Metal surface treatment method for enforcing condensation heat transfer

Abstract

The invention discloses a metal surface treatment method for enforcing condensation heat transfer, which comprises the following step of repeatedly rolling the surface of a metal by using a roller to make the surface of the metal form nano twin crystal, wherein the lamellar thickness of the nano twin crystal is less than 200 nm; and during rolling, the roller revolves around an axis of revolution and performs horizontal relative movement with the metal at a speed of 0.1 to 50 mm / minute, and the revolution speed of the roller is 100 to 300 rpm. The metal surface treatment method for enforcing the condensation heat transfer overcomes the defects of low bond strength and short service life of a coat and a metal substrate in the conventional technology for preparing a hydrophobic coat on a metal surface and the defects of high cost and the like of ion implantation technology by changing the chemical compositions on the metal surface, reduces surface free energy by changing a microscopic structure and a stress state of the metal surface, realizes a dropwise and film co-existing or dropwise condensation mode of the metal surface, remarkably enforces the condensation heat transfer process of stream on the metal surface, and improves heat transfer effect.

Description

technical field [0001] The invention belongs to the technical field of heat transfer enhancement and energy saving, and in particular relates to a metal surface treatment method. Background technique [0002] Vapor condensation widely exists in the industrial field and in nature, and it is one of the important heat transfer processes in the fields of petrochemical, power generation, energy power, refrigeration and air conditioning, and energy saving. The condensation method of steam can be divided into film condensation and drop condensation according to the degree of wetness between the condensate and the condensation surface. At present, there are two main ways to enhance condensation, one is to enhance film condensation, which mainly reduces the thickness of the condensate film on the surface, and the other is to change the film condensation to droplet or droplet film coexistence condensation mode through surface treatment . Droplet condensation is the most ideal way to...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is to overcome the defects of low bonding strength and short life between the coating layer and the metal matrix existing in the existing technology of preparing a hydrophobic coating layer on the metal surface in order to achieve a good condensation effect, and by The high cost and other defects of the ion implantation technology that changes the chemical composition of the metal surface provide a completely different metal surface treatment method that can enhance the condensation heat transfer effect of the metal. This method changes the microstructure of the metal surface And the state of stress, reducing the surface free energy, thereby changing the condensation mode of the metal surface from complete film condensation to drop film coexistence or complete drop condensation mode, which significantly strengthens the condensation heat transfer process of steam on the metal surface, and improves the Heat transfer effect

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