Structure Optimization And Numerical Simulation Research Of New Type Association Of Dynamic And Static Blade Coarse Powder Separator

The dynamic coarse pulverized coal separator is an important part of the coalpulverizing system of boiler, Its performance parameters affect the operation security andstability of the boiler directly. This topic was based on computational fluid dynamics(CFD), which calculated the three-dimensional gas-solid two-phase flow of the dynamiccoarse pulverized coal separator by the numerical simulation software FLUENT,furthermore, we researched the internal flow characteristics of flow field and separationmechanism of the coal particles. We obtain the best operating condition of the separatorand the best dimension of the impact cone area and test the results of simulation in thehot field test. The specific research process is as follows:Firstly, the coarse powder separator after transforming was simulated on Fluent.The simulation results tell the varying patterns of separation efficiency, export powderfineness, circulation ratio, and the internal resistance under different conditions.Theresult shows that when the dynamic impeller speed is70m/s, the static impeller angle is45°, and the inlet wind speed is from17to19m/s reaches the best operating condition forthe dynamic coarse pulverized coal separator. Secondly, the hot test was taken for themodified separator, we changed the operation mode of the dynamic coarse powderseparator and got the change of separation characteristic data. After reconstructionof a300MW boiler, the boiler efficiency can increase more than0.5%, save about2million yuan, the reduced emissions of CO2and SO2reach7000t/y and12t/y,respectively. The goal of energy conservation and emissions reduction is achieved.Thirdly, in this subject, the effects on the separation properties of the changes of theimpact cone area size were discussed. Through simulating the combined model ofdifferent impact cone bottom diameter and the height of the entrance to impact cone, theseparation characteristics of the separator were obtained. The results show that the bestsize of the impact cone bottom diameter is850mm, and the best height of the entrance toimpact cone is900mm.