二氧化碳、水和氮气稀释条件下甲烷MILD氧燃烧的实验研究  

Experimental Investigation on MILD O_(x)y-combustion of Methane Under CO, HO and N Dilution

作　　者：王国昌 舒子云 司济沧 王勃 朱荣[4] 米建春[1] WANG Guochang;SHU Ziyun;SI Jicang;WANG Bo;ZHU Rong;MI Jianchun(College of Engineering,Peking University,Haidian District,Beijing 100871,China;China Ship Development and Design Center,Wuhan 430072,Hubei Province,China;Beijing Municipal Office for Science and Technology Awards,Haidian District,Beijing 100444,China;School of Metallurgical and Ecological Engineering,University of Science&Technology Beijing,Haidian District,Beijing 100083,China)

机构地区：[1]北京大学工学院,北京市海淀区100871 [2]中国舰船研究设计中心,湖北省武汉市430072 [3]北京市科学技术奖励工作办公室,北京市海淀区100444 [4]北京科技大学冶金与生态工程学院,北京市海淀区100083

出　　处：《中国电机工程学报》2021年第18期6312-6320,共9页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51776003)。

摘　　要：中度与极度低氧稀释(moderate or intense low-oxygen dilution,MILD)氧燃烧技术能同时实现低碳和超低NO_(x)排放,是一种创新性的燃烧技术。通过实验方法研究了不同稀释剂(N_(2)、CO_(2)和H_(2)O)、氧气浓度、当量比和氧化剂预热温度下甲烷非预混MILD氧燃烧和排放特性。实验发现,N_(2)、CO_(2)和H_(2)O稀释的所有工况中均没有观察到火焰。但N_(2)稀释时,炉内温度和NO排放都比较高,且当氧浓度、当量比或氧化剂温度增加时,NO排放急剧升高(>100×10^(-6)),因此无法实现较好的MILD氧燃烧。与之相比,CO_(2)或H_(2)O稀释下,炉内温度较低,NO排放也非常低(<10×10^(-6));并且NO排放对氧浓度、当量比和氧化剂温度的变化不敏感,能在更宽的范围内建立起低排放的MILD氧燃烧。此外,CO_(2)稀释时会产生较高的CO排放(>20×10^(-6)),但H_(2)O稀释下几乎没有CO排放,且NO排放最低(≈1× 10^(-6))。因此,H_(2)O稀释最有利于实现超低排放的MILD氧燃烧。但实际炉膛应用时需要注意防止H_(2)O稀释造成的炉壁汲水和因此导致的热效率降低、甚至熄火。The moderate or intense low-oxygen dilution(MILD) oxy-combustion is an innovative technology of combustion,which can simultaneously realize low carbon and ultra-low NO_(x) emissions.This work experimentally investigated the combustion and emission characteristics of non-premixed MILD oxy-combustion firing methane under various oxidant conditions,such as diluent type,oxygen concentration XO_(2),equivalence ratio Φ and oxidant preheating temperature Tin.Results show that no flame is observed in all the investigated cases under N_(2),CO_(2) or H_(2)O dilution.However,when N_(2) is used as the diluent,the in-furnace temperature and the NO emission are very high,and NO emission increase abruptly(>100×10^(-6)) at higher XO_(2),Φ,or Tin.Thus,MILD oxy-combustion cannot be well established under N_(2) dilution.Relatively,under CO_(2) or H_(2)O dilution,the in-furnace temperature and the NO emission(<10×10^(-6)) are very low and not sensitive to the variations of XO_(2),Φ and Tin.Therefore,low emission MILD oxy-combustion can be realized in a wide range of oxidant conditions under CO_(2) or H_(2)O dilution.Moreover,the CO emission is high(>20×10^(-6)) under CO_(2) dilution,but it is nearly zero under H_(2)O dilution.The NO emission(≈1×10^(-6)) is also lower for the latter.Therefore,H_(2)O dilution is most beneficial for establishing ultra-low emission MILD oxy-combustion.Cautiously,when use H_(2)O dilution for practical application,the prevention should be made from the furnace wall absorbing water,which will reduce thermal efficiency and even make extinction to occur.

关 键 词：中度与极度低氧稀释氧燃烧 非预混 氧浓度 CO_(2)稀释 H_(2)O稀释 N_(2)稀释 NO_(x)排放 

分 类 号：TK16[动力工程及工程热物理—热能工程]