PEMFC purging at low operating temperatures: An experimental approach

Omrani, Reza; Mohammadi, Saeed Seif; Mafinejad, Yasser; Paul, B.; Islam, Rafiqul; Shabani, Bahman

doi:10.1002/er.4783

Cited by 15 publications

(16 citation statements)

References 70 publications

(184 reference statements)

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“…When the current is 25 A, the voltage of Cell 13, Cell 15, and Cell 17 gradually decreases, as shown in Figure A. Gradual voltage drop happens due to the accumulation of water . These phenomena proved the occurrence of the anode flooding.…”

Section: Resultsmentioning

confidence: 91%

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Rapid degradation characteristics of an air‐cooled PEMFC stack

et al. 2020

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Summary Durability is one of the obstacles to the large‐scale commercialization of proton exchange membrane fuel cell (PEMFC) stacks. Understanding its decay behavior is a prerequisite for improving durability. In this study, rapid degradation characteristics of an air‐cooled PEMFC stack are investigated. Due to the simultaneous presence of various degradation sources, the maximum power of the PEMFC stack has been reduced by 39.6% after just 74.6 h of operations. Performance degradation characteristics are sought by analyzing the cell voltage, temperature distribution, ion chromatography, and surface morphology of the gas diffusion layer. The result shows that abnormal cell voltage and temperature distribution can reflect the problematic location. The fluoride ion emission rate is 0.111 mg/day, which proves that the membrane has been seriously degraded. Contact angle reduction and impurities attached to the surface of the gas diffusion layer lead to the water management failure. It is also found that the main factor for performance degradation could be different under different current conditions. And more information can be found under higher current conditions during monitoring the decay of PEMFCs. This study helps to deepen the understanding of performance degradation characteristics.

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Section: Resultsmentioning

confidence: 91%

“…Gradual voltage drop happens due to the accumulation of water. 38 These phenomena proved the occurrence of the anode flooding. Liquid water blocked the gas passage in the anode GDL, so that the reaction gas entering the catalytic layer was greatly reduced.…”

Section: Characteristic Of the Cell Voltagementioning

confidence: 91%

Rapid degradation characteristics of an air‐cooled PEMFC stack

et al. 2020

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“…The effects of gas purging on water management have been investigated through both experiments and numerical simulations. 25,26 Zhang et al 27 systematically studied the effects of the purging parameters on the performance of a high-temperature proton exchange membrane fuel cell (HT-PEMFC). The results showed that the anode purging process could improve both the performance and fuel utilization.…”

Section: Introductionmentioning

confidence: 99%

Effect of gas purging on the performance of a proton exchange membrane fuel cell with dead‐ended anode and cathode

Shen

Chan

2021

Intl J of Energy Research

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Water management is an important issue to be addressed to maintain the stable and efficient operation of a proton exchange membrane fuel cell (PEMFC).Gas purging is commonly performed to remove accumulated water in a PEMFC, especially in a dead-ended fuel cell system. A 3D dynamic model with a user-defined inlet boundary condition is proposed to study the effect of gas purging with different purge durations in an H 2 /O 2 PEMFC. The results show that the performance immediately deteriorates and then recovers to the original level during gas purging. Purging has a significant effect on the flow and mass transfer in the flow channel, and it leads to efficient removal of water from the PEMFC. The voltage variation tendency is consistent with the water content of the membrane. Membrane dehydration is the main reason for the performance degradation. Notable variations could be observed with increments in the purge duration. Water in a PEMFC is more sensitive and responsive to changes of operating conditions than the reactants. In addition, the performance is significantly deteriorated at a higher operating temperature. A large amount of water is removed during the gas purging, resulting in low water content in the membrane and low water saturation at the interface between the flow channel and the gas diffusion layer.

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“…The anode fuel supply management impacts directly the PEMFC operation efficiency and durability. In general, three anode modes including flow‐through mode, dead‐end mode, and recirculation mode, are used to supply hydrogen in a PEMFC system 1,2 . Hydrogen recirculation mode can improve the efficiency and durability of the fuel cell with the advantage of humidifying the dry supplied hydrogen, discharging water timely, and distributing accumulated inert gases 3 .…”

Section: Introductionmentioning

confidence: 99%

“…In general, three anode modes including flowthrough mode, dead-end mode, and recirculation mode, are used to supply hydrogen in a PEMFC system. 1,2 Hydrogen recirculation mode can improve the efficiency and durability of the fuel cell with the advantage of humidifying the dry supplied hydrogen, discharging water timely, and distributing accumulated inert gases. 3 Hence an effective hydrogen recirculation device is of great importance to enhance the performance of PEMFC systems.…”

Section: Introductionmentioning

confidence: 99%

Performance investigation of a multi‐nozzle ejector for proton exchange membrane fuel cell system

et al. 2020

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Summary Due to its merit of no consuming energy, no moving part, and less requiring space, and maintenance, the ejector is one of the most promising hydrogen recirculation devices for proton exchange membrane fuel cell (PEMFC) applications. However, the prominent problem is its poor adaptability of the conventional ejector to meet the power range requirements of the PEMFC system. Thus, a multi‐nozzle ejector was investigated to widen the applicable power range of a PEMFC system. The designed multi‐nozzle ejector consists of one central nozzle (CN) and two symmetrical nozzles (SNs). The CN mode is activated under low power conditions, while the SNs mode is switched to adapt high power conditions. A 3D computational fluid dynamics (CFD) model was established to simulate the performance of ejectors, and an experimental test bench was built to validate the accuracy of the CFD model. The results indicated that the mixing chamber diameter (Dm) and throat tilt angle of SNs (αt) have a significant effect on the entrainment performance. It was found that the multi‐nozzle ejector can broaden the hydrogen supply range from 0.27 to 1.6 g/s (22‐100 kW) with the optimal combination of a Dm of 5.0 mm and αt of 8°. Nevertheless, the hydrogen supply range is 0.48 to 1.6 g/s (37‐100 kW) when using a conventional single‐nozzle ejector with a Dm of 5.0 mm. Moreover, the temperature, pressure, and relative humidity of the secondary flow have a great influence on the hydrogen entrainment ratio with the change of stack power.

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PEMFC purging at low operating temperatures: An experimental approach

Cited by 15 publications

References 70 publications

Rapid degradation characteristics of an air‐cooled PEMFC stack

Rapid degradation characteristics of an air‐cooled PEMFC stack

Effect of gas purging on the performance of a proton exchange membrane fuel cell with dead‐ended anode and cathode

Performance investigation of a multi‐nozzle ejector for proton exchange membrane fuel cell system

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