H2作为新能源重要发展方向之一,与传统化石燃料相比,具有热值高、产物不污染环境、来源广泛、可再生的显著优势,被称为未来的清洁能源,将成为人类未来解决日益严峻的能源和环境问题的一条新途径。H2运输是氢能利用的重要环节,采用可靠的管道输送方式连接H2气源与目标用户,是优化能源消耗、推动氢能利用的关键。相比于高纯氢管道,混氢天然气管道具有资源调配灵活、资源利用率高的特点,可供上游H2产品掺混进入天然气管道,实现同管远程输送,这将是未来较为热门的H2资源运输和利用途径。H2作为量子气体,难压缩、难混合、难保存,同时H2易泄漏,且爆炸极限宽(4%～75%),掺入天然气后,介质特性更复杂,必须重点关注其安全设计问题。基于H2物理特性,结合混氢天然气存在的问题分析,对比常规天然气管道安全设计问题,深入剖析混氢天然气管道的安全设计要点,以期进一步揭示相关规律。研究结果表明:设备与管道停运后混氢天然气将出现较明显的组分分层现象;混氢天然气管道放空设计需避免介质自燃问题;混氢天然气管道安全设计尚需开展大量工作。研究成果可为混氢天然气管道安全设计提供相关参考。

As one of the important development directions of new energy resources, hydrogen, compared with traditional fossil fuels, has the significant advantage of high calorific value, pollution free, wide source of supply and is renewable. It is called clean energy of the future and will become a new way for mankind to deal with the worsening energy issues and environmental situations in the future. Hydrogen transportation is an important part of hydrogen energy utilization. The use of reliable pipeline transportation to connect hydrogen gas sources with target users is the key to optimize energy consumption and promote the utilization of hydrogen energy. Compared with the high-purity hydrogen pipeline, the hydrogen blended natural gas pipeline has the characteristics of flexible resource allocation and high resource utilization rate, which can be used for the blending of upstream hydrogen products into adjacent natural gas pipelines and realize the transportation of multiple media in the same pipeline. This will be a popular way to transport and utilize H₂ resources in the future. Hydrogen, as a quantum gas, is difficult to compress, mix, and store. At the same time, hydrogen leaks easily, and has a wide range of explosion limit (4% to 75%). When natural gas is blended with hydrogen, the mixture is much more complex and attention must be paid to its safety in design. Based on the physical properties of hydrogen, combined with the analysis of the existing issues of hydrogen-blended natural gas, this paper compares the safety in design with conventional natural gas pipeline, and provides an in-depth analysis for the safety in design of hydrogen-blended gas pipelines, in order to further reveal the laws of nature. The research results show that there will be obvious component stratification upon the shutdown of hydrogen blended natural gas distribution equipment and pipelines; the design of the venting of the hydrogen-blended natural gas pipeline shall have to avoid auto ignition of the vented gas. There is still much work to be done on the safety in design of hydrogen blended natural gas pipelines. The results of this study can provide relevant references for the safety in design of hydrogen-blended natural gas pipelines.