Research On Temperature Uniformity Optimization Of Microwave Heating System Based On Consistency Algorithm

As an efficient heating method,microwave heating has been widely used in various fields of industrial production.However,the internal heat transfer mode and the random distribution of hot spots of microwave heating make it difficult to obtain the accurate temperature by conventional measurement.The hot spots are mainly due to the uneven distribution of electric field in the resonant cavity and the nonlinear coupling relationship between the properties of the sample and the temperature.At present,in the research of microwave heating optimization design,the designed radiation singlemode stirrer microwave heating system and the analysis and calculation model of the sample movement heating method can improve the uniformity of temperature distribution to a certain extent and reduce the generation of local hot spots.Due to the deep coupling of the multiple physical field and the time varying characteristics of boundary conditions in microwave heating system,the focuses have been on how to coordinate the state characteristics of the mode stirrers and effectively calculate the temperature field to carry out the optimization of temperature uniformity.Therefore,under the support of China's National Natural Science Foundation Project "Modeling and Optimal Control of Microwave and Polymetallic Mineral Interaction Process"(61863020),theoretical and experimental researches on the optimization and calculation of temperature field of microwave heating system are studied.Based on the single-mode stirrer microwave heating system and sample motion heating optimization method,this thesis further explores the temperature uniformity and calculation problems of the microwave heating system with multiple mode stirrers and the microwave heating process in which the sample moves according to different trajectories.The consensus algorithm has been used to describe the state information of the mode stirrers,and the optimal value of the uniform distribution of the temperature field can be effectively worked out.The temperature finite element model of the sample movement heating and the formation transformation process of the mode stirrer is constructed from the optimization problem of mixing integer variables and continuous variables,and effective calculations are carried out for the optimal solution of the uniform distribution of the temperature field.The main research process is summarized as follows:(1)The time-varying field boundary conditions of the electromagnetic in heated space are characterized by formation,and the transformation formation is expressed by the combination of position and state information of mode stirrers.(2)The microwave heating process was divided by time,the position of the mode stirrer was updated between adjacent time steps,and the time step inheritance method was used to fit the continuous changes of the electromagnetic field and the temperature field.(3)The finite element model of the electromagnetic field,temperature field and the microwave heating process of the sample movement were established and the numerical calculation was carried out.The research on the optimized trajectory of microwave heating samples is extended to three-dimensional space,and the uniformity of temperature distribution between different sections and the optimization effect of microwave heating efficiency are compared and analyzed.(4)The sample motion heating optimization calculation model is combined with the multi-mode stirrer microwave heating system to achieve further optimization of the temperature field distribution and microwave heating efficiency.The results of numerical calculation show that it is feasible,efficient and accurate for the proposed consensus algorithm and its calculation method to optimize the uniformity of temperature distribution of microwave heating.