Numerical Simulation And Control Research Of Tunnel-type Multi-microwave Source Heating System

Due to its unique heating mechanism,microwave heating has many incomparable advantages over traditional heating and has shown great application value in industrial applications.Due to the complex structure of the industrial microwave heating system,the coupling of multiple physical fields in the heating chamber,the variation of dielectric constant and physical properties of the medium with temperature,and the limited parameters that can be obtained during the heating process,these factors greatly increase the difficulty of the practical application of microwave heating.Tunnel microwave source heating system,the author of this paper medium heating drying process,based on the physical field simulation software in the process of microwave heating the influence of various factors on medium heat and heating mode is analyzed,and put forward reasonable control strategy according to the optimization of heating mode to control the microwave source power,complete medium heating drying.The main research contents are as follows:(1)Based on numerical simulation,the influence of various factors on the heating of media in the heating process was studied to obtain the optimal parameter combination of the multi-microwave source heating system and improve the heating uniformity of media.Combined with the basic theory of electromagnetism and heat transfer,the electromagnetic field model and heat transfer model were derived.The simulation software COMSOL Multiphysics was used to simulate the tunnel multi-microwave source heating system.The simulation model was established according to the equal scaling of the actual equipment to compare the difference between the media heating in the moving and static state of the transmission belt.The influence of microwave power,the number and combination of feedports,the transport speed of the conveyor belt,the thickness of the media and other factors on the media heating in the microwave heating process was successively explored.After a clear understanding of the influence of various factors on the temperature distribution of the medium,the parameters are constantly changed according to the experiment and simulation to find the optimal parameter combination suitable for the microwave heating system.(2)Based on the simulation analysis,a reasonable and efficient control strategy is proposed to achieve the heating target of the media.According to the simulation analysis results and control targets,the controlled object is reasonably simplified,and the control object of the tunnel-type multi-microwave source heating system is determined as the No.5 microwave source in the No.3 cavity.In the heating process,the power of No.1,2,3 and 4 microwave sources is fixed to preheat,and the heating target is achieved by real-time control of No.5 microwave source power.According to the controlled temperature rise curve using ARX(autoregressive traversal)identify system mathematical model,based on the mathematical model successively introduced fuzzy adaptive algorithm,an improved BP neural network and genetic algorithm to enhance the performance of the PID controller,compared the advantages and disadvantages of four kinds of algorithms and the control performance,finally through the experiment verify the validity of the algorithm.