化工学报 ›› 2022, Vol. 73 ›› Issue (6): 2622-2635.DOI: 10.11949/0438-1157.20211427
收稿日期:
2021-10-08
修回日期:
2022-01-11
出版日期:
2022-06-05
发布日期:
2022-06-30
通讯作者:
刘梦溪
作者简介:
牛犁(1993—),女,博士,工程师,基金资助:
Li NIU1(),Mengxi LIU2(),Haibei WANG1
Received:
2021-10-08
Revised:
2022-01-11
Online:
2022-06-05
Published:
2022-06-30
Contact:
Mengxi LIU
摘要:
在一套流化床冷模实验装置中对黄沙颗粒和黄沙-硅微粉 (20 μm)混合颗粒进行实验。测量固含率时间序列信号并进行统计分析,提出并建立复杂光纤脉动信号的解耦方法,实现稠密气固流中介尺度流动结构的准确识别。基于统计矩一致性原理提出气泡阈值的计算方法,通过遍历法确定气泡阈值。对气泡阈值变化规律进行分析,发现加入细颗粒有助于改善流化质量,随表观气速的增加,气泡阈值减小。对气泡、乳化和聚团三相的相分率进行统计,发现在黄沙颗粒中加入少量(5%,质量分数)细颗粒能够显著改善流化质量,细颗粒添加量过多时(10%),对流化质量的改善将减弱。对气泡的流体力学特性进行分析,发现加入10%硅微粉后,气泡弦长增大,频率降低,速度略有降低。对颗粒聚团流体力学特性进行分析,发现随硅微粉含量增加,表观气速对聚团速度的影响减弱,聚团弦长略有减小。加入5%硅微粉后,颗粒聚团的出现频率较小且径向上分布均一。加入10%硅微粉后,聚团频率有所增大,说明加入过多硅微粉会促进聚团的形成。
中图分类号:
牛犁, 刘梦溪, 王海北. 密相流化床中介尺度流动结构的流体力学特性研究[J]. 化工学报, 2022, 73(6): 2622-2635.
Li NIU, Mengxi LIU, Haibei WANG. Hydrodynamic of mesoscale flow structure in dense phase fluidized bed[J]. CIESC Journal, 2022, 73(6): 2622-2635.
颗粒种类 | 平均粒径/μm | 堆积密度/(kg/m3) | 颗粒密度/(kg/m3) |
---|---|---|---|
黄沙 | 385 | 1587 | 2486 |
硅微粉 | 20 | — | 2649 |
表1 颗粒物理性质
Table 1 Physical properties of particles
颗粒种类 | 平均粒径/μm | 堆积密度/(kg/m3) | 颗粒密度/(kg/m3) |
---|---|---|---|
黄沙 | 385 | 1587 | 2486 |
硅微粉 | 20 | — | 2649 |
颗粒种类 | 颗粒粒径dp/μm | 颗粒密度ρp/(kg/m3) | 起始流化 固含率 |
---|---|---|---|
黄沙 | 385 | 2486 | 0.67 |
黄沙+硅微粉 (5%,质量分数) | 364 | 2495 | 0.60 |
黄沙+硅微粉 (10%,质量分数) | 347 | 2503 | 0.55 |
表2 混合颗粒性质
Table 2 Physical properties of mixed particles
颗粒种类 | 颗粒粒径dp/μm | 颗粒密度ρp/(kg/m3) | 起始流化 固含率 |
---|---|---|---|
黄沙 | 385 | 2486 | 0.67 |
黄沙+硅微粉 (5%,质量分数) | 364 | 2495 | 0.60 |
黄沙+硅微粉 (10%,质量分数) | 347 | 2503 | 0.55 |
图16 平均聚团弦长随表观气速和径向位置的变化(h=512 mm)
Fig.16 Radial distribution of chord length of particle agglomerates for various superficial gas velocities(h=512 mm)
1 | Zhang M Z, Sun Z N, Zhu J, et al. Studies on the local flow characteristics and flow regime transitions in a square fluidized bed[J]. Powder Technology, 2021, 385: 306-316. |
2 | Lerou J J, Ng K M. Chemical reaction engineering: a multiscale approach to a multiobjective task[J]. Chemical Engineering Science, 1996, 51(10): 1595-1614. |
3 | 葛蔚, 刘新华, 任瑛, 等. 从多尺度到介尺度: 复杂化工过程模拟的新挑战[J]. 化工学报, 2010, 61(7): 1613-1620. |
Ge W, Liu X H, Ren Y, et al. From multi-scale to meso-scale: new challenges for simulation of complex processes in chemical engineering[J]. CIESC Journal, 2010, 61(7): 1613-1620. | |
4 | Bi H, Zhu J, Jin Y, et al. Forms of particle aggregations in CFB[C]//Proceedings of the Sixth Chinese Conference on Fluidization.Wuhan, China, 1993. |
5 | Manyele S V, Pärssinen J H, Zhu J X. Characterizing particle aggregates in a high-density and high-flux CFB riser[J]. Chemical Engineering Journal, 2002, 88(1/2/3): 151-161. |
6 | Afsahi F A, Sotudeh-Gharebagh R, Mostoufi N. Clusters identification and characterization in a gas-solid fluidized bed by the wavelet analysis[J]. The Canadian Journal of Chemical Engineering, 2009, 87(3): 375-385. |
7 | Yang T Y, Leu L P. Multiresolution analysis on identification and dynamics of clusters in a circulating fluidized bed[J]. AIChE Journal, 2009, 55(3): 612-629. |
8 | Yan Z H, Fan Y P, Bi X T, et al. Dynamic behaviors of feed jets and catalyst particles in FCC feed injection zone[J]. Chemical Engineering Science, 2018, 189: 380-393. |
9 | Breault R W, Casleton E M, Guenther C P. Chaotic and statistical tests on fiber optic dynamic data taken from the riser section of a circulating fluidized bed[J]. Powder Technology, 2012, 220: 151-163. |
10 | Tuzla K, Sharma A K, Chen J C, et al. Transient dynamics of solid concentration in downer fluidized bed[J]. Powder Technology, 1998, 100(2/3): 166-172. |
11 | Wang J W. High-resolution Eulerian simulation of RMS of solid volume fraction fluctuation and particle clustering characteristics in a CFB riser[J]. Chemical Engineering Science, 2008, 63(13): 3341-3347. |
12 | Hirai K, Hukaya K, Simada A, et al. Fluidization of solid particles[J]. Chemical Engineering, 1953, 17(11): 438-447. |
13 | Jia Y, Zhang Y, Xu J, et al. Coarse-grained CFD-DEM simulation to determine the multiscale characteristics of the air dense medium fluidized bed[J]. Powder Technology, 2021, 389: 270-277. |
14 | Breault R W. An analysis of clustering flows in a CFB riser[J]. Powder Technology, 2012, 220: 79-87. |
15 | Liu X H, Gao S Q, Li J H. Characterizing particle clustering behavior by PDPA measurement for dilute gas-solid flow[J]. Chemical Engineering Journal, 2005, 108(3): 193-202. |
16 | Xu J, Zhu J. A new method for the determination of cluster velocity and size in a circulating fluidized bed[J]. Industrial & Engineering Chemistry Research, 2012, 51(4): 2143-2151. |
17 | Lackermeier U, Rudnick C, Werther J, et al. Visualization of flow structures inside a circulating fluidized bed by means of laser sheet and image processing[J]. Powder Technology, 2001, 114(1/2/3): 71-83. |
18 | Chew J W, Hays R, Findlay J G, et al. Cluster characteristics of Geldart group B particles in a pilot-scale CFB riser ( Ⅱ ) : Polydisperse systems[J]. Chemical Engineering Science, 2012, 68(1): 82-93. |
19 | Krohn D A. Intensity modulated fiber optic sensors overview[C]//SPIE Proceedings, Fiber Optic and Laser Sensors Ⅳ. Cambridge, MA, 1987: 2-11. |
20 | Ellis N. Hydrodynamics of gas-solid turbulent fluidized beds[D]. Vancouver, BC, Canada: University of British Columbia, 2003. |
21 | 黄亚航, 刘梦溪, 胡娟. 气固流化床中颗粒聚团的流动特性[J]. 过程工程学报, 2016, 16(3): 374-379. |
Huang Y H, Liu M X, Hu J. Flow characteristic of particle agglomerates in a gas-solid fluidized bed[J]. The Chinese Journal of Process Engineering, 2016, 16(3): 374-379. | |
22 | Kiani A, Sotudeh-Gharebagh R, Mostoufi N. Cluster size distribution in the freeboard of a gas-solid fluidized bed[J]. Powder Technology, 2013, 246: 1-6. |
23 | Niu L, Huang Y H, Chu Z M, et al. Identification of mesoscale flow in a bubbling and turbulent gas–solid fluidized bed[J]. Industrial & Engineering Chemistry Research, 2019, 58(19): 8456-8471. |
24 | Bi X. Flow regime transitions in gas-solid fluidization and transport[D]. Vancouver, BC, Canada: University of British Columbia, 1994. |
25 | Bi H T, Su P C. Local phase holdups in gas-solids fluidization and transport[J]. AIChE Journal, 2001, 47(9): 2025-2031. |
26 | Zhu J, Qi M Z, Barghi S. Identification of the flow structures and regime transition in gas-solid fluidized beds through moment analysis[J]. AIChE Journal, 2013, 59(5): 1479-1490. |
27 | Cocco R, Shaffer F, Hays R, et al. Particle clusters in and above fluidized beds[J]. Powder Technology, 2010, 203(1): 3-11. |
28 | McMillan J, Shaffer F, Gopalan B, et al. Particle cluster dynamics during fluidization[J]. Chemical Engineering Science, 2013, 100: 39-51. |
29 | Liu M X, Shen Z Y, Yang L J, et al. Microscale two-phase flow structure in a modified gas-solid fluidized bed[J]. Industrial & Engineering Chemistry Research, 2014, 53(34): 13475-13487. |
30 | Soong C, Tuzla K, Chen J. Identification of particle clusters in circulating fluidized bed[J]. Circulating Fluidized Bed Technology Ⅳ, 1994, 615: 620. |
31 | Soong C. Experimental determination of cluster size and velocity in circulating fluidized bed[J]. Fluidization, 1996: 219-227. |
32 | Jayaweera K O L F, Mason B J, Slack G W. The behaviour of clusters of spheres falling in a viscous fluid (Ⅰ): Experiment[J]. Journal of Fluid Mechanics, 1964, 20(1): 121-128. |
[1] | 肖明堃, 杨光, 黄永华, 吴静怡. 浸没孔液氧气泡动力学数值研究[J]. 化工学报, 2023, 74(S1): 87-95. |
[2] | 邵苛苛, 宋孟杰, 江正勇, 张旋, 张龙, 高润淼, 甄泽康. 水平方向上冰中受陷气泡形成和分布实验研究[J]. 化工学报, 2023, 74(S1): 161-164. |
[3] | 袁佳琦, 刘政, 黄锐, 张乐福, 贺登辉. 泡状入流条件下旋流泵能量转换特性研究[J]. 化工学报, 2023, 74(9): 3807-3820. |
[4] | 岳林静, 廖艺涵, 薛源, 李雪洁, 李玉星, 刘翠伟. 凹坑缺陷对厚孔板喉部空化流动特性影响研究[J]. 化工学报, 2023, 74(8): 3292-3308. |
[5] | 王海, 林宏, 王晨, 许浩洁, 左磊, 王军锋. 高压静电场强化多孔介质表面沸腾传热特性研究[J]. 化工学报, 2023, 74(7): 2869-2879. |
[6] | 王泽栋, 石至平, 刘丽艳. 考虑气泡非均匀耗散的矩形反应器声流场数值模拟及结构优化[J]. 化工学报, 2023, 74(5): 1965-1973. |
[7] | 张银宁, 王进卿, 冯致, 詹明秀, 徐旭, 张光学, 池作和. 升温条件下多孔介质内气泡的生长和聚并行为[J]. 化工学报, 2023, 74(4): 1509-1518. |
[8] | 项星宇, 王忠东, 董艳鹏, 李守川, 朱春英, 马友光, 付涛涛. 微通道内屈服应力型流体的流变特性及多相流研究进展[J]. 化工学报, 2023, 74(2): 546-558. |
[9] | 盛林, 昌宇, 邓建, 骆广生. 阶梯式T型微通道内有序气泡群的形成和流动特性研究[J]. 化工学报, 2023, 74(1): 416-427. |
[10] | 张童, 杨扬, 叶丁丁, 陈蓉, 朱恂, 廖强. 催化剂分布对可渗透阳极微流体燃料电池性能特性影响的研究[J]. 化工学报, 2022, 73(9): 4156-4162. |
[11] | 苏巧玲, 王军锋, 张伟, 詹水清, 吴天一. 低电导率工质中气泡的极化运动实验研究[J]. 化工学报, 2022, 73(9): 3861-3869. |
[12] | 解文潇, 贾胜坤, 张会书, 罗祎青, 袁希钢. 受限空间内浮升气泡与液体间传质行为实验研究[J]. 化工学报, 2022, 73(7): 2902-2911. |
[13] | 闫美月, 邓坚, 潘良明, 马在勇, 李想, 邓杰文, 何清澈. 基于流量振荡的窄矩形通道内临界热通量机理模型[J]. 化工学报, 2022, 73(7): 2962-2970. |
[14] | 陈泉, 郑泽希, 李然, 孙其诚, 杨晖. 散斑能见度光谱法测量筒仓内颗粒流的颗粒温度[J]. 化工学报, 2022, 73(6): 2603-2611. |
[15] | 唐天琪, 何玉荣. 磁场对湿颗粒流化床系统中介尺度结构影响机制研究[J]. 化工学报, 2022, 73(6): 2636-2648. |
阅读次数 | ||||||||||||||||||||||||||||||||||||||||||||||||||
全文 212
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||
摘要 299
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||