链箅机回转窑球团热废气循环工艺及数值模拟研究

何璐瑶; 王鑫; 胡兵; 甘敏; 朱亮; 魏进超; 代友训

doi:10.7513/j.issn.1004-7638.2021.04.015

链箅机回转窑球团热废气循环工艺及数值模拟研究

doi: 10.7513/j.issn.1004-7638.2021.04.015

何璐瑶^1,,
王鑫^2, ,,
胡兵^{1, 3},
甘敏²,
朱亮²,
魏进超^{1, 3},
代友训¹

1.
中冶长天国际工程有限责任公司，湖南长沙 410205
2.
中南大学资源加工与生物工程学院，湖南长沙410083
3.
国家烧结球团装备系统工程技术研究中心，湖南长沙 410205

基金项目: 湖南省自然科学基金（2019JJ51007）资助项目

详细信息

作者简介:
何璐瑶（1983−），硕士研究生，主要从事烧结球团领域专利情报分析工作，E-mail：heluyao@cie-cn.com

通讯作者:
王鑫（1996−），硕士研究生，主要从事冶金过程数值模拟的研究，E-mail：xingxiang@csu.edu.cn

中图分类号: TF046，X756
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出版历程
- 收稿日期: 2020-12-11
- 刊出日期: 2021-08-10

Recirculating process of pellet exhaust gas from grate-kiln and numerical simulation

He Luyao^1
,,
Wang Xin^{2
, ,},
Hu Bing^{1, 3},
Gan Min²,
Zhu Liang²,
Wei Jinchao^{1, 3},
Dai Youxun¹

1.
Zhongye Changtian International Engineering Co., Ltd., Changsha 410205, Hunan, China
2.
School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, Hunan, China
3.
National Engineering Research Center of Sintering and Pelletizing Equipment System, Changsha 410205, Hunan, China

摘要

摘要: 针对链箅机回转窑环冷机生产过程中废气外排量大、余热利用率低的问题，在原有废气循环的基础上，提出了一种将过渡预热段的热废气循环到环冷机二段的废气循环工艺，并对新模式下的球团冷却过程进行模拟仿真研究。基于计算流体力学理论基础，结合局部非热力学平衡理论和磁铁矿氧化反应模型，采用CFD软件建立了数值仿真模型，揭示了废气循环对球团冷却的影响规律。研究结果表明，采用新的烟气循环系统之后，冷却二段的废气温度从511 ℃提高到523 ℃，提高了热利用效率。采用该废气循环模式，可减少废气排放11.5%，循环回收热量占球团生产热量总支出的3.45%。为球团生产进一步节能减排提供了新的方向，对于球团清洁生产具有重要意义。
- 球团 /
- 链箅机-回转窑-环冷机 /
- 废气循环 /
- 数值模拟 /
- 节能减排
Abstract: Aiming at the problems of large exhaust gas discharge and low waste heat utilization rate of the grate-kiln ring cooler, a waste gas cycle technology that recycles the hot waste gas from the transitional preheating section to the second section of the circular cooling machine, was proposed. Then the pellet cooling process after using the waste gas cycle was simulated and studied. Based on the theory of computational fluid dynamics and combined with the local non-thermodynamic equilibrium theory and the magnetite oxidation reaction model, a numerical simulation model was established by CFD software to reveal the influence of exhaust gas cycle on pellet cooling. The results show that the exhaust gas temperature of the second cooling stage increases from 511 ℃ to 523 ℃ after adapting the flue gas circulation system, improving the heat utilization efficiency. The exhaust gas emission can be reduced by 11.5%, and the energy occupying 3.45% of the total heat expenditure for pellet production can be recovered. This study provides a new direction for further energy saving and emission reduction in pellet production, which is of great significance for pellet cleaner production.
- pellet /
- grate-kiln ring cooler /
- exhaust gas circulation /
- numerical simulation /
- energy saving

HTML全文

图 1 链箅机-回转窑-环冷机过程示意

Figure 1. Process diagram of grate-kiln ring cooler

下载: 全尺寸图片幻灯片

图 2 环冷机台车几何模型

Figure 2. Geometric model of circular cooler car

下载: 全尺寸图片幻灯片

图 3 环冷机球团温度云图

图中各颜色对应的温度见右侧温度标尺

Figure 3. Pellet temperature contour in circular cooling machine

下载: 全尺寸图片幻灯片

图 4 环冷二段和三段末台车高度方向上的温度云图

Figure 4. Temperature contour in the height direction of the second and third section in the circular cooling machine

下载: 全尺寸图片幻灯片

图 5 循环前后环冷机二段、三段末球团温度对比

Figure 5. Comparison of pellet temperatures of the second and third section in the circular cooling machinebefore and after the cycle

下载: 全尺寸图片幻灯片

表 1 TPH段风箱废气组成

Table 1. Composition of bellows waste gas in TPH section

风箱号	O₂/%	NO×10⁶	SO₂×10⁶	CO₂/%	温度/℃
6^#	19.25	116	132	0.7	154
7^#	19.85	70	65	0.5	170
8^#	17.22	268	295	1.7	215

下载: 导出CSV

表 2 球团矿物性参数

Table 2. Pellet property parameters

球团矿密度 /(kg·m⁻³)	球团矿比表面积/(m²·m⁻³)	球团半径/mm	料床孔隙率/%	料床导热系数/ [J·(m·s·K)⁻¹]
2400	303	14	0.4	3.0

下载: 导出CSV

表 3 温度模拟值和实测值比较

Table 3. Comparison between the simulated and measured temperature values

	模拟值/℃	实测值/℃	误差/%
一段烟罩中心	930	902	+3.1
二段烟罩中心	517	536	−3.5
三段烟罩中心	303	281	+7.8

下载: 导出CSV

表 4 废气循环对环冷机不同位置断面平均温度的影响

Table 4. Influence of exhaust gas cycle on average temperature of different positions on circular cooler ℃

是否循环	项目	环冷一段			环冷二段			环冷三段
是否循环	项目	初始	结束	平均	初始	结束	平均	初始	结束	平均
未循环	球团矿	1238	684	961	684	334	509	334	132	233
未循环	烟气	1072	656	864	656	366	511	366	129	248
废气循环	球团矿	1238	684	961	684	359	522	359	144	252
废气循环	烟气	1072	656	864	656	389	523	389	139	264

下载: 导出CSV

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