Design of electrocaloric multilayer refrigerators via multi-scale modeling

通过多尺度建模设计电热多层制冷机

• 批准号: 226715796
• 负责人: Professor Dr. Karsten Albe
• 金额: --
• 依托单位: Fachgebiet Mechanik Funktionaler Materialien
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/226715796?language=en
• 关键词: Design; electrocaloric; multilayer; refrigerators; via

By combining relaxor ferroelectrics that provide a significant electrocaloric capacitywith thermal switches consisting of ferroelectric materials with tunable thermal conductivity cooling devices can be build, which do not require the motion of solid or fluid parts. This project aims at the conceptual design and optimization of such multilayer solid-state cooling units that represent micro-cooling systems operating at low voltage.Both, continuum scale and atomistic simulations are planned to support the materials design and to optimize the cooling performance of the multilayer stacks. On the continuum level, finite element modeling will be carried out to study the transient heat conduction in refrigerators. Novelties of the FE simulations include domain-structure-based calculation of the EC heat generation/absorption, consideration of thermal switch layer with tunable conductivity, and atomistic-simulation-based interface conduction model. Besides, the FE modeling is readily to be coupled with electrostatics and mechanics. In the conceptual design and numerical optimizations geometric parameters such as layers thickness and electrode configurations will be investigated. On the atomic scale characteristic materials parameters will be calculated. We will explore the relation between the ECE and the relaxor behaviorof \NBT \, and \BST \, and continue with the development of model Hamiltonians that allow for quantitativepredicitions. The goal is to have model systems with different levels of sophistication and efficiency (Ising-type, Landau-type andab-initio based) available to systematically study the key factors affecting the ECE in electrocaloric materials. A new aspect will be the modelling of interfaces between the electrocaloric material and the thermal switches.

通过将提供显著电热容量的弛豫铁电体与由具有可调热导率的铁电材料组成的热开关相结合，可以构建不需要固体或流体部件运动的冷却装置。本项目旨在对这种多层固态冷却单元进行概念设计和优化，以代表在低电压下运行的微冷却系统。计划采用连续尺度和原子模拟来支持多层堆的材料设计和优化冷却性能。在连续介质水平上，将进行有限元建模以研究冰箱中的瞬态热传导。的FE模拟的新颖性包括域结构为基础的EC热生成/吸收的计算，考虑热开关层与可调的电导率，和原子模拟为基础的界面传导模型。此外，有限元建模易于与静电学和力学耦合。在概念设计和数值优化的几何参数，如层的厚度和电极配置将进行调查。在原子尺度上计算材料的特征参数。我们将探讨ECE与\NBT \和\BST \的弛豫行为之间的关系，并继续发展模型哈密顿量，允许定量预测。我们的目标是有不同水平的复杂性和效率的模型系统（伊辛型，朗道型和从头算为基础），系统地研究影响电热材料的ECE的关键因素。一个新的方面将是电热材料和热开关之间的界面建模。