JP4874365B2 - Plate heat exchanger and refrigeration cycle apparatus using the heat exchanger - Google Patents

Description

  The present invention relates to a plate heat exchanger, and more particularly to improvement of pressure resistance of a heat transfer plate.

  Conventionally, as a technique for increasing the pressure resistance of a heat transfer plate, for example, in a plate heat exchanger in which a plurality of herringbone plates having an uneven herringbone pattern are stacked and a flow path is formed between each herringbone plate, Reinforcing plates are laminated between the herringbone plates, the top of the herringbone pattern and the reinforcing plate are line-contacted and brazed, and a large number of through holes are formed in the portion excluding the brazed joint of the reinforcing plate. A plate-type heat exchanger characterized by being formed is known (for example, see Patent Document 1).

Japanese Patent Laying-Open No. 2005-282916 (Claim 1, FIG. 1)

In the plate-type heat exchanger of Patent Document 1 described above, a reinforcing plate is inserted between the heat transfer plates in order to ensure the pressure resistance, which leads to an increase in weight and cost of the heat exchanger itself. It was.
Further, when the reinforcing plate is not inserted, it is necessary to increase the thickness of the pressure plate in order to ensure the pressure strength, which causes a problem of increasing the weight and cost of the heat exchanger itself.

  An object of this invention is to provide the plate-type heat exchanger which has the herringbone-shaped heat-transfer plate which improved the pressure strength in a center part, and the refrigerating-cycle apparatus using the heat exchanger.

In a plate-type heat exchanger in which a plurality of heat transfer plates are stacked and assembled together by brazing and fixing, and fluid passages through which two kinds of fluids for heat exchange are circulated alternately are formed between the heat transfer plates. The heat transfer plate has a herringbone-shaped ridge, and the herringbone-shaped ridge has a curved shape that protrudes toward the symmetric axis from the periphery of the heat transfer plate toward the vertex provided on the symmetric axis. It is formed and the curvature in the vicinity of the vertex is made smaller than the curvature in the peripheral portion.

  In the present invention, by forming the herringbone ridges of the heat transfer plate in a curved shape, it is possible to increase the number of brazed joints between the heat transfer plates to be laminated, particularly in the center, Along with the improvement of pressure resistance, the pressure plate can be reduced in weight and cost.

It is a basic lineblock diagram of a plate type heat exchanger. It is a longitudinal cross-sectional view of the plate type heat exchanger which concerns on Embodiment 1 of this invention. It is a front view of the heat exchanger plate which concerns on Embodiment 1 of this invention. FIG. 4 is a front view of a heat transfer plate in which the shape of the heat transfer plate of FIG. 3 is reversed. (a) It is a figure which shows the state which laminated | stacked the heat exchanger plates shown by FIG.3 and FIG.4 which concern on Embodiment 1 of this invention. (b) It is a figure which shows the state which laminated | stacked the linear herringbone-shaped heat-transfer plates. It is a front view of the heat-transfer plate which has a straight herringbone-shaped ridge. (a) It is a figure which shows the state which laminated | stacked the heat-transfer plate of FIG. 4 which concerns on Embodiment 2 of this invention, and the heat-transfer plate of FIG. (b) It is a figure which shows the state which laminated | stacked the linear herringbone-shaped heat-transfer plates. It is a figure which shows an example of the refrigerating-cycle apparatus using the plate type heat exchanger which concerns on this invention.

Embodiment 1 FIG.
<About configuration>
FIG. 1 is a basic configuration diagram of a plate heat exchanger.
The arrows shown in FIG. 1 represent two types of heat transfer fluid flows. Solid arrows indicate the flow of the low temperature fluid 6, and broken arrows indicate the flow of the high temperature fluid 7.
FIG. 1 shows a stack of heat transfer plates 1 having herringbone-shaped ridges, a low temperature side inlet 2, a low temperature side outlet 3, a high temperature side inlet 4, a high temperature side outlet 5, and a low temperature fluid 6. A high temperature fluid 7, a flow port 8, and a pressure plate 11 are shown. In FIG. 1, the heat transfer plates 1 are arranged at a predetermined interval, but in reality, the heat transfer plates 1 adjacent in the vertical direction are brazed and fixed to be in close contact with each other. The lowermost heat transfer plate 1 is fixed to the pressure plate 11 by brazing. The two types of heat transfer fluids form flow paths on the upper side and the lower side of the heat transfer plate 1 through the distribution port 8, and the mechanism in which the low temperature fluid 6 and the high temperature fluid 7 alternately flow on both sides of the heat transfer plate 1 It has become. Hereinafter, expressions of the first fluid and the second fluid are used as the two types of refrigerants having different temperatures.

FIG. 2 is a cross-sectional view of the plate heat exchanger 9 according to Embodiment 1 of the present invention.
The plate heat exchanger 9 includes a heat transfer plate 10, a pressure plate 11, a first fluid channel 12, a second fluid channel 13, cylinders 14 (a) and 14 (b), And a peripheral edge 15.
FIG. 3 is a front view of the heat transfer plate 10 constituting the plate heat exchanger 9 according to Embodiment 1 of the present invention.
Hereinafter, the configuration of the plate heat exchanger 9 will be described with reference to FIGS. 2 and 3.

A plate heat exchanger 9 shown in FIG. 2 is formed by stacking a plurality of heat transfer plates 10 having herringbone-shaped ridges between pressure plate 11 provided at the top and bottom, and the pressure plate 11 and the heat transfer plate 10 are stacked. Between the heat transfer plates 10 and between the heat transfer plates 10, two fluid flow paths (first fluid flow path 12 and second fluid flow path 13) are formed. Further, a peripheral edge portion 15 that is slightly higher than the thickness of the flow path formed between the heat transfer plates 10 is provided along the peripheral edge of the heat transfer plate 10.
The pressure-resistant plate 11 and the peripheral edge 15 of the heat transfer plate 10 arranged above and below are brazed and joined. Moreover, the top part of the herringbone-shaped ridges of the heat transfer plate 10 and the pressure-resistant plates 11 arranged above and below the brazing joint are brazed. The flow path formed between the pressure-resistant plate 11 and the heat transfer plate 10 is configured to communicate with every other layer.

  FIG. 3 shows an example of the heat transfer plate 10 in FIG. The front surface of the heat transfer plate 10 has a substantially rectangular shape, and four corners are removed. At the four corners of the heat transfer plate 10, flow ports 16 through which the first fluid or the second fluid passes are provided, and a herringbone-shaped flange 17 is provided on the laminated surface of the heat transfer plate 10. The shape of the heat transfer plate 10 is not limited to a substantially rectangular shape.

  The herringbone ridge 17 is provided with a vertex 18 on the symmetrical axis of the opposite sides of the substantially rectangular heat transfer plate 10 (on the short side symmetry axis in FIG. 3). It is curved toward the part. In the vicinity of the vertex 18, the curve has a smaller curvature than the peripheral portion.

  The herringbone-shaped ridges 17 are formed to increase the surface area of the heat transfer plate 10 and to generate turbulence in the fluid flowing through the first flow path 12 or the second flow path 13. Two kinds of heat transfer fluids (first fluid or second fluid) flow into or out of the flow port 16.

The heat transfer plate 19 shown in FIG. 4 is obtained by inverting the herringbone-shaped rod 17 included in the heat transfer plate 10 of FIG.
FIG. 5 (a) is a stack of the heat transfer plate 10 of FIG. 3 and the heat transfer plate 19 of FIG. That is, the two heat transfer plates are laminated with their herringbone patterns reversed. The part where the trough valley of one heat transfer plate is in contact with the trough peak of the other heat transfer plate is the brazing contact 20.

The brazing contacts 20 in FIGS. 5 (a) and 5 (b) are partially marked with black dots (●) to clearly show the distribution on the plate. Note that the brazing contact 20 exists on the entire heat transfer surface other than the black dots that are clearly shown.
As a comparative example, FIG. 5B shows a state in which straight herringbone heat transfer plates are stacked. As can be seen from FIG. 5 (a), the brazing contact point 20 has a larger number of points in the central portion than in the peripheral portion, so that the strength of the central portion having a weak pressure resistance can be improved.

<About operation>
Hereinafter, the flow of the fluid in the plate heat exchanger 9 will be described with reference to FIG.
The first fluid flows into the plate heat exchanger 9 from the cylindrical portion 14 (a), is blocked by the cylindrical portion 14 (a), and enters the second fluid flow path 13 without fluid pressure. As a result, the lowest level of the flow path 12 of the first fluid is reached. The first fluid goes up the flow path communicating with every other layer, and is discharged to the outside of the plate heat exchanger 9.
The second fluid flows into the plate heat exchanger 9 from the cylindrical portion 14 (b), and in the same manner, without entering the first fluid channel 12, the second fluid channel 13 is the most. Reach the bottom. The second fluid goes up the flow path communicating with every other layer and is discharged to the outside of the plate heat exchanger 9.

  During this time, heat exchange is efficiently performed between the first fluid and the second fluid. By increasing the number of brazing contacts 20 at the center of the heat transfer plate 10, the possibility of damage to the brazed joint due to fluid pressure is reduced.

FIG. 6 shows a heat transfer plate 21 having straight herringbone-shaped ridges.
FIG. 7 (a) shows another example regarding the laminated form of the heat transfer plate 10. As shown in FIG. FIG. 7A shows a structure in which the heat transfer plate 10 and the heat transfer plate 21 are laminated. The brazing contacts 20 at the time of lamination are partially marked with black dots (●). For comparison, FIG. 7B shows a state in which conventional heat transfer plates are stacked. As shown in FIG. 7 (a), the brazing contact point 20 has a larger number of points in the central portion than in the peripheral portion, so that the strength of the central portion having a weak pressure resistance can be improved.

  The detailed structure of the plate heat exchanger 9 is not limited to the first embodiment. For example, the number of heat transfer plates 10, the herringbone pattern, and the like can be selected as appropriate. Further, the plate heat exchanger 9 shown above is used for a general refrigeration cycle apparatus 27 including a compressor 24, a plate heat exchanger 9, an expansion device 25, and a heat exchanger 26 as shown in FIG. can do.

  1 Heat Transfer Plate, 2 Low Temperature Side Inlet, 3 Low Temperature Side Outlet, 4 High Temperature Side Inlet, 5 High Temperature Side Outlet, 6 Low Temperature Refrigerant, 7 High Temperature Refrigerant, 8 Distribution Port, 9 Plate Heat Exchanger, 10 Heat Transfer Plate, 11 Pressure plate, 12 first fluid flow path, 13 second fluid flow path, 14 (a) cylinder part, 14 (b) cylinder part, 15 peripheral edge part, 16 distribution port, 17 herringbone ridge, 18 apex, 19 Heat-transfer plate with inverted herringbone-shaped scissors 17, 20 brazed contact, 21 heat-transfer plate, 22 straight herringbone-shaped scissors, 23 laminate of heat-transfer plates, 24 compressor, 25 expansion device, 26 heat Exchanger, 27 Refrigeration cycle apparatus.

Claims (3)

In a plate-type heat exchanger in which a plurality of heat transfer plates are stacked and assembled together by brazing and fixing, and fluid passages through which two kinds of fluids for heat exchange are circulated alternately are formed between the heat transfer plates.
The heat transfer plate has a herringbone-shaped ridge,
The herringbone ridge is
From the periphery of the heat transfer plate toward the vertex provided on the symmetry axis, the curve is formed in a curved shape convex toward the symmetry axis, and the curvature in the vicinity of the vertex is smaller than the curvature at the periphery. A plate-type heat exchanger characterized by In a plate-type heat exchanger in which a plurality of heat transfer plates are stacked and assembled together by brazing and fixing, and fluid passages through which two kinds of fluids for heat exchange are circulated alternately are formed between the heat transfer plates.
The heat transfer plate has a herringbone-shaped ridge,
A first heat transfer plate in which the herringbone ridges are linear;
The herringbone-shaped ridges are alternately stacked with the second heat transfer plate having a curved shape,
The curved wrinkles in the second heat transfer plate are
From the periphery of the second heat transfer plate toward the vertex provided on the symmetry axis, the curve is formed in a curved shape convex toward the symmetry axis , and the curvature in the vicinity of the vertex is greater than the curvature at the periphery. Is a plate-type heat exchanger characterized by a smaller size. The plate type heat exchanger according to claim 1 or 2 is used for at least one of an indoor heat exchanger and an outdoor heat exchanger in the refrigeration cycle apparatus.

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