利用液态CO2提高水煤浆煤水配比对气化效果影响的数值模拟

提高水煤浆气化碳转化率和冷煤气效率，是强化气化过程的必然结果。利用FLUENT软件平台，该文用数值模拟方法模拟了水煤浆气化过程中水煤浆煤、水配比和氧、碳原子比对气化过程和出口煤气成分的影响；尤其是研究了利用添加液态CO2的方法提高水煤浆煤、水配比，对提高气化炉碳转化率和冷煤气效率的影响。模拟结果显示：随着液态CO2浓度的不断升高，煤气成分中CO大幅上升，H2略有降低，CO2浓度升高；气化炉的碳转化率和冷煤气效率都有较大幅度提高，分别达到最大值98.58%、76.74%，比原工况分别提高了3.7%、6.1%；气化炉温度先降低后变化趋缓。结果证明添加液态CO2后强化了气化炉内的二次反应，提高了焦炭燃烧速率。

Mathematical Simulation for Coal Water Slurry Gasification by Adding Liquid Carbon Dioxide

In order to improve the carbon conversion and cold gas efficiency, some effective action must be taken to strengthen coal water slurry gasification process,In this paper,the mathematical simulation analysis about adding liquid carbon dioxide on both carbon conversion and cold gas efficiency were conducted ,also the effect of the o/c ratio in the coal-water-slurry(CWS) in CWS gasification was considered. The results showed that the concentration of CO and CO2 increased ,but H2 reduced with the increase of liquid carbon dioxide concentration;at the same time ,the carbon conversion and cold gas efficiency enhanced sharply,up to the maximum of 98.58%, 76.74% respectively,which were 3.7%, 6.1% higher than that of before;the temperature of gasifier declined in the beginning , then changed slowly. These results indicated that adding liquid carbon dioxide could strengthen the secondary reaction in the gasifier ,which also increased the coke burnout velocity.