【作者】 王宇；

【导师】 周淑文；

【作者基本信息】 东北大学 ， 机械工程（专业学位）， 2020， 硕士

【摘要】 危险品收纳车是应对危险品道路运输泄漏事故处置而生的多功能收纳车,主要处理事故泄漏的液体与颗粒危险品。而采用真空负压收集上来的颗粒危险品属于气固混合物,事故处置装置对这种混合物处理不慎就会导致危险品颗粒重新泄漏于大气中,导致二次污染。为了减少这种现象,将旋风分离器和滤筒式过滤器进行组装成一种新的过滤设备,利用其各自的优点达到对固体颗粒的有效分离。所以研究这种事故处置装置(高效率气固分离器)具有重要的理论意义和应用价值,其具体的研究内容如下:(1)为了对组合分离器的优化与改进奠定基础,一方面总结滤筒的材质、规格、工作特点与原理。另一方面由于旋风分离器的缺点是低效率,所以对旋风分离器的低效率原因进行分析,对其内部的颗粒运动状态进行跟踪,总结颗粒直径、密度和入口速度对效率的影响特点,增加直管来降低“灰斗返混”现象。(2)将独立性(网格数量与数值仿真结果无关)与高质量ICEM流体网格导入FLUENT软件中,分析组合分离器的压力场、速度场与湍动能的分布特点,研究组合分离器内颗粒运动轨迹规律,总结组合分离器的能量损失原因。由于压降、分离效率、过滤风速和流量分配是组合分离器的四个主要性能指标,必须同时兼顾才能发挥组合分器的优点,所以对滤筒的上升气流与过滤风速指标进行研究。对滤筒的布置方式和个数进行了设计,平均分配流量到每个滤筒上。另外增加了环形挡板来降低整体滤筒局部过滤风速过大的问题,降低气流对滤筒的冲刷,提高滤筒过滤风速分配的均匀性。(3)最后针对过滤设备(组合模型)的不同结构影响因素,选取影响分离性能较大的四个结构参数作为优化变量。应用Design-Expert软件的响应面法设计试验,利用模数据建立分离效率的数学模型,根据数学模型进行结构参数优化分析。最终得出内排气管直径和圆锥体高度对组合模型离心分离部分分效率影响较大,内排气管直径和长度的交互作用影响也比较明显。四个影响因素中内排气管长度存在一个最优值,其他三个因数对分离效率的影响是单调的,但只有内排气管直径对压降影响明显,而且随着直径的增大压降单调递减的。在总体分离效率99.99%,尽量降低压力损失提高离心分离部分的分离效率的前提下,离心部分(合理区间内优化后的组合模型)能除去所有密度为2700kg/m3的1μm颗粒的81.33%,只有将近18.67%由滤筒负责除去。更多还原

【Abstract】 Hazardous materials collection truck is a multi-functional storage truck that responds to the disposal of hazardous materials road transport accidents.It mainly deals with liquid and particulate hazardous materials leaked from accidents.Hazardous materials collected by vacuum negative pressure are gas-solid mixtures.Accident disposal device’s careless handling of this mixture will cause hazardous materials particles to leak back into the atmosphere and cause secondary pollution.So researching this kind of accident disposal device(high efficiency gas-solid separator)has important theoretical significance and application value.In order to meet the filtration separation of hazardous materials on hazardous materials collection truck,this paper combines the most commonly used separation device cyclone separator and filter cartridge filter to form a new filtration device.This combined device has the advantages of two separators,which can achieve effective separation of solid particles and prevent secondary pollution.The specific research content is as follows:(1)In order to lay the foundation for the optimization and improvement of the combined separator.On the one hand,the material,specifications,working characteristics and principles of the filter cartridge are summarized.on the other hand the reasons for the low efficiency of the cyclone separator are analyzed.The movement of particles inside the separator is tracked,and the characteristics of the influence of particle diameter,density and inlet speed on efficiency are summarized.Increase the straight pipe to reduce the "ash bucket back mixing"phenomenon.(2)Import independence and high-quality ICEM fluid mesh into FLUENT software.Analysis of pressure,velocity and turbulent kinetic energy distribution characteristics of combined separators.The law of particle trajectory in the combined separator was studied,and the reasons for the energy loss of the combined separator were summarized.It is necessary to take into account the pressure drop,separation efficiency and filtration wind velocity of the combined separator three main performance indexes in order to exert the advantages of the combined distributor.So analyzing the updraft and filter wind speed indicators of the filter cartridge.The arrangement and number of filter cartridges are designed to distribute the filtered wind speed to each filter cartridge.In addition,an annular baffle is added to reduce the problem of excessive partial wind speed of the whole filter cartridge,and to reduce the flushing of the filter cartridge by the airflow.(3)Finally,for the different structural influencing factors of the filtering equipment(combined model),four structural parameters that affect the separation performance are selected as the optimization variables.The response surface method of Design Expert software is applied to design experiments,using mathematical data to establish a mathematical model of separation efficiency,and parameter optimization analysis based on mathematical models.Finally,the diameter of the inner exhaust pipe and the height of the cone have a great influence on the efficiency of the centrifugal separation part of the combined model.The interaction between the diameter and length of the inner exhaust pipe is also obvious.There is an optimal value for the length of the inner exhaust pipe among the four influencing factors,and the influence of the other three factors on the separation efficiency is monotonous.However,only the diameter of the inner exhaust pipe has an obvious influence on the pressure drop,and the pressure drop monotonously decreases as the diameter increases.Under the premise that the overall separation efficiency is 99.99%and the pressure loss is minimized to improve the separation efficiency of the centrifugal separation part,the centrifugal part can remove 81.33%of all lum particles(2700kg/m3),and only 18.67%is removed by the filter cartridge.更多还原