氧煤比对气流床煤气化过程的影响

Effect of oxygen-coal ratio on gasification process in entrained-flow gasifier

为研究氧煤比对气流床煤气化炉气化过程的影响,对某厂运行的Texaco气化炉进行了数值模拟研究。利用所建立的数学模型,分析了Texaco气化炉内的气化过程,以及氧煤比对炉内温度、气相成分及炉膛出口合成气成分的影响规律。结果表明：Texaco气化炉内下行火焰的长度约占气化炉高度的1/3,炉膛上部火焰高度区域内气相温度及主要成分浓度的变化梯度最大,而在炉膛下部气相成分及温度的变化均不明显;随着氧煤比的增大（0.95~1.10）,气化炉出口合成气有效成分（H2＋CO）浓度逐渐降低,CO2和H2O的浓度及气化炉内气相温度逐渐升高;在保证顺利排渣和合适的出口合成气成分的条件下,存在一个最佳氧煤比。

To study the effect of oxygen-coal ratio on gasification process in entrained-flow gasifier,a simulation study for a Texaco gasifier running in a factory was carried out.Using the CFD model proposed,the gasification process in Texaco gasifier was analyzed under typical cases.And the effects of oxygen-coal ratio on the gas temperature,composition concentrations in the gasifier and the product gas compositions were obtained.The results show that the length of the downward flame is about one third of the height of the gasifier.The variation gradients of gas temperature and main composition concentrations are the biggest in the zone about the height of the flame in the Texaco gasifier,and the changes of gas temperature and compositions are not obvious in the lower part of the gasifier.With increasing oxygen-coal ratio（0.95~1.10）,the concentration of effective composition（CO＋H2） in product gas decreases gradually,and the concentration of CO2 and H2O and the temperature in the gasifier increases gradually.There exists a best oxygen-coal ratio for ensuring the discharge of the molten slag smoothly and gaining the most suitable product gas components.