Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Journal articles
  4. Design guidelines for Al-12%Si latent heat storage encapsulations to optimize performance and mitigate degradation
 
Loading...
Thumbnail Image
research article

Design guidelines for Al-12%Si latent heat storage encapsulations to optimize performance and mitigate degradation

Binder, Selmar  
•
Haussener, Sophia  
March 1, 2020
Applied Surface Science

We provide detailed insight into the growth kinetics of intermetallic layers formed at the interface of molten Al-12%Si with cylindrical encapsulations of 316L stainless steel. This knowledge is relevant for the design and operation of high-temperature latent heat storage and energy harvesting devices at application-relevant conditions. Our continuous experiments on iron-aluminide deposition rates at 600 degrees C and 700 degrees C lasted up to 120 days. The layer thickness was determined in metallographic cross sections by light microscopy. We observed deviations from standard growth models, including a delayed layer growth onset at 600 degrees C and strongly nonparabolic kinetics at 700 degrees C. We developed a numerical diffusion model that accommodated temperature dependent kinetics and explained the observed deviations by incorporating de-passivation and dissolution phenomena. Numerical fitting of the model to the experiments provided optimized mobility parameters that agree with those reported for the Fe2Al5 compound, whose presence was confirmed by energy dispersive X-ray elemental analysis. Differential scanning calorimetry revealed reductions in heat of fusion and melting temperature, of -10% and -10 K, respectively, after 120 days at 700 degrees C. Fe concentration in the melt increased from < 0.3% to 2.6%, under the same conditions. The validated model was then used to provide design guidance for heat storage applications including degradation. For 8760 h of full-load-charging: a energy density of 370 kJ/kg was conserved, with variable source temperature distribution. For high power density configurations (1430 kW/m(3)) narrow source temperature distributions were beneficial. Our multi-month experimental campaigns enable more accurate degradation and performance predictions and provide guidelines that result in better long-term performance of the Al-12%Si phase change media.

  • Details
  • Metrics
Type
research article
DOI
10.1016/j.apsusc.2019.143684
Web of Science ID

WOS:000510846500001

Author(s)
Binder, Selmar  
•
Haussener, Sophia  
Date Issued

2020-03-01

Publisher

ELSEVIER

Published in
Applied Surface Science
Volume

505

Article Number

143684

Subjects

Chemistry, Physical

•

Materials Science, Coatings & Films

•

Physics, Applied

•

Physics, Condensed Matter

•

Chemistry

•

Materials Science

•

Physics

•

formation kinetics

•

iron chromium silicon aluminide

•

steel aluminum melt interaction

•

reaction diffusion

•

encapsulated phase change medium

•

molten metal corrosion

•

latent heat storage

•

thermal-energy storage

•

phase-change materials

•

solid iron

•

intermetallic compounds

•

interfacial reaction

•

eutectic alloys

•

aluminum

•

growth

•

steel

•

corrosion

Peer reviewed

REVIEWED

Written at

EPFL

EPFL units
LRESE  
Available on Infoscience
March 12, 2020
Use this identifier to reference this record
https://infoscience.epfl.ch/handle/20.500.14299/167205
Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés