【作者】 程报；

【导师】 左承基；

【作者基本信息】 合肥工业大学 ， 动力机械及工程， 2007， 硕士

【摘要】 微粒和NO_x是柴油机排放的主要污染物，受柴油机本身固有缺陷－“微粒-NO_x权衡曲线”(particulate-NO_x trade-off curve)限制，同时降低柴油机的微粒和NO_x排放难度较大。氢气是公认的内燃机理想能源，柴油机EGR掺氢燃烧不仅可以有效降低微粒和NO_x的排放量，而且可以提高经济性。本文在ZS195柴油机上分别进行了EGR、掺氢及EGR掺氢试验研究，在不同转速和负荷下分析比较了不同EGR率和掺氢率对发动机的排放和经济性影响。结果表明：柴油机掺氢燃烧可以不同程度降低微粒和N0_x，提高有效热效率。柴油废气重整利用柴油机废气与柴油进行催化重整，产生的重整气(富氢)送入进气管，再与空气混合后进入气缸内燃烧。将柴油废气重整技术用到柴油机中能够有效改善柴油机的性能。论文介绍了柴油废气重整制氢的基本概念和反应机理，以正庚烷代替柴油，利用CHEMKIN软件建立了柴油废气重整反应的化学动力学模型，该模型由气相反应机理和表面反应机理两部分构成，其中气相反应机理部分包含37种组分和58个反应；表面机理部分包含20种组分和47个反应。模拟比较了气体温度、氧碳比、水碳比及空速等因素对重整过程的影响，且与试验结果进行对比，结果表明：模拟值与试验值基本吻合。设计一套柴油废气重整装置，该装置能够满足控制入口气体温度、水碳比、氧碳比的要求，为柴油重整制氢规律奠定实验基础。更多还原

【Abstract】 Particulate and NOx emissions are diesel engine major pollutants controlled by the diesel engine itself inherent defects-(particulate-NOX trade-off curve) limit, So it is very difficult to reduce particulate and NOx emissions together. Hydrogen is recognized as ideal energy of internal combustion engine. Diesel EGR (exhaust gas recirculation) with small amounts of hydrogen combustion can not only reduce particulate and NOx emissions effectively, but also improve the economy.In this thesis, EGR,adding hydrogen to diesel and EGR added hydrogen experiments have been carried out on a ZS195 diesel engine. Different ratio of EGR and ratio of hydrogen added to impact on engine emissions and the economic was analyzed and compared under different speed and load. The results show that: adding hydrogen to engine combustion can reduce particulate and NOx in different degrees and improve the effective thermal efficiency.The reformed gas (hydrogen-rich) which produced form diesel exhaust gas catalytic reforming, mixed with the air into the intake manifold and combusted in the cylinder. Diesel engine can improve its performance effectively by using the technology of diesel exhaust gas reforming. This paper introduces the basic concepts and reaction mechanism of diesel exhaust steam reforming.The chemical kinetics model of exhaust gas diesel fuel has been developed using the CHEMKIN platform and n-heptane instead of diesel. The model include gas-phase reaction mechanism and surface reaction mechanism, consists of 57 species and 105 reactions. The simulation compare the gas temperature, water/ carbon ratio, Oxygen/ carbon ratio and space velocity factors impact the reforming process. The simulation results consistent with the experimental with the experimental results well.Under the guide of the simulation conclusions design a suitable diesel exhaust reforming device, which can meet the gas temperature, water/carbon ratio, Oxygen/ carbon ratio and space velocity control requirements. For a more comprehensive understanding of fuel reforming laws laid experimental basis.更多还原