WO2006073135A1

WO2006073135A1 - Heat exchange tube, heat exchanger, and refrigerating cycle

Info

Publication number: WO2006073135A1
Application number: PCT/JP2005/024252
Authority: WO
Inventors: Akihiko Takano
Original assignee: Valeo Thermal Systems Japan Corporation
Priority date: 2005-01-07
Filing date: 2005-12-27
Publication date: 2006-07-13
Also published as: JPWO2006073135A1

Abstract

A heat exchange tube exchanging a heat with a medium, comprising flow passages (201) for flowing the medium therein. The heat exchange tube is formed by molding and brazing a band-like material. Beads (202) forming the flow passages are formed on the material, and a plate body (210) to which the tops of the beads are brazed is installed in the heat exchange tube. In the heat exchange, flat parts are formed by forming the material to face each other, the beads are formed on the flat parts, and the plate body is installed between the flat parts. Also, the heat exchange tube is installed in a heat exchanger, and the heat exchanger is installed in a refrigerating cycle.

Description

Uzuki Itoda β

Heat exchange tubes, heat exchangers, and refrigeration cycles

The present invention includes a flow path for circulating a medium, a heat exchange tube for exchanging heat of the medium by heat transmitted to the heat exchange tube, a heat exchanger provided with the heat exchange tube, and the heat exchanger The refrigeration cycle provided. Background art

For heat exchangers such as radiators and evaporators used in refrigeration cycles, flat heat exchange tubes and corrugated outer fins are laminated alternately to form a core, and One with an end connected to the tank is known. The refrigerant, which is a medium, is taken into the heat exchanger from the inlet provided in the tank, flows through the heat exchange tube while being heat-exchanged by the heat transmitted to the core, and passes through the outlet provided in the tank to the outside. Discharged. Such a heat exchanger is manufactured by integrally assembling components such as a heat exchange tube, a fin, and a tank, and brazing the assembly;

Patent Documents 1 to 5 described below disclose heat exchange tubes constituting a heat exchanger. As a heat exchange tube, a tube formed by forming a strip-shaped material into a predetermined shape and brazing it is known. The material is formed by roll forming. The brazing of the heat exchange tube is performed at the same time as the brazing of the assembly in the furnace.

This type of heat exchange tube has a configuration in which beads are provided at important points of the material and the flow paths are partitioned by the beads. The top of the bead is brazed inside the flow path. By dividing the flow path with a bead, it is possible to improve the pressure resistance strength of the heat exchange tube and the heat exchange efficiency of the medium.

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In addition to this, the heat exchange tube is an extruded tube. It has been known. Compared to extrusion molding, the heat exchange tube has a merit that an A1-Zn alloy layer can be provided on the outer surface of the tube. According to the A 1—Zn alloy layer, the corrosion resistance of the heat exchange tube is improved, and as a result, the thickness of the heat exchange tube can be further reduced.

Patent Document 1 Japanese Utility Model Publication 6 3— 1 6 5 0 8

Patent Document 2 Japanese Patent Application Laid-Open No. 5-1 7 7 2 8 6

Patent Document 3 Japanese Patent Laid-Open No. 11-2 4 8 3 8 3

Patent Document 4 Japanese Patent Laid-Open No. 2 0 0 1— 1 7 4 1 6 7

Patent Document 5 International Publication No. 0 0/5 2 4 0 9 Pamphlet In recent years, heat exchange tubes have tended to be downsized and refined to further improve the performance of heat exchangers. In improving manufacturability, improving the reliability of brazing and securing brazing strength are increasingly important issues. In particular, in a supercritical refrigeration cycle in which the pressure inside the radiator exceeds the critical point of the medium (that is, the refrigerant), the heat exchange tubes used in the radiator are required to have very high pressure resistance. Therefore, a configuration for manufacturing the heat exchange tube by mouth forming is currently being studied. The present invention has been made in view of such circumstances, and an object of the present invention is to obtain a heat exchange tube having a more rational structure in consideration of the current manufacturing technology. Disclosure of the invention

The invention described in claim 1 of the present application includes a flow path through which a medium is circulated, and in the heat exchange tube for exchanging heat of the medium by heat transmitted to the heat exchange tube, the heat exchange tube has a strip shape. The material is molded and brazed,

A bead for partitioning the flow path is provided in the material, and a heat exchange tube having a structure in which a plate body for brazing the top of the bead is provided in the heat exchange tube. The invention described in claim 2 of the present application is the heat exchanger tube according to claim 1, wherein the heat exchange tube has flat portions formed by facing the materials to each other, and the beads are provided in the flat portions, respectively. The body is a heat exchange tube having a configuration provided between the flat portions.

The invention described in claim 3 of the present application is the heat exchange tube according to claim 1 or 2, wherein the heat exchanger tube is used for a heat exchanger of a refrigeration cycle in which the pressure on the high pressure side exceeds the critical point of the medium.

The invention described in claim 4 of the present application is a heat exchanger configured to include the heat exchange tube according to any one of claims 1 to 3.

The invention described in claim 5 of the present application is a refrigeration cycle including the heat exchanger described in claim 4. Brief Description of Drawings

FIG. 1 is an explanatory diagram showing a refrigeration cycle according to an embodiment of the present invention. FIG. 2 is a front view showing a heat exchanger according to an embodiment of the present invention. FIG. 3 is an explanatory view showing a cross section of a heat exchange tube according to an embodiment of the present invention.

FIG. 4 is an explanatory view showing a brazed portion of the heat exchange tube according to the embodiment of the present invention.

FIG. 5 is an explanatory view showing a cross section of a heat exchange tube according to an embodiment of the present invention.

FIG. 6 is an explanatory view showing a cross section of a heat exchange tube according to an embodiment of the present invention.

FIG. 7 is an explanatory view showing a cross section of a heat exchange tube according to an embodiment of the present invention.

FIG. 8 is an explanatory view showing a cross section of a heat exchange tube according to an embodiment of the present invention.

FIG. 9 is an explanatory view showing a cross section of a heat exchange tube according to an embodiment of the present invention. FIG. 10 is an explanatory view showing a brazed portion of a heat exchange tube according to a conventional example. BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described below with reference to the drawings.

The refrigeration cycle 1 shown in FIG. 1 is for in-vehicle air conditioning installed in an automobile. The compressor 2 compresses the refrigerant, the radiator 10 cools the refrigerant compressed by the compressor 2, and the radiator. The decompressor 3 expands by decompressing the refrigerant cooled at 10; the evaporator 4 that evaporates the refrigerant decompressed by the decompressor 3; and the refrigerant that flows out of the evaporator 4 is separated into a gas layer and a liquid layer. And an accumulator 5 for sending the refrigerant in the air layer to the compressor 2. C 0 ₂ is used as the refrigerant, and the pressure inside the radiator 10 exceeds the critical point of the refrigerant depending on the usage conditions such as the temperature. Further, an internal heat exchanger 6 for exchanging heat between the high pressure side and the low pressure side of the refrigerant is provided between the radiator 10 and the decompressor 3 and between the accumulator 5 and the compressor 2. The internal heat exchanger 6 improves the efficiency of the refrigeration cycle 1 by exchanging heat between the high-pressure side refrigerant and the low-pressure side refrigerant. The arrows in Fig. 1 indicate the direction of refrigerant circulation.

As shown in FIG. 2 to FIG. 4, the radiator 100, which is a heat exchanger of this example, has alternating flat tubes 20 0 through which a refrigerant as a medium flows and corrugated fins 30 0 alternately. A plurality of cores 5 0 0 into which end portions of the tubes 2 0 0 are respectively inserted and connected, and a refrigerant inlet portion 6 0 0 provided in the tank 5 0 0 and And an outlet portion 7 0 0. In addition, side braids 800 as reinforcing members are provided on the upper and lower sides of the core 400. The end of side braid 800 is supported by each tank 300. The refrigerant sent from the compressor 2 flows from the inlet portion 600. The refrigerant that has flowed out of the outlet portion 700 is sent to the expansion valve 3. The core 4 0 0 is ventilated by a fan (not shown), and the refrigerant is heat-exchanged by heat transmitted to the core 4 0 0. O

The radiator 100 is composed of a plurality of aluminum alloys constituting a tube 200, a fin 300, a tank 50, an inlet 60, an outlet 70, and a side plate 80. After assembling the manufactured parts together, the assembly is manufactured by brazing in a furnace. In addition, when brazing in the furnace, brazing materials and flux required for brazing are provided at the key points of each member.

As shown in FIG. 3, the heat exchange tube 20 0 of this example includes a plurality of flow paths 2 0 1 that circulate the medium, and heat exchange of the refrigerant is performed by heat transmitted to the heat exchange tube 2 0 0. To do. This heat exchange tube 200 is formed by molding and brazing a strip-shaped material made of aluminum alloy. The material is formed by roll forming.

The material is provided with a bead 2 0 2 that partitions the flow path 2 0 1. In addition, a plate body 2 10 made of aluminum alloy for brazing the top of the bead 20 2 is provided inside the heat exchange tube 2 0 0.

This heat exchange tube 200 is of a flat type and has a flat portion 20 3 made of materials facing each other. One end of the heat exchange tube 200 in the width direction is a bent portion 20 4 formed by bending the material, and the other end is a joined end formed by joining the end portions of the material. It is 2 0 5. The beads 20 2 are provided in the flat portions 20 3, respectively. In this example, the thickness of the material is 0.25 to 0.45 mm, the thickness of the plate body 2 1 0 is 0.05 to 0.20 mm, and the thickness of the heat exchange tube is 1. 2 to 1.8 mm.

The plate body 2 10 is provided between the flat portions 20 3 and is brazed to the bead 2 0 2 and the end portion in the width direction of the material. According to such a configuration, it is possible to reliably improve the brazing strength at the top of the bead 220. As a result, the pressure resistance performance of the heat exchange tube 200 is improved.

That is, according to the configuration of this example, as shown in Fig. 4 (A), a large fillet F by brazing can be secured, and the brazing width a can be Can be enlarged. If the tops of the beads 20 2 are brazed directly, the brazing width a may be smaller than the bead width b, as shown in FIG. 10 (A). However, in this example, by securing a large fillet F, the brazing width a becomes larger than the width of the bead 20 2. This is because the brazing angle of the brazed portion is reduced by providing the plate body 2 10. Stress concentration occurs in the part where the brazing width a is smaller than the width b of the bead 20 2 due to the pressure of the refrigerant, and this causes a significant decrease in pressure resistance. In this case, such inconvenience can be avoided.

Furthermore, according to the configuration of this example, as shown in FIG. 4 (B), even if the positional deviation occurs in the bead 20 2 due to the influence of a delicate dimensional error, the brazing width a is It never gets smaller. If the tops of the beads 20 2 are brazed directly, as shown in Fig. 10 (B), the brazing width a is further reduced, but according to this example, Inconvenience can be avoided. In other words, it has excellent robustness against dimensional errors (r 0 b u st: robustness).

The brazing material necessary for such brazing was not provided for the strip-shaped material, but was provided on the plate body 210. That is, the plate body 2 10 is a brazing sheet formed by cladding a brazing material. With this configuration, it is possible to minimize the brazing material. The concept is explained below.

First, the brazing material containing silicon is indispensable for brazing, but after brazing, it becomes a factor that erodes the core material (that is, a factor of erosion). desirable. The member made by brazing the brazing material is manufactured by superposing the core material and the brazing material at a predetermined ratio and rolling them, so that the thickness of the brazing layer of the brazing material is reduced. Is lower than the thickness of the material. According to current technology, the lower limit of the cladding layer thickness is about 5% of the material thickness. Furthermore, comparing the plate thickness of the material with the plate thickness of the plate body 210, The thickness of the material can be set thinner than the thickness of the material due to the structure of the heat exchange tube 200. Therefore, in order to keep the brazing material to a small amount, it is better to clad the brazing material only on the plate body 2 10. According to such a configuration, the amount of brazing material used can be reduced, and the depth of the silicon diffusion layer in the material can be reduced, so that the thickness of the material can be made thinner.

Furthermore, an Al-Zn alloy layer is provided as a sacrificial layer for improving the corrosion resistance of the heat exchange tube 200 on one surface of the material that is the outer surface of the heat exchange tube 200. The plate body 210 does not contain Zn in the brazing material and the core material. Here, if the plate body 2 1 0 contains Zn, the diffusion of Z η also occurs from the inside of the heat exchange tube 2 0 0, so that the remaining core material thickness in the material is reduced and heat exchange is performed. Although the corrosion resistance of the exchange tube 20 0 is deteriorated, according to this example, since the plate body 2 1 0 does not contain Ζη, such inconvenience is avoided.

As described above, the radiator tube 200 in this example is more rationally constructed based on the current manufacturing technology, and in particular, according to the pressure of the refrigerant that is in the supercritical state. Thus, the reliability of brazing is surely improved to ensure the required pressure resistance. The configuration of the heat exchange tube 200 in this example can also be applied to a heat exchange tube used for the evaporator 4.

The configuration of each part in this example can be appropriately changed in design within the technical scope described in the claims, and is of course not limited to the above. The plate body 2 1 0 may be appropriately drilled. In this example, the brazing material is provided on the plate body 210, but it is also possible to clad the filter material on the belt-shaped material if the corrosion resistance is sufficiently secured.

Further, as shown in FIG. 5, the shapes of the bent end portion 20 4 and the joint end portion 20 5 can be arbitrarily changed. As shown in FIG. 6, it is also possible to extend the plate body 2 10 from the joining end 2 0 5 and wind it around the outer periphery of the heat exchange tube 2 0 0.

As shown in FIG. 7, it is also possible to assemble a pair of materials each provided with a bead 20 2 by winding a plate body 2 10. In this case, both end portions in the width direction of the heat exchange tubes 20 0 become joint end portions 2 5.

Further, as shown in FIGS. 8 and 9, the plate body 2 10 may be provided with a hook portion 2 11. If the pair of materials are assembled by using the hook portion 211, the heat exchange tube 200 can be more accurately and firmly formed. Industrial applicability

The heat exchange tube of the present invention can be used very suitably as a heat exchange tube used in a radiator of a supercritical refrigeration cycle. In addition, a radiator including this heat exchange tube is suitable for a supercritical refrigeration cycle.

Claims

Range of wording

1. In a heat exchange tube having a flow path through which a medium flows and exchanging heat of the medium by heat transferred to the heat exchange tube,

The heat exchange tube is formed by molding and brazing a strip-shaped material.

The material is provided with a bead that partitions the flow path,

A heat exchange tube, wherein a plate body for brazing the top of the bead is provided inside the heat exchange tube.

2. The heat exchange tube has flat portions formed by facing the materials to each other,

The bead is provided on the flat portion,

The heat exchange tube according to claim 1, wherein the plate body is provided between the flat portions.

3. The heat exchange tube according to claim 1 or 2, wherein the heat exchange tube is used in a heat exchanger of a refrigeration cycle in which a pressure on a high pressure side exceeds a critical point of the medium.

4. A heat exchanger comprising the heat exchange tube according to any one of claims 1 to 3.

5. A refrigeration cycle comprising the heat exchanger according to claim 4.