The Numerical Simulation And Experiment Study Of Gas And Solid Discrete Phase Flow In The Coal Drying Tube

Lignitic coal resource is rich in China. Humidity ratio of lignitic coal is high, if they are used directly for combustion, not only the boiler combustion is unstable, but also the plant efficiency is low. Humidity ratio is so high that lignitic coal can be used locally, which greatly limits the mining of lignitic coal. Therefore, the development of advanced drying technology and equipments has great significance for improving the market competitiveness of lignitic coal and lowering electricity cost of plant.The behaviors of gas stream and solid discrete phase had been studied by numerical simulation and experimental method in coal drying tube. Based on two-phase flow theory, we put forward three-dimensional mathematical model of wet coal particles flow in the drying process. The 3D mathematical model takes into account the heat transfer and mass transfer between gas and solid, the variations of temperature and humidity ratio in drying tube. The commercial CFD software FLUENT6.2 was used to simulate the flow field in coal drying tube. The velocity, temperature, pressure and coal particles distributions of gas and solid discrete phase in drying tube have been obtained, which have been used to analyze the factors affecting coal humidity ratio in order to provide a theoretical basis for coal drying. And then they have been proved in the experiments. The research in this paper has great significance for industrial production.