臺灣博碩士論文加值系統

由於目前溫室產業的發展越來盛行，為了提升作物的品質且降低生產成本，於是本文選定栽培杏鮑菇的溫室為研究課題，深入探討溫室之內部的流場與溫度場分佈；期望以不增加元件配置且節省成本作為設計之基礎，利用CFD軟體FLUENT來分析計算其結果。本文首先探討以原始設計分析出內部流場情形，發現主要在入風口處產生的逆流現象，所以造成入風口的風速降低，這將使內部的氣體流動不易，導致熱空氣無法按照設計路線排出，因而使溫室內部溫度較不易達到均溫。接著針對入風口位置變動及增加出風口之方案，與原始設計比較其差異性，並分析改善後所得之結果，最後以分析之最佳氣流設計為基礎，做一系列參數化分析及探討；針對不同入風口配置做模擬分析，以了解其對於溫室整體流場之影響，並藉由其流場觀察得到最佳之操作參數，使得整體設計更加完善。由模擬的結果可得知，在改良方案中變更入風口配置使入風口的平均風速比原始設計增加12 ％，在改良方案A2中增加出風口為8個將使溫室中心點流速提昇由0.04 m/s為0.24 m/s；這兩個改良方案皆能使內部流速提高、積熱迅速排除及減少作物置放架內部迴流，得以達到最適合作物的生長環境，而所得結論亦可提供關於溫室之建造及改良參考，以達到提升作物品質與產量。

Due to the growing concerns on environmental quality and energy consumption of the greenhouse, this work intends to study the fluid field inside a closed greenhouse for mushroom plantation. With the aids of CFD code FLUENT, the flow simulation is firstly executed numerically and analyzed for identifying the drawbacks of the original greenhouse design. Several severe circulations and reversed flows are found near the intakes of cooling air. These phenomena result in velocity decrease and non-uniformity on the cooling air stream; thus the environmental quality is downgraded for the crops growing. Thereafter, two alternatives, changing the inlet location and adding extra exhausting outlets, are proposed for diminishing these reversed flows and circulations. These CFD results indicate that changing inlet location can eliminate the reversed flow and increase the air speed by 12%. Also, the cooling air speed is enhanced further from 0.04 m/sec to 0.24 m/sec at the center of greenhouse by optimizing the exhausting outlet number. Both modifications have significant influence in modifying the flow field feature for the corps growing. In summary, this study successfully enhances the air velocity and distribution inside greenhouse for improving mushroom plantation by using a systematic and rigorous CFD technique.

中文摘要 I
中文摘要 II
誌謝 III
目錄 IV
圖索引 VII
表索引 IX
符號索引 X
第一章 緒 論 1
1-1 前言 1
1-2 文獻回顧 2
1.3 研究動機與目的 7
1.4 本文架構 11
第二章 數值分析方法 13
2.1 統御方程式 16
2.2 紊流模式 16
2.2.1 k-ε紊流方程式 16
2.2.2 紊流模式其壁面處理方式 18
2.3 數值計算方法 22
2.3.1離散化方式 24
2.3.2壓力與速度耦合的處理 28
2.3.3風扇邊界條件 30
2.4 網格之品質 32
第三章 數值計算與實驗結果之驗證 34
3.1 溫室內部配置與量測 34
3.1.1 溫室物理模型介紹 34
3.1.2 實驗之量測 39
3.2 實驗之量測及結果 45
3.3 數值模型建立與網格獨立性測試 53
3.3.1 數值模型建立 53
3.3.2 網格獨立性測試 54
3.4 數值驗證結果 59
第四章 原始設計之數值結果及討論 62
4.1溫室之整體流場分析 62
4.2整體溫室之流場分析與改善方案 78
第五章 改良設計之數值結果與討論 80
5.1 變更溫室入風口位置的配置 47
5.2 增加溫室出風口的數量 91
第六章 結論與建議 47
6.1 結論 100
6.1.1 原始設計 100
6.1.2 變更入風口配置之設計 101
6.1.3 增加出風口數量之設計 102
6.2 建議 103
參考文獻 105
作者簡介 109

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