FLOW-INDUCED CORROSION KINETICS MODEL OF CARBON STEEL IN FLOW LOOP SYSTEM

Wall function, k-e turbulence model are used in the present study.The numerical hydrodynamics models and mass transfer models in flow loop system are defined in accordance with the basic theory of hydrodynamics and conservation of mass,momentum or energy.Flow-induced corrosion kinetics model of carbon steel in flowing 3.5% NaCl solution is set up on the basis of determining main controlling factors and analyzing their degree of influence in flow-induced corrosion by some electrochemical experiments. The numerical method used in this study is based on the control volume approach for discretization of partial differential equations that express the characteristics of fluid flow and mass transfer.The power law scheme is also used in discretization of convection-diffusion equations.In this manner,the resulting discretization equations express the conservation principle for mass,momentum and energy over the finite control volume,just as the differential equations express the same principle for the infinitesimal volume.In this way,the formulation is straightforward.The user program is compiled.In accordance with flow-induced corrosion kinetics models,flow-induced corrosion rates are numerically calculated with SIMPLE algorithm.The flow-induced corrosion rates calculated by numerical method are compared with the ones measured by weight loss.The numerically computed flow-induced corrosion rates are mostly equal to the ones measured by weight loss experiments.If proves that the flow-induced corrosion kinetics models are correct and accurate,and that the user program is reasonable.The models are founded on the basis of some electrochemical experiments and reasonable hypothesis.Corrosion electrochemical factor plays a dominant role in flow-induced corrosion of carbon steel in flowing 3.5% NaCl solution.