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毕业论文-对流作用下单颗粒煤着火过程的实验研究，共75页，29761字
中文摘要
本文实验研究了自然对流和强迫对流对单颗粒煤粒着火特性的影响，搭
建了单颗粒煤粒的电加热管式炉试验台，研究了不同对流强度下粒径为
1.5mm 大小的烟煤和无烟煤颗粒在不同炉温、不同氧气浓度等条件下的着火
模式、着火延迟时间和着火温度的变化规律。实验结果表明：对于烟煤颗粒，
在较低的炉温 Tw 下，在自然对流和弱强迫对流的环境中呈均相着火趋势，
在强对流作用下呈异相着火趋势，而处于中间实验状态则更易发生联合着
火；对流对着火温度和着火延迟时间的作用与颗粒所属的着火模式有关。对
于无烟煤颗粒，在实验条件下均呈异相着火趋势，在自然对流和较低对流强
度下，对流强度增加可以减小着火延迟时间，在对流强度大于一定值时，对
流强度的增加却转变为增加着火延迟时间；较高 Tw 条件下，无论是对流强
度还是氧气浓度对着火延迟时间的影响作用不明显；较低 Tw 条件下，对流
强度的变化对着火温度的影响作用不明显，而氧气浓度的变化对着火温度的
影响作用更加明显。分析表明：对流对煤粒着火的影响可以归纳为三方面：
可以吹扫析出的挥发分；增强氧气向颗粒表面地扩散；以及吹扫煤焦表面一
次反应生成的以 CO 为主的可燃组分。
关键词：煤颗粒；着火模式；对流；着火延迟时间；着火温度
ABSTRACT
In this paper, an experimental study on the ignition of single coal particles
under various convection intensities was conducted. An experimental system
with an electrically heating tube furnace was built. The ignition mechanism,
ignition time and ignition temperature of bituminous and anthracite coal particles
in 1.5mm diameter at different furnace temperatures Tw’s and intensities of
convection were assessed and measured. Experimental results showed that at low
Tw’s, for bituminous coal of which volatile content matter was high, ignition
happened homogeneously at natural and weak forced convection conditions,
while at intense forced convection condition, ignition happened heterogeneously.
With medium forced convection intensity, coal ignition happened in a combined
mode. The intensity of convection could have obvious influence on ignition
delay time and ignition temperature of the coal particles, depending on the
ignition mode. For anthracite coal, ignition occurred heterogeneously at all
experimental conditions. Under natural and weak forced convection, the
increasing convection intensity deceased ignition time first while after the
convection intensity increase to a certain degree, further increasing convection
intensity enhanced ignition time. At high Tw’s, neither intensive convection nor
high oxygen concentration significantly affected ignition time. At low Tw’s,
compared with convection intensity, oxygen concentration influenced the
ignition temperature more significantly. The
influences of the convection on
the ignition of single coal particles can be summarized in three effects: it can
sweep away the released volatile matter surrounding around the particle, and it
accelerate oxygen diffusion to the particle surface and it sweeps flammable gas
products, mainly carbon monoxide, from char reaction.
Keywords：coal,
ignition,
convection,
ignition mechanism,
ignition
temperature

目录
第 1 章 引言.....1
1.1 课题研究背景及意义.. 1
1.2 煤着火特性研究现状.. 2
1.2.1 煤着火机理 ..... 2
1.2.2 单颗粒煤着火理论模型 4
1.2.3 单颗粒煤着火实验研究 7
1.2.4 对流对着火的影响作用 8
1.3 课题研究内容..... 10
第 2 章 实验装置与实验方法 ... 11
2.1 实验装置与方法. 11
2.1.1 实验装置与数据准备.. 11
2.1.2 炉温标定 12
2.2 数字图像技术..... 14
2.2.1 CCD 成像原理 ...... 14
2.2.2 彩色 CCD 色度学原理 ...... 14
2.2.3 基于彩色三基色的双色法温度图像检测方法 .... 16
2.2.4 CCD 模式选择 ...... 17
2.2.5 黑体炉标定 ... 22
第 3 章 实验结果与讨论 .... 25
3.1 大同烟煤实验现象和结论...... 25
3.1.2 对流强度与着火延迟时间及着火模式的关系 .... 26
3.1.3 氧气浓度与着火延迟时间及着火模式的关系 .... 28
3.1.4 氧气浓度与着火温度的关系.... 30
3.1.5 对流和氧气浓度对均相着火的影响.... 31
3.2 龙岩无烟煤的实验现象和结论 ..... 32
3.2.1 对流强度与着火延迟时间及着火模式的关系 .... 34
3.2.2 氧气浓度与着火延迟时间及着火模式的关系 .... 35
3.2.3 对流强度与着火温度的关系.... 36
3.2.4 氧气浓度与着火温度的关系.... 38
第 4 章 结论与展望 ..... 39
4.1 全文总结...... 39
4.2 全文展望...... 40
插图索引.... I
表格索引. III
参考文献. IV
致谢 VII
声明..... VIII
附录 A 外文资料的调研阅读报告（或书面翻译） ... IX
综合论文训练记录表 .XXVIII