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

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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.

Original languageEnglish
Title of host publicationElectrical Power and Energy Systems
Pages322-327
Number of pages6
DOIs
Publication statusPublished - 2012 Jun 5
Event1st International Conference on Energy and Environmental Protection, ICEEP 2012 - Hohhot, China
Duration: 2012 Jun 232012 Jun 24

Publication series

NameAdvanced Materials Research
Volume516-517
ISSN (Print)1022-6680

Other

Other1st International Conference on Energy and Environmental Protection, ICEEP 2012
CountryChina
CityHohhot
Period12-06-2312-06-24

All Science Journal Classification (ASJC) codes

  • Engineering(all)

Fingerprint Dive into the research topics of 'Inaccuracy of heat transfer characteristics of a metal duct neglecting heat radiation effect in ambient air'. Together they form a unique fingerprint.

Cite this