Enhancing fuel-air mixing in COG-BOG non-premixed combustion: A CFD analysis with different turbulent models

The present study investigates non-premixed combustion using a mixture of coke oven gas (COG) and blast oven gas (BOG) as fuel, with the help of computational fluid dynamics (CFD). The mixing and conversion were compared by employing three turbulent models: standard k-epsilon, renormalization group (RNG), and Reynolds stress model (RSM). Variations in oxidizer inlet angles (0 degrees, 5 degrees, and 10 degrees) were explored for improved fuel-air mixing. Analyzing these models and designs also allowed the understanding of the flow phenomena. Flame patterns and maximum temperature produced were examined with varying fuel-oxidizer velocity ratios. The finding shows the RSM model with a 10 degrees oxidizer inlet angle was outperforming the others, predicting a 4 % higher outlet temperature. In the case of analyzing a suitable turbulent model for simulating the combustion of COG-BOG mixture, the study revealed, the RNG model records 35 % lower temperatures which means poor conversion due to poor mixing. The produced temperature was closely related to the fuel-oxidizer ratio and a range of this ratio helped to identify the optimized controlling parameter. This research advances knowledge of COG-BOG combustion simulation, aiding in the compatibility of turbulence models, oxidizer-fuel optimization, and improvements to phase flow.