Nucleate boiling is considered as one of the most efficient and technologically controlled heat transfer mechanisms, due to the significant change in enthalpy at low temperature differences, which in engineering applications enables efficient removal of high heat fluxes. In this work, we describe the production of structured surfaces with variable wettability and their heat transfer characteristics during nucleate pool boiling at atmospheric pressure. The boiling surfaces were treated with a combination of laser structuring and the application of a hydrophobic coating in order to produce biphilic surfaces with spacings between hydrophobic spots in the range of 0.6-3 mm. As part of the experimental work, we compared the heat transfer coefficients, the critical heat fluxes, and the boiling curves in the nucleate boiling regime on the prepared samples. The results of the experiments show that the structured copper biphilic surface, which exhibits the highest heat transfer coefficient at low heat flux does not provide the largest improvement, even in the area of high heat fluxes. The highest heat transfer coefficient of 411,2 kW m-2 K-1 was achieved at a heat flux of ~1400 kW m-2 K-1 on the surface with a spacing between hydrophobic sites of 1.25 mm.
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