液-固下行循环流化床中的颗粒碰撞行为

摘要设计并构建了一套冷模液-固下行循环流化床蒸发器,考察了颗粒对壁面的碰撞行为随轴向位置和操作参数的变化规律,以便更好地揭示循环流化床强化传热和防、除垢的机理。实验中,选用水和不同粒径的聚甲醛颗粒和玻璃珠作为工质,对不同颗粒加入量(0~2.0%)和循环流量(2.15~5.16 m³·h^-1)下的碰撞加速度信号进行了功率谱密度、峰度和标准偏差等频域和时域分析。研究结果表明:液相和固相碰撞加速度信号的频率范围分别为0~2 000 Hz和6 000~16 000 Hz。沿着下行床的轴向位置从上到下,颗粒对壁面碰撞加速度信号的标准偏差先减小,后增大;峰度增大。随着颗粒加入量和循环流量的增加,标准偏差增大,峰度减小。颗粒加入量较低时,标准偏差随着聚甲醛颗粒粒径的增加先减小、后增大;而峰度随着粒径的增加明显增大。颗粒加入量较高时,标准偏差和峰度随着粒径的增加而增大,但增大的幅度较小。玻璃珠的标准偏差较小,但峰度明显高于聚甲醛颗粒。构建了操作参数对颗粒碰撞行为影响的三维图。研究结果有助于促进流化床换热防垢节能技术的工业化应用。

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	姜峰
	刘艺
	齐国鹏
	李修伦

关键词：颗粒碰撞行为液-固循环流化床下行床功率谱密度标准偏差峰度

Abstract： A cold-model liquid-solid down-flow circulating fluidized bed evaporator is designed and built. The effect of the axial position and operating parameters on the particle-to-wall collision behavior is investigated to reveal the heat transfer enhancement and fouling prevention mechanism. Water and different sizes of polyformaldehyde particles and glass beads are selected as the working media in the experiments. The collision acceleration signals are dealt with the frequency and time domains analyses such as the power spectral density, kurtosis and standard deviation under different operating parameters including the amount of added particles (0—2.0%) and circulation flow rate (2.15—5.16 m³·h^-1). The results show that the frequency range of the collision acceleration signals are from 0 to 2 000 Hz and 6 000 to 16 000 Hz for the liquid and solid phases, respectively. The standard deviation of the particle-to-wall collision acceleration signals initially decreases and then increases along the axial direction of the down-flow bed from the top to the bottom; however, the kurtosis increases. The standard deviation increases, but the kurtosis decreases with the increases of the amount of added particles and circulation flow rate. The standard deviation of the polyformaldehyde particles initially decreases and then increases with the increase of particle size at low amount of added particles; however, the kurtosis obviously increases. The standard deviation and kurtosis of the polyformaldehyde particles increase with the increase of particle size at high amount of added particles, but the amplitude of the increase in kurtosis is small. The standard deviation of the glass bead is small, but the kurtosis is obviously higher than that of the polyformaldehyde particles. The three-dimensional diagrams are established to reflect the effect of the operating parameters on the particle collision behavior. The findings are beneficial to promoting the industrial application of the fluidized bed heat transfer and fouling prevention technology.

Keywords： particle collision behavior liquid-solid circulating fluidized bed down-flow bed power spectral density standard deviation kurtosis

Received 2021-03-10;

Fund:化学工程国家重点实验室开放项目(SKL-CHE-18B03);天津市科技支撑计划重点项目(2009ZCKFGX01900)。

Corresponding Authors: 姜峰,副教授,E-mail:jiangfeng@tju.edu.cn。 Email: jiangfeng@tju.edu.cn

About author: 姜峰(1975-),男,博士,副教授,现从事多相流强化传热与防、除垢方面的研究。

引用本文:

姜峰, 刘艺, 齐国鹏, 李修伦.液-固下行循环流化床中的颗粒碰撞行为[J]. 化学工业与工程, 2022,39(3): 49-59

JIANG Feng, LIU Yi, QI Guopeng, LI Xiulun.Study on particle collision behavior in a liquid-solid down-flow circulating fluidized bed[J]. Chemcial Industry and Engineering, 2022,39(3): 49-59

[1] 刘燕, 李洪彬, 王晋刚, 等. 带有Kenics静态混合器的水平液固两相流化床换热管的压降研究[J]. 化工进展, 2013, 32(11): 2579-2582 LIU Yan, LI Hongbin, WANG Jingang, et al. Researches on pressure drop of horizontal liquid-solids two-phase fluidized bed heat exchang tube with Kenics static mixer[J]. Chemical Industry and Engineering Progress, 2013, 32(11): 2579-2582(in Chinese)
[2] 刘德新. 油田污水处理[M]. 山东东营: 中国石油大学出版社, 2015
[3] 陈健生, 李修伦, 张少峰, 等. 汽液固三相循环流化床蒸发器强化传热和防垢研究[J]. 化学工业与工程, 2000, 17(1): 15-18, 62 CHEN Jiansheng, LI Xiulun, ZHANG Shaofeng, et al. Studies of heat transfer enhancement and fouling prevention in a vapor liquid solid three phase circulating fluidized bed evaporator[J]. Chemical Industry and Engineering, 2000, 17(1): 15-18, 62(in Chinese)
[4] LIU M, TANG X, JIANG F. Studies on the hydrodynamic and heat transfer in a vapor-liquid-solid flow boiling system with a CCD measuring technique[J]. Chemical Engineering Science, 2004, 59(4): 889-899
[5] WEN J, ZHOU H, LI X. Performance of a new vapor-liquid-solid three-phase circulating fluidized bed evaporator[J]. Chemical Engineering and Processing: Process Intensification, 2004, 43(1): 49-56
[6] JIANG F, ZHAO P, QI G, et al. Pressure drop in horizontal multi-tube liquid-solid circulating fluidized bed[J]. Powder Technology, 2018, 333: 60-70
[7] MÜLLER-STEINHAGEN H. Heat transfer fouling: 50 years after the Kern and Seaton model[J]. Heat Transfer Engineering, 2011, 32(1): 1-13
[8] JIANG F, YANG M, QI G, et al. Heat transfer and antiscaling performance of a Na₂SO₄ circulating fluidized bed evaporator[J]. Applied Thermal Engineering, 2019, 155: 123-134
[9] 姜峰, 王锦锦, 齐国鹏, 等. 水平双管程液-固循环流化床中颗粒分布和压降[J]. 化学工业与工程, 2021, 38(2): 30-38, 68 JIANG Feng, WANG Jinjin, QI Guopeng, et al. Particle distribution and pressure drop in a horizontal two-pass liquid-solid circulating fluidized bed[J]. Chemical Industry and Engineering, 2021, 38(2): 30-38, 68(in Chinese)
[10] NAZIR S, FARID M M. Modeling ice removal in fluidized-bed freeze concentration of apple juice[J]. AIChE Journal, 2008, 54(11): 2999-3006
[11] SONG J, CHI J. Heat transfer enhancement of a three phase circulating fluidized bed fruit juice evaporator using inert particles[J]. International Journal of Food Engineering, 2011, doi:10.2202/1556-3758.2111
[12] CHOWDHURY N, ZHU J, NAKHLA G, et al. A novel liquid-solid circulating fluidized-bed bioreactor for biological nutrient removal from municipal wastewater[J]. Chemical Engineering & Technology, 2009, 32(3): 364-372
[13] 吴若琼, 湛雪辉, 刘今. 防止氧化铝厂蒸发器结垢的新方法[J]. 中南工业大学学报(自然科学版), 1999, 30(1): 45-48 WU Ruoqiong, ZHAN Xuehui, LIU Jin. A new method of antiscale deposition in evaporator of alumina factory[J]. Journal of Central South University of Technology(Natural Science), 1999, 30(1): 45-48(in Chinese)
[14] LIU M, YANG Y, LI X, et al. Concentration of Gengnian’an extract with a vapor-liquid-solid evaporator[J]. AIChE Journal, 2005, 51(3): 759-765
[15] RAUTENBACH R, KATZ T. Survey of long time behavior and costs of industrial fluidized bed heat exchangers[J]. Desalination, 1997, 108(1/2/3): 335-344
[16] PRONK P, INFANTE FERREIRA C A, WITKAMP G J. Prevention of fouling and scaling in stationary and circulating liquid-solid fluidized bed heat exchangers: Particle impact measurements and analysis[J]. International Journal of Heat and Mass Transfer, 2009, 52(15/16): 3857-3868
[17] PRONK P, INFANTE FERREIRA C A, WITKAMP G J. Mitigation of ice crystallization fouling in stationary and circulating liquid-solid fluidized bed heat exchangers[J]. International Journal of Heat and Mass Transfer, 2010, 53(1/2/3): 403-411
[18] KANG H, LEE B C, AHN S W, et al. Numerical and experimental analyses of anti-fouling and heat transfer in the heat exchanger with circulating fluidized bed[J]. The Canadian Journal of Chemical Engineering, 2011, 89(2): 240-253
[19] 张少峰, 王琦, 高川博, 等. 液固两相外循环流化床压力波动信号的统计及频谱分析[J]. 过程工程学报, 2006, 6(6): 878-883 ZHANG Shaofeng, WANG Qi, GAO Chuanbo, et al. Statistical and frequency analysis of pressure fluctuations in liquid-solid exterior circulating fluidized bed[J]. The Chinese Journal of Process Engineering, 2006, 6(6): 878-883(in Chinese)
[20] SHEIKHI A, SOTUDEH-GHAREBAGH R, MOSTOUFI N, et al. Frequency-based characterization of liquid-solid fluidized bed hydrodynamics using the analysis of vibration signature and pressure fluctuations[J]. Powder Technology, 2013, 235: 787-796
[21] SPENIK J L, LUDLOW J C. Use of piezoelectric pressure transducers to determine local solids mass flux in the riser of a cold flow circulating fluidized bed[J]. Powder Technology, 2010, 203(1): 86-90
[22] ABBASI M, SOTUDEH-GHAREBAGH R, MOSTOUFI N, et al. Non-intrusive monitoring of bubbles in a gas-solid fluidized bed using vibration signature analysis[J]. Powder Technology, 2009, 196(3): 278-285
[23] MA Y, LIU M, AN M, et al. Experimental investigation of collision behavior of fluidized solid particles on the tube wall of a graphite evaporator by vibration signal analysis[J]. Powder Technology, 2017, 316: 303-314
[24] BUFFIÈRE P, MOLETTA R. Collision frequency and collisional particle pressure in three-phase fluidized beds[J]. Chemical Engineering Science, 2000, 55(22): 5555-5563
[25] AN M, LIU M, MA Y, et al. Multi-scale vibration behavior of a graphite tube with an internal vapor-liquid-solid boiling flow[J]. Powder Technology, 2016, 291: 201-213
[26] EHSANI M, MOVAHEDIRAD S, SHAHHOSSEINI S. The effect of particle properties on the heat transfer characteristics of a liquid-solid fluidized bed heat exchanger[J]. International Journal of Thermal Sciences, 2016, 102: 111-121
[27] ABBASI M, MOSTOUFI N, SOTUDEH-GHAREBAGH R, et al. A novel approach for simultaneous hydrodynamic characterization of gas-liquid and gas-solid systems[J]. Chemical Engineering Science, 2013, 100: 74-82
[28] 李正周.数字信号处理与应用[M].北京:清华大学出版社,2005 LI Zhengzhou. Digital signal processing and applications [M]. Beijing: Tsinghua University Press, 2005 (in Chinese)
[29] 马悦, 刘明言, 安敏, 等. 汽-液-固三相流对石墨加热管内壁面磨损的实验研究[J]. 化学工业与工程, 2016, 33(4): 61-66 MA Yue, LIU Mingyan, AN Min, et al. Experimental study on attrition of vapor-liquid-solid flow against wall of a graphite tube in heat exchanger[J]. Chemical Industry and Engineering, 2016, 33(4): 61-66(in Chinese)
[30] 安敏. 管内汽-液-固流动沸腾激发的石墨管的多尺度振动行为[D]. 天津: 天津大学, 2016 AN Min. Multi-scale vibration behavior of a graphite heat transfer tube with vapor-liquid-solid flow boiling[D]. Tianjin: Tianjin University, 2016 (in Chinese)
[31] JIANG B, TIAN M C, CHENG L. Research on vibration and heat transfer characteristics of an optimized structure of elastic tube bundle[J]. Advanced Materials Research, 2013, 816/817: 260-265
[32] LV S, JIANG F, QI G, et al. Pressure drop of liquid-solid two-phase flow in a down-flow circulating fluidized bed[J]. Powder Technology, 2020, 375: 136-145