JP2022549942A - Fins and heat exchangers for heat exchangers - Google Patents

Abstract

Fins (1) for heat exchanger and heat exchanger. Said heat exchanger fin comprises a core layer (11), a first layer (12) and a second layer (13), the material of the core layer (11) is industrial pure aluminum or aluminum alloy The material of the second layer (13) is an aluminum alloy, and the second layer (13) is provided on at least one of the two sides of the core layer that are arranged to face each other in the thickness direction. The element of the material of the first layer (12) contains an alloying element that does not react with the aluminum element to form a binary intermetallic compound, and the thickness direction of the core layer (11) and the thickness of the first layer (12) direction is substantially parallel to the thickness direction of the second layer (13). A first layer (12) is provided on one side of the second layer (13) that is farther from the core layer (11) in the thickness direction. The material of the second layer (13) and the material of the core layer (11) have different types of alloying elements, different alloying element contents, or both. At least some grain boundaries of the materials of the second layer (13) and the core layer (11) are not shared. Embodiments of the present disclosure are used to improve post-weld corrosion resistance performance of fins (1) for heat exchangers. Application of the fins (1) to a heat exchanger can extend the life of the heat exchanger.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the priority and benefit of Chinese Patent Application No. 201910944330.9 filed on September 30, 2019, which is incorporated by reference into this application in its entirety.

TECHNICAL FIELD The present disclosure relates to the technical field of heat exchange devices, and in particular to bending fins and heat exchangers for heat exchangers.

In the application of heat exchange between a heat exchanger and air, fins are provided between adjacent heat transfer tubes, and the fins and adjacent heat transfer tubes are welded and connected. This enhances the heat exchange with the air. The corrosion resistance of the fins in air affects the heat exchange performance of the heat exchanger, is related to the life of the heat exchanger, and is an important indicator of the performance of the fins.

The present disclosure is based on the inventor's discovery and recognition of the following facts and problems.
In the related art, the fin of the heat exchanger includes an aluminum alloy core layer and a brazing layer, and the brazing layer directly covers the aluminum alloy core layer to facilitate welding the core layer and the heat transfer tube. ing. The material of the brazing layer is also an aluminum alloy. However, the applicant found that when the brazing layer directly covers the core layer, due to the limited thickness of the fins, the alloying elements in the brazing layer diffuse to the grain boundaries of the core layer material during welding. did. Here, some alloying elements are not formed into a binary intermetallic compound together with the aluminum element, and these alloying elements are formed into a crystal phase with a relatively low potential at the grain boundaries of the core layer. After welding, the intergranular corrosion resistance performance of the fin material is significantly lower than before welding, affecting the life of the heat exchanger.

Accordingly, an embodiment of one aspect of the present disclosure provides a fin for a heat exchanger. The fin includes material layers containing different alloying element types and/or alloying elements to provide improved corrosion resistance after welding. Application of the fins to a heat exchanger can extend the life of the heat exchanger.

Another aspect of the present disclosure provides a heat exchanger.

In an embodiment of the first aspect of the present disclosure, the fin for heat exchanger includes a core layer, a first layer and a second layer, the material of the core layer is industrial pure aluminum or aluminum alloy The core layer includes a first side surface and a second side surface that are arranged to face each other in the thickness direction. The material of the second layer is an aluminum alloy, and the second layer is provided outside at least one of the first side and the second side of the core layer. The element of the material of the first layer includes an alloy element that does not react with the aluminum element to form a binary intermetallic compound, and the thickness direction of the core layer, the thickness direction of the first layer, and the second layer. It is substantially parallel to the thickness direction of the layer. The second layer includes two sides arranged to face each other in its thickness direction, one of the two sides of the second layer being far from the core layer. The first layer is provided outside the one side of the second layer. The material of the second layer and the material of the core layer have different types of alloying elements, different contents of one or more alloying elements, or both. Also, at least some grain boundaries of the materials of the second layer and the core layer are not shared.

According to the heat exchanger fin of the embodiment of the present disclosure, by adding the second layer between the core layer and the first layer, the first layer reacts with the aluminum element during brazing to form a binary Alloying elements that do not form intermetallic compounds diffuse into the second layer. The alloying element diffuses in a large amount at the grain boundary of the second layer, but since the materials of the second layer and the core layer are different (element types and/or element contents are different), at least a part of the second layer and The crystal grains of the core layer are not fused and form more grain boundaries. In addition, since these grain boundaries are not directly connected to the grain boundaries in the second layer, they extend or interfere with the alloying elements diffusing along the second layer grain boundaries, and the core layer grain boundaries of the alloying elements distribution is reduced, improving the corrosion resistance performance of the fin. By applying the fins to a heat exchanger, the service life of the heat exchanger can be extended.

In some embodiments, the material of the first layer comprises elemental silicon and the material of the first layer is an Al—Si based alloy.

In some embodiments, the solidus and liquidus temperatures of the material of the core layer are greater than the solidus and liquidus temperatures of the second layer, or the solidus and liquidus temperatures of the second layer equal to the liquidus temperature.

In some embodiments, the second layer comprises multiple layers of material, wherein the multiple layers of the second layer differ in the type of alloying element from the material of adjacent layers, or contain one or more alloying elements. Different or both.

In some embodiments, the material of the first layer and the material of the core layer have different types of alloying elements, different contents of one or more alloying elements, or both. The material of the first layer and the material of the second layer have different types of alloying elements, different contents of one or more alloying elements, or both. The materials of the first layer and the second layer do not share at least some grain boundaries.

In some embodiments, the fin includes a first side surface and a second side surface that are arranged to face each other in the thickness direction thereof, and the first layer overlaps the second layer in the thickness direction of the fin. becomes the first side or the second side of the fin.

In some embodiments, the thickness of the first layer is 3% to 15% of the thickness of the fin.

In some embodiments, the thickness of the second layer is between 10% and 50% of the thickness of the fin.

A heat exchanger according to an embodiment of the second aspect of the present disclosure includes first header piping, second header piping, a plurality of heat transfer tubes, and fins. The first header pipe and the second header pipe are spaced apart. In order to connect the first header pipe and the second header pipe, one end of the heat transfer pipe is connected to the first header pipe, and the other end of the heat transfer pipe is connected to the second header pipe. The fins are provided between the adjacent heat transfer tubes, and the fins are the fins for the heat exchanger according to any one of the embodiments. A core layer of the fin is welded to the heat transfer tube through the first layer of the fin. The grain boundaries of the materials of the second layer of the fin and the core layer are at least partially unshared.

In some embodiments, the heat transfer tubes are flat tubes and the fins have a length, width and thickness. The longitudinal direction of the fins and the thickness direction of the flat tube are substantially parallel, and the width direction of the fins and the width direction of the flat tube are substantially parallel. The fins are provided with a plurality of through-holes or slots for installing a plurality of the flattened tubes in combination.

1 is a configuration diagram of a fin for a heat exchanger according to an embodiment of the present disclosure; FIG. FIG. 4 is a configuration diagram of fins for a heat exchanger according to another embodiment of the present disclosure; 1 is a configuration diagram of a heat exchanger according to an embodiment of the present disclosure; FIG.

Embodiments of the present disclosure are described in detail below. Examples of said embodiments are shown in the drawings. The embodiments illustrated by the following drawings are exemplary and are intended to be used to explain, not limit, the present disclosure. In describing this disclosure, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "top", "bottom", "front", "back" , "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", " Directions or positional relationships indicated by "radial", "circumferential", etc. are based on the directions or positional relationships shown in the drawings and are intended to facilitate and simplify the description of the present disclosure. and should not be construed as a limitation on the present disclosure, as it does not indicate or imply that any device, element, or fixture should be in, or configured and operated in, any particular orientation. not.

As shown in FIGS. 1-2, a fin 1 for a heat exchanger according to embodiments of the present disclosure includes a core layer 11, a first layer 12 and a second layer 13. As shown in FIG. The material of the core layer 11 is industrially pure aluminum or an aluminum alloy. Here, the aluminum alloy of the core layer 11 may be rust-preventive aluminum, aluminum alloy, and other aluminum alloys. Specifically, the temperature of the solidus line and the liquidus line of the material of the core layer 11 is 615° C. or higher.

The core layer 11 includes a first side surface and a second side surface that are arranged to face each other in the thickness direction. As shown in FIG. 1, the thickness direction of the core layer 11 is in the vertical direction, and the core layer 11 includes an upper side surface and a lower side surface that are arranged to face each other in the vertical direction.

A second layer 13 is provided outside at least one of the first and second side surfaces of the core layer 11 . That is, even if the second layer 13 is provided only outside the first side surface of the core layer 11, or if the second layer 13 is provided only outside the second side surface of the core layer 11, the first side surface of the core layer 11 and A second layer 13 may be provided on the outside of both of the second sides.

The material of the second layer 13 is an aluminum alloy. Here, the aluminum alloy of the second layer 13 may be antirust aluminum or other aluminum alloys. Specifically, the temperature of the solidus line and the liquidus line of the material of the second layer 13 is 615° C. or higher.

The element of the material of the first layer 12 includes an alloy element that does not react with the aluminum element to form a binary intermetallic compound, and when the alloy element and the aluminum element are heated, only a solid solution is formed. Optionally, the material of the first layer 12 may contain elemental silicon. Furthermore, the material of the second layer 13 is an Al-Si based alloy.

The thickness direction of the core layer 11, the thickness direction of the first layer 12, and the thickness direction of the second layer 13 are substantially parallel. The second layer 13 includes two side surfaces arranged to face each other in its thickness direction, one of the two side surfaces of the second layer 13 being farther from the core layer 11 and the second layer 13 A first layer 12 is provided on the outside of said one side of the . That is, the core layer 11, the second layer 13 and the first layer 12 are arranged in sequence, the core layer 11 and the second layer 13 are in contact with each other, and the second layer 13 and the first layer 12 are in contact with each other. there is

As shown in FIG. 1, the thickness direction of the core layer 11, the thickness direction of the first layer 12, and the thickness direction of the second layer 13 are all in the vertical direction, and the second layers 13 face each other in the vertical direction. Includes upper and lower surfaces. The second layer 13 is arranged on the upper surface of the core layer 11 . That is, the lower surface of the second layer 13 and the upper surface of the core layer 11 are connected, and the first layer 12 is arranged on the upper surface of the second layer 13 .

During brazing, the material of the first layer 12 tends to diffuse many alloying elements such as Si into the core layer 11 . Specifically, the material of the first layer 12 is solder, and the heat exchanger fin 1 according to the embodiment of the present disclosure is brazed to other parts of the heat exchanger through the first layer 12. be.

Here, the material of the second layer 13 and the material of the core layer 11 have different types of alloying elements, different contents of one or more alloying elements, or both. In addition, at least part of the grain boundaries of the material of the second layer 13 and the material of the core layer 11 are not shared.

In other words, the ingredients of the material of the second layer 13 and the material of the core layer 11 do not match. That is, whether the material of the second layer 13 and the material of the core layer 11 have different types of alloy elements, or the material of the second layer 13 and the material of the core layer 11 have different alloy element contents, or The material of the layer 13 and the material of the core layer 11 differ in type and content of alloying elements. Furthermore, some grain boundaries are not shared between the materials of the second layer 13 and the core layer 11 .

According to the heat exchanger fin 1 of the present disclosure, by adding the second layer 13 between the core layer 11 and the first layer 12, the aluminum element reacts with the aluminum element in the first layer 12 during brazing. An alloy element (such as Si element) that does not form a binary intermetallic compound diffuses into the second layer 13 . The alloy elements are diffused in a large amount at the grain boundaries of the second layer 13, but since the material components of the second layer 13 and the core layer 11 are different (element types and/or element contents are different), at least one The crystal grains of the second layer 13 and the core layer 11 in the portion are not fused and form more grain boundaries. In addition, since these grain boundaries are not directly connected to the grain boundaries in the second layer 13, the alloy elements that diffuse along the second layer 13 grain boundaries are extended or obstructed, and the core layer of the alloy elements The distribution at 11 grain boundaries is reduced, improving the corrosion resistance performance of the fin 1 . By applying the fins 1 to a heat exchanger, the service life of the heat exchanger can be extended.

Specifically, the heat exchanger fin 1 according to the embodiment of the present disclosure has a multi-layer structure, and the multi-layer fin 1 includes a core layer 11, a second layer 13, and a first layer 12, which are subjected to hot heating. Processed by rolling and compounded (welded). The initial state of the crystal grains of the materials of the core layer 11, the second layer 13, and the first layer 12 is not shared at all, and during rolling such as hot rolling, some of the crystal grains near the interface of adjacent layers The parts merge as one. That is, some grains become shared by both, but are not fully shared by all grains. The greater the difference in the composition of the materials on either side of the grain boundary, the less likely the grains on both sides of the grain boundary will fuse together, and the lower the proportion of fused grains. That is, the larger the difference in the material components between the second layer 13 and the core layer 11, the more the crystal grains of the materials of the core layer 11 and the second layer 13 do not grow completely in one place, The effect of blocking the diffusion of alloy elements such as Si in the first layer 12 from the second layer 13 is good.

While Si in the first layer 12 is diffusing into the second layer 13 during rolling/brazing (diffusion occurs both at the grain boundary and inside the grain, the diffusion rate at the grain boundary is ), when an alloy element such as Si diffuses to the interface between the second layer 13 and the core layer 11, if the crystal grains on both sides of the interface are shared (the grain boundary is also shared ), alloying elements such as Si diffuse relatively easily into the core layer 11 along the grain boundaries. When the crystal grains on both sides of the interface are not shared (the grain boundary is also not shared), the diffusion path from the alloy element such as Si to the core layer 11 becomes long, and the alloy element such as Si diffusing to the grain boundary of the core layer 11 less.

Furthermore, by providing the second layer 13 between the core layer 11 and the first layer 12, the diffusion of elements in the core layer 11 to the first layer 12 is also controlled during brazing. Therefore, by adding more beneficial alloying elements to the core layer 11, the strength of the fin 1 can be improved without affecting the brazing performance while improving the strength and corrosion resistance performance of the core layer 11. can be done. A high strength fin 1 material helps control fin 1 thickness and cost.

In some embodiments, the solidus and liquidus temperatures of the material of the core layer 11 are greater than the solidus and liquidus temperatures of the second layer 13 , or Equal to the line and liquidus temperatures.

In some embodiments, the second layer 13 comprises multiple layers of material, the multiple layers of the second layer 13 differing in type of alloying element from the material of adjacent layers, or contain one or more alloying elements. Different or both. In other words, a multilayer material is provided between the core layer 11 and the first layer 12, and one layer of material adjacent to the core layer 11 in the multilayer material is in contact with the core layer 11, and the second layer of the multilayer is in contact with the core layer 11. One layer of material adjacent to the first layer 12 at 13 is in contact with the third layer. Also, the material components of the layers adjacent to the second layer 13 do not match. That is, the materials of the layers adjacent to the second layer 13 have different types of alloying elements, the materials of the layers adjacent to the second layer 13 have different alloying element contents, or the materials of the layers adjacent to the second layer 13 have different alloying element contents. The type and content of are different.

Thereby, the material of the adjacent layer of the second layer 13 is different, and at least part of the material of one layer of the adjacent layer of the second layer 13 does not fuse with the crystal grains of the material of the other layer, and the grain boundary is formed. Because there is no direct connection, alloying elements such as Si in the first layer 12 have more time to diffuse in the multi-layer material in the second layer 13 .

In some embodiments, the material of the first layer 12 and the material of the core layer 11 have different types of alloying elements, different contents of one or more alloying elements, or both. The material of the first layer 12 and the material of the second layer 13 have different types of alloying elements, different contents of one or more alloying elements, or both. The materials of the first layer 12 and the second layer 13 do not share at least some grain boundaries. That is, both the material of the first layer 12 and the material of the second layer 13 differ from the composition of the material of the core layer 11, and the composition of the material of the first layer 12 and the material of the second layer 13 do not match. Some grain boundaries are not shared between the materials of the second layer 13 and the core layer 11 and between the materials of the first layer 12 and the core layer 11 .

During brazing, Si elements present in the first layer 12 diffuse into the second layer 13 . Since the materials of the first layer 12 and the second layer 13 have different components (different element types and/or element contents), at least part of the crystal grains of the materials of the first layer 12 and the second layer 13 are fused. It is possible to extend and block Si diffusing from the first layer 12 , and further reduce the distribution of Si at the grain boundaries of the core layer 11 , thereby improving the corrosion resistance of the fin 1 . By applying the fins 1 to a heat exchanger, the service life of the heat exchanger can be extended.

In some embodiments, as shown in FIG. 2, both the first side and the second side, which are arranged to face each other along the thickness direction of the core layer 11, are provided with the first layer 12, and the core A second layer 13 is provided between the layer 11 and the first layer 12 on the first side of the core layer 11, and a second layer 13 is provided between the core layer 11 and the first layer 12 on the second side of the core layer 11. be provided. That is, the core layer 11 includes a first side surface and a second side surface that are arranged to face each other along the thickness direction, and the first layer 12 is provided on the first side surface and the second side surface of the core layer 11. , the second layer 13 is provided between the core layer 11 and the first layer 12 on the first side of the core layer 11, and the second layer is provided between the core layer 11 and the first layer 12 on the second side of the core layer 11 13 are provided.

between the core layer 11 and the first layers 12 corresponding to the two sides of the core layer 11 when all the two opposing sides of the core layer 11 are provided as the first layers 12 of solder By providing the second layer 13 on the fin 1, the corrosion resistance performance of the fin 1 is further improved. By applying the fins 1 to a heat exchanger, the service life of the heat exchanger can be further extended.

Furthermore, the fin 1 includes a first side surface and a second side surface that are arranged to face each other in the thickness direction, and the first layer 12 is arranged on one side surface of the second layer 13 in the thickness direction. Farther away, it will be the first side or the second side of the fin 1 . As shown in FIGS. 1 and 2, the thickness direction of the fin 1 is the vertical direction, and the fin 1 includes an upper side surface and a lower side surface that are arranged to face each other in the vertical direction. In the embodiment shown in FIG. 1 , the bottom surface of the first layer 12 and the top surface of the second layer 13 are in contact with each other, and the top surface of the first layer 12 is far from the second layer 13 . The upper surface of the first layer 12 is the upper surface of the fin 1 , and the lower surface of the core layer 11 is the lower surface of the fin 1 . In the embodiment shown in FIG. 2 , the top side of the first layer 12 on top is the top side of the fin 1 , and the bottom side of the first layer 12 on the bottom is the bottom side of the fin 1 .

Here, the first layer 12 is solder to allow the fins 1 to be brazed to other parts of the heat exchanger via the first layer 12 .

In addition, as shown in FIG. 1, the first layer 12 is provided only on one surface of the two surfaces of the core layer 11 that are arranged to face each other, and the first layer 12 and the core layer 11 It should be understood that there may be a second layer 13 in between.

In some embodiments, the thickness of first layer 12 accounts for 3% to 15% of the thickness of fin 1 . By designing the thickness of the first layer 12 to account for 3% to 15% of the total thickness of the fin 1, the strength and brazeability of the fin 1 are improved, and the fin 1 after welding is improved. Corrosion resistance can be improved.

In some embodiments, the thickness of the second layer 13 accounts for 10%-50% of the thickness of the fin 1 . By designing the thickness of the second layer 13 to account for 10% to 50% of the total thickness of the fin 1, the strength and brazeability of the fin 1 are improved, and the fin 1 after welding is improved. Corrosion resistance can be improved.

The thickness of the first layer 12, the thickness of the second layer 13, and the thickness of the fin 1 are all the thicknesses before the fin 1 and other parts are welded.

As shown in FIG. 3, the fins 1 for heat exchangers according to embodiments of the present disclosure can be used in heat exchangers. Specifically, the heat exchanger includes a first header pipe (not shown), a second header pipe (not shown), a plurality of heat transfer tubes 2, and fins. The first header pipe and the second header pipe are spaced apart. Specifically, the longitudinal direction of the first header pipe coincides with the longitudinal direction of the second header pipe. That is, the first header pipe and the second header pipe are arranged in parallel.

In order to connect the first header pipe and the second header pipe, one end of each heat transfer pipe 2 is connected to the first header pipe, and the other end of the heat transfer pipe 2 is connected to the second header pipe. . In other words, the plurality of heat transfer tubes 2 are connected between the first header piping and the second header piping to connect the first header piping and the second header piping. The fins are provided between adjacent heat transfer tubes 2 . Here, the fin is the fin 1 for the heat exchanger according to the embodiment of the present disclosure, the core layer 11 of the fin 1 is welded to the heat transfer tube 2 via the first layer 12 of the fin 1, and the fin At least some of the crystal grains of the material of the second layer 13 and the core layer 11 are not shared.

In some specific embodiments, the heat transfer tubes 2 are flat tubes, the flat tubes comprising at least one channel extending along the longitudinal direction of the flat tubes, the channel length being the length of the flat tubes. It is. A flat pipe connects the first header pipe and the second header pipe through the channel. As shown in FIG. 3, the longitudinal direction of the flat tube is parallel to the front-rear direction, and the thickness direction of the flat tube is parallel to the vertical direction. Moreover, the width direction of the flat tube is parallel to the left-right direction. The flattened tube includes a plurality of channels, each extending along the anterior-posterior direction through the flattened tube. The plurality of channels are spaced apart along the left-right direction.

The fin 1 has a length, width and thickness. The longitudinal direction of the fins 1 and the thickness direction of the flat tube are substantially parallel, and the width direction of the fins and the width direction of the flat tube are substantially parallel. As shown in FIG. 3, the longitudinal direction of the fin 1 is parallel to the vertical direction, and the width direction of the fin 1 is parallel to the horizontal direction. Moreover, the thickness direction of the fin 1 is parallel to the front-rear direction.

The fin 1 is provided with a plurality of through holes or slots for installing a plurality of said flat tubes in combination. As shown in FIG. 3, the fins 1 are provided with through holes or slots penetrating the fins 1 along the front-rear direction. The flat tubes can pass through the fins 1 via through holes or slots.

The heat exchanger includes a plurality of fins 1, which are spaced along the length of the flat tube. As shown in FIG. 3, the plurality of fins 1 are spaced apart along the longitudinal direction, and the through holes or slots in the plurality of fins 1 are provided correspondingly. Along its longitudinal direction, the flattened tube passes through correspondingly provided through-holes or slots of the fins 1 in sequence. It should be understood that the flat tube and the wall surface of the through hole or the wall surface of the slot are in contact with each other.

A fin for a heat exchanger according to an embodiment of the present disclosure is described below.

The fin 1 has a three-layer structure, a first layer 12, a second layer 13 and a core layer 11 in order. The first layer 12 adopts AA4343 aluminum alloy, the second layer 13 adopts industrial pure aluminum AA1100, and the core layer 11 adopts AA3003. The thickness of the first layer 12 and the second layer 13 respectively account for 10% and 30% of the thickness of the fin 1, and the finished thickness of the fin 1 is 0.1 mm.

Semi-continuous casting is adopted to obtain the required AA4343, AA1100 and AA3003 ingots respectively, the ingot is homogenized, and the required thickness ratio of AA4343 and AA1100 is obtained through rolling and face milling. Three plate-shaped raw materials are stacked in order and hot-rolled. After hot rolling to a thickness of 3 to 5 mm, the fin 1 is cold rolled to the required thickness.

When the fins 1 are applied to a heat exchanger, they are trimmed and lined according to the required size of the fins of the heat exchanger. The end paper should ensure that the first layer 12 of the fin 1 is in good contact with the heat transfer tube. The assembled heat exchanger cores are brazed in a furnace. During brazing, the actual maximum temperature of the heat exchanger core is above 590° C., but below the solidus temperature of the core layer 11 material. The duration of 590°C or higher is 1 minute or longer. After cooling, a heat exchanger core is obtained in which the fins 1 and the heat exchange tubes are well brazed.

During heat treatment and brazing heating, the second layer 13 of AA1100 reduces the diffusion of Si of the first layer 12 to the grain boundaries of the core layer 113003, so that the core layer 11 can maintain good intergranular corrosion resistance performance. do.

Fins for heat exchangers according to other embodiments of the present disclosure are described below.

The fin 1 has a three-layer structure, a first layer 12, a second layer 13 and a core layer 11 in order. The first layer 12 adopts AA4343 aluminum alloy, the second layer 13 adopts industrial pure aluminum AA1050, the core layer 11 adopts 1.5wt. AA3003 with % zinc (Zn) is employed. The thickness of the first layer 12 and the second layer 13 respectively account for 10% and 50% of the thickness of the fin 1, and the finished thickness of the fin 1 is 0.1 mm.

The required AA4343, AA1050, and 1.5 wt. % Zn, the ingot was homogenized, and the required thickness ratios of AA4343, AA1050, and 1.5 wt. AA3003 containing % Zn is obtained. Three plate-shaped raw materials are stacked in order and hot-rolled. After hot rolling to a thickness of 3 to 5 mm, the fin 1 is cold rolled to the required thickness.

When the fins 1 are applied to a heat exchanger, they are trimmed and lined according to the required size of the fins of the heat exchanger. The end paper should ensure that the first layer 12 of the fin 1 is in good contact with the heat transfer tube. The assembled heat exchanger cores are brazed in a furnace. During brazing, the actual maximum temperature of the heat exchanger core is above 590° C., but below the solidus temperature of the core layer 11 material. The duration of 590°C or higher is 1 minute or longer. After cooling, a heat exchanger core is obtained in which the fins 1 and the heat exchange tubes are well brazed.

During heat treatment and brazing heating, the second layer 13 of AA1050 reduces the diffusion of Si of the first layer 12 to the grain boundaries of the core layer 11 so that the core layer 11 can maintain good intergranular corrosion resistance performance. do. At the same time, 1.5 wt. % Zn, the corrosion potential of the core layer 11 is lower than that of the solder joints and the second layer 13 . The low potential core layer 11 can play a protective role in a corrosive environment and further improve the corrosion life of the fin 1 .

Fins for heat exchangers according to still other embodiments of the present disclosure are described below.

The fin 1 has a three-layer structure, a first layer 12, a second layer 13 and a core layer 11 in order. The first layer 12 adopts AA4343 aluminum alloy, the second layer 13 adopts industrial pure aluminum AA1100, and the core layer 11 adopts AA3005. The thickness of the first layer 12 and the second layer 13 respectively account for 10% and 30% of the thickness of the fin 1, and the finished thickness of the fin 1 is 0.09mm.

Semi-continuous casting is adopted to obtain the required AA4343, AA1100, AA3005 ingots respectively, the ingot is homogenized, and the required thickness ratio of AA4343, AA1100 and AA3005 is obtained through rolling and face milling. Three plate-shaped raw materials are stacked in order and hot-rolled. After hot rolling to a thickness of 3 to 5 mm, the fin 1 is cold rolled to the required thickness.

When the fins 1 are applied to a heat exchanger, they are trimmed and lined according to the required size of the fins of the heat exchanger. The end paper should ensure that the first layer 12 of the fin 1 is in good contact with the heat transfer tube. The assembled heat exchanger is brazed in a furnace. During brazing, the actual maximum temperature of the heat exchanger core is above 590° C., but below the solidus temperature of the core layer 11 material. The duration of 590°C or higher is 1 minute or longer. After cooling, a heat exchanger core is obtained in which the fins 1 and the heat exchange tubes are well brazed.

During heat treatment and brazing heating, the second layer 13 of AA1100 reduces the diffusion of Si of the first layer 12 to the grain boundaries of the core layer 11 so that the core layer 11 can maintain good intergranular corrosion resistance performance. do. At the same time, the second layer 13 can also control the diffusion of Mg in the core layer 11 to the first layer 12, so even for the multi-layer fin 1 containing Mg, a protective atmosphere brazing furnace may be used. Can be soldered. In addition, since the strength of the AA3005 material is higher than that of the conventional AA3003 aluminum alloy, the thickness of the fin 1 having the core layer 11 of AA3005 is appropriately thinner than the thickness of the core layer 11 of AA3003 in the first embodiment. be able to.

Fins for heat exchangers according to other embodiments of the present disclosure are described below.

The fin 1 has a three-layer structure, a first layer 12, a second layer 13 and a core layer 11 in order. The first layer 12 adopts AA4343 aluminum alloy, the second layer 13 adopts rust-proof aluminum AA3003, and the core layer 11 adopts AA7072. The thickness of the first layer 12 and the second layer 13 respectively account for 10% and 40% of the thickness of the fin 1, and the finished thickness of the fin 1 is 0.1 mm.

Semi-continuous casting is adopted to obtain the required AA4343, AA3003, AA7072 ingots respectively, the ingot is homogenized, and the required thickness ratio of AA4343, AA3003 and AA7072 is obtained through rolling and face milling. Three plate-shaped raw materials are stacked in order and hot-rolled. After hot rolling to a thickness of 3 to 5 mm, the fin 1 is cold rolled to the required thickness.

When the fins 1 are applied to a heat exchanger, they are trimmed and lined according to the required size of the fins of the heat exchanger. The end paper should ensure that the first layer 12 of the fin 1 is in good contact with the heat transfer tube. The assembled heat exchanger is brazed in a furnace. During brazing, the actual maximum temperature of the heat exchanger core is above 590° C., but below the solidus temperature of the core layer 11 material. The duration of 590°C or higher is 1 minute or longer. After cooling, a heat exchanger core is obtained in which the fins 1 and the heat exchange tubes are well brazed.

During heat treatment and brazing heating, the second layer 13 of AA3003 reduces the diffusion of Si of the first layer 12 to the grain boundaries of the core layer 11 so that the core layer 11 can maintain good intergranular corrosion resistance performance. do. At the same time, the corrosion potential of the AA7072 core layer 11 containing about 1% Zn is lower than the corrosion potential of the solder joints and the second layer 13 . The low potential core layer 11 can play a protective role in a corrosive environment and further improve the corrosion life of the fin 1 .

Fins for heat exchangers according to still other embodiments of the present disclosure are described below.

The fin 1 has a three-layer structure, a first layer 12, a second layer 13 and a core layer 11 in order. The first layer 12 adopts AA4045 aluminum alloy, the second layer 13 adopts industrial pure aluminum AA1100, and the core layer 11 adopts AA6063. The thickness of the first layer 12 and the second layer 13 respectively account for 8% and 30% of the thickness of the fin 1, and the finished thickness of the fin 1 is 0.08mm.

Semi-continuous casting is adopted to obtain the required AA4045, AA1100, AA6063 ingots respectively, the ingot is homogenized, and the required thickness ratio of AA4045, AA1100 and AA6063 is obtained through rolling and face milling. Three plate-shaped raw materials are stacked in order and hot-rolled. After hot rolling to a thickness of 3 to 5 mm, the fin 1 is cold rolled to the required thickness.

When the fins 1 are applied to a heat exchanger, they are trimmed and lined according to the required size of the fins of the heat exchanger. The end paper should ensure that the first layer 12 of the fin 1 is in good contact with the heat transfer tube. The assembled heat exchanger is brazed in a furnace. During brazing, the actual maximum temperature of the heat exchanger core is above 590° C., but below the solidus temperature of the core layer 11 material. The duration of 590°C or higher is 1 minute or longer. After cooling, a heat exchanger core is obtained in which the fins 1 and the heat exchange tubes are well brazed.

During heat treatment and brazing heating, the second layer 13 of AA1100 reduces the diffusion of Si of the first layer 12 to the grain boundaries of the core layer 11 so that the core layer 11 can maintain good intergranular corrosion resistance performance. do. At the same time, the second layer 13 can also control the diffusion of Mg in the core layer 11 to the first layer 12, so even for the multi-layer fin 1 containing Mg, a protective atmosphere brazing furnace may be used. Can be soldered. In addition, since the AA6063 material has a strengthening effect within a certain period of time, the strength of the fin 1 after welding is higher than that of the conventional AA3003 alloy, and the thickness of the fin 1 having the core layer 11 of AA6063 is the same as that of the first embodiment. It can be appropriately thinner than the thickness of the core layer 11 of AA3003 in the form.

References herein such as "one embodiment," "some embodiments," "examples," "specific examples," "some examples," and other descriptions may refer to embodiments or examples. are meant to be included in at least one embodiment or example of the present disclosure. The exemplary descriptions of such terms in this specification do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Moreover, where not contradicted by each other, persons of ordinary skill in the art can combine and combine different embodiments or implementations and features of different embodiments or implementations described herein.

While the embodiments of the present disclosure have been shown and described above, the above embodiments are illustrative and should not be construed as limiting the present disclosure, and those skilled in the art will appreciate the It should be understood that changes, modifications, substitutions and modifications can be made within the scope of the disclosure.

1: Fin 11: Core layer 12: First layer 13: Second layer 2: Heat transfer tube

The element of the material of the first layer 12 includes an alloy element that does not react with the aluminum element to form a binary intermetallic compound, and when the alloy element and the aluminum element are heated, only a solid solution is formed. Optionally, the material of the first layer 12 may contain elemental silicon. Furthermore, the material of the first layer 12 is an Al-Si based alloy.

In some embodiments, the second layer 13 comprises multiple layers of material, the multiple layers of the second layer 13 differing in type of alloying element from the material of adjacent layers, or contain one or more alloying elements. different or both. In other words, a multilayer material is provided between the core layer 11 and the first layer 12, and one layer of material adjacent to the core layer 11 in the multilayer material is in contact with the core layer 11, and the second layer of the multilayer is in contact with the core layer 11. A layer of material adjacent to the first layer 12 at 13 is in contact with the first layer. Also, the material components of the layers adjacent to the second layer 13 do not match. That is, the materials of the layers adjacent to the second layer 13 have different types of alloying elements, the materials of the layers adjacent to the second layer 13 have different alloying element contents, or the materials of the layers adjacent to the second layer 13 have different alloying element contents. The type and content of are different.

During heat treatment and brazing heating, the second layer 13 of AA1100 reduces the diffusion of Si of the first layer 12 to the grain boundaries of the core layer 11 of AA3003, and the core layer 11 maintains good intergranular corrosion resistance performance. It can be so.

Claims (10)

A fin for a heat exchanger,
The fin includes a core layer, a first layer, and a second layer, the material of the core layer is industrial pure aluminum or an aluminum alloy, and the core layer has, in its thickness direction, The material of the second layer is an aluminum alloy, and at least one of the first side and the second side of the core layer is provided. The second layer is provided on the outer side of one side, the element of the material of the first layer includes an alloy element that does not react with the aluminum element to form a binary intermetallic compound, and the thickness direction of the core layer; The thickness direction of the first layer and the thickness direction of the second layer are substantially parallel, and the second layer includes two side surfaces arranged to face each other in the thickness direction, One of the two sides of the second layer is far from the core layer, the first layer is provided outside the one side of the second layer, and the material of the second layer and the The materials of the core layer have different types of alloying elements, or have different contents of one or more alloying elements, or both, and at least part of the grain boundaries of the materials of the second layer and the core layer are shared. A fin for a heat exchanger, characterized in that: The fin for a heat exchanger according to claim 1, characterized in that the material of said first layer contains silicon element, and the material of said first layer is an Al-Si based alloy. The solidus and liquidus temperatures of the core layer material are greater than or equal to the solidus and liquidus temperatures of the second layer. A fin for a heat exchanger according to claim 1 or 2, characterized in that: The second layer comprises multiple layers of material, wherein the multiple layers of the second layer differ in type of alloying elements from materials in adjacent layers, or differ in content of one or more alloying elements, or both. A fin for a heat exchanger according to claim 1 or 2, characterized in that: The material of the first layer and the material of the core layer have different types of alloying elements, different contents of one or more alloying elements, or both, wherein the material of the first layer and the The material of the first layer and the material of the second layer are different in type of alloying elements from the material of the second layer, or different in content of one or more alloying elements, or both, and the materials of the first layer and the second layer are at least partially 3. A fin for a heat exchanger according to claim 1 or 2, characterized in that the grain boundaries are not shared. The fin includes a first side and a second side arranged to face each other in the thickness direction thereof, the first layer being far from one side of the second layer in the thickness direction thereof, A fin for a heat exchanger according to any one of claims 1 to 5, characterized in that it serves as a first side surface or a second side surface of said fin. A fin for a heat exchanger according to any one of claims 1 to 6, characterized in that the thickness of said first layer accounts for 3% to 15% of the thickness of said fin. A fin for a heat exchanger according to any one of claims 1 to 7, characterized in that the thickness of said second layer accounts for 10% to 50% of the thickness of said fin. a heat exchanger,
the heat exchanger includes a first header pipe, a second header pipe, a plurality of heat transfer pipes, and fins, the first header pipe and the second header pipe being spaced apart;
In order to connect the first header pipe and the second header pipe, one end of the heat transfer pipe and the first header pipe are connected, and the other end of the heat transfer pipe and the second header pipe are connected,
The fins are provided between the adjacent heat transfer tubes, wherein the fins are the fins for a heat exchanger according to any one of claims 1 to 8, wherein the core layer of the fins comprises the A heat exchanger characterized in that the heat exchanger is welded to the heat transfer tubes through the first layer of fins, and at least some of the crystal grains of the material of the second layer of fins and the core layer are not shared. The heat transfer tube is a flat tube, the flat tube includes one or more channels extending along the longitudinal direction of the flat tube, the length of the channel is equal to the length of the flat tube, and the fins are the length of the flat tube. , a length, a width and a thickness, wherein the longitudinal direction of the fins and the thickness direction of the flat tube are substantially parallel, and the width direction of the fins and the width direction of the flat tube are substantially parallel. 10. The heat exchanger according to claim 9, wherein said fins are provided with a plurality of through-holes or slots for installing a plurality of said flat tubes in combination.

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