Enhancing temperature uniformity and recirculation in MILD combustion furnace: A study on angle of Burner's bluff body
Mahdi Zourazmai, Mohammad Zabetian Targhi, Ali Ashouri
Abstract
This study compares the burner geometry modifications, specifically adjusting fuel and air inlet angles (α), on MILD combustion furnace performance. The objective is to improve temperature uniformity, enhance internal recirculation, and reduce pollutant emissions by replacing the curved bluff body with a linear configuration at varying α. Results show that optimizing α significantly enhances performance, with α = 15° yielding the best results. This configuration reduced the maximum temperature by 20 K, increased the average temperature by 7 K, and improved internal recirculation by 20.6 %, ensuring better fuel-air mixing and a more extended reaction zone. The Damköhler number decreased by 33.3 %, indicating a transition to a mixing-dominated reaction regime. Additionally, NO and CO emissions for α = 15° were reduced to below 1 mg/kJ and 2 ppm, respectively, meeting EPA standards. These improvements are attributed to enhanced vortex mixing, which lowers peak temperatures and stabilizes combustion. Quantitative assessments of heat release rate and OH radical distribution confirmed the effectiveness of the modifications in maintaining MILD combustion conditions. In conclusion, optimizing burner geometry significantly improves MILD combustion stability, efficiency, and emissions, demonstrating the potential of burner design refinements for sustainable industrial applications.