纯氢管道泄漏扩散规律研究

Research on the Leakage and Diffusion Law of Pure Hydrogen Pipeline

为了有效减少纯氢管道泄漏引发的消防安全事故,采用数值模拟方法研究了纯氢管道不同位置泄漏时氢气的扩散规律和分布状态,并结合已有文献的相关数据验证了仿真模型的准确性。模拟结果表明:纯氢管道泄漏后会在泄漏孔附近形成仅有少量扩散的射流区域。由于空气浮力的作用,管道下方泄漏时在泄漏孔附近的氢气分布呈倒锥形,侧方泄漏时氢气云团末端明显向上偏移。在4 MPa压力和泄漏孔直径2 mm条件下,氢气传感器与管道的最佳距离为0.25 m。管道上方、下方和侧方泄漏时,泄漏方向上0.25 m处的氢气浓度分别在80 s、30 s和60 s后趋于稳定。在对纯氢管道进行泄漏监测时,可先通过数值模拟分析确定氢气传感器的最佳位置,以提高其泄漏监测范围,防范管道燃爆事故的发生。

In order to effectively reduce the fire safety accidents caused by the leakage of pure hydrogen pipeline,the diffusion law and distribution state of hydrogen were studied by numerical simulation method when the pure hydrogen pipeline leaks at different positions,and the accuracy of the simulation model was verified by combining relevant data of existing literatures.The simulation results show that the leakage of pure hydrogen pipeline will form a jet region with only a small amount of diffusion near the leakage hole.Due to the buoyancy of air,the distribution of hydrogen near the leakage hole is inverted cone when leaking under the pipeline,and the end of hydrogen cloud is obviously shifted upward when the pipeline leaks on the side.Under the conditions of 4 MPa pressure and 2 mm diameter of leakage hole,the optimal distance between the hydrogen sensor and the pipeline is 0.25 m.When the pipeline leaks above,below and sideways,the hydrogen concentration at 0.25 m in the leakage direction tends to be stable after 80 s,30 s and 60 s respectively.When monitoring the leakage of pure hydrogen pipeline,the optimal position of hydrogen sensor can be determined by numerical simulation analysis first,so as to improve its leakage monitoring range and prevent the occurrence of pipeline explosion accidents.