Research And Realization Of Control Strategy For One-through Boiler Based On Multifuel Co-Firing

The multi-fuel co-firing one-through boiler, built by BAOSTEEL with Germany advanced technology, can increase gas comprehensive utilization and reduce pollutant emission, thus playing an important role in the "energy conservation and emission reduction" strategy for enterprise. The boiler is featured by unique technology and complexity of device, so there is still no any successful experience to learn in China or abroad.Relying on an existing project, combining both advanced control technology abroad and key ideas of domestic similar boilers, and based on researching in one-through boiler features and co-firing boiler characteristics, the paper designs a detailed control strategy for multi-fuel co-firing boiler, and provides its detailed implementation process in distributed control system (DCS).Firstly, the paper studies the working principle and static/dynamic characteristics of one-through boiler, and describes the key points of feed water control and steam temperature control strategy for one-through boiler, by comparing with drum boiler. Secondly, it examines the firing control theory of boiler and burner control mode of co-firing boiler, and discusses the focal points of fuel control and air control strategy for co-firing boiler, by comparing with traditional boiler. Finally, it analyses the tracking principle and core algorithms of DCS, illustrates DCS configuration process of water-steam and firing system for the boiler, and also gives the engineering tuning of its control parameters.The control strategy designed by the paper has been adapted and achieved excellent results in BAOSTEEL co-firing one-through boiler, which is in operation continuously till now. Its operation experience and control strategy has great engineering value. If it can be applied to other similar enterprise, it must pave a new road to obtain the goal of"energy conservation and emission reduction"for steel industry in China.