某化工企业乙烯储罐爆炸后果的两种模型预测

以某化工企业为例,分别采用蒸气云爆炸（VCE）模型和沸腾液体扩展蒸气爆炸（BLEVE）模型进行分析,预测不同情况下乙烯储罐爆炸产生后果的严重程度,根据最大危险原则,按照乙烯扩展蒸气爆炸考虑相关事故后果。由于乙烯爆炸后果十分严重,应采取相应措施降低事故发生率,以达到降低企业风险的目的。     

天然气管道泄漏蒸气云爆炸后果评估方法研究

在对天然气管道泄漏事故后果分析的基础上,采用建立与选择数学模型、伤害准则的方法对泄漏后果蒸气云爆炸评估方法进行研究,并进行了工程实例验证。天然气泄漏后蒸气云爆炸是最主要的伤害形式,考虑极端情况,提出了以小孔模型代替管道模型来确定泄漏量的计算方法,同时考虑天然气为混合气体的特性,给出了相应的计算模型。采用TNT当量法来评估天然气的爆炸效应,给出了冲击波超压对人员和建筑伤害的相关模型。研究结果表明,该方法对于评价极端情况下天然气管道泄漏的蒸气云爆炸后果具有较好的适用性,对类似情况下天然气管道泄漏后果评估具有一定参考价值。     

蒸气云火灾爆炸模型模拟计算软件的开发与应用

重大事故后果分析,最重要的是可燃气体泄漏引起的开放空间蒸气云爆炸。本文结合研究成果,介绍了蒸气云火灾爆炸模型,并在此基础上开发了蒸气云火灾爆炸模型模拟计算软件,将编制的程序用于化工生产中的氢气场所,应用表明,本软件能够对蒸气云的后果（危险区域范围、人员伤亡和经济损失等）进行定量的模拟计算。     

LPG储罐的蒸气云爆炸后果模拟

液化石油气是一种常见的危险化学品,对其储罐发生事故的后果进行分析,对预防控制事故和保证安全生产都具有重要的意义。本文在分析液化石油气的危险特性和发生蒸气云爆炸事故特点的基础上,用两种常用的蒸气云爆炸后果模拟方法TNT当量法和TNO多能法对液化石油气储罐发生蒸气云爆炸的后果进行计算,分别得到死亡、重伤、轻伤和财产损失半径。对两种方法的计算过程和结果进行了分析和讨论,并给出了罐区设计时的建议。     

LNG储罐蒸气云爆炸后果分析

采用蒸气云爆炸定量评价模型对广州某燃气公司液化天然气LNG储罐发生泄漏导致LNG蒸气云爆炸事故后果进行了分析评价,评价得出:LNG储罐全部泄漏,发生蒸气云爆炸事故,约102.4 m为半径的范围内,会造成人员伤亡(死亡、重伤、轻伤)和财产损失,为企业制定应急救援预案提供参考。     

氯乙烯泄漏发生蒸气云爆炸后果模拟分析

介绍了蒸气云爆炸后果模拟分析模型,在此模型的基础上,对不同体积的液化氯乙烯泄漏后发生蒸气云爆炸伤害与破坏半径进行了估算,分析泄漏量与伤害和破坏半径间的关系并拟合方程,为化工生产企业和安监部门制定应急救援预案和日常防范提供科学依据。     

液氨储罐区重大事故后果分析

火灾、爆炸和中毒模型是化工罐区常见的三种事故后果分析模式。本文首先分别利用TNT当量法和TNO多能法（荷兰）对液氨储罐发生蒸气云爆炸事故的伤害半径进行了预测,然后鉴于高斯模型在分析计算非重气泄漏扩散事故的复杂性,给出了一种简单实用确定毒气扩散范围的方法,对液氨储罐泄漏事故伤害范围进行了预测。对于液氨储罐区防火、防爆和防中毒设计具有参考意义,同时对于液氨事故应急工作的开展也具有指导作用。     

某涉氨制冷企业液氨储罐泄漏事故的后果分析

以某涉氨制冷企业液氨储罐为例,选用蒸气云爆炸、沸腾液体扩展蒸气爆炸和中毒模型对液氨储罐泄漏事故进行后果分析,定量地得出各类伤害半径,为企业制定应急救援预案和政府进行安全监管提供科学依据。     

天然气管道泄漏爆炸后果的定量分析

天然气管道泄露可能引发多种事故,其中爆炸可能引起人员伤亡,设备财产损失,后果严重。以蒸气云爆炸模型,对某段天然气管道泄漏发生爆炸的后果进行模拟,为天然气管道定性定量评价提供参考依据。     

LPG蒸气云爆炸风险评估中的参数不确定性分析

分析了液化石油气的危险特性及其事故性爆炸的主要特点,针对蒸气云爆炸定量风险评估中不确定因素无法精确确定而导致的结果不确定性问题,即蒸气云爆炸事故造成的危害存在不确定性,建立了蒸气云爆炸风险评估模型,提出了一种基于Monte Carlo模拟的不确定性处理方法,计算了LPG蒸气云爆炸波伤害范围和事故风险概率曲线,对于定量评估VCE事故风险具有重要意义。     

氯乙烯共聚弹性体对聚氯乙烯的改性及性能影响

以氯乙烯-丙烯酸丁酯-甲基丙烯酸甲酯共聚弹性体（VCE）增韧改性PVC树脂提高聚氯乙烯（PVC）的抗冲击性能，并与传统抗冲击改性剂甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物（MBS）、ACR及氯化聚乙烯（CPE）改性的PVC材料比较。对改性PVC的流变性能、力学性能、热变形性能及断面结构进行表征和微观观察。结果表明，随着VCE含量的增加，PVC的拉伸强度与弯曲强度逐渐减小，抗冲击强度与断裂伸长率逐渐增加，热变形温度逐渐降低；在相同用量的条件下，VCE对 PVC的改性效果优于ACR及CPE，达到MBS改性PVC的水平，VCE能够增韧PVC，提高PVC的抗冲击性能，是一种性能优异的新型PVC抗冲击改性剂。     

Diffusion and sorption of nitroplasticizers in vinyl copolymer elastomer and its composites

To study the aging behavior of cured vinyl copolymer elastomer (VCE) under thermal and nitroplasticizer (NP) environment, we investigated the sorption and diffusion of NP in VCE and its composites. The sorption kinetics of NP into VCE and its composites with respect to filler concentration (0–80%) and temperature (18–70°C) were investigated by conventional gravimetric method. The NP sorption process is endothermic. Kinetic studies show that Fickian diffusion can describe the NP sorption in the VCE polymer. The samples with a high filler concentration show more complicated behavior at low temperature than that at high temperature. The present article discusses the dependences of diffusion coefficient and other related parameters on the polymer concentration and morphological structures of the samples. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40729.     

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。     

In vitro antioxidant and anti-proliferation activities of polysaccharides from various extracts of different mushrooms

Polysaccharides were extracted from eight kinds of Chinese mushrooms using three solvents and were evaluated for their total carbohydrate, polyphenolic and protein contents, and antioxidant and anti-proliferation activities. The results suggested that all the polysaccharides had significant antioxidant capacities (EC(50) ranged from 1.70 ± 0.42 to 65.98 ± 1.74 μM TE/g crude polysaccharide inhibition of ABTS(+), EC(50) ranged from 5.06 ± 0.12 to 127.38 ± 1.58 mg VCE/g CP scavenging of OH· and EC(50) ranged from 0.70 ± 0.04 to 33.54 ± 0.49 mg VCE/g CP inhibition of lipid peroxidation) (TE: trolox equivalent; VCE: VC equivalent; CP: crude polysaccharide). The acid extracts of Russula vinosa Lindblad had the highest ABTS(+) scavenging activity. Aqueous extracts of Dictyophora indusiata and Hohenbuehelia serotina possessed, respectively, the highest OH· scavenging capacity and ability to inhibit lipid peroxidation. Mushroom extracts also inhibited proliferation of HeLa and HepG2 cells in a dose-dependent manner. These results indicate that the mushroom polysaccharides might be potential antioxidant resources.     

Predicting vapor cloud explosions in enclosed spaces

For the example of 80 organic solvents, the methods developed by the All-Russian Research Institute for Fire Protection (ARIFP) and the Dutch ME-TNO method for vapor cloud explosions (VCE) in enclosed spaces are compared. The comparison focuses on the safe volume of the building. The correlation between the results of the two methods is established. After introducing a correction factor of 1.42, the METNO method for third-class VCE may be used to categorize production buildings in terms of explosion safety.     

Synthesis of 5‐vinyl‐m‐ phenylene‐m′‐phenylene‐32‐ crown‐10 and its radical polymerization behavior

Synthesis of a vinyl monomer, containing a 32‐membered crown ether unit (VCE) as a pendant group, was achieved by using tetra(ethylene glycol) dichloride, resorcinol, and 3,5‐dihydroxyacetophenone as starting materials. The product was identified by means of FTIR and ¹H‐NMR. It was found that this monomer readily polymerizes by the conventional radical initiator 2,2′‐ azobisisobutyronitrile (AIBN) to afford a polymer whose number‐average molecular weight is 36 kg/mol; however, the final conversion of the polymer was < 80%. The results of the copolymerization of VCE with styrene (ST) or acrylonitrile (AN) are also discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2372–2379, 2002     

The critical mass for the unconfined vapour cloud explosion of compressed and liquid hydrogen

The (unconfined) vapour cloud explosion (VCE) is a dramatic phenomenon that generates a severe pressure wave with a high potential to damage assets and produce injuries in the far field. This definition applies also to hydrogen. Nevertheless, no clear tools and methodology have been so far developed and tested for this highly reactive gas, and even advanced numerical simulations lack validation and suffer from large uncertainties. In this view, the comprehension of the physic which subtends this dramatic phenomenon for the specific case of hydrogen is still a central issue. This paper revises some of the most adopted theories on VCE based on classical acoustic theory and models for pressure wave propagation and provides a consequence-based, threshold (minimum) value for the critical mass of hydrogen $m_f^{\text{crit}}\left(4.0\mathrm{kg}\right)$ which is needed—at a stoichiometric concentration in air—for a vapour cloud to behave as a VCE. To this regard, any non-stoichiometric hydrogen concentration in air or lower amount of hydrogen would decrease either the flame Mach number $M_{\mathrm{f}}$ or the total energy, thus resulting in negligible overpressure. In this sense, the effects of buoyancy, diffusivity, and weather conditions on the dispersion of hydrogen should be taken into account. The results are valid either for compressed or cryogenic liquid tanks and can be adopted for the sake of distinction between hydrogen flash fire and VCE; for the hazard analysis of hydrogen production and storage; and more in general for the risk assessment of hydrogen systems.     

折流式超重力旋转床转子结构对气相压降的影响

折流式超重力旋转床是继旋转填料床之后出现的一种新型高效的气液传质设备.今采用空气-水系统对折流式旋转床进行了气相压降实验,考查了折流式转子结构对气相压降的影响,建立了折流式旋转床干床气相压降的理论模型.实验结果表明:折流式旋转床转子结构对气相压降影响较大,在动静折流圈结构不变的情况下,动静盘垂直间距存在某一最优值,通过实验得到了实验中所用的折流式旋转床的最佳转子高度为90 mm,实验也验证了旋转床设计时采用的等通流面积原则是符合气体运动规律的;干床压降理论模型的计算结果与实验值符合较好,为建立湿床压降模型奠定了基础.     

Synthesis of poly(vinyl alcohol) derivatives containing amidoxime groups

The modification reaction of poly(vinyl alcohol) (PVAL) with acrylonitrile in alkaline medium was studied. The structure of the resulting polymers was determined by means of IR, ¹H and ¹³C NMR spectroscopy. The influence of solvent composition, catalyst and temperature was evaluated. ¹³C NMR spectroscopy was used for the determination of the sequence distribution of cyanoethylated PVAL (considered as a vinyl alcohol (VAL)-(2-cyanoethyl) vinyl ether (VCE) copolymer). The ¹³C NMR spectra of the methylene carbons in the main chain show three split peaks, the intensities of which change with copolymer composition. These peaks can be assigned to the three dyad sequences. The obtained results show that VCE units have an alternating tendency in the copolymer. Nitrile groups in cyanoethylated PVAL were converted to amidoxime groups by reaction with hydroxylamine. The reaction showed second order kinetics. The activation energy was found to be 51.6 kJ/mol. Soluble polymeric chelates between amidoximated PVAL and cupric ions have been prepared. It is noteworthy that not all the amidoxime groups participate in binding cupric ions.