Study On Correlation Velocity Measurement Of Gas-solid Two-phase Flow Using Electrostatic Sensor

With the development of society, science and technology, the system of gas-solid two-phase flow is playing a more important role in the national economy and daily life, the measurement of gas-solid two-phase flow has already become the important problem in the research of gas-solid two-phase. Among these measuring parameters of gas-solid two-phase flow, the velocity is a key parameter.The gas-solid two-phase flow is a kind of multi-phase flow, which is difficult to be measured. The electrostatic sensor combined with the correlation techniques provides a new solution to velocity measurement of gas- solid two- phase flow. With the development of electronics, a new digital signal controller (DSC) which has the merit of the micro-controller and digital signal processor has been produced. It supplies the possibility to design a real time and on-line embedded correlation system with low power consumption and flexible control. The correlation velocity measurement of gas-solid two-phase flow using electrostatic sensor was studied in this paper. The primary work is as followed:The principle of correlate measurement and the sensing characteristic of electrostatic sensor was studied and a circular electrostatic sensor was designed.A signal condition circuit was developed, considering the electrostatic noise and the sensor's characteristics.Factors which affect the results of correlate measurement were analyzed. The selecting principle of the sampling frequency and the number of points sampled was presented for the design of the system, which gave a reference to the design of real time, on-line correlation system.A correlate measurement system based on virtual instruments was developed. A platform of off-line experiment was constructed and some experiments were carried out.By using DSC, a digital correlator with low power consumption, small volume, flexible control and high computing power was designed.The dynamic experiments were done on the test facility. The regularity of the correlation velocity and concentration was analyzed, which constructed the basis of the future research.