用于气固两相流检测的环式静电传感器频率响应特性的研究

Research on Frequency Response Characteristics of Ring Type Electrostatic Sensor for Gas-Solid Two-Phase Flow Detection

气固两相流广泛存在于工业生产的材料输送中,静电法由于具有成本低、易检测、适应性强等优点而被广泛应用在两相流的测量中。基于静电感应原理,采用有限元分析法对传感器的结构参数(管壁厚度、电极宽度、电荷、位置等)进行了设定;在不同电极宽度下,对传感器的空间灵敏度进行了研究;根据静电传感器的静动态特性,研究分析了传感器的幅频特性。经仿真实验得出:静电传感器在空间频域上具有低通滤波特性;粒子通过管道时,越靠近管道中心,空间频带越窄;粒子在管道中的速度越快,传感器的频带越宽;电极的轴向长度越长,信号的振幅越大。在确定电极宽度的情况下,可以得到电极在管道内的最佳感测范围。

Gas-solid two-phase flow is widely used in the transportation of materials in industrial production.The electrostatic method is widely used in the measurement of two-phase flow due to its disadvantages of low cost,easy detection,and strong adaptability.Based on the principle of electrostatic induction,the structure parameters(thickness of tube wall,electrode width,charge,position,etc.)of the sensor are set by finite element analysis method.The spatial sensitivity of the sensor is studied under different electrode width.The amplitude frequency characteristics of the sensor are studied and analyzed according to the static and dynamic characteristics of the electrostatic sensor.Simulation results show that:the electrostatic sensor has low-pass filtering characteristics in the spatial frequency domain;the closer the particles pass through the pipeline,the narrower the spatial frequency band;the faster the speed of those particles in the pipeline,the wider the frequency band of the sensor;the longer the axial length of the electrode,the greater the amplitude of the signal.When the electrode width is determined,the best sensing range of the electrode in the pipeline can be obtained.