Heat Transfer and Flow Characteristics of CO2-Hydrate Mixture in Pipeline

Abstract

Heat transfer and flow characteristics of CO2 hydrate mixture was experimentally and numerically investigated. The formation and flow of hydrate in CO2 pipelines may impact on various transport processes such as flow and heat transfer parameters. CO2 hydrate mixture was generated by injection techniques from a mixture of water and CO2. The mixture, whose flow rate of 3.15 to 5.16 kgmin-1 under about 4000kPa, was passed through a 4 m long double tube test section with inner diameter of 9.52mm. The heat transfer coefficients of the CO2 hydrate mixture range from 127 to 997 Wm-2K-1, and the pressure drop changes from 295 to 973kPa. A two-dimensional (2D) axial-symmetric, Eulerian-Eulerian two-phase model coupled with heat transfer was developed by taking into account phase transition phenomena through melting of hydrate particles. A coupled turbulent multiphase and non-isothermal heat transfer model was built using COMSOL Multiphysics to investigate mixture flow, particle distribution and phase transition. The results for heat transfer coefficient, pressure drop, particle distribution, velocity field, temperature profile and evolution of phase transition of CO2 hydrate fraction were presented.