Abstract

This work analyzes and compares the thermal characteristics of two enclosures heated using different methods: one is heated using two-phase thermosyphons and the other is heated with a more conventional approach; hot exhaustion gases flowing into the enclosure. The first type has been evaluated for application to baking ovens, while the second type is already commonly used for this application in some countries. The methodology used to compare the two enclosures was developed by the present authors and is presented in the literature. The results show that the enclosure heated using thermosyphons has more uniform temperature and radiative heat transfer coefficient distributions compared to the conventional approach. The conventional enclosure tends to present larger convective heat transfer coefficients than the thermosyphon assisted enclosure because of the exhaustion gases movement. The thermosyphon assisted enclosure present a very uniform temperature distribution, which causes the air to become stagnant and the heat transfer coefficients to be low. The radiation field inside the thermosyphon assisted enclosure is more uniform than the conventional enclosure. A more uniform radiation field is obviously better when applying the enclosure for cooking as it makes the process more even. (c) 2005 Elsevier SAS. All rights reserved.