A CFD-Based Analysis on Trends of Heat Exchanger Fouling

With the use of finite volume method, this study focuses on the two-equation K-Epsil turbulence model with enhanced wall treatment and with water as its working medium. The fluid domain is discretized in the mode of second order discretization. A 20cm- diameter 1m-long heat exchanger is taken for an example. The velocity distribution on four 3mm- thick baffles with 35% baffle cut is studied. Heat exchange tubes are 8mm in diameter and are arranged in a square pattern. Heat exchange and flow are studied for the 96 tubes with an interval of 16mm. Through particle tracking and slice contours in the model, the trajectory of the fluid in the fluid domain of the shell and the flow, heat exchange, and pressure loss of fluid elements in all phases are studied. With their rates of change, a qualitative analysis can be made on the trends of fouling of shell-side fluid flow at all locations and provide theoretic support for further improvement of shell structure design of heat exchangers.