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(11) | EP 4 345 407 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | HEAT EXCHANGER |
| (57) Provided is a heat exchanger. The heat exchanger includes a plurality of refrigerant
tubes through which refrigerant flows, a fin disposed between adjacent refrigerant
tubes to conduct heat, and a sacrificial sheet configured such that a first surface
thereof contacts the refrigerant tube and a second surface thereof contacts the fin.
A corrosion potential of the sacrificial sheet is lower than a corrosion potential
of the refrigerant tube.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Republic of Korea Patent Application No. 10-2020-, filed on September 29, 2022.
BACKGROUND
Field
Related Art
[0003] Generally, a heat exchanger may be used as a condenser or an evaporator in a refrigerating cycle device including a compressor, a condenser, an expansion mechanism, and an evaporator.
[0004] Further, the heat exchanger is installed in a vehicle, a refrigerator or the like to exchange heat between refrigerant and air.
[0005] The heat exchanger may be classified into a fin tube type heat exchanger, a micro channel type heat exchanger, and the like, according to the structure.
[0006] Recently, copper is replaced by aluminum as a material for the heat exchanger in view of cost, processability, and corrosion resistance. This is because aluminum is light, inexpensive, and has high thermal conductivity.
[0007] The aluminum material for the heat exchanger mainly use pure aluminum (A1XXX) that is advantageous in extrusion, has high thermal conductivity, and is inexpensive, and aluminum-manganese (A3XXX) that is slightly lower in extrudability than the pure aluminum but has relatively high strength and corrosion resistance.
[0008] Table 1 shows the compositions of A1070 and A3003, which are mainly used as a conventional aluminum material for a heat exchanger. A1070 is pure aluminum material, while A3003 is 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 | Rem. |
| A3003 | 0.158 | 0.084 | 0.421 | 0.034 | 0.001 | 1.021 | 0.014 | Rem. |
[0009] The A1070 material is low in material cost and extrusion cost, so that it is used as a tube and fin material of a condenser for a home appliance, such as an air conditioner and a refrigerator, which does not require high strength but is important in economic efficiency. In contrast, the A3003 material is superior to the A1070 in strength and corrosion resistance but is slightly high in extrusion cost, so that it is used as an extruded tube and fin material for a heat exchanger such as an intercooler and a radiator for a vehicle.
[0010] On the other hand, aluminum is a metal that is easily activated but has high corrosion resistance by forming an oxide film on a surface in the atmosphere. However, pitting corrosion occurs in which corrosion occurs only in a local region where the oxide film is damaged when aluminum is corroded. Further, corrosion is intensively propagated to a portion by electrochemical action with various impurities contained in aluminum alloy. Due to the corrosion mechanism of aluminum, the aluminum heat exchanger may be locally penetrated, thus causing the leakage of refrigerant or high-temperature fluid therefrom.
[0011] In order to prevent the corrosion, Patent Document 1 has attempted to adjust the contents of copper, silicon, iron, and zirconium and use properties of zirconium elements that control a corrosion product and induce uniform corrosion.
[0012] However, Patent Document 1 is problematic in that zirconium is a very expensive rare metal, so that manufacturing cost is expensive, and the material loses corresponding characteristics during the recrystallization of elements in the material when fins and tubes are subjected to brazing welding at high temperature, so that it is difficult to use this technology in mass production.
[0013] Referring to FIG. 7, according to the prior art, in order to prevent corrosion, there has been used a method of applying zinc particles 203 onto a tube 204 and brazing it with a fin 201. The fin 201 is usually coated with cladding 202.
[0014] However, as shown in FIGS. 8 and 9, in the process of melting the fin 201 and zinc, zinc concentration is not constant, thus leading to a section (portion of the tube 204 close to the fin 201) in which the zinc concentration is excessive and a section in which the zinc concentration is insufficient. Further, the method of applying zinc has technical limitations in that quality deviation occurs in terms of accurate application amount and uniformity.
[0015] Therefore, as shown in FIG. 10, the fin 201 and the tube 204 may be separated from each other in the section where the zinc concentration is excessive, and corrosion may start in the section where the zinc concentration is low.
[Documents of Related Art]
[Patent Document]
SUMMARY
[0017] An objective of the present disclosure provides a heat exchanger that uses a sacrificial sheet having a potential difference, thus preventing the corrosion of a fin and a tube and preventing the fin from being separated from the tube.
[0018] Another objective of the present disclosure provides a heat exchanger that uses a sacrificial sheet on an outer surface of a tube, thus enabling easy manufacture and reducing manufacturing cost.
[0019] A further objective of the present disclosure provides a heat exchanger, in which a sacrificial sheet can be easily aligned and coupled to an outer surface of a tube.
[0020] The objectives to be achieved by the present disclosure are not limited to the above-mentioned objectives, and other objectives which are not mentioned will be clearly understood by those skilled in the art from the following description.
[0021] In an aspect, a heat exchanger according to the present disclosure is characterized in that a corrosion potential of a sacrificial sheet between a fin and a refrigerant tube is lower than that of the refrigerant tube.
[0022] Further, a heat exchanger according to the present disclosure is characterized in that the sacrificial sheet between the fin and the refrigerant tube is zinc.
[0023] To be more specific, the present disclosure provides a heat exchanger including a plurality of refrigerant tubes through which refrigerant flows, a fin disposed between adjacent refrigerant tubes to conduct heat, and a sacrificial sheet configured such that a first surface thereof contacts the refrigerant tube and a second surface thereof contacts the fin. A corrosion potential of the sacrificial sheet is lower than a corrosion potential of the refrigerant tube.
[0024] The corrosion potential of the sacrificial sheet may be lower than a corrosion potential of the fin.
[0025] The corrosion potential of the fin may be lower than the corrosion potential of the refrigerant tube.
[0029] The sacrificial sheet may be positioned on each of upper and lower surfaces of the refrigerant tube.
[0030] The sacrificial sheet may include a first region, and a second region with a step between the first region and the second region.
[0037] A thickness of the refrigerant tube may be thicker than a thickness of the sacrificial sheet.
[0039] The heat exchanger may further include a header coupled to first ends of the plurality of refrigerant tubes to supply the refrigerant into the plurality of refrigerant tubes.
[0040] The material of the sacrificial sheet may be different from that of the fin and the refrigerant tube.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041]
FIG. 1 is a diagram illustrating a refrigerating cycle device according to an embodiment of the present disclosure.
FIG. 2 is a perspective view illustrating the outside of an outdoor unit shown in FIG. 1.
FIG. 3 is a perspective view illustrating a heat exchanger according to an embodiment of the present disclosure.
FIG. 4 is a longitudinal sectional view of the heat exchanger shown in FIG. 3.
FIG. 5 is a sectional view taken along line 5-5' of FIG. 4.
FIG. 6A is a sectional perspective view of FIG. 5.
FIG. 6B is an enlarged view of a portion of FIG. 6A.
FIGS. 7 and 8 are diagrams illustrating a method of coupling a fin and a tube according to the prior art.
FIG. 9 is a zinc distribution diagram of FIG. 8.
FIG. 10 a diagram illustrating the separation of the fin and the tube according to the prior art.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0042] The above and other objectives, features, and advantages of the present disclosure will be easily understood from the following preferred embodiments in conjunction with the accompanying drawings. However, the disclosure may be embodied in different forms without being limited to the embodiments set forth herein. Rather, the embodiments disclosed herein are provided to make the disclosure thorough and complete and to sufficiently convey the scope of the present disclosure to those skilled in the art. Like reference numerals refer to like parts throughout various figures and embodiments of the present disclosure.
[0043] The spatially relative terms "below", "beneath", "lower", "above", "upper", etc. may be used to easily describe a relationship between one component and another component as shown in the drawings. The spatially relative terms should be understood as encompassing different directions of components in use or operation in addition to directions shown in the drawings. For example, when reversing components shown in the drawings, components described as being "below" or "beneath" other components may be placed "above" the other components. Thus, the exemplary term "below" may include directions of both below and above. The components may also be oriented in other directions, and thus the spatially relative terms may be interpreted according to an orientation.
[0044] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. In the present disclosure, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprise", "include", "have", etc. when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or combinations of them but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or combinations thereof.
[0045] Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0046] The size or shape of components shown in the drawings may be exaggerated for the clarity and convenience of description. Further, the size and area of each component do not entirely reflect the actual size and area.
[0047] Further, angles and directions mentioned in the process of describing the structure of the embodiment are based on those described in the drawings. In the description of the structure according to the embodiment in the specification, if the reference point and the positional relationship for the angle are not clearly mentioned, refer to the related drawings.
[0048] Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings.
[0049] FIG. 1 is a diagram illustrating a refrigerating cycle device according to an embodiment of the present disclosure, and FIG. 2 is a perspective view illustrating the outside of an outdoor unit shown in FIG. 1.
[0050] Referring to FIGS. 1 and 2, the refrigerating cycle device according to this embodiment may include a compressor 10 that compresses a refrigerant, an outdoor heat exchanger 11 that exchanges heat between the refrigerant and outdoor air, an expansion mechanism 12 that expands the refrigerant, and an indoor heat exchanger 13 that exchanges heat between the refrigerant and indoor air.
[0051] The refrigerant compressed by the compressor 10 may be condensed by exchanging heat with outdoor air while passing through the outdoor heat exchanger 11.
[0053] The refrigerant condensed in the outdoor heat exchanger 11 may flow to the expansion mechanism 12 and then be expanded. The refrigerant expanded by the expansion mechanism 12 may be evaporated by exchanging heat with indoor air while passing through the indoor heat exchanger 13.
[0054] The indoor heat exchanger 12 may be used as an evaporator that evaporates the refrigerant. The refrigerant evaporated by the indoor heat exchanger 12 may be recovered to the compressor 10.
[0055] The heat exchanger may include the indoor heat exchanger 12 and the outdoor heat exchanger 11.
[0056] The refrigerant is operated in a refrigerating cycle while circulating through the compressor 10, the outdoor heat exchanger 11, the expansion mechanism 12, and the indoor heat exchanger 13.
[0057] An intake path of the compressor 10 that guides the refrigerant passing through the indoor heat exchanger 13 to the compressor 10 may be connected to the compressor 10. An accumulator 14 in which a liquid refrigerant is accumulated may be installed in the intake path of the compressor 10.
[0058] The indoor heat exchanger 13 may form a refrigerant path through which the refrigerant passes.
[0059] The refrigerating cycle device may be a separable type air conditioner in which an indoor unit I and an outdoor unit O are separated. In this case, the compressor 10 and the outdoor heat exchanger 11 may be installed in the outdoor unit I. Further, the refrigerating cycle device may be a refrigerator, and the indoor heat exchanger 13 may be disposed to exchange heat with air inside a food storage, and the outdoor heat exchanger 11 may exchange heat with air outside the food storage. In the case of the refrigerator, the indoor unit I and the outdoor unit O may be disposed together in a main body.
[0060] The expansion mechanism 12 may be installed in either of the indoor unit I or the outdoor unit O.
[0062] An outdoor fan 15 may be installed in the outdoor unit O to blow outdoor air to the outdoor heat exchanger 11. In addition, the compressor 10 may be installed in a machine room of the outdoor unit O.
[0063] An indoor fan 16 may be installed in the indoor unit I to blow indoor air to the indoor heat exchanger 13.
[0064] In the conventional heat exchange, a liquid phase and a gas phase of the refrigerant are mixed. When the two-phase refrigerant flowing into a header is introduced into a refrigerant tube, the gas phase and the liquid phase may be unevenly introduced.
[0065] In order to solve the problem, a heat exchanger 100 according to the present disclosure will be described in detail.
[0066] FIG. 3 is a perspective view illustrating a heat exchanger according to an embodiment of the present disclosure, 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' of FIG. 4.
[0067] Referring to FIGS. 3 to 5, the heat exchanger 100 is a device that exchanges heat between the refrigerant of a refrigerating cycle and outside air. Preferably, the heat exchanger 100 evenly distributes the refrigerant therein, and has a large heat transfer area.
[0068] The heat exchanger 100 may be arranged with a plurality of rows, and the flow direction of the refrigerant in one row may be alternately changed.
[0069] For example, the heat exchanger 100 includes a plurality of refrigerant tubes 50 through which the refrigerant flows, a fin 60 disposed between adjacent refrigerant tubes 50 to conduct heat, and a sacrificial sheet 90 configured such that one surface thereof contacts the refrigerant tube 50 and the other surface contacts the fin 60.
[0070] The heat exchanger 100 further includes a header 70 to which one end of each of the plurality of refrigerant tubes 50 is coupled to supply the refrigerant into the refrigerant tubes 50, an outer pipe 110 provided inside the header 70, and an inner pipe 120 provided inside the outer pipe 110.
[0071] The refrigerant tube 50 has a fine inner diameter so that the refrigerant flows therein to maximize a contact area with the air. The plurality of refrigerant tubes 50 are connected to the header 70. The refrigerant tubes 50 extend in a direction transverse to the header 70.
[0072] To be more specific, the refrigerant tubes 50 may be arranged long in a horizontal (front-rear) direction (LeRi), and the plurality of refrigerant tubes 50 may be stacked in a vertical (longitudinal) direction (UD). While air passes through a space between the plurality of refrigerant tubes 50 stacked in the vertical direction, the air exchanges heat with the refrigerant in the refrigerant tubes 50. The plurality of refrigerant tubes 50 stacked horizontally define a heat exchange surface together with the fins 60 that will be described later.
[0073] The refrigerant tube 50 may include a plurality of micro channels 50a therein. The plurality of micro channels 50a defines a space through which the refrigerant passes. The plurality of micro channels 50a may extend in parallel with the refrigerant tube 50.
[0074] To be more specific, as shown in FIG. 5, the sectional shape of the refrigerant tube 50 may be a rectangular shape whose horizontal length is greater than a vertical length, and the sectional shape of the micro channel 50a may be a rectangular shape.
[0075] The micro channels 50a are usually stacked in one row in a direction (front-rear direction) FR crossing the longitudinal direction of the refrigerant tube 50.
[0076] The fin 60 transfers heat from the refrigerant tube 50. The fin 60 increases the contact area with air to improve heat dissipation performance.
[0077] The fin 60 is disposed between adjacent refrigerant tubes 50. The fin 60 may have various shapes, but may be formed by bending a plate that has the same width as the refrigerant tube 50. The fin 60 may be coated by cladding 601.
[0078] The fin 60 may connect two refrigerant tubes 50 stacked in the vertical direction to conduct heat. The fin 60 may directly contact the refrigerant tube 50, and may be connected to the refrigerant tube 50 by the sacrificial sheet 90.
[0079] When seen from the front-rear direction, a contact portion between the fin 60 and the sacrificial sheet 90 is formed in a U- or V-shape.
[0080] The fins 60 and the refrigerant tubes 50 are alternatively stacked in the vertical direction, and the refrigerant tubes 50 are positioned at the lowermost end and the uppermost end of the fin 60. The refrigerant tubes 50 are connected to the upper end of the fin 60 and the lower end of the fin 60.
[0081] Assuming that the refrigerant tube 50 located at the uppermost end is defined as a first refrigerant tube 50 or 51 and the refrigerant tube 50 located under the first refrigerant tube 50 or 51 is defined as a second refrigerant tube 50 or 52, the fin 60 between the first refrigerant tube 50 or 51 and the second refrigerant tube 50 or 52 may be defined as a first fin 60 or 61. In this way, an nth refrigerant tube and an nth fin may be defined.
[0082] The header 70 may be coupled to one end of each of the plurality of refrigerant tubes 50 to supply the refrigerant into the plurality of refrigerant tubes 50. Further, the header 70 may be coupled to one end of the refrigerant tube 50 to collect the refrigerant discharged from the refrigerant tube 50 and supply the collected refrigerant to another device.
[0083] The header 70 has a diameter, inner diameter, or size larger than that of the refrigerant tubes 50, and extends in the vertical direction. The header 70 may include a left header 71 connected to one end of the refrigerant tube 50, and a lower header 70 or 81 connected to the other end of the refrigerant tube 50.
[0084] The right header 81 communicates with right sides of the plurality of refrigerant tubes 50. The right header 81 extends long in the vertical direction, and is connected to an inlet pipe 22. The interior of the right header 81 is formed as one space, so that the refrigerant introduced through the inlet pipe 22 is distributed and supplied to the plurality of refrigerant tubes 50. The inlet pipe 22 is an example of a refrigerant supply unit.
[0086] The left header 71 communicates with the left sides of the plurality of refrigerant tubes 50. The left header 71 extends long in the vertical direction, and is connected to an outlet pipe 24. The interior of the left header 71 is formed as one space to guide the refrigerant, discharged to the upper side of the plurality of refrigerant tubes 50, to the outlet pipe 24.
[0087] Of course, the refrigerant discharged from the left header 71 may be supplied to the header 70 of another heat exchanger 100.
[0088] In the heat exchanger 100, the outer pipe 110 and the inner pipe 120 may be positioned to prevent the refrigerant from being biased inside the header 70. The refrigerant is uniformly distributed through holes of the outer pipe 110 and the inner pipe 120.
[0089] FIG. 6A is a sectional perspective view of FIG. 5, and FIG. 6B is an enlarged view of a portion of FIG. 6A.
[0090] Referring to FIGS. 5 and 6, one surface of the sacrificial sheet 90 contacts the refrigerant tube 50, and the other surface contacts the fin 60, so that the sacrificial sheet is corroded instead of the fin 60 and the refrigerant tube 50, thus suppressing the corrosion of the fin 60 and the refrigerant tube 50 and preventing the separation of the fin 60 from the refrigerant tube 50.
[0091] For example, the corrosion potential of the sacrificial sheet 90 may be lower than the corrosion potential of the refrigerant tube 50. If corrosion occurs while two metals contact each other, the metal with the lower corrosion potential is corroded first, so that the sacrificial sheet 90 is corroded instead of the refrigerant tube 50, thus preventing the refrigerant tube 50 from corroding and preventing the refrigerant from leaking out.
[0092] Further, the corrosion potential of the sacrificial sheet 90 may be lower than the corrosion potential of the fin 60. Even if only the refrigerant tube 50 is not corroded, the leakage of the refrigerant is prevented. However, when the fin 60 is corroded, the flow of air is hindered and the efficiency of the refrigerant is lowered. Thus, the corrosion potential of the sacrificial sheet 90 is preferably lower than the corrosion potential of the fin 60.
[0093] If the corrosion potential of the sacrificial sheet 90 is lower than the corrosion potential of the fin 60, the sacrificial sheet 90 is corroded first instead of the fin 60, thus preventing the fin 60 from being corroded.
[0094] Preferably, the corrosion potential of the fin 60 may be lower than the corrosion potential of the refrigerant tube 50. Among the fin 60 and the refrigerant tube 50, a dangerous part when corrosion occurs is the refrigerant tube 50. When the fin 60 is corroded, efficiency may be slightly lowered. However, when the refrigerant tube 50 is corroded, the refrigerant leaks out and the air conditioner is not operated, causing a major problem.
[0095] Therefore, according to the present disclosure, the corrosion potential of the fin 60 is set to be lower than the corrosion potential of the refrigerant tube 50, so that the fin 60 is corroded prior to the refrigerant tube 50, thus preventing the corrosion of the refrigerant tube 50.
[0096] 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.
[0097] To be more specific, the corrosion potential of the sacrificial sheet 90 may range from - 0.97V to - 1.1V, the corrosion potential of the fin 60 may range from -0.75V to - 0.95V, and the corrosion potential of the refrigerant tube 50 may range from -0.6V to - 0.7V
[0098] Further, the corrosion potential of the sacrificial sheet 90 may be lower than the corrosion potential of the fin 60, or may be lower than the corrosion potential of the refrigerant tube 50.
[0099] The material of the sacrificial sheet 90 may be different from the material of the fin 60 and the material of the refrigerant tube 50. The material of the sacrificial sheet 90 may include metal or alloy that satisfies the corrosion potential. Considering cost, the ease of manufacture, thermal conductivity, etc., the sacrificial sheet 90 preferably includes zinc or an alloy of zinc and aluminum. However, the material of the sacrificial sheet 90 is not limited thereto.
[0100] The material of the fin 60 may include metal or alloy that satisfies the corrosion potential. Considering cost, the ease of manufacture, thermal conductivity, etc., the fin 60 preferably includes at least one of aluminum, copper, and aluminum alloy. However, the material of the fin 60 is not limited thereto.
[0101] The material of the refrigerant tube 50 may include metal or alloy that satisfies the corrosion potential. Considering cost, the ease of manufacture, thermal conductivity, etc., the refrigerant tube 50 preferably includes at least one of aluminum, copper, and aluminum alloy. However, the material of the refrigerant tube 50 is not limited thereto.
[0102] The sacrificial sheet 90 is positioned on the upper surface and/or lower surface of the refrigerant tube 50. The sacrificial sheet 90 is in surface contact with the upper surface and/or lower surface of the refrigerant tube 50. Preferably, the sacrificial sheet 90 may cover the entire upper surface and/or lower surface of the refrigerant tube 50.
[0103] The width of the sacrificial sheet 90 in the front-rear direction may be at least equal to the width of the fin 60 and the refrigerant tube 50 or larger than the width of the fin 60 and the refrigerant tube 50. This is because when the width of the sacrificial sheet 90 is reduced, corrosion first occurs in a portion where the sacrificial sheet 90 is not present.
[0104] The sacrificial sheet 90 may have a structure that enhances a coupling force with the refrigerant tube 50 and facilitates alignment with the refrigerant tube 50.
[0105] For example, the sacrificial sheet 90 may include a first region 92 and a second region 91 with a step between the first region 92 and the second region. The width of the first region 92 may be greater than that of the second region 91.
[0106] 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 drawing a portion of the first region 92. The second region 91 may protrude toward the refrigerant tube 50 contacting the sacrificial sheet 90. As another example, the second region 91 may be formed by recessing a portion of the first region 92.
[0107] The second region 91 may be continuously or intermittently formed in the longitudinal 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.
[0108] The refrigerant tube 50 may further include a matching portion 50b corresponding to the second region 91. The matching portion 50b is a portion matched with the second region 91. The matching portion 50b may be inserted into the second region 91 or may be a space into which the second region 91 is inserted. Preferably, the matching portion 50b may be configured as a groove.
[0109] The thickness T3 of the sacrificial sheet 90 may be thicker than the thickness T1 of the fin 60. The thickness of the refrigerant tube 50 may be thicker than the thickness T3 of the sacrificial sheet 90.
[0110] If the thickness T3 of the sacrificial sheet 90 is too thin, it is rapidly corroded, thus shortening the lifespan of the heat exchanger. If the thickness T2 of the sacrificial sheet 90 is too thick, cost burden increases and thermal conductivity also deteriorates.
[0111] Therefore, the thickness T2 of the sacrificial sheet 90 preferably has a value between the thickness T1 of the fin 60 and the thickness T3 of the refrigerant tube 50.
[0113] First, the present disclosure is advantageous in that a sacrificial sheet disposed between a fin and a refrigerant tube has a low corrosion potential, so that the sacrificial sheet is corroded prior to the refrigerant tube and the fin by external water or air, thus preventing the corrosion of the fin and the tube and preventing the fin from being separated from the tube.
[0114] Second, the present disclosure is advantageous in that a sacrificial sheet covers both the upper and lower surfaces of a refrigerant tube to have a thick thickness, so that it can withstand corrosion for a long time, and consequently, sacrificial corrosion is performed for a long time, thus increasing the lifespan of a heat exchanger.
[0115] Third, the present disclosure is advantageous in that a sacrificial sheet is attached to an outer surface of a refrigerant tube, and a fin is brazed on the sacrificial sheet, so that it facilitates manufacture, reduces manufacturing time, and reduces manufacturing cost compared to brazing by applying zinc particles, and zinc concentration around the fin becomes uniform.
[0116] Fourth, the present disclosure is advantageous in that a region of a sacrificial sheet is inserted into a groove of a refrigerant tube, so that the refrigerant tube and the sacrificial sheet are easily aligned, and the separation of the refrigerant tube from the sacrificial sheet is prevented.
[0117] Although the present disclosure has been described with respect to the accompanying drawings, the present disclosure may be embodied in several forms without being limited to the above embodiments. It is apparent to those skilled in the art that the present disclosure can be implemented in other specific forms without changing the technical scope or essential characteristics of the present disclosure. Therefore, the above-described embodiments are illustrative and not restrictive.
1. A heat exchanger comprising:
a plurality of refrigerant tubes (50, 51, 52) through which refrigerant flows;
a fin (60, 61) disposed between adjacent refrigerant tubes (50, 51, 52) to conduct heat; and
a sacrificial sheet (90) configured such that a first surface thereof contacts the refrigerant tube (50, 51, 52) and a second surface thereof contacts the fin (60, 61),
wherein a corrosion potential of the sacrificial sheet (90) is lower than a corrosion potential of the refrigerant tube (50, 51, 52).
2. The heat exchanger of claim 1, wherein the corrosion potential of the sacrificial
sheet (90) is lower than a corrosion potential of the fin (60, 61).
3. The heat exchanger of claim 2, wherein the corrosion potential of the fin (60, 61)
is lower than the corrosion potential of the refrigerant tube (50, 51, 52).
4. The heat exchanger of any one of claims 1 to 3, wherein the sacrificial sheet (90)
comprises zinc or alloy of zinc and aluminum.
5. The heat exchanger of any one of claims 1 to 4, wherein the fin (60, 61) comprises
at least one of aluminum, copper and aluminum alloy.
6. The heat exchanger of any one of claims 1 to 5, wherein the refrigerant tube (50,
51, 52) comprises at least one of aluminum, copper and aluminum alloy.
7. The heat exchanger of any one of claims 1 to 6, wherein the sacrificial sheet (90)
is positioned on each of upper and lower surfaces of the refrigerant tube (50, 51,
52).
8. The heat exchanger of any one of claims 1 to 7, wherein the sacrificial sheet (90)
comprises:
a first region (92); and
a second region (91) with a step between the first region (92) and the second region (91).
9. The heat exchanger of claim 8, wherein the second region (91) is formed by protruding
a portion of the first region (92).
10. The heat exchanger of claim 8 or 9, wherein the second region (91) protrudes toward
the refrigerant tube (50, 51, 52) contacting the sacrificial sheet (90).
11. The heat exchanger of claim 8, wherein the second region (91) is formed by recessing
a portion of the first region (92).
12. The heat exchanger of any one of claims 8 to 11, wherein the refrigerant tube (50,
51, 52) comprises a matching portion (50b) corresponding to the second region (91).
13. The heat exchanger of any one of claims 8 to 12, wherein a width of the first region
(92) is greater than a width of the second region (91).
14. The heat exchanger of any one of claims 1 to 13, wherein a thickness of the sacrificial
sheet (90) is thicker than a thickness of the fin (60, 61), and
wherein a thickness of the refrigerant tube (50, 51, 52) is thicker than a thickness of the sacrificial sheet (90).
wherein a thickness of the refrigerant tube (50, 51, 52) is thicker than a thickness of the sacrificial sheet (90).
15. The heat exchanger of any one of claims 1 to 14, wherein the sacrificial sheet (90)
comprises zinc, and
wherein the refrigerant tube (50, 51, 52) comprises at least one of aluminum, copper and aluminum alloy.
wherein the refrigerant tube (50, 51, 52) comprises at least one of aluminum, copper and aluminum alloy.
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.
Patent documents cited in the description