Exergy analysis of solid-oxide fuel-cell (SOFC) systems
Exergy analysis of solid-oxide fuel-cell (SOFC) systems
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DOI：
10.1016/s0360-5442(96)00119-3
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发表时间：
1997-04
期刊：
影响因子：
9
通讯作者：
K. Bedringås;I. S. Ertesvåg;Stale Byggstoyl;B. Magnussen
中科院分区：
文献类型：
--
作者：
K. Bedringås;I. S. Ertesvåg;Stale Byggstoyl;B. Magnussen
用(火用)的概念分析了两个甲烷燃料SOFC系统。这些系统包括燃料和空气的预热，甲烷重整为氢气，以及在加力燃烧室中燃烧剩余燃料。开发了一种使用顺序模块化方法的迭代计算机程序，并用于分析。对外重整的SOFC系统进行了模拟，得到了第一定律效率为58%，第二定律效率为56%，理论空气效率为600%。加力燃烧室释放的热量被用来重整甲烷，汽化水，预热空气和燃料。当满足这些热量要求时，废气温度非常低，只能用于取暖房间或水。由于系统对热量的要求，燃料电池的燃料利用率(FU)被限制在75%。剩下的燃料用于预热和重整。减少过量空气导致减少热量需求，并可能在FC中产生更高的FU。不可逆性也减少了，效率提高了。循环燃料和水蒸气的第一定律和第二定律效率分别为75.5%和73%，理论空气量为600%时，避免了水的汽化，FU较大。
The exergy concept has been used to analyze two methane-fueled SOFC systems. The systems include preheating of fuel and air, reforming of methane to hydrogen, and combustion of the remaining fuel in an afterburner. An iterative computer program using a sequential-modular approach was developed and used for the analyses. Simulation of an SOFC system with external reforming yielded first-law and second-law efficiencies of 58 and 56%, respectively, with 600% theoretical air. Heat released from the afterburner was used to reform methane, vaporize water, and preheat air and fuel. When these heat requirements were satisfied, the exhaust-gas temperature was so low that it could only be used for heating rooms or water. Because of heat requirements in the system, fuel utilization (FU) in the FC was limited to 75%. The remaining fuel was used for preheating and reforming. Reduced excess air led to reduced heat requirements and the possibility of a higher FU in the FC. Irreversibilities were also reduced and efficiencies increased. Recycling fuel and water vapor from the FC resulted in first-law and second-law efficiencies of 75.5 and 73%, respectively, with 600% theoretical air, vaporization of water was avoided and the FU was greater.