Study On Numerical Simulation And Optimization Of Temperature Field In Nitride-production Furnace

The uniformity of temperature field in furnace is the key to decide thequality of nitride-production and the length of fire period. So the uniformtemperature field and the reasonable heating schedule can improveproductivity and decrease the energy consumption effectively. Resolvingtemperature field is helpful for controlling the working conditions andprolonging the longevity of the furnace, and has guidance meaning todesign, reform furnace equipment, and optimize the schedule parameters.Based on the project "Numerical simulation and optimization oftemperature field and velocity field in nitride-production furnace", aimedat nitride-production furnaces (shuttle furnace and electrical furnace) ofSAILON Compound Material Ltd., the numerical simulation andoptimization of temperature field in furnace has been studied in thisdissertation.The main conclusion and innovation of the paper are as follow:1) The nitride reaction mechanism of silicon has been studied, andthe nitride reaction model of silicon grain has been developed.Based on the commercial software FLUENT, the computationmodel of furnace has been constructed. The reaction heat istreated as heat source in the energy equation, which gives thecombination of the reaction model and computation model for thefirst time, and realizes the numerical simulation of temperaturefield in furnace.2) The computation results of temperature field in two kinds offurnace have been analyzed, which draws the conclusion that thelonger time of heat preservation couldn't reduce the temperaturedifference in the furnace effectively. Compared to measured data,the average error of temperature simulation in shuttle furnace is about 10% in heating section and 1% in reaction section; but inelectrical furnace it is 5% and 2% respectively. So the validity ofcomputation model has been proved.3) After analyzing the temperature field in furnace, and extractingcharacteristic data, the advantage and disadvantage of two kind offurnace has been compared synthetically for the first time. Theconclusion is that the shuttle furnace performs much better thanelectrical furnace to product firebrick, and the result offerspowerful evidence for shuttle furnace to generalize in refractoryindustry.4) Based on the numerical simulation results of a real thermalprocess, and aimed at improving the quality of nitride-production,shortening the fire period, and decreasing the energy consumption,the optimized schedule of furnace has been made. In optimizedheat schedule, the highest reaction temperature of firebrick is1400℃, and the fire period time in shuttle furnace and electricalfurnace decreases to 87.1% and 87.9% respectively, and the unitenergy consumption decreases 18.1% and 13.2%.