Saturated Flow Boiling Heat Transfer Correlation for Small Channels Based on R134a Experimental Data

Abstract

In the literature, the modeling of saturated flow boiling heat transfer characteristics of R134a flowing through small channels is still questionable since it is based on very limited operational data. This study proposes a new evaporative heat transfer model based on R134a for micro- and macro-tubes. The proposed correlation is developed from 3594 data points, which are obtained from 19 different studies. Ranges of the database cover mass fluxes between 50.0 and 1500.0 kg/m2 s, heat fluxes between 3.0 and 150.0 kW/m2, hydraulic diameter between 0.5 and 13.84 mm, saturation temperatures between −8.8 and \({52.4 ^{\circ} {\rm C}}\), and vapor qualities up to 1.0. Findings of the proposed method are compared with those of the most quoted flow boiling heat transfer correlations developed for micro- and macro-tubes. Results of the comparison indicate that new method, which has a mean absolute deviation of 19.1 % and captures 66.7 and 83.2 % of the experimental data within ±20 and ±30 % error bands correspondingly, outperforms the available flow boiling correlations in the literature in terms of prediction accuracy.