Abstract: | 本論文是利用內徑2.4mm外徑3mm的銅管做震盪式熱管實驗。比較20nm的銀奈米流體在不同濃度(100ppm、450ppm)或不同充填量(20%、40%、60%、80%)下,在不同加熱瓦數(5w、15w、25w、35w、45w、55w、65w、75w、85w)下效率之探討,並與純水(Pure Water)做比較。總括而言,充填率在中間值(40%、60%)的效果較好,其中又以60%效率較好的居多,此可能是因為此兩個充填量在高瓦數時氣泡生成量與脈動效果勢均力敵,因此在顯熱交換方面效果相當,但60%相對於40%而言有較多的液柱可供顯熱交換,因此比較上充填率60%的散熱效果較好。整體而言各組最佳的充填率是60%,而各個充填率下最佳的充填液體是100ppm的銀奈米水溶液。其在充填率60%下加熱瓦數85W時,溫差較同充填量下的純水低了7.79℃,熱阻低了0.092℃∕W。 This paper reports on preliminary experimental results on using copper tube having internal and external diameter with 2.4 mm and 3 mm respectively to carry out the experimental pulsating heat pipe. In order to study and measure the efficiency, we compare with 20 mm silver nano-fluid at different concentration (100ppm and 450ppm) or in the different filled ratio (20%, 40%, 60% and 80%), also applying with different heating power (5W, 15W, 35W, 45W, 55W, 65W, 75W and 85W). Finally we make a comparison with pure water. In a word, the result in the mid value (40%, 60%) of filled ratio is better. In the majority 60% of efficiency is considered much better. May be in these two filled ratio at high heating power, the power in the bubble production amount and pulsation gets balanced. The result is analogous in sensible heat exchange, 60% has more liquid slugs that are suitable for sensible heat exchange as to 40%, so in 60% of filled ratio, heat dissipation result is better than 40%. On the whole the best filled ratio is 60%, and the best filled fluid is 100ppm in silver nano-fluid. When the filled ratio is 60% and the heating power is 85 W, the difference of temperature is less than 7.79 ℃ at this same filled ratio, and the thermal resistance is also less than 0.092℃/W. |