The direct-connected supersonic combustor experiment is finished for kerosene fuel ignition in H_2/O_2 preheated impulse facility. The entrance parameter of combustor corresponds to scramjet flight Mach number 3.5. Ke...The direct-connected supersonic combustor experiment is finished for kerosene fuel ignition in H_2/O_2 preheated impulse facility. The entrance parameter of combustor corresponds to scramjet flight Mach number 3.5. Kerosene ignition is realized by using hydrogen as pilot flame. Wall pressure distributions of combustion are measured and flame photographs of ultraviolet ray are got. Experiment indicates that it is very difficult for kerosene fuel to realize self-ignition at low entrance temperature (below 900K) in supersonic combustor. Hydrogen pilot flame is one of the efficient methods for realizing kerosene ignition.展开更多
基于CONVERGE建立了高压直喷(high-pressure direct injection,HPDI)天然气低速船机三维仿真模型,并基于该模型研究了米勒循环和废气再循环(exhaust gas recirculation,EGR)对发动机燃烧特性及污染物排放的影响规律,探究了米勒循环耦合...基于CONVERGE建立了高压直喷(high-pressure direct injection,HPDI)天然气低速船机三维仿真模型,并基于该模型研究了米勒循环和废气再循环(exhaust gas recirculation,EGR)对发动机燃烧特性及污染物排放的影响规律,探究了米勒循环耦合EGR路线满足TierⅢ排放法规的可行性。研究结果表明,单独使用30%EGR率可满足TierⅢ排放标准,但指示油耗和碳烟排放增加显著;应用米勒循环降低NO x排放的潜力低于EGR;过大的排气门晚关角度会增大压气机工作负荷,且降低等量NO x排放情况下油耗牺牲较大;采用25%EGR率耦合小程度米勒循环(排气门关闭时刻推迟5°曲轴转角)并适当提前天然气喷射正时(提前2°曲轴转角),可在指示油耗仅增加1.58%的前提下降低77%的NO x排放,是满足TierⅢ排放法规可行的技术路线。展开更多
文摘The direct-connected supersonic combustor experiment is finished for kerosene fuel ignition in H_2/O_2 preheated impulse facility. The entrance parameter of combustor corresponds to scramjet flight Mach number 3.5. Kerosene ignition is realized by using hydrogen as pilot flame. Wall pressure distributions of combustion are measured and flame photographs of ultraviolet ray are got. Experiment indicates that it is very difficult for kerosene fuel to realize self-ignition at low entrance temperature (below 900K) in supersonic combustor. Hydrogen pilot flame is one of the efficient methods for realizing kerosene ignition.
文摘基于CONVERGE建立了高压直喷(high-pressure direct injection,HPDI)天然气低速船机三维仿真模型,并基于该模型研究了米勒循环和废气再循环(exhaust gas recirculation,EGR)对发动机燃烧特性及污染物排放的影响规律,探究了米勒循环耦合EGR路线满足TierⅢ排放法规的可行性。研究结果表明,单独使用30%EGR率可满足TierⅢ排放标准,但指示油耗和碳烟排放增加显著;应用米勒循环降低NO x排放的潜力低于EGR;过大的排气门晚关角度会增大压气机工作负荷,且降低等量NO x排放情况下油耗牺牲较大;采用25%EGR率耦合小程度米勒循环(排气门关闭时刻推迟5°曲轴转角)并适当提前天然气喷射正时(提前2°曲轴转角),可在指示油耗仅增加1.58%的前提下降低77%的NO x排放,是满足TierⅢ排放法规可行的技术路线。
