Heat transfer through a low-pressure gas enclosure as a thermal insulator: Design considerations

Y. Demirel, S. C. Saxena

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Heat transfer through gases at low pressures, rarefied media, plays a very significant role in the design of solar receivers and low-temperature cooling equipment. It is shown here that low-pressure and transition regimes of heat transfer prevail in such applications. State-of-the-art procedures for estimating these heat-transfer rates are presented together with an improved expression for the thermal accommodation coefficient for monatomic gases on engineering surfaces. The latter are characterized with values of thermal accommodation and reflection coefficients. Numerical calculations relevant to design engineers interested in these industrial applications are presented and the same are discussed for the dependencies of the heat-transfer rates on different design and operating parameters. It is shown that the values of surface reflectivity coefficient have a pronounced contribution in low density heat-transfer calculations at low gas temperatures, and are negligibly small for the temperatures greater than 900 K.

Original languageEnglish (US)
Pages (from-to)327-338
Number of pages12
JournalInternational Journal of Energy Research
Volume20
Issue number4
DOIs
Publication statusPublished - Jan 1 1996

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Keywords

  • Free conduction regime
  • Rarefied gas heat transfer
  • Reflection coefficient
  • Thermal accommodation coefficient
  • Thermal insulator

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Nuclear Energy and Engineering
  • Fuel Technology
  • Energy Engineering and Power Technology

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