The Experts below are selected from a list of 9258 Experts worldwide ranked by ideXlab platform

Wenquan Tao - One of the best experts on this subject based on the ideXlab platform.

  • numerical investigation of liquid water distribution in the cathode side of proton exchange membrane fuel cell and its effects on cell performance
    International Journal of Hydrogen Energy, 2012
    Co-Authors: Li Chen, Taofeng Cao, Zhaohui Li, Yaling He, Wenquan Tao
    Abstract:

    A three-dimensional unsteady two-phase model for the cathode side of proton exchange membrane fuel cell (PEMFC) consisting of gas diffusion layer (GDL) with hybrid structural model is developed to investigate liquid water behaviors under different operating and geometrical conditions and to quantitatively evaluate effects of liquid water distribution on reactant transport and current density distribution. Simulation results reveal that liquid water transport processes and distributions are significantly affected by Inlet Air Velocity, wall wettability and water Inlet position, which in turn play a prominent role on local reactant transport and cause considerable disturbances of the current density. Liquid water film spreading on the gas channel (GC) top wall is identified as the most desirable flow pattern in the GC based on overall evaluations of current density magnitude, uniformity of current density distribution and pressure drop in the GC. Modification to GDL structure is proposed to promote the formation of the desirable flow pattern.

  • numerical investigation of liquid water distribution in the cathode side of proton exchange membrane fuel cell and its effects on cell performance
    International Journal of Hydrogen Energy, 2012
    Co-Authors: Li Chen, Taofeng Cao, Wenquan Tao
    Abstract:

    A three-dimensional unsteady two-phase model for the cathode side of proton exchange membrane fuel cell (PEMFC) consisting of gas diffusion layer (GDL) with hybrid structural model is developed to investigate liquid water behaviors under different operating and geometrical conditions and to quantitatively evaluate effects of liquid water distribution on reactant transport and current density distribution. Simulation results reveal that liquid water transport processes and distributions are significantly affected by Inlet Air Velocity, wall wettability and water Inlet position, which in turn play a prominent role on local reactant transport and cause considerable disturbances of the current density. Liquid water film spreading on the gas channel (GC) top wall is identified as the most desirable flow pattern in the GC based on overall evaluations of current density magnitude, uniformity of current density distribution and pressure drop in the GC. Modification to GDL structure is proposed to promote the formation of the desirable flow pattern.

Li Chen - One of the best experts on this subject based on the ideXlab platform.

  • numerical investigation of liquid water distribution in the cathode side of proton exchange membrane fuel cell and its effects on cell performance
    International Journal of Hydrogen Energy, 2012
    Co-Authors: Li Chen, Taofeng Cao, Zhaohui Li, Yaling He, Wenquan Tao
    Abstract:

    A three-dimensional unsteady two-phase model for the cathode side of proton exchange membrane fuel cell (PEMFC) consisting of gas diffusion layer (GDL) with hybrid structural model is developed to investigate liquid water behaviors under different operating and geometrical conditions and to quantitatively evaluate effects of liquid water distribution on reactant transport and current density distribution. Simulation results reveal that liquid water transport processes and distributions are significantly affected by Inlet Air Velocity, wall wettability and water Inlet position, which in turn play a prominent role on local reactant transport and cause considerable disturbances of the current density. Liquid water film spreading on the gas channel (GC) top wall is identified as the most desirable flow pattern in the GC based on overall evaluations of current density magnitude, uniformity of current density distribution and pressure drop in the GC. Modification to GDL structure is proposed to promote the formation of the desirable flow pattern.

  • numerical investigation of liquid water distribution in the cathode side of proton exchange membrane fuel cell and its effects on cell performance
    International Journal of Hydrogen Energy, 2012
    Co-Authors: Li Chen, Taofeng Cao, Wenquan Tao
    Abstract:

    A three-dimensional unsteady two-phase model for the cathode side of proton exchange membrane fuel cell (PEMFC) consisting of gas diffusion layer (GDL) with hybrid structural model is developed to investigate liquid water behaviors under different operating and geometrical conditions and to quantitatively evaluate effects of liquid water distribution on reactant transport and current density distribution. Simulation results reveal that liquid water transport processes and distributions are significantly affected by Inlet Air Velocity, wall wettability and water Inlet position, which in turn play a prominent role on local reactant transport and cause considerable disturbances of the current density. Liquid water film spreading on the gas channel (GC) top wall is identified as the most desirable flow pattern in the GC based on overall evaluations of current density magnitude, uniformity of current density distribution and pressure drop in the GC. Modification to GDL structure is proposed to promote the formation of the desirable flow pattern.

Ramon Costa-castelló - One of the best experts on this subject based on the ideXlab platform.

  • Model-based analysis for the thermal management of open-cathode proton exchange membrane fuel cell systems concerning efficiency and stability
    Journal of Process Control, 2016
    Co-Authors: Stephan Strahl, Ramon Costa-castelló
    Abstract:

    In this work we present a dynamic, control-oriented, concentrated parameter model of an open-cathode proton exchange membrane fuel cell system for the study of stability and efficiency improvement with respect to thermal management. The system model consists of two dynamic states which are the fuel cell temperature and the liquid water saturation in the cathode catalyst layer. The control action of the system is the Inlet Air Velocity of the cathode Air flow manifold, set by the cooling fan, and the system output is the stack voltage. From the model we derive the equilibrium points and eigenvalues within a set of operating conditions and subsequently discuss stability and the possibility of efficiency improvement. The model confirms the existence of a temperature-dependent maximum power in the moderate temperature region. The stability analysis shows that the maximum power line decomposes the phase plane in two parts, namely stable and unstable equilibrium points. The model is capable of predicting the temperature of a stable steady-state voltage maximum and the simulation results serve for the design of optimal thermal management strategies.

Yifeng Gao - One of the best experts on this subject based on the ideXlab platform.

  • long term performance of Air side heat transfer and pressure drop for finned tube evaporators of Air conditioners under intermittent operation conditions
    International Journal of Refrigeration-revue Internationale Du Froid, 2010
    Co-Authors: Guoliang Ding, Yifeng Gao
    Abstract:

    Abstract In this study, the effects of long-term intermittent operations on the Air-side heat transfer and pressure drop performance of finned tube evaporators of Air conditioners were investigated by experiments on an aluminum-fin evaporator and a copper-fin evaporator. In order to simulate intermittent operations of on–off controlled Air conditioners, the temperatures of the two evaporators changed to 5 ± 0.5 °C at first and then to 27 ± 0.5 °C repeatedly. The repetition number was up to 4800, and the Air-side heat transfer and pressure drop of the two evaporators were tested after every 300 repetitions. The test results indicate that after long-term intermittent operations, the Air-side heat transfer coefficient decreases and the pressure drop increases. The variations of the heat transfer coefficient and the pressure drop are more obvious at lower Inlet Air Velocity, and the influence of long-term intermittent operations on the aluminum-fin evaporator is greater than that on the copper-fin evaporator.

  • effects of biofouling on Air side heat transfer and pressure drop for finned tube heat exchangers
    International Journal of Refrigeration-revue Internationale Du Froid, 2009
    Co-Authors: Yifeng Gao
    Abstract:

    Experimental investigations on the effects of biofouling on Air-side heat transfer and pressure drop for three biofouled finned tube heat exchangers and one clean finned tube heat exchanger were performed. Artificial accelerated method of microorganism growth on the fin surface was used for simulating the biofouled finned tube heat exchangers. Experimental results indicate that the effects of biofouling on the Air-side heat transfer coefficient decreases 7.2% at 2.0 m/s when the biofouled area ratio is 10%, while it decreases 15.9% at 2.0 m/s when the biofouled area ratio is 60%, and biofouling causes a 21.8% ∼ 41.3% increase in pressure drop when the Air Velocity is between 0.5 and 2.0 m/s. The increase of Inlet Air Velocity is helpful to improve the long-term performance of finned tube heat exchanger. Biofouling makes the hydrophilic coating failure, and the condensation water easily converges on the fin surface where biofouling grows.

G Correa - One of the best experts on this subject based on the ideXlab platform.

  • analysis of the cathode side of a pemfc varying design parameters to optimize current distribution and power density
    Journal of Electroanalytical Chemistry, 2020
    Co-Authors: T Falaguerra, P Munoz, G Correa
    Abstract:

    Abstract The amount and distribution over the active area of current density produced by the stack is a key aspect of a fuel cell performance. The performance of a proton exchange membrane fuel cell (PEMFC) is affected by many factors, including the operating conditions, flow field and manifold design, and membrane performance. In the present study, a 3D multiphysics model of a PEMFC half-cell focused in the cathode side is developed. Statistical analysis tools are proposed to quantitatively evaluate the current density distribution on the active area of the electrode in order to guarantee a proper distribution while maintaining power density. The analysis was done choosing four design parameters at three different levels on which a fractional factorial experimental design provided by the Taguchi method was applied. Finally the 0.65 V working potential, that guarantees a good power generation and its adequate density current distribution on the active area of the cell, is selected. The best conditions were obtained with geometries of parallel channels, maximum gas diffusion layer porosity, maximum Inlet Air Velocity and minimum vapor fraction, this combination improves 2.31 times the power generated in the worst case analyzed.