轴流风机地性能测定.doc

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1、目录摘要··························································31轴流式风机概述1.1轴流式风机的工作原理·········································11.2轴流式风机的基本形式·········································11.3轴流式风机的构造·············································22通风机性能参数2.1空气动力性能曲线的基本参数·······························

2、···42.2压力的测量··················································62.3流量的测量···················································82.4转速的测量···················································82.5功率的测量···················································93通风机空气动力性能的实验室测定3.1轴流式风机空气动力性能的实验装置···············

3、··············103.2轴流式风机的性能曲线分析·····································104通风机性能测试实验4.1轴流式风机的性能实验·········································114.2离心式风机的性能实验·········································165通风机现场试验···············································25总结··········································

4、···················26参考文献························································28主要符号Q----------------------通风机流量(m/s)P----------------------全压(N/m)P----------------------动压(N/m)P----------------------静压(N/m)N----------------------轴功率----------------------全压效率----------------------静压效率D----

5、------------------风管直径P----------------------大气压力(P)A----------------------风管面积(m)----------------------空气温度(K)---------------------空气密度(kg/m)轴流风机的性能测定摘要通风机是电厂中重要的辅机之一，其运行安全性和经济性尤为重要，通风机性能实验是保证通风机质量和获得通风机性能特性的一项重要工作。所以使用前对通风机性能进行测试是必不可少的。通风机性能试验，包括空气动力性能试验和噪声性能实验两部分。通风机性能试验的目的，在于通过测试与计算，求得风机在

6、给定转速下的流量、压力、所耗功率、效率、噪声等是否达到设计规定的要求，并绘制其特性曲线。关键词：轴流式通风机、性能参数、性能曲线1轴流式风机概述1.1轴流式风机的工作原理轴流式风机得名于流体从轴向流人叶轮并沿轴向流出。其工作原理基于叶翼型理论：气体由一个攻角。进入叶轮时，在翼背上产生一个升力，同时在翼腹上产生一个大小相等方向相反的作用力，该力使气体排出叶轮呈螺旋形沿轴向向前运动。同时，风机进口处由于压差的作用，气体不断地被吸入。对动叶可调轴流式风机，攻角越大，翼背的周界越大，则升力越大，风机的压差就越大，而风量越小。当攻角达到临界值时，气体将离开翼背的型线而发生涡流，导致风机压力

7、大幅度下降而产生失速现象。轴流式风机中的流体不受离心力的作用，所以由于离心力作用而升高的静压能为零，因而它所产生的能头远低于离心式风机。故一般适用于大流量低扬程的地方，属于高比转数围。轴流风机中当原动机驱动浸在工质中的叶轮旋转时，叶轮流体就相对叶片作用一个升力，而叶片同时给流体一个与升力大小相等方向相反的反作用力，称为推力，这个叶片推力对流体做功使流体能量增加。1.2轴流式风机的基本形式轴流式通风机可分为以下四种基本型式：a）在机壳中只有一个叶轮，没有导叶。如图3-2(a)所示，