The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform

Kui Jiao - One of the best experts on this subject based on the ideXlab platform.

  • multi phase models for water and thermal management of proton exchange membrane fuel cell a review
    Journal of Power Sources, 2018
    Co-Authors: Guobin Zhang, Kui Jiao
    Abstract:

    Abstract The 3D (three-dimensional) multi-phase CFD (computational fluid dynamics) model is widely utilized in optimizing water and thermal management of PEM (proton exchange membrane) fuel cell. However, a satisfactory 3D multi-phase CFD model which is able to simulate the detailed gas and liquid two-phase flow in channels and reflect its effect on performance precisely is still not developed due to the coupling difficulties and computation amount. Meanwhile, the agglomerate model of CL (catalyst layer) should also be added in 3D CFD model so as to better reflect the Concentration Loss and optimize CL structure in macroscopic scale. Besides, the effect of thermal management is perhaps underestimated in current 3D multi-phase CFD simulations due to the lack of coolant channel in computation domain and constant temperature boundary condition. Therefore, the 3D CFD simulations in cell and stack levels with convection boundary condition are suggested to simulate the water and thermal management more accurately. Nevertheless, with the rapid development of PEM fuel cell, current 3D CFD simulations are far from practical demand, especially at high current density and low to zero humidity and for the novel designs developed recently, such as: metal foam flow field, 3D fine mesh flow field, anode circulation etc.

Yan Xiang - One of the best experts on this subject based on the ideXlab platform.

  • numerical and experimental analyses on deviated Concentration Loss with alkaline anion exchange membrane fuel cells
    Journal of Physical Chemistry C, 2015
    Co-Authors: Sikan Peng, Jian Gong, Xin Xu, Shanfu Lu, Yan Xiang
    Abstract:

    The polarization curves of low-temperature fuel cells, such as polymer electrolyte membrane fuel cells, typically have three distinct regimes dictated by certain limiting factors. These kinetic, ohmic, and Concentration-Loss regimes have overpotentials that are dictated by electrochemical activation, ohmic Loss, and reactant Concentration, respectively. However, a peculiar polarization curve with a deviated Concentration Loss regime was recently presented for alkaline anion-exchange membrane fuel cells (AEMFCs), and the cause of this deviation remains unknown to date. In this work, a 2D, steady-state H2/O2 model was developed to simulate transport and reactions in an AEMFC in order to explore the origin and mechanism of deviations in the polarization curve. According to the model, the charge transfer and hydroxyl ion transport resistances in the cathode catalyst layer were rate-limiting factors and contributed to the deviated Concentration Loss above ∼450 mA cm–2, which was observed in baseline simulation...

Kyoungyoun Kim - One of the best experts on this subject based on the ideXlab platform.

  • numerical study on the effects of gas humidity on proton exchange membrane fuel cell performance
    International Journal of Hydrogen Energy, 2016
    Co-Authors: Hyoyup Kim, Kyoungyoun Kim
    Abstract:

    Abstract To examine the effects of gas humidity on proton-exchange membrane fuel cells (PEMFCs), three-dimensional multi-phase non-isothermal fuel cell model simulations were performed. Various inlet gas humidity conditions were independently imposed at the inlets of the anode and cathode flow channels. This numerical simulations revealed that fuel cell performance is significantly affected by both anode and cathode humidification. The ohmic Loss is influenced by both anode and cathode inlet gas humidity, whereas the Concentration Loss is mainly affected by the cathode inlet gas humidity. The gas humidity in the flow channel can be controlled by adjusting the bipolar plate temperature. Additional simulations assessed different bipolar temperature distributions. When the temperature of the bipolar plate was increased in the direction of gas flow, the Concentration Loss decreased, owing to the reduced condensation of liquid water in the catalyst layer. Consequently, fuel cell performance increased, especially in the high current density region.

Serhat Yesilyurt - One of the best experts on this subject based on the ideXlab platform.

  • nitrogen front evolution in purged polymer electrolyte membrane fuel cell with dead ended anode
    Journal of The Electrochemical Society, 2010
    Co-Authors: Jason B Siegel, Stanislav V Bohac, Anna G Stefanopoulou, Serhat Yesilyurt
    Abstract:

    In this paper, we model and experimentally verify the evolution of liquid water and nitrogen fronts along the length of the anode channel in a proton exchange membrane fuel cell operating with a dead-ended anode that is fed by dry hydrogen. The accumulation of inert nitrogen and liquid water in the anode causes a voltage drop, which is recoverable by purging the anode. Experiments were designed to clarify the effect of N2 blanketing, water plugging of the channels, and flooding of the gas diffusion layer. The observation of each phenomenon is facilitated by simultaneous gas chromatography measurements on samples extracted from the anode channel to measure the nitrogen content and neutron imaging to measure the liquid water distribution. A model of the accumulation is presented, which describes the dynamic evolution of a N2 blanketing front in the anode channel leading to the development of a hydrogen starved region. The prediction of the voltage drop between purge cycles during nonwater plugging channel conditions is shown. The model is capable of describing both the two-sloped behavior of the voltage decay and the time at which the steeper slope begins by capturing the effect of H2 Concentration Loss and the area of the H2 starved region along the anode channel.

Guobin Zhang - One of the best experts on this subject based on the ideXlab platform.

  • multi phase models for water and thermal management of proton exchange membrane fuel cell a review
    Journal of Power Sources, 2018
    Co-Authors: Guobin Zhang, Kui Jiao
    Abstract:

    Abstract The 3D (three-dimensional) multi-phase CFD (computational fluid dynamics) model is widely utilized in optimizing water and thermal management of PEM (proton exchange membrane) fuel cell. However, a satisfactory 3D multi-phase CFD model which is able to simulate the detailed gas and liquid two-phase flow in channels and reflect its effect on performance precisely is still not developed due to the coupling difficulties and computation amount. Meanwhile, the agglomerate model of CL (catalyst layer) should also be added in 3D CFD model so as to better reflect the Concentration Loss and optimize CL structure in macroscopic scale. Besides, the effect of thermal management is perhaps underestimated in current 3D multi-phase CFD simulations due to the lack of coolant channel in computation domain and constant temperature boundary condition. Therefore, the 3D CFD simulations in cell and stack levels with convection boundary condition are suggested to simulate the water and thermal management more accurately. Nevertheless, with the rapid development of PEM fuel cell, current 3D CFD simulations are far from practical demand, especially at high current density and low to zero humidity and for the novel designs developed recently, such as: metal foam flow field, 3D fine mesh flow field, anode circulation etc.