综合管廊中掺氢天然气泄漏安全性分析

In order to understand the impact of various coupled factors, such as hydrogen blending, on the dispersion of hydrogen-blended gas leakage in pipeline transportation is studied based on the underground comprehensive pipe galleries in three common gas transmission scenarios. The study starts from the feature that confined space is prone to cause gas cloud accumulation and combustion, with consideration given to factors such as different leakage directions, hydrogen doping ratios, and pipeline pressures, and the simulation of potential leakage scenarios within the comprehensive pipe galleries is conducted using Fluent software. The distribution characteristics of internal gases are examined, and a safety analysis of alarm probe positioning and spacing is performed. The simulation results show that the distribution of gas is significantly influenced by the directions of the leakage port, with a more obvious accumulation of gas observed in the near-wall region of secondary flows. The installation of probes at a distance of 30 cm from the top of the side walls effectively reduces alarm delays. With a 20% hydrogen blending, the leakage rate increases by 9. 03%, leading to an intensification of gas accumulation near the leakage port and a slight increase in risk at the distant end of the port. The explosion concentration range (gas concentration >4%) at 5 seconds of gas leakage is found to be 1. 54 m, and the addition of 10% and 20% hydrogen increases this distance by 16. 2% (1. 79 m) and 36. 4% (2. 10 m), respectively. Furthermore, as pipeline pressure increases to 0. 8, 1.2, 1.6 MPa, the time required to reach the alarm concentration is respectively shortened by 18. 9%, 28. 3%, 32. 1%. Valuable insights for the safe transportation of hydrogen-blended natural gas in comprehensive pipe galleries can be provided by this study.