双截面电阻层析成像系统设计

Design of Twin-Plane Electrical Resistance Tomography System

为了扩展电阻层析成像系统的测量范围,提出了一种采用电压激励、电流测量模式的双截面电阻层析成像(ERT)系统,可避免因负载电阻增大而导致的电压饱和现象.分析了双截面ERT系统采用异步工作模式的不足,提出了双截面同步工作模式,并给出了该模式下的三维敏感场有限元仿真方法.实验结果表明,该系统的测量数据相对变化量的均方根误差最大值不超过0.15%,各通道测量数据的标准方差可控制在0.03%～0.12%之间,显示出良好的数据重复性及通道一致性.竖直管内的气/液两相流实验表明,系统测量范围得到了有效扩展,该双截面ERT系统可实现两相流的在线测量,实现流型和截面气体持率的在线监测.

In order to extend the measurement range of electrical resistance tomography（ERT）,a twin-plane ERT system with voltage-driving/current-measuring strategy has been put forward,which can overcome voltage saturation resulting from the increase of resistance load.Based on analysis of the disadvantages of the asynchronous driving mode in twin-plane ERT system,a synchronous driving mode has been proposed and the finite element method based on three-dimensional field has been introduced.Experimental results show that the root mean square error of relative variation of the measured data is less than 0.15% and the standard deviation value of channel consistency ranges from 0.03% to 0.12%,which proves good measurement repeatability and channel consistency of the system.Experiments of gas/liquid two phase flow in the vertical pipe indicate that the measurement range of the system is significantly extended and online measurement of the two-phase flow is facilitated by the proposed twin-plane ERT system,which helps to realize online monitoring of flow regime classification and gas holdup computation.