引风机变频改造后振动特性分析与动平衡研究

发布时间：2018-02-21 07:05

本文关键词： 引风机变频改造振动故障动静不平衡　出处：《昆明理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来,随着电力行业的不断发展,电厂新增加了许多大容量机组。但随着我国人民自身素质的提高,节能减排意识也越来越强,电厂鼓引风机的节能改造,变得越来越重要。我国火电厂锅炉鼓引风机耗电约占厂用电的25%～30%,鼓引风机因锅炉负荷变化而经常处于一种低效率状态,大量能量浪费在起调节风量作用的风道挡板上。在锅炉鼓引风机上安装变频调速装置,它可以根据锅炉的燃烧状况和负荷变化情况,自动调节鼓引风机的转速,实现风压和风量的调节,从而达到节能降耗的目的。引风机变频改造后,云南电网统调火电厂锅炉鼓引风机频繁发生振动故障,造成电厂减负荷、停机等事故,已经影响到火电机组正常运行及带负荷能力,在一定程度上影响了云南电网的安全稳定运行和电力供需平衡。引风机变频改造后,叶片出现了裂纹及断裂的故障,这是由于改变频率之后,引风机运行速度发生变化,经常在临界转速区域运转,造成引风机叶轮共振导致的。研究曲靖电厂、昆明二电厂、阳宗海电厂、大唐红河电厂和巡检司电厂变频引风机出现的叶片裂纹及断裂事故案例,分析振动故障测试数据包括振动幅值、相位(水平、垂直、轴向三个方向的数值)等因素对振动故障的综合影响,通过分析振动波德图、振动趋势图、振动频谱图,对引风机振动故障进行诊断。针对引风机故障,提出相应的解决方案,如叶片加筋调频,加特殊围带,加平衡块做动平衡等方案。介绍了静态试验和动态试验,静平衡与动平衡各自的适用范围、实施的步骤、需要注意的问题等。在分析研究了各种因素对振动故障的综合影响之后,建议采用做动平衡加平衡块的方法来解决振动大的问题。现场通过试加平衡块,风机振动降低,能在安全条件下运行。证明对引风机变频改造振动故障的判断是正确的,采取的措施有效解决了振动大的问题,保证了机组安全稳定运行。本研究利用EPP振动采集分析仪和208-P DAIU振动仪对测试过程中的振动数据进行采集。通过利用叶片加筋调频、加特殊围带、加平衡块做动平衡的方法,对引风机振动特性的类型及表现特征进行归类,并提出各类型故障的应对方法,为引风机在安全条件下运行,提供了一定的理论基础。
[Abstract]:In recent years, with the continuous development of the power industry, many new large capacity units have been added in power plants. However, with the improvement of the quality of the people in our country, the awareness of energy saving and emission reduction is becoming stronger and stronger. It has become more and more important. The power consumption of boiler drum induced fan in thermal power plant in China accounts for 25% of the total power consumption. The drum induced fan is often in a low efficiency state because of the change of boiler load. A large amount of energy is wasted on the air duct baffle which regulates the air volume. A frequency conversion speed regulating device is installed on the boiler drum induced fan, which can automatically adjust the speed of the drum induced fan according to the burning condition and load change of the boiler. Realize the adjustment of wind pressure and air volume to achieve the purpose of saving energy and reducing consumption. After the frequency conversion transformation of the induced fan, frequent vibration faults occurred in the boiler drum induced fan in Yunnan Power Grid, which caused the power plant to reduce the load and shut down, which has affected the normal operation and the capacity of the thermal power unit with load. To some extent, it affects the safe and stable operation of Yunnan power grid and the balance of power supply and demand. After the frequency conversion transformation of the induced fan, there are cracks and breakages in the blade. This is due to the change of the frequency, the speed of the induced fan is changed, and the fan often runs in the critical speed area. The case of blade crack and fracture in Qujing Power Plant, Kunming No. 2 Power Plant, Yangzonghai Power Plant, Datang Honghe Power Plant and Patrol Department Power Plant is studied. The comprehensive effects of vibration amplitude, phase (horizontal, vertical, axial) on vibration fault are analyzed. By analyzing the vibration wave diagram, vibration trend chart, vibration spectrum diagram, and so on, the vibration fault test data are analyzed, which include vibration amplitude, phase (horizontal, vertical, axial) and so on. The vibration fault of induced fan is diagnosed. In view of the fault of induced fan, the corresponding solutions are put forward, such as the reinforcement and frequency modulation of the blade, the addition of special girth, and the dynamic balancing with the balance block, etc. The static test and dynamic test are introduced, and the scope of application of static balance and dynamic balance are introduced. After analyzing and studying the comprehensive influence of various factors on vibration failure, it is suggested that the method of dynamic balancing and balancing block be used to solve the problem of large vibration. The vibration of the fan is reduced and can be operated under the safe conditions. It is proved that the fault judgement of the frequency conversion transformation of the induced fan is correct. The measures taken can effectively solve the problem of large vibration and ensure the safe and stable operation of the unit. In this study, EPP vibration acquisition analyzer and 208-P DAIU vibrator are used to collect the vibration data in the testing process. The types and performance characteristics of induced fan vibration characteristics are classified, and the corresponding methods of various types of faults are put forward, which provides a certain theoretical basis for the operation of induced fan under safe conditions.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM621.2

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