关键词: 电容层析成像, 图像重建, 组合电极, 激励测量模式

Abstract: Electrical capacitance tomography (ECT) is a technique for two-phase flow measurement. The image reconstruction of ECT is a nonlinear and ill-posed inverse problem. The sensitivity distribution of ECT is inhomogeneous and only few measurements can be obtained, which causes the low quality of reconstructed images for the objects in the center. More measurements can be obtained by increasing the number of electrodes. But it will cause the decrease of measurement values and lower measurement accuracy. Under the condition of ensuring the measurement accuracy,the 24 combined-electrode sensor for ECT was proposed and two exciting-measuring modes were studied. The values and the dynamic range of measured capacitance values, the uniformity of sensitivity distribution and the reconstructed images of different flow regimes were compared with the conventional 12-electrode sensor. Simulation results showed that the sensitivity distribution was more uniform and the reconstructed images for the objects in the central locations were improved obviously by using 24 combined-electrode ECT sensor.

Key words: electrical capacitance tomography, image reconstruction, combined-electrode, exciting-measuring mode