Thermal Stress Analysis of Solid Oxide Fuel Cell with Z-type and Serpentine-Type Channels Considering Pressure Drop

Abstract

A thermo-electro-chemo-mechanical coupled 3D model was applied to simulate the performance and thermal stress of a doublesided cathode structured solid oxide fuel cell (DSC-SOFC) with two different air channel configurations: Z-type parallel and tripleparallel serpentine. The distribution of temperature, current density, fuel gas and thermal stress under different voltages in DCS-SOFC was illustrated, and the output power density of the cell was analyzed considering both the electrochemical power and the dissipative power caused by the pressure drop. It was found that the Z-type parallel cell gave a better performance under a low current density, while the triple-parallel serpentine cell was more efficient at a current density higher than 6330 A•m −2 . A comparison of thermal stress distributions between the two flow field designs showed a small difference in maximum 1st principle stresses under the same operational voltages. Compared to the Z-type parallel flow field, the maximum 1st principle stress in the triple-parallel serpentine was much smaller under the same current density or electrochemical power, while much larger under the same output power.

Thermal Stress Analysis of a Solid Oxide Fuel Cell Considering Interconnect Deformation

“…Effect of interconnect deformation on thermal stress of electrolyte layer.-Figure 8 shows the maximum first principal stress curve of the electrolyte layer at different voltages comparing with interconnect and without interconnect. 33 It can be seen from the figure that the first principal stress increases nonlinearly with the decrease in working voltage. At 0.3 V, the maximum first principal stress is 228 MPa.…”

“…Effect of interconnect on electrolyte layer temperature.-Figure 6 shows the temperature variation of the SOFC electrolyte layer with voltage comparing with interconnect and without interconnect. 33 The figure shows that the electrolyte layer temperature grows nonlinearly with the operating voltage, with the highest temperature occurring when the operating voltage is 0.3 V. The figure also shows that at the same operating voltage, the temperature of the electrolyte layer decreases due to heat dissipation of the interconnect and gradually increases with decreasing operating 33 voltage. When the operating voltage is reduced to 0.3 V, the temperature difference in the electrolyte layer decreases by 41.4%, from 290 K to 170 K.…”

“…Figure 8. Comparison of the maximum 1st principal stress at different voltages of electrolyte with and without interconnect 33. …”

Analysis of Thermal Stress in a Solid Oxide Fuel Cell Due to the Sulfur Poisoning Interface of the Electrolyte and Cathode

“…Due to the TEC difference of the SOFC component, the thermal stress distribution differs within different cell components. , When there is a big stress difference between components and the loading force exceeds the yield point, the cell components undergo deformation and failure . Therefore, it is generally believed that an even and smaller stress distribution inside an SOFC is beneficial for stability and performance.…”