Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/2079
標題: 熱傳對甲醇─水蒸汽重組影響之數值探討
Numerical study on heat transfer effect on the Methanol-Steam reforming
作者: 陳立昌
Chen, Li-Chung
關鍵字: Methanol-Steam reforming;甲醇-水蒸氣重組反應;Numerical simulation;數值模擬
出版社: 機械工程學系所
引用: [1]. 林昇佃、余子隆等人合著,燃料電池:新世紀能源,滄海書局,2004。 [2]. S. Ahmed, M. Krumpelt, Hydrogen from hydrocarbon fuels for fuel cells, Int. J. Hydrogen Energy 26 (2001) 291-301. [3].潘英豪,陣列型甲醇重組器分析探討,碩士論文,中興大學機械工程研究所,2007。 [4]. H.A. Liebhafsky, E.J. Cairns, Fuel cells and fuel batteries, a guide to their research and development, New York, NY: Wiley, 1968. [5]. J. Bravo, A. Karim, T. Conant, G. P. Lopez, A. Datye, Wall coating of a CuO/ZnO/Al2O3 methanol steam reforming catalyst for micro-channel reformers, Chem. Eng. J. 101 (2004) 113-121. [6]. J.C. Amphlett, K.A.M. Davis, R.F. Mann, B.A. Peppley,and D.M. Stokes, Hydrogen production by steam reforming of methanol for polymer electrolyte fuel cells, Int. J. Hydrogen Energy 19 (1994) 131–137. [7]. A. Karim, J. Bravo, A. Datye, Nonisothermality in packed bed reactors for steam reforming of methanol, Appl. Cata. A: Gen 282 (2005) 101-109. [8]. A. Karim, J. Bravo, D. Gorm, T. Conant, A. Datye, Comparison of wall-coated and packed-bed reactors for steam reforming of methanol, Catalysis Today 110 (2005) 86-91. [9]. H.G. Park, J.A. Malen, W.T. Piggott, III, J.D. Morse, R. Greif, C.P. Grigoropoulos, R. Upadhye, M.A. Havstad, Methanol steam reformer on a silicon wafer, J. Microelectromech. Syst, 15 (2006) 976-985. [10]. B.A. Peppley, J.C. Amphlett, L.M. Kearns, R.F. Mann, Methanol-steam reforming on Cu/ZnO/Al2O3 catalysts : Part 2. A comprehensive kinetic model, Appl. Catal. A:Gen 179 (1999) 31-49. [11]. M.T. Lee, R. Greif, C.P. Grigoropoulos, H.G. Park, F.K. Hsu, Transport in packed-bed and wall-coated steam-methanol reformers, J. Power Sources 166 (2007) 194-201.. [12]. J.S. Suh, M.T. Lee, R. Greif, C.P. Grigoropoulos, A study of steam methanol reforming in a microreactor, J. Power Sources 173 (2007) 458-466. [13] A.V. Pattekar, M. V. Kothare, A microreactor for hydrogen production in micro fuel cell applications, J. Microelectromech. Syst. 13 (2004) 7-18. [14] G.G. Park, D.J. Seo, S.H. Park, Y.G. Yoon, C.S Kim, W.L. Yoon, Development of microchannel methanol steam reformer, J. Chem. Eng. 101 (2004) 87-92. [15].G.G. Park, S.D. Yima, Y.G. Yoon, C.S Kim, D.J. Seo, K. Eguchi, Hydrogen production with integrated microchannel fuel processor for portable fuel cell systems, Catalysis Today 110 (2005) 108-113. [16]. T. Kim, S. Kwon, Design, fabrication and testing of a catalytic microreactor for hydrogen production, J. Micromech. Microeng. 16 (2006) 1760-1768. [17].H. Darcy, Les fontaines publiques de la ville de Dijon, Paris Victor Dallmont, 1856. [18]. Adrian Bejan, Convection Heat Transfer, Wiley Publication, 1984. [19]. H.C. Brinkman, A Calculation of the viscous force expected by a flowing fluid on a dense swarm of particles, Applied Science Reserch A1, (1947) 27-34. [20]. A.F. Mills, Mass Transfer, Prentice Hall, Upper Saddle River, N.J., 2001. [21].W.L. McCabe, J.C. smith, P. Harriot, Unit Operations of Chemical Engineering, fifth ed. New York: McCraw-Hill,1993, ch. 7. [22]. J. Agrell, H. Birgersson, M. Boutonnet, Steam reforming of methanol over a catalyst: a kinetic analysis and strategies for suppression of CO formation, J. Power Sources 106 (2002) 249-257. [23]. J.K. Lee, J.B. Ko, D.H. Kim, Methanol steam reforming over catalyst: kinetics and effectiveness factor, Appl. Cata. A: Gen 278 (2004) 25-35. [24]. H.W. Xiang, A Laesecke, M.L. Huber, A New Reference Correlation for the Viscosity of Methanol, J. Phys. Chem. Ref. Data 35 (2006) 1597-1620. [25]. D. Poulikakos, M. Kazmierczak, Forced convection in a duct partially filled with a porous material, J. Heat Transfer 109 (1987) 653-662. [26]. Y. Choi, H.G. Stenger, Kinetics, simulation and optimization of methanol steam reformer for fuel applications, J. Power Sources 142 (2005) 81-91.
摘要: 
本文對使用在燃料電池上的重組器進行甲醇─水蒸汽重組反應之模擬分析。首先,使用Comsol Multiphysics數值分析軟體探討圓管反應器中,以不同觸媒層厚度變化進行熱傳對重組反應之影響。接著,使用網格建構能力較好的分析軟體Fluent,進行填充床式觸媒的微流道重組器重組反應探討,其模擬結果將與文獻數據作比較。
圓管反應器的模擬方面,首先單就無反應時,不同觸媒層厚度下流場與熱傳的狀況與過去文獻進行Nu值的比對。在得到與文獻良好的一致性後,以此進行甲醇─水蒸汽重組反應之模擬。模擬結果在有重組反應,觸媒層厚度為圓管半徑0.9倍長度時有最高溫度和甲醇轉換效率(95%),但較高的溫度也使得CO濃度較其他厚度還高。
微流道重組器方面,在以同樣space time條件下和文獻實驗中圓管填充床反應器比較後,前者在225~300℃間有較高的甲醇轉換率和氫氣產量。在微流道反應器中,填充式需要比壁面塗佈式更高的熱通量來達成相同的甲醇轉換率,但較高的熱通量產生的高反應溫度使得氫氣產率反而較低於壁面塗佈式,並隨燃料流率增加越加明顯。

Numerical simulation of methanol-steam reforming (MSR) is presented in this study. The main goal of this study is to understand the effect of heat transfer on the MSR performance. First, heat transfer effect on MSR with different catalyst layer thicknesses in plug flow reactors (PFR) is investigated. Secondly, performances of MSR in packed-bed microchannel reactors are investigated. It is intend to enhance the MSR performance by enhancing the heat transfer using the characteristics of microchannel heat sink. The catalyst layer is formed by packing CuO/ZnO/Al2O3 catalyst particles with a certain porosity and permeability.
From the simulated results on the PFR, it is found that the heat and mass transfer depend on the catalyst layer thickness. Under heat supplied by wall heat flux conditions, higher reforming temperature can be obtained for the wall-coated reformer compared with the packed-bed reformer when the catalyst layer thickness is in a range between 0.2 and 1 times the reformer radius. It is also found that minimum heat transfer coefficient, maximum methanol conversion and maximum carbon monoxide production can be obtained when the catalyst layer thickness is 0.9 times the reformer radius.

Under the same space time condition, it is found that packed-bed microchannel reactors have higher methanol concentration and hydrogen production for reforming temperature in the range of 225~300C as compared with the results of PFR. It is also found that higher heat flux is necessary for the packed-bed microchannel reactor to reach the same performance of the wall-coated microchannel reactor. However, high heat flux generates high reforming temperature that increasing the carbon dioxide generation rate.
URI: http://hdl.handle.net/11455/2079
其他識別: U0005-2108200822482900
Appears in Collections:機械工程學系所

Show full item record
 

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.