Mixed steam condensation heat transfer reinforcement surface, preparation method and application thereof

Abstract

The invention belongs to technical field of reinforcement heat transfer and energy conservation, and in particular, relates to a V-shaped groove super-hydrophobic surface and application thereof to mixed steam condensation heat transfer reinforcement. A condensation surface is of a two-grade structure, and consists of a sub-millimetric V-shaped groove structure and a nanometer rough structure. Inthe condensation process of mixed steam, based on the characteristics of non-condensable gas accumulated in the sub-millimetric V-shaped groove, under high supercool degree, condensation liquid dropsat the top of the V-shaped groove are in a Wenzel wet mode, quick condensation of the liquid drops can be realized; condensation liquid drops at the bottom of the V-shaped groove are in a Cassie wet mode; and growth is slow. Along with growth of the Wenzel liquid drops, under the effect of Laplace pressure, the liquid drops perform a self-driven motion out of the V-shaped groove; and the solid-liquid contact area is reduced, that is, the adhesive force between the liquid drops and the surface is reduced. When the liquid drops grow to enable the radius to be equal to the top width of the V-shaped groove, the liquid drops fall in a scouring form, so that the condensation wall surface is updated, disturbance on a non-condensable gas layer can be realized, and mixed steam condensation heat transfer can be reinforced.

Description

technical field [0001] The invention belongs to the technical field of heat transfer enhancement and energy saving, and in particular relates to the preparation and application of a condensation heat transfer enhanced surface. Specifically, the heat exchange surface is processed and modified, and applied to the mixed steam condensation heat exchange equipment. Background technique [0002] The steam condensation heat transfer process group is one of the most basic operating processes in industrial production and application, and has a wide range of application backgrounds in the fields of refrigeration, chemical industry, power, power generation, and aerospace thermal control technology. Steam condensation heat transfer enhancement technology plays a vital role in the efficiency and integration of energy power systems. There are many ways to strengthen the steam condensation process in practical applications, such as increasing the flow rate of mixed steam, installing baffl...

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Problems solved by technology

[0004] However, for ordinary superhydrophobic surfaces with only nanostructures or micro-nano secondary structures, droplet bouncing has very strict requirements on condensation conditions, and droplet bouncing can only be achieved at a small degree of supercooling, while at high Under the supercooling degree, the condensed droplet presents a Wenzel wetting mode, the adhesion force between it and the surface increases, the droplet movement ability is weakened, and the droplet cannot merge and bounce. After falling off, a thick liquid film remains, which increases the heat transfer resistance and greatly limits the application of superhydrophobic surfaces in condensation

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