高压直喷天然气发动机外特性燃烧及NO_x排放  

Combustion and NO_x emission characteristics of high pressure direct injection natural gas engine at full load

作　　者：李孟涵[1] 张强[1] 李国祥[1] 邵思东 

机构地区：[1]山东大学能源与动力工程学院,山东济南250061 [2]潍柴控股集团有限公司,山东潍坊261001

出　　处：《华中科技大学学报（自然科学版）》2015年第2期30-34,共5页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家高技术研究发展计划资助项目(2060303)

摘　　要：以六缸增压中冷发动机为研究对象,采集不同工况下示功图并对NOx排放进行了测试,分析了外特性燃烧特性及排放随转速的变化规律.试验结果表明：在外特性整个转速范围内,瞬时放热率呈先急后缓的趋势,转速越高,瞬时放热率峰值越低;由于低速时滞燃期较长,因此天然气预混燃烧比例较大,各燃烧阶段分界较明显,转速升高到1 100r/min时,滞燃期明显缩短,天然气预混燃烧比例减小,扩散燃烧成为天然气主导的燃烧模式;转速小于900r/min时,NOx排放随转速升高而增加;转速在900∽1 600r/min之间时,随转速升高而降低;转速高于1 600r/min时,NOx排放没有明显变化.In order to investigation the effect of engine speed on combustion characteristics and emission characteristics at full load,indicator diagram and NOxemissions were measured on a turbocharged intercooled high-pressure direct-injection natural gas engine.The results indicate that in the whole speed range at full load,the heat release rate shows a trend of first rapid then slow and the peak value decreases with the increase of speed;more fuel is burned during the premixed combustion phase and each combustion phase is more distinguishable due to the longer ignition delay at lower engine speed,when the speed is above 1 100r/min,the ignition delay is significantly shortened,the proportion of premixed combustion is reduced and mixing-controlled combustion phase becomes the dominant combustion mode;NOxemissions increase with the speed when engine speed is lower than 900r/min,decrease with speed in the speed range of 900r/min to 1 600r/min,remain stable when the engine speed is above 1 600r/min.

关 键 词：天然气发动机 高压直喷 外特性 燃烧特性 排放特性 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]