Numerical Study On Combustion And Heat Transfer In The Heating Furnace Of The Scrap Steel Preheating System

The iron and steel industry is the key industry of Chinese economic development,and energy consumption cannot be ignored.Green and low-carbon are the development direction and emphasis for future.Under the dual pressure of increased production costs and increased environmental pollution,more and more iron and steel enterprises choose to increase the scrap ratio to reduce costs,improve production capacity and reduce pollution.However,the insufficient heat of scrap makes the production efficiency greatly limited.The use of scrap preheating method can effectively improve the physical heat of scrap and supplement the heat consumption of converter.The key to this method is to reasonably design the heating device to meet the production requirements in the waste steel preheating system.In this paper,the heating furnace is used for scrap steel preheating.This paper briefly summarizes the research and current situation of the development of numerical simulation technology for heating furnaces in both native and foreign countries.Based on a large amount of relevant literature and materials,using computational fluid dynamics research methods,based on fluid dynamics theory,combustion and heat transfer process mechanism,a numerical model of turbulence,combustion and heat transfer in the heating furnace was created,and the thermal process of steady-state heating furnaces is numerically solved and analyzed.The standard two-equation turbulence model,probability density function combustion model and discrete coordinate radiation model were used for simulation and solution.The distribution characteristics of temperature field,velocity field and concentration field in the furnace were obtained from the analysis results.By changing the nozzle arrangement and the equivalent ratio,this paper analyzed the uniformity of temperature distribution in the heating furnace under various working conditions.The simulation results supply a reference for further optimizing the heating furnace.At the same time,accurate three-dimensional temperature field distribution information lays the foundation for the research of energy-saving control technology for heating furnaces.Based on the simulation of the heating furnace,this paper investigates the temperature field changes of the billet after a period of heating.The three-dimensional unsteady simulation of the temperature change process of the billet is carried out.The temperature data of the reheating furnace is introduced to imitate the three-dimensional temperature distribution of the outer surface and the center section of the steel billet.This thesis comparatively analyzes the variation law of the temperature field of the billet and the curve diagram of billet temperature changing with time.The whole heating process conforms to the heat transfer characteristics of the billet,and the billet temperature is evenly distributed,which achieves the purpose of preheating the scrap steel.At the same time,the simulation results provide a reference for the establishment of the billet temperature field prediction model.