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Effects of particle type on the particle fluidization and distribution in a liquid–solid circulating fluidized bed boiler

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Chinese Journal of Chemical Engineering 2023年第2期54卷 53-66页

作者： Feng Jiang Xiao Li guopeng qi Xiulun Li School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China School of Biological and Environmental Engineering Tianjin Vocational InstituteTianjin 300410China Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology Tianjin UniversityTianjin 300350China

A liquid-solid circulating fluidized bed boiler is designed and built for visualization research by applying the fluidized bed heat transfer and fouling prevention technology to the water side of the boiler. Four types of engineering plastic particles with different physical properties are selected as the solid working media. The effect of particle types on the fluidization and distribution of particles in the boiler is investigated under different feedwater flow rates and amount of added particles by using the charge couple device image measurement and acquisition system. The results show that all kinds of particles can't be normally fluidized and accumulate in the drum at low amount of added particles and feedwater flow rate. The particles with great density and low sphericity are more likely to accumulate. The average solid holdup in the riser tubes increases with the increase in feedwater flow rate and the amount of added particles. The non-uniform degree of particle distribution in the riser tubes generally decreases with the increase in feedwater flow rate and the amount of added particles. The particles with small density and settling velocity have high average solid holdup in the riser tubes under close sphericity. In generally,the smaller the density and settling velocity, the more uniform the particle distribution in the riser ***-dimensional diagrams of the non-uniform degree of particle distribution in the riser tubes of the boiler are established.

关键词： Circulating fluidized bed boiler Particle type Particle distribution Visualization Fouling prevention

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Particle collision behavior and heat transfer performance in a Na_(2)SO_(4) circulating fluidized bed evaporator

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Chinese Journal of Chemical Engineering 2022年第6期35卷 40-52页

作者： Feng Jiang Di Xu Ruijia Li guopeng qi Xiulun Li School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology Tianjin UniversityTianjin 300350China School of Biological and Environmental Engineering Tianjin Vocational InstituteTianjin 300410China

The particle collision behavior and heat transfer performance are investigated to reveal the heat transfer enhancement and fouling prevention mechanism in a Na_(2)SO_(4) circulating fluidized bed *** particle collision signals are analyzed with standard deviation by varying the amount of added particles ε(1%–3%),circulation flow velocity u(0.37–1.78 m·s^(-1)),and heat flux q(7.29–12.14 kW·m^(-2)).The results show that the enhancement factor reach up to 14.6%by adding polytetrafluoroethylene particles at ε=3%,u=1.78 m·s^(-1),and q=7.29 kW·m^(-2).Both the standard deviation of the particle collision signal and enhancement factor increase with the increase in the amount of added *** standard deviation increases with the increase in circulation flow velocity;however,the enhancement factor initially decreases and then *** standard deviation slightly decreases with the increase in heat flux at low circulation flow velocity,but initially increases and then decreases at high circulation flow *** enhancement factor decreases with the increase in heat *** enhancement factor in Na_(2)SO_(4) solution is superior to that in water at high amount of added *** empirical correlation for heat transfer is established,and the model results agree well with the experimental data.

关键词： Heat transfer enhancement Particle collision behavior Circulating fluidized bed Evaporation Na2SO4 Standard deviation

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Effect of Flow Directions on Multiphase Flow Boiling Heat Transfer Enhanced by Suspending Particles in a Circulating Evaporation System

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Transactions of Tianjin University 2019年第3期25卷 201-213页

作者： Feng Jiang Teng Jiang guopeng qi Xiulun Li School of Chemical Engineering and Technology Tianjin University School of Biological and Environmental Engineering Tianjin Vocational Institute

A circulating fluidized bed evaporator(including down-flow, horizontal, and up-flow beds) was constructed to study the effect of flow directions on multiphase flow boiling heat transfer. A range of experimental investigations were carried out by varying amount of added particles(0-2%), circulation flow rate(2.15-5.16 m^3/h) and heat flux(8-16 kW/m^2). The comparison of heat transfer performance in different vertical heights of the horizontal bed was also discussed. Results reveal that the glass bead particle can enhance heat transfer compared with vapor-liquid two-phase flow for all beds. At a low heat flux(q = 8 kW/m), the heat-transfer-enhancing factor of the horizontal bed is obviously greater than those of the up-flow and down-flow beds. With the increase in the amount of added particles, the heat-transfer-enhancing factors of the up-flow and down-flow beds increase, whereas that of the horizontal bed initially increases and then decreases. However, at a high heat flux(q=16 kW/m), the heat-transfer-enhancing factors of the three beds show an increasing tendency with the increase in the amount of added particles and become closer than those at a low heat flux. For all beds, the heat-transfer-enhancing factor generally increases with the circulation flow rate but decreases with the increase in heat flux.

关键词： Heat transfer enhancement Circulating fluidized bed evaporator Flow direction Down-flow bed Up-flow bed Horizontal bed

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Pressure Drop of Liquid–Solid Two-Phase Flow in the Vertical Tube Bundle of a Cold-Model Circulating Fluidized Bed Evaporator

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Transactions of Tianjin University 2019年第6期25卷 618-630页

作者： Feng Jiang Siyao Lv guopeng qi Xiaoling Chen Xiulun Li School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China School of Biological and Environmental Engineering Tianjin Vocational InstituteTianjin 300410China

A cold-model vertical multi-tube circulating fluidized bed evaporator was designed and built to conduct a visualization study on the pressure drop of a liquid–solid two-phase flow and the corresponding particle *** and polyformaldehyde particle(POM)were used as the liquid and solid phases,*** effects of operating parameters such as the amount of added particles,circulating flow rate,and particle size were systematically *** results showed that the addition of the particles increased the pressure drop in the vertical tube *** maximum pressure drop ratios were 18.65%,21.15%,18.00%,and 21.15%within the experimental range of the amount of added particles for POM1,POM2,POM3,and POM4,*** pressure drop ratio basically decreased with the increase in the circulating flow rate but fluctuated with the increase in the amount of added particles and particle *** difference in pressure drop ratio decreased with the increase in the circulating flow *** the amount of added particles increased,the difference in pressure drop ratio fluctuated at low circulating flow rate but basically decreased at high circulating flow *** pressure drop in the vertical tube bundle accounted for about 70%of the overall pressure drop in the up-flow heating chamber and was the main component of the overall pressure within the experimental ***-dimensional phase diagrams were established to display the variation ranges of the pressure drop and pressure drop ratio in the vertical tube bundle corresponding to the operating *** research results can provide some reference for the application of the fluidized bed heat transfer technology in the industry.

关键词： Pressure drop Liquid-solid two-phase flow Circulating fluidized bed evaporator Vertical tube bundle Heat transfer enhancement Fouling prevention Descaling

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Heat Transfer Characteristics and Pressure Drop in a Horizontal Circulating Fluidized Bed Evaporator

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Transactions of Tianjin University 2021年第6期27卷 487-504页

作者： Xu Liang Feng Jiang guopeng qi Jinjin Wang Xinhua Dong Wenyue Jing Ruijia Li Xiulun Li School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China School of Biological and Environmental Engineering Tianjin Vocational InstituteTianjin 300410China

A vapor-liquid-solid horizontal circulating fluidized bed evaporation setup was constructed to study the thermal-exchange properties and pressure *** influences of the operating variables,including the amount of added particles,heat flux,and circulating flow velocity,were systematically inspected using resistance temperature detectors and pressure *** results showed that the heat transfer eff ect was improved with the increase in the amount of added particles,circulating flow velocity,and particle diameter,but decreased with increasing heat *** pressure drop fluctuated with the increase in operating parameters,except circulating flow *** enhancing factor reached up to 71.5%.The enhancing fac-tor initially increased and then decreased with the increase in the amount of added particles and circulating flow velocity,fluctuated with increasing particle diameter,and decreased with increasing heat *** diagrams showing the variation ranges of the operation variables for the enhancing factor were constructed.

关键词： Heat transfer characteristics Pressure drop Horizontal circulating fluidized bed evaporator Vertical heights Fouling prevention and removal

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Alkylation mechanism of benzene with 1-dodecene catalyzed by Et_3NHCl-AlCl_3

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Science China Chemistry 2010年第5期53卷 1101-1106页

作者： qi guopeng 1,JIANG Feng 1,SUN XueWen 2 & ZHAO Suoqi 2 1School of Chemical Engineering,Tianjin University,Tianjin 300072,China 2State key Laboratory of Heavy Oil Processing,Petroleum University of China,Beijing 102249,China School of Chemical Engineering Tianjin University Tianjin China State key Laboratory of Heavy Oil Processing Petroleum University of China Beijing China

The isotope exchange method was employed to investigate the catalytic mechanism of ionic liquid in alkylation of benzenes with *** is proposed that alkylation was induced by the Lewis acid AlCl3 which attracted π electrons of 1-dodecene to shift toward 1-carbon,thus forming a carbonium *** carbonium ion further reacted with benzenes to form a *** to unstabilit of the complex,a deuterated ring proton was transferred into an electronegative 1-carbon of the side chain to substitute for the AlCl3,accordingly 2-phenyldodecane was generated.

关键词： ionic liquid alkylation mechanism deuteriobenzene isotope exchange method

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[Bmim]Br-AlCl_3催化苯与1-十二烯烃烷基化反应机理的研究

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有机化学 2009年第12期29卷 1963-1968页

作者：齐国鹏孙学文赵锁奇天津大学化工学院天津300072 中国石油大学(北京)重质油加工实验室北京102249

利用同位素取代法考察了[Bmim]Br-AlCl3催化苯与1-十二烯烃烷基化反应机理.首先进行了[Bmim]Br-AlCl3催化氘代苯与1-十二烯烃的反应,通过GC-MS及NMR分析产物十二烷基苯同分异构体的结构,验证了氘原子与产物侧链1-位碳相连的结论.示踪氘... 详细信息

利用同位素取代法考察了[Bmim]Br-AlCl3催化苯与1-十二烯烃烷基化反应机理.首先进行了[Bmim]Br-AlCl3催化氘代苯与1-十二烯烃的反应,通过GC-MS及NMR分析产物十二烷基苯同分异构体的结构,验证了氘原子与产物侧链1-位碳相连的结论.示踪氘原子推导了烷基化反应机理,结果表明:[Bmim]Br-AlCl3催化苯与长链烯烃的烷基化反应是由[Al2Cl6Br]-发生平衡移动,生成Lewis酸AlCl3引发的;AlCl3吸电子作用使1-十二烯烃的π电子向1-碳转移,在烯烃的2-碳上形成正电荷中心,碳正离子与苯发生亲电反应生成不稳定的σ络合物,与σ络合物环上的σ-C相连的D+转移到负电的侧链1-C上形成C—D键,AlCl3离去,生成产物2-十二烷基苯.Lewis酸催化机理为离子液体催化苯与长链烯烃的反应中,2-十二烷基苯选择性高于H质子催化产物提供了理论依据.

关键词：氘代苯离子液体烷基化反应机理

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CO_2介质中离子液体催化苯与1-十二烯烃连续式反应

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化学反应工程与工艺 2008年第4期24卷 323-327页

作者：齐国鹏赵锁奇孙学文中国石油大学重质油加工国家重点实验室北京102249

为了解决离子液体催化苯与长链烯烃连续式反应中离子液体相与反应液相互溶性差的问题,在[Bmim]Br-AlCl_3催化苯与1-十二烯烃连续式反应中引入了 CO_2作为反应介质,并考察了 CO_2-苯-1-十二烷基苯-[Bmim]Br-AlCl_3四元物系的相平衡和 CO_... 详细信息

为了解决离子液体催化苯与长链烯烃连续式反应中离子液体相与反应液相互溶性差的问题,在[Bmim]Br-AlCl_3催化苯与1-十二烯烃连续式反应中引入了 CO_2作为反应介质,并考察了 CO_2-苯-1-十二烷基苯-[Bmim]Br-AlCl_3四元物系的相平衡和 CO_2压力、温度、空时和苯烯比对烷基化反应的影响。结果表明,在30～60℃,7.90～8.10 MPa 的条件下,反应物在离子液体相与反应液相浓度分布均一,有利于提高烯烃的转化率。提高苯烯比对改善单取代烷基苯产率的作用明显。在60℃,8.10 MPa 和空时为2 min的条件下,苯烯物质的量之比为2时,单取代十二烷基苯产率最高为59.2%,苯烯物质的量之比为12时,单取代烷基苯的产率为85.9%。

关键词：离子液体苯 1-十二烯烃二氧化碳连续式反应

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离子液体-银纳米粒子修饰电极的制备及其在测定维生素C中的应用

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理化检验（化学分册） 2017年第6期53卷 664-668页

作者：齐国鹏姜峰天津职业大学生物与环境工程学院天津300410 天津大学化工学院天津300072

分别制备了离子液体[BMIM]BF4和银纳米粒子(AgNPs),并配制1.5 mol·L^(-1)AgNPs溶液,将上述离子液体与AgNPs溶液按4∶96的体积比混合后滴于经抛光的玻碳电极(GCE)上,将此经修饰的电极置于30℃真空干燥5 min,即得[BMIM]BF4-AgNPs/GCE修... 详细信息

分别制备了离子液体[BMIM]BF4和银纳米粒子(AgNPs),并配制1.5 mol·L^(-1)AgNPs溶液,将上述离子液体与AgNPs溶液按4∶96的体积比混合后滴于经抛光的玻碳电极(GCE)上,将此经修饰的电极置于30℃真空干燥5 min,即得[BMIM]BF4-AgNPs/GCE修饰电极。对此修饰电极的电化学特性以及维生素C(Vc)在此电极上的电化学行为作了研究。结果表明:用上述修饰电极作为工作电极,SCE为参比电极,Pt电极为辅助电极,方波伏安法测定Vc时,Vc浓度在5~100μmol·L^(-1)内与相应的峰电流值之间呈线性关系,测定的灵敏度为0.4μA·μmol^(-1)。应用此方法测定了Vc片剂中Vc的含量,测定值与文献值一致,测定值的相对标准偏差(n=5)小于2.0%。

关键词：银纳米粒子离子液体修饰电极维生素C

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银纳米粒子复合材料在电化学传感器中的应用研究进展

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化工新型材料 2017年第9期45卷 12-13,16页

作者：齐国鹏姜峰天津职业大学生物与环境工程学院天津300410 天津大学化工学院天津300072

银纳米粒子具有良好的传导性、大的比表面积及优良的生物兼容性,成为近年来研究的热点。由于银纳米粒子能够提高电子的迁移速率,改善传感器的灵敏度,已被广泛应用于电化学传感器的开发中。银纳米粒子与石墨碳、金属纳米粒子及大分子物... 详细信息

银纳米粒子具有良好的传导性、大的比表面积及优良的生物兼容性,成为近年来研究的热点。由于银纳米粒子能够提高电子的迁移速率,改善传感器的灵敏度,已被广泛应用于电化学传感器的开发中。银纳米粒子与石墨碳、金属纳米粒子及大分子物质结合开发的新型复合材料不仅兼具了银纳米粒子的特点,同时使材料具备了复合物的优良性能,拓宽了新型复合材料在电化学分析中的应用。

关键词：银纳米粒子纳米复合材料电化学传感器

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