Research And Application On Distributed Control System For Alkali Recovery Of Papermaking

Our country is a papermaking powerhouse, and paper can produce a kind of calling black liquor pollution, direct emissions will not only cause the waste of resources, but also serious environmental pollution. Papermaking chemical recovery can not only reduce environmental pollution, to form a good social benefits. And at the time of recovery from the black liquor caustic soda preheated to generate electricity, has very high economic benefits. Since12th five-year Plan, the State vigorously promote energy conservation and emissions reduction, and our country papermaking chemical recovery plant automation level is low, operation maintenance cost is high not only reduces the enterprise benefit and do not conform to the country’s long-term interests, thus developed a high level automation, stable and reliable, suitable for China’s national conditions of alkali recovery automatic control system, has the very vital significance.In order to make the process of alkali recovery in harsh industrial environments, continuous, stable, reliable and accurate, the requirement of control system has higher requirements than the general process control system. The topic is based on a alkali recovery project in sichuan as the research background, and designs a set of high levels of monitoring and control system for the alkali recovery workshop. The system consists of computer management, evaporation subsystem, subsystem of combustion workshop workshop. The topic is designed based on Siemens SIMATIC PCS7the hardware and software of the distributed control system, and according to the characteristics of the combustion workshop process design based on xinhua Tisnet-XDC800distributed control system, realizing the intearation of management and control.This article first introduces the alkali recovery process, and then puts forward the system based on the requirement of process control.In view of the system control requirements, the analysis of the various control system after the system control scheme is proposed. Then the management level, control level, field level automatic control equipment are designed and selected on the part of the hardware system, in view of the high reliability requirement, combustion workshop system from the controller to the IO channel according to1:1redundant design; In the of the software system,this topic narrates the hardware configuration, control, programming and the development of the monitor screen in two sections, and it is difficult for black liquor concentration, and the boiler liquid level control variable control strategy is analyzed and the preparation of the control program. Finally, this system is described in detail in the industrial field debugging method in practical application.