Double tube heat exchanger with novel enhancement: part II—single phase convective heat transfer

Abstract

The study is conducted to evaluate the heat transfer characteristics of two new and versatile enhancement configurations in a double tube heat exchanger annulus. The novelty is that they are usable in single phase forced convection, evaporation and condensation. Heat transfer coefficients are determined by the Wilson Plot technique in laminar and turbulent flow and correlations are proposed for Nusselt numbers. Comparisons are then made between heat transfer and flow friction.

Double tube heat exchanger with novel enhancement: part 3—convective condensation

“…The experimental procedure for determination of condensation characteristics utilizes results from earlier investigations of the authors [1,2]. Hence it is presented in Fig.…”

“…These correlations are then used to extract the condensation heat transfer coefficient from the overall condensation process where phase change of the refrigerant occurs from superheated vapor to subcooled liquid. The correlation for the single phase heat transfer coefficient has been obtained in Tiruselvam and Raghavan [2]. From the initial analysis of the current experiments, it was found that the flows of both superheated vapor and subcooled liquid in the annulus are in the turbulent flow region.…”

“…The first part of the study dealt with the hydrodynamic characteristics in single phase flow [1]. The second paper presented the single phase convective heat transfer aspects [2]. The current work considers the condensation performance of these surfaces.…”

“…The current work considers the condensation performance of these surfaces. The figures and tube dimensional details of the test sections can be found in [1,2].…”

“…where h i is the convective heat transfer coefficient of the inner tube side, obtained from Tiruselvam et al [2], for straight double tube:Plain Tube, Turbulent, Re [ 8,000…”