A Correlation for the Prediction of Nucleate Pool Boiling Performance of Pure Liquids from Enhanced Tubes

This investigation is devoted to study the enhancement factor of single enhanced tubes boiling pure liquids. Two surfaces of the integral machined structure; Gewa-T and low finned, tubes were considered. A new correlation for the estimation of the heat transfer coefficient in the nucleate region was developed based on the Buckingham (ð) theorem for these tubes. The enhancement factor is a strong function of the fin shape of the enhanced surface structure and boiling liquids physical properties. Five liquids boiling at atmospheric pressure were considered, R-113, n-pentane, ethanol, water and R-11, for a heat flux in the range between (10) and (50) kW/m2. The total mean absolute errors of the enhancement factors were (6%) and (9%) for the low finned and Gewa-T surfaces respectively. The present correlation showed a good agreement with the available experimental data in the literatures for the nucleate pool boiling heat transfer coefficient. It correlated the available data with a corresponding total mean absolute errors were (9.5%) and (13.5 %) for the low finned and Gewa-T surfaces respectively.