Revealing the Misfire Mechanism of Tri-propylene Glycol Monomethyl Ether Combining Experimental and Chemical Kinetic Modeling Methods
摘要
Tri-propylene glycol monomethyl ether (TPGME) is a renewable oxygenated biofuel that can alleviate the energy crisis and mitigate pollution issues. TPGME exhibits low-temperature exothermic performance compared with conventional fuels, and exploring its critical auto-ignition temperature can expand its application scope. In this study, TPGME spray auto-ignition experiments were carried out based on a constant volume combustor chamber. Moreover, the misfire mechanism at low temperatures was revealed via chemical kinetic modeling. The results show that the temperatures of TPGME spray auto-ignition are 713 K, 663 K, 653 K, and 643 K at ambient densities of 20.2 kg/m3, 15.7 kg/m3 ,11.2 kg/m3, and 6.7 kg/m3, respectively. There are two main reasons for the misfire. Firstly, 0D modeling indicates that the mass fraction of OH (Y-OH) decreases by orders of magnitude within the equivalence ratio (Φ) range of Φ < 0.5 or Φ > 1.75, which limits the high-temperature ignition (HTI). Results from 3D modeling show that the equivalence ratio of the first ignition site (Φ0) decreases as the ambient temperature (Ta) decreases. At critical ignition conditions, Φ0 drops below 0.5, Y-OH decreases dramatically, and no HTI occurs. Secondly, the heat release rate of key low-temperature exothermic reactions decreases as Ta decreases, which inhibits the HTI.