Effects of pre-injection strategy on combustion performance of methanol/diesel dual fuel engine at low load

In this paper, the effect of pre-injection timing on combustion and emission performance methanol/diesel high premixed charge compression ignition (HPCCI) mode at low load was studied by three-dimensional numerical simulation. The simulation is carried out under conditions 1900 r/min 25% load, diesel mass remains constant changed 50% 60% methanol ratio respectively. results show that with delay timing, evaporation pre-injected fuel in cylinder becomes faster, temperature reaction enhanced, peak value heat release rate higher. addition, distribution position impact wall are important factors affecting cylinder, when injection -35 °CA ATDC, characteristics engine optimal. Finally, comparing traditional RCCI mode, enhancement ability HPCCI efficiency verified analyzed.