高温烟气水冷换热管的数值模拟及结构优化
Numerical Simulation and Structural Optimization of High Temperature Flue Gas Water-cooled Heat Exchange Pipe
吕林 1虞斌 1王风录 1尚宇勋1
作者信息
摘要
由于烟气水冷热交换器烟气侧温度很高,能快速提升换热管的温度,如果此时冷却水吸收的热量不足以冷却换热管则会造成换热管超温爆管.采用FLUENT软件对某新型烟气急冷器换热管进行数值模拟,并进行结构优化.结果显示,由于烟气入口侧的温度较高,流速较快,造成换热管壁面温度也较高,从而导致换热管外的冷却水形成膜状沸腾.对异形换热管进行数值模拟,发现与圆形换热管相比冷却水侧产生的水蒸气分布更均匀,在壁面处不会形成局部水蒸气含量过多的情况,同时能使换热管壁面最高温度降低约265 K,使换热管壁面平均温度降低4.8%～8.3%.并且研究了烟气处理量对换热管的影响,发现随着烟气处理量的增加,烟气出口温度和换热管壁面温度也随之升高;在相同的烟气处理量下,异形管外冷却水吸收的热量多于圆形管外冷却水吸收的热量.
Abstract
The high temperature on the flue gas side of the flue gas water-cooled heat exchanger can raise temperature of the heat exchange tube quickly and the insufficient heat absorbed by cooling water will overheat the heat exchange tube and burst.In this paper,having FLUENT software adopted to simulate new flue gas quenching cooler's heat exchange tube and optimize its structure was implemented.The re-sults show that,high temperature at the inlet side of the flue gas and the fast flow rate,as well as high wall temperature of the heat exchange tube can incur cooling water's film boiling outside the heat exchange tube.The numerical simulation results show that,compared with the circular heat exchanger,the distribu-tion of water vapor generated on the cooling water side becomes more uniform and the local water vapor is not excessive at the wall.At the same time,the wall's maximum temperature of the heat exchanger tube can be reduced by about 265 K and the wall's average temperature there reduced by 4.8%to 8.3%.Inves-tigating the effect of flue gas treatment on heat exchange pipe indicates that,with the increase of flue gas treatment,both outlet temperature of flue gas and wall temperature of heat exchange pipe rises.Under the same amount of flue gas treatment,the heat absorbed by the cooling water outside the profiled tube is more than that absorbed by the cooling water outside the circular tube.
关键词
急冷换热器/高温烟气/沸腾吸热/异形管/数值模拟Key words
quenching heat-exchanger/high-temperature flue gas/boiling endothermic/special-shaped pipe/numerical simulation引用本文复制引用
出版年
2024
NETL
NSTL
万方数据