Model-based gas leakage detection and isolation in a pressurized system via Laguerre spectrum analysis

This paper deals with gas-leakage detection and isolation in a fine coal injection vessel for a blast furnace process. Functions describing the expected time-domain behaviour of different leakages are developed, thus reducing the leakage isolation problem to pattern recognition. In order to lower the computational burden while preserving the essential dynamic behaviour of a leakage, a truncated Laguerre series representation is used. The generalized likelihood ratio method is employed to compare the Laguerre spectrum of the residual with the Laguerre spectra of the predefined typical leakage functions. Tests of the developed algorithm have been successfully performed at SSAB Tunnplat, Lulea