Thermal conductivity of composite sorbents "salt in porous matrix" for heat storage and transformation

Yuri Yu Tanashev, Alexandr V. Krainov, Yuri I. Aristov

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The thermal conductivity of composites "inorganic salt in porous matrix" was measured as function of the water uptake w by a "hot wire" method. Three hygroscopic salts (CaCl2, MgCl2, LiBr) were confined to the pores of a commercial KSK silica gel. For CaCl 2, an alumina was used as host matrix, too. Similar dependencies λ(w) were found for the three silica based sorbents: a smooth rise at w < w* = 0.4-0.55 and a sharp increase within the narrow w-range near the threshold uptake w*. Regardless the salt confined, this increase occurs at the same fraction ν of the pore volume occupied by the salt solution, ν* = 0.60-0.64. At ν > ν* the solution starts to leak out of the pores to form a liquid film on the external surface of silica particles that strongly facilitates the heat transfer between adjacent particles and enhances the heat conductivity of the whole bed. No such threshold behaviour was found for CaCl2/alumina composites. The data obtained can be used for analysing open and closed adsorptive units for heat transformation, gas drying, extraction of potable water from the atmosphere, etc. For user friendliness, the experimental λ(w)-dependences were approximated by polynomial equations.

Original languageEnglish
Pages (from-to)401-407
Number of pages7
JournalApplied Thermal Engineering
Volume61
Issue number2
DOIs
Publication statusPublished - 17 Sep 2013

Fingerprint

Heat storage
Sorbents
Thermal conductivity
Alumina
Silica
Salts
Composite materials
Liquid films
Silica gel
Potable water
Drying
Polynomials
Wire
Heat transfer
Gases
Water
Hot Temperature

Keywords

  • Adsorptive heat transformation and storage
  • Composite sorbent
  • Thermal conductivity
  • Threshold effect of sorbed water

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Industrial and Manufacturing Engineering

Cite this

Thermal conductivity of composite sorbents "salt in porous matrix" for heat storage and transformation. / Tanashev, Yuri Yu; Krainov, Alexandr V.; Aristov, Yuri I.

In: Applied Thermal Engineering, Vol. 61, No. 2, 17.09.2013, p. 401-407.

Research output: Contribution to journalArticle

Tanashev, Yuri Yu ; Krainov, Alexandr V. ; Aristov, Yuri I. / Thermal conductivity of composite sorbents "salt in porous matrix" for heat storage and transformation. In: Applied Thermal Engineering. 2013 ; Vol. 61, No. 2. pp. 401-407.
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