姚秀颖1,徐 博1, 2,刘梦溪1,卢春喜1
(1. 中国石油大学(北京)重质油国家重点实验室,北京 昌平 102249;2. 东方电气集团东方锅炉股份有限公司,四川 自贡 643001)
DOI:10.13732/j.issn.1008-5548.2022.01.001
收稿日期: 2021-07-30,修回日期:2021-08-26,在线出版时间:2021-11-09。
基金项目:国家自然科学基金项目,编号:21706280; U1862202; 91834303; 21961132026。
第一作者简介:姚秀颖(1985—),女,讲师,博士,研究方向为多相流传递与反应。E-mail:xyyao2014@126.com。
通信作者简介:卢春喜(1962—),男,教授,博士,博士生导师,研究方向为石油化工装备。E-mail:lcx725@sina.com。
摘要:为了探明间壁式流化床换热器内热管对气固流动状态的影响,采用欧拉双流体模型,并应用能量最小多尺度(energy minimization multi-scale, EMMS)曳力模型,对可实现2种物性相近催化剂热管间壁换热的湍动流化床流动特性进行模拟研究。结果表明:通过与实验数据进行比较,证明模型是有效的;比较热管对床内固含率轴向分布的影响,发现热管的设置可减小气泡尺寸、有效降低颗粒被夹带量;热管对固含率的影响主要位于热管末端,其仅存在于热管所在区域,且随着径向位置靠近隔板逐渐减小;沿热管轴向存在隔板影响区和主换热区,主换热区随着轴向高度的增加而减小,随着表观气速的增大而增大。
关键词:倾斜管;湍流床;管表面;固含率
Abstract:In order to investigate the effect of heat pipes on gas-solid flow state in the fluidized bed heat exchanger with heat pipes, the Euler two-fluid model with the energy minimization multi-scale(EMMS) drag force model was employed to investigate turbulent fluidized bed with tilted heat pipes, which could realize the efficient heat transfer between two catalysts with similar physical properties by heat pipes. The results show that the validity of the model is verified by comparing with experimental data. Compared with the effect of heat pipe on the axial distribution of solids holdup, it is found that the heat pipe can reduce the bubble size and the particle entrained amount. The influence of heat pipe on solids holdup is mainly located at the end of heat pipe in the radial direction and in the axial direction where the heat pipe is located. And the solids holdup decreases gradually as the radial position is close to the baffle. The size of main heat transfer zone decreases with the increasing of axial height and increases with the increasing of superficial gas velocity.
Keyword: inclined heat pipe; turbulent fluidized bed; pipe surface; solids holdup
参考文献(References):
[1]张海莹,赵东风.催化裂化烟气脱硫脱硝优化技术研究[J].当代化工, 2019, 48(4): 851-854.
[2]刘克宁, 刘同仁, 李磊.催化裂化再生烟气净化催化剂研究进展[J].山东化工, 2017, 46(14): 51-54.
[3]姚秀颖, 卢春喜.催化裂化再生催化剂取热技术研究进展[J].石油学报(石油加工), 2018, 34(2): 217-228.
[4]郭大为, 张久顺, 张执刚, 等.一种烟气脱硫脱氮吸附剂再生过程中的换热方法: 200910162162.4[P].2011-03-23.
[5]郭大为, 张久顺, 毛安国, 等.一种烟气脱硫脱氮吸附剂再生过程中的换热方法: 200810113392.7[P].2009-12-02.
[6]姚秀颖, 李建涛, 卢春喜, 等.流化床间壁换热再生耦合装置:202020183168.1[P].2020-10-30.
[7]JOUHARA H, CHAUHAN A, NANNOU T, et al.Heat pipe based systems-Advances and applications[J].Energy, 2017, 128: 729-754.
[8]徐连青.热管技术在热能工程中的应用[J].科技传播, 2012, 5:140-141.
[9]YAO X, ZHANG Y, LU C, et al.Systematic study on heat transfer and surface hydrodynamics of a vertical heat tube in a fluidized bed of FCC particles[J].AIChE J, 2015, 61: 68-83.
[10]GERHARD H, GERHARD S, TOBIAS P.Acting on hydrodynamics to improve the local bed-to-wall heat transfer in bubbling fluidized beds[J].Chem Eng Res Des, 2018, 134: 309-318.
[11]YANG Z, ZHANG Y, OLORUNTOBA A, et al.MP-PIC simulation of the effects of spent catalyst distribution and horizontal baffle in an industrial FCC regenerator.part I: effects on hydrodynamics[J].Chem Eng J, 2021, 412: 128-634.
[12]KIM S W, KIM S D.Heat transfer characteristics in a pressurized fluidized bed of fine particles with immersed horizontal tube bundle[J].Int J Heat Mass Transf, 2013, 64: 269-77.
[13]MICKLEY H S, FAIRBANKS D F.Mechanism of heat transfer to fluidized beds[J].AIChE J, 1955, 1: 374-384.
[14]LI J, YAO X, LIU L, et al.Bed-to-wall heat transfer in a gas-solid fluidized bed with external solids circulation: Modified packet renewal model[J].Powder Technol, 2021, 383: 19-29.
[15]AL-BUSOUL M A, ABU-EIN S K.Local heat transfer coefficients around a horizontal heated tube immersed in a gas fluidized bed[J].Heat Mass Transf, 2003, 39(4): 355-358.
[16]TAWFIK M, RWANG J.Flow structures inside a large-scale turbulent fluidized bed of FCC particles: eulerian simulation with an EMMS-based sub-grid scale model[J].Particuology,2010, 8(2): 176-185.
[19]吴诚, 高希, 成有为, 等.湍动流化床过渡段固含率分布特征的实验及数值模拟[J].化工学报,2013, 64(3): 858-866.
[20]LAN X, YAN W, XU C, et al.Hydrodynamics of gas-solid turbulent fluidized bed of polydisperse binary particles[J].Powder Technol,2014, 262: 106-123.
[21]CHEN J, LI H, LV X, et al.A structure-based drag model for the simulation of Geldart A and B particles in turbulent fluidized beds[J].Powder Technol,2015, 274: 112-122.
[22]CHANG J, ZHAO J, ZHANG K, et al.Hydrodynamic modeling of an industrial turbulent fluidized bed reactor with FCC particles[J].Powder Technol,2016, 304: 134-142.
[23]VARGHESE M M, VAKAMALLA T R, MANTRAVADI B, et al.Effect of drag models on the numerical simulations of bubbling and turbulent fluidized beds[J].Chem Eng Technol,2021, 44(5): 865-874.
[24]孟振亮, 刘梦溪, 李飞, 等.新型气固环流反应器内颗粒流动的CFD模拟[J].化工学报, 2016, 67(8): 3234-3243.
[25]MENG Z, LIU M, XIE J, et al.Comparative study on the hydrodynamics and mixing characteristics of a new-type particle mixer[J].Powder Tech, 2018, 332: 90-105.
[26]傅梦倩, 姚秀颖, 范怡平, 等.双层喷嘴提升管进料区内气固流动特性的数值模拟[J].过程工程学报, 2020, 20(7): 757-769.
[27]徐逞祥.无序环流取热器内气固两相流动和内循环特性研究[D].北京: 中国石油大学(北京), 2020.
[28]ZHANG Y, LU C.Experimental study and modeling on effects of a new multilayer baffle in a turbulent fluid catalytic cracking regenerator[J].Ind Eng Chem Res, 2014, 53(5): 2062-2066.EFAAT D M, MOHMED A H.An experimental investigation of wall-bed heat transfer and flow characteristics in a swirling fluidized bed reactor[J].Appl Therm Eng, 2019, 155: 501-507.
[17]BAO Z, HUANG Y, DUAN L, et al.Heat transfer characteristics of horizontal tubes in the dilute phase of the pressurized fluidized bed[J].Int Commun Heat Mass,2021, 126: 105-370.
[18]WANG J.Flow structures inside a large-scale turbulent fluidized bed of FCC particles: eulerian simulation with an EMMS-based sub-grid scale model[J].Particuology,2010, 8(2): 176-185.
[19]吴诚, 高希, 成有为, 等.湍动流化床过渡段固含率分布特征的实验及数值模拟[J].化工学报,2013, 64(3): 858-866.
[20]LAN X, YAN W, XU C, et al.Hydrodynamics of gas-solid turbulent fluidized bed of polydisperse binary particles[J].Powder Technol,2014, 262: 106-123.
[21]CHEN J, LI H, LV X, et al.A structure-based drag model for the simulation of Geldart A and B particles in turbulent fluidized beds[J].Powder Technol,2015, 274: 112-122.
[22]CHANG J, ZHAO J, ZHANG K, et al.Hydrodynamic modeling of an industrial turbulent fluidized bed reactor with FCC particles[J].Powder Technol,2016, 304: 134-142.
[23]VARGHESE M M, VAKAMALLA T R, MANTRAVADI B, et al.Effect of drag models on the numerical simulations of bubbling and turbulent fluidized beds[J].Chem Eng Technol,2021, 44(5): 865-874.
[24]孟振亮, 刘梦溪, 李飞, 等.新型气固环流反应器内颗粒流动的CFD模拟[J].化工学报, 2016, 67(8): 3234-3243.
[25]MENG Z, LIU M, XIE J, et al.Comparative study on the hydrodynamics and mixing characteristics of a new-type particle mixer[J].Powder Tech, 2018, 332: 90-105.
[26]傅梦倩, 姚秀颖, 范怡平, 等.双层喷嘴提升管进料区内气固流动特性的数值模拟[J].过程工程学报, 2020, 20(7): 757-769.
[27]徐逞祥.无序环流取热器内气固两相流动和内循环特性研究[D].北京: 中国石油大学(北京), 2020.
[28]ZHANG Y, LU C.Experimental study and modeling on effects of a new multilayer baffle in a turbulent fluid catalytic cracking regenerator[J].Ind Eng Chem Res, 2014, 53(5): 2062-2066.