Heat exchanger

Abstract

To improve a diversion property into a flow passage of gas-liquid two-phase refrigerant.SOLUTION: A heat exchanger composed of a plurality of metal plates having: a plurality of first metal plates; and a plurality of second metal plates. Each of the plurality of first metal plates is provided with: a first flow path in which a first fluid flows; and a first through hole forming a header space for flowing the first fluid into the first flow path. Each of the plurality of second metal plates is provided with: a second flow path in which a second fluid flows; and a second through hole forming the header space. A first side wall is provided at a peripheral edge part of each of the plurality of first metal plates, and a second side wall is provided at a peripheral edge part of each of the plurality of second metal plates. The header space is formed by laminating the plurality of first metal plates and the plurality of second metal plates. The header space is provided with a cross-sectional area adjustment part for adjusting a flow path cross-sectional area of the header space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] There is a heat exchanger (stacked microchannel heat exchanger) in which multiple metal plates, each having a flow path through which a gas-liquid two-phase refrigerant (hereinafter referred to as the first fluid) flows, and multiple metal plates, each having a flow path through which a liquid refrigerant (hereinafter referred to as the second fluid) flows, are alternately stacked and integrated. Such a heat exchanger is provided with an inlet and an outlet for the first fluid and an inlet and an outlet for the second fluid. The heat exchanger also has a header space for dividing the fluids flowing in from each inlet into the respective flow paths. The header space extends in the stacking direction of the multiple metal plates. Such a heat exchanger is used, for example, as an evaporator.

[0003] However, even if a heat exchanger has a header space, the gas-liquid two-phase refrigerant that flows into the header space does not necessarily flow evenly into the flow paths. One reason for this is that the gas-liquid two-phase refrigerant may not maintain a circular flow state midway through the header space and may become a separated flow. In such cases, the liquid refrigerant evaporates quickly in flow paths with a low liquid refrigerant flow rate, resulting in heat exchange only through the sensible heat change of the gas refrigerant, reducing the heat transfer coefficient of the heat exchanger.

[0004] One solution to this problem is to provide an inlet header between the header space and the flow path, separate from the header space (see, for example, Patent Document 1). For example, a tapered inlet header is provided between the header space and the flow path to prevent the formation of separate flows of the gas-liquid two-phase refrigerant before it flows into the flow path. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-189352 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the above structure, even if the inlet header has a tapered shape, the refrigerant flow rate is low near the tip of the inlet header. As a result, the gas-liquid two-phase refrigerant cannot maintain a circular flow near the tip of the inlet header and becomes a separated flow, making it difficult for the liquid refrigerant to flow evenly from the header space into the flow paths. If the gas-liquid two-phase refrigerant is not properly separated into the flow paths, the liquid refrigerant will not flow evenly through the flow paths, reducing the heat transfer coefficient of the heat exchanger.

[0007] In view of the above circumstances, an object of the present invention is to provide a heat exchanger that improves the separation of gas-liquid two-phase refrigerant into flow paths.

[0008] In order to achieve the above object, a heat exchanger according to one embodiment of the present invention is a heat exchanger formed by stacking a plurality of metal plates. The plurality of metal plates includes a plurality of first metal plates and a plurality of second metal plates. Each of the plurality of first metal plates is provided with a first flow path through which a first fluid flows, and a first through hole that forms a header space through which the first fluid flows into the first flow path. Each of the plurality of second metal plates is provided with a second flow path through which a second fluid flows and a second through hole that forms the header space. A first side wall is provided on the periphery of each of the plurality of first metal plates, and a second side wall is provided on the periphery of each of the plurality of second metal plates. The header space is formed by stacking the plurality of first metal plates and the plurality of second metal plates. A cross-sectional area adjusting portion that adjusts the flow path cross-sectional area of ​​the header space is provided in the header space.

[0009] Such a heat exchanger improves the efficiency of dividing the gas-liquid two-phase refrigerant into the flow paths.

[0010] The heat exchanger may further include a third metal plate and a fourth metal plate sandwiching a stacked block body formed by stacking the plurality of first metal plates and the plurality of second metal plates in the stacking direction, wherein the header space is closed by the fourth metal plate, an insertion hole communicating with the header space is formed in the third metal plate, and the cross-sectional area adjustment portion is formed by a columnar rod extending from the fourth metal plate in the stacking direction in the header space.

[0011] Such a heat exchanger can improve the efficiency of dividing the gas-liquid two-phase refrigerant into the flow paths.

[0012] In the heat exchanger, a cross-sectional area of ​​the rod in a direction perpendicular to the stacking direction may decrease from the fourth metal plate toward the third metal plate.

[0013] Such a heat exchanger can improve the separation of the gas-liquid two-phase refrigerant into the flow paths.

[0014] In the heat exchanger, the rod may be formed from a single rod material.

[0015] Such a heat exchanger can improve the efficiency of dividing the gas-liquid two-phase refrigerant into the flow paths.

[0016] In the heat exchanger, the rod may be formed by a stack of a plurality of fifth metal plates stacked in the stacking direction.

[0017] Such a heat exchanger can improve the separation of the gas-liquid two-phase refrigerant into the flow paths.

[0018] In the heat exchanger, each of the plurality of fifth metal plates may be connected to any one of the plurality of first metal plates or any one of the plurality of second metal plates via a bridge member.

[0019] Such a heat exchanger can improve the efficiency of dividing the gas-liquid two-phase refrigerant into the flow paths.

[0020] In the heat exchanger, the length of the rod in the stacking direction may be shorter than the length of the header space in the stacking direction.

[0021] Such a heat exchanger can improve the efficiency of dividing the gas-liquid two-phase refrigerant into the flow paths.

[0022] In the heat exchanger, the cross-sectional area adjusting portion may be formed by at least one plate portion that is erected in the header space and narrows a part of the flow path cross section of the header space.

[0023] Such a heat exchanger can improve the efficiency of dividing the gas-liquid two-phase refrigerant into the flow paths.

[0024] The heat exchanger further includes a third metal plate and a fourth metal plate that sandwich a laminated block body formed by stacking the plurality of first metal plates and the plurality of second metal plates in the stacking direction, The stacked block main body has a side surface formed between the third metal plate and the fourth metal plate, the side surface having a first side surface, a second side surface opposite the first side surface, a third side surface connected to the first side surface and the second side surface, and a fourth side surface connected to the first side surface and the second side surface and opposite the third side surface, the header space being positioned closer to the first side surface than to the second side surface and closer to the third side surface than to the fourth side surface, the first fluid flowing into the first flow path may flow from the side of the first side surface to the side of the second side surface, and the plate portion may extend in the header space in a direction from the first side surface to the second side surface.

[0025] Such a heat exchanger can improve the efficiency of dividing the gas-liquid two-phase refrigerant into the flow paths.

[0026] The heat exchanger may further include a third metal plate and a fourth metal plate sandwiching a stacked block body formed by stacking the plurality of first metal plates and the plurality of second metal plates in the stacking direction, wherein the header space is closed by the fourth metal plate, an insertion hole communicating with the header space is formed in the third metal plate, and the flow path cross-sectional area of ​​the header space may be larger on the side of the third metal plate than on the side of the fourth metal plate.

[0027] Such a heat exchanger can improve the efficiency of dividing the gas-liquid two-phase refrigerant into the flow paths.

[0028] In the heat exchanger, the flow path cross-sectional area of ​​the header space may decrease continuously or stepwise from the fourth metal plate toward the third metal plate.

[0029] Such a heat exchanger can improve the efficiency of dividing the gas-liquid two-phase refrigerant into the flow paths. [Effects of the Invention]

[0030] According to the present invention, a heat exchanger is provided which has improved flow division performance for a gas-liquid two-phase refrigerant into flow paths. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a schematic perspective view showing a heat exchanger of the present embodiment. [Figure 2] FIG. 2 is a schematic perspective view showing metal plates forming a laminated block body before being diffusion-bonded. [Figure 3] Figure (a) is a schematic perspective view showing the metal plates that form the ceiling panel before diffusion bonding, and Figure (b) is a schematic perspective view showing the metal plates that form the floor panel before diffusion bonding. [Figure 4] FIG. 10 is a schematic perspective view showing an example in which a rod is provided as a cross-sectional area adjusting portion on a diffusion-bonded floor panel. [Figure 5] FIG. 2 is a schematic perspective view showing an installation state of the heat exchanger when the heat exchanger is in use. [Figure 6]5 is a schematic cross-sectional view illustrating the operation of the heat exchanger according to the reference example. FIG. [Figure 7] 5 is a schematic cross-sectional view illustrating the operation of the heat exchanger according to the reference example. FIG. [Figure 8] FIG. 2 is a schematic cross-sectional view illustrating an example of the operation of the heat exchanger according to the present embodiment. [Figure 9] FIG. 2 is a schematic cross-sectional view illustrating an example of the operation of the heat exchanger according to the present embodiment. [Figure 10] FIG. 10 is a schematic cross-sectional view of a cross-sectional area adjusting portion according to a first modified example. [Figure 11] FIG. 10 is a schematic cross-sectional view of a second modified example of the cross-sectional area adjusting portion. [Figure 12] FIG. 10 is a schematic cross-sectional view of a third modified example of the cross-sectional area adjusting portion. [Figure 13] 1A is a schematic plan view of the cross-sectional area adjusting portion according to Modification 3, and FIGS. 1B and 1C are schematic perspective views of the cross-sectional area adjusting portion according to Modification 3. FIG. [Figure 14] FIG. 10 is a schematic cross-sectional view of a fourth modified example of the cross-sectional area adjusting portion. [Figure 15] 10A is a schematic plan view of the cross-sectional area adjusting portion according to the fourth modification, and FIGS. 10B and 10C are schematic perspective views of the cross-sectional area adjusting portion according to the fourth modification. [Figure 16] FIG. 10 is a schematic cross-sectional view of a fifth modified example of the cross-sectional area adjusting portion. [Figure 17] FIG. 10 is a schematic cross-sectional view of another modified example 5 of the cross-sectional area adjusting portion. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. XYZ axis coordinates may be introduced in each drawing. Furthermore, the same components or components having the same functions may be assigned the same reference numerals, and after describing the components, the description may be omitted as appropriate. Furthermore, the numerical values ​​shown below are examples and are not limited to these examples.

[0033] (heat exchanger) Fig. 1 is a schematic perspective view showing a heat exchanger of this embodiment. The heat exchanger 1 shown in Fig. 1 is a stacked heat exchanger (stacked microchannel heat exchanger) in which multiple metal plates are stacked and joined. The heat exchanger 1 includes a stacked block body 2, a ceiling panel 3, and a floor panel 4.

[0034] The laminated block body 2 includes a plurality of metal plates 21 (first metal plates) and a plurality of metal plates 22 (second metal plates). The laminated block body 2 is sandwiched between a ceiling plate 3 (third metal plate) and a floor plate 4 (fourth metal plate) in the stacking direction of the heat exchanger 1. The laminated block body 2 is a block body in which the metal plates 21 and 22 are alternately stacked and bonded by diffusion bonding. Examples of diffusion bonding include solid-state bonding, hot pressure welding, and cold pressure welding. Because high-temperature fluid and low-temperature fluid exchange heat in the laminated block body 2, the metal plates 21 and 22 may also be referred to as heat transfer plates. In FIG. 1 , the metal plate 22 is located in the uppermost layer of the laminated block body 2. In the laminated block body 2, the metal plate 21 may also be located in the uppermost layer.

[0035] The ceiling plate 3 is a block body formed by stacking multiple metal plates 30 and bonding them together by diffusion bonding. The floor plate 4 is a block body formed by stacking multiple metal plates 40 and bonding them together by diffusion bonding. The ceiling plate 3 and the laminated block main body 2 are bonded together by diffusion bonding. The floor plate 4 and the laminated block main body 2 are bonded together by diffusion bonding. The ceiling plate 3 may be formed from a single metal plate having the same thickness as the thickness of the multiple stacked metal plates 30, and the floor plate 4 may be formed from a single metal plate having the same thickness as the thickness of the multiple stacked metal plates 40. When the metal plate 22 is located in the uppermost layer of the laminated block main body 2, the ceiling plate 3 functions as a blocking plate that closes the flow paths and through holes (described later) provided in the metal plate 22 from the stacking direction.

[0036] The heat exchanger 1 has an upper surface 1u formed on the ceiling panel 3 side, a lower surface 1d formed on the floor panel 4 side, and a side surface 1wa (first side surface), a side surface 1wb (second side surface), a side surface 1wc (third side surface), and a side surface 1wd (fourth side surface). Each of the side surfaces 1wa, 1wb, 1wc, and 1wd is connected to the upper surface 1u and the lower surface 1d, and is formed between the ceiling panel 3 and the floor panel 4. The side surfaces 1wa and 1wb face each other. The side surfaces 1wc and 1wd face each other. The side surface 1wa intersects with the side surfaces 1wc and 1wd and is connected to the side surfaces 1wc and 1wd. The side surface 1wb intersects with the side surfaces 1wc and 1wd and is connected to the side surfaces 1wc and 1wd. Side surface 1wc intersects with side surface 1wa and side surface 1wb and is continuous with side surface 1wa and side surface 1wb. Side surface 1wd intersects with side surface 1wa and side surface 1wb and is continuous with side surface 1wa and side surface 1wb.

[0037] An inlet / outlet pipe 53, an inlet / outlet pipe 54, an inlet / outlet pipe 55, and an inlet / outlet pipe 56 are provided on the upper surface 1u of the heat exchanger 1. The inlet / outlet pipe 53 is provided near the corner of the heat exchanger 1 where the side surface 1wb and the side surface 1wc intersect, the inlet / outlet pipe 54 is provided near the corner of the heat exchanger 1 where the side surface 1wa and the side surface 1wd intersect, the inlet / outlet pipe 55 is provided near the corner of the heat exchanger 1 where the side surface 1wa and the side surface 1wc intersect, and the inlet / outlet pipe 56 is provided near the corner of the heat exchanger 1 where the side surface 1wb and the side surface 1wd intersect.

[0038] Furthermore, entrance / exit pipes 55 and 54 are lined up on the side of side 1wa. Entrance / exit pipes 56 and 53 are lined up on the side of side 1wb. Entrance / exit pipes 53 and 55 are lined up on the side of side 1wc. Entrance / exit pipes 54 and 56 are lined up on the side of side 1wd. The direction from entrance / exit pipe 53 to entrance / exit pipe 54 intersects with the direction from entrance / exit pipe 55 to entrance / exit pipe 56.

[0039] When the heat exchanger 1 is used as an evaporator, the inlet / outlet pipe 55 serves as an inlet pipe for a first fluid (low-temperature fluid), and the inlet / outlet pipe 56 serves as an outlet pipe for the first fluid. In this embodiment, the first fluid is a refrigerant that undergoes phase change. The first fluid flows through the inlet / outlet pipe 55 in a two-phase gas-liquid state and exits through the inlet / outlet pipe 56 as a gas refrigerant that has evaporated into a gas phase. The inlet / outlet pipe 53 serves as an inlet pipe for a second fluid (high-temperature fluid), and the inlet / outlet pipe 54 serves as an outlet pipe for the second fluid. In this embodiment, the second fluid is, for example, water. The first fluid flows from the side surface 1wa to the side surface 1wb, and the second fluid flows from the side surface 1wb to the side surface 1wa. The temperature of the first fluid is lower than that of the second fluid, and the first fluid in a two-phase gas-liquid state absorbs heat from the second fluid in a liquid state and evaporates. On the other hand, the temperature of the second fluid is higher than the temperature of the first fluid, and the second fluid is cooled by dissipating heat to the first fluid.

[0040] Header spaces 23, 24, 25, and 26 are formed at the four corners of the heat exchanger 1, penetrating the laminated block body 2 in the stacking direction. Header space 23 is provided near the corner of the heat exchanger 1 where side surface 1wb and side surface 1wc intersect, header space 24 is provided near the corner of the heat exchanger 1 where side surface 1wa and side surface 1wd intersect, header space 25 is provided near the corner of the heat exchanger 1 where side surface 1wa and side surface 1wc intersect, and header space 26 is provided near the corner of the heat exchanger 1 where side surface 1wb and side surface 1wd intersect.

[0041] For example, the header space 23 is arranged closer to the side surface 1wb than to the side surface 1wa and closer to the side surface 1wc than to the side surface 1wd. The header space 24 is arranged closer to the side surface 1wa than to the side surface 1wb and closer to the side surface 1wd than to the side surface 1wc. The header space 25 is arranged closer to the side surface 1wa than to the side surface 1wb and closer to the side surface 1wc than to the side surface 1wd. The header space 26 is arranged closer to the side surface 1wb than to the side surface 1wa and closer to the side surface 1wd than to the side surface 1wc.

[0042] The header space 25 and the header space 24 are aligned on the side of the side surface 1wa. The header space 26 and the header space 23 are aligned on the side of the side surface 1wb. The header space 23 and the header space 25 are aligned on the side of the side surface 1wc. The header space 24 and the header space 26 are aligned on the side of the side surface 1wd. The direction from the header space 23 to the header space 24 intersects with the direction from the header space 25 to the header space 26. Each of the header spaces 23, 24, 25, and 26 is closed by the floor plate 4. In the YZ-axis plane, the outer shape of each of the header spaces 23, 24, 25, and 26 is, for example, circular. Each of the header spaces 23, 24, 25, and 26 is formed in a cylindrical shape extending in the Z-axis direction, with its bottom surface having a circular outer shape.

[0043] Furthermore, the header space 23 communicates with an inlet / outlet pipe 53. The header space 24 communicates with an inlet / outlet pipe 54. The header space 25 communicates with an inlet / outlet pipe 55. The header space 26 communicates with an inlet / outlet pipe 56. The header spaces 25 and 26 are connected to a flow path (described later) provided in the metal plate 21. The header spaces 23 and 24 are connected to a flow path (described later) provided in the metal plate 22.

[0044] The header space 25 is also provided with a cross-sectional area adjusting portion that adjusts the flow path cross-sectional area of ​​the header space 25. Here, the cross-sectional area adjusting portion is formed by a columnar rod 61 extending from the floor plate 4 in the header space 25 in the stacking direction. The rod 61 is arranged so that the central axis of the rod 61 coincides with the central axis of the header space 25. The rod 61 is also formed out of contact with the laminated block main body 2. That is, a gap is formed between the rod 61 and the laminated block main body 2, and when the header space 25 is viewed from the stacking direction, an annular gap is formed. Note that the "flow path cross-sectional area of ​​the header space 25" refers to the cross-sectional area of ​​the header space 25 perpendicular to the direction in which the fluid flows in the header space 25 (the area of ​​the annular gap). Note that the "flow path cross-section of the header space 25" refers to the cross-section of the header space 25 perpendicular to the direction in which the fluid flows in the header space 25 (the surface of the annular gap).

[0045] In the drawings of this embodiment, solid lines are drawn at the boundaries of each of the multiple metal plates stacked in the stacking direction, but in a diffusion-bonded heat exchanger 1, these solid lines may disappear without being visible. The X-axis direction shown in the drawings corresponds to the stacking direction of the heat exchanger 1, the Z-axis direction is approximately perpendicular to the X-axis and Y-axis directions and corresponds to the direction from the inlet / outlet pipe 55 toward the inlet / outlet pipe 53, and the Y-axis direction is approximately perpendicular to the Z-axis and X-axis directions and corresponds to the direction from the inlet / outlet pipe 55 toward the inlet / outlet pipe 54. "Approximately perpendicular" includes not only a completely perpendicular state, but also a state close to perpendicular due to an error.

[0046] The metal plates 21, 22, 30, and 40 have high thermal conductivity and are made of, for example, the same material. The material of these metal plates is, for example, aluminum, stainless steel, copper, aluminum alloy, titanium, magnesium alloy, etc. The material of the rod 61 is, for example, aluminum, stainless steel, copper, aluminum alloy, titanium, magnesium alloy, etc.

[0047] 2(a) and 2(b) are schematic perspective views showing the metal plates forming the laminated block body before diffusion bonding. Fig. 2(a) shows metal plate 21, and Fig. 2(b) shows metal plate 22.

[0048] As shown in FIG. 2( a), the metal plate 21 has a rectangular planar shape, and is provided with a partition wall 211, a plurality of protrusions 212 protruding from the partition wall 211, and a side wall (first side wall) 213 as an outer periphery surrounding the partition wall 211. The protrusions 212 have, for example, a circular shape when viewed from above. The side wall 213 is provided on the peripheral edge (outer periphery) of the metal plate 21. In the metal plate 21, there is a step between the partition wall 211 and the side wall 213, and the thickness of the partition wall 211 is formed to be thinner than the thickness of the side wall 213. In other words, a recess 216 is formed in the metal plate 21 by the partition wall 211 and the side wall 213. The recess 216 is surrounded by the side wall 213.

[0049] By providing the partition wall 211 with a plurality of protrusions 212, each portion between the plurality of protrusions 212 on the partition wall 211 (the portion between adjacent protrusions 212 in the XZ-axis plane) becomes a flow path 215 (first flow path) of the metal plate 21. The flow path 215 is formed in the recessed portion 216. The flow path 215 is formed, for example, by half-etching. The partition wall 211 and the plurality of protrusions 212 are provided, for example, on each of the plurality of metal plates 21 included in the laminated block main body 2. An example in which the partition wall 211 does not have the protrusions 212 is also included in this embodiment. In this case, the thin space surrounded by the recessed portion 216 on the partition wall 211 becomes the flow path 215.

[0050] At the four corners of the metal plate 21, a through hole 251 (first through hole) serving as an inlet / outlet, a through hole 261 serving as an inlet / outlet, a through hole 231, and a through hole 241 are provided. Each of the through hole 251 and the through hole 261 is connected to the flow path 215 and functions as an inlet / outlet header communicating with the flow path 215. Furthermore, in the metal plate 21, an isolation portion (seal portion) 2310 is provided so as to surround the through hole 231. The isolation portion 2310 is formed continuously from the side wall 213 on the flow path 215 side of the through hole 231. The isolation portion 2310 separates the flow path 215 and the through hole 231. By providing the isolation portion 2310 between the through hole 231 and the flow path 215, the through hole 231 and the flow path 215 are separated from each other. Furthermore, in the metal plate 21, an isolation portion (seal portion) 2410 is provided so as to surround the through hole 241. The separating portion 2410 is formed continuously from the side wall 213 on the flow path 215 side of the through hole 241. The separating portion 2410 separates the flow path 215 from the through hole 241. By providing the separating portion 2410 between the through hole 241 and the flow path 215, the through hole 241 and the flow path 215 are separated from each other.

[0051] When the heat exchanger 1 (FIG. 1) is used as an evaporator, the header space 25 functions as a header that allows a first fluid in a gas-liquid two-phase refrigerant state to flow into the flow path 215 of the metal plate 21. The through-hole 251 serves as an inlet for the first fluid in a gas-liquid two-phase refrigerant state in the metal plate 21. The gas-liquid two-phase refrigerant flows through the flow path 215, and the through-hole 261 serves as an outlet for the first fluid in a gas refrigerant state that has evaporated from the gas-liquid two-phase refrigerant and is now in a gas phase. A second fluid in a liquid state passes through each of the through-holes 231 and 241.

[0052] As shown in FIG. 2(b), the metal plate 22 has a rectangular planar shape, and is provided with a partition wall 221, a plurality of protrusions 222 protruding from the partition wall 221, and a side wall (second side wall) 223 as an outer periphery surrounding the partition wall 221. The protrusions 222 have, for example, a circular shape when viewed from above. The side wall 223 is provided on the peripheral edge (outer periphery) of the metal plate 22. In the metal plate 22, there is a step between the partition wall 221 and the side wall 223, and the thickness of the partition wall 221 is formed to be thinner than the thickness of the side wall 223. In other words, a recess 226 is formed in the metal plate 22 by the partition wall 221 and the side wall 223. The recess 226 is surrounded by the side wall 223.

[0053] By providing the partition wall 221 with a plurality of protrusions 222, each portion between the plurality of protrusions 222 on the partition wall 221 (the portion between adjacent protrusions 222 in the XZ-axis plane) becomes a flow path 225 (second flow path) of the metal plate 22. The flow path 225 is formed in the recessed portion 226. The flow path 225 is formed, for example, by half-etching. The partition wall 221 and the plurality of protrusions 222 are provided, for example, on each of the plurality of metal plates 22 included in the laminated block main body 2. An example in which the partition wall 221 does not have the protrusions 222 is also included in this embodiment. In this case, a thin space surrounded by the recessed portion 226 on the partition wall 221 becomes the flow path 215.

[0054] At the four corners of the metal plate 22, a through hole 232 serving as an inlet / outlet, a through hole 242 serving as an inlet / outlet, a through hole 252 (second through hole), and a through hole 262 are provided. Each of the through hole 232 and the through hole 242 is connected to the flow path 225 and functions as an inlet / outlet header communicating with the flow path 225. In the metal plate 22, a separator (sealing portion) 2520 is provided so as to surround the through hole 252. The separator 2520 is formed continuously from the side wall 223 on the flow path 225 side of the through hole 252. The separator 2520 separates the flow path 225 and the through hole 252. By providing the separator 2520 between the through hole 252 and the flow path 225, the through hole 252 and the flow path 225 are separated from each other. In addition, in the metal plate 22, a separator (sealing portion) 2620 is provided so as to surround the through hole 262. The separating portion 2620 is formed continuously from the side wall 223 on the flow path 225 side of the through hole 262. The separating portion 2620 separates the flow path 225 from the through hole 262. By providing the separating portion 2620 between the through hole 262 and the flow path 225, the through hole 262 and the flow path 225 are separated from each other.

[0055] For example, when the heat exchanger 1 (FIG. 1) is used as an evaporator, the header space 23 functions as a header that allows the second fluid in a liquid state to flow into the flow path 225 of the metal plate 22. The through-hole 232 serves as an inlet for the second fluid in the metal plate 22. The second fluid flows into the flow path 225, and the through-hole 242 serves as an outlet for the second fluid. The first fluid in a gas-liquid two-phase state passes through the through-hole 252, and the first fluid in a gas state passes through the through-hole 262.

[0056] The header space 23, the header space 24, the header space 25, and the header space 26 are each formed by alternately stacking a plurality of metal plates 21 and a plurality of metal plates 22 in the stacking direction. For example, a through hole 231 provided in the metal plate 21 and a through hole 232 provided in the metal plate 22 are connected in the stacking direction to form the header space 23 in the laminated block main body 2. A through hole 241 provided in the metal plate 21 and a through hole 242 provided in the metal plate 22 are connected in the stacking direction to form the header space 24 in the laminated block main body 2. A through hole 251 provided in the metal plate 21 and a through hole 252 provided in the metal plate 22 are connected in the stacking direction to form the header space 25 in the laminated block main body 2. A through hole 261 provided in the metal plate 21 and a through hole 262 provided in the metal plate 22 are connected in the stacking direction to form the header space 26 in the laminated block main body 2.

[0057] FIG. 3(a) is a schematic perspective view showing the metal plates that form the ceiling panel before diffusion bonding, and FIG. 3(b) is a schematic perspective view showing the metal plates that form the floor panel before diffusion bonding.

[0058] As shown in FIG. 3(a), the metal plate 30 is a metal plate having a rectangular planar shape. Also, as shown in FIG. 3(b), the metal plate 40 is a metal plate having a rectangular planar shape. Here, a through hole 331, a through hole 341, a through hole 351, and a through hole 361 are provided at the four corners of the metal plate 30 shown in FIG. 3(a). By stacking a plurality of metal plates 30, the through holes 331 provided in the metal plates 30 are connected in the stacking direction to form an insertion hole 530 (FIG. 1) into which the inlet / outlet pipe 53 is inserted. The insertion hole 530 is connected to the header space 23. Furthermore, the through holes 341 provided in the metal plates 30 are connected in the stacking direction to form an insertion hole 540 (FIG. 1) into which the inlet / outlet pipe 54 is inserted. The insertion hole 540 is connected to the header space 24. Furthermore, the through holes 351 provided in the metal plates 30 are connected in the stacking direction to form an insertion hole 550 (FIG. 1) into which the inlet / outlet pipe 55 is inserted. The insertion hole 550 is connected to the header space 25. Furthermore, the through holes 361 provided in the metal plates 30 are connected in the stacking direction to form an insertion hole 560 into which the inlet / outlet pipe 56 is inserted. The insertion hole 560 is connected to the header space 26. Each inlet / outlet pipe is fixed to the corresponding insertion hole by, for example, brazing. Furthermore, a through hole 410 is provided in one of the four corners of the metal plate 40 shown in FIG. 3(b). By stacking multiple metal plates 40, the through holes 410 provided in the metal plates 40 are connected in the stacking direction to form a hole portion 41 (FIG. 4 described later) into which the rod 61 is inserted.

[0059] For example, when the heat exchanger 1 is used as an evaporator, the through-hole 351 serves as an inlet for a first fluid in a gas-liquid two-phase state, and the through-hole 361 serves as an outlet for the first fluid in a gaseous state. Also, the through-hole 331 serves as an inlet for a second fluid in a liquid state, and the through-hole 341 serves as an outlet for the second fluid in a liquid state.

[0060] FIG. 4 is a schematic perspective view showing an example in which a rod is provided as a cross-sectional area adjusting portion on a diffusion-bonded floor plate.

[0061] For example, the rod 61 is fitted into the hole 41 (an insertion hole formed by connecting the through holes 410 in the stacking direction) provided in the floor plate 4. The rod 61 is joined to the floor plate 4 by, for example, welding. This prevents the first fluid from leaking between the hole 41 and the rod 61. The rod 61 is disposed in the header space 25. The rod 61 is formed of a single rod material (bar material). In the stacking direction, the length L61 of the rod 61 protruding from the floor plate 4 is, for example, substantially the same as the length (thickness) of the laminated block main body 2 in the stacking direction. In other words, in the stacking direction, the length L61 of the rod 61 is substantially the same as the length of the header space 25 provided in the laminated block main body 2. The rod 61 is formed, for example, in a cylindrical shape, and the outer shape of the rod 61 is, for example, circular in the YZ-axis plane. The rod 61 may also be a prismatic rod. Note that "substantially the same" includes not only a state of being completely the same, but also a state of being close to the same due to a margin of error. The holes 41 may be formed by post-processing the floor board 4 formed by diffusion bonding, without providing the through holes 410 in the metal plate 40.

[0062] (action) 5 is a schematic perspective view showing the installation state of the heat exchanger when in use. The heat exchanger 1 is used, for example, with the side surface 1wa facing downward and the side surface 1wb facing upward. Here, a first fluid in a gas-liquid two-phase state flows in through an inlet / outlet pipe 55, absorbs heat from a second fluid, becomes gaseous, and flows out through an inlet / outlet pipe 56. The first fluid in a gas-liquid two-phase state flows from the bottom to the top in the heat exchanger 1 installed with the side surface 1wa facing downward. Meanwhile, the second fluid in a liquid state flows in through an inlet / outlet pipe 53, dissipates heat to the first fluid, and flows out through an inlet / outlet pipe 54.

[0063] Before describing the operation of the heat exchanger 1 of this embodiment, the operation of the heat exchanger in the case where the rod 61 as the cross-sectional area adjusting portion is not provided in the header space 25 will be described as a reference example.

[0064] 6 and 7 are schematic cross-sectional views illustrating the operation of a heat exchanger according to a reference example. FIG. 6 corresponds to a cross-section of the heat exchanger 1 taken along the XZ-axis plane along line A1-A2 shown in FIG. 5. FIG. 7(a) is a cross-section showing the first fluid in a gas-liquid two-phase state at position P10 (YZ-axis plane) in FIG. 6, and FIG. 7(b) is a cross-section showing the first fluid in a gas-liquid two-phase state at position P20 (YZ-axis plane) in FIG. 6. In the header space 25 shown in FIG. 6, the portions indicated by dark dots represent the first fluid in a liquid phase, and the portions indicated by light dots represent the first fluid in a gas phase. Each of the flow paths 215 of the multiple metal plates 21 communicates with the header space 25.

[0065] The first fluid in a gas-liquid two-phase state that flows into the header space 25 from the inlet / outlet pipe 55 has a high flow velocity in the header space 25 near the inlet / outlet pipe 55 (for example, at the position P10), and therefore forms an annular flow. This state is shown in FIG. 7(a). In the header space 25 near the inlet / outlet pipe 55, the first fluid in a liquid phase is distributed in an annular shape, which makes it easy for the first fluid in a liquid phase to flow evenly into each of the flow paths 215 of the multiple metal plates 21. Here, an annular flow is one type of gas-liquid two-phase flow, and is a flow in which the liquid phase fluid forms a liquid film on the pipe wall and the gas phase fluid containing a large number of liquid droplets is present in the center of the pipe cross section.

[0066] However, the flow rate of the first fluid in a gas-liquid two-phase state gradually decreases as the first fluid in a gas-liquid two-phase state advances toward the back of the header space 25 (toward the floor plate 4). Therefore, the flow velocity decreases toward the back of the header space 25 (for example, at the position P20), and the first fluid in a gas-liquid two-phase state tends to form a separated flow. This state is shown in Figure 7(b). Here, a separated flow is a type of gas-liquid two-phase flow in which the liquid and gas phases exist separately within the pipe, and the liquid phase is distributed at the bottom of the pipe due to the influence of gravity.

[0067] Therefore, at the rear side of the header space 25, the first fluid in a liquid state is likely to accumulate at the bottom (side surface 1wa side) of the header space 25. Furthermore, the first fluid in a liquid state is driven to the header space 25 near the floor plate 4 by its own inertial force. This results in poor flow separation of the first fluid in a liquid state at the rear side of the header space 25. In other words, at the rear side of the header space 25, it becomes difficult for the first fluid in a liquid state to flow into the respective flow paths 215 of the multiple metal plates 21, and it becomes easier for the first fluid in a gas state to flow into the respective flow paths 215 of the multiple metal plates 21.

[0068] As in the reference example, when the first fluid in liquid phase does not flow evenly into each flow path 215 of the multiple metal plates 21, in flow paths 215 where the flow rate of the first fluid in liquid phase is low, the sensible heat change of the first fluid in gas phase becomes dominant, resulting in a decrease in the heat transfer coefficient of the heat exchanger.

[0069] 8 and 9 are schematic cross-sectional views illustrating an example of the operation of the heat exchanger according to this embodiment. FIG. 8 corresponds to a cross-section of the heat exchanger 1 taken along the XZ-axis plane along the line A1-A2 shown in FIG. 5. FIG. 9(a) is a cross-section showing the first fluid in a gas-liquid two-phase state at position P1 (YZ-axis plane) in FIG. 8, and FIG. 9(b) is a cross-section showing the first fluid in a gas-liquid two-phase state at position P2 (YZ-axis plane) in FIG. 8. In the header space 25, the portions indicated by dark dots represent the first fluid in a liquid phase, and the portions indicated by light dots represent the first fluid in a gas phase.

[0070] The first fluid in a gas-liquid two-phase state that flows into the header space 25 from the inlet / outlet pipe 55 has a high flow velocity in the header space 25 near the inlet / outlet pipe 55 (for example, at the position P1), and therefore forms an annular flow. This state is shown in Figure 9(a). In the header space 25 near the inlet / outlet pipe 55, the first fluid in a liquid phase is distributed in an annular shape, and therefore the first fluid in a liquid phase tends to flow evenly into each of the flow paths 215 of the multiple metal plates 21.

[0071] In the reference example, the flow rate of the first fluid in a gas-liquid two-phase state gradually decreased as it advanced toward the back of the header space 25. For this reason, in the reference example, the flow velocity decreased toward the back of the header space 25, making it easier for the first fluid in a gas-liquid two-phase state to form separate flows. In contrast, in the present embodiment, a rod 61 is provided in the header space 25. A predetermined space 257 is formed between a base 61A of the rod 61 joined to the floor plate 4 (a portion of the rod 61 protruding from the floor plate 4) and an inner peripheral wall 256 of the header space 25. This space 257 is connected to the inlet side of the header space 25.

[0072] As a result, the flow path cross-section of the header space 25 in this embodiment is narrower than that of the reference example, and the decrease in the flow velocity of the first fluid in a gas-liquid two-phase state is mitigated. Therefore, even at the rear of the header space 25, the first fluid in a gas-liquid two-phase state is more likely to maintain a circular flow. Furthermore, the presence of the predetermined space 257 allows the first fluid in a liquid state to exist in the respective flow paths 215 of the multiple metal plates 21, even when separate flows are formed. As a result, even if the first fluid in a liquid state at the rear of the header space 25 is driven toward the header space 25 near the floor plate 4 due to its own inertial force, the rod 61 pushes the liquid surface of the first fluid in the liquid state toward the metal plate 21. This state is shown in FIG. 9(b). As a result, the first fluid in a liquid state is more likely to reach the respective flow paths 215 of the multiple metal plates 21, even at the rear of the header space 25.

[0073] Therefore, in the header space 25 of the heat exchanger 1, the first fluid in a liquid phase state tends to flow evenly into the respective flow paths 215 of the plurality of metal plates 21. As a result, the sensible heat change of the first fluid in a liquid phase state becomes dominant in the respective flow paths 215 of the plurality of metal plates 21, improving the heat transfer coefficient of the heat exchanger.

[0074] (Variation 1) Fig. 10 is a schematic cross-sectional view of a first modified example of the cross-sectional area adjusting section. In the rod 62 shown in Fig. 10, the cross-sectional area of ​​the rod 62 in a direction perpendicular to the stacking direction (cross-sectional area in the YZ-axis plane) decreases from the floor board 4 toward the ceiling board 3 (approaching the inlet for the first fluid). For example, the rod 62 may be provided in a conical shape or a pyramidal shape. Furthermore, the rod 62 may be provided in a truncated conical shape or a truncated pyramidal shape.

[0075] Even with this structure, the flow velocity of the first fluid in a gas-liquid two-phase state is high in the header space 25 near the inlet / outlet pipe 55, so an annular flow is formed. Furthermore, by providing the rod 62 in the header space 25, the flow path cross section of the header space 25 narrows toward the rear of the header space 25. Therefore, the decrease in the flow velocity of the first fluid in a gas-liquid two-phase state is mitigated toward the rear of the header space 25, making it easier for the first fluid in a gas-liquid two-phase state to maintain an annular flow at the rear of the header space 25. Furthermore, due to the presence of the space 257 formed between the base 62A of the rod 62 and the inner circumferential wall 256 of the header space 25, even if separated flows are formed, the first fluid in a liquid phase can be present to flow in each of the flow paths 215 of the multiple metal plates 21. As a result, even if the first fluid in a liquid phase at the rear of the header space 25 is driven toward the header space 25 near the floor plate 4 due to its own inertial force, the rod 62 pushes the liquid level of the first fluid in a liquid phase toward the metal plate 21.

[0076] As a result, in the header space 25, the first fluid in a liquid phase state tends to flow evenly into the flow paths 215 of the multiple metal plates 21, improving the heat transfer coefficient of the heat exchanger. In addition, since the flow path cross-sectional area in the vicinity of the inlet / outlet pipe 55 of the header space 25 is increased, the pressure loss of the first fluid in a gas-liquid two-phase state in the header space 25 is reduced.

[0077] (Variation 2) 11 is a schematic cross-sectional view according to Modification 2 of the cross-sectional area adjusting section. As with the rod 63 shown in FIG. 11, the length of the rod 63 in the stacking direction may be shorter than the length of the laminated block main body 2 in the stacking direction (the length of the header space 25 provided in the laminated block main body 2). For example, the rod 63 is provided on the floor plate 4 and extends from the floor plate 4 to partway through the header space 25. Since the rod 63 is formed partway through the header space 25, a wider space is formed in the header space 25 from the tip 631 of the rod 63 to the vicinity of the inlet / outlet pipe 55.

[0078] Even with this structure, the flow velocity of the first fluid in a gas-liquid two-phase state is high in the header space 25 near the inlet / outlet pipe 55, so an annular flow is formed. Furthermore, the rod 63 narrows the flow path cross section of the header space 25 at the rear side of the header space 25. This alleviates the decrease in flow velocity, making it easier for the first fluid in a gas-liquid two-phase state to maintain an annular flow at the rear side of the header space 25. Furthermore, the presence of the space 257 formed between the base 63A of the rod 63 and the inner circumferential wall 256 of the header space 25 allows the first fluid in a liquid phase to exist in the respective flow paths 215 of the multiple metal plates 21, even if separated flows are formed. Therefore, even if the first fluid in a liquid phase at the rear side of the header space 25 is driven toward the header space 25 near the floor plate 4 by its own inertial force, the rod 63 pushes the liquid level of the first fluid in a liquid phase toward the metal plate 21.

[0079] As a result, in the header space 25, the first fluid in a liquid phase state tends to flow evenly into the flow paths 215 of the multiple metal plates 21, improving the heat transfer coefficient of the heat exchanger. In addition, since the flow path cross-sectional area in the vicinity of the inlet / outlet pipe 55 of the header space 25 is increased, the pressure loss of the first fluid in a gas-liquid two-phase state in the header space 25 is reduced.

[0080] (Variation 3) Fig. 12 is a schematic cross-sectional view of Modified Example 3 of the cross-sectional area adjusting section. Fig. 13(a) is a schematic plan view of Modified Example 3 of the cross-sectional area adjusting section, and Figs. 13(b) and 13(c) are schematic perspective views of Modified Example 3 of the cross-sectional area adjusting section. Fig. 13(a) shows Fig. 12 as viewed in the X-axis direction from the ceiling board 3 side, Fig. 13(b) shows the state of metal plate 21 before diffusion bonding, and Fig. 13(c) shows the state of metal plate 22 before diffusion bonding.

[0081] 12 is formed by a laminate in which a plurality of base plates 217 (disk-shaped metal plates) and a plurality of base plates 227 (circular metal plates) are alternately stacked in the stacking direction. The plurality of base plates 217 and the plurality of base plates 227 are diffusion-bonded alternately in the stacking direction. The plurality of base plates 217 and the plurality of base plates 227 are collectively referred to as a fifth metal plate.

[0082] Each of the plurality of base plates 217 forming the rod 64 is connected to one of the plurality of metal plates 21 via a thin bridge body 218. For example, each of the plurality of base plates 217 is connected via the bridge body 218 to an inner peripheral wall 2510 of a through hole 251 formed in the metal plate 21 that faces the base plate 21 in the Z-axis direction. Furthermore, each of the plurality of base plates 227 forming the rod 64 is connected to one of the plurality of metal plates 22 via a thin bridge body 228. For example, each of the plurality of base plates 227 is connected via the bridge body 228 to an inner peripheral wall 2520 of a through hole 252 formed in the metal plate 22 that faces the base plate 21 in the Z-axis direction. The thickness of the bridge body 218 may be any thickness that provides strength sufficient to maintain the base plate 227 connected to the metal plate 21 when the metal plate 21 is alone. Similarly, the thickness of the bridge body 228 may be any thickness that provides the strength to maintain the state in which the metal plate 228 is connected to the metal plate 22 when the metal plate 22 is alone.

[0083] Each of the multiple bridge bodies 218 and each of the multiple bridge bodies 228 extends in the Z-axis direction. For example, FIG. 13( a) shows a bridge body 228 extending in the Z-axis direction in the header space 25. Behind this bridge body 228, another bridge body 218 adjacent to the bridge body 228 is located. The rod 64 is supported on the laminated block main body 2 by the multiple bridge bodies 218 and the multiple bridge bodies 228. Furthermore, adjacent bridge bodies 218 and bridge bodies 228 in the X-axis direction are spaced apart by a predetermined distance. This predetermined distance may be any distance that provides a gap (flow path height) that allows liquid refrigerant to flow circumferentially within the header space 25 without any problems.

[0084] FIG. 13(b) shows an enlarged view of the vicinity of the through-hole 251 of the metal plate 21 before diffusion bonding. The base plate 217 is connected to the metal plate 21 via the bridge body 218. The flow path 215 of the metal plate 21, the base plate 217, and the bridge body 218 are formed from the same metal plate by etching. The base plate 217 and the bridge body 218 are formed integrally with the metal plate 21. The bridge body 218 is formed together with the flow path 215 by half-etching. The thickness of the bridge body 218 is approximately the same as the thickness of the partition wall 211 of the metal plate 21. The bridge body 218 is formed flush with the partition wall 211. The thickness of the base plate 217 is also approximately the same as the thickness of the metal plate 21 (the thickness of the side wall 213 of the metal plate 21).

[0085] FIG. 13(c) shows an enlarged view of the vicinity of the through-hole 252 of the metal plate 22 of the metal plate 22 according to Modification 3. The base plate 227 is connected to the metal plate 22 via the bridge body 228. The flow path 225 of the metal plate 22, the base plate 227, and the bridge body 228 are formed from the same metal plate by etching. The base plate 227 and the bridge body 228 are formed integrally with the metal plate 22. The bridge body 228, together with the flow path 225, is formed by half-etching. The thickness of the bridge body 228 is approximately the same as the thickness of the partition wall 221 of the metal plate 22. The bridge body 228 is formed flush with the partition wall 221. The thickness of the base plate 227 is approximately the same as the thickness of the metal plate 22 (the thickness of the side wall 223 of the metal plate 22).

[0086] Even with this structure, the flow velocity of the first fluid in a gas-liquid two-phase state is high in the header space 25 near the inlet / outlet pipe 55, so an annular flow is formed. Furthermore, the rod 64 narrows the flow path cross section of the header space 25 toward the back of the header space 25. This alleviates the decrease in the flow velocity of the first fluid in a gas-liquid two-phase state, making it easier to maintain an annular flow at the back of the header space 25. Furthermore, the presence of the space 257 formed between the rod 64 and the inner circumferential wall 256 of the header space 25 allows the first fluid in a liquid phase to exist in the respective flow paths 215 of the multiple metal plates 21, even if separate flows are formed. Therefore, even if the liquid-phase refrigerant at the back of the header space 25 is driven toward the header space 25 near the floor plate 4 due to its own inertial force, the rod 64 pushes the liquid level of the first fluid in a liquid phase toward the metal plate 21.

[0087] As a result, in the header space 25, the first fluid in a liquid phase easily flows uniformly into the respective flow paths 215 of the plurality of metal plates 21, improving the heat transfer coefficient of the heat exchanger. Furthermore, gaps are formed between adjacent bridge bodies 218 and 228 in the stacking direction. Therefore, the first fluid in a gas-liquid two-phase state can flow through these gaps. Furthermore, the bridge bodies 218 and 228 extend in substantially the same direction as the flow direction of the first fluid in a gas-liquid two-phase state (from bottom to top in FIG. 5 ). Therefore, the bridge bodies 218 and 228 do not impede the flow of the first fluid in a gas-liquid two-phase state flowing from the header space 25 into the respective flow paths 215 of the plurality of metal plates 21. Furthermore, the plurality of base plates 217 and the plurality of base plates 227 are alternately stacked and diffusion-bonded, thereby ensuring the mechanical strength of the rod 64.

[0088] (Variation 4) Fig. 14 is a schematic cross-sectional view of Modified Example 4 of the cross-sectional area adjusting section. Fig. 15(a) is a schematic plan view of Modified Example 4 of the cross-sectional area adjusting section, and Figs. 15(b) and 15(c) are schematic perspective views of Modified Example 4 of the cross-sectional area adjusting section. Fig. 15(a) shows Fig. 14 as viewed in the X-axis direction from the ceiling board 3 side, Fig. 15(b) shows the state of metal plate 21 before diffusion bonding, and Fig. 15(c) shows the state of metal plate 22 before diffusion bonding.

[0089] The cross-sectional area adjusting portion may be formed by at least one plate portion that is erected in the header space 25 and narrows a portion of the flow path cross section of the header space 25. For example, as shown in FIG. 14 , a plurality of plate portions 219 and a plurality of plate portions 229 are provided at the rear side of the header space 25. When the heat exchanger 1 is viewed from the Y-axis direction, each of the plurality of plate portions 219 and each of the plurality of plate portions 229 extends in a direction from the side surface 1wa side toward the side surface 1wb side of the heat exchanger 1. FIG. 15( a) shows the state in which the plate portion 229 is provided below the header space 25. Behind this plate portion 229, the plate portion 219 adjacent to the plate portion 229 is located.

[0090] FIG. 15(b) shows an enlarged view of the vicinity of the through-hole 251 of the metal plate 21 before diffusion bonding. The plate portion 219 is connected to the metal plate 21. The flow path 215 and the plate portion 219 of the metal plate 21 are formed from the same metal plate by etching. The plate portion 219 is formed integrally with the metal plate 21. For example, the plate portion 219 is formed together with the flow path 215 by half-etching. The thickness of the plate portion 219 and the thickness of the partition wall 211 of the metal plate 21 are approximately the same. The thickness of the plate portion 219 does not necessarily have to be set to be approximately the same as the thickness of the partition wall 211 of the metal plate 21, and may be set to be approximately the same as the thickness of the metal plate 21 (the thickness of the side wall 213 of the metal plate 21), for example.

[0091] 15(c) shows an enlarged view of the vicinity of the through-hole 252 of the metal plate 22 before the diffusion bonding. The plate portion 229 is connected to the metal plate 22. The flow path 225 and the plate portion 229 of the metal plate 22 are formed from the same metal plate by etching. The plate portion 229 is formed integrally with the metal plate 22. For example, the plate portion 229 is formed together with the flow path 225 by half-etching. The thickness of the plate portion 229 and the thickness of the partition wall 221 of the metal plate 22 are approximately the same. The thickness of the plate portion 229 does not necessarily have to be set to be approximately the same as the thickness of the partition wall 221 of the metal plate 22, and may be set to be approximately the same as the thickness of the metal plate 22 (the thickness of the side wall 223 of the metal plate 22), for example.

[0092] Even with this structure, the flow velocity of the first fluid in a gas-liquid two-phase state is high in the header space 25 near the inlet / outlet pipe 55, so an annular flow is formed. Furthermore, at the rear side of the header space 25, the flow path cross section of the header space 25 is narrowed further by the plate portion 219 or the plate portion 229. This alleviates the decrease in the flow velocity of the first fluid in a gas-liquid two-phase state, making it easier to maintain the annular flow at the rear side of the header space 25. Furthermore, due to the presence of the space 257 formed between the plate portion 219 and the inner circumferential wall 256 of the header space 25 or between the plate portion 229 and the inner circumferential wall 256 of the header space 25, even if separated flows are formed, the first fluid in a liquid phase can be present to flow in each of the flow paths 215 of the multiple metal plates 21. As a result, even if the first fluid in liquid phase at the back of the header space 25 is driven into the header space 25 near the floor plate 4 by its own inertial force, the liquid surface of the first fluid in liquid phase is pushed up toward the metal plate 21 by the plate portion 219 or the plate portion 229.

[0093] As a result, in the header space 25, the first fluid in a liquid phase state tends to flow evenly into the flow paths 215 of the plurality of metal plates 21, improving the heat transfer coefficient of the heat exchanger.

[0094] (Variation 5) The above-described plate portions 219 and 229 may be used to form a step portion or a slope portion in which the flow path cross-sectional area of ​​the header space 2 decreases stepwise or continuously from the floor plate 4 to the ceiling plate 3 within the header space 25. This makes the flow path cross-sectional area of ​​the header space 25 larger on the ceiling plate 3 side than on the floor plate 4 side.

[0095] For example, Fig. 16 shows a schematic cross-sectional view according to Modification 5 of the cross-sectional area adjustment section. For example, Fig. 16 shows a step portion 65 provided in the header space 25. In the step portion 65, the thickness of the plate portion 219 and the thickness of the metal plate 21 (the thickness of the side wall 213 of the metal plate 21) are set to be approximately the same, and the thickness of the plate portion 229 and the thickness of the metal plate 22 (the thickness of the side wall 223 of the metal plate 22) are set to be approximately the same. Then, the plurality of plate portions 219 and the plurality of plate portions 229 are arranged alternately in the stacking direction, and the length of each plate portion in the Z-axis direction is set to become shorter in stages from the floor board 4 toward the ceiling board 3.

[0096] 17 shows a schematic cross-sectional view according to another modified example 5 of the cross-sectional area adjusting portion. For example, FIG. 17 shows an inclined portion 66 provided in the header space 25. In the inclined portion 66, the thickness of the plate portion 219 and the thickness of the metal plate 21 (the thickness of the side wall 213 of the metal plate 21) are set to be approximately the same, and the thickness of the plate portion 229 and the thickness of the metal plate 22 (the thickness of the side wall 223 of the metal plate 22) are set to be approximately the same. The multiple plate portions 219 and the multiple plate portions 229 are arranged alternately in the stacking direction, and the length of each plate portion in the Z-axis direction is set to be gradually shorter from the floor board 4 toward the ceiling board 3, and further, the inclined surface 660 of the inclined portion 66 is set to be smoothly inclined.

[0097] Even with this structure, the flow velocity of the first fluid in a gas-liquid two-phase state is high in the header space 25 near the inlet / outlet pipe 55, so an annular flow is formed. Furthermore, the cross section of the flow path of the header space 25 is narrower at the back side of the header space 25 due to the step portion 65 or the inclined portion 66. This alleviates the decrease in the flow velocity of the first fluid in a gas-liquid two-phase state, making it easier to maintain the annular flow at the back side of the header space 25. Furthermore, due to the presence of the space 257 formed between the step portion 65 and the inner circumferential wall 256 of the header space 25 or between the inclined portion 66 and the inner circumferential wall 256 of the header space 25, even if separate flows are formed, the first fluid in a liquid phase can be present to flow in each of the flow paths 215 of the multiple metal plates 21. As a result, even if the first fluid in a liquid phase at the back of the header space 25 is driven into the header space 25 near the floor plate 4 by its own inertial force, the liquid surface of the first fluid in a liquid phase is pushed up toward the metal plate 21 by the step portion 65 or the inclined portion 66.

[0098] As a result, in the header space 25, the first fluid in a liquid phase state tends to flow evenly into the flow paths 215 of the plurality of metal plates 21, improving the heat transfer coefficient of the heat exchanger.

[0099] Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above-described embodiments and various modifications can be made. Each embodiment is not limited to an independent form, and can be combined as far as technically possible. [Explanation of symbols]

[0100] 1...Heat exchanger 1d…Bottom surface 1u…Top surface 1wa, 1wb, 1wc, 1wd...side 2...Stacked block body 3...Ceiling board 4...Floorboard 21...Metal plate 22...Metal plate 23...Header space 24...Header space 25...Header space 26...Header space 30...Metal plate 40...Metal plate 41...hole 410...Through hole 53…Entrance / exit pipe 54…Entrance / exit pipe 55…Entrance / exit pipe 56…Entrance / exit pipe 61, 62, 63, 64... Rods 61A, 62A, 63A...Base 65...Step 66…Slope part 660…Slope surface 211…Bulkhead 212...Protrusion 213…Side wall 215...Flow path 216...recess 217...Base material plate 218...Bridge body 219...Plate part 227...Base material plate 228...Bridge body 229...Plate part 221...Bulkhead 222...protrusion 223…Side wall 225...Flow path 226...recess 231...Through hole 232...Through hole 241...Through hole 242...Through hole 251...Through hole 252...Through hole 2510, 2520…Inner peripheral wall 256…Inner peripheral wall 257…space 261...Through hole 262...Through hole 331...Through hole 341...Through hole 351...Through hole 361...Through hole 530, 540, 550, 560...Insertion holes 2310...Isolation Department 2410…Isolation Department 2520…Isolation Department 2620...Isolation Department 631...Tip

Claims

1. A heat exchanger formed by stacking a plurality of metal plates, the plurality of metal plates include a plurality of first metal plates and a plurality of second metal plates; Each of the plurality of first metal plates is provided with a first flow path through which a first fluid flows, and a first through hole that forms a header space through which the first fluid flows into the first flow path, Each of the plurality of second metal plates is provided with a second flow path through which a second fluid flows and a second through hole that forms the header space, a first side wall is provided on a peripheral edge portion of each of the plurality of first metal plates, and a second side wall is provided on a peripheral edge portion of each of the plurality of second metal plates; the header space is formed by stacking the plurality of first metal plates and the plurality of second metal plates, A cross-sectional area adjusting portion that adjusts the flow path cross-sectional area of ​​the header space is provided in the header space. heat exchanger.

2. 2. The heat exchanger according to claim 1, The laminated block body is formed by stacking the first metal plates and the second metal plates. The laminated block body further includes a third metal plate and a fourth metal plate sandwiched between the third metal plate and the fourth metal plate in the stacking direction. The header space is closed by the fourth metal plate, an insertion hole communicating with the header space is formed in the third metal plate; The cross-sectional area adjusting portion is formed by a columnar rod extending from the fourth metal plate in the stacking direction in the header space. heat exchanger.

3. 3. The heat exchanger according to claim 2, The cross-sectional area of ​​the rod in a direction perpendicular to the stacking direction decreases from the fourth metal plate toward the third metal plate. heat exchanger.

4. 4. The heat exchanger according to claim 2 or 3, The rod is formed from a single piece of rod material. heat exchanger.

5. 4. The heat exchanger according to claim 2 or 3, The rod is formed by a laminate in which a plurality of fifth metal plates are stacked in the stacking direction. heat exchanger.

6. 6. The heat exchanger according to claim 5, Each of the plurality of fifth metal plates is connected to any one of the plurality of first metal plates or any one of the plurality of second metal plates via a bridge body. heat exchanger.

7. 4. The heat exchanger according to claim 2 or 3, The length of the rod in the stacking direction is shorter than the length of the laminated block body in the stacking direction. heat exchanger.

8. 2. The heat exchanger according to claim 1, The cross-sectional area adjusting portion is formed by at least one plate portion that is erected in the header space and narrows a part of the flow path cross section of the header space. heat exchanger.

9. 9. The heat exchanger according to claim 8, The stacked block body is formed by stacking the first metal plates and the second metal plates. The stacked block body is sandwiched between a third metal plate and a fourth metal plate in the stacking direction. the laminated block body has a side surface formed between the third metal plate and the fourth metal plate, The aspect is A first aspect; a second side surface opposite the first side surface; a third side surface connected to the first side surface and the second side surface; a fourth side surface connected to the first side surface and the second side surface and facing the third side surface; and the header space is disposed closer to the first side surface than to the second side surface and closer to the third side surface than to the fourth side surface, the first fluid that has flowed into the first flow path flows from the side of the first side surface to the side of the second side surface, The plate portion extends in the header space in a direction from the first side surface to the second side surface. heat exchanger.

10. 2. The heat exchanger according to claim 1, The stacked block body is formed by stacking the first metal plates and the second metal plates. The stacked block body is sandwiched between a third metal plate and a fourth metal plate in the stacking direction. The header space is closed by the fourth metal plate, an insertion hole communicating with the header space is formed in the third metal plate; The flow path cross-sectional area of ​​the header space is larger on the side of the third metal plate than on the side of the fourth metal plate. heat exchanger.

11. 11. The heat exchanger according to claim 10, the flow path cross-sectional area of ​​the header space decreases continuously or stepwise from the fourth metal plate toward the third metal plate; heat exchanger.

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