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Kinetic Mass Transfer Between Non-aqueous Phase Liquid and Gas During Soil Vapor Extraction 被引量:1
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作者 李鑫钢 黄国强 沈铁孟 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第5期610-613,共4页
The mass transfer between non-aqueous phase liquid(NAPL) phase and soil gas phase in soil vapor extraction(SVE) process has been investigated by one-dimensional venting experiments. During quasi-steady volatilization ... The mass transfer between non-aqueous phase liquid(NAPL) phase and soil gas phase in soil vapor extraction(SVE) process has been investigated by one-dimensional venting experiments. During quasi-steady volatilization of three single-component NAPLs in a sandy soil, constant initial lumped mass transfer coefficient (λgN,0) canbe obtained if the relative saturation (ξ) between NAPL phase and gas phase is higher than a critical value (ξc), andthe lumped mass transfer coefficient decreases with ξ when ξ<ξc. It is also shown that the lumped mass transfercoefficient can be increased by blending porous micro-particles into the sandy soil because of the increasing of theinterfacial area. 展开更多
关键词 kinetic mass transfer soil vapor extraction non-aqueous phase liquid soil remediation
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Recovery of carbon monoxide from flue gases by reactive absorption in ionic liquid imidazolium chlorocuprate(I): Mass transfer coefficients 被引量:2
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作者 Gabriel Zarca Inmaculada Ortiz Ane Urtiaga 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第5期769-774,共6页
Recovery of carbon monoxide from flue gases by selective absorption of carbon monoxide in an imidazolium chlorocuprate(l) ionic liquid is considered in this work as an alternative to the use of molecular volatile so... Recovery of carbon monoxide from flue gases by selective absorption of carbon monoxide in an imidazolium chlorocuprate(l) ionic liquid is considered in this work as an alternative to the use of molecular volatile solvents such as aromatic hydrocarbons. The present work evaluates the CO mass transfer rates from the gas phase to the ionic liquid solutions in the absence of chemical reaction. To that end, carbon dioxide was employed as an inert model gas and absorption experiments were performed to assess the influence of different process variables in a batch reactor with fiat gas-liquid interface. The experimental mass transfer coefficients showed significant var- iation with temperature, (3.4-10.9) × 10^-7 m·s^-1 between 293 and 313 K; stirring speed, (10.2- 33.1)× 10^-7 m.s 1 between 100 and 300 r·min^-1; and concentration of copper(1), (6.6-10.2) × 10^-7 m·s^-1 between 0.25 and 2 mol· L^- 1. In addition, the mass transfer coefficients were eventually found to follow a poten- tial proportionality of the type kL ∝μ^-0.5 and the dimensionless correlation that makes the estimation of the mass transfer coefficients possible in the studied range of process variables was obtained: Sh=10^-2.64 Re^1.07 , Sc^0.75,These results constitute the first step in the kinetic analysis of the reaction between CO and imidazolium chlorocuprate(I) ionic liquid that determines the design of the separation units. 展开更多
关键词 Carbon monoxide Ionic liquid Copper(I)Reactive absorption mass transfer kinetics mass transfer coefficient Carbon dioxide
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A convenient method for measuring gas-liquid volumetric mass transfer coefficient in micro reactors
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作者 Haoyang Wang Ronghao Zhang +1 位作者 Yanlun Ren Li Zhang 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第4期389-392,共4页
The research on gas-liquid multiphase reactions using micro reactors is becoming increasingly widespread, given their excellent mass transfer performance. Establishing an accurate and reliable method to measure the ga... The research on gas-liquid multiphase reactions using micro reactors is becoming increasingly widespread, given their excellent mass transfer performance. Establishing an accurate and reliable method to measure the gas-liquid mass transfer performance of micro reactors is crucial for evaluating and optimizing the design of micro reactor structure. In this paper, the physical absorption method of aqueous solution-CO_(2) and the chemical absorption method of sodium carbonate solution-CO_(2) were proposed. By analyzing the chemical reaction equilibrium during the absorption process, the relationship between the mass transfer of CO_(2) and the solubility of hydroxide ions in the solution was established, and the total gas-liquid mass transfer coefficient was immediately obtained by measuring the p H value. The corresponding testing platform and process have been established based on the characteristics of the proposed method to ensure fast and accurate measurement. In addition, the chemical absorption method takes into account temperature factors that were not previously considered. The volumetric mass transfer coefficient measured by these two methods is in the same range as those measured by other methods using the same microchannel structure in previous literature. The methods have the advantages of low equipment cost, faster measurement speed, and simpler procedures, which can facilitate its wide application to the evaluation of the mass transfer performance and hence can guide the structure optimization of microchannel reactors. 展开更多
关键词 volumetric mass transfer coefficient measurement Gas-liquid two phase Micro reactors Physical absorption Chemical absorption
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Prediction of mass transfer coefficients in an asymmetric rotating disk contactor using effective diffusivity 被引量:2
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作者 Meisam Torab-Mostaedi Mehdi Asadollahzadeh Jaber Safdari 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第3期288-293,共6页
Mass transfer characteristics have been investigated in a 113 mm diameter asymmetric rotating disk contactor of the pilot plant scale for two different liquid–liquid systems. The effects of operating parameters inclu... Mass transfer characteristics have been investigated in a 113 mm diameter asymmetric rotating disk contactor of the pilot plant scale for two different liquid–liquid systems. The effects of operating parameters including rotor speed and continuous and dispersed phase velocities on the volumetric overall mass transfer coefficients are investigated. The results show that the mass transfer performance is strongly dependent on agitation rate and interfacial tension, but only slightly dependent on phase flow rates. In this study, effective diffusivity is used instead of molecular diffusivity in the Grober equation for estimation of dispersed phase overall mass transfer coefficient.The enhancement factor is determined experimentally and there from an empirical expression is derived for prediction of the enhancement factor as a function of Reynolds number. The predicted results compared to the experimental data show that the proposed correlation can efficiently predict the overall mass transfer coefficients in asymmetric rotating disk contactors. 展开更多
关键词 Asymmetric rotating disk contactor mass transfer coefficient Enhancement factor Interfacial area Dispersed phase holdup
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Use of axial dispersion model for determination of Sherwood number and mass transfer coefficients in a perforated rotating disc contactor 被引量:1
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作者 Mehdi Asadollahzadeh Alireza Hemmati +3 位作者 Meisam Torab-Mostaedi Mansour Shirvani Ahad Ghaemi Zahra Sadat Mohsenzadeh 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第1期53-61,共9页
The mass transfer process in a perforated rotating disk contactor(PRDC) using a toluene-acetone-water system was investigated.The volumetric overall mass transfer coefficients are calculated in a PRDC column.Both mass... The mass transfer process in a perforated rotating disk contactor(PRDC) using a toluene-acetone-water system was investigated.The volumetric overall mass transfer coefficients are calculated in a PRDC column.Both mass transfer directions are considered in experiments.The influences of operating variables containing agitation rate,dispersed and continuous phase flow rates and mass transfer in the extraction column are studied.According to obtained results,mass transfer is significantly dependent on agitation rate,while the dispersed and continuous phase flow rates have a minor effect on mass transfer in the extraction column.Furthermore,a novel empirical correlation is developed for prediction of overall continuous phase Sherwood number based on dispersed phase holdup,Reynolds number and mass transfer direction.There has been great agreement between experimental data and predicted values using a proposed correlation for all operating conditions. 展开更多
关键词 Perforated rotating disk contactor mass transfer coefficient dispersed phase holdup Interfacial area
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Extraction of Neodymium by Emulsion-Liquid-Membrane within Hollow-Fiber-contactor and Its Mass Transfer Properties
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作者 Gong Fuzhong Luo Yan +1 位作者 Ma Peihua Zhang Limei 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第3期280-280,共1页
A non-dispersive extraction technique, using an emulsion liquid membrane within a hollow-fiber-contactor for the extraction and enrichment of Nd^3+ from the dilute feed aqueous, was applied. The emulsion system is co... A non-dispersive extraction technique, using an emulsion liquid membrane within a hollow-fiber-contactor for the extraction and enrichment of Nd^3+ from the dilute feed aqueous, was applied. The emulsion system is consisted of span80 [ sorbitian monooleate], paraffin oil, D2EHPA [ 2-( 2-ethylhexyl- phosphonic acid)], kerosene as well as HCl solution. The extraction under various conditions such as the span80 concentrations, the flow rate of aqueous, the extraction time and HCl concentrations in receiving phase were studied. Results show that the lower the flow rates of aqueous are, the higher the extraction percentage and enrichment-fold are, and the extraction percentage increases with the increasing of HCl concentrations. When the initial Nd^3+ concentration in feed is maintained at 1000 mg· L^-1 and the emulsion is recycled with 70 times by a counter-flow, 展开更多
关键词 emulsion liquid membrane hollow-fiber-membrane non-dispersive extraction mass-transfer coefficient NEODYMIUM rare earths
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A Mass Transfer Model for Devolatilization of Highly Viscous Media in Rotating Packed Bed 被引量:13
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作者 李沃源 毋伟 +3 位作者 邹海魁 初广文 邵磊 陈建峰 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第2期194-201,共8页
A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer e... A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer experiments of thin film were conducted in a designed diffusion cell including vacuum and feeding system. In this study,acetone was used as the volatile organic compound(VOC) and syrup as the highly viscous media.The thickness of thin film was changed by using different liquid distributor.It was found that bubbling played an important role in the devolatilization.The correlation of diffusion coefficient of acetone in highly viscous dilute solution was proposed.The relative error between predicted and experimental data was within the range of ± 30% for diffusion coefficient of acetone in syrup.A comparison of experimental data of RPB with model indicated that the relative error was within ± 30% for efficiency of acetone removal. 展开更多
关键词 mass transfer highly viscous liquid volatile organic compound diffusion coefficient rotating packed bed
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A liquid chromatography with tandem mass spectrometry method for quantitating total and unbound ceritinib in patient plasma and brain tumor 被引量:1
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作者 Xun Bao Jianmei Wu +1 位作者 Nader Sanai Jing Li 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2018年第1期20-26,共7页
A rapid, sensitive, and robust reversed-phase liquid chromatography with tandem mass spectrometry method was developed and validated for the determination of total and unbound ceritinib, a secondgeneration ALK inhibit... A rapid, sensitive, and robust reversed-phase liquid chromatography with tandem mass spectrometry method was developed and validated for the determination of total and unbound ceritinib, a secondgeneration ALK inhibitor, in patient plasma and brain tumor tissue samples. Sample preparation involved simple protein precipitation with acetonitrile. Chromatographic separation was achieved on a Waters ACQUITY UPLC BEH C_(18) column using a 4-min gradient elution consisting of mobile phase A(0.1% formic acid in water) and mobile phase B(0.1% formic acid in acetonitrile), at a flow rate of 0.4 m L/min. Ceritinib and the internal standard([^(13)C_6]ceritinib) were monitored using multiple reaction monitoring mode under positive electrospray ionization. The lower limit of quantitation(LLOQ) was 1 n M of ceritinib in plasma. The calibration curve was linear over ceritinib concentration range of 1–2000 n M in plasma. The intra-and interday precision and accuracy were within the generally accepted criteria for bioanalytical method( o15%).The method was successfully applied to assess ceritinib brain tumor penetration, as assessed by the unbound drug brain concentration to unbound drug plasma concentration ratio, in patients with brain tumors. 展开更多
关键词 Ceritinib REVERSED-phase liquid chromatography with tandem mass spectrometry (LC–MS/MS) FRACTION unbound in PLASMA FRACTION unbound in BRAIN tissue BRAIN tumor penetration Unbound brain-to-plasma partition coefficient
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基于[bmim][BF_(4)]相转移催化的氟代碳酸乙烯酯高效合成 被引量:1
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作者 蒋方涛 钱刚 +2 位作者 周兴贵 段学志 张晶 《化工学报》 EI CSCD 北大核心 2024年第4期1543-1551,共9页
氟代碳酸乙烯酯(FEC)是锂电池电解液添加剂的重要组分之一,其工业制备方法主要为卤素交换法,即氯代碳酸乙烯酯(CEC)与氟化钾(KF)通过取代反应制备FEC。该工艺中,取代反应速率受限于KF相际传质速率,且CEC易发生消去反应生成碳酸亚乙烯酯... 氟代碳酸乙烯酯(FEC)是锂电池电解液添加剂的重要组分之一,其工业制备方法主要为卤素交换法,即氯代碳酸乙烯酯(CEC)与氟化钾(KF)通过取代反应制备FEC。该工艺中,取代反应速率受限于KF相际传质速率,且CEC易发生消去反应生成碳酸亚乙烯酯副产物。针对上述问题,研究了相转移催化剂(PTC)结构对KF相际传质速率和CEC制FEC主副反应能垒的影响规律和调控机制。优化条件下,PTC为[bmim][BF_(4)](1-丁基-3-甲基咪唑四氟硼酸盐),溶剂为乙腈,反应温度为乙腈回流温度(81.6℃),n(KF)∶n(CEC)=2.5∶1,此时FEC收率高达91.94%(摩尔分数)。密度泛函理论计算表明,在乙腈中[bmim][BF_(4)]能与KF形成配合物,增加K+和F-的核间距并降低KF的溶解自由能,从而强化相际传质并降低取代反应能垒,实现CEC经KF取代高效制备FEC。 展开更多
关键词 离子液体 相转移催化 配合物 传质 氟代碳酸乙烯酯 密度泛函理论
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亚毫米气泡和常规尺寸气泡气液两相流流动与传质特性对比 被引量:1
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作者 崔怡洲 李成祥 +4 位作者 翟霖晓 刘束玉 石孝刚 高金森 蓝兴英 《化工学报》 EI CSCD 北大核心 2024年第1期197-210,F0004,共15页
通过实验和数值模拟系统研究了亚毫米气泡鼓泡塔与常规鼓泡塔在流动和传质特性上的区别,并建立了适用于亚毫米气泡气液两相流流动和传质过程的数值模拟方法。研究结果表明,相比常规鼓泡塔,相同操作条件下亚毫米气泡鼓泡塔的气泡尺寸分... 通过实验和数值模拟系统研究了亚毫米气泡鼓泡塔与常规鼓泡塔在流动和传质特性上的区别,并建立了适用于亚毫米气泡气液两相流流动和传质过程的数值模拟方法。研究结果表明,相比常规鼓泡塔,相同操作条件下亚毫米气泡鼓泡塔的气泡尺寸分布更窄,平均尺寸降至前者3%左右,气含率提高2倍以上,比表面积提高2个数量级。另外亚毫米气泡气液两相流中气液径向分布更均匀,轴向返混程度更小。亚毫米气泡鼓泡塔的相界面积是强化传质的关键控制因素,其液相传质系数虽低于常规鼓泡塔,但依靠巨大的相界面积,其体积传质系数是常规鼓泡塔的10倍左右。针对大规模鼓泡塔反应器的模拟结果也表明,亚毫米气泡可使反应器达到更均匀的气含率分布,受初始气液分布的影响小。 展开更多
关键词 亚毫米气泡 鼓泡塔 气液两相流 传质 数值模拟 过程强化
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CO_(2)多气泡上升过程传质特性的数值分析
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作者 曾乐翔 裴东号 +1 位作者 王现刚 曹军 《化学工程》 CAS CSCD 北大核心 2024年第9期37-42,48,共7页
为了揭示CO_(2)多气泡上升行为和气液传质过程的相互作用机制,通过VOF(流体体积法)多相流模型结合自定义程序,实现气泡流动与传质的耦合,数值模拟结果表明:CO_(2)多气泡上升过程出现了聚并、破碎、自由上升和排斥等相互作用现象,气泡尾... 为了揭示CO_(2)多气泡上升行为和气液传质过程的相互作用机制,通过VOF(流体体积法)多相流模型结合自定义程序,实现气泡流动与传质的耦合,数值模拟结果表明:CO_(2)多气泡上升过程出现了聚并、破碎、自由上升和排斥等相互作用现象,气泡尾流经历对称脱落、过渡态和周期性脱落3个阶段,气泡初始间距、气泡初始大小和液相物性等因素共同影响着多气泡的运动和传质过程。初始间距较小时气泡易聚并,聚并过程减小了气液接触面积,不利于传质;初始直径较小时气泡运动越不稳定,停留时间长,可以促进气液传质;液相黏度越大阻力越大,抑制了气相在尾流的扩散,不利于传质。 展开更多
关键词 CO_(2)气泡 气液两相流 传质 数值模拟 聚并
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微通道内气液磺化及其传质特性研究
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作者 张坤 张鸿 +3 位作者 张玮 胡恒 于嘉朋 李耀 《现代化工》 CAS CSCD 北大核心 2024年第2期97-102,108,共7页
以气相SO3作磺化剂,设计了合成十二烷基苯磺酸(DBSA)的气液微磺化系统。依据响应面法分析各因素间交互作用;通过高速摄像机对微通道内伴有磺化反应的气液两相流型进行表征,并测量液膜厚度;通过湍流扩散系数考察湍流对传质的影响,并以此... 以气相SO3作磺化剂,设计了合成十二烷基苯磺酸(DBSA)的气液微磺化系统。依据响应面法分析各因素间交互作用;通过高速摄像机对微通道内伴有磺化反应的气液两相流型进行表征,并测量液膜厚度;通过湍流扩散系数考察湍流对传质的影响,并以此计算液相传质系数和Hatta数。结果表明,微通道内伴有反应气液两相呈带波浪环状流,液膜平均厚度在90~160μm之间;增加液相流量会增大湍流扩散系数,从而增大传质系数。同时,传质系数会随十二烷基苯(DDB)转化率的增加而显著降低,表明随着反应的进行,特别是在反应后期,反应产物将严重阻碍传质过程;此外,Hatta数计算结果表明,其值均大于3,表明微通道中磺化反应仍然是一个快速但受扩散控制的反应。 展开更多
关键词 微通道 气液磺化 传质特性 气液两相流型 十二烷基苯磺酸
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多孔板鼓泡塔流动与传质特性数值模拟
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作者 王娟 李秀明 +5 位作者 邵炜涛 丁续 霍莹 付连超 白云宇 李迪 《化工学报》 EI CSCD 北大核心 2024年第3期801-814,F0002,共15页
采用Euler-Euler双流体模型对安装不同数量的水平多孔板的鼓泡塔内气液两相流动及传质特性进行数值模拟研究,并探究了不同表观气速条件对鼓泡塔内气含率、气泡直径分布和气液传质系数的影响。结果表明,不同数量的多孔板和不同位置的多... 采用Euler-Euler双流体模型对安装不同数量的水平多孔板的鼓泡塔内气液两相流动及传质特性进行数值模拟研究,并探究了不同表观气速条件对鼓泡塔内气含率、气泡直径分布和气液传质系数的影响。结果表明,不同数量的多孔板和不同位置的多孔板都会影响气含率的分布;随着多孔板的数目增加,鼓泡塔液相上方区域的气含率增加,但影响区域有限;安装多孔板后,鼓泡塔内径向位置的平均气含率变化明显,出现“M”形状的分布。不同表观气速下,未安装多孔板的鼓泡塔内直径为1~2mm的微小气泡占比超过30%;安装多孔板后,微小气泡占比明显增加;气液传质系数在中心区域(径向无量纲为-0.5~0.5)较为平缓,波动不大。最后将模拟计算得到的气液体积传质系数与Akita的关联式计算值进行比较,本文计算结果略高。 展开更多
关键词 鼓泡塔 CFD-PBM模型 气泡直径 气含率 气液体积传质系数
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激光选区熔化制备梯度多孔镍电极及其电解水制氢性能
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作者 王见 宋嘉薇 +6 位作者 董东东 刘太楷 王先彬 闫星辰 毛杰 邓春明 张楠楠 《材料研究与应用》 CAS 2024年第3期487-494,共8页
镍是目前应用最广泛的碱式电解水制氢电极材料之一。对镍电极进行多孔化处理,可有效提高其析氢效率并降低制氢能耗。然而,现有报道仅研究了孔隙率、平均孔径等对电极析氢性能的影响,缺乏针对梯度多孔电极孔隙尺寸和分布等影响的研究。为... 镍是目前应用最广泛的碱式电解水制氢电极材料之一。对镍电极进行多孔化处理,可有效提高其析氢效率并降低制氢能耗。然而,现有报道仅研究了孔隙率、平均孔径等对电极析氢性能的影响,缺乏针对梯度多孔电极孔隙尺寸和分布等影响的研究。为此,设计了4组具有不同孔隙尺寸和排布方式的多孔电极模型,并且采用激光选区熔化技术制备高精度成型电极样品,表征了样品的表面形貌、截面微观组织、电化学性能及稳定性,深入分析和研究了样品的析氢性能。结果表明,4组样品均呈现出粗糙微观表面,为析氢反应提供更多的活性位点。所有样品均表现出优异的电解稳定性,经测试后未见明显的性能衰减。梯度多孔结构有利于气液传质,减小气泡层电阻,降低析氢过电位。当电流密度为10 mA∙cm^(−2)时,梯度多孔样品的析氢过电位虽仅为406 mV,但气液传质效果较差,而气泡层电阻较大的均匀多孔样品的析氢过电位却高达766 mV。梯度多孔结构的构筑可显著提高镍电极的析氢动力学特性,梯度多孔样品的Tafel斜率最低为129 mV∙dec^(−1),明显低于均匀多孔电极的Tafel斜率168和211 mV∙dec^(−1)。析氢过程受Volmer步骤控制,尽管镍电极析氢动力学特性得到提升,但并未改变镍电极的析氢机理,所有样品的Tafel斜率均高于120 mV∙dec^(−1)。因此,引入梯度多孔结构可有效降低镍电极材料的析氢过电位,提升析氢性能。本研究为镍电极的结构优化设计及析氢性能的提升,提供了新思路。 展开更多
关键词 碱式电解水 激光选区熔化 梯度多孔结构 孔隙尺寸 电解性能 析氢动力学 气液传质 析氢性能
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气液两相流对直接接触膜蒸馏传质强化和阻垢性能研究 被引量:1
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作者 邓会宁 马淑洁 +2 位作者 张伟 张忠明 张少峰 《天津大学学报(自然科学与工程技术版)》 EI CAS CSCD 北大核心 2023年第6期595-603,共9页
系统研究了气液两相流对板框式膜组件内直接接触膜蒸馏过程的传质强化特性和阻垢性能,结合对流道内气泡尺寸和流动特性的观察和定量分析,讨论了不同进料温度、进料浓度、进气流量和进料流量条件下鼓泡对膜蒸馏的传质强化效果.研究结果表... 系统研究了气液两相流对板框式膜组件内直接接触膜蒸馏过程的传质强化特性和阻垢性能,结合对流道内气泡尺寸和流动特性的观察和定量分析,讨论了不同进料温度、进料浓度、进气流量和进料流量条件下鼓泡对膜蒸馏的传质强化效果.研究结果表明:在相同鼓泡强度下,低进料温度和高进料浓度的系统由于温差极化和浓差极化更严重,鼓泡对传质的强化效果更显著;随着进气流量的增加,气泡尺寸增大,气泡的上升速度随气泡尺寸先增大后减小,对膜通量的提高比也先增加后减小.50~100 mm^(2)的气泡具有最快的上升速度,对膜面边界层扰动最强,传质强化效果最好;大于100 mm^(2)的气泡由于体积过大,受到来自隔网、壁面的阻力也会更大,导致气泡的上升速率减小,且过大的气泡尺寸使料液与膜壁接触面积减小,导致有效传质面积减小,强化效果减弱.随着进料流量提高,隔网对气泡的剪切作用增强,气泡变小,最佳进气流量增大.研究结果也表明鼓泡能提升高盐溶液浓缩过程的水通量,推迟晶体在膜面沉积发生的时间,显著减缓结垢层的增长速度.研究结果将为气液两相流对膜分离过程的传质强化研究提供重要参考. 展开更多
关键词 直接接触膜蒸馏 过程强化 气液两相流 极化现象 传质
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阵列凸起微通道内气液两相传质特性研究 被引量:3
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作者 何万媛 陈一宇 +3 位作者 朱春英 付涛涛 高习群 马友光 《化工学报》 EI CSCD 北大核心 2023年第2期690-697,共8页
研究了阵列凸起微通道内N-甲基二乙醇胺(MDEA)吸收CO_(2)过程的气液两相传质特性。在弹状流型下,考察了气液两相流量、MDEA浓度对体积传质系数、CO_(2)吸收效率、压力降以及能量损耗的影响。弹状气泡受到阵列凸起的挤压作用发生形变,促... 研究了阵列凸起微通道内N-甲基二乙醇胺(MDEA)吸收CO_(2)过程的气液两相传质特性。在弹状流型下,考察了气液两相流量、MDEA浓度对体积传质系数、CO_(2)吸收效率、压力降以及能量损耗的影响。弹状气泡受到阵列凸起的挤压作用发生形变,促进了气液两相间的传质。与平滑通道相比,阵列凸起微通道在实验条件下具有更好CO_(2)吸收效率。在相同的能量损耗时,阵列凸起微通道具有更大的体积传质系数。 展开更多
关键词 阵列凸起微通道 气液两相流 传质 吸收 CO_(2)
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基于R290工质的直接接触冷凝器内流动与传热数值研究
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作者 宁静红 杨挺然 +2 位作者 刘华阳 贾永勤 刘兴华 《绿色科技》 2023年第2期230-236,共7页
为探究直接接触冷凝器内传热传质特性,针对R290直接接触冷凝制冷系统中R290过热蒸气与R290过冷液直接接触冷凝过程,提出了3种不同尺寸的筒型正交混合式冷凝器,采用Fluent软件对其进行了气液两相热质传递的数值模拟。结果发现:在相同冷... 为探究直接接触冷凝器内传热传质特性,针对R290直接接触冷凝制冷系统中R290过热蒸气与R290过冷液直接接触冷凝过程,提出了3种不同尺寸的筒型正交混合式冷凝器,采用Fluent软件对其进行了气液两相热质传递的数值模拟。结果发现:在相同冷凝工况下,体积较小的A型冷凝器内部流型为环状流,体积较大的B、C型冷凝器内部流型为泡状流;A型冷凝器内几乎不发生传热传质;在产生泡状流的冷凝器中,冷凝器体积越大,传热传质效果越好;冷凝器体积传热系数随体积增大而减小;在相同冷凝热负荷的情况下,直接接触冷凝器所需换热面积仅为间壁式冷凝器的8%~14%。研究结果可为直接接触冷凝器设计优化提供可行方案。 展开更多
关键词 直接接触 冷凝器 气液两相流 传热传质
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生物反应器气液传质强化的研究进展 被引量:1
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作者 黎兴燕 甘建 +4 位作者 陈家俊 刘华宗 李干禄 李辉 陈可泉 《生物加工过程》 CAS 2023年第5期564-573,共10页
生物反应器是生物过程工程的核心设备,应用广泛,已实现了巨大的经济价值,但仍然存在较低的气液传质效率,这是降低生物转化效率的关键因素。本文综述了生物反应器中基于溶质渗透模型的传质机制及常用的体积传质系数(k_(L)a)测量方法,剖... 生物反应器是生物过程工程的核心设备,应用广泛,已实现了巨大的经济价值,但仍然存在较低的气液传质效率,这是降低生物转化效率的关键因素。本文综述了生物反应器中基于溶质渗透模型的传质机制及常用的体积传质系数(k_(L)a)测量方法,剖析了气含率(Φ)、气泡直径(d B)、扩散系数(D_(L))、湍动能耗散率(ε)、液相密度(ρ)、流体黏度(μ)以及表面张力(σ)等因素对k_(L)a的影响机制,论述了最新的气液传质强化方法及应用进展,以期为生物反应器的气液传质强化提供研究思路。 展开更多
关键词 生物反应器 传质强化 气液界面 体积传质系数 气液传质
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基于锂离子固相传质速率设计正极材料的技术研究
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作者 马洪运 刘承喆 +2 位作者 易阳 王睿 许刚 《电源技术》 CAS 北大核心 2023年第7期857-860,共4页
研究对比了不同形貌和不同尺度大小特征的高镍正极材料LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(简称NCM811)的电化学反应活性及锂离子固相传质速率性能,通过复配交换电流密度、固相传质系数和传质阻抗更相近的单晶颗粒和多晶大颗粒材料,使... 研究对比了不同形貌和不同尺度大小特征的高镍正极材料LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(简称NCM811)的电化学反应活性及锂离子固相传质速率性能,通过复配交换电流密度、固相传质系数和传质阻抗更相近的单晶颗粒和多晶大颗粒材料,使得材料整体的电化学反应速率和传质速率更加均匀。与目前常规的大、小颗粒多晶掺混方案相比,单晶颗粒和大颗粒多晶掺混方案的材料比容量发挥提升了1.3 mAh/g,同时该掺混方案的45℃的循环寿命得到明显提升,60℃下高温存储21 d内阻增长率降低1.85%,60℃高温存储30 d的残余容量保持率提高0.54%。基于相近的锂离子固相传质速率设计的单晶颗粒和大颗粒多晶两种正极材料进行掺混,可以克服材料整体的不均衡反应活性和材料稳定性引起的失效。 展开更多
关键词 固相传质系数 电化学反应活性 高镍正极材料 电化学性能
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被动式微混合器内液-液两相流的研究进展
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作者 王梦娜 张珂 +1 位作者 田晋平 李秉正 《山西化工》 CAS 2023年第7期13-15,共3页
微通道内的液-液两相流反应混合与传质效率高,反应速度快,同时可以有效控制化学反应过程,降低安全隐患。综述了被动式微混合器内液-液两相流的最新研究进展,两相流的混合与传质主要受流体物性、流速、微通道尺寸和几何特征的影响,在微... 微通道内的液-液两相流反应混合与传质效率高,反应速度快,同时可以有效控制化学反应过程,降低安全隐患。综述了被动式微混合器内液-液两相流的最新研究进展,两相流的混合与传质主要受流体物性、流速、微通道尺寸和几何特征的影响,在微通道内加入障碍物和凹槽,流体分流或引入二次流,可以有效改善液-液两相流的混合与传质。 展开更多
关键词 微通道 被动式微混合器 液-液两相流 混合 传质
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