Theoretical analysis of supercooled states of water generated below the freezing point in a PEFC

Yuji Ishikawa, Masahiro Shiozawa, Masaaki Kondo, Kohei Ito

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

The water produced in a proton exchange fuel cell can exist in supercooled states during cold start operation. Visualization studies of unit cells under cold start conditions have confirmed that supercooled states exist in the cells and that they are eventually released. However, these supercooled states have not been quantitatively characterized, and it is difficult to predict them. Moreover, it has not been clarified what determines the supercooling degree and the release of supercooled states in each part of the cells, such as the gas flow channels, gas diffusion layers, and catalyst layer. In this work, a theoretical model was developed to predict the release of supercooled states on the basis of heterogeneous nucleation theory and by considering the surface wettability of the porous media in the cells. This model was evaluated through comparison to our in situ visualization study of a cell during a cold start. The developed model reproduced the supercooled state in the cell well, specifically its release time, and quantitatively clarified the impact of the pore diameter and wettability on the supercooled states.

Original languageEnglish
Pages (from-to)215-227
Number of pages13
JournalInternational Journal of Heat and Mass Transfer
Volume74
DOIs
Publication statusPublished - Jan 1 2014

Fingerprint

Freezing
melting points
Wetting
Water
Visualization
cells
water
Supercooling
Diffusion in gases
wettability
Flow of gases
Porous materials
Protons
Fuel cells
Ion exchange
Nucleation
Catalysts
gaseous diffusion
supercooling
fuel cells

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

Cite this

Theoretical analysis of supercooled states of water generated below the freezing point in a PEFC. / Ishikawa, Yuji; Shiozawa, Masahiro; Kondo, Masaaki; Ito, Kohei.

In: International Journal of Heat and Mass Transfer, Vol. 74, 01.01.2014, p. 215-227.

Research output: Contribution to journalArticle

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