GAS PERMEATION OF SEGMENTED POLYURETHANES AND THEIR BLENDS WITH PVC

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土壤中总石油烃测定——3种前处理方法的对比

土壤中总石油烃测定——3种前处理方法的对比

2019,28(3)福建分析测试Fujian Analysis &Testing土壤中总石油烃测定——3种前处理方法的对比段旭,李慧慧,杨柳晨,田凯(国土资源部西安矿产资源监督检测中心,陕西西安710054)收稿日期:2019-1-8基金项目:全国土壤污染详查贵州福建等10省质量监控样制备及质量监督检查(121201105000168509)项目资助。

作者简介:段旭(1991—),女,汉族,陕西西安人,助理工程师,主要从事化学分析方面的研究。

E-mail :han10260@摘要:文章通过设计试验,分别采用振荡提取法,超声波提取法和快速溶剂萃取法对土壤中总石油烃进行前处理。

通过提取率试验,结果表明,快速溶剂萃取法的提取效率最高。

通过对快速溶剂萃取-气相色谱法测定土壤中总石油烃进一步实验条件优化,得出丙酮:二氯甲烷为1:1(体积比)时,对土壤中总石油烃的提取效率优于丙酮:二氯甲烷为1:1(体积比)时,并且采用丙酮:正己烷为1:1(体积比)溶液浸提时循环萃取两次即可达到最大提取效率。

关键词:土壤石油烃;振荡提取;超声波提取;快速溶剂萃取中图分类号:O657.71文献标识码:A文章编号:1009-8143(2019)03-0047-04Doi:10.3969/j.issn.1009-8143.2019.03.10Three pretreatment methods of determination of total petroleum hydrocarbon in soilDuan Xu ,Li Hui-hui ,Yang Liu-chen ,Tian Kai(Xi ’an Testing and Quality Supervision Center for Geological and Mineral Products ,The Ministry of Land and Resource ,Xi ’an ,Shaanxi 710054,China )Abstract:In this paper ,the total petroleum hydrocarbon in soil was pretreated by oscillating extraction ,ultrasonic extraction and rapid solvent extraction respectively.The results of extraction rate test showed that the extraction efficiency of rapid sol⁃vent extraction was the highest.By optimizing the experimental conditions of accelerated solvent extraction-gas chromatog⁃raphy for determination of total petroleum hydrocarbon in soil ,it was concluded that acetone :n-hexane of 1:1(volume ),total petroleum hydrocarbons in the soil of the extraction efficiency is better than that of acetone ,methylene chloride of 1:1(volume ),and using acetone :n-hexane of 1:1(volume )in solution leaching cycle extraction twice can achieve maximum extraction efficiency.Key words :Soil petroleum hydrocarbon ;Oscillation extraction ;Ultrasonic extraction ;Rapid solvent extraction石油烃是石油的主要成分,包括10~40个碳原子的烷烃、烯烃和多环芳烃等组分。

延迟焦化分馏塔喷淋脱过热与循环比的拟合计算

延迟焦化分馏塔喷淋脱过热与循环比的拟合计算

第49卷第9期 当 代 化 工 Vol.49,No.9 2020年9月 Contemporary Chemical Industry September,2020收稿日期: 2019-11-18作者简介: 周超强(1983-),男,辽宁省大连市人,工程师,硕士研究生,2009年毕业于哈尔滨工程大学应用化学专业,研究方向:石油化工工艺设计。

E -mail:**************************.cn。

延迟焦化分馏塔喷淋脱过热与循环比的拟合计算周超强,王俊,王吉峰(中国石油集团 东北炼化工程有限公司,大连 116085)摘 要:通过PROⅡ软件模拟计算,对某炼厂延迟焦化装置进行了核算改造,将装置循环比从原0.6降低至0.2,大大提高了装置的总液收率和经济效益。

在分馏塔脱过热段采用蜡油喷淋替代原焦化原料上进料与焦化油气换热的脱过热方式,大大提高了气液传质效率及对焦化油气中焦粉的洗涤效果,提高了焦化蜡油的指标,减少了原人字板的结焦及焦化液体产品中焦粉的夹带量。

着重介绍了降低循环比后主分馏塔的工艺调整计算及脱过热段蜡油喷淋量与循环比的拟合计算过程,并简述了脱过热段的改造工程方案。

关 键 词:延迟焦化;喷淋;循环比;脱过热中图分类号:TE 624 文献标识码: A 文章编号: 1671-0460(2020)09-2088-05Fitting Calculation of the Recycle Ratio and the Spraying Intensityof De-superheating Gas Oil in DCU Fractionating ColumnZHOU Chao-qiang , WANG Jun , WANG Ji-feng(CNPC Northeast Refining & Chemical Engineering Co., Ltd., Dalian 116085, China)Abstract : Based on the simulation by PRO Ⅱ, the recycle ratio of DCU in a North China refinery was reduced from 0.6 to 0.2,which rapidly increased the liquid product yield and the overall economic benefits of the unit. In the de-superheating section of the main fractionator, the trays were replaced by sprinklers and the wax oil was sprayed as the quench oil instead of the heavy residue oil, which greatly improved the gas-liquid mass transfer efficiency and the washing effect of coke powder in the reaction gas, reduced the coke powder in the liquid products and the risk of coking in this section. In this paper, the process adjustment calculation of the main fractionator and how to match the sprayed gas oil and the recycle ratio were introduced emphatically. The engineering modification of the main fractionator was also mentioned briefly.Key words : Delayed coking unit; Spray; Recycle ratio; De-superheating延迟焦化因原料适应性强、技术成熟、投资和操作费用低等特点,是渣油加工的主要手段之一[1]。

《油层物理》名词及解释

《油层物理》名词及解释

《油层物理》名词及解释1、《《油层物理油层物理》》名词解释名词解释岩石物理性质岩石物理性质petrophysicalproperties指岩石的力学、热学、电学、声学、放射学等各种参数和物理量,在力学特性上包括渗流特性、机械特性〔硬度、弹性、压缩和拉伸性、可钻性、剪切性、塑性等〕。

流体物理性质流体物理性质fluidproperties油层流体是指油层中储集的油、气、水,它们的物理性质主要包括各种特性参数、相态特征、体积特征、流淌特征、互相之间的作用特征及驱替特征等。

水基泥浆取心水基泥浆取心water-basemudcoring水基泥浆钻井时所进行的取心作业。

油基泥浆取心油基泥浆取心oil-basemudcoring油基泥浆钻井时所进行的取心作业;它保证所取岩心不受2、外来水侵扰,通常在需要测取油层初始油〔水〕饱和度时选用。

岩心岩心core利用钻井取心工具获取的地下或地面岩层的岩石。

岩样岩样coresample从岩心上钻取的供分析化验、试验讨论用的小样〔一般长2.5cm~10.0cm、直径2.5cm~3.8cm〕。

井壁取心井壁取心sidewallcoring用井壁取心器从井壁获取地层岩石的取心方法。

岩心收获率岩心收获率corerecovery指取出岩心的长度与取心时钻井进尺之比,以百分数表示。

密闭取心密闭取心sealingcoredrilling 用密闭技术,使取出的岩心保持地层条件下流体饱和状态的取心方法。

保压取心保压取心pressurecoring用特别取心工艺和器具,使取出的岩心能保持地层压力的取心3、方法。

定向取心定向取心orientationalcoring能知道所取岩心在地层中所处方位的取心方法。

冷冻取心冷冻取心freezingcore 用冷冻来防止岩石中流体损失和胶结疏松砂岩岩心破裂的岩心爱护方法。

常规岩心分析常规岩心分析routinecoreanalysis常规岩心分析分为部分分析和全分析。

基于HS-SPME-GC-MS与电子鼻分析芹菜贮藏期间挥发性物质的变化

基于HS-SPME-GC-MS与电子鼻分析芹菜贮藏期间挥发性物质的变化

芦佳琪,吴玉珍,张瑞,等. 基于HS-SPME-GC-MS 与电子鼻分析芹菜贮藏期间挥发性物质的变化[J]. 食品工业科技,2024,45(5):212−222. doi: 10.13386/j.issn1002-0306.2023040101LU Jiaqi, WU Yuzhen, ZHANG Rui, et al. Change of the Volatile Compounds from Celery Leaves during Storage Based on HS-SPME-GC-MS and E-nose[J]. Science and Technology of Food Industry, 2024, 45(5): 212−222. (in Chinese with English abstract). doi:10.13386/j.issn1002-0306.2023040101· 分析检测 ·基于HS-SPME-GC-MS 与电子鼻分析芹菜贮藏期间挥发性物质的变化芦佳琪1,吴玉珍1,张 瑞1,韩晶晶1,熊爱生2,郁志芳1, *(1.南京农业大学食品科技学院,江苏南京 210095;2.南京农业大学园艺学院,江苏南京 210095)摘 要:采用顶空固相微萃取技术结合气相色谱-质谱联用(headspace solid phase microextraction-gas chromato-graphy-mass spectrometry ,HS-SPME-GC-MS )和电子鼻技术分析了20.0 ℃贮藏期间芹菜叶片挥发性物质的组成和含量的变化。

结果显示,采用HS-SPME-GC-MS 技术从芹菜中共检测到108种挥发性物质,单萜类(43.2%~52.92%)和苯酞类(19.93%~28.97%)为主要组分,其中D-柠檬烯含量丰富(6600.64~48566.12 μg/kg )。

气相色谱 恒温 英文

气相色谱 恒温 英文

气相色谱恒温英文英文回答:Gas chromatography (GC) is a separation technique used to analyze the volatile components of a sample. It is based on the principle that different compounds have different affinities for a stationary phase and a mobile phase. The sample is injected into a heated column that contains a stationary phase. The mobile phase, which is a carrier gas, flows through the column and carries the sample components along with it. The different compounds in the sample will interact with the stationary phase to varying degrees, causing them to elute from the column at different times.The elution time of a compound is determined by its boiling point, its polarity, and its molecular weight. Compounds with lower boiling points will elute from the column first, followed by compounds with higher boiling points. Polar compounds will interact more strongly with the stationary phase than nonpolar compounds, and they willtherefore elute later. Heavier compounds will also interact more strongly with the stationary phase than lighter compounds, and they will therefore elute later.The elution of the sample components is detected by a detector, which is located at the end of the column. The detector generates a signal that is proportional to the concentration of the compound in the mobile phase. Thesignal from the detector is recorded on a chromatogram, which is a graph of the detector signal versus time.GC is a powerful analytical technique that can be usedto identify and quantify the components of a sample. It is widely used in a variety of applications, including environmental analysis, food analysis, and pharmaceutical analysis.中文回答:气相色谱(GC)是一种用于分析样品中挥发性成分的分离技术。

陈酿时间对玫瑰醋挥发性风味物质的影响

陈酿时间对玫瑰醋挥发性风味物质的影响

陈建红,沈海锋,杨明,等. 陈酿时间对玫瑰醋挥发性风味物质的影响[J]. 食品工业科技,2024,45(3):270−276. doi:10.13386/j.issn1002-0306.2023030281CHEN Jianhong, SHEN Haifeng, YANG Ming, et al. Effect of Aging Time on Volatile Flavor Substances of Rosy Vinegar[J]. Science and Technology of Food Industry, 2024, 45(3): 270−276. (in Chinese with English abstract). doi: 10.13386/j.issn1002-0306.2023030281· 分析检测 ·陈酿时间对玫瑰醋挥发性风味物质的影响陈建红1, *,沈海锋2,杨 明3,嵇国华4,冯 纬2,5,翁云丹5,徐光亮5,陈雅琴2(1.浙江商业职业技术学院,浙江杭州 310000;2.浙江五味和食品有限公司,浙江杭州 310000;3.杭州郝姆斯食品有限公司,浙江杭州 310000;4.杭州松鲜鲜自然调味品有限公司,浙江杭州 310000;5.杭州市食品酿造有限公司,浙江杭州 310000)摘 要:为研究不同陈酿时间对玫瑰醋挥发性风味物质的影响,采用顶空固相微萃取-气相色谱-质谱(headspace solid-phase microextraction-gas chromatography-mass spectrometry ,HS-SPME-GC-MS )、主成分分析(principal component analysis ,PCA )和层次聚类分析(hierarchical clustering analysis ,HCA )对新醋、一年陈、三年陈、十年陈样品进行理化和挥发性风味成分分析。

页岩气水平井分段压裂复杂缝网形成机制

页岩气水平井分段压裂复杂缝网形成机制

油气藏评价与开发第7卷第5期2017年10月RESERVOIR EVALUATION AND DEVELOPMENT页岩气水平井分段压裂复杂缝网形成机制许文俊,李勇明,赵金洲,陈曦宇,彭瑀(西南石油大学油气藏地质及开发工程国家重点实验室,四川成都610500)摘要:水平井分段压裂是页岩气高效开发的重要技术手段,有意识地利用水力裂缝沟通页岩储层中的天然裂缝,使其闭合的部分重新开启,开启的部分又相互连通,从而在地层中形成具有较大规模的复杂裂缝网络,有利于实现地层中页岩气向井筒的高效流动。

为了合理优化页岩储层压裂设计方案,提高页岩储层压裂改造效果,需先认清页岩水平井分段压裂复杂缝网形成机制。

基于位移不连续理论,建立了水平井分段压裂多裂缝干扰模式下的地应力场模型,分析了天然裂缝在复杂地应力场和存在压裂液滤失作用的情况下,发生张开或剪切破裂形成复杂缝网的机理。

分析表明:水力裂缝诱导应力虽能降低地层原始水平应力差,但也会增加地层中天然裂缝发生张开和剪切破裂的难度,不利于复杂裂缝网络的形成。

压裂液滤失是导致地层中天然裂缝发生张开和剪切破裂形成复杂裂缝网络的关键因素,天然裂缝的剪切破裂区域要远大于张开破裂区域,多条水力裂缝滤失效应的叠加更有利于形成具有较大波及区域的复杂裂缝网络。

充分考虑压裂液滤失对复杂裂缝网络形成的影响,对提高页岩气水平井分段多簇压裂改造效果具有重要意义。

关键词:分段压裂;位移不连续理论;剪切破裂区域;张开破裂区域;复杂缝网中图分类号:TE357文献标识码:AFormation mechanism of complex fracture network under horizontal well stagedfracturing in shale gas reservoirXu Wenjun,Li Yongming,Zhao Jinzhou,Chen Xiyu and Peng Yu(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan610500,China)Abstract:Horizontal well staged fracturing is an important technology for shale gas production,whose essence is to use hydraulic fracture to activate natural fractures.The natural fractures can make closed parts reopen and opened parts interconnect,and then form complex fracture network in shale reservoirs,accordingly,shale gas will flow to the wellbore through complex fracture network efficiently.In order to optimize shale reservoir fracturing design and improve the effects of shale reservoir fracturing,it is necessary to fully understand the formation mechanism of complex fracture network in staged fractured shale horizontal wells.Based on the displacement discontinuity theory,a complex stress field calculation model which takes into consideration hydraulic fracture inter⁃ference is established,which analyzes the mechanism that natural fractures occur open and shear fracture,and then the complex fracture network under the circumstance of complex ground stress field and fracturing fluid leak-off was formed.The results demon⁃strate that although the hydraulic fracture induced stress field can reduce the original horizontal stress difference,it would also in⁃crease the difficulty of natural fractures opening and shearing,which is unbeneficial for the formation of complex fracture network. Moreover,it is attained that fracturing fluid leak-off is the key factor that leads to the open and shear fracture of natural fractures in the formation of complex fracture network and the shear rupture zone of natural fractures is much larger than the open rupture zone, furthermore,the superposition of multiple hydraulic fracture filtration effect is more favorable for the formation of complex fracture network with a larger spread area.The impacts of fracturing fluid leak-off on complex fracture network have important significance for improving staged fracturing transformation of shale horizontal wells.Key words:staged fracturing,displacement discontinuity theory,shear rupture zone,open rupture zone,complex fracture network收稿日期:2016-10-31。

储层岩石的压缩问题

储层岩石的压缩问题

储层岩石的压缩问题李传亮【摘要】岩石的应力敏感与岩石的压缩性密切相关.为了搞清岩石的应力敏感程度,深入分析了岩石的压缩问题.岩石孔隙体积的压缩是因为骨架体积的压缩所致,因此孔隙压缩系数与孔隙度和骨架性质有关.因存在系统误差,体积法测量的孔隙压缩系数数值偏高,且存在逻辑反转现象.弹性模量法消除了系统误差,测量结果符合科学逻辑.岩石孔隙、骨架和外观体积的压缩系数定义的压力不同,不能互相替代.孔隙度为0时,孔隙压缩系数为0,骨架压缩系数和外观体积压缩系数皆不为0,且骨架压缩系数等于外观体积压缩系数.岩石的应力敏感指数可由岩石的孔隙压缩系数求出.由于致密岩石的孔隙压缩系数极低,因此,低渗透储层的应力敏感程度极弱,生产过程可将其忽略.【期刊名称】《石油钻采工艺》【年(卷),期】2010(032)005【总页数】5页(P120-124)【关键词】低渗透;油藏;压缩系数;应力敏感;岩石【作者】李传亮【作者单位】西南石油大学油气藏地质及开发工程国家重点实验室,四川成都,610500【正文语种】中文【中图分类】TE328笔者在文献[1]中提出“低渗透储层不存在强应力敏感”的观点,在其他文献中又不断强化了这个观点,阐述了其理论依据。

文献[2]对笔者的观点进行了质疑,题目是关于应力敏感的,质疑的内容大都是岩石的压缩问题,关于应力敏感的内容极少,现撰文对其进行回复,以期达到更广泛的共识。

Systematic error problem“体积法”测量的岩石压缩系数出现了逻辑反转现象(Hall图版)[3,4],即高渗透疏松岩石的压缩系数低,低渗透致密岩石的压缩系数高,而且,岩石压缩系数的测量值超过了地层流体[5]。

笔者认为这是由于实验的系统误差所致,实验时将岩心放入柔软的橡胶封套中,由于封套与岩心表面之间存在微间隙,实验测量到了微间隙中流体(包括气泡)的压缩系数,而非完全是岩石的压缩系数。

由于流体的压缩性强,加之封套的塑性变形,实际测到的压缩系数才很高,若是岩石本身的压缩系数,不可能超过地层流体。

混合气体在典型多孔介质内扩散过程的数值模拟

混合气体在典型多孔介质内扩散过程的数值模拟

混合气体在典型多孔介质内扩散过程的数值模拟谷伟;张虎;李增耀;陶文铨【摘要】The diffusion processes of gas mixture in typical porous media were simulated by the Maxwell-Stefan model to study the effect of pore radius on the diffusion process and the interaction between each species of multicomponent during diffusion in porous media. The model and the numerical method adopted here were verified by the experimental data in literature. Then the effect of pore radius was examined on the diffusion process of CH4 /Ar mixture and the interaction between CH4/Ar/H2 during diffusion in porous media. The results show that the diffusion of CH4/Ar will rise with an increase in the pore radius when it is smaller than 0. 5 μm while the diffusion process is independent on the pore radius when it is larg er than 0. 5 μm. Moreover, the adverse diffusion may occur when the dragging effect is stronger than the concentration gradient effect. In addition, species with small molecules diffuse faster than those with big molecules. These results imply that the Maxwell-Stefan model can describe the diffusion process of multi-component gas mixture efficiently.%为研究孔径大小对扩散过程的影响及组分之间在扩散过程中的相互作用,采用MaxwellStefan模型对混合气体在典型多孔介质内的扩散过程进行了数值模拟.首先引用前人的实验结果验证了该模型及数值方法的可靠性.在此基础上,采用该模型研究了孔径大小对CH4/Ar二元混合气体在多孔介质内扩散过程的影响,以及CH4/Ar/H2三元混合气体在多孔介质内扩散过程中各组分之间的相互作用.研究表明:当孔半径小于0.5 μm时,CH4/Ar的扩散过程随孔半径的增大而加快,当孔半径大于0.5 μm时,CH4/Ar的扩散过程不受孔半径的影响;当不同组分之间的相互拖带作用大于自身的浓度梯度作用时,可能产生逆向扩散、局部压力回升现象;小分子较大分子扩散得快;Maxwell-Stefan模型能够有效地模拟多元混合气体的扩散过程.【期刊名称】《西安交通大学学报》【年(卷),期】2012(046)003【总页数】6页(P107-112)【关键词】多孔介质;孔径大小;Maxwell-Stefan模型;拖带作用;逆向扩散【作者】谷伟;张虎;李增耀;陶文铨【作者单位】西安交通大学热流科学与工程教育部重点实验室,710049,西安;西安交通大学热流科学与工程教育部重点实验室,710049,西安;西安交通大学热流科学与工程教育部重点实验室,710049,西安;西安交通大学热流科学与工程教育部重点实验室,710049,西安【正文语种】中文【中图分类】O121.8;G558合理地描述多元混合气体在孔道内的扩散过程,对于模拟和设计混合气体在多孔介质内的吸附扩散过程具有重要的意义.在传统的化学工程中,Fick定律被广泛用来描述扩散过程,该定律认为扩散通量与浓度梯度存在线性关系.1962年,Duncan 等[1]通过 H 2、N2、CO2 三元混合气体在两个储气元间的等摩尔反向扩散实验,观察到了N2逆着浓度梯度扩散的现象,因此Fick定律并不是所有情况下都成立,仅能应用在下述情形[2]:①二元组分的扩散;②多组分系统中稀有组分的扩散;③多组分系统中各组分分子大小和性质相近;④无外力场(电场、离心力等)作用.工程实际中绝大部分物系都是多元物系,由于各组分间的交互作用,使得多元传质的特性完全不同于二元传质[2],某些组分可能会产生渗透传质、传质障碍、逆向传质等交互现象[3-5].对于这些现象,传统的Fick定律都无法解释,因此需要提出一种更有效的方法来描述复杂多组分系统的扩散过程.在过去的20余年间,Krishna等[6]基于 Maxwell(1866年)和Stefan (1871年)理论,发展了用于定量分析多组分系统中各组分扩散过程的Maxwell-Stefan模型,该模型考虑了热力学的非理想性和外部力场的影响,可定量表达各种作用如温度梯度、电势差、化学势梯度对物质扩散的影响,被广泛用于描述单组分或复杂多组分系统的传质过程.本文以多孔介质为背景,基于Maxwell-Stefan模型对多元混合气体在孔道内的扩散过程进行模拟,研究了不同组分之间在扩散过程中的交互作用.1 Maxwell-Stefan模型1.1 传输形式气体在孔道内的传输形式可分为以下4类[7].(1)努森扩散:这种扩散是由气体分子与孔壁碰撞引起的.(2)主体扩散:混合气体在扩散过程中不同种类分子之间将通过碰撞产生动量交换,从而引起主体扩散.(3)表面扩散:对于被吸附在孔壁表面的分子,不同种类分子与孔壁表面的相互作用程度不同,从而导致不同种类分子在孔壁表面具有不同的迁移特性,因此这种扩散如努森扩散一样可以分离不同种类的分子.(4)黏性流:这种扩散以总压力梯度为推动力,所有组分以同一速度在孔道中扩散.本文不考虑表面扩散的作用.1.2 扩散通量对于不考虑吸附的n元组分系统的扩散问题,Maxwell-Stefan模型由努森扩散、主体扩散和黏性流所引起的总扩散通量表示为[7-8]式中为扩散通量为压力;R 为气体常数;T 为温度;B 0=r2/8为黏性流参数,r 为孔的半径;z为沿扩散方向的位置坐标;ηm为混合气体的动力黏度,可采用Wilke等[9-10]提出的半经验公式得出.组分i的动力黏度计算可采用Chung公式[11]式中:η为动力黏度;M 为摩尔质量;V c为临界状态摩尔体积;Ωv为黏性碰撞积分;F c为修正参数.矩阵B和Λ为二元扩散系数、努森扩散系数和摩尔分数x的函数二元扩散系数Di,j为总压力和温度的函数[11]式中:为组分中各原子扩散容积之和.如果知道参考状态P 0、T 0下的二元扩散系数,则任意状态下的扩散系数可由下式得出努森扩散系数可由下式得出式(6)假定扩散孔的截面为圆形,对于非圆柱孔的努森扩散系数计算表达式参见文献[6].1.3 质量守恒方程通过质量守恒方程,可以建立各组分的压力随时间和位置的变化通过解方程(7)可得出各组分的压力在不同时间下沿扩散距离的分布.对于n元混合气体,式(7)为n个非线性耦合偏微分方程,只能采用数值方法进行求解,本文采用FVM数值方法[12].2 模型及数值方法的验证为验证该模型及数值方法的准确性,本文对Duncan等[1]在1962年所做的实验进行了模拟.如图1所示,左右两边容器的容积分别为7.8×10-5 m3和7.86×10-5 m3,连通管的长度和直径分别为86 mm和2.08 mm.两容器内总压力均为101.3 k Pa,实验温度为35℃,容器内的工质为 H 2/N2/CO2三元混合气体.图1 文献[1]实验示意图35℃、101.3 k Pa下的二元扩散系数为初始时刻两边容器内各组分的摩尔分数见表1.表1 左右容器各组分初始浓度设置容器位置 x(H 2) x(N2) x(CO2)左边0.000 00 0.500 86 0.499 14右边0.501 21 0.498 79 0.000 00采用FVM对方程(7)进行离散,连通管沿扩散方向被划分为50个节点.由于式(7)为3个非线性耦合偏微分方程组,即使采用全隐格式,如果时间步长取得过大,计算结果仍会发散,因此采用亚松弛技术以避免计算结果发散.图2是时间步长为0.01 s、松弛因子为0.1时模拟结果与实验结果的对比,可以看出,该模型及数值方法能够获得可靠的模拟结果.3 多孔介质模型基于Maxwell-Stefan模型及上述数值方法,本文对三元混合气体在如图3所示的多孔介质内的扩散过程进行了模拟.用迂曲度τ对多孔介质内的D i,j和D i,Kn 进行修正,即根据活性碳的特性,设定迂曲度为4.7,孔半径为0.8μm,孔隙率为0.31[13]. 图2 模拟结果与文献[1]的实验结果对比图3 多孔介质示意图边界条件为初始条件为解方程组(7)可得到各组分的压力随时间和沿扩散位置的变化,从而得到多孔介质内部各组分的平均压力随时间的变化4 模拟结果及分析4.1 孔半径对扩散过程的影响以CH 4/Ar二元混合气体为例,通过改变多孔介质的孔半径来研究孔径大小对扩散过程的影响.表2列出了组分之间的二元扩散系数,表3列出了各组分的摩尔质量及动力黏度.将充满CH 4的如图3所示的多孔介质放入H 2环境中,观察不同孔半径下的扩散过程.本文取L=20 cm,T=300 K.表2 300 K、0.1 MPa下的二元扩散系数cm2·s-1参数 CH 4/H 2 H 2/Ar CH 4/Ar D i,j 0.728 6 0.805 3 0.212 5表3 各组分的摩尔质量和300 K下的动力黏度参数 CH4 H2 Ar摩尔质量/g·mol-1 16.043 44.010 39.948动力黏度/kg·m-1·s-1 1.09×10-5 0.9×10-52.22×10-5CH 4和Ar的初始压力分别为0.1 MPa和0 Pa,背压分别为0 Pa和0.1 MPa. 图4 孔半径对扩散过程影响的模拟结果图4为CH 4/Ar二元混合气体在不同孔半径的多孔介质内扩散过程的模拟结果.由图4可以看出:当孔半径小于0.5μm时,CH 4/Ar的扩散过程随孔半径的增大而加快;当孔半径大于0.5μm时,CH 4/Ar的扩散过程不受孔半径的影响.这是因为随着孔径的减小,气体分子的主导扩散形式逐渐由主体扩散向努森扩散转变.CH 4/Ar混合气体的分子有效直径为0.365 nm,其平均分子自由程可由下式得出当孔半径大于0.5μm时,CH 4/Ar的扩散形式以主体扩散为主,当孔半径小于0.5μm时,随着孔半径的减小,扩散形式逐渐向努森扩散转变,直到孔半径小于0.03μm,CH 4/Ar开始完全进行努森扩散.由式(4)、(6)可知,二元扩散系数与孔半径无关,而努森扩散系数与孔半径的3/2次方成正比,因此当孔半径小于0.5μm时,CH 4/Ar的扩散过程随孔半径的减小而减缓,当孔半径大于0.5μm时,CH 4/Ar的扩散过程与孔半径无关.4.2 三元组分系统的扩散以CH 4/Ar/H 2三元混合气体为例,通过设置不同的初始和边界条件来研究三元混合气体在图3所示的多孔介质内扩散时的相互作用.计算所需的二元扩散系数可从表2中查得.本文取L=20 cm,r=0.8μm,T=300 K.各工况的初始及边界条件如下.工况1:CH 4、Ar和H 2的初始压力分别为0.5 MPa、0.5 MPa和0 Pa,背压分别为0 Pa、0.5 MPa和0.5 MPa.工况2:CH 4、Ar和 H 2的初始压力分别为0 Pa、0.5 MPa和0.5 MPa,背压分别为0.5 MPa、0.5 MPa和0 Pa.图5为上述两种工况下的模拟结果.对于工况1,前2 ks内Ar在多孔介质内的平均压力要小于背压,随着Ar不断地由内部向外部扩散,即逆着浓度梯度方向扩散,这种现象至2 ks左右即Ar在内部的平均压力达到最低值时消失.这是因为CH 4相对于H 2为大分子,CH 4/Ar之间的相互作用要强于H 2/Ar之间,所以CH 4在由多孔介质内部向外部扩散的过程中会拖带一部分Ar到外部,直到内部CH 4的浓度降低到一定程度,其对Ar的拖带作用小于Ar内外浓度梯度的推动作用,随后Ar在自身浓度差的推动下开始向内部扩散.为进一步说明这种分子之间的相互拖带作用,我们在模拟时相互调换了CH 4和H 2的初始压力和背压(即工况2).从模拟结果可以看出,Ar正如预期的那样出现了逆向扩散现象,即Ar在前2 ks内逆着浓度梯度向多孔介质外部扩散.图5 三元混合气体在多孔介质内扩散过程的模拟结果图6 工况1各组分在不同时刻的压力和摩尔通量分布为了进一步了解扩散过程中组分之间的相互作用,图6列出了工况1各组分在不同时刻的压力和摩尔通量的分布情况.CH 4和H 2的压力分布与预期的一样,而Ar的压力分布(图6c)形式比较特别,这是由CH 4及H 2在扩散过程中对Ar共同作用的结果.前500 s时Ar在靠近多孔介质入口处的压力明显低于两侧,这是由于入口区域的CH 4首先受到边界条件的影响而向外部扩散,并将该区域的部分Ar带到外部(500 s以前,Ar入口处的摩尔通量大于0),从而引起该处Ar局部压力下降,而在10、50 s时,Ar的压力在靠近内部处出现了微升,这是由于小分子H 2相对CH 4扩散较快,率先进入孔内拖带未受CH 4拖带区域的Ar向孔内扩散(10、50 s时,Ar在对应区域的局部摩尔通量小于0),从而引起内部Ar的压力局部升高.当整个区域的CH 4开始向外部扩散时,Ar在整个区域的压力将会不断下降,直到达到最低值,此时Ar在各处的摩尔通量均为0(对应图6d中2 000 s的曲线),之后Ar将由外部向内部扩散,从而引起内部Ar的压力回升.5 结论本文首先引用Duncan和Toor的实验验证了Maxwell-Stefan模型及数值方法的可靠行,在此基础上,采用该模型研究了孔径大小对CH 4/Ar二元混合气体在多孔介质内扩散过程的影响,以及CH 4/Ar/H 2三元混合气体在多孔介质内扩散过程中各组分之间的相互作用,主要得出以下结论.(1)当孔半径小于0.5μm时,CH 4/Ar的扩散过程随孔半径的增大而加快;当孔半径大于0.5μm时,CH 4/Ar的扩散过程不受孔半径的影响,主要受多孔材料本身的迂曲度和孔隙率的影响.(2)当不同组分之间的相互拖带作用大于自身的浓度梯度作用时,可能产生逆向扩散、局部压力回升现象.(3)小分子较大分子扩散得快.(4)Maxwell-Stefan模型能够有效地模拟多元混合气体的扩散过程.【相关文献】[1] DUNCAN J B,TOOR H L.An experimental study of three component gas diffusion [J].AIChE Journal,1962,8(1):38-41.[2] TAYLOR R,KRISHNA R.Multicomponent mass transfer[M].New York,USA:Wiley,1993.[3] CARTY R,SCHRODT T.Concentration profiles in ternary gaseous diffusion[J].Industrial &Engineering Chemistry Fundamentals,1975,14(3):276-278. [4] DUNCAN J B,TOOR H L.An experimental study of three component gas diffusion [J].AIChE Journal,1962,8(1):38-41.[5] KRISHNA R,STANDART G.Mass and energy transfer in multicomponent systems [J].Chemical Engineering Communications,1979,3(4):201-275.[6] KRISHNA R,WESSELINGH J A.The Maxwell-Stefan approach to mass transfer [J].Chemical Engineering Science,1997,52(6):861-911.[7] DO D D.Adsorption analysis-equilibria and kinetics[M].London,UK:ImperialCollege Press,1998.[8] KRISHNA R.A unified approach to the modelling of intraparticle diffusion in adsorption processes[J].Gas Separation &Purification,1993,7(2):91-104.[9] DO H D,DO D D.Maxwell-Stefan analysis of multicomponent transient diffusion in a capillary and adsorption of hydrocarbons in activated carbon particle[J].Chemical Engineering Science,1998,53(6):1239-1252.[10]BIRD R B,STEWART W E,LIGHTFOOT E N.Transport phenomena [M].2nd ed.New York,USA:Wiley,2002.[11]POLING B E,PRAUSNITZ J M,O’CONNELL J P.The properties o f gases and liquids[M].New York,USA:McGraw-Hill,2001.[12]陶文铨.数值传热学[M].2版.西安:西安交通大学出版社,2001.[13]DO D.Dynamics of adsorption in heterogeneous solids[J].Studies in Surface Science and Catalysis,1997,104:777-835.。

激光内送粉变姿态熔覆非水平熔池流场的数值模拟

激光内送粉变姿态熔覆非水平熔池流场的数值模拟

表面技术第53卷第9期激光内送粉变姿态熔覆非水平熔池流场的数值模拟陈海俊a,朱刚贤a*,贺继宏a,王丽芳b(苏州大学 a.机电工程学院 b.工程训练中心,江苏 苏州 215137)摘要:目的提高激光内送粉变姿态熔覆层成形质量,对变姿态熔覆时非水平熔池流场随基板倾斜角的演变规律进行研究。

方法首先,利用FLUENT软件中离散相模型对喷嘴流场进行模拟,获取粉末频次的分布规律。

其次,采用流体体积法耦合熔化/凝固模型对熔池流场进行计算。

通过施加质量源项引入同步送粉,施加能量源项模拟激光热输入,选取姿态角为30°、60°、90°进行计算,对熔池流场及熔覆层界面进行追踪分析。

最后,基于激光内送粉熔覆工艺进行实验测定。

结果粉斑内粉末量呈“中间均匀,两端密集”的分布规律。

熔池流动为“双环流”分布特征,但流动方向受重力影响,产生偏转。

取3种姿态角计算时间同为0.3 s时,熔池中心处流体的偏转角分别为2°、4°、6°,并且随着倾斜角的增大,熔覆层高度分别增加了0.28%、0.83%、1.45%,熔覆层宽度减小了1.19%、1.28%、1.73%,熔覆层顶点偏移量增大到48.08、86.54、105.76 μm。

最后结合实验测定,数值计算与实验结果一致。

结论Marangoni应力使得激光内送粉熔覆熔池流体产生由中心向边界流动的“双环流”分布特征,非水平熔池流动方向受重力影响产生偏转。

随着基板倾斜角增大,熔覆层截面高度增加、宽度降低、顶点偏移量增加。

为提高不便摆平非水平基面的激光内送粉变姿态熔覆再制造成形质量提供了指导。

关键词:激光熔覆;光内送粉;变姿态;熔池流场;数值模拟中图分类号:TN249;TG665 文献标志码:A 文章编号:1001-3660(2024)09-0190-10DOI:10.16490/ki.issn.1001-3660.2024.09.018Numerical Simulation on Flow Field of Non-horizontalMolten Pool by Laser Cladding Based on Inside-beamPowder Feeding with Variable PostureCHEN Haijun a, ZHU Gangxian a*, HE Jihong a, WANG Lifang b(a. School of Mechanical and Electrical Engineering, b. Center of Engineering Training,Soochow University, Jiangsu Suzhou 215137, China)ABSTRACT: Laser cladding and laser remanufacturing technology is based on horizontal reference planes at present, however,收稿日期:2023-01-30;修订日期:2023-08-02Received:2023-01-30;Revised:2023-08-02基金项目:国家级大学生创新创业训练计划项目(202110285032);江苏省大学生创新创业训练计划项目(202110285032Z);苏州市科技计划项目(SYC2022143);国家重点研发计划项目(2016YFB1100300)Fund:National College Student Innovation and Entrepreneurship Training Program Project (202110285032); Jiangsu Province College Student Innovation and Entrepreneurship Training Program Project (202110285032Z); The Sci-Tech Plan of Suzhou Municipal of China (SYC2022143); The National Key Research and Development Plan (2016YFB1100300)引文格式:陈海俊, 朱刚贤, 贺继宏, 等. 激光内送粉变姿态熔覆非水平熔池流场的数值模拟[J]. 表面技术, 2024, 53(9): 190-199.CHEN Haijun, ZHU Gangxian, HE Jihong, et al. Numerical Simulation on Flow Field of Non-horizontal Molten Pool by Laser Cladding Based on Inside-beam Powder Feeding with Variable Posture[J]. Surface Technology, 2024, 53(9): 190-199.*通信作者(Corresponding author)第53卷第9期陈海俊,等:激光内送粉变姿态熔覆非水平熔池流场的数值模拟·191·this way greatly limits its extensive application. The molten pool flow behavior of the laser cladding has a direct impact on the morphology and forming quality of the cladding layer. However, it is difficult to observe and study the flow behavior in the molten pool by experimental method due to the limitation of high temperature and instantaneous evolution of the molten pool.Consequently, the simulation analysis of the heat transfer, flow behavior and morphology evolution in the molten pool by numerical simulation technology is a research hotspot in laser cladding technology. In addition, the flow field distribution of the non-horizontal molten pool is still lack of systematic research with variable attitudes based on inside-beam powder feeding way by laser cladding. In order to improve the forming quality of cladding layers under variable attitudes based on inside-beam powder feeding, the flow field evolution rules of a non-horizontal molten pool with a substrate inclination angle were studied. In this paper, the discrete phase model based on FLUENT Software was adopted to compute the flow field of the nozzle and obtain the powder distribution rules. And then, the flow field of the molten pool was calculated based on the Volume of Fluid and Melting/Solidification Model. Attitude angles of 30°, 60° and 90° were chosen to compute the flow field of the non-horizontal molten pool, respectively. The flow field of the molten pool was tracked and the interfaces of the cladding layer were analyzed by applying the mass source item and the energy source item to simulate the process of synchronous powder feeding and laser thermal input. Finally, experimental measurements were carried out based on the inside-beam powder feeding cladding process.The results showed that the powder distribution in the powder spot was "even in the middle and dense at both ends". The flow field of the non-horizontal molten pool was characterized by "double annular flow" distribution, but the flow direction was deflected due to the influence of gravity. When the computation time of three attitude angles was 0.3 s, the deflection angles of the fluid at the center of the molten pool were 2°, 4°, and 6°, respectively. With the inclination angle increased, the height of the cladding layer increased by 0.28%, 0.83% and 1.45%, the width of the cladding layer decreased by 1.19%, 1.28% and 1.73%, and the vertex offsets of the cladding layer increased to 48.08 μm, 86.54 μm and 105.76 μm. Finally, the numerical calculations were consistent with the experimental results through the experimental determination. The Marangoni stress makes the fluid flow in the molten pool from the center to the boundary with a double-circle distribution characteristic. The flow direction of the non-horizontal molten pool is deflected by the influence of gravity. While the inclination angle increases, the height of the cladding layer increases, the width of the cladding layer decreases and the vertex offset of the cladding layer gradually increases.It provides guidance for improving the laser cladding and laser remanufacturing quality in the light of parts that are inconvenient to flatten the non-horizontal base surface by the inside-beam powder feeding way.KEY WORDS: laser cladding; inside-beam powder feeding; variable attitude; molten pool flow field; numerical simulation激光熔覆再制造是基于激光熔覆为主体手段的修复技术,它利用高能激光束将添覆材料与受损基体表面共同熔化/凝固,形成与基体呈冶金结合的表面涂层,以修复受损表面,可显著提升基体表面耐磨损、耐腐蚀、耐高温及抗氧化性能[1-3],适用于高端装备关键易损件的严苛修复需求,能使之变废为宝,减少资源浪费。

不同甜香风味特征的酱香型白酒中挥发性物质分析

不同甜香风味特征的酱香型白酒中挥发性物质分析

莫新良,杨亮,吴德光,等. 不同甜香风味特征的酱香型白酒中挥发性物质分析[J]. 食品工业科技,2022,43(18):311−321. doi:10.13386/j.issn1002-0306.2022030067MO Xinliang, YANG Liang, WU Deguang, et al. Analysis of Volatile Compounds in Sauce-flavor Baijiu with Different Sweet Flavor Characteristics[J]. Science and Technology of Food Industry, 2022, 43(18): 311−321. (in Chinese with English abstract). doi:10.13386/j.issn1002-0306.2022030067· 分析检测 ·不同甜香风味特征的酱香型白酒中挥发性物质分析莫新良,杨 亮,吴德光,滕明德,钟艳霞(茅台学院酿酒工程系,贵州仁怀 564501)摘 要:为探究不同甜香风味特征酱香型白酒的主要挥发性物质组成及香气物质差异,本研究运用感官品评方法选取酱香型酒样,采用顶空固相微萃取(headspace solid phase microextraction ,HS-SPME )结合气相色谱-质谱法剖析其中的挥发性成分,通过偏最小二乘判别分析法(partial least squares discriminant analysis ,PLS-DA )解析不同酒样及其风味差异物质。

结果表明:样品被分为三组,每组的甜香强度值分别为4.0~5.0、3.0~4.0和0.0~3.0;共鉴定出68种风味物质,包括酯类27种、醇类12种、醛酮类10种、酸类3种、芳香族化合物10种和萜烯类物质6种。

其中,具有甜香和水果香的酯类、芳香族类和醇类物质是酒样中含量最为丰富的三类化合物,且在甜香强度大于3.0的酒样中含量最高,说明这三类物质对甜香风味特征有重要影响;影响三组酒样的潜在差异物质有25个,与之相关的甜香风味标志性物质主要为3-甲基丁醇、辛酸乙酯、乳酸异丁酯和苯乙酸乙酯,说明这些物质是造成不同甜香酒样之间差异的重要香气物质。

有机烃、热释汞剖面测量方法

有机烃、热释汞剖面测量方法

有机烃、热释汞剖面测量方法英文回答:Organic hydrocarbons are compounds that contain carbon and hydrogen atoms. They are widely found in nature and can be produced through various processes, such as the decomposition of organic matter or the extraction of fossil fuels. These hydrocarbons play a crucial role in our daily lives, as they are the main constituents of fuels, plastics, and other important materials.One common method used to measure organic hydrocarbonsis through the use of gas chromatography. This technique separates the different components of a sample based ontheir volatility and affinity for the stationary phase. By analyzing the resulting chromatogram, scientists can determine the types and concentrations of organic hydrocarbons present in the sample.Another method that can be used to measure organichydrocarbons is through the use of infrared spectroscopy. This technique involves exposing the sample to infrared radiation and measuring the absorption of the radiation at different wavelengths. Each organic compound has a unique infrared absorption spectrum, which can be used to identify and quantify the compounds present in the sample.Now let's move on to the measurement of thermal release mercury profiles. This technique is used to determine the distribution of different forms of mercury in a sample. Mercury is a toxic metal that can exist in various forms, such as elemental mercury, inorganic mercury compounds, and organic mercury compounds. By measuring the thermal release of mercury from a sample at different temperatures, scientists can obtain information about the different forms of mercury present.To measure thermal release mercury profiles, a sampleis heated in a controlled environment, and the released mercury is captured and analyzed. The temperature at which each form of mercury is released can provide insights into its chemical composition and potential sources. For example,organic mercury compounds are typically released at lower temperatures compared to inorganic mercury compounds.中文回答:有机烃是含有碳和氢原子的化合物。

质子交换膜燃料电池气体扩散层研究进展

质子交换膜燃料电池气体扩散层研究进展

2021年第3期曹婷婷崔新然马千里王茁韩聪米新艳于力娜张克金(一汽解放商用车开发院,长春130011)【摘要】气体扩散层(GDL )是质子交换膜燃料电池(PEMFC )的重要组件,在燃料电池电堆中起到电子传导、反应气体传输、电堆水热管理的作用。

近年来,随着质子交换膜燃料电池的开发和应用愈发广泛,气体扩散层的开发已成为加快燃料电池产业落地的关键因素。

重点阐述了质子交换膜燃料电池气体扩散层的市场发展、制备技术及工艺优化问题,评价了最新的气体扩散层表征手段与测试方法,并结合当前燃料电池电堆研究进展,指出当前气体扩散层研究中的不足及优化方向,并为气体扩散层的开发工作提出新的方向。

主题词:质子交换膜燃料电池气体扩散层气体传导电子传递水管理中图分类号:O646;TM911.4文献标识码:A DOI:10.19822/ki.1671-6329.20200198Research Progress of Gas Diffusion Layer in Proton ExchangeMembrane Fuel CellsCao Tingting,Cui Xinran,Ma Qianli,Wang Zhuo,Han Cong,Mi Xinyan,Yu Lina,Zhang Kejin (Commercial Vehicle Development Institute,FAW Jiefang Co.Ltd,Changchun 130011)【Abstract 】GDL is an important component of membrane electrode,which is the core part of PEMFC.It plays an important role in the conduction of electrons,in the transmission of reaction gases,in the management of water and heat in the fuel cell stack.In recent years,with the development and application of PEMFC becoming more and more extensive,GDL has become a key factor to accelerate realization of fuel cell industry.In this paper,the technology and development of gas diffusion layer in PEMFC are briefly introduced,the preparation technology and process optimization are described,the latest characterization and test methods of gas diffusion layer are evaluated and the application of GDL is carried out based on the current research progress of fuel cell stack.The shortcomings and optimization direction in the currentresearch are pointed out.Key words:Proton Exchange Membrane Fuel Cells(PEMFC),Gas Diffusion Layer (GDL ),Gastransport,Electron transport,Water management质子交换膜燃料电池气体扩散层研究进展【欢迎引用】曹婷婷,崔新然,马千里,等.质子交换膜燃料电池气体扩散层研究进展[J].汽车文摘,2021(3):8-14.【Cite this paper 】Cao T,Cui X,Ma Q,et al.Research Progress of Gas Diffusion Layer in Proton Exchange Membrane Fuel Cells [J].Automotive Digest (Chinese),2021(3):8-14.缩略语GDL Gas Diffusion Layer GDB Gas Diffusion Barrier PEMFC Proton Exchange Membrane Fuel CellsMPLMicro-Porous Layer1前言近年来,质子交换膜燃料电池电堆因其清洁、高效的优点,受到国内外的广泛关注。

气相色谱发分析流程

气相色谱发分析流程

气相色谱发分析流程英文回答:Gas Chromatography Analysis Procedure.Gas chromatography (GC) is a separation technique used to analyze the chemical composition of a sample. It is based on the principle that different compounds have different affinities for a stationary phase and a mobile phase. The stationary phase is typically a solid or liquid coated onto a glass or metal column. The mobile phase is a gas that flows through the column, carrying the sample compounds with it.The sample is injected into the GC column, and the compounds are separated as they pass through the column. The compounds with the highest affinity for the stationary phase will elute (exit the column) first, followed by the compounds with the lowest affinity. The elution order of the compounds is determined by their boiling points,molecular weights, and polarity.The separated compounds are detected by a detector, which is located at the end of the column. The detector generates a signal that is proportional to the concentration of the compound in the sample. The signal is recorded on a chart or computer, and the resulting chromatogram is used to identify and quantify the compounds in the sample.GC is a versatile technique that can be used to analyze a wide variety of samples, including食品, 药品, and environmental samples. It is a powerful tool foridentifying and quantifying compounds in complex mixtures.中文回答:气相色谱分析流程。

制药工艺尾气中丙酮的膜法回收

制药工艺尾气中丙酮的膜法回收

进行分离处理,回收得到丙酮;光电催化氧化法消耗电能,将丙酮分解为二氧化碳和水排放,同样无法回收丙酮。

膜分离法安全性好、运行费用低、工艺简单、回收效果好、无二次污染,可谓是一种“绿色高新技术”。

该制药企业最终选择采用膜分离法来回收含丙酮尾气中的丙酮。

2 膜分离法应用2.1 膜分离法原理膜分离法的核心在于膜组件,卷式膜组件由中心管、导流网、膜、隔网等组成,膜对于丙酮分子和空气分子具有不同的选择透过性,丙酮尾气在膜内外压差的作用下,丙酮分子优先通过膜并富集在一侧,空气分子被截留在另一侧富集,从而实现丙酮和空气的物理分离,使得丙酮被回收利用,空气中丙酮含量大大降低,进一步处理后排放。

2.2 工艺说明如图1所示,丙酮尾气汇集后,先经丝网除雾器除去尾气中可能夹带的微量水分,再经膜前冷凝器进一步冷凝水分或者过高含量的丙酮后进入膜前缓冲罐,当膜前缓冲罐压力达到设定的高限值时,真空泵启动,丙酮尾气进入膜法回收丙酮设备撬块,富集的丙酮气体经过真空泵进入真空泵后冷凝器冷凝,丙酮凝液进入丙酮回收罐收集,收集后的丙酮通过丙酮转料泵打至丙酮用点,未冷凝的丙酮气体重新返回膜前缓冲罐,回收丙酮后的尾气汇入车间尾气排放总管集中进入光电催化氧化系统处理达标后排放。

当膜前缓冲罐压力低于设定的低限值时,真空泵停止运行。

整个过程的运行通过膜前缓冲罐上的压力自动控制。

0 引言丙酮,又名二甲基(甲)酮、阿西通,是一种无色透明的易流动流体,有芳香气味,沸点56.5 ℃,20 ℃下的饱和蒸汽压为24 kPa ,极易挥发,高度易燃,对眼造成严重的刺激,可引起昏昏欲睡或眩晕,蒸汽与空气混合,能形成爆炸性混合物。

丙酮与水混溶,可混溶于乙醇、乙醚、氯仿、油类、烃类等多数有机溶剂,为基本的有机原料和低沸点溶剂[1]。

在制药企业中,丙酮作为溶剂被广泛应用,使用过程中产生大量含丙酮尾气,尾气中的丙酮具有很大的回收价值。

1 工艺尾气处理方法《制药工业大气污染物排放标准》[2]对于排放大气的TVOC 含量具有限值要求,对于非重点地区的TVOC 排放限值为150 mg/m 3,重点地区的TVOC 排放限值为100 mg/m 3,丙酮作为挥发性有机物,必须进行处理。

麻油中邻苯二甲酸二丁酯的太赫兹时域光谱研究

麻油中邻苯二甲酸二丁酯的太赫兹时域光谱研究

麻油中邻苯二甲酸二丁酯的太赫兹时域光谱研究衣玲学;高磊;张平【摘要】Plasticizer can be easily transferred to the atmosphere,soil,water and food,and cause great harm to the human body and the environment.Dibutyl phthalate (DBP) is one of common plasticizers.In this paper,DBP and the mixture of DBP and Sesame oil were selected as experimental subjects.Terahertz time-domain spectroscopy (TDS) was used to get the absorbance and the refractive index in 0.3~2.25THz band.The partial least squares regression (PLSR) method was used to the mixture of different concentrations of the corresponding absorbance spectrum after Fourier transform modeling analysis.The results showed that the content of DBP in sesame oil and terahertz frequency domain spectra are highly correlated,the calculated correlation coefficient was 0.9893,root mean square error (RMSEC) was 0.46%,and root mean square error of prediction (RMSEP) was 1.18%.It was proved that the using of terahertz time-domain spectroscopy combined PLSR method can accurately analyze plasticizer content in sesame oil.%塑化剂极易转移到大气、土壤、水体和食品中,对环境和人体造成极大的伤害.邻苯二甲酸二丁酯(DBP)是一种常见的塑化剂,本文以DBP为实验对象,利用太赫兹时域光谱技术(THz-TDS)在室温环境下对麻油及其与DBP的混合物进行检测,得到其在0.3~2.25THz波段的折射率和吸收光谱.利用偏最小二乘回归(PLSR)的方法对不同浓度的混合物的吸收光谱进行建模分析,结果表明麻油中DBP含量与太赫兹波段吸收光谱具有很高的相关性,相关系数R为0.9893,校正最大均方根误差(RMSEC)为0.46%,预测最大均方根误差(RESEP)为1.18%,证明了利用太赫兹时域光谱技术结合PLSR方法能够精确分析麻油中塑化剂含量.【期刊名称】《物理与工程》【年(卷),期】2017(027)004【总页数】4页(P34-36,41)【关键词】太赫兹时域光谱技术;邻苯二甲酸二丁酯;食品安全;偏最小二乘回归;定量检测【作者】衣玲学;高磊;张平【作者单位】中国石油大学(北京)油气光学探测技术北京市重点实验室,北京102249;中国石油大学(北京)油气光学探测技术北京市重点实验室,北京 102249;中国石油大学(北京)油气光学探测技术北京市重点实验室,北京 102249【正文语种】中文邻苯二甲酸酯类(Phthalic Acid Esters,简称PAEs),其主要用作塑料的增塑剂,添加后可让微粒分子更均匀散布,能增加延展性、弹性及膨胀性。

含气水合物沉积物速度的biot-gassmann理论

含气水合物沉积物速度的biot-gassmann理论

含气水合物沉积物速度的biot-gassmann
理论
Biot-Gassmann理论是由法国地球物理学家·比奥特和德国物理学家约翰·加斯曼提出的理论,它可以用来研究包含气水合物沉积物的岩石和土壤变形的机制。

该理论建立在三个基本假设上:岩石的孔隙水可以在岩石的孔隙中扩散,岩石的弹性模量和泊松比可以被改变,以及岩石的孔隙结构可以被加载。

该理论的主要原理是,在岩石和土壤中存在着多种不同类型的晶体,比如铁、硅、钙、镁等。

这些晶体以一定的比例存在于岩石和土壤中,比例可以用百分比表示。

这些晶体中的一些可能具有比较大的渗透性,而另一些可能具有比较小的渗透性。

当气体和水合物流入岩石和土壤时,它们可以在晶体的孔隙中扩散,并且可以改变晶体的弹性模量和泊松比。

因此,在改变晶体的结构之后,岩石和土壤的变形速度将会受到影响。

Biot-Gassmann理论可以用来研究包含气水合物沉积物的岩石和土壤变形的机制。

它可以帮助研究人员了解在岩石和土壤中晶体结构和流体属性之间的相互作用,以及这种相互作用如何影响岩石和土壤的变形速度。

此外,该理论还可以用来研究岩石和土壤变形的复杂机制,如孔隙结构的变化、压力-温度对流体流动的影响等等。

总之,Biot-Gassmann理论是一种用来研究包含气水合物沉积物的岩石和土壤变形机制的理论。

它可以帮助研究人员理
解岩石和土壤变形速度的影响因素,以及岩石和土壤变形的复杂机制。

它也为地质学家和地质工程师提供了一种有效的工具,用来研究岩石和土壤的变形过程。

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