Heat exchanger

Abstract

To provide a heat exchanger that can be easily produced.SOLUTION: A heat exchanger is equipped with a header that has a header opening through which a heat medium flows in or discharges out, and a header channel in which the heat medium circulates, and a plurality of branch pipes disposed at intervals in an extending direction of the header channel, connected to the header so as to communicate with the header channel, and having the same pipe diameter. The plurality of branch pipes has a throttling portion throttling a channel cross-sectional area in the plurality of branch pipes. The plurality of branch pipes is provided so that the flow resistance of the heat medium in the plurality of branch pipes increases from the branch pipe apart from the header opening toward the branch pipe close to the header opening of the plurality of branch pipes.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a heat exchanger. [Background technology]

[0002] There is a heat exchanger that includes a header provided on each of the inlet and outlet sides of the heat medium, and a plurality of branch pipes provided in parallel between the inlet header and the outlet header. In such a heat exchanger, the flow rate of the heat medium flowing through the branch pipe connected to the header at a position close to the header opening tends to be higher than that of the branch pipe connected to the header at a position away from the header opening through which the heat medium flows in or out. In contrast, Patent Document 1 discloses a heat exchanger that includes a header into which a refrigerant flows in from one longitudinal direction, and a number of heat transfer tubes that are connected in sequence along the longitudinal direction of the header, in which the cross-sectional area of ​​the refrigerant passages in the multiple heat transfer tubes gradually increases from one longitudinal end side to the other longitudinal end side of the header so that the refrigerant flows approximately evenly within the multiple heat transfer tubes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3284904 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the heat exchanger described in Patent Document 1, multiple types of heat transfer tubes with different diameters are used in order to make the cross-sectional areas of the refrigerant passages of the multiple heat transfer tubes connected to the header different. Accordingly, in order to connect the heat transfer tubes, multiple types of holes corresponding to the diameters of the heat transfer tubes need to be formed in the header. This poses the problem that it takes time and effort to manufacture the header.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a heat exchanger that is easy to manufacture. [Means for solving the problem]

[0006] In order to solve the above problems, the heat exchanger of the present disclosure comprises a header having a header opening through which a heat medium flows in or out and a header flow path through which the heat medium flows, and a plurality of branch pipes having the same pipe diameter, which are arranged at intervals in the direction in which the header flow path extends and connected to the header so as to communicate with the header flow path, wherein the plurality of branch pipes have constriction sections that constrict the flow path cross-sectional areas in the plurality of branch pipes, and the plurality of branch pipes are arranged such that the flow resistance of the heat medium in the plurality of branch pipes increases from a branch pipe among the plurality of branch pipes that is farther from the header opening to a branch pipe among the plurality of branch pipes that is closer to the header opening. Effect of the Invention

[0007] According to the heat exchanger of the present disclosure, it is possible to provide a heat exchanger that is easy to manufacture. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a heat exchanger according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an enlarged cross-sectional view showing a branch pipe of a heat exchanger according to an embodiment of the present disclosure. [Diagram 3] FIG. 11 is an enlarged cross-sectional view showing a branch pipe according to a first modified example of the embodiment of the present disclosure. [Figure 4] FIG. 11 is an enlarged cross-sectional view showing a branch pipe according to a second modified example of the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a heat exchanger according to an embodiment of the present disclosure will be described with reference to FIGS.

[0010] (Heat exchanger configuration) As shown in FIG. 1, the heat exchanger 10A includes an inlet header 20A, an outlet header 20B, and a plurality of branch pipes . In the heat exchanger 10A, the heat medium flows from an inlet header 20A through a plurality of branch pipes 40 to an outlet header 20B. In this embodiment, the heat transfer medium is a liquid. In this embodiment, the heat medium is water. The heat medium is not limited to water, but may be an antifreeze liquid. The heat exchanger 10A heats or cools the heat medium.

[0011] For example, when the heat exchanger 10A in this embodiment is a gas cooler, heat exchange is performed between a heat medium (water) flowing through the multiple branch pipes 40 and a gas flowing outside the multiple branch pipes 40, so that the heat exchanger 10A cools the gas, while the heat medium flowing through the heat exchanger 10A is heated. For example, when the heat exchanger 10A in this embodiment is a gas heater, heat exchange is performed between a heat medium (water) flowing through the multiple branch pipes 40 and a gas flowing outside the multiple branch pipes 40, so that the heat exchanger 10A heats the gas, while the heat medium flowing through the heat exchanger 10A is cooled.

[0012] The heat medium flows into the inlet header 20A from the outside of the heat exchanger 10A through a supply pipe (not shown). The inlet side header 20A has a header body 21A and a curved pipe portion 22A. The header body 21A is made of a tube that extends linearly in one direction. One end of the curved pipe portion 22A is connected to one end of the header body 21A. The other end of the header body 21A is closed. The curved pipe portion 22A is curved, for example, in a U-shape. The other end of the curved pipe portion 22A is connected to a supply pipe. The other end of the curved pipe portion 22A is formed with a header opening 23A into which the heat medium flows from the supply piping.

[0013] The inlet side header 20A has a header flow path 24A, through which a heat medium flows, inside a header main body 21A and a curved pipe portion 22A. In the inlet header 20A, the heat medium supplied from an external supply pipe flows into the header flow path 24A from the header opening 23A. The heat medium that has flowed into the header flow passage 24A of the inlet header 20A branches into a plurality of branch pipes 40 and flows therethrough.

[0014] The heat transfer medium flows into the outlet header 20B via a plurality of branch pipes 40. The outlet header 20B discharges the heat medium to a discharge pipe (not shown) outside the heat exchanger 10A. The outlet side header 20B has a header body 21B and a curved pipe portion 22B. The header body 21B is made of a tube that extends linearly in one direction. One end of the curved pipe portion 22B is connected to one end of the header body 21B. The other end of the header body 21B is closed. The curved pipe portion 22B is curved, for example, in a U-shape. The other end of the curved pipe portion 22B is connected to a discharge pipe. The other end of the curved pipe portion 22B is formed with a header opening 23B through which the heat medium flows out to the discharge piping.

[0015] The outlet header 20B has a header flow path 24B, through which the heat medium flows, inside a header main body 21B and a curved pipe portion 22B. In the outlet header 20B, the heat medium that has passed through a plurality of branch pipes 40 flows into a header flow path 24B. The outlet header 20B discharges the heat medium that has flowed into the header flow passage 24B from a header opening 23B to an external discharge piping.

[0016] The branch pipes 40 are provided between the inlet header 20A and the outlet header 20B. The branch pipes 40 are provided in parallel between the inlet header 20A and the outlet header 20B. The branch pipes 40 are arranged at intervals in the extension direction of the header flow path 24A of the header body 21A of the inlet side header 20A and the header flow path 24B of the header body 21B of the outlet side header 20B.

[0017] As shown in FIGS. 1 and 2, a plurality of branch pipes 40 are provided. In this embodiment, for example, four branch pipes 40 are provided. The number of branch pipes 40 is not limited to four, but may be two, three, five or more. In this embodiment, the plurality of branch pipes 40 include a first branch pipe 40A, a second branch pipe 40B, a third branch pipe 40C, and a fourth branch pipe 40D. First branch pipe 40A, second branch pipe 40B, third branch pipe 40C, and fourth branch pipe 40D have the same pipe diameter (outer diameter D, inner diameter d0: see FIG. 2).

[0018] Each of the multiple branch pipes 40 (first branch pipe 40A, second branch pipe 40B, third branch pipe 40C, fourth branch pipe 40D) is arranged at intervals in the direction in which the header flow paths 24A and 24B extend relative to the inlet side header 20A and the outlet side header 20B. Each of the multiple branch pipes 40 (first branch pipe 40A, second branch pipe 40B, third branch pipe 40C, fourth branch pipe 40D) has one end in its extension direction joined to the inlet header 20A by brazing, welding, or the like. Each of the multiple branch pipes 40 (first branch pipe 40A, second branch pipe 40B, third branch pipe 40C, fourth branch pipe 40D) has the other end in the extension direction joined to the outlet header 20B by brazing, welding, or the like.

[0019] The heat medium flows into the flow passages formed inside each of the branch pipes 40 from the header flow passage 24A of the inlet header 20A. The heat medium that has flowed into the flow passages formed inside each of the branch pipes 40 flows out into the header flow passage 24B of the outlet header 20B. In each of the branch pipes 40, heat exchange takes place between the heat medium flowing through the internal flow path and the gas flowing outside the branch pipe 40. In this embodiment, a gas pipe (not shown) through which gas flows is wound in a spiral shape around the outer circumferential surface of each of the branch pipes 40. In each of the branch pipes 40, heat exchange takes place between the heat medium flowing through the internal flow passage and the gas flowing through the gas pipe wrapped around the outer circumferential surface of the branch pipe 40. The gas does not have to flow through the gas pipe wrapped around the outer circumferential surface of the branch pipe 40. For example, the gas may flow through the space outside each branch pipe 40, come into contact with the outer circumferential surface of each branch pipe 40, and exchange heat with the heat medium flowing through each branch pipe 40.

[0020] The multiple branch pipes 40 are arranged such that the flow resistance of the heat medium in the multiple branch pipes 40 gradually increases, with respect to a path along the header flow path 24A, from the branch pipe 40 away from the header opening 23A to the branch pipe 40 closer to the header opening 23A. In addition, the multiple branch pipes 40 are arranged such that the flow resistance of the heat medium in the multiple branch pipes 40 gradually increases, with respect to the path along the header flow path 24B, from the branch pipe 40 away from the header opening 23B to the branch pipe 40 closer to the header opening 23B.

[0021] Hereinafter, "close to the header opening 23A" simply means close to the header opening 23A with respect to the path along the header flow path 24A. Moreover, hereinafter, simply saying "away from the header opening 23A" means away from the header opening 23A with respect to the path along the header flow passage 24A. Moreover, hereinafter, "close to the header opening 23B" simply means close to the header opening 23B with respect to a path along the header flow path 24B. Moreover, hereinafter, simply saying "away from the header opening 23B" means away from the header opening 23B with respect to a path along the header flow passage 24B.

[0022] The branch pipes 40 each have a throttle portion 51 that throttles the cross-sectional area of ​​the flow passage in the branch pipes 40 . At least one of the branch pipes 40 has a throttle portion 51 . In this embodiment, of the multiple branch pipes 40, at least the first branch pipe 40A closest to the header opening 23A has a throttle portion 51. Hereinafter, the term "throttled portion 51" refers to a series of portions of each branch pipe 40 whose inner diameter is smaller than the inner diameter d0 of the portion other than the throttle portion 51.

[0023] Specifically, of the plurality of branch pipes 40, the first branch pipe 40A closest to the header opening 23A has, as the throttle portion 51, a throttle portion 51A. Among the plurality of branch pipes 40, the second branch pipe 40B which is second closest to the header opening 23A has a throttle portion 51B as the throttle portion 51. Among the plurality of branch pipes 40, the third branch pipe 40C which is the third closest to the header opening 23A has, as the throttle portion 51, a throttle portion 51C.

[0024] Each of the throttle portions 51 throttles the cross-sectional area of ​​the flow passage in the corresponding branch pipe 40 . Each of the narrowed portions 51 is formed by narrowing the pipe diameter of the branch pipe 40 at a part of the branch pipe 40 in the extension direction.

[0025] The constricted portion 51A has an inner diameter smaller than the inner diameter d0 of the portion other than the constricted portion 51A, which is obtained by constricting the pipe that forms the first branch pipe 40A by an appropriate drawing process. The constricted portion 51B has an inner diameter smaller than the inner diameter d0 of the portion other than the constricted portion 51B by drawing the pipe that forms the second branch pipe 40B by an appropriate drawing process. The tube that forms third branch tube 40C is drawn by an appropriate drawing process, so that the inner diameter of narrowed portion 51C is smaller than the inner diameter d0 of the portion other than narrowed portion 51C. In this embodiment, among the multiple branch pipes 40, the fourth branch pipe 40D, which is the farthest from the header opening 23A, does not have a throttle portion 51 and is formed in a straight pipe shape with its inner diameter d0 being constant throughout the entire extension direction of the fourth branch pipe 40D.

[0026] Hereinafter, the "inner diameter of the narrowed portion 51" refers to the inner diameter of the narrowed portion 51 at the portion having the smallest inner diameter. In other words, "the inner diameter of the narrowed portion 51A" refers to the inner diameter at the portion with the smallest inner diameter in the entire narrowed portion 51A. Moreover, "the inner diameter of the narrowed portion 51B" refers to the inner diameter at the portion with the smallest inner diameter in the entire narrowed portion 51B. Moreover, "the inner diameter of the narrowed portion 51C" refers to the inner diameter at the portion with the smallest inner diameter in the entire narrowed portion 51C.

[0027] In this embodiment, the inner diameter d of the constriction section 51 is made different in the multiple branch pipes 40, so that the flow resistance of the heat medium in the multiple branch pipes 40 gradually increases from the branch pipes 40 farther from the header opening 23A to the branch pipes 40 closer to the header opening 23A. The first branch pipe 40A closest to the header opening 23A is provided with a throttle portion 51A having an inside diameter d1. The second branch pipe 40B, which is second closest to the header opening 23A, is provided with a throttle portion 51B having an inner diameter d2. The third branch pipe 40C, which is the third closest to the header opening 23A, is provided with a throttle portion 51C having an inner diameter d3. The inner diameter d3 of the constricted portion 51C, the inner diameter d2 of the constricted portion 51B, and the inner diameter d1 of the constricted portion 51A are set so that the dimensions become smaller in this order.

[0028] In this embodiment, the first branch pipe 40A closest to the header opening 23A is also, of the multiple branch pipes 40, the branch pipe 40 closest to the header opening 23B. In this embodiment, the second branch pipe 40B, which is second closest to the header opening 23A, is also, among the multiple branch pipes 40, the branch pipe 40 that is second closest to the header opening 23B. Furthermore, in this embodiment, third branch pipe 40C, which is third closest to header opening 23A, is also, among the multiple branch pipes 40, the branch pipe 40 third closest to header opening 23B. In this embodiment, the fourth branch pipe 40D, which is the farthest from the header opening 23A, is also, of the multiple branch pipes 40, the branch pipe 40 that is the farthest from the header opening 23B.

[0029] That is, of the two adjacent first branch pipes 40A and second branch pipes 40B in the direction in which the header flow paths 24A and 24B extend, the inner diameter d1 of the throttle portion 51A of the first branch pipe 40A located closer to the header openings 23A and 23B is smaller than the inner diameter d2 of the throttle portion 51B of the second branch pipe 40B located away from the header openings 23A and 23B. Of the two second branch pipes 40B and third branch pipes 40C adjacent to each other in the direction in which the header flow paths 24A and 24B extend, the inner diameter d2 of the throttle portion 51B of the second branch pipe 40B located closer to the header openings 23A and 23B is smaller than the inner diameter d3 of the throttle portion 51C of the third branch pipe 40C located away from the header openings 23A and 23B. Of the two adjacent third branch pipes 40C and fourth branch pipes 40D in the direction in which the header flow paths 24A and 24B extend, the inner diameter d3 of the throttle section 51C of the third branch pipe 40C located closer to the header openings 23A and 23B is smaller than the inner diameter d0 of the fourth branch pipe 40D which is located away from the header openings 23A and 23B and does not have a throttle section 51.

[0030] As shown in FIG. 2, in this embodiment, one end of each of the multiple branch pipes 40 (first branch pipe 40A, second branch pipe 40B, third branch pipe 40C, and fourth branch pipe 40D) protrudes into the header flow path 24A of the inlet header 20A. Each of the branch pipes 40 has an opening 42A that faces the direction in which the branch pipe 40 extends and communicates with the header flow passage 24A. In each of the branch pipes 40, the heat medium flows between each of the branch pipes 40 and the header flow path 24A through the opening 42A. In each of the branch pipes 40, the heat medium flowing through the header flow passage 24A flows into the branch pipe 40 through the opening 42A.

[0031] At this time, the closer the branch pipe 40 is to the header opening 23A, the smaller the inner diameter d (d1 to d3) of the constriction section 51 is, and therefore the greater the flow resistance of the heat medium in the branch pipe 40 is, and therefore the more difficult it is for the heat medium flowing through the header flow path 24A to flow into the branch pipe 40 through the opening 42A. In addition, the further away from the header opening 23A the branch pipe 40 is, the larger the inner diameter d of the constriction section 51 is. Furthermore, since the fourth branch pipe 40D does not have a constriction section 51, the flow resistance of the heat medium in the branch pipe 40 is small, and the heat medium circulating through the header flow path 24A easily flows into the branch pipe 40 through the opening 42A.

[0032] Similarly, the closer the branch pipe 40 is to the header opening 23B, the smaller the inner diameter d (d1 to d3) of the constriction section 51 is, and therefore the greater the flow resistance of the heat medium within the branch pipe 40 is, and therefore the more difficult it is for the heat medium flowing through the branch pipe 40 to flow into the header flow path 24B through the opening 42B. In addition, the further away from the header opening 23B the branch pipe 40 is, the larger the inner diameter d of the constriction section 51 is. Furthermore, since the fourth branch pipe 40D does not have a constriction section 51, the flow resistance of the heat medium in the branch pipe 40 is small, and the heat medium circulating in the branch pipe 40 is more likely to flow out into the header flow path 24B through the opening 42B.

[0033] In this manner, the flow resistance of the heat medium in the multiple branch pipes 40 is made different among the multiple branch pipes 40, thereby making the flow rate of the liquid medium uniform. This improves the heat exchange efficiency in the heat exchanger 10A. Furthermore, the improvement in the heat exchange efficiency in the heat exchanger 10A makes it possible to reduce the size and cost of the heat exchanger 10A. Furthermore, compared to a case where the flow rate of the heat medium in the branch pipes is higher closer to the header opening and, as a result, the branch pipes 40 are more likely to corrode, the heat exchanger 10A can reduce the flow rate of the heat medium in the branch pipes 40 near the header openings 23A and 23B by making the flow rate of the liquid medium uniform among the multiple branch pipes 40. As a result, corrosion of the branch pipes 40 is suppressed.

[0034] (Action and Effects) According to this embodiment, in the heat exchanger 10A, the multiple branch pipes 40 are provided with the throttle sections 51, so that the flow resistance of the heat medium in the multiple branch pipes 40 gradually increases from the branch pipes 40 that are farther away from the header openings 23A and 23B toward the branch pipes 40 that are closer to the header openings 23A and 23B. As a result, the flow resistance of the heat medium within the branch pipes 40 close to the header openings 23A and 23B is greater than that of the branch pipes 40 away from the header openings 23A and 23B, making it more difficult for the heat medium to flow from the header flow paths 24A and 24B into the branch pipes 40. Conversely, the flow resistance of the heat medium within the branch pipe 40 that is far from the header openings 23A and 23B is smaller than that within the branch pipe 40 that is close to the header openings 23A and 23B, and therefore the heat medium easily flows from the header flow paths 24A and 24B into the branch pipe 40. In this manner, the flow rate of the heat medium among the plurality of branch pipes 40 can be made uniform. In this case, since the multiple branch pipes 40 have the same pipe diameter (outer diameter D), there is no need to form holes in, for example, the inlet side header 20A and the outlet side header 20B to connect the branch pipes 40 having multiple types of pipe diameters. Therefore, the structures of the inlet side header 20A and the outlet side header 20B can be simplified. As a result, it is possible to provide a heat exchanger 10A that is easy to manufacture.

[0035] Furthermore, according to one example of this embodiment, the inner diameter d of the constriction section 51 in the branch pipe 40 arranged closer to the header openings 23A and 23B is smaller than the inner diameter d of the constriction section 51 in the branch pipe 40 arranged away from the header openings 23A and 23B. This allows the flow resistance of the heat medium in multiple branch pipes 40 to be increased from the branch pipes 40 away from the header openings 23A, 23B toward the branch pipes 40 closer to the header openings 23A and 23B, while using branch pipes 40 having the same pipe diameter (outer diameter D).

[0036] Furthermore, according to one example of this embodiment, the flow resistance of the heat medium in three or more branch pipes 40 can be gradually increased from the branch pipe 40 farther away from the header openings 23A, 23B toward the branch pipe 40 closer to the header openings 23A, 23B. Therefore, the flow rate of the heat medium among the three or more branch pipes 40 can be made uniform.

[0037] In the above embodiment, the throttle sections 51A-51C having different inner diameters d are provided in order to gradually increase the flow resistance of the heat medium in the multiple branch pipes 40 from the branch pipe 40 farther from the header opening 23A toward the branch pipe 40 closer to the header opening 23A, but the present invention is not limited to this. Modifications thereof will be described below.

[0038] (First Modification of the Embodiment) As a first modified example, in a heat exchanger 10B, the branch pipes 40 may have throttle sections 52 that throttle the cross-sectional areas of the flow paths in the branch pipes 40, as shown in FIG. That is, at least one of the branch pipes 40 may have a throttle portion 52 . In the first modified example, at least the first branch pipe 40A, which is closest to the header opening 23A, of the multiple branch pipes 40 has a throttle portion 52. Specifically, among the multiple branch pipes 40, the first branch pipe 40A closest to the header opening 23A, the second branch pipe 40B second closest to the header opening 23A, and the third branch pipe 40C third closest to the header opening 23A may each have a throttle section 52. Each of the throttle portions 52 restricts the cross-sectional area of ​​the flow passage in the corresponding branch pipe 40 . Each of the narrowed portions 52 is formed by narrowing the pipe diameter of the branch pipe 40 at a part of the branch pipe 40 in the extension direction. In this first modified example, among the multiple branch pipes 40, the fourth branch pipe 40D, which is the farthest from the header opening 23A, does not have a throttle portion 52, and is formed in a straight pipe shape with its inner diameter d0 being constant throughout the entire extension direction of the fourth branch pipe 40D. Hereinafter, the term "length of each narrowed portion 52" refers to the length of the portion of each branch pipe 40 where the inner diameter is smaller than the inner diameter d0 of the portion other than each narrowed portion 52.

[0039] In this first modified example, the length L of the constriction section 52 in the extension direction of the branch pipes 40 is made different for the multiple branch pipes 40, so that the flow resistance of the heat medium in the multiple branch pipes 40 gradually increases from the branch pipes 40 farther away from the header opening 23A to the branch pipes 40 closer to the header opening 23A.

[0040] The first branch pipe 40A closest to the header opening 23A is provided with a throttle portion 52A having a length L1 in the extension direction. The second branch pipe 40B, which is second closest to the header opening 23A, is provided with a throttle portion 52B having a length L2 in the extension direction. The third branch pipe 40C, which is third closest to the header opening 23A, is provided with a throttle portion 52C having a length L3 in the extension direction. The length L3 of the narrowed portion 52C, the length L2 of the narrowed portion 52B, and the length L1 of the narrowed portion 52A are set so that the dimensions increase in this order.

[0041] That is, of the two first branch pipes 40A and second branch pipes 40B adjacent to each other in the direction in which the header flow paths 24A and 24B extend, the length L1 of the throttle section 52A of the first branch pipe 40A located closer to the header openings 23A and 23B is greater than the length L2 of the throttle section 52B of the second branch pipe 40B located away from the header openings 23A and 23B. Of the two second branch pipes 40B and third branch pipes 40C adjacent to each other in the direction in which the header flow paths 24A and 24B extend, the length L2 of the throttle section 52B of the second branch pipe 40B located closer to the header openings 23A and 23B is greater than the length L3 of the throttle section 52C of the third branch pipe 40C located away from the header openings 23A and 23B. Of the two adjacent third branch pipes 40C and fourth branch pipes 40D in the direction in which the header flow paths 24A and 24B extend, the length L3 of the throttle section 52C of the third branch pipe 40C located closer to the header openings 23A and 23B is greater than the length of the throttle section 52 of the fourth branch pipe 40D located away from the header openings 23A and 23B and which does not have a throttle section 52 (the length is 0 because no throttle section 52 is provided).

[0042] In this way, the closer the branch pipe 40 is to the header opening 23A, the greater the flow resistance of the heat medium in the branch pipe 40 due to the greater length L of the throttle section 52. As a result, the closer the branch pipe 40 is to the header opening 23A, the more difficult it is for the heat medium flowing through the header flow path 24A to flow into the branch pipe 40 through opening 42A. Also, the farther the branch pipe 40 is from the header opening 23A, the smaller the flow resistance of the heat medium in the branch pipe 40 is, so the more easily the heat medium flowing through the header flow path 24A can flow into the branch pipe 40 through opening 42A.

[0043] Hereinafter, "the inner diameter of the narrowed portion 52A" refers to the inner diameter at the portion with the smallest inner diameter in the entire narrowed portion 52A. Moreover, "the inner diameter of the narrowed portion 52B" refers to the inner diameter at the portion with the smallest inner diameter in the entire narrowed portion 52B. Moreover, "the inner diameter of the narrowed portion 52C" refers to the inner diameter at the portion with the smallest inner diameter within the entire narrowed portion 52C.

[0044] For example, the throttle portion 52 of the branch pipe 40 away from the header openings 23A and 23B and the throttle portion 52 of the branch pipe 40 close to the header openings 23A and 23B may have the same inner diameter. Furthermore, the throttle portion 52A, the throttle portion 52B, and the throttle portion 52C may have the same inner diameter d11.

[0045] (Action and Effects) According to this first modified example, in the heat exchanger 10B, as in the above embodiment, a plurality of branch pipes 40 are provided with a throttle section 52 in the branch pipes 40 so that the flow resistance of the heat medium in the plurality of branch pipes 40 gradually increases from the branch pipes 40 farther away from the header openings 23A, 23B to the branch pipes 40 closer to the header openings 23A, 23B. This makes it possible to make the flow rate of the heat medium uniform among the multiple branch pipes 40. In this case, since the multiple branch pipes 40 have the same pipe diameter (outer diameter D), there is no need to form holes in the inlet side header 20A and the outlet side header 20B to connect branch pipes 40 of multiple different pipe diameters. As a result, it is possible to provide the heat exchanger 10B that is easy to manufacture.

[0046] Furthermore, according to this first modified example, the length L of the throttle section 52 in the branch pipe 40 arranged closer to the header openings 23A and 23B is greater than the length L of the throttle section 52 in the branch pipe 40 arranged away from the header openings 23A, 23B. This allows the flow resistance of the heat medium in multiple branch pipes 40 to be increased from the branch pipes 40 away from the header openings 23A, 23B toward the branch pipes 40 closer to the header openings 23A and 23B, while using branch pipes 40 having the same pipe diameter (outer diameter D).

[0047] Furthermore, according to one example of the first modified example, the constriction portion 52 of the branch pipe 40 away from the header openings 23A and 23B and the constriction portion 52 of the branch pipe 40 close to the header openings 23A and 23B have the same inner diameter, so that multiple constriction portions 52 can be manufactured in a similar process. Therefore, it is possible to provide the heat exchanger 10B that is easy to manufacture.

[0048] Furthermore, according to one example of the first modified example, the flow resistance of the heat medium in three or more branch pipes 40 can be gradually increased from the branch pipe 40 farther away from the header openings 23A, 23B toward the branch pipe 40 closer to the header openings 23A, 23B. Therefore, the flow rate of the heat medium among the three or more branch pipes 40 can be made uniform.

[0049] (Second Modification of the Embodiment) As a second modified example, in a heat exchanger 10C, the branch pipes 40 may have throttle sections 53 that throttle the cross-sectional areas of the flow paths in the branch pipes 40, as shown in FIG. That is, at least one of the branch pipes 40 may have a throttle portion 53 . In the second modified example, at least the first branch pipe 40A, which is closest to the header opening 23A, of the multiple branch pipes 40 has a throttle portion 53. Specifically, among the multiple branch pipes 40, the first branch pipe 40A closest to the header opening 23A, the second branch pipe 40B second closest to the header opening 23A, and the third branch pipe 40C third closest to the header opening 23A may each have a throttle section 53. Each of the throttle portions 53 throttles the cross-sectional area of ​​the flow passage in the corresponding branch pipe 40 . Each of the narrowed portions 53 is formed by narrowing the pipe diameter of the branch pipe 40 at a part of the branch pipe 40 in the extension direction. In this second modified example, among the multiple branch pipes 40, the fourth branch pipe 40D, which is the farthest from the header opening 23A, does not have a throttle portion 53 and is formed in a straight pipe shape with its inner diameter d0 being constant throughout the entire extension direction of the fourth branch pipe 40D.

[0050] In this second modified example, the number N of constriction sections 53 is varied among the multiple branch pipes 40, so that the flow resistance of the heat medium in the multiple branch pipes 40 gradually increases from the branch pipes 40 farther from the header opening 23A to the branch pipes 40 closer to the header opening 23A. The first branch pipe 40A closest to the header opening 23A has, for example, three (number N=3) throttle portions 53A in the extending direction. The second branch pipe 40B, which is second closest to the header opening 23A, is provided with, for example, two (number N=2) throttle portions 53B in the extending direction. The third branch pipe 40C, which is the third closest to the header opening 23A, is provided with, for example, one (number N=1) throttle portion 53C in the extending direction. The number N of the throttle portions 53C, the number N of the throttle portions 53B, and the number N of the throttle portions 53A are set to increase in this order.

[0051] That is, of the two first branch pipes 40A and second branch pipes 40B adjacent to each other in the direction in which the header flow paths 24A and 24B extend, the number N (N=3) of the throttle sections 53A of the first branch pipe 40A located closer to the header openings 23A and 23B is greater than the number N (N=2) of the throttle sections 53B of the second branch pipe 40B located away from the header openings 23A and 23B. Of the two second branch pipes 40B and third branch pipes 40C adjacent to each other in the direction in which the header flow paths 24A and 24B extend, the number N (N=2) of the throttle sections 53B of the second branch pipe 40B located closer to the header openings 23A and 23B is greater than the number N (N=1) of the throttle sections 53C of the third branch pipe 40C located away from the header openings 23A and 23B. Of the two third branch pipes 40C and fourth branch pipes 40D adjacent to each other in the direction in which the header flow paths 24A and 24B extend, the number N (N=1) of the throttling sections 53C of the third branch pipe 40C located closer to the header openings 23A and 23B is greater than the number N of the throttling sections 53 of the fourth branch pipe 40D located away from the header openings 23A and 23B and not having a throttling section 53 (N=0 because no throttling section 53 is provided).

[0052] In this way, the closer the branch pipe 40 is to the header opening 23A, the greater the number N of throttle sections 53, and therefore the greater the flow resistance of the heat medium in the multiple branch pipes 40. As a result, the closer the branch pipe 40 is to the header opening 23A, the more difficult it is for the heat medium flowing through the header flow path 24A to flow into the branch pipe 40 through opening 42A. Also, the farther the branch pipe 40 is from the header opening 23A, the smaller the flow resistance of the heat medium in the branch pipe 40 is, and therefore the more easily the heat medium flowing through the header flow path 24A can flow into the branch pipe 40 through opening 42A.

[0053] Hereinafter, "the inner diameter of the restrictor 53A" refers to the inner diameter at the portion with the smallest inner diameter among the entirety of each of the three restrictor portions 53A. Moreover, "the inner diameter of the narrowed portion 53B" refers to the inner diameter of the entire portion of each of the two narrowed portions 53A at the portion where the inner diameter is smallest. Moreover, "the inner diameter of the narrowed portion 53C" refers to the inner diameter at the portion with the smallest inner diameter in the entire narrowed portion 53C.

[0054] For example, the throttle portion 53 of the branch pipe 40 away from the header openings 23A and 23B and the throttle portion 53 of the branch pipe 40 close to the header openings 23A and 23B may have the same inner diameter. Furthermore, the three throttle portions 53A may have the same inner diameter d12. Furthermore, the two throttle portions 53B may have the same inner diameter d12. Furthermore, the inner diameter d12 of the three throttle portions 53A, the inner diameter d12 of the two throttle portions 53B, and the inner diameter d12 of the one throttle portion 53C may be the same.

[0055] (Action and Effects) According to the second variant, in the heat exchanger 10C, as in the above embodiment, a plurality of branch pipes 40 are provided with a throttle section 53 in the branch pipes 40 so that the flow resistance of the heat medium in the plurality of branch pipes 40 gradually increases from the branch pipes 40 farther away from the header openings 23A, 23B toward the branch pipes 40 closer to the header openings 23A and 23B. This makes it possible to make the flow rate of the heat medium uniform among the multiple branch pipes 40. In this case, since the branch pipes 40 have the same pipe diameter, it is not necessary to form holes in the header for connecting the branch pipes 40 having different pipe diameters. As a result, it is possible to provide a heat exchanger 10C that is easy to manufacture.

[0056] In addition, according to the second modified example, the number N of the throttle sections 53 in the branch pipes 40 arranged on the side closer to the header openings 23A and 23B is made greater than the number N of the throttle sections 53 in the branch pipes 40 arranged on the side away from the header openings 23A and 23B. This allows the flow resistance of the heat medium in multiple branch pipes 40 to be increased from the branch pipes 40 away from the header openings 23A and 23B toward the branch pipes 40 closer to the header openings 23A and 23B, while using branch pipes 40 having the same pipe diameter (outer diameter D).

[0057] In addition, according to one example of the second modified example, the constriction portion 53 of the branch pipe 40 away from the header openings 23A and 23B and the constriction portion 53 of the branch pipe 40 close to the header openings 23A and 23B have the same inner diameter, so that multiple constriction portions 53 can be manufactured in a similar process. Therefore, it is possible to provide a heat exchanger 10C that is easy to manufacture.

[0058] Furthermore, according to one example of the second modified example, the flow resistance of the heat medium in three or more branch pipes 40 can be gradually increased from the branch pipe 40 farther away from the header openings 23A, 23B toward the branch pipe 40 closer to the header openings 23A, 23B. Therefore, the flow rate of the heat medium among the three or more branch pipes 40 can be made uniform.

[0059] (Other Modifications of the Embodiments) In the above embodiment and the first and second modified examples, the narrowed portions 51-53 are formed by narrowing the pipe diameter (outer diameter) of the branch pipe 40 in a part of the extension direction of the branch pipe 40, but this is not limited to this. The narrowed portions 51-53 may be formed by narrowing the inner diameter by increasing the wall thickness of the branch pipe 40 toward the radially inward direction of the branch pipe 40, which has a constant outer diameter, in a part of the extension direction of the branch pipe 40. Furthermore, as the throttle portions 51 to 53, for example, so-called orifice members (orifice valves) which are plate members extending along a plane intersecting the extension direction of the branch pipe 40 and having through holes formed therein may be used. Also, various valve mechanisms other than orifices may be used as the throttle sections 51 to 53. For example, by varying the opening degree of the valves among the multiple branch pipes 40, the flow resistance of the heat medium in the multiple branch pipes 40 may be gradually increased from the branch pipes 40 farther from the header opening 23A toward the branch pipes 40 closer to the header opening 23A.

[0060] In the above embodiment, the first modified example, and the second modified example, the positions of the throttle portions 51 to 53 in the extension direction of the branch pipe 40 are not limited in any way. In the above embodiment, the first modified example, and the second modified example, the narrowed portions 51-53 are formed by drawing the pipes forming the branch pipes 40, but this is not limited to the above. A separate member provided with the narrowed portions 51-53 may be joined or incorporated into a part of the pipes forming the branch pipes 40 in the extending direction.

[0061] Furthermore, in the above embodiment, and the first and second modified examples, the fourth branch pipe 40D, which is the farthest from the header opening 23A among the multiple branch pipes 40, is configured not to have the throttling portions 51-53, but this is not limited to the above, and the fourth branch pipe 40D may also be configured to have the throttling portions 51-53. In addition, it is also possible to appropriately combine the configuration shown in the above embodiment with the configuration shown in the above modified example.

[0062] Although some embodiments of the present disclosure have been described above, these embodiments are presented as examples and are not intended to limit the scope of the disclosure. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the disclosure. These embodiments and their modifications are included in the scope of the present disclosure and its equivalents, as well as in the scope and gist of the disclosure.

[0063] <Additional Notes> The heat exchangers 10A to 10C described in the embodiment can be understood, for example, as follows.

[0064] (1) Heat exchangers 10A to 10C according to a first aspect include a header having header openings 23A, 23B through which a heat medium flows in or out, and header flow paths 24A, 24B through which the heat medium flows, and a plurality of branch pipes 40 having the same pipe diameter D, which are arranged at intervals in the direction in which the header flow paths 24A, 24B extend and are connected to the headers 20A, 20B so as to communicate with the header flow paths 24A, 24B, wherein the plurality of branch pipes 40 have constriction sections 51 to 53 that constrict a flow cross-sectional area in the plurality of branch pipes 40, and the plurality of branch pipes 40 are arranged such that the flow resistance of the heat medium in the plurality of branch pipes 40 increases from a branch pipe 40 that is far from the header openings 23A, 23B to a branch pipe 40 that is closer to the header openings 23A, 23B.

[0065] According to this embodiment, in heat exchangers 10A to 10C, the multiple branch pipes 40 are provided with throttle sections 51 to 53, so that the flow resistance of the heat medium in the multiple branch pipes 40 increases from the branch pipes 40 that are farther away from the header openings 23A, 23B toward the branch pipes 40 that are closer to the header openings 23A, 23B. As a result, the flow resistance of the heat medium in the branch pipes 40 close to the header openings 23A, 23B is greater than that in the branch pipes 40 away from the header openings 23A, 23B, so that the heat medium does not easily flow from the header flow paths 24A, 24B into the branch pipes 40. Conversely, the flow resistance of the heat medium in branch pipes 40 that are far from header openings 23A, 23B is smaller than that in branch pipes 40 that are close to header openings 23A, 23B, so that the heat medium more easily flows from the header flow paths 24A, 24B into branch pipes 40. In this manner, the flow rate of the heat medium can be made uniform among the plurality of branch pipes 40. In this case, since the plurality of branch pipes 40 have the same pipe diameter D, for example, it is not necessary to form holes in the headers 20A, 20B for connecting the branch pipes 40 of different pipe diameters. This allows the structure of the headers 20A and 20B to be simplified. As a result, it is possible to provide the heat exchangers 10A to 10C that are easy to manufacture.

[0066] (2) A heat exchanger 10A according to a second aspect is the heat exchanger 10A of (1), wherein the branch pipe 40 away from the header openings 23A, 23B and the branch pipe 40 close to the header openings 23A, 23B each have the throttle portion 51, and the inner diameter d of the throttle portion 51 in the branch pipe 40 close to the header openings 23A, 23B is smaller than the inner diameter d of the throttle portion 51 in the branch pipe 40 away from the header openings 23A, 23B.

[0067] According to this embodiment, the inner diameter d of the throttle section 51 in the branch pipe 40 arranged closer to the header openings 23A, 23B is smaller than the inner diameter d of the throttle section 51 in the branch pipe 40 arranged away from the header openings 23A, 23B. This makes it possible to increase the flow resistance of the heat medium in multiple branch pipes 40 from the branch pipes 40 farther from the header openings 23A, 23B toward the branch pipes 40 closer to the header openings 23A, 23B, while using branch pipes 40 having the same pipe diameter D.

[0068] (3) A heat exchanger 10B according to a third aspect is a heat exchanger 10B according to (1) or (2), wherein the branch pipe 40 away from the header openings 23A, 23B and the branch pipe 40 close to the header openings 23A, 23B each have the throttle portion 52, and the length L of the throttle portion 52 in the branch pipe 40 close to the header openings 23A, 23B is greater than the length L of the throttle portion 52 in the branch pipe 40 away from the header openings 23A, 23B.

[0069] According to this embodiment, the length L of the throttle section 52 in the branch pipe 40 arranged closer to the header openings 23A, 23B is greater than the length L of the throttle section 52 in the branch pipe 40 arranged away from the header openings 23A, 23B. This makes it possible to increase the flow resistance of the heat medium in multiple branch pipes 40 from the branch pipes 40 farther from the header openings 23A, 23B toward the branch pipes 40 closer to the header openings 23A, 23B, while using branch pipes 40 having the same pipe diameter D.

[0070] (4) A heat exchanger 10B according to a fourth aspect is the heat exchanger 10B of (3), in which the constriction portion 52 of the branch pipe 40 away from the header openings 23A, 23B and the constriction portion 52 of the branch pipe 40 close to the header openings 23A, 23B have the same inner diameter.

[0071] According to this embodiment, a plurality of narrowed portions 52 can be produced in the same process. Therefore, it is possible to provide the heat exchanger 10B that is easy to manufacture.

[0072] (5) A heat exchanger 10C according to a fifth aspect is a heat exchanger 10C according to any one of (1) to (4), wherein the branch pipe 40 away from the header openings 23A, 23B and the branch pipe 40 close to the header openings 23A, 23B each have the throttle portion 53, and the number N of the throttle portions 53 in the branch pipe 40 close to the header openings 23A, 23B is greater than the number N of the throttle portions 53 in the branch pipe 40 away from the header openings 23A, 23B.

[0073] According to the present embodiment, the number N of the throttle sections 53 in the branch pipe 40 arranged closer to the header openings 23A, 23B is made greater than the number N of the throttle sections 53 in the branch pipe 40 arranged away from the header openings 23A, 23B. This makes it possible to increase the flow resistance of the heat medium in multiple branch pipes 40 from the branch pipes 40 farther from the header openings 23A, 23B toward the branch pipes 40 closer to the header openings 23A, 23B, while using branch pipes 40 having the same pipe diameter D.

[0074] (6) A heat exchanger 10C according to a sixth aspect is the heat exchanger 10C of (5), in which the constriction portion 53 of the branch pipe 40 away from the header openings 23A, 23B and the constriction portion 53 of the branch pipe 40 close to the header openings 23A, 23B have the same inner diameter.

[0075] According to this embodiment, a plurality of narrowed portions 53 can be manufactured in the same process. Therefore, it is possible to provide a heat exchanger 10C that is easy to manufacture.

[0076] (7) A heat exchanger 10A-10C according to a seventh aspect is any one of the heat exchangers 10A-10C according to (1) to (6), wherein the plurality of branch pipes 40 include three or more branch pipes 40 arranged so that the flow resistance gradually increases from the branch pipe 40 away from the header openings 23A, 23B to the branch pipe 40 closer to the header openings 23A, 23B.

[0077] According to this embodiment, the flow resistance of the heat medium in three or more branch pipes 40 can be gradually increased from the branch pipes 40 farther from the header openings 23A, 23B toward the branch pipes 40 closer to the header openings 23A, 23B. Therefore, the flow rate of the heat medium among the three or more branch pipes 40 can be made uniform. [Explanation of symbols]

[0078] 10A~10C…Heat exchanger 20A…Inlet header 20B…Outlet side header 21A…Header body 21B…Header body 22A, 22B...Bent pipe section 23A, 23B...Header opening 24A, 24B...Header flow passage 40…Branch pipe 40A…First branch pipe 40B…Second branch pipe 40C…Third branch pipe 40D…Fourth branch pipe 42A…Aperture 51, 51A~51C, 52, 52A~52C, 53, 53A~53C...Throttling section D…Outer diameter (pipe diameter) d, d0, d1, d2, d3, d11, d12...inner diameter L, L1~L3...Length

Claims

1. a header having a header opening through which the heat medium flows in or out and a header flow path through which the heat medium flows; a plurality of branch pipes having the same pipe diameter, the branch pipes being arranged at intervals in a direction in which the header flow path extends and connected to the header so as to communicate with the header flow path; the plurality of branch pipes each have a constriction portion that constricts a flow path cross-sectional area within the plurality of branch pipes, The plurality of branch pipes are provided such that a flow resistance of the heat medium in the plurality of branch pipes increases from a branch pipe farther from the header opening among the plurality of branch pipes toward a branch pipe closer to the header opening among the plurality of branch pipes. heat exchanger.

2. each of the branch pipes away from the header opening and the branch pipes close to the header opening has the throttle portion; The inner diameter of the constricted portion of the branch pipe close to the header opening is smaller than the inner diameter of the constricted portion of the branch pipe away from the header opening.

2. The heat exchanger of claim 1.

3. each of the branch pipes away from the header opening and the branch pipes close to the header opening has the throttle portion; The length of the restriction in the branch pipe close to the header opening is greater than the length of the restriction in the branch pipe away from the header opening.

2. The heat exchanger of claim 1.

4. The throttle portion of the branch pipe away from the header opening and the throttle portion of the branch pipe close to the header opening have the same inner diameter.

4. The heat exchanger of claim 3.

5. each of the branch pipes away from the header opening and the branch pipes close to the header opening has the throttle portion; The number of the throttle portions in the branch pipes close to the header opening is greater than the number of the throttle portions in the branch pipes away from the header opening.

2. The heat exchanger of claim 1.

6. The throttle portion of the branch pipe away from the header opening and the throttle portion of the branch pipe close to the header opening have the same inner diameter.

6. The heat exchanger according to claim 5.

7. The plurality of branch pipes include three or more branch pipes that are provided such that the flow resistance gradually increases from the branch pipe that is farther away from the header opening toward the branch pipe that is closer to the header opening. A heat exchanger according to any one of claims 1 to 6.

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