複合金網ウイックヒートパイプの熱輸送限界

Abstract

Maximum heat transfer rates due to capillary limitation were investigated in planar heat pipes with composite wicks which consisted of a fine screen on top of a coarse screen wick. Water was used as a working fluid. The liquid-vapor interface in an evaporator seems to recede into wick and to terminate at the first layer from the heat transfer surface. An equation for the permeability of the composite screen wicks was derived by taking account of the free surface and the interface between the fine and the coarse screen wicks. The maximum heat transfer rates were predicted by using the permeability obtained above and by considering the recess of the liquid-vapor interface in the evaporator. Consequently, the calculated maximum heat transfer rates agreed with the experimental ones within a +/- 30 percent error.

目の粗い金網の上に目の細かい金網を積層した複合ウイックを用いた平面ヒートパイプにおける、毛細管圧力限界に基づく最大熱輸送量について研究した。作動流体として水を用いた。蒸発部の気液界面がウイック内へ後退し、伝熱面の最初の層で終了するものとした。自由表面および細および粗金網ウイック界面を考慮して複合金網ウイックの浸透方程式を導出した。上記導出の浸透係数を用い、蒸発部での気液界面の後退を考慮して最大熱輸送量を予測した。その結果、最大熱輸送量の計算値は実験値と±30％の誤差内で一致した。