周賢福臺灣大學：機械工程學研究所劉家良Liu, Chia-LiangChia-LiangLiu2007-11-282018-06-282007-11-282018-06-282005http://ntur.lib.ntu.edu.tw//handle/246246/61412近年來，由於溫室效應的影響，冷凍空調設備的需求量也與日俱增，如何有效的提高冷凍空調系統的工作效率，即可大量的降低用電量。本研究是將噴霧裝置應用在複合式熱交換器上，探討各種不同的操作條件下，如噴霧顆粒大小、風扇吹否、不同型式的複合式熱交換器等，對於熱傳效率的影響，以找出最佳化的設計，應用在冷凍空調設備上。 研究的結果顯示複合式熱交換器(有裸露銅管)在噴霧顆粒較小及有風扇吹拂時的熱傳效果最好；在風扇不吹拂的情況下，噴霧顆粒較大的反而熱傳效果較好；只吹風不噴霧又比只噴霧不吹風的熱傳效果好。總體而言，噴霧裝置應用在熱交換器上，大大的提升了傳統熱交換器的熱傳效果。Recently, due to the global warming caused by the green house effect of various gases, the need of refrigeration and air-conditioning has been increased day by day. Increasing the efficiency of the refrigeratiion and air-conditioning system could reduce the electrical power consumption directly. The objective of present study is to apply the swirl atomizer to spray fine droplets on the composite heat exchangers, in order to perform an investigation on the controlling parameters associated with the droplet diameter, the forced convective effect, the changes in the types of the heat exchangers, and the effect on the over all heat transfer rate. Optimal operating conditions adapt to the refrigeration and the air-conditioning system is to be found. According to the experimental results, the simultaneously effects of evaporation cooling with smaller spraying droplets and forced convection cooling could significantly enhance the heat transfer efficiency of the composite heat exchangers. But with no fan operating for forced convection, the heat transfer efficiency of spraying with the large droplets is better than the one with the small droplets. The efficiency of forced convection is better than spraying droplets when each one is operated alone. In conclusion, applying swirl atomizers to the composite heat exchanger could provide pronounced enhancement on its heat transfer efficiency.第一章 導論 1.1 研究動機................................................................................1 1.2 文獻回顧................................................................................2 1.3 研究目的................................................................................4 第二章 理論基礎 2.1 實驗系統................................................................................6 2.2 噴霧散熱之總熱傳係數..................................................7 2.2.1 液膜區...........................................................................7 2.2.2 乾燥區.........................................................................11 2.2.3 總熱傳係數U..............................................................12 第三章 實驗設備與步驟 3.1 實驗設備..............................................................................14 3.2 量測裝置..............................................................................16 3.3 實驗步驟..............................................................................17 第四章 結果與討論 4.1 理論預估..............................................................................19 4.1.1 噴霧顆粒大小的影響...................................................19 4.1.2 有無風扇吹拂之影響..................................................20 4.1.3 不同型式的複合式熱交換器之影響..........................21 4.2 實驗結果.............................................................................21 4.2.1 噴霧散熱與傳統風扇散熱的探討..............................21 4.2.2 不同噴霧顆粒對熱傳效果的探討..............................23 4.2.3 不同複合式熱交換器對熱傳效果的探討..................23 4.3 誤差討論.............................................................................25 4.4 最佳化設計……………………………………………….25 第五章 結論與建議 5.1 結論......................................................................................27 5.2 後續研究之建議..................................................................29 參考文獻..................................................................................................31 附圖..........................................................................................................34 附表.........................................................................................................51 附錄.........................................................................................................66648424 bytesapplication/pdfen-US噴霧霧化熱交換器swirl atomizerheat exchangerthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/61412/1/ntu-94-R92522318-1.pdf