Optimization of the Relative Humidity of Reactant Gases in Hydrogen Fuel Cells Using Dynamic Impedance Measurements

Janicka, Ewa; Mielniczek, Michal; Gawel, L.; Darowicki, Kazimierz

doi:10.3390/en14113038

Cited by 8 publications

(2 citation statements)

References 45 publications

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“…Their model concluded that a higher power demand (increased anode stoichiometry) and higher cathode relative humidity (above 60%) could make the system more at risk for floods. The importance of finding an optimal range for the relative humidity was shown in Janicka et al's examination [15]. Their measurement concluded that the relative humidity of the inlet gases should be above 50% at a lower current density, and for operation at a higher current density, a lower relative humidity value below 30% was set to obtain the best performance.…”

Section: Introductionmentioning

confidence: 99%

Bypass Configurations of Membrane Humidifiers for Water Management in PEM Fuel Cells

Vu,

Trinh,

Truong Le Tri

et al. 2023

Energies

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Water management is an important criterion in the operation of proton-exchange membrane fuel cells to maintain the high performance and reliability of the system. The water content in the cathode air that is supplied to the cathode channel contributes to the membrane humidification and the transport of protons inside the membrane structure. In automotive applications, the supply air is typically driven through an external membrane humidifier to absorb more moisture from the recirculated cathode exhaust. In the literature, humidifiers and fuel cell stacks have been separately investigated without considering whole-system configurations for water management. This study investigates changes in the cathode air characteristics through a membrane humidifier and compares two configurations using a humidifier bypass of the supply flow and exhaust flow to adjust the cathode inlet air relative humidity. Each component in the system was modeled using mathematical relations and converted into blocks of inputs and outputs in MATLAB/Simulink for simulation. The bypass valve was demonstrated to effectively reduce the relative humidity of the supply air from the saturation rate to above 60%, with a bypass fraction of up to 0.6 in both configurations. These adjustments provide system flexibility to accommodate load changes and prevent flooding in the stack channels. Bypassing the supply air through the humidifier effectively maintained consistent cathode inlet humidity across a wide operational range. A 0.4 bypass fraction on the supply side sustained a relative humidity of around 80% for the whole range of operating flow rates. In contrast, the exhaust-side bypass had a smaller impact, and the relative humidity of the cathode air was reduced when the flow rate and bypass fraction increased. This study further supports the control system design to regulate the bypass fraction according to load transients.

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Section: Introductionmentioning

confidence: 99%

Bypass Configurations of Membrane Humidifiers for Water Management in PEM Fuel Cells

Vu,

Trinh,

Truong Le Tri

et al. 2023

Energies

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show abstract

“…The dynamic operating model is thus an important factor in determining the reaction response of fuel cells via hydrogen regulation. For example, dynamic characteristics testing is a response to changes in load over time. , Figure depicts the functional relationship between the fuel cell and the dynamics test. It was discovered that the electricity demand is unstable; the change increases and decreases over a specified period, and there is a cyclical change in which, while changing from one charge of electricity to another, hydrogen is used in various reactions …”

Section: Introductionmentioning

confidence: 99%

Hydrogen Flow Controller Applied to Driving Behavior Observation of Hydrogen Fuel Cell Performance Test

2022

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Fuel cell performance tests for automotive applications include static and dynamic tests, and the dynamic load test is typically carried out to investigate the cell operating performance related to driving behavior in the particular use of fuel cell electric vehicles. The automatic hydrogen flow controller, utilized to regulate the hydrogen flow as a function of time, is one of the imperative apparatuses applied for the dynamic test. The driving behavior generally consists of rapid load fluctuations, several loads running at idle, full power, overload circumstances, start−stop repeats, and cold starting, and these dynamic variations are directly related to the power required for propelling a vehicle and the demand for hydrogen volume fluctuation throughout time. The desired automatic hydrogen flow controller was designed and manufactured for the dynamic performance test via the driving simulation protocol of a heavy-duty vehicle. The main experimental activities were performed to observe the responsibility and accuracy of the invented controller. The relation between the reliability of using the automatic hydrogen flow controller and the performance improvement of fuel cell operation was studied to gain ideas for further fuel cell modification. The hydrogen flow rates controlled by the created flow controller presented a data tolerance of approximately 0.84% which was not significantly different from the theoretical figure based on T-test analysis. The controller reacted to variations in flow rates in as little as 1−2 s, which was acceptable for the dynamic test. Regarding the performance enhancement, this automatic hydrogen flow controller assisted a single cell to generate 16% more power and 33% more energy at 45 mA as a minimum current demand in comparison with the results obtained from a test system using a traditional hydrogen controller with a constant flow rate.

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Multi-objective optimization design of a planar membrane humidifier based on NSGA-II and entropy weight TOPSIS

Chen

et al. 2023

J Therm Anal Calorim

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Optimization of the Relative Humidity of Reactant Gases in Hydrogen Fuel Cells Using Dynamic Impedance Measurements

Cited by 8 publications

References 45 publications

Bypass Configurations of Membrane Humidifiers for Water Management in PEM Fuel Cells

Bypass Configurations of Membrane Humidifiers for Water Management in PEM Fuel Cells

Hydrogen Flow Controller Applied to Driving Behavior Observation of Hydrogen Fuel Cell Performance Test

Multi-objective optimization design of a planar membrane humidifier based on NSGA-II and entropy weight TOPSIS

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