【作者】 孙勇；

【导师】 杨英； 石连军；

【作者基本信息】 东北大学 ， 机械工程， 2008， 硕士

【摘要】 负压式真空吸尘车是继公路清扫车和吸扫式清洁车之后发展起来的一种集灰尘吸取、分离和运输为一体的高效除尘设备。它一般由吸尘系统、一次集尘箱、二次集尘箱、粉尘回收系统以及行走系统等组成。其中吸尘口和沉降室作为真空吸尘车气路系统最为关键的两个核心部件,它们的结构形式与吸尘和分离效率对吸尘车的工作性能有着决定性的影响。本文着重对真空吸尘车的气路系统进行研究,采取实体建模和计算流体力学相结合的方法对真空吸尘车的吸尘口和重力沉降室进行流场仿真分析与结构优化。首先在三维软件中建模,进行初步方案设计,然后导入到CFD中进行流场分析。仿真时采用非结构网格对吸尘口和沉降室进行网格划分,运用k-ε标准双方程作为湍流计算模型。通过对初始设计方案的流场仿真分析,得出影响吸尘和沉降效率的原因为初始结构所引起的不合理流场分布,然后根据分析结果进行方案改进直至得到理想的流场分布和设计方案。文章主要包括了以下两方面内容：1>.吸尘系统的设计与分析：本文针对吸尘口作三个方面研究：一是分析尘粒在气流作用下的受力情况和起动过程,弄清影响尘粒起动的气流速度与灰尘粒度和密度之间的函数关系；二是通过简化吸尘口结构形式,提出一种基于吸尘口内部局部压力损失最小的计算方法；三是用计算流体力学(CFD)技术对不同结构吸尘口内的流场进行仿真分析,进行初步性能评估,从而提出合理的优化方案。2>.除尘系统的设计与分析：本文从三个方面对重力沉降室进行研究：一是分析灰尘颗粒在气流中的运动和在层流中的沉降机理,提出重力沉降室结构尺寸设计的沉降临界公式；二是分析真空吸尘车上重力沉降室设计的特点及影响因素,提出真空吸尘车重力沉降室结构设计的方法；三是应用计算流体力学(CFD)技术对重力沉降室内流场进行仿真分析,找出不合理结构,通过改进,提高重力沉降室内尘粒分离的效能,达到设计要求。更多还原

【Abstract】 The vacuum sweeper is a highly efficient de-dusting vehicle combined with the functions of dust-sucking, separation and transportation developed after the road cleaning vehicle and the sucking & sweeping vehicle. It consists of a sucking system, a primary dust box, a secondary dust box, a dust recovery system and a traveling system etc.As the most important two key parts in the pneumatic system on the vacuum sweeper, the style of construction and separation efficiency of the sucking mouth and gravity settling chamber make decisive effects.This paper pay high attention to study the pneumatic system on the vacuum sweeper, Combine the methods of manufacture a factual modeling and computational fluid dynamics to study the sucking mouth and gravity settling chamber of the vacuum sweeper’pneumatic system.It analyse their flow field analysis and optimization construction.At first made a modeling through the three-dimension software and design the first scheme and then enter the CFD to study the flow field analysis.Un-struction meshes were used to generate grids and the k-εmodel was used to simulate the turbulent flow.Through the simulation analysis of the beginning design scheme,it indicates uneven floe field caused by unreasonable structure reduces the dust suction efficiency.At last according to the result of the analysis to improve on the cheme till we obtained the perfect flow field distribution and design scheme.This paper mainly covers the following two aspects:1> Design of and analysis on the sucking system:This paper aims at the study at the following three aspects for the sucking mouth:First, it is to analyze the force conditions and initial moving process of dust particles subject to air stream, to make clear the function relation of the air velocity to cause the dust particles to move with the dust size and density; Second, it is to work out the formula for calculating the local pressure loss inside the sucking hole by way of simplifying the structure of the sucking hole, and propose a design optimization method for minimizing the local pressure loss inside the sucking hole; Third, it is to carry out simulation analysis on the flow fields inside sucking holes of different structures with the CFD technology, to execute preliminary performance assessment, and make judgment on the rationality of the optimization solution.2> Design of and analysis on the de-dusting system:This paper aims at the study at the following three aspects for the gravity settling chamber:First, it is to analyze the settling mechanism of dust particles in the settling process and in laminar flow, and propose a critical settling formula for the design of the gravity settling chamber; Second, it is to analyze the characters and impact factors for the design of the gravity settling chamber on the vacuum sweeper, and to propose a sizing method for the gravity settling chamber; Third, it is to execute simulation analysis on the flow filed inside the gravity settling chamber with the CFD technology, to find out the irrational structure and propose an improvement solution, with the purpose to lower the bottom air velocity, improve the separation efficiency of the dust particles in the gravity settling chamber, and meet the design requirements.更多还原