23863

MEC2 256

كارشناسي ارشد

مهندسي مكانيك - تبديل انرژي

فني و مهندسي

1403/06/26

80 ص.

ابراهيم افشاري , مسعود ضيائي راد

الكترولايزر غشاء تبادل پروتون , خنك كاري , افت فشار , دماي بيشينه , شاخص يكنواختي دما , نانوسيال

Due to the importance of the energy issue and concerns about global warming and the reduction of fossil fuels, much attention has been paid to alternative fuels. Hydrogen is a very attractive alternative to fossil fuels due to its low pollution, renewable nature and easy transportation. Among many methods of hydrogen production, environmentally friendly and high purity hydrogen can be produced from water electrolysis. Proton exchange membrane (PEM) electrolyzers are more interested due to the production of pure hydrogen, high efficiency and ability to work in high current density. The heat generated in the high-temperature PEM electrolyzer causes the temperature of the electrolyzer to rise, and if this heat is not removed well, it causes the destruction of the membrane and the catalyst layer and strongly affects the efficiency of the electrolyzer. For this reason, the cooling of the high temperature PEM electrolyzer is particularly important. In this study, electrolyzer cooling using five cooling fluids including air, water and Al2O3/water nanofluid with three volume fractions of 0.5%, 1% and 1.5% was numerically investigated in four different flow field patterns. Four inlet Reynolds values of 375, 525, 625 and 875 were considered to investigate the fluid flow. The cooling performance of the electrolyzer using five cooling fluids, four flow field patterns and different Reynolds inlets were compared in terms of pressure drop, maximum temperature and index of uniform temperature. The results show that the use of nanofluid improves the cooling condition and the temperature parameters that affect the efficiency and performance of the electrolyzer; It has a significant effect. Also, increasing the input Reynolds number causes better cooling of the electrolyzer. The lowest maximum temperature occurs in the volume fraction of 1.5% Al2O3/water nanofluid and the inlet Reynolds number of 875 in the multi-serpentine flow field pattern with the maximum temperature value of 97.72°C. In terms of index of uniform temperature, the new serpentine model showed better performance; After this model, the multi-serpentine flow field had a better index of uniform temperature with a very small difference compared to the new serpentine model. By increasing the nanofluid volume fraction to 1.5%, the maximum temperature decreased by 1.6%, the temperature uniformity index decreased by 2.8%, and the pressure drop increased by 8.3%.

Proton exchange membrane (PEM) electrolyzer , Cooling , Pressure drop , Maximum temperature , Index of uniform temperature , Nanofluid

Numerical Investigation of High-Temperature PEM Electrolyzer Cooling using Nanofluid

مهندسي مكانيك

Due to the importance of the energy issue and concerns about global warming and the reduction of fossil fuels, much attention has been paid to alternative fuels. Hydrogen is a very attractive alternative to fossil fuels due to its low pollution, renewable nature and easy transportation. Among many methods of hydrogen production, environmentally friendly and high purity hydrogen can be produced from water electrolysis. Proton exchange membrane (PEM) electrolyzers are more interested due to the production of pure hydrogen, high efficiency and ability to work in high current density. The heat generated in the high-temperature PEM electrolyzer causes the temperature of the electrolyzer to rise, and if this heat is not removed well, it causes the destruction of the membrane and the catalyst layer and strongly affects the efficiency of the electrolyzer. For this reason, the cooling of the high temperature PEM electrolyzer is particularly important. In this study, electrolyzer cooling using five cooling fluids including air, water and Al2O3/water nanofluid with three volume fractions of 0.5%, 1% and 1.5% was numerically investigated in four different flow field patterns. Four inlet Reynolds values of 375, 525, 625 and 875 were considered to investigate the fluid flow. The cooling performance of the electrolyzer using five cooling fluids, four flow field patterns and different Reynolds inlets were compared in terms of pressure drop, maximum temperature and index of uniform temperature. The results show that the use of nanofluid improves the cooling condition and the temperature parameters that affect the efficiency and performance of the electrolyzer; It has a significant effect. Also, increasing the input Reynolds number causes better cooling of the electrolyzer. The lowest maximum temperature occurs in the volume fraction of 1.5% Al2O3/water nanofluid and the inlet Reynolds number of 875 in the multi-serpentine flow field pattern with the maximum temperature value of 97.72°C. In terms of index of uniform temperature, the new serpentine model showed better performance; After this model, the multi-serpentine flow field had a better index of uniform temperature with a very small difference compared to the new serpentine model. By increasing the nanofluid volume fraction to 1.5%, the maximum temperature decreased by 1.6%, the temperature uniformity index decreased by 2.8%, and the pressure drop increased by 8.3%.

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