Heat transfer and exergy loss in conical spring turbulators

Abstract

It would be misleading to consider only the construction costs of heat exchangers in their design because high service costs during their service life may also greatly increase total costs. Therefore energy saving aspects are very important in the design, construction and operation of the heat exchangers. For this reason, various active or passive methods have been sought to save energy by increasing the heat transfer coefficients in the cold and warm fluid sides in the heat exchangers. Conical spring turbulators (CST) are devised in this study. Performances of heat transfer and pressure drop in a pipe with the CST are experimentally examined for the CSTs' angle (theta) of 30 degrees, 45 degrees and 60 degrees in Reynolds number (Re) range of 10,000-34,000. Heat transfer, pressure loss and exergy analysis were made for the conditions with and without turbulators and compared to each other. Some empirical correlations expressing the results were also derived and discussed. (C) 2013 Elsevier Ltd. All rights reserved.