Response surface method-based optimisation of spray parameters during impingement cooling of hot steel in rolling

Response surface methodology was employed for optimising the complex air-water spray mechanisms that occur in hot surface cooling processes where forced convection exists. Results from a physical air-water spray cooling experiment were generated and the experimental parameters were optimised for achieving heat flux from the surface of a hot steel test plate of dimension 120 mm × 120 mm. The thickness of the plate was considered as one of the variable (4 mm, 6 mm and 8 mm) during the experimentation. The other variables in the problem were the nozzle to plate distance, air pressure and water pressure. The experiments were carried out based on the response surface design of experiments. The heat flux was calculated by using Newton's convection model. The optimisation of the controlling parameters was carried out by using the response surface method (RSM). A new mathematical correlation was developed for optimisation of the surface heat flux.