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1.
蒋小华  王玮  宫敬 《化工学报》2008,59(3):721-727
以渤海SZ36-1稠油、矿化水为工质配制了2组不同液滴直径的W/O型乳状液,研究了温度、含水率、剪切率和液滴直径对乳状液黏度的影响。结果表明,温度对乳状液表观黏度的影响非常明显,而对相对黏度的影响却较小;同时含水率、剪切率和液滴直径也是影响乳状液黏度的重要因素,低含水率下,剪切率、液滴直径对黏度的影响不明显,而当含水率较高时,剪切率、液滴直径的影响非常突出,乳状液呈现出强烈的剪切稀释特性。利用国内外现有的一些黏度模型对实验获得的黏度数据进行了预测分析,发现Brinkman(1952)模型具有较好的预测精度。  相似文献   

2.
以棉籽油生物柴油(CSME)为原料测定其化学组成,与0号柴油(0PD)调合,研究CSME及其调合油的低温流动性能,并添加FlowFit改善CSME及其调合油的低温流动性.研究表明,CSME主要由脂肪酸甲酯组成,其中饱和脂肪酸甲酯和不饱和脂肪酸甲酯的质量分数分别为27.69%和71.65%,冷滤点(CFPP)为-1℃,40℃时运动黏度为4.63 mm2/s;在CSME调合比例为50%时,调合油的CFPP降至-8 ℃,且在相同温度下调合油的运动黏度均低于CSME.添加Flow Fit能显著改善CSME及调合油的低温流动性能,在添加Flow Fit体积分数不超过3%时,CSME、B50、B20、B10、B7、B5分别从-1,-8,-5,-4,-3,-3 ℃降低到-5,-16,-25,-24,-25,-23 ℃.  相似文献   

3.
高导热低黏度环氧树脂灌封胶   总被引:1,自引:0,他引:1  
以E-51型环氧树脂为基体,Al2O3为导热填料,CYH-277为稀释剂制备高导热低黏度环氧树脂灌封胶。优化了硅烷偶联剂KH-560、稀释剂CYH-277的用量;分别采用NDJ-7型旋转式黏度计和Hot Disk型热常数分析仪测试其黏度和导热系数。结果表明:硅烷偶联剂KH-560用量为1.25%(wt)时效果最优;随CYH-277用量的增加灌封胶黏度、耐热性能均逐渐下降,最佳用量为25%(wt);随Al2O3用量增加,灌封胶的黏度、导热系数均增大;用量相同时,填充20μm Al2O3的树脂体系相比于填充6μm Al2O3树脂体系黏度小、导热系数大,复配两种粒径Al2O3对应树脂体系的导热性最好;复配Al2O3用量为86%(wt)时,导热系数达到2.23W/(m·K),此时灌封胶的黏度为30100mPa·s,仍保持较好的加工流动性。  相似文献   

4.
采用两步法制备体积分数为0.005%~1%的Al2O3-TiO2-Cu/水三元混合纳米流体,粒子体积比为40∶40∶20。为了提高其稳定性,添加少量的PVP(0.005%)表面活性剂,并用XRD、TEM、紫外分光光度计和沉淀观察法共同表征纳米流体的稳定特性。测量温度为20~60℃的黏度和热导率,并与相对应的单一纳米流体作对比。试验结果表明,三元混合纳米流体由于各种粒子的粒径和表面能不同,小粒径的Al2O3颗粒填充在大粒径TiO2和Cu颗粒形成的间隙里,可形成致密的固液界面层。三元混合纳米流体由于粒子的特殊排布,使其热导率明显高于相同体积分数下对应的单一纳米流体,黏度却无明显增大。当体积分数和温度分别为1%和60℃时,与Al2O3/水纳米流体对比,其热导率增大了5.5%,黏度下降了2.6%。热导率随温度和浓度的升高而升高;而黏度随浓度的升高而升高,随温度的升高而下降,这与单一纳米流体的性质一致。最后,基于试验数据,对热导率和黏度分别进行与温度的拟合,R2分别为0.9835和0.9820,能较精确地预测Al2O3-TiO2-Cu/水三元混合纳米流体的热导率和黏度。  相似文献   

5.
氧化铝有机纳米流体的流动传热基础特性   总被引:1,自引:0,他引:1       下载免费PDF全文
钟勋  俞小莉  吴俊 《化工学报》2009,60(1):35-41
以氧化铝为纳米粒子、丙二醇和水为基础液体制备了氧化铝有机纳米流体,分别测量了它的沸点、热导率、比热容和黏度。以1%~5%(体积分数)的氧化铝纳米流体作为冷介质,测试了在车用机油冷却器中的传热系数和流动阻力。试验结果表明,纳米粒子能够显著强化基础液体在机油冷却器中的换热能力,粒子体积分数和流体温度是影响纳米流体热物性的重要因素。氧化铝纳米流体的沸点高于120℃,比热容随体积分数增加而降低,热导率、黏度和在机油冷却器中的传热系数均随粒子体积分数的增加而提高。在试验Ⅱ中,5%(体积分数)纳米流体的平均传热系数比基础液体提高了124.56%,而流动阻力增幅较小。  相似文献   

6.
The accurate prediction of the viscosity of emulsions is highly important for oil well exploitation. Commonly used models for predicting the viscosity of water‐in‐oil (W/O) emulsions composed by two or three factors cannot always fit well the viscosity of W/O emulsions, especially in the case of non‐Newtonian W/O emulsions. An innovative and comprehensive method for predicting the viscosity of such emulsions was developed based on the Lederer, Arrhenius, and Einstein models, using experimental data. Compared with the commonly applied W/O emulsion viscosity models, the proposed method considers more factors, including temperature, volume fraction of water, shear rate, and viscosity of the continuous (oil) and dispersed phase (water). Numerous published data points were collected from the literature to verify the accuracy and reliability of the method. The calculation results prove the high accuracy of the model.  相似文献   

7.
研究了乙醇回流法提取银杏叶总黄酮的工艺条件。通过单因素实验考察料液比、乙醇体积分数、提取时间、提取温度对银杏叶总黄酮提取率的影响,通过正交实验确定优化的提取工艺条件为:料液比1∶45(g∶mL)、乙醇体积分数50%、提取时间2.0h、提取温度70℃,在此条件下,银杏叶总黄酮提取率为0.918%。以优化的工艺条件为基础进一步运用微波辅助提取银杏叶总黄酮,发现在微波功率为640W时,采用间歇式提取,提取时间为15×10s,总黄酮提取率达到0.91%,接近传统方法提取3h的提取率。  相似文献   

8.
《Applied Clay Science》1999,14(1-3):83-103
Bentonites, montmorillonites, and hectorites were used as colloidal stabilizers of oil-in-water (O/W) emulsions. The enrichment of the solid particles on the oil–water interface was attained by the addition of nonionic coemulsifiers (glycerol monostearate (GMS), deca(ethylene glycol) hexadecyl ether, alkyl polyglucoside, and lecithin). The clay mineral content of the aqueous dispersion was 2% (w/w). Stable emulsions required amounts of 0.5–1.5 g coemulsifier per 100 ml aqueous dispersion. Oil volume fraction was varied between φ=0.17 and φ=0.50. At φ>0.50 the O/W emulsions changed into water-in-oil (W/O) emulsions. The number average diameter of the droplets was about 25 nm. The volume average diameter (50–100 nm) more strongly depended on the clay mineral/coemulsifier combinations. Wyoming bentonite and the corresponding delaminated sodium montmorillonite were useful stabilizers; technical, soda-activated bentonites yielded unstable emulsions, or emulsification was not successful. A synthetic hectorite which caused pronounced thickening of the coherent phase was an effective stabilizer. Creaming was often observed because of the buoyancy of the large droplets. Most of the creamed emulsions were stable over long periods and did not separate an oil phase. The resistance against creaming increased with the oil volume fraction. An increase of the solid content had to be accompanied by an increase of the coemulsifier concentration to reduce the rate of creaming.  相似文献   

9.
孤岛原油乳状液稳定性影响因素研究   总被引:4,自引:1,他引:4  
通过乳状液稳定性实验考察了孤岛原油乳状液稳定性影响因素。结果表明,低剪切作用下,部分水解聚丙烯酰胺(HPAM)与原油作用1d和54d,所测得其浓相体积分数很快接近零,即HPAM与原油所形成的乳状液稳定性较低。而当溶液中存在50μg/g固体颗粒蒙脱土时,测得其与原油作用1d和54d后的浓相体积分数都约0.08。当溶液中同时含有固体颗粒与HPAM时,测得其与原油作用后所形成的乳状液浓相体积分数很快达到零,固体颗粒与HPAM的协同作用对原油乳状液稳定性有较大影响。另外,随着盐浓度、温度的增加,孤岛原油所形成的乳状液稳定性降低。在30000r/min高速剪切作用下,测得聚合物、固体颗粒模拟水体系与原油间所形成的乳状液浓相体积分数约为0.3,可形成较稳定的乳状液。  相似文献   

10.
The silicon carbide whisker (SiCw) and silicon carbide particle (SiCp) were employed to prepare polystyrene/silicon carbide whisker/silicon carbide particle (PS/SiCw/SiCp) thermal conductivity composites, and the titanate coupling reagent of NDZ‐105 was introduced to functionalize the surface of fillers. The thermal conductive coefficient λ improved from 0.18 W/mK for native PS to 1.29 W/mK for the composites with 40% volume fraction of SiCw/SiCp (volume fraction, 3 : 1) hybrid fillers. Both the thermal decomposition temperature and dielectric constant of the composites increased with the addition of SiCw/SiCp hybrid fillers. At the same addition of SiCw/SiCp hybrid fillers, the surface modification of hybrid fillers by NDZ‐105 could improve the thermal conductivity and the mechanical properties of the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

11.
应用LVDV-Ⅲ+型可编程流变仪测定了粒度分布与微米级氧化铁水悬浮液凝聚处理后的流变特性的关系。实验结果表明,在一定的固相体积分数下,悬浮液的表观粘度随悬浮液中颗粒中位径的增大而减小。颗粒半径越小,溶剂化导致的体积增加越多,颗粒在悬浮体系中所占的体积分数也越大,结果是运动阻力增大,悬浮液粘度增加。悬浮液固相体积分数从3...  相似文献   

12.
张辛铖  何林  隋红  李鑫钢 《化工进展》2022,41(7):3534-3544
重质油包水(W/O)乳液普遍存在于石油开采与加工过程中,因其高黏度、高密度、强界面稳定特性,导致重质油包水乳液分离困难,生产成本增加。为了提高重质W/O乳液的分离效率,本文探究了温度与甲苯加入量对重质油黏度的影响规律。在此基础上,研究了上述降黏过程与脱水率之间的协同机制。采用自制的TJU-3破乳剂对重质W/O乳液进行破乳,通过调整破乳剂在乳液中的浓度和破乳温度得到了最佳工艺条件。利用分子模拟的方法构建了重质油平均分子模型并计算了SARA四组分在不同甲苯含量的重质油中的扩散系数,分析了甲苯添加量对重质油中SARA四组分相互作用的影响规律,研究了沥青质分子和TJU-3破乳剂分子在油水界面的运移过程。结果表明:重质油的黏度降低到1500mPa·s时,可实现在1h内完全破乳;黏度降低到50mPa·s时可实现在20min内完全破乳。当破乳剂在乳液中的浓度为400mg/L时,乳液的脱水率最高;破乳温度为60℃时,破乳速度最快。SARA四组分中胶质的扩散系数增大最显著,是重质油的黏度能被甲苯迅速降低的主要原因。TJU-3分子能够破坏沥青质界面膜,进而实现破乳。该协同机制和工艺条件可为石油工业中重质W...  相似文献   

13.
注凝成型微孔梯度陶瓷材料制备新工艺的研究(Ⅰ)   总被引:15,自引:1,他引:14  
本文采用90年代初发明的注凝成型技术制备微孔梯度陶瓷材料。研究低粘度的Al2O3(不同粒度)和高温粘结剂混合物的浆料的制备方法;并以调整浆料的流变性为重点,研究了pH值、分散剂、固体含量、高温粘接剂、颗粒度对浆料粘度的影响。通过上述各种影响因素的工艺优化制备出了低粘度(0.364Pa*s)、高固体含量(体积分数为50%~54%)的Al2O3(W0.5,W1,W7和W10)浆料。  相似文献   

14.
制备以SiO_2-Al_2O_3为载体、W为活性组分的加氢精制W/SiO_2-Al_2O_3催化剂,并考察了温度、氢压、氢油体积比和空速的影响。研究了在W/SiO_2-Al_2O_3催化剂作用下,润滑油基础油的加氢精制效果。结果表明,在精制温度260℃、氢压9.0 MPa、氢油体积比700:1和空速1.25 h^(-1)条件下,氮含量从63.4μg·g^(-1)降至0.9 μg·g^(-1),硫含量从110.2μg·g^(-1)降至0.32 μg·g^(-1),液体油收率92.7%,运动黏度、闪点、凝点与原料油相比变化不大,加氢精制效果较理想。  相似文献   

15.
Preparation of alumina by aqueous gelcasting   总被引:6,自引:0,他引:6  
The alumina ceramic was prepared by aqueous gelcasting. The effects of zeta potentials, solid loading, dispersant content and milling time on the alumina suspension were studied systematically. The dispersant content has remarkable effects on the viscosity of the suspension. The appropriate dispersant concentration for alumina aqueous slurry with the solid loading of 55 vol.% is 0.6 wt.%. It can be seen that all suspensions (50–56 vol.% solid loading) exhibited a shear-thinning behavior and relatively low viscosity, which was suitable for casting. The degree of shear thinning and the viscosity at high shear rates increased with increasing volume fraction of solid. As the milling time prolongs, viscosity of the suspension decreases first, then the plateau appears and the average diameter keeps changeless. When the milling time was shorter than 20 h, the viscosity of slurries decreased gradually as the time of milling increased. After 20 h milling, the viscosity of the slurry tended to be consistent. Therefore, the ball milling time should be equal to or more than 20 h to obtain a stable suspension at equilibrium. The time available for casting the slurry (idle time) can be controlled by the amounts of initiator and catalyst added to the slurry as well as by the processing temperature. Micrograph of the gelcast green body was homogeneous.  相似文献   

16.
将碱法制浆黑液与稠油混合,可明显降低稠油的粘度.用均匀设计法设计试验,讨论了黑液浓度、稠油酸值、水油比(体积)、温度及水的矿化度对稠油降粘作用的影响.结果表明,黑液浓度为5%~15%,酸值为3~4.5mg/g(KOH/油)时,体系粘度最低,在试验范围内,水油比越大,温度越高,矿化度越小体系的粘度越低.  相似文献   

17.
研究了以D-葡萄糖酸钠作为晶形控制剂、石灰乳液碳化法制备类球状纳米碳酸钙的工艺条件,以及十二烷基磺酸钠为改性剂的湿法改性工艺条件。XRD,TEM等表征结果表明:在温度50℃、搅拌转速800 r/min、晶形控制剂质量分数1.5%、Ca(OH)2初始质量分数7%、CO2气体流速60 mL/min时,制备的纳米碳酸钙样品属于方解石型六方晶系,形貌类似球状,粒径均匀(50~100 nm)。吸油量测定结果表明:在改性剂质量分数3.5%、改性温度70℃、改性时间50 min时,改性所得样品吸油量(以100 g计)约44 mL,符合国家工业碳酸钙行业标准(GB/T 19281—2003《碳酸钙分析方法》)一等品的要求[吸油量(以100 g计)小于60 mL]。  相似文献   

18.
In this paper we have tried to build effective model for classification of motor oils by base stock and viscosity class. Three (3) sets of near infrared (NIR) spectra (1125, 1010, and 1050 spectra) were used for classification of motor oils into 3 or 4 classes according to their base stock (synthetic, semi-synthetic, and mineral), kinematic viscosity at low temperature (SAE 0W, 5W, 10W, and 15W) and kinematic viscosity at high temperature (SAE 20, 30, 40, and 50). The abilities of three (3) different classification methods: regularized discriminant analysis (RDA), soft independent modelling of class analogy (SIMCA), and multilayer perceptron (MLP) - were also compared. In all cases NIR spectroscopy was found to be quite effective for motor oil classification. MLP classification technique was found to be the most effective one.  相似文献   

19.
崔洁  郑晓园  金余其  马晓军  郑耀根 《化工学报》2015,66(11):4380-4387
利用HAKKE VT550旋转黏度计对罐底油泥的黏度特性进行了研究,筛选出合适的黏度模型,分析比较了加热(20~60℃)、添加表面活性剂(曲拉通X-100)水溶液(质量分数为0.5%)和添加溶剂(正戊醇和120#溶剂油)对油泥黏度的影响。结果表明,由于罐底油泥包含大量固体颗粒,在0~600 s-1剪切速率范围内,具有塑性流体和假塑性流体的双重特性,Casson模型为最适合的黏度模型,拟合决定系数为0.986。在3种降黏措施中,将样品加热至50℃与20℃下添加质量分数为10%的表面活性剂水溶液均可使油泥黏度下降50%,样品流型向假塑型转变。掺入溶剂的降黏效果优于前两者,最佳效果为在20℃、300 s-1剪速下,添加质量分数为10%的120#溶剂油,黏度下降达90%,样品流型向牛顿型转变。  相似文献   

20.
贾振梅  陈双俊  金宇  张军 《橡胶工业》2012,59(7):423-427
制备耐油室温硫化(RTV)硅橡胶,并对其性能进行研究。耐油RTV硅橡胶优化制备条件为:端乙烯基硅油(粘度为1.5Pa·s)/支链型乙烯基硅油(粘度为4.8Pa·s)用量比100/20,含氢硅油(氢质量分数为0.01)/乙烯基摩尔比2,白炭黑/云母用量比15/15。采用该条件制备的RTV硅橡胶物理性能和耐油性能良好。  相似文献   

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