Micro computed tomography and CFD simulation of drop deposition on gas diffusion layers

32nd UIT (Italian Union of Thermo–fluid-dynamics) Heat Transfer Conference

物理学;力学

Guilizzoni, M.^1 ; Santini, M.^2 ; Lorenzi, M.^3 ; Knisel, V.^1 ; Fest-Santini, S.^2

Dipartimento di Energia, Politecnico di Milano, via Lambruschini 4, Milan

20156, Italy^1

Dipartimento di Ingegneria, Università di Bergamo, viale Marconi 5, Dalmine (BG)

24044, Italy^2

School of Engineering and Mathematical Sciences, City University London, Northampton Square, London

EC1V 0HB, United Kingdom^3

关键词: Complex chemistry;    Electrochemical power generation;    Electrode flooding;    Fluorinated polymers;    Gas diffusion layers;    High energy efficiency;    Micro computed tomography (micro-CT);    Microcomputed tomography;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/547/1/012028/pdf
DOI  :  10.1088/1742-6596/547/1/012028

学科分类：力学，机械学

来源: IOP

【 摘 要 】

Fuel cells are electrochemical power generation system which may achieve high energy efficiencies with environmentally friendly emissions. Among the different types, Proton Exchange Membrane fuel cells (PEMFC) seem at present one of the most promising choices. A very important component of a PEMFC is the gas diffusion layer (GDL), which has the primary role of managing water in the cell, allowing reactant gases transport to the catalyst layer while keeping the membrane correctly hydrated and preventing electrode flooding. Therefore, GDLs have to be porous and very hydrophobic. Carbon clothes or carbon papers coated with a hydrophobizing agent-typically a fluoropolymer-are used. Given the complex chemistry and morphology of the GDLs, wettability analyses on them present some critical issues when using the conventional contact angle measurement techniques. In this paper, the deposition of a drop on a GDL (produced using polytetrafluoroethylene-co-perfluoroalcoxy vinyl ether as the fluorinated polymer) was investigated by means of micro computed tomography (microCT) and numerical simulation. The microCT facility operational at the University of Bergamo was used to acquire a 3D tomography of a water drop deposed on a sample GDL. The reconstructed drop dataset allows thorough understanding of the real drop shape, of its contact area and contact line. The GDL dataset was used to create a realistic mesh for the numerical simulation of the drop deposition, which was performed using the OpenFOAM®interFOAM solver.