离心压缩机动静干涉信号特征识别方法

离心式压缩机由于内部静、动叶片排的相对运动,气流在压缩机内部流动时会产生动静干涉,从而会产生不定常气流激振力和高振幅压力脉动。这种非定常动静干涉对压缩机的稳定正常运行和实际工作效率有着重要的影响。为了有效研究动静干涉的信号特征,首先,对某模型级压缩机试验台离心叶轮进行运行模态仿真计算从而得到叶轮干涉图;其次,确定进口导叶(inlet guide vanes,简称IGV)和出口扩压器(outlet guide vanes,简称OGV)对叶轮存在干涉的转速;最后,在确定的试验转速工况下进行应变测试和压力脉动测试。通过分析对比,验证了仿真转速工况下干涉特征频率的存在,也证实了应变信号更适用于识别干涉信号特征。通过总结干涉较严重的转速工况干涉特征频率与叶轮固有频率的关系,为离心压缩机进一步改进设计奠定了基础。

Investigation on Signal Characteristics Recognition Methods of Rotor Stator Interaction for Centrifugal Compressor

For a centrifugal compressor, as a result of the relative motion of static and dynamic blade rows, it will cause the rotor-stator interaction induced by the airflow in the compressor, to produce the unsteady airflow exciting force and the high amplitude pressure pulsation. The unsteady rotor-stator interaction has an important influence on the stability, normal operation and practical efficiency of the compressor. In order to effectively study the signal characteristics of rotor-stator interaction, the operational modal simulation calculation for the impeller of a model centrifugal compressor test rig is carried out to obtain the impeller interferogram, and determine the speed conditions at which the inlet guide vanes (IGV) or the outlet guide vanes (OGV) has interference to the impeller. Finally, a strain test and a pressure fluctuation test are carried out under the determined experimental speed conditions. Through the analysis and comparison, the existence of the interference characteristic frequency under the simulated rotating speed conditions is verified, and the strain signal is also proved to be more suitable for identifying the characteristics of the interference signal. Through summing up the relationship between the interference characteristic frequencies of the serious interference speed conditions and the natural frequencies of the impeller, it lays the foundation for further improvement of centrifugal compressor.