Electrical Resistance Tomography Based On Equipotential Line Electrode And Design Of Simulation Platform

Electrical Resistance Tomography (ERT) is one of Process Tomography (PT) techniques based on the principle of impedance measurement, and has been developed very fast over the last decade. ERT is particularly suitable for the two-phase (or multi-phase) flow applications having a conductive continuous phase, and is able to provide 2D/3D visualization information of the parameters of a multi-phase mixture flowing inside a closed pipe or vessel. ERT offers some excellent cutting edges in measurement such as capable of yielding process images, non-intrusive to the flow media, fast-responding, low-cost, non-radiation, flexible measurement options etc. The work described in this paper reports some unique results on the ERT research undergone in China University of Petroleum (East China). It includes an ERT-FEM model formed by a hybrid triangular-quadrangular mesh structure in dealing with electrodes under Neumann boundary condition, by which the current vectors should theoretically leave or enter the electrode surface. It also includes a rather important development on electrode modeling through which the equipotential feature on electrode surface is established under Neumann boundary condition. Both theoretical and analytical approaches for the equipotential electrode model are discussed and the results are given. The resolved analytical solution is first of its kind and can be used for any electrode applications mounted on a circular containing a homogeneous medium under Neumann boundary condition. Comparisons of image reconstruction results obtained from using different electrode models are presented. A non-iterative algorithm, namely the Linear Back Projection algorithm, and an iterative algorithm, namely the Modified Newton Raphson algorithm are chosen to perform the image reconstruction to observe the influence of electrode models used in the forward solver. Finally a Matlab based ERT simulation package developed by author is presented to summarize some of the functionalities relevant to the work described above.