Simulation and experimental investigation on the static mixer of natural gas mixed with hydrogen.

Hydrogen mixing technology in natural gas pipelines facilitates the large-scale application of hydrogen energy, thereby promoting energy savings and emission reductions. The performance of gas equipment is significantly influenced by the mixing uniformity of hydrogen mixing devices within the natural gas. This study involves the design and optimization of a static mixer structure for hydrogen mixing in natural gas, employing a combination of numerical simulations and experimental approaches. The effects of mixing pressure, mixing ratio, and mixing flow rate on the mixing uniformity are analyzed. Results indicate that the mixing effect can be improved by adding an expanding pipe, adding solid boards, and introducing hydrogen into the natural gas pipeline via swirl and sidewall annular gap entry methods. Increasing the diameter of the natural gas pipe or adding an expanding pipe effectively reduces pressure loss. The influence of mixing pressure on mixing uniformity is minimal. As the mixing ratio or mixing flow rate increases, the uniformity initially improves and then declines, peaking at a mixing ratio of 10 % and a mixing flow rate of 10 m³/h, respectively. [Display omitted] • A new static mixer for mixing hydrogen into natural gas pipeline is designed. • The experiment of static mixer for natural gas mixing with hydrogen is supplemented. • Static mixers for blending hydrogen with natural gas are designed and optimized. • The influence of static mixer structure on the mixing effect is studied. • The influence of operating conditions like mixing ratio on uniformity is studied. [ABSTRACT FROM AUTHOR]