Abstract
This paper proposes an anomaly cause identification technique in the case of a single anomaly occurring in a plant. The technique 1) defines anomaly modes based on a functional model and the structure for each component or system of plants, 2) uses estimation rules collected previously as a knowledge base to judge the occurrence of each anomaly mode, and 3) identifies the anomaly cause by expanding the search space using the component connection information from the part model including the component where an anomalous behavior is detected. A simple technique is also formulated and implemented to estimate the values of unobserved flow rates based on mass balance equations. The applicability of the proposed anomaly cause identification technique is demonstrated through the applications to several anomaly scenarios for a system around a main fractionator of an oil refinery plant.
