Microwave Heating Simulation And Simulation Accuracy Improvement

The microwave heating principle was discovered more than 60 years ago,and various kinds of microwave ovens showed the great potential of this heating-type.And now the application of microwave heating has no longer been limited to the use of kitchen appliances,it is also widely applied in the industrial,agricultural,chemical,medical and other industries.The research of microwave heating has been greatly promoted by the intensive study of the application,the development of cross disciplines and the generation of a variety of devices with excellent performance.Microwave oven is the most common microwave heating equipment.The upgrading of its core technology will undoubtedly promote the development of the microwave heating project.It is significant to improve the microwave performance,the structure,the production process and even the cost.The traditional research methods are iteratively updated in the old generation of products,improving the performance of a component or a matching system by experiments and modifying by experience and electromagnetic simulation software such as HFSS adjusting the structure,increasing the new materials and so on,until a basic performance index is reached.It has made a series of achievements with the increasingly sophisticated functions of simulation software.But there is no more mature electromagnetic simulation theory and reliable data in the most intuitive actual heating effect such as microwave heating uniformity and efficiency because of the limited development of simulation technology and other factors.Those problems are derived from the complex load characteristics of microwave source,the specific food model and the electromagnetic thermal parameters which are difficult to determine.This paper start from the principle of microwave heating and device,using the HFSS and workbench simulation software and experimental test to explore the process of microwave heating water,oil and mashed potato by existing microwave oven products,getting the specific microwave heating uniformity data.Meanwhile,an electromagnetic thermal coupling simulation method is established and then improved by studying the change of microwave frequency of microwave source,and obtaining the simulation data.By measuring the operating frequency of the magnetron and optimizing the simulation model,the simulation results show that the uniformity of microwave heating for five cups of water is about 76.75%,which is close to the measured value of 71.88%.The simulation results by improving the frequency using VSWR show that the heating uniformity of five cups of oil temperature is 65%,which is within the range of the measured value.In the same way,through the simulation of VSWR to improve the simulation frequency,the simulation temperature of the microwave oven heating mashed potato can be compared with the measured temperature.The simulation data are close to the experimental data,which confirms the feasibility of the simulation method for the uniformity of microwave heating.