The Gas-solid Of Two-phase Flow ECT Data Acquisition System

ECT(Electrical Capacitance Tomography)is a high technology in industrial process of visualization parameters detection, which relies on the measurement change of capacitance sensor in insulation pipe electrode, algorithm of the image reconstruction can present non conducting material in insulation pipeline location and movement information,which monitor the pipelines in the state of matter. especially in the two-phase flow field of petroleum, chemical, natural gas pipeline transmission, it has a wide range of application prospects. ECT data acquisition system is key in the whole ECT system, the ability of anti disturbance, the speed of acquisition, the measuring accuracy of the performance directly relates to the quality of the image. Therefore, it has great practical significance and application value to carry out the research of ECT data acquisition system.According to the practical application of gas-solid flow detection problem, using ECT technology to complete the design of data acquisition system, the specific work of this paper is as follows:Compare ECT data acquisition system in traditional discrete element with new integrated chip of the capacitance measurement method, analysis new integrated chip capacitance measurement method of CDC(capacitance to digital converter) technology in measuring capacitance advantages. a set of gas-solid flow ECT data acquisition system is proposed, which is based on the chip of pcap01.Complete capacitance detection circuit of the ECT data acquisition system, which's based on the chip of pcap01. design logic switching circuit, which's based on the chip of ADG412. design control circuit, which's based on the chip of STM32. design the insulation pipe,which has 8 capacitance sensor. In order to reduce the external interference, the coaxial shielding cable is connected with the logic switch circuit and the pipeline electrode plate capacitance sensor, the experimental platform of the ECT data acquisition system for gas-solid flow is built.ECT data acquisition system is designed, which can realize the loop control of the 8 electrode plate capacitance transducer, as well as the collection and transmission of the capacitance data of the plate capacitance. In order to reduce the interference of stray capacitance in the circuit, the Pcap01 capacitor test software is used to set up the error compensation and design digital signal filter to cope with it.In the aspect of image reconstruction, the COMSOL Multiphysics software is used to model pipeline, create mesh and solve the sensitivity matrix. the MATLAB software prepare the program of image reconstruction for conjugate gradient.The experimental platform of the ECT data acquisition system for gas-solid flow is built. complete the experiment of pipeline in stope and gas-solid flow, analysis the experimental results and reconstruct image, test the design of ECT data acquisition system for gas-solid flow is feasible.