Numerical simulation of a novel static mixer for hydrogen blended into natural gas

Injecting hydrogen into a natural gas pipeline network to deliver it directly to end-users as fuel is an effective method for reducing greenhouse gas emissions. Once hydrogen is injected, it must be uniformly mixed over short distances to ensure the safe operation of downstream equipment. This study introduces a static mixer comprising three corrugated‐plate structures. Numerical simulations were employed to investigate the effects of key parameters—including vertex angle, rotation angle, plate thickness, length‐to‐diameter ratio, placement position, body rotation angle, and number of mixing units—on mixing performance. An optimal design was explored using a comprehensive evaluation index based on the mixing uniformity and pressure loss. The results demonstrate that optimal mixing performance is achieved when the mixing units are installed 3D downstream of the initial mixing position (where D is the pipe diameter), the spacing between adjacent units is 10 times the plate thickness, and 2 mixing units are employed. Furthermore, the new design is structurally simpler than traditional static mixers and achieves the required industrial mixing uniformity within a shorter pipe length under identical operating conditions.