Affiliation: | aLaboratorio di Tecnica del Freddo, DETEC, Faculty of Engineering, Università degli Studi di Napoli Federico II, 80125 Naples, Italy bLaboratory of Heat and Mass Transfer (LTCM), Faculty of Engineering Science (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland |
Abstract: | In this paper, existing and new two phase pressure drop data are used to run an extensive comparison to predictive methods. The database used is for seven refrigerants (R22, R134a, R404A, R407C, R410A, R417A, and R507A) over a wide range of operating conditions. The procedure used for the comparison is a model of general validity since it is independent of the data reduction procedure. Four quoted methods and a new one by Moreno Quibén and Thome are used. The statistical analysis showed that the methods by Grönnerud and by Moreno Quibén and Thome are equally the best. Segregating the data by flow regimes and taking into account for the prediction of the data trends, the method by Moreno Quibén and Thome is able to give reliable predictions in all the range of vapour qualities, especially in the regions of the intermittent flow and dry-out. |