缓冲板对煤气化闪蒸罐内冲蚀过程的影响研究

Study on impact of baffle on erosion in flash tank of coal gasification

针对煤气化闪蒸罐易被黑水中煤粉颗粒冲蚀的问题,考察设置不同结构人字形缓冲板对入口区域流动和气-固冲蚀过程的影响,采用欧拉-拉格朗日方法耦合冲蚀模型进行数值模拟,得到不同结构条件下闪蒸罐和三通接管内的流场分布以及冲蚀样貌。结果表明:闪蒸罐入口区域三通接管的冲蚀速率最高且分布范围广,最大冲蚀速率比闪蒸罐内筒壁高两至三个数量级;设置人字形缓冲板可以有效降低含固气流对闪蒸罐内筒壁的冲蚀速率,且设置圆弧形不开孔人字板时外筒壁处的最大冲蚀速率最小,防冲蚀效果最佳,可以将闪蒸罐内筒壁处的最大冲蚀速率降低至初始结构的1/43,并且从冲蚀失效的角度来看,可以延长外筒壁的使用寿命。

Aiming at the problem that the flash tank of coal gasification was easily eroded by pulverized coal particles in black water,the effects of herringbone buffer plates with different structures on the flow and gas-solid erosion process in the inlet region were investigated.The Euler-Lagrange method coupled with erosion model was used for numerical simulation to obtain the flow field distribution and erosion appearance in the flash tank and tee with different structures.The results showed that in the inlet region of the flash tank,the erosion rate of the tee was the highest and the distribution range was wide,and the maximum erosion rate was two to three orders of magnitudes higher than that of the inner cylinder wall of the flash tank;the herringbone buffer plate could effectively reduce the erosion rate of the solid-containing gas flow on the inner cylinder wall of the flash tank,and the tank with arc-shaped non-perforated baffle had the lowest erosion rate on the outer wall.Therefore,it had the optimum effect:it could reduce the maximum erosion rate of the inner wall of flash tank to 1/43 of the initial structure,and it could also extend the service life of the outer wall from the perspective of erosion failure.