Inhibition of the erosion-corrosion of elbow by synergistic action of swirling flow and inhibitor

Abstract

The experiments of using inhibitors to inhibit the erosion-corrosion of elbows under the conditions of liquid-solid non-swirling flow and swirling flow were designed to evaluate the inhibition of erosion-corrosion of elbows under the combined action of swirling flow and inhibitors. The experiments were carried out by a circulating loop system in combination with a variety of test methods and computational fluid dynamics (CFD) simulation. It is demonstrated that the addition of inhibitors under non-swirling flow and swirling flow conditions can inhibit effectively the erosion-corrosion rate and its four components (pure corrosion, pure erosion, corrosion-enhanced erosion, and erosion-enhanced corrosion). The comprehensive inhibition efficiencies of the synergistic action of swirling flow and inhibitor on the four components of erosion-corrosion are higher than the inhibition efficiencies of inhibitor acting on the four components alone. The hydrodynamic characteristics of swirling flow produce the sand suspension effect and mass transfer enhancement effect which facilitate the adsorption of inhibitor on the working electrode surface and acting in conjunction with the oxide film to form a lamellar protective corrosion product layer with stronger integrity and compactness.