Research on heat transfer of gas-solid two-phase flow in CFB boilers

doi:10.3969/j.issn.1674-1951.2021.10.007

Abstract

Abstract:

The particle size distribution of bed materials in circulating fluidized bed （CFB） boilers is wide.Gas-solid flow,a kind of multi-fluid composite flows,is of a complicated heat-transfer process.The common heat transfer mechanism of the two-phase flow in different states is analyzed,and its influencing factors,mechanism models and numerical simulation are investigated.The calculation methods for the heat transfer mechanisms of three gas-solid two-phase flows are summarized：solid-phase flow heat transfer,gas-phase flow heat transfer and radiation heat transfer.The important influencing factors of heat transfer are air velocity,particle size,bed pressure and temperature.The particle movement characteristics and concentration distribution are crucial for the heat transfer in CFB boilers.The improvement of the current calculation model should focus on wide particle size distribution.Optimizing the heat transfer efficiency of gas-solid two-phase flow in CFB boilers can boost the energy utilization rate and facilitate the achievement of carbon peaking and carbon neutrality.

Key words: carbon peaking, carbon neutrality, CFB boiler, gas-solid two-phase flow, heat transfer mechanism, heat transfer coefficient, wide particle size distribution

CLC Number:

TK124

TAN Xuemei, LIU Shijie, ZHAO Bing, GONG Taiyi, WANG Jialin, HU Nan. Research on heat transfer of gas-solid two-phase flow in CFB boilers[J]. Huadian Technology, 2021, 43(10): 61-67.

Figures/Tables 2

References 40

[1]	吴占松, 马润, 汪展文. 流化态技术基础与应用[M]. 北京: 化学工业出版社, 2006.
[2]	魏捷. 论循环流化床锅炉技术现状及发展前景[J]. 南方农机, 2020, 51(7): 118.
	WEI Jie. Development of circulating fluidized bed boiler technology[J]. China Southern Agricultural Machinery, 2020, 51(7): 118.
[3]	黄中, 杨娟, 车得福. 大容量循环流化床锅炉技术发展应用现状[J]. 热力发电, 2019, 48(6): 1-8.
	HUANG Zhong, YANG Juan, CHE Defu. Development and application of large capacity circulating fluidized bed boiler technology[J]. Thermal Power Generation, 2019, 48(6): 1-8.
[4]	岳光溪, 吕俊复, 徐鹏, 等. 循环流化床燃烧发展现状及前景分析[J]. 中国电力, 2016, 49(1): 1-13.
	YUE Guangxi, LYU Junfu, XU Peng, et al. Development and prospect analysis of circulating fluidized bed combustion[J]. Electric Power. 2016, 49(1): 1-13.
[5]	蔡润夏, 吕俊复, 凌文, 等. 超(超)临界循环流化床锅炉技术的发展[J]. 中国电力, 2016, 49(12): 1-7.
	CAI Runxia, LYU Junfu, LIN Wen, et al. Development of Super(super)criticality of circulating fluidized bed boiler technology[J]. Electric Powe, 2016, 49(12): 1-7.
[6]	姚禹歌, 黄中, 张缦, 等. 中国循环流化床燃烧技术的发展与展望[J/OL]. 热力发电: 1-8(2021-07-08)[2021-09-15]. http://kns.cnki.net/kcms/detail/61.1111.TM.20210528.1721.002.html.
	YAO Yuge, HUANG Zhong, ZHANG Man, et al. Development and prospect of circulating fluidized bedcombustion technology in China[J/OL]. Thermal Power Generation: 1-8(2021-07-08)[2021-09-15]. http://kns.cnki.net/kcms/detail/61.1111.TM.20210528.1721.002.html.
[7]	宋畅, 吕俊复, 杨海瑞, 等. 超临界及超超临界循环流化床锅炉技术研究与应用[J]. 中国电机工程学报, 2018, 38(2): 338-347.
	SONG Chang, LYU Junfu, YANG Hairui, et al. Research and application of supercritical and ultra-supercritical circulating fluidized bed boiler[J]. Proceedings of the CSEE, 2018, 38(2): 338-347.
[8]	张瑞卿. 涵盖不同流型的气固床层与壁面换热研究[D]. 北京:清华大学, 2014.
[9]	吕俊复, 田勇, 彭晓峰, 等. 循环流化床内颗粒运动与换热分析[J]. 化工学报, 2003(9): 1224-1229.
	LYU Junfu, TIAN Yong, PENG Xiaofeng, et al. Analysis of particles motion and convection heat transfer in circulating fluidized bed[J]. Journal of Chemical Industry and Engineering, 2003(9): 1224-1229.
[10]	WU R L, GRACE J R, LIM C J. A model for heat transfer in circulating fluidized beds[J]. Chemical Engineering Science, 1990, 45(12): 3389-3398. doi: 10.1016/0009-2509(90)87144-H
[11]	NAG P K, NAWSHER M, MORAL A. Effect of probe size on heat transfer at the wall in circulating fluidized beds[J]. International Journal of Energy Research, 2010, 14(9): 965-974. doi: 10.1002/(ISSN)1099-114X
[12]	高翔, 周劲松, 骆仲泱, 等. 气固两相流中颗粒运动强化器壁对流传热的机理[J]. 化工学报, 1998(3): 294-302.
	GAO Xiang, ZHOU Jingsong, LUO Zhongyang, et al. Mechanics of enhancement of convective heat transfer due to particle impact in gas-solid two phase flow[J]. Journal of Chemical Industry and Engineering, 1998(3): 294-302.
[13]	武锦涛, 陈纪忠, 阳永荣. 移动床中颗粒接触传热的数学模型[J]. 化工学报, 2006(4): 719-725.
	WU Jingtao, CHEN Jizhong, YANG Yongrong. Model of contact heat transfer in granular moving bed[J]. Journal of Chemical Industry and Engineering, 2006(4): 719-725.
[14]	刘传平, 李传, 李永亮, 等. 气固两相流强化传热研究进展[J]. 化工学报, 2014(7): 2485-2494.
	LIU Chuanping, LI Chuan, LI Yongliang, et al. Heat transfer enhancement in gas-solid flow[J]. Journal of Chemical Industry and Engineering, 2014(7): 2485-2494.
[15]	郑莹, 赵亮, 张晟. 填充床气固传热系数的研究进展[J]. 冶金能源, 2019, 38(6): 10-13.
	ZHENG Ying, ZHAO Liang, ZHANG Sheng. Research progress of heat transfer coefficient in packed bed[J]. Energy for Metallurgical Industry, 2019, 38(6): 10-13.
[16]	WU R L, GRACE J R, JIM C J, et al. Suspension to surface heat transfer in a circulating-fluidized-bed combustor[J]. AIChE journal, 1989, 35(10): 1685-1691. doi: 10.1002/(ISSN)1547-5905
[17]	程乐鸣, 骆仲泱, 倪明江, 等. 循环流化床辐射传热模型[J]. 中国电机工程学报, 2001(9): 100-104.
	CHENG Leming, LUO Zhongyang, NI Mingjiang, et al. Radiation heat transfer model of a circulating fluidized bed[J]. Proceedings of the CSEE, 2001(9): 100-104.
[18]	吕俊复, 张建胜, 岳光溪, 等. 循环流化床锅炉燃烧室受热面传热系数计算方法[J]. 清华大学学报(自然科学版), 2000(2): 94-97.
	LYU Junfu, ZHANG Jiansheng, YUE Guangxi, et al. Calculation method of heat transfer coefficient of heating surface in combustion chamber of circulating fluidized bed boiler[J]. Journal of Tsinghua University(Science and Technology), 2000(2): 94-97.
[19]	BOTTERILL J.S.M, TEOMAN Y, YÜREGIR K.R. Factors affecting heat transfer between gas-fluidized beds and immersed surfaces[J]. Powder Technology, 1984, 39(2): 177-189. doi: 10.1016/0032-5910(84)85035-4
[20]	CHEN C, CHEN K. Analysis of simultaneous radiative and conductive heat transfer in fluidized beds[J]. Chemical Engineering Communications, 1981, 9(1-6): 255-271. doi: 10.1080/00986448108911027
[21]	漆小波, 黄卫星, 祝京旭, 等. 循环流化床提升管中颗粒速度的径向分布及其沿轴向的发展[J]. 高校化学工程学报, 2002(2): 168-173.
	QI Xiaobo, HUANG Weixing, ZHU Jingxu, et al. Radial distribution and axial development of particle velocity in circulating fluidized bed[J]. Journal of Chemical Engineering of Chinese Universities, 2002(2): 168-173.
[22]	ACHENBACH E. Heat and flow characteristics of packed beds[J]. Experimental Thermal and Fluid Science, 1995, 10(1): 17-27. doi: 10.1016/0894-1777(94)00077-L
[23]	王焱鹏, 董群, 王立娟, 等. 循环流化床固-固换热系统传热规律[J]. 石化技术与应用, 2006(3): 191-193.
	WANG Yangpeng, DONG Qun, WANG Lijuan, et al. Heat transfer law of solid-solid system incirculating fluidized[J]. Petrochemical Technology and Application, 2006(3): 191-193.
[24]	李金晶, 李燕, 吕俊复, 等. 循环流化床锅炉炉内传热的影响因素[J]. 清华大学学报(自然科学版), 2007(11): 2026-2030.
	LI Jinjing, LI Yan, LYU Junfu, et al. Factors affecting the heat transfer in a circulating fluidized bed[J]. Journal of Tsinghua University(Science and Technology), 2007(11): 2026-2030.
[25]	黄卫星, 漆小波, 潘永亮, 等. 气固循环床提升管内的局部颗粒浓度及流动发展[J]. 高校化学工程学报, 2002(6): 626-631.
	HUANG Weixing, QI Xiaobo, PAN Yongliang, et al. Development and particle concentration of gas-solid circulating fluidized bed[J]. Journal of Chemical Engineering of Chinese Universities, 2002(6): 626-631.
[26]	SMICKLEY H, TRILLING C. Heat transfer characteristics of fluidized beds[J]. Industrial and Engineering Chemistry Research, 1949, 41(6): 1135-1147. doi: 10.1021/ie010605j
[27]	HERB B. Distribution of solid concentration in circulating fluidized beds[J]. Fluidization IV, 1989:65-72.
[28]	TUNG Y, LI J, KWAUK M. Radial voidage profiles in a fast fluidized bed[J]. Chemical Reaction Engineering and Technology, 1988(1): 75-81.
[29]	ZHANG W, TUNG Y, JOHNSSON J E. Radial voidage profiles in fast fluidized beds of different diameters[J]. Chemical Engineering Science, 1991, 46: 3045-3052. doi: 10.1016/0009-2509(91)85008-L
[30]	PATIENCE G S, CHAOUKI J. Solids hydrodynamics in the fully developed region of CFB risers[J]. Fluidisation VIII, 1995:33-40.
[31]	田子平, 钟志强, 陈永国, 等. 循环流化床中气固两相流动特性的可视化研究[J]. 热能动力工程, 2003(2): 120-124.
	TIAN Ziping, ZHONG Zhiqiang, CHEN Yongguo, et al. Study on visualization of gas-solid two-phase flow characteristics in circulating fluidized bed[J]. Journal of Engineering and Thermal Power, 2003(2): 120-124.
[32]	杨磊. 循环流化床双床反应器中气固流动、流型及多尺度特性研究[D]. 湘潭:湘潭大学, 2018.
[33]	刘宝勇. 大型循环流化床底部区域气固两相流动特性研究[D]. 北京:中国石油大学, 2008.
[34]	EOLSSON S, ALMSTEDT A. Local instantaneous and time-averaged heat transfer in a pressurized fluidized bed with horizontal tubes:Influence of pressure,fluidization velocity and tube-bank geometry[J]. Chemical Engineering Science, 1995, 50(20): 3231-3245. doi: 10.1016/0009-2509(95)00150-4
[35]	PANKAJ K, PINAKESWAR M, UJJWAL K. Some studies on wall-to-bed heat transfer in a pressurized circulating fluidized bed unit[J]. Procedia Engineering, 2013, 56: 163-172. doi: 10.1016/j.proeng.2013.03.103
[36]	THRING R. Fluidised bed combustion for the stirling engine[J]. Pergamon, 1977, 20(9): 911-918.
[37]	GUO Z, SUN Z, ZHANG N, et al. CFD analysis of fluid flow and particle to fluidheat transfer in packed bed with radial layered configuration[J]. Chemical Engineering Science, 2018, 197(6): 357-370. doi: 10.1016/j.ces.2018.12.034
[38]	PENG Wenping, XU Min, HUAI Xiulan, et al. CFD study on local fluid to wall heat transfer in packed beds and field synergy analysis[J]. Journal of Thermal Science, 2016, 25(2): 161-170. doi: 10.1007/s11630-016-0847-x
[39]	LIU Xu, GUI Nan, YANG Xingtuan, et al. A new discrete element-embedded finite element method for transient deformation,movement and heat transfer in packed bed[J]. International Journal of Heat and Mass Transfer, 2021, 165: 120714. doi: 10.1016/j.ijheatmasstransfer.2020.120714
[40]	NICOLIN V, CLEARY P, MEHRAN K, et al. The effect of particle shape on the packed bed effective thermal conductivity based on DEM with polyhedral particles on the GPU[J]. Chemical Engineering Science, 2020, 219: 1-17.