Prediction of flow boiling heat transfer data for R134a, R600a and R290 in minichannels

In the paper presented is the analysis of the results of calculations using a model to predict flow boiling of refrigerants such as R134a, R600a and R290. The latter two fluids were not used in the development of the model semiempirical correction. For that reason the model was verified with present experimental data. The experimental research was conducted for a full range of quality variation and a relatively wide range of mass velocity. The aim of the present study was also to test the sensitivity of developed model to a selection of the model of two-phase flow multiplier and the nonadiabatic effects. For that purpose two models have been analysed namely the one due to Muller-Steinhagen and Heck, and Friedel. In addition, the work shows the importance of taking surface tension into account in the calculation of the flow structure.