Research On Electrostatic Sensor Design And Weak Signal Detection Method

Gas-solid two-phase flow technology has been widely used in industrial production.The detect for its flow parameters is an urgent problem to be solved by modern industry.At present,the electrostatic method has been developed rapidly.Electrostatic is based on the principle of electrostatic induction,using the electrostatic sensor to measure the gas-solid two-phase flow speed,fineness and other parameters.Electrostatic sensor has a simple structure,easy installation,low cost,high sensitivity,and has great potential for development in the future.This article uses the principle of electrostatic induction,design two types of electrostatic sensors:Plug-in electrostatic sensor and inductive electrostatic sensor.By studying the performance characteristics of electrostatic sensor,analyze the factors that affect the accuracy of the electrostatic sensor and the advantage and disadvantage of two kinds of electrostatic sensors,and verify the electrostatic sensor.The main contents include:First,analyzing the working model of gas-solid two-phase flow in thermal power plant,use PVC pipes,funnels,switch valves,valves,iron frame,copper film and other equipment to build independent experimental platform in the laboratory,and verify the performance of electrostatic sensors.Second,according to the principle of electrostatic induction,the mathematical model of the inserted electrostatic sensor and the induction electrostatic sensor is analyzed.At the same time,the material selection and structural design of two kinds of electrostatic sensors are tested and compared,and the advantages and disadvantages of two kinds of electrostatic sensors are compared.Third,design electrostatic signal processing circuit,the circuit mainly includes analog circuit and digital circuit.Analog circuit using dual operational amplifier LM358 charge voltage conversion,pre-amplification,filtering and signal polarity adjustment,use PGA202 and PGA203 to complete the two-stage amplification of the signal.Digital circuit includes signal acquisition,storage,display,and so on.The experimental results show that the static signal processing circuit has high SNR and strong anti-jamming ability.Forth,the Fourier transform method is used to detect the weak signal,and the simulation is carried out by using MATLAB to analyze the error of the measurement frequency.Fifth,the two types of electrostatic sensors are tested and verified based on the laboratory independent experimental platform.Testing two types of static sensor measurement accuracy,real-time,repeatability,and the anti-jamming capability in the practical application.And analyze the measurement error,advantages and disadvantages of the two types of sensors according to the experimental data.