Particle motion characteristics of atomization process in impinging entrained-flow gasifier

doi:10.11949/0438-1157.20190721

Abstract

Abstract:

Based on the laboratory scale of the impinging entrained-flow bed gasifier, the coal gas slurry was used as the raw material for gasification experiments. The particle information in images was identified by image post-processing algorithm and the particle tracking algorithm was used to calculate the particle trajectory. The particle size, particle velocity and particle motion angle were analyzed by statistical method. The results show that the averaged particle size of the jet flow region near the burner tip concentrates at 325－375 μm, which is larger than the original coal particles. The velocity of most particles concentrates at 1－2 m·s^-1 and almost keeps constant during the movement. The motion angles of most particles do not change with time, which means the trajectories of most particles show rectilinear motion. The distribution of all particle trajectories shows a fan-shaped ray starting from the burner tip.

Key words: impinging entrained-flow gasifier, atomization process, particle trajectory, visualization technology, statistical analysis

摘要：

基于实验室规模的撞击气流床气化炉，以水煤浆为原料进行气化实验，采用高温内窥镜及工业相机组成的可视化成像系统，在操作条件下，对水煤浆雾化过程进行拍摄。运用图像处理算法来识别和检测所得图像中的颗粒信息，利用颗粒示踪算法对颗粒进行轨迹测算。对颗粒的平均粒径、速度及角度进行统计分析。结果表明，喷嘴出口射流区内平均粒径主要集中在325～375 μm，相较于原煤颗粒较大；大部分颗粒速度集中在1～2 m·s^-1且运动过程中速度变化不大；大部分颗粒运动方向不随时间而变化，呈简单直线运动；颗粒轨迹呈现以喷嘴为起始点的扇形射线。

关键词: 撞击气流床气化炉, 雾化过程, 颗粒轨迹, 可视化技术, 统计分析

CLC Number:

TQ 546

Chen CHENG, Zhicun XUE, Qinghua GUO, Yan GONG, Guangsuo YU. Particle motion characteristics of atomization process in impinging entrained-flow gasifier[J]. CIESC Journal, 2019, 70(12): 4536-4545.

程晨, 薛志村, 郭庆华, 龚岩, 于广锁. 撞击气流床气化炉内雾化过程中颗粒运动特性[J]. 化工学报, 2019, 70(12): 4536-4545.

Figures/Tables 18

Fig.1 Experimental flow chart of bench-scale impinging entrained-flow gasifier

Fig.2 Sketch diagram of burner plane cross section

Table 1 Coal properties

工业分析/%（质量分数）			元素分析/%（质量分数）					灰熔点/℃
A_d	V_d	FC_d	C_d	H_d	N_d	S_d	O_d	DT	ST	HT	FT
9.82	31.42	58.76	73.96	4.47	0.75	0.77	10.23	1162	1248	1310	1335

Table 2 Properties of CWS

平均颗粒直径/μm	质量分数/%	黏度/(mPa·s)	密度/(kg·m^-3)
46.5	61	274.3	1129

Table 3 Operating conditions of CWS gasi?cation

水煤浆流速/(kg·h^-1)	O₂流速/(m³·h^-1)	(O/C)/(mol·mol^-1)
10	4.21	1.0

Fig.4 Schematic diagram of image post-processing

Fig.3 Calibration system and sample of images

Fig.5 Block diagram of particle tracing algorithm

Fig.6 Initial state of jet region

Fig.7 Combination diagram of particle location information

Fig.8 Particle trajectories

Fig.9 Schematic diagram of validation

Fig.10 Curve of particle velocity changes with time

Fig.11 Curve of particle motion angle changes with time

Fig.12 Coal particle size distribution of CWS

Fig.13 Particle size distribution in atomization process

Fig.14 Distribution diagram of particle velocity

Fig.15 Distribution of particle deflection angle

References 31

1	王辅臣, 于广锁, 龚欣，等 . 大型煤气化技术的研究与发展[J]. 化工进展, 2009, 28(2): 173-180.
	Wang F C , Yu G S , Gong X , et al . Research and development of large-scale coal gasification technology[J]. Chemical Industry and Engineering Progress, 2009, 28(2):173-180.
2	Pilch M , Erdman C A . Use of breakup time data and velocity history data to predict the maximum size of stable fragments for acceleration-induced breakup of a liquid drop[J]. International Journal of Multiphase Flow, 1987, 13(6): 741-757.
3	Chigier N , Reitz R D . Regimes of jet breakup and breakup mechanisms physical aspects[M]//Recent Advances in Spray Combustion: Spray Atomization and Drop Burning Phenomena. Virginia:American Institute of Aeronautics and Astronautics, 1996: 109-135
4	McCarthy M J , Molloy N A . Review of stability of liquid jets and the influence of nozzle design[J]. The Chemical Engineering Journal, 1974, 7(1): 1-20.
5	Ranz W E . On sprays and spraying: a survey of spray technology for research and development engineers(1)[R]. Department of Engineering Research, Pennsylvania State University, Bulletin, 1956: 65.
6	Rayleigh L . On the instability of jets[J]. Proceedings of the London Mathematical Society, 1878, 1(1): 4-13.
7	Weber C . Disintegration of liquid jets[J]. Z. Angew. Math Mech., 1931, 11(2): 136-159.
8	Lefebvre A H , McDonell V G . Atomization and Sprays[M]. Boca Raton:CRC Press, 2017.
9	原鲲, 陈丽芳, 吴承康 . 水煤浆多级喷嘴的雾化和流动特性[J]. 燃烧科学与技术, 2003, 9(1): 77-80.
	Yuan K , Chen L F , Wu C K . Atomization and spray characteristics of a multi-stage airblast nozzle for coal-water slurry[J]. Journal of Combustion Science and Technology, 2003, 9(1): 77-80.
10	程维, 赵辉, 孟沁玮, 等 . 水煤浆气流雾化的初次破裂特性[J]. 化工学报, 2011, 62(1): 25-31.
	Cheng W , Zhao H , Meng Q W , et al . Primary breakup characteristics of air-blast atomization of coal-water slurry[J]. CIESC Journal, 2011, 62(1): 25-31.
11	Zhao H , Liu H F , Xu J L , et al . Breakup and atomization of a round coal water slurry jet by an annular air jet[J]. Chemical Engineering Science, 2012, 78: 63-74.
12	Zhao H , Liu H F , Xu J L , et al . Secondary breakup of coal water slurry drops[J]. Physics of Fluids, 2011, 23(11): 113101.
13	赵辉 . 同轴气流式雾化机理研究[D]. 上海: 华东理工大学, 2012.
	Zhao H . Study on the mechanism of coaxial air-blast atomization[D]. Shanghai: East China University of Science and Technology. 2012.
14	Xuan Y , Jihong P , Wanhai Y . Firing particle flow detection and tracking in sequence images[C]//Proceedings of the 3rd World Congress on Intelligent Control and Automation Cat. No. 00EX393). IEEE, 2000, 4: 2666-2670.
15	双凯, 董守平 . 粒子成像测速图像的模糊聚类识别[J]. 石油大学学报(自然科学版), 2000, 24(6): 66-68, 71.
	Shuang K , Dong S P . Fuzzy clustering identification of particle imaging velocimetry images[J]. Journal of China University of Petroleum (Edition of Natural Science), 2000, 24(6): 66-68, 71.
16	Zhang L , Binner E , Qiao Y , et al . High-speed camera observation of coal combustion in air and O₂/CO₂ mixtures and measurement of burning coal particle velocity[J]. Energy & Fuels, 2009, 24(1): 29-37.
17	Matthes J , Hock J , Waibel P , et al . A high-speed camera based approach for the on-line analysis of particles in multi-fuel burner flames[J]. Experimental Thermal and Fluid Science, 2016, 73: 10-17.
18	吴占松 . 发光火焰的图像处理及其在燃烧检测中的应用[D]. 北京: 清华大学, 1988.
	Wu Z S . Image processing of luminous flame and its application in combustion detection[D]. Beijing: Tsinghua University, 1988.
19	刘双科, 徐旭常, 邓国强, 等 . 高速摄像技术在循环床锅炉出口区域颗粒运动测量中的应用[J]. 流体力学实验与测量, 2001, 15(3): 62-66.
	Liu S K , Xu X C , Deng G Q , et al . Measuring particles motion at the exit zone in circulating fluidized bed boilers by high-speed video camera system[J]. Journal of Experiments in Fluid Mechanics, 2001, 15(3): 62-66.
20	刘浩, 周怀春, 娄春, 等 . 燃煤锅炉炉膛断面温度场可视化实验研究[J]. 热科学与技术, 2003, 2(3): 250-254.
	Liu H , Zhou H C , Lou C , et al . Experimental research on visualization of two-dimensional temperature distributions in coal-fired furnace[J]. Journal of Thermal Science and Technology, 2003, 2(3): 250-254.
21	Lou C , Zhou H C . Deduction of the 2-D temperature distribution in a cross-section of boiler furnace from flame radiation images [J]. Combustion and Flame, 2005, 143(1/2): 97-105.
22	曾佳, 娄春, 程强, 等 . 大型电站锅炉炉内三维燃烧温度场可视化实验研究[J]. 工程热物理学报, 2004, 25(3): 523-526.
	Zeng J , Lou C , Cheng Q , et al . Visualization and detection of tridimensional temperature field in large-scale power plant boiler[J]. Journal of Engineering Thermophysics, 2004, 25(3): 523-526.
23	Zhou H C , Lou C , Cheng Q , et al . Experimental investigations on visualization of three-dimensional temperature distributions in a large-scale pulverized-coal-fired boiler furnace[J]. Proceedings of the Combustion Institute, 2005, 30(1): 1699-1706.
24	Wang H , Huang Z , Wang D , et al . Measurements on flame temperature and its 3D distribution in a 660 MWe arch-fired coal combustion furnace by visible image processing and verification by using an infrared pyrometer[J]. Measurement Science and Technology, 2009, 20(11): 114006.
25	王勤辉, 赵晓东, 石惠娴, 等 . 循环流化床内颗粒运动的PIV测试[J]. 热能动力工程, 2003, 18(4): 378-381.
	Wang Q H , Zhao X D , Shi H X , et al . PIV test of particle motion in a circulating fluidized bed[J]. Journal of Engineering for Thermal Energy and Power, 2003, 18(4): 378-381.
26	马志刚, 方梦祥, 骆仲泱, 等 . 矩形截面流化床内颗粒运动可视化试验研究[J]. 中国电机工程学报, 2007, 27(14): 24-30.
	Ma Z G , Fang M X , Luo Z Y , et al . Visual measurement of particle movement in rectangular circulating fluidized bed[J]. Proceedings of the CSEE, 2007, 27(14): 24-30.
27	龚岩 . 多喷嘴对置式气化炉内火焰可视化研究[D]. 上海: 华东理工大学, 2013.
	Gong Y . Study on flame visualization in multi-nozzle opposed gasifier[D]. Shanghai: East China University of Science and Technology, 2013.
28	Xue Z , Guo Q , Gong Y , et al . In-situ atomization and flame characteristics of coal water slurry in an impinging entrained-flow gasifier[J]. Chemical Engineering Science, 2018, 190: 248-259.
29	Xue Z , Guo Q , Gong Y , et al . Detailed deposition characteristics around burner plane in an impinging entrained-flow coal gasifier[J]. Chemical Engineering Science, 2019, 19: 85-97.
30	张庆 . 多喷嘴对置式气化炉内火焰辐射发光及颗粒特性可视化研究[D]. 上海: 华东理工大学, 2017.
	Zhang Q . Visualization of flame radiation luminescence and particle characteristics in multi-nozzle opposed gasifier[D]. Shanghai: East China University of Science and Technology, 2017.
31	Zhang Q , Gong Y , Guo Q H , et al . Experimental study of particle evolution characteristics in an opposed multi-burner gasifier[J]. Chemical Engineering Science, 2017, 162: 104-119.

[1]	LIU Jieyu, GONG Yan, WU Xiaoxiang, GUO Qinghua, YU Guangsuo, WANG Fuchen. Visualization study on particle volatile flame opposed multi-burner impinging entrained-ﬂow gasiﬁer [J]. CIESC Journal, 2021, 72(3): 1275-1282.
[2]	HU Tingting, WANG Fan, SHI Hongbo. Factor analysis process monitoring method based on probabilistic information of variables [J]. CIESC Journal, 2017, 68(7): 2844-2850.
[3]	TONG Cong1，LI Shuangyue1，LI Xiang2. Numerical simulation on particles classification trajectory using unsteady tracking [J]. Chemical Industry and Engineering Progree, 2013, 32(09): 2061-2067.