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  • Küçük Resim Yok
    Öğe
    Effects of fabrication parameters on the performance of solid oxide electrolyzer cell
    (PERGAMON-ELSEVIER SCIENCE LTD, 2016) Korkmaz, Hatice; Timurkutluk, Bora; Timurkutluk, Cigdem
    The microstructure has a great impact on the performance of solid oxide fuel/electrolyzer cells while the cell fabrication parameters mainly determine the microstructure of the cell components. In this study, a number of five-layered cells with 16 cm(2) active area are fabricated and the effects of several cell fabrication parameters including sintering temperature and electrode composition on the hydrogen production performance are investigated. The experimental results showed that the optimum sintering temperature of the electrolyte, cathode and anode should be 1400 degrees C, 1250 degrees C and 1075 degrees C, respectively, while the solid weight ratio of both NiO-ScSZ cathode and LSM-ScSZ anode functional layer should be 1:1. The optimized cell produces 38 Sccm H-2 at an operation temperature of 800 degrees C and 1.5 V. Then, the cell size is increased to a commercial size of 81 cm(2) active area. The final cell exhibits an acceptable H-2 production of 154 Sccm H-2 at 800 degrees C and 1.5 V. The relatively lower performance of the commercial-size cell is attributed to the inadequate current distribution/collection due to the increased surface area. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
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    Katı oksit elektrolizör performansına etki eden parametrelerin deneysel incelenmesi
    (Niğde Üniversitesi, 2015) Korkmaz, Hatice; Timurkutluk, Bora
    Bu yüksek lisans çalıGmasında, katı oksit elektrolizör (KOE) sisteminin kilit elemanı olan membran elektrot grubu (MEG) için bir dizi önemli üretim parametrelerinin optimizasyonu üzerine yoğunlaGılmıGtır. Bu kapsamda farklı özelliklere sahip birçok elektrolit destekli MEG imal edilmiGtir. MEG?lerin elektrolit tabakaları Gerit döküm, anot ve katot elektrotları ise ipek baskı tekniği ile üretilmiGtir. Kurulan bir deneysel düzenek ile MEG?lerin elektriksel performansı test edilmiGtir ve en yüksek performansı (en düGük elektrik gereksinimi) ortaya koyan üretim parametreleri tespit edilmiGtir. Bütün bu çalıGmalar malzeme kaybını minimize etmek adına küçük boyutlu (16 cm2 aktif alan) MEG?ler üzerinde gerçekleGtirilmiGtir. Optimizasyon çalıGmalarının ardından aynı özelliklere sahip ticari boyutta (81 cm2 aktif alan) yüksek performanslı bir KOE hücresi imal ve test edilmiGtir. Hücre800°C çalıGma sıcaklığında ve 1,5V çalıGma voltajında 20A güç çekerek dakikada 154Sccm hidrojen üretimi ortaya koymuştur.
  • Küçük Resim Yok
    Öğe
    Strength evaluation of glass-ceramic composites containing yttria stabilized zirconia after thermal cycling
    (ELSEVIER SCI LTD, 2015) Timurkutluk, Bora; Ciflik, Yelda; Korkmaz, Hatice
    The effect of YSZ (yttria stabilized zirconia) on the thermal cycling stability of commercial glass ceramics powders as a solid oxide fuel cell (SOFC) sealant material is investigated. Four different composite sealants are prepared including 1, 3, 5 and 10 wt% of YSZ with respect to the total powders. A sealant without YSZ is also prepared as the base case for comparison. The fabrication of the sealant is achieved by using cost-effective tape casting routes. The samples are then placed between two metallic interconnectors and a high temperature glass forming process is performed. The mechanical performances are measured via tensile tests before and after a number of thermal cycles. The results indicate that the fracture strength is adversely affected by the amount of YSZ loading due to reduced glass ceramics powders in the composites. However, when the thermal cycling stability is the issue, the samples with YSZ show relatively small rate of decrease. Therefore, the addition of YSZ is found to be beneficial for improving the thermal cycle stability of glass-ceramics. The optimum YSZ content is determined to be 5 wt%, since these samples exhibit almost a stable mechanical performance after each thermal cycles considered in this study. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.