Effects of burner configuration modification on CH4-H2 fueled industrial steam cracking furnaces: Heat transfer, pollutant emission, and furnace performance

Coke formation, hot spots, temperature non-uniformity, and pollutant emissions remain major challenges in industrial steam cracking furnaces, adversely impacting operational efficiency, maintenance costs, and product quality. This study aims to address these challenges by numerically comparing the performance of floor premixed and non-premixed burners in terms of combustion behavior, heat transfer, vortex formation, and pollutant emission in a 6.7 MW industrial steam cracking furnace. A detailed three-dimensional model of a one-third segment of this furnace was developed using the Partially Stirred Reactor (PaSR) combustion model for the first time in cracking furnace simulations. The results reveal that the non-premixed configuration significantly enhances furnace performance: it increases maximum and average furnace temperatures, improves temperature uniformity by 5 % from 80.4 % to 85.12 %, and reduces the temperature difference between the reactor tubes by 35 %, promoting more uniform heat transfer. Enhanced flow recirculation and developing secondary vortices promote better flue gas mixing, mitigating localized hot spots and reducing coke formation risks. Pollutant analysis indicates that although NOx and CO emissions increase with the non-premixed burners, they remain well below EPA limits, ensuring compliance with environmental standards. This study highlights the trade-offs between burner configurations, and directly demonstrates the advantage of non-premixed burners in improving heat transfer and temperature distribution while maintaining acceptable emission levels in industrial steam cracking furnace design.