| As one kind of new and high-performance materials,carbon fiber has attracted more and more people's attentions.In recent years,the carbon fiber industry in china has developed greatly.However,comparing with the advanced technology at abroad, there still has significant difference between domestic and foreign processing technology.In this paper,we choose the pre-oxidation equipment of carbon fiber as the breakthrough point,then analyze existing problems in this area,and propose the corresponding solutions.This paper mainly completes some work in the following aspects:(1) A new control system,which is based on programmable computer control, was designed according to the complicated characteristics of the carbon fiber production process and various control parameters.Some characteristics of this system,such as distinctive real-time multitasking operating,powerful network communication ability and friendly programming platform,enables this system to handle many kinds of field control tasks very well.At the same time,the system takes the solutions of mixing visual and control,which display the control of processing technology directly on the operation screen.This kind of design greatly facilitates the operation of technical staffs.(2) The characteristics of pre-oxidation furnace heating process,i.e.large inertia,pure time-delay and non-linear,leads to the instability of controlling temperatures and poor controlling effect.In this paper,the intelligent fuzzy control and reliable PID control were integrated and a kind of parameter self-tuning fuzzy PID controller was designed,which uses fuzzy inference methods to achieve PID parameter tuning online.And professional software Matlab was used to verify simulation.The results showed that this strategy could control temperature precisely, perform smoothly,eliminate outside interference quickly,and complete the task of controlling temperatures perfectly. (3) According to the characteristics of pre-oxidation technology,a new type of pre-oxidation furnace project was designed.The furnace setting consisted of ten temperature zones,and every two of them belong to one system.At the same time, blowers which were adopted to form warm wind circulation and the wind deflector enabled the temperature field distribution in pre-oxidation furnace more uniform. Plus,professional liquid software- Fluent was used to simulate and calculate.The final result revealed that the whole temperature field distribution was uniform,and the fluctuation of interior temperature in pre-oxidation furnace was controlled less than 0.5℃,except little temperature blind- area in corners.(4) The application of new type of pre-oxidation equipment in practically processing process was analyzed.A lot of experiments were carried out according to the pre-oxidation processing parameters of PAN carbon fiber in this lab.The characteristics of resulting pre-oxidation fibers were detected by microscope,SEM, XRD and FTIR.The results showed that:this equipment practically runs well,and all characteristics of pre-oxidation carbon fiber which were produced by this equipment achieved desirable requirements.The carbon fiber production lines based on this subject has been run successfully in a cooperative enterprise.Through this production line,many experimental groups taking silk have been carried out,and the characteristics of pre-test related oxygen silk are detected and compared with that of conventional technology.Actual results show that the overall design of the production line is reasonable and operates stably;the control system is easy to operate and has high precision;optimized pre-oxidation furnace reached to shorten the pre-oxidation time;the productivity of carbon fiber is enhanced and the purpose of reducing power consumption is achieved.
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