Design And Study On Advanced Control System Of The Chemistry Process In Batch Reactor

Fine chemicals are the special chemical products with nature of small-quantities, multi-speciesand high additional value. At present a chemical procedure which named batch reaction is used inmajor ifne chemical product process industry. Reactor is the most common and cirticalequipment in the process of ifne chemical production. Beacause of the complicated reactionmachenism,the batch reactor has characteirstics of time-vairant, pure delay and nonlinear, andhas been a hot spot for research in the ifeld of process control. Especially the tempetature controlresult impacts directly on the quality of products and economic beneifts of production.According to the process charateirstics of the DME production batch reactor in a company inLianyungang, this paper designed a batch reactor advanced control system consisting of IPC,PLC and RS-232C. For this distirbuted control system, OMRON PLC executed the basic controlfunction, IPC was the operator station to management information and realize the operation ofintelligent control algorith method off-line. The way of data access between PLC and IPC wasrealized by RS-232C technology. The hardware composition and software conifgruation of theadvanced control system laid a good foundation for the realization of the engineeirng.Through the analysis of the heat-balance principle and the heat-transfer relation between batchreactor, this paper established mathematical model of temperature inside the batch reactor by themethod of comprehensive analysis. Traditional PID control has many advantages of a simplecontrol pirnciple, good stability, high reliability and easy adjustment of parameters. But thedesign of objects depends on the precise mathematical model, and there are modeling and controldiiffculties in batch reactor. For these problems, the general PID controller can not be achievedon the precise control of batch reactor. Fuzzy control does not need the precise mathematicalmodel in the design with quick response, short-time transient, good robustness. But there aremany parameters of fuzzy controller must be designed and the adjustment is complicated, thefuzzy controller can not be the optimal replacing scheme. In order to solve the problems, theFuzzy-PID controller had been designed. Through the comparison of the setted temperature valueand measurement temperature value to get the difference which is error. Adopting differentcontrol method accroding to the error. Using fuzzy controller when the error is too large andusing PID controller while the error is too small. The Fuzzy-PID control system has more stablecontrol performance, higher reliability, and the real-time performance, adaptability, robustnessare increased, and the static and dynamic characteirstics of the control system improved.