摘要
随着大型汽轮发电机组等大型旋转设备的日益细长化和复杂化,转子系统的支承点的增加,对转子系统的动力特性和状态监测与故障诊断也提出了更高的要求。本文以大型汽轮发电机组的核心部分—多支承转子系统为研究对象,首先以单跨二支承多轮盘转子为引入对象,应用邓柯莱法、传递矩阵法、有限元法对其临界转速进行了计算,并对三种方法的特点与使用范围进行了分析比较。针对转子系统中的各种参数对临界转速的影响,提出了结构参数对临界转速的敏感度概念。进而以搭建的四跨八支承多轮盘转子系统为研究对象,采用ANSYS中的旋转结构模块仿真得到临界转速并提取了临界转速的Campbell图,并分析得到系统各单跨转子与系统转子模态振型及临界转速的关系。通过对瞬态启动响应分析可知:可以通过适当提高启动加速度的方式减小转子系统通过共振区的最大振动幅值,保证其能够更加安全可靠的运行,从而延长使用寿命。
通过单跨二支承单轮盘转子试验台的试验研究,获取了系统幅频特性和波德图,进而得到系统临界转速试验值。将此试验值与通过ANSYS仿真得到得临界转速结果对比分析:结果数据比较吻合,说明利用ANSYS中的旋转结构模块对转子的临界转速计算方法是可行的。
搭建了四跨八支承多轮盘转子试验台中的第四跨转子并安装调试了测试系统,包括对传感器的选用与标定。对课题组自行研制的某二维轴承负荷传感器进行了静态标定试验与静动态仿真标定,可知其静动态特性较好,能够准确地对轴承负荷实施测量。由于提取轴心轨迹中的故障特征能够对转子系统进行监测与故障诊断,试验中提取了两种不同稳态转速下的轴心轨迹,通过去噪处理后与仿真获得的轴心轨迹进行比较分析,得到了轴心轨迹在不同稳态转速下的轨迹特点。
As the large steam turbine-generator and other large rotating equipments are more and more tenuous and sophisticated, the number of rotor support points are increasing, Higher requirements on the technology—the dynamic character of the rotor system and condition monitoring and fault diagnosis—are putted forward.The research object of this article is part-multi-support rotor system, which is the core part of large steam turbine generator. Single span and two supporting roulette rotor is taken as the research object, while DengKe-lai method, transfer matrix method, and the method of finite element are applied to the calculation of critical speed of it. Characteristics and range of application of the three kinds of method are analyzed and compared. According to the influence—the rotor system various parameters produce—on the critical speed, concept of the sensitivity of the structure parameters on the critical speed is putted forward. And then, the eight-supporting multi-bearing rotor system is taken as the research object, the critical speed is obtained by ANSYS simulation module of rotating structure. By the extracting of critical speed Campbell figure, the relationship of each single rotor system on modal shape and critical speed is obtained. The biggest amplitude while rotor system passing the resonant vibration can be reduced by appropriate increasing Start acceleration, and ensure the safety operation, so as to prolong service life.
By the research on rotor, amplitude frequency characteristics and wave DE figure of the system are obtained, and the critical speed system test value is got. This test value and critical speed results by the ANSYS simulation are contrasted and analysed, and showed that:the results data consistent and the calculation method of rotor critical speed by ANSYS rotating structure module of is feasible.
Eight-supporting many roulette rotor test bench and installation debugging the test system which including the selection of sensor with the calibration is built. The static calibration test and calibration of static and dynamic simulation on the two-dimension bearing load sensor,which is developed by a group are realized, which shows that the static and dynamic characteristics is good and be able to accurately measure the bearing load. Fault features, such as axis path, can be used on stator subsystems monitoring and fault diagnosis. Been denoising treated, Axis path—can be got by the system test in two different extracting the steady rotating speed—is compared with that getting by the simulation. As a result, the axis path in the track of the steady-state rotating speed different characteristics can be obtained.
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