Research And Application On The DCS Of The Circulating Fluidized Bed Boiler

Circulating Fluidized Bed (CFB) burning technology is a high effective and clean technology. CFB has the ability of cleaning, burning effectively, well adjustment of load. CFB Boiler (CFBB) is a control plant that has features of distributing parameter, coupling tightly multivariable, non-linear, time-variable and large delay. Currently the automation level in factory is still out of date, many control circles are handled by manual operation. So it is necessary to design a DCS (Distributed Control System) to fulfill the control request.Based on the engineering practice, some researches have been done in the 240t/h CFBB DCS Development. The main work is as follows:1. CFBB analysis and research on algorithm. On the base of analyzing CFBB, decoupling control is used to the complex CFBB system, with dividing it into each individual sub-system. Water level control system is studied, and using the three-impulse water control algorithm, then simulating results are given.2. Equipment option and system design. By many investigation and practice, a DCS for middle or small power plant boiler control is designed, and FAMA series control hardware (from Mirle Inc.) and SoftPLC control software (from SoftPLC Inc.) are integrated in DCS.3. DCS configuration and debugging. DCS configuration methods are discussed in this thesis, including data collecting, communication, PLC programming, MMI configuration, warning and history data querying. In the end, Ideal control effect is achieved when system is running.This DCS is a new and effective control system. In the experience of the engineering, the control effect reaches the request of design for the CFBB control system. Limited by the time and condition, some control circles, as the combustion control, are not concerned. That will be a question for discussion in the future.