Inaccuracy of heat transfer characteristics of a metal duct neglecting heat radiation effect in ambient air

King Leung Wong, Wen-Lih Chen, Yung Chin Chiu

研究成果: Conference contribution

摘要

A heat radiation equation contains 4 th exponential order of temperature which makes mathematics analysis complicated and time-consumption. Most heat transfer experts and scholars believe, based on their own experiences, that the heat radiation effect can be ignored in situations of small temperature difference between duct surfaces and surroundings. This paper studies in detail for complete heat transfer characteristics of a circular duct with heat radiation effect taken into account. It is found that, in some practical conditions, the heat radiation effect can not be ignored especially in cases of lower ambient convection heat coefficients and larger surface emissivities, as well as the smaller the duct size and/or the greater the duct conductivity and/or internal fluid convection coefficients, even though the temperature-difference between inner and outer fluid-temperatures of duct is low to 1 °C. It is found that the conventional LMTD method (ignoring heat radiation) cannot be applied to calculate the total heat transfer rate of a single-duct heat exchanger located in ambient air, such as condenser and evaporator.

原文English
主出版物標題Electrical Power and Energy Systems
頁面322-327
頁數6
DOIs
出版狀態Published - 2012 六月 5
事件1st International Conference on Energy and Environmental Protection, ICEEP 2012 - Hohhot, China
持續時間: 2012 六月 232012 六月 24

出版系列

名字Advanced Materials Research
516-517
ISSN(列印)1022-6680

Other

Other1st International Conference on Energy and Environmental Protection, ICEEP 2012
國家China
城市Hohhot
期間12-06-2312-06-24

指紋

Radiation effects
Heat radiation
Ducts
Heat transfer
Air
Metals
Condensers (liquefiers)
Heat convection
Temperature
Fluids
Evaporators
Heat exchangers
Enthalpy

All Science Journal Classification (ASJC) codes

  • Engineering(all)

引用此文

Wong, K. L., Chen, W-L., & Chiu, Y. C. (2012). Inaccuracy of heat transfer characteristics of a metal duct neglecting heat radiation effect in ambient air. 於 Electrical Power and Energy Systems (頁 322-327). (Advanced Materials Research; 卷 516-517). https://doi.org/10.4028/www.scientific.net/AMR.516-517.322
Wong, King Leung ; Chen, Wen-Lih ; Chiu, Yung Chin. / Inaccuracy of heat transfer characteristics of a metal duct neglecting heat radiation effect in ambient air. Electrical Power and Energy Systems. 2012. 頁 322-327 (Advanced Materials Research).
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abstract = "A heat radiation equation contains 4 th exponential order of temperature which makes mathematics analysis complicated and time-consumption. Most heat transfer experts and scholars believe, based on their own experiences, that the heat radiation effect can be ignored in situations of small temperature difference between duct surfaces and surroundings. This paper studies in detail for complete heat transfer characteristics of a circular duct with heat radiation effect taken into account. It is found that, in some practical conditions, the heat radiation effect can not be ignored especially in cases of lower ambient convection heat coefficients and larger surface emissivities, as well as the smaller the duct size and/or the greater the duct conductivity and/or internal fluid convection coefficients, even though the temperature-difference between inner and outer fluid-temperatures of duct is low to 1 °C. It is found that the conventional LMTD method (ignoring heat radiation) cannot be applied to calculate the total heat transfer rate of a single-duct heat exchanger located in ambient air, such as condenser and evaporator.",
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Wong, KL, Chen, W-L & Chiu, YC 2012, Inaccuracy of heat transfer characteristics of a metal duct neglecting heat radiation effect in ambient air. 於 Electrical Power and Energy Systems. Advanced Materials Research, 卷 516-517, 頁 322-327, 1st International Conference on Energy and Environmental Protection, ICEEP 2012, Hohhot, China, 12-06-23. https://doi.org/10.4028/www.scientific.net/AMR.516-517.322

Inaccuracy of heat transfer characteristics of a metal duct neglecting heat radiation effect in ambient air. / Wong, King Leung; Chen, Wen-Lih; Chiu, Yung Chin.

Electrical Power and Energy Systems. 2012. p. 322-327 (Advanced Materials Research; 卷 516-517).

研究成果: Conference contribution

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