Changes of Internal Stress in Solid-Oxide Fuel Cell During Red-Ox Cycle Evaluated by In Situ Measurement With Synchrotron Radiation

2005 ◽  
Vol 3 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Hirofumi Sumi ◽  
Kenji Ukai ◽  
Misuzu Yokoyama ◽  
Yasunobu Mizutani ◽  
Yoshihisa Doi ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Internal Stress ◽  
Coefficient Of Thermal Expansion ◽  
High Energy ◽  
Solid Oxide ◽  
In Situ Measurement ◽  
Oxide Fuel ◽  
Reduction Cycle ◽  
Increasing Temperature

The internal stress in anode-supported solid-oxide fuel cells (SOFCs) was evaluated by in situ measurement using high-energy x-ray synchrotron radiation. The oxidized cell had a compression of ∼400MPa in the c-ScSZ electrolyte thin film and a tension of 50–100 MPa in the NiO-YSZ anode substrate at room temperature. The internal stress decreased with increasing temperature, becoming approximately zero at 1000 K. Although the internal stress returned to its initial value after the thermal cycle, the stress decreased to ∼200MPa in the electrolyte after the reduction cycle because of the decrease of the coefficient of thermal expansion mismatch between the electrolyte and anode. The red-ox cycle would be detrimental for anode-supported SOFC.

In Situ Synchrotron Measurement of Internal Stresses in Solid-Oxide Fuel Cell during Red-Ox Cycle

2008 ◽  
Vol 571-572 ◽  
pp. 339-344 ◽  
Author(s):  
Keisuke Tanaka ◽  
Yoshiaki Akiniwa ◽  
Hidehiko Kimura ◽  
Kenji Ukai ◽  
Misuzu Yokayama ◽  
...  
Keyword(s):  
Internal Stress ◽  
Thermal Cycle ◽  
High Energy ◽  
Thermal Reduction ◽  
Solid Oxide ◽  
Internal Stresses ◽  
Oxide Fuel ◽  
Air Atmosphere ◽  
Unit Cells

The internal stress in solid-oxide fuel cells (SOFCs) was evaluated during the thermal, reduction and re-oxidation cycles by using high-energy X-ray synchrotron radiation of about 70 keV at Beam line BL02B1 of SPring-8. The oxidized cell has a compression of about 400 MPa in the c-ScSZ electrolyte and a tension of 50-100 MPa in the NiO-YSZ anode at room temperature. In-situ measurement during the thermal cycle in an air atmosphere, the internal stress decreased with increasing temperature, becoming approximately zero at 1000 K. After the thermal cycle, the internal stress returned to its initial value. In the measurement during the reduction cycle, the internal stress was smaller than that measured during the cooling cycle after the anode was reduced from NiO-YSZ to Ni-YSZ. In the re-oxidation cycle of a reduced cell, the internal stress in the electrolyte went into tension above 800 K when the anode was re-oxidized from Ni-YSZ to NiO-YSZ. This tensile stress is responsible for possible fracture of unit cells in SOFCs.

Synchrotron Radiation Study on Alloy 617 and Alloy 230 for VHTR Application

2011 ◽  
Author(s):  
Kun Mo ◽  
Hsiao-Ming Tung ◽  
Xiang Chen ◽  
Weiying Chen ◽  
Jon B. Hansen ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Internal Stress ◽  
Applied Stress ◽  
Lattice Strain ◽  
High Energy ◽  
Uniaxial Tensile ◽  
X Ray Diffraction ◽  
Alloy 617 ◽  
X Ray

High-energy synchrotron radiation has proven to be a powerful technique for investigating fundamental deformation processes for various materials, particularly metals and alloys. In this study, high-energy synchrotron X-ray diffraction (XRD) was used to evaluate Alloy 617 and Alloy 230, both of which are top candidate structural materials for the Very-High-Temperature Reactor (VHTR). Uniaxial tensile experiments using in-situ high-energy X-ray exposure showed the substantial advantages of this synchrotron technique. First, the small volume fractions of carbides, e.g. ∼6% of M6C in Alloy 230, which are difficult to observe using lab-based X-ray machines or neutron scattering facilities, were successfully examined using high-energy X-ray diffraction. Second, the loading processes of the austenitic matrix and carbides were separately studied by analyzing their respective lattice strain evolutions. In the present study, the focus was placed on Alloy 230. Although the Bragg reflections from the γ matrix behave differently, the lattice strain measured from these reflections responds linearly to external applied stress. In contrast, the lattice strain evolution for carbides is more complicated. During the transition from the elastic to the plastic regime, carbide particles experience a dramatic loading process, and their internal stress rapidly reaches the maximum value that can be withstood. The internal stress for the particles then decreases slowly with increasing applied stress. This indicates a continued particle fracture process during plastic deformations of the γ matrix. The study showed that high-energy synchrotron X-ray radiation, as a non-destructive technique for in-situ measurement, can be applied to ongoing material research for nuclear applications.

In-Situ Measurement of Residual Stress in Solid Oxide Fuel Cells

2021 ◽  
Vol MA2021-03 (1) ◽  
pp. 37-37
Author(s):  
Keiji Yashiro ◽  
Takumi Komaya ◽  
Zaka Ruhma ◽  
Satoshi Watanabe ◽  
Kazuhisa Sato ◽  
...  
Keyword(s):  
Residual Stress ◽  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
In Situ Measurement ◽  
Oxide Fuel

In-situ Measurement of the Current Distributions in an Electrolyte-Supported Planar Solid Oxide Fuel Cell by Segmented Electrodes

2016 ◽  
Vol 2016 (0) ◽  
pp. J2220305
Author(s):  
Tatsuhiro OCHIAI ◽  
Takahiro KOSHIYAMA ◽  
Takahiro KARIMATA ◽  
Hironori NAKAJIMA ◽  
Tatsumi KITAHARA ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
In Situ Measurement ◽  
Oxide Fuel ◽  
Current Distributions

Synchrotron Radiation Study on Alloy 617 and Alloy 230 for VHTR Application

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Kun Mo ◽  
Hsiao-Ming Tung ◽  
Jonathon Almer ◽  
Meimei Li ◽  
Xiang Chen ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Internal Stress ◽  
Applied Stress ◽  
Lattice Strain ◽  
High Energy ◽  
Uniaxial Tensile ◽  
X Ray Diffraction ◽  
Alloy 617 ◽  
X Ray

High-energy synchrotron radiation has proven to be a powerful technique for investigating fundamental deformation processes for various materials, particularly metals and alloys. In this study, high-energy synchrotron X-ray diffraction (XRD) was used to evaluate Alloy 617 and Alloy 230, both of which are top candidate structural materials for the very-high-temperature reactor (VHTR). Uniaxial tensile experiments using in-situ high-energy X-ray exposure showed the substantial advantages of this synchrotron technique. First, the small volume fractions of carbides, e.g., ∼6% of M6C in Alloy 230, which are difficult to observe using laboratory-based X-ray machines or neutron scattering facilities, were successfully examined using high-energy X-ray diffraction. Second, the loading processes of the austenitic matrix and carbides were separately studied by analyzing their respective lattice strain evolutions. In the present study, the focus was placed on Alloy 230. Although the Bragg reflections from the γ matrix behave differently, the lattice strain measured from these reflections responds linearly to external applied stress. In contrast, the lattice strain evolution for carbides is more complicated. During the transition from the elastic to the plastic regime, carbide particles experience a dramatic loading process, and their internal stress rapidly reaches the maximum value that can be withstood. The internal stress for the particles then decreases slowly with increasing applied stress. This indicates a continued particle fracture process during plastic deformations of the γ matrix. The study showed that high-energy synchrotron X-ray radiation, as a nondestructive technique for in-situ measurement, can be applied to ongoing material research for nuclear applications.

scholarly journals Multiphysics simulation of a solid oxide fuel cell based on COMSOL method

2021 ◽  
Vol 245 ◽  
pp. 01005
Author(s):  
Qiao Yaoxuan ◽  
Fan Cheng ◽  
Sun Kening
Keyword(s):  
Three Dimensional ◽  
High Energy ◽  
Scientific Basis ◽  
Solid Oxide ◽  
Utilization Efficiency ◽  
Oxide Fuel ◽  
Three Dimensional Model ◽  
Increasing Temperature ◽  
Single Flow ◽  
Energy Conversion Devices

Solid oxide fuel cells (SOFCs) are promising high-effective energy conversion devices for wide fuel sources and high energy efficiency. Based on non-linear kinetics at triple-phase-boundary, a three-dimensional model with a single flow channel was constructed. Distribution of mass flow, temperature and current density in a different configuration and working conditions were investigated. Critical factors in voltage output, power output, and reactant utilizations were determined. It is concluded that increasing temperature can give better performances. The increase of inlet flow results in an increased of power density but a decrease of fuel utilization efficiency. The numerical simulation provides a scientific basis for control strategy and structural design of SOFC.

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