钒钛磁铁矿球团煤基还原颗粒运动及煤粉喷射燃烧数值模拟

刘鹏; 宇文超; 龚斯宇; 刘秉国; 张利波; 彭金辉

doi:10.7513/j.issn.1004-7638.2021.04.017

钒钛磁铁矿球团煤基还原颗粒运动及煤粉喷射燃烧数值模拟

doi: 10.7513/j.issn.1004-7638.2021.04.017

刘鹏^{1, 2,},
宇文超^{1, 2},
龚斯宇^{1, 2},
刘秉国^{1, 2, ,},
张利波^{1, 2},
彭金辉^{1, 2}

1.
昆明理工大学冶金与能源工程学院，云南昆明 650093
2.
昆明理工大学非常规冶金省部共建教育部重点实验室，云南昆明 650093

基金项目: 国家重点研发计划（2018YFC1900500）

详细信息

作者简介:
刘鹏（1989−），男，辽宁葫芦岛人，博士在读，研究方向：钒钛磁铁矿非高炉冶炼技术，E-mail：786538903@qq.com；

通讯作者:
刘秉国，教授，博士，电话：0871-5191046，E-mail：bingoliu@126.com

中图分类号: TF55, TF046
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- 文章访问数: 499
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- 被引次数: 0
出版历程
- 收稿日期: 2021-05-14
- 刊出日期: 2021-08-10

Simulation on particle movement and pulverized coal jet combustion of titano-magnetite pellets during the reduction with coal in rotary kiln

Liu Peng^{1, 2
,},
Yu Wenchao^{1, 2},
Gong Siyu^{1, 2},
Liu Bingguo^{1, 2
, ,},
Zhang Libo^{1, 2},
Peng Jinhui^{1, 2}

1.
Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
2.
Yunnan Provincial Key Laboratory of Intensification Metallurgy, Kunming 650093,Yunnan, China

摘要

摘要: 开展了回转窑内钒钛磁铁矿球团煤基还原颗粒运动及煤粉喷射燃烧数值模拟研究。结果表明，回转窑内三种颗粒在运动过程中存在分层现象和离散料堆现象。离散料堆现象导致了颗粒数轴向周期性波动分布，并结合反应焓变推导出了单个周期内的平均波动能量为$ \tilde {{E}}$= 25.58 MJ；煤粉喷射燃烧过程中燃料射流在重力作用下会形成反弹效果，作用区间长度约2 m，该区域内传质传热过程被强化，易出现局部过热现象，可通过附着配碳和外配碳球团混合配碳的方式削弱能量波动与局部过热，矿石颗粒的附着配碳量约为18.9 g/kg。
- 钒钛磁铁矿 /
- 回转窑 /
- 还原 /
- 数值模拟 /
- 颗粒运动 /
- 煤粉喷射燃烧
Abstract: In this paper, the numerical simulation of on particle movement and pulverized coal injection combustion duringin the coal coal-based reduction of titano-magnetite pellets in rotary kiln was carried out. The results show that there were delamination phenomenon and discrete pile phenomenon in the movement process of three kinds of particles in rotary kiln. The discrete particle piles led to the axial periodic fluctuation distribution of particle number. Combined with the change of reaction enthalpy, the average fluctuation energy in a single period was deduced as $\tilde {{E}}$ = 25.58 MJ; in the process of pulverized coal injection combustion, the fuel jet would form a rebound effect under the action of gravity, and the length of the action zone was about 2 m. The mass and heat transfer process in this zone was strengthened, and the local overheating phenomenon was readily to occur. The energy fluctuation and local overheating could be reduced by the way of attaching carbon with coal powder on the surface of ore pellets and mixing carbon with external coal pellets. The amount of carbon distribution by adhering to ore particles is about 18.9 g/kg.
- titanomagnetite /
- rotary kiln /
- reduction /
- simulation /
- particle movement /
- pulverized coal jet combustion

HTML全文

图 1 回转窑的模拟简化结构

(a)回转窑结构；(b)颗粒运动模拟简化结构；(c)煤粉喷射燃烧模拟网格划分

Figure 1. Simplified simulation structure of rotary kiln

下载: 全尺寸图片幻灯片

图 2 颗粒运动模拟结果

(a)休止角计算与分层现象；(b)反应区域内颗粒数轴向波动性分析；(c)反应区域内反应焓引起的能量轴向波动性分析

Figure 2. Simulation results of particle motion

下载: 全尺寸图片幻灯片

图 3 还原过程中相关反应的热力学分析

（a）固相还原反应；（b）间接气相还原反应

Figure 3. Thermodynamic analysis of related reactions in reduction process

下载: 全尺寸图片幻灯片

图 4 煤粉喷射燃烧温度场分布模拟结果（径向截面与左视图）

Figure 4. Simulation results of temperature field distribution of pulverized coal injection combustion (radial section and left view)

下载: 全尺寸图片幻灯片

图 5 煤粉喷射燃烧速度场分布模拟结果（反弹长度指数-RLI）

反应区域内重力作用下燃料射流的反弹效果

Figure 5. Simulation results of velocity field distribution of pulverized coal injection combustion (Rebound Length Index-RLI)

下载: 全尺寸图片幻灯片

表 1 钒钛磁铁矿精矿主要化学成分

Table 1. Main chemical compositions of titano-magnetite concentrate %

Fe₃O₄	TiO₂	Al₂O₃	SiO₂	MgO	CaO	MnO	Na₂O	Co₃S₄	ZnS	CuS
68.51	13.41	5.00	6.77	4.45	1.17	0.29	0.16	0.15	0.050	0.019

下载: 导出CSV

表 2 模拟过程（颗粒运动）中的颗粒生成参数

Table 2. Particle formation parameters used in simulation study (particle motion)

	实体密度 ρ/(g·cm⁻³)	半径分布/ mm	生成速率/ (kg·s⁻¹)	质量分数/ %
煤粒	1.5	N(10,0.25)	0.2062	11.42
熔剂	2.6	N(5,0.25)	0.1461	11.50
矿粒	3.6	N(7.5,0.25)	1.2083	77.08
注：N(10,0.25)表示模拟过程中颗粒半径按正态分布生成，10 为半径平均值（单位：mm），0.25为标准差。

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表 3 模拟过程中（煤粉喷射燃烧）燃料参数

Table 3. Fuel parameters used in simulation study (pulverized coal injection combustion)

燃料空气混合物组成/%				工业分析/%				元素分析w/%
煤粉	O₂	CO₂	H₂O	挥发分	C固	灰分	水分	C	H	O	N
20	18.4	0.1	0.1	10	75	10	5	90	5	4	1
注：燃料热值为29.67 MJ/kg。

下载: 导出CSV

表 4 模拟过程中（煤粉喷射燃烧）燃料喷射速度

Table 4. Fuel injection velocity used in simulation study (pulverized coal injection combustion)

煤粉喷射速度/(m·s⁻¹)	质量流动/(kg·s⁻¹)
6	0.0666691
7	0.0777806
8	0.0888922
9	0.100004
10	0.111115

下载: 导出CSV

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