%0 Journal Article %A Kandlikar, Satish G. %A Raykoff, Taavo %D 2017 %I Begell House %K Enhanced flow boiling, flow boiling augmentation, microfin tube, evaporation, flow boiling correlation %N 1-6 %P 313-326 %R 10.1615/JEnhHeatTransf.v24.i1-6.160 %T FLOW BOILING HEAT TRANSFER OF REFRIGERANTS IN MICROFIN TUBES %U https://www.dl.begellhouse.com/journals/4c8f5faa331b09ea,7c902f7e71298fc5,6ac1c9db4036ad2a.html %V 24 %X Microfin tubes are used in evaporators and condensers of refrigeration systems. The performance of different microfin tubes has been experimentally determined by a number of investigators, and the data are available in literature. In order to use this information in the design of equipment, it is necessary to correlate this data into a readily usable form. It is desirable that the correlation not only fit the available data well, but also reflect the parametric trends correctly. Kandlikar (1991a) presented a correlation scheme to correlate flow boiling data for augmented tubes and compact evaporators. This correlation was based on the original correlation by Kandlikar (1990) for smooth tubes which accurately represented various trends in heat transfer coefficient with important system parameters. In the present work, the Kandlikar (1991a) correlation is modified to correctly account for the Reynolds number exponent in the single-phase flow. Also the missing (k/D) ratio is introduced in the single-phase heat transfer correlation. The augmented tube correlation scheme is applied to five sets of microfin tube flow boiling data available in literature. A single set of constants is found to correlate different refrigerant data sets obtained with the same microfin tube geometry. Parametric trends in heat transfer coefficient for microfin tubes obtained from the correlation are presented. It has been found that the enhancements in the nucleate boiling and the convective boiling contributions in the microfin tubes are influenced by the microfin geometry. To further improve the correlation capability for microfin tubes, it is recommended that single-phase heat transfer data should be obtained for that tube over a wide range of Reynolds number. %8 2018-04-23