【作者】 张世海；

【导师】 李录平；

【作者基本信息】 长沙理工大学 ， 动力机械及工程， 2009， 硕士

【摘要】 本文采用理论与实验相结合的方法,研究汽轮机叶片振动动态测量方法与技术。叶片振动动态测量主要有两种方法,一种是接触式的应变片法,另一种是非接触式间断相位法的,本文重点研究叶片振动的非接触式测量方法。在理论研究方面,本文结合传统的非接触式叶片振动测量方法,分析了基于该方法测量叶片振动的基本原理,建立了相应的数学模型,并同实际情况相结合,改进了叶片振动的计算方法,特别是振幅的计算方法。研究表明,改进的计算方法能获取更高的计算精度,减少测量误差。同时,本文对基于应变片的测量方法也进行了研究,并推导出了叶片振幅的计算公式。实验台建设方面,本文对叶片动态特性实验台进行了改进设计,并对实验台进行了改造。该实验台由空压机、储气罐、喷嘴、电机、转子及相应的管路系统组成,同时开发出了叶片振动测试系统,利用该实验台可以完成叶片动态特性测量实验及叶片碰磨减振实验。利用LabVIEW开发平台,本文开发出了非接触式叶片振动测量系统和基于应变片的接触式叶片振动测量系统。该测量系统主要包括数据采集模块、数据处理模块、数据分析模块、数据保存模块及数据回放模块等,能实现对叶片动态特性的实时监测,并可以通过数据回放模块进行离线数据分析。在实际进行叶片测量时,还需要进行叶片编号,本文开发出了叶片编号的程序,该程序能够减小叶片节距不均匀带来的测量误差,提高测量精度。利用叶片动态特性实验台及其测试系统,本文进行了叶片振动的非接触式测量实验,实验分为四个工况进行,并将测量结果与理论计算及基于应变片的接触式测量实验结果进行了对比,做了误差分析,结果表明本文中的非接触式测量方法是切实可行的。基于以上的研究成果及其它研究者的研究成果,对将该系统应用到现场检测的可能性进行了初探。更多还原

【Abstract】 By using theoretical and experimental ways,methods and technology for dynamic measurement of turbine blade vibration were studied. There are two different ways to measure the dynamic parameters of turbine blade vibration: one is contact measurement which is called strain gauge -telemetry method or strain gauge- slip ring method,another is non-contact measurement which is called Tip-timing method. In this paper,the Tip-timing method is mainly studied.On the theoretical study,based on the traditional non-contact measurement,the basic theory of blades vibration measurement was researched,and the mathematical model was established. The blade vibration calculation method,especially the method of amplitude calculation based on the actual situation was modified. The results of the analysis indicate that there will be higher calculation accuracy and less measurement error with the improved method. In this paper,the measurement based Strain gauge - slip ring method was studied,and the formula of amplitude was deducted too.On the building of rotor experiment table,the bench of blade dynamic characters was improved according the theory of measurement. The improved test-rig is composed of air compressor,gasholder,three nozzles,motor,and rotor and so on. At same time,the measurement system was developed too. The experiment of blades dynamic characteristicsand the mechanism of vibro-impact could be made on this bench. With the use of software development platform LabVIEW,the test system of blades vibration based the non-contact measurement theory and system based the strain gauge- slip ring method were developed in this paper, which were composed of signal acquisition model,signal processing model,signal analysis model,signal preservation model and the data recalling model. With the use of the test system, the on-time vibration of blades can be measured. The numbers must be given to blades when the on-spot test is conducted, so the number system of blades was also developed in this paper.On the experimental study,the non-contact measurement experiment was done with the rotor experiment table and the test system,and the test results was compared with the results of theoretical calculation and the results based on the strain gauge- slip ring method. Study results indicate that the non-contact measurement method mentioned in this paper is practicable.On the base of the study results mentioned above and research results of other investigators,the possibility of on-site application of the non-contact measurement system developed in this paper was studied.更多还原