Research On The Heat Effective Energy Transfer And Its Modeling In The Microwave Heating Process

As a new type of green metallurgy and material preparation method,microwave radiation heating technology has been listed as a new energy source and a technology to revitalize modern manufacturing by the US Department of Energy.Compared with the traditional heating method,microwave heating has the advantages of high heating speed,high energy utilization rate,selective heating and cleaning.But the temperature change of the dielectric material mainly depends on the distribution of electromagnetic field and the dielectric properties of the dielectric material and geometrical shape etc during heating.Various complicated factors can cause the heated medium to be unevenly heated or "thermal runaway",thereby reducing the utilization of microwave energy.Therefore,this degree paper is based on the National Natural Science Foundation of China project "Modeling and Optimal Control of Microwave and Polymetallic Mineral Interaction Processes"(61863020),conducting theoretical and experimental research on the utilization rate of microwave energy.This paper take the energy efficiency of microwave thermal effects in the interaction between microwave and solid materials as the object of study,used the "thermal-efficient energy" analysis method to analyze the energy efficiency of microwave thermal effects in the interaction between microwave and solid materials.This method can reflect the energy efficiency more accurately.By recognizing and understanding the energy conversion inside the heating process and quantifying the energy loss,the energy dissipation link can be obtained.It can more accurately obtain the temperature distribution and analyze the global efficiency of the heating process.In view of the energy efficiency of microwave heating,this paper aims to establish a model of thermal efficient energy transfer in microwave heating systems,and carry out numerical analysis and calculation of the model.Firstly,based on the relationship between energy and work,the effective energy of microwave electromagnetic energy is analyzed by combining Maxwell's equation,Poynting's theorem and resonant cavity wall loss.Secondly,establish the mathematical model of microwave heating.The three basic modes of heat transfer,heat convection and heat radiation are considered in the heat transfer process of the medium.According to the effective energy analysis method analyze the microwave heat energy transfer process,establish the microwave heat efficient energy transfer model,and carry out the numerical calculation of the mode to obtain the numerical calculation temperature of the microwave heat efficient energy transfer model and the general model.Finally,the microwave heating experiments of potatoes and ilmenite concentrate were carried out to measure the surface temperature of potatoes and ilmenite concentrate during the heating process.The comparison of numerical calculation temperature and the measured temperature of the proposed model and the general model show that the microwave thermal-efficient energy transfer model established in this paper has higher precision,which can more accurately express the heat efficient energy transfer process in actual microwave heating.Providing a theoretical basis for improving the microwave energy utilization rate and reducing the irreversibility of microwave heat energy.