本文係延續先前研究【9】有關固液相變化微粒懸浮流體之矩型熱虹迴路幾何尺寸對迴路加熱與冷卻段的熱傳遞效率之數值模擬；所考慮迴路係由置於下方水平段之等熱通量加熱段、迴路右垂直段上方之等溫冷卻段、及其間隔之絕熱段所組成。本研究旨在探討考慮迴路管壁熱傳導與相變化微粒懸浮流體自然對流共軛熱傳遞特性對加熱段與冷卻段熱傳遞效率之影響。本文數值模擬所考慮迴路相關幾何參數係依先前研究【9】研究所得加熱段與冷卻段最佳熱傳效率之組合；分別為：（1）加熱段最佳效率的尺寸：寬高比AR=1、加熱段無因次長度lh*=0.4、冷卻段中心位置距水平段無因次高度lz=0.75；（2）冷卻段最佳效率的尺寸：AR=1，lh*=0.8，lz=2。此外，本文相關物理參數之探討範圍則為：修正萊利數，Ra*=10E10~10E11、管壁對流體的熱傳導係數比，kwf*=0.1~100、PCM微粒體積濃度，cv=0~10% 。數值結果顯示在選擇適當的管壁厚度(tw)與管壁對流體的熱傳導係數比(kwf*)下，管壁與迴路相變化微粒懸浮流體之共軛熱傳遞現象有進一步提升加熱段或冷卻段熱傳效率之效。

　　This work is a follow-up to the earlier study [9] in which the optimum geometric parameters have been found numerically for effectiveness of temperature control/heat transfer enhancement over heated/cooled sections, respectively, in a rectangular natural circulation loop containing the soli-liquid phase change material suspension. The loop considered was composed of a heated section of constant heat flux along the bottom horizontal leg, a cooled section of constant wall temperature, and two adiabatic sections between them. Here the conjugate heat transfer characteristics associated with the axial conduction along the loop wall were taken into account for the optimum geometric parameters found in [9], which are: (1) for optimum temperature-control effectiveness over the heated section: aspect ratio of rectangular loop AR=1, the dimensionless length of heated section lh*=0.4, the dimensionless mean relative elevation of the cooled section to the bottom horizontal leg lz=0.75; and (2) for optimum heat transfer effectiveness along the cooled sections: AR=1，lh*=0.8，lz=2. The physical parameters relevant to the present problem and their ranges are as follows: the modified Rayleigh number, Ra*=10E10~10E11; the thermal conductivity ratio of wall to suspending fluid, kwf*=0.1~100; volumetric fraction of PCM particles, cv=0~10%. Numerical results reveal that with proper selections of tw and kwf* the conjugate heat transfer between the loop wall and PCM suspension can lead to further enhanced heat transfer effectiveness over the heated as well as the cooled sections of the rectangular loop.

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