质子交换膜燃料电池多孔电极有效输运系数预测
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摘要
本文采用格子Boltzmann方法,根据质子交换膜燃料电池中气体扩散层及微孔层的实际微观物理结构,重构了不同孔隙率的气体扩散层及微孔层结构,建立了三维格子Boltzmann模型,对气体扩散层及微孔层的有效扩散系数及渗透率进行了预测,与宏观模型中广泛采用的经验方程进行了对比,并拟合了适用于微孔层有效扩散系数的预测方程。研究结果发现,在宏观模型多孔电极有效扩散系数预测中广泛应用的Bruggeman公式相较于实际孔隙结构的预测结果偏高,微孔层渗透率较气体扩散层渗透率小1～2个数量级,且由于微孔层孔隙率较小,其渗透率随孔隙率的变化范围同样较小。
In this study, the micro structures of gas diffusion layer(GDL) and micro porous layer(MPL) of a fuel cell were reconstructed according to the real physical structures, then a 3-D lattice Boltzmann model was established to predict the effective transport coefficients of GDL and MPL.The results were fitted an equation of effective transport coefficient for MPL and compared with the empirical equations that are widely used in the macro models. The results show that the predicted results of Bruggeman equation are higher than the results based on the real micro structures of porous electrodes. The permeability of MPL is 1-2 orders of magnitude lower than that of GDL, and due to the low porosity of MPL, the variation range of permeability is also smaller than that of GDL.
In this study, the micro structures of gas diffusion layer(GDL) and micro porous layer(MPL) of a fuel cell were reconstructed according to the real physical structures, then a 3-D lattice Boltzmann model was established to predict the effective transport coefficients of GDL and MPL.The results were fitted an equation of effective transport coefficient for MPL and compared with the empirical equations that are widely used in the macro models. The results show that the predicted results of Bruggeman equation are higher than the results based on the real micro structures of porous electrodes. The permeability of MPL is 1-2 orders of magnitude lower than that of GDL, and due to the low porosity of MPL, the variation range of permeability is also smaller than that of GDL.
引文
[1] Jiao Kui, Li Xianguo. Water Transport in Polymer Electrolyte Membrane Fuel Cells[J]. Progress in Energy and Combustion Science, 2011, 37:221-291
[2] Chen Li, Kang Qinjun, Mu Yutong, et al. A Critical Review of the Pseudopotential Multiphase Lattice Boltzmann Model:Methods and Applications[J]. International Journal of Heat and Mass Transfer, 2014, 76:210-236
[3] Chen Li, Luan Huibao, He Yaling, et al. Pore-scale Flow and Mass Transport in Gas Diffusion Layer of Proton Exchange Membrane Fuel Cell With Interdigitated Flow Field[J]. International Journal of Thermal Sciences, 2012,51:132-144
[4] Ashorynejad H R, Javaherdeh K. Investigation of a Waveform Cathode Channel on the Performance of a PEM Fuel Cell by Means of a Pore-scale Multi-component Lattice Boltzmann Method[J]. Journal of the Taiwan Institute ofChemical Engineers, 2016, 66:126-136
[5] Niu Xiaodong, Munekata T, Hyodo S, et al. An Investigation of Water-gas Transport Processes in the Gasdiffusion-layer of a PEM Fuel Cell by a Multiphase Multiple-relaxation-time Lattice Boltzmann Model[J].Journal of Power Sources, 2007, 172:542-552
[6] Han Bo, Yu Ji, Meng Hua. Lattice Boltzmann Simulations of Liquid Droplets Development and Interaction in a Gas Channel of a Proton Exchange Membrane Fuel Cell[J]. Journal of Power Sources, 2012, 202:175-183
[7] Nam J, Kaviany M. Effective Diffusivity and Watersaturation Distribution in Single-and Two-layer PEMFC Diffusion Medium[J]. International Journal of Heat and Mass Transfer, 2003, 46(24):4595-4611
[8] Tomadakis M M, Sotirchos S V. Ordinary and Transition Regime Diffusion in Random Fiber Structures[J]. AIChE Journal, 1993, 39:397-412
[9] Gostick J T, Fowler M W, Ioannidis M A. Capillary Pressure and Hydrophilic Porosity in Gas Diffusion Layers for Polymer Electrolyte Fuel Cells[J]. Journal of Power Sources, 2006, 156(2):375-387
[10] Feser J P, Prasad A K, Advani S G. Experimental Characterization of in-plane Permeability of Gas Diffusion Layers[J]. Journal of Power Sources, 2006, 162(2):1226-1231
[11] Wu Wei, Jiang Fangming. Microstructure Reconstruction and Characterization of PEMFC Electrodes[J]. International Journal of Hydrogen Energy, 2014, 39(28):15894-15906
[12] Baghalha M, Eikerling M, Stumper J. The Effect of MPL Permeability on Water Fluxes in PEM fuel Cells:A Lumped Approach[J]. The Electrochemical Society, 2010,33(1):1529-1544
[13] Pant L M, Mitra S K, Secanell M. Absolute Permeability and Knudsen Diffusivity Measurements in PEMFC Gas Diffusion Layers and Micro Porous Layers[J]. Journal of Power Sources, 2012, 206:153-160
[14] Deng Hao, Jiao Daokuan, Zu Meng, et al. Modeling of Passive Alkaline Membrane Direct Methanol Fuel Cell[J].Electrochimica Acta, 2015, 154:430-446
[2] Chen Li, Kang Qinjun, Mu Yutong, et al. A Critical Review of the Pseudopotential Multiphase Lattice Boltzmann Model:Methods and Applications[J]. International Journal of Heat and Mass Transfer, 2014, 76:210-236
[3] Chen Li, Luan Huibao, He Yaling, et al. Pore-scale Flow and Mass Transport in Gas Diffusion Layer of Proton Exchange Membrane Fuel Cell With Interdigitated Flow Field[J]. International Journal of Thermal Sciences, 2012,51:132-144
[4] Ashorynejad H R, Javaherdeh K. Investigation of a Waveform Cathode Channel on the Performance of a PEM Fuel Cell by Means of a Pore-scale Multi-component Lattice Boltzmann Method[J]. Journal of the Taiwan Institute ofChemical Engineers, 2016, 66:126-136
[5] Niu Xiaodong, Munekata T, Hyodo S, et al. An Investigation of Water-gas Transport Processes in the Gasdiffusion-layer of a PEM Fuel Cell by a Multiphase Multiple-relaxation-time Lattice Boltzmann Model[J].Journal of Power Sources, 2007, 172:542-552
[6] Han Bo, Yu Ji, Meng Hua. Lattice Boltzmann Simulations of Liquid Droplets Development and Interaction in a Gas Channel of a Proton Exchange Membrane Fuel Cell[J]. Journal of Power Sources, 2012, 202:175-183
[7] Nam J, Kaviany M. Effective Diffusivity and Watersaturation Distribution in Single-and Two-layer PEMFC Diffusion Medium[J]. International Journal of Heat and Mass Transfer, 2003, 46(24):4595-4611
[8] Tomadakis M M, Sotirchos S V. Ordinary and Transition Regime Diffusion in Random Fiber Structures[J]. AIChE Journal, 1993, 39:397-412
[9] Gostick J T, Fowler M W, Ioannidis M A. Capillary Pressure and Hydrophilic Porosity in Gas Diffusion Layers for Polymer Electrolyte Fuel Cells[J]. Journal of Power Sources, 2006, 156(2):375-387
[10] Feser J P, Prasad A K, Advani S G. Experimental Characterization of in-plane Permeability of Gas Diffusion Layers[J]. Journal of Power Sources, 2006, 162(2):1226-1231
[11] Wu Wei, Jiang Fangming. Microstructure Reconstruction and Characterization of PEMFC Electrodes[J]. International Journal of Hydrogen Energy, 2014, 39(28):15894-15906
[12] Baghalha M, Eikerling M, Stumper J. The Effect of MPL Permeability on Water Fluxes in PEM fuel Cells:A Lumped Approach[J]. The Electrochemical Society, 2010,33(1):1529-1544
[13] Pant L M, Mitra S K, Secanell M. Absolute Permeability and Knudsen Diffusivity Measurements in PEMFC Gas Diffusion Layers and Micro Porous Layers[J]. Journal of Power Sources, 2012, 206:153-160
[14] Deng Hao, Jiao Daokuan, Zu Meng, et al. Modeling of Passive Alkaline Membrane Direct Methanol Fuel Cell[J].Electrochimica Acta, 2015, 154:430-446