TY  - EJOU
AU  - Wang, Mengjie 
AU  - Li, Jingfa 
AU  - Yu, Bo 
AU  - Wang, Nianrong 
AU  - Wang, Xiaofeng 
AU  - Hu, Tao 

TI  - Experimental Study of Hydrogen Distribution in Natural Gas under Static Conditions
T2  - Fluid Dynamics \& Materials Processing

PY  - 2025
VL  - 21
IS  - 12
SN  - 1555-2578

AB  - The adaptation of existing natural gas pipelines for hydrogen transportation has attracted increasing attention in recent years. Yet, whether hydrogen and natural gas stratify under static conditions remains a subject of debate, and experimental evidence is still limited. This study presents an experimental investigation of the concentration distribution of hydrogen–natural gas mixtures under static conditions. Hydrogen concentration was measured using a KTL-2000M-H hydrogen analyzer, with a measurement range of 0–30% (by volume), an accuracy of 1% full scale (FS), and a resolution of 0.01%. Experiments were conducted in a 300 cm riser, filled with uniformly mixed hydrogen–methane standard gas, under various static conditions, including different hydrogen blending ratios (5.03%, 10.03%, and 19.79%), pressures (0.5 MPa, 2 MPa, and 4 MPa), and inclination angles (0°, 45°, and 90°). Results show that, at identical pressures and an inclination angle of 90°, the presence of hydrogen at both ends of the riser remain nearly the same, indicating that the blending ratio exerts no significant influence on stratification. Moreover, across different pressures, the composition of the mixture remains highly uniform, with the maximum difference between the top and bottom of the riser limited to approximately 0.02%, well within the instrument’s margin of error—demonstrating that pressure has a negligible effect on hydrogen stratification. Similarly, variations in inclination angle exert minimal influence on hydrogen distribution. At 4 MPa, the concentration difference between the top and bottom ranges from 0.01% to 0.02%, confirming the absence of measurable stratification within experimental accuracy.
KW  - Hydrogen-blended natural gas; hydrogen blending ratio; concentration distribution; hydrogen stratification; riser; inclination angle

DO  - 10.32604/fdmp.2025.071675