Shell气流床的煤粉富氧水蒸气气化模拟

Simulation of pulverized coal gasification with enriched oxygen and steam in Shell entrained flow bed

利用Aspen Plus软件建立煤粉在Shell气流床中的气化模型,模拟结果与文献值吻合良好。利用灵敏度分析模块研究了蒸汽煤比、氧气浓度对气化结果的影响,并以煤气热值、碳转化率及冷煤气效率为目标研究氧气浓度、氧煤比、蒸汽煤比三者共同作用下的气化结果。结果表明:随蒸汽煤比的增加,H_(2)、CO_(2)浓度逐渐升高,CO浓度逐渐降低,碳转化率及冷煤气效率逐渐升高;随氧气浓度的增加,气化温度逐渐升高,N_(2)浓度逐渐降低,H_(2)、CO浓度逐渐升高,气化气热值逐渐升高,碳转化率、冷煤气效率先增加后保持不变;氧气浓度、氧煤比、蒸汽煤比的增加均可提高气化过程中的碳转化率,而三者对于冷煤气效率及气化气热值的作用效果是相互影响的,当氧煤比为0.6 kg/kg、氧气浓度为100%、蒸汽煤质量比为0.8时,冷煤气效率可达最大值89.4%,气化气热值可达最大值12.4 MJ/Nm^(3)。

The model of pulverized coal gasification in shell entrained flow bed is established by Aspen Plus software,and the simulation results are in good agreement with the literature values.The sensitivity analysis module is used to study the influence of steam coal ratio and oxygen concentration on gasification results,and the gasification results under the combined action of oxygen concentration,oxygen coal ratio and steam coal ratio are studied with the goal of gas heat value,carbon conversion rate and cold gas efficiency.The results show that with the increase of steam coal ratio,the concentration of H_(2) and CO_(2) increases and CO decreases gradually,the carbon conversion rate and cold gas efficiency increase gradually;with the increase of oxygen concentration,the gasification temperature increases gradually,the concentration of H_(2) and CO increases and N_(2) decreases gradually,the gas heat value increases gradually,and the carbon conversion and cold gas efficiency first increase and then remain unchanged.The increase of oxygen concentration,oxygen coal ratio and steam coal ratio can improve the carbon conversion rate in the gasification process,and the effects of the three factors on the cold gas efficiency and the heat value of the gasified gas are interactive.When the oxygen coal ratio is 0.6 kg/kg,the oxygen concentration is 100%,and the steam coal ratio is 0.8 kg/kg,the cold gas efficiency can reach the maximum value of 89.4%,and the gas heat value can reach the maximum value of 12.4 MJ/Nm^(3).