Parametric Experiments of Water Transport Characteristic in Nafion® Membrane

2018 ◽  
Author(s):  
Jaemin Son ◽  
Sangseok Yu
Keyword(s):  
Fuel Cell ◽  
Relative Humidity ◽  
Water Transport ◽  
Transport Mechanism ◽  
Test Chamber ◽  
Water Diffusion ◽  
Operating Pressure ◽  
Concentration Difference ◽  
Transport Characteristic ◽  
Water Contents

In a PEMFC (Proton electrolyte membrane fuel cell), water transport mechanism inside the membrane is very important in performance and durability of whole fuel cell stack. Diffusion of water through the membrane is governed by humidity conditions of outer layers and the humidity conditions of gases depend on temperature, pressure and operating pressures. Since those parameters are varied non-linearly, it is necessary to investigate water transport mechanism by concentration difference between both sides of membrane. In this study, water contents of Nafion® membrane is measured in terms of relative humidity, temperatures, and operating pressure. Water diffusion is also measured at different pressures in both sides. Test chamber is designed to fix membrane in the middle of chamber and the membrane separates chambers in two spaces. Parametric study is conducted to measure the water contents of membranes in terms of temperatures 30°C, 50°C, 70°C, 90°C and 0 to 100% relative humidity. When the water diffusivity is calculated by measured data, the water concentrations in both sides are determined by harmonic averages of inlet and exit water humidity. Additionally, water flux is also investigated in terms of both sides humidity, operating pressure and temperatures. As a result, the water diffusion coefficient was explained by the operating temperature and the relative humidity and operating pressures.

scholarly journals Quantifying Cathode Water Transport via Anode Relative Humidity Measurements in a Polymer Electrolyte Membrane Fuel Cell

Energies ◽  
2017 ◽  
Vol 10 (8) ◽  
pp. 1222 ◽  
Author(s):  
Logan Battrell ◽  
Aubree Trunkle ◽  
Erica Eggleton ◽  
Lifeng Zhang ◽  
Ryan Anderson
Keyword(s):  
Fuel Cell ◽  
Relative Humidity ◽  
Polymer Electrolyte ◽  
Water Transport ◽  
Polymer Electrolyte Membrane ◽  
Electrolyte Membrane ◽  
Humidity Measurements

Water Transport in the MEA of a PEM Fuel Cell

2009 ◽  
Author(s):  
JuanFang Liu ◽  
Nobuyuki Oshima ◽  
Eru Kurihara ◽  
LitanKumar Saha
Keyword(s):  
Fuel Cell ◽  
Water Content ◽  
Water Transport ◽  
Liquid Water ◽  
Knudsen Diffusion ◽  
Catalyst Layer ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Anode Surface ◽  
Operating Pressure

In the paper, a one-dimensional model of water transport across the entire cell is presented for the proton exchange membrane fuel cell. In the model, the catalyst layer is treated as a separate computing domain, not an interface between the gas diffusion layer and membrane. Meanwhile, in the membrane mechanisms of back diffusion and electro-osmotic drag are considered, while pure diffusion process is taken into account for the gas-phase flow in the cell. In the catalyst layer, except for Knudsen diffusion, water vapor in the pore is coupled with liquid water in the ionomor phase by the isotherm sorption and in equilibrium with each other. The results indicate both the operating pressure and mean current density are the important factors to affect the water transport process in the cell. Moreover, it is found that the liquid water diffusivity dependent on water content in the ionomer phase would lead to the water content distribution at the different degree nonuniformity. Additionally, the thinner membranes result in the higher and more uniform distribution of water content in the membrane phase. Furthermore, the concentration-gradient driven water flux based on Henry’law is exposed on the anode surface of the membrane as the boundary condition, which is more appropriate to present the reality of water content in the ionomer phase. The numerical results imply that it is very necessary to investigate the interaction among different components of a cell, so as to predict correctly the coupled transport phenomena occurred in the entire fuel cell.

scholarly journals Study of water transport mechanism based on the single straight channel of proton exchange membrane fuel cell

AIP Advances ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 105206
Author(s):  
Wei Yuan ◽  
Jie Li ◽  
Zhongxian Xia ◽  
Shizhong Chen ◽  
Xuyang Zhang ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Water Transport ◽  
Transport Mechanism ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Straight Channel ◽  
Exchange Membrane

scholarly journals Effect of combinations of different operating parameters on performance of proton exchange membrane fuel cell

2021 ◽  
pp. 70-70
Author(s):  
Prem Thiyagarajan ◽  
Kanchana Jeganathan ◽  
Manoj Panthalingal ◽  
Naveen Rajappa
Keyword(s):  
Fuel Cell ◽  
Relative Humidity ◽  
Proton Exchange Membrane ◽  
Three Dimensional ◽  
Proton Exchange ◽  
Operating Parameters ◽  
Operating Pressure ◽  
Isothermal Model ◽  
Ansys Fluent ◽  
Exchange Membrane

The present study mainly focuses on the different combinations of significant operating parameters like inlet relative humidity of anode gas and cathode gas, operating pressure and nature of cathode gas on the performance of Proton Exchange Membrane Fuel Cell (PEMFC) using validated three- dimensional (3D), single-phase, and non-isothermal model with the help of ANSYS Fluent 18.1 package. The results of different combinations on the performance of PEMFC are compared with independent effects of the operating parameters. Results revealed that the combined operating parameters? effect on the performance of the PEMFC is deviated significantly (up to 5 %) compared to the expected summation of individual parameters effect which is considerable in fuel cell scaling and stack applications. Nature of gas, operating pressure, and inlet cathode gas relative humidity are the most significant parameters in the automobile applications which have to be dealt with care where the combination of changes in operating parameters is quite phenomenal.

Experiments Toward Fundamental Validation of PEM Fuel Cell Models

2005 ◽  
Author(s):  
Q. G. Yan ◽  
Q. Y. Liu ◽  
H. Toghiani ◽  
J. X. Wu
Keyword(s):  
Fuel Cell ◽  
Relative Humidity ◽  
Operating Conditions ◽  
Cell Performance ◽  
Experimental Results ◽  
Polarization Curves ◽  
Polymer Electrolyte Fuel Cell ◽  
Operating Pressure ◽  
Cell Models ◽  
Fuel Cell Performance

Detailed experimental parameters are controlled and measured under widely varying operating conditions. In addition to polarization curves, feed gas flow rates, temperatures, pressure drop, and relative humidity are all measured accurately. Performance of a polymer electrolyte fuel cell (PEFC) was studied using steady-state polarization curves and electrochemical impedance spectroscopy (EIS) techniques. The effects of relative humidity, temperature, pressure and feed gas stoichiometry on fuel cell performance were investigated. It was found that the humidity of both the anode and cathode inlet gases had a significant effect on fuel cell performance. The experimental results showed that a decrease in the cathode humidity has a more detrimental effect on cell performance than a comparable decrease in the anode humidity. The obtained results will be used to define conditions of optimal hydration of the membrane. Based on the performance and resistance measurements, optimal humidification can be achieved. The polarization curves of the cell at different operating temperatures showed that fuel cell performance was improved with increasing temperature from 65 to 75°C. The fuel cell performance also improved as the operating pressure was increased from 1 atm to 4 atm. The resistance of the working fuel cell showed that the membrane resistance increased as the feed gas relative humidity (RH) decreased. The experimental results were compared with the results of a CFD mathematical model. These experimental data will provide a baseline for validation of fuel cell models.

scholarly journals Experimental investigation on water-injected twin-screw compressor for fuel cell humidification

2012 ◽  
Vol 226 (12) ◽  
pp. 2925-2932 ◽  
Author(s):  
Talal Ous ◽  
Elvedin Mujic ◽  
Nikola Stosic
Keyword(s):  
Fuel Cell ◽  
Relative Humidity ◽  
Constant Pressure ◽  
Water Injection ◽  
Injection Rate ◽  
Fuel Cell Stack ◽  
Balance Of Plant ◽  
Air Supply ◽  
Twin Screw ◽  
Mass Flow Rates

Water injection in twin-screw compressors was examined in order to develop effective humidification and cooling schemes for fuel cell stacks as well as cooling for compressors. The temperature and the relative humidity of the air at suction and exhaust of the compressor were monitored under constant pressure and water injection rate and at variable compressor operating speeds. The experimental results showed that the relative humidity of the outlet air was increased by the water injection. The injection tends to have more effect on humidity at low operating speeds/mass flow rates. Further humidification can be achieved at higher speeds as a higher evaporation rate becomes available. It was also found that the rate of power produced by the fuel cell stack was higher than the rate used to run the compressor for the same amount of air supplied. The efficiency of the balance of plant was, therefore, higher when more air is delivered to the stack. However, this increase in the air supply needs additional subsystems for further humidification/cooling of the balance-of-plant system.

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