两级轴流式通风机级间流动分析及叶片优化设计

发布时间：2018-04-01 11:00

本文选题：轴流式通风机　切入点：级间干涉　出处：《浙江理工大学》2017年硕士论文

【摘要】：太阳能、风能、水能、电能、热能、机械能等能源之间的转化很多都是依靠叶轮机械来完成的。叶轮机械广泛的运用了国民生活中,例如,化工、农业、冶金、矿井、制药、电力等各个领域,而叶轮机械中非常重要的一类机械是风机。有关资料显示,我国风机消耗的能源占煤炭消耗量的12%左右。轴流式通风机相对于离心式通风机有很多优势的地方,如今在很多关键产业、关键位置中,离心式通风机逐步被轴流式通风机所代替。因此,提高轴流式通风机研究能力和设计水平,对节约能源和环境保护均有着非常重要的意义。为了深入认识轴流式通风机内外部流场的流动特性,并且采用合理的优化方法对轴流式通风机进行优化,以达到提高轴流式通风机气动性能的目的,本文以两级轴流式通风机为研究对象,采用数值模拟的方法深入研究了风机结构对轴流式通风机气动性能的影响及风机内外部流场的分布情况,并在此基础上,对提高叶轮气动性能进行了研究。主要研究成果分为以下三个方面:(1)研究了两级轴流式通风机级间的流动情况,结果表明:级间的流动特征主要决定于转动件,也就是说,第一级叶轮对叶轮—导叶级的级间流动影响更大,第一级叶轮尾迹干涉强于导叶势流干涉;第二级叶轮对导叶—叶轮级的级间流动影响更大,第二级叶轮势流干涉强于导叶的尾迹干涉。(2)研究了叶片厚度对风机气动性能的影响,结果表明:叶片厚度的改变对风机气动性能有很大影响,相对而言,薄叶片风机有更好的气动性能,但是厚叶片风机稳定工作区间更大;叶片厚度的改变,主要改变了叶片前缘的流动情况和叶片压力面的压力分布情况。(3)对两级轴流式通风机的第一级叶轮进行优化,以叶片各截面安装角为优化参数,对轴流叶轮进行了正交试验优化,优化后的叶片很好的提高叶轮气动性能,在整个流量区间,静压、全压、效率都有大幅提高,在设计流量点,全压增加了16.1pa,相对增量为7%,静压增加了12.5pa,相对增量为20%,效率提高了2.38%,相对增量为4.6%;而且分析发现叶顶附近的截面安装角对叶轮的全压影响大,叶根附近的截面安装角对叶轮效率影响大。
[Abstract]:Many of the transformations between solar, wind, water, electricity, heat, mechanical energy and so on depend on impeller machinery, which is widely used in national life, such as chemicals, agriculture, metallurgy, mines, pharmaceuticals, etc. Power and other fields, and the most important type of machinery in turbomachinery is blower. Relevant data show that. Fan consumption in China accounts for about 12% of coal consumption. Axial fan has many advantages over centrifugal fan. Nowadays, in many key industries, key positions, The centrifugal fan is gradually replaced by the axial fan. Therefore, the research ability and design level of the axial fan are improved. It is of great significance to save energy and protect the environment. In order to understand the flow characteristics of the inner and outer flow field of axial-flow fan deeply, and adopt reasonable optimization method to optimize the axial-flow fan, In order to improve the aerodynamic performance of axial-flow fan, this paper takes two-stage axial fan as the research object. The influence of fan structure on the aerodynamic performance of axial flow fan and the distribution of flow field inside and outside the fan are studied by numerical simulation. In this paper, the aerodynamic performance of impeller is studied. The main results are as follows: 1) the flow between stages of two stage axial flow fan is studied. The results show that the flow characteristics between stages mainly depend on the rotating parts, that is to say, The first stage impeller has more influence on the flow between the impellers and the guide vane, the first stage impeller wake interference is stronger than the guide blade potential flow interference, and the second stage impeller has more influence on the interstage flow between the guide vane and the impeller stage. The influence of blade thickness on the aerodynamic performance of fan is studied. The results show that the change of blade thickness has great influence on the aerodynamic performance of fan. The thin blade fan has better aerodynamic performance, but the thick blade fan has a larger stable working range. The first stage impeller of the two-stage axial flow fan is optimized by changing the flow situation of the leading edge of the blade and the pressure distribution of the blade pressure surface. The installation angle of each section of the blade is taken as the optimized parameter. The axial flow impeller has been optimized by orthogonal test. The optimized blade can improve the aerodynamic performance of impeller greatly in the whole flow range, static pressure, total pressure and efficiency. The total pressure increased by 16.1 paa, the relative increment was 7, the static pressure increased 12.5 paa, the relative increment was 20, the efficiency increased 2.38 and the relative increment was 4.6. The cross section installation angle near the blade root has a great influence on the impeller efficiency.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH43

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