An evaluation method of gas distribution quality in dynamic process of proton exchange membrane fuel cell

Chen, Huicui; Zhao, Xin; Qu, Bingwang; Zhang, Tong; Pei, Pucheng; Li, Congxin

doi:10.1016/j.apenergy.2018.09.031

Cited by 47 publications

(9 citation statements)

References 33 publications

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“…With significantly increased oxygen concentration, the hydrogen‐oxygen PEMFCs demonstrate different characteristics and performance from the hydrogen‐air PEMFCs, 3 which can be used as power sources for underwater vehicles and unmanned aerial vehicles 4‐6 . The transient response is essential for both the hydrogen‐air and hydrogen‐oxygen PEMFCs, when used as mechanical power sources 7 . Unfavorable undershoot could occur during the loading process; dynamic voltage drops below the voltage at the steady state 8 .…”

Section: Introductionmentioning

confidence: 99%

Load changing characteristics of the hydrogen‐air and hydrogen‐oxygen proton exchange membrane fuel cells

Huang

Xing

2021

Intl J of Energy Research

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Summary Load changing performance is significant for the application of proton exchange membrane fuel cells (PEMFCs). This paper compares experimental results of the hydrogen‐air and hydrogen‐oxygen PEMFC and analyzes their dynamic performance under various operating conditions. We use electrochemical impedance spectroscopy to investigate the intrinsic mechanism during load changing. Due to the higher oxygen concentration, the hydrogen‐oxygen PEMFC responds faster (within 1 second) and operates more steadily than the hydrogen‐air PEMFC (2‐20 seconds). The experimental results show that the total polarization resistance of the hydrogen‐air PEMFC and the Ohmic resistance of the hydrogen‐oxygen PEMFC decrease dramatically with the appropriately increased operating temperature. Whereas at over‐elevated operating temperature, the resistance value increases due to the dehydration of the membrane electrode assembly. Load changing performance can be improved by increasing operating pressure and relative humidity. Increased stoichiometry is beneficial for the hydrogen‐air PEMFC, while the opposite trend is observed for the hydrogen‐oxygen PEMFC. Novelty statement Comparison of experimental results of hydrogen‐air and hydrogen‐oxygen proton exchange membrane fuel cell (PEMFC), dynamic performance at start‐up, and load changing performance are studied. Two PEMFCs' performances are quite different at various operating conditions. Overall, H2/O2 PEMFCs response faster (1 second) and operate more steadily than H2‐air (2‐20 seconds). Ohmic, polarization, and mass transfer resistance values are measured and analyzed.

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Section: Introductionmentioning

confidence: 99%

Load changing characteristics of the hydrogen‐air and hydrogen‐oxygen proton exchange membrane fuel cells

Huang

Xing

2021

Intl J of Energy Research

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“…However, performance differences occurred when working current density gradually increased, which could be attributed to the assumption that the water in the fuel cell was all in the form of gas. 10,23 Therefore, it was necessary to explore the effects of flow fields on the reaction gas and water distribution with simulation and experiment considered together. Finally, as shown from Figure 3B, the calculation result was independent of the number of the grid.…”

Section: Model Validationmentioning

confidence: 99%

Performance improvement in a proton exchange membrane fuel cell with an innovative flow field design

Huang

Xing

2021

Intl J of Energy Research

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The flow field of the proton exchange membrane fuel cell (PEMFC) controls mass and water transfer; it significantly impacts the fuel cell's performance. It is critical to innovate the flow field design for optimizing the performance. This paper proposes a new-designed flow field (NDFF) patterned with the built-in blockage and trap-shape rib association. The novel design was analyzed numerically and experimentally. A three-dimensional isothermal numerical model was first established based on COMSOL software. This model demonstrated that the NDFF transformed the traditional diffusion mass transfer into the optimized diffusion and convection mass transfer combination.Compared with the conventional straight flow field, the effective mass transfer coefficient was considerably improved. Moreover, the new-designed structures enforced cyclical variation of local velocity and pressure, forming forced-convection, which was beneficial for water management. At 0.45AÁcm À2 , the steady-state voltage and the initial dynamic response voltage were increased by 0.08 V and 0.16 V; power density was increased by 20.1%. The experimental results were collected to validate the enhanced performance of PEMFC with the NDFF. Energy efficiency ratio (EER) was proposed as an evaluation criterion; EER results suggested NDFF can improve the net output power. Highlights• A new flow field patterned with built-in blockage and trap shape rib association• Energy efficiency ratio, effective mass transfer coefficient used for evaluation • Steady-state and dynamic performances are greatly improved at an increased Energy efficiency ratioenergy efficiency ratio, flow field, oxygen and water distribution, proton exchange membrane fuel cell | INTRODUCTIONClimate change caused by environmental pollution and global warming is getting great attention; PEMFCs demonstrated outstanding potential for their advantage of zero-pollution. 1-3 Significant progress has been achieved in developing PEMFC's technologies; however, the cost is still one main obstacle that restricts the large-scale commercialization. 4 The cost can be reduced by improving PEMFC's performance. 5 Flow field significantly affects a fuel cell's performance, whose difference among PEMFCs with

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“…Different from the traditional internal combustion engine, the fuel cell stack replaces the combustion chamber, and its efficiency is not limited by the Kano cycle. In addition to the traditional internal combustion requirements of the air filter and pressure for the supply system, the fuel cell stack needs to be humidified [28,29]. In order to effectively prevent the water flooding phenomenon of the vehicle fuel cell, Pei et al [30] carried out the relevant research.…”

Section: Arh Model Descriptionmentioning

confidence: 99%

Asymptotic Analysis for the Effects of Anode Inlet Humidity on the Fastest Power Attenuation Single Cell in a Vehicle Fuel Cell Stack

et al. 2018

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A three-dimensional and isothermal anode relative humidity (ARH) model is presented and used to study the anode inlet humidity effects on the fastest power attenuation single cell in a vehicle fuel cell stack. The ARH model is based on the phenomenon that the anode is more sensitive than the cathode to water flooding. The pressure drop is considered in the ARH model, and saturation pressure is established by a pressure drop. Based on the pressure drop and relative humidity, simulations and tests are completed. First, the geometric model and computational grids are established, based on real structure of the proton exchange membrane fuel cell (PEMFC). Second, single cell distribution in the stack, test schematic and experimental conditions are demonstrated. Finally, polarization curves with 10 cells are displayed and discussed under these conditions that working temperature 70 °C, and diverse relative humidity (40%, 55%, 70%, 85%, and 100%). The test results of 34 cm2 fuel cell stack are compared against simulation results. The results show that C10 (the single cell with the farthest distance from the gas inlet) power attenuation is the fastest and that its performance is the poorest under the experimental conditions. The polarization curves predicted by the ARH model indicate fairly good coherence with the experimental results, compared against the Fluent original model. The ARH model calculation deviation is 28% less than the Fluent model at 360 mA·cm−2 for a relative humidity of 85%. The current density distribution is almost uniform, and membrane water content is negatively affected by high humidity.

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An evaluation method of gas distribution quality in dynamic process of proton exchange membrane fuel cell

Cited by 47 publications

References 33 publications

Load changing characteristics of the hydrogen‐air and hydrogen‐oxygen proton exchange membrane fuel cells

Load changing characteristics of the hydrogen‐air and hydrogen‐oxygen proton exchange membrane fuel cells

Performance improvement in a proton exchange membrane fuel cell with an innovative flow field design

Asymptotic Analysis for the Effects of Anode Inlet Humidity on the Fastest Power Attenuation Single Cell in a Vehicle Fuel Cell Stack

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