Study On Two-phase Flow Measurement Based On Multi-sensor Fusion

The two-phase flow exists in the nature and industrial processes widely. The accurate measurement of two-phase flow is always a very tough problem in the field of engineering techology and science research.At present, Electrical Resistance Tomography (ERT) technology with visualization measurement and noninvasive characteristics has potential advantage in two-phase flow measurement field. But there are shortcomings in the measurement of dynamic parameters of fluid, such as average velocity etc. Therefore, the new measurement method by combining ERT and electromagnetic flowmeter for parameters measurement of two-phase flow is put forward in this paper. the advantages of Electromagnetic flow-meter for conducting fluid are used to make up the shortages of ERT in the aspect of continuous phase measurment. Their fusion not only expands application range of electromagnetic flowmeter into the two-phase flow fields, and deepens the theory of electromagnetic flowmeter measurements, but also implements multi-parameters measurement of two-phase flow.In view of the theory of electromagnetic induction flow measurement, boundary conditions of electromagnetic field are analyzed and established in this thesis. Furthermore, distribution properties of electromagnetic field are simulated by PDE Toolbox. From the perspective of electromagnetic field, the reasons why the output characteristics of electromagnetic flowmeter in the condition of two-phase flow differ from single-phase flow's are explained. The integral equation of electromagnetic flowmeter output potential is solved.Based on the theory of Multi-sensor fusion, the theoretical basis and measurement mechanism of fusion of the ERT and electromagnetic flowmeter are analyzed. From the principle of electromagnetism, the feasibility of their fusion is expounded. The fusion equations of ERT and electromagnetic flow-meter are established, and then the functional equation between velocity and flow rate of liquid and bubble parameters are deduced. It provides an important theoretical basis for realizing multi-parameters measurement of continuous phase and discrete phase of two-phase flow.