Three-Dimensional Modeling and Performance Study of High Temperature Solid Oxide Electrolysis Cell with Metal Foam

Optimizing the flow field of solid oxide electrolysis cells (SOECs) has a significant effect on improving performance. In this study, the effect of metal foam in high temperature SOEC electrolysis steam is investigated by a three-dimensional model. The simulation results show that the SOEC performance is improved by using metal foam as a gas flow field. The steam conversion rate of the SOEC increases from 72.21% to 76.18% and the diffusion flux of steam increases from 2.3 × 10−4 kg/(m2∙s) to 2.5 × 10−4 kg/(m2∙s) at 10,000 A/m2. In addition, the permeability, temperature, steam mole fraction, and gas utilization are investigated to understand the effect of the improved performance of the SOEC with metal foam. The results of this study provide a baseline for the optimal design of SOECs with metal foam

The Effect of Clamping Force on the Wear Behavior of a Steam Generator Tube

Anti-vibration bars (AVBs) are essential components of a steam generator (SG) and are used to prevent steam generator tubes (SGTs) from vibrating intensely because of flow-induced vibration. However, the contact force generated at contact surfaces between AVBs and tubes can change the natural frequency and wear behavior of the tube. Contact force is represented by clamping force in this study. Considering the effect of the clamping force on the natural frequency and sliding distance of SGT, dynamic wear behavior under different clamping forces was analyzed based on the finite element method, and the natural frequency of the tube was measured in the present work. Moreover, the wear experiment was conducted at room temperature to verify the conclusions of dynamic behavior analysis. The increase in clamping force reduces the sliding distance of SGT, and wear depth affected by both clamping force and sliding distance also decreases

The Effect of Clamping Force on the Wear Behavior of a Steam Generator Tube

Anti-vibration bars (AVBs) are essential components of a steam generator (SG) and are used to prevent steam generator tubes (SGTs) from vibrating intensely because of flow-induced vibration. However, the contact force generated at contact surfaces between AVBs and tubes can change the natural frequency and wear behavior of the tube. Contact force is represented by clamping force in this study. Considering the effect of the clamping force on the natural frequency and sliding distance of SGT, dynamic wear behavior under different clamping forces was analyzed based on the finite element method, and the natural frequency of the tube was measured in the present work. Moreover, the wear experiment was conducted at room temperature to verify the conclusions of dynamic behavior analysis. The increase in clamping force reduces the sliding distance of SGT, and wear depth affected by both clamping force and sliding distance also decreases

Weibull stress analysis in local approach to fracture

As a measure of the probability of cleavage fracture, the Weibull stress within the framework of local approach has the potential capability to predict constraint effects on fracture of structural steels. This paper mainly analyzes Weibull stress considering constraint effect using constraint parameters T-stress and Q. Weibull stress is solved with constraint effects characterized by T-stress for elastic material and Q for elastic plastic material. These solutions are verified with existing solutions for T = 0 and finite element solutions including modified boundary layer models, contact tension models and single-edge bend models. Good agreement has been obtained in all cases. The Weibull stress solutions can be further adopted to predict scale fracture toughness