An examination of exergy destruction in organic Rankine cycles
An examination of exergy destruction in organic Rankine cycles
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DOI：
10.1002/er.1406
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发表时间：
2008-08
影响因子：
4.6
通讯作者：
P. Mago;K. Srinivasan;L. Chamra;C. Somayaji
中科院分区：
文献类型：
--
作者：
P. Mago;K. Srinivasan;L. Chamra;C. Somayaji
用拓扑法对R113有机朗肯循环（ORC）的火用损失进行了定量估算。使用火用轮给出了火用流的详细路线图，这种可视化表示清楚地描绘了与每个热力学过程相关的火用核算。分析表明，蒸发器占最大的有效能破坏的ORC和负责这是一个有限的温差传热过程。此外，结果证实了再生ORC的热力学优势，因为再生加热有助于抵消大量的有效能在蒸发器中被破坏，从而导致在热力学上更有效的过程。热力学影响系数和热力学完善程度等参数被确定为有用的设计指标，以帮助基于火用的设备设计。本文还研究了运行参数，如蒸发器压力和进入蒸发器的热气体的入口温度对ORC性能的影响。结果表明，蒸发器压力越高，涡轮机进口温度越低，损失越小。最后，分析揭示了潜在的火用拓扑方法作为一个强大的技术，以确定与实际的热系统中的真实的热力学过程的不可逆性的大小。版权所有© 2008约翰威利父子有限公司。
The exergy topological method is used to present a quantitative estimation of the exergy destroyed in an organic Rankine cycle (ORC) operating on R113. A detailed roadmap of exergy flow is presented using an exergy wheel, and this visual representation clearly depicts the exergy accounting associated with each thermodynamic process. The analysis indicates that the evaporator accounts for maximum exergy destroyed in the ORC and the process responsible for this is the heat transfer across a finite temperature difference. In addition, the results confirm the thermodynamic superiority of the regenerative ORC over the basic ORC since regenerative heating helps offset a significant amount of exergy destroyed in the evaporator, thereby resulting in a thermodynamically more efficient process. Parameters such as thermodynamic influence coefficient and degree of thermodynamic perfection are identified as useful design metrics to assist exergy‐based design of devices. This paper also examines the impact of operating parameters such as evaporator pressure and inlet temperature of the hot gases entering the evaporator on ORC performance. It is shown that exergy destruction decreases with increasing evaporator pressure and decreasing turbine inlet temperatures. Finally, the analysis reveals the potential of the exergy topological methodology as a robust technique to identify the magnitude of irreversibilities associated with real thermodynamic processes in practical thermal systems. Copyright © 2008 John Wiley & Sons, Ltd.