THERMAL SCIENCE

International Scientific Journal

PERFORMANCE OF LOW-PRESSURE FANS OPERATING WITH HOT AIR

ABSTRACT
Performance characteristics of fans are generally provided for the normal temperature and pressure conditions (tI = 20 °C, pI = 101.325 kPa, ρI = 1.2 kg/m3). Very often, fans operate in different air conditions, occasionally at different air temperatures. In these cases, equations obtained by the law of similarity are usually used for recalculation of the fan operating parameters. Increasing the inlet air temperature causes a decrease in the characteristic of Reynolds number, and may lead to efficiency lowering of the fan. There are also some empirical formulas for recalculation of fan efficiency, when operating at different air temperatures. In this paper, the common way for obtaining fan performance for different operating conditions (air temperature changing) is presented. The results, obtained by recalculation of fan parameters using a law of similarity, are compared to numerical simulation results of the axial-flow fan operating with different air temperatures. These results are compared with results obtained by some recommended empirical formulas, as well. This paperwork is limited to low-pressure and mid-pressure fans, which represents the majority of all fans used in practice, for different purposes.
KEYWORDS
PAPER SUBMITTED: 2016-04-14
PAPER REVISED: 2016-07-18
PAPER ACCEPTED: 2016-09-26
PUBLISHED ONLINE: 2016-12-25
DOI REFERENCE: https://doi.org/10.2298/TSCI16S5435B
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2016, VOLUME 20, ISSUE Supplement 5, PAGES [S1435 - S1447]
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© 2019 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence