标题: | 高液压成型机台之研发与其在燃料电池上之应用 Studies on a novel high-pressure hydroforming apparatus and its application in fuel cells |
作者: | 林志嘉 Lin, Chih-Chia 洪景华 Hung, ChingHua 机械工程系所 |
关键字: | 燃料电池;高液压成形机台;金属双极板;微流道;有限元素分析;最佳化分析;Fuel cell;high-pressure hydroforming apparatus;metallic bipolar plate;micro-flow channels;finite element analysis;optimization analysis |
公开日期: | 2012 |
摘要: | 近年来随着绿能科技崛起以及携带型3C产品需求增加,可携式质子交换膜燃料电池逐渐受到瞩目。而金属材质的双极板由于其具有低成本、优异的热、电与机械性质以及能够有较薄之厚度(0.1-0.5 mm),因而成为了可携式燃料电池中的主要零件。然而,以现有之成形技术仍无法在金属薄板上有效成形出符合实际燃料电池所需具有高深宽比的流道结构。 本研究利用自行研发之高液压成形机台,藉由提升成形制程中之成形压力来达到提升微流道深宽比之目的。此设计包含了三个部分:一个能够产生二段增压的机械结构、一个能够乘载高液压的高压承载筒,以及能够将液压密封的高压密封元件。透过此研究,建立了一套完整的高液压成形技术,并在现阶段应用于可携式燃料电池之金属双极板的制作上。 由实际实验可知,此研发之高液压成形机台不论在制程控制或是成形试片的重现性上均是合理且可接受的。在施加高达250 MPa之成形压力下,其微流道之深宽比能够达到0.392,比传统液压成形所能得到之深宽比(0.31)提升了26.5%。后续,再经过有限元素以及最佳化分析后,将可更有效率的利用此高液压成形技术以获得此成形机台的最佳成形能力,使成形试片上的微流道深宽比再提升4.8%。 Portable proton exchange membrane fuel cells (PEMFCs) have received considerable attention recently because of the suitable material of the development of 3C production processes and green energy techniques. For the key component of portable PEMFCs, bipolar plates, metals such as stainless steel are becoming popular because of their excellent mechanical, electrical, and thermal properties, as well as a low degree of thickness (0.1–0.5 mm). However, current forming techniques cannot efficiently fabricate micro-flow-channels with a high aspect ratio on thin metallic blanks to satisfy the practical demands on portable fuel cells. This study presents the development of a high-pressure hydroforming technique and explains the design and construction of an experimental high-pressure hydroforming apparatus. The apparatus is composed of a two-stage pressure-increase structure to provide high fluid pressure, a high-pressure container and high-pressure seals to maintain and seal the high fluid pressure. Conclusively, this research develops a complete high-pressure hydroforming technique and be applied in forming metallic bipolar plates for portable PEMFCs. The results of our investigation indicate that the process control for the developed apparatus and the repeatability for hydroformed specimens are reasonably acceptable. The aspect ratio of micro-flow channels formed using this apparatus can achieve 0.392 when a working pressure of 250 MPa is applied. Compared with the maximum channel aspect ratio of 0.31 formed using the traditional hydroforming process, the channel aspect ratio formed using the new technique and device is 26.5% higher. Furthermore, finite element and optimization analyses can be performed to boost the forming capability of the developed technique. Consequently, the aspect ratio of formed micro-flow channels can be further increased by 4.8%. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT079714801 http://hdl.handle.net/11536/72767 |
显示于类别: | Thesis |
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