Design and techno-economic analysis of high efficiency reversible solid oxide cell systems for distributed energy storage
Design and techno-economic analysis of high efficiency reversible solid oxide cell systems for distributed energy storage
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DOI：
10.1016/j.apenergy.2016.03.054
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发表时间：
2016-06
期刊：
影响因子：
11.2
通讯作者：
C. Wendel;R. Braun
中科院分区：
文献类型：
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作者：
C. Wendel;R. Braun
可逆固体氧化物电池（ReSOC）系统的概念化和分析，以评估分布式储能应用（100千瓦/800千瓦时）的技术性能。ReSOC系统在产生燃料的电解和产生电力的燃料电池模式之间顺序地操作，其中反应物和产物的中间储罐。在系统级保持实验室规模电池测试中看到的高转换效率需要仔细的系统设计，以集成存储和电化学转换功能。通过利用C-O-H反应化学和在中间温度下操作，ReSOC在两种操作模式下都是温和放热的，这简化了设备平衡集成和热管理。本文所探索的系统配置的范围从具有最小的设备平衡部件的简单系统到包括用于增加电效率的涡轮机膨胀和用于更高能量密度存储的分离水的更复杂系统。这些配置的效率，能量密度和资本成本的权衡是通过计算建模量化。结果表明，对于被配置为存储含水蒸气气体的系统，在相对低的罐能量密度（1020 kWh/m3）下实现了接近74%的往返效率。单独储存冷凝水增加了储存的能量密度，但是基于在电解操作期间蒸发反应物水的能量成本，将效率限制在68%。能量密度的进一步增加（至90 kWh/m3）需要更高的存储压力（例如，50-巴标称值），这将往返效率降低到约65%。能量存储的成本受到堆功率和系统能量密度的强烈影响，因为存储罐和堆构成系统资本成本的大部分。
Reversible solid oxide cell (ReSOC) systems are conceptualized and analyzed to assess technical performance in distributed energy storage applications (100 kW/800 kWh). The ReSOC systems operate sequentially between fuel-producing electrolysis and power-producing fuel-cell modes with intermediate tanking of reactants and products. Maintaining the high conversion efficiencies seen in laboratory-scale cell tests at the system-level requires careful system design to integrate storage and electrochemical conversion functions. By leveraging C–O–H reaction chemistry and operating at intermediate temperature, the ReSOC is mildly exothermic in both operating modes, which simplifies balance-of-plant integration and thermal management. System configurations explored herein range from a simple system with minimal balance-of-plant components to more complex systems including turbine expansion for increased electrical efficiency, and separating water for higher energy density storage. The efficiency, energy density, and capital cost tradeoffs of these configurations are quantified through computational modeling. Results indicate that a roundtrip efficiency of nearly 74% is achieved with relatively low tanked energy density (∼20 kWh/m3) for systems configured to store water-vapor containing gases. Separately storing condensed water increases energy density of storage, but limits efficiency to 68% based on the energetic cost of evaporating reactant water during electrolysis operation. Further increases in energy density (to 90 kWh/m3) require higher storage pressures (e.g., 50-bar nominal) which lower roundtrip efficiency to about 65%. Cost of energy storage is strongly influenced by stack power and system energy densities because the storage tanks and stack comprise a majority of the system capital cost.