旋风分离器内气相旋转流动态特性分析与表征

Analysis and characterization of gas swirling flow dynamic characteristics in a cyclone separator

旋风分离器内的气相旋转流具有很强的动态特性,表现为流场瞬时参数随时间波动变化。为了对旋风分离器内气相旋转流动态特性进行表征,本文基于热线/热膜风速仪(HWFA)和动态压力传感器测量的旋风分离器内瞬时切向速度和瞬时压力,从时域和频域两个方面进行了分析。结果表明,旋风分离器内瞬时切向速度信号时域上的波形分布与旋转流的摆动存在联系,时域上的标准偏差可以直观地表征旋风分离器内旋转流的波动强度;频域的主频和功率谱密度(PSD)可以表征旋转流动态参数波动的准周期行为、传递行为和强度衰减特征,也是旋转流摆动行为及其影响范围的反映。基于瞬时切向速度和瞬时压力的时域和频域分析能较好地反映旋转流流场的波动特点,均可用于表征旋风分离器内气相旋转流的动态特性。

Gas swirling flow in the cyclone separator exists strong dynamic characteristics,which are characterized by the instantaneous parameters fluctuate over time.In order to characterize the dynamic characteristics of the gas swirling flow in a cyclone separator,the instantaneous tangential velocity and instantaneous pressure in the cyclone measured by the hot wire/film anemometer(HWFA)and dynamic pressure sensor were analyzed on both time and frequency domain.The results showed that the waveform distribution of the instantaneous tangential velocity in the time domain wass related to the gas swirling flow swing,and the standard deviation was dependent on the fluctuation intensity of gas swirling flow.The dominant frequency and power spectral density(PSD)in the frequency domain were used to illustrate the quasi-periodic behavior,transmission behavior and attenuation characteristics of the swirling flow dynamic parameter.It is also the reflection of the swirling flow swing behavior and its range of influence.Therefore,time-frequency analysis based on the instantaneous tangent velocity and the instantaneous pressure might better indicate the fluctuation characteristics of the swirling flow,consequently,which can be applied to characterize the dynamic characteristics of the gas swirling flow in the cyclone separator.