O2/CO2气氛下炉内煤粉切圆燃烧数值研究

对某电厂600 MW切圆燃烧锅炉进行了O2/CO2气氛下炉内流动、传热和燃烧过程的数值研究。结果表明:在O2/CO2气氛下,随着氧气摩尔浓度的增加,炉内温度升高,高温区变大,对煤粉的着火燃烧有利;但考虑到燃烧器安全和水冷壁结渣,氧气摩尔浓度不能太高,对燃用文中煤质的锅炉其极限摩尔浓度在40%至45%之间。O2/CO2气氛对现有切圆燃烧锅炉的上层燃烧器煤粉的燃烧影响较小,对下层燃烧器煤粉的燃烧影响较大。与空气气氛煤粉燃烧相比,炉内火焰中心上移,且在氧气摩尔浓度不太高时,炉内温度分布特性有利于防止水冷壁的结渣。

Numerical Study on Pulverized Coal Tangential Firing in Furnace Under O2/CO2 Atmosphere

The numerical study on furnace flow,heat transfer and combustion process of the 600 MW tangential firing boiler in power plant under the O2/CO2 atmosphere is studied.The results show that: with the O2 molar concentration increase under the O2/CO2 atmosphere,the temperature in furnace is increased and the high temperature region becomes larger,which is favorable to pulverized coal ignition;but considering the safety of burner and water-wall slagging,the O2 molar concentration is not too large,and the limiting O2 molar concentration is between 40% and 45% for the boiler that firing coal quality in this paper.The influence of the O2/CO2 atmosphere for the pulverized coal combustion of the upper burner has little influence,but has great influence to the lower layer burner.Compared with pulverized coal combustion under the air atmosphere,the furnace flame central position is moved up,and the characteristic of temperature distribution in furnace is beneficial to preventing water-wall slagging under the condition that O2 molar concentration is not too large.