INVESTIGATION OF THE EFFECT OF OPERATING PARAMETERS ON NERNST VOLTAGE IN HYDROGEN-OXYGEN FUEL CELLS

Year 2024, Volume: 44 Issue: 1, 59 - 69, 03.06.2024

Muhittin Bilgili Yunus Emre Gönülaçar

https://doi.org/10.47480/isibted.1494033

Abstract

In hydrogen-oxygen fuel cells, operating parameters have an influence on the maximum expected open circuit (Nernst) voltage. Even though fuel cells have been the subject of many research, none of them have theoretically investigated the impact of various operating parameters, particularly concerning Nernst voltage and maximum thermodynamic efficiency. In this study, a computer program was developed to theoretically determine the effect of various operating parameters on the Nernst voltage in hydrogen-oxygen fuel cells. This computer program was developed in MATLAB to mathematically examine the effects of hydrogen and oxygen mole ratios, anode and cathode pressures, and operating temperatures on the maximum expected open circuit voltage. When calculating Nernst voltages and maximum thermodynamic efficiency for fuel cell reactions containing water as a by-product, the effects of higher heating value (HHV) and lower heating value (LHV) are also considered in the solutions. As a result, it was also concluded that temperature increase reduces the fuel cell Nernst voltage and maximum thermodynamic efficiency. Therefore, it was observed from the figures that the best conditions for the Nernst voltage occur when HHV is assumed, the temperature is 353 K, the mole ratios of hydrogen and oxygen are 1.0, the anode and cathode pressures are 5 atm and 6 atm, respectively. In terms of thermodynamic efficiency, it was determined that there was a maximum increase of 92.2% in the LHV assumption compared to the HHV assumption at the temperature of 1000 K, provided that other operating parameters were kept constant.

Keywords

Nernst voltage, Fuel cell, Thermodynamic efficiency, Hydrogen-oxygen

HİDROJEN-OKSİJEN YAKIT HÜCRELERİNDE ÇALIŞMA PARAMETRELERİNİN NERNST VOLTAJINA ETKİSİNİN İNCELENMESİ

Abstract

Hidrojen-oksijen yakıt hücrelerinde çalışma parametrelerinin beklenen maksimum açık devre (Nernst) voltajı üzerinde etkisi vardır. Yakıt hücreleri birçok araştırmaya konu olmasına rağmen hiçbiri, özellikle Nernst voltajı ve maksimum termodinamik verimlilikle ilgili çeşitli çalışma parametrelerinin etkisini teorik olarak incelememiştir. Bu çalışmada, hidrojen-oksijen yakıt hücrelerinde çeşitli çalışma parametrelerinin Nernst voltajına etkisini teorik olarak belirlemek için bir bilgisayar programı geliştirilmiştir. Bu bilgisayar programı, hidrojen ve oksijen mol oranlarının, anot ve katot basınçlarının ve çalışma sıcaklıklarının beklenen maksimum açık devre voltajı üzerindeki etkilerini matematiksel olarak incelemek için MATLAB'da geliştirilmiştir. Yan ürün olarak su içeren yakıt hücresi reaksiyonları için Nernst voltajları ve maksimum termodinamik verim hesaplanırken, çözümlerde üst ısıl değeri (HHV) ve alt ısıl değerinin (LHV) etkileri de dikkate alınmaktadır. Sonuç olarak sıcaklık artışının yakıt hücresi Nernst voltajını ve maksimum termodinamik verimi azalttığı sonucuna varılmıştır. Dolayısıyla Nernst voltajı için en iyi koşulların HHV kabulünde, sıcaklığın 353 K, hidrojen ve oksijenin mol oranlarının 1,0, anot ve katot basınçlarının sırasıyla 5 atm ve 6 atm olduğu durumlarda oluştuğu, grafiklerden gözlemlenmiştir. Termodinamik verim açısından diğer çalışma parametrelerinin sabit tutulması koşuluyla 1000 K sıcaklıkta LHV varsayımında HHV varsayımına göre maksimum %92,2 oranında bir artış olduğu tespit edilmiştir.

Keywords

Nernst voltajı, Yakıt hücresi, Termodinamik verim, Hidrojen-oksijen

References

• Abouemara K., Shahbaz M., Boulfrad S., Mckay G., and Al-ansari T., 2024, Design of an Integrated System That Combines the Steam Gasification of Plastic Waste and a Solid Oxide Fuel Cell for Sustainable Power Generation, Energy Conversion and Management: X, 21, 100524, doi: 10.1016/j.ecmx.2024.100524.
• Amadane Y., Mounir H., Elmarjani A., and Ayad G., 2018, Modeling the Temperature Effect on PEM Fuel Cell Performance, Eleven International Conference on Thermal Engineering: Theory and Applications, Doha, Qatar.
• Arıç, T., Bilgili M., and Özsunar A., 2019, Numerical Analysis of Two Units PEM Fuel Cell Stack Tugay, Gazi University Journal of Science Part C: Design and Technology, 7(4), 999–1011, doi: 10.29109/gujsc.623951.
• Bo C., Yuan C., Zhao X., Wu C. B., and Li M. Q., 2009, Parametric Analysis of Solid Oxide Fuel Cell, Clean Technologies and Environmental Policy, 11, 391–99, doi: 10.1007/s10098-009-0197-4.
• Çavuşoğlu A., 2006, Fuel Cells and Their Applications, M.Sc. Thesis, Uludağ University, Bursa, Turkey.
• Cellek M., and Bilgili M., 2021, Investigation of the Effect of Stoichiometry Ratio on Two-Cell PEM Fuel Cell Stack Performance, Gazi University Journal of Science Part C: Design and Technology, 9(1), 134–47, doi: 10.29109/gujsc.799620.
• Duncan K. L., Lee K., and Wachsman E. D., 2011, Dependence of Open-Circuit Potential and Power Density on Electrolyte Thickness in Solid Oxide Fuel Cells with Mixed Conducting Electrolytes, Journal of Power Sources, 196(5), 2445–51, doi: 10.1016/j.jpowsour.2010.10.034.
• Gonzatti F., and Farret F. A., 2017, Mathematical and Experimental Basis to Model Energy Storage Systems Composed of Electrolyzer, Metal Hydrides and Fuel Cells, Energy Conversion and Management, 132, 241–50, doi: 10.1016/j.enconman.2016.11.035.
• Hernández-Gómez Á., Ramirez V., and Guilbert D., 2020, Investigation of PEM Electrolyzer Modeling: Electrical Domain, Efficiency, and Specific Energy Consumption, International Journal of Hydrogen Energy, 45(29), 14625–39, doi: 10.1016/j.ijhydene.2020.03.195.
• Işık R., 2019, Numerical and Experimental Investigation of the Effect of Flow Type on Performance and Temperature Distribution in Solid Oxide Fuel Cell, M.Sc. Thesis, Ömer Halisdemir University, Niğde, Turkey.
• Khotseng L., 2020, Thermodynamics and Energy Engineering (First Ed.), IntechOpen, London, United Kingdom, 3-19.
• Liu Y., Tu Z., and Hwa S., 2023, Water Management and Performance Enhancement in a Proton Exchange Membrane Fuel Cell System Using Optimized Gas Recirculation Devices, Energy, 279, 128029, doi: 10.1016/j.energy.2023.128029.
• Lyu J., Kudiiarov V., and Lider A., 2020, Corrections of Voltage Loss in Hydrogen-Oxygen Fuel Cells, Batteries, 6(9), 1-8, doi: 10.3390/batteries6010009.
• Matsui T., Kosaka T., Inaba M., Mineshige A., and Ogumi Z., 2005, Effects of Mixed Conduction on the Open-Circuit Voltage of Intermediate-Temperature SOFCs Based on Sm-Doped Ceria Electrolytes, Solid State Ionics, 176(7–8), 663–68, doi: 10.1016/j.ssi.2004.10.010.
• Mench M., 2008, Fuel Cell Engines, John Wiley & Sons, New Jersey, ABD.
• Mitra U., Arya A., and Gupta S., 2023, A Comprehensive and Comparative Review on Parameter Estimation Methods for Modelling Proton Exchange Membrane Fuel Cell, Fuel, 335, 127080, doi: 10.1016/j.fuel.2022.127080.
• Nascimento A. L., Yahyaoui I., Fardin J. F., Encarnação L. F., and Tadeo F., 2020, Modeling and Experimental Validation of a PEM Fuel Cell in Steady and Transient Regimes Using PSCAD/EMTDC Software, International Journal of Hydrogen Energy, 45(55), 30870–81, doi: 10.1016/j.ijhydene.2020.04.184.
• Outeiro M. T., Chibante R., Carvalho A. S., and de Almeida A. T., 2008, A Parameter Optimized Model of a Proton Exchange Membrane Fuel Cell Including Temperature Effects, Journal of Power Sources, 185(2), 952–60, doi: 10.1016/j.jpowsour.2008.08.019.
• Pachauri R. K., and Chauhan Y. K., 2015, A Study, Analysis and Power Management Schemes for Fuel Cells, Renewable and Sustainable Energy Reviews, 43, 1301–19, doi: 10.1016/j.rser.2014.11.098.
• Riad, A. J., Hasanien H. M., Turky R. A., and Yakout A. H., 2023, Identifying the PEM Fuel Cell Parameters Using Artificial Rabbits Optimization Algorithm, Sustainability, 15(4625), 1–17.
• Sadeghi M., Jafari M., Hajimolana Y. S., Woudstra T., and Aravind P. V., 2021, Size and Exergy Assessment of Solid Oxide Fuel Cell-Based H 2 -Fed Power Generation System with Alternative Electrolytes : A Comparative Study, Energy, Conversion and Management 228, 113681, doi: 10.1016/j.enconman.2020.113681.
• Sahli Y., Zitouni B., and Ben-Moussa H., 2017, Solid Oxide Fuel Cell Thermodynamic Study, Çankaya University Journal of Science and Engineering, 14(2), 134–51.
• Şefkat G., and Özel M. A., 2018, Simulink Model and Analysis of PEM Fuel Cell, Uludağ University Journal of The Faculty of Engineering, 23(2), 351–66, doi: 10.17482/uumfd.400337.
• Tu B., Wen H., Yin Y., Zhang F., Su X., Cui D., and Cheng M., 2020, Thermodynamic Analysis and Experimental Study of Electrode Reactions and Open Circuit Voltages for Methane-Fuelled SOFC, International Journal of Hydrogen Energy, 45(58), 34069–79, doi: 10.1016/j.ijhydene.2020.09.088.
• Wang Y., Wu K., Zhao H., Li J., Sheng X., Yin Y., Du Q., Zu B., Han L., and Jiao K., 2023, Degradation Prediction of Proton Exchange Membrane Fuel Cell Stack Using Semi-Empirical and Data-Driven Methods, Energy and AI, 11, 100205, doi: 10.1016/j.egyai.2022.100205.
• Zhang J., Tang Y., Song C., Zhang J., and Wang H., 2006, PEM Fuel Cell Open Circuit Voltage (OCV) in the Temperature Range of 23 °C to 120 °C, Journal of Power Sources, 163(1), 532–37, doi: 10.1016/j.jpowsour.2006.09.026.
• Zhao L., Hong J., Yuan H., Ming P., Wei X., and Dai H., 2023, Dynamic Inconsistent Analysis and Diagnosis of Abnormal Cells within a High-Power Fuel Cell Stack, Electrochimica Acta, 464, 142897. doi: 10.1016/j.electacta.2023.142897.