JPH10281690A - Air conditioner, heat exchanger and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent frosting as far as possible and lengthen a defrosting period by applying a heat exchanger having an air side water repellent heat transfer surface and a heat exchanger having an air side hydrophylic heat transfer surface to an outdoor heat exchanger unit. SOLUTION: Hydrophilic fins are formed by forming an etching layer 21 with the thickness, for example, about 4 micrometer on an aluminium base 20 to form macro protrusions and recesses and further forming a hydrate oxide layer 22 with the thickness, for example, about 0.2 micrometer and having protrusions and recesses on the surface thereof. Water repellent fins are formed by coating the surfaces of the hydrophilic fins 4 with a water repellent film composed of a hydrophobic compound. In an outdoor heat exchanger unit 10, a plurality of heat transfer tubes 15 are vertically inserted into a plurality of laminated fins 11 to have a heat exchanger 16 having water repellent fins and water droplets scattered from the heat exchanger 16 with the water repellent fins are captured by a capture plate 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type air conditioner, and more particularly, to an indoor heat exchanger unit using an air-side heat transfer surface having hydrophilicity and an outdoor unit using an air-side heat transfer surface having water repellency. The present invention relates to a high-performance air conditioner, a heat exchanger, and a method for manufacturing the same, which are combined with heat exchanger units.

[0002]

2. Description of the Related Art Generally, an air conditioner includes an indoor heat exchanger unit, an outdoor heat exchanger unit, a compressor, a four-way valve, an expansion valve, a connection pipe, and the like. Conventionally, the air-side heat transfer surface used for the indoor heat exchanger and the air-side heat transfer surface used for the outdoor heat exchanger are subjected to hydrophilic treatment on the outer surface to form condensed water generated on the air-side heat transfer surface into a film. A method of reducing the ventilation resistance by flowing down has been put to practical use.

For example, an air-side heat transfer surface material coated with a hydrophilic resin or subjected to a chemical conversion treatment such as a boehmite treatment is used. As an example of such a treatment, a hydrated oxide film is formed on the air-side heat transfer surface as shown in JP-A-63-238285, and then a silicon compound or an interface is formed. Those coated with an activator and water-based resin paint have been put to practical use,
The performance of the heat exchanger is improved, such as noise reduction.

However, in this method, in the outdoor heat exchanger, the surface temperature of the air-side heat transfer surface causes the generated condensed water to freeze,
If the temperature is below the frosting temperature, for example, when the outside air temperature is low during the heating operation, frost occurs on the air-side heat transfer surface,
The amount gradually increases, and eventually blocks the air flow path. If left unchecked, the performance of the air conditioner will deteriorate, so the heating operation must be periodically stopped to defrost the heat exchanger. Therefore, there is a problem that the indoor comfort is impaired.

As a countermeasure against this problem, a method has been proposed in which the surface of the air-side heat transfer surface used in the outdoor heat exchanger is made water-repellent (Japanese Patent Laid-Open No. Hei 9-113181). The contents are
Fluorine- or silicon-based water repellency with a boehmite film with a thickness of 0.1 µm or more formed on the surface of an aluminum base material that is an air-side heat transfer surface material and a contact angle of 90 ° or more when applied to a smooth surface The coating is applied to the surface of the coating at 0.1 to 10 mg / dm ² to form a water-repellent coating, which prevents condensed water from remaining on the air-side heat transfer surface and greatly suppresses the generation of frost. To prevent frost formation.

[0006]

SUMMARY OF THE INVENTION Performance improvement of a heat exchanger,
The demand for miniaturization is increasing year by year, so that the heat transfer heat transfer area is increasing, the air-side heat transfer surface pitch is narrow, and the slit shape of the air-side heat transfer surface is becoming complicated. However, in such a heat exchanger, condensed water accumulates in the slits and collars of the air-side heat transfer surface, making it easier to form a bridge between the air-side heat transfer surfaces, increasing ventilation resistance and increasing wind noise. Trouble occurs. Therefore, a heat exchanger having better water drainage properties is demanded as an indoor unit. Also,
When the air conditioner is started to use for the first time, there is a problem that an unpleasant odor expressed as "mold odor" is generated from the indoor heat exchanger unit.

On the other hand, in the outdoor heat exchanger unit,
Since performance deteriorates due to frost generated on the air-side heat transfer surface during the heating operation, a countermeasure is one of the important issues. In the above-mentioned conventional frost prevention technology, the surface irregularities are formed mainly of boehmite, and then a fluorine-based or silicon-based water-repellent paint is applied, and the contact angle is 15
A coating of 0 to 164 degrees is realized.

However, at such a contact angle, condensed water generated at the time of dew condensation adheres to the entire surface of the coating film, and further coalesces with the growth of the condensed water to form water droplets having a diameter of about 1 mm before the air side. It was found to fall on the heat transfer surface. When this coating is applied to an outdoor heat exchanger,
Frost formation during the heating operation can be prevented to some extent, and an increase in ventilation resistance can be suppressed. However, at the time of dew, condensed water droplets having a diameter of about 1 mm adhere to the air-side heat transfer surface used in the heat exchanger, which causes a problem of an increase in ventilation resistance.

Further, the durability of the water-repellent coating is extremely important, and even if the initial performance is good, a change over time occurs, and if the water-repellency is reduced, there is a problem in application to an actual product. In the prior art, durability is not sufficiently considered. When a film of a fluorine compound (fluoroalkylsilane) is formed on the boehmite layer, the initial water repellency is excellent, the contact angle of water is 172 degrees, and there is an effect of preventing frost formation. Performing blackening degrades the water repellency.

As a result of intensive studies on the deterioration of water repellency,
It has been found that not only peeling of the water-repellent coating but also adhesion of dust and dirt is one of the main causes. The mechanism is considered as follows. In a conventional water repellent coating, condensed water droplets of about 1 mm adhere to the coating surface. Dust, dirt, and the like are present in the adhered water droplets, and the dirt, dirt, and the like remain on the film surface as the water of the condensed water droplet evaporates.

Then, this becomes the starting point, and the dirt fills the concave portions of the film with the passage of time and further grows on the film to cover the surface of the film. As a result, the water repellency is reduced, and the condensed water droplets do not fall, grow on the air-side heat transfer surface, freeze and frost, and clog between the air-side heat transfer surfaces. As described above, the prior art has not examined the durability of the coating. An object of the present invention is to minimize the formation of frost on the air-side heat transfer surface during the heating operation, thereby extending the defrost cycle time, and to form a coating with extremely high durability on the air-side heat transfer surface. Heat exchanger with water repellent air side heat transfer surface formed on the surface,
Air-side heat transfer with excellent hydrophilicity and extremely high durability for condensed water generated on the air-side heat transfer surface during the cooling operation for the outdoor heat exchanger unit. It is an object of the present invention to provide a high-performance air conditioner in which a heat exchanger with a hydrophilic air-side heat transfer surface using a surface is configured for an indoor heat exchanger unit, and a method for manufacturing these heat exchangers. It is another object of the present invention to provide a heat exchanger capable of preventing "mold odor" by eliminating mold generated on an air-side heat transfer surface of an indoor heat exchanger unit and further reducing an unpleasant odor existing in a room space. .

[0012]

To achieve the above object, an air conditioner according to the present invention comprises an indoor heat exchanger unit, an outdoor heat exchanger unit, a compressor, a four-way valve, an expansion valve, and a connection pipe. In an air conditioner that constitutes a heat pump refrigeration cycle, condensed water generated during operation under the dew point or lower condition becomes a film on the heat exchanger air-side heat transfer surface. Is applied to the indoor heat exchanger unit, and the condensed water generated during operation under the condition of the dew point or less is condensed on the heat exchanger air-side heat transfer surface and repelled from the surface. A heat exchanger with a water-based air-side heat transfer surface and a heat exchanger with a hydrophilic air-side heat transfer surface that captures water droplets scattered from the heat exchanger with a water-repellent air-side heat transfer surface are applied to the outdoor heat exchanger unit. It is characterized by having done.

In order to achieve the above object, an air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect, wherein the heat exchanger with the hydrophilic air-side heat transfer surface is the heat exchanger according to the third or fourth aspect described below. A heat exchanger with a hydrophilic air-side heat transfer surface according to the description,
The heat exchanger with a water-repellent air-side heat transfer surface is described later.
Or a heat exchanger with a water-repellent air-side heat transfer surface according to any one of (6) and (7).

In order to achieve the above object, the heat exchanger with a hydrophilic air-side heat transfer surface according to the third aspect of the present invention is characterized in that the surface of the air-side heat transfer surface is formed with macro unevenness of several micrometers or more. A composite uneven structure in which a hydrated oxide having micro unevenness on the order of nanometers to micrometer order is formed on the surface thereof, and the effective area expansion rate of the hydrated oxide is 500 times or more. It is characterized by being.

According to a fourth aspect of the present invention, there is provided a heat exchanger with a hydrophilic air-side heat transfer surface according to the second aspect of the present invention. ,
The present invention is characterized in that the catalyst layer has a structure in which a catalyst layer having one or a plurality of functions of fungicide is formed.

To achieve the above object, a heat exchanger with a water-repellent air-side heat transfer surface according to the invention of claim 5 is characterized in that the surface of the air-side heat transfer surface has macro unevenness of several micrometers or more, Furthermore, a composite uneven structure in which a hydrated oxide having micro unevenness on the order of nanometers to micrometer order is formed on its surface, and
The effective area expansion rate of the hydrated oxide is 800 times or more, and the critical surface tension of the hydrated oxide is 20 dyn / c.
It is characterized by having a structure covered with a water-repellent coating made of a hydrophobic compound of m or less.

In order to achieve the above object, the heat exchanger with a water-repellent air-side heat transfer surface according to the invention of claim 6 is characterized in that the heat exchanger according to claim 4 has a surface on the surface of the hydrated oxide layer formed on the surface. It has a structure in which a water-repellent coating is formed using an alkoxysilane compound having a fluoro group.

In order to achieve the above object, a method of manufacturing a heat exchanger with a hydrophilic air-side heat transfer surface according to the invention of claim 7 comprises:
A step of degreasing the air-side heat transfer surface substrate made of aluminum or aluminum alloy, a step of forming macro unevenness by etching with an aqueous solution containing hydrochloric acid, and further forming a hydrated oxide having micro unevenness on the surface to form a composite On the concave-convex structure surface, and through a step of increasing the effective area expansion rate by 500 times or more, a hydrophilic air-side heat transfer surface is manufactured, and a heat exchanger is manufactured using the air-side heat transfer surface. It is a feature.

To achieve the above object, a method for manufacturing a heat exchanger with a water-repellent air-side heat transfer surface according to the invention of claim 8 comprises:
A step of degreasing the air-side heat transfer surface substrate made of aluminum or aluminum alloy, a step of forming macro unevenness by etching with an aqueous solution containing hydrochloric acid, and further forming a hydrated oxide having micro unevenness on the surface to form a composite A step of increasing the area expansion rate to 800 times or more on the surface of the uneven structure, and vaporizing a compound having a hydrophobic group having a surface energy of 20 dyn / cm or less at a critical surface tension on the surface of the air-side heat transfer surface and chemically adsorbing the compound. Then, a water-repellent air-side heat transfer surface is manufactured through a step of forming a water-repellent coating, and a heat exchanger is manufactured using the air-side heat transfer surface.

In order to achieve the above object, a method of manufacturing a heat exchanger with a hydrophilic air-side heat transfer surface or a heat exchanger with a water-repellent air-side heat transfer surface according to the invention of claim 9 is as defined in claim 6 or 7. An aluminum or aluminum alloy material having a mechanical extension of 15% or more is used as an air-side heat transfer surface material for a heat exchanger.

In order to solve the above problems, various surface treatment methods were intensively studied. As a result, the perfluoro groups having the surface energy of 20 dyn / cm or less as a critical surface tension or less at the end of the fluoroalkoxysilane compound are oriented on the surface of the air-side heat transfer surface at high density, thereby eliminating the adhesion of water droplets. It was found that adhesion of dust, dirt, and the like could be prevented, and that water repellency was maintained for a long time.

In the means, the surface of the air-side heat transfer surface is etched using an aqueous solution containing hydrochloric acid to form macro unevenness on the surface of several micrometers or more, and further, on the surface thereof, from nanometer order to several micrometers. A hydrated oxide having an orderly micro unevenness is formed to form a complex uneven structure, and the effective area expansion ratio (actual surface area / geometric area) is 800 times or more. Further, the surface energy is 20 dyn / cm or less as a critical surface tension,
Heating the fluoroalkoxysilane compound to a predetermined temperature,
By vaporizing and adsorbing on the surface of the air-side heat transfer surface, the CF ₃ group is oriented on the outermost surface of the coating, and one end has a strong binding force by chemically adsorbing with the hydroxyl group on the surface, A film having a high adhesion density can be obtained.

Further, the thickness of this coating is several tens of nanometers or less, and the unevenness formed by the underlying hydrated oxide is maintained without being filled by the coating. It will not be reduced. By forming such a coating, a high water-repellent coating that maintains water repellency can be obtained, and condensed water generated on the surface of the air-side heat transfer surface during dew condensation can be as small as several microns. Separates and scatters from surface.

On the other hand, an air-side heat transfer surface material having an area expansion ratio of 500 times or more formed with the composite unevenness by the above-mentioned method is an air having a surface having excellent hydrophilicity, high drainage performance and durability. It becomes the side heat transfer surface.

The air-side heat transfer surface having excellent hydrophilicity according to the above method is applied to an indoor heat exchanger, and the air-side heat transfer surface having excellent water repellency according to the above method is applied to an outdoor heat exchanger, and these are combined. By using an air conditioner, the increase in ventilation resistance can be suppressed, the initial performance can be maintained for a long time, and furthermore, the formation of hard frost can be achieved. realizable.

In the air conditioner of the present invention, the air-side heat transfer surface for the heat exchanger is subjected to a degreasing step, an etching step, and a hydrated oxide forming step. It can be achieved by preparing for an outdoor heat exchanger by a process of forming a hydrophobic group by gas-phase chemical adsorption on, and combining and combining these heat exchangers.

Alternatively, the air-side heat transfer surface material may be previously subjected to a hydrophilic treatment and a water-repellent treatment, and then the air-side heat transfer surface may be formed to manufacture a heat exchanger. In this case, a material having an elongation rate of 15% or more in mechanical properties of aluminum or aluminum alloy is used, so that cracks are prevented from occurring at the time of air-side heat transfer surface processing, collar formation, slit formation, and the like. Can be.

In the etching step, it is preferable to use an aqueous solution containing Cl ions, for example, an aqueous hydrochloric acid solution. Cl ions are likely to generate pitting corrosion, at a predetermined temperature and for a predetermined time,
When aluminum or an aluminum alloy is immersed in a hydrochloric acid aqueous solution, a large number of pits are generated on the surface, and macro unevenness is formed. The macro unevenness contributes to an increase in the surface area of the hydrated oxide formed in a later step.

In the hydrated oxide forming step, water, preferably deionized water, or ammonia water, carbonate,
In addition to oxalate, triethanolamine, hydrazine or seawater components, a combination of magnesium ion and hydrogen carbonate ion, a combination of magnesium, hydrogen carbonate ion and sulfate ion, a combination of hydroxide ion and lithium ion, a hydroxide ion, lithium ion And salts such as combinations of silicate ions, combinations of hydroxide ions and calcium ions, and combinations of hydroxide ions, lithium ions and nitrate ions.

Further, the antibacterial, antifouling, and antifouling materials have such a thickness that the micro unevenness formed by the hydrated oxide is not buried on the hydrated oxide on the surface of the air-side heat transfer surface for the indoor heat exchanger. mold, a catalyst layer having a deodorizing action, such as zeolite, activated carbon, T _i O ₂ such as Ag on an inorganic particle carrier of, Cu, catalysts obtained by singly or plural carrying Zn, or zeolites, the inorganic particle carrier such as activated carbon which was supported T _i O ₂ to,
Or by forming a layer made of T _i O ₂ film, odor room space, decomposing dirt such as oil adhered to the air-side heat transfer surface surface, prevention of the mold growth, antimicrobial, etc., the air-side heat transfer surface surface Can be purified, and the durability of the hydrophilic property can be improved.

[0031] In the case of use of T _i O ₂ photocatalyst,
It is preferable to install a UV lamp, a black light or the like near the heat exchanger air-side heat transfer surface. Furthermore, when the heat transfer tube that is in contact with the air-side heat transfer surface is made of a copper material, by forming an electrical insulating coating on the surface of the heat transfer tube, it is possible to prevent direct contact of dissimilar metals and further improve corrosion resistance. it can. In addition, by using a material having plasticity for the electrical insulating film, the contact thermal resistance of the air-side heat transfer surface and the heat transfer tube can be reduced.

[0032]

According to the present invention, there is provided a composite surface in which macro unevenness is formed on the air-side heat transfer surface of a heat exchanger, and a hydrated oxide having micro unevenness on the order of nanometer to micrometer is formed on the surface. By making the surface of the hydrated oxide an air-side heat transfer surface with an uneven surface, the heat exchanger using the air-side heat transfer surface having this structure has excellent hydrophilicity. Will have.

When this is used as an indoor heat exchanger at the time of cooling, the condensed water droplets generated on the surface of the air-side heat transfer surface are instantaneously formed into a film, and the drainage property is improved. Can be suppressed, heat exchange performance can be improved, and noise can be reduced. Further, the hydrated oxide on the air-side heat transfer surface has a large area. If a catalyst layer is formed thereon, the area of the catalyst layer can be increased, and the catalyst exhibits extremely high activity.

On the other hand, using a fluoroalkoxysilane having a critical surface tension of 20 dyn / cm or less on the surface of the air-side heat transfer surface, a film having a structure in which CF ₃ groups are oriented on the outermost surface by chemical adsorption was formed. In the heat exchanger using the air-side heat transfer surface, when used as an outdoor heat exchanger during heating,
The condensed water droplets generated on the air-side heat transfer surface have a small diameter of several micrometers to several tens of micrometers and are separated and scattered from the air-side heat transfer surface, and have high water repellency. The increase in the resistance is suppressed, and the frosting phenomenon hardly occurs even under the frosting condition, so that the increase of the ventilation resistance can be suppressed, the frost formation is difficult, and the defrost cycle time can be largely extended.

Further, since the surface of the air-side heat transfer surface has a complex concavo-convex structure and the surface area of the hydrated oxide is increased, fluoroalkoxysilane is directly applied to the surface of the hydrated oxide without using a solvent. Since the film is formed by adsorption, the adhesion density of the hydrophobic group is increased and the film exhibits more water repellency. Therefore, the condensed water droplets hardly adhere, and the adhesion of dirt can be prevented. Thereby, the water repellency of the air-side heat transfer surface can maintain the initial performance for a long time. Also,
Since the coating is chemically adsorbed to the hydrated oxide, the coating has high adhesion strength and durability.

Therefore, in the air conditioner combined with the above heat exchanger, it is possible to improve the heating capacity at a low temperature, reduce the power, reduce the noise, improve the durability of the heat exchanger, and the like.

In the production of a heat exchanger, a heat exchanger having high hydrophilicity and excellent durability is obtained by a series of steps.
Since a heat exchanger having high water repellency and excellent durability can be manufactured, cost can be reduced.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to FIGS. FIG. 1 is a sectional view of an indoor heat exchanger unit 1 according to the present invention. The indoor heat exchanger unit 1 has a front heat exchanger 3 having a structure in which a plurality of heat transfer tubes 5 vertically penetrate the stacked fins 4.
a, rear heat exchanger 3b, fan 6, front suction port 2
a, the upper suction port 2b.

FIG. 2 is an enlarged view of the fin portion of the heat exchanger of this embodiment. The fin 4 is provided with a number of slits 4a, and the periphery of the heat transfer tube 5 is coated with an epoxy resin 4b having a thickness of about 5 micrometers so as to be in contact with the collar portion of the fin. In this case, it is electrically insulated and corrosion is prevented.

FIG. 3 is a partially enlarged schematic view of the fin 4 of FIG. 2, and FIG. 4 is a SEM observation view thereof. An etching layer 21 having a thickness of about 4 micrometers is formed on the upper portion of the aluminum substrate 20 to form macro unevenness. Further, a hydrated oxide layer 22 having micro unevenness having a thickness of about 0.2 μm is formed on the surface.

FIG. 5 is a sectional view of an outdoor heat exchanger unit 10 according to one embodiment of the present invention. The outdoor heat exchanger unit 10 mainly scatters from the heat exchanger 16 with water-repellent fins, in which the plurality of heat transfer tubes 15 are vertically inserted into the plurality of fins 11 stacked, and the heat exchanger 16 with the water-repellent fins. It comprises a catching plate 13 also serving as a heat exchanger made of hydrophilic fins for catching water droplets, a fan 12, and a compressor 14.

FIG. 6 is a partially enlarged schematic view of the fin 11. In this embodiment, after performing the same processing as that of the fin shown in FIG. 3, a hydrophobic base layer 23 is provided on the hydrated oxide layer 22.

Next, a method for treating the surface of the fin of the heat exchanger will be described. The indoor heat exchanger including the heat transfer tubes 5 and the fins 4 and the outdoor heat exchanger including the heat transfer tubes 15 and the fins 11 are immersed in a basic degreasing solution heated to about 373K for 15 minutes to perform degreasing. Wash with water. Then, about 3
The fin surface is etched by immersing in a 1.5% hydrochloric acid aqueous solution heated to 48K for 5 minutes. Next, it is washed with water and immersed in deionized water heated to 368K or more for 10 minutes to form a hydrated oxide layer on the etched surface.
Thereafter, washing and drying are performed. The fins of the indoor heat exchanger are surface treated in this way.

The surface area of the fin was measured by the BET method to find the effective area enlargement ratio, which was 1150 times. When a water droplet is dropped on the fin surface, the water droplet instantaneously spreads on the fin surface so that the contact angle cannot be measured.
The contact angle was less than 10 degrees, indicating high hydrophilicity.

The fins for the outdoor heat exchanger are set in a vessel heated to 443 K, and the fins for the outdoor heat exchanger are vaporized in advance to heptadecatridecylfluoroalkylsilane (structural formula CF ₃ (CF ₂ ) _7. (CH ₂ ) ₂ S
i (OCH ₃ ) ₃ ) is introduced into the vessel and chemisorbed onto the fin surface. The surface of the fin for an outdoor heat exchanger produced by this surface treatment method had a contact angle of 172 degrees or more and exhibited extremely high water repellency.

The heating operation and the cooling operation of the air conditioner 100 combined with the indoor and outdoor heat exchangers manufactured as described above were performed. FIG. 7 is a system conceptual diagram of the overall structure of the air conditioner 100. In FIG. 7, the air conditioner 1
00 constitutes a heat pump refrigeration cycle,
Indoor heat exchanger 1 having hydrophilic fins arranged indoors
And an outdoor heat exchanger 10 having water-repellent fins disposed outdoors, a compressor 14 connected thereto, a four-way valve 31 and an expansion valve 32 for switching the flow of refrigerant in cooling and heating. I have.

During the cooling operation in which the four-way valve 31 is switched as shown by the solid line in the figure, the indoor heat exchanger 1 functions as an evaporator and the outdoor heat exchanger 10 functions as a condenser.
During the heating operation in which the four-way valve 31 is switched as shown by the broken line in the figure, the indoor heat exchanger 1 functions as a condenser, and the outdoor heat exchanger 10 functions as an evaporator.

During the heating operation, it was observed that most of the condensed water droplets generated on the fin surface of the outdoor heat exchanger were small water droplets having a diameter of 5 μm to 30 μm and adhered without scattering. Therefore, even in a sub-zero environment, water droplets on the fin surface are unlikely to freeze and frost.

In an air conditioner in which a conventional heat exchanger with hydrophilic fins is used as an outdoor heat exchanger, in an environment below the freezing point, for example, when the outside air temperature is 275K and the relative humidity is 85%,
Frost is formed on the fin surface, and the defrost cycle time is 30 minutes to 4
Although it is 5 minutes, in the air conditioner 100 of the present embodiment, the defrost cycle time is significantly extended to 160 minutes or more, and frost formation can be suppressed.

Observation of the behavior of water droplets scattered from the front row heat exchanger 16 revealed that about 70% of the water droplets fell to the lower drain receiver, and about 30% of the water droplets scattered to the rear.
All of the 30% water droplets were captured by the rear capturing plate 13, and no adhesion to the fan 12 was observed.

In addition, condensed water droplets generated on the fin surface of the indoor heat exchanger during the cooling operation are instantaneously formed on the film without staying as water droplets on the fin surface and fall down along the fin surface. Compared with indoor heat exchangers that adopt pre-coated fins with hydrophilic resin,
An increase in ventilation resistance can be suppressed and reduced, and noise can be reduced.

8 and 9 are electron micrographs of the fin surface of the outdoor heat exchanger showing one embodiment of the present invention. The magnification is
8 is 300 times and FIG. 9 is 30,000 times. From the photograph of FIG. 8, the etching state of the fin surface can be seen, and a large number of macro irregularities ranging from several micrometers to several tens of micrometers can be observed. When this surface is further enlarged, FIG.
It was observed that a petal-shaped micro uneven structure of several tens to several hundreds of nanometers was formed on the macro uneven surface.

When the fin surface of the indoor heat exchanger was observed with an electron microscope in the same manner, unevenness having the same shape was found. An X-ray diffraction analysis of this surface revealed that the compound having this shape was a boehmite hydrated oxide. Although a heptadecatridecylfluoroalkylsilane compound layer was formed on the surface of FIG. 9, it could not be confirmed.

As described above, the fin surface forms a complex uneven structure combining macro unevenness and micro unevenness over a wide range from nanometer order to micrometer order to increase the surface area of the hydrated oxide layer. I'm trying. Therefore, since the hydrophilic groups or the hydrophobic groups are arranged at high density on the fin surface, the fin surface of the heat exchanger exhibits high hydrophilicity or water repellency.

Next, the water repellency and the durability of the hydrophilicity of the fin material of this example were examined. The durability was evaluated by an accelerated test using a sunshine carbon arc lamp type weather resistance tester (Suga Test Machine Co., Ltd.). The dimensions of the test piece are 50 mm × 150 mm × 0.10 mm. This test piece was subjected to a hydrophilic and water-repellent surface treatment under the same conditions as in Example 1. Next, the test piece was placed in a sunshine carbon arc lamp type weather resistance tester, irradiated for a predetermined time, taken out, and a 1.0 μl water drop was dropped on the test piece to measure a contact angle.

For comparison with the present invention, heptadeca was used as a method for forming a hydrophobic group by using a test piece on which a hydrated oxide was formed after etching and a test piece on which only a hydrated oxide (boehmite) was formed. Tridecylfluoroalkylsilane is converted to a perfluorocarbon solvent (Structural formula C ₈ F ₁₈ ,
Each test piece was immersed for 30 minutes in a solution adjusted to a concentration of 3% in 3M (manufactured by Three M Co.).
A test piece formed by heating at 3K for 30 minutes and a commercially available hydrophilic resin-coated precoated aluminum fin material were also evaluated. The results are shown in Table 1 and FIG.

[0057]

[Table 1]

As can be seen from Table 1, the hydrophilic coating of the present invention did not cause any deterioration in hydrophilicity, and the irradiation time was 1000 hours.
Deterioration is hardly observed even after the time, and there is no problem with excellent durability.

As can be seen from FIG. 10, the water-repellent coating in Example 1 of the present invention maintains its initial performance even after an irradiation time of 1000 hours, and has extremely high durability. You can see that there is. On the other hand, dipping test specimens and test specimens with only boehmite treatment
In any of the test pieces used in Example 1 to which the fluorine compound was chemically adsorbed in the gas phase, the contact angle decreased with the irradiation time, and there was a problem in durability.

Further, when the fin surface etched in the same manner was coated with heptadecatridecylfluoroalkylsilane by a gas phase chemical adsorption method, the initial contact angle was 171 °, showing excellent water repellency. However, the contact angle decreased with the passage of irradiation time, and reached about 40 degrees in about 50 hours, and there was no durability of water repellency. This is presumably because the hydrated oxide is hardly formed by the etching treatment alone, the chemical adsorption of the fluorine compound is hard to occur, and the coating peels off.

In this embodiment, an insulating film made of epoxy resin is provided on the surfaces of the copper heat transfer tubes 5 and 15 on the surfaces where the copper heat transfer tubes 5 and 15 and the aluminum fins 4 and 11 constituting the heat exchanger are in contact. This prevents direct contact between copper and aluminum and enhances corrosion resistance. In addition, by using a plastic material such as a silicon resin or an acrylic resin as the insulating coating, air existing on the contact surfaces between the heat transfer tubes 5 and 15 and the fins 4 and 11 which are generated at the time of the tube expansion process. The number of layers can be reduced to reduce the contact thermal resistance. Note that the thickness of the insulating film at this time is preferably 10 μm or less from the viewpoint of heat transfer characteristics.

The problem of galvanic corrosion caused by the direct contact of dissimilar metals can be solved by manufacturing the entire heat exchanger using only aluminum or an aluminum alloy. In this case, it is easy to weld the fin to the heat transfer tube, and the problem of contact heat resistance is eliminated.

[0063]

As described above, according to the present invention,
The condensed water generated under the operating conditions below the dew point instantaneously forms a film on the surface.The heat exchanger using the air-side heat transfer surface is installed in the indoor heat exchanger unit, and the condensed water generated under the operating conditions below the dew point. Coagulation on the surface, departure, the heat exchanger using the air-side heat transfer surface scattered to the outdoor heat exchanger unit, by using the air conditioner applied, during either cooling operation or heating operation By suppressing the increase in ventilation resistance of each heat exchanger, it is possible to improve the heat exchange performance, improve the heating capacity at low temperatures, harden frost, reduce noise during operation, etc. It is possible to maintain the air conditioner with excellent durability.

In the manufacture of a heat exchanger, a heat exchanger having high hydrophilicity and a heat exchanger having high water repellency can be manufactured by a series of common steps, so that the manufacturing steps can be shortened and the cost can be reduced. Reduction can be achieved. Further, by providing the catalyst layer, antibacterial, antifungal, antifouling, and deodorizing of the indoor heat exchanger unit can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an air conditioning indoor heat exchanger unit showing one embodiment of the present invention.

FIG. 2 is a partial view of a fin of the indoor heat exchanger showing one embodiment of the present invention.

FIG. 3 is a schematic partial sectional view of a fin of an indoor heat exchanger showing one embodiment of the present invention.

FIG. 4 is an electron micrograph of a fin cross section of an indoor heat exchanger according to one embodiment of the present invention.

FIG. 5 is a sectional view of an outdoor heat exchanger unit showing one embodiment of the present invention.

FIG. 6 is a schematic partial cross-sectional view of a fin of an outdoor heat exchanger showing one embodiment of the present invention.

FIG. 7 is a conceptual diagram showing the overall structure of an air conditioner according to an embodiment of the present invention.

FIG. 8 is an electron micrograph of a fin surface of an outdoor heat exchanger according to one embodiment of the present invention.

FIG. 9 is an electron micrograph of a fin surface of an outdoor heat exchanger according to one embodiment of the present invention.

FIG. 10 shows the results of a sunshine weather test of a water-repellent film test piece according to one embodiment of the present invention.

[Explanation of symbols]

1: indoor heat exchanger unit, 3a, 3
b: indoor heat exchanger, 11: fin,
6, 12 ... fan, 15 ... heat transfer tube
10 outdoor heat exchanger unit, 1
3: capture plate, 16: outdoor heat exchanger, 20: aluminum substrate,
21: etching layer, 22: hydrated oxide layer,
23: hydrophobic base layer, 31: four-way valve
32 ... Expansion valve 100 ... Air conditioner

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Kogure 800 Tomita, Ohira, Shimotsuga-gun, Tochigi Pref.

Claims (9)

[Claims] 1. An air conditioner comprising a heat pump refrigeration cycle comprising an indoor heat exchanger unit, an outdoor heat exchanger unit, a compressor, a four-way valve, an expansion valve, a connection pipe, and the like, operated under a dew point or lower condition. Applying a heat exchanger with a hydrophilic air-side heat transfer surface in which condensed water generated at the time becomes a film on the heat exchanger air-side heat transfer surface to the indoor heat exchanger unit, and under the condition of a dew point or lower. Generated at the time of operation in the heat exchanger aggregates on the surface of the air-side heat transfer surface of the heat exchanger and separates from the surface, and the heat exchanger with the water-repellent air-side heat transfer surface and heat exchange with the water-repellent air-side heat transfer surface An air conditioner wherein a heat exchanger with a hydrophilic air-side heat transfer surface for catching water droplets scattered from a heat exchanger is applied to the outdoor heat exchanger unit. 2. The heat exchanger with a hydrophilic air side heat transfer surface according to claim 3, wherein the heat exchanger with a hydrophilic air side heat transfer surface is the heat exchanger with a hydrophilic air side heat transfer surface. The air conditioner according to claim 1, wherein the heat exchanger with a heat transfer surface is the heat exchanger with a water-repellent air-side heat transfer surface according to claim 5. 3. The surface of the air-side heat transfer surface has macro unevenness on the order of several micrometers or more, and further has a hydrated oxide having micro unevenness on the order of nanometers to micrometer on the surface. A heat exchanger with a hydrophilic air-side heat transfer surface, wherein the heat exchanger has a complex concavo-convex structure and an effective area expansion ratio of the hydrated oxide is 500 times or more. 4. The heat exchanger with a hydrophilic air-side heat transfer surface, wherein a catalyst layer having any one or more of deodorant, antifouling, antibacterial, and antifungal functions is formed on the surface of the hydrated oxide. 3. The structure according to claim 2, wherein the structure is formed.
4. The heat exchanger with a hydrophilic air side heat transfer surface according to item 1. 5. A macro unevenness of several micrometers or more is formed on the surface of the air-side heat transfer surface,
A composite uneven structure in which hydrated oxides having micro unevenness on the order of nanometers to micrometers are formed on the surface thereof, and the effective area expansion rate of the hydrated oxide is 800 times or more, and A heat exchanger having a water-repellent air-side heat transfer surface, the surface of which is coated with a water-repellent coating made of a hydrophobic compound having a critical surface tension of 20 dyn / cm or less. 6. The heat exchanger with a water-repellent air-side heat transfer surface, wherein a water-repellent coating is formed by using an alkoxysilane compound having a perfluoro group on the surface of the hydrated oxide layer formed on the surface. The heat exchanger with a water-repellent air-side heat transfer surface according to claim 4, wherein the heat exchanger has a structure in which the heat exchanger is provided. 7. A step of degreasing an air-side heat transfer surface substrate made of aluminum or an aluminum alloy, a step of forming macro unevenness by etching with an aqueous solution containing hydrochloric acid, and a step of forming a hydrated oxide having micro unevenness on its surface. Forming and forming a hydrophilic air-side heat transfer surface through a step of increasing the effective area enlargement ratio by 500 times or more on the composite uneven structure surface, and using the air-side heat transfer surface to form a heat exchanger A method for manufacturing a heat exchanger with a hydrophilic air-side heat transfer surface, which is manufactured. 8. A step of degreasing the air-side heat transfer surface substrate made of aluminum or an aluminum alloy, a step of forming macro unevenness by etching with an aqueous solution containing hydrochloric acid, and a step of forming a hydrated oxide having micro unevenness on the surface. A step of forming the composite uneven structure surface and increasing the area expansion rate to 800 times or more, and a compound having a surface energy of 20 dyn / cm or less in critical surface tension on the surface of the air-side heat transfer surface. A water-repellent air-side heat transfer surface through a process of forming a water-repellent film by vaporizing and chemically adsorbing the water-repellent film, and manufacturing a heat exchanger using the air-side heat transfer surface. Manufacturing method of heat exchanger with air-side heat transfer surface. 9. The hydrophilic material according to claim 6, wherein an aluminum or aluminum alloy material having an elongation of 15% or more is used as an air-side heat transfer surface material for a heat exchanger. A method for manufacturing a heat exchanger with an air-side heat transfer surface or a heat exchanger with a water-repellent air-side heat transfer surface.