英语翻译第6课英语翻译第6课.doc

Lesson Six COMBUSTIBLE MIXTURE FORMATION AND COMBUSTION IN DIESEL ENGINES （柴油机可燃混合气的形成与燃烧） 1.INTRODUCTION（引言） The increasing interest in the study of diesel engine combustion, emissions and economy is caused by growing concern about energy resources and the environment.(对能源和环境的日益关注导致对柴油机燃烧、排放和经济性的研究兴趣的日益增加)The diesel engine, being the most economical known power plant, has gained popularity in many applications, including heavy and medium duty vehicles.( 柴油发动机是最经济的已知的，已在许多应用中得到普及，包括重型和中型车辆。 More recently it has been considered in many parts of the world as a replacement for the regular spark ignition, or S.I. (gasoline or petrol) engine in some passenger car applications.( 近来，它已经在世界许多地方，作为一种常规的火花点火，或The high thermal efficiency of the diesel engine is mainly caused by the relatively high compression ratio required to start the autoignition process, the lower pumping losses as a result of the absence of the throttle valve (which is needed in S.I. engines to control the power output), and the overall lean mixture required to achieve an efficient heterogeneous combustion process.（柴油机的热效率高，主要是由启动所需的自燃过程相对较高的压缩，由于节流阀的缺失（这是在汽油发动机需要控制的输出功率）泵气损失并要求达到高效的异构燃烧过程的整体混合物Most diesel engines emit less carbon monoxide and unburned hydrocarbons than comparable S.I. engines. There are some pollutants, however, characteristic of the heterogeneous mixture used in the diesel combustion process which are not found with the S.I. engine.（大多数柴油机排放比汽油发动机的一氧化碳和未燃烧的碳氢化合物。然而These are odor constituents, visible smoke, and noise.（包括气味成分，可见烟雾，噪声。This chapter deals with these pollutants as well as with unburned hydrocarbons, carbon monoxide, nitric oxide, oxygenated hydrocarbons, sulfur compounds, and particulates.（本章讨论这些污染物以及未燃烧的碳氢化合物，一氧化碳，氮氧化物，含氧化合物，硫化合物，和微粒。Since all these emitted pollutants are a result of the combustion process, it is necessary first to study the mechanisms of combustion in diesel engines.（由于所有这些排放的污染物是燃烧过程，有必要首先研究柴油机燃烧机理。This combustion process is very complex and its detailed