脱酸塔烟气内流特征的数值模拟研究  

Numerical Simulation of Indrawal Characteristics of Flue Gas in Deacidification Tower

作　　者：贾振南 李春曦[1] 尹水娥[2] 叶学民[1] 

机构地区：[1]华北电力大学电站设备状态监测与控制教育部重点实验室,河北保定071003 [2]中国城市建设研究院,北京100120

出　　处：《华北电力大学学报（自然科学版）》2018年第1期101-110,共10页Journal of North China Electric Power University：Natural Science Edition

基　　金："十二五"国家科技支撑计划(2014BAC12B00)

摘　　要：脱酸塔是吸收烟气中酸性气体的关键装置,其内流特征与脱酸效率密切相关。建立了某脱酸塔物理模型和数学模型,采用数值模拟分析了不同烟气流速、雾化盘转速和喷雾量对内流特征和烟气平均停留时间的影响。结果表明:改变烟气进口速度将改变液气比、速度分布和气液混合程度,并影响烟气回流区的大小和分布;提高雾化盘转速有利于液滴破碎,但对烟气停留时间的影响很小;喷雾可在雾化盘出口附近形成小回流区,有利于脱酸反应的进行,低喷雾量时部分烟气携带吸收剂喷射到塔壁上,增加了塔壁腐蚀的风险;在烟气流速为8 m/s、转速为10 000 r/min、喷雾量为4 kg/s情形下的烟气停留时间适中(26.4s)、流场更均匀,有利于烟气脱酸过程。烟气进口速度是影响烟气在塔内停留时间的主要因素。The deacidification tower is a key device to absorb acid gas in flue gas,whose indrawal characteristics are closely related to its deacidification efficiency.This paper,based on the established physical and mathematical models of a deacidification tower,adopts numerical simulation to analyze the effects of different gas flow rates,rotational speeds of atomizer and spray quantities on the indrawal features and average residence time of gas.Results show that the variation of gas inlet velocity would change the liquid-gas ratio,velocity distribution and gas-liquid mixing degree,and influence the size and distribution of flue gas recirculation zone.Increasing rotational speed of atomizer has a large influence on the breakdown of droplets,with little effect on the residence time of flue gas.The small recirculated zone formed by spray in the vicinity of the atomizer outlet,is favorable for the deacidification reaction.However,when there is a low amount of spray,part of flue gas carrying with absorbent will be sprayed to the tower walls,leading to the corrosion risk; when the flue gas flow rate is 8 m/s,the rotational speed of atomizer 10 000 r/min,and the spray quantity4 kg/s,the residence time of flue gas is moderate（26.4 s） and the flow field tends to be more balanced,which is in favor of deacidification.The inlet velocity is the main factor influencing the residence time of flue gas in tower.

关 键 词：脱酸塔 雾化盘 内流特征 停留时间 数值模拟 

分 类 号：X701[环境科学与工程—环境工程]