싱글 사이클 엔진을 이용한 희박 연소 한계의 측정

In medium and heavy duty engines for vehicles heavier than 3.5 tons(GVW), an implementation of lean burn technology is very important to lower thermal load and enhance fuel economy. To meet EURO-5 emission regulations, the optimized emission characteristics are also important design factors. In this work, with lean burn technology, a swirl enhancing valve was used in the intake port to improve combustion. Also, the injection position was varied to see its effect on stratification of air fuel mixture, which thus may enhance lean burn characteristics. This work concluded that, with swirl enhancing valve, although torque was decreased, there exist conditions where NOx and THC emissions were reduced at the same level of torque compared with the baseline case. Whereas by varying injection positions with tumble port injection, the combustion characteristics was not satisfactory in terms of torque and emissions.