Research On The Numerical Simulation Of High Efficient Anthracite Combustion In HFC Precalciner

This paper combined with major science and technology projects in the city of Chenzhou : Anthracite calcined cement with high efficiency combustion and low NOX technology research and researched anthracite combustion in the precalciner.The purpose of the study is that it is more perfect for the new dry cement production technology to move towards the "ecological environment".With the industrial analyzer and thermogravimetric analyzer, researched combustion characteristics of bituminous coal and anthracite in the cement plant of Chenzhou city, Hunan province. Measured powder coal moisture, ash, volatile, fixed carbon,ignition temperature and etc. Used ignition characteristic index, burning intensity and combustion characteristic index to evaluate bituminous coal and anthracite coal, learned the combustion characteristic of anthracite coal.It would make Theoretical guidance for optimization of structure and operation parameters about anthracite combustion in the precalciner.Making the optimization of structure and operation parameters aimed at achieving high efficient combustion of anthracite coal in the precalciner.Used GAMBIT 、 FLUENT 、 ICEM and other fluid simulation software to establish geometric model,mesh generation and optimization and simulation research for precalciner producing 2500 tons of cement per day. Selected Reynolds average standard k ?? double equation and discrete phase model(DPM) for the simulation of gas and solid flowing in the precalciner and species transport model with eddy dissipation concept(EDC) model for anthracite combustion and carbonate decomposition in the precalciner and the precalciner grading air. Acquired velocity distribution,velocity vector distribution,particle trajectory, temperature distribution and component concentration distribution related substances. The simulation results are analyzed and compared with the actual test values and in good agreement with actual engineering. The optimization about efficient combustion of anthracite in the precalciner based on these simulations. By raising the raw material tube position to delay raw material into the precalciner so that anthracite combustion would have a fairly stable area;Adjusted the temperature of tertiary air to accelerate the chemical reaction rate of coke; Used four coal burners to make coal particles distribute better in the low part of precalciner,it makes coal particles heat transfer better and efficientcombustion. When the height of the raw material tube was 8.5m,tertiary air temperature was 1223 K and Used four coal burners, the simulation results were best.The anthracite burnout rates of the precalciner and using staged combustion for precalciner respectively were 97.21% and 97.35%,the rates of carbonate decomposition were 92.5% and 93.6%. the precalciner grading air is more conducive to reduce the emission of pollutants, the anthracite combustion and carbonate decomposition and the simulation results make theoretical guidance for cement production.