Pool boiling of ammonia/water and its pure components:: Comparison of experimental data in the literature with the predictions of standard correlations

Although ammonia/water has been used for decades as a working pair in absorption cycles for industrial refrigeration, very limited data are available on boiling heat transfer of this mixture. The intention of this work is to carry out a bibliographic revision of the information available in the open literature about nucleate pool boiling of the ammonia/water mixture and its pure components. The experimental data have been compared with existing prediction correlations for the pure components and also for their mixtures. For water, all the pure component pool boiling correlations gave similar predictions and were in good agreement with experimental data. For ammonia the prediction of the correlation and the experimental data showed more differences. At a given heat flux, the experimental data show that the mixture pool boiling heat transfer coefficient is lower than that obtained with pure components. Three of the well-known correlations for mixtures were compared against the experimental data. None of these correlations provided a good prediction of the mixture pool boiling heat transfer coefficient over a wide range of mass fraction. Furthermore, a new correlation has been proposed. (c) 2007 Elsevier Ltd and IIR. All rights reserved.