Simulation And Experimental Study On Rotary Microwave Heater

Since the invention of the microwave oven in the early 20 th century,the microwave oven has been greatly developed in various industries because of its high efficiency,low loss,and selective heating.However,microwave heating,like conduction heat transfer,also has the phenomenon of uneven energy absorption.Therefore,it has been a focus of many scholars to improve the efficiency of microwave heating and improve its uniformity.Among many methods,rotary heating is widely used because it can improve the uniformity of heating.However,the traditional rotary heating method has little improvement on heating efficiency,especially for heating objects with poor conduction performance.The heating efficiency and uniformity are challenging to be effectively improved.To solve this problem,based on the microwave heating principle and multi-physical field calculation method,the rotating heating method is studied,and a more efficient and uniform microwave heating method is proposed.The method increases the constant velocity movement in the vertical direction based on keeping the turntable’s horizontal rotation,and the motion is in the spiral ascending and descending state.The heating object can absorb relatively uniform microwave energy from the unit time at each position of the heating object and finally improve the heating uniformity and efficiency.The main work of this paper is summarized as follows:(1)The related theories of the microwave heating principle are summarized,including the characteristics of the microwave,heating principle,waveguide excitation,standard numerical calculation methods of microwave heating,and the application of simulation software.(2)Based on the research of traditional rotary heating methods,this paper establishes a spiral rotary heating model and compares the heating effects of the two methods through simulation.For ordinary rotary heating,the influence of dynamic adjustment of rotation direction on heating effect is studied.It is concluded that the adjustment of rotation direction has little influence on heating efficiency and heating uniformity.Traditional rotary heating can only significantly improve the same layer’s efficiency and uniformity,but the heating effect in the vertical direction is lacking.Therefore,we consider changing the space level,put forward a new spiral heating method,and discuss the influence of the change of ascending and descending rate on the heating efficiency and uniformity.Finally,we compare the effect of ordinary rotary heating and spiral rotary heating and conclude that the spiral heating simulation results have higher heating efficiency and uniformity than ordinary rotary heating.(3)The corresponding experimental system is designed and built through multiphysical field analysis,and the experimental results of traditional rotation and spiral rotation heating methods are further compared.The results show that there is an apparent delamination phenomenon in the object heated by rotation,and the spiral heating device can better make up for this delamination phenomenon to improve the heating efficiency and heating uniformity.