KNOWLEDGE-BASED EXPERT-SYSTEM FOR FOULING ASSESSMENT OF INDUSTRIAL HEAT-EXCHANGERS

The paper emphasises the need for the development of the expert system as a tool for the mitigation of the fouling processes. Particular ref erence is given to the design margin lifetime assessment, fouling proc ess control, fouling removal assessment and heat-exchanger safety by t he expert system for industrial heat exchangers. This paper presents t he concept of a heat-exchanger on-line system. The heat-exchanger effi ciency is defined by the NTU concept for the simple parallel co-curren t heat exchanger. The respective methodology is used for the descripti on of the generic behaviour of the heat-exchanger system. Particular a ttention was paid to the recognition of those situations leading to th e degradation of the efficiency of the heat exchanger. The paper descr ibes the selection of the diagnostic variables and their on-line measu rements, including the logging system for the monitoring and acquisiti on of the data. The knowledge base is derived from the definition of t he heat-exchanger efficiency. The approach presented is based on an ob ject-attribute-value structured knowledge base. It includes hot and co ld stream flow rate and hot and cold fouling thickness assessment. In this respect, particular attention was paid to the fouling process ass essment and its effect on the efficiency degradation of the heat excha nger. For the specific heat exchanger, the expert system assessment of different situations was shown with this approach.