Dynamic characteristic analysis and combustion control for a fluidized bedincinerator

Since thermal plants are multi-input, multi-output systems, it is important to capture the characteristics of the system for precise combustion contro l. Furthermore, in refuse incinerator plants (RIPs), the properties of the fuel are unstable, and minimization of the exhaust emissions is required. T hus, optimization of efficiency from an overall standpoint, including consi deration of sensor and control technology, is required in RIPs. In particul ar, in comparison with stoker incinerators, the combustion cycle in fluidiz ed bed incinerators (FBIs) is short, and combustion processes occur in mult iple layers within the incinerator. As a result, analysis of the dynamic ch aracteristics is considered most the effective way of grasping the characte ristics of FBIs. This paper has focused on an operating FBI, where a hybrid system consistin g of fuzzy systems and neural networks has been realized, which assesses th e fuel-feeding state on the basis of measured values and combustion image p rocessing, and operates with low CO/NOx concentrations by means of air-fuel ratio control. Furthermore, a proposed tuning method for the fuzzy systems simplifies the evaluation of speculative results, and the determination of control rules, by the utilization of an operation support system based on a numerical model. (C) 1998 Elsevier Science Ltd. All rights reserved.