Model optimizes exchanger cleaning

Abstract

There are many simple models about fouling in the literature that calculate the optimum period for heat exchanger operation. Because of the assumptions and simplifications they contain, these models always yield, and often incorrectly, an optimum point. However, a more rigorous analysis indicates that the trend of fouling costs (which we try to minimize) can be increasing or decreasing, and certain conditions must be achieved for the existence of that optimum. This analysis applies to shell-and-tube heat exchangers in a crude oil preheat train, but it can be made suitable for any case with adequate changes.