面,数值案例中存在34个独立的污染源,扰动法则需要35次模拟,而时空数值源解析方法的结果通过单次模拟就可得到,说明时空数值源解析方法具有明显的计算效率优势.而通过对结果的进一步分析可以发现,时空数值源解析方法可以提供更精确的源贡献的动态描述.     

废弃电子塑料在超临界异丙醇中的液化特性

研究了废弃含溴化阻燃剂的电子塑料在超临界异丙醇中的液化特性.研究结果表明塑料在超临界异丙醇中发生了解聚,产生油、气以及固体残渣,塑料中的溴化阻燃剂发生了脱溴降解.反应时间、固/液比、溶剂填充度对塑料解聚及阻燃剂脱溴降解影响较大,在最佳工艺条件(温度:400℃,反应时间:60min,固/液比:1/10,溶剂填充度:50%)下获得60%的产油率及95.3%的脱溴率.油以苯系物及酚类物质为主要组成物质,其热值为37.5MJ/kg.超临界异丙醇处理含溴化阻燃剂塑料主要包括溴化阻燃剂的萃取、脱溴降解和塑料高温解聚等过程.     

Corrosion behavior of steels for CO2 injection

The process chain for Carbon Capture and Sequestration (CCS) includes tubing for injection of CO₂ into saline aquifers. The compressed CO₂ is likely to contain specific impurities; small concentrations of SO₂ and NO₂ in combination with oxygen and humidity are most harmful. In addition, CO₂ saturated brine is supposed to rise in the well when the injection process is interrupted. The material selection has to ensure that neither CO₂ nor brine or a combination of both will leak out of the inner tubing. In this comprehensive paper the investigated materials range from low-alloy steels and 13% Cr steels up to high-alloy materials. Electrochemical tests as well as long term exposure tests were performed in CO₂, in brine and combination of both; pressure was up to 100 bar, temperature up to 60 °C. Whereas the CO₂ stream itself can be handled using low alloy steels, combinations of CO₂ and brine require more resistant materials to control the strong tendency to pitting corrosion. The corrosion behavior of heat-treated steels depends on factors such as microstructure and carbon content. For different sections of the injection tube, appropriate materials should be used to guarantee safety and consider cost effectiveness.     

Toxicological studies of zinc oxide nanomaterials in rats

In this study, we have evaluated the ability of zinc oxide (ZnO) nanoparticles to induce pulmonary and extrapulmonary toxicities was examined in rats following intratracheal (IT) instillation. Lungs of rats were instilled IT with either phosphate-buffered saline (PBS)?+?1% Tween 80, ZnO nanoparticles, carbonyl iron or quartz particles at a dose of 1 or 5?mg?kg^?1 body weight. Following exposure, bronchoalveolar lavage (BAL) fluid, blood samples and organs including lung, liver, kidneys, heart, pancreas, and brain were collected at 24?h, 1 week, or 1 month of post instillation of nanoparticles and different parameters estimated to assess toxicity. BAL fluid was analyzed for lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) to assess pulmonary toxicity. Exposures to ZnO or quartz particles produced transient dose-dependant increase in BAL fluid LDH and ALP activities at all post exposure periods. Blood samples were analyzed for the tissue damage biomarkers to assess extrapulmonary toxicity. Histopathological examination of lung, liver and kidneys revealed dose-dependent degeneration and necrosis which worsened at 1 week post-instillation periods but recovered at 1 month post instillation. Histopathological examination of rat pancreas, heart, and brain exposed to quartz or ZnO particles showed no marked changes. Data suggest the instillation of ZnO nanoparticles produced a greater pulmonary toxicity in rats comparable with quartz; and extrapulmonary toxicities of these ZnO nanoparticles might be due to translocation into liver and kidney.     

Polychlorinated biphenyls and organochlorine pesticides in amniotic fluids of pregnant women in south-central Turkey†

The concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in amniotic fluid of 200 pregnant women from the Cukurova region of Turkey. The concentrations of OCPs [hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), dichlorodiphenyl trichloroethane (p,p′-DDT), and various metabolites], and different PCB congeners (28, 52, 101, 118, 138, 153, 180) were determined by gas chromatography with electron capture detection as follows: HCB 6.6 ± 4.7, ΣHCH 21.6 ± 14.2, ΣDDT 12.5 ± 7.5, and ΣPCBs 74.0 ± 54 ng mL^?1. Correlations of maternal or gestational age and levels of OCPs and PCBs were not significant. The levels of these organochlorine compounds (OCs) were below detection limit for 5% of the samples, 80% contained more than one OC. This study illustrates that prenatal exposure of a fetus to OCs is prevalent in the Cukurova region.     

废弃钻井液作为沙漠改良剂的应用研究

油气田开发产生的废弃钻井液具有富含水、有机质和黏粒的特点,是改良沙漠土壤的有用成分,可用来提高沙漠土壤团粒和黏粒数量,提高土壤肥力。探讨了一种既能实现在沙漠、半沙漠草地环境下对废弃钻井液实现环境友好处理,又能提高沙漠土壤保水、保肥和增肥能力的沙漠改良技术。     

钻井废弃液中石油污染物及细菌生态多样性

采用GC/MS分析方法,发现平湖油田钻井废弃液中含有烃类、酸类和酯类等23种有机污染物质,含量达到49 800 mg/L。运用16S rRNA基因分析法测得的微生物生态多样性表明,废弃液中微生物种类丰富,包括γ和β变形杆菌,γ-Proteobacteria是优势菌群,占克隆总数78.6%。Oceanospirillales、Pseudomonadales和Enterobacteriales是γ-Proteobacteria纲的主要菌群。     

印刷线路板的超临界流体分离实验

目前印刷线路板(Printed Circuit Board, PCB)的资源化循环利用方法存在材料回收率低和环境污染的不足,采用一种新的超临界流体技术对PCB中的金属及其它成分进行分离处理,在采用丙酮、CO2及Lewis-酸的混合介质及优化的温度和压力反应条件下,获得了90%的金属回收率,高于目前的机械破碎分选实验结果.该方法为线路板的资源化循环再利用提供了一个新的有效选择.