面向零碳电力的氨燃烧技术研究进展

Recent advances on ammonia combustion technology for zero-carbon power

在全球碳减排大背景下,无碳燃料产业发展面临巨大机遇和挑战。氨能源具有生产技术工业化成熟、储存运输难度小以及燃烧零碳环保等优势,是化石替代能源的有力竞争者。氨燃料的研究与应用将有助于改善我国传统能源结构,实现碳减排目标。但氨作为燃料存在燃烧不稳定、层流火焰速度低以及NO_(x)排放高等问题,氨燃烧技术研究亟待推进。结合国内外氨燃烧技术研究成果,综述了氨燃料的物化特性和化学反应动力学研究,梳理了氨燃料在燃气轮机、内燃机、燃料电池以及锅炉等应用背景下的研究进展。相较于传统氢气、甲烷等燃料,氨层流火焰速度低,反应活性较弱,为燃烧器优化设计带来了挑战。针对不同掺混系统,学者已建立丰富的氨化学反应动力学模型,为氨燃烧应用打下基础。氨燃料燃气轮机已完成纯氨燃烧试验,结合SCR装置可实现较低NO_(x)排放,温和燃烧与液氨喷射等技术进一步优化了氨在燃烧器内的燃烧性能。结果表明,氨在内燃机中可通过混合的方式实现大比例掺烧,且当掺混比例小于60%时,实现较低排放。对氨/煤小比例混燃进行试验,证明了20%氨掺烧的可行性,并探讨了不同注入位置对NO_(x)排放的影响。最后针对目前氨燃烧技术研究存在的问题对未来进行展望,指出氨/氢燃料系统是未来研究重点,在燃气轮机与内燃机领域,开发燃烧器设计、喷射策略优化等技术将极大改善氨的燃烧性能,氨/煤掺烧锅炉试验较为匮乏,相关研究亟待开展。

Under the background of global carbon emission reduction,the carbon-free fuel industry faces both great opportunities and chal⁃lenges.Ammonia,as an alternative of fossil energy,has the advantages of mature industrial production technology,easy storage and trans⁃portation,and zero carbon emission,et al.The research and application of ammonia fuel is one of the promising pathway to improve China′s traditional energy structure and achieve carbon emission reduction target.However,there are still some remaining problems in ammo⁃nia combustion,such as unstable combustion,low laminar flame velocity and high NO_(x) emission.Therefore,the research on ammonia com⁃bustion technology is urgently needed.Combined with the recent achievements of ammonia combustion technology at home and abroad,the burning characteristic of the ammonia as a fuel and chemical reaction kinetics were reviewed.Specifically,the research progress of ammo⁃nia fuel in different applications including gas turbines,internal combustion engine,fuel cell and boiler were introduced.Compared with traditional fuels such as hydrogen and methane,the ammonia laminar flame velocity is low and the reaction activity is weak,which brings challenges to the optimization design of burner.For different mixing systems,the rich kinetic models of ammonia chemical reactions were established,laying the foundation for ammonia combustion applications.Pure ammonia combustion tests have been completed for am⁃monia-fueled gas turbines and combined with SCR devices,the lower NO_(x) emissions can be achieved,The combustion performance of am monia in the combustor is further optimized by technologies such as mild combustion and liquid ammonia injection.The research results show that ammonia can be blended in internal combustion engines by mixing in a large proportion,and when the blending ratio is less than 60%,the lower emissions can be achieved.The feasibility of mixed combustion of 20%ammonia can be proved by the experiment of small proportion mixed combustion of ammonia and coal.The effect of different injection locations on emissions was explored.The problems of current ammonia combustion technology research were pointed out and the future development focus direction was prospected.It is point⁃ed out that ammonia/hydrogen fuel system is the focus of future research,and in the field of gas turbine and internal combustion engine,technologies such as burner design,injection strategy optimization will greatly improve the combustion performance of ammonia,and ammo⁃nia/coal blending boiler experiments are urgently needed.