Items with full text/Total items : 56804/90523 (63%)
Visitors : 12092943
Online Users : 160
Please use this identifier to cite or link to this item:
|Other Titles: ||The design and performance investigation of the current collector openings for the direct methanol fuel cell with application of the fractal geometry|
|Authors: ||張靜怡;Chang, Jing-yi|
李世鳴;Lee, Shi-min;管衍德;Kuan, Yean-der
|Keywords: ||直接甲醇燃料電池;集電板;碎形;交流阻抗分析;Direct Methanol Fuel Cell;Current Collector;Fractal;Electrochemical Impedance Spectroscopy|
|Issue Date: ||2010-01-11 06:38:06 (UTC+8)|
The fractal theory is a methodology to systematically segment the space. There are many real examples in the engineering applications, such as heat transfer, cooling, fin design of heatsink, and automatic polishing path. This dissertation adopts fractal geometries to apply on the design of the current collectors of the direct methanol fuel cell and discuss the effect on the cell performance as well as the electrochemical spectroscopy impedance by the free open style, the total free open ratio, and total perimeter length of openings on the current collectors.
This dissertation presents three geometric designs on the current collectors. The first design is to adopt the Sierpinski carpet fractal geometry to systematically make separate segments on the current collectors. The maximum total free open ratio is 30% by this design. The higher fractal order could provide the current collectors larger total free open ratio as well as longer total perimeter length of openings, such leads the cell have better performance and lower electrochemical impedance.
The second design is to adopt the Hilbert curve fractal geometry to systematically make continuous segments on the current collectors. Such open style could give effective line extension and average openings spread in the planar area. The maximum free open ratio could reach 50% by this design. The higher fractal order could further provide larger total free open ratio as well as longer total perimeter length of openings, such leads the cell have better performance and lower electrochemical impedance.
The third design is to adopt the regular rectangle free openings design on the current collectors. The free open ratio is 30%, 40%, 50%, and 60%, respectively. The arrangement of the free openings distribution is 5x5, 7x7, and 10x10, respectively. The proper free openings design could allow the methanol and air uniformly distribute to the membrane electrolyte assembly, such that the electrochemical reactions are able to proceed and the carbon dioxide produced at the anode side could drain successfully, and the cell performance would be further enhanced.
|Appears in Collections:||[Graduate Institute & Department of Mechanical and Electro-Mechanical Engineering] Thesis|
All items in 機構典藏 are protected by copyright, with all rights reserved.