金屬發泡材質子交換膜燃料電池堆流場特性之研究

Study on Flow Field Characteristics of Metal Foam Proton Exchange Membrane Fuel Cell Stack

陳東傑(Tung-chieh Chen)

指導教授 ： 曾重仁

國立中央大學/工學院/機械工程研究所碩士在職專班/碩士(2012年)

摘要

為了使燃料電池的應用符合功率與適當大小反應面積的需求，一般皆會組合單電池成為燃料電池堆，但此過程中每片單電池之性能會下降。下降之主因為反應氣體分布不均所造成的部分較弱單電池的影響。以金屬發泡材取代傳統流道所組成之質子交換膜燃料電池堆，有希望改善此問題。
本研究主要利用商用之CFD軟體 COMSOL，建構金屬發泡材之質子交換膜燃料電池堆之三維模型，並透過供/排氣歧管的配置方式與結構尺寸設計、連接管的結構尺寸設計與金屬發泡材的滲透率選擇等，進行電堆模型流場系統之流動速度、壓力與壓力降的分析。
根據本研究之模擬結果，採用新穎之環- Type設計的燃料電池堆，具有優於U-Type與Z-Type之流場流動分佈特性，其在電池與電堆歧管間的連接管尺寸設計上，應使用大的寬度，減少電堆歧管的背壓增加，而歧管截面尺寸的設計上，越大的尺寸時，歧管內的平均壓力與壓力降可以被降低，也對流場分佈有絕對的改善成果，在金屬發泡材的滲透率選擇上，低的滲透率能有不錯的流場流動分佈結果，當使用環- Type設計的燃料電池堆，滲透率降至1.95e-9m2時，流動分佈指標 可以降到2%以下。

關鍵字

金屬發泡材、質子交換膜燃料電池堆、燃料電池堆歧管配置

並列摘要

Single cells are connected in series to form a fuel cell stack in order to produce proper power output. The power output per cell in a stack is usually smaller than that of a single cell. The degradation of efficiency is known to be caused by some weaker single cells, caused primarily by the unequal flow distribution of fuel and oxidant. Using metal foam to replace conventional flow channels may solve the problem.
In this study, I first construct a 3D model of metal foam PEM fuel cell stack by using commercial CFD software COMSOL. The pressure and flow field characteristics are analyzed and effects of inlet and outlet manifolds arrangement, the configuration and sizes of ducts, and metal foam permeability are investigated.
The results show that the novel circular-type design out-performs conventional U-Type and Z-Type designs. The diameter of the ducts between cells and manifolds should be large enough in order to reduce internal back pressure. Similarly, the diameter of the manifolds should also be large enough to reduce the pressure drop in the manifolds. On the other hand, the permeability of metal foam should be small to have uniform flow distribution. The flow non-uniformity index is under 2% if the permeability is smaller than 1.95e-9m2 when using circular-type design.

並列關鍵字

manifold arrangement ； metal foam ； PEMFC

參考文獻

[8] 蘇仁寶，「流體於歧管式微型裝置流道內流場不均勻狀況數值分析」，碩士論文，中原大學機械工程學系，(2007)。

[1] W. Zhang, P. Hu, X. Lai, L. Peng, “ Analysis and optimization of flow distribution in parallel-channel configurations for proton exchange membrane fuel cells,” Journal of Power Sources, Vol. 194, pp. 931-940, (2009).

[2] M. PAN, Z. Dehuai, T. Yong and C. Dongqing, “ CFD-based study of velocity distribution among multiple parallel microchannels,” Journal of Computers, Vol. 4, pp. 1133-1138, (2009).

[4] S. Y. Kim, W. N. Kim, “ Effect of cathode inlet manifold configuration on performance of 10-cell proton-exchange membrane fuel cell,” Journal of Power Sources, Vol. 166, pp. 430-434, (2007).

[5] A. C. Chang, J. St-Pierre, J. Stumper, B. Wetton, “Flow distribution in proton exchange membrane fuel cell stacks,” Journal of Power Sources, Vol. 162, pp. 340-355 (2006).