基于粗糙度的煤体表面接触角数值模拟研究

张健; 许博; 魏建平; 张鹏妍; 蔡茂林; 张凯旋

doi:10.13199/j.cnki.cst.2021-0871

基于粗糙度的煤体表面接触角数值模拟研究

张健^{1, 2,},
许博^{1, 2, ,},
魏建平^{1, 2},
张鹏妍^{1, 2},
蔡茂林^{1, 2},
张凯旋^{1, 2}

1.
河南省瓦斯地质与瓦斯治理重点实验室—省部共建国家重点实验室培育基地, 河南焦作　454000
2.
河南理工大学安全科学与工程学院, 河南焦作　454000

基金项目:

国家自然科学基金资助项目（52174171）；河南省高等学校重点科研计划资助项目（22A440012）；河南理工大学安全与能源工程学部“双一流”学科创建工程资助项目（AQ20230741）

详细信息

作者简介:
张健: (1988—)，男，河南商丘人，副教授，博士。E-mail：zhangjian@hpu.edu.cn

通讯作者:
许博: (1997—)，男，河南驻马店人，硕士研究生。E-mail：1242056370@qq.com

中图分类号: TD714
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出版历程
- 收稿日期: 2021-08-12
- 录用日期: 2022-01-31
- 网络出版日期: 2023-05-10
- 刊出日期: 2023-04-29

Numerical simulation of coal surface contact angle based on roughness

ZHANG Jian^{1, 2,},
XU Bo^{1, 2, ,},
WEI Jianping^{1, 2},
ZHANG Pengyan^{1, 2},
CAI Maolin^{1, 2},
ZHANG Kaixuan^{1, 2}

1.
State Key Laboratory Cultivation Base for Gas Geology and Gas Control, Jiaozuo 454000, China
2.
School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China

Funds:

National Natural Science Foundation of China (52174171); Key Research Project of Colleges and Universities of Henan Province (22A440012); Double First-class Discipline Creation Project, Department of Safety and Energy Engineering, Henan Polytechnic University (AQ20230741)

摘要

摘要:
煤尘是煤矿的七大灾害之一，它不仅影响作业人员的身心健康，还能致使发生煤尘爆炸。煤的润湿效果对除尘有很大的影响，已有研究表明煤的润湿效果与煤的润湿性、表面粗糙度和表面活性剂等有关。为了有效地解决井下煤尘问题，选取了亲水性的哈密褐煤、疏水性的安阳焦煤和弱亲水性的赵固二矿无烟煤作为研究对象，使用光学接触角形貌联用仪测量3种煤样的均方粗糙度，测定3种煤样的本征接触角，利用COMSOL数值软件构建二维物理模型，设置模拟条件，调整模拟参数，分析对比试验值和模拟值，验证COMSOL数值模拟的可行性，研究了煤体表面粗糙度对煤体表面接触角的影响。结果表明：数值模拟的液滴铺展过程、液滴铺展速度及液滴铺展形态和试验情况类似，但模拟接触角值比试验接触角值大；随着煤体表面粗糙度的增加，褐煤接触角从60.7°降低到50.9°，变化范围在10°左右，焦煤接触角从96.5°增加到112.7°，变化范围在16°左右，无烟煤接触角从89.7°降低到78.3°，变化范围在11°左右；同种表面活性剂对3种煤样接触角的模拟值和试验值具有相同的变化趋势，但模拟值比试验值大。采用数值模拟的方法，研究煤体表面粗糙度对煤体表面接触角的影响具有一定的可行性。煤体表面受粗糙度影响的润湿情况符合Wenzel模型。表面活性剂的存在不改变3种煤样的接触角随表面粗糙度变化的规律。
- 煤尘 /
- 除尘 /
- 煤体润湿 /
- 表面粗糙度 /
- 接触角 /
- COMSOL模拟
Abstract:
Coal dust is one of the seven disasters in coal mine. It affects the health of workers and causes coal dust explosion. The wetting effect of coal has a great influence on dust removal. Studies have shown that the wetting effect of coal is related to the wettability, surface roughness and surfactants of coal. In order to effectively solve the problem of coal dust under the mines, which selects hydrophilic Hami lignite, hydrophobic Anyang coking coal and weakly hydrophilic anthracite of Zhaogu No.2 mine as the research objects. The mean square roughness of the three coal samples were measured by the optical contact angle morphology combined instrument, the intrinsic contact angles of the three coal samples were measured, the two-dimensional physical model was constructed by COMSOL numerical software, the simulation conditions were set, the simulation parameters were adjusted, the experimental and simulation values were analyzed and compared, the feasibility of COMSOL numerical simulation was verified, and the influence of coal surface roughness on coal surface contact angle was studied. The results show that the droplet spreading process, the droplet spreading velocity and the droplet spreading shape of numerical simulation are similar to those of experiment, but the simulated contact angle is larger than that of experiment. With the increase of coal surface roughness, the contact angle of lignite decreases from 60.7° to 50.9°, the variation range is about 10°, the contact angle of coking coal increases from 96.5° to 112.7°, the variation range is about 16°, and the contact angle of anthracite decreases from 89.7° to 78.3°, and the variation range is about 11°. The simulated and experimental values of contact angle of three kinds of coal samples with the same surfactant have the same change trend, but the simulated value is larger than the experimental value. It is feasible to study the influence of coal surface roughness on coal surface contact angle by numerical simulation. The wetting of coal surface affected by roughness conforms to Wenzel model. The existence of surfactant does not change the variation of contact angle with surface roughness of three coal samples.
- coal dust /
- remove dust /
- coal wetting /
- surface roughness /
- contact angle /
- COMSOL simulation

HTML全文

图 1 条纹投影相移技术原理

Figure 1. Principle of fringe projection and phase-shifting technology

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图 2 3种煤样的光学图像

Figure 2. Optical images of three coal samples

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图 3 3种煤样的二维形貌

Figure 3. 2D topography images of three coal samples

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图 4 3种煤样的三维形貌

Figure 4. 3D topography images of three coal samples

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图 5 不同砂纸处理煤样的接触角

Figure 5. Contact angle of the coal samples treated with various sandpapers

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图 6 模拟几何模型

Figure 6. Geometric model of the simulation

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图 7 不同粗糙度表面

Figure 7. Diagram of different roughness surfaces

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图 8 边界条件

Figure 8. Boundary conditions

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图 9 网格剖分

Figure 9. Mesh generation

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图 10 3种煤样的模拟液滴铺展过程

Figure 10. Simulated droplet spreading process of three coal samples

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图 11 3种煤样在不同粗糙度下的模拟值

Figure 11. Three coal sample simulation values with different roughness

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图 12 Wenzel模型曲线

Figure 12. Wenzel model curve

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图 13 3种煤样的模拟值和试验值

Figure 13. Simulated and experimental values of three coal sample

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表 1 煤样的工业分析和坚固性系数

Table 1 Proximate analysis and firmness coefficient of coal samples

煤样 M_ad/% A_ad/% V_daf/% 坚固性系数f

哈密褐煤 5.94 10.05 33.61 0.78
安阳焦煤 0.57 12.23 23.17 1.12
赵无烟煤 2.98 15.55 7.98 1.92

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表 2 试验和模拟接触角对比

Table 2 Comparison of experimental and simulated contact angles

煤样接触角
试验模拟

褐煤
45.9° 46.5°
焦煤
113.8° 114.1°
无烟煤
82.2° 82.9°

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