大型汽轮发电机组轴系扭振特性分析

发布时间：2018-03-20 16:29

本文选题：汽轮发电机转子轴系　切入点：传递矩阵　出处：《华北电力大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着我国电力工业的发展,我国现今的火电机组普遍采用单机容量为600MW-1000MW的大型汽轮发电机组。由于机组容量的增大和电网峰谷差日益增大,使得大型火力发电机组不可避免地参与调峰运行,机组轴系的扭振问题变得日益突出。本文以某国产600MW超临界机组轴系为研究对象,用集总参数法建立轴系的多段集中质量模型,用传递矩阵法对机组轴系的扭振特性进行研究分析。本文的主要工作和结论如下： 1)用集总参数法对转子轴系进行离散简化,并用传递矩阵法计算轴系的扭振固有模态,并计算了轴系前三阶共振时的应力分布,一阶共振时扭应力的最大值出现在1#低压转子和2#低压转子的轴颈之间,二阶共振的最大扭应力出现在2#低压转子和发电机转子的轴颈之间,三阶共振时轴系最大扭应力出现在高中压转子和1#低压转子之间。 2)学习整理了国内三大电机厂生产的600MW级汽轮发电机组的轴系结构,绘制出轴系的结构简图,介绍了汽轮发电机组的运行特性和国内的主要调峰方式。 3)将传递矩阵法和数值积分方法相结合,计算轴系的扭振响应,通过对计算结果得到轴系的最大应力出现在低压2#转子与发电机转子的联轴器处。应用局部应力应变法对轴系疲劳寿命损耗进行分析,得出机组轴系在发电机出口处发生两相短路时,引起的轴系扭振疲劳损耗最大。 4)计算轴系在机组快速变负荷时的扭振响应,通过对计算结果的时域和频域分析,得出结论：轴系在快速变负荷时,轴系的扭矩波形图的主要频率成分包含了轴系的前三阶扭振固有频率,不包含工频。
[Abstract]:With the development of electric power industry in China, large turbogenerator units with a single unit capacity of 600MW-1000MW are widely used in our country. Due to the increase of unit capacity and the increasing difference between peak and valley of power grid, The torsional vibration problem of shafting becomes more and more prominent due to the inevitable participation of large thermal power generating units in peak shaving operation. In this paper, the shafting of a domestic 600MW supercritical unit is taken as the research object. The multi-stage mass model of shafting is established by lumped parameter method, and the torsional vibration characteristics of shafting system are analyzed by transfer matrix method. The main work and conclusions are as follows:. 1) the rotor shaft system is discretized simplified by lumped parameter method, and the natural mode of torsional vibration of shaft system is calculated by transfer matrix method, and the stress distribution of the first three order resonance of shaft system is calculated. The maximum torsional stress of the first order resonance occurs between the journal of the 1# low voltage rotor and the 2# low pressure rotor, and the maximum torsional stress of the second order resonance occurs between the 2# low voltage rotor and the generator rotor journal. The maximum torsional stress of the shaft appears between the high pressure rotor and the 1# low pressure rotor during the third order resonance. 2) the shafting structure of 600MW class turbine-generator set produced by three major electric power plants in China has been studied, and the schematic diagram of the shafting structure has been drawn. The operation characteristics of the turbogenerator unit and the main peak shaving methods in China have been introduced. 3) the transfer matrix method and numerical integration method are combined to calculate the torsional vibration response of shafting. The results show that the maximum stress of shafting appears in the coupling of low-voltage rotor and generator rotor. The fatigue life loss of shafting is analyzed by using local stress-strain method. It is concluded that when two phase short circuit occurs at generator outlet, the fatigue loss of shaft system torsional vibration is the largest. 4) the torsional vibration response of shafting under fast load change is calculated. By analyzing the calculated results in time domain and frequency domain, it is concluded that the shafting is under fast load changing. The main frequency components of the shafting torque waveform include the first three natural frequencies of the shafting torsional vibration, not the power frequency.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM311

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