Ultra-low-emission diesel engine fuelled with dimethoxymethane-diesel fuel blends

The influences of dimethoxymethane (DMM content), exhaust gas recirculation (EGR) and post-processor on combustion and emission were studied experimentally, and the approaches to meet the Euro III regulation were discussed. Results showed that, for diesel blending fuel with 50 per cent DMM volume fraction, on setting the EGR rate at 28 per cent for low and medium loads and at 7 per cent at high loads, nitrogen oxide and soot emissions are both reduced markedly; a diesel oxidation catalyst (DOC) reduces hydrocarbon and carbon monoxide emissions. Comparison of the combustion process with diesel fuel indicated that application of DMM-diesel blended fuel increases both premixed and diffusion combustion, leading to a higher peak pressure and a pressure rise. EGR does not lengthen the combustion duration significantly. A naturally aspirated diesel engine in the test fuelled with a high percentage of DMM component in the blend, together with EGR and DOC, makes it possible to meet the Euro III emission standard for a vehicle diesel engine.