Design And Experiment Of Calender Heating System Based On Electromagnetic Induction Heating

In order to apply the calender to a variety of processing fields such as leather,non-woven fabrics and body armor materials,the temperature zone of the calender heating roller needs to be improved.However,the traditional heating method can only reach a limited temperature and it is difficult to meet the calendering temperature requirements.The electromagnetic induction heating has high heat conversion efficiency,which can effectively increase the temperature of the heating roller surface and reduce the preheating time.Therefore,this thesis chooses electromagnetic induction heating as an alternative heating method,and completes the heating of the heating roller by the induction heating power supply.The main research contents of this thesis are as following:(1)It has finished the factors that affect the heating temperature.determined the heating scheme and completed the three-dimensional modeling according to the heating scheme.According to the electromagnetic field theory,a mathematical model was established,and it is concluded that the heating temperature is mainly related to the magnitude and frequency of the current flowing through the induction coil and the distance between the induction coil and the heating roller.Combined with the characteristics of electromagnetic induction heating,the heating scheme was determined,and the three-dimensional modeling of the heating scheme was performed using Solidworks.(2)The main circuit structure of the induction heating power supply was determined,and the parameter calculation and selection of the main circuit components were completed.By analyzed the characteristics of the series resonant inverter circuit and the design requirements,a half-bridge series resonant inverter circuit was selected as the main circuit structure,the load to work in a small inductive state.The influencing factors of the output power of the induction heating power supply were analyzed,and through comparison of several power adjustment methods,the DC side chopped power adjustment was selected as the power adjustment method.It was determined that the main circuit was composed of three-phase uncontrolled rectification,chopping,half-bridge inverter,and resonant circuit.The parameters of each circuit device were calculated and selected according to the design requirements to provide data support for the construction of the induction heating power model.(3)Power closed-loop control and frequency phase-locked tracking circuit was designed,and a simulation model was established in Matlab/Simulink,then simulations are conducted.According to the driving requirements,it has selected the inverter circuit drive module,designed the chopped power regulation closed-loop control scheme,and utilized the phase-locked loop circuit to achieve the capturing and tracking of the operating fr-equency.Setting up a half-bridge series resonant induction heating power supply simulation model in Matlab/Simulink to simulate it.The simulation results verify the feasibility of closed-loop control of chopped power modulation and frequency phase-locked tracking.The design of the induction heating power supply meets the control requirements.(4)Setting up an experimental prototype,the heating experiment under different working parameters are completed,and the results are analyzed.Based on the model established in Solidworks,a simple experimental prototype was built,and the output power of the induction heating power,the distance between the induction coil and the heating roller,and the surface speed of the heating roller were selected as the influencing factors.Single-factor and multi-factor orthogonal experiments were performed.The experimental results show that the influence of power and spacing on heating temperature is large,but the effect of linear speed is not obvious,the designed prototype can meet the heating requirements of the calender heating roller.