Knowledge-based expert system for fouling assessment of industrial heat exchangers

Abstract

Abstract The paper emphasises the need for the development of the expert system as a tool for the mitigation of the fouling processes. Particular reference is given to the design margin lifetime assessment, fouling process control, fouling removal assessment and heat-exchanger safety by the expert system for industrial heat exchangers. This paper presents the concept of a heat-exchanger on-line system. The heat-exchanger efficiency is defined by the NTU concept for the simple parallel co-current heat exchanger. The respective methodology is used for the description of the generic behaviour of the heat-exchanger system. Particular attention was paid to the recognition of those situations leading to the degradation of the efficiency of the heat exchanger. The paper describes the selection of the diagnostic variables and their on-line measurements, including the logging system for the monitoring and acquisition of the data. The knowledge base is derived from the definition of the heat-exchanger efficiency. The approach presented is based on an object-attribute-value structured knowledge base. It includes hot and cold stream flow rate and hot and cold fouling thickness assessment. In this respect, particular attention was paid to the fouling process assessment and its effect on the efficiency degradation of the heat exchanger. For the specific heat exchanger, the expert system assessment of different situations was shown with this approach.