Research And Design Research Of A Curved Waveguide Slot Array Heating Structure

As a clean energy source,microwave has received much attention in recent years,and microwave heating is an important direction for the application of microwave energy.Compared to traditional heating methods,it has advantages of selective heating,high heating efficiency,and easy control,which make it widely used in various fields.However,in actual industrial production,the application of high-power microwave sources in heating equipment may result in uneven heating of materials due to uneven distribution of electric field in the resonant cavity and differences in the ability of heating materials to absorb microwaves,which reduces the effectiveness and safety of microwave energy application.Especially for strong absorbing materials in industrial heating,due to their physical characteristics of the heating rate is fast during the heating process.However,if the temperature is too high,problems such as damage and burning of the heating material can occur.At the same time,uneven distribution of the electric field can cause local hot spots in the material.Therefore,this paper designs a curved waveguide slot array heating structure that utilizes the slot waveguide array to couple electromagnetic fields with the heating cavity.By generating multi-mode electromagnetic fields in the resonant cavity,the uniformity of the electric field distribution in the cavity is improved,thereby achieving the goal of improving the uniformity of material micro wave heating.The specific research content is as follows:1.Studied the basic principle of microwave heating.Introduced the fundamental principle of microwave heating and the influence of dielectric constant on the heating process.Studied the basic theories of electromagnetic fields and heat conduction control equations involved in the microwave heating process.Introduced the main structural components of general microwave heating equipment: magnetron,waveguide,and resonant cavity.The coupling method between the waveguide feed source and the resonant cavity was studied,and the waveguide wide edge slot array coupling method was ultimately adopted.2.Starting from the relevant theory of resonant cavities,the influence of key design parameters of cylindrical heating cavities on resonant modes was studied.The optimal design parameters of resonant cavities were obtained by comparing the electric field uniformity and heating uniformity of different sizes of resonant cavities.3.For the design of waveguide slot arrays,the effects of parameters such as slot length and spacing on the performance of the heating structure were simulated and optimized.The positions of the slots were designed using the theory of uniform distribution and Taylor distribution.Finally,two curved waveguide slot array heating structures were obtained.To verify the improvement of this design method in addressing the issue of uneven heating,a comparative study was conducted with traditional box single feed heating cavities of the same power density.4.Selecting strong absorbing material rubber as the heating material,and comparing it with traditional heating structures,it is shown that the curved waveguide slot array structure designed based on the theory of uniform distribution and Taylor distribution,although the heating speed is relatively slow,can effectively control the heating process of the material and avoid hot spot problems due to the rapid heating characteristics of strong absorbing materials,And the coefficient of temperature difference of these two structures reached 0.68 and 0.70,respectively,of which the uniformity increased by 50% and 51.4% compared to traditional box microwave heating structures.5.The feasibility of this design was further verified through data analysis and comparison of heating different types of materials and different shapes of the same material in two heating structures.