Leakage diffusion and safety assessment of CO2 pipeline transportation flange based on CFD simulation

Carbon capture and storage technologies play crucial roles in mitigating atmospheric greenhouse gases (GHGs). Pipeline transportation is the primary method of CO₂ transportation, making pipeline safety a priority. In this study, Fluent software was used to create a model for annular edge leakage flanges, which significantly differs from the traditional pinhole leakage model. This study aims to examine the impact of CO₂ pipeline flow and pressure on the diffusion of gas leaking from the flange and to develop a precise correlation between the diffusion distance and substance concentration. The results indicate that an increase in flow and pressure intensifies the diffusion of the flange leakage. Specifically, for a leakage lasting 96 s at flow rates of 0.7 and 10 m³/h, the diffusion ranges for the 5% concentration alarm threshold are 0.47 and 2.86 m, respectively. Furthermore, at a speed of 10 m/s and a pressure of 0.4 MPa, the diffusion ranges for 5 and 2% alarms are similar, spanning from 0.33 to 0.35 m. This study provides theoretical support and technical improvements to ensure the safe operation of pipelines. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.