层流火焰下氨/乙醇裂解气燃烧与NO_(x)生成分析

Analysis of Combustion and NO_(x)Generation for Ammonia/Ethanol Cracking Gas Under Laminar Flames

为改善氨燃料的燃烧性能,本文研究了氨燃料裂解以及掺混乙醇对层流火焰下燃烧和排放特性的影响。建立了包含159种组分、1450步反应的氨/氢/乙醇混合燃料燃烧化学动力学机理,并通过已有实验数据进行验证,预测准确性较高。结果表明,随着乙醇掺混比的增大,NO_(x)的生成量先增大后减小;当乙醇比例为40%时,氨裂解使得混合燃料的层流燃烧速度增加,当裂解比例超过60%时,稀燃条件下NO生成量显著降低,混合燃料的燃烧和排放同时得到改善。

To enhance the combustion performance of ammonia,the effects of ammonia cracking and ethanol blending ratios on combustion and emission characteristics were investigated.A chemical kinetic mechanism for ammonia/hydrogen/ethanol blended fuel containing 159 species and 1450 reactions was developed,and well-validated against experimental data.The results showed that the NO_(x)production is increased firstly and then decreased with the increase of ethanol blending ratios.At an ethanol blending ratio of 40%,the ammonia cracking can improve the laminar burning velocity.When the ammonia cracking ratio exceeds 60%,there is a significantly reduction in NO_(x)generation.The overall analysis showed that the high ammonia cracking and ethanol blends can enhance the combustion performance and reduce NO emissions as well under lean-burn condition.