| Finite element study of different parameter effects on the gas diffusion layer compression |
| کد مقاله : 1059-THFC |
| نویسندگان |
|
حامد افراسیاب *، کامران حسن زاده داودی1، محمد مهدی برزگری2، مقداد غلامی1، علی حسنی1 1Babol, Iran 2مرکز تحقیقات علم و فناوری شمال، دانشگاه صنعتی مالک اشتر، ایران |
| چکیده مقاله |
| Recently, proton exchange membrane fuel cells (PEMFCs) have received increasing attention as a clean energy conversion device due to global warming issues. These devices have outstanding advantages including high power density, excellent energy conversion efficiency, zero greenhouse gas emissions, and the fast transient operation. In the structure of PEMFC, the gas diffusion layer (GDL) plays a key role. GDL which is a porous fibrous medium composed of carbon fiber, and a carbon-based binder has a significant effect on the fuel cell performance. it provides pathways between the catalyst layer and the flow channel and for supplying reactants, conducting electrons and heat, and removing product water [1]. During the PEMFC performance, the GDL is compressed under the assembly pressure resulting in significant changes in its mechanical, electrical and thermal properties. Therefore, modeling of the inhomogeneous GDL compression under the bipolar plates (BPPs) is essential for characterizing the fuel cell performance [2]. For this purpose, a three-dimensional finite element model is developed in this article using the ABAQUS/standard software. Due to the repetitive channel-rib pattern of the bipolar plates, only a portion of the contact area between the GDL and BPPs have been modeled and appropriate symmetry boundary conditions are prescribed on the model as shown in Figure 1. In this figure t_GDL is the GDL thickness, w_rib denotes the half-width of the rib, and w_GDL represents the distance between the rib and the channel midplane. A nonlinear orthotropic model has been employed for describing the GDL constitutive behavior and a UMAT subroutine has been developed to implement this model in the ABAQUS. The effect of different geometric and structural parameters on the GDL response factors such as its porosity distribution has been investigated as shown in Figure 2 and 3. Based on these figures, by decreasing the rib width, the size of the low porosity area under the rib decreases correspondingly. But since the impact of the rib compression less effectively transmits to regions under the channel, the GDL intrusion and the porosity increase in these regions. Furthermore, decreasing the GDL thickness leads to higher porosities under the channel. It also makes the transition fan like region between the channel and rib becomes more localized due to the higher concentration of rib edge effects. |
| کلیدواژه ها |
| PEM fuel cell, Gas diffusion layer, Inhomogeneous compression, porosity. |
| وضعیت: چکیده برای ارائه پذیرفته شده است |