Investigation of Emission Gas by using the Intake Manifold Gasket Blade

흡기 매니폴드 가스켓 블레이드 적용에 따른 배출가스 고찰

Abstract

Incomplete combustion in automotive engines is a major cause of harmful exhaust gases. In this study, to prevent incomplete combustion and reduce exhaust gas emissions, a gasket blade for increasing the air velocity was applied to the intake manifold, and the change in exhaust gas was investigated theoretically and experimentally. First, simulation analysis for flow according to the number and angle of the gasket blade was performed using a 3D flow analysis program. As an analysis result, the internal average velocity of the gasket blade was optimum at 6-blade with an angle of $30^{\circ}$. Based on the simulation results, experiments were conducted to verify the effects of the gasket blades on the exhaust gas in a non-load engine simulation system. As the engine speed was increased from 2000 to 4000 rpm, exhaust gases of HC, CO, and NOx decreased by 23.4%, 16.5%, and 3.8%, respectively, and the emission decreasing effect was reduced.

자동차의 엔진에서 불완전 연소는 유해 배기가스 생성의 주요 원인이다. 따라서 본 연구에서는 자동차 엔진에서 불완전 연소를 방지하고 배출되는 배기가스의 양을 줄이기 위하여 흡기 매니폴드에 가스켓 블레이드를 적용하여 유입되는 공기의 유속 증가에 따른 배기가스의 변화를 해석과 실험을 통하여 고찰하였다. 먼저 3D 유동 해석 프로그램을 사용하여 가스켓 블레이드의 개수와 각도에 따른 유동 해석을 수행하였으며, 해석 결과 가스켓 블레이드를 적용한 흡기 매니폴드 출구에서 공기의 평균 유속은 블레이드 개수가 6개와 $30^{\circ}$각도에서 가장 좋게 나타났다. 해석 결과를 기반으로 무부하 엔진 시뮬레이션 시스템에서 가스켓 블레이드가 배기가스에 미치는 영향을 확인하기 위하여 실험을 진행하였으며 엔진 회전수가 2000 rpm에서 4000 rpm으로 증가함에 따라 배기가스인 HC, CO, NOx는 평균적으로 각각 23.4%, 16.5%, 3.8% 감소하였으며 배기가스의 배출량 감소 효과는 점점 줄어드는 것으로 나타났다.

Fig. 1. Intake manifold according to the number of various gasket blades

Fig. 2. Modeling of intake manifold

Fig. 3. Photos of manufactured gasket blade and mounted on intake manifold

Fig. 4. Emission simulation system

Fig. 5. Maximum air velocity in the intake manifold with the number of gasket blade

Fig. 6. Turbulence kinetic energy in the intake manifold with the number of gasket blade

Fig. 7. Maximum air velocity in the intake manifold with the angle of gasket blade

Fig. 8. Turbulence kinetic energy in the intake manifold with the angle of gasket blade

Fig. 9. Outlet average air velocity in the intake manifold with the angle of gasket blade

Fig. 10. Variation of HC according to engine speed

Fig. 11. Variation of CO according to engine speed

Fig. 12. Variation of NOx according to engine speed

Table 1. Emission gas regulations of European passenger car

Table 2. Analysis conditions of intake manifold

Table 3. Specifications of gasoline engine

Table 4. Emission measure equipments