Patent ID: 6567795
Filing Date: 2003-05-20
Classification: G05B,G06N,Y10S

Abstract:
A process for determining a boiler tube leak event in industrial boilers said process comprising:(a) determining for a boiler, a set of tube universal leak sensitive variables ULSVs; (b) representing each of said ULSVs with a fuzzy set comprising linguistic statements; (c) building a knowledge base for a first inference engine which contains a set of fuzzy rules describing a fuzzy map between each of said ULSVs and a relative magnitude of said leak event; (d) building a database for said first inference engine which defines membership functions used in the fuzzy rules of said knowledge base, and said first inference engine further comprising a reasoning mechanism for performing inference procedures upon said set of fuzzy rules for decision-making on the magnitude of said leak event; (e) determining for said boiler a set of tube local leak sensitive variables LLSV's; (f) representing each of said LLSVs with a fuzzy set comprising linguistic statements; (g) building a knowledge base for each of a set of second inference engines, each of said second interference engines in said set corresponding to one LLSV, and each such knowledge base comprising a set of fuzzy rules describing a fuzzy map between the LLSV corresponding to that second inference engine and the location of said leak event; (h) for each of said second inference engines for which a knowledge base is built in step (g), supra, building a database which defines membership functions used in the fuzzy rules with the knowledge base corresponding to said second inference engine and said second inference engines further comprising a reasoning mechanism for performing inference procedures upon its corresponding set of fuzzy rules for decision-making on the location of said leak event; (i) thereafter monitoring said boiler for occurrence of a leak event by observing changes in values in said boiler for each of said ULSVs and supplying said observed changes in values to said first inference engine for generating a fuzzy output therefrom; (j) comparing the fuzzy output in step (i), supra, to a ranking of the linguistic statements represented in step (b), supra; (k) if the linguistic statement compared in step (j), supra, is greater than a predetermined rank, concluding that a leak event is occurring and thereafter observing changes in values from said boiler for each of said LLSVs and supplying said observed changes in values to said LLSV's corresponding second inference engine for simultaneously producing therefrom a fuzzy output; and (l) simultaneously introducing each fuzzy output produced in step (k), supra, to a third inference engine, said third inference engine being provided with a knowledge base comprising a set of fuzzy rules describing a fuzzy map between location of said leak event and each LLSV, a database defining membership functions used in the fuzzy rules of the third inference engine knowledge base, and a reasoning mechanism for performing inference procedures upon each of said fuzzy rules for determining the location, in said boiler, of said leak event.