Analysis of pollutant formation and control and fuel economy in diesel engines

Abstract

Publisher Summary This chapter presents a comparison between the characteristics of the diesel and other automobile engines. 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, and the overall lean mixture required to achieve an efficient heterogeneous combustion process. The chapter describes high speed diesel engines used for automotive applications. Pollutants from the automotive power plants are found to be a major contributor of the photochemical smog formation in the atmosphere and a cause of social and health problems. The preignition processes in diesel engines may be divided into physical and chemical processes. The physical processes include spray disintegration and droplet formation; heating of the liquid fuel and evaporation; and diffusion of the vapor into the air to form a combustible mixture. The chemical processes include the decomposition of the heavy hydrocarbons into lighter components and the preignition chemical reactions between the decomposed components and oxygen.