Study On Erosion-corrosion Of Pipeline In The Gas-liquid Two-phase Flow

There is wide process industrial background for gas-liquid two-phase flow erosion-corrosion, which includes complex dispersed bubble caused erosion-corrosion. Besides, because of the complexity of the turbulent flow field, the study on the mechanism of flow-accelerated corrosion is required to improve and clear further. Contents of research can provide references to theoretical development and experiment investigation of corrosion in gas-liquid two-phase flow, it is very useful and valuable to study erosion-corrosion phenomenon from both theoretical aspect and engineering application aspect.The bubbles are a form of the nonuniform state in pipeline, and are generated randomly along with the change of flow rate and pressure. The discrete particles phase model simulating the actual operation is more effective. Introducing the kinetic theory of particulate phase, analyse impact force from particles collision and shear stress from particles erosion. Considering bubbles particle stochastic trajectory model, it is necessary to calculate fluid control equation and particles motion equation, meanwhile, the effects of both flow-accelerated corrosion and bubble-induced erosion-corrosion factors are also computed.Physical parameters of fluid and bubbles induced erosion-corrosion are employed to simulate the pipeline model with bubbles in water using the Euler-Lagrange equation. Pressure distribution and bubbles’ movement track distribution are investigated separately. The distribution of gas phase volume fraction, velocity field and shear stress is analysed in the elbow pipe and reducer. The level of erosion-corrosion damage on the surface of wall is reported by the value of erosion-corrosion rate.The result of analysis indicates that erosion-corrosion is created by variation of flow rate and shear stress on the wall is influenced by flow rate. The effect of bubbles’ erosion accelerates process of corrosion. Moreover, corrosive medium being in the pipeline is the essential factor of material corrosion damage.On the basis of researching and simulating turbulence and wall that suffers impact when bubbles collapse, that corrosive medium generates electrochemical corrosion on the surface of wall is taken into account. By the distribution of medium accretion rate, danger zone and damage law of corrosion are evaluated.Finally, this paper summarizes the interaction among fluid flow, bubble-induced erosion-corrosion and medium-induced electrochemical corrosion, which is the reason of pipeline corrosion damage. According to numerical simulation method, the law of collision damage is got from gas-liquid two-phase flow in the process equipment pipeline. Research work is significant in directing to practical engineering application.