Energy and exergy analyses of a bottoming Rankine cycle for engine exhaust heat recovery
Energy and exergy analyses of a bottoming Rankine cycle for engine exhaust heat recovery
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DOI：
10.1016/j.energy.2013.06.031
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发表时间：
2013-09
期刊：
影响因子：
9
通讯作者：
Sipeng Zhu;K. Deng;S. Qu
中科院分区：
文献类型：
--
作者：
Sipeng Zhu;K. Deng;S. Qu
本文从能量平衡和(火用)平衡的角度，对发动机余热回收的底部朗肯循环的热力学过程进行了理论研究。给出了以废气为唯一热源时，在简化条件下定性分析主要运行参数的理论公式和火用分布图。利用MatLab软件对不同型号发动机常选用的五种典型工质在不同工况下进行了对比分析。结果表明，工质性质、蒸发压力和过热温度是影响系统设计和性能的主要因素。在典型工况下，整体回收效率不超过0.14。乙醇和R113在整个排气温度范围内表现出较好的热力学性能。此外，发动机排气余热回收中通常不存在最佳蒸发压力，且(火用)破坏的分布因工质种类和系统设计约束而不同。
In this paper, a theoretical study on the thermodynamic processes of a bottoming Rankine cycle for engine waste heat recovery is conducted from the viewpoints of energy balance and exergy balance. A theoretical formula and an exergy distribution map for qualitative analyses of the main operating parameters are presented under simplified conditions when exhaust gas is selected as the only heat source. Five typical working fluids, which are always selected by manufacturers for different types of engines, are compared under various operating conditions in Matlab software. The results show that working fluid properties, evaporating pressure and superheating temperature are the main factors influencing the system design and performances. The global recovery efficiency does not exceed 0.14 under typical operating conditions. Ethanol and R113 show better thermodynamic performances in the whole exhaust gas temperature range. In addition, the optimal evaporating pressure usually does not exist in engine exhaust heat recovery, and the distributions of exergy destruction are varied with working fluid categories and system design constraints.