A condenser for an air conditioning system, a surface coating thereof, and a method for preparing the coating.

Abstract

An air conditioning system condenser, its surface coating, and a coating preparation method are disclosed. The surface coating is a nanoscale film material formed by spraying and / or dipping onto the condenser surface. The film material contains nanoscale powder materials with a size of 1-100 nm, which fill the micropores of the organic coating on the condenser surface when forming the surface coating, making the surface coating a nearly pore-free, dense coating. This invention is applied to the air conditioning system condensers of large trucks or vehicles operating in harsh environments. It has anti-corrosion, wear-resistant, and self-cleaning functions, and can withstand the erosion of the substrate by various corrosive gases, ions, and water molecules. It can effectively solve the problems of low hardness of the aluminum alloy substrate of the condenser and the lack of wear resistance due to flying sand during truck operation or flying stones during loading and unloading. The surface of the truck air conditioning system condenser after spraying the film material is smooth, and the surface coating has low surface energy, making it difficult for dust and water droplets to adhere, thus avoiding heat exchanger clogging and affecting heat exchange efficiency.

Description

Technical Field

[0001] This invention relates to the field of condenser technology for truck air conditioning systems, and in particular to an air conditioning system condenser, its surface coating, and a coating preparation method. Background Technology

[0002] Large truck air conditioner condensers generally use aluminum flat tubes as heat exchange materials. Trucks operate in harsh environments, such as coal mining areas, where corrosive media such as sulfides and dust severely affect the corrosion resistance of the condenser. In as little as one and a half months, environmental corrosion can cause the heat exchange flat tubes of the condenser to corrode and perforate, leading to the failure of the entire unit. Summary of the Invention

[0003] To address the problem that the service environment of large trucks has a serious impact on the corrosion resistance of air conditioning condensers, this invention provides an air conditioning system condenser, its surface coating, and a coating preparation method. The surface coating is prepared using nanoscale film materials and has anti-corrosion, wear-resistant, and self-cleaning functions. This improves the problems of dirt clogging and easy corrosion caused by harsh environments, enhances the corrosion resistance of condensers exposed to the atmosphere, and extends the service life of the entire unit.

[0004] To achieve the above objectives, the present invention employs the following technical solution: a surface coating for an air conditioning system condenser, wherein the surface coating is a nanoscale film material formed by spraying and / or dipping onto the condenser surface, and the material components of the film material include:

[0005] 40-65 wt% n-butyl acetate;

[0006] Solvent naphtha 8-20 wt%;

[0007] Propylene glycol methyl ether acetate 0-5 wt%;

[0008] Isobutyl methacrylate 0-3 wt%;

[0009] 0-3 wt% 2-Methylpropanolacetic acid;

[0010] Polysiloxane 10-20wt%;

[0011] 5-10 wt% of silazane.

[0012] Preferably, the surface coating is composed of a polymer network structure membrane material containing nano-sized powder materials of 1-100nm, which fills the micropores of the organic coating on the condenser surface when forming the surface coating, making the surface coating a dense coating with almost no pores.

[0013] Preferably, the nanoscale film material is sprayed and / or dip-coated onto the condenser surface to form a surface coating, and a film-metal bonding layer is formed between the surface coating and the condenser surface. The bonding force of the film-metal bonding layer between the surface coating and the condenser metal surface is greater than the expansion stress between the surface coating and the condenser metal surface caused by the corrosive electrochemical reactants.

[0014] On the other hand, the present invention adopts the following technical solution: an air conditioning system condenser, the air conditioning system condenser including two manifolds and a heat exchange group located between the two manifolds, the heat exchange group including a plurality of heat exchange flat tubes with both ends inserted into the manifolds and a straight tube placed between two adjacent heat exchange flat tubes; the manifolds, heat exchange flat tubes and straight tubes are coated with a film material by spraying and / or dipping to form the surface coating of the above-mentioned air conditioning system condenser.

[0015] Preferably, the width of the heat exchange flat tube is smaller than the diameter of the manifold so that when the heat exchange flat tube extends into the manifold, both ends are located inside the manifold, and the ends abut against the axial position of the manifold so that the length of the heat exchange flat tube is equal to the distance between the centers of the two manifolds.

[0016] Preferably, the manifold is provided with a partition for dividing the space inside the manifold into multiple spaces, and the partitions of the two manifolds are staggered so that a space for medium flow is formed between the two manifolds and the multiple heat exchange flat tubes. One of the manifolds has an inlet assembly and an outlet assembly. The inlet assembly is installed between one end of the manifold and the partition, and the outlet assembly is provided between the other end and the partition.

[0017] As another technical solution of the present invention, zinc spraying is performed on the surface of the manifold and heat exchange flat tube of the condenser to form a surface zinc coating. The zinc wire is melted at high temperature, and the molten zinc liquid is sprayed onto the surface of the substrate at high speed to form a zinc coating that wraps the substrate. After the condenser is wrapped with zinc coating, the zinc layer corrodes preferentially in the initial stage of corrosion reduction. In the middle stage, part of the zinc coating is corroded and perforated, exposing the aluminum substrate. Because the surface of the aluminum substrate has a stable oxide film, the uncorroded zinc layer will act as a sacrificial anode to protect the aluminum substrate and slow down the corrosion of the substrate.

[0018] On the other hand, the present invention employs the following technical solution: a method for preparing a surface coating on an air conditioning system condenser, wherein the surface coating forms a film substance on the condenser surface through the following coating steps:

[0019] Prepared air conditioning system condenser after processing;

[0020] Rough cleaning and fine cleaning are performed using a cleaning agent aqueous solution to remove oil.

[0021] Rinse at least once with tap water and dry to ensure the condenser surface is free of moisture and water stains;

[0022] The material components of the membrane material are prepared into a coating, which is then sprayed and / or dipped onto the surface of the condenser using a spray gun to form a membrane material coating layer on the condenser surface.

[0023] The coating material is cured at room temperature to form a surface coating for the condenser.

[0024] Preferably, the coating step includes:

[0025] The condenser was roughly cleaned and degreased for 2-3 minutes at 40-60℃ using a 5% concentration aqueous cleaning agent solution.

[0026] The condenser was thoroughly cleaned and degreased for 2-3 minutes at 40-60℃ using a 2% concentration aqueous cleaning agent solution.

[0027] Rinse the condenser with tap water at room temperature for 3-5 minutes, and rinse at least once.

[0028] Allow the condenser surface to air dry naturally to ensure that there is no moisture or water stains on the condenser surface.

[0029] Preferably, the coating step includes:

[0030] A coating is prepared by using 40-65 wt% n-butyl acetate, 8-20 wt% solvent naphtha, 0-5 wt% propylene glycol methyl ether acetate, 0-3 wt% isobutyl methacrylate, 0-3 wt% 2-methylpropanol acetate, 10-20 wt% polysiloxane, and 5-10 wt% silazane.

[0031] The condenser surface is sprayed and / or dipped with a spray gun, and the coating is applied repeatedly until the coating is evenly covered on the condenser surface, so that a film coating layer is formed on the condenser surface.

[0032] The coating material is cured at 15-25℃, surface dry in 90 minutes, and fully dry in 48 hours to form a surface coating for the condenser.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] This invention is applied to the condenser of the air conditioning system of large trucks or vehicles operating in harsh environments. It has anti-corrosion, wear-resistant, and self-cleaning functions, and can withstand the erosion of the substrate by various corrosive gases, ions, water molecules, etc. It can effectively solve the problems of low hardness of aluminum alloy substrate of condenser and lack of wear resistance to flying sand during truck operation or flying stones during loading and unloading. The surface of the truck air conditioning system condenser after spraying the film material is smooth, and the surface coating has low surface energy, so dust and water droplets are not easy to adhere. Even if a small amount of floating dust adheres, the condensate water during the operation of the unit can easily wash it away, avoiding the heat exchanger from being dirty and clogged, which affects the heat exchange efficiency. Attached Figure Description

[0035] To more clearly illustrate the technical solution, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a flowchart illustrating the implementation of Case 1.

[0037] Figure 2 This is a structural diagram for implementing Case 2.

[0038] In the diagram: 100, manifold; 110, baffle; 120, inlet assembly; 130, outlet assembly; 200, heat exchange group; 210, heat exchange flat tube; 220, straight tube. Detailed Implementation

[0039] In order to clearly and completely understand the technical solution, the present invention will be further described in conjunction with the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Implementation Case 1:

[0041] like Figure 1 As shown, a surface coating for an air conditioning system condenser is a nanoscale film material formed by spraying and / or dipping onto the condenser surface. The material composition of the film material includes:

[0042] 58 wt% n-butyl acetate; 15 wt% solvent naphtha; 2 wt% propylene glycol methyl ether acetate; 1 wt% isobutyl methacrylate; 1 wt% 2-methylpropanol acetate; 15 wt% polysiloxane; 8 wt% silazane.

[0043] The surface coating is formed on the condenser surface by the following coating steps:

[0044] The air conditioning system condenser, which has been prepared for processing, is subjected to rough cleaning and fine cleaning with a cleaning agent aqueous solution. This includes rough cleaning and degreasing of the condenser with a 5% concentration cleaning agent aqueous solution at 50°C for 2 minutes, and fine cleaning and degreasing of the condenser with a 2% concentration cleaning agent aqueous solution at 50°C for 2 minutes.

[0045] After degreasing, rinse the condenser with tap water at room temperature of 15-25℃ for 3 minutes. Rinse two to three times until the cleaning agent and residue on the condenser are cleaned. Then let the condenser surface air dry naturally to ensure that there is no moisture or water stains on the condenser surface.

[0046] The membrane material components are prepared into a coating, which includes 58 wt% n-butyl acetate; 15 wt% solvent naphtha; 2 wt% propylene glycol methyl ether acetate; 1 wt% isobutyl methacrylate; 1 wt% 2-methylpropanol acetate; 15 wt% polysiloxane; and 8 wt% silazane. The coating is sprayed and / or dipped onto the condenser surface using a spray gun, and repeated spraying or dipping is performed until the condenser surface is uniformly covered with the coating, thus forming a membrane material coating layer on the condenser surface. The membrane material coating layer is cured at 15-25°C, with a surface dryness of 90 min and a complete dryness of 48 h, to form a surface coating of the condenser.

[0047] The micropores of the organic coating on the condenser surface and the adhesion between the coating and the base metal are important factors in the continuous participation of corrosive media in the electrochemical corrosion reaction. The surface coating described in this embodiment is composed of a polymer network structure film containing nano-sized powder materials (1-100 nm). These powders fill the micropores of the organic coating on the condenser surface, resulting in a dense, almost pore-free coating.

[0048] Due to the micropores present in organic coatings, media necessary for electrochemical reactions, such as O2, H2O, and substances that dissociate into H+ and OH-, can continuously enter the substrate metal surface to maintain the electrochemical corrosion reaction. This is one of the main factors that enable the electrochemical corrosion reaction to continuously develop on the metal surface. However, no matter how dense a coating is, it is impossible to form an absolutely dense coating. Due to the material structure and process of the film-forming materials in traditional ordinary coatings, the three types of "micropores" listed in the table below are unavoidable.

[0049]

[0050] The film material in this embodiment contains nanoscale powder materials ranging from 1 to 100 nm. At the 1-100 nm range, the microstructure of the cured surface coating is a polymer network structure composed of large-particle pigments, whereas conventional coatings typically have micropores with "structural pores" (lO). -5 cm~10 -7The film-forming material contains nanoscale powder materials, which fill the "structural pores" (pore size greater than 1 nm) that are unavoidable in conventional organic coatings, forming a dense coating that is almost pore-free, which is impossible with traditional conventional coatings. Therefore, the surface coating in this embodiment basically eliminates the penetration of various corrosive media in the environment, that is, it can achieve "zero penetration" of corrosive media in the environment into the coating.

[0051] In this embodiment, a film-metal bonding layer exists between the surface coating and the condenser surface. The bonding force of the film-metal bonding layer between the surface coating and the condenser metal surface is greater than the expansion stress of the corrosive electrochemical reactants between the surface coating and the condenser metal surface.

[0052] When the raw materials for nano-coatings are reduced to the nanoscale, not only does the number of atoms on the particle surface increase rapidly, but the specific surface area and surface energy of the particles also increase rapidly. For example, nanoparticles of metals and their oxides, with an average particle size of 30 nm (such as nano zinc oxide nmZnO), have a surface area of ​​40–60 m². 2 / g, while spherical SiO2, with a particle size of 15nm, has a larger specific surface area of ​​160m². 2 With such a huge specific surface area, the surface energy increases due to the large number of atoms on the surface. The crystal field environment and binding energy of the surface atoms are different from those of the atoms inside the material. The lack of adjacent atoms around the surface atoms, especially on the outward-facing side, creates many dangling bonds, which have unsaturated properties and are easily combined with other atoms to stabilize them. Therefore, they have great activity. The smaller the particle size, the larger the specific surface area, the more surface atoms there are, the greater the increase in chemical activity, and the greater the surface energy. The enormous surface area and surface energy of the coating have the most direct effect of significantly increasing the bonding strength between the unsaturated bonds of the protected metal and the coating. This transforms the adhesion between the coating and the substrate metal from van der Waals forces (approximately 0.4–4 KJ / mol) generated by molecular adsorption and hydrogen bonds (4.18–148 KJ / mol) formed by chemisorption into a combination of molecular adsorption, chemisorption, diffusion bonding, and chemical bonding. In other words, the surface activity of nanoparticles triggers a series of chemical reactions at the nano-coating-metal interface, resulting in a composite system similar to ClO2 and SiO2 nano-coatings, where there is no clear interface between the coating and the substrate metal. Because the molecules in this composite system are interpenetrating, the adhesion between the nano-coating and the substrate metal surface is greatly increased, exceeding the concept of "adhesion" in conventional coatings.

[0053] The adhesion of conventional coatings in traditional technologies is achieved solely by the transfer of coating macromolecules to the metal surface through molecular motion. The hydrogen bonding force generated by the attraction between polar groups in the coating macromolecules when the distance is less than 5 nm is still the adhesion formed by the affinity between the coating and the metal surface, even though this hydrogen bonding force is 10-40 times stronger than van der Waals forces.

[0054] In this embodiment, a film-metal bonding layer is constructed between the surface coating and the metal substrate on the condenser surface. The bonding force of the film-metal bonding layer is much greater than the expansion stress of the corrosion electrochemical reactants on the surface coating and the metal surface. This causes the corrosion electrochemical reaction between the metal substrate and the surface coating on the condenser surface, due to the presence of electrolyte and oxygen, to lose the space to extend in all directions and cannot continue, thus achieving the purpose of inhibiting corrosion.

[0055] In this embodiment, the surface coating acts as a barrier and shield against corrosive media in the environment (such as atmospheric oxygen, water vapor, and corrosive industrial gases, acids, alkalis, salts, and other strong electrolyte solutions), preventing direct contact between the metal surface and the corrosive media, thereby inhibiting the electrochemical corrosion reaction on the metal surface. The surface coating also blocks electrostatic conduction, reducing the activity of corrosive media ions and decreasing their diffusion capacity and rate, thus preventing or delaying the corrosion reaction.

[0056] The film material formed in this embodiment also has a resistive effect. Since the film-forming material of the nanoscale coating is mainly a nanomaterial with high impedance, it can prevent the movement of ions when the micro-electrons formed by the corrosive medium on the metal surface undergo electrochemical reactions, thereby increasing the polarization of the reaction and hindering the electrochemical reaction. On the other hand, if the base metal of the protected condenser surface and the corrosive medium condensed on the base metal surface are regarded as two systems in the electrochemical process, the surface coating inserts a resistive layer into these two systems, thereby preventing the contact between the two systems and preventing the electrochemical reaction from taking place.

[0057] This implementation case is applied to the condenser of the air conditioning system of large trucks or vehicles serving in harsh environments. It has anti-corrosion, wear-resistant and self-cleaning functions. It can withstand the erosion of the substrate by various corrosive gases, ions and water molecules. It can effectively solve the problem of low hardness of the aluminum alloy substrate of the condenser and the lack of wear resistance to flying sand or flying stones when the truck is running or stopping for loading and unloading. The surface of the truck air conditioning system condenser after spraying the film material is smooth. The surface coating has low surface energy, and dust and water droplets are not easy to adhere. Even if a small amount of floating dust adheres, the condensate water during the operation of the unit can easily wash it away, avoiding the heat exchanger from being dirty and clogged, which affects the heat exchange efficiency.

[0058] Implementation Case 2:

[0059] like Figure 2As shown, an air conditioning system condenser includes two manifolds 100 and a heat exchange assembly 200 located between the two manifolds 100. The heat exchange assembly includes a plurality of heat exchange flat tubes 210 with both ends inserted into the manifolds 100 and a straight tube 220 placed between two adjacent heat exchange flat tubes 210. The width of the heat exchange flat tubes 210 is smaller than the diameter of the manifolds 100 so that when the heat exchange flat tubes 210 extend into the manifolds 100, both ends are located inside the manifolds 100, and the ends abut against the axial position of the manifolds 100 so that the length of the heat exchange flat tubes 210 is equal to the distance between the centers of the two manifolds 100. The manifold 100 is equipped with an end cap at one end and multiple partitions 110 for dividing the internal space of the manifold 100 into multiple segments. The partitions 110 of two manifolds are staggered to create a space for medium flow between the two manifolds and the multiple heat exchange flat tubes. One manifold has an inlet assembly 120 and an outlet assembly 130. The inlet assembly 120 is installed between the end cap at one end of the manifold 100 and the partition near the end cap. The outlet assembly 130 is installed between the end cap at the other end and the partition near the end cap. Medium is introduced through the inlet assembly, enters the manifold 100, and flows along the heat exchange flat tubes to the manifold on the other side. In the manifold on the other side, due to the partitions, the medium flows from the heat exchange flat tube below to the manifold on the side of the inlet assembly. Due to the partitions, the medium continues to flow to the manifold on the other side until it flows out from the outlet assembly, thus circulating.

[0060] The manifold 100, heat exchange flat tube 210, and straight tube 220 are coated with a film material to form a surface coating of the condenser of an air conditioning system according to Embodiment 1. After the surface coating is formed on the heat exchange flat tube and the manifold, the corrosion protection performance of the condenser is greatly improved and the service life of the whole unit is extended. On the other hand, the surface coating has a hydrophobic effect and a self-cleaning function, which effectively solves the problem of condenser dirt and blockage caused by dust in the environment and ensures the heat exchange efficiency of the air conditioning system.

[0061] In another embodiment of the present invention, zinc spraying is performed on the surfaces of the condenser's manifold and heat exchange flat tubes to form a surface zinc coating. Zinc wire is melted at high temperature, and the molten zinc is sprayed uniformly onto the substrate surface at high speed, forming a zinc coating that encapsulates the substrate. This improves the corrosion resistance of the condenser exposed to the atmosphere while ensuring the heat exchange performance of the air conditioning system. After the condenser is encapsulated by the zinc coating, in the initial stage of corrosion reduction, the zinc layer corrodes preferentially; in the middle stage, part of the zinc coating is corroded through, exposing the aluminum substrate. Because the aluminum substrate has a stable oxide film, the uncorroded zinc layer acts as a sacrificial anode, protecting the aluminum substrate and slowing down its corrosion.

[0062] The above disclosures are merely one or more preferred embodiments of the present invention, intended to help understand the inventive concept of the technical solution, and are not intended to limit the present invention in any other way. Any other equivalent or conventional substitution schemes made by those skilled in the art based on the features defined by the present invention shall still fall within the scope of the present invention.

Claims

1. A surface coating for an air conditioning system condenser, characterized in that: The surface coating is a nanoscale film material formed by spraying and / or dipping onto the surface of the condenser, and the material composition of the film material includes: 40-65 wt% n-butyl acetate Solvent naphtha 8-20 wt%; 2-5 wt% propylene glycol methyl ether acetate; Isobutyl methacrylate 1-3 wt%; 1-3 wt% 2-Methylpropanolacetic acid; Polysiloxane 10-20wt%; 5-10 wt% silazane; The surface coating is composed of a polymer network structure membrane material containing nano-sized powder materials of 1-100nm. When forming a surface coating on the condenser surface, it is used to fill the micropores of the organic coating on the condenser surface, making the surface coating a non-porous and dense coating. There is a film-metal bonding layer between the surface coating and the condenser surface. The bonding force of the film-metal bonding layer between the surface coating and the condenser metal surface is greater than the expansion stress between the surface coating and the condenser metal surface caused by the corrosive electrochemical reactants.

2. A condenser for an air conditioning system, characterized in that: The air conditioning system condenser includes two manifolds and a heat exchange assembly located between the two manifolds. The heat exchange assembly includes a plurality of heat exchange flat tubes with both ends inserted into the manifolds and a straight tube placed between two adjacent heat exchange flat tubes. The manifolds, heat exchange flat tubes and straight tubes are coated with a film material by spraying and / or dipping to form a surface coating of an air conditioning system condenser as described in claim 1.

3. A condenser for an air conditioning system according to claim 2, characterized in that: The width of the heat exchange flat tube is smaller than the diameter of the manifold so that when the heat exchange flat tube is inserted into the manifold, both ends are located inside the manifold, and the ends abut against the axial position of the manifold so that the length of the heat exchange flat tube is equal to the distance between the centers of the two manifolds.

4. A condenser for an air conditioning system according to claim 2, characterized in that: The manifold is equipped with baffles for dividing the internal space of the manifold into multiple spaces, and the baffles of the two manifolds are staggered so that a space for medium flow is formed between the two manifolds and the multiple heat exchange flat tubes. One of the manifolds has an inlet assembly and an outlet assembly. The inlet assembly is installed between one end of the manifold and the baffle, and the outlet assembly is installed between the other end of the manifold and the baffle.

5. A condenser for an air conditioning system according to claim 2, characterized in that: The manifold and heat exchange flat tube are treated with zinc spraying to form a zinc coating on the surface.

6. A method for preparing a surface coating on an air conditioning system condenser, characterized in that, The surface coating of an air conditioning system condenser as described in claim 1 forms a film on the condenser surface through the following coating steps: Prepared air conditioning system condenser after processing; Rough cleaning and fine cleaning are performed using a cleaning agent aqueous solution to remove oil. Rinse at least once with tap water and dry to ensure the condenser surface is free of moisture and water stains; The material components of the membrane material are prepared into a coating, which is then sprayed and / or dipped onto the surface of the condenser using a spray gun to form a membrane material coating layer on the condenser surface. The coating material is cured at room temperature to form a surface coating for the condenser.

7. The method for preparing a surface coating for an air conditioning system condenser according to claim 6, characterized in that, The coating step includes: The condenser was roughly cleaned and degreased for 2-3 minutes at 40-60℃ using a 5% concentration cleaning agent aqueous solution. The condenser was thoroughly cleaned and degreased for 2-3 minutes at 40-60℃ using a 2% concentration cleaning agent aqueous solution. Rinse the condenser with tap water at room temperature for 3-5 minutes, and rinse at least once. Allow the condenser surface to air dry naturally to ensure that there is no moisture or water stains on the condenser surface.

8. The method for preparing a surface coating for an air conditioning system condenser according to claim 6, characterized in that, The coating step includes: A coating is prepared by using 40-65 wt% n-butyl acetate, 8-20 wt% solvent naphtha, 2-5 wt% propylene glycol methyl ether acetate, 1-3 wt% isobutyl methacrylate, 1-3 wt% 2-methylpropanol acetate, 10-20 wt% polysiloxane, and 5-10 wt% silazane. The condenser surface is sprayed and / or dipped with a spray gun, and the coating is applied repeatedly until the coating is evenly covered on the condenser surface, so that a film coating layer is formed on the condenser surface. The coating material is cured at 15-25℃, surface dry in 90 minutes, and fully dry in 48 hours to form a surface coating for the condenser.

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