improvement of flame pattern of convection burners in a methanol plant through optimization of airflow distribution

Furnaces are essential in the oil, gas, and petrochemical industries, consuming significant energy and playing a crucial role in various processes. this study focuses on a typical methanol reforming furnace addressing the critical issue of non-uniform airflow distribution in the convection section. non-uniform airflow disrupts burner performance, causing incomplete combustion, refractory damage, and decreased energy efficiency. using computational fluid dynamics (cfd) simulations, the airflow patterns in the existing duct geometry were analyzed. two optimization strategies were employed: (1) geometric modifications to the duct elbow, such as introducing mitered and bended designs to minimize vortex formation, and (2) adjustment of burner dampers to equalize airflow rates among the twelve convection burners. the objective function is to minimize the variance in airflow rates, aiming for uniform distribution. the results demonstrated that geometric modifications significantly reduced airflow variance, with bended and mitered elbows achieving 35% and 17% reductions, respectively. further optimization through damper adjustments decreased variance by an additional 81%, ensuring near-uniform airflow distribution. these changes improved flame consistency, reduced refractory damage, and enhanced overall system efficiency. this study highlights the importance of integrating duct design improvements with precise damper adjustments to optimize furnace performance. the findings provide a practical framework for addressing airflow challenges in industrial furnaces, ensuring operational reliability and energy efficiency.