An analytical model for predicting the particle-deposited fin efficiency

Fins of heat exchangers are gradually deposited by dust particles in most application scenarios, and so a model of particle-deposited fin efficiency is needed for heat transfer prediction. In this study, the expression of fin efficiency for a particle-deposited annular fin was developed by simplifying the fin as two two-dimensional coating layers on a one-dimensional clean fin firstly, and then this expression was extended to rectangular fins with circular holes by the equivalent radius transformation. The analytical solutions for a typical rectangular fin show that the attenuation rate of fin efficiency may increase up to 23.9% if the fin surface is covered by a fouling layer with an average thickness of 4.0 mm. This model can be used to predict the heat transfer rate of fouled heat exchanger with multi-fins, and the validation results show that the accuracy of the proposed model is acceptable in engineering applications.