Design Of Control System For Electromagnetic Induction Heating Of Carbon Fiber Composite

Carbon fiber composite is widely used in aerospace,military industry,automobile,industry,energy and chemical industry because of its high specific rigidity,high specific strength,corrosion resistance,easy forming and good conductivity.In the manufacturing process of carbon fiber composite materials,it usually needs to be heated and solidified.However,the traditional heating and curing methods,such as heat convection and heat radiation,have some disadvantages,such as uneven heating,poor forming effect,high energy consumption and slow heating speed.Due to the conductive property of carbon fiber,induction heating of carbon fiber is used to realize resin curing and fiber composite.This method can shorten the production cycle of carbon fiber composite products,realize the heating of the whole composite,and ensure the uniformity of the overall temperature distribution of the induction heating of carbon fiber composite.In this paper,the principle of induction heating of carbon fiber is studied,the rule of temperature field of induction heating is analyzed,and the temperature control system of induction heating is designed to realize the solidification of carbon fiber.Based on the theory of electromagnetic induction and heat conduction,the simulation model of induction heating of carbon fiber composite laminates is established by using the finite element numerical analysis method and the COMSOL finite element analysis software.The distance between the coil and the laminate,the volume fraction of carbon fiber in the laminate,the frequency of induction heating and the influence of heating coil diameter on the temperature field distribution of carbon fiber composite laminates during induction heating.The results show that with the decrease of the distance between the coil and the laminate,the heating temperature amplitude increases;with the increase of the carbon fiber volume fraction in the laminate,the more uniform the temperature field distribution is,the greater the heating temperature amplitude is;with the increase of the induction heating frequency,the average heating rate of the heating temperature increases,but the change of the frequency will also affect the uniformity of the temperature field distribution;with the increase of the coil volume fraction,the more uniform the temperature field distribution is With the increase of the diameter,the diameter of the annular high temperature region increases,and the area of the central low temperature region increases.In order to realize the precise temperature control of carbon fiber electromagnetic induction heating,the transfer function models of the control system,such as induction heating power supply,induction heating coil,induction heating carbon fiber composite material and control system,are analyzed,and the incremental PID algorithm is adopted to realize the closed-loop temperature control of the electromagnetic induction heating system.According to the requirements of temperature control in carbon fiber curing process,the design of constant temperature control strategy for induction heating is completed,and a carbon fiber curing temperature control system based on infrared temperature detection,PLC and digital electromagnetic induction heating power supply is built.The results show that the control system is stable,the temperature field of carbon fiber composite laminates is uniform,and the temperature control effect is good.