分层喷孔对船舶柴油机燃烧排放的影响研究
Study on the effect of multi-row nozzles on combustion emissions of Marine diesel engine
以分层喷孔为研究对象,建立了船舶柴油机模型,通过仿真计算,分析了传统多喷孔与分层喷孔燃烧特性和排放污染物生成的机理。结果表明,分层喷孔上排火焰传播速度相比于下排更快,可以加强预混燃烧,提高喷雾火焰对燃烧室容积的利用,改善火焰回流,并减少火焰撞壁。针对分层喷孔布置能有效减少富油聚集,使SOOT后期的氧化更剧烈的特性,设计不同孔径配比分层喷孔方案,降低了燃烧持续期,提高了等容度。综合考虑方案的燃烧、排放情况,分层喷孔最优方案在传统多喷孔方案的基础上指示热效率提升 1.77%,SOOT排放降低 43.06%,未燃HC降低58.93%,且不提高NOx排放。
The model of Marine diesel engine is established with multi-row nozzles as the research object.The combustion characteristics and pollutant generation mechanism of traditional nozzles and multi-row nozzles were analyzed through simulation.The results show that the propagation speed of the upper row flame is faster than that of the lower row,which can strengthen the premixed combustion,improve the utilization of the combustion chamber volume of the spray flame,reduce the flame backflow,and reduce the flame wall collision.Aiming at the characteristics that multi-row nozzles layout can effectively reduce fuel-rich accumulation and make SOOT later oxidation more intense,we designed multi-row nozzles cases with different nozzle diameter combinations,which can reduce the combustion duration and increase the constant volume.Based on the comprehensive consideration of combustion and emission of the case,the optimal case with multi-row nozzles can increase the indicated thermal efficiency by 1.77%,reduce SOOT emission by 43.06%,reduce unburned HC by 58.93%,and not increase NOx emission.
蒋志远;刘龙;王洋;
哈尔滨工程大学 动力与能源工程学院,哈尔滨 150001;哈尔滨工程大学 动力与能源工程学院,哈尔滨 150001;哈尔滨工程大学 动力与能源工程学院,哈尔滨 150001;
TK422
marine diesel engine multi-row nozzles indicated thermal efficiency emission
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