Abstract:

In order to study the effect of Polyoxymethylene ether （PODE） mixing on the transient emissions of hybrid diesel engines， based on a single-shaft parallel hybrid test platform， this paper uses 0# diesel and diesel/PODE fuel mixture with PODE in volume ratios of 10% and 20% respectively. The test transient conditions are that the diesel engine speed is 1 900 r/min and the throttle changes from 25% to 35% with the transient working conditions of 0， 2 and 5 s transition time and 800 r/min drag dynamic quick start conditions. The results show that under constant speed and variable throttle conditions， as the transition time decreases， the cumulative NO_x and Soot emission peaks during the change process increase. With the increase of the PODE ratio， the transient distortion of Soot emission first increases and then decreases. Compared with burning 0# diesel， when burning diesel/PODE fuel mixture， the cumulative NO_x emission value during the transient process increases， but the Soot emission peak value drops significantly. When the transition time is 0 s， the Soot emission peak value is reduced by 37% and 63% respectively. When the transition time is 2 s， the peak Soot emission is reduced by 31% and 59%， respectively； when the transition time is 5 s， the peak Soot emission is reduced by 34% and 57%， respectively. Under fast starting conditions， compared to burning 0# diesel， when burning diesel/PODE fuel mixture， the peak CO emission during the starting process is reduced by 10% and 26% respectively， and the peak Soot emission is reduced by 53% and 60% . The change of NO_x emission is not significant.

Key words: hybrid diesel engine, Polyoxymethylene dimethyl ether, transient conditions, quick start, emission