Research On Control Of Electrothermal Nano-iron Powder Decomposing Furnace Under Variable Conditions

Nano-iron powder has been widely used in the fields like magnetic recording,gas sensor,light absorbing material and high efficiency catalysis because of its special properties in magnetism,light,electricity and sensitivity.Nano-iron powder electrothermal decomposition process and the structure of decomposing furnace are analyzed in this paper.The importance of decomposing furnace temperature control and the necessity of variable condition constraint are elaborated.Nano-iron powder decomposing furnace is cascaded by four partitions according to the process requirements.Different partition temperatures couple with each other during the operation of decomposing furnace.Temperatures of each partition are now manually given by experience interiorly and there is no corresponding temperature prediction technology.Each partition is also designed to be controlled by separate controller,which cannot meet the requirement of coordinated control and result in a high energy consumption.The nano-iron powder grain products cannot come up to expectation because of the low control precision of decomposing furnace.The following studies are carried out based on Jilin Jien Nickel Industry Co.,Ltd100t/y nano-iron powder production line in this paper to realize the control of decomposing furnace under variable conditions:Firstly,nano-iron powder electrothermal decomposing furnace temperature prediction model under variable conditions based on T-S fuzzy and SAPSO-ELM is built.The prediction effect of this model is tested and the experiments verify its accuracy and generalization.Then,the incremental digital PID is introduced to be the controller of nano-iron powder electrothermal decomposing furnace temperature control system which is based on cascade PID control.The system is tested by simulation and the results show that the system has good control effect.Finally,the basic structure of nano-iron powder electrothermal decomposing DCS is analyzed.The hardware and software of the nano-iron powder electrothermal decomposing furnace temperature control system built in this paper are designed.The nano-iron powder decomposing furnace temperature control software is developed based on MFC graphical programming which is on account of VC++6.0 to apply the research findings in this paper to industrial production.The nano-iron powder electrothermal decomposing furnace temperature prediction model under variable conditions based on T-S fuzzy and SAPSO-ELM can effectivelyreflect the change of decomposing furnace working conditions and make accurate prediction of decomposing furnace temperature.The nano-iron powder electrothermal decomposing furnace temperature control system based on cascade PID control can realize the coordinated control of multiple decomposing furnace partitions,which solves the problem that the temperature of every partition couples with each other.