HOME > Profile > NATSUME, Kyohei
- TEL
- 029-863-5436
- Address
- 305-0003 3-13 Sakura Tsukuba Ibaraki JAPAN [Access]
Accepting Students
Research
PublicationsNIMS affiliated publications since 2004.
Research papers
- Tsuyoshi Shirai, Mohamed G. Gado, Takashi Hirayama, Kyohei Natsume, Koji Kamiya, Masayoshi Ishida. Mechanical work and efficiency evaluation of a tandem active magnetic regenerator for hydrogen liquefaction. Cryogenics. 161 (2026) 104405 10.1016/j.cryogenics.2026.104405
- Koji Kamiya, Kyohei Natsume, Akira Uchida, Takenori Numazawa, Tsuyoshi Shirai, Akiko T. Saito, Koichi Matsumoto, Shinji Masuyama. Hydrogen liquefaction by active magnetic regenerative refrigeration. Cryogenics. 152 (2025) 104205 10.1016/j.cryogenics.2025.104205 Open Access
- Mohamed G. Gado, Tsuyoshi Shirai, Yusuke Yoshida, Akira Uchida, Takashi Hirayama, Takenori Numazawa, Kyohei Natsume, Koji Kamiya. Experimental assessment and comparative analysis of active magnetic regenerative refrigeration for hydrogen liquefaction using HoAl2 and ErAl2. Cryogenics. 158 (2026) 104347 10.1016/j.cryogenics.2026.104347
Proceedings
- KAMIYA, Koji, NATSUME, Kyohei, NUMAZAWA, Takenori, 松本 宏一, SAITO, Akiko, SHIRAI, Tsuyoshi, UCHIDA, Akira. Magnetic refrigerators for hydrogen liquefaction. Proceedings of 26th International Congress of Refrigeration 2023. 1 (2023) 46-60 10.18462/iir.icr.2023.1148
- 増山 新二, NATSUME, Kyohei, KAMIYA, Koji, 沼澤 健則. Achievement of 120 W at 80 K by Synchronous Operation of Two Single-Stage G-M Cold Heads Driven by a 2 W Class Compressor. Cryocoolers 23. NA (2024) 185-191
Presentations
- GADO, Mohamed, SHIRAI, Tsuyoshi, NATSUME, Kyohei, UCHIDA, Akira, NUMAZAWA, Takenori, KAMIYA, Koji. SURVEYING DIFFERENT MAGNETOCALORIC MATERIALS USING AN ACTIVE MAGNETIC REGENERATIVE REFRIGERATOR (AMRR) FOR HYDROGEN LIQUEFACTION. THERMAG XI 2026 | 11th IIR International Conference on Caloric Cooling and Energy Harvesting. 2026 Open Access
- GADO, Mohamed, SHIRAI, Tsuyoshi, NATSUME, Kyohei, UCHIDA, Akira, Takenori Numazawa, KAMIYA, Koji. Evaluation of magnetic hydrogen liquefaction system using potential magnetocaloric materials. 第111回 低温工学・超電導学会研究発表会. 2026 Open Access
- 白井 毅, ガド モハメド ゲーバーアブデルサイド, 山本 春海, 内田 公, 平山 貴士, 夏目 恭平, 神谷 宏治, 石田 政義. 磁気冷凍における磁場勾配設計による投入仕事低減. 第111回 低温工学・超電導学会研究発表会. 2026 Open Access
Misc
- 神谷 宏治, 夏目 恭平, 沼澤 健則, 飯田光人, 篠崎慶亮, 島田潤. 推薬液化エネルギーを低減する磁気冷凍技術の研究開発. 第66回宇宙科学技術連合講演会 予稿集. 該当なし [該当なし] (2022) JSASS-2022-4054
- 夏目 恭平, 神谷 宏治. 磁気冷凍による水素液化. 金属. 93 [7] (2023) 23-27
- 松永 信之介, 神谷 宏治, 夏目 恭平, 荻野 靖之, 島田 潤. 月面における推薬液化用磁気冷凍機の成立性の検討. 宇宙科学技術連合講演会講演集. 66 [0] (2023) 2L12
Published patent applications
- 低温ポンプを用いた磁気冷凍装置及び液化装置 (2026)
- 磁気冷凍装置および磁気冷凍方法 (2025)
- 低温ポンプを用いた磁気冷凍装置及び液化装置 (2026)
Society memberships
低温工学・超電導学会
Research Center for Energy and Environmental Materials (GREEN)
Development of a high-efficiency hydrogen liquefier/refrigerator
Magnetic refrigeration, liquid hydrogen, cryogenics
Overview
LLiquid hydrogen is attracting attention as one of the candidate new energy carriers in a society aiming for carbon neutrality, and it is expected to play a new role and offer new possibilities in distributed power generation systems using renewable energy, as well as in mobility applications (buses, trucks, railways, ships, aircraft, and so on). While liquid hydrogen is a promising carrier from the standpoint of energy density, liquefaction requires cooling it to an extremely low temperature of 20 K (-253°C) at 1 atmosphere. In addition, during transport and storage, gas continuously evaporates due to natural heat ingress from the surroundings. In this research, we are developing and improving the efficiency of hydrogen liquefiers and of re-condensers, which reliquefy the evaporated gas (boil-off gas) and return it to the storage tank.
Novelty and originality
● Compared to conventional gas-cycle refrigerators that use gas compression and expansion, magnetic refrigerators have a higher theoretical liquefaction efficiency.
● Since it does not require a compressor, which is necessary for gas-cycle refrigerators, it enables a smaller size, lower power consumption, and quieter operation.
● By using a magnetic material optimized for the hydrogen liquefaction temperature (~20 K), the magnetocaloric effect can be maximized.
● With a new method called Active Magnetic Refrigeration (AMR), it is possible to expand the operating temperature range, which had previously been considered a weakness of magnetic refrigeration.
Details
In AMR, granular magnetic working material is packed into a container, and heat exchange gas is made to flow through the gaps between the particles in synchronization with the application of the magnetic field, thereby transporting the heat/cold generated in the magnetic working material. In the opposed-arrangement type AMR, the magnetic working material is located in two places, and a single magnet that generates the magnetic field moves back and forth. In the four-fold opposed-arrangement rotary AMR developed at NIMS, the magnetic working material is arranged in eight equal segments, and the magnetic field is varied by rotating four magnets.
This research aims to develop a magnetic refrigeration system that is more efficient than conventional systems. The figure above shows an example of a magnetic refrigerator built for hydrogen re-condensation; we are using this device to study how to improve the efficiency of hydrogen re-condensation through magnetic refrigeration. By changing the magnetic working material and the magnet material, the system can be adapted to a wide range of temperature ranges, giving it broad applicability.
Summary
[Achievements to Date] We succeeded in developing and demonstrating the principle of a refrigerator for hydrogen re-condensation that combines permanent magnets with a four-fold opposed-arrangement rotary AMR.
[Future Challenges] Further improvement in efficiency is desirable. Key challenges include optimizing the thermal design, including the heat exchangers, increasing the magnetic field strength of the magnets, and increasing the capacity of the magnetic working material.
[Path to Practical Application] We aim to conduct element-level tests of each component and, by integrating them, achieve a proof of concept toward practical application.
