Abstract:In order to realize an effective repair and a supply of inhibitor in a follow-up normal injection process for an inhibitor to exhibit corrosion protection effect, the distribution of corrosion inhibitor in a gas pipeline needs to be studied in detail. Software Fluent was used to simulate the gas and liquid turbulent flow and inhibitor distribution in a pipeline based on the Euler-Euler model, RNG k-ε turbulence model and VOF method. The distribution of inhibitor liquid film along the inner wall of the gas pipeline is obtained, and the influences of surface tension of the corrosion inhibitor on the liquid film distribution under scouring and gravity are clarified. The results show that the inhibitor settles toward pipe bottom due to the gravity, which accounts for 1/3 of the cross-section of the pipe. The secondary flow in the elbow can destroy the initial distribution of corrosion inhibitor, and drive the inhibitor along the secondary flow path to damp it on the bottom of the elbow. Therefore, the pipe and elbow top should be monitored carefully in engineering practice. The higher surface tension the inhibitor possesses, the more adhesion work the pipe wall has, in consequence the more uniform distribution of corrosion inhibitor and the higher inhibitor volume fraction adhered to the wall. As a result, the highest corrosion inhibitor volume fraction can be as large as 100%. It suggests that an inhibitor with stronger adhesiveness and higher surface tension should be chosen in pre-filming process.
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