Application Of DCS On 135MW CFB Cogeneration Unit

Circulating fluidized bed (CBF)boiler is widely employed by many large power plants with the advantages of low pollution,high efficiency, fuel flexibility and convenient load regulating capability. However,because of its complex control parameters and complicated combustion control process, conventional instrumentations can not meet the demand of CFB boiler controlling, it is necessary to introduce new control system with excellent performance, distributed control system (DCS) have been widely adopted by lots of large-scale CFB boiler units. In recent years, in order to meet theneeds of control unit of CBF boiler, through continuous learning from experience, design improving, designers, manufacturers and users of DCS have effectively improve the performance of reliability, real-time and accuracy of . DCS control system.In this dissertation, the developing process and the main features of CFB boiler are introduced firstly, then the similarities and differences between CFB boiler and pulverized coal furnace are compared on the aspects of controlling method; many principles and functions have been analyzed and explained,such as furnace safety supervisory system (FSSS), regulation and control systems, combustion control system ignition start control system, steam conditioning system, in the end, corresponding control programs are put forward in accordance with the characteristics of CFB boiler.With DCS designing configurations of 2×135MW CFB boilers in Xinzhuangzi Power Plant technical innovation project, the characteristics and the main functions of Network-6000+ DCS units are introduced in this dissertation;Aimed to resolve the the main problems encountered in the process of DCS engineering designing, installing and commissioning, DAS, MCS, SCS, ECS program are detailedly discussed respectively, actual operating in power plants shows that DCS controlling system achieved good results, it not only helps operating staff to reduce labor intensity, but also ensures that the units operate safely, efficiently and effectively.