Analysis And Optimization Of Capacitive Sensor With3D Finite Element

The capacitance sensor in this paper is applying for pulverized coal in blast furnace which belongs to the dense-phase pneumatic conveying. In the case, flow patterns have influence on the transmission performance and parameter detect. In order to get better optimal design of sensor structure, taking dynamics as a part of research and studying the flow pattern of object, laying the foundation on flow-electrostatic field coupling.This subject is set in the dense phase pneumatic conveying process, taking the finite element software ANSYS and fluid analysis software FLUENT as the research platform. The research object is helical capacitive phase concentration sensor. The paper makes use of the research method on the simulation and experimental validation and makes a deep discussion on the sensor optimization. The main works are as follows:(1) The basic concept and the mechanics theory on gas-solid two-phase flow have been researched; The gas-solid two-phase turbulent double fluid model has been established, the flow process has been simulated with FLUENT and the concentration distribution, the velocity distribution have been analyzed; The flow characteristics under different working conditions have been studied, single slug flow and multiple slugs flow have been simulated;(2) The theoretical basis on the optimization of capacitive phase concentration sensor has been studied, which includes the basic structure parameters, the measuring principle of sensor, and finite element method in electrostatic field; According to the analysis of operating principle of capacitance sensor, it establishes the Finite Element Model(FEM). On the basis of FEM, this paper adopts electric charge method to calculate capacitance on the electrode.(3) The effect on evaluation index with various structural parameters has been analyzed; According to various structure parameters, two kinds of common pipe of capacitance sensor have been designed optimally; According to different radius of pipeline, a lot of optimize experiments have been made. Finally different models have been got, which have small size, small uniformity error and can satisfy the measurement requirements;(4) Slug flow has been simulated to verification the optimal capacitance sensor; Under the laboratory conditions, sensor has been made according to the results of simulation; Different concentrations of slug models have been made. The experiment results are proved that the static test results are consistent with theoretical results. The sensor has good uniformity which can satisfy the need of dense-phase pneumatic conveying;...