CN117781516A

CN117781516A - Heat exchanger

Info

Publication number: CN117781516A
Application number: CN202311258215.9A
Authority: CN
Inventors: 朴敏济; 朴珉洙; 金炯范; 金周赫; 李成燮
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2022-09-29
Filing date: 2023-09-26
Publication date: 2024-03-29
Also published as: US20240110755A1; KR20240044900A; EP4345407A1

Abstract

The heat exchanger of the present invention is characterized by comprising: a plurality of refrigerant pipes through which a refrigerant flows; fins arranged between the refrigerant tubes adjacent to each other to transfer heat; and a sacrificial plate, one surface of which is in contact with the refrigerant tube and the other surface of which is in contact with the fin; the sacrificial sheet has a corrosion potential lower than that of the refrigerant tube.

Description

Heat exchanger

Technical Field

The present invention relates to a heat exchanger having high corrosion resistance.

Background

In general, a heat exchanger can be used as a condenser or an evaporator in a refrigeration cycle apparatus including a compressor, a condenser, an expansion mechanism, and an evaporator.

The heat exchanger is provided in a vehicle, a refrigerator, or the like, and exchanges heat between the refrigerant and air.

The heat exchanger may be classified into a finned tube type heat exchanger, a microchannel heat exchanger, etc. according to the structural division.

In recent years, heat exchanger materials have replaced copper with aluminum for reasons of price, processing difficulty, corrosion resistance, and the like. This is because the aluminum material is lightweight, inexpensive, and has high thermal conductivity.

As the aluminum material for heat exchangers, a pure aluminum system (A1 XXX) which is advantageous in extrusion, has high thermal conductivity, and is inexpensive, and an aluminum-manganese system (A3 XXX) which has a slightly lower extrusion performance than the pure aluminum system, but has relatively high strength and corrosion resistance, are mainly used.

Table 1 shows the components a1070 and a3003 that have been mainly used as aluminum materials for heat exchangers. A1070 is a pure aluminum material, and a3003 is an aluminum-manganese material.

TABLE 1

Material name	Cu	Si	Fe	Zn	Mg	Mn	Ti	Al
									A1070	0.03	0.20	0.25	0.04	0.03	0.03	0.03	Residual of
A3003	0.158	0.084	0.421	0.034	0.001	1.021	0.014	Residual of

The material of the a1070 material is inexpensive and does not require high strength, and therefore is used as a tube and fin material (fin) for condensers and the like of home appliances such as air conditioners, refrigerators and the like, for which economic efficiency is important. In contrast, the material a3003 is excellent in strength and corrosion resistance as compared with the material a1070, but has a slightly high extrusion cost, and is therefore used as an extruded tube and fin material for heat exchangers such as an intercooler and a radiator for automobiles.

On the other hand, aluminum is a metal that is easily activated, but in air, an oxide film is formed on the surface thereof, and has high corrosion resistance. In the case where aluminum is corroded, pitting corrosion (Pitting Corrosion) occurs in which corrosion occurs only in a local region where the oxide film is damaged. In addition, corrosion is locally concentrated and diffused by electric and chemical actions with various impurities contained in the aluminum alloy. By the corrosion principle of aluminum, the aluminum heat exchanger is partially penetrated, and the refrigerant or the high-temperature fluid inside is leaked.

In patent document 1, in order to prevent such corrosion, the contents of copper, silicon, iron and zirconium are adjusted, and the zirconium element is used to control corrosion products, leading to uniform corrosion properties.

However, in the case of patent document 1, zirconium is a rare metal which is expensive, and the manufacturing cost is high, and when the fin and the tube are brazed at high temperature, elements of the material lose many corresponding characteristics during recrystallization, so that there is a problem that it is difficult to use it in mass production.

Referring to fig. 7, in the prior art, in order to prevent corrosion, a method of coating zinc particles 203 on a tube 204 and brazing with fins 201 is used. The fins 201 are typically coated with a cladding 202.

However, as shown in fig. 8 and 9, in the process of melting the fin 201 and zinc, there are a region in which the zinc concentration is too high (a portion of the tube 204 close to the fin 201) and a region in which the zinc concentration is too low because the zinc concentration is not constant. In addition, there are technical limitations to the manner in which zinc is applied, resulting in quality deviations in terms of accurate coating quantity and uniformity.

Therefore, as shown in fig. 10, the fins 201 and the tubes 204 are peeled off in the region where the zinc concentration is too high, and there is a problem that corrosion starts in the region where the zinc concentration is too low.

Prior art literature

Patent literature

Patent document 1-Korean laid-open publication No. 20150035416

Disclosure of Invention

The present invention provides a heat exchanger which prevents corrosion of fins and tubes and prevents the fins from being peeled off from the tubes by using sacrificial sheets having a potential difference.

Another object of the present invention is to provide a heat exchanger that can be easily manufactured and that can reduce manufacturing costs by using a sacrificial sheet on the outer surface of a tube.

Another object of the present invention is to provide a heat exchanger in which a sacrificial plate is easily aligned with and bonded to the outer surface of a tube.

The problems of the present invention are not limited to the above-described problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

The heat exchanger of the present invention is characterized in that the corrosion potential of the sacrificial sheet between the fin and the refrigerant tube is lower than the corrosion potential of the refrigerant tube.

In the heat exchanger according to the present invention, the sacrificial sheet between the fin and the refrigerant tube is zinc.

Specifically, the heat exchanger of the present invention is characterized by comprising: a plurality of refrigerant pipes through which a refrigerant flows; fins arranged between the refrigerant tubes adjacent to each other and transferring heat; and a sacrificial plate, one surface of which is in contact with the refrigerant tube and the other surface of which is in contact with the fin; the sacrificial sheet has a corrosion potential lower than that of the refrigerant tube.

The sacrificial sheet may have a corrosion potential lower than the corrosion potential of the fin.

The corrosion potential of the fins may be lower than the corrosion potential of the refrigerant tubes.

The sacrificial sheet may comprise zinc or an alloy of zinc and aluminum.

The fin may include at least one of aluminum, copper, and an aluminum alloy.

The refrigerant pipe may include at least one of aluminum, copper, and an aluminum alloy.

The sacrificial sheets may be disposed at the top and bottom surfaces of the refrigerant tube.

The sacrificial sheet may include a first region and a second region stepped with the first region.

The second region may be formed such that a portion of the first region protrudes.

The second region may protrude toward the refrigerant tube contacting the sacrificial sheet.

The second region may be formed by recessing a portion of the first region.

The refrigerant pipe may include a matching portion corresponding to the second region.

The width of the first region may be greater than the width of the second region.

The sacrificial sheet may have a thickness greater than a thickness of the fin.

The thickness of the refrigerant tube may be greater than the thickness of the sacrificial sheet.

The interior of each of the refrigerant tubes may include a plurality of micro-channels.

The present invention may further include a header coupled to one end of the plurality of refrigerant tubes and supplying refrigerant to the inside of the plurality of refrigerant tubes.

The material of the sacrificial sheet may be different from the material of the fins and the refrigerant tube.

Drawings

Fig. 1 is a diagram showing a refrigeration cycle apparatus according to an embodiment of the present invention.

Fig. 2 is a perspective view illustrating the outside of the outdoor unit shown in fig. 1.

Fig. 3 is a perspective view of a heat exchanger according to an embodiment of the present invention.

Fig. 4 is a longitudinal sectional view of the heat exchanger shown in fig. 3.

Fig. 5 is a cross-sectional view taken along line 5-5' of fig. 4.

Fig. 6a is a cross-sectional perspective view of fig. 5.

Fig. 6b is an enlarged view of a portion of fig. 6 a.

Fig. 7 and 8 are diagrams showing a bonding method of a fin and a tube of the related art.

Fig. 9 is a zinc profile of fig. 8.

FIG. 10 is a diagram of a prior art fin and tube separation.

Detailed Description

The advantages, features and methods of implementing the present invention will become more apparent from the following detailed description of embodiments with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various forms different from each other, and the present embodiment is provided only for fully disclosing the present invention to those skilled in the art, and fully disclosing the scope of the present invention, which is determined only by the scope of the claims. Throughout the specification, the same constituent elements are given the same reference numerals.

As shown in the figures, the terms "lower", "upper", and the like, which are spatially relative terms, may be used for ease of explanation of the interrelationship between one component and another component. Spatially relative terms, when used or acted upon, are understood to comprise terms of orientation of the elements which differ from one another in the direction shown in the figures. For example, when the components shown in the drawings are inverted, the component described as "lower" or "lower" of the other component may be provided on "upper" of the other component. Thus, the exemplary term "lower" may include both lower and upper directions. The constituent elements may be arranged in other directions, and thus, spatially relative terms may be construed according to the direction of arrangement.

The terminology used in the description is for the purpose of describing embodiments only and is not intended to be limiting of the invention. In this specification, unless specifically mentioned otherwise, phrases in the singular include plural. The use of "comprising" and/or "including … …" in the specification does not preclude the presence or addition of one or more other components, steps and/or acts than the present components, steps and/or acts.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification can be used as commonly understood by one of ordinary skill in the art to which this invention belongs. Furthermore, terms defined in a dictionary that are commonly used should not be interpreted perfectly or excessively unless specifically defined explicitly.

For convenience and clarity of illustration, thicknesses or dimensions of the respective constituent elements are exaggerated, omitted, or schematically illustrated in the drawings. In addition, the size and area of each constituent element do not fully reflect the actual size or area.

In addition, in describing the structure of the embodiment, the angles and directions mentioned are based on the drawings. In the description, in the description of the structure constituting the embodiment, reference should be made to the related drawings without explicitly referring to the reference points of angles and positional relationships.

The present invention will be specifically described below with reference to the drawings.

Fig. 1 is a view illustrating a refrigeration cycle apparatus according to an embodiment of the present invention, and fig. 2 is a perspective view illustrating an outside of an outdoor unit shown in fig. 1.

Referring to fig. 1 to 2, the refrigeration cycle apparatus of the present embodiment may include: a compressor 10 compressing a refrigerant; an outdoor heat exchanger 11 for exchanging heat between the refrigerant and the outdoor air; an expansion mechanism 12 that expands the refrigerant; and an indoor heat exchanger 13 for exchanging heat between the refrigerant and the indoor air.

The refrigerant compressed in the compressor 10 may be condensed by heat exchange with outdoor air through the outdoor heat exchanger 11.

The outdoor heat exchanger 11 may be used as a condenser.

The refrigerant condensed in the outdoor heat exchanger 11 may flow to the expansion mechanism 12 and expand. The refrigerant expanded by the expansion mechanism 12 can be heat-exchanged with indoor air through the indoor heat exchanger 13 and evaporated.

The indoor heat exchanger 13 may be used as an evaporator that evaporates the refrigerant. The refrigerant evaporated in the indoor heat exchanger 13 may be recovered to the compressor 10.

The heat exchangers may include an indoor heat exchanger 13 and an outdoor heat exchanger 11.

The refrigerant may circulate through the compressor 10, the outdoor heat exchanger 11, the expansion mechanism 12, and the indoor heat exchanger 13, and may be operated in a refrigeration cycle.

A compressor 10 suction flow path that guides the refrigerant passing through the indoor heat exchanger 13 to the compressor 10 may be connected to the compressor 10. The compressor 10 may be provided with an accumulator 14 for accumulating liquid refrigerant in a suction flow path.

The indoor heat exchanger 13 may be formed with a refrigerant flow path through which the refrigerant passes.

The refrigeration cycle apparatus may be a split type air conditioner in which the indoor unit I and the outdoor unit O are separated, and in this case, the compressor 10 and the outdoor heat exchanger 11 may be provided inside the outdoor unit O. The refrigeration cycle device may be a refrigerator, and the indoor heat exchanger 13 may be configured to exchange heat with air in the food storage, and the outdoor heat exchanger 11 may be configured to exchange heat with air outside the food storage. In the case of a refrigerator, the indoor unit I and the outdoor unit O may be configured with the main body.

The expansion mechanism 12 may be provided at either the indoor unit I or the outdoor unit O.

The indoor heat exchanger 13 may be disposed inside the indoor unit I.

The outdoor unit O may be provided with an outdoor fan 15 that blows outdoor air to the outdoor heat exchanger 11. The compressor 10 may be provided in the machine room of the outdoor unit O.

An indoor fan 16 that blows indoor air toward the indoor heat exchanger 13 may be provided at the indoor unit I.

In the conventional heat exchange, since the refrigerant is in a state in which the liquid state and the vapor state are mixed, there is a problem in that the vapor state and the liquid state unevenly flow when the abnormal refrigerant flowing in the inside of the header flows into the refrigerant tube.

The heat exchanger 100 according to the present invention for solving such a problem will be described in detail below.

Fig. 3 is a perspective view of a heat exchanger according to an embodiment of the present invention, fig. 4 is a longitudinal sectional view of the heat exchanger shown in fig. 3, and fig. 5 is a sectional view taken along line 5-5' in fig. 4.

Referring to fig. 3 to 5, the heat exchanger 100 is a device that exchanges heat between a refrigerant in a refrigeration cycle and outside air. The heat exchanger 100 preferably distributes refrigerant uniformly inside, with a large heat transfer area.

The heat exchangers 100 may be arranged in a plurality of columns, or the direction of the refrigerant traveling in one column may be alternately changed.

For example, the heat exchanger 100 includes: a plurality of refrigerant tubes 50 through which a refrigerant flows; fins 60 disposed between the refrigerant tubes 50 adjacent to each other and transmitting heat; and a sacrificial plate 90 having one surface in contact with the refrigerant tube 50 and the other surface in contact with the fin 60.

In addition, the heat exchanger 100 further includes: a header 70 coupled to one end of the plurality of refrigerant tubes 50 and supplying a refrigerant to the inside of the plurality of refrigerant tubes 50; an outer tube 110 inside the header 70; and an inner tube 120 inside the outer tube 110.

The refrigerant pipe 50 has a minute inner diameter so that the refrigerant flows inside and the contact area with air is maximized. A plurality of refrigerant tubes 50 are connected to a header 70. The refrigerant tube 50 extends in a direction intersecting the header 70.

Specifically, the refrigerant tubes 50 may be disposed long in the horizontal (front-rear) direction (LeRi), and a plurality of refrigerant tubes 50 may be stacked in the vertical (longitudinal) (UD). The air passes through spaces between the plurality of refrigerant tubes 50 stacked in the vertical direction and exchanges heat with the refrigerant in the refrigerant tubes 50. The plurality of horizontally stacked refrigerant tubes 50 define a heat exchange surface together with fins 60 described later.

The interior of the refrigerant tube 50 may include a plurality of micro-channels 50a. The plurality of micro channels 50a provide a space for the refrigerant to pass through. The plurality of micro channels 50a may extend in a direction side by side with the refrigerant tube 50.

Specifically, as shown in fig. 5, the cross-sectional shape of the refrigerant tube 50 may be a quadrilateral shape having a larger width in the left-right direction than in the up-down direction, and the cross-sectional shape of the microchannel 50a may be a quadrilateral shape.

The microchannels 50a are generally stacked in a row in a direction (front-rear direction) (FR) intersecting the longitudinal direction of the refrigerant tube 50.

The fins 60 transfer heat from the refrigerant tube 50. The fins 60 increase the contact area with air to improve heat dissipation.

The fins 60 are arranged between the refrigerant tubes 50 adjacent to each other. Although the fin 60 may have various shapes, it may be formed by bending a plate having the same width as the refrigerant tube 50. The fins 60 may be coated with a cladding 601.

The fin 60 may connect two refrigerant tubes 50 stacked in the up-down direction to transfer heat. The fins 60 may be in direct contact with the refrigerant tube 50 or may be connected to the refrigerant tube 50 by the sacrificial sheet 90.

The contact portion of the fin 60 with the sacrificial plate 90 may be U-shaped or V-shaped when viewed in the front-rear direction.

The fins 60 and the refrigerant tubes 50 are alternately stacked in the up-down direction, and the refrigerant tubes 50 are disposed at the lowermost ends and uppermost ends of the fins 60. The refrigerant tube 50 is connected to the upper end of the fin 60 and the lower end of the fin.

If the refrigerant tube 50 located at the uppermost end is defined as a first refrigerant tube 50, 51, the refrigerant tube 50 located below the first refrigerant tube 50, 51 is defined as a second refrigerant tube 50, 52, and the fin 60 between the first refrigerant tube 50, 51 and the second refrigerant tube 50, 52 may be defined as a first fin 60, 61. In this way, the nth refrigerant tube and the nth fin can be defined.

The header 70 may be coupled to one end of the plurality of refrigerant tubes 50 and supply the refrigerant to the inside of the plurality of refrigerant tubes 50. In addition, the header 70 may be coupled to one end of the refrigerant pipe 50 to collect and supply the refrigerant discharged from the refrigerant pipe 50 to another device.

The header 70 has a larger diameter, inner diameter or size than the refrigerant tube 50 and extends in the up-down direction. Header 70 may include a left header 71 connected to one end of refrigerant tube 50 and a right header 81 connected to the other end of refrigerant tube 50.

The right header 81 communicates with the right side of the plurality of refrigerant tubes 50. The right header 81 is disposed so as to extend long in the up-down direction and is connected to the inflow pipe 22. The right header 81 is formed in a space inside thereof to distribute and supply the refrigerant flowing in through the inflow tube 22 to the plurality of refrigerant tubes 50. The inflow tube 22 is an example of a refrigerant supply portion.

An inflow pipe 22 is connected to a region adjacent to the lower end of the right header 81.

The left header 71 communicates with the left side of the plurality of refrigerant tubes 50. The left header 71 is disposed so as to extend long in the up-down direction and is connected to the outflow pipe 24. The inside of the left header 71 is formed as a space, and the refrigerant discharged to the upper side of the plurality of refrigerant tubes 50 is guided to the outflow tubes 24.

Of course, the refrigerant flowing out of the left header 71 may be supplied to the header 70 of the other heat exchanger 100.

The heat exchanger 100 may be provided with an outer tube 110 and an inner tube 120 for preventing the generation of a bias of the refrigerant in the header 70. The refrigerant is uniformly dispersed by the holes of the outer tube 110 and the inner tube 120.

Fig. 6a is a cross-sectional perspective view of fig. 5, and fig. 6b is an enlarged view of a portion of fig. 6 a.

Referring to fig. 5 and 6, one side of the sacrificial sheet 90 is in contact with the refrigerant tube 50 and the other side is in contact with the fins 60, and the sacrificial sheet 90 is corroded instead of the fins 60 and the refrigerant tube 50, thereby inhibiting corrosion of the fins 60 and the refrigerant tube 50 and preventing peeling of the fins 60 and the refrigerant tube 50.

For example, the corrosion potential of the sacrificial sheet 90 may be lower than the corrosion potential of the refrigerant tube 50. When corrosion occurs in a state where two metals are in contact, the corrosion starts from a metal having a low corrosion potential, and therefore, the sacrificial sheet 90 is corroded instead of the refrigerant tube 50, and the refrigerant tube 50 can be prevented from being corroded to flow out the refrigerant.

In addition, the sacrificial sheet 90 may have a corrosion potential lower than that of the fin 60. Although the outflow of the refrigerant is prevented so long as the refrigerant tube 50 is not corroded, and thus no problem occurs, if the fin 60 is corroded, the flow of air is hindered and the refrigerant efficiency is lowered, and therefore, it is preferable that the corrosion potential of the sacrificial sheet 90 is lower than the corrosion potential of the fin 60.

When the corrosion potential of the sacrificial sheet 90 is lower than that of the fins 60, the sacrificial sheet 90 is corroded in place of the fins 60, so that corrosion of the fins 60 can be prevented.

Preferably, the corrosion potential of the fins 60 may be lower than the corrosion potential of the refrigerant tubes 50. When corrosion occurs in the fins 60 and the refrigerant tube 50, a dangerous location is the refrigerant tube 50. When the fin 60 is corroded, although there is a problem in that the efficiency is slightly lowered, when the refrigerant pipe 50 is corroded, there is a problem in that the refrigerant flows out and the air conditioner is not operated.

Therefore, in the present invention, the corrosion potential of the fin 60 is made lower than the corrosion potential of the refrigerant tube 50, whereby the fin 60 is corroded earlier than the refrigerant tube 50, thereby preventing the corrosion of the refrigerant tube 50.

In conclusion, the corrosion potential of the sacrificial sheet 90 may be lower than the corrosion potential of the refrigerant tube 50, the corrosion potential of the sacrificial sheet 90 may be lower than the corrosion potential of the fin 60, and the corrosion potential of the fin 60 may be lower than the corrosion potential of the refrigerant tube 50.

Specifically, the corrosion potential of the sacrificial sheet 90 may be-0.97V to-1.1V, the corrosion potential of the fin 60 may be-0.75V to-0.95V, and the corrosion potential of the refrigerant tube 50 may be-0.6V to-0.7V.

In addition, the sacrificial sheet 90 may have a corrosion potential lower than that of the fin 60, and may have a corrosion potential lower than that of the refrigerant tube 50.

The material of the sacrificial sheet 90 may be different from the material of the fins 60 and the material of the refrigerant tube 50. The material of the sacrificial sheet 90 may include a metal or alloy that satisfies the corrosion potential. The sacrificial sheet 90 is preferably an alloy including zinc or zinc and aluminum in view of cost, manufacturing difficulty, thermal conductivity, and the like. However, the material of the sacrificial sheet 90 is not limited thereto.

The material of the fins 60 may include a metal or alloy that satisfies the corrosion potential. The fin 60 preferably includes at least one of aluminum, copper, and an aluminum alloy in view of cost, manufacturing difficulty, thermal conductivity, and the like. However, the material of the fin 60 is not limited thereto.

The material of the refrigerant tube 50 may include a metal or alloy that satisfies the corrosion potential. The refrigerant pipe 50 preferably includes at least one of aluminum, copper, and an aluminum alloy in view of cost, manufacturing difficulty, thermal conductivity, and the like. However, the material of the refrigerant tube 50 is not limited thereto.

The sacrificial sheet 90 is located on the top or/and bottom surface of the refrigerant tube 50. The sacrificial sheet 90 is in surface contact with the top or/and bottom surface of the refrigerant tube 50. Preferably, the sacrificial sheet 90 may cover the entire top surface or/and the entire bottom surface of the refrigerant tube 50.

The width of the sacrificial sheet 90 in the front-rear direction may be at least equal to the width of the fins 60 and the refrigerant tubes 50, or greater than the width of the fins 60 and the refrigerant tubes 50. This is because if the width of the sacrificial sheet 90 is small, corrosion may occur first in a portion where the sacrificial sheet 90 is not present.

The sacrificial sheet 90 may have a structure to improve coupling force with the refrigerant pipe 50 and to be easily aligned with the refrigerant pipe 50.

For example, the sacrificial sheet 90 may include a first region 92 and a second region 91 stepped with the first region 92. The width of the first region 92 may be greater than the width of the second region 91.

The second region 91 is a region having a height difference from the first region 92. For example, the second region 91 may be formed by protruding a portion of the first region 92. The second region 91 may protrude in the direction of the refrigerant tube 50 contacting the sacrificial sheet 90. As another example, the second region 91 may be formed by recessing a part of the first region 92.

The second region 91 may be continuously or intermittently formed along the length direction (left-right direction) of the refrigerant tube 50. The second region 91 may be continuously or intermittently formed in the width direction (front-rear direction) of the refrigerant tube 50.

The refrigerant tube 50 may further include a matching portion 50b corresponding to the second region 91. The matching portion 50b is a portion that matches the second region 91. The matching portion 50b may be inserted into the second region 91 or a space into which the second region 91 is inserted. Preferably, the matching portion 50b may be configured as a groove.

The thickness T2 of the sacrificial sheet 90 may be greater than the thickness T1 of the fin 60. The thickness T3 of the refrigerant tube 50 may be greater than the thickness T2 of the sacrificial sheet 90.

If the thickness T2 of the sacrificial sheet 90 is too thin, it is corroded soon and shortens the life of the heat exchanger, but if the thickness T2 of the sacrificial sheet 90 is too thick, it increases the cost burden and reduces the thermal conductivity.

Accordingly, the thickness T2 of the sacrificial sheet 90 is preferably a value between the thickness T1 of the fin 60 and the thickness T3 of the refrigerant tube 50.

The heat exchanger of the present invention has one or more of the following effects.

First, in the present invention, since the sacrificial sheet disposed between the fins and the refrigerant tube has a low corrosion potential, it is corroded earlier in corrosion of external water or air than the refrigerant tube and the fins, thereby having an advantage of preventing corrosion of the fins and the tubes and preventing the fins from being peeled off from the tubes.

Second, in the present invention, since the sacrificial sheet covers the entire top and bottom surfaces of the refrigerant tube and has a thick thickness, it is resistant to corrosion for a long time, and as a result, the sacrificial corrosion time is long, thereby having an advantage of improving the life of the heat exchanger.

Third, in the present invention, the sacrificial sheet is attached to the outer surface of the refrigerant tube, and the fin is brazed to the sacrificial sheet, so that the manufacturing is easier, the manufacturing time is reduced, the manufacturing cost is reduced, and the zinc concentration around the fin becomes uniform, compared to the brazing by coating zinc particles.

Fourth, the present invention has an advantage of easily aligning the refrigerant tube and the sacrificial sheet by inserting a part of the region of the sacrificial sheet into the groove of the refrigerant tube and preventing the refrigerant tube and the sacrificial sheet from being peeled off.

While the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the embodiments, and various forms different from each other can be produced, and it is understood that those skilled in the art to which the present invention pertains can realize other specific forms without changing the technical spirit or essential features of the present invention. The foregoing detailed description is, therefore, not to be taken in a limiting sense, but is to be construed as exemplary in all aspects.

Claims

1. A heat exchanger, comprising:

a plurality of refrigerant pipes through which a refrigerant flows;

fins arranged between the refrigerant tubes adjacent to each other to transfer heat; and

a sacrificial plate having one surface in contact with the refrigerant tube and the other surface in contact with the fin;

the sacrificial sheet has a corrosion potential lower than that of the refrigerant tube.

2. A heat exchanger according to claim 1 wherein,

the sacrificial sheet has a corrosion potential lower than the corrosion potential of the fin.

3. A heat exchanger according to claim 1 wherein,

the corrosion potential of the fins is lower than the corrosion potential of the refrigerant tubes.

4. A heat exchanger according to claim 1 wherein,

the sacrificial sheet comprises zinc or an alloy of zinc and aluminum.

5. A heat exchanger according to claim 1 wherein,

the fin includes at least one of aluminum, copper, and an aluminum alloy.

6. A heat exchanger according to claim 1 wherein,

the refrigerant tube includes at least one of aluminum, copper, and an aluminum alloy.

7. A heat exchanger according to claim 1 wherein,

the sacrificial plates are disposed on the top and bottom surfaces of the refrigerant tube.

8. A heat exchanger according to claim 1 wherein,

the sacrificial sheet includes a first region and a second region stepped with the first region.

9. The heat exchanger of claim 8, wherein the heat exchanger is configured to heat the heat exchanger,

the second region is formed by protruding a part of the first region.

10. The heat exchanger of claim 8, wherein the heat exchanger is configured to heat the heat exchanger,

the second region protrudes toward the refrigerant tube in contact with the sacrificial sheet.