Numerical Simulation of Supercritical CO₂ Blocking Flow Based on the Peng-Robinson Equation

To address the issue of choked flow during high-pressure drop throttling in pipelines, multiple sets of typical throttling parameters (with inlet temperature and pressure as the primary variables) and various structural configurations were designed. Computational Fluid Dynamics (CFD) methods were employed to analyze the steady-state flow field within the throttling device, with a focus on pressure and velocity variations, while coupling the temperature field to investigate the Joule-Thomson effect during the throttling process. The relationship between pressure drop and temperature drop was also examined. The results indicate that as the length-to-diameter ratio increases, the overall flow rate exhibits a multistage growth trend. For achieving higher flow rates, structures with a length-to-diameter ratio greater than 3 are recommended. However, an increase in length-to-diameter ratio and a reduction in temperature intensify noise hazards. Therefore, structures with a length-to-diameter ratio of less than 2, combined with low-temperature conditions, are advised to mitigate noise. Additionally, no risk of hydrate blockage was identified during throttling within the studied temperature and pressure range.