JP4827909B2 - Plate heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger for exchanging heat between a heat medium made of fluid and a heat-medium made of fluid, and in particular, a plurality of heat transfer plates are laminated, and each heat transfer plate serves as a boundary. The present invention relates to a plate-type heat exchanger in which a first space for circulating a heat exchanger and a second space for circulating a heat-receiving medium are alternately formed.

  This type of plate heat exchanger, that is, a plate heat exchanger in which a plurality of heat transfer plates are stacked to form the first flow path and the second flow path, has high heat exchange efficiency and heat exchange between fluids. Widely used for the purpose of

  In particular, in the air conditioning field, the corrugated ridges or ridges having an angle with the center line are formed on the heat transfer plate, and the directions according to the angles of the corrugations are alternately reversed. Plate-type heat exchangers that are stacked and permanently joined by brazing at portions where the wave shapes intersect and abut each other are widely used (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2005-326074 (FIG. 6)

  However, in the case where laminated wave-shaped heat transfer plates are permanently joined together by brazing, around the original joint where the wave shapes intersect and abut, along the wave-shaped ridgeline An unwelcome joint called a fillet is formed, which is formed by the brazing material that has accumulated, and the flow path is blocked by the fillet. For this reason, the actual flow path width of the heat medium and the heat-receiving medium flowing through the first space and the second space is narrowed by the fillet generation width.

  And since a heat medium and a to-be-heated medium flow so that a fillet may be avoided, a flow concentrates locally and a flow velocity rises locally. As a result, pressure loss increases.

  Moreover, when the angle of the corrugation of the ridges or ridges formed on the heat transfer plate is large (70 ° to 80 °), the contact distance of the original joint where the corrugations intersect and contact each other becomes long. For this reason, the width of the surrounding fillet is also widened, the actual flow path width through which the heat medium and the heated medium are circulated is further reduced, leading to an increase in local flow velocity, and pressure loss is further increased.

  Furthermore, the heat transfer area is reduced due to the increase in the area of the fillet, and the heat transfer area and the heat-receiving medium tend to stagnate in the downstream part of the fillet, making it impossible to effectively use the heat transfer area. The heat exchange performance of the is reduced.

By the way, it is conceivable to widen the flow path area through which the heat medium and the heat-receiving medium flow by flattening the wave shape between the fillets of the heat transfer plate. In this case, however, the heat transfer area is reduced. As a result, a new problem of lowering the heat exchange performance of the plate heat exchanger occurs.
In other words, the joint portion narrows the flow path width and increases the pressure loss and shrinks the heat transfer surface, but is also a reinforcing portion that connects adjacent heat transfer plates, and disturbs the flow of internal fluid. It also plays a role in promoting heat. That is, if there is no joint at all, the strength is insufficient and the flow stirring effect is reduced.

  In any case, there has been no proposal for a solution to the problem of an increase in pressure loss and a decrease in heat exchange performance due to an increase in the width of the fillet, which is an unwelcome joint.

  The technical problem of the present invention is to make it possible to reduce pressure loss while suppressing deterioration in heat exchange performance.

The plate heat exchanger according to the present invention has the following configuration. In other words, there are openings at both ends of the plate, a plurality of these openings are installed in parallel to form the first opening and the second opening, and the center line extends from the center line of the plate to both side edges. A plurality of heat transfer plates formed so that the corrugations of the ridges or grooves having a predetermined angle cross each other, and these heat transfer plates are opposite to each other according to the angle of the corrugation. The portions that are alternately laminated so that the wave shapes intersect and contact each other when viewed from the lamination direction are joined to each other by brazing, and the outer peripheral edge portions of the heat transfer plates are also joined by brazing. Thus, the first space through which the heat medium made of fluid flows and the second space through which the medium to be heated flow are defined by each heat transfer plate as a boundary, and the edge of the first opening of the stacked heat transfer plates Join every other part The first flow path through which the heat medium flows in communication with the first space via the first opening is formed between them, and the edge of the second opening of the laminated heat transfer plate is By joining every other so as to be different from each other in the stacking direction with the joining portion at the edge of the first opening, the heat-receiving medium communicates with the second space via the second opening between them. A plate-type heat exchanger that exchanges heat through the heat transfer plate between the first flow path and the second flow path, the wave in at least one of the heat transfer plates adjacent in the stacking direction. Provided with a predetermined interval on both sides along the corrugated ridge line from the center of the joint where the shapes intersect and abut, and provided with a recess that is recessed from the abutment surface of the joint , brazing material to the recess It accumulates and suppresses the generation of fillets .

According to the plate heat exchanger of the present invention , a predetermined interval is placed on both sides along the corrugated ridge line from the center of the joint where the corrugations intersect at least one of the heat transfer plates adjacent in the stacking direction. In addition , a concave portion that is recessed from the contact surface of the joint portion is provided , and brazing material is accumulated in the concave portion to suppress the generation of fillets. Therefore, the width of the fillet is reduced as compared with the conventional case, and the area of the fillet occupying the entire flow path width is reduced. For this reason, the heat medium and the heat-receiving medium concentrated in the flow path other than the fillet are dispersed, the local flow velocity is reduced, and the pressure loss can be reduced. Further, the reduction of the area of the fillet in the entire flow path width can minimize the reduction of the heat transfer area, thereby suppressing the deterioration of the heat exchange performance. Furthermore, it is possible to make it difficult for the heat medium and the heat-receiving medium to stagnate at the downstream portion of the fillet, and the heat transfer area can be used effectively. That is, pressure loss can be reduced while suppressing a decrease in heat exchange performance, and an energy saving effect can be obtained.

Embodiment 1. FIG.
The present invention will be described below with reference to illustrated embodiments.
1 is a perspective view showing a wave-shaped joint portion of a heat transfer plate constituting a plate heat exchanger according to Embodiment 1 of the present invention, FIG. 2 is a plan view showing the entire structure of the heat transfer plate, FIG. FIG. 4 is a schematic view showing the laminated heat transfer plate transparently from the lamination direction so that the joint portion can be seen, and FIG.

  In the plate heat exchanger of the present embodiment, a plurality of heat transfer plates 100 are stacked as shown in FIG. 4, and the first space 12 through which the heat medium is circulated with each heat transfer plate 100 as a boundary, and the heated medium Are formed alternately.

  More specifically, the heat transfer plate 100 has openings at both ends as shown in FIGS. 1 to 3, and a plurality of these openings are installed in parallel to form the first openings 1a and 1b and the first openings 1a and 1b. The wave shape of the ridge 7a or the ridge 7b is formed in the two openings 2a and 2b, and the angle θ with the center line 50 is set to 70 ° to 80 ° from the center line 50 to both side ends. It is shaped as follows. That is, the wave shape of the ridges 7a or the ridges 7b is formed in a dogleg shape so that the bent portion is positioned on the center line 50, and the regions on both sides of the center line 50 are in a mirror image relationship. It is formed as follows. The heat transfer plates 100 are laminated with the in-plane directions alternately different by 180 ° so that the directions of the wave shapes of the waves are opposite to each other. The portions where the wave shapes intersect and contact each other become the original joints 80 by brazing and are joined to each other, and each heat transfer plate outer peripheral edge 5 is also joined by brazing, so that the heat medium made of fluid The first space 12 through which the heat medium flows and the second space 13 through which the heat-receiving medium circulates are defined by the heat transfer plates 100 as boundaries.

  Also, every other edge 3a, 3b of the first openings 1a, 1b of the heat transfer plate 100 laminated as shown in FIG. 4 is joined, so that the first openings 1a, 1b are between them. A first flow path through which the heat medium flows is formed so as to communicate with the first space 12 via the. That is, the first openings 1a and 1b function as the header 11A of the first flow path.

  Also, the edges 4a, 4b of the second openings 2a, 2b of the laminated heat transfer plate 100 are different from the joints of the edges 3a, 3b of the first openings 1a, 1b in the stacking direction. By joining every other, a second flow path is formed between them, which communicates with the second space 13 via the second openings 2a and 2b and through which the heat-receiving medium flows. . That is, the second openings 2a and 2b function as the header 11B of the second flow path. In FIG. 4, for convenience of explanation, the headers 11 </ b> A and 11 </ b> B are shown as communicating with the first flow path that is continuous with the first space 12. As described above, the headers 11 </ b> B having different positions communicate with only the second flow path continuous with the second space 13.

  The above shows the basic configuration of the plate heat exchanger that performs heat exchange through the heat transfer plate 100 between the first flow path and the second flow path. The present embodiment further has the following configuration. That is, in a portion at a distance of 0.5 mm to 1.5 mm from the center 8 of the joint 80 formed in a portion where the wave shapes of the heat transfer plates 100 adjacent to each other in the stacking direction intersect and contact each other. A recessed portion 10 having a width of 0 mm to 3.0 mm and a depth of 0.2 mm to 0.4 mm from the contact surface of the joint 80 is provided.

  The fillet 9, which is an unwelcome joint where the brazing material staying along the corrugated ridges is solidified, is a gap between the original joint 80 where the corrugations of adjacent heat transfer plates 100 intersect and abut in the stacking direction. This occurs when the distance between the two becomes 0.2 mm or less. For this reason, in order not to produce a fillet around the original joint 80, it is necessary to keep the interval between adjacent heat transfer plates around the original joint 80 at 0.2 mm or more.

  In the plate heat exchanger of the present embodiment, the lower limit value of the concave depth of the concave portion 10 is set to 0.2 mm because, as described above, the concave portion 10 shallower than 0.2 mm is caused by the staying brazing material. This is because a fillet 9 is generated that is bonded at a portion where the heat transfer plates 100 adjacent to each other in the stacking direction should not be bonded. Further, the reason why the upper limit value of the concave depth of the concave portion 10 is set to 0.4 mm is due to manufacturing limitations. That is, the wave shape of the heat transfer plate 100 is press-molded, but if the concave portion 10 deeper than 0.4 mm is formed in the wave-shaped convex stripe portion, the heat transfer plate 100 may be cracked. It is.

  By the way, when the angle of the wave shape is 70 ° to 80 °, the generation width of the fillet to be joined is 5 to 7 mm when the concave portion is not provided. The upper limit of the width of the recessed portion 10 is set to 3 mm because when the original joint 80 has a width of 1 mm, if not provided with a recessed portion of 3 mm on both sides, the wave angle is 80 ° on both sides. This is because an extra fillet 9 is produced. In addition, the lower limit of the width of the recessed portion 10 is set to 1 mm because of manufacturing restrictions and when the width of the original joint portion 80 is 3 mm, if the recessed portions are not provided 1 mm on both sides, the wave angle is This is because an extra fillet 9 is produced on both sides in the case of 70 °. As a result of experiments by the present inventors, it is found that a sufficient strength (about 20 MPa) can be obtained if the width of the original joint 80 is about 1 mm.

  As described above, in the present embodiment, the recessed portion 10 is recessed by 0.2 mm to 0.4 mm from the contact surface of the bonding portion 80 at a portion spaced 0.5 mm to 1.5 mm from the center 8 of the bonding portion 80. Since brazing material is provided, the brazing material flows into the recessed portion 10 and accumulates, and the occurrence of the fillet 9 is suppressed. For this reason, even if the fillet 9 is generated, its width is reduced, the area of the fillet 9 occupying the entire flow path width is reduced, and the heat medium and the heat-receiving medium concentrated in the flow path other than the fillet 9 are dispersed. As a result, the local flow rate is reduced, and the pressure loss can be reduced.

  Moreover, the reduction of the area of the fillet 9 occupying the entire flow path width can minimize the reduction of the heat transfer area, and the deterioration of the heat exchange performance can be suppressed.

  Furthermore, the reduction of the area of the fillet 9 can make it difficult for the heat medium and the heat-receiving medium to stagnate in the downstream portion of the fillet 9, and the heat transfer area can be used effectively. That is, pressure loss can be reduced while suppressing a decrease in heat exchange performance, and an energy saving effect can be obtained.

  By the way, the width at which the fillet 9 is generated depends on the corrugated angle θ with respect to the center line 50 of the heat transfer plate 100 as described above. For this reason, in order to suppress the occurrence of fillets, the width of the recessed portion 10 may be adjusted according to the angle θ (70 ° to 80 °).

  In the present embodiment, the width of the recessed portion 10 is set to 1.0 mm to 3.0 mm and is adjusted according to the angle θ (70 ° to 80 °). It can be adjusted freely.

Embodiment 2. FIG.
FIG. 5 is a schematic view showing the laminated heat transfer plate of the plate heat exchanger according to the second embodiment of the present invention transparently from the lamination direction so that the joint portion can be seen. Parts corresponding to those of 1 are denoted by the same reference numerals. In the description, reference is made to FIG. 1 and FIG. 4 described above.

  In the plate heat exchanger of the present embodiment, the recessed portion 10 described in the first embodiment is provided only on one of the heat transfer plates 200 adjacent in the stacking direction. That is, the contact of the joint 80 is placed at a portion spaced 0.5 mm to 1.5 mm from the center 8 of the original joint 80 where the wave shapes on one of the heat transfer plates 200 adjacent in the stacking direction intersect and contact each other. A recessed portion 10 that is recessed 0.2 mm to 0.4 mm from the contact surface is provided. All other configurations are the same as those of the first embodiment.

  Since the plate heat exchanger of the present embodiment is provided with the recessed portion 10 only on one of the heat transfer plates 200 adjacent in the stacking direction, the effect of reducing the width of the fillet 9 is that of the first embodiment. Although inferior, almost the same effect can be obtained. For this reason, the area of the fillet 9 occupying the entire flow path width is reduced, the heat medium and the heated medium concentrated in the flow path other than the fillet 9 are dispersed, the local flow velocity is reduced, and the pressure loss is reduced. Can be reduced.

  Further, by reducing the area of the fillet 9 occupying the entire flow path width, the reduction of the heat transfer area can be minimized as in the case of the first embodiment, and the deterioration of the heat exchange performance can be suppressed. .

  Further, by reducing the area of the fillet 9, it is possible to make it difficult for the heat medium and the heat-receiving medium to stagnate in the downstream portion of the fillet 9, as in the first embodiment, and to effectively use the heat transfer area. can do. That is, it is possible to reduce pressure loss while suppressing a decrease in heat exchange performance.

It is a perspective view which shows the wave-shaped junction part of the heat exchanger plate which comprises the plate type heat exchanger which concerns on Embodiment 1 of this invention. It is a top view which shows the whole structure of the heat exchanger plate of the plate type heat exchanger which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows transparently the laminated heat-transfer plate of the plate-type heat exchanger which concerns on Embodiment 1 of this invention from the lamination direction so that the junction part can be understood. It is a longitudinal cross-sectional view which shows the entrance / exit periphery of the heat medium and to-be-heated medium of the plate-type heat exchanger which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows transparently the laminated heat-transfer plate of the plate-type heat exchanger which concerns on Embodiment 2 of this invention from a lamination direction so that the junction part can be understood.

Explanation of symbols

  1a, 1b first opening, 2a, 2b second opening, 3a, 3b edge of first opening, 4a, 4b edge of second opening, 5 outer peripheral edge, 7a ridge, 7b groove , 8 center of joint, 10 recessed portion, 12 first space, 13 second space, 50 center line, 80 joint, 100, 200 heat transfer plate.

Claims (4)

Openings are formed at both ends of the plate, a plurality of sets of these openings are installed in parallel to form the first opening and the second opening, and with respect to the centerline from the centerline of the plate to both ends A plurality of heat transfer plates formed so as to cross the wave shape of the ridges or grooves having a predetermined angle,
These heat transfer plates are alternately stacked so that the directions of the wave shapes are opposite to each other, and the portions where the wave shapes intersect and contact each other when viewed from the stacking direction are joined together by brazing. Also, the outer peripheral edge of each heat transfer plate is joined by brazing, so that the first space through which the heat medium made of fluid flows and the second space through which the heat medium flows circulates each heat transfer plate. Defined in
Furthermore, every other edge of the first opening of the laminated heat transfer plate is joined, so that the heat medium communicates with the first space via the first opening between them. A first flow path is formed,
Further, the edges of the second openings of the laminated heat transfer plates are joined alternately so that they are different in the lamination direction from the joints of the edges of the first openings. A second flow path is formed through which the heat-receiving medium flows and communicates with the second space through the second opening,
A plate-type heat exchanger that performs heat exchange between the first flow path and the second flow path through the heat transfer plate,
Contact surfaces of the joints at predetermined intervals on both sides along the ridge line of the wave shape from the center of the joints where the wave shapes intersect and contact each other in at least one of the heat transfer plates adjacent in the stacking direction. A plate-type heat exchanger characterized in that a recessed portion that is further recessed is provided , and brazing material is accumulated in the recessed portion to suppress the occurrence of fillets .   The angle of the wave shape of the ridges or the recesses with respect to the center line of the plate is set to 70 ° to 80 °, and the recesses are spaced from the center of the joint by 0.5 mm to 1.5 mm. 2. The plate heat exchanger according to claim 1, wherein the depth of the recessed portion from the contact surface of the joint portion is set to be 0.2 mm to 0.4 mm in the portion.   The plate-type heat exchanger according to claim 2, wherein a width of the recessed portion is set to 1.0 mm to 3.0 mm.   The plate-type heat exchanger according to any one of claims 1 to 3, wherein the recessed portion is formed on both of the heat transfer plates adjacent in the stacking direction.

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