MultiPCM – Multi-Scale Simulation of Latent Heat Storage for the inverse design of Carnot Batteries

点击翻译按钮获取中文摘要

The development of Carnot-Batteries with high round-trip efficiency and low cost requires sophisticated thermal energy storage (TES) systems and a comprehensive understanding of their transient behavior. The conspicuous lack of validated and computationally efficient TES models for latent heat storage represents an important barrier to successful inverse design of Rankine based Carnot-Batteries. The present project intends to bridge this gap by developing an accurate, computationally efficient and experimentally validated latent-heat TES multi-scale simulation model and providing the result to the members of the priority program. Moreover, the project aims at the formulation of a framework for describing Carnot-Battery concepts consistently across the priority program using uniform high-quality metadata. Thermal energy storage is a key component in a Carnot-Battery. For Rankine-based Carnot Batteries, latent heat storage systems promise a high roundtrip efficiency because of the excellent temperature matching between the isothermal melting/solidification in the storage and the evaporation/ condensation of the working fluid during charging/discharging of the storage. In state-of-the-art latent heat storage systems, a heat exchanger is embedded into the phase change material (PCM) to enable heat transfer between the working fluid and the storage medium. As typical storage materials have a low thermal conductivity, extended heat transfer respectively fins structures are required to ensure sufficiently high power densities. Complex transient temperature and phase distribution fields arise in between these structures during charging and discharging. Knowledge of the local and temporal progression of the temperature and melting phase distribution is a prerequisite for the design of the storage and the identification of an optimal design that ensures high roundtrip efficiency of the Carnot battery. An integration of this model complexity in higher-level design optimizations for an entire Carnot battery is however not yet possible. Current design and simulation tools for latent heat storage are furthermore rarely validated. The current project consists of a main part (MP), formulated by the first principal investigator (Vandersickel) and devoted to the development of a consistent multiscale model for latent TES and a transfer module (TM) formulated by the second PI (Thess) serving the distribution of the developed methodology across the priority program. As a result of the MP, this project will provide a well validated latent heat storage model and a model reduction/parametrization suited for the simultaneous optimization of storage and Carnot Battery design and operation. As a result of the TM, the project will supply a methodology for a uniform description of Carnot-Battery systems using metadata as well selected transient data of the DLR Carnot Battery pilot plant to all interested members of the priority program.