E3S Web Conf.
Volume 197, 202075th National ATI Congress – #7 Clean Energy for all (ATI 2020)
|Number of page(s)||10|
|Section||Energy Storage and Integration of Energy Networks. Technologies|
|Published online||22 October 2020|
Constant-volume vapor-liquid equilibrium for thermal energy storage: Generalized analysis of pure fluids
Politecnico di Milano, Dipartimento di Energia, Via R. Lambruschini 4A, 20156, Milano, Italy.
* Corresponding author: email@example.com
Thermal energy storage is of great interest both for the industrial world and for the district heating and cooling sector. Available technologies present drawbacks that reduce the margin of application, such as low energy density, limited temperature range of work, and investment costs. Phase transition is one of the main phenomena that can be exploited for thermal energy storage because of its naturally high energy density. Constant-volume vapor-liquid transition shows higher flexibility and increased heat transfer properties with respect to available technologies. This work presents a description of the behavior of these types of systems. The analysis is carried out through a generalized approach using the Corresponding State Principle. Variation of internal energy as a function of temperature over a fixed range is calculated at constant volume at different values of specific volume. It is shown that, for lower specific volumes, larger temperature ranges of work can be achieved without occurring in the steep pressure increase typically given by the expansion of liquid. Maximum operating temperature range is increased by up to 20% of the critical temperature with minimal energy loss. In optimal subsets of these ranges of temperature, the energy storage capacity of vapor-liquid systems increases at lower volumes, with energy storage capacity increasing to up to 40% with a 50% increase of the reduced volume. This is especially valid for more complex fluids, which are more interesting for these applications because of their higher heat capacity.
© The Authors, published by EDP Sciences, 2020
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.