测量液体管内含气率的电容传感器系统的设计

Design of Capacitance Sensor System for Measuring Gas-holdup in Liquid Pipe

文中设计了一个阵列式结构的电容传感器系统,对液体管内含气率进行测量。首先,基于Comsol仿真软件对传感器的结构参数进行优化,并完成传感器的设计与制作。然后,设计用于极板工作状态切换的门电路和用于微小电容测量的C/V转换电路,再设计FPGA程序进行电路控制和上下位机通讯,并对上位机采集的信号进行滤波、解调。最后,用BP神经网络完成管道截面处的含气率重构。进一步采用可视化验证方法对电容传感器系统的准确性进行验证。电容传感器系统和可视化方法得到的平均截面含气率的偏差不超过8.48%,均值偏差为5.62%,均方根偏差为5.51%。设计的电容传感器系统具有很好的测量准确性。

In this study, a capacitance sensor system based on an array structure was designed to measure the gas-holdup in liquid pipe.Firstly, the structural parameters of the sensor were optimized by Comsol software, and its design and manufacture were completed.The gate circuit and C/V conversion circuit were designed, FPGA program was written for circuit control and communication between upper and lower machines.In addition, the signals collected by the host computer were filtered.Finally, BP(back propagation) neural network was used to reconstruct the gas-holdup at the pipeline section.In this study, a visual verification method was adopted to verify the accuracy of gas-holdup measurement.The deviation of the average section gas-holdup obtained by the gas holdup measurement and visualization method was no more than 8.48%,the mean deviation was 5.62%,and the root mean square deviation was 5.51%.The capacitance sensor system designed in this research has good measurement accuracy.