Numerical Simulation on Heat Transfer Behaviors of Single‐Flow Post‐Combustion Oxygen Lance with Water Cooling

In converter steelmaking, the single‐flow post‐combustion oxygen lance (S‐PCL) effectively increases the scrap ratio. However, its tip life is influenced by high temperatures from O 2 ‐CO combustion and the cooling structure. A 3D fluid‐solid‐thermal coupling model for combustion characteristics in the water cooling oxygen lance and converter gas area is established to compare the combustion behavior and temperature distribution of jets, the cooling water flow behavior, and the surface temperature distribution between S‐PCL and traditional five‐hole lance (CL). Results reveal that at H = 5D t , 10D t , 20D t , and 30D t , the combustion area of S‐PCL is 3.24, 2.89, 2.28, and 1.69 times that of CL. The center temperature of the S‐PCL tip face is lower than that of CL, while the end face temperature near the center is higher. For both lances, the sidewall temperature first decreases and then increases with distance from the end face corner, and their radial temperature trends are similar. The maximum sidewall temperature difference at different heights ranges from 73 to 302 K for S‐PCL and 10 K to 31 K for CL. Their high‐temperature positions lie at the secondary hole and main hole axes. Industrial tests confirm that S‐PCL and CL exhibit similar service lives.