Analysis of low-temperature characteristics and pipeline stress in venting system of gas transmission stations

As a critical safety facility, the venting system of gas transmission stations is designed to provide rapid pressure relief in emergencies, thereby preventing equipment damage. However, various incidents, such as abnormal pipeline stress and material damage, frequently occur during operation. This is partly due to the lack of clarity regarding the system's operating characteristics under low-temperature dynamic conditions and the corresponding effects on pipeline stress. This study conducted a systematic analysis of the dynamic evolution pattern of pipeline stress based on the characteristics of sudden changes in fluid temperature, pressure, and pipe wall temperature during the venting process. This analysis was supported by data from numerical simulations and field monitoring. A fluid-structure coupling model was developed using ANSYS software, which incorporates pipe parameters and condition data from real-world applications to quantify the temperature gradient distribution under low-temperature shocks and to replicate the mechanisms influencing stress concentration. Based on the systematic analysis of low-temperature characteristics and pipeline stress in the venting system of gas transmission stations under dynamic operating conditions during the venting process, the findings provide a theoretical basis for the safe design and operational management of the system. They also offer practical guidance for preventing pipeline failure under low-temperature conditions.