Auto-ignition of polyoxymethylene dimethyl ether 3 (PODE3) blended with diesel and gasoline via combustion under homogeneous charge compression ignition

Abstract

• PODE 3 /diesel/gasoline blends in a HCCI engine are studied for the first time. • High temperature kinetic reactions are dependent on cetane number of fuel blend. • Oxygen from PODE 3 helps promote better ignition when gasoline is added to PODE 3 . • Gasoline addition to PODE 3 presents higher efficiency than diesel addition. • PODE 3 demonstrates high potential in encouraging clean combustion. With high oxygen content and cetane number, PODE 3 is a favorable renewable fuel for engines. PODE 3 /diesel/gasoline blends in a HCCI engine are numerically studied for the first time. The effects of fuel blend ratio and equivalence ratio (ER) on auto-ignition are investigated. A highly compact and robust chemical mechanism has been implemented. Crank angle at which 50 percent of heat is released (CA50) displays higher sensitivity towards blend ratio in leaner mixtures with 50% PODE 3 displaying a change of 12.31 CAD at 0.34 ER and only 6.19 CAD at 0.5 ER when made in comparison to their respective CA50 at 100% PODE 3 . Furthermore, indicated thermal efficiency (ITE) is observed to be better with higher ER with 100% PODE 3 having a 23.3% increase in ITE at 0.5 ER than at 0.34 ER, and is generally higher with increased PODE 3 . Neat PODE 3 displays lowest CO and highest CO 2 for all cases, manifesting high oxidation reactivity. Additionally, acetylene levels are substantially lower for combustions at 0.5 ER as compared to 0.34 ER. Lastly, PODE 3 yields only 2.04 × 10 −10 g/cycle and 5.67 × 10 −11 g/cycle of C 2 H 2 at 0.34 ER and 0.5 ER respectively. With nearly no soot precursors, PODE 3 demonstrates high potential in encouraging clean combustion.