Simulation Study On The Heating Characteristics Of Square And Triangular Lattice Photonic Crystal Microwave Reactors

Microwave heating has the characteristics of fast,transient and easy to control,and is widely used in food processing,industrial production,medical treatment and many other fields.However,the traditional microwave reaction cavity has the problem of low heating efficiency and poor heating uniformity,which directly leads to low production efficiency and general low quality of related products that hinder the promotion of microwave heating as a green energy utilization method.Photonic crystals also have energy band characteristics in the microwave band,which can have a restraining effect on electromagnetic waves of specific frequencies and modes.By introducing it into a conventional microwave reaction cavity,the electromagnetic waves can be fully or partially confined.When combined with appropriate modulation,this can have the effect of improving the heating efficiency and uniformity of microwave heating.In this paper,we present a detailed analysis of the electromagnetic theory,the energy band theory,the resonant cavity theory and the microwave heating theory of photonic crystals,based on the special energy band electromagnetic characteristics of photonic crystals,loaded square and triangular lattice photonic crystals into conventional cylindrical and rectangular microwave reaction cavity,designed and investigated the effect of cylindrical and elliptical cylindrical aluminum trioxide ceramic photonic crystal unit.The main research works are as follows:(1)Using the Maxwell equations to analytically calculate the energy band properties of the six photonic crystal structures near 2.45 GHz,we obtained the pass/no pass band solutions in the commonly used microwave heating band(2.4 GHz-2.5 GHz).(2)Based on the specific parameters of the obtained photonic crystals,we designed constrained TM mode microwave reaction cavities for square lattice cylindrical/elliptical photonic crystals and triangular lattice cylindrical/elliptical photonic crystals,and investigated the heating efficiency and uniformity of these cavities in five heating modes(static heating,dynamical defect point heating,multiangle discrete heating,turntable heating,and verification heating).The research result showed that both the heating efficiency and the uniformity are superior to the microwave reaction chamber without the loading of photonic crystals.(3)Study and calculation of the structures of TE mode band gap and full mode band gap of photonic crystals,based on the design of a square lattice bar shaped photonic crystal microwave reaction cavity with constrained TE mode and a triangular lattice honeycomb shaped photonic crystal microwave reaction cavity with constrained full mode,and study the heating efficiency and uniformity of the two types of microwave reaction cavity.The research results indicate that the introducing of appropriate structure of photonic crystal into the microwave reaction cavity can improve the microwave heating efficiency and heating uniformity,which provides a method and evidence for the design of new photonic crystal microwave reaction cavity.