Degradation Monitoring of Industrial Heat Exchangers.

This paper presents the results of monitoring device-level and system-level faults in industrial heat exchangers. The device-level faults refer to degradation of sensors and control actuators. In the case of heat exchanger (HX) studies presented here, system-level fault refers to fouling of HX tubing during plant operation. The objective of the research performed at The University of Tennessee was to develop techniques to detect and isolate both sensor faults and fouling-related degradation in a tube-and-shell heat exchanger. This was achieved by monitoring the changes in the relationship among a set of system-bound variables for different fault types. The measurement-based models were established using experimental data of fouling progression in a tube and shell industrial heat exchanger. Direct and inferred measurements of fluid temperatures, flow rates, pressure drops, and thermal resistance were used to perform the fault diagnosis. An approach called the Group Method of Data Handling (GMDH) was developed to characterize the interrelationships among several measurements [ABSTRACT FROM AUTHOR]