液体水素中での気泡の発生・成長の可視化に成功 ―大規模水素サプライチェーンの実現に貢献―

2026-08-19 東北大学

東北大学と宇宙航空研究開発機構(JAXA)の研究グループは、20 K(約−253℃)の極低温環境にある液体水素中で、加熱面から発生する気泡の生成・成長・離脱過程を可視化することに成功した。液体水素は大規模な貯蔵・輸送に適している一方、輸送中の気化を抑えることが重要な課題となっている。今回、気泡の発生頻度や成長速度を定量的に測定するとともに、液体水素特有と考えられる気泡の振動現象を発見した。これは、低密度という液体水素の物性が気泡挙動に影響することを示す成果である。液体水素の沸騰や気液二相流、熱・物質移動の理解を深めることで、液化水素の輸送・貯蔵設備の設計高度化や気化損失の低減につながり、大規模な水素サプライチェーンの構築への貢献が期待される。

液体水素中での気泡の発生・成長の可視化に成功 ―大規模水素サプライチェーンの実現に貢献―

図1. 20 Kの液体水素中に設置した加熱面から発生する気泡の挙動を捉えた画像。

<関連情報>

液体水素プール沸騰における気泡挙動と熱伝達特性の可視化 Visualization of bubble behavior and heat transfer characteristics in liquid hydrogen pool boiling

Masaharu Kubota, Yuki Sakamoto, Junnosuke Okajima
International Communications in Heat and Mass Transfer  Available online: 30 July 2026
DOI:https://doi.org/10.1016/j.icheatmasstransfer.2026.112160

Highlights

  • High-speed imaging visualized liquid hydrogen pool boiling at 0.1–0.3 MPa.
  • Hydrogen boiling curves and critical heat flux determined at 0.1–0.3 MPa.
  • Rohsenow correlation empirical constant calibrated to 0.021 for hydrogen‑copper.
  • Fluid and solid heat conduction govern bubble growth and departure frequency.

Abstract

Visualization and evaluation of the heat transfer characteristics of liquid hydrogen boiling are essential for establishing a hydrogen supply chain. In this study, pool boiling experiments were conducted under 0.1–0.3 MPa to investigate the effects of pressure on cryogenic boiling using high-speed visualization. The results indicated that pressurized conditions yielded higher values of the boiling heat transfer coefficient and critical heat flux in this pressure range. The measured boiling heat transfer coefficients were compared with existing correlations, suggesting that the Rohsenow correlation demonstrated good agreement with our findings. Specifically, the empirical coefficient of the Rohsenow correlation was determined to be 0.021 for the liquid hydrogen‑copper combination within the pressure range of 0.1–0.3 MPa. Furthermore, the boiling characteristics of liquid hydrogen were successfully visualized under steady-state nucleate and film boiling regimes. High-speed visualization of the isolated liquid hydrogen bubbles demonstrated that their growth is governed by heat conduction within both the fluid and solid. While vertical oscillations associated with capillary waves were observed, we hypothesize that, in the low buoyancy environment, minute bubbles accumulate and coalesce into a larger mass before undergoing macroscopic departure.

0105熱工学
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