低封入率型自励振動ヒートパイプの熱輸送性能に関する基礎的研究（設置姿勢が熱輸送性能に及ぼす影響）

抄録

The heat generation density of electronic components has increased as they have become smaller and more powerful. Various types of heat pipes have been used as thermal control devices, utilizing heat transport by the gas-liquid phase change of refrigerant. Pulsating Heat Pipe (PHP) has attracted much attention because of its compactness and high heat transport performance. This study is on Low Filling Ratio Pulsating Heat Pipe (LFR-PHP), which can realize more efficient heat transport than conventional PHP. The appearance and experimental outline are the same as those of the conventional PHP, but the amount of working fluid filled is extremely low (10 vol.%), which is considered to cause dry-out in the conventional system. Although the LFR-PHP achieves highly efficient heat transport, the details of the heat transport characteristics, such as the operating principle, have not yet been clarified. In this report, the effects of the installation posture of LFR-PHP (bottom-heat, horizontal-heat, and top-heat posture) on the heat transport performance were investigated. As a result, In the bottom-heat position, the minimum thermal resistance of LFR-PHP was 0.18 K/W, which was about 1/5 times higher than that of conventional PHP and it was confirmed to operate at filling ratios of 3 to 10 vol.%. Experiments with different heat exchange section ratios in the bottom-heat and horizontal positions showed that the heat transport distance was increased and the heat transport performance was improved by adding 60 area.% of adiabatic section area. in the horizontal position, the LFR-PHP was cooled efficiently by placing the heating section in the center of the LFR-PHP, and heat transport performance of it was approximately the same as that of bottom-heat position. In the top-heat posture, it operated when the heating section was 50 area.%, with a minimum thermal resistance of 0.22 K/W.