بررسی عددی میزان کاهش انتقال حرارت جابجایی و تشعشعی بین دو استوانه هم‌مرکز متناهی با استفاده از سپرهای تشعشعی

نوع مقاله : پژوهشی

نویسندگان

دانشگاه سمنان

چکیده

در این مقاله، مطالعه عددی تاثیر قرارگیری سپرهای تشعشعی در محفظه‌ای متشکل از دو استوانه متناهی هم‌محور در میزان تلفات حرارتی ناشی از جابجایی آزاد و انتقال حرارت تابش مورد بررسی قرار گرفته است. محفظه مورد مطالعه شامل دو استوانه هم‌محور بوده که استوانه داخلی دارای دمای بالاتری می‌باشد و بین این دو استوانه از یک و یا دو سپر تشعشعی با جنس‌های مختلف (آلومینیوم، مس و استیل) در فواصل مختلف استفاده شده است. تاثیر خواص فیزیکی (جنس سپرهای تشعشعی)، فاصله سپرهای تشعشعی، دمای استوانه داخلی و فشار محفظه بر میزان تلفات حرارتی مورد بررسی قرار گرفته است. نتایج به دست آمده برای دماهای مختلف استوانه داخلی (473.15 و 673.15 کلوین) و فشارهای مختلف محفظه (0.2 و 1.0اتمسفر) ارائه شده است، که نشان‌دهنده تاثیر مستقیم فشار محفظه و ضریب جذب سپر تشعشعی بر میزان تلفات حرارتی بین استوانه داخلی و خارجی می‌باشد.

کلیدواژه‌ها


عنوان مقاله [English]

Numerical Investigation of Convection and Radiation Heat Loss Reduction between Two Finite Concentric Cylinders Using Radiation Shields

نویسندگان [English]

  • Seyfolah Saedodin
  • Mohammad Sadegh Motaghedi Barforoush
چکیده [English]

Investigation of the radiation and natural convection heat losses from two finite concentric cylinders with radiation shields is performed numerically. The enclosure consists of two concentric cylinders with hotter inner cylinder and radiation shields with three different materials (aluminum, copper and steel) are inserted between the cylinders at different radial positions. The effects of physical properties (material), geometrical effects of radiation shields, inner cylinder temperature, and enclosure pressure on the heat losses have been investigated. The calculations were performed for two different inner temperatures as 473.15, and 673.15 K, and at two enclosure pressures of 0.2 and 1.0 atm. Results showed that the enclosure pressure and radiation shield emissivity together reduce the total heat loss from the inner cylinder.

کلیدواژه‌ها [English]

  • Free convection
  • radiation
  • Finite cylinders
  • Radiation shields
  • Enclosure
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