A two-dimensional heterogeneous model for the control of a chain-grate stoker

The combustion of coal on a chain-grate stoker presents a complex problem to the control engineer. Although such rigs can operate continuously with a minimum of supervision emission requirements and the need for greater fuel efficiency are leading to a review of operating practice. The principal problems that are being addressed are the variation in the coal feed quality and distribution, and unscheduled secondary air. The variations that these cause in both the heat and emissions output of the boiler are in need of regulation. In an attempt to bring modern control theory to the problem a new general control system is being designed for chain-grate stoker rigs in a collaborative project between Exeter University and CRE Group Ltd. The control of chain-grate stokers is made difficult by the imbalance between the complex and distributed process on the one hand, and the relatively few measurements available on commercial plants on the other. The control system must reflect this. However it is both expensive and possibly hazardous to carry out this development on-line. Another vehicle on which to develop the control system is required