| Many countries are paying more attention to sewage sludge effective treatment and residues utilization, while the low temperature pyrolysis of sludge is a new sludge treatment technology which developed in recent years. The control of the Rotary Pyrolysis Kiln not only ensure both the stabilization of produce and equipment's safety, but make the process to an optimal state, which can reach to the aim of high quality, high efficiency, low consumption. It is a grand strategy task to increase the control level of the Pyrolysis Kiln, put the advanced control system and control strategy to the process of produce.This paper introduced characteristics and development of programmable controller first, according to the technical requirement of Pyrolysis Kiln, this paper presents a control strategy that is DCS control system. PLC completed the collection and disposed of data, and accepted computer's instruction so that could export signal to complete kinds of control function. The PC completes the stakeout, control and so on. The hardware and software has been designed. The selection of the industrial control compute and PLC ware completed. PC monitor software adopts "King View" industry control software, which is designed to realize collecting data, alarming, report forms and database. PLC chooses to use the programmable controller of the Siemens S7-300; the control procedure was made use of STEP7 software by the place of honor machine to write. The system communication strategy also has been designed. The network structure of Pyrolysis Kiln control system is a top and bottom two layers of network. The upper level adopts the industrial Ethernet. It uses for the communication industrial control computer and each of station with main PLC. The first floor adopts the PROFIBUS the spot total line with 12M. It uses for a conjunction to the inverter machine, intelligence gauge and weaving a distance machine.The Rotary Pyrolysis Kiln calefaction system is a complex control system. Especially the temperature has bigger delay. The design improved traditional PID, combined intelligence fuzzy control and tradition PID. The fast dynamic respond and stabilization temperature can be obtained through used the fuzzy PID self regulating control strategy. At the same time, this article carried on the simulation experiment with this control method in MATLAB. We obtain the result that uses the fuzzy self regulating to decide the PID control can satisfy the design proposal.Finally, for the need in industrial production, this article uses STEP7, the software for S7-300 PLC, realize the fuzzy self regulating PID control algorithm through the programming way. It used the off-line to compute the fuzzy questionnaire, used the on-line inquiry for the output of the fuzzy control quantity, and then added the PID parameter and datum value, obtained the PID parameter fact value, finally carried on the PID operation and obtained the controlled member actuator.The heat transfer part of the system has the following problem during application test, that is, heat exchangers working for some time, its ability of transfer heat decreases. So it fails to obtain the heat transfer purpose. To solve this problem, the temperature data has been processed using "King View" industry control software. This article also carried on the simulation experiment in lab, and it proved this method had achieved the alarm function. |
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