Numerical simulation of leakage and diffusion distribution of natural gas and hydrogen mixtures in a closed container. (5th October 2022)

• Record Type: Journal Article
• Authors: Li, Hao; Cao, Xuewen; Du, Huimin; Teng, Lin; Shao, Yanbo; Bian, Jiang
• Is Part Of: International journal of hydrogen energy. Volume 47:Number 84(2022)
• Page Start: 35928
• Page End: 35939
• Publication Date: 2022-10-05
• Subjects: Hydrogen -- Natural gas -- Mixtures -- Leakage diffusion -- Flammability limits; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2022.08.142
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The transportation and utilization of hydrogen blended natural gas have received extensive attention. The dangerous characteristics of hydrogen such as high diffusivity and wide flammability/explosion limit also increase the leakage risk of hydrogen blended natural gas. In this paper, a numerical model is established for the leakage and diffusion of hydrogen blended natural gas in a closed container. The evolution of the distribution, diffusion law and flammable area of different proportions of hydrogen blended natural gas after leaking into a closed container is investigated. The results show that the flammable area with low hydrogen ratios (20% and below) will disappear within 2.7 s–11.1 s after the leakage, which is relatively safer, while the high hydrogen ratio (80% and above) reaches 3875 s–4555 s with a significant increase in risk duration. After the 50% hydrogen ratio leakage, the thickness of the flammable area is higher than 15.67% for the 80% hydrogen ratio and 30.25% higher than pure hydrogen at 120 s after leakage, and the risk is higher in a short time. Due to the difference in the diffusion rates between methane and hydrogen, hydrogen diffuses to the middle and lower part of the enclosed container faster, and the risk in the middle and lower part also deserves attention. Highlights: Leakage and diffusion of CH4 –H2 mixtures with different ratios are investigated. Physical and mathematical model for diffusion of CH4 –H2 mixture is established. The diffusive motion difference between CH4 & H2 in closed container is analyzed. Distributions of different ratios of CH4 –H2 in closed container are studied. The development of flammable areas of different ratios of NG-H2 are obtained.