瓦斯细水雾输送系统中正态分布式弧形板除雾器性能研究

发布时间：2018-01-22 12:02

本文关键词： 瓦斯细水雾正态分布式弧形板数值模拟试验研究除雾器　出处：《河南理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：煤矿低浓度瓦斯细水雾两相流安全输送技术在煤矿中成功投入使用,促进了低浓度瓦斯发电的快速发展。然而用来发电的低浓度瓦斯气体中细水雾的存在直接影响着发电机组的效率,故对低浓度瓦斯中细水雾的分离还需进一步的研究。本文通过对低浓度瓦斯细水雾两相流在正态分布式除雾器中的流动进行分析,得到不同结构参数和工况参数下除雾器的分离效率和压降,其结果为煤矿低浓度瓦斯细水雾两相流体安全输送系统中脱水设备的结构设计提供一定的理论基础。本文针对正态分布式弧形板除雾器的除雾效率及压降情况进行分析研究。首先,基于湍流的横混模型,通过对细水雾颗粒在瓦斯流场中的受力和运动情况进行分析,得到除雾效率的计算式,运用均相流动和分相流动模型,对瓦斯细水雾两相流在除雾器内压降变化进行理论分析,得到除雾器的压降计算式;其次,采用FLUENT软件对正态分布式弧形板除雾器内气雾两相流场、除雾效率和压降进行数值模拟,模拟过程中选用RNG k-?湍流模型和DPM离散相模型;最后搭建试验平台,根据试验对除雾器的分离效率和压降进行验证。数值模拟和试验结果表明:在相同结构参数下工况参数的变化对除雾器效率的影响较为明显,同时进一步得出了适合不同雾滴直径的叶片结构组合型式,除雾器叶片长度H=150mm,转折角?=60o,板间距L=20mm时可以除去10~20?m的雾滴;除雾器叶片长度H=150mm,转折角?=90o,板间距L=30mm时可以除去20?m以上的雾滴;除雾器板间距、叶片长度、叶片转折角和气流速度等变化对压降都不同程度的影响,其中瓦斯气流速度的变化对除雾器压降的影响较大,除雾器压降随瓦斯气流速度的增加而增大;转折角的变化对除雾器压降的影响最大,除雾器压降随着叶片转折角的增大而减小。在不同瓦斯气流速度下对一级、两级除雾器的压降值对比,得知随着瓦斯气流速度增大,一级除雾器的压降缓慢增大,而两级除雾器的压降显示出急剧的增大,两级除雾器的除雾效率较一级除雾器的除雾效率稍微有提高,不过两级除雾器压降变化却很大。
[Abstract]:The two-phase flow safe transportation technology of low concentration gas mist in coal mine has been successfully put into use. It promotes the rapid development of low concentration gas power generation. However, the existence of water mist in low concentration gas gas directly affects the efficiency of generating units. Therefore, the separation of water mist in low concentration gas still needs further study. In this paper, the flow of two-phase flow of water mist in normal distribution is analyzed. The separation efficiency and pressure drop of the demister are obtained under different structure parameters and operating conditions. The results provide a theoretical basis for the structural design of dewatering equipment in the safe two-phase fluid conveying system of low concentration gas mist in coal mine. This paper aims at the defogging efficiency and pressure drop of the normal distribution type arc plate mist eliminator. First of all. Based on the cross mixing model of turbulence, through the analysis of the force and movement of water mist particles in gas flow field, the formula of defogging efficiency is obtained, and the homogeneous and separated flow models are used. The variation of pressure drop of gas water mist two-phase flow in the demister is analyzed theoretically, and the formula of pressure drop of the demister is obtained. Secondly, the two-phase flow field in the normal distribution arc plate demister is numerically simulated by using FLUENT software. The efficiency and pressure drop of fog removal are numerically simulated, and RNG k-? Turbulence model and DPM discrete phase model; Finally, the test platform is built. The separation efficiency and pressure drop of the demister are verified according to the test. The numerical simulation and the experimental results show that the influence of the operating parameters on the efficiency of the demister is obvious under the same structural parameters. At the same time, the blade structure combination type suitable for different droplet diameters is obtained, the blade length of the mist remover is 150 mm, turning angle? When the plate spacing is 20 mm, it can be removed from 10? M fog droplets; blade length of mist eliminator H150 mm, turning angle? When the plate spacing is 30 mm, it can be removed 20? Fog droplets above m; The changes of plate spacing, blade length, blade turning angle and airflow velocity have different effects on the pressure drop, and the change of gas flow velocity has a great effect on the pressure drop of the demister. The pressure drop of the demister increases with the increase of gas flow velocity. The change of turning angle has the greatest influence on the pressure drop of the demister, and the pressure drop of the demister decreases with the increase of the turning angle of the blade. It is known that with the increase of gas flow velocity, the pressure drop of the first stage demister increases slowly, while the pressure drop of the two stage demister shows a sharp increase. The de-fogging efficiency of the two-stage demister is slightly higher than that of the first-stage demister, but the pressure drop of the two-stage demister varies greatly.
【学位授予单位】：河南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TD712

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