Heat transfer by bubble boiling is considered one of the most efficient methods of heat transfer, allowing for the dissipation of high heat flux densities at low surface superheats. This study examines the impact of various laser-structured surfaces combined with graphene coatings on the enhancement of heat transfer during pool boiling of distilled water at atmospheric pressure. Additionally, the stability of graphene coatings is compared to laser-textured surfaces. We experimentally evaluated boiling before and after the application of graphene on untreated surfaces, laser-structured surfaces with uniform wettability and laser-structured surfaces with variable wettability. During the experimental phase, we recorded boiling curves in the nucleate boiling regime, their critical heat flux (CHF) values and heat transfer coefficients at specific heat flux densities on the prepared surfaces. The CHF values ranged 777,9–1463,1 kW m-². The highest CHF value was achieved by the reference surface after graphene application, representing a 56 % improvement compared to before the graphene application. The highest heat transfer coefficient values were achieved by the laser-structured surfaces before the graphene application (~250 kW m-2 K-1), showing a 347 % improvement compared to the reference surface. After the graphene application, the improvement was 223 % compared to the reference surface. We demonstrated that despite CHF improvements on certain surfaces, the use of graphene coatings on laser-textured surfaces relatively reduces the heat transfer efficiency by lowering the heat transfer coefficient. However, it consistently enhances the stability of the boiling process, which is a known limitation of many functionalized surfaces.
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