JP5249264B2 - Plate heat exchanger - Google Patents

Description

  The present invention relates to a plate heat exchanger used in electric water heaters, industrial equipment, and the like.

  A plate-type heat exchanger is known in which a plurality of heat transfer plates are stacked, a flow path for the heat exchange medium and the heat exchange medium is formed between the heat transfer plates, and heat exchange is possible between the respective media. ing. This type of plate-type heat exchanger has convex corrugated or concave corrugated corrugated plate-shaped portions formed on the heat transfer plate for the purpose of enlarging the heat transfer area, and heat exchange media and four corners of the heat transfer plate. An opening serving as a doorway for the heat exchange medium is provided. The above heat transfer plate is generally manufactured by drawing a material made of a thin plate such as stainless steel or titanium in the thickness direction by press molding. For this reason, the above-described convex corrugated corrugated plate shape or concave corrugated corrugated shape or the projecting slope portion including the four corner openings are formed while the thickness of the material is increased, so that the thickness is reduced compared to the flat portion. Such heat transfer plates are in a state of being laminated, and are tightly bonded to each other by brazing or the like, thereby ensuring water tightness of each heat exchange medium passage. In addition, the concave corrugation and the corrugated corrugated shape formed in the heat transfer surface function as contact points of brazing joints at the apexes, and therefore, the heat transfer surface has contacts in a staggered manner over the entire surface. On the other hand, since the periphery of the opening at the four corners functions as an entrance / exit of the heat exchange medium, the number of junction points is smaller than that in the heat transfer surface and a wide space is provided. Therefore, the periphery of the opening is brazed and joined with the edges of the horizontal plane portions as contacts.

  However, in a brazing type plate heat exchanger, the vertices of a convex waveform or a concave waveform are often joined to each other within the heat transfer surface formed into a convex waveform or a concave waveform by brazing or the like. The pressure strength is relatively higher than the pressure strength around the openings at the four corners. On the other hand, the periphery of the opening at the four corners is often formed in a flat shape for the convenience of arranging parts such as nozzles that introduce the heat exchange medium and heat exchange medium into the heat exchanger, compared to the flow path surface. The pressure strength is low. Therefore, when an internal pressure is applied to the plate heat exchanger, it can be said that high stress is generated at the boundary between the heat transfer surface and the periphery of the opening at the four corners, and the heat exchanger may burst. In order to solve this problem, for example, Patent Document 1 discloses a plate-type heat which improves the pressure resistance capability by adding thick reinforcing plates to both the front and back surfaces of the heat transfer plate constituting the outermost surface of the plate laminate. An exchanger is disclosed.

Japanese Utility Model Publication No. 5-79274

  However, in a device such as an electric water heater in which a heat exchange medium is used at a relatively low pressure, a reinforcing plate may not be necessary on a heat transfer surface with many joint points. In such a case, as described in Patent Document 1, the plate-type heat exchanger is excessive in a full-surface reinforcement structure in which the periphery of the heat transfer surface and the openings at the four corners are sandwiched by two thick plate reinforcement plates. In some cases, it is reinforced, which may increase the weight of the entire heat exchanger.

  The present invention has been made to solve such problems, and can improve the pressure resistance of the plate heat exchanger, and is lighter and lower in cost than conventional plate heat exchangers. The purpose is to provide an exchange.

The plate-type heat exchanger according to the present invention has an outermost surface heat transfer plate in which corrugated plate-shaped portions are formed between flat portions provided at both ends, and first to fourth openings are provided in flat portions at four corners. 4 openings corresponding to the first to fourth openings are provided at the four corners between the flat plate provided at both ends and the end plate in which the corrugated plate-shaped portion is formed between the flat portions provided at both ends. A plate laminate formed by laminating a plurality of thermal plates, the periphery of the first opening, and the boundary between the flat surface and the corrugated plate shape, and avoiding the periphery of the second opening, Cover the first reinforcing plate (A) disposed on the surface heat transfer plate, the third opening, the boundary between the flat surface and the corrugated plate, and avoid the periphery of the fourth opening. The first reinforcing plate (B) disposed on the outermost surface heat transfer plate, the flat portion of the end plate, and the flat portion and the corrugated plate It is obtained by a second reinforcing plate disposed so as to cover the boundary between Jo portion. A higher pressure is applied to the first opening and the third opening than to the second opening and the fourth opening.

  The present invention can suppress minute deformation due to repeated pressure applied in the long-term use of the plate heat exchanger, and as a result, improves the pressure resistance capability of the plate heat exchanger for a long period of time. It can be used across. In addition, the amount of material used can be greatly reduced as compared with the conventional full-surface reinforcing structure, and the cost of the plate heat exchanger can be reduced.

It is the perspective view which looked at the plate type heat exchanger in embodiment of this invention from the front side. It is the top view which looked at the plate type heat exchanger in embodiment of this invention from the front side. It is sectional drawing in the AA of FIG. It is the perspective view which looked at the plate type heat exchanger in embodiment of this invention from the back side. It is sectional drawing in the BB line of FIG.

  FIG. 1 is a perspective view of a plate heat exchanger according to the present embodiment as viewed from the front side. FIG. 2 is a plan view of the plate heat exchanger as viewed from the front side, and FIG. 3 is a cross-sectional view taken along line AA in FIG. 4 is a perspective view of the plate heat exchanger as viewed from the back side, and FIG. 5 is a cross-sectional view taken along line BB in FIG. Hereinafter, with reference to FIGS. 1-5, the plate-type heat exchanger in this Embodiment is demonstrated.

  The plate heat exchanger 100 is applied to various devices such as a hot water heater and a hot water floor heater, and includes a plate laminate 1, a surface reinforcing plate (first reinforcing plate) 21, and a back surface reinforcing plate ( 2nd reinforcement plate) 41 and 42 are provided. This plate laminate 1 is formed by laminating heat transfer plates 11 with a predetermined number of intervals, and between the heat transfer plates 11, a heat exchange medium flow path 51 and a heat exchange medium flow path 52 are provided. Are formed alternately.

  In the heat transfer plate 11, corrugated plate-shaped portions 15 each having a convex waveform 13 and a concave waveform 14 are formed between the flat portions 12 provided at both ends, and openings 16 to 16 are formed in the flat portions 12 at the four corners. 19 is provided. As shown in FIG. 3, protrusions 53 are formed around the openings 16 to 19 of the heat transfer plate 11 that forms the outermost surface of the plate laminate 1. Further, as shown in FIG. 4, the end plate 10 which is the heat transfer plate forming the back surface of the plate laminate 1 has no openings at the four corners, but the wave between the flat portions provided at both ends. The point in which the plate-shaped part is formed is the same structure as the heat transfer plate 11.

  The heat exchange medium flows in from the opening 16, passes through the heat exchange medium flow path 51, and flows out from the opening 17. On the other hand, the heat exchange medium flows in from the opening 18, passes through the heat exchange medium flow path 52, and flows out from the opening 19. Moreover, watertightness is ensured by fixing a brazing material to the gap and the peripheral edge of each heat transfer plate 11.

  As shown in FIGS. 1 to 3, the heat transfer plate 11 that forms the surface of the plate laminate 1 is provided with a surface reinforcing plate 21 that is smaller than the heat transfer plate 11 and around the openings 16 and 17. 31 is integrally joined to a portion 32 of the apex of the corrugated plate of the heat transfer surface by brazing or the like. As shown in FIGS. 3 and 4, the end plate 10 forming the back surface of the plate laminate 1 has back surface reinforcing plates 41 and 42 smaller than the end plate 10 from the back surface periphery 34 of the opening. A part 33 of the apex of the corrugated plate on the hot surface is permanently joined together by brazing or the like. The plate thickness of the surface reinforcing plate 21 and the back reinforcing plates 41 and 42 is formed to be thicker than that of the heat transfer plate 11 and the end plate 10.

  Here, as shown in FIG. 3, the front surface reinforcing plate 21 and the back surface reinforcing plate 41 are formed in a corrugated shape 2 on the heat transfer surface from the flat surface portions 31 and 41 around the opening of the heat transfer plate 11 or the end plate 10. It is integrally joined to the heat transfer plate 11 or the end plate 10 by brazing joining or the like over ~ 3 waves. The back reinforcing plate 42 not shown in FIG. 3 is also joined to the end plate 10 similarly to the back reinforcing plate 41.

  In the present embodiment, as shown in FIG. 1, the surface reinforcing plate 21 covers only the periphery of the openings 16 and 17 to which high pressure is applied, among the openings 16 to 19 of the heat transfer plate 11. Although formed, a surface reinforcing plate may be arranged so as to cover all the openings 16 to 19.

  Next, the operation when the heat exchange medium and the heat exchange medium flow through the plate heat exchanger 100 according to the present embodiment will be described.

  When both media flow through the plate heat exchanger 100, a state in which a static pressure from a water source or the like is applied to the heat exchange medium and the heat exchange medium itself, or a state in which a dynamic pressure is applied by a device such as a circulation pump is present. Since it occurs periodically, pressure fluctuations are applied to the inside of the plate heat exchanger when the heat exchange medium is in circulation and when it is not. Further, a pressure difference is generated between the heat exchange medium flow path 51 and the heat exchange medium flow path 52. These pressure fluctuations or pressure differences cause minute repeated deformations in the heat transfer plate 11 constituting the plate heat exchanger 100.

  In particular, the openings 16 to 19 at the four corners of the heat transfer plate 11 and the peripheral portions thereof have a wide rigidity between the brazed contacts and a low rigidity structure that is easily deformed by a pressure load. On the other hand, the heat transfer surface on which the corrugated plate portions 15 of the convex waveform 13 and the concave waveform 14 on which heat exchange is performed has a corrugated plate shape of the convex waveform or the concave waveform of the upper and lower heat transfer plates 11. Since the apexes are brazed and joined as contact points, and the brazing contact interval is short for one wave of the corrugated plate shape, the structure is highly rigid and hardly deforms against pressure load. In the boundary portion 35 between the periphery of the opening that is easily deformed against this pressure deformation and the heat transfer surface that is difficult to deform, a very high stress is generated in the heat transfer plate 11 as compared with other portions, and therefore the pressure resistance capability is high. Low and easy to burst by repeated deformation.

  As described above, the thick plate surface reinforcing plate 21 and the back surface reinforcing plates 41 and 42 are brazed to the heat transfer plate 11 having the boundary portion 35 having different rigidity around the heat transfer surface and the opening. By integrally joining to the heat transfer plate by a method such as the above, the rigidity of the boundary portion 35 is improved, and deformation and rupture can be suppressed and the pressure resistance capability can be improved.

  When the plate heat exchanger 100 is configured as described above, even when a high pressure is applied to the heat exchange medium flow path 51, the rupture or deformation of the periphery of the heat transfer plate opening and the boundary portion 35 is suppressed. Moreover, the heat transfer surface having a corrugated shape with a corrugated shape or a concave corrugated shape, to which no reinforcing plate is attached, has sufficient pressure resistance strength between the heat transfer plate and the brazed contact, so even when a high pressure is applied. Since it is not necessary to increase the plate thickness, the plate thickness of the heat transfer plate 11 can be relatively reduced, and as a result, the entire plate heat exchanger can be manufactured to be lightweight.

  Further, the shape of the surface reinforcing plate 21 covering the periphery of the opening is formed into a shape that fits into the protruding shape 53 rising from the opening of the heat transfer plate 11, so that the surface reinforcing plate 21 and the heat transfer plate 11 are formed. When performing integral joining, the surface reinforcing plate 21 can be positioned simply by placing it on the heat transfer plate 11 without the need for a temporary fixing step such as spot welding or caulking, thereby simplifying the mounting process of the reinforcing plate. can do.

  In addition, it is needless to say that the above-described embodiment, description of components, and the like are merely examples, and the technical scope of the present invention is not limited to these descriptions.

  DESCRIPTION OF SYMBOLS 1 Plate laminated body, 10 End plate, 11 Heat-transfer plate, 12 Plane part, 13 Convex corrugation, 14 Convex corrugation, 15 Corrugated plate shape part, 16-19 Opening part, 21 Surface reinforcement plate, 31-33 Brazing Contact, 34 Brazed surface of back side reinforcing plate, 35 border, 41, 42 Back plate reinforcing plate, 51 heat exchange medium flow path, 52 heat exchange medium flow path, 53 protrusion.

Claims (4)

An outermost surface heat transfer plate in which corrugated plate-shaped portions are formed between the flat portions provided at both ends, and the first to fourth openings are provided in the flat portions at the four corners, and the flat portions provided at both ends A plurality of heat transfer plates each having four openings provided at four corners corresponding to the first to fourth openings are stacked between the end plate having the corrugated plate-shaped portion formed between them. A plate laminate,
The first opening disposed on the outermost surface heat transfer plate so as to cover the periphery of the first opening and the boundary between the flat surface portion and the corrugated plate-shaped portion and avoiding the periphery of the second opening . 1 reinforcing plate (A) ;
A first plate disposed on the outermost surface heat transfer plate so as to cover the periphery of the third opening and the boundary between the flat portion and the corrugated plate-shaped portion and avoiding the periphery of the fourth opening. 1 reinforcing plate (B);
A second reinforcing plate disposed so as to cover a flat portion of the end plate and a boundary portion between the flat portion and the corrugated plate-shaped portion ;
A plate heat exchanger in which a higher pressure is applied to the first opening and the third opening than to the second opening and the fourth opening . The first reinforcing plate (A) is provided so as to be fitted with a protrusion rising from the first opening , and the first reinforcing plate (B) is a protrusion rising from the third opening. The plate type heat exchanger according to claim 1, wherein the plate type heat exchanger is provided so as to be fitted to the portion . The first reinforcing plate (A, B) and the second reinforcing plate are thicker than the outermost surface heat transfer plate and the end plate, respectively. Plate heat exchanger. The first reinforcing plate (A, B) and the second reinforcing plate are joined to the outermost surface heat transfer plate and the end plate by brazing, respectively. 4. The plate heat exchanger according to any one of 3 above.

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