An investigation of bubbly boiling of environment-friendly refrigerating media

The article describes results of investigations of heat transfer and pressu re drop during saturated bubbly boiling of new environment-friendly refrige rating media. Taking advantage of the experimental results, an analytical m odel of heat transfer and pressure drop is worked out. An essential feature of the model is that it accounts for components of the heat flux density i n the boundary sublayer due to convection, interaction of heat sinks, and t urbulence effects. The comparison of computational results and experimental data, from the present study and from other investigations, shows that the proposed method of determination of heat transfer coefficients and pressur e drop can be applied to a number of refrigerating media with a wide range of heat and flow parameters, assuring accuracy to +/-20%. Therefore, the me thod can be used in design of heat exchangers for refrigeration units as we ll as complete refrigeration units.