WO2021235472A1

WO2021235472A1 - Multilayer body, heat exchanger and air conditioner

Info

Publication number: WO2021235472A1
Application number: PCT/JP2021/018937
Authority: WO
Inventors: 崇志中島; 亮平川端; 宏徳栗木
Original assignee: 三菱電機株式会社
Priority date: 2020-05-22
Filing date: 2021-05-19
Publication date: 2021-11-25
Also published as: JPWO2021235472A1; JP7286015B2

Abstract

This multilayer body (40) is obtained by stacking and combining a plurality of plate materials including one plate material that is at least provided with a hole, thereby forming an internal space (40a). This multilayer body has a portion where the end face of a plate material is out of alignment, and at least a part of the thus-exposed surface of the plate material has a layer (43) that contains, as a component, a base material which has a lower redox potential than the base layer of the plate material.

Description

Laminates, heat exchangers and air conditioners

The present disclosure relates to a laminate in which an internal space is formed, a heat exchanger, and an air conditioner.

Conventionally, a laminated body in which a plurality of plate materials are laminated and a heat exchanger in which the laminated body is used are known. The heat exchanger is provided in, for example, the outdoor unit and the indoor unit of the air conditioner. Since the heat exchanger installed in the outdoor unit is used outdoors, water may adhere to it due to rainfall, etc., and the metal material constituting the heat exchanger laminate may corrode, resulting in performance deterioration and malfunction. There is. Since the heat exchanger installed in the indoor unit may be exposed to dew when the air conditioner is in cooling operation, the metal material constituting the heat exchanger laminate is corroded and the performance deteriorates. And dysfunction may occur. Therefore, the entire laminate including the end face of the laminate may be protected by applying a paste-like flux containing a material having a lower redox potential than the material of the laminate and baking the laminate. Examples of the material of the laminate include an aluminum alloy, and examples of the material having a lower redox potential than the material of the laminate include zinc. It is known that such a material having a low redox potential not only protects the coated portion but also has a remote anticorrosion action to protect the portion slightly distant from the coated portion.

Patent Document 1 discloses an aluminum alloy material in which an aluminum alloy layer having a zinc concentration of about 1% to 2% is laminated and coated. In Patent Document 1, two or more aluminum alloy layers having a higher zinc concentration than the core material are laminated and coated on at least one surface of the aluminum-based material as the core material. As a result, Patent Document 1 attempts to improve the corrosion resistance of the surface layer of the core material.

Japanese Unexamined Patent Publication No. 7-52308

However, although the aluminum alloy material disclosed in Patent Document 1 can protect the surface layer of the core material, it cannot improve the corrosion resistance of the end face of the core material.

This disclosure is made to solve the above-mentioned problems, and provides a laminate, a heat exchanger, and an air conditioner that improve the corrosion resistance of the end face.

The laminated body according to the present disclosure is a laminated body in which a plurality of plate materials having at least one plate material having holes are combined and laminated to form an internal space, and there is a portion where the end faces of the plate materials are displaced. At least a part of the surface of the plate material exposed as a result of the displacement has a layer containing a base material having a lower redox potential than the base layer of the plate material as a component.

According to the present disclosure, the position of the end face of the surface of a base material having a redox potential lower than that of the base layer, or a material having both a component having a redox potential lower than that of the base layer and a brazing material component is the surface. It is out of alignment with the position of the end face of the material that is joined next to each other. Therefore, the remote anticorrosion action provided by the base material of one plate material extends to the end face of the other plate material. Therefore, the corrosion resistance of the end face can be improved.

It is a circuit diagram which shows the air conditioner which concerns on Embodiment 1. FIG. It is a front view which shows the heat exchanger which concerns on Embodiment 1. FIG. It is a side view which shows the heat exchanger which concerns on Embodiment 1. FIG. It is sectional drawing which shows the laminated body which concerns on Embodiment 1. FIG. It is sectional drawing which shows the laminated body which concerns on Embodiment 1. FIG. It is a schematic diagram which shows the remote anticorrosion action of zinc. It is a graph which shows the remote anticorrosion action of zinc. It is sectional drawing which shows the laminated body which concerns on Embodiment 2. It is sectional drawing which shows the laminated body which concerns on Embodiment 3. It is sectional drawing which shows the laminated body which concerns on Embodiment 4. It is an exploded perspective view which shows the laminated body which concerns on Embodiment 5. It is sectional drawing which shows the laminated body which concerns on Embodiment 5.

Hereinafter, embodiments of the laminate, heat exchanger, and air conditioner of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the embodiments described below. Further, in the following drawings including FIG. 1, the relationship between the sizes of the constituent members may differ from the actual one. In addition, in the following description, terms indicating directions are appropriately used to facilitate understanding of the present disclosure, but these terms are for the purpose of explaining the present disclosure, and these terms are intended to limit the present disclosure. is not it. Examples of the term indicating the direction include "top", "bottom", "right", "left", "front", "rear", and the like. In some drawings, the hatching of the cross-sectional view is partially omitted.

Embodiment 1.
FIG. 1 is a circuit diagram showing an air conditioner 1 according to the first embodiment. As shown in FIG. 1, the air conditioner 1 is a device for adjusting the air in the indoor space, and includes an outdoor unit 2 and an indoor unit 3 connected to the outdoor unit 2. The outdoor unit 2 is provided with a compressor 6, a flow path switching device 7, a heat exchanger 8, an outdoor blower 9, and an expansion unit 10. The indoor unit 3 is provided with an indoor heat exchanger 11 and an indoor blower 12.

A compressor 6, a flow path switching device 7, a heat exchanger 8, an expansion unit 10, and an indoor heat exchanger 11 are connected by a refrigerant pipe 5, and a refrigerant circuit 4 through which a refrigerant as a working gas flows is configured. The compressor 6 sucks in a refrigerant in a low temperature and low pressure state, compresses the sucked refrigerant into a refrigerant in a high temperature and high pressure state, and discharges the sucked refrigerant. The flow path switching device 7 switches the direction in which the refrigerant flows in the refrigerant circuit 4, and is, for example, a four-way valve. The heat exchanger 8 exchanges heat between, for example, outdoor air and a refrigerant. The heat exchanger 8 acts as a condenser during the cooling operation and as an evaporator during the heating operation.

The outdoor blower 9 is a device that sends outdoor air to the heat exchanger 8. The expansion unit 10 is a pressure reducing valve or an expansion valve that decompresses and expands the refrigerant. The expansion unit 10 is, for example, an electronic expansion valve whose opening degree is adjusted. The indoor heat exchanger 11 exchanges heat between, for example, indoor air and a refrigerant. The indoor heat exchanger 11 acts as an evaporator during the cooling operation and as a condenser during the heating operation. The indoor blower 12 is a device that sends indoor air to the indoor heat exchanger 11.

(Operation mode, cooling operation)
Next, the operation mode of the air conditioner 1 will be described. First, the cooling operation will be described. In the cooling operation, the refrigerant sucked into the compressor 6 is compressed by the compressor 6 and discharged in a high temperature and high pressure gas state. The high-temperature and high-pressure gas-state refrigerant discharged from the compressor 6 passes through the flow path switching device 7 and flows into the heat exchanger 8 acting as a condenser, and in the heat exchanger 8, the outdoor blower 9 causes the refrigerant to flow into the heat exchanger 8. It exchanges heat with the sent outdoor air, condenses and liquefies. The condensed liquid-state refrigerant flows into the expansion unit 10 and is expanded and depressurized in the expansion unit 10 to become a low-temperature and low-pressure gas-liquid two-phase state refrigerant. Then, the refrigerant in the gas-liquid two-phase state flows into the indoor heat exchanger 11 that acts as an evaporator, and in the indoor heat exchanger 11, heat is exchanged with the indoor air sent by the indoor blower 12, and is evaporated and gasified. do. At this time, the indoor air is cooled, and cooling is performed indoors. The evaporated low-temperature and low-pressure gas-state refrigerant passes through the flow path switching device 7 and is sucked into the compressor 6.

(Operation mode, heating operation)
Next, the heating operation will be described. In the heating operation, the refrigerant sucked into the compressor 6 is compressed by the compressor 6 and discharged in a high temperature and high pressure gas state. The high-temperature and high-pressure gas-state refrigerant discharged from the compressor 6 passes through the flow path switching device 7 and flows into the indoor heat exchanger 11 acting as a condenser, and in the indoor heat exchanger 11, the indoor blower. It exchanges heat with the indoor air sent by No. 12, condenses and liquefies. At this time, the indoor air is warmed and heating is performed in the room. The condensed liquid-state refrigerant flows into the expansion unit 10 and is expanded and depressurized in the expansion unit 10 to become a low-temperature and low-pressure gas-liquid two-phase state refrigerant. Then, the refrigerant in the gas-liquid two-phase state flows into the heat exchanger 8 that acts as an evaporator, and in the heat exchanger 8, heat is exchanged with the outdoor air sent by the outdoor blower 9 to evaporate and gasify. The evaporated low-temperature and low-pressure gas-state refrigerant passes through the flow path switching device 7 and is sucked into the compressor 6.

FIG. 2 is a front view showing the heat exchanger 8 according to the first embodiment, and FIG. 3 is a side view showing the heat exchanger 8 according to the first embodiment. Next, the heat exchanger 8 will be described in detail. As shown in FIGS. 2 and 3, the heat exchanger 8 is, for example, a parallel flow type heat exchanger 8. The heat exchanger 8 may be a fin tube type heat exchanger 8 or a finless type heat exchanger 8. The heat exchanger 8 includes a heat transfer tube 20, fins 30, and a laminate 40. The heat transfer tube 20 is a tube through which a refrigerant flows, and a plurality of heat transfer tubes 20 are arranged and made of aluminum or an aluminum alloy. Further, the heat transfer tube 20 may use a clad material having aluminum as a core material. The heat transfer tube 20 is, for example, a flat tube in which a plurality of flow paths 21 (see FIG. 4) through which a refrigerant flows are formed in a row. The heat transfer tube 20 may be a circular tube.

The fin 30 is a member that transfers the heat of the refrigerant flowing through the heat transfer tube 20, and is, for example, a corrugated fin that is bent and arranged between the heat transfer tube 20 and the heat transfer tube 20. The fin 30 is made of, for example, aluminum. As described above, the fin 30 may be made of the same material as the heat transfer tube 20, or may be made of a different material. The fin 30 may be a plate fin.

The laminated body 40 is made of aluminum, for example, in which the refrigerant flows in the internal space 40a (see FIG. 4) and the refrigerant is diverted to the plurality of inserted heat transfer tubes 20. As described above, the laminated body 40 may use the same material as the heat transfer tube 20, or may use a different material.

FIG. 4 is a cross-sectional view showing the laminated body 40 according to the first embodiment, and is a cross-sectional view taken along the line AA of FIG. FIG. 5 is a cross-sectional view showing the laminated body 40 according to the first embodiment, and is a cross-sectional view taken along the line BB of FIG. Next, the laminated body 40 will be described in detail. As shown in FIGS. 4 and 5, the laminated body 40 includes a first plate material 41 and a second plate material 45.

The first plate material 41 is a plate-shaped member having a base layer 42 and a brazing material layer 43, and is, for example, a clad material. The base layer 42 is made of, for example, aluminum. The brazing filler metal layer 43 is made of a brazing filler metal containing a base material. The base material is a material provided on the surface of the base layer 42 and having a lower redox potential than the base layer 42, and is, for example, zinc. The brazing material is formed by brazing and joining the first plate material 41, the second plate material 45, the laminate 40, and the heat transfer tube 20. In the first embodiment, the brazing filler metal layer 43 is provided on both sides of the base layer 42. Although the case where the brazing material layer 43 in which the base material is mixed with the brazing material is used in the first embodiment, the base material and the brazing material may be individually provided in the base layer 42.

The second plate material 45 is a plate-shaped member that is alternately laminated with the first plate material 41 to form an internal space 40a in the laminated body 40 together with the first plate material 41, and is, for example, a bare material. The second plate material 45 is not limited to the bare material but may be a clad material. As described above, in order to laminate the laminated body 40 to form the internal space 40a, the brazing material layer 43 is formed on the surface layer of the first plate material 41 or the surface layer of the second plate material 45. The brazing material layer 43 is not provided on the surface of the second plate material 45. The second plate material 45 may be made of aluminum as in the base layer 42. Then, in the laminated body 40, the end surface of the second plate material 45 and the end surface of the first plate material 41 are misaligned. Specifically, the end face of the first plate member 41 protrudes from the end face of the second plate member 45 by a predetermined length T. Further, as shown in FIG. 5, the first plate material 41 protrudes from the second plate material 45 over the entire circumference.

FIG. 6 is a schematic diagram showing the remote anticorrosion action of zinc. Here, the anticorrosion action of a base material such as zinc, which has a lower redox potential than aluminum, will be described. It is known that when aluminum is exposed to a corroded environment, the surface in contact with the corroded environment corrodes relatively slowly and entirely in the same manner, and pitting corrosion that progresses locally at a relatively high speed. By providing the aluminum alloy member containing zinc with respect to the member made of aluminum, it is possible to promote corrosion of the aluminum alloy member having a low oxidation-reduction potential and prevent pitting corrosion of the member made of aluminum. Further, as shown in FIG. 6, such a base material having a low redox potential not only protects the coated portion but also protects a position slightly distant from the coated portion by remote protection. It is known to have an action.

In FIG. 6, the region R1 containing zinc on the surface protects the region R2 containing no zinc on the surface. On the other hand, in FIG. 6, the region R1 containing zinc on the surface is separated from R2, and the region R3 containing no zinc on the surface is not protected against corrosion.

FIG. 7 is a graph showing the remote anticorrosion effect of zinc. This assumes that the aluminum member is exposed to the environment in which the outdoor unit of the air conditioner is generally placed. In FIG. 7, the horizontal axis indicates the width X of R1 and the vertical axis indicates the width Y of R2. As shown in FIG. 7, R1 has a remote anticorrosion action up to a position 5 mm away. In the first embodiment, in consideration of the graph of FIG. 7, as shown in FIG. 4, the thickness S of the second plate material 45 is set to be within 10 mm (= 5 mm × 2). As described above, in the surface layer of the laminated body 40, the maximum width of the portion having no base material is 10 mm or less. As a result, the entire end face of the second plate material 45 falls within the range of a distance of 5 mm from the brazing material layer 43 of the first plate material 41, so that corrosion is prevented.

As described above, the laminated body 40 is a laminated body 40 in which a plate material having no holes and a plate material having holes formed are combined and laminated to form an internal space 40a. Some plate materials have the same or different surface layers on the front and back of the base layer. The surface layer includes the base layer 42 and the same material as the base layer 42, a base material having a lower redox potential than the base layer 42, a brazing material, or both a component having a base redox potential than the base layer and a brazing material component. Is one of the materials having. Then, there is a portion where the end face of the plate material is displaced, and the surface of the plate material exposed as a result of the displacement has a layer containing a base material having a lower redox potential than the base layer of the plate material as a component.

According to the first embodiment, there is a portion where the end face of the plate material is displaced, and the surface of the plate material exposed as a result of the displacement includes a layer containing a base material having a lower redox potential than the base layer of the plate material as a component. Have. Therefore, the remote anticorrosion action provided by the base material of one plate material extends to the end face of the plate material itself and the end face of the other plate material. Therefore, the corrosion resistance of the end face can be improved. As described above, since the end surface of the second plate material 45 and the end surface of the first plate material 41 are displaced from each other, the redox potential of the brazing material layer 43 of the first plate material 41 is a base material, which is a remote effect. The anticorrosion action extends to the end faces of the first plate material 41 and the second plate material 45. Therefore, the corrosion resistance of the end face of the laminated body 40 can be improved.

Further, the base layer 42 is aluminum, the base material contained in the brazing material layer 43 is zinc, and the distance from the first plate material 41 to the second plate material 45 is 5 mm or less. As a result, as shown in FIG. 7, the corrosion resistance of the end face of the laminated body 40 can be reliably improved.

Although the first embodiment illustrates the heat exchanger 8 provided in the outdoor unit 2, the indoor heat exchanger 11 may have the same configuration.

Embodiment 2.
FIG. 8 is a cross-sectional view corresponding to FIG. 4 showing the laminated body 140 according to the second embodiment. The laminated body 140 according to the second embodiment is different from the first embodiment in that the brazing filler metal layer 43 is provided on one surface of the base layer 42. In the second embodiment, the parts common to the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and the differences from the first embodiment will be mainly described.

As shown in FIG. 8, the brazing filler metal layer 43 is provided on one surface of the base layer 42. A second brazing filler metal layer 44 containing no base material having a lower redox potential than the base layer 42 is provided on the other surface of the base layer 42. When the length L1 (the length of the arrow in FIG. 8) from the brazing filler metal layer 43 to the brazing filler metal layer 43 on the end face is shorter than a predetermined length, the remote anticorrosion action of zinc extends over a wide range of the end face, so that the base layer 42 If the brazing filler metal layer 43 containing zinc is provided on only one surface, the anticorrosion action is sufficient. In this case, the length L1 is within 10 mm (= 5 mm × 2). As a result, the entire end faces of the first plate material 41 and the second plate material 45 fall within the range of a distance of 5 mm from the brazing material layer 43 of the first plate material 41, so that they are protected from corrosion. As described above, in the second embodiment, the amount of the base material having a lower redox potential than that of the base layer 42 can be reduced.

Embodiment 3.
FIG. 9 is a cross-sectional view showing the laminated body 240 according to the third embodiment. In the laminated body 240 according to the third embodiment, the amount of deviation between the end face of the second plate material 45 and the end face of the first plate material 41 is different from that of the first embodiment. In the third embodiment, the parts common to the first and second embodiments are designated by the same reference numerals, the description thereof will be omitted, and the differences from the first and second embodiments will be mainly described.

As shown in FIG. 9, at one end of the laminated body 240, the position of the end surface of the second plate material 45 and the position of the end surface of the first plate material 41 coincide with each other. When the length L2 (the length of the arrow in FIG. 9) in the depth direction of the second plate 45 is shorter than the predetermined length, the remote anticorrosion action of zinc of the first plate 41 extends over the entire depth direction. Therefore, it is not necessary for the first plate material 41 to protrude from the second plate material 45. Further, at the other end of the laminated body 240, the length of the end surface of the first plate material 41 protruding from the position of the end surface of the second plate material 45 is shorter than that of the first embodiment. When the length L2 (the length of the arrow in FIG. 9) in the depth direction of the second plate material 45 is short, the remote anticorrosion action of zinc of the first plate material 41 extends over the entire depth direction. Therefore, the amount of the first plate material 41 protruding from the second plate material 45 can be reduced. In this case, the length L2 is within 10 mm (= 5 mm × 2). As a result, the entire end faces of the first plate material 41 and the second plate material 45 fall within the range of a distance of 5 mm from the brazing material layer 43 of the first plate material 41, so that they are protected from corrosion.

Embodiment 4.
FIG. 10 is a cross-sectional view showing the laminated body 340 according to the fourth embodiment. As shown in FIG. 10, in the laminated body 340 according to the fourth embodiment, the first plate material 41 does not have a brazing material component, and the second plate material 45 does not contain a base material. It differs from the first to third embodiments in that the material layer 44 is provided. The laminate 340 is provided with a sacrificial layer 46 on one surface of the base layer 42, in which the first plate material 41 has only a base material having a lower redox potential than the base layer 42 added to the components of the base layer 42.

According to the fourth embodiment, neither the first plate material 41 nor the second plate material 45 requires a brazing material layer 43 made of a brazing material containing a base material. Since the brazing material layer 43 made of a brazing material containing a base material is generally a custom-made specification, there are restrictions when procuring it. On the other hand, the second brazing material layer 44 and the sacrificial layer 46 containing no base material can be manufactured as general-purpose specifications by a manufacturer of the clad material, and are easily available.

Embodiment 5.
FIG. 11 is an exploded perspective view showing the laminated body 440 according to the fifth embodiment. As shown in FIG. 11, in the laminated body 440 according to the fifth embodiment, the first layer 60, the second layer 61, the third layer 62, and the fourth layer 63 are overlapped with each other and the heat transfer tube 64 in the first row. It is configured by brazing the heat transfer tube 65 in the second row. Here, the first layer 60, the second layer 61, the third layer 62, and the fourth layer 63 have different shapes. A heat transfer tube insertion hole 66 is formed in the first layer 60, and the heat transfer tube 64 in the first row and the heat transfer tube 65 in the second row are inserted. A connecting hole 67 is formed in each of the second layer 61 and the third layer 62.

FIG. 12 is a cross-sectional view showing the laminated body according to the fifth embodiment. As shown in FIG. 12, the connecting holes 67 formed in the second layer 61 and the third layer 62 overlap each other to form a large internal space 40a. Here, focusing on the specifications of the material of the plate material, as shown in FIG. 12, the first layer 60, the second layer 61, and the third layer 62 contain a base material on one surface of the surface of the base layer 42. A brazing filler metal layer 43 is provided, and a sacrificial layer 46 is provided on the other surface. The fourth layer 63 is a material composed of only the base layer 42.

Regarding the deviation of the end faces between the plate materials, the size of the plate materials may be alternately increased or decreased as shown in FIG. 4 or the like, or as shown in FIG. 12, depending on the required dimensions of the plate materials. The end face may be displaced in a stepped manner.

Here, the fifth embodiment is different from the first to fourth embodiments in that the fourth layer 63 does not contain a base material having a lower redox potential than the base layer 42. In general, the portion such as the outermost surface 68 in FIG. 12 includes a base material having a lower redox potential than the base layer 42, and the anticorrosion effect of the entire surface is enhanced. It is known that when the base layer is aluminum and the base material is zinc, if the base layer has a thickness of about 3 mm, the possibility of opening a hole penetrating the plate material due to corrosion is practically reduced. In the fifth embodiment, since the fourth layer 63 has a plate thickness of 4 mm, the outermost surface 68 remains as the base layer. As described above, if the outermost surface 68 can be left as the base layer, there is an effect that the amount of the clad material, which is expensive and has restrictions on availability, can be reduced.

1 air conditioner, 2 outdoor unit, 3 indoor unit, 4 refrigerant circuit, 5 refrigerant pipe, 6 compressor, 7 flow path switching device, 8 heat exchanger, 9 outdoor blower, 10 expansion part, 11 indoor heat exchanger, 12 indoor blower, 20 heat transfer tube, 21 flow path, 30 fins, 40 laminate, 40a internal space, 41 first plate material, 42 base layer, 43 brazing material layer, 44 second brazing material layer, 45 second plate material , 46 sacrificial layer, 50 flat tube, 60 1st layer, 61 2nd layer, 62 3rd layer, 63 4th layer, 64 heat transfer tube, 65 heat transfer tube, 66 heat transfer tube insertion hole, 67 connecting hole, 68 outermost surface , 140 laminated body, 240 laminated body, 340 laminated body, 440 laminated body.

Claims

It is a laminated body in which a plurality of plate materials having at least one plate material having holes formed are combined and laminated to form an internal space.
A laminated body having a layer containing a base material having a lower redox potential than the base layer of the plate material as a component on at least a part of the surface of the plate material exposed as a result of the deviation of the end face of the plate material. ..
A base layer, a plate-shaped first plate material provided on the surface of the base layer and having a base material having a lower redox potential than the base layer, and a plate-like first plate material.
A plate-shaped second plate material that is laminated on the first plate material to form an internal space together with the first plate material and whose end face is deviated from the end face of the first plate material.
It is a laminated body equipped with
A laminated body in which a brazing material layer is formed on the surface layer of the first plate material or the surface layer of the second plate material in order to form an internal space by laminating.
The base layer is aluminum
The base material is zinc,
The laminate according to claim 1 or 2, wherein the maximum width of the portion of the surface layer having no base material is 10 mm or less.
The laminate according to claim 3, wherein at least the outermost surface is a base material having a redox potential lower than that of the base layer.
When the thickness of the material with the outermost surface is 3 mm or more,
The laminate according to claim 3, wherein the outermost surface is not a base material having a redox potential lower than that of the base layer.
The laminate according to any one of claims 1 to 5, wherein the at least one plate material does not have a brazing material component, and at least one plate material is provided with a brazing material layer containing no base material.
The laminate according to any one of claims 1 to 6, which does not contain a base material having a lower redox potential than the base layer and has a layer composed of only the base layer.
With the laminate according to any one of claims 1 to 7.
A plurality of heat transfer tubes inserted into the internal space of the laminated body and flowing a refrigerant inside,
A heat exchanger equipped with.
An air conditioner comprising the heat exchanger according to claim 8.