A homogeneous relaxation model for multi-phase CO2 jets following the release of supercritical CO2 pipelines

The pressurized CO2 pipeline is a necessary component of Carbon Capture and Storage (CCS) infrastructures. However, the potential risk caused by CO2 pipeline is still not very clear. Especially the scientific community is focusing on the understanding of multi-phase (gas-liquid-solid) flow of CO2 jet in the near-field of dispersion. In this paper, a compressible multi-phase Computational Fluid Dynamics (CFD) model considering real gas behavior is developed to predict the strength of source terms of CO2 release. The model is based on a Homogeneous Relaxation Model (HRM) and accounts for non-equilibrium phase transition. A CO2 release experiment was carried out to obtain near-field data, and it was used to validate the CFD model. The results show that the predictions are in good agreement with the experimental data in terms of velocity and jet structure. The relaxation time has a significant impact on the jet temperature and the condensed phase fraction.