EP2420791A2

EP2420791A2 - Plate heat exchanger

Info

Publication number: EP2420791A2
Application number: EP10764664A
Authority: EP
Inventors: Sang Chul Han; Sin Ii Choi; Rak Gyun Kim
Original assignee: Estra Automotive Systems Co Ltd
Current assignee: Estra Automotive Systems Co Ltd
Priority date: 2009-04-16
Filing date: 2010-04-15
Publication date: 2012-02-22
Also published as: WO2010120125A2; CN102395853B; EP2420791A4; US20120031598A1; KR100950689B1; WO2010120125A3; CN102395853A

Abstract

A plate heat exchanger capable of increasing the fluidity of a fluid and realizing improved heat exchange efficiency, wherein each of stacked heat exchange elements are formed by assembling upper and lower plates, with first and second flow channels for first and second fluids respectively defined in each element and between the elements, inlet and outlet ports formed in opposite ends of the element, upper and lower flanges formed on the respective upper and lower plates, and upper and lower flow grooves diagonally extending on the lower surface of the upper plate and on the upper surface of the lower plate and intersecting with each other to define the first flow channel, wherein a flow guide structure for guiding the first fluid in at least two flow directions is provided on each of the areas around the inlet and outlet ports of the upper and lower plates.

Description

[Technical Field]

The present invention relates, in general, to a plate heat exchanger and, more particularly, to a plate heat exchanger which can increase the fluidity of a fluid, thereby realizing improved heat exchange efficiency.

[Background Art]

A heat exchanger is a device for transferring heat from a higher temperature fluid to a lower temperature fluid through a heat transfer wall, and is used in an air conditioning system, a transmission oil cooler, etc. of an automobile. To be accommodated in a limited space in which the heat exchanger is installed, it is required to realize compactness of the heat exchanger and, accordingly, a plate heat exchanger has been widely used.
The plate heat exchanger includes a plurality of heat exchange elements that are stacked to define a flow channel between neighboring plates of the elements. The flow channel includes at least two flow channels through which different heat exchange medium can flow. In the plate heat exchanger, the different heat exchange medium exchange heat with each other through the heat exchange elements when the medium pass through the respective flow channels. Further, each of the respective plates of the heat exchange elements has an inlet port and an outlet port in opposite ends thereof, wherein the inlet ports and the outlet ports of the respective plates communicate with each other. An inlet cap and an outlet cap are mounted to the inlet and outlet ports of the uppermost plate by brazing, etc.
As shown in Fig. 8, a heat exchange element of a conventional plate heat exchanger is fabricated by assembling a pair of plates 1 and 2 with each other. Here, on the facing surfaces of the respective plates 1 and 2, a plurality of diagonal grooves 1a and 2a are formed by embossing the plates 1 and 2 in such a way that the grooves 1a and 2a extend diagonally. When the plates 1 and 2 are assembled with each other, the grooves 1a and 2a form a flow channel. Further, opposite ends of the respective plates 1 and 2 are provided with respective through holes 1b and 2b for forming an inlet port and an outlet port. Depressed edges 1c and 2c are formed around the respective through holes 1b and 2b.
During the operation of the plate heat exchanger, a fluid in the flow channel flows along the grooves 1a and 2a of the respective plates 1 and 2, so that the fluid flows in an diagonal direction. Therefore, the flow of fluid may easily stagnate on the depressed edges 1c and 2c around the through holes 1b and 2b, so that the conventional plate heat exchanger excessively reduces the fluidity of the fluid and, accordingly, reduces the heat exchange efficiency.

[Disclosure]

[Technical Problem]

Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and is intended to provide a plate heat exchanger which can increase the fluidity of a fluid, thereby realizing improved heat exchange efficiency.

[Technical Solution]

In an aspect, the present invention provides a plate heat exchanger, including:

a plurality of heat exchange elements stacked in such a way that one is laid on top of another, each of the heat exchange elements being formed by assembling an upper plate and a lower plate, with a first flow channel defined in each of heat exchange elements and allowing a first fluid to pass therethrough, and a second flow channel defined between the heat exchange elements and allowing a second fluid to pass therethrough, further including:
- an inlet port and an outlet port formed in opposite ends of each of the heat exchange elements, an upper flange formed on the upper plate by extending upwards from each of the inlet and outlet ports, a lower flange formed on the lower plate by extending downwards from each of the inlet and outlet ports,
- a plurality of upper flow grooves diagonally extending on a lower surface of the upper plate, and a plurality of lower flow grooves diagonally extending on an upper surface of the lower plate, wherein the upper plate and the lower plate are assembled with each other in such a way that the upper flow grooves intersect with the lower flow grooves, thereby defining the first flow channel in each of the heat exchange elements, further including:
  - a flow guide structure for guiding the first fluid in at least two flow directions, the flow guide structure being provided on at least one of areas around the inlet and outlet ports of the upper plate and on at least one of areas around the inlet and outlet ports of the lower plate.

The upper flow grooves may extend to the areas around the upper flanges of the upper plate, with at least one upper subsidiary groove being formed in each of the upper flanges of the upper plate, wherein the at least one upper subsidiary groove intersects with the upper flow grooves.
The lower flow grooves may extend to the areas around the lower flanges of the lower plate, with at least one lower subsidiary groove being formed in each of the lower flanges of the lower plate, wherein the at least one lower subsidiary groove intersects with the lower flow grooves.
In the plate heat exchanger, at least one upper spacing lug may be formed on an upper surface of the upper plate, and at least one lower spacing lug may be formed on a lower surface of the lower plate.
The upper spacing lug of each of the heat exchange elements may be in contact with the lower spacing lug of a neighboring heat exchange element, the upper spacing lug and the lower spacing lug having respective through holes on contact surfaces thereof so that the first flow channels of the heat exchange elements communicate with each other.

[Advantageous Effects]

As described above, the plate heat exchanger according to the present invention uses a flow guide structure, by which the fluid can be guided in at least two flow directions in the area around the upper flange of the upper plate and/or around the lower flange of the lower plate, so that the present invention prevents stagnation of the fluid in the areas around the inlet ports and the outlet ports of the heat exchange elements and allows the fluid to smoothly and constantly flow for the whole length of the respective plates and, accordingly, increases the fluidity of the fluid and realizes improved heat exchange efficiency.

[Description of Drawings]

Fig. 1 is a perspective view illustrating a plate heat exchanger according to an embodiment of the present invention;
Fig. 2 is a sectional view illustrating the axial cross-section of the plate heat exchanger according to the embodiment of the present invention;
Fig. 3 is an exploded perspective view illustrating upper and lower plates of a heat exchange element according to the present invention when the upper and lower plates are separated from each other;
Fig. 4 is an enlarged perspective view illustrating a portion designated by the arrow A in Fig. 3;
Fig. 5 is a bottom view of the upper plate viewed in a direction designated by the arrow C in Fig. 4;
Fig. 6 is an enlarged perspective view illustrating a portion designated by the arrow B in Fig. 3;
Fig. 7 is a bottom view of the lower plate viewed in a direction designated by the arrow D in Fig. 6; and
Fig. 8 is a view illustrating a heat exchange element of a conventional plate heat exchanger.

[Mode for Invention]

Hereinbelow, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
Figs. 1 through 7 show a plate heat exchanger according to an embodiment of the present invention.
As shown in Fig. 1, the plate heat exchanger of the present invention includes a plurality of heat exchange elements 10, wherein the plurality of heat exchange elements 10 is stacked in such a way that one is laid on top of another.
As shown in Fig. 2, each of the heat exchange elements 10 defines therein a first flow channel 18, through which a first fluid, such as oil or refrigerant, passes. Each of the heat exchange elements 10 is formed by assembling an upper plate 11 with a lower plate 12 into a single structure. The upper plate 11 and the lower plate 12 are made of a metal material having excellent heat conductivity, such as aluminum, and are joined together along the edges 11a and 12a by brazing.
As shown in Fig. 2, the upper plate 11 and the lower plate 12 are provided on facing surfaces thereof with a plurality of flow grooves 11b and 12b. Described in detail, the lower surface of the upper plate 11 is provided with a plurality of upper flow grooves 11b and the upper surface of the lower plate 12 is provided with a plurality of lower flow grooves 12b. The upper flow grooves 11b of the upper plate 11 and the lower flow grooves 12b of the lower plate 12 diagonally extend on a flat plane. Here, the upper plate 11 and the lower plate 12 are stacked in such a way that the upper flow grooves 11b of the upper plate 11 intersect with the lower flow grooves 12b of the lower plate 12. Due to the intersection stack of the upper flow grooves 11b and the lower flow grooves 12b, the first flow channel 18 is defined in the heat exchange element 10. Therefore, in the heat exchange element 10, the first fluid, for example, oil, can flow zigzag through the first flow channel 18, so that the flow rate of the first fluid can be increased and the contact surface of the first fluid relative to the heat exchange element can be enlarged to realize improved heat exchange efficiency.
Here, the plurality of the flow grooves 11b and 12b may be formed by subjecting the upper and lower plates 11 and 12 to die-casting or pressing, such as stamping. Further, bulging parts 13a and 14a are formed in the heat exchange element 10 at locations opposed to the flow grooves 11b and 12b, with a plurality of depressed parts 13b and 14b defined between the plurality of bulging parts 13a and 14a. Due to the flow grooves 11b and 12b, the upper and lower plates 11 and 12 have respective wave structures 13 and 14.
As shown in Fig. 2, each of the heat exchange elements 10 is provided with an inlet port 43 in one end thereof and with an outlet port 44 in the other end thereof. In each of the heat exchange elements 10, the inlet port 43 and the outlet port 44 communicate with the first flow channel 18. Further, when the plurality of the heat exchange elements 10 are stacked, the inlet ports 43 and the outlet ports 44 of the elements 10 communicate with each other.
Further, the upper plate 11 has an upper flange 23 which is raised upwards from each of the inlet and outlet ports 43 and 44, and the lower plate 12 has a lower flange 24 which protrudes downwards from each of the inlet and outlet ports 43 and 44. Here, the upper flange 23 and the lower flange 24 are assembled with each other through fitting. Described in detail, the upper flanges 23 of a lower heat exchange element 10 may be fitted over the respective lower flanges 24 of an upper heat exchange element 10 or the lower flanges 24 of an upper heat exchange element 10 may be fitted into the respective upper flanges 23 of a lower heat exchange element 10, so that the desired fluid tightness can be realized. Alternatively, the neighboring upper and lower flanges 23 and 24 may be integrated with each other by brazing in a leak proof manner. Therefore, the inlet ports 43 and the outlet ports 44 of the heat exchange elements 10 are hermetically sealed from a second flow channel 28.
In the uppermost heat exchange element 10, an inlet fitting 25 is mounted to the upper flange 23 of the inlet port 43 and an outlet fitting 26 is mounted to the upper flange 23 of the outlet port 44. The inlet fitting 25 has an opening 25a to which an inlet pipe is connected. The outlet fitting 26 has an opening 26a to which an outlet pipe is connected.
The upper flow grooves 11b of the upper plate 11 extend to areas around the upper flanges 23 and the lower flow grooves 12b of the lower plate 12 extend to areas around the lower flange 24. Further, in the heat exchange element 10, the upper flow grooves 11bof the upper plate 11 intersect with the lower flow grooves 12b of the lower plate 12, thereby defining the first flow channel 18 having an intersecting structure. Therefore, when the first fluid is introduced from the inlet port 43 into the first flow channel 18, the first fluid flows zigzag both through the upper flow grooves 11b of the upper plate 11 and through the lower flow grooves 12b of the lower plate 12 prior to being discharged through the outlet port 44.
Here, in the areas around the inlet port 43 and the outlet port 44, the first fluid severally flows along the intersecting upper and lower flow grooves 11b and 12b, so that the first fluid may stagnate in the areas around the inlet and outlet ports 43 and 44 of the heat exchange element 10. In an effort to avoid the stagnation of the fluid in the areas around the inlet and outlet ports 43 and 44, the present invention provides a flow guide structure capable of guiding the first fluid in such a way that the fluid can flow in at least two directions, in other words, the fluid can flow in radial directions in the areas around the inlet and outlet ports 43 and 44. Therefore, the present invention can prevent the stagnation of the first fluid and can realize increased fluidity of the first fluid.
To this end, as shown in Fig. 3 through Fig. 7, the upper plate 11 is provided with at least one upper subsidiary groove 63 in an area around each of the upper flanges 23 and the lower plate 12 is provided with at least one lower subsidiary groove 64 in an area around each of the lower flanges 24.
As shown in Figs. 4 and 5, the upper subsidiary groove 63 is formed by embossing, etc. in such a way that the upper subsidiary groove 63 can intersect with the upper flow grooves 11b of the upper plate 11 at a predetermined angle of intersection.
Further, as shown in Figs. 4 and 5, the upper flow grooves 11b of the upper plate 11 are formed on the rear surfaces of the bulging parts 13a of the wave structure 13, so that the bulging parts 13a and the upper flow grooves 11b are oriented in the same direction and, accordingly, the upper subsidiary groove 63 intersects with the bulging parts 13a at the predetermined angle of intersection. Therefore, in the area around each of the upper flanges 23 of the upper plate 11, the first fluid can flow in main flow directions (the directions designated by arrow K) in which the fluid flows along the upper flow grooves 11b and, at the same time, can flow in at least one subsidiary flow direction (the direction designated by arrow U) in which the fluid flows along at least one upper subsidiary groove 63. Therefore, in the area around each of the upper flanges 23 of the upper plate 11, the first fluid can cross-flow both in the main flow directions and in the at least one subsidiary flow direction, so that the first fluid can more evenly, smoothly and constantly flow for the whole length of the upper plate 11 with increased fluidity.
As shown in Figs. 6 and 7, the lower subsidiary groove 64 is formed by embossing, etc. in such a way that the lower subsidiary groove 64 can intersect with the lower flow grooves 12b of the lower plate 12 at a predetermined angle of intersection.
As shown in Figs. 6 and 7, the lower flow grooves 12b of the lower plate 12 are formed on the rear surfaces of the bulging parts 14a of the wave structure 14 and, accordingly, the bulging parts 14a and the lower flow grooves 12b are oriented in the same direction. Therefore, the lower subsidiary groove 64 intersects with the bulging parts 14a at the predetermined angle of intersection. Thus, in the area around each of the lower flanges 24 of the lower plate 12, the first fluid can flow in main flow directions (the directions designated by arrow J) in which the fluid flows along the lower flow grooves 12b and, at the same time, can flow in at least one subsidiary flow direction (the direction designated by arrow W) in which the fluid flows along at least one lower subsidiary groove 64. Therefore, in the area around each of the lower flanges 24 of the lower plate 12, the first fluid can cross-flow both in the main flow directions and in the at least one subsidiary flow direction, so that the first fluid can more evenly, smoothly and constantly flow for the whole length of the lower plate 12 with increased fluidity.
As described above, in the present invention, at least one upper subsidiary groove 63 is formed in the area around each of the upper flanges 23 of the upper plate 11 and at least one lower subsidiary groove 64 is formed in the area around each of the lower flanges 24 of the lower plate 12, thereby guiding the first fluid to at least two flow directions in the area around each of the inlet and outlet ports 43 and 44 of the heat exchange element 10. Therefore, the present invention can prevent stagnation of the first fluid in the areas and, accordingly, can allow the fluid to smoothly and constantly flow for the whole length of the respective plates 11 and 12. That is, the present invention increases the fluidity of the first fluid and, accordingly, realizes improved heat exchange efficiency.
Further, a second flow channel 28 through which a second fluid, such as cooling water, passes is defined between the stacked heat exchange elements 10. The second flow channel 28 is defined because the plurality of heat exchange elements 10 are spaced apart from each other at a predetermined interval.
To this end, the upper and lower surfaces of each of the heat exchange elements 10, that is, the upper surface of the upper plate 11 and the lower surface of the lower plate 12 are provided with a plurality of upper and lower spacing lugs 21 and 22. Here, the plurality of upper spacing lugs 21 are formed on the upper surface of each bulging part 13a of the upper plate 11 in such a way that the lugs 21 are spaced apart from each other at regular intervals. In the same manner, the plurality of lower spacing lugs 22 are formed on the lower surface of each bulging part 14a of the lower plate 12 in such a way that the lugs 22 are spaced apart from each other at regular intervals. Here, the lower spacing lugs 22 of the upper heat exchange elements 10 are brought into contact with the upper spacing lugs 21 of the lower heat exchange elements 10. Because the plurality of upper and lower spacing lugs 21 and 22 are brought into contact with each other as described above, the interval between the stacked heat exchange elements 10 is increased and, accordingly, the sectional area of the second flow channel 28 is increased. Further, the spacing lugs 21 and 22 which are in contact with each other may be joined to each other by brazing, etc. The upper spacing lugs 21 and the corresponding lower spacing lugs 22 are located on points at which the upper flow grooves 11b and the lower flow grooves 12b intersect with each other, so that the stacked structure of the heat exchange elements can have a stable structure.
The spacing lugs 21 and 22 may be shaped in the form of any one of a trapezoidal cross-section, a curved cross-section, such as a circular or elliptical cross-section, and a square cross-section. Further, the upper surfaces 21a of the respective upper spacing lugs 21 can be brought into close contact with the lower surfaces 22a of the corresponding lower spacing lugs 22, so that the integration of the upper and lower plates 11 and 12 can be more easily accomplished.
Further, as shown in Fig. 2, the contact surfaces 21a and 22a of the upper and lower spacing lugs 21 and 22, that is, the upper surfaces 21a of upper spacing lugs 21 and the lower surfaces 22a of the lower spacing lugs 22 are provided with respective through holes 21c and 22c. Further, the through holes 21c and 22c of neighboring spacing lugs 21 and 22 which are in contact with each other communicate with each other. Therefore, the first flow channels 18 of the respective heat exchange elements 10 communicate with each other by means of the through holes 21c and 22c. Therefore, the first fluid, such as oil, inside a heat exchange element 10 can freely flow to the first flow channel 18 of a neighboring heat exchange element 10 through the through holes 21c and 22c, so that the first fluid can be mixed in all of the heat exchange elements 10 and, accordingly, desirably improves the heat exchange efficiency.
Further, the upper plate 11 and the lower plate 12 have positioning grooves 11c and positioning protrusions 12c on corresponding ends 11a and 12a thereof. Due to the positioning grooves and positioning protrusions, the upper plate 11 and the lower plate 12 can be easily positioned and, accordingly, the preliminary assembly of the upper and lower plates 11 and 12 can be quickly finished during a process of assembling the plates. Therefore, the precise and firm assembly of the upper and lower plates 11 and 12 can be realized.

Claims

A plate heat exchanger, comprising:
a plurality of heat exchange elements stacked in such a way that one is laid on top of another, each of the heat exchange elements being formed by assembling an upper plate and a lower plate, with a first flow channel defined in each of heat exchange elements and allowing a first fluid to pass therethrough, and a second flow channel defined between the heat exchange elements and allowing a second fluid to pass therethrough, further comprising:
an inlet port and an outlet port formed in opposite ends of each of the heat exchange elements, an upper flange formed on the upper plate by extending upwards from each of the inlet and outlet ports, a lower flange formed on the lower plate by extending downwards from each of the inlet and outlet ports,

a plurality of upper flow grooves diagonally extending on a lower surface of the upper plate, and a plurality of lower flow grooves diagonally extending on an upper surface of the lower plate, wherein the upper plate and the lower plate are assembled with each other in such a way that the upper flow grooves intersect with the lower flow grooves, thereby defining the first flow channel in each of the heat exchange elements, further comprising:
a flow guide structure for guiding the first fluid in at least two flow directions, the flow guide structure being provided on at least one of areas around the inlet and outlet ports of the upper plate and on at least one of areas around the inlet and outlet ports of the lower plate.
The plate heat exchanger as set forth in claim 1, wherein, in the areas around the inlet and outlet ports of the upper plate, the first fluid is guided in a main flow direction extending along the upper flow grooves of the upper plate and in at least one subsidiary flow direction intersecting with the main flow direction.
The plate heat exchanger as set forth in claim 1, wherein the upper flow grooves extend to the areas around the upper flanges of the upper plate, with at least one upper subsidiary groove being formed in each of the upper flanges of the upper plate, wherein the at least one upper subsidiary groove intersects with the upper flow grooves.
The plate heat exchanger as set forth in claim 1, wherein, in the areas around the inlet and outlet ports of the lower plate, the first fluid is guided in a main flow direction extending along the lower flow grooves of the lower plate and in at least one subsidiary flow direction intersecting with the main flow direction.
The plate heat exchanger as set forth in claim 1, wherein the lower flow grooves extend to the areas around the lower flanges of the lower plate, with at least one lower subsidiary groove being formed in each of the lower flanges of the lower plate, wherein the at least one lower subsidiary groove intersects with the lower flow grooves.
The plate heat exchanger as set forth in claim 1, wherein at least one upper spacing lug is formed on an upper surface of the upper plate, and at least one lower spacing lug is formed on a lower surface of the lower plate.
The plate heat exchanger as set forth in claim 1, wherein the upper spacing lug of each of the heat exchange elements is in contact with the lower spacing lug of a neighboring heat exchange element, the upper spacing lug and the lower spacing lug having respective through holes on contact surfaces thereof so that the first flow channels of the heat exchange elements communicate with each other.
The plate heat exchanger as set forth in claim 1, wherein the upper plate and the lower plate have a positioning groove and a positioning protrusion on corresponding ends thereof, respectively.