Enhanced Boiling Heat Transfer of T-shaped Finned Tubes: Experiment and Simulation

Abstract

Tubes with enhanced surface usually have high boiling heat transfer coefficients which can greatly improve the heat transfer performance under the condition of pool nucleate boiling. In this paper, the boiling heat transfer enhancement behavior was carried out for T-shaped finned tubes, improved T-shaped finned tubes, trapezoidal finned tubes and smooth tubes. The heat transfer enhancement mechanism in high boiling medium with different fin shapes was explored. Experimental data show that the boiling heat transfer coefficients of finned tubes with different shapes are 1.4 to 3 times higher than that of the smooth tubes in the same heat load range. Moreover, the tested results were fitted by the correlation formula of heat transfer coefficient, which can provide guidance for industrial applications. Furthermore, combined with the field coordination theory, the heat transfer characteristics of machining finned tubes were obtained by the software of Fluent. The simulated enhanced heat transfer performances under different heat transfer flux are in good agreement with experimental data. Interestingly, the vapor phase volume fraction of the finned tube is almost 5 times that of the smooth tube.