板翅式微裝置之模擬分析與最佳化設計

藉由微加工技術，近年來使用各種微裝置之微化工程序技術已獲得快速的發展。微裝置因其微小尺寸，可提供許多優異熱質傳特性，但也因為許多尺度效性與裝置配置特性，無法使用傳統尺寸裝置之理論或關聯式描述其傳輸特性。針對廣為使用之板翅式微通道裝置，本論文利用實驗設計與計算流體力學模擬，完成了傳輸係數分析，並建立了摩擦因子、熱傳係數與質傳係數關聯式，且與文獻關聯式進行比較，結果顯示有相當程度之差異。本論文並進一步利用所建立之關聯式，使用基因演算法，針對單一相態之微熱交換器及甲醇微反應器完成了多目標最佳化分析。就單一相態微熱交換器，考量摩擦因子及熱傳係數之雙目標函數，就甲醇微反應器則另考量了質傳係數。最佳化分析結果提供了裝置參數之設計方向。

關鍵字

微反應器；微熱交換器；微燃料處理系統；計算流體力學；多目標最佳化

並列摘要

Due to its small dimensions, micro devices provide many excellent heat and mass transfer characteristics. On the other hand, due to many scaling effects and particular device configurations, conventional theoretical equations or correlations of transfer characteristics are not applicable to micro devices. In this study, for the widely employed plate-fin type micro devices in single-phase flow applications, the transfer coefficients are systematically studied by computational fluid dynamics simulation. Air and liquid water are adopted for the fluid flow and heat transfer analysis. The gaseous mixture of methanol and steam is used for mass transfer analysis. The flow is limited in laminar region. Correlations are obtained for friction factor, Nusselt number and Sherwood number in terms of fluid flow conditions, fluid properties and device parameters. With respect to transfer coefficients, the comparisons indicate that the major benefit of micro plate-fin devices is on the heat transfer. These correlations are useful to the analysis and design of plate-fin micro devices. In this study, using these correlations and applying the genetic algorithm, multiobjective optimization analysis are accomplished for heat exchanger and reactor applications. The multiple objective functions considered include the friction factor, Nusselt number and Sherwood number. The analysis provides multiple solutions with trade-off relations and reveals the optimal values of decision variables.

並列關鍵字

plate-fin ； micro heat exchanger ； microreactor ； CFD ； optimization ； transfer coefficients

參考文獻

Anxionnaz, Z., Cabassud, M., Gourdon, C., Tochon, P., “Heat exchanger/reactors (HEX reactors): concepts, technologies: state-of-the-art,” Chemical Engineering and Processing, 2008, 47, 2029-2050.

Becht, S., Franke, R., Geiselmann, A., Hahn, H., “Micro process technology as a means of process intensification,” Chemical Engineering Technology, 2007, 30, 295-299.

Chang, H., Hou, W.-C., “Optimization of membrane gas separation systems using genetic algorithm,” Chemical Engineering Science, 2006, 61, 16, 5355-5368.

Cheng, S.-H., Chang, H. , Chen, Y.-H., Chen, H.-J., Chao, Y.-K., Liao, Y.-H., “Computational Fluid Dynamics-Based Multiobjective Optimization for Catalyst Design,” Industrial & Engineering Chemistry Research, 2010, 49, 10153-11120.

Cheng, S.-H., Chen, H.-J., Chang, H., Chang, C.-K., Chen, Y.-M., “Multi-objective optimization for two catalytic membrane reactors - methanol synthesis and hydrogen production,” Chemical Engineering Science, 2008, 63, 6, 1428-1437.

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板翅式微裝置之模擬分析與最佳化設計

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