Research And Simulation Analysis Of Electromagnetic Distribution Of Microwave Heating Cavity

Microwave heating technology is a new type of heating technology which developed rapidly in recent years.Compared with the traditional heating technology,microwave heating has the following characteristics:Instantaneity?High efficiency?Selective heating?Energy conservation and Environmen protection.In order to be able to make better use of microwave heating technology,we should to design a high power density and good uniformity of field of the microwave heating cavity and understand the electromagnetic distribution of the microwave heating cavity.In this paper,we study the calculation of the electromagnetic of microwave heating cavity,and analyse the influence factors of cavity field distribution and microwave heating efficiency by simulation software.Provide a reference for designing cavity and microwave heating applications.The main research content is summarized as follows:Firstly,based on the finite difference time domain method(FDTD)with two kinds of different boundary conditions PEC and PML calculate the electromagnetic distribution of rectangular cavity.The results show that the reflection of PML boundary conditions is very weak,the reflection of PEC boundary conditions is strong.With PEC as the boundary conditions for solving the electromagnetic field distribution in microwave heating cavity is more suitable.Secondly,this paper analysed the factors of the distribution of the microwave heating cavity by the CST simulation software.The simulation results show that multi-source can improve the power density and uniformity of the field distribution.Orthogonal opening direction can decrease the coupling between the excitation source.The distribution of excitation source on the cavity has a greater influence on the electromagnetic field of cavity.We optimized the distance between the excitation source.Lastly,this paper studied the influence of load dielectric characteristics on heating efficiency and the electromagnetic distribution of cavity.With the load placed,the electromagnetic distribution of cavity is changed a lot.Different loads have different influence.By changing the load dielectric constant and loss tangent,variation of dielectric constant of the load has a little influence on the ability of load absorbing microwave,and has greater influence on the electromagnetic distribution of cavity.Dielectric constant is large,the value of electromagnetic is bigger.Beyond a certain range,the ability of load absorbing microwave decreased with the loss tangent increased,it has little influence on the distribution uniformity of the cavity.The ability of load absorbing microwave is proportional to microwave frequency.Lastly,we heated allochroic silicagel by microwave and got the temperature distribution in different position.The experimental results and the numerical results show that the simulation results have higher credibility and provide a reference for designing cavity and microwave heating applications.