Hydrothermal Stress Coefficient: A Novel Model for Predicting Heat Exchanger Fouling in Cooling Systems

August 19, 2019

Authors: D. B. DeWitt-Dick, G. F. Hays, E. S. Beardwood, National Heat Transfer Conference, Baltimore, Maryland, August 1997. AICHE Symposium Series 314, Volume 93, 1997, Pages 311-316, ISBN 0-8169-0739-0

ABSTRACT: Traditionally, heat exchanger water – side fouling predictions were based upon calculations of mineral salt solubilities at some temperature, be it the bulk return water or the hottest heat exchanger outlet temperature. Practical experience has demonstrated that this method of predicting the potential for fouling of a given heat exchanger is not always accurate. In a given system, therefore, the effect of water chemistry is secondary to the physical design and operation of the heat exchange equipment. Fouling requires the attachment of one or more classes of foulants to the heat transfer surface. Thus, it follows that any predictive model must consider the parameters that influence attachment. Over the past two decades, more than 5 million hours of fouling data were generated from a patented on-line cooling water simulation and monitoring systems. Based upon this thesis and analysis of the many fouling experiments, a novel predictive model was developed. The model was then applied at several process industry facilities and correlation between the model and actual operation was verified. This paper will discuss all the findings and bases for the model building which empirically solves the attachment coefficient.