Investigation of swirler effect on combustion and exergy efficiency of hydrogen/chlorine combustor based on entropy generation analysis

Inefficient reagent reaction limits the development of compact combustion-based HCl synthesis production. To address this issue, a non-premixed HCl synthesis combustor that combines a swirler at the hydrogen channel with a porous nozzle at the chlorine channel is proposed. A three-dimensional non-premixed combustion model is used to investigate the effects of this combustor structure on the combustion efficiency, exergy efficiency, and pressure loss coefficient. The entropy generation analysis is employed to evaluate multiple irreversible losses for different structures and flow states. Through experimental validation and numerical simulation analysis, the effects of the swirler installation, inlet flow rate, and H2/Cl2 equivalence ratio on the combustion and heat transfer characteristics are investigated. The results demonstrate that the combustor with the swirler and porous nozzle improves exergy efficiency, leading to higher HCl purity and a reduced flame height for faster reactions under low-flow states. Chemical reactions contribute to over 96 % of entropy generation during combustion, with the swirler reducing total entropy by approximately 5 %. Optimal heat transfer effects and minimized entropy generation are achieved when the swirler is installed below the combustor spray hole. The installation of the swirler can increase the exergy efficiency of the H2/Cl2 combustor to approximately 43.73 %.