6. Conclusion

Free boiling is an efficient but complex heat transfer method, due to the coupling of hydraulic and thermal phenomena. A number of theories relating to the fundamental mechanisms governing boiling are well known, and have led to the development of a body of practical knowledge for the design and sizing of two-phase heat exchangers, notably in the form of macroscopic heat exchange laws in relation to boiling regimes, including boiling of fluid mixtures. The influence of a number of operating parameters is also now well established. For engineers, this macroscopic knowledge enables them to carry out preliminary designs and rapidly estimate the performance of two-phase heat exchangers.

On the other hand, free boiling remains a subject of research to better understand microscopic or local phenomena (geometrical effects such as fluid confinement, effects induced by the...