鼓泡流化床中流动特性的多尺度数值模拟

王帅; 于文浩; 陈巨辉; 张天浴; 孙立岩; 陆慧林

doi:10.6052/0459-1879-15-089

鼓泡流化床中流动特性的多尺度数值模拟

doi: 10.6052/0459-1879-15-089

1.
哈尔滨工业大学能源科学与工程学院, 哈尔滨 150001
2. 哈尔滨理工大学机械动力工程学院, 哈尔滨 150080

基金项目: 国家自然科学基金(51390494,51406045),中国博士后基金(2015M581443)和黑龙江省博士后基金(LBH-Z15055)资助项目.

详细信息

通讯作者:
王帅,E-mail:shuaiwang@hit.edu.cn

中图分类号: TK224
计量
- 文章访问数: 857
- HTML全文浏览量: 64
- PDF下载量: 940
- 被引次数: 0
出版历程
- 收稿日期: 2015-03-18
- 修回日期: 2016-03-24
- 刊出日期: 2016-05-18

MULTI-SCALE SIMULATION ON HYDRODYNAMIC CHARACTERISTICS IN BUBBLING FLUIDIZED BED

1.
School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
2. School of Mechanical Engineering, Harbin University of Science and Technology, Harbin 150080, China

摘要

摘要: 鼓泡流化床因其较高的传热特性以及较好的相间接触已经被广泛应用于工业生产中,而对鼓泡流态化气固流动特性的充分认知是鼓泡流化床设计的关键.在鼓泡流化床中,气泡相和乳化相的同时存在使得床中呈现非均匀流动结构,而这种非均匀结构给鼓泡流化床的数值模拟造成了很大的误差.基于此,以气泡作为介尺度结构,建立了多尺度曳力消耗能量最小的稳定性条件,构建了适用于鼓泡流化床的多尺度气固相间曳力模型.结合双流体模型,对A类和B类颗粒的鼓泡流化床中气固流动特性进行了模拟研究,分析了气泡速度、气泡直径等参数的变化规律.研究表明,与传统的曳力模型相比,考虑气泡影响的多尺度气固相间曳力模型给出的曳力系数与颗粒浓度的关系是一条分布带,建立了控制体内曳力系数与局部结构参数之间的关系.通过模拟得到的颗粒浓度和速度与实验的比较可以发现,考虑气泡影响的多尺度曳力模型可以更好地再现实验结果.通过A类和B类颗粒的鼓泡床模拟研究发现,A类颗粒的鼓泡床模拟受多尺度曳力模型的影响更为显著.
- 曳力系数 /
- 气泡 /
- 流化床 /
- 多尺度
Abstract: Bubbling fluidized beds have been widely applied to various industrial processes owing to superior inter-phase contact and high heat transfer characteristics. Fundamental knowledge of the hydrodynamic characteristics is essential for the design of such reactors. In bubbling fluidized bed systems,the non-uniform flow structure in the form of bubbleemulsion phases makes the accuracy of numerical model limited. Bubbles are the typical meso-scale structures in bubbling fluidized beds. To describe the e ects of such meso-scale structures, a bubble structure-dependent (BSD) drag model is developed with one extremum condition of energy dissipation consumed by the drag force, which is incorporated into the two fluid model. The simulations of gas-solid flow behavior in bubbling fluidized beds with with Geldart A and B particles are performed and some parameters including bubble velocity and bubble diameter are analyzed. The results indicate that the present model with consideration of bubble e ects obtains a zonal distribution of the drag coe cient with solid concentration, which establishes a relationship between the drag coe cient and the local structural parameters. Comparisons with experimental data, the BSD drag model can obtain a better prediction than the conventional drag model. Meanwhile, the simulation reveals that the BSD drag model has a more significant impact on the predition of bubbling fluidization with Geldart A particles.
- drag coefficient /
- bubble /
- fluidized bed /
- multiscale

HTML全文

参考文献(30)

1 Cloete S, Zaabout A, Johansen ST, et al. The generality of the standard 2D TFM approach in predicting bubbling fluidized bed hydrodynamics. Powder Technology, 2013, 235: 735-746

2 Herzog N, Schreiber M, Egbers C, et al. A comparative study of different CFD codes for numerical simulation of gas-solid fluidized bed hydrodynamics. Computers & Chemical Engineering. 2012,39: 41-46

3 Zhao Y, Lu B, Zhong Y. Influence of collisional parameters for rough particles on simulation of a gas-fluidized bed using a twofluid model. International Journal of Multiphase Flow , 2015, 71:1-13

4 王帅,郝振华,徐鹏飞等. 粗糙颗粒动理学及稠密气固两相流动的数值模拟. 力学学报, 2012, 44(2): 278-286 (Wang Shuai, Hao Zhenhua, Xu Pengfei, et al. Kinetic theory of rough spheres and numerical simulation of dense gas-particles flow. Chinese Journal of Theoretical and Applied Mechanics, 2012, 44(2): 278-286 (in Chinese))

5 Schneiderbauer S, Pirker S. Filtered and heterogeneity-based subgrid modifications for gas-solid drag and solid stresses in bubbling fluidized beds. AIChE Journal, 2014, 60(3): 839-854

6 Igci Y, Sundaresan S. Constitutive models for filtered two-fluid models of fluidized gas-particle flows. Industrial & Engineering Chemistry Research, 2011, 50: 13190-13201

7 Igci Y, Andrews AT, Sundaresan S, et al. Filtered two-fluid models for fluidized gas-particle suspensions. AIChE Journal , 2008, 54:1431-1448

8 Li JH, Cheng CL, Zhang ZD, et al. The EMMS model-its application, development and updated concepts. Chemical Engineering Science, 1999, 54: 5409-5425

9 Yang N, Wang W, Ge W, et al. CFD simulation of concurrent-up gas-solid flow in circulating fluidized beds with structure-dependent drag coefficient. Chemical Engineering Journal, 2003, 96: 71-80

10 Wang W, Li J. Simulation of gas-solid two-phase flow by a multiscale CFD approach-extension of the EMMS model to the sub-grid level. Chemical Engineering Science, 2007, 62: 208-231

11 Wang J, Liu Y. EMMS-based Eulerian simulation on the hydrodynamics of a bubbling fluidized bed with FCC particles. Powder Technology,2010, 197: 241-246

12 Shi Z, Wang W, Li J. A bubble-based EMMS model for gas-solid bubbling fluidization. Chemical Engineering Science, 2011, 66:5541-5555

13 Lungu M, Zhou Y, Wang J, et al. A CFD study of a bi-disperse gassolid fluidized bed: Effect of the EMMS sub grid drag correction. Powder Technology, 2015, 280: 154-172

14 Wang Y, Zou Z, Li H, et al. A new drag model for TFM simulation of gas-solid bubbling fluidized beds with Geldart-B particles. Particuology, 2013, 8: 176-185

15 Wang J, van der Hoef MA, Kuipers JAM. Coarse grid simulation of bed expansion characteristics of industrial-scale gas-solid bubbling fluidized beds. Chemical Engineering Science, 2010, 65: 2125-2131

16 Lü X, Li H, Zhu Q. Simulation of gas-solid flow in 2D/3D bubbling fluidized beds by combining the two-fluid model with structurebased drag model. Chemical Engineering Journal, 2014, 236: 149-157

17 Yang S, Li HZ, Zhu QS. Experimental study and numerical simulation of ba ed bubbling fluidized beds with Geldart A particles in three dimensions. Chemical Engineering Journal, 2015, 259: 338-347

18 Richardson JF, Zaki WN. Sedimentation and fluidization. Transactions of the Institution of Chemical Engineers, 1954, 32: 35-53

19 Mori S,Wen CY. Estimation of bubble diameter in gaseous fluidized beds. AIChE Journal, 1975, 21: 109-115

20 Gidaspow D. Multiphase flow and fluidization: continuum and kinetic theory descriptions. Boston, MA: Academic Press Inc., 1994

21 Darton RC, Harrison D. The rise of single gas bubbles in liquid fluidized bed. Transactions of the Institution of Chemical Engineers,1974, 52: 301-304

22 Ishii M, Zuber N. Drag coefficient and relative velocity in bubbly, droplet or particulate flows. AIChE Journal , 1979, 25: 843-855

23 Gidaspow D. Hydrodynamics of fluidization and heat transfer: supercomputer modeling. Applied Mechanics Reviews, 1986, 39: 1-23

24 Zhang DZ, Van der Heyden WB. The effects of mesoscale structures on the macroscopic momentum equations for two-phase flows. International Journal of Multiphase Flow, 2002, 28: 805-822

25 Zuber N. On the dispersed two-phase flow in the laminar flow regime. Chemical Engineering Science, 1964, 19: 897-917

26 Thomas DG. Transport characteristics of suspension: VIII. A note on the viscosity of Newtonian suspensions of uniform spherical particles. Journal of Colloid and Interface Science, 1965, 20: 267-277

27 Zhu H, Zhu J, Li G, et al. Detailed measurements of flow structure inside a dense gas-solid fluidized bed. Powder Technology, 2008,180: 339-349

28 Wang J, van der Hoef MA, Kuipers JAM. Why the two-fluid model fails to predict the bed expansion characteristics of Geldart A particles in gas-fluidized beds: a tentative answer. Chemical Engineering Science , 2009, 64: 622-625

29 Laverman JA, Roghair I, Annaland MV, et al. Investigation into the hydrodynamics of gas-solid fluidized beds using particle image velocimetry coupled with digital image analysis. Canadian Journal of Chemical Engineering, 2008, 86: 523-535

30 Schneiderbauer S, Puttinger S, Pirker S. Comparative analysis of sub-grid drag modications for dense gas-particle flows in bubbling fluidized beds. AIChE Journal, 2013, 59: 4077-4099

施引文献

资源附件(0)

访问统计