Research On Key Technology Of Electrostatic Gas-solid Two Phase Flow Parameter Testing System

Nowadays the gas-solid two phase flow has been applied in the actual industrial production processes widely,such as power plant,steel making,chemical and food industry,etc.And the on-line parameter measurement of fluid particles has been an important index to measure the mass flow of gas-solid two phase flow.In recent years,many scholars have proposed the method of measuring the velocity of fluid by electrostatic sensor based on the electrostatic induction characteristic of solid particles in the transmission process.Compared with other methods,such as capacitance method,attenuation method and optical method,the electrostatic measurement method has the characteristics of simple structure,low cost and high sensitivity,which makes it has a good prospect in the parameters measurement of gas-solid two phase flow.Based on the electrostatic method,this paper designed the electrostatic sensor system with the principle of cross-correlation,and verified its feasibility and reliability for the on-line measurement of fluid velocity.In this paper,aiming at two phase flow flowing characteristics designed and built two phase flow pipeline simulation experiment system,and interpolated two groups of electrostatic sensor measuring system in the pipe system.Firstly,the design principle of the electrostatic sensor was introduced,its main theoretical basis is that solid particles would generate electrostatic induction charge due to friction and collision in the pneumatic transport process;and according to the analysis of these charge characteristics,designed material and structure of the electrostatic sensor,and signal detection conditioning circuit,as well as expounded the cross-correlation velocity measurement mechanism.Secondly,used the finite element analysis software MAXWELL of the ANSOFT company to carry out the sensitivity simulation analysis of the designed sensor;and the distribution of the charge on the electrode,when the charged particle is passed through the sensor sensitive region,was obtained,which proved the rationality of the electrode design.Finally,the experimental platform was set up,and the data acquisition control and the design of the PC software platform was completed;and starting from the simple conditions and actual situation designed the two kinds of verification experiment,to verify the rationality and feasibility of the system design.The experimental results show that the system meets the design requirements.It solves the problem with the fluid velocity detection of gas-solid two phase flow and proposed a cross-correlation measuring method about the electrostatic sensor.It has the advantages of novel method,good repeatability,high precision and strong practicability,etc.