Pool boiling heat transfer of propane, isobutane and their mixtures on enhanced tubes with reentrant channels

Pool boiling heat transfer experiments were carried out on a conventional smooth tube and four enhanced tubes with reentrant surfaces using propane, isobutane and their mixtures as working fluids for six saturation temperatures. The heat transfer performance is very different for different surface–fluid combinations. Compared to the smooth tube, the mixture boiling heat transfer degradation is more significant for the enhanced tubes. The current data are compared with available literature data for the same fluids and also with data for R12 and R134a. Experimental results of boiling hysteresis and for twin-tube bundles are also provided. Further explanations for the different heat transfer performances is provided by means of visualization in an accompanying paper [Y. Chen, M. Groll, R. Mertz, R. Kulenovic, Visualization and mechanisms of pool boiling of propane, isobutane and their mixtures on enhanced tubes with reentrant channels, submitted to Int. J. Heat Mass Transfer (H/S 04016)].