JP4029628B2 - Anti-frosting member and heat exchanger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a frost prevention member and a heat exchanger, and more particularly to a frost prevention member and a heat exchanger that suppress frost growth.
[0002]
[Prior art and problems to be solved by the invention]
When the heat exchanger that cools the air operates at a temperature of zero degrees or less, moisture in the air frosts on the heat transfer surface of the heat exchanger. Conventionally, various techniques have been proposed in order to prevent frost from adhering to the heat exchanger.
[0003]
As a technique for preventing adhesion of frost to the metal surface, there is a technique in which a water-repellent material is applied to the metal surface to make it more hydrophobic to water than the metal substrate. Regarding water-repellent materials, in JP-A-5-115845 and JP-A-5-1177, a fluorine-based material, a silicone-based material, a polypropylene-based material, a polyethylene-based material, and a resin are used as basic materials, and roughness is imparted to them. An invention for increasing water repellency has been proposed.
[0004]
The heat exchanger can delay the initial growth of frost when such a water repellent material is applied. As a result, it is possible to prevent a rapid deterioration in the performance of heat exchange due to the rapid growth of frost and to operate for a long time.
[0005]
In addition, the water repellent material is often applied to a portion of the heat exchanger where frost formation is likely to occur. This is for the purpose of uniformly frosting the entire heat exchanger and using the entire heat exchanger as a heat exchanger, and for increasing the amount of frost that can be retained in the entire heat exchanger.
[0006]
As described above, various conventional techniques allow frost to grow uniformly and slow the growth rate. That is, the operation failure of the heat exchanger due to frost adhesion, specifically, the passage inhibition (increase in pressure loss) of the fluid to be cooled is to be delayed as much as possible.
[0007]
However, since active frosting activates heat exchange, there is a problem that the performance of the heat exchanger deteriorates when trying to prevent frosting by the water repellent film. Therefore, it has been impossible to achieve both the long-time operation of the heat exchanger by preventing frost formation and the maintenance of the heat exchange performance.
[0008]
This invention is proposed in order to solve the subject mentioned above, the frost formation prevention member which can suppress the growth of frost, and the heat exchanger which prevents the fall of heat exchange performance using it. The purpose is to provide.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, the first groove row in which a plurality of grooves are formed in parallel in a predetermined direction, and the hydrophilicity is higher than the first groove row, and the first groove row And a second groove row in which a plurality of grooves having a density lower than the density of each groove of the first groove row is formed in the intersecting direction .
[0010]
The water repellent part and the hydrophilic part are determined by their relative properties. Here, the water repellency increases in the order of, for example, a hydrophilic film, a metal substrate, and a water repellent film. Conversely, the hydrophilicity increases in the order of, for example, a water-repellent film, a metal substrate, and a hydrophilic film. Therefore, the water repellent part may be a water repellent film or a metal substrate as long as the water repellent part has a relatively higher water repellency than the hydrophilic part. Similarly, the hydrophilic part may be a hydrophilic film or a metal substrate as long as the hydrophilic part is relatively more hydrophilic than the water repellent part.
[0011]
Since the water repellent part has a relatively high water repellency, frost hardly adheres. On the other hand, frost tends to adhere to the hydrophilic portion. Therefore, frost does not grow greatly in the water repellent part, but frost grows greatly in the hydrophilic part. The frost in the hydrophilic part grows large and then collapses when it cannot resist the flow of air. And it repeats growth and collapse again.
[0012]
As described above, the first groove row in which a plurality of grooves are formed in parallel in a predetermined direction, and the hydrophilicity is higher than that of the first groove row, and the direction intersects the first groove row. And a second groove row formed with a plurality of grooves having a density lower than the density of each groove of the first groove row, thereby promoting frost growth by promoting repeated frost growth and collapse. Can be suppressed .
[0013]
According to a second aspect of the present invention, a first groove row in which a plurality of grooves are formed in parallel in a predetermined direction and a water repellent film is applied, and the first groove row in a direction intersecting the first groove row. And a hydrophilic portion formed by removing a part of the water-repellent film on the convex portion of one groove row. With such a configuration of this, the growth of frost can be suppressed to promote the repetition of frost growth and collapse.
[0015]
A third aspect of the present invention is the frost prevention member according to the first aspect, wherein the hydrophilic portion is formed by dissolving a part of the water-repellent film .
[0019]
According to a fifth aspect of the invention, together constitute at frost formation prevention member according to the heat transfer surface to claim 1, such that the direction of the second groove array is perpendicular or inclined to the wind direction on the heat transfer surface It is the heat exchanger which has arrange | positioned the said frost prevention member.
[0020]
Heat transfer surface of the heat exchanger is constituted by a frost formation prevention member according to claim 1. Furthermore, the direction of the second groove row is orthogonal or inclined with respect to the wind direction on the heat transfer surface. Thereby, the frost adhering to the second groove row comes into strong contact with the air on the heat transfer surface, and the growth / collapse cycle is accelerated. As a result, frost adhering to the heat exchanger can be suppressed as a whole. Moreover, while ensuring frost resistance by parts other than a 2nd groove row , it can be made to frost repeatedly on a 2nd groove row, and the fall of heat exchange efficiency can be suppressed.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
[0022]
[First Embodiment]
FIG. 1 is a schematic perspective view of a fin tube type heat exchanger (hereinafter referred to as “heat exchanger”) 1. The heat exchanger 1 includes a tube 10 through which a low-temperature and low-pressure refrigerant passes, and fins 20 for removing heat from air in a predetermined wind direction to obtain cold air.
[0023]
Since the fin 20 also dehumidifies the air when taking heat from the air, the condensed moisture is easily attached thereto, and frost is attached depending on the temperature of the air. Therefore, the heat transfer surface of the fin 20 is composed of a frost-preventing aluminum member that suppresses frost growth.
[0024]
The frost prevention aluminum member according to the first embodiment is manufactured by the following manufacturing method from the first step to the third step, for example.
[0025]
In the first step, water-resistant paper is hung in a predetermined direction (X-axis direction) on the surface of the plate-like aluminum member 31.
[0026]
2A is a perspective view of the aluminum member 31 after the first step, and FIG. 2B is a cross-sectional view of the aluminum member 31 as viewed from the X-axis direction. Through the first step, kerfs 32 parallel to the X axis are formed on the surface of the aluminum member 31 (hereinafter referred to as “uneven surface 34”), and convex portions 33 are formed between the kerfs 32. The The surface roughness Rs = 20 μm.
[0027]
The processing method of the concavo-convex surface 34 may be any of cutting, laser processing, and etching in addition to the above-described water-resistant paper hanging, and is not particularly limited. Further, the surface roughness Rs is not particularly limited as long as it is μm to mm.
[0028]
In the second step, a water repellent film is applied to the uneven surface 34, and the water repellent film is baked and fixed as necessary.
[0029]
In the third step, water-resistant paper is hung on the uneven surface 34 in the Y-axis direction orthogonal to the X-axis. Here, it is necessary to use a water-resistant paper finer than the water-resistant paper used in the first step, and the surface roughness Rs <20 μm.
[0030]
FIG. 3A is a perspective view of the frost prevention aluminum member according to the first embodiment after the third step, and FIG. 3B is a cross-sectional view of the frost prevention aluminum member viewed from the Y-axis direction. is there. By the third step, the upper portion of the convex portion 33 is cut in the Y-axis direction, and the cutout portion 35 is formed. That is, on the uneven surface 34, a plurality of cutout portions 35 that are fresh surfaces of the aluminum substrate appear discretely.
[0031]
The cutting direction in the third step is not limited to the Y-axis direction, and may be other oblique directions. That is, if the notches 35 appear discretely, the cutting direction in the third step is not particularly limited. The reason for setting the surface roughness Rs <20 μm is to make the notches 35 appear discretely on the uneven surface 34.
[0032]
Thus, by cutting the surface of the aluminum member 31 in two directions, two effects can be obtained.
[0033]
First, the water-repellent effect can be improved by forming the uneven surface 34 in the first step and applying a water-repellent film in the second step. This is because the Wenzel effect is generated by the water repellent film and the fine roughness. Therefore, the uneven surface 34 is preferably as fine as possible.
[0034]
Second, by cutting the upper portion of the convex portion 33 in the Y-axis direction in the third step, the notched portions 35 having a discrete lattice pattern can be easily formed. The notch 35 is 20 μm in the present embodiment, and is preferably μm or more as will be described later.
[0035]
The ratio of the total area of the notches 35 to the area of the surface of the water-repellent film on the uneven surface 34 (hereinafter referred to as “water-repellent surface”) can be arbitrarily determined from 0% to 100%. In this embodiment,
(Water repellent surface): (Notch) = 5: 1
It was.
[0036]
Next, the relationship between the frost prevention aluminum member and the wind direction will be described.
[0037]
The water repellent surface and the fresh surface have different frost growth rates, particularly the initial growth rate. Here, the fresh surface functions like a hydrophilic surface due to a relative relationship with the water repellent surface. The growth rate of frost on the water repellent surface is slower than the growth rate of frost on the hydrophilic surface. Therefore, small frost is formed on the water repellent surface, while large frost is formed on the hydrophilic surface. This is a state in which weak frost is planted on the hydrophilic surface. When the grown frost can't resist the wind, it collapses. And frost grows again and repeats to collapse when it can't resist the wind.
[0038]
In order to repeat frost growth and collapse, it is necessary to receive as much wind as possible. In FIG. 3A, since the distance between the notches 35 in the X-axis direction is long, the direction of the frost haze is the Y-axis direction. On the other hand, the wind direction is the X-axis direction. Therefore, this frost is susceptible to wind, so the growth / collapse cycle is faster.
[0039]
FIG. 4 is a diagram illustrating the frost formation height with respect to time of the frost prevention aluminum member. The test conditions are 0 ° C. and a relative humidity of 85%, and the surface temperature is −10 ° C. The water repellent material has an ethylene group that is hydrophobic. For comparison, the “non-treated surface” (aluminum member not subjected to any treatment) and the “water repellent surface” (aluminum member coated with a water repellent material) are also illustrated. Further, “orthogonal to the wind direction” indicates that the direction of the frost haze is orthogonal to the wind direction, and “parallel to the wind direction” indicates that the direction of the frost haze is parallel to the wind direction. The same applies to FIG. 5 described later.
[0040]
As shown in FIG. 4, the growth rate of frost on the “water repellent surface” was slower than that on the “untreated surface”, and the difference in the growth increased with time. In the case of “parallel to the wind direction”, the growth rate of the frost was not significantly different from that of the “water repellent surface”. However, in the case of “perpendicular to the wind direction”, the growth rate of the frost was slower than that of the “water repellent surface”. That is, by considering the direction of the frost haze and the wind direction, the frost growth rate can be changed, and when the direction of the frost haze is orthogonal to the wind direction, the frost growth rate is the slowest. That is, the growth of frost was most suppressed.
[0041]
FIG. 5 is a view showing the frost formation height with respect to time of the frost prevention aluminum member. The test conditions and the like are the same as in FIG. 4 except that the water repellent material is a hydrophobic fluorine group. As shown in FIG. 5, in the case of “perpendicular to the wind direction”, the growth rate of frost was the slowest and a remarkable effect could be obtained.
[0042]
In this case, especially at the frost detection point 0.878 mm above the surface, no further frost arrives even after 3 hours from the start of the experiment, and it is possible to indirectly confirm frost growth and collapse. did it. Moreover, when the experimental result of FIG. 4 was compared, it turned out that the growth of frost can be suppressed, so that the water-repellent effect is excellent.
[0043]
As described above, the heat exchanger 1 using the frost-preventing aluminum member according to the present embodiment uses the difference in frost growth rate between the water-repellent surface and the hydrophilic surface, and the frost on the hydrophilic surface grows and collapses. By repeating the pattern formation of the water repellent surface and the hydrophilic surface, the overall frost growth can be suppressed. Furthermore, by arranging the direction of the frost haze so as to be substantially orthogonal to the wind direction, the cycle of frost growth / collapse can be promoted, and as a result, frost growth can be greatly suppressed. As a result, by delaying the growth of frost to a certain height, it is possible to operate for a long time while avoiding the situation where frost is buried between fins and air cannot pass therethrough.
[0044]
Moreover, while ensuring frost resistance by a water repellent surface, the fall of heat exchange efficiency can be suppressed by making it frost repeatedly on a hydrophilic surface.
[0045]
That is, the heat exchanger 1 not only suppresses the growth of frost on the heat transfer surface but also improves the heat exchange rate as compared with the conventional one and enables continuous operation.
[0046]
In addition, the manufacturing method of an anti-frosting aluminum member is not limited to the above-described method, and other methods may be used as long as an independent region with reduced water-repellent effect exists in the water-repellent surface. . For example, the super water-repellent film may be dissolved so that the metal substrate appears discretely on the uneven surface 34 coated with the super water-repellent material.
[0047]
In addition, for example, a hydrophilic film may be discretely applied to the aluminum member 31 with a metal base except the first step. Thereby, the metal substrate can function like a water-repellent film due to the relative relationship between the metal substrate and the hydrophilic film.
[0048]
[Second Embodiment]
Next, a frost prevention aluminum member according to the second embodiment will be described. In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment, and the overlapping description is abbreviate | omitted.
[0049]
FIG. 6 is a perspective view showing an anti-frosting aluminum member according to the second embodiment. This anti-frosting aluminum member is manufactured in substantially the same manner as the manufacturing method described in the first embodiment, but in the third step, a water resistant paper finer than the first embodiment is applied. It has been. Therefore, as shown in the figure, the convex portion 33 is formed with a plurality of cutout portions 35 that are finer than those of the first embodiment.
[0050]
Since the interval between the adjacent notch portions 35 on the X axis is short, the notch portions 35 are arranged along the X axis direction, and frost is also formed in the X axis direction. Therefore, in order to allow the frost haze to efficiently hit the wind, the frost prevention aluminum member is arranged so that the wind direction is the Y-axis direction. Thereby, the said frost prevention aluminum member can suppress the growth of frost similarly to 1st Embodiment.
[0051]
Of course, in the present embodiment, the method for manufacturing the frost-preventing aluminum member is not particularly limited.
[0052]
[Third to Fourteenth Embodiments]
Hereinafter, the frosting prevention metal member according to the third to fourteenth embodiments will be described with reference to a manufacturing method.
[0053]
FIG. 7A is a perspective view of a frost prevention metal member according to the third embodiment, and FIG. 7B is an enlarged cross-sectional view of the frost prevention metal member. The frost prevention metal member according to the third embodiment is manufactured, for example, by the following manufacturing method.
[0054]
First, a water repellent film 42 is formed by applying a water repellent material to the surface of the plate-like metal member 41. Next, a straight groove 43 having a rectangular cross section is formed at predetermined intervals in a predetermined direction, and a part of the water repellent film 42 is removed.
[0055]
Since the frost prevention metal member comprised as mentioned above has the groove | channel 43 whose cross section is a rectangle, it can enlarge the area of a metal base. Therefore, when wind power is large, the growth / collapse of large frost can be further promoted, and the amount of heat exchange can be increased.
[0056]
FIG. 8A is a perspective view of a frost prevention metal member according to the fourth embodiment, and FIG. 8B is an enlarged cross-sectional view of the frost prevention metal member. The frost prevention metal member according to the fourth embodiment is manufactured by, for example, the following manufacturing method.
[0057]
First, a water repellent film 42 is formed by applying a water repellent material to the surface of the plate-like metal member 41. Next, a trapezoidal and straight groove 43 is formed at predetermined intervals in a predetermined direction, and a part of the water repellent film 42 is removed.
[0058]
Since the frost prevention metal member configured as described above has the trapezoidal groove 43 in cross section, the area of the metal substrate can be increased. Therefore, when wind power is large, the growth / collapse of large frost can be further promoted, and the amount of heat exchange can be increased. Furthermore, the ratio of the water-repellent film 42 and the metal substrate can be arbitrarily set by adjusting the trapezoidal shape (the length of each of the upper base and the lower base, the length from the upper base to the lower base).
[0059]
FIG. 9A is a perspective view of a frost prevention metal member according to the fifth embodiment, and FIG. 9B is an enlarged sectional view of the frost prevention metal member. The frost prevention metal member according to the fifth embodiment is manufactured by, for example, the following manufacturing method.
[0060]
First, a water repellent film 42 is formed by applying a water repellent material to the surface of the plate-like metal member 41. Next, a groove 43 having a circular arc shape and a straight line is formed at predetermined intervals in a predetermined direction, and a part of the water repellent film 42 is removed.
[0061]
Since the frosting prevention metal member comprised as mentioned above has the groove | channel 43 whose cross section is circular arc shape, the frost formed on the groove | channel 43 mutually interferes. This causes the frost to collapse even if it receives less wind. Therefore, the dependence on the wind direction can be reduced, and the degree of freedom in the installation direction can be increased.
[0062]
FIG. 10A is a perspective view of a frost prevention metal member according to the sixth embodiment, and FIG. 10B is an enlarged sectional view of the frost prevention metal member. On the surface of the metal member 51 (hereinafter referred to as “uneven surface 52”), parallel grooves 53 are formed along a predetermined direction. The cross section of the groove 53 is wedge-shaped. The frost prevention metal member according to the sixth embodiment is manufactured by, for example, the following manufacturing method.
[0063]
First, the water repellent film 54 is applied to the uneven surface 52 of the metal member 51. Next, the water repellent film 54 formed in the groove 53 is removed every predetermined number. In this embodiment, every other water-repellent film 54 formed in the groove 53 is removed.
[0064]
The anti-frosting metal member configured as described above can reinforce the water-repellent effect, and the frost formed in the groove 53 interferes with each other to suppress the overall growth of frost. Can do.
[0065]
FIG. 11A is a perspective view of a frost prevention metal member according to the seventh embodiment, and FIG. 11B is an enlarged cross-sectional view of the frost prevention metal member. The metal member 51 is configured similarly to the sixth embodiment. Further, the apex angle θ of the convex portion constituted by the adjacent grooves 53 is set to be within 90 degrees. The frost prevention metal member according to the seventh embodiment is manufactured by, for example, the following manufacturing method.
[0066]
First, the water repellent film 54 is applied to the uneven surface 52 of the metal member 51. Next, the water repellent film 54 formed on one side surface of each groove 53 is removed.
[0067]
Since the frost prevention metal member comprised as mentioned above makes the other side surface collide the frost growing on one side surface of the groove | channel 53, it can suppress the growth of frost.
[0068]
FIG. 12A is a perspective view of a frost prevention metal member according to the eighth embodiment, and FIG. 12B is an enlarged cross-sectional view of the frost prevention metal member. Although it is substantially the same as 7th Embodiment, it differs only in that apex angle (theta) of the convex part comprised by the adjacent groove | channel 53 is 90 degree | times or more.
[0069]
The frost prevention metal member configured as described above grows without causing frost attached to one side surface of the groove 53 to collide with the other side surface. And the growth of frost can be suppressed by collapsing the frost with a wind pressure.
[0070]
FIG. 13 is a perspective view of a frost prevention metal member according to the ninth embodiment. The frost prevention metal member according to the present embodiment is manufactured as follows. First, a water repellent film 62 is formed by applying a water repellent material to the plate-shaped metal member 61. Next, the surface of the metal member 61 covered with the water repellent film 62 is scraped off like sandblast.
[0071]
The anti-frosting metal member configured as described above can obtain the metal substrate 63 that is uniformly distributed two-dimensionally, and can be installed in any direction regardless of the wind direction.
[0072]
FIG. 14 is a sectional view of a frost prevention metal member according to the tenth embodiment. The said frost prevention metal member is manufactured as follows. First, a water repellent film 72 is formed by applying a water repellent material on the surface of the metal member 71 on which the metal substrate appears. Next, the water repellent film 72 is removed in a predetermined pattern (every predetermined interval). Thereby, the frost formation prevention metal member can suppress the overall growth of frost similarly to 1st Embodiment.
[0073]
FIG. 15 is a cross-sectional view of a frost prevention metal member according to the eleventh embodiment. The said frost prevention metal member is manufactured as follows. First, a water repellent film 72 is formed by applying a water repellent material on the surface of the metal member 71 on which the metal substrate appears. Next, the water repellent film 72 is removed in a predetermined pattern (every predetermined interval). Finally, the part from which the water repellent film has been removed is hydrophilized to form a hydrophilic film 73. Thereby, the frost formation prevention metal member can suppress the overall growth of frost similarly to 1st Embodiment.
[0074]
FIG. 16 is a cross-sectional view of a frost prevention metal member according to the twelfth embodiment. The said frost prevention metal member is manufactured as follows. First, the hydrophilic film 73 is formed on the surface of the metal member 71 on which the metal substrate appears. Next, the hydrophilic film 73 is removed in a predetermined pattern (every predetermined interval). At this time, the metal substrate functions like a water-repellent film due to the relative relationship between the metal substrate and the hydrophilic film 73. Thereby, the frosting prevention metal member can acquire the effect similar to 1st Embodiment by adjusting the ratio which removes the hydrophilic film | membrane 73. FIG.
[0075]
FIG. 17 is a sectional view of a frost prevention metal member according to a thirteenth embodiment. The said frost prevention metal member is manufactured as follows. First, the hydrophilic film 73 is formed on the surface of the metal member 71 on which the metal substrate appears, and the water repellent film 72 is further formed thereon. Then, the water repellent film 73 is removed in a predetermined pattern. The frosting prevention metal member is easily subjected to hydrophilic treatment as compared with the twelfth embodiment. A connectable buffer layer may be provided at the interface between the water repellent film 72 and the hydrophilic film 73.
[0076]
FIG. 18 is a cross-sectional view of a frost prevention metal member according to the fourteenth embodiment. The said frost prevention metal member is manufactured as follows. First, the water repellent film 72 is formed on the surface of the metal member 71 on which the metal substrate appears, and the hydrophilic film 73 is further formed thereon. Then, the hydrophilic film 72 is removed in a predetermined pattern. The frosting prevention metal member can obtain the same effects as those of the thirteenth embodiment. A connectable buffer layer may be provided at the interface between the water repellent film 72 and the hydrophilic film 73.
[0077]
Although the first to fourteenth embodiments have been described above, the present invention is not limited to these descriptions, and various design changes are made within the scope described in the claims. be able to.
[0078]
For example, although the first and second embodiments have been described by taking aluminum as an example of the metal member, other metals such as copper may be used. Also in the third to fourteenth embodiments, the metal member is not particularly limited. Of course, specific materials for the water-repellent film and the hydrophilic film and the method for producing the anti-frost metal member are not particularly limited.
[0079]
【The invention's effect】
Frost prevention member according to the present invention can encourage the growth and collapse of the frost adhering to the parent water portion, to suppress the overall growth of the frost.
[0081]
Heat exchanger according to the present invention is to constitute the heat transfer surface in the frost prevention member, by the direction of the second groove row is orthogonal or inclined wind direction on the heat transfer surface, the second groove array The frost that adheres to the heat transfer surface is strongly applied to the air on the heat transfer surface, thereby speeding up the cycle of the growth and collapse of the frost, thereby suppressing the overall growth of the frost.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a fin tube type heat exchanger.
2A is a perspective view of an aluminum member after the first step, and FIG. 2B is a cross-sectional view of the aluminum member as viewed from the X-axis direction.
3A is a perspective view of the frost prevention aluminum member according to the first embodiment after the third step, and FIG. 3B is a cross-sectional view of the frost prevention aluminum member when viewed from the Y-axis direction. FIG.
FIG. 4 is a diagram showing a frost formation height with respect to time of a frost prevention aluminum member.
FIG. 5 is a diagram showing the frost formation height with respect to time of a frost prevention aluminum member.
FIG. 6 is a perspective view showing a frost prevention aluminum member according to a second embodiment.
7A is a perspective view of a frost prevention metal member according to a third embodiment, and FIG. 7B is an enlarged cross-sectional view of the frost prevention metal member.
FIG. 8A is a perspective view of a frost prevention metal member according to a fourth embodiment, and FIG. 8B is an enlarged cross-sectional view of the frost prevention metal member.
FIG. 9A is a perspective view of a frost prevention metal member according to a fifth embodiment, and FIG. 9B is an enlarged cross-sectional view of the frost prevention metal member.
10A is a perspective view of a frost prevention metal member according to a sixth embodiment, and FIG. 10B is an enlarged cross-sectional view of the frost prevention metal member.
11A is a perspective view of a frost prevention metal member according to a seventh embodiment, and FIG. 11B is an enlarged cross-sectional view of the frost prevention metal member.
12A is a perspective view of a frost prevention metal member according to an eighth embodiment, and FIG. 12B is an enlarged cross-sectional view of the frost prevention metal member.
FIG. 13 is a perspective view of a frost prevention metal member according to a ninth embodiment.
FIG. 14 is a cross-sectional view of a frost prevention metal member according to a tenth embodiment.
FIG. 15 is a cross-sectional view of a frost prevention metal member according to an eleventh embodiment.
FIG. 16 is a cross-sectional view of a frost prevention metal member according to a twelfth embodiment.
FIG. 17 is a cross-sectional view of a frost prevention metal member according to a thirteenth embodiment.
FIG. 18 is a cross-sectional view of a frost prevention metal member according to a fourteenth embodiment.
[Explanation of symbols]
31 Aluminum member 32 Cut groove 33 Convex part 34, 52 Uneven surface 35 Notch part 41, 51, 61, 71 Metal member 42, 54, 62, 72 Water repellent film 43, 53 Groove 63 Metal substrate 73 Hydrophilic film

Claims (4)

A first groove row in which a plurality of grooves are formed in parallel in a predetermined direction;
A second groove array in which a plurality of grooves having a higher hydrophilicity than the first groove array and shallower than each groove of the first groove array are formed in a direction intersecting the first groove array. When,
The frost prevention member provided with . A first groove row in which a plurality of grooves are formed in parallel in a predetermined direction and a water repellent film is applied;
A hydrophilic portion formed by removing a part of the water-repellent film on the convex portion of the first groove row in a direction intersecting the first groove row;
The frost prevention member provided with . The hydrophilic portion was formed by dissolving a part of the water repellent film.
The frost prevention member according to claim 2 . Together comprise a frost formation prevention member according to the heat transfer surface to claim 1, placing the frost prevention member such that the direction of the second groove array is perpendicular or inclined to the wind direction on the heat transfer surface Heat exchanger.

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