Research On The On-Line Measurement Technology Of Pulverized Coal Particle Size Based On Image Processing Techniques

Pulverized coal particle size is an important characteristic parameter, which affects the economic operation and safety of the boiler. The existing measurement technologies are unable to meet the requirements of on-line measurement, field measurement, cost control and so on. Therefore, it is important to research on an on-line measurement system of pulverized coal particle size which is simple, cheap, and visual.The measurement of pulverized coal particle size based on imaging method has the advantages of direct viewing, high accuracy and low interference effect. It is a kind of measurement method of industrial application prospect. The method appearing in the last century eighty’s could only be used to analyze the parameters of the convection field because of being limited to the level of the software and hardware at that time. With the rapid development of laser technology and imaging sensor, the technique of particle size measurement using imaging method has a great development space. However, it is restricted by some problems such as the image acquisition window contamination, the difficulty of obtaining grain size distribution under high flow velocity and so on.In this paper, comprehensive research work of online measurement technology of particle size based on image processing techniques has been done in three aspects the measurement principle and algorithm, measurement system design and equipment selection and experimental analysis. The research status of pulverized coal particle size measurement technology is summarized. The basic equation and flow characteristics of gas-solid two-phase flow are described, and the two phase flow model based on fuzzy image processing is established. The particle size measurement principle, image processing algorithm and image processing flow are elaborated. The scheme design and hardware selection of the measurement system are carried out. Two kinds of window anti fouling devices are designed to solve the problem of image acquisition window contamination.Finally, the experimental platform is built, and the measurement system is verified by experiments. In this paper, static and dynamic experiments are carried out, and the experimental results are in good agreement with the theoretical values. The experimental results show that the method can be used for the measurement of pulverized coal particle size, and has high accuracy and reliability. The factors affecting the measurement results are analyzed, which proves that the method can accurately measure the particle size distribution under higher flow velocity.