EFFECT OF COMBINATION OF EGR, DOC, AND DPF TECHNOLOGIES FOR REDUCING EXHAUST EMISSION OF A DIESEL ENGINES

Abstract

The Vietnamese government has tightened up vehicle emission standards by applying Euro IV Emission Standard for automobiles and Euro III Emission Standard for motorcycle since July 2017. However, these standards only apply to new vehicles; meanwhile, there are a large number of in used vehicles with high exhaust emissions still circulate in Vietnam. This paper presents a solution to reduce emissions of in vehicles retrofitted diesel engine by using a combination of EGR, DOC, and DPF technologies. Consequently, the experimental study was conducted on a diesel bus engine with and without exhaust reduction technologies for the comparison. The research results showed that EGR, DOC and DPF technologies resulted in reducing up to approximately 67.99% of NO_x and 57.09% of PM in comparison with the original engine. In addition, HC and CO also reduced 50.81% and 41.18%, respectively. The combination system also compacts and can suitably assembly in the vehicle. The results of this research are foundations to solve the serious problem relating to the exhaust emission of buses in Vietnam.