WO2013080573A1

WO2013080573A1 - Method of producing heat exchanger and method of using same

Info

Publication number: WO2013080573A1
Application number: PCT/JP2012/050076
Authority: WO
Inventors: 勝利松永; 久美松矢
Original assignee: 三浦工業株式会社
Priority date: 2011-11-30
Filing date: 2012-01-05
Publication date: 2013-06-06
Also published as: JP5896116B2; JP2013111640A

Abstract

The present invention makes it possible to readily and reliably weld plates together in the production of a heat exchanger in which plates are placed atop each other and welded together, and thereafter a fluid is injected into a predetermined region, which is swelled and deformed to form a flow path. The present invention also makes it possible to readily vacuum from between plates and to inject fluid into a swelled part. In a peripheral welding step, a plurality of plates (2), (3) are superposed and the full periphery is welded (17) at a peripheral end face. In a subsequent pressure reduction step, air remaining in a gap between the plates is suctioned and discharged from openings (11), (12) previously provided to surfaces of the plates. In a subsequent interior welding step, the plates are welded together (6) at the surfaces of the plates in a state where the gap between the plates is kept under reduced pressure, and the plates are divided into a swelled part (4) and a non-swelled part (5). In a subsequent swelling step, fluid is injected into the swelled part (4), which is then swelled and deformed. In the interior welding step, keeping the gap between plates under reduced pressure allows for reliable welding between the plates. Because the openings are provided to the surfaces of the plates, the pressure reduction step and the swelling step are readily carried out.

Description

Method of manufacturing and using heat exchanger

The present invention relates to a heat exchanger in which a plate material is overlapped and welded, and then a fluid is press-fitted into a predetermined region to bulge and deform to form a flow path, and more particularly to a method of manufacturing and using such a heat exchanger. It is. This application claims priority based on Japanese Patent Application No. 2011-262606 for which it applied to Japan on November 30, 2011, and uses the content here.

In Patent Document 1 below, the openings of the hollow containers (2, 3) face each other, and a seal member (6) is interposed between the flanges (2a, 3a) of both containers (2, 3). It is disclosed that the two flanges (2a, 3a) are welded while the flanges (2a, 3a) are brought close to each other by evacuating from the space (A) between (2, 3).

In Patent Document 2 below, the outermost peripheral end surface (13) is welded to the outermost peripheral end surface (13) of the overlapped metal plates (12, 12) while leaving a plurality of openings (14), and the non-expanding is performed. It is disclosed that after welding the protruding portion (15), a fluid is press-fitted from the opening (14) to bulge and form a portion other than the non-bulged portion (15).

JP-A-62-192287 Japanese Patent No. 2506722

In the invention described in Patent Document 1, when welding the flanges (2a, 3a) of the containers (2, 3), vacuuming is performed from the space (A) formed between the containers (2, 3). Is. That is, vacuuming is performed in order to weld the outer peripheral portions of the containers (2, 3), and the gap between the outer peripheral portions between the containers (2, 3) is closed beforehand by welding prior to vacuuming. It is not a thing. If the outer peripheral parts of the container (2, 3) are welded together, further vacuuming is not required.

In such a configuration, the seal member (6) is required between the flanges (2a, 3a) of the container (2, 3), and even if the seal member (6) is disposed, the seal is broken during decompression. And air may flow into the space (A) from the outside. In the first place, it is a premise that a recess for the space (A) is formed in the container (2, 3) in advance, and it is not intended to further exclude air from the gap between the stacked plate members. .

On the other hand, in the invention described in Patent Document 2, the outermost peripheral end surface (13) is welded leaving the opening (14) on the outermost peripheral end surface (13) of the metal plate (12). As described above, since the invention described in Patent Document 1 performs evacuation in order to weld the outer peripheral portions, the metal plates (12) are overlapped as in the invention described in Patent Document 2. In addition, after welding the outermost peripheral end face (13), the metal plates (12) are further excluded while removing air from the gaps between the metal plates (12) and between the metal plates (12) made of flat plates without any recesses. ) The idea of welding each other cannot happen.

Further, in the invention described in Patent Document 2, since the opening (14) is disposed on the end face, it is difficult to press the fluid into the gap between the opening (14) and the metal plate (12). Furthermore, since the welding of the outermost peripheral end surface (13) of the metal plate (12) serves to stop the refrigerant during use, the refrigerant leaks to the outside immediately when the welding of the outermost peripheral end surface (13) is broken. Become.

The problem to be solved by the present invention is to easily and surely weld plate materials together in a heat exchanger that forms a bulged portion after welding by overlapping plate materials. It is another object of the present invention to easily perform evacuation from between plate members and press-fitting fluid into the bulging portion. It is another object of the present invention to provide a heat exchanger that can prevent leakage to the outside and can detect leakage even if the welding of the bulging portion is broken during use of the heat exchanger.

The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is a peripheral welding step in which a plurality of plate materials are overlapped to weld the entire circumference at the outer peripheral end surface, and the plate surface of the plate material. In the pressure reducing step for sucking and discharging the air remaining in the gap between the plate materials to the outside from the mouth provided in advance, and welding the plate materials on the plate surface of the plate material while holding the pressure gap between the plate materials under reduced pressure Then, an internal welding step for dividing the bulging portion into a non-bulging portion and a bulging step for bulging and deforming the fluid by press-fitting a fluid into the bulging portion are sequentially manufactured. Is the method.

According to the first aspect of the present invention, after overlapping the plate materials and welding the entire circumference at the outer peripheral end surface, the bulge is formed by welding to the plate surface in a state where the gap between the plate materials is reduced. Since the gap between the plate materials is closed in advance around the entire outer peripheral end surface, the gap between the plate materials can be reliably decompressed and welded, and the reliability of welding between the plate materials is increased. Moreover, since the evacuation from between the plate materials and the press-fitting of the fluid into the bulging portion are performed from the mouth provided on the plate surface, they can be easily performed.

The invention according to claim 2 uses two plate materials, and forms in advance two or more of the mouth portions in advance on the plate surface of one or both of the plate materials, and each mouth portion is made of the plate material. After forming a hole in the plate surface, the end of the cylindrical nozzle is fixed to the hole, and the plate materials are overlapped so that the nozzle protrudes from the surface opposite to the overlapping surface The peripheral welding step is performed, and in the internal welding step, the bulging portion is formed by meandering, and the plate members are welded together so that the nozzles are disposed at both ends of the bulging portion, and the bulging portion is formed. 2. The bulging portion formed by a region surrounded by welding applied to the plate surface of the plate material is bulged and deformed in an outfeeding step, inside the outer peripheral portion of the plate material. It is a manufacturing method of this heat exchanger.

According to the second aspect of the present invention, since the cylindrical nozzle is provided so as to protrude from the plate surface, evacuation from between the plate materials, press-fitting of fluid into the bulging portion, or the bulging portion during use is performed. The fluid can be easily taken in and out using a nozzle. Moreover, since the bulging part is arranged meandering and the nozzles are arranged at both ends thereof, the heat exchange performance is also good. Furthermore, since the bulging part is formed from the area surrounded by the welding applied to the plate surface of the plate material on the inner side of the outer peripheral part of the plate material, the welding of the bulging part is damaged when the heat exchanger is used. However, leakage of fluid to the outside can be prevented by welding the outermost periphery.

The invention according to claim 3 provides a first nozzle and a second nozzle as the nozzles at both ends of the bulging portion, while providing a third nozzle at the non-bulging portion, A vacuum pump is connected to at least one of the nozzles, and a pressure gauge is provided to at least one of the remaining nozzles. If there are remaining nozzles, the opening is closed. After depressurizing the gap between the plate members by operating the vacuum pump, the vacuum pump is stopped and the pressure change of the pressure gauge is performed to check the vacuum leakage from between the plate members and the welding failure. It is a manufacturing method of the heat exchanger of Claim 2.

According to the third aspect of the present invention, it is possible to easily find a welding defect in the outer peripheral portion.

According to a fourth aspect of the present invention, after the bulging step, a welding failure is confirmed by checking whether or not there is a fluid leak from the bulging portion while maintaining a pressurized state of the gap between the plate members. The method for producing a heat exchanger according to any one of claims 1 to 3.

According to the invention of the fourth aspect, it is possible to easily find a welding defect in the bulging portion.

The invention according to claim 5 is characterized in that in the internal welding step, welding is performed with a width smaller than the plate thickness of the plate material. It is a manufacturing method.

According to the fifth aspect of the present invention, even if the weld of the bulging portion is broken, it can be broken in the direction in which the plate members are separated from each other. Therefore, even if the welding of the bulging portion is broken, the leakage of the fluid in the bulging portion to the outside can be reliably prevented by the welding of the outermost peripheral portion.

The invention according to claim 6 is characterized in that one or both of the two plate materials are subjected to a treatment for increasing the surface roughness on at least the plate surface on the side to be the overlapping surface. The method for producing a heat exchanger according to any one of claims 1 to 5.

According to the sixth aspect of the present invention, it is possible to easily perform evacuation from the gap between the plate materials by performing a process for increasing the surface roughness on the overlapping surface of at least one plate material.

The invention according to claim 7 is the method of manufacturing a heat exchanger according to claim 6, wherein the treatment for increasing the surface roughness is hairline finishing.

According to the seventh aspect of the present invention, it is possible to easily perform evacuation from the gap between the plate materials by using the plate material subjected to the hairline finish.

The invention according to claim 8 is a method of using the heat exchanger manufactured by the manufacturing method according to any one of claims 1 to 7, wherein the non-expanding is performed during use of the heat exchanger. This is a method of using a heat exchanger characterized by monitoring the pressure in the gap between the plate members in the section and detecting the destruction of the internal weld by the pressure increase.

According to the invention described in claim 8, during use of the heat exchanger, it is possible to easily and quickly detect the breakage of the weld at the bulging portion.

Furthermore, the invention according to claim 9 is a method of using the heat exchanger manufactured by the manufacturing method according to any one of claims 1 to 7, wherein the heat exchanger is placed in a water storage tank. A method of using a heat exchanger, comprising: submerging and freezing a part of water in the water storage tank through a refrigerant through the bulging portion; and using cold water in the water storage tank. is there.

According to the invention described in claim 9, it can be used as a heat exchanger of an ice heat storage tank.

According to the present invention, the plate materials can be easily and reliably welded in the heat exchanger that forms the bulged portion after the plate materials are overlapped and welded. In addition, it is possible to easily perform evacuation from between the plate members and press-fitting the fluid into the bulging portion. Furthermore, even when the welding of the bulging portion is broken during use of the heat exchanger, leakage to the outside can be prevented and leakage can be easily detected.

It is the schematic which shows one Example of the heat exchanger of this invention. It is a figure which shows the initial stage of the manufacturing method of the heat exchanger of FIG. 1, and has shown two board | plate materials and the nozzle provided in them. It is a figure which shows the continuation of FIG. 2, and has shown the periphery welding process. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is a figure which shows the continuation of FIG. 3, and has shown the pressure reduction process. It is a figure which shows the continuation of FIG. 5, and has shown the internal welding process. It is a figure which shows the continuation of FIG. 6, and has shown the swelling process. It is a figure which shows a part of cross section of the heat exchanger after implementing the swelling process of FIG. It is a figure which shows the continuation of FIG. 7, and has shown the leak confirmation process by submergence. It is a figure which shows an example of the usage method of the heat exchanger of FIG. 1, and has shown the example utilized as a heat exchanger of an ice thermal storage tank.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing an embodiment of the heat exchanger 1 of the present invention. The heat exchanger 1 of the present embodiment is divided into the bulging portion 4 and the non-bulging portion 5 by overlapping the two

plate members

2 and 3 and performing appropriate welding, and then the bulging portion 4. The fluid is press-fitted and the bulging portion 4 is bulged and deformed. As a result, as shown in FIG. 8, in the bulging portion 4, a gap is formed between the

plate members

2 and 3, and a fluid flow path is formed.

The bulging portion 4 is formed by applying an annular weld 6 in an appropriate shape on the plate surface. That is, the inner region surrounded by the annular weld 6 becomes the bulging portion 4. However, a part of the region in the bulging portion 4 may be further divided into appropriate regions by welding 6 ′. Moreover, you may form the some bulging part 4 in a plate surface.

When the heat exchanger 1 is used, a fluid for heat exchange is passed through the bulging portion 4, and the

mouth portions

7 and 8 are formed in the bulging portion 4. The formation positions of the

mouth portions

7 and 8 are not particularly limited, but are formed at both end portions of the bulging portion 4 in this embodiment.

The shape of the bulging portion 4 is not particularly limited, but in this embodiment, the bulging portion 4 is formed to meander from side to side from the top to the bottom of the plate surface in FIG. More specifically, in FIG. 1, the linear portions along the left-right direction are arranged at equal intervals in the vertical direction, and the linear portions adjacent to each other in the vertical direction are alternately connected by a semicircular shape portion on the left and right sides. Is formed. Then, fluid is taken in and out of the bulging portion 4 when the heat exchanger 1 is used at both ends in the longitudinal direction (upper right and lower right in FIG. 1) of the bulging portion 4 formed in such a meandering manner.

Mouth portions

7 and 8 are provided. The bulging portion 4 may be divided into a plurality (three in the illustrated example) in the width direction as appropriate by welding 6 ′ except for both ends in the longitudinal direction. Note that the end 6 ″ of the weld 6 ′ for this purpose is folded back in a loop shape to ensure the welding strength.

Hereinafter, the manufacturing method of the heat exchanger 1 of a present Example is demonstrated.
FIG. 2 to FIG. 9 are schematic diagrams sequentially illustrating a method for manufacturing the heat exchanger 1 of the present embodiment.

As shown in FIG. 2, two plate materials (for example, a thin flat plate having a thickness of about 1 to 1.5 mm) 2 and 3 having the same shape and size are prepared. Each of the

plate members

2 and 3 is square in this embodiment, but may be rectangular or other shapes. The

plates

2 and 3 are not particularly limited in material, but are made of stainless steel in this embodiment.

Each of the

plate members

2 and 3 may be composed of a plate member having a smooth front surface and back surface. However, as will be described later, one or both of the two

plate members

2 and 3 become at least a superposed surface. You may give the process which increases surface roughness to the board surface of the side. As a process for increasing the surface roughness, there is a hairline finish in which long and narrow polishing eyes such as hair are formed along a predetermined direction. The

plate members

2 and 3 of the present embodiment have the same configuration, and the same hairline finish is applied to the front and back surfaces.

Each of the

plate members

2 and 3 is provided with the

mouth portions

7 and 8 at appropriate positions. In the present embodiment, the

mouth portions

7 and 8 are configured by forming

holes

9 and 10 in the lower plate 2 and providing

cylindrical nozzles

11 and 12 in the

holes

9 and 10. That is, as shown in FIG. 4, the end portion of the nozzle 11 (12) is fitted into the hole 9 (10) and the both are welded (for example, TIG welding) 13. At this time, it is preferable that the nozzle 11 (12) and the welded portion 13 do not protrude to the side of the overlapping surface of the

plate members

2 and 3.

In this embodiment, the first nozzle 11 and the second nozzle 12 are provided in the front and rear corners on the right side of the lower plate 2 as the

mouth portions

7 and 8 provided in the bulging portion 4 in FIG. Further, in the present embodiment, the non-bulged portion 5 is also provided with a mouth portion 14. In the present embodiment, as the mouth portion 14 provided in the non-bulged portion 5, a third nozzle 16 is provided in a hole 15 provided in one of the front and rear corners on the left side of the upper plate 3 in FIG. The position of the third nozzle 16 may be the center in the front-rear direction, but in the present embodiment, the third nozzle 16 is disposed at a position close to the front-rear direction in relation to the welding position in the internal welding process described later.

Thereafter, as shown in FIGS. 3 and 4, the two

plates

2 and 3 are overlapped, and the entire circumference is welded 17 (for example, laser welding) at the outer peripheral end face (peripheral welding process). When the plate materials are overlapped, the

nozzles

11, 12, and 16 are arranged so as to protrude from the surface opposite to the overlap surface. Further, in this embodiment, as shown in FIG. 2, the two

plates

2 and 3 are overlapped so that the directions of the hairlines of the

plates

2 and 3 intersect each other.

Thereafter, as shown in FIG. 5, a vacuum pump 18 is connected to the first nozzle 11 and the second nozzle 12. A pressure gauge 19 and a valve 20 are provided on the piping between the

nozzles

11 and 12 and the vacuum pump 18. On the other hand, the third nozzle 16 is provided with a pressure gauge 21.

In the illustrated example, each of the first nozzle 11 and the second nozzle 12 is provided with a vacuum pump 18, but the piping from each

nozzle

11, 12 is joined and connected to a common vacuum pump 18. May be. Alternatively, in the illustrated example, the vacuum pumps 18 are individually provided for the first nozzle 11 and the second nozzle 12, but the installation of either one of the vacuum pumps 18 is omitted, and the vacuum pump 18 is not installed. The nozzle on the side may be closed (that is, the valve 20 is closed).

In any case, the vacuum pump 18 connected to the first nozzle 11 and / or the second nozzle 12 is operated to suck and discharge the air remaining in the gap between the

plate members

2 and 3 to the outside. The pressure gap is reduced (pressure reduction step). Since the outer peripheral end surface between the

plate members

2 and 3 is closed in advance by the peripheral welding process in advance, evacuation from the gap between the

plate members

2 and 3 can be reliably achieved by the decompression step.

After evacuating to the set time or set pressure, the vacuum pump 18 is stopped and the valves 20 are closed. It can hold | maintain for a predetermined time in this state, and can confirm the vacuum leak from between the board |

plate materials

2 and 3 and a welding defect. If there is a defect in the peripheral welding process and the gap between the

plates

2 and 3 communicates with the outside, the pressure of the pressure gauge 21 of the third nozzle 16 increases after the vacuum pump 18 is stopped. Thereby, a defect in the peripheral welding process can be detected. The pressure of the pressure gauge 21 is recorded by a predetermined recorder (not shown).

Thereafter, with the gap between the

plate members

2 and 3 held under reduced pressure, the

plate members

2 and 3 are welded to each other on the plate surfaces of the

plate members

2 and 3 as shown in FIG. 6 (6, 6 ′) (for example, laser welding). And it divides into the bulging part 4 and the non-bulging part 5 (internal welding process). During this welding, the gap between the

plate members

2 and 3 is maintained under reduced pressure. For this reason, the plate member is also closed by the vacuum pump 18 in the internal welding step in addition to closing the

nozzles

11, 12 and 16 after the pressure reduction step. The evacuation from the gap between two or three may be continued. In any case, by reducing the gap between the

plate members

2 and 3, the

plate members

2 and 3 can be welded in a state where the

plate members

2 and 3 are in close contact with each other, and easy and reliable welding is performed. be able to. Even if the two plates are about to separate due to thermal distortion caused by welding, the reduced pressure state between the

plate members

2 and 3 prevents this, and highly reliable welding can be performed.

Then, as shown in FIG. 7, with the second nozzle 12 closed by the valve 20, an appropriate fluid is press-fitted from the first nozzle 11 into the bulging portion 4 (bulging step). Thereby, as shown in FIG. 8, the bulging portion 4 is bulged and deformed so as to open a gap between the

plate members

2 and 3 in the bulging portion 4. Here, high-pressure nitrogen gas is blown from the cylinder 22 to bulge and deform the bulging portion 4. When the fluid is press-fitted from the first nozzle 11, it is possible to confirm the press-fitting of gas into the entire bulging portion 4 by the pressure gauge 19 provided in the second nozzle 12. The pressure of the pressure gauge 19 is recorded by a predetermined recorder (not shown).

Thereafter, whether or not there is a fluid leak from the bulging portion 4 while maintaining the pressurized state of the gap between the plates 2 and 3 (the pressurized state may be reduced more than the bulging step, but higher than the atmospheric pressure). Thus, it is preferable to check the welding failure (leak confirmation step). The method for confirming the fluid leakage is not particularly limited. For example, as shown in FIG. 9, the heat exchanger 1 is submerged in a state where all the

nozzles

11, 12, 16 are closed, and bubbles from the heat exchanger 1 are The presence or absence of spillage can be confirmed visually.

By the way, in order to easily and quickly evacuate between the

plate members

2 and 3 in the decompression step, one or both of the two

plate members

2 and 3 are at least on the side that becomes the overlapping surface. The plate surface is preferably subjected to a treatment for increasing the surface roughness. Therefore, in this embodiment, as described above, a plate material having a hairline finish (for example, a finish of No. 50 to No. 200, preferably No. 80 to No. 150) is used, and the directions of the hairline lines cross each other. It arrange | positions and the board |

plate materials

2 and 3 are piled up.

However, the treatment such as hairline finishing may be omitted for one plate or may be omitted for the surface opposite to the overlapping surface. May be aligned or crossed in a direction other than a right angle. Furthermore, you may increase the surface roughness of the overlapping surface of the board |

plate materials

2 and 3 by methods other than hairline finishing.

Hereinafter, the usage method of the heat exchanger 1 of a present Example is demonstrated.
The heat exchanger 1 of the present embodiment is used by passing a fluid through the bulging portion 4 using the

nozzles

11 and 12 provided in the bulging portion 4. For example, the fluid is introduced from the first nozzle 11 and the fluid is led out from the second nozzle 12 to the bulging portion 4 of the heat exchanger 1. Thereby, heat exchange between the fluid passing through the bulging portion 4 and the surrounding fluid outside the heat exchanger 1 can be achieved. In addition, although the nozzle 16 of the non-bulging part 5 is obstruct | occluded, you may install a pressure gauge so that it may mention later. The application of the heat exchanger 1 is not particularly limited. For example, as shown in FIG. 10, the heat exchanger 1 can be used as a heat exchanger for an ice heat storage tank.

Specifically, the heat exchanger 1 is submerged in the water tank 23, and the refrigerant from the refrigeration apparatus (condensing unit) 24 is passed through the expansion portion 4 via an expansion valve (not shown). The water in the water storage tank 23 can be used in the cold water use facility 25. In the illustrated example, four heat exchangers 1 are installed in parallel, but it goes without saying that the number and arrangement of the heat exchangers 1 can be changed as appropriate.

In the case of such a configuration, typically, the refrigeration apparatus 24 is operated using nighttime electricity with a low electricity bill, and a low-temperature refrigerant is passed through the heat exchanger 1 to cool or partially cool the water in the water tank 23. Freeze. In the daytime, the cold water in the water storage tank 23 is used in the cold water use facility 25. The cold water use facility 25 is not particularly limited, but is, for example, an air conditioning facility or a food machine. That is, the cold water in the water storage tank 23 can be used for cooling or food cooling.

In addition, since the two plate |

board materials

2 and 3 which comprise the heat exchanger 1 are welded all the circumferences in the outer peripheral end surface, even if the heat exchanger 1 is submerged in the water storage tank 23, between plate |

plate materials

2 and 3 There is no risk of water entering the gap. If there is no welding at the outer peripheral end surface between the

plate materials

2 and 3, water may enter the gap between the

plate materials

2 and 3, and the water may freeze and expand, causing the weld between the

plate materials

2 and 3 to peel off. According to the heat exchanger 1 of this embodiment, since the entire outer peripheral portion is welded, there is no such inconvenience.

By the way, if the pressure in the gap between the

plate members

2 and 3 is monitored in the non-bulged portion 5 while the heat exchanger 1 is in use, the destruction of the internal welding (welding in the internal welding process) 6 is detected by the pressure increase. Can do. Specifically, in the case of the present embodiment, a pressure gauge is provided in the third nozzle 16, and the breakdown of internal welding can be detected by the pressure increase. In particular, in the internal welding process, if welding is performed with a width Y (Y <X) smaller than the plate thickness X of the

plate members

2 and 3, if the internal weld breaks, the

plate members

2 and 3 are damaged in the direction of separating them. It can be easily detected and can be detected by the pressure gauge of the third nozzle 16. Moreover, since the weld 17 is applied to the outermost peripheral portion of the heat exchanger 1, it can be detected before the fluid leaks to the outside of the heat exchanger 1.

The manufacturing method and the usage method of the heat exchanger 1 of the present invention are not limited to the configuration of the above embodiment, and can be changed as appropriate.

In the above embodiment, TIG welding is used for installing the

nozzles

11, 12, 16 on the

plate members

2, 3, and laser welding is used for the peripheral welding process and the internal welding process, but the type of welding can be changed as appropriate. However, laser welding is suitable for internal welding processes because it can be welded deeply with a narrow width.

In the above-described embodiment, it goes without saying that the peripheral welding process, the internal welding process, the bulging process, etc. can be set and operated on a jig suitable for each. For example, a jig for sandwiching the

stacked plate members

2 and 3 from above and below may be used in the peripheral welding process, and it is preferable to sandwich the

plate members

2 and 3 from above and below so that the

plate members

2 and 3 are not distorted by heat. In the bulging process, it is preferable to use a cover-shaped jig for adjusting the deformation of the bulging portion 4 to a predetermined level.

In the above-described embodiment, the

mouth portions

7, 8, and 14 are configured by providing the

nozzles

11, 12, and 16 made of the cylindrical material in the

holes

9, 10, and 15 formed in the

plate materials

2 and 3, but the

mouth portions

7 and 8 14 and

nozzles

11, 12, and 16 can be changed as appropriate. For example, as a cylindrical nozzle, a block-like member having a through hole may be used in addition to a simple pipe. Moreover, you may provide couplings, such as a screw for connection to piping, and a ferrule, in the

opening parts

7, 8, and 14 (

nozzles

11, 12, and 16) suitably.

In the above embodiment, the number and formation positions of the

mouth portions

7, 8, and 14 (

nozzles

11, 12, and 16) can be changed as appropriate. What is necessary is just to form two or more opening parts (nozzles) in the total of the two board |

plate materials

2 and 3 in the board surface of the one or both board |

plate materials

2 and 3. FIG. In the depressurization step, the vacuum pump 18 is connected to at least one of the nozzles, and a pressure gauge is provided to at least one of the remaining nozzles. With the closed, the vacuum pump 18 is operated to depressurize the gap between the plate members. Thereafter, it is possible to check for a vacuum leak from the

plate members

2 and 3 and thus a welding failure by changing the pressure of the pressure gauge while the vacuum pump 18 is stopped. Thereafter, in the internal welding process, each nozzle may be closed and welded to the plate surface while maintaining the reduced pressure state of the gap between the

plate members

2 and 3, or may be welded to the plate surface while operating the vacuum pump 18. Thereafter, in the bulging step, fluid may be pressed into the bulging portion from at least one of the nozzles provided in the bulging portion 4.

In the above embodiment, the installation of the nozzle 16 of the non-bulged portion 5 can be omitted depending on circumstances. Moreover, in the said Example, although nitrogen gas was used at the swelling process, you may use the pressurized gas thru | or liquid other than this.

In the said Example, although the end surfaces were welded in the state piled up so that a mutual end surface might correspond using the board |

plate materials

2 and 3 of the same magnitude | size, using the board | plate material from which a magnitude | size differs, The peripheral welding process may be performed so that the gap between the plate surface of one plate member and the end surface of the other plate member is closed by welding in a state where the end surface of the other plate member is disposed inside the end surface. Further, the plate thicknesses of the

plate members

2 and 3 may be different from each other.

In the above-described embodiment, the two

plate members

2 and 3 are used. However, in some cases, three or more plate members may be used. In this case as well, the gap at the outer peripheral portion between the plate members may be closed by welding, and then the plate surface may be welded to form the bulge portion, and the bulge portion between the plate members may be formed to bulge.

1 Heat exchanger 2 Plate material (lower plate)
3 Plate material (upper plate)
4 Swelling part 5 Non-swelling part 6 Welding (internal welding)
7 Portion 8 Portion 9 Hole 10 Hole 11 First Nozzle 12 Second Nozzle 13 Welding Portion 14 Portion 15 Hole 16 Third Nozzle 17 Welding (Peripheral Welding)
18 Vacuum pump 19 Pressure gauge 20 Valve 21 Pressure gauge 22 Cylinder 23 Water tank 24 Reservoir 24 Refrigeration equipment 25 Cold water use equipment X Plate thickness Y Internal weld width

Claims

A peripheral welding process in which a plurality of plate materials are overlapped to weld the entire circumference at the outer peripheral end surface;
A pressure reducing step for sucking and discharging the air remaining in the gap between the plate members from the mouth portion provided in advance on the plate surface of the plate members;
In a state where the gap between the plate members is held under reduced pressure, an internal welding step of welding the plate members to each other on the plate surface of the plate member to divide into a bulging portion and a non-bulging portion,
And a bulging step of bulging and deforming the fluid by press-fitting a fluid into the bulging portion.
Using two plate materials, in advance, on the plate surface of one or both plate materials, a total of two or more of the mouths,
Each of the mouth portions is formed by forming a hole in the plate surface of the plate member, and then fixing the end portion of the cylindrical nozzle to the hole,
The peripheral welding process is performed by overlapping the plate members so that the nozzle protrudes from the surface opposite to the overlapping surface,
In the internal welding step, the plate members are formed by meandering, and the plate members are welded so that the nozzles are disposed at both ends of the bulge portion,
2. The bulging step includes bulging and deforming the bulging portion including a region surrounded by welding applied to a plate surface of the plate material inside an outer peripheral portion of the plate material. The manufacturing method of the heat exchanger as described in 1 ..
While providing a first nozzle and a second nozzle as the nozzles at both ends of the bulging portion, a third nozzle is provided at the non-bulging portion,
In the depressurization step, a vacuum pump is connected to at least one of the nozzles, and a pressure gauge is provided to at least one of the remaining nozzles. In a closed state, the vacuum pump is operated to depressurize the gap between the plate members, and the vacuum pump is stopped and the pressure change of the pressure gauge is performed to check the vacuum leakage between the plate members and the welding failure. The method for manufacturing a heat exchanger according to claim 2, wherein:
The welding failure is confirmed by the presence or absence of fluid leakage from the bulging portion while maintaining the pressurized state of the gap between the plate members after the bulging step. The manufacturing method of the heat exchanger of Claim 1.
The method for manufacturing a heat exchanger according to any one of claims 1 to 4, wherein, in the internal welding step, welding is performed with a width smaller than a plate thickness of the plate member.
The one or both of the two plate members are subjected to a treatment for increasing the surface roughness on at least the plate surface on the side to be overlapped. The manufacturing method of the heat exchanger of Claim 1.
The method for manufacturing a heat exchanger according to claim 6, wherein the treatment for increasing the surface roughness is hairline finishing.
A method of using the heat exchanger manufactured by the manufacturing method according to any one of claims 1 to 7,
During use of the heat exchanger, the pressure of the gap between the plate members of the non-bulged portion is monitored, and the destruction of the internal weld is detected by the pressure increase.
A method of using the heat exchanger manufactured by the manufacturing method according to any one of claims 1 to 7,
Submerge the heat exchanger in a water tank,
A method for using a heat exchanger, comprising: a step of freezing a part of water in the water storage tank through a refrigerant through the bulging portion; and a step of using cold water in the water storage tank.