Evaluation of the Performance of Capacitance Sensor for Concentration Measurement of Gas/Solid Particles Flow by Coupled Fields

This paper proposed a real-time dynamic 3-D numerical simulation method to evaluate the performance of capacitance sensor in the concentration measurement of gas/solid two-phase flow by the coupling of electrostatic and fluid fields. Compared with static simulations, this method can inform the optimal design of capacitance sensors for concentration measurement that incorporate the dynamic characteristics of two-phase flows. The fluid-electrostatic models with different sensor structures are built. Under different test positions and different particle concentrations the flow characteristics and the corresponding capacitance signals can be obtained. The system sensitivity correlation coefficient and standard deviation are calculated to evaluate the performance of the sensors. The effects of flow regimes on concentration measurement are investigated in this paper. To validate the results of the simulation, an experimental platform with horizontal test section for volume concentration measurement of solid/gas two-phase flow is built and the experimental results are in good agreement with the simulation conclusions. The simulation and test results show that the coupling models can give useful reference data for the design and collection of sensor structure, which is very important in the practical process of a pneumatic conveying system.