固定床熔渣气化炉蒸氧喷嘴前燃烧区数值模拟OA

In order to study the state of the combustion zone in foreside of the steam-oxygen nozzle of the fixed-bed slagging gasifier,the influence of the steam-oxygen parameters and the design parameters of the steam-oxygen nozzles on the operation of the gasifier,a mathematical model of the combustion zone in foreside of the steam-oxygen nozzles of fixed-bed slagging gasifiers was established with reference to the relevant research on the raceway in foreside of the tuyeres of blast furnaces,and the combustion zones of fixed-bed slagging gasifiers using bituminous coal and lignite in the industrial production were respectively numerically simulated using this model.Based on this,the effects of the steam-to-oxygen ratio and nozzle jet velocity on the gas composition and temperature distribution in the combustion zone were analyzed.The numerical simulation results show that the gas composition and temperature distribution in the combustion zone in foreside of steam-oxygen nozzles of the two fixed bed slagging gasifiers are similar,but due to the difference of coal quality,the gas composition and temperature in the combustion zone of bituminous coal change slowly relatively,and the position of the highest gas temperature is further from the front of the nozzles.The operating temperature of gasifiers can be adjusted by changing the steam-oxygen ratio.Taking lignite as an example,when the steam-oxygen ratio changes between 0.85 and 1.05,the maximum temperature in the combustion zone decreases from 2 478℃to 1 993℃,and the mole fraction of H2 in gas increases from 26.4%to 28.8%.Besides,the jet velocity of nozzles has an effect on the composition and temperature distribution of the gas in the combustion zone.When the jet velocity increases from 110 m/s to 200 m/s,the distance from the position at the highest gas temperature to the nozzle increases from 0.225 m to 0.245 m.