Transportation of Mixed Hydrogen Gas in Buried Pipelines in Permafrost Areas

The application of existing gas transmission pipelines to deliver hydrogen-blended natural gas is the most operable method among many delivery methods. Hydrogen-blended natural gas with different hydrogen-blending ratios after passing through the throttling element is not the same. Using FLUENT to analyze the temperature variation after the Joule–Thomson effect for 0%, 5%, 10%, 20%, and 30% hydrogen mixing ratios. Workbench is used to analyze the soil temperature field around the pipeline and the stress displacement of the buried pipeline in the permafrost zone under different hydrogen mixing ratios. The analysis revealed that as the hydrogen mixing ratio increases, the temperature of the same point gradually increases after the Joule–Thomson effect, the low-temperature area around the buried pipe is gradually replaced by the high-temperature area, and the stress of the buried straight pipe also gradually decreases; while the maximum stress of the pipe initially decreases and then increases, and the displacement has no obvious change.