Circulating Fluidized Bed Boiler Combustion Fuzzy Control Study

Recently, the combustion technology of Circulating Fluidized Bed (CFB) has been developed all over the world. The technology has been widely applied in boiler due its high efficiency, low environmental pollution and economy, known as 3E utilization technology. The commercialization and fast development of CFB proposes higher requirements for the automation of its operation.However, CFB technology itself is developing fast, and the combustion process of CFB is highly non-linear, with high uncertainty, large time delay and high multi-variable coupling, making the process complicated. So far, the research on the combustion mechanism and its fuzziness is immature, therefore, there is no good model for real-time control of the process. Hence, the automation level of the bed temperature, one of the most important parameters for the combustion control of CFB, cannot be improved effectively.This thesis first studies the hydrokinetics, heat transfer characteristics, combustion and dynamics of CFBB. three types of single fuzzy controllers and a kind of synthetically fuzzy controller are designed, through the analysis of the control system of a certain plant. The performance of the schemes are compared, and the results show that the synthetically fuzzy controller can achieve better control performance and more robust.