Application of fuzzy control theory to direct-heating furnace control system

On the basis of bias-flow analysis and the tackling method, a control scheme is present to resolve the bias-flow problem. Three fuzzy controllers are built by us based upon three pipes absolute temperature-difference as the input, the openness of the valve as the controlled object. After realizing this control scheme, the problem of bias-flow has been resolved perfectly. Now coked pipes are burned once a year, and almost no-coking occurs. We have been using this control scheme from beginning to now for seven years and there is no need to replace the heating-pipes at all. The new design method of discrete fuzzy controller presented in this paper can resolve the bias-flow problem in other fluid distribution control system.