Thermal analysis of solar thermal energy storage in a molten-salt thermocline
Thermal analysis of solar thermal energy storage in a molten-salt thermocline
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DOI：
10.1016/j.solener.2010.03.007
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发表时间：
2010-06
期刊：
影响因子：
6.7
通讯作者：
Zhen Yang;S. Garimella
中科院分区：
文献类型：
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作者：
Zhen Yang;S. Garimella
建立了一个综合的双温模型来研究熔盐温跃层中的能量储存。以石英岩为填料的市售熔盐HITEC为例。熔盐与石英岩之间的换热用间隙换热系数表示。采用体积平均质量和动量方程，用Brinkman-Forchheimer扩展的达西定律来模拟多孔介质的阻力。采用有限体积法求解控制方程。首先通过文献实验对模型进行了验证，然后系统地研究了温跃层蓄热系统的放电行为。热特性包括温度分布和放电效率的研究。制定了设计太阳温跃层系统的准则。结果表明，在小雷诺数和大罐高条件下，排气效率有所提高。填料粒度对间隙换热率有很大影响，从而影响排料效率。
A comprehensive, two-temperature model is developed to investigate energy storage in a molten-salt thermocline. The commercially available molten salt HITEC is considered for illustration with quartzite rocks as the filler. Heat transfer between the molten salt and quartzite rock is represented by an interstitial heat transfer coefficient. Volume-averaged mass and momentum equations are employed, with the Brinkman–Forchheimer extension to the Darcy law used to model the porous-medium resistance. The governing equations are solved using a finite-volume approach. The model is first validated against experiments from the literature and then used to systematically study the discharge behavior of thermocline thermal storage system. Thermal characteristics including temperature profiles and discharge efficiency are explored. Guidelines are developed for designing solar thermocline systems. The discharge efficiency is found to be improved at small Reynolds numbers and larger tank heights. The filler particle size strongly influences the interstitial heat transfer rate, and thus the discharge efficiency.