Development of Radial Expansion microchannel Cooler for High Heat Flux Data Center Cooling

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04320
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: University of Fukui (2021-2022); The University of Tokyo (2020)
• Principal Investigator: Dang Chaobin 福井大学, 学術研究院工学系部門, 准教授 (30401227)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 流動安定性 / 自己吸引沸騰 / 高熱流束冷却 / データセンター冷却 / 薄液膜蒸発 / 濡れ性 / レーザ共焦点変位計

Outline of Final Research Achievements

Firstly, the characteristics of thin liquid films in microchannels were evaluated using a laser confocal displacement meter and numerical analysis, confirming that the liquid films in triangular and rectangular tubes are thin. In addition, the characteristics of flow boiling and self-suction boiling using expanded channels were evaluated. The spontaneous flow characteristics of bubbles in the flow path were studied, revealing that expansion forces and surface tension affect the movement of the bubbles. Flow boiling experiement using expanded channels confirmed the configuration of a cooler network is possible through the series and parallel connection of coolers proposed. Furthermore, experimental results of boiling heat transfer characteristics of the heated surface facing downwards using expanded channels, and the self-suction boiling with a porous layer on the expanded flow path, confirmed that self-suction boiling has a higher cooling performance than pool boiling.

Free Research Field

熱工学

Academic Significance and Societal Importance of the Research Achievements

データセンターなどの電子機器やシステムの性能が向上するとともに、効率的な冷却手法の開発が求められている。本研究では、拡張流路を用いた流動沸騰および自己吸引沸騰手法を提案した。従来のシステムより流動安定性と伝熱性能が優れている上に、高熱流束や多熱源への対応も可能である。また、加熱面が下向きの条件での高性能な冷却を確認し、微小重力環境でも相変化伝熱システムの構築が可能になる。
さらに、薄液膜蒸発の流動と伝熱特性について実験、数値解析を行った結果、伝熱管の形状、流体の物性、運転条件が伝熱特性にどのように影響を与えるかを明らかにした。