本研究所設計的迴路式虹吸熱管包含蒸發室（內徑25mm，高度25mm）、冷凝區、汽相流道（外徑6mm）與液相流道（外徑4mm）四個部分，以銅銀硬銲的方式接合。冷凝區的設計包含七個平滑的垂直管(外徑4 mm, 長80mm)，其外部尺寸為80mm x 12mm x 104mm。採用三種增強沸騰結構，分別為無燒結結構、厚度1mm與4mm的燒結結構，其長寬尺寸為17.3mm x 17.3mm，銅粉末平均粒徑與孔隙率分別為185.5μm與53.7%，使用甲醇與去離子水為工作流體。探討充填量與增強沸騰結構對於性能影響，經由實驗獲得以下的結論： 1.在各組實驗測試中，甲醇與去離子水的最佳充填率分別為10%與30%。甲醇比去離子水呈現較低的加熱面溫度。 2.工作流體為甲醇時，較佳的效能為燒結厚度1mm，充填量為最佳的10％，與無燒結結構比較，其有效降低加熱面溫度平均為9.21℃。 3.工作流體為去離子水時，較佳的效能為燒結厚度1mm，充填量為最佳的30％，但是厚度4mm的燒結結構與之無太大的差異，與無燒結結構比較，其有效降低加熱面溫度平均為3.50℃。 4.由實驗結果顯示冷卻水溫度越低，真空度越高其散熱性能越好。 Abstract: The loop thermosyphon in this research paper is consisting of an evaporator (inner diameter 25mm, height 25mm), a condenser, riser (outer diameter 6mm) and downcomer (outer diameter 4mm) are investigated experimentally. All parts are made of copper, and welded together. And most importantly the condenser consists of 7 vertical smooth copper tubes (4 mm OD, 80mm length), and the outer dimensions (90mm x 19mm x 106mm). The experimented shows that there are three types of enhanced boiling structures. The first type evaporator is flat with smooth boiling surface. The others are 17.3mm square, 1mm and 4mm thickness of sintered copper. The average diameter of copper powder and the porosity is 185.5μm and 53.7% respectively while obviously using D.I. water and methanol as working fluid. The experiment was investigated to evaluate the optimum filling ratio of working fluid and the performance of the enhanced boiling sintered copper structure. The results of the successful performance are as follows: 1.The optimum filling ratio of methanol and D.I. water are 10% and 30% respectively in each experimental test. Methanol always shows a lower Die temperature than D.I. water. 2.The better performance for using methanol is 1mm thickness sinter with 10% filling ratio. Comparing with the smooth plate and the effect of 1mm sintered copper for temperature of Die, the average reduction was shown 9.21°C with methanol. 3.The better performance for using D.I. water is used 1mm thickness sinter with 30% filling ratio. Comparing with the smooth plate and the effect of 1mm sintered copper for temperature of Die, the average reduction was indicated 3.50°C with D.I. water. But the performance of 4mm thickness sinter is nearly to 1mm thickness sinter. 4.The lower the temperature of cooling water and the higher vacuum, which causes to lead the higher performance.