离心通风机内部流动特性的数值模拟与优化设计

发布时间：2018-01-21 00:27

本文关键词： 离心通风机 CFD 优化设计扩散器内泄漏　出处：《安徽理工大学》2012年硕士论文　论文类型：学位论文

【摘要】：离心通风机是用于输送气体的叶轮机械设备,在国民经济各部门的应用非常广泛,是工农业生产中主要耗能设备之一。随着我国环保意识的增强,工农业生产的不断发展,精心设计、制造和合理使用通风机,对节能和减小噪声污染具有重要意义。实验研究法是早期研究叶轮机械内部流动的一种重要方法,通常可以在与所研究的问题完全相同的情况下使用,或大体相同的条件下对实际问题进行观测,从而能够综合考虑影响流动的各种因素。但是实验研究方法往往要受到模型尺寸的限制,此外还有边界影响,相似准则不完全满足等问题的困扰。实验的手段、数据的精度和可靠性,受测试仪器仪表性能和环境的制约,直接导致实验研究的方法对复杂流场的整体分析能力以及对细微流动结构的认识、分析能力非常有限同时,实验研究由于成本高、周期长,对于离心风机内部流场的研究有着很大的局限性。现代优化设计方法以三维理论为基础,运用通用或专用软件由计算机计算求解。在此基础上确定离心通风机部件主要几何参数的新方法,为简化计算步骤、提高风机的可靠性提供帮助。本课题利用CFD软件fluent对低压力后向叶片型离心通风机进行数值模拟计算,归纳起来,本文进行了以下几个方面的研究：第一,利用CFD软件对离心风机内部流场进行了详细的研究,为后面的研究提供了可靠依据；第二,对内泄漏进行了详细分析,得出风机在安装过程中叶轮存在偏心的情况下对风机性能的影响；第三,对扩散器进行优化设计,进行了详细分析并得出了扩散器的最佳尺寸；第四,对离心风机蜗舌进行了优化设计---台阶蜗舌,提高了风机的效率。
[Abstract]:Centrifugal ventilator is a kind of impeller machinery used to transport gas. It is widely used in various departments of national economy and is one of the main energy consuming equipments in industrial and agricultural production. The continuous development of industrial and agricultural production, careful design, manufacture and rational use of ventilators are of great significance to energy saving and noise pollution reduction. Experimental method is an important method for the early study of the internal flow of impeller machinery. It can usually be used in the same case as the studied problem or under the same conditions to observe the actual problem. However, the experimental research methods are often limited by the model size, in addition to the boundary effects, similarity criteria are not fully satisfied and other problems. The accuracy and reliability of the data are restricted by the performance and environment of the testing instruments and instruments, which directly lead to the overall analytical ability of the experimental method to the complex flow field and the understanding of the fine flow structure. At the same time, because of the high cost and long period, the research on the internal flow field of centrifugal fan has a great limitation. The modern optimization design method is based on three-dimensional theory. Based on this, a new method for determining the main geometric parameters of centrifugal fan components is presented, which can be used to simplify the calculation steps and improve the reliability of the fan. In this paper, the CFD software fluent is used to simulate and calculate the low pressure backward centrifugal fan. In conclusion, the following aspects are studied in this paper: Firstly, the flow field of centrifugal fan is studied in detail by using CFD software, which provides a reliable basis for the later research. Secondly, the internal leakage is analyzed in detail, and the influence of the eccentric impeller on the performance of the fan is obtained. Thirdly, the optimal design of diffuser is carried out, and the optimum size of diffuser is obtained. In 4th, the optimum design of the centrifugal fan cochlear tongue-step cochlear tongue was carried out to improve the efficiency of the fan.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH432

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