JP2009121758A - Heat exchanger and cryogenic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger and a cryogenic system, improving joining reliability. <P>SOLUTION: This heat exchanger 10 includes: a first flat pipe 1 having a first refrigerant passage where a first refrigerant flows; a second flat pipe 2 having a second refrigerant passage where a second refrigerant flows and joined at the flat surface to the flat surface of the first flat pipe; a pair of first headers 3 connected to both ends of the first flat pipe 1; and a pair of second headers 4 connected to both ends of the second flat pipe, wherein a brazing filler metal staying part 23 is provided at a first header joining part connecting the first flat pipe 1 and the first header 3 or a second header joining part connecting the second flat pipe 2 and the second header 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat exchanger that performs heat exchange between a first refrigerant that is a low-temperature fluid or a high-temperature fluid and a second refrigerant. The present invention also relates to a cooling system using this heat exchanger.

  The conventional heat exchanger is connected to the high-pressure strip tube and the low-pressure strip plate tube for heat exchange of the refrigerant, the high-pressure header connected to both ends of the high-pressure strip plate tube, and both ends of the low-pressure strip tube. Some have a low-pressure header (see, for example, Patent Document 1). In this conventional heat exchanger, the high-pressure strip tube and the low-pressure strip tube are brought into close contact with each other so as to overlap each other, and are further laminated to braze the joining surface between the planes. The high-pressure header is brazed and connected by inserting one end of the high-pressure strip plate tube into the insertion groove, and the low-pressure header is brazed and connected by inserting one end of the low-pressure strip plate tube into the insertion groove.

JP 2002-340485 (pages 4-5, FIG. 1)

  In such a conventional heat exchanger, when the brazing process is heated, the molten brazing material does not flow uniformly into the entire joint portion between the end portion of the flat tube (band plate tube) and the insertion groove of the header. There is a problem in that the reliability of the joint is deteriorated, for example, the airtightness of the joint cannot be secured because it does not stay in the joint and flows out to the other.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a heat exchanger and a cooling / heating system that improve the bonding reliability.

  The heat exchanger according to the present invention has a flat first flat tube having a first refrigerant flow path through which the first refrigerant flows, and a second refrigerant flow path through which the second refrigerant flows, and is flat and has a first flat shape. A flat second flat tube joined to the flat surface of the tube, a pair of first headers connected to both ends of the first flat tube, and a pair of second connected to both ends of the second flat tube. A header and a brazing material retaining portion at a first header joint that connects the first flat tube and the first header or a second header joint that connects the second flat tube and the second header. is there.

  Moreover, the cooling-heat system which concerns on this invention is equipped with the said heat exchanger.

  According to the heat exchanger and the cooling / heating system of the present invention, it is possible to improve the joining reliability.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing the configuration of a heat exchanger according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view showing the configuration of the heat exchanger according to Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view showing the configuration of the heat exchanger according to Embodiment 1 of the present invention, and FIG. 3 (a) is a cross-sectional view of the heat exchanger shown in FIG. Moreover, FIG.3 (b) and FIG.3 (c) are sectional drawings which show the other structure of the heat exchanger by Embodiment 1 of this invention. In the drawings, the same reference numerals are the same or equivalent, and this is common throughout the entire specification.

  As shown in FIGS. 1, 2 and 3A, the heat exchanger 10 has a flat first flat tube 1 having a plurality of first refrigerant flow paths through which the first refrigerant flows, and the second refrigerant flows. A flat second flat tube 2 having a substantially rectangular second refrigerant flow path, a tubular first header 3 connected to both ends of the first flat tube 1, and both ends of the second flat tube 2 It has a tubular second header 4.

  The second flat tube 2 of the heat exchanger 10 is made of a material having good heat conductivity, for example, aluminum alloy, copper, and stainless steel. After the flat plate is bent by roll forming or the like, the joints at both ends of the flat plate are formed. Is formed by electro-sewing (welding), a cylinder is roll-formed or press-molded, or extruded or pultruded.

On the other hand, the first flat tube 1 of the heat exchanger 10 is made of a material having good thermal conductivity, such as aluminum alloy, copper, and stainless steel, and is manufactured by extrusion molding or pultrusion molding. As shown in FIG. 2, rectangular insertion holes 28 into which the ends of the first flat tube 1 or the second flat tube 2 are respectively inserted are provided on the circumferential side surfaces of the first header 3 and the second header 4. The first header joint that connects the first flat tube 1 and the first header 3 is brazed using a brazing material 21 such as aluminum-silicon, and the second flat tube 2 and the second header 4 The second header joint connecting the two is brazed using a brazing material 21 such as an aluminum-silicon system. In addition, the 1st header 3 and the 2nd header 4 are connected to the refrigerant circuit of refrigeration systems, such as a heat pump apparatus which mounts the heat exchanger 10 mentioned later.
The heat exchanger 10 shown in FIGS. 1, 2 and 3A is a flat tube between the flat surface of the first flat tube 1 and the flat surface of the second flat tube 2 formed as described above. The joint is manufactured by brazing using a brazing material 21 such as an aluminum-silicon system.

  The second flat tube 2 is not limited to the substantially rectangular shape shown in FIG. 3A, but has an elliptical shape or a trapezoidal shape as shown in FIG. 3B or 3C. May be. That is, the second flat tube 2 only needs to have a flat surface facing the first flat tube 1 and may be roughly rectangular.

  4 is a cross-sectional view showing one end of the second flat tube of the heat exchanger according to Embodiment 1 of the present invention, and FIG. 5 is a second view of the heat exchanger according to Embodiment 1 of the present invention. FIG. 6 is a cross-sectional view showing the insertion hole of the header, and FIG. 6 is a cross-sectional view showing a joint portion between the second flat tube and the second header of the heat exchanger according to Embodiment 1 of the present invention.

As shown in FIG. 4 and FIG. 6, the second flat tube 2 has an end portion narrowed to reduce the outer periphery, and a reduced tube portion 26 having an outer peripheral length shorter than that of the central portion is provided. Yes.
In the first embodiment of the present invention, the second flat tube 2 is provided with the contracted tube portion 26 at the end thereof and the brazing material retaining portion 23 is provided, so that the insertion of the second header 4 shown in FIG. When the second flat tube 2 is connected to the hole 28, as shown in FIG. 6, the brazing material 21 easily flows along the contracted tube portion 26, and the amount of brazing material 21 necessary for joining is fastened only to the necessary portion. be able to. Therefore, brazing defects are less likely to occur and the joining reliability can be improved. In addition, since the brazing material 21 does not easily enter the second flat tube 2 and the second header 4, it is difficult to cause an increase in flow resistance or a blockage, and the reliability can be improved. Furthermore, since the fillet of the brazing material 21 is generated around the brazing gap 22, the bonding strength can be improved.

FIG. 7 is a cross-sectional view showing another heat exchanger shown in Embodiment 1 of the present invention.
As shown in FIGS. 7A to 7C, in another heat exchanger 10 according to the first embodiment of the present invention, the second flat tube 2 is composed of a plurality of rectangular tubes 7 having a rectangular shape. Then, the flat tube joint portion between the flat surface of each of the plurality of rectangular tubes 7 and the flat surface of the first flat tube 1 is brazed and bonded simultaneously using the brazing material 21. Specifically, the brazing material 21 is provided at the flat tube joint between the flat surface of the first flat tube 1 and the flat surfaces of the plurality of rectangular tubes 7, and the first flat tube 1 and the plurality of rectangular tubes 7. Are fixed by using a jig or the like, and a brazing material 21 is provided at the joining portion, and the brazing material 21 is put into a furnace, so that the joining can be performed by a single brazing operation. By configuring the second flat tube 2 from a plurality of rectangular tubes 7, the heat transfer area between the second flat tube 2 and the second refrigerant increases, and the heat transfer performance can be improved.

FIG. 8 is a sectional view showing a joint portion between the second flat tube and the second header of the heat exchanger according to Embodiment 1 of the present invention.
When the second flat tube 2 is composed of a plurality of rectangular tubes 7 and the adjacent rectangular tubes 7 are arranged in close contact with each other, as shown in FIG. If it connects to the insertion hole 28 of the 2nd header 4, the quantity of brazing material 21 required for joining can be fastened only to a required site | part, and the effect similar to the heat exchanger 10 shown in FIG. 6 can be acquired. it can. If the width of the brazing gap 22 where the brazing material 21 stays between the insertion hole 28 and the rectangular tube 7 is preferably 50 μm to 200 μm, more preferably 50 μm to 150 μm, the brazing material 21 easily flows. In particular, when the outer periphery of the rectangular tube 7 is rounded or chamfered, a gap is generated between the adjacent rectangular tube 7 and the insertion hole 28. In this case, the insertion hole 28 is connected to the rectangular tube 7. The brazing material 21 can be made to flow uniformly into the joint portion by inserting the insertion member or the like into the gap so that the brazing gap 22 falls within the above range.

FIG. 9 is a cross-sectional view showing another heat exchanger according to Embodiment 1 of the present invention. Moreover, FIG. 10 is sectional drawing at the time of manufacturing the other heat exchanger by Embodiment 1 of this invention.
As shown in FIG. 9, the second flat tube 2 of the heat exchanger 10 is composed of a plurality of rectangular tubes 7, and a gap 9 is provided between adjacent rectangular tubes 7. As shown in FIG. 10, if a plurality of rectangular tubes 7 are fixed and brazed using a comb-shaped jig 25, the rectangular tubes 7 can be arranged uniformly to form the heat exchanger 10.

FIG. 11 is a cross-sectional view showing a joint portion between a second flat tube and a second header of another heat exchanger according to Embodiment 1 of the present invention, and FIG. 12 shows heat according to Embodiment 1 of the present invention. It is sectional drawing which shows the insertion hole of the 2nd header of an exchanger.
When the second flat tube 2 is constituted by a plurality of rectangular tubes 7 and the adjacent rectangular tubes 7 are arranged via the gaps 9, a rectangular shape is formed on the side surface of the second header 4 as shown in FIGS. 11 and 12. The insertion hole 28 corresponding to each of the tubes 7 is provided, and the rectangular tube 7 provided with the contraction tube portion 26 may be connected to each of the insertion holes 28. By comprising as mentioned above, the quantity of brazing material 21 required for joining can be fastened only to a required part, and the effect similar to the heat exchanger 10 shown in FIG. 6 can be acquired.

Note that a brazing material 21 may be provided in the gap 9 for brazing. When brazing is performed by providing the brazing material 21 in the gap 9, the heat transfer path becomes large, and the heat transfer performance is further improved.
In the first embodiment, the rectangular tube 7 has the same shape as that of the rectangular tube 7 in FIG. 7A. However, the rectangular tube 7 has the shape of the rectangular tube in FIG. 7B. Alternatively, even in the case similar to the shape of the rectangular tube in FIG.

FIG. 13: is sectional drawing and the perspective view of a rectangular tube in the other heat exchanger by Embodiment 1 of this invention.
As shown in FIG. 13, the rectangular tube 7 is formed by pressing or the like other than both ends from a round tube having a substantially circular cross section. With such a configuration, in addition to the above effect, the contact area between the first flat tube 1 and the rectangular tube 7 can be increased, and the representative flow length is reduced due to the flat flow path, so that the heat transfer performance is improved. Since it becomes higher, the heat exchange performance is improved. Furthermore, since both ends are still round tubes, the interval between the insertion holes 28 of the second header 4 into which the rectangular tube 7 is inserted can be increased, so that the brazing process is facilitated and the brazing reliability is improved. To do.

  When the adjacent rectangular tubes 7 are arranged via the gap 9, the following other effects can be obtained. Since the second flat tube 2 is composed of a plurality of rectangular rectangular tubes 7, the shape and number of the refrigerant flow paths can be freely selected, the pressure loss of the refrigerant is small, and a suitable combination with high heat transfer performance is obtained. The degree of freedom in design increases. In particular, when there is a difference in thermophysical values such as specific heat and density, flow rate, pressure conditions, etc. between the first refrigerant and the second refrigerant, for example, carbon dioxide or a fluorocarbon refrigerant is used as the first refrigerant. Thus, when water is used as the second refrigerant, the optimum number of refrigerant channels between the first flat tube and the second flat tube is often different, which is effective. Further, since the plurality of second flat tubes 2 can be evenly arranged with respect to the flat heat transfer surface of the first flat tube 1, the heat flux distribution on the heat transfer surface of the first flat tube 1 is uniform. The heat transfer performance can be improved evenly without being biased. In the unlikely event that the second flat tube 2 is cracked or pinholed due to corrosion or the like and the second refrigerant is leaked, or the first flat tube 1 is cracked or pinholed due to corrosion or the like, the first Even when the refrigerant leaks and penetrates the brazing filler metal 21, the gap 9 is present, so that the leaked refrigerant flows out to the outside through the gap 9, and there is an effect that it is easy to find a crack or the like.

FIG. 14 is a cross-sectional view showing another heat exchanger according to Embodiment 1 of the present invention.
As shown in FIG. 14A, the second flat tube 2 has a plurality of flow path walls 6 serving as a heat transfer path for the refrigerant therein, and has a plurality of refrigerant flow paths. Since the plurality of flow path walls 6 are provided inside the second flat tube, the heat transfer area is increased and the heat transfer performance can be improved.

  The second flat tube 2 only needs to have a flat surface facing the first flat tube, and the shape of the second flat tube may be any of those shown in FIGS. 14 (a) to 14 (c). . Any of the second flat tubes shown in FIGS. 14A to 14C is formed by extrusion or drawing. Even in this case, the second flat tube 2 can obtain the same effect when the end portion is narrowed to provide the contracted tube portion 26 and the retention portion 23 of the brazing material 21.

  The rectangular tube 7 of the second flat tube 2 shown in the first embodiment preferably has a structure in which both are in close contact with each other. Therefore, the rectangular tube 7 preferably has the shape shown in FIG. 7B than the shape shown in FIG. 7C, and the shape shown in FIG. 7A rather than the shape shown in FIG. 7B. Is preferred.

  In the first embodiment, the second flat tube 2 or the plurality of rectangular tubes 7 that are the second flat tubes 2 are provided with the contracted tube portions 26 at the end portions thereof, and the retention portions 23 of the brazing material 21 are used. The same effect can be acquired by making the 1st flat tube 1 into the same structure.

  The heat exchanger 10 shown in Embodiment 1 of the present invention is mounted on a heat pump system that uses hot or cold heat. When using hot heat, the high temperature 1st refrigerant | coolant from a refrigerant circuit is supplied to the 1st flat tube 1 through one 1st header 3, and returns to a refrigerant circuit through the 1st header 3 of the other. On the other hand, the second refrigerant is supplied to the second flat tube through one second header 4, and applied to, for example, heating or hot water supply on the use side through the other second header 4. The first refrigerant and the second refrigerant flow through the first flat tube 1 and the second flat tube 2 in a counterflow or parallel flow to exchange heat.

FIG. 15 is a configuration diagram showing a heat pump system that uses warm heat using the heat exchanger according to Embodiment 1 of the present invention.
As shown in FIG. 15, the heat pump system is a first refrigerant circuit in which a first refrigerant flows, a second refrigerant circuit in which a second refrigerant flows, and Embodiment 1 of the present invention that performs heat exchange between the first refrigerant and the second refrigerant. The heat exchanger 10 shown in FIG. In this example, R410A is used as the first refrigerant, and water is used as the second refrigerant. The first refrigerant circuit has a compressor 31, an expansion valve 33, an outdoor heat exchanger 34, and a fan 39, and the second refrigerant circuit has a use side heat exchanger 35 and a pump 36. In the first refrigerant circuit, the first refrigerant that has become high temperature and high pressure in the compressor 31 is condensed by exchanging heat with the second refrigerant in the heat exchanger 10. Further, the first refrigerant is decompressed by the expansion valve 33, is evaporated by exchanging heat with the air from the fan 39 by the outdoor heat exchanger 34, and returns to the compressor 31. In the second refrigerant circuit, the second refrigerant heated by the heat exchanger 10 is supplied to the use-side heat exchanger 35 by the pump 36 and radiates heat. As the use-side heat exchanger 35, for example, a radiator or a floor heating heater is applied and used as a heating system. In addition, when using water like this Embodiment, the part which the 2nd flat tube 2 and the 2nd header 4 contact with water of the heat exchanger 10, such as forming with a corrosion resistant material, has the corrosion resistance with respect to water. It is desirable to have such a configuration.

  In the heat exchanger 10 shown in FIG. 3, the refrigerant flow path area of the second flat tube 2 is larger than that of the first flat tube 1, but it is not necessarily different. When there is a difference in thermophysical values such as specific heat and density, flow rate, pressure conditions, fluid properties, etc. between the first refrigerant and the second refrigerant, the refrigerant flow channel area is set to the first flat tube 1. And the second flat tube 2 may be different. For example, when using carbon dioxide or a fluorocarbon refrigerant as the first refrigerant and using tap water or the like whose water quality is not sufficiently controlled as the second refrigerant, in order to improve heat exchange performance, In order to suppress an increase in pressure loss due to adhesion of scale to the second flat tube 2, it is better that the second flat tube 2 is larger than the first flat tube 1.

FIG. 16 is a configuration diagram showing another example of a heat pump system that uses heat using the heat exchanger 10 according to Embodiment 1 of the present invention.
The heat pump system shown in FIG. 16 is used as a hot water supply system in which a use-side heat exchanger 35 is installed in a tank 38 and water supplied into the tank is heated to take water. Other configurations and functions are the same as those of the heat pump system shown in FIG.

  As shown in FIG. 15 and FIG. 16, the conventional boiler is used as a heat source by heating or hot-watering the heat pump system using the heat exchanger according to Embodiment 1 of the present invention as a heat source in the use-side heat exchanger 35. There is an energy saving effect compared to a heating or hot water supply system.

FIG. 17 is a configuration diagram showing a heat pump system using cold heat using the heat exchanger according to Embodiment 1 of the present invention.
Also in the heat pump system shown in FIG. 17, R410A was used as the first refrigerant, and water was used as the second refrigerant. The first refrigerant that has become high temperature and high pressure in the compressor 31 is condensed by exchanging heat with the air from the fan 39 in the outdoor heat exchanger 34. Further, the first refrigerant is decompressed by the expansion valve 33, exchanges heat with the second refrigerant in the heat exchanger 10, evaporates, and returns to the compressor 31. The second refrigerant cooled by the heat exchanger 10 is supplied to the use side heat exchanger 35 by the pump 36. As the use side heat exchanger 35, for example, an air heat exchanger may be applied and used as a cooling system or a radiant cooling system using a cold water panel or the like.

FIG. 18 is a configuration diagram showing a heat pump system using warm and cold using the heat exchanger according to Embodiment 1 of the present invention.
The heat pump system of FIG. 15 and FIG. 17 has shown the example which utilizes warm temperature or cold respectively, respectively. As shown in FIG. 18, if a four-way valve 32 is used, it can be used by switching between hot and cold. Also in the hot water supply system of FIG. 16, by changing the refrigerant circuit (not shown) and using a four-way valve (not shown) in the same manner as described above, not only for hot water use, but also for cold water, It can be used by switching between hot water and cold water.

  In the present embodiment, R410A is used as the refrigerant of the first flat tube 1, and water is used as the refrigerant of the second flat tube 2. The type of the refrigerant is not limited to this, and the first refrigerant may be another fluorocarbon refrigerant, or a natural refrigerant such as carbon dioxide or hydrocarbon. The second refrigerant may be a fluorocarbon refrigerant, a natural refrigerant such as carbon dioxide or hydrocarbon, or water such as tap water, distilled water, or brine.

Embodiment 2. FIG.
In the heat exchanger shown in the second embodiment, the second flat tube is composed of a plurality of rectangular tubes, a gap is provided between adjacent rectangular tubes, and a spacer is provided between the plurality of rectangular tubes. A brazing material staying part is provided. Other configurations and functions are the same as those of the heat exchanger shown in the first embodiment.

FIG. 19 is a cross-sectional view showing one end of the second flat tube of the heat exchanger 10. Moreover, Fig.20 (a) is sectional drawing which shows the connection part of the 2nd flat tube and 2nd header of the heat exchanger by Embodiment 2 of this invention, FIG.20 (b) is implementation of this invention It is sectional drawing which shows the connection part of the 2nd flat tube and 2nd header of the other heat exchanger by the form 2.
As shown in FIG. 19, a brazing gap 22 is provided between the plurality of rectangular tubes 7 that are the second flat tubes 2, and is an end portion of the rectangular tube 7 between the adjacent rectangular tubes 7. A spacer 30 is provided. Since the rectangular tube 7 which is the second flat tube 2 is joined to the second header by brazing, the retaining portion 23 (FIG. 5) where the brazing material 21 stays between the spacer 30, the rectangular tube 7 and the second header 4. The dotted circle inside). Therefore, when connecting the 2nd flat tube 2 to the insertion hole 28 of the 2nd header 4 shown in FIG. 5, as shown to Fig.20 (a), the brazing material 21 expands only to the position of the retention part 23. As shown in FIG. The amount of brazing material 21 necessary for joining can be fastened only to the necessary portion. Therefore, brazing defects are less likely to occur, and the joining reliability can be improved. In addition, since the brazing material 21 does not easily enter the second flat tube 2 and the second header 4, it is difficult to cause an increase in flow resistance or a blockage, and the reliability can be improved. Furthermore, since the fillet of the brazing material 21 is generated around the brazing gap 22, the bonding strength can be improved. If the width of the spacer 30 is preferably 50 μm to 200 μm, more preferably 50 μm to 150 μm, the brazing material 21 can easily flow.

  19 and 20 (a), the spacer 30 has a substantially rectangular shape. However, as shown in FIG. 20 (b), the spacer 30 has a width of the brazing gap 22 which is a staying portion 23 of the brazing material 21, and The width of the gap 9 between the adjacent rectangular tubes 7 may be different, and the width of the brazing gap 22 may be narrower than the width between the adjacent rectangular tubes 7. For example, the width of the gap 9 between adjacent rectangular tubes 7 may be about 1 mm, and the width of the brazing gap 22 may be about 100 μm. By doing so, the brazing material 21 stays in the staying portion 23 by capillarity in the portion of the brazing gap 22, and the wide portion between the adjacent rectangular tubes 7 becomes a weir and the brazing material 21 becomes the staying portion. It expands only to the position of 23, and the amount of brazing material 21 required for joining can be fastened only to the necessary portion.

  In the second embodiment, a brazing gap 22 is provided between the plurality of rectangular tubes 7 that are the second flat tubes 2, and a spacer is provided between the adjacent rectangular tubes 7 at the end of the rectangular tube 7. 30 is provided, but the first flat tube 1 is composed of a plurality of rectangular tubes, a brazing gap is provided between the rectangular tubes, and a spacer is provided between the adjacent rectangular tubes at the end of the rectangular tube. Thus, the same effect can be obtained by brazing the first flat tube 1 and the first header 3.

Embodiment 3 FIG.
In the heat exchanger shown in the third embodiment, the second flat tube is composed of a plurality of rectangular tubes, and a brazing gap is provided between adjacent rectangular tubes as shown in the second embodiment. Although it is the same as a heat exchanger, the end of a plurality of rectangular tubes is provided with an expanded pipe portion having a longer outer peripheral length than the central portion, and the point that the space between the expanded portions is a brazing material retention portion is implemented. Different from the heat exchanger shown in form 2. Other configurations and functions are the same as those of the heat exchanger shown in the second embodiment.

FIG. 21 is a cross-sectional view showing one end of the second flat tube of the heat exchanger according to Embodiment 3 of the present invention, and FIG. 22 shows the second part of the heat exchanger according to Embodiment 3 of the present invention. It is sectional drawing which shows the junction part of a flat tube and a 2nd header.
As shown in FIG. 21 and FIG. 22, the rectangular tube 7 that is the second flat tube 2 includes an expanded tube portion 29 having an enlarged end portion and an expanded outer periphery and a longer outer peripheral length than the central portion, and adjacent expanded tube portions 29. The brazing gap 22 serves as a retention portion 23 for the brazing material 21.

  In the third embodiment of the present invention, since the expanded portions 29 are provided at the ends of the plurality of rectangular tubes 7 and the retention portions 23 of the brazing material 21 are provided, the insertion of the second header 4 shown in FIG. When the rectangular tube 7 which is the second flat tube 2 is connected to the hole 28, the brazing material 21 does not expand except the staying portion 23 as shown in FIG. 21 can be fastened only to a necessary part. Accordingly, brazing defects are less likely to occur without using the spacer 30 and the joining reliability is increased. In addition, since the brazing material 21 does not easily enter the rectangular tube 7 and the second header 4 that are the second flat tubes 2, it is difficult to increase flow resistance, blockage, and the like, thereby improving reliability. it can. Furthermore, since the fillet of the brazing material 21 is generated around the brazing gap 22, the bonding strength can be improved. If the brazing gap 22 between adjacent expanded portions 29 is preferably 50 μm to 200 μm, more preferably 50 μm to 150 μm, the brazing material 21 can easily flow.

  In the third embodiment, the expanded portion 29 is provided at the end of the plurality of rectangular tubes 7 which are the second flat tubes 2 to form the brazing material retaining portion 23. However, as shown in FIG. 2 The flat tube 2 is composed of a single flat tube, and an expanded portion is provided at the end of the second flat tube 2 as a brazing material retaining portion, and the second flat tube 2 and the second header 4 are brazed. The same effect can be obtained.

  In the third embodiment, the second flat tube 2 or the plurality of rectangular tubes 7 that are the second flat tubes 2 are provided with the expanded portion 29 at the end portion of the rectangular tube 7, and the retention portion 23 of the brazing material is used. The same effect can be acquired by making the flat tube 1 into the same structure.

Embodiment 4 FIG.
In the heat exchanger shown in the first embodiment, the end portion of the second flat tube is provided with a contracted tube portion whose outer peripheral length is shorter than the central portion, and the brazing material is interposed between the contracted tube portion and the second header. It is a staying part. In the heat exchanger shown in this Embodiment 4, the groove part dented inside is provided in the edge part of a 2nd flat tube, and the point from which this groove part is a retention part of a brazing material shows in Embodiment 1. FIG. Different from heat exchanger. Other configurations and functions are the same as those of the heat exchanger shown in the first embodiment.

FIG. 23 is a cross-sectional view showing one end portion of the second flat tube of the heat exchanger according to Embodiment 4 of the present invention, and FIG. 24 shows the second part of the heat exchanger according to Embodiment 4 of the present invention. It is sectional drawing which shows the junction part of a flat tube and a 2nd header.
As shown in FIG. 23 and FIG. 24, the second flat tube 2 includes a groove portion 27 recessed inward at the end portion, and serves as a retention portion 23 of the brazing material 21.

  In Embodiment 4 of the present invention, the second flat tube 2 is provided with a groove portion 27 at the end, and this groove portion 27 serves as a brazing material retaining portion 23. Therefore, the insertion of the second header 4 shown in FIG. When the second flat tube 2 is connected to the hole 28, as shown in FIG. 24, the brazing material 21 does not expand to other than the groove 27, and the amount of brazing material 21 necessary for joining may be retained only at a necessary portion. it can. Therefore, brazing defects are less likely to occur and the joining reliability can be improved. In addition, since the brazing material 21 does not easily enter the second flat tube 2 and the second header 4, it is difficult to cause an increase in flow resistance or a blockage, and the reliability can be improved. Furthermore, since the fillet of the brazing material 21 is generated, the bonding strength can be improved. Moreover, since the inner peripheral part of the insertion hole 28 and the outer peripheral part of the 2nd flat tube 2 can be made to contact, positioning is easy.

FIG. 25 is a cross-sectional view showing another example of the joint portion between the second flat tube and the second header of the heat exchanger according to Embodiment 4 of the present invention.
As shown in FIG. 9, when the second flat tube 2 is composed of a plurality of rectangular tubes 7 and a gap 9 is provided between adjacent rectangular tubes 7, as shown in FIG. An insertion hole 28 corresponding to each of the rectangular tubes 7 may be provided on the side surface. As shown in FIG. 25, the rectangular tube 7 provided with the groove 27 may be connected to each of the insertion holes 28 of the second header 4.

FIG. 26 is a cross-sectional view showing still another example of the joint portion between the second flat tube and the second header of the heat exchanger according to Embodiment 12 of the present invention.
As shown in FIG. 7, when the second flat tube 2 is composed of a plurality of rectangular tubes 7 and adjacent rectangular tubes 7 are arranged in close contact with each other, as shown in FIG. The rectangular tube 7 may be connected to the insertion hole 28 of the second header 4 shown in FIG.

  In the fourth embodiment, the groove portions 27 are provided at the end portions of the plurality of rectangular tubes 7 that are the second flat tubes 2, and the stay portions 23 of the brazing material 21 are used. However, as shown in FIG. 2 The flat tube 2 is composed of a single flat tube, provided with a groove at the end of the second flat tube 2 and used as a brazing material retaining portion, and by brazing the second flat tube 2 and the second header 4, Similar effects can be obtained. In addition, even when a plurality of flow path walls 6 are provided inside the second flat tube 2 shown in FIG. 14, the same effect can be obtained by applying this embodiment.

  In the fourth embodiment, the second flat tube 2 or the plurality of rectangular tubes 7 that are the second flat tubes 2 are provided with the groove portions 27 at the end portions of the rectangular tubes 7 and are used as the stay portions 23 of the brazing material 21. The same effect can be acquired by making the flat tube 1 into the same structure.

Embodiment 5 FIG.
The heat exchanger according to the fifth embodiment is a heat exchanger 10 having a first header 3 at both ends of the first flat tube 1 and a second header 4 at both ends of the second flat tube 2 shown in FIG. In addition, the tapered portion 12 is provided in the insertion hole 28 of the second header, and the tapered portion 12 is used as the staying portion 23 of the brazing material 21. Other configurations are the same as those of the heat exchanger shown in the first embodiment.

FIG. 27 is a cross-sectional view showing an insertion hole of the second header of the heat exchanger according to Embodiment 5 of the present invention, and FIG. 28 shows a second flat tube of the heat exchanger according to Embodiment 13 of the present invention. It is sectional drawing which shows the junction part of a 2nd header.
As shown in FIGS. 27 and 28, the second header 4 includes a tapered portion 12 in the insertion hole 28, and the tapered portion 12 serves as a staying portion 23 of the brazing material 21. When the second flat tube 2 and the second header 4 are joined by brazing, the brazing material 21 can easily flow into the tapered portion 12 and brazing failure is unlikely to occur, so that the joining reliability can be improved. In addition, since the brazing material 21 does not easily enter the second flat tube 2 and the second header 4, it is difficult to cause an increase in flow resistance or a blockage, and the reliability can be improved. Furthermore, since the fillet of the brazing material 21 is generated around the tapered portion 12, the bonding strength can be improved.

  As shown in FIG. 28A, the size of the portion where the area of the insertion hole 28 is minimum may be formed larger than that of the second flat tube 2. Further, as shown in FIG. 28B, the clearance between the second flat tube 2 and the second header 4 may be eliminated. By eliminating the clearance between the second flat tube 2 and the second header 4, excessive flow of the brazing material 21 into the second header 4 can be suppressed, and the joining reliability can be improved.

  In the fifth embodiment, the second flat tube 2 is composed of one flat tube, but the same effect can be obtained when the second flat tube 2 is composed of a plurality of rectangular tubes 7. . The same effect can be obtained even when a plurality of flow path walls 6 are provided inside the second flat tube 2 shown in FIG.

  In the fifth embodiment, the tapered portion 12 is provided in the insertion hole 28 of the second header 4, but the tapered portion is provided in the insertion hole 28 of the first header 3, so that the first header 3 and the first header 3 The same effect can be obtained when the flat tube 1 is brazed.

It is a perspective view which shows the structure of the heat exchanger by Embodiment 1 of this invention. It is sectional drawing which shows the structure of the heat exchanger by Embodiment 1 of this invention. It is sectional drawing which shows the structure of the heat exchanger by Embodiment 1 of this invention. It is sectional drawing which shows one edge part of the 2nd flat tube of the heat exchanger by Embodiment 1 of this invention. It is sectional drawing which shows the insertion hole of the 2nd header of the heat exchanger by Embodiment 1 of this invention. It is sectional drawing which shows the junction part of the 2nd flat tube and 2nd header of the heat exchanger by Embodiment 1 of this invention. It is sectional drawing which shows the heat exchanger shown in Embodiment 1 of this invention. It is sectional drawing which shows the junction part of the 2nd flat tube and 2nd header of the heat exchanger by Embodiment 1 of this invention. It is sectional drawing which shows the heat exchanger by Embodiment 1 of this invention. It is sectional drawing at the time of manufacturing the heat exchanger by Embodiment 1 of this invention. It is sectional drawing which shows the junction part of the 2nd flat tube and 2nd header of the heat exchanger by Embodiment 1 of this invention. It is sectional drawing which shows the insertion hole of the 2nd header of the heat exchanger by Embodiment 1 of this invention. It is sectional drawing and the perspective view of a rectangular tube of the heat exchanger by Embodiment 1 of this invention. It is sectional drawing which shows the heat exchanger by Embodiment 1 of this invention. It is a block diagram which shows the heat pump system using the heat using the heat exchanger by Embodiment 1 of this invention. It is a block diagram which shows the other example of the heat pump system using the heat using the heat exchanger by Embodiment 1 of this invention. It is a block diagram which shows the heat pump system using the cold heat using the heat exchanger by Embodiment 1 of this invention. It is a block diagram which shows the heat pump system using the heat and cold using the heat exchanger by Embodiment 1 of this invention. It is sectional drawing which shows one edge part of the 2nd flat tube of the heat exchanger by Embodiment 2 of this invention. It is sectional drawing which shows the connection part of the 2nd flat tube and 2nd header of the heat exchanger by Embodiment 2 of this invention. It is sectional drawing which shows one edge part of the 2nd flat tube of the heat exchanger by Embodiment 3 of this invention. It is sectional drawing which shows the junction part of the 2nd flat tube and 2nd header of the heat exchanger by Embodiment 3 of this invention. It is sectional drawing which shows one edge part of the 2nd flat tube of the heat exchanger by Embodiment 4 of this invention. It is sectional drawing which shows the junction part of the 2nd flat tube and 2nd header of the heat exchanger by Embodiment 4 of this invention. It is sectional drawing which shows the other example of the junction part of the 2nd flat tube and 2nd header of the heat exchanger by Embodiment 4 of this invention. It is sectional drawing which shows the further another example of the junction part of the 2nd flat tube and 2nd header of the heat exchanger by Embodiment 4 of this invention. It is sectional drawing which shows the insertion hole of the 2nd header of the heat exchanger by Embodiment 5 of this invention. It is sectional drawing which shows the junction part of the 2nd flat tube and 2nd header of the heat exchanger by Embodiment 5 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 1st flat tube, 2nd 2nd flat tube, 3rd header, 4th header, 5 Heat transfer path, 6 Flow path wall, 7 Rectangular tube, 8 Outer peripheral tube, 9 Gap, 10 Heat exchanger, 12 Taper Part, 21 brazing material, 22 brazing gap, 23 staying part, 25 jig, 26 contraction pipe part, 27 groove part, 28 insertion hole, 29 expansion part, 30 spacer, 31 compressor, 32 four-way valve, 33 expansion valve, 34 outdoor heat exchanger, 35 utilization side heat exchanger, 36 pump, 38 tank, 39 fan, 40 flat plate, 41 joint, 42 plane part, 43 cylinder.

Claims (10)

A flat first flat tube having a first refrigerant flow path through which the first refrigerant flows;
A flat second flat tube that has a second refrigerant flow path through which the second refrigerant flows and is joined to the flat surface of the first flat tube by a flat surface;
A pair of first headers connected to both ends of the first flat tube;
A pair of second headers connected to both ends of the second flat tube,
The first header joint connecting the first flat tube and the first header or the second header joint connecting the second flat tube and the second header has a brazing material retaining portion. The heat exchanger according to claim 1. The first flat tube or the second flat tube has a plurality of rectangular tubes, and the retention portion of the brazing material is formed by providing a spacer between adjacent rectangular tubes. Heat exchanger. The retention portion of the brazing material is provided at an end portion of the first flat tube or an end portion of the second flat tube, and is an expanded tube portion having an outer peripheral length longer than a central portion. The described heat exchanger. The first flat tube or the second flat tube has a plurality of rectangular tubes,
2. The heat exchanger according to claim 1, wherein the retention portion of the brazing material is an expanded tube portion provided at an end portion of the rectangular tube and having an outer peripheral length longer than that of the central portion. The stay part of the brazing material is provided at an end part of the first flat tube or an end part of the second flat tube, and is a contracted tube part whose outer peripheral length is shorter than that of the central part. The heat exchanger as described in. The first flat tube or the second flat tube has a plurality of rectangular tubes,
2. The heat exchanger according to claim 1, wherein the brazing material retaining portion is a contracted tube portion provided at an end portion of the rectangular tube and having an outer peripheral length shorter than a central portion. The heat exchanger according to claim 1, wherein the retention portion of the brazing material is a groove portion provided at an end portion of the first flat tube or an end portion of the second flat tube and recessed inward. . The first flat tube or the second flat tube has a plurality of rectangular tubes,
The heat exchanger according to claim 1, wherein the retention portion of the brazing material is a groove portion provided at an end portion of the rectangular tube and recessed inward. The heat exchanger according to any one of claims 1 to 8, wherein a taper portion is provided in the insertion hole of the first header or the insertion hole of the second header. A cooling system comprising the heat exchanger according to any one of claims 1 to 9.

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