为了从科学和技术的角度展望民用航空发动机低排放燃烧室技术的发展方向,基于污染物生成机理及控制原理阐述了富油和贫油燃烧的污染排放控制方法,回顾了富油-焠熄-贫油燃烧（RQL）、贫油预混预蒸发燃烧（LPP）和贫油直接喷射燃烧（LDI）...为了从科学和技术的角度展望民用航空发动机低排放燃烧室技术的发展方向,基于污染物生成机理及控制原理阐述了富油和贫油燃烧的污染排放控制方法,回顾了富油-焠熄-贫油燃烧（RQL）、贫油预混预蒸发燃烧（LPP）和贫油直接喷射燃烧（LDI）3种低污染燃烧技术的发展现状,并分析了新一代民用航空低排放燃烧室技术目前所达到的低污染排放水平.采用贫油燃烧技术的双环预混旋流器燃烧室（TAPS）已经应用于型号并取证,其NOx排放比CAEP/6（Com-mittee on Aviation Environmental Protection/6）标准低50.0％～65.8％,达到了超低排放水平,证明了贫油燃烧的发展潜力.要实现Nq排放比CAEP/6低75.o％以上的超超低排放目标,需要利用燃烧数值模拟和光学诊断等先进工具,对燃烧室内喷雾、混合、流动、燃烧及它们之间的非定常相互作用开展更深入的研究.展开更多
Rich burn industrial natural gas engines offer best in class post catalyst emissions by using a non-selective catalyst reduction aftertreatment technology. However, they operate with reduced power density when compare...Rich burn industrial natural gas engines offer best in class post catalyst emissions by using a non-selective catalyst reduction aftertreatment technology. However, they operate with reduced power density when compared to lean burn engines. Dedicated exhaust gas recirculation (EGR) offers a possible pathway for rich burn engines to use non-selective catalyst reduction aftertreatment technology without sacrificing power density. In order to achieve best in class post catalyst emissions, the precious metals and washcoat of a non-selective catalyst must be designed according to the expected exhaust composition of an engine. In this work, a rich burn industrial natural gas engine operating with dedicated EGR was paired with a commercially available non-selective catalyst. At rated brake mean effective pressure (BMEP) the air-fuel ratio was swept between rich and lean conditions to compare the catalyst reduction efficiency and post catalyst emissions of rich burn and dedicated EGR combustion. It was found that due to low oxides of nitrogen (NO<sub>x</sub>) emissions across the entire air-fuel ratio range, dedicated EGR offers a much larger range of air-fuel ratios where low regulated emissions can be met. Low engine out NO<sub>x</sub> also points towards a possibility of using an oxidation catalyst rather than a non-selective catalyst for dedicated EGR applications. The location of the NO<sub>x</sub>-CO tradeoff was shifted to more rich conditions using dedicated EGR.展开更多
文摘为了从科学和技术的角度展望民用航空发动机低排放燃烧室技术的发展方向,基于污染物生成机理及控制原理阐述了富油和贫油燃烧的污染排放控制方法,回顾了富油-焠熄-贫油燃烧（RQL）、贫油预混预蒸发燃烧（LPP）和贫油直接喷射燃烧（LDI）3种低污染燃烧技术的发展现状,并分析了新一代民用航空低排放燃烧室技术目前所达到的低污染排放水平.采用贫油燃烧技术的双环预混旋流器燃烧室（TAPS）已经应用于型号并取证,其NOx排放比CAEP/6（Com-mittee on Aviation Environmental Protection/6）标准低50.0％～65.8％,达到了超低排放水平,证明了贫油燃烧的发展潜力.要实现Nq排放比CAEP/6低75.o％以上的超超低排放目标,需要利用燃烧数值模拟和光学诊断等先进工具,对燃烧室内喷雾、混合、流动、燃烧及它们之间的非定常相互作用开展更深入的研究.
文摘Rich burn industrial natural gas engines offer best in class post catalyst emissions by using a non-selective catalyst reduction aftertreatment technology. However, they operate with reduced power density when compared to lean burn engines. Dedicated exhaust gas recirculation (EGR) offers a possible pathway for rich burn engines to use non-selective catalyst reduction aftertreatment technology without sacrificing power density. In order to achieve best in class post catalyst emissions, the precious metals and washcoat of a non-selective catalyst must be designed according to the expected exhaust composition of an engine. In this work, a rich burn industrial natural gas engine operating with dedicated EGR was paired with a commercially available non-selective catalyst. At rated brake mean effective pressure (BMEP) the air-fuel ratio was swept between rich and lean conditions to compare the catalyst reduction efficiency and post catalyst emissions of rich burn and dedicated EGR combustion. It was found that due to low oxides of nitrogen (NO<sub>x</sub>) emissions across the entire air-fuel ratio range, dedicated EGR offers a much larger range of air-fuel ratios where low regulated emissions can be met. Low engine out NO<sub>x</sub> also points towards a possibility of using an oxidation catalyst rather than a non-selective catalyst for dedicated EGR applications. The location of the NO<sub>x</sub>-CO tradeoff was shifted to more rich conditions using dedicated EGR.
