Reduced Two-Dimensional One-Phase Model for Analysis of the Anode of a DMFC

Birgersson, Erik; Nordlund, Joakim; Ekström, Henrik; Vynnycky, Michael; Lindbergh, Göran

doi:10.1149/1.1606455

Cited by 66 publications

(50 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The energy conversion process of DMFC can be modeled by a coupling of the governing equations of continuity, momentum and species transportation, as mentioned in Equations (3), (10) and (12). The source term S m and S mon in Section 2.2.…”

Section: Numerical Implementationsmentioning

confidence: 99%

“…The flow fields can be determined by solving Equations (3) and (10). The obtained flow rate − → v is then applied in Equation (12) to determine the convection and diffusion of species. Because of the technical limitations, not all the the parameters involved in governing equations can take a definitive value from experimental measurements.…”

Section: Numerical Implementationsmentioning

confidence: 99%

“…During the past decades, several mechanical models based on Computational Fluid Dynamics (CFD) techniques were proposed to study the energy conversion process of DMFC systems, from one-dimensional [11], two-dimensional [12,13] to three-dimensional (3D) [14][15][16][17][18][19] points of view.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Numerical Investigations of the Combined Effects of Flow Rate and Methanol Concentration on DMFC Performance

Wang

Chen

et al. 2017

Energies

View full text Add to dashboard Cite

Abstract:A modified 3D numerical model on the energy conversion process in the anode side of a Direct Methanol Fuel Cell (DMFC) system was constructed and validated to published experimental results. Systematic simulations were performed to investigate the underlying mechanisms of the energy conversion process, and the combined effects of inlet flow rate and input methanol concentration were summarized systematically. The increase of flow rate was found to be an effective strategy to accelerate the internal flow fields, while the diffusion layer was proposed to be a critical component in the design of high-performance DMFC. The frontier for optimal conditions of DMFC's output was also determined, which can be helpful to improve the energy conversion performance of DMFC in practical applications.

show abstract

Section: Numerical Implementationsmentioning

confidence: 99%

Section: Numerical Implementationsmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Investigations of the Combined Effects of Flow Rate and Methanol Concentration on DMFC Performance

Wang

Chen

et al. 2017

Energies

View full text Add to dashboard Cite

show abstract

“…15, it is generally assumed that no CO 2 , in either the liquid or gas phase, can permeate through the membrane. 1,6,7,[28][29][30][31] Some authors have studied this experimentally and have found that CO 2 does indeed cross over through the membrane to the cathode and the amount present may be negligible 32 or nonnegligible 33,34 based on the operating conditions. In this paper, however, CO 2 crossover was neglected, and should provide an indication of the most aggressive requirements for CO 2 removal.…”

Section: 2223mentioning

confidence: 99%

Modeling of Coupled Multiphase Transport in Direct Methanol Fuel Cell Diffusion Layers

Garvin

Meyers

2011

J. Electrochem. Soc.

View full text Add to dashboard Cite

A one-dimensional, two-phase model for the anode diffusion layer (DL) of a liquid-feed direct methanol fuel cell (DMFC) is developed. This model incorporates the use of Stefan-Maxwell formulation of multiphase diffusion to model the mass transport of water (H 2 O), methanol, and carbon dioxide (CO 2 ) in both the liquid and gas phases throughout the porous DL. The model uses a muticomponent equation of state to model the equilibrium between each species in its gas and liquid form inside the porous medium. It is shown how the properties of the DL, including the permeability, contact angle, porosity, and thickness, affect the performance of the DMFC, in terms of ability to remove CO 2 and modify the methanol concentration at the diffusion layer=catalyst layer (CL) interface. Specifically, we find that having a small permeability and a thick DL will both promote a lower methanol concentration and enhance CO 2 removal, but the other parameters result in a tradeoff in performance. The preferred transport properties depend strongly on the specified operating temperature of the cell, as both methanol and water partition more preferentially to the vapor phase as the temperature is increased. Direct methanol fuel cells (DMFCs) are ideal for powering portable devices. Unlike batteries, they do not require an external power source to be recharged, can be refueled within minutes, and can operate at low temperatures. There are numerous obstacles that need to be addressed before they can be extensively commercialized, however. One of these issues is that of multicomponent mass transport of the reactant and product species. These mass transport problems occur in all of the domains of the fuel cell, including the fuel or gas channels, diffusion layers, catalyst layers, and the membrane. One of the critical domains is the anode diffusion layer whose mass transport issues can negatively affect the transport in the membrane, cathode catalyst layer, and anode fuel channel. Mass transport issues affect the performance of the fuel cell, its stability, and energy density.There have been several attempts to model the anode of a DMFC. One of the first attempts was made by Baxter et al.,1 who developed a model for the porous anode of a liquid fed DMFC. Many other authors have modeled the fuel cell as only having single phase flow in one or two dimensions. 2-7A few recent models of the liquid-feed DMFC have incorporated more of the species in each of the phases. [8][9][10][11][12][13][14] At steady state, all three species will be present in both the liquid and gas phases. Wang and Wang developed a one-dimensional two-phase model with multicomponent transport.10 They assumed that the liquid and gas phase are in thermodynamic equilibrium, that the gas phase is saturated with H 2 O and methanol vapor, and used Henry's law type relationships to calculate their vapor pressures. They also assumed the amount of CO 2 in the liquid phase is the liquid saturation concentration. A few later models have performed a similar analysis but instead of as...

show abstract

“…Since the membranes are basically identical, the same can be said of the membrane models [121,174,[235][236][237][238][239][240][241][242][243]. A benefit of DMFCs is that liquid water exists on both sides of the membrane (in most cases at high enough current densities), and thus it remains liquidequilibrated throughout.…”

Section: Direct-methanol Fuel Cellsmentioning

confidence: 99%