Research On Heat Transfer And Temperature Control Of Machine Barrel Of Extruding Granulator

Large extruding granulator is the core equipment for producing resin,rubber and synthetic fiber.High productivity,high reliability and high adaptability are the development trend of large extruding granulator.Because of its complex structure,high requirement for technological parameters and strong compatibility,large extruding granulator is difficult to be designed and manufactured.At present,domestic manufacture of the large mixing extruding granulator is still a blank,which results in the nation relying on imports for a long time,so it is urgent to realize its localization.As the core part of large extruding granulator,the cylinder rotor system works in the environment of high temperature,high speed and high load,Influenced by many heat sources,such as heaters,friction and shear,the temperature presents the characteristics of large lag,overshoot and nonlinearity,The conventional PID system can not get the desired control effect,which results in the produced materials' low rate of reaching the standard.Therefore,it is of great significance to ensure the normal operation of the whole equipment by studying the heat transfer and temperature control of the barrel of extruding granulator.(1)Based on the finite element method,the model of cylinder is established in the Fluent simulation software.With the simulation and analysis of the preheating and cooling process of the barrel,the characteristics of temperature nonlinearity and large delay are further determined,which lays the foundation for further research.(2)First,the parameters of the system model are identified based on step response curve method.Then,aiming at the problems of temperature fast change,nonlinearity and lag delay in the system,PID control has the characteristics of simple structure and fast response,It combines the advantages of fuzzy control with adaptive ability.the machine barrel's temperature controllers of the conventional PID,integral separation PID,incomplete differential PID and fuzzy PID are designed respectively.At the same time,a variable universe fuzzy PID machine barrel temperature controller is designed with the idea of variable domain control,which solves the contradiction between control rules and system complexity in fuzzy control.Finally,with the control system model of PID control,fuzzy PID control and variable domain fuzzy PID control constructed based on the system mathematical model in the Matlab\Simulink environment,the characteristics of each controller are simulated and analyzed.(3)The experimental control system is designed based on STM32 microcontroller and LabVIEW test software.Based on the idea of modularization,the functional modules of the control system are divided reasonably,and the hardware and software parts of the system are designed respectively.At the same time,in order to facilitate system debugging and monitoring,a temperature monitoring software system is designed based on LabVIEW.Finally,on the experimental platform of machine barrel,the control algorithm and control system are verified through the temperature control experiment.