Accounting for fouling in plate heat exchanger design

Abstract

The fouling removal mechanism for plate heat exchanger (PHE) heat transfer surface controlled by shear stress is considered. The semi-empirical formula to predict asymptotic value of fouling thermal resistance velocity dependence based on heat and momentum transfer analogy is proposed. The correlation is in a good agreement with literature data and was checked for PHEs installed in District Heating systems of a number of cities in Ukraine. As a result the modified method for PHE heat transfer surface area calculation is proposed, which takes into account the influence of flow velocity and heat transfer enhancement in channels on fouling thermal resistance. The obtained correlation can also be used for estimation of fouling rate in process PHEs where one media is water, e.g. in distilleries, nitric and phosphoric acids, fertilizers productions.