基于噪声信号分析的轴流风机故障诊断

Axial Flow Fan Fault Diagnosis Based on Noise Signal Analysis

噪声是风机运行过程产生的一种信号,包含了风机结构振动的信息特征,据此提出通过分析风机噪声信号来实现风机不停机故障诊断的方法。结合风机噪声信号模型,对轴流风机轴系不对中、转子不平衡、基座松动、叶片损坏4种典型故障的Fourier频谱特征做出了理论分析预测。通过现场检测试验,采集了电机的转速信号与风机的噪声信号,分析了风机噪声的时域波形,初步诊断该风机存在故障。再分析了轴流风机噪声信号的Fourier频谱,提取出相关故障特征频率,发现频谱中n倍高次谐波比较明显,并且其中2n倍高次谐波占主导地位,因此判断该风机故障种类为轴系不对中。经过重新校正与检修,该风机恢复正常运转。试验及分析结果成功验证了基于噪声信号诊断轴流风机故障理论方法的可行性,对于工业领域通过噪声信号来诊断风机故障具有一定的指导作用。

Noise is generated during the fan running,which contains the characteristics of the structural vibration of the fan.Therefore,a method was proposed to detect the fault of the fan without stopping the machine by analyzing its noise signal.According to the noise signal model of the fan fault,the Fourier spectrum characteristics of the axial fan four typical faults,shafting misalignment,rotor imbalance,base loose,and blade damage,were theoretically analyzed and predicted.Through the field test,the speed signal of the motor and the noise signal of the fan were collected,and the time-domain waveform of the noise signal was analyzed,diagnosing the fan existed a fault preliminarily.The Fourier spectrum of the noise signal of the axial flow fan was analyzed then,and the fault characteristic frequency was extracted,observing that the n-times high-order harmonics in the spectrum were obvious and the 2n-times high-order harmonics were dominant.Therefore,the type of the fan fault was diagnosed to be shaft misalignment.After recalibration and overhaul,the fan returned to normal operation.The result of the experiment and analysis successfully verifies the feasibility of the theoretical method of diagnosing axial fan faults through acoustic analysis way,which is helpful to diagnose the fan faults via noise signal analysis in the industrial field.