실험계획법을 적용한 배기가스 저감용 후처리장치의 성능 평가

Abstract

This paper was performed to evaluate the performance of aftertreatment system on the reduction of smoke and NOx emissions in a direct injection diesel engine by DOE (Design of Experiment). Control factors were four types of catalysts and two levels of exhaust gas temperatures in order to reduce the exhaust emissions selected as responses. An aftertreatment system filled with catalyst-coated beads was installed to the exhaust pipe line of 1 m behind from the exhaust manifold and the exhaust gas flow path of the engine was controlled by a butterfly valve. Engine tests were carried out at an engine speed of 1,500 rpm and various engine loads. This study showed that smoke was not affected under all catalysts and exhaust gas temperatures, but NOx emission was affected by the types of catalyst and exhaust gas temperature. The C4 catalyst for NOx emissions was more effective when the exhaust gas temperature was higher than when it was low. Through the DOE it has been proved that the C4 type catalyst and higher exhaust temperature was effective and adequate to reduce the NOx emissions without deterioration of smoke.