基于相似理论的煤调湿实验装置研究
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摘 要
我国作为全球焦炭生产、消费和出口大国，炼焦用煤却普遍存在含水量
偏高的问题，年平均含水率达 11%左右。根据相关资料报道：炼焦过程中煤中水
分每增加 1%，多耗热能 62.0MJ/t(干煤)计算。解决此类问题的方法为使用煤调湿
技术。若采用煤调湿技术，将煤中水分由 11%降至 6%，则可节省炼焦耗热能
10.6kgce/t(干煤)，然而炼焦用煤湿度降低后，煤料中细颗粒在运输途中，采用露
天方式易扩散至空气中造成污染，采用管道运输方式易发生粉尘爆炸造成安全威
胁，同时，炼焦煤中细颗粒增加对焦炉煤气的后续处理也会造成很大影响，故在
新型煤调湿工艺（装置）流程中嵌入了细颗粒选粉工序。
本文对现有细颗粒选粉装置进行研究，提出了一种新型鼓泡流化床方式的选
粉装置。该装置的选粉工作机理采用鼓泡流化状态为设计原理，根据不同流化速
度与煤颗粒关系，结合流化床自由空域内颗粒扬析与夹带的概念设计沉降室与装
置结合，保证 200μm细颗粒能够完全带出选粉装置并且 300μm颗粒能够沉降回
装置内，由物料出口带出。本文通过理论计算设计处理量为 200t/h 的细颗粒选粉
装置数学模型，并以相似理论为方法，将模型缩小为处理量为 2t/h 的相似模型。
由于煤颗粒粒径分布跨度大，在实验途中易发生破碎等容易影响实验结果等不利
因素存在，设计将选粉物质更换为石英砂的细颗粒选粉装置模型，并分别对两种
相似模型进行 Fluent 模拟仿真，研究颗粒运动情况，为实际工程装置的设计制造
和运行操作提供理论依据。
通过对煤颗粒模型和石英砂模型的仿真模拟数据的分析、整理、计算及归纳，
得出以下几点结论：
1、细颗粒选粉装置设计能够满足 300μm粗颗粒充分沉降，通过减少选粉装
置的处理量来延长颗粒在装置内的停留时间的方法，可以增加单位时间内细颗粒
的带出率，达到增加沉降室出口处 200μm细颗粒带出比例的作用。
2、在使用相似理论将模型外形尺寸缩小的基础上，使用煤颗粒为选粉物质
的模型在气体出口处颗粒带出率与选粉装置设计装置的计算值比较，粒径为
200μm~300μm颗粒带出率平均偏差为 23%；使用石英砂颗粒为选粉物质的模型
平均偏差为 18%，这个偏差数值是工程可以接受范围之内的。
3、在 Fluent 仿真软件平台上，对两种模型进行模拟仿真，分别绘制其运动
轨迹以及颗粒浓度曲线，发现同等处理量下 200μm煤颗粒模型气体出口颗粒浓
度与理论计算值偏差为 14.73%，石英砂颗粒模型为 12.85%，偏差均在工程允许
范围内。
本文设计的细颗粒选粉装置不仅从理论上验证了装置可行性，还通过仿真模
拟，进一步确认模型假设，为装置由设计阶段上升至实际运行阶段，并推广至所
有焦化行业解决选粉问题提供参考借鉴。
关键字：煤调湿 选粉 相似理论 DPM 模型
ABSTRACT
China is the largest coke country for production, consumption and export, coking
coal. But the coal prevalently has the problem of high water content which reached
average 11%. According to the relevant date, the moisture of coal increased every 1%,
the consumption of thermal energy will increased 62.0 MJ/t (dry coal). To solve this
problem is using the Coal Moisture Control technology. It makes the moisture of coal
decreased from 11% to 6% that saves thermal energy 10.6 kgce/t (dry coal). However,
the low moisture of coal will made the cohesiveness of coal decreased. With the
transport method of the open way, the fine particles will spread to the air and pollute
the environment. With the transport method of the pipeline, the dust is liked to
explosion. Moreover, the fine particles will make the manage process of coke oven
gas harder. So it is significant to add the classifier particle process in the coal moisture
control process.
This paper is about the classifier particle device. It gives a new form of bubbling
fluidized bed. This device is based on the bubbling fluidized theory. According to the
relationship of fluidization velocity and coal particle, it confines the 200μm fine
particles can completely out and the 300μm can settling back in the device which
combined with the theory of entrainment particles in TDH and the design of subside
chamber. This paper designed a capacity for 200t/h theoretical model, and built a
model which the capacity narrow to 2t/h by taking the similar theory. Because of coal
particle size distribution span, the particles are liked to crush into fine particles. So we
instead the classifier particles into sands which has steady quality and simulate the
two model through Fluent to get the particle movement situation. It will provide
theoretical basis for design and operation.
Through the analysis, calculate and summarize the data on the coal particle model
and the simulation model of the quartz sand. We get the following conclusions:
1. To insure the particle size 300μm could deposit completely, using the method
of reducing the capacity to prolong the residence time of particles. It can increase the
grain out rate of 200μm fine particle.
2. By using the similarity theory, the model is shrunk. When the coal particles are
regarded as powder-selecting material, the deviation of the grain out rate for 200μm
~300μm fine particles in outlet is 23%, when the quartz sand particles are regarded as
powder-selecting material, the deviation is 18%. Both deviations are acceptable in
engineering applications.
3. In the Fluent simulation software platform, the soft simulate the coal and the
sand model. It draws its trajectory and particle concentration curve. It finds that
200μm coal particle model’s deviation is 14.73% compared with the theoretical model,
and the sand model is 12.85%. The deviation is allowed in engineering.
This paper presents the device could run smoothly which proved by the theory
and the simulation. It can provide theoretical basis for design and operation.
Keywords: Coal Moisture Control, classifier particle, the similarity
theory, DPM model
目 录
第一章 绪 论............................................................................................................ 1
1.1 本课题研究背景及意义............................................................................... 1
1.2 煤调湿技术的研究概况............................................................................... 2
1.2.1 煤调湿技术简介.................................................................................. 2
1.2.2 内置热式煤调湿工艺流程.................................................................. 5
1.2.3 煤调湿技术应用现状.......................................................................... 6
1.3 选粉装置简介............................................................................................... 8
1.3.1 选粉装置结构简介.............................................................................. 9
1.3.2 选粉装置研究现状............................................................................ 10
1.4 相似原理模型实验法................................................................................. 12
1.4.1 相似原理模型实验法简介及发展历程............................................ 12
1.4.2 相似原理模型实验法准则及应用范围............................................ 13
1.5 本课题研究目标及内容............................................................................. 14
第二章 细颗粒选粉装置数学模型.......................................................................... 15
2.1 引言............................................................................................................. 15
2.2 细颗粒选粉装置选粉机理......................................................................... 15
2.3 细颗粒选粉装置结构及参数..................................................................... 17
2.3.1 物理模型描述.................................................................................... 17
2.3.2 数学模型建立.................................................................................... 17
2.3.3 细颗粒选粉装置参数选取................................................................ 21
2.4 细颗粒选粉装置颗粒夹带率..................................................................... 23
2.4.1 物理模型描述及假设........................................................................ 23
2.4.2 数学模型建立及求解........................................................................ 24
2.4.3 不同固体颗粒粒径夹带率................................................................ 27
2.5 本章小结..................................................................................................... 28
第三章 以煤粉为流化介质的相似模型.................................................................. 29
3.1 引言............................................................................................................. 29
3.2 相似模型建立............................................................................................. 29
3.2.1 相似理论的一般研究方法................................................................ 29
3.2.2 相似模型准则导出............................................................................ 30
3.3 细颗粒选粉装置相似模型修正................................................................. 33
3.3.1 以流化状态为判定依据.................................................................... 33
3.3.2 以选粉效果为判定依据..................................................................... 35
3.4 FLUENT 仿真模拟 .................................................................................... 36
3.4.1 GAMBIT 绘制框架及网格 ................................................................ 36
3.4.2 建立空床模型.................................................................................... 41
3.4.3 引入 DPM 模型添加煤粉 ................................................................. 46
3.4.4 模拟结果............................................................................................ 48
3.5 模拟结果分析及改进意见......................................................................... 53
3.6 本章小结..................................................................................................... 55
第四章 使用石英砂为流化介质的相似模型.......................................................... 56
4.1 引言............................................................................................................. 56
4.2 模型建立及修正......................................................................................... 56
4.2.1 相似模型的建立................................................................................ 56
4.2.2 相似模型的修正................................................................................ 57
4.3 FLUENT 仿真模拟 .................................................................................... 60
4.4 本章小结..................................................................................................... 64
第五章 结论及建议.................................................................................................. 65
5.1 结论............................................................................................................. 65
5.2 进一步工作建议......................................................................................... 66
符 号 表...................................................................................................................... 67
参考文献...................................................................................................................... 68
在读期间公开发表的论文和承担科研项目及取得成果.......................................... 72
致 谢.......................................................................................................................... 73
摘要：
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摘要我国作为全球焦炭生产、消费和出口大国，炼焦用煤却普遍存在含水量偏高的问题，年平均含水率达11%左右。根据相关资料报道：炼焦过程中煤中水分每增加1%，多耗热能62.0MJ/t(干煤)计算。解决此类问题的方法为使用煤调湿技术。若采用煤调湿技术，将煤中水分由11%降至6%，则可节省炼焦耗热能10.6kgce/t(干煤)，然而炼焦用煤湿度降低后，煤料中细颗粒在运输途中，采用露天方式易扩散至空气中造成污染，采用管道运输方式易发生粉尘爆炸造成安全威胁，同时，炼焦煤中细颗粒增加对焦炉煤气的后续处理也会造成很大影响，故在新型煤调湿工艺（装置）流程中嵌入了细颗粒选粉工序。本文对现有细颗粒选粉装置进行研究，提...
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作者：赵德峰
分类：高等教育资料
价格：15积分
属性：77 页
大小：3.23MB
格式：PDF
时间：2024-11-11
