Parasitic heat transport in thermal energy storage for Carnot batteries

卡诺电池热能存储中的寄生热传输

• 批准号: 525893212
• 负责人: Professor Dr.-Ing. Christian Cierpka
• 金额: --
• 依托单位: Technische Thermodynamik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/525893212?language=en
• 关键词: Parasitic; heat; transport; thermal; energy

For the efficiency of Carnot-Batteries, the thermal energy storage (TES) is a key component. It should store large amounts of thermal energy over a long time at low cost. Often liquid materials like water or molten salt are used. The storage can be applied as a two-tank system with cold fluid in one tank and the hot fluid in the other tank, or as a stratified storage, where hot fluid is stored directly above the cold fluid. However, even in single storage tanks with initially uniform temperature, thermal stratification develops due to heat losses to the surrounding. Since the wall material typically has a larger thermal conductivity than the storage medium, heat is transferred from the hot region via the wall to colder regions an vice versa. This drives thermal convection close to the wall, which enforces mixing and thus destroys exergy. The effect can be seen in small systems, but also in larger systems in industrial scale. The understanding of these parasitic convective flows is of fundamental interest for many fluid mechanical and heat transfer problems in nature and engineering. More important, it will help to improve the overall efficiency in terms of energy and exergy of TES for Carnot-Batteries, but also for TES in general for other heating applications. Thus, the project aims also to be a valuable contribution to achieve the 'Wärmewende'.

对于卡诺 - 爆炸的效率，热储能（TES）是关键组成部分。它应该长时间以低成本存储大量的热能。通常使用液体材料，例如水或熔融盐。该存储可以用作一个两坦克系统，在一个水箱中使用冷流体，在另一个水箱中的热流体，或将热流体直接存储在冷液上方。但是，即使在最初温度均匀的单个储罐中，由于周围的热量损失，热分层也会出现。由于壁材料通常比存储介质具有更大的导热率，因此热量通过壁向较冷的区域转移到较冷的区域。这将驱动靠近墙壁的热结构，从而强化混合并破坏运动。该效果可以在小型系统中看到，也可以在工业规模的较大系统中看到。对这些寄生对流流的理解对于自然界和工程中的许多流体机械和传热问题具有根本的兴趣。更重要的是，它将有助于提高卡诺 - 爆炸的能源和TES的总体效率，但对于TES，对于其他供暖应用来说，也是TES的总体效率。这也是该项目的目标是实现“Wärmewende”的宝贵贡献。