CN111141163B

CN111141163B - Welded plate heat exchanger

Info

Publication number: CN111141163B
Application number: CN201910716826.0A
Authority: CN
Inventors: 赵亨锡; 安成国; 任盛彬
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-11-06
Filing date: 2019-08-05
Publication date: 2021-09-24
Anticipated expiration: 2039-08-05
Also published as: CN111141163A; KR101987600B1

Abstract

The invention relates to a welded plate heat exchanger, comprising a heat conducting component which forms a plurality of unit heat conducting plates in an up-down direction in a laminated way, wherein the unit heat conducting plates are provided with a first heat conducting surface and a second heat conducting surface which are mutually opposite; forming a first flow channel between the first and second heat-conducting surfaces, and alternately forming a second flow channel between adjacent unit heat-conducting plates; at least one first anti-expansion part is formed on the first heat conduction surface; at least one second expansion-preventing portion is formed on the second heat-conducting surface; when the unit heat-conducting plates are laminated, the upper part of the first expansion-proof part and the lower part of the adjacent upper second expansion-proof part are mutually embedded in a surface contact manner; the upper part of the second expansion-preventing part and the lower part of the adjacent upper first expansion-preventing part are mutually embedded in a surface contact manner to fix the laminated unit heat-conducting plates, so that the friction force is maximized through the mutual surface contact, and the pressure resistance of the welded plate-shaped heat exchanger can be further improved.

Description

Welded plate heat exchanger

Technical Field

The present invention relates to a plate heat exchanger, and more particularly, to a welded plate heat exchanger formed by stacking heat transfer plates welded by seam welding or the like.

Background

Typically, heat exchangers are used to transfer heat from one fluid to another without physical contact. That is, the device is a device that transfers only heat without mixing fluids, and is a device used when indirectly heating or cooling one fluid.

In the past, shell & tube (shell & tube) type heat exchangers were mainly used, but recently, plate heat exchangers that are compact and excellent in heat transfer property were mainly used.

Because of high heat transfer performance, light weight, and economical efficiency, plate heat exchangers are also introduced into power plants and industrial facilities, and thus, a durable plate heat exchanger is required to be able to overcome severe environments such as high service pressure (about 15 to 35 bar) and high service temperature (about 100 to 600 ℃).

In the plate heat exchanger type, the gasket type heat exchanger or the brazed type heat exchanger has many problems such as leakage, corrosion, thermal deformation and the like under the above-described environment, and thus the welded type plate heat exchanger is required as a plate heat exchanger to be used in place of the shell and tube type heat exchanger.

Fig. 1 shows a schematic structure of a conventional welded plate heat exchanger 1, which is manufactured by stacking a plurality of heat transfer surfaces 10 on top of each other and then wrapping them with a housing from the outside.

Such a conventional welded plate-shaped heat exchanger does not flow a fluid to one side, but is formed to be elongated in a length direction compared to a width for increasing a heat exchange length.

However, when a high-pressure fluid flows through the inside of the welded plate-shaped heat exchanger that is long in the longitudinal direction, the heat transfer surface expands and deforms at the center, and there is a problem that a crack occurs at a portion where the outer shell and both ends of the heat transfer surface are welded to each other.

Therefore, in order to use the welded plate heat exchanger under high pressure, it is required to develop a welded plate heat exchanger having a tool capable of preventing the deformation of the heat transfer surface.

National research and development project supporting the invention

Subject original number: 1415156817

Department name: department of industry general commercial resources

Research and management specialized institution: korea institute of energy technology evaluation

Name of research project: energy demand management core technology development (energy special)

Name of research topic: heat conduction area for factory equipment is 100m²Technology development of welded plate heat exchanger

Contribution rate: 1/1

The main pipe mechanism: SAM HO CHEM-MACH MFG Co., Ltd

Study time: 2017.05.01-2019.12.31

Disclosure of Invention

(problem to be solved)

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a welded plate heat exchanger having an improved structure for preventing the central portion of the heat transfer surface from being expanded and deformed when the welded plate heat exchanger is used under high pressure.

(means for solving the problems)

In order to achieve the above object, the welded plate heat exchanger according to the first embodiment of the present invention includes a heat conductive member 100, the heat conductive member 100 being stacked in an up-down direction to form a plurality of unit heat conductive plates 110, wherein the unit heat conductive plates 110 are arranged with a first heat conductive surface 111 and a second heat conductive surface 112 facing each other; a first flow channel 115 is formed between the first and second heat-conducting

surfaces

111, 112, and a second flow channel 118 is alternately formed between the adjacent unit heat-conducting plates 110; at least one first expansion-preventing part 300 is formed on the first heat-conducting surface 111, the first expansion-preventing part 300 is formed to protrude towards the adjacent second heat-conducting surface 112 on the upper side, and the length of the protruding formation of the first expansion-preventing part 300 is larger than the vertical distance between the first and second heat-conducting

surfaces

111 and 112; at least one second expansion-preventing portion 400 is formed on the second heat-conducting surface 112, the second expansion-preventing portion 400 is formed to protrude toward the adjacent upper first heat-conducting surface 111, and the length of the second expansion-preventing portion 400 at a position corresponding to the first expansion-preventing portion 300 is greater than the vertical distance between the first and second heat-conducting

surfaces

111, 112; when the unit heat conduction plates 110 are stacked, the upper portion of the first expansion-preventing portion 300 and the lower portion of the adjacent upper second expansion-preventing portion 400 are fitted in surface contact with each other; the upper portion of the second expansion-preventing portion 400 is fitted to the lower portion of the adjacent upper first expansion-preventing portion 300 in surface contact with each other, and the stacked unit heat-conducting plates 110 are fixed.

In addition, in the welded plate heat exchanger of the first embodiment of the present invention, the first expansion-preventing part 300 includes a first side surface part 310 constituting a side surface and a first upper surface part 320 connecting the ends of the first side surface part 310; the first side surface 310 is formed to be protruded toward the center at a predetermined angle longer than the vertical distance between the first and second heat-conducting

surfaces

111 and 112; the second expansion-preventing part 400 includes a second side surface part 410 constituting a side surface and a second upper surface part 420 connecting ends of the second side surface part 410; the second side surface portion 410 is formed to protrude with a predetermined angle toward the center, and the second side surface portion 410 protrudes to be longer than the vertical distance between the first and second

heat conduction surfaces

111 and 112; when the unit heat transfer plates 110 are stacked, the upper outer surface of the first side surface part 310 is in surface contact with the lower inner surface of the adjacent upper second side surface part 410, and the upper outer surface of the second side surface part 410 is in surface contact with the lower inner surface of the adjacent upper first side surface part 310.

In addition, the welded plate heat exchanger according to the second embodiment of the present invention is characterized in that the length of the first and second

side surface parts

310 and 410 in the vertical direction is longer than 2 times the vertical distance between the first and second

heat transfer surfaces

111 and 112.

In addition, in the welded plate heat exchanger according to the third embodiment of the present invention, the first expansion-preventing part 300 includes a first side surface part 310 constituting a side surface and a first upper surface part 320 connecting the ends of the first side surface part 310; the first side surface 310 is vertically protruded to a length corresponding to a vertical distance between the first and second heat-conducting

surfaces

111 and 112; a first protrusion 330 vertically protruded to a predetermined length at the first upper surface part 320; the second expansion-preventing part 400 includes a second side surface part 410 constituting a side surface and a second upper surface part 420 connecting ends of the second side surface part 410; the second side surface 410 is vertically protruded to a length longer than the vertical distance between the first and second

heat conduction surfaces

111 and 112; when the unit heat transfer plates 110 are stacked, the second heat transfer surfaces 112 are supported by the first upper surface parts 320 excluding the first protrusions 330, the outer surfaces of the protrusions 330 are in surface contact with the inner surfaces of the lower parts of the adjacent upper second side surface parts 410, and the outer surfaces of the upper parts of the second side surface parts 410 are in surface contact with the inner surfaces of the lower parts of the adjacent upper first side surface parts 310.

In addition, the horizontal distance a between the outer side surfaces of the first protrusions 330 is shorter than the horizontal distance b between the outer side surfaces of the first side surface parts 310 by 4 times the thickness t of the first heat conduction surface 111, and is the same as the horizontal distance a between the inner side surfaces of the second side surface parts 410.

In addition, in the welded plate heat exchanger according to the fourth embodiment of the present invention, the vertical length of the outer side surface of the first projecting portion 330 is longer than the vertical distance between the first and second

heat conduction surfaces

111 and 112; the vertical length of the second side portion 410 is longer than the vertical length of the outer side surface of the first protrusion 330.

In addition, the welded plate heat exchanger of the present invention further includes a housing 200, and the heat conductive assembly 100 is disposed inside the housing 200.

(Effect of the invention)

According to the embodiment of the invention, the following advantages are provided: in the welded plate heat exchanger, the first and second

expansion preventing parts

300 and 400 are in surface contact with each other while being inserted into each other, so that friction is maximized, and expansion between the first and second heat

conductive surfaces

111 and 112 or between adjacent unit heat conductive plates 110 is prevented to improve pressure resistance.

In addition, when the pressures of the first fluid and the second fluid are different, the surface contact portion between the first and second

expansion preventing parts

300 and 400 is further compressed by the fluid having a high pressure, and thus, the coupling force therebetween can be increased.

Drawings

Fig. 1 is a schematic view showing a conventional welded plate heat exchanger.

Fig. 2 is a schematic view showing a welded plate heat exchanger of the present invention.

Fig. 3 is a sectional view of the heat conductive assembly of the first embodiment of the present invention, shown along the line a-a' of fig. 2.

Fig. 4 is a schematic view illustrating a manufacturing process of the heat conductive assembly of the present invention.

Fig. 5 is a sectional view of a heat conductive assembly of a second embodiment of the present invention, shown along line a-a' of fig. 2.

Fig. 6 is a sectional view of a heat conductive assembly of a third embodiment of the present invention, shown along line a-a' of fig. 2.

Fig. 7 is a sectional view of a heat conductive assembly of a fourth embodiment of the present invention, shown along the line a-a' of fig. 2.

(description of reference numerals)

100: the heat conducting component 110: unit heat conducting plate

111: first heat-conductive surface 112: second heat-conducting surface

113: first inlet 114: first outlet

115: first flow passage 116: second inlet

117: second outlet 118: second flow channel

200: outer casing

300: first expansion prevention portion 310: first side surface part

320: first upper surface portion 330: first projecting part

400: the second expansion prevention portion 410: second side surface part

420: second upper surface

Detailed Description

Hereinafter, a welded plate heat exchanger according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in fig. 2, the welded plate-shaped heat exchanger of the present invention generally includes a heat conductive assembly 100 and a housing 200, the housing 200 having the heat conductive assembly 100 disposed therein.

First, as shown in fig. 2 and 3, the heat conduction member 100 is formed by laminating a plurality of unit heat conduction plates 110. In this case, the unit heat conduction plates 110 are stacked on the heat conduction surface in the vertical direction, and the vertical direction is determined as shown in fig. 3.

The unit heat conduction plate 110 has a first heat conduction surface 111 and a second heat conduction surface 112, and the first heat conduction surface 111 and the second heat conduction surface 112 are disposed to face each other to form a space between the first heat conduction surface 111 and the second heat conduction surface 112. At this time, in order to flow the first fluid in the space between the first and second

heat transfer surfaces

111 and 112, a first inlet 113 is formed on one side of the first and second

heat transfer surfaces

111 and 112, and a first outlet 114 is formed on the other side, so that a first flow channel 115 is formed between the first inlet 113 and the first outlet 114 in the space between the first and second

heat transfer surfaces

111 and 112.

There are a plurality of unit heat conductive plates 110, and a first fluid flows inside each unit heat conductive plate 110.

The heat-conducting surface of the unit heat-conducting plate 110 may be formed with an embossed pattern in which mountain portions and valley portions are repeatedly arranged. At this time, a space between the first heat-transfer surface 111 and the second heat-transfer surface 112 after being arranged to face each other, i.e., a vertical distance between the first and second heat-

transfer surfaces

111 and 112 may correspond to a height of the embossed pattern 500.

The first flow channel 115 of the unit heat conduction plate 110 may be formed by welding the first heat conduction surface 111 and the second heat conduction surface 112 with the remaining edge positions except for the first inlet and

outlet ports

113 and 114.

The welding may be by seam welding, CO₂Welding or Tig welding.

In addition, as shown in fig. 4, the first heat-conducting surface 111 and the second heat-conducting surface 112 of the unit heat-conducting plate 110 may be two surfaces facing each other by bending one heat-conducting surface formed integrally by 180 degrees with respect to the center line thereof. At this time, the first flow passage 115 of the unit heat conductive plate 110 may be formed by welding edge positions except for the first outlet and

inlet ports

113 and 114 and the bent portions in the first and second heat

conductive surfaces

111 and 112, whereby the welded portion may be minimized.

The heat conductive member 100 is formed by stacking a plurality of unit heat conductive plates 110 in an up-down direction while being stacked to form spaces between adjacent unit heat conductive plates 110, thereby flowing the second fluid in each space.

The first fluid flows inside each unit heat conductive plate 110 and the second fluid flows between each adjacent unit heat conductive plate 110, and thus the flow channels through which the first and second fluids flow are alternately formed with each other, so that the heat conductive area between the first and second fluids can be maximized.

The space between the adjacent unit heat conduction plates 110, specifically, the space between the first heat conduction surface 111 and the second heat conduction surface 112 is formed in the adjacent two unit heat conduction plates 110, wherein the first heat conduction surface 111 is positioned at the upper side in the unit heat conduction plate 110 positioned at the lower side, and the second heat conduction surface 112 is positioned at the lower side in the unit heat conduction plate 110 positioned at the upper side.

In order to flow the second fluid in the space between the adjacent unit heat conductive plates 110, a second inlet 116 is formed at the other side of the adjacent unit heat conductive plates 110 and a second outlet 117 is formed at one side, and a second flow passage 118 is formed between the second inlet and

outlet

116, 117 in the space between the adjacent unit heat conductive plates 110.

Like the first flow channel formed by welding the edge positions of the first and second heat-

transfer surfaces

111 and 112 of the unit heat-transfer plates 110, the edge positions of the adjacent unit heat-transfer plates 110 may be all welded to form the second flow channel 118, but this manufacturing process is difficult and requires a lot of time and effort, and therefore, a flow channel-forming member having a predetermined thickness is provided between the edge positions except for the second inlet and

outlet ports

116 and 117 in the adjacent unit heat-transfer plates 110, and the second flow channel 118 may be formed.

The flow passage forming part is provided at the edge position between the adjacent unit heat conduction plates 110, and thus the thickness of the flow passage forming part is adjusted, and the distance between the adjacent unit heat conduction plates 110 can be adjusted. That is, the vertical distance between the first and second heat-conducting

surfaces

111 and 112 can be adjusted. In addition, the distance can be adjusted by the height of the embossed patterns formed on the heat conductive surface of the unit heat conductive plate 110, as in the first flow channel 115.

The heat conductive member 100 is disposed inside the casing 200, and the casing 200 is provided with a header connected to the drain pipe at a position corresponding to the first and

second inlets

113 and 116 and the first and

second outlets

114 and 117.

As shown in fig. 2 and 3, when a high-pressure fluid flows into the longitudinally long welded plate heat exchanger, the first and second heat transfer surfaces 111 and 112 or the adjacent unit heat transfer plates 110 are expanded and the center portions of the heat transfer surfaces are deformed by expansion, so that cracks may occur in the welded portions. To prevent this, a means for preventing the heat-conducting surface from deforming may be provided. That is, the expansion preventing portion may be disposed on the heat conductive surface.

Specifically, at least one first expansion-preventing portion 300 is provided on the first heat-transfer surface 111 toward the second heat-transfer surface 112, and the first expansion-preventing portion 300 is formed to protrude longer than the vertical distance between the first and second heat-

transfer surfaces

111, 112.

At least one second expansion-preventing portion 400, which is formed to the first heat transfer surface 111 adjacent to the upper side of the second heat transfer surface 112, is provided at a position corresponding to the first expansion-preventing portion 300, and the second expansion-preventing portion 400 is formed to be protruded longer than the vertical distance between the first and second heat transfer surfaces 111, 112.

At this time, when the unit heat conduction plates 110 are stacked, the upper portion of the first expansion-preventing part 300 is inserted and fitted into the lower portion of the adjacent upper second expansion-preventing part 400; the upper portion of the second expansion-preventing part 400 is inserted into and fitted into the lower portion of the adjacent upper first expansion-preventing part 300, and the stacked unit heat-conducting plates 110 are firmly fixed to each other.

The first expansion preventing portion 300 and the second expansion preventing portion 400 are preferably fitted to each other in surface contact. The friction between the first and second

expansion preventing parts

300 and 400 is increased by the surface contact, and the unit heat conduction plates 110 are firmly fixed to each other.

The embossings of the conventional welded plate heat exchanger support the first and second heat transfer surfaces 111 and 112, and prevent the interval between the first and second heat transfer surfaces 111 and 112 from being narrowed, but do not have a portion where they are joined to each other, so that the interval between the embossings cannot be prevented from being widened. In addition, in the case where the first and second heat conduction surfaces 111 and 112 are partially welded and fixed to each other, even if the first and second heat conduction surfaces 111 and 112 are prevented from being spaced apart from each other, welding is difficult in the state where the heat conduction assembly 100 is stacked, and there are disadvantages that there is a risk of leakage at the welded portion and a large amount of manufacturing cost and time are required.

However, the first and second

expansion preventing parts

300 and 400 according to the present invention have the following advantages: the first and second expansion-preventing

parts

300 and 400 are inserted and fitted into each other and are in surface contact with each other to maximize frictional force, thereby preventing expansion between the first and second heat-conducting

surfaces

111 and 112 or between adjacent unit heat-conducting plates 110, and having no welded portion, thereby preventing leakage, and having advantages of reduced manufacturing cost and shortened manufacturing time.

The first and second

expansion preventing parts

300 and 400 may be disposed at the same distance in the longitudinal direction and may be concentratedly disposed at the middle position in the longitudinal direction of the heat conductive member, which is the position where the most expansion deformation occurs due to the high pressure fluid, and the respective unit heat conductive plates 110 are fixed by the first and second

expansion preventing parts

300 and 400, and thus the deformation of the surrounding unit heat conductive plates 110 may not occur, and the entire deformation of the unit heat conductive plates 110 may be reduced.

The more the first and second

expansion preventing parts

300 and 400 are disposed, the more the deformation of the unit heat conducting plate 110 can be minimized.

In terms of production, the first and second

expansion preventing portions

300 and 400 are preferably formed in the same shape. As shown in fig. 2, the cross section of the first and second

expansion preventing parts

300 and 400 in the vertical direction is preferably formed in a circular shape or an elliptical shape, but may be formed in various shapes such as a polygonal shape.

With respect to the shapes of the first and second

expansion preventing parts

300, 400 of the first embodiment of fig. 3, the first expansion preventing part 300 includes a first side surface part 310 constituting a side surface and a first upper surface part 320 connecting the ends of the first side surface part 310; the first side surface part 310 is inclined toward the center by a predetermined angle and may be protruded to be formed longer than a vertical length between the first and second heat conduction surfaces 111 and 112. In addition, the second anti-swelling part 400 includes a second side surface part 410 constituting a side surface and a second upper surface part 420 connecting ends of the second side surface part 410; the second side surface part 410 is inclined toward the center by a predetermined angle and may be protruded to be formed longer than a vertical distance between the first and second heat conduction surfaces 111 and 112.

At this time, when the unit heat transfer plates 110 are stacked, the outer side surface of the upper portion of the first side surface part 310 is fitted into the inner side surface of the lower portion of the adjacent upper second side surface part 410, and is fixed to each other while being in surface contact; similarly, the outer surface of the upper portion of the second side surface portion 410 is fitted into the inner surface of the lower portion of the adjacent upper first side surface portion 310, and is fixed to each other while making surface contact.

The first and second side surfaces 310 and 410 are protruded to be longer than the vertical distance between the first and second heat-

transfer surfaces

111 and 112, thereby increasing the surface contact portion when being inserted and increasing the friction force, thereby preventing the expansion or leakage between the first and second heat-

transfer surfaces

111 and 112 or between the adjacent unit heat-transfer plates 110.

Furthermore, the first side portion 310 can be divided into an upper portion embedded in the lower portion of the second side portion 410 and a lower portion not embedded therein. The inclination angle of the upper portion of the first side surface portion 310 is made smaller than that of the lower portion, so that the coupling force can be maximized when the first and second

expansion preventing portions

300 and 400 are engaged with each other. This also applies to other embodiments.

The shape of the first and second expansion-preventing

parts

300 and 400 of the second embodiment of fig. 5 is similar to that of the first embodiment, but is characterized in that the vertical direction length d between the first and second

side surface parts

310 and 410 is longer than 2 times the vertical distance c between the first and second heat conduction surfaces 111 and 112.

The first and second

expansion preventing parts

300 and 400 of the second embodiment have enlarged portions which are inserted into and fixed to each other to be in surface contact with each other, compared to the first and second

expansion preventing parts

300 and 400 of the first embodiment, and the first expansion preventing part 300 of the first heat conduction surface 111 is inserted into and fixed to each other to be in surface contact with not only the second expansion preventing part 400 of the adjacent upper second heat conduction surface 112 but also the first expansion preventing part 300 of the adjacent upper first heat conduction surface 111 of the second heat conduction surface 112, thereby maximizing the coupling force between the first and second

expansion preventing parts

300 and 400 and preventing the expansion between the first and second heat conduction surfaces 111 and 112 or between the adjacent unit heat conduction plates 110 due to high pressure.

If the pressures of the first and second fluids are different, for example, the pressure of the second fluid is greater than that of the first fluid, the second side portion 410 further compresses the first side portion 310 due to the pressure of the second fluid between the adjacent unit heat conductive plates 110 to increase the coupling force therebetween; in addition, the second side surface portion 410 compresses the first side surface portion 310 and also compresses the inner second side surface portion 410 surface-contacted by the first side surface portion 310, thereby more effectively preventing the expansion between the first and second heat transfer surfaces 111 and 112 and between the adjacent unit heat transfer plates 110.

The first and second expansion-preventing

portions

300 and 400 of the third embodiment of fig. 6 have a shape having projections and recesses, unlike the trapezoidal first and second expansion-preventing

portions

300 and 400 of the first and second embodiments.

Specifically, the first anti-swelling part 300 includes a first side part 310 constituting a side surface and a first upper part 320 connecting ends of the first side part 310; the first side surface 310 is vertically protruded to a length corresponding to a vertical distance between the first and second heat conduction surfaces 111 and 112; the first upper surface part 320 may have a first protrusion 330, and the first protrusion 330 protrudes vertically by a predetermined length.

The second expansion-preventing part 400 includes a second side surface part 410 constituting a side surface and a second upper surface part 420 connecting ends of the second side surface part 410; the second side surface portion 410 may be vertically protruded to have a length longer than a vertical distance between the first and second heat conduction surfaces 111 and 112.

At this time, when the unit heat transfer plates 110 are stacked, the second heat transfer surfaces 112 are supported by the first upper surface parts 320 except the first protrusion parts 330, the outer side surfaces of the first protrusion parts 330 are inserted and fitted into the lower portions of the adjacent upper second side surface parts 410, the outer side surfaces of the upper portions of the second side surface parts 410 are inserted and fitted into the lower portions of the adjacent upper first side surface parts 310, and the stacked unit heat transfer plates 110 are firmly fixed to each other.

Preferably, the outer surface of the first protruding portion 330 is surface-contact-fitted with the inner surface of the lower portion of the adjacent upper second side surface portion 410; similarly, the outer surface of the upper portion of the second side surface portion 410 and the inner surface of the lower portion of the adjacent upper first side surface portion 310 are fitted in surface contact with each other. The frictional force between the first and second

expansion preventing parts

300 and 400 is increased by the surface contact, and the coupling force of the unit heat conducting plate 110 can be increased.

As shown in fig. 6, in order to fit and fix the outer side surfaces of the first protrusions 330 to the lower portions of the adjacent upper second side surface portions 410, the horizontal distance a between the outer side surfaces of the first protrusions 330 is shorter than the horizontal distance b between the outer side surfaces of the first side surface portions 310 by 4 times the thickness t of the first heat-conducting surface 111, and is preferably equal to the horizontal distance a between the inner side surfaces of the second side surface portions 410.

The shapes of the first and second expansion-preventing

portions

300, 400 relating to the fourth embodiment of fig. 7 are similar to those of the third embodiment, but the vertical direction length e of the outer side surface of the first projecting portion 330 is longer than the vertical distance c between the first and second heat conduction surfaces 111, 112; the vertical length f of the second side portion 410 is longer than the vertical length e of the outer side surface of the first protrusion 330.

The first and second

expansion preventing parts

300 and 400 of the fourth embodiment are more enlarged in the portions that are inserted and fixed to each other to be in surface contact than the first and second

expansion preventing parts

300 and 400 of the third embodiment, and the first expansion preventing part 300 of the first heat conduction surface 111 is inserted and fixed to each other not only to the second expansion preventing part 400 of the adjacent upper second heat conduction surface 112 to be in surface contact but also to the first expansion preventing part 330 of the adjacent upper first heat conduction surface 111 of the second heat conduction surface 112 to be in surface contact, so that the coupling force between the first and second

expansion preventing parts

300 and 400 is maximized, and thus it is possible to prevent the expansion between the first heat conduction surfaces 111 and 112 or between the adjacent unit heat conduction plates 110 due to high pressure.

In the case where the pressure of the first fluid is different from that of the second fluid, particularly, the pressure of the first fluid is higher than that of the second fluid, the first side surface portion 310 further compresses the second side surface portion 410 between the first and second heat transfer surfaces 111 and 112 due to the pressure of the first fluid, thereby increasing the coupling force therebetween; further, the first side surface portion 310 compresses the second side surface portion 410 and further compresses the outer side surface of the first protrusion 330 inside the second side surface portion 410 in surface contact therewith, thereby more effectively preventing the expansion between the first and second heat transfer surfaces 111 and 112 and between the adjacent unit heat transfer plates 110.

The present invention is not limited to the above-described embodiments, and of course, has various applicable ranges, and various modifications can be made by those having ordinary knowledge in the art to which the present invention pertains without departing from the gist of the present invention claimed in the claims.

It is needless to say that the characteristic technical configurations described in the respective embodiments can be applied to other embodiments.

Claims

1. A welded plate heat exchanger comprising a heat conductive member (100), the heat conductive member (100) being formed with a plurality of unit heat conductive plates (110) stacked in an up-down direction,

the unit heat-conducting plates (110) are provided with a first heat-conducting surface (111) and a second heat-conducting surface (112) facing each other,

first flow passages 115 are formed between the first and second heat transfer surfaces 111 and 112, second flow passages 118 are alternately formed between adjacent unit heat transfer plates 110,

at least one first anti-expansion part (300) is formed on the first heat conduction surface (111), the first anti-expansion part (300) is formed to protrude towards the adjacent upper second heat conduction surface (112), the protruding length of the first anti-expansion part (300) is larger than the vertical distance between the first and second heat conduction surfaces (111, 112),

at least one second expansion-preventing portion (400) is formed at a position of the second heat-conducting surface (112) corresponding to the first expansion-preventing portion (300), the second expansion-preventing portion (400) is formed to protrude toward the adjacent upper first heat-conducting surface (111), and the protruding length of the second expansion-preventing portion (400) is greater than the vertical distance between the first and second heat-conducting surfaces (111, 112),

when the unit heat conduction plates (110) are stacked, the upper part of the first anti-expansion part (300) is embedded with the lower part of the adjacent upper second anti-expansion part (400) in a surface contact manner; the upper part of the second anti-expansion part (400) and the lower part of the adjacent upper first anti-expansion part (300) are mutually embedded in a surface contact way, and further the laminated unit heat conduction plate (110) is fixed,

the first anti-swelling part (300) includes a first side part (310) constituting a side surface and a first upper part (320) connecting ends of the first side part (310),

the first side surface part (310) is vertically protruded to a length corresponding to a vertical distance between the first and second heat-conducting surfaces (111, 112),

a first protrusion part (330) vertically protruded to form a predetermined length is provided at the first upper surface part (320),

the second anti-swelling part (400) includes a second side part (410) constituting a side surface and a second upper part (420) connecting ends of the second side part (410),

the second side surface part (410) is vertically protruded to a length longer than the vertical distance between the first and second heat-conducting surfaces (111, 112),

when the unit heat-conducting plates (110) are stacked, the second heat-conducting surface (112) is supported by the first upper surface section (320) excluding the first projecting section (330), the outer surface of the first projecting section (330) and the inner surface of the lower section of the adjacent upper second side surface section (410) are fitted in surface contact with each other, and the outer surface of the upper section of the second side surface section (410) and the inner surface of the lower section of the adjacent upper first side surface section (310) are fitted in surface contact with each other.

2. The welded plate heat exchanger of claim 1,

the horizontal distance (a) between the outer side surfaces of the first projecting portions (330) is shorter than the horizontal distance (b) between the outer side surfaces of the first side surface portions (310) by 4 times the thickness (t) of the first heat-conducting surface (111), and is the same as the horizontal distance (a) between the inner side surfaces of the second side surface portions (410).

3. The welded plate heat exchanger of claim 2,

the length of the outer side surface of the first bulge (330) in the vertical direction is longer than the vertical distance between the first heat conduction surface (111) and the second heat conduction surface (112); the vertical length of the second side surface part (410) is longer than that of the outer side surface of the first protruding part (330), and the second upper surface part (420) is in contact with the bottom end of the first upper surface part (320) on the adjacent upper side.

4. The welded plate heat exchanger of claim 1, further comprising:

a housing (200) inside which the heat conductive assembly (100) is disposed.