On-line model-based performance monitoring of a shell-and-tube type heat exchanger using steam and water

The on-line performance monitoring of a shell-and-tube type heat exchanger using steam and water, which is one of the key components of distributed energy supply systems, has been developed on the basis of a theoretical model. In this on-line performance monitoring, output process variables and performance of the heat exchanger in response to the variation in measured input process variables are first estimated by using its steady-state model. These estimated values are then compared with the measured ones. Its effectiveness has been confirmed by the demonstration experiments conducted not only in the steady and transient states but also under the condition of air accumulation in the shell as one of the common failures of this type of heat exchanger. The results confirm the sufficient accuracy of estimating the output process variables and heat exchange performance in a wide operating range, and the capability of detecting the deterioration of the heat exchange performance due to the air accumulation in a short period.