A new method to identify the optimal temperature of latent-heat thermal-energy storage systems for power generation from waste heat
A new method to identify the optimal temperature of latent-heat thermal-energy storage systems for power generation from waste heat
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DOI：
10.1016/j.ijheatmasstransfer.2019.119111
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发表时间：
2020-03
影响因子：
5.2
通讯作者：
M. White;A. Sayma
中科院分区：
文献类型：
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作者：
M. White;A. Sayma
在废热回收发电系统中集成热能存储（TES）具有在具有可变和/或间歇性废热流的许多工业过程中提高能量效率的潜力。本文的第一个目标是提出一种新的模型，这些系统，可用于在早期的设计阶段，以提供快速和准确的估计性能。更具体地，该方法可以仅基于已知的热源和散热器条件（即，温度、质量流率和比热容），并且可以评估单级和级联系统。该模型已被验证对最佳的有机朗肯循环系统确定从热力学循环优化。第二个目标是确定不同热源配置文件的最佳系统的特性。结果表明，对于一个给定的应用程序，存在一个最佳的温度为潜热TES系统，主要取决于散热器的相对大小。此外，它被发现，对于一个热力发动机与TES操作，额定功率的范围之间的25%和60%的相应额定功率的最佳热力发动机，没有TES操作，即时适应热源波动，而总的能量生产分别减少了45%和85%之间。最后，在所考虑的不同热源所获得的结果之间观察到一个小的偏差，这表明这些发现可以外推到本研究中未考虑的其他热源。
The integration of thermal-energy storage (TES) within waste-heat recovery power generation systems has the potential to improve energy-efficiency in many industrial processes with variable and/or intermittent waste-heat streams. The first objective of this paper is to present a novel model of these systems that can be used at an early design stage to provide fast and accurate estimates of performance. More specifically, the method can identify the optimal temperature of latent-heat TES systems for waste-heat recovery applications based only on the known heat-source and heat-sink conditions (i.e., temperature, mass-flow rate and specific-heat capacity), and can assess both single-stage and cascaded systems. The model has been validated against optimal organic Rankine cycle systems identified from a thermodynamic cycle optimisation. The second objective is to identify the characteristics of optimal systems for different heat-source profiles. The results indicate that, for a given application, there exists an optimal temperature for the latent-heat TES system that depends primarily on the relative size of the heat sink. Moreover, it is found that, for a heat engine operating with TES, the power rating ranges between 25% and 60% of the corresponding power rating for an optimal heat engine, operating without TES, that adapts instantaneously to heat-source fluctuations, whilst the total energy production is reduced by between 45% and 85% respectively. Finally, a small deviation is observed between the results obtained for the different heat sources considered, which suggests that these findings can be extrapolated to other heat sources not considered within this study.