水煤浆水冷壁废锅气化过程的模拟研究

采用Aspen Plus流程模拟软件模拟了水煤浆水冷壁废锅气化过程,并将模拟结果与工业运行数据对比,验证了模型准确性。在此基础上,分析了气化压力和水煤浆浓度对气化温度、有效气产量、合成气组成、氧煤比、比氧耗和比煤耗等气化参数的影响。结果表明,气化压力对气化过程基本没有影响,可根据需要选择适宜压力;当保持氧气流量恒定时,随水煤浆浓度增大,有效气含量增加,气化温度升高,即提高水煤浆浓度易导致气化炉飞温,因此进一步研究了在前述模拟条件不变,且保持气化温度恒定时,水煤浆浓度变化对气化参数的影响。结果表明,随水煤浆浓度增大,氧煤比降低,有效气含量增加,比氧耗、比煤耗降低,因此在气化炉不超温的情况下,应尽量提高水煤浆的浓度,以降低系统能耗。

Simulation Study on Gasification Process of Coal Water Slurry Waste Heat Boiler with Membrane Wall

The coal water slurry gasification process of waste heat boiler with membrane wall was simulated with the process simulation software Aspen Plus.Furthermore,the simulation results were compared with the industrial operation data to validate the model accuracy.Based on them,the analysis was made on the impact of gasification pressure and coal water slurry concentration on gasification parameters,including gasification temperature,effective gas production,syngas composition,ratio of oxygen to coal,specific oxygen consumption and specific coal consumption.The results showed that the gasification pressure basically had no impact on the gasification process.Therefore,the appropriate gasification pressure could be selected according to the needs.When the oxygen flow rate was constant,the effective gas content and gasification temperature increased with the rise of coal water slurry concentration.That is to say,the increase of coal water slurry concentration could easily induce the gasifier temperature runaway.Thus,with the above simulation conditions unchanged,the influence of coal water slurry concentration on gasification parameters under the constant gasification temperature was studied.The results showed that the increase of coal water slurry concentration could lead to the decrease of the ratio of oxygen to coal,increase of effective gas content and decrease of the specific oxygen consumption and specific coal consumption.Therefore,under the condition of no overheating of the gasifier,the coal water slurry concentration should be as high as possible to lower the system energy consumption.