Research On The Method Of Structural Design For Swirl Aggregate Drying Pulverized Coal Burner

Aggregate drying is an important step in the asphalt mixing process.The heavy oil,light oil,diesel oil,natural gas and coal water slurry are used as fuel in aggregate drying burner at present.If pulverized coal is used as fuel,the operating cost of the aggregate drying process can be greatly reduced.Due to the swirler can intensify the mixing of fuel and oxygen,and it is easy to improve the efficiency of pulverized coal combustion,the research on the design of the swirl aggregate pulverized coal burner has been carried out.Analyse the process of aggregate drying and thermodynamic requirements to establish a reasonable mathematical model for coal combustion behavior,and evaluation indicators.To explore the effect of swiler structure on combustion efficiency and NO emissions,and optimize the parameters of the key structure for swiler.Then,a multi-parameter and multi-objective coupling design method was proposed based on the Isight platform,and to design the structure of the swirl aggregate pulverized coal burner use this method.The specific research content is as follows:1.Based on the process of aggregate drying and the mechanism of pulverized coal combustion,the mathematical model for the combustion behavior of pulverized coal was constructed,and a swiler was initially designed.Combining the process of aggregate drying and the mechanism of pulverized coal combustion,the standard k-?model is used to describe the turbulent movement of pulverized coal,the P1 model is used to describe the heat radiation in the pulverized coal combustion process,and the stochastic trajectory model is used to describe the movement trajectory of the pulverized coal particles,the kinetics/diffusion-limited model is used to describe the combustion of coke.The axial straight-bladed swirler was designed as a design object,and its structure was initially designed.2.Explore the effect of structure parameters of swirler on the behavior of pulverized coal combustion.Combine with the main design parameters of the swirler,the control variable method was used to analyze the effect of swirler outer diameter,number of blades,and the installation angle of blade on the mass fraction of CO₂,CO,NO,and the internal particle trajectory of the burner.3.The structure of the swirler is optimized.Taking the outer diameter of the swirler,the installation angle of blade and the number of blades as optimization variables,the Box-Behnken method was used to design the test,and a dynamic response model of combustion efficiency and NO emission was established.The structure parameters of the swirler were optimized by the method of NSGA II in Multi-objective optimization.4.Based on the Isight platform,a multi-parameter and multi-objective coupling design method was built with 3D modeling,meshing,numerical simulation and parameter optimization.Taking the swirl aggregate pulverized coal burner as a design example,a multi-objective coupling design with a total of 10 parameters of structural parameters and control parameters is completed.The research results of this thesis will provide theoretical support for the development of aggregate pulverized coal burners.