Anion Exchange Membrane Water Electrolysis (AEMWE) technology plays an important role in achieving efficient and sustainable energy conversion. There are many factors contributing to the performance of the AEMWE. This study aims to investigate the effects of parallel flow field design on fluid transport within AEMWE systems. While PEMWE properties are well-documented, comprehensive analysis of AEMWE performance, especially regarding catalysts, flow fields, and bipolar plate fluid dynamics, remains limited. Advancements in these areas are crucial for enhancing electrolyzer efficiency and durability. Through ANSYS Fluent Computational Fluid Dynamics (CFD) simulations, seven flow field models were evaluated, revealing the critical influence of flow field geometry on pressure distribution, hydrogen concentration, and current density. The single-inlet parallel flow field design demonstrated superior pressure uniformity and operational simplicity, with an optimal channel-to-rib ratio of η = 1, improving both efficiency and manufacturability. The results also show that while increasing voltage enhances hydrogen production, it introduces flow turbulence and localized flooding risks, necessitating precise control of operational parameters. The simulation achieved a hydrogen concentration of 35.52 mol/m³ under standard operating conditions, with an improved RMSE of 0.0274, reflecting better accuracy than earlier models. These findings underscore the importance of optimizing both geometric and operational factors to enhance the performance and reliability of AEMWE systems. This research opens the path for efficient energy conversion processes and contributes to the advancement of sustainable energy technologies.
標題:陰離子交換膜水電解(AEMWE)平行設計中流場與流體動力學之參數化研究 摘要: 陰離子交換膜水電解(AEMWE)技術在實現高效且可持續的能源轉換中扮演重要角色。影響AEMWE效能之因素甚多,本研究旨在探討平行流場設計對AEMWE系統內流體傳輸之影響。儘管質子交換膜水電解(PEMWE)之特性已被廣泛記載,惟針對AEMWE效能之全面分析,特別是觸媒、流場及雙極板流體動力學方面,仍有所匱乏。這些領域之進展對於提升電解槽效率與耐久性至關重要。透過ANSYS Fluent計算流體動力學(CFD)模擬,本研究評估了七種流場模型,揭示了流場幾何形狀對壓力分佈、氫氣濃度及電流密度之關鍵影響。單入口平行流場設計展現出優異之壓力均勻性與操作簡便性,其最佳通道-肋寬比為η = 1,同時提升效率與可製造性。研究結果亦顯示,電壓提升雖能增加氫氣產量,卻會引發流動紊流與局部積水風險,故須精確控制操作參數。本模擬在標準操作條件下達到35.52 mol/m³之氫氣濃度,RMSE為0.0274,展現較先前模型更佳之準確性。這些發現強調了優化幾何與操作因素對提升AEMWE系統效能與可靠性之重要性。本研究為高效能源轉換程序開闢了路徑,並促進可持續能源技術之發展。
This paper presents the modelling and estimation of capacity fade in vanadium redox flow battery (VRFB) storage with an objective to study its impact on the field performance of a kW-scale VRFB system. The dynamic behavior of electrolyte volume and reactant concentrations has been considered in estimating VRFB capacity fading model, in MATLAB/Simulink environment. The proposed model demonstrates that electrolyte rebalancing can improve VRFB capacity recovery by up to 36%. Over 1000 charge/discharge cycles, VRFB capacity fade has been reduced from 81.8% to 45.8% which is a significant improvement. The long-term estimations using the proposed model indicate a viable VRFB cycle life of 16,000 cycles, with a capacity fade of 83.42% after 20,000 cycles. A practical case study on a solar-VRFB microgrid indicates that systematic electrolyte rebalancing of VRFB can significantly satisfy peak load delivery over a long period of around 10000 cycle life. The proposed capacity fade model and recovery strategy for VRFB is a generalized solution and suitable for long-term analysis in large-scale VRFB storage deployments.
本研究針對釩氧化還原液流電池(VRFB)儲能系統,提出容量衰減之模型建立與估測方法,旨在探討其對千瓦級VRFB系統現場效能之影響。本研究在建構VRFB容量衰減模型時,考慮了電解液體積與反應物濃度之動態行為,並於MATLAB/Simulink環境中進行模擬分析。所提出之模型顯示,電解液再平衡技術可使VRFB容量恢復提升達36%。在超過1,000次充放電循環後,VRFB容量衰減由81.8%降低至45.8%,此為顯著之改善效果。根據該模型之長期估測結果顯示,VRFB可達到16,000次循環之可行循環壽命,且於20,000次循環後容量衰減為83.42%。針對太陽能-VRFB微電網之實務案例研究結果表明,系統性電解液再平衡策略可使VRFB在約10,000次循環壽命之長期運行期間內,有效滿足尖峰負載供應需求。本研究所提出之VRFB容量衰減模型與恢復策略為一通用性解決方案,適用於大規模VRFB儲能系統之長期分析與部署規劃。