Effect of oxygen enrichment and NH3 pre-cracking on laminar burning velocity and intrinsic instability of NH3/bio-syngas

This paper investigates the laminar burning velocity (SL) and instability of NH3/bio-syngas under different biosyngas contents, oxygen enrichment factors (Q), and the cracking ratio of NH3 (4) using a constant-volume combustion bomb. The results show that increasing bio-syngas, Q, and 4 effectively enhance the SL of the fuel. Around 4 = 60%, the relationship between SL and the NH3 content before cracking is reversed. Increasing the bio-syngas and 4 enhance SL through the chemical effect, while Q primarily enhances SL through the thermal effect. When Q = 50%, the contribution of thermal effect can reach up to 94.53%. Linear stability analysis indicates that increasing the bio-syngas content and 4 reduces the critical Peclet number (Pec), while Q increases Pec. As the bio-syngas content and 4 increase, the growth rate of perturbation (& sum;) monotonically increases, indicating instability. Q, on the other hand, decreases & sum;, making it negative.