BGL炉煤气化过程建模和模拟  

Modeling and simulation of gasification process in BGL furnace

作　　者：李英泽 杨路 王琦 杨思宇[1] LI Yingze;YANG Lu;WANG Qi;YANG Siyu(College of Chemistry and Chemical Engineering,South China University of Technology,Guangzhou 510000,Guangdong,China)

机构地区：[1]华南理工大学化学与化工学院,广东广州510000

出　　处：《化工学报》2020年第3期1174-1188,共15页CIESC Journal

基　　金：国家自然科学基金重点项目(21736004)。

摘　　要：建立了BGL气化炉的三维非稳态煤气化模型,模型考虑煤炭颗粒的收缩过程,应用收缩核模型集成煤热解模型、气相湍流模型、气固流动模型、气固异相反应模型、气相均相反应模型、能量守恒方程以及相间传热模型等。该模型充分考虑了气化炉内部三维空间的温度和组成分布,通过煤热解段模型化学计量参数优化,得到CO/H2摩尔比在1.59左右,符合BGL炉热解段运行机制;然后对BGL炉气化段过程进行三维非稳态模拟,模拟出口气组成(CO,H2,CO2,CH4,H2O,O2)与文献结果对比,误差均小于4%。证明了BGL模型的准确性。基于该模型,本文对煤气化过程的主要参数进行影响分析。分析结果表明:煤气化效率随汽氧比的增加而提高,当汽氧比确定在1~1.3之间可以满足工艺要求及生产的需要,适合本文研究所用褐煤的特点;氧煤比增加会降低煤气化效率,但合成气中有效气的含量呈现出先增大后减小的趋势,当氧煤比在0.17左右时有效气含量达到峰值;随着煤粒直径的增加,BGL炉内的温度呈降低趋势,最高温度从2536.77 K降到了2047.81 K;同时,煤粒直径增加会减小CO、H2和CH4的生成量,并增大CO2的生成量。A three-dimensional unsteady coal gasification model of BGL gasifier is established in this paper. The model considers the shrinkage process of coal particles, the coal core pyrolysis model, gas phase turbulence model,gas-solid flow model, gas-solid heterogeneous reaction model, gas phase homogeneous reaction model, energy conservation equation and phase-to-phase heat transfer model. This model fully considers the temperature and composition distribution of the three-dimensional space inside the gasifier. Through the optimization of the stoichiometric parameters of the coal pyrolysis section model, the CO/H2 molar ratio is about 1.59, which is consistent with the BGL furnace pyrolysis section operating mechanism;The three-dimensional unsteady simulation of the gasification section of the gasifier is used to simulate the composition of the outlet gas(CO, H2, CO2, CH4,H2O, O2) compared with the literature results, and the error is less than 4%, which proves the accuracy of the BGL model. Based on this model, we analyze the main parameters of the coal gasification process in this paper. The results show that the coal gasification efficiency increases with the increase of steam-oxygen ratio. When the steamoxygen ratio is determined to be between 1-1.3, it can meet the process and production requirements, which is suitable for the characteristics of lignite used in this paper;the coal gasification efficiency will decrease with the increase of oxygen-coal ratio, but the content of effective gas in syngas shows a trend of increasing first and then decreasing. When the oxygen-coal ratio is around 0.17, the effective gas content will reach a peak value. With the increase of coal particle diameter, the temperature in BGL furnace decreases, the maximum temperature is dropping from 2536.77 K to 2047.81 K;as for the composition, the increase of coal particle diameter will reduce the production of CO, H2 and CH4, and increase the amount of CO2.

关 键 词：BGL炉 煤热解化学计量参数优化 动态建模 汽氧比 氧煤比 气化效率 颗粒物料 

分 类 号：TQ021.8[化学工程]