Temperature Field Simulation And Parameter Optimization In Asphalt Mixing Heating Furnace

With the increasing mileage of highways in China,asphalt pavement enters the stage of repair and maintenance.In order to solve the problems of low heating efficiency of old asphalt materials,uneven mixing temperature and low waste reutilization rate in the process of road construction and maintenance,which lead to the poor effect of in-situ thermal regeneration of asphalt mixture,we combine the original mixing and heating furnace structure of the enterprise,optimize the structural parameters of the furnace and mixing parameters,and analyze the temperature distribution in the heating furnace and the temperature uniformity of asphalt mixture under different shovel angles and different rotational speeds.To improve the heating effect of the asphalt mixture in the mixing furnace.Based on the interaction between the airflow and the asphalt mixture,the key influencing factors of the temperature distribution of the asphalt mixture are studied,which is of great significance to improve the heating effect of the asphalt mixture.The following research work was carried out for the structural parameters and mixing parameters that affect the heating effect of asphalt mixture mixing:(1)By testing the velocity and temperature of the hot flue gas at the burner outlet,determining the boundary conditions of the simulation inlet,constructing a simulation model of the temperature field of the heating furnace,analyzing the influence of structural parameters such as the height of the furnace wall,the angle of the inlet,and the thickness of the bottom plate on the temperature field of the hot flue gas in the heating furnace,and taking the average temperature of the eight outlets and the temperature of the hot flue gas at the cross section of Y=0.6M as the evaluation index,determining the height of the furnace wall as 375 mm The model parameters of the furnace with the best temperature distribution when the wall height is375 mm,the thickness of the bottom plate is 68 mm and the inlet angle is 18° are determined.(2)The JKR contact model and Heat Conduction model were selected as the two basic physical models in the simulation process,and various parameters of the asphalt mixture were derived through the stacking angle experiment and the measurement of the thermal properties of the asphalt mixture,and the temperature uniformity of the asphalt mixture at different rotational speeds and different mixing shovel angles were analyzed by the coupling of CFD and DEM,and the The temperature uniformity of asphalt mixture in the mixing kettle is better when the angle of mixing shovel is 45° and the mixing speed is 100 rpm parameter.(3)Relying on the enterprise pavement repair vehicle RWQ621 as the experimental object,the stirring and heating experiments of asphalt mixture with different speed in the stirring and heating furnace were completed,and the temperature data of the asphalt mixture measured by the on-board temperature controller and the experiment were collected,and it was determined that the simulation results and the experimental data had good consistency.The temperature of the asphalt mixture after paving was measured by zoning to further determine the uniformity of the asphalt mixture temperature.