Importance of fuel injection system for low emissions, combustion noise and low fuel consumption

Abstract

Due to increasingly stringent global regulations on engine and noise emissions, the fuel injection system plays a key role in reaching the stricter limits. The performance, low level of emissions and noise of a diesel engine is directly influenced by the fuel injection system which the main purpose is to deliver fuel at high pressure into engine's cylinders. Another aspect of a diesel engine is that it generates much more noise compared to a gasoline one. For this problem, the appropriate fuel injection system, such as a common-rail system, has made it possible to reduce combustion noise. The strategy consists in the use of a split injection into the combustion chamber by splitting the main injection. The purpose of this paper is to emphasize the difference between servo-controlled electrohydraulic injectors and direct acting (piezoelectric) injectors of the common-rail injection system and to explain how they can support the engine in achieving stricter emissions and noise regulations.