【作者】 牟春宇；

【导师】 姜大志；

【作者基本信息】 江南大学 ， 机械设计及理论， 2008， 硕士

【摘要】 旋风除尘器作为一种干式气-固分离设备,广泛用于化工、石油、冶金、建筑等工业部门。工业水平的发展和环保要求的提高对旋风除尘器的效率和能耗方面提出了更高的要求。在以实验和经验公式为主的传统研究方法不能满足设计要求的前提下,基于计算流体动力学(简称CFD)的研究方法已成为开发高效除尘器的重要途径。但目前应用CFD对旋风除尘器的分离性能所做的具体研究还不成熟,国内外也没有统一、系统的分析计算方法。鉴于此,本文对旋风除尘器内部流场进行了数值模拟,并将计算得出的速度流场与实验数据进行了比较,在获取可靠流场后,详细分析了除尘器入口气流的运动轨迹,得出了旋风除尘器顶部“尘环”产生的机理;总结出粉尘在进气口的不同进入位置对除尘器分离性能的影响,并进行了实验分析,提出了相关的改进措施;采用确定轨道模型对分离器内固体颗粒的运动进行了模拟,提出了计算除尘器分离效率的“集群算法”的概念;在考虑颗粒与壁面的碰撞效果上,运用CFD数值模拟技术并结合正交数值实验方法,分析并确定了除尘器内粉尘与壁面碰撞作用最为剧烈的部位,继而提出了“壁面因子集群算法”并与前者的计算结果进行了比较;采用随机轨道模型对颗粒在湍流作用下的运动进行了模拟,通过分析湍流对颗粒的脉动作用以及概率因素,提出了“概率加权算法”并进行效率的计算;结合实验所测分离效率,对以上三种方法得出的效率进行了误差分析,并总结出其运用的范围、所需条件及发展方向。更多还原

【Abstract】 Cyclone separator, A kind of gas-solid separating equipment, is widely used in many fields such as chemical engineering,metallurgy, environmental protection, architecture and other industrial department. With the development of industry and highly requirement form the environment protection, even higher quality and efficiency should be owned by the separator. However, the traditional design ways upon experiment and experiential-formula can’t satisfy the requirements sufficiently. CFD, short for computational fluid dynamics, as a new designing method play a important role on studying high quality cyclone separator. But the investigation on the separation efficiency of separator with the CFD is seldom and couldn’t estimate and forecast its efficiency properly. In this thesis, flow in cyclone separator is simulated by using of FLUENT and validate its result with experimental data. Through the analysis of flowing path form the different position of inlet, the principle particle loop shapes at the top of the separator is uncovered and made a conclusion to the efficiency influenced by the air flow form different position of the inlet. A experiment research is made to testify that conclusion and some advice is afforded in the end.Concrete trajectory model is used to simulate the particle’s movement in separator, A new concept named mass arithmetic using for calculating separating efficiency is afforded and the calculating result with this method is contrast to the experimental data. Then another arithmetic named wall-factor mass arithmetic that could refine the primary one is also added. For checking the turbulence effect onto the particle trajectory, the random trajectory model is applied. After analyzing the pulse effecting to the particle, the notion of probability and statistics is introduced to the efficiency calculating and form the probability integration arithmetic, all the calculating results of the three arithmetic for separating efficiency are testified by the experiment data .then the range, the limits, the qualification and trend of applying these arithmetic is concluded by the thesis.更多还原