Fault detection and diagnosis of pulp mill process

Abstract

The hybrid fault diagnosis method based on a combination of the signed digraph and the partial least-squares (PLS) has the advantage of improving the diagnosis resolution, accuracy and reliability, compared to those of previous qualitative methods, and of enhancing the ability to diagnose multiple fault. In this study, the method is applied for the fault diagnosis of the pulp mill process, which is used to produce pulp from wood chips. It is one of the biggest processes tested in the fault diagnosis area, and it will be a new benchmark process to test the fault diagnosis method. In order to consider large time delay in the process, the diagnosis model was modified to include the information of the time delay between process vaiables. Through case studies, the proposed method demonstrated good diagnosis capability compared to the previous hybrid method not considering time delay.