油气润滑ECT传感器的管道电容及其影响

Pipeline Capacitance of Oil-Air Lubricated ECT Sensor and Its Influence

采用COMSOL软件建立油气润滑电容层析成像传感器的三维物理模型,推导计入管道电容的数学模型;定义管道电容影响系数,分析管道厚度和管道半径对其影响。在算法中计入管道电容对环状流进行图像重建,并对重建图像质量进行评价。研究结果表明:管道电容影响系数可以表征管道电容对测量电容的影响;管道厚度增加或管道半径减少,管道电容对测量电容的影响增大,特别是对于油气润滑小管径,管道电容对测量电容有较大影响;计入管道电容影响后,重建图像质量有一定提高。

The COMSOL software was employed to establish a three-dimensional physical model of electrical capacitance tomography(ECT)sensor for an oil-air lubrication system,and its mathematical model considering the capacitance of the pipeline was got.The influence factor of the pipeline capacitance was defined,and the influence of the thickness and the radius of the pipeline on the measured capacitance was analyzed.The image of the annular flow was reconstructed by using LBP algorithm and considering the pipeline capacitance,and the quality of reconstructed image was evaluated.The results show that the influence of pipeline capacitance on the measured capacitance can be represented by the influence factor of the pipeline capacitance,the effect of the pipe capacitance on the measured capacitance will increase with the increasing of pipleline thickness or the decreasing of pipeline radius,especially the pipeline capacitance has a greater impact on the measured capacitance for small diameter pipes in an oil-air lubrication system.The quality of reconstructed image is improved in a certain extent when the pipeline capacitance value is taken into account in the algorithm.