Effects of Equivalence Ratio on Hydrogen Combustion Flow and NOX Emission Characteristics in a Jet-Trapped Vortex Combustor

The jet-trapped vortex combustor presented in this study was designed based on the trapped vortex combustor with good flame stability by introducing a jet flame-stabilization method. Leveraging the superior air-fuel mixing efficiency and enhanced heat and mass transfer of the jet stabilization method, this configuration addresses the inherent limitations of heat and mass transfer between the mainstream flow and the cavity in a conventional trapped vortex combustor. To investigate the influence of different hydrogen-air equivalence ratios on the flow dynamics, combustion performance, and emission within the jet-trapped vortex combustor, numerical simulations were conducted in this study. The results show that under different equivalence ratios, a vortex pair structure can be formed in the mixing zone between the hydrogen jet and the air jet. Complete combustion can be achieved at all equivalence ratios except for Φ = 1.56. When Φ is below 0.86, the axial distance required to achieve complete combustion progressively decreases as the equivalence ratio is reduced. The temperature distribution in the combustor is more uniform with minimal variation, and the concentration of NO emissions decreases progressively. Among these cases, the combustion efficiency, temperature distribution, and NO emission characteristic of the combustor are relatively better at Φ = 0.34.