Plateau Environment Experimental Study On Bio-diesel Engine Fitted With The DOC System

Faced with the increasingly serious energy crisis and the environmental pollution problems as well as the increasingly stringent emission regulations, the development and use of alternative fuels as well as installing post-processing techniques extremely urgent. Biodiesel's properties are not only similar but also better than diesel, thus it is being widely noticed at home and abroad. Because the DOC system has simple structure, low cost and maintenance friendly, it has become the main technology to meet the Euro 3 and over Euro 3 emission regulations in foreign countries. But the application study of biodiesel and DOC systems on diesel engine diesel engine is far behind foreign countries, especially in the plateau region this study is very little. Therefore, this article studied the effect of biodiesel and DOC systems on diesel engine performance.This study conducted dynamic property, economical efficiency, noise and emission performance contrast test on 4100QBZL engine, when the engine fueled with diesel, pure biodiesel and different volume ratio of diesel/biodiesel blends, as well as retrofitting DOC system under 81kPa atmospheric pressures (Kunming).The result showed that:when fueled with biodiesel, the engine power and economy will decrease with the increase of biodiesel mixed ratio, but the brake thermal efficiency of pure biodiesel was above diesel; The noise power of biodiesel mixed ratio within 30% were equivalent to diesel, while the pure biodiesel's noise power was lower than diesel; compared with diesel, CO, HC and soot emissions significantly reduced, they averagely reduced by 11.2%～39.9%,7.6%～21.9% and 13.4%～49.5% respectively, but the NOx emissions of pure biodiesel slightly increased and its brake specific emission was above Euro 1 emission standard by 6.5%; After installing the DOC, the power and economy of diesel and biodiesel slightly declined; CO, HC and soot emissions reduced to varying degrees, their highest conversion rates were 91.1%,86.3% and 37.9% respectively, NOx emissions also slightly decreased. But in more than 400℃temperature, DOC will be affected by sulfur easily, so the reduction efficiency will decreased and the reduction efficiency of diesel was inferior to biodiesel.