Kulish Vladimir, Hyhlík Tomáš, Sláma Pavel
Department of Thermodynamics and Fluid Mechanics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Prague, Czech Republic.
Sci Rep. 2021 Oct 15;11(1):20522. doi: 10.1038/s41598-021-00079-y.
This paper presents a new general theoretical model of thermal energy harvesting devices (TEHDs), which utilise phase-change materials (PCMs) for energy storage. The model's major goal is to identify a set of parameters under which these devices perform optimally, that is, attain the largest thermal buffering capacity and exchange heat with the surrounding phase as quickly as possible. For the first time, an expression for the characteristic harvesting time is developed from the constructal theory viewpoint under the optimal performance assumption, and a dimensionless criterion that characterizes PCM performance is provided. Furthermore, a new non-field solution of the energy equation governing the process of heat transfer within TEHDs with PCMs has also been derived. An expression for the effective thermal effusivity is then obtained. Finally, under a given set of boundary conditions and geometrical constraints, a novel simple technique for the optimal choice of PCMs in TEHDs has been established.
本文提出了一种新型的热能收集装置（TEHDs）通用理论模型，该装置利用相变材料（PCM）进行能量存储。该模型的主要目标是确定一组参数，在这些参数下这些装置能实现最优性能，即获得最大的热缓冲能力并尽快与周围介质进行热交换。首次从建构理论的角度在最优性能假设下推导出特征收集时间的表达式，并提供了一个表征PCM性能的无量纲准则。此外，还推导了用于控制含PCM的TEHDs内热传递过程的能量方程的一种新的非场解。进而得到了有效热逸散率的表达式。最后，在给定的一组边界条件和几何约束下，建立了一种用于在TEHDs中最优选择PCM的新颖简单技术。
