Taking D30 diesel engine equipped with high pressure common rail and the diesel oxidation catalyst(DOC) + catalytic particulate filter(CDPF) after-treatment system as a research engine

and using diesel fuel mixed with 0%

10%

and 30% polymethoxy dimethyl ether(PODE) as fuels of P0

P10 and P30

the effects of PODE blending ratio on the performance of diesel engine and after-treatment system were studied through engine bench test. The results showed that at load conditions

with the increase of the blending ratio of PODE

the brake specific fuel consumption increased. At low speed and high load

the brake thermal efficiency with P30 fuel was the highest among all the blended fuels. The blending of PODE significantly deteriorated NOx and HC emissions

and only lowered the specific emission of CO by about 33% at low speeds. At 1 600 r/min

the blended fuel effectively reduced the smoke emissions of diesel engine

but the aftertreatment system had a significant temperature increase

and the efficiency of converting NO to NO2 was reduced. At 2 400 r/min

with the increase of the blending ratio

the concentration of NO2 at the rear end of CDPF increased. Compared with P0 and P10 fuels

P30 fuel lowered the temperature after turbocharger by about 30 ℃. The higher the blending ratio of PODE

the lower the exhaust pressures before DOC and CDPF

thus reducing the risk of CDPF carrier blockage.