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[摘要]：Maya crude oil fouling reveals a straightforward dependency of initial fouling rate on surface temperature but a rather complex dependency on velocity in bare tubes, the initial fouling rate showing a maximum and then decreasing significantly towards zero as the velocity is increased. Surface shear stress clearly is an important parameter. CFD simulation of fluid flow in a tube fitted with a hiTRAN (R) insert reveals a complex distribution of surface shear stress. To compare the insert situation with the bare tube, an equivalent velocity concept is introduced on the basis that at a given average velocity the fluid flow results in the same average wall shear stress regardless of whether the tube is bare or is fitted with an insert. Using the equivalent velocity concept, the fouling data obtained using both a bare tube and a tube fitted with inserts can be correlated using a single model. Moreover, the fouling threshold conditions below which fouling is negligible, can be predicted for both situations. (C) 2011 Elsevier Ltd. All rights reserved. |
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