Mechanism And Methods Of Coal Moisture Measurement Based On Microwave Transmission Method

Coal moisture content is a critical index of coal quality. It is of vital importance in fundamental theory and researsh in processing and uitilization of coal, which is also an important index of procedures like coal-blended combustion, boiler heat balance calculation, and boiler load regulation. In order to realize the on-line monitoring of coal delivered to the boiler, it is imperative to make utilization of on-line monitoring of coal moisture content and timely stastic processing. Therefore, on-line monitoring of coal moisture content is an significant approach to conservation of energy, optimization of combution, which is important to accquire the maximum economic profit of the power unit.This thesis analysed the essence of microwave transmission method through the principle of dielectric and do a detailed research on its theory and derived the relationship model of microwave signal phase difference and moisture content of blend of water and coal, which lay a solid foundation of application of coal moisture content on-line monitoring devices. Moreover, amounts of experimentation were done on the coal moisture content measuring device in the lab. On account of the unevitabale noise errors of the measuring and modeling, an lease square support vector machine model between measuring value and actual value was established based on MATLAB, which correct the former model to some degree. In the end, through the analysis of error of experimentation statistic, the conclusion that the measurement accuracy of the moisture content measuring amended model is 6.11%, reducing 1.66%than the former one is got, and the average relative error is 3.70%, reducing 3.63%than the former one. Therefore, the theoretical model of the paper is applicable to coal moisture content on-line monitoring of power plant, which is precise, valid, functional, and also meet the demand of practical production.