隨著全球減碳呼聲又起，如何有效率地利用生質能源，以達成環保與經濟雙贏，已經成為各國政府不可避免之問題。由於流體化床氣化爐具有高效率、低燃燒溫度、低汙染物排放及燃料選擇限制較低等優點。本研究以ANSYS-FLUENT為模擬工具，進行尤加利木屑於鼓泡式流體化床氣化爐內的模擬，並進行氣化爐操作參數之測試及分析。另外，本文以鼓泡式流體化床氣化爐為基礎，進一步建立雙流體化床氣化爐(Dual Fluidized-Bed Gasifier)之循環流場數值模擬分析。此雙流體化床氣化爐採用FICFB (Fast Internal Circulating Fluidized Bed)概念來設計，共分成兩個區塊：氣化流體化床區與燃燒流體化床區。這兩區域間利用固體顆粒流動串成一個循環迴路，並將燃燒產生之熱從燃燒區傳至氣化區，以利生質燃料之氣化反應。在生質燃料氣化模擬部分，顯示隨著ER值增加，合成氣中CO、CH4 和H2 的含量有下降的趨勢，而CO2 則呈現上升趨勢，此結果與實驗相符合。在雙流體化床氣化爐冷流場分析方面，這兩區域間利用床砂的流動來形成一個循環迴路，但氣體則保持分離。由模擬計算結果發現，在固相流場方面顯示床砂的流動已形成一個循環迴路。

With the global trend of low carbon emissions, it is inevitable to utilize biomass resources effectively. Since fluidized-bed gasifiers are characterized by the merits of high efficiency, low combustion temperature, low pollutant emissions, and less limitation on fuel selection, an analytical technology for the simulation of a bubbling gasifier with eucalyptus wood chips as the fuel has be developed in the present study by using the commercial CFD software, FLUENT. In addition, the numerical simulation of dual fluidized-bed gasifier is also developed in this study. The dual fluidized-bed gasifier is designed by adopting the concept of FICFB (Fast Internal Circulating Fluidized Bed), including two parts: the gasification zone and the combustion zone. Two zones are linked together as a circulation loop by flowing solid particles through the two zones. As a result, the heat produced in the combustion zone can be transferred to the gasification zone, facilitating the gasification reaction of biomass fuel. With increasing ER values, the content of CO, CH4, and H2 decrease, and that of CO2 increases in the bubbling gasifier. The result is consistent with the experiment. For the dual fluidized-bed gasifier, the solid particles looping through the two zones have been successfully simulated.

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