掺氢对乙醇喷雾点火和燃烧特性的影响研究

Based on the constant volume combustionvessel, the ignition and combustion characteristics of ethanol spray combustion at different ignition timings, injection pressures and hydrogen equivalence ratios were investigated. The experimental conditions are 353 K, standard atmospheric pressure, ignition timing (0-50 ms afterstartof injection), injection pressure (5, 15, 25 MPa), and hydrogen premixed equivalence ratio (0.05, 0.1, 0.2). The results show that ethanol direct injection combined with hydrogen enrichment can achieve successignition under ultra-lean condition (global equivalence ratio 0.15, 67% ethanol/33% hydrogen). In addition, with the delay of ignition timing, the probability of ignition increases first and then decreases; As the injection pressure and hydrogen ratio increase, the probability of ignition increases. However, under high injection pressure, liquid spray has a better evaporation effect, making the mixed fuel more uniform, leading to incomplete combustion in extremely lean areas. Hydrogen enrichment not only stabilizes the ignition process, but also improves the overall combustion characteristics. Stable ignition and combustion can be achieved at an earlier ignition timing (2-3 ms), moderate injection pressure (15 MPa), and a minimum global equivalence ratio of 0.2 (50% ethanol/50% hydrogen).