Heat exchanger

Abstract

To provide a lamination type heat exchanger that uses fluids having different physical properties, utilizes the characteristics of the respective fluids, and achieves both the improvement of heat transfer performance and the securing of reliability.SOLUTION: A heat exchanger is formed by laminating a plurality of heat transfer plates. The plurality of heat transfer plates comprise a plurality of first heat transfer plates and a plurality of second heat transfer plates, and the first heat transfer plates and the second heat transfer plates are alternately laminated. First flow passages through which a first fluid flows are formed in the plurality of first heat transfer plates respectively, and second flow passages through which a second fluid flows are formed in the plurality of second heat transfer plates respectively. The first flow passages are formed by first flow passage walls, and the second flow passages are formed by second flow passage walls. The length of the first flow passage walls is shorter than the length of the second flow passage walls.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] There is a stacked heat exchanger in which multiple heat transfer plates with flow paths are stacked and integrated by diffusion bonding. The multiple heat transfer plates are stacked alternately, with first heat transfer plates carrying water as a first fluid and second heat transfer plates carrying a refrigerant as a second fluid. In such a heat exchanger, heat is exchanged between different fluids.

[0003] In conventional laminated heat exchangers, the first and second heat transfer plates are made of the same thickness and have the same flow passages to ensure reliable diffusion bonding and sufficient pressure resistance. Therefore, when the physical properties of different fluids, such as heat transfer coefficients and pressure losses, are different, the heat exchanger may not be able to achieve a sufficient heat exchange rate, or the power required to circulate the fluid through the refrigerant circuit including the heat exchanger may increase, resulting in a decrease in the refrigeration capacity and operating efficiency of the refrigeration equipment using the heat exchanger.

[0004] In contrast, there are plate heat exchangers with a structure similar to that of stacked heat exchangers, in which the cross-sectional area of ​​the flow path for a first fluid, which has a higher heat transfer coefficient and pressure loss than a second fluid, is made relatively large (see, for example, Patent Document 1). This structure reduces the pressure loss of the first fluid and ensures the heat transfer performance of the second fluid, which has a lower heat transfer coefficient, thereby improving the refrigeration capacity and operating efficiency of the refrigeration system that uses the heat exchanger. There are also examples in which this technology has been applied to stacked heat exchangers (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-288480 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-172588 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in a stacked heat exchanger, heat transfer plates stacked alternately (hereinafter referred to as the stack) are pressurized in the stacking direction during diffusion bonding. If there are hollows in the stack that receive pressure from the pressurization, the hollows may affect the transfer of pressure, preventing reliable diffusion bonding. Or, the flow paths may be deformed during diffusion bonding, making it impossible to ensure sufficient reliability as a heat exchanger.

[0007] In view of the above circumstances, the object of the present invention is to provide a stacked heat exchanger that uses fluids with different physical properties, making use of the characteristics of each fluid, thereby achieving both improved heat transfer performance and ensuring reliability. [Means for solving the problem]

[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 heat transfer plates. The plurality of heat transfer plates includes a plurality of first heat transfer plates and a plurality of second heat transfer plates, and the first heat transfer plates and the second heat transfer plates are stacked alternately. A first flow path through which a first fluid flows is formed in each of the plurality of first heat transfer plates, and a second flow path through which a second fluid flows is formed in each of the plurality of second heat transfer plates. The first flow path is defined by a first flow path wall, and the second flow path is defined by a second flow path wall. The length of the first flow path wall is shorter than the length of the second flow path wall.

[0009] In such a heat exchanger, in a stacked heat exchanger using fluids with different physical properties, the characteristics of each fluid are utilized, thereby improving heat transfer performance and ensuring reliability at the same time.

[0010] In the heat exchanger, the first flow path wall and the second flow path wall may overlap in a stacking direction in which the plurality of heat transfer plates are stacked. heat exchanger.

[0011] In such a heat exchanger, in a stacked heat exchanger using fluids with different physical properties, the characteristics of each fluid are better utilized, thereby improving heat transfer performance while ensuring reliability.

[0012] In the heat exchanger, the first flow path walls may be arranged discontinuously in a direction in which the first fluid flows.

[0013] In such a heat exchanger, in a stacked heat exchanger using fluids with different physical properties, the characteristics of each fluid are better utilized, thereby improving heat transfer performance while ensuring reliability.

[0014] In the heat exchanger, a length of the group of first flow path walls in which the first flow path walls are arranged discontinuously may be less than a length of the second flow path wall.

[0015] In such a heat exchanger, in a stacked heat exchanger using fluids with different physical properties, the characteristics of each fluid are better utilized, thereby improving heat transfer performance while ensuring reliability.

[0016] In the heat exchanger, the second flow path walls may be arranged discontinuously in a direction in which the second fluid flows.

[0017] In such a heat exchanger, in a stacked heat exchanger using fluids with different physical properties, the characteristics of each fluid are better utilized, thereby improving heat transfer performance while ensuring reliability.

[0018] In the heat exchanger, the width of the first flow path wall may be equal to or smaller than the width of the second flow path wall.

[0019] In such a heat exchanger, in a stacked heat exchanger using fluids with different physical properties, the characteristics of each fluid are better utilized, thereby improving heat transfer performance while ensuring reliability. [Effects of the Invention]

[0020] According to the present invention, a stacked heat exchanger using fluids with different physical properties is provided, which makes use of the characteristics of each fluid and achieves both improved heat transfer performance and ensured reliability. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic perspective view showing a heat exchanger of the present embodiment. [Figure 2] Fig. 1(a) is a schematic perspective view showing a metal plate 3 before being diffusion bonded, and Fig. 1(b) is a schematic perspective view showing a metal plate 4 before being diffusion bonded. [Figure 3] FIG. 2 is a schematic diagram showing a heat transfer plate forming a laminated block body. [Figure 4] FIG. 10 is a schematic plan view showing a state in which a flow path wall provided on a heat transfer plate 21 and a flow path wall provided on a heat transfer plate 22 overlap in the stacking direction. [Figure 5] Fig. 5(a) is a schematic cross-sectional view illustrating the operation of a reference example, and Fig. 5(b) is a schematic cross-sectional view illustrating an example of the operation of this embodiment. [Figure 6] FIG. 1 is a schematic plan view showing a first modified example of the present embodiment. [Figure 7] FIG. 10 is a schematic plan view showing a second modified example of the present embodiment. [Figure 8] FIG. 10 is a schematic plan view showing a third modified example of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings. XYZ axis coordinates may be used in each drawing. In addition, the same reference numerals may be used to designate identical components or components having the same functions, and after describing the components, the description may be omitted as appropriate.

[0023] (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 type heat exchanger in which a plurality of heat transfer plates and metal plates are stacked and joined together. The heat exchanger 1 includes a stacked block body 2, a metal plate 3, and a metal plate 4.

[0024] The laminated block body 2 includes a plurality of heat transfer plates 21 (first heat transfer plates) and a plurality of heat transfer plates 22 (second heat transfer plates). The laminated block body 2 is sandwiched between metal plates 3 and 4 in the stacking direction of the heat exchanger 1. The laminated block body 2 is a block body in which the heat transfer plates 21 and 22 are alternately stacked and bonded by diffusion bonding. The metal plates 3 and the laminated block body 2 are bonded by diffusion bonding, and the metal plates 4 and the laminated block body 2 are bonded by diffusion bonding. Examples of diffusion bonding include solid-state bonding, hot pressure welding, and cold pressure welding. In the heat exchanger 1, high-temperature fluid and low-temperature fluid exchange heat. The number of stacked heat transfer plates 21 and 22 shown in FIG. 1 is a schematic example and is not limited to this example.

[0025] In the laminated block body 2, when the heat transfer plate 22 is in contact with the metal plate 3, the metal plate 3 functions as a closing plate that closes the flow paths and through holes (which will be described later) provided in the heat transfer plate 22 from the stacking direction. Also, in the laminated block body 2, when the heat transfer plate 21 is in contact with the metal plate 3, the metal plate 3 functions as a closing plate that closes the flow paths and through holes provided in the heat transfer plate 21 from the stacking direction.

[0026] The heat exchanger 1 has a main surface 1u formed on the metal plate 3 side, a main surface 1d formed on the metal plate 4 side, a side surface 1wa, a side surface 1wb, a side surface 1wc, and a side surface 1wd. The side surfaces 1wa, 1wb, 1wc, and 1wd are connected to the main surface 1u and the main surface 1d, respectively, and are formed between the metal plates 3 and 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. The side surface 1wc intersects with the side surfaces 1wa and 1wb and is connected to the side surfaces 1wa and 1wb. Side 1wd intersects with side 1wa and side 1wb and is continuous with side 1wa and side 1wb.

[0027] 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 main 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 1wa and the side surface 1wd intersect, the inlet / outlet pipe 54 is provided near the corner of the heat exchanger 1 where the side surface 1wb 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 1wc intersect.

[0028] Furthermore, entrance / exit pipes 55 and 53 are lined up on the side of side 1wa. Entrance / exit pipes 54 and 56 are lined up on the side of side 1wb. Entrance / exit pipes 55 and 56 are lined up on the side of side 1wc. Entrance / exit pipes 53 and 54 are lined up on the side of side 1wd. The direction from entrance / exit pipe 53 to entrance / exit pipe 56 intersects with the direction from entrance / exit pipe 54 to entrance / exit pipe 55.

[0029] When the heat exchanger 1 is used as an evaporator, the inlet / outlet pipe 56 serves as an inlet pipe for a first fluid (high-temperature fluid), and the inlet / outlet pipe 55 serves as an outlet pipe for the first fluid. The first fluid flows from the side surface 1wb to the side surface 1wa. Here, the first fluid is, for example, water. The inlet / outlet pipe 53 serves as an inlet pipe for a second fluid (low-temperature fluid), and the inlet / outlet pipe 54 serves as an outlet pipe for the second fluid. The second fluid flows from the side surface 1wa to the side surface 1wb. Here, the second fluid is a refrigerant that undergoes a phase change. The second fluid flows in a gas-liquid two-phase refrigerant state through the inlet / outlet pipe 53 and evaporates from the gas-liquid two-phase refrigerant through the inlet / outlet pipe 54. The temperature of the first fluid is higher than that of the second fluid, and the second fluid in the gas-liquid two-phase state absorbs heat from the first fluid in a liquid state and evaporates. On the other hand, the temperature of the second fluid is lower than the temperature of the first fluid, and the first fluid is cooled by dissipating heat into the second fluid.

[0030] When the heat exchanger 1 is used as a condenser, the first fluid is a low-temperature fluid and the second fluid is a high-temperature fluid. For example, the first fluid is water, which is lower in temperature than the second fluid. In this case, the second fluid flows in from the inlet / outlet pipe 53 in a gas-liquid two-phase refrigerant state, and flows out from the inlet / outlet pipe 53 in a liquid refrigerant state after the gas-liquid two-phase refrigerant condenses into a liquid phase. In the following, this embodiment will be described using an evaporator as an example.

[0031] 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 1wa and side surface 1wd intersect, header space 24 is provided near the corner of the heat exchanger 1 where side surface 1wb 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 1wc intersect.

[0032] For example, the header space 23 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 24 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. 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 1wc than to the side surface 1wd.

[0033] The header space 23 and the header space 25 are aligned on the side of the side surface 1wa. The header space 24 and the header space 26 are aligned on the side of the side surface 1wb. The header space 25 and the header space 26 are aligned on the side of the side surface 1wc. The header space 23 and the header space 24 are aligned on the side of the side surface 1wd. The direction from the header space 23 to the header space 26 intersects with the direction from the header space 25 to the header space 24. Each of the header spaces 23, 24, 25, and 26 is closed by a metal plate 4. In the XY-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.

[0034] 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 heat transfer plate 21. The header spaces 23 and 24 are connected to a flow path (described later) provided in the heat transfer plate 22.

[0035] In the drawings of this embodiment, solid lines are drawn at the boundaries of the heat transfer plates 21 and 22 stacked in the stacking direction, the boundary between the metal plate 3 and the laminated block body 2, and the boundary between the metal plate 4 and the laminated block body 2. However, in a diffusion-bonded heat exchanger 1, these solid lines may disappear without being visible. The Z-axis direction shown in the drawings corresponds to the stacking direction of the heat exchanger 1, and the X-axis direction is approximately perpendicular to the Z-axis direction and the Y-axis direction and corresponds to the direction from the inlet / outlet pipe 56 to the inlet / outlet pipe 54 or from the inlet / outlet pipe 55 to the inlet / outlet pipe 53. The Y-axis direction is approximately perpendicular to the Z-axis direction and the X-axis direction and corresponds to the direction from the inlet / outlet pipe 55 to the inlet / outlet pipe 56 or from the inlet / outlet pipe 53 to 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. The X-axis, Y-axis, and Z-axis in this embodiment do not refer to so-called three-dimensional Cartesian coordinates, but are defined to explain the shape of the heat exchanger 1 and the laminated block body 2 shown in this embodiment. Therefore, the relationship between the axes is expressed as being approximately perpendicular as described above.

[0036] The heat transfer plates 21 and 22 and the metal plates 3 and 4 are made of the same material with high thermal conductivity, such as aluminum, stainless steel, copper, aluminum alloy, titanium, or magnesium alloy.

[0037] Fig. 2(a) is a schematic perspective view showing a metal plate 3 before being diffusion bonded, and Fig. 2(b) is a schematic perspective view showing a metal plate 4 before being diffusion bonded.

[0038] As shown in FIGS. 2(a) and 2(b), the metal plates 3 and 4 are metal plates having a substantially rectangular planar shape. When viewed from above, the metal plates 3 and 4 have a substantially rectangular shape. At the four corners of the metal plate 3 (FIG. 2(a)), a through hole 33, a through hole 34, a through hole 35, and a through hole 36 are provided. The through hole 33 is connected to the header space 23 and is an insertion hole into which an inlet / outlet pipe 53 is inserted. The through hole 34 is connected to the header space 24 and is an insertion hole into which an inlet / outlet pipe 54 is inserted. The through hole 35 is connected to the header space 25 and is an insertion hole into which an inlet / outlet pipe 55 is inserted. The through hole 36 is connected to the header space 26 and is an insertion hole into which an inlet / outlet pipe 56 is inserted. Each inlet / outlet pipe is inserted into each insertion hole and fixed by brazing or welding.

[0039] For example, when the heat exchanger 1 is used as an evaporator, the through-hole 36 serves as an inlet for a first fluid in a liquid state, and the through-hole 35 serves as an outlet for the first fluid in a liquid state. The through-hole 33 serves as an inlet for a second fluid in a gas-liquid two-phase state, and the through-hole 34 serves as an outlet for the second fluid in a gas state.

[0040] 3(a) and 3(b) are schematic diagrams showing the heat transfer plates that form the laminated block body. Fig. 3(a) shows a plan view of heat transfer plate 21 and a cross-sectional view taken along line A1-A2 of the plan view. Fig. 3(b) shows a plan view of heat transfer plate 22 and a cross-sectional view taken along line B1-B2 of the plan view. The cross-sectional view also shows the depth of the cross section.

[0041] The heat transfer plate 21 shown in FIG. 3(a) has a substantially rectangular planar shape. The heat transfer plate 21 is provided with partition walls 211, a plurality of flow path walls 212a (first flow path walls) protruding from the partition walls 211, and side walls 213 as an outer periphery surrounding the partition walls 211. The flow path walls 212a are arranged intermittently in the direction from the through hole 261 to the through hole 251 (or from the through hole 241 to the through hole 231), and the plurality of flow path walls 212a arranged intermittently in this direction are further arranged in a row in the direction from the through hole 231 to the through hole 251 (or from the through hole 241 to the through hole 261). When viewed from above, the flow path walls 212a have, for example, an intermittent band shape, and each of the intermittently arranged flow path walls 212a has a wave shape. Furthermore, both ends of the flow path walls 212a are formed, for example, in a sharpened shape. The side walls 213 are provided on the peripheral edge (outer periphery) of the heat transfer plate 21. In the heat transfer plate 21, there is a step between the partition walls 211 and the side walls 213, and the thickness of the partition walls 211 is formed to be thinner than the thickness of the side walls 213. In other words, the partition walls 211 and the side walls 213 form recesses 216 in the heat transfer plate 21. The recesses 216 are surrounded by the side walls 213.

[0042] By providing the partition wall 211 with a plurality of flow path walls 212a, each portion between the plurality of flow path walls 212a on the partition wall 211 (a portion between adjacent flow path walls 212a in the XY-axis plane) becomes a flow path 215 (first flow path) of the heat transfer plate 21. That is, the flow path 215 is formed in the recess 216 by the plurality of flow path walls 212a. The first fluid flows through the flow path 215. The flow path 215 is formed by, for example, half-etching. The partition wall 211, the plurality of flow path walls 212a, and the flow path 215 are provided in, for example, each of the plurality of heat transfer plates 21 included in the laminated block main body 2.

[0043] At the four corners of the heat transfer plate 21, a through hole 251 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. In addition, in the heat transfer plate 21, a separator 2310 is provided between the through hole 231 and the recess 216. The separator 2310 is formed continuously from the side wall 213 on the flow path 215 side of the through hole 231. The separator 2310 separates the flow path 215 and the through hole 231. By providing the separator 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. In addition, in the heat transfer plate 21, a separator 2410 is provided between the through hole 241 and the recess 216. 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.

[0044] When the heat exchanger 1 is used as an evaporator, the header space 26 (FIG. 1) functions as a header that allows the first fluid in a liquid state to flow into the flow paths 215 of the heat transfer plate 21. The through-holes 261 serve as an inlet for the first fluid in a liquid state in the heat transfer plate 21. The first fluid in a liquid state flows into the flow paths 215, and the through-holes 251 serve as an outlet for the first fluid in a liquid state. The second fluid in a gas-liquid two-phase state passes through the through-holes 231, and the second fluid in a gas state passes through the through-holes 241.

[0045] The heat transfer plate 22 shown in FIG. 3(b) has a substantially rectangular planar shape. The heat transfer plate 22 is provided with partition walls 221, a plurality of flow path walls 222a (second flow path walls) protruding from the partition walls 221, and side walls 223 as an outer periphery surrounding the partition walls 221. The flow path walls 222a are continuously formed in the direction from the through hole 232 to the through hole 242 (or from the through hole 252 to the through hole 262), and are further arranged in a row in the direction from the through hole 232 to the through hole 252 (or from the through hole 242 to the through hole 262). When viewed from above, the flow path walls 222a have, for example, a continuous band-like shape and a continuous wave shape. The side walls 223 are provided on the peripheral portion (outer periphery) of the heat transfer plate 22. In the heat transfer 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, the partition wall 221 and the side wall 223 form a recess 226 in the heat transfer plate 22. The recess 226 is surrounded by the side wall 223.

[0046] By providing the partition wall 221 with a plurality of flow path walls 222a, each portion between the plurality of flow path walls 222a on the partition wall 221 (a portion between adjacent flow path walls 222a in the XZ-axis plane) becomes a flow path 225 (second flow path) of the heat transfer plate 22. That is, the flow path 225 is formed in the recess 226 by the plurality of flow path walls 222a. The second fluid flows through the flow path 225. The flow path 225 is formed by, for example, half-etching. The partition wall 221, the plurality of flow path walls 222a, and the flow path 225 are provided in, for example, each of the plurality of heat transfer plates 22 included in the laminated block main body 2.

[0047] At the four corners of the heat transfer plate 22, a through hole 232 serving as an inlet / outlet, a through hole 242 serving as an inlet / outlet, a through hole 252, 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 heat transfer plate 22, a separator 2520 is provided between the through hole 252 and the recess 226. 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 heat transfer plate 22, a separator 2620 is provided between the through hole 262 and the recess 226. 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.

[0048] For example, when the heat exchanger 1 is used as an evaporator, the header space 24 (FIG. 1) functions as a header that allows the second fluid in a gas-liquid two-phase state to flow into the flow path 225 of the heat transfer plate 22. The through-hole 242 serves as an inlet for the second fluid in the heat transfer plate 22. The second fluid flows into the flow path 225, and the through-hole 232 serves as an outlet for the second fluid. The first fluid in a liquid state passes through the through-hole 252, and the first fluid in a liquid state passes through the through-hole 262.

[0049] The header spaces 23, 24, 25, and 26 are each formed by alternately stacking the heat transfer plates 21 and 22 in the stacking direction. For example, a through hole 231 provided in the heat transfer plate 21 and a through hole 232 provided in the heat transfer 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 heat transfer plate 21 and a through hole 242 provided in the heat transfer 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 heat transfer plate 21 and a through hole 252 provided in the heat transfer 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 heat transfer plate 21 and a through hole 262 provided in the heat transfer plate 22 are connected in the stacking direction to form the header space 26 in the laminated block main body 2.

[0050] 4 is a schematic plan view showing a state in which the flow path wall provided in the heat transfer plate 21 and the flow path wall provided in the heat transfer plate 22 overlap in the stacking direction. In FIG. 4, the flow path wall 212a of the heat transfer plate 21 is shown in front of the flow path wall 222a of the heat transfer plate 22.

[0051] As shown in Fig. 4, the length of the flow path wall 212a is shorter than the length of the flow path wall 222a. Here, the length of the flow path wall is the length along the flow path wall in the longitudinal direction of the flow path wall. In other words, it is the length when the corrugated flow path wall is deformed into a straight line. Furthermore, when the heat transfer plate 21 is viewed from above in the stacking direction, the flow path wall 212a and the flow path wall 222a overlap.

[0052] The flow path walls 212a are arranged intermittently in the flow direction D1 of the first fluid. Here, the flow direction of the first fluid is the direction in which the entire first fluid in a liquid state flows. The direction D1 corresponds to the direction from the side wall 1wb to the side wall 1wa of the heat exchanger 1, the direction from the header space 26 to the header space 25, the direction from the inlet / outlet pipe 56 to the inlet / outlet pipe 55, the direction from the through hole 261 to the through hole 251 of the heat transfer plate 21, etc.

[0053] Furthermore, the length of a group (set) 212G of flow path walls 212a in which the flow path walls 212a are arranged discontinuously in the direction D is formed to be less than the length of the flow path walls 222a. Here, the length of the group of flow path walls 212a is the length obtained by adding the length of each of the plurality of flow path walls 212a to the distance between adjacent flow path walls 212a. In this embodiment, the portion of the distance between adjacent flow path walls 212a is illustrated as a discontinuous portion 212h. The discontinuous portion 212h is a portion where no flow path wall 212a exists relative to the overlapping flow path walls 222a.

[0054] For example, the length of the group 212G of flow path walls 212a from position P1 to position P2 is shorter than the length of the flow path wall 222a. The length of the group 212G of flow path walls 212a from position P3 to position P4 is approximately the same as the length of the flow path wall 222a. Thus, the length of the group 212G may be different from or approximately the same as the length of the flow path wall 222a. The flow path walls 212a and the discontinuous portions 212h in the group 212G may be alternately and periodically arranged along the Y-axis direction as shown in FIG. 4, or may not be periodically arranged. The flow path walls 212a and the discontinuous portions 212h in adjacent groups 212G in the X-axis direction are alternately formed in the same pattern as shown in FIG. 4, but they may also be formed in different patterns. Note that "approximately the same" includes not only a state of being completely equal, but also a state of being close to equal due to a margin of error. The width 212w of the flow path wall 212a is formed to be equal to or smaller than the width 222w of the flow path wall 222a.

[0055] (action) Fig. 5(a) is a schematic cross-sectional view illustrating the operation of a reference example. Fig. 5(b) is a schematic cross-sectional view illustrating an example of the operation of this embodiment. Figs. 5(a) and 5(b) show the state when multiple heat transfer plates stacked in the stacking direction (Z-axis direction) are diffusion bonded. During diffusion bonding, pressure is applied from above and below to the stack of multiple heat transfer plates.

[0056] 5(a), for example, in the heat transfer plate 21R and the heat transfer plate 22R, a hollow portion 21h is formed below the flow path wall 222a of the heat transfer plate 22R, where the flow path wall 212a of the heat transfer plate 21R is not located. Also, a hollow portion 22h is formed below the flow path wall 212a of the heat transfer plate 21R, where the flow path wall 222a of the heat transfer plate 22R is not located.

[0057] When pressure is applied in the stacking direction to a stack of heat transfer plates 21R and 22R stacked alternately in this state, the influence of hollow portion 21h or hollow portion 22h can cause insufficient pressure to be applied to the bonding surface between the upper end of flow path wall 212a and the partition wall 221 above it, and to the bonding surface between the upper end of flow path wall 222a and the partition wall 211 above it (pressure loss), which can prevent reliable diffusion bonding. If reliable diffusion bonding is not achieved, fluid leakage or damage due to insufficient pressure resistance can occur during use of the heat exchanger, resulting in insufficient reliability as a heat exchanger. Alternatively, during diffusion bonding, hollow portion 21h may be crushed by pressure from flow path wall 222a located above hollow portion 21h, or hollow portion 22h may be crushed by pressure from flow path wall 212a located above hollow portion 22h. This can cause deformation of flow path 215 or flow path 225, making it impossible to ensure the heat transfer performance and sufficient reliability expected of a heat exchanger. Furthermore, when the heat transfer plate 21R or the heat transfer plate 22R is deformed, fluid leaks from between the heat transfer plate 21R and the heat transfer plate 22R, and the pressure resistance of the partition wall 211 or the partition wall 221 decreases.

[0058] 5(b), the flow path walls 222a of the heat transfer plate 22 and the flow path walls 212a of the heat transfer plate 21 overlap in the stacking direction, so that the flow path walls 222a of the heat transfer plate 21 are located below the flow path walls 222a of the heat transfer plate 22. Also, the flow path walls 222a of the heat transfer plate 22 are located below the flow path walls 212a of the heat transfer plate 21. In this state, the pressure force acting downward from the flow path walls 222a is received by the solid flow path walls 212a, and the pressure force acting downward from the flow path walls 212a is received by the solid flow path walls 222a. Alternatively, the pressure force acting upward from the flow path wall 212a is received by the solid flow path walls 222a, and the pressure force acting upward from the flow path wall 222a is received by the solid flow path walls 212a. As a result, sufficient pressure is applied to the bonding surface between the upper end of the flow path wall 212a and the partition wall 221 above it, and to the bonding surface between the upper end of the flow path wall 222a and the partition wall 211 above it, respectively, thereby achieving reliable diffusion bonding. As a result, the heat exchanger 1 is free from leakage of the flowing fluid during use, damage due to insufficient pressure resistance, and the like, and can ensure sufficient reliability as a heat exchanger.

[0059] Furthermore, since flow paths 215 and 225 do not deform, heat exchanger 1 can achieve the heat transfer performance expected at the time of design. Furthermore, since flow paths 215 and 225 do not deform, the possibility that the multiple flow paths in the heat exchanger will be subjected to unexpected pressure from the fluid flowing therethrough is reduced. As a result, for example, deterioration or damage to the heat exchanger due to pressure imbalance can be prevented, and sufficient reliability as a heat exchanger can be ensured.

[0060] Furthermore, in the heat transfer plate 21 of this embodiment, the flow path walls 212a are arranged intermittently in the flow direction of the first fluid. The length of the group 212G of intermittently arranged flow path walls 212a is formed to be less than the length of the flow path walls 222a, and the width 212w of the flow path walls 212a is formed to be equal to or less than the width 222w of the flow path walls 222a. This reduces the frequency with which the first fluid collides with the flow path walls 212a, thereby reducing pressure loss of the first fluid. As a result, the power consumption of the pump that supplies the first fluid to the heat exchanger 1 can be reduced. Furthermore, since a pump with low power consumption is sufficient, a smaller pump can be used.

[0061] On the other hand, in the heat transfer plate 22, the flow path walls 222a are formed longer than the flow path walls 212a of the heat transfer plate 21. As a result, the second fluid collides with the flow path walls 222a more frequently, improving the heat transfer coefficient of the second fluid. Furthermore, since the heat transfer coefficient of the second fluid is improved, it is possible to reduce the number of stacked heat transfer plates in the heat exchanger and to reduce the size of the heat exchanger (size in the XY plane). As described above, the heat exchanger 1 of this embodiment can provide a stacked heat exchanger that uses fluids with different physical properties, making use of the characteristics of each fluid, thereby achieving both improved heat transfer performance and ensured reliability.

[0062] (Variation 1) 6 is a schematic plan view showing Modification 1 of this embodiment. The flow path walls provided on the heat transfer plate 22 may be arranged discontinuously in the direction D2 in which the second fluid flows.

[0063] 6 illustrates flow path walls 222b arranged intermittently in direction D2. Here, the flow direction of the second fluid refers to the direction in which the entire second fluid in a gas-liquid two-phase state or gas state flows. Direction D2 corresponds to the direction from side wall 1wa to side wall 1wb of heat exchanger 1, the direction from header space 23 to header space 24, the direction from inlet / outlet pipe 53 to inlet / outlet pipe 54, the direction from through hole 232 to through hole 242 of heat transfer plate 22, and the like.

[0064] The flow path walls 222b are arranged intermittently in the direction from the through hole 232 to the through hole 242 (or from the through hole 252 to the through hole 262), and further, a plurality of flow path walls 212b arranged intermittently in this direction are arranged in a row in the direction from the through hole 232 to the through hole 252 (or from the through hole 242 to the through hole 262). When viewed from above, the flow path walls 212a have, for example, an intermittent band shape, and each of the intermittently arranged flow path walls 222b has a wave shape. However, the length of the flow path walls 222b is formed longer than the length of the flow path walls 212a of the heat transfer plate 21.

[0065] With this structure, the flow path walls 222b of the heat transfer plate 22 are formed longer than the flow path walls 212a of the heat transfer plate 21, so that the second fluid collides with the flow path walls 222b more frequently. This improves the heat transfer coefficient of the second fluid. Furthermore, because the heat transfer coefficient of the second fluid is improved, it is possible to reduce the number of stacked heat transfer plates in the heat exchanger and to reduce the size of the heat exchanger (size in the XY plane). Furthermore, because the flow path walls 222b are arranged discontinuously, the pressure loss for the second fluid is reduced.

[0066] (Variation 2) 7(a) and 7(b) are schematic plan views showing Modification 2 of this embodiment. The planar shape of the flow path wall when viewed from above may be a zigzag shape or a serpentine shape.

[0067] 7(a) is provided with discontinuous, band-like, bent flow path walls 212c. The flow path walls 212c are arranged discontinuously in the direction from the through hole 261 to the through hole 251 (or from the through hole 241 to the through hole 231), and the plurality of flow path walls 212c arranged discontinuously in this direction are further arranged in a row in the direction from the through hole 231 to the through hole 251 (or from the through hole 241 to the through hole 261).

[0068] 7(b) is provided with flow path walls 222c that are continuous bands and have a periodically bent shape (zigzag shape). The flow path walls 222c are formed continuously in the direction from the through hole 232 to the through hole 242 (or from the through hole 252 to the through hole 262), and are further lined up in a row in the direction from the through hole 232 to the through hole 252 (or from the through hole 242 to the through hole 262). The flow path walls 222c of the heat transfer plate 22 and the flow path walls 212c of the heat transfer plate 21 overlap in the stacking direction.

[0069] Even with this structure, the flow path wall 222c of the heat transfer plate 22 and the flow path wall 212c of the heat transfer plate 21 overlap in the stacking direction, so that during diffusion bonding, the pressure is reliably transmitted to the bonding surface between the upper end of the flow path wall and the partition wall above it. As a result, reliable diffusion bonding is achieved, and no leakage of the flowing fluid or damage due to insufficient pressure resistance occurs during use, ensuring the reliability of the heat exchanger.

[0070] Furthermore, since no pressure is applied to the hollow portion during diffusion bonding, heat transfer plates 21 and 22 are less likely to deform, ensuring sufficient reliability as a heat exchanger. Furthermore, since heat transfer plates 21 and 22 do not deform, the heat transfer performance expected at the time of design can be obtained. Furthermore, for example, deterioration or damage to the heat exchanger due to pressure imbalance can be prevented, ensuring sufficient reliability as a heat exchanger.

[0071] Furthermore, the flow path walls 212c are arranged intermittently in the direction of flow of the first fluid. This reduces the frequency with which the first fluid collides with the flow path walls 212c, thereby reducing pressure loss of the first fluid. On the other hand, the flow path walls 222c are formed longer than the flow path walls 212c. This increases the frequency with which the second fluid collides with the flow path walls 222c, thereby improving the heat transfer coefficient of the second fluid. In this way, in a stacked heat exchanger using fluids with different physical properties, it is possible to obtain a heat exchanger that makes use of the characteristics of each fluid and achieves both improved heat transfer performance and ensured reliability.

[0072] (Variation 3) 8(a) and 8(b) are schematic plan views showing Modification 3 of this embodiment. The planar shape of the flow path wall when viewed from above may be straight.

[0073] For example, in the heat transfer plate 21 shown in Figure 8(a), the flow path walls 212d, which are in the form of discontinuous bands and each of which is straight, are arranged discontinuously in the direction from the through hole 261 to the through hole 251 (or from the through hole 241 to the through hole 231), and further, a plurality of flow path walls 212d arranged discontinuously in this direction are arranged in a row in the direction from the through hole 231 to the through hole 251 (or from the through hole 241 to the through hole 261).

[0074] 8(b), straight, band-like flow path walls 222d are continuously formed in the direction from the through hole 232 to the through hole 242 (or from the through hole 252 to the through hole 262), and are further lined up in a row in the direction from the through hole 232 to the through hole 252 (or from the through hole 242 to the through hole 262). The flow path walls 222d of the heat transfer plate 22 and the flow path walls 212d of the heat transfer plate 21 overlap in the stacking direction.

[0075] Even with this structure, the flow path wall 222d of the heat transfer plate 22 and the flow path wall 212d of the heat transfer plate 21 overlap in the stacking direction, so that during diffusion bonding, the pressure is reliably transmitted to the bonding surface between the upper end of the flow path wall and the partition wall above it. As a result, reliable diffusion bonding is achieved, and no leakage of the flowing fluid or damage due to insufficient pressure resistance occurs during use, ensuring the reliability of the heat exchanger.

[0076] Furthermore, since no pressure is applied to the hollow portion during diffusion bonding, heat transfer plates 21 and 22 are less likely to deform, ensuring sufficient reliability as a heat exchanger. Furthermore, since heat transfer plates 21 and 22 do not deform, the heat transfer performance expected at the time of design can be obtained. Furthermore, for example, deterioration or damage to the heat exchanger due to pressure imbalance can be prevented, ensuring sufficient reliability as a heat exchanger.

[0077] Furthermore, the flow path walls 212d are arranged intermittently in the direction of flow of the first fluid. This reduces the frequency with which the first fluid collides with the flow path walls 212d, thereby reducing pressure loss of the first fluid. On the other hand, the flow path walls 222d are formed longer than the flow path walls 212d. This increases the frequency with which the second fluid collides with the flow path walls 222d, thereby improving the heat transfer coefficient of the second fluid.

[0078] In this way, in the heat exchanger 1 of this embodiment, in a stacked heat exchanger that uses fluids with different physical properties, it is possible to obtain a heat exchanger that makes use of the characteristics of each fluid and achieves both improved heat transfer performance and ensured reliability.

[0079] 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]

[0080] 1...Heat exchanger 1wa, 1wb, 1wc, 1wd...side 1u…main surface 1d…main surface 2...Stacked block body 3, 4...metal plate 21, 22, 21R, 22R...Heat transfer plate 21h, 22h...Hollow part 23, 24, 25, 26...Header space 33, 34, 35, 36, 231, 232, 241, 242, 251, 252, 261, 262...Through holes 53, 54, 55, 56...Inlet / outlet pipe 211, 221...Bulkhead 212a, 212c, 212c, 212d, 222a, 222b, 222c, 222d...channel walls 212h: Discontinuous part 212G...Group 213, 223...side wall 215, 225...flow path 216, 226...recesses 2310, 2410, 2520, 2620…Isolation Department

Claims

1. A heat exchanger formed by stacking a plurality of heat transfer plates, The plurality of heat transfer plates include a plurality of first heat transfer plates and a plurality of second heat transfer plates, and the first heat transfer plates and the second heat transfer plates are alternately stacked, a first flow path through which a first fluid flows is formed in each of the plurality of first heat transfer plates, and a second flow path through which a second fluid flows is formed in each of the plurality of second heat transfer plates; the first flow path is formed by a first flow path wall, and the second flow path is formed by a second flow path wall; The length of the first flow path wall is shorter than the length of the second flow path wall. heat exchanger.

2. 2. The heat exchanger according to claim 1, The first flow path wall and the second flow path wall overlap in the stacking direction of the plurality of heat transfer plates. heat exchanger.

3. 3. The heat exchanger according to claim 1 or 2, The first flow path walls are arranged discontinuously in the direction in which the first fluid flows. heat exchanger.

4. 4. The heat exchanger according to claim 3, The length of the group of first flow path walls in which the first flow path walls are intermittently arranged is less than the length of the second flow path wall. heat exchanger.

5. 3. The heat exchanger according to claim 1 or 2, The second flow path walls are arranged discontinuously in the direction in which the second fluid flows. heat exchanger.

6. 3. The heat exchanger according to claim 1 or 2, The width of the first flow path wall is formed to be equal to or smaller than the width of the second flow path wall. heat exchanger.

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