Multiphase Flow Simulation Of High-Pressure Hydrate Slurry Loop

The research on the flow characteristics of hydrate slurry is the core of flow safety assurance.However,due to limitations of experimental conditions and equipment,it is impossible to fully grasp the flow information through loop experiments.Computational Fluid Dynamics(CFD)studies,as a valuable tool in flow assurance research,could reproduce the invisible insight of the flow characteristics in the experiment,enhance the understanding of hydrate slurry flow,and therefore provide solutions for the prevention and control of hydrate blockage in the subsea pipes.In this paper,a set of CFD-models including the straight and curved segment models of the high-pressure hydrate slurry loop were established based on the loop experiment.Fully considering the properties of the hydrate slurry and hydrate particles,the multiphase flow of the hydrate slurry was simulated in three dimensions using Euler method,Lagrangian method and Hydrate model in CFD package TransAT and FLUENT respectively.The Euler models for the straight segment of the loop were validated by compared with the experimental data,and were used to analyze the influences of key factors including the inlet velocity of slurry,the inlet volume fraction of hydrate particles and the particle diameter,which will affect the multiphase flow of hydrate slurry.The Hydrate model was a good try to describe the phase change of hydrate in the multiphase flow of the slurry.And the Euler models for the curved segment of the loop were established to give a good prediction of the flow condition of hydrate slurry and the deposition of hydrate particles in the invisible part of the loop.By using Lagrangian Particle Tracking Method,the hydrate particles were considered as separated Lagrangian objects,which could better demonstrate the particle deposition mechanism from the perspective of hydrate particles.Besides,the applicability of TransAT and FLUENT in the numerical simulation of the multiphase flow of hydrate slurry was evaluated according to the results.