| 摘要: | 本實驗將震盪型熱管原理應用於均熱片，期望克服金屬均熱片的缺陷，並利用對流方式增強均熱性能。本研究共設計了兩種不同尺寸、兩種不同流道迴路以及兩種不同流道寬度的平板震盪型熱管均熱片，並實驗20 %、50 %以及80 %三種不同填充率，希望藉由實驗得知不同設計參數之平板震盪型熱管均熱片性能差異。 固定熱源大小為10 × 10 mm，若均熱片尺寸較大，會因為驅動力無法克服流動阻力，因此無法觀察到震盪現象。在相同加熱量及填充率的條件下，單一迴路流道設計的熱傳性能優於雙向迴路式的設計。將填充率固定為50 %，則發現流道寬度1mm時，加熱量15 W即可發現震盪現象。流道寬度0.5 mm，則於加熱量20 W時才有震盪現象。在改變填充率的實驗中發現，填充率20 %於加熱量15 W時可降低擴散熱阻，但是當加熱量提高，則無此作用。當加熱量超過20 W，填充率為50 %以及80 %時，皆能降低擴散熱阻。 由於流道所產生之流動阻力會影響液體流動性，因此僅產生微幅震盪，對均熱性的提升有限。因此需盡量減少流動阻力，使得震盪幅度增加，才能有效增強均熱性。 This article is trying to develop a new kind heat spreader, which were used the theory of pulsating heat pipes. Channels were manufactured on copper plate, to finish the flat plate pulsating heat pipes. When heat input, fluid makes phase changes, produce the vapor pressure difference between the evaporation area and condensation area, the major heat transfer mechanism in a pulsating heat pipe is the sensible heat of liquid. Channels arrangement designed to two types, which were single loop and double side loop. In order to understand the influence by the wide of channel, there are two kinds of channel size, which wide were 0.5 mm and 1 mm. In this article, also experiment three fill rate, which were 20 %、50 % and 80 %. The heat transfer characteristics of flat plat pulsating heat pipes were investigated experimentally. The experimental results at the same input heat and same fill rate, the single loop design which heat transfer performance better than the double side loop. When fix the fill rate as 50 %, the minimum heating power is 15 W at 1 mm wide channel, 20 W at 0.5 mm wide channel. In the experiment of different fill rate, when fill rate 20 %, pulsation only occurs at heating power 15 W, as the heating power increase, pulsation stop. Also found that the optimal fill rate is around 50 % and 80 %. The drag force which caused by the channel walls will decrease the liquidity, also decrease the range of pulsation. In order to decrease the spreading resistance, we should make the design of channel better. |
