KNOWLEDGE-BASED CONTROL STRUCTURING OF A DISTILLATION PLANT START-UP

A prccess-knowledge-based control structuring method for process start -up is presented. The methodology leads to a definition of tracking ta sks. Tile tasks contain properties to describe some sub-procedures in the whole start-up procedure. Operational safety aspects are included into the task properties. By combining the tasks, a complete procedure for closed loop start-up can be described. This method is able to han dle process constraints, operational safety aspects and time-varying p rocess characteristics. For the practical solution of this challenging set of control problems the start-up methodology is implemented using fuzzy-logic control. Experimental investigation of the closed-loop st art-up of an energy integrated distillation plant revealed a significa ntly facilitated start-up for the operator. The start-up also demonstr ated more than 25 % reduction in energy expenditure and time compared to a manual implementation of the same procedure.