Researchers from Technische Universität Darmstadt, including Lauritz Zendel, Chiara Springer, Frank Dammel, and Peter Stephan, have recently published a study focused on improving the modeling of Latent Thermal Energy Storage (LTES) units for use in energy systems. Their work aims to simplify the complex modeling process to make it more practical for designing and simulating energy storage systems.
Latent Thermal Energy Storage (LTES) units are particularly useful in energy systems because they can store thermal energy within a narrow temperature range. This makes them ideal for integration into Rankine-based Carnot Batteries, which are a type of energy storage system that converts heat into electricity. To design these systems effectively, accurate simulations are crucial. However, modeling the physical phenomena within LTES units, such as natural convection, is complex and often requires simplified models for practical use.
The researchers focused on a specific LTES unit design that features a shell and tube heat exchanger structure. In this design, the phase change material (PCM), which in this case is sodium nitrate, is located between hexagonal aluminum fins and around finned tubes. Aluminum fins are used to enhance the thermal conductivity of the system, compensating for the lower thermal conductivity of the sodium nitrate. The interaction between the fins and the PCM is complex, making it challenging to model accurately.
To address this complexity, the researchers used a numerical approach to gain insights into the behavior of the LTES unit. They developed a model of a section with a single finned tube using COMSOL software. By varying the effective thermal conductivity in a simplified model and comparing the results with more complex models, they were able to determine the effective thermal conductivity of the system. This effective thermal conductivity can then be used as an input for simplified system models, making the modeling process more efficient and practical.
The results of this study provide valuable input for simplified system models of Carnot Batteries and other energy storage systems. By simplifying the modeling process, the researchers have made it easier to design and simulate these systems, potentially leading to more efficient and effective energy storage solutions. The research was published in the journal Applied Energy.
This article is based on research available at arXiv.