臺灣大學: 機械工程學研究所顏瑞和鄭兆偉2013-04-012018-06-282013-04-012018-06-282011http://ntur.lib.ntu.edu.tw//handle/246246/256082由於太陽能噴射式製冷系統技術日益成熟，無論是量產化地裝設在各家各戶，或是巨大尺寸的設計，成本的負擔絕對不容小覷；因此，本研究特地針對噴射器中最顯著的長度-等截面段長度進行研究，在不影響性能的前提下，節省最多的噴射器長度，以符合成本與性能的最佳平衡。 本研究使用商用計算流體力學(CFD)軟體Fluent，針對噴射器流場研究後發現，等截面段長度的改變對流場的影響與冷凝器溫度造成的影響幾乎雷同，且定義了最佳化等截面段長度，可維持最佳化性能且得到最短的等截面段長度。配合可調式噴嘴噴射器，分析產生器溫度、蒸發器溫度、冷凝器溫度以及主噴嘴喉部面積對最佳化等截面段長度的影響；其中，當操作在較高溫的蒸發器溫度時，對於縮短等截面段長度有顯著的效果，同時也具有提昇臨界溫度及抽吸比等優點。當操作溫度範圍為產生器溫度90~110℃、蒸發器溫度8~20℃以及冷凝器溫度35~40℃時，最佳化等截面段長度為95mm，相較於原始等截面段長度100mm僅能縮短5％；然而，操作在高蒸發器溫度如20℃時，在不同的產生器以及冷凝器溫度的變化下，最佳化等截面段長度可縮短至50mm，縮短了50％的等截面段長度，其中，當產生器溫度為90℃、蒸發器溫度為20℃、冷凝器溫度為35℃時，等截面段可再縮短至20mm，縮短80％的等截面段長度。未來可結合Huang、汪與吳等人的太陽能輔助製冷供熱技術，其噴射器系統中，蒸發器具有可操作在較高溫度的特性，可為等截面段長度帶來更顯著的節省效果。For the practical use and reducing manufacture cost, it needs to make the ejector system in compact form. Therefore, the topic of this research is to reduce the significant length of an ejector, the constant area throat length, L3. In this study, a commercial CFD package, FLUENT, was used to research and design the ejectors. The influence of the ejector flow field by L3 is similar with the condenser temperature. And the optimal constant area throat length, L3*, was defined in this research. L3* changes significantly when the evaporator temperature is changed. As a conclusion in a variable throat nozzle ejector, operating with wide range of the generator temperature, Tg, from 90℃ to 110℃, evaporator temperature, Te, from 8 to 20℃ and condenser temperature, Tc, from 35 to 40℃, L3* can only be 5% shorter than that of the original design. As the ejector is applied to the hybrid solar-assisted cooling system in which the evaporator can operating at a higher temperature as at 20℃, L3* can be 50% shorter than the original design. As Tg at 90℃, Te at 20℃, Tc at 35℃, L3* can be 80% shorter than the original design.17919034 bytesapplication/pdfen-US太陽能噴射式製冷系統噴射器等截面段數值模擬Solar-driven ejector refrigerationEjectorConstant area throat lengthNumerical simulation.thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/256082/1/ntu-100-R98522116-1.pdf