Analysis of Advanced Direct-Injection Diesel Engine Development Strategies

摘要

The methodology of achieving a high power density (HPD, or brake mean effective pressure) direct-injection Diesel engine has been studied, which is directed to using high fuel/air ratio, high-speed and ceramic engine components. Among the main thrust to achieve these engine changes for an advanced Diesel engine is the design of a high injection pressure (HIP) fuel system. During the course of the present study, two Cummins 903 engines mated with a Rutger-built HIP were employed to investigate the engine response to HIP and in-cylinder processes by using the Rutgers high-speed infrared (IR) spectral digital imaging system. Five separate technical publications were prepared to report results obtained from the study. The main findings include: The HIP system permits engine operation at an air/fuel ratio of as rich as 18 to 1 with smoke emission not worse than with the conventional mechanical (low pressure) injection system; A high injection pressure improves HPD of a Diesel engine; A HIP unit promotes the (invisible) preflame reactions during the ignition delay period; The formation of the very first flame kernel is significantly affected by a cetane improver (fuel additive); The new three-color method developed in the present study was used to determine simultaneous distributions of temperature, soot and water vapor in the engine cylinder; and more. The techniques developed on the present ARO-sponsorship were employed in other engine studies and carried out under the sponsorship of industrial members and other U.S. governmental components.