점화시스템의 희박연소 기관의 성능에 미치는 영향(I) (종류 및 성능)

Much effort has been devoted during the last decades to improving the efficiency of converting the energy stored in an air-fuel mixture in the internal combustion engine into thermal energy without the introduction of unacceptable levels of pollutants. In general, a significant reduction of exhaust pollutants can be achieved by lowering the compression ratio or using a leaner air-fuel mixture. Unlike the effect of lowering of the compression ratio, the use of a lean mixture can also lead to an increasing in the thermal efficiency. However, unstable engine driving conditions caused by misfire or partial bum and the increase in HC emission makes it difficult to allow adequate lean operations. Therefore, to extend the lean limit, improvement in fuel composition and engine configuration such as air-fuel dynamics flow in the combustion chamber and the ignition system is being studied. This literature survey deals with the papers which have studied the ignition process or various ignition systems. These ignition systems make extend the lean misfire limit, reduce the HC emission and stabilize the operating condition of the lean burn engine by modifying the ignition process or increasing ignition energy.