Effect of High Temperature and High Pressure on the Explosion Characteristics of Ternary Premixed Fuel

As a new alternative fuel, ethanol/methane/hydrogen (C₂H₅OH/CH₄/H₂) is of great significance for the sustainable development of new energy in China. The effects of different equivalence ratios (0.8−1.4), initial pressures (0.1, 0.2 and 0.4 MPa) and initial temperatures (370, 400 and 450 K) on key explosion characteristics such as peak explosion pressure, peak explosion pressure rise rate, explosion time and deflagration index were analyzed from the experimental and chemical kinetics perspectives. The results show that the explosion characteristic parameters exhibit extreme values when the equivalence ratios between 1.2 and 1.3. The peak explosion pressure is positively correlated with initial pressure and negatively correlated with initial temperature, and this correlation is linear. With the increase in initial pressure, the crack and cytochemical degree of the flame front deepened, and the peak explosion pressure increased. In addition, the maximum deflagration index evaluated under experimental conditions was 20.83 MPa·m/s, indicating that the combustion of premixed fuel/air was at a relatively safe level. The reaction sensitivity analysis of the motives showed that the deflagration reaction was closely related to the H and OH radicals, and R1, R8, R24 and R96 were the top four motif reactions that had the most important impact on the explosion reaction intensity. This work can provide a valuable reference for the application of C₂H₅OH/CH₄/H₂ ternary mixed fuel in actual combustion units, the evaluation of fuel safety, and the prevention of explosion accidents.