天然气泄漏燃烧对管道钢管性能影响研究

天然气集输站场小间距并行管道如果发生泄漏,可燃气体扩散受管道布局影响,在管道附近积聚,点燃后产生的喷射火焰将严重影响周边管道和设备的运行安全。针对集输站场并行管道小间距架空敷设的特点,建立泄漏扩散模型,模拟分析并行管道的喷射火焰高温覆盖范围,以此研究钢管理化性能的变化规律。研究结果表明,在天然气向平面喷射的情况下被点燃后,当管道间距不超过2 m时,泄漏点周围30 m的空间可产生1000 K以上的高温,从而使该高温范围内的钢管发生软化、组织相变,并出现附加内应力及裂纹等。建议集输站场内并行天然气管道的间距应大于2 m,并采用埋地铺设管道,以利用土壤进行火灾爆炸防护。

The Effect of Natural Gas Leakage Combustion on the Performance of Pipeline Steel Pipe

Once leakage occurs in the small spacing parallel pipelines of the natural gas gathering station,combustible gas diffusion is affected by pipeline layout and accumulates near the pipeline.The jet fire generated after ignition will seriously affect the operation safety of surrounding pipelines and equipment.In this paper,a leakage and diffusion model is established to numerically simulate the high temperature coverage area of the parallel pipelines with jet fire,so as to study the variation of the physical and chemical properties of steel pipes.The results show that under the condition of plane injection of natural gas,when the distance between pipelines is no more than 2 m,high temperature of more than 1000 K is generated in a space of 30 m around the leakage point after jet fire is generated in parallel pipelines,which can cause softening of steel pipe,microstructure transformation,internal stress and crack,etc.It is suggested that the spacing of parallel natural gas pipelines in the gathering and transportation station should not be less than 2 m,and the buried laying should be adopted,so as to protect pipelines against fire and explosion with soil.