Modeling of a Refuse Incineration Plant and Its Application to Combustion Control Problem

Proper knowledge of static and dynamic behavior for refuse combustion process is necessary not only for operation of refuse incineration plants but also for designing the automatic combustion control system of the plants. However, the incineration process is very complex and the experimental measurement of dynamic characteristics is not easy because of fluctuation of physical and chemical characteristics in the refuse as a fuel. This paper deals with the studies concerning the analyses of dynamic characteristics to the refuse incinerator, and then the automatic combustion control system aimed at stabilizing steam flow rate in the waste heat boiler of the incineration plants. In order to reduce fluctuation taking place in the steam flow rate, we propose effective utilization of refuse agitation, which is practically available for a quick recovery of the heat release rate in the furnace. As a result of simulation, we show that good responses to reference inputs are obtained for the PI control system with an effective agitating apparatus, in comparisonwith the conventional PID control system without agitating one. Furthermore, the refuse incineration process is shown by that of the system with time delay in state variables.