Research Of Flow Parameters Detection Methods In Gas-Solid Two-phase Flow

With the development of science and technology, gas-solid two-phase flow systemsare more and more widely applied in modern industrial and agricultural production. Forexample, power plant, ferrous metallurgical and fluid bed reactor, their productive processalmost involve material pneumatic conveying which belongs to gas-solid two-phase flowsystems. The gas-solid two-phase flow parameters’ accurate measurement and real-timemonitoring are very important for the stable operation of the production process and productquality. Because of gas-solid two-phase flow belongs to the complex flow system, its flowparameter’s detection method is a technical difficulty for a long time.This paper selected electrical capacitance tomography technology as an entry pointbecause of there are some technological merit.Such as noncontact; visualization; and so on.The main contributions and works are as follows:Firstly, this thesis made a statistical research on the electrical capacitance tomographytechnology, also, established the2-D and3-D model, and got the capacitance quickly bymeans of ANSYS software. Compared with the method by MATLAB or VC, the improvedmethod by ANSYS can greatly save the time and reduce the cost of development.Secondly, this paper simulated a typical eight-electrode sensor and analyzed it whichis used in ECT system. The experiment gave the sensitivity distribution of this sensor. Thepaper reconstructioned pipe internal material distribution image using the neural network.The result indicated that the eight-electrodes sensor doesn’t have uniform sensitivity fielddistribution and higher sensitivity, and it brings difficulties to image reconstruction.Lastly, in order to solve the problem mentioned in the preceding part of the paper, theauthor simulated and analyzed the coaxial capacitance sensor and spiral capacitance sensor.Experiment result indicates that the coaxial capacitance sensor and spiral capacitancesensor have uniform sensitivity field distribution and higher sensitivity. And theircapacitance value of this sensor has nothing to do with flow pattern which is only related tosolid concentration change. Therefore, capacitance value can reflect solid concentrationdirectly and avoid the step that got the solid concentration by image reconstruction.Based on what is researched above, the coaxial capacitance sensor and spiralcapacitance sensor can measure concentration and speed parameters on-line in air/liquid,liquid/liquid two-phase flow combined with cross-correlation technologies and they have abroad application prospect.