JP2006313030A - Plate fin type heat exchanger and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plate fin type heat exchanger having a high sealing property. <P>SOLUTION: This plate fin type heat exchanger 1A composed by alternately stacking a plurality of plates 5 and a plurality of fins 7 is provided with: first side bars 9 installed on side parts of the plates 5 for forming, in cooperation with the plates 5, passages 11 for heat exchange for running a primary gas G1 and a secondary gas G2 therethrough; and second side bars 10 installed in the side parts of the plates 5 and outside the first side bars 9 for forming, in cooperation with the plates 5 and the first wall side bars 9, second spaces 13 independent of the passages 11 for heat exchange and the outside. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plate fin heat exchanger formed by alternately laminating plates and fins and a method for manufacturing the plate fin heat exchanger.

  Conventionally, a plate fin heat exchanger formed by alternately laminating plates and fins is known (Patent Document 1). The plate fin type heat exchanger has an advantage that it can be configured more compactly than other heat exchangers such as a fin tube type heat exchanger.

JP-A-8-200902

However, since the plate fin type heat exchanger has a flow path formed by joining the upper and lower plates and the side plate sandwiched and fixed between the plates, a sealed flow path without leaks. It becomes difficult to form. In particular, when joining by brazing is employed in view of mass productivity, brazing defects may occur unless brazing conditions such as temperature and pressure are appropriately selected.
In addition, when a header for guiding a fluid for heat exchange is attached to the core portion formed by the plate and the fins, if welding is performed on the joint portion between the header and the core portion, the thermal shock due to welding May cause cracks in the brazed portion of the core. If a crack occurs, the flow path cannot be sealed.
For example, when considering application to an intermediate heat exchanger of a high-temperature gas reactor (HTTR), a radioactively polluted primary gas and a secondary gas circulating in the power generation system flow in the intermediate heat exchanger. The gas tightness (air tightness) of the gas flow path is particularly important.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the plate fin type heat exchanger which has high airtightness, and its manufacturing method.

In order to solve the above problems, the plate fin type heat exchanger and the manufacturing method thereof of the present invention employ the following means.
That is, the plate fin type heat exchanger according to the present invention is a plate fin type heat exchanger in which a plurality of plates and fins are alternately stacked, and is installed at a side portion of the plate so that a heat exchange fluid flows. A first wall that forms a flow path with the plate, and a second space that is installed on the side of the plate and outside the first wall and independent of the flow path for heat exchange and the outside. And a second wall formed together with the first wall.

Even if the heat exchange fluid flowing through the heat exchange channel leaks from the first wall, the second space independent from the outside is formed by the second wall, so the leaked heat exchange fluid Stays in the second space and does not leak outside.
Further, even when the external fluid leaks through the second wall, the second wall independent of the heat exchange channel is formed by the second wall, so the leaked external fluid is It stays in the second space and does not leak into the heat exchange channel.

  Furthermore, the plate fin heat exchanger according to the present invention is characterized in that a detection flow path for detecting the fluid flowing into the second space is provided on the second wall.

The heat exchange fluid leaked from the first wall flows into the second space, and then flows into the detection flow path provided on the second wall. The detection flow path is connected to, for example, detection means (a pressure gauge, a gas analyzer, etc.) provided on the downstream side, thereby detecting leakage of the heat exchange fluid.
In addition, it is possible to detect an external fluid flowing into the second space through the second wall.
The second space and the detection flow path are set to a pressure lower than the pressure of the heat exchange flow path and / or the external pressure, and the leakage of the fluid is judged by checking the pressure increase of the second space or the detection flow path. It's also good.

  The plate fin heat exchanger according to the present invention includes a core portion in which a plurality of plates and fins are alternately stacked and fixed by brazing, and is fixed to the upper surface of the core portion by brazing. An upper end plate having a protruding piece whose tip is fixed by welding to a header for guiding a fluid flowing in and out of the core, and a fluid fixed to the lower surface of the core portion by brazing and flowing into and out of the core portion A lower end plate having a protruding piece whose front end is fixed by welding to the header for guiding the core, and a side surface of the core portion, and is fixed to a side edge of the upper end plate and the lower end plate by brazing. And a side plate forming a protruding portion connected to the header.

A protruding portion to which the header is fixed is formed by the protruding pieces and the side plates of the upper and lower end plates. The leading end of the header is fixed to the leading end of the protruding portion by welding. That is, the brazed part that is affected by heat due to welding is limited to the brazed part at the tip of the protrusion. In addition, since the welded portion and the core portion can be separated by the length of the protruding portion, welding is performed at a position away from the core portion where there are many brazed portions for partitioning the flow path. Therefore, the crack of the brazing part by welding can be avoided as much as possible.
In addition, when a plurality of plate fin heat exchangers are connected via a header to achieve a large-scale heat exchanger group such as an intermediate heat exchanger of a high-temperature gas furnace, such a heat exchanger group In order to braze the whole, a vacuum furnace having a size capable of accommodating the entire heat exchanger group is required. However, this is not practical because its size is too large. In this invention, a header can be connected by welding, after producing each plate fin type heat exchanger by brazing by employ | adopting a protrusion part. Therefore, a large-scale heat exchanger group can be configured by preparing a plurality of plate fin heat exchangers and connecting these plate fin heat exchangers via a header by welding. .

  The plate fin heat exchanger according to the present invention corresponds to the plate having the header hole for the header for guiding the heat exchange fluid, and the header hole installed on the plate. A spacer having a header wall provided at a position and a heat exchange channel forming wall that forms a heat exchange channel through which the heat exchange fluid flows; and the heat exchange installed on the plate A fin disposed in the flow path, and the plate, the spacer, and the fin are repeatedly stacked, and the plate and the spacer are stacked to form the header hole portion of the plate. The header wall portion of the spacer is connected, and the header flow path is formed in the stacking direction.

  Since the header flow path is formed by laminating the plate and the spacer, the header can be formed integrally. Therefore, the process of fixing the header to the core portion is unnecessary, and the brazed portion is not cracked by welding.

  Further, in the method for manufacturing a plate fin heat exchanger according to the present invention, a plurality of plates and fins are alternately stacked to form a core portion, and the core portion is flowed into and out of the upper surface of the core portion. An upper end plate having a protruding piece whose tip is fixed to the header for guiding the fluid by welding is installed, and the tip is welded to the lower surface of the core portion and the header for guiding the fluid flowing into and out of the core portion. A lower end plate having a protruding piece to be fixed is installed, and the core portion, the upper end plate and the lower end plate are heated and joined by brazing to cover the side surfaces of the core portion, and the upper end plate and the lower end plate A side plate that forms a protruding portion connected to the header together with each protruding piece is installed on a side edge of the plate, and the brazed core portion, the upper end plate, the lower end plate, and the side plate are heated. By brazing To focus, characterized in that.

A protruding portion to which the header is fixed is formed by the protruding pieces and the side plates of the upper and lower end plates. The leading end of the header is fixed to the leading end of the protruding portion by welding. That is, the brazed part that is affected by heat due to welding is limited to the brazed part at the tip of the protrusion. In addition, since the welded portion and the core portion can be separated by the length of the protruding portion, welding is performed at a position away from the core portion where there are many brazed portions for partitioning the flow path. Therefore, the crack of the brazing part by welding can be avoided as much as possible.
In addition, when a plurality of plate fin heat exchangers are connected via a header to achieve a large-scale heat exchanger group such as an intermediate heat exchanger of a high-temperature gas furnace, such a heat exchanger group In order to braze the whole, a vacuum furnace having a size capable of accommodating the entire heat exchanger group is required. However, this is not practical because its size is too large. In this invention, a header can be connected by welding, after producing each plate fin type heat exchanger by brazing by employ | adopting a protrusion part. Therefore, a large-scale heat exchanger group can be configured by preparing a plurality of plate fin heat exchangers and connecting these plate fin heat exchangers via a header by welding. .

  The plate fin heat exchanger manufacturing method according to the present invention is provided at a position corresponding to the header hole on the plate on which the header hole for the header for guiding the heat exchange fluid is formed. A spacer having a heat exchange flow path forming wall portion that forms a heat exchange flow path through which the header wall portion and the heat exchange fluid flow, and fins disposed in the heat exchange flow path are installed. The plate, the spacer and the fin are repeatedly laminated to form a laminated body, and the laminated body is joined by brazing by heating, and the plate and the spacer are laminated and joined, The header hole portion of the plate and the header wall portion of the spacer are connected, and the header flow path is formed in the stacking direction.

  Since the header flow path is formed by laminating the plate and the spacer, the header can be formed integrally. Therefore, the process of fixing the header to the core portion is not necessary, and a significant cost reduction is realized.

  Since the second wall is provided and the heat exchange channel and the second space independent from the outside are provided, the heat exchange fluid flowing through the heat exchange channel leaks from the first wall. However, the leaked heat exchange fluid is not leaked to the outside. Further, even when an external fluid leaks through the second wall, the leaked external fluid stays in the second space and does not leak to the heat exchange channel. Therefore, it is possible to provide a plate fin type heat exchanger with high airtightness.

  Since the detection flow path for detecting the fluid flowing into the second space is provided, the leakage is detected before leaking to the outside or before the two fluids for heat exchange are mixed. Can do.

  Since the projecting piece and the side plate of the upper and lower end plates form a projecting portion to which the header is fixed, even if the tip of the header is fixed to the tip of the projecting portion by welding, the thermal effect of welding is exerted. The brazing portion can be limited to the brazing portion at the tip of the protrusion. Further, since the welded portion and the core portion can be separated by the length of the protruding portion, welding can be performed at a position away from the core portion where there are many brazed portions for partitioning the flow path. Therefore, the crack of the brazing part by welding can be avoided as much as possible, and a plate fin type heat exchanger with high airtightness can be provided.

  Since the header flow path is formed by laminating the plate having the header hole and the spacer having the header wall, the header can be configured integrally. Therefore, the process of fixing the header to the core portion is unnecessary, and the brazed portion is not cracked by welding. Therefore, it is possible to provide a plate fin type heat exchanger with high airtightness. In addition, since the welding process can be omitted, a significant cost reduction is realized.

Embodiments of a plate fin heat exchanger and a method for manufacturing the same according to the present invention will be described below with reference to the drawings.
[First embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the plate fin heat exchanger 1 </ b> A according to the present embodiment exchanges heat between the primary gas G <b> 1 and the secondary gas G <b> 2 in the core portion 3.
At the four corners of the core portion 3, four tubular intermediate rings 2 are fixed by brazing (or welding or the like). A header (not shown) is fixed to the tip of each intermediate ring 2 by welding. The primary gas G1 or the secondary gas G2 is supplied from this header, flows into the core portion 3 via the intermediate ring 2, and flows out to other headers via another intermediate ring 2 positioned on the diagonal line.
The primary gas G1 and the secondary gas G2 flow in and out from an inlet and an outlet provided on a diagonal line when the core portion 3 is viewed in plan, respectively. It is flowed to become. Specifically, in FIG. 1, the primary gas G <b> 1 flows in from the intermediate ring 2 a on the left front side, flows from the left to the right on the core portion 3, and then flows out from the intermediate ring 2 b on the right rear side. The secondary gas G2 flows in from the middle ring 2c on the right front side, flows from the right to the left on the core portion 3, and then flows out from the middle ring 2d on the back of the left hand.
Instead of the counterflow as shown in FIG. 1, the primary gas G <b> 1 and the secondary gas G <b> 2 may be a cross flow that flows in the vertical direction in the core portion 3.

As shown in FIGS. 2 and 3, the core portion 3 is configured in a state where the plates 5 and the fins 7 are alternately stacked.
The plate 5 is a plate-like body having a substantially hexagonal shape in the present embodiment in plan view.
The fins 7 are fixed by brazing while being sandwiched between the plates 5 positioned above and below. The fin 7 has a shape obtained by bending a plate-like body into a corrugated shape. Thus, the heat transfer area is increased by the corrugated fins, thereby increasing the heat exchange efficiency.
A first side bar (first wall) 9 and a second side bar (second wall) 10 are provided on the side of the plate 5. The first side bar 9 and the second side bar 10 are respectively fixed by brazing while being sandwiched between the upper and lower plates 5.

  The first side bar 9 forms a heat exchange channel 11 through which a primary gas G1 or a secondary gas G2 used as a heat exchange fluid flows together with the plates 5 positioned above and below. The primary gas G1 and the secondary gas G2 flow in the vertical direction on the paper surface of FIGS. In the heat exchange flow path 11 configured in this way, the primary gas G1 and the secondary gas G2 flow alternately in the stacking direction. For example, in FIG. 2, the primary gas G1 flows through the upper and lower heat exchange channels 11a and 11c, and the secondary gas G2 flows through the heat exchange channel 11b sandwiched between the heat exchange channels 11a and 11c. Flowing.

  The first sidebar 9 is arranged as shown in FIGS. 4 and 5, and the flow path, that is, the entrance / exit of the gases G <b> 1 and G <b> 2 is determined by the installation position of the first sidebar 9. For example, FIG. 4 shows the flow path of the primary gas G1, and when the plate 5 is viewed in plan, the primary gas G1 flows in from the lower left inflow port 4a, and the upper right at the diagonal position. It flows out from the outlet 4b. FIG. 5 shows the flow path of the secondary gas G2, and when the plate 5 is viewed in plan, the secondary gas G2 flows in from the lower right inflow port 4c and is located on the diagonally upper left position. Flows out from the outlet 4d.

  As shown in FIGS. 2 to 5, the second side bar 10 is provided on the side of the plate 5 and outside the first side bar 9. The second side bar 10 forms a second space 13 together with the plate 5 and the first side bar 9 positioned above and below.

  As shown in FIG. 1, in the present embodiment, for example, a gas leak detection pipe 15 having a shape in which a circular pipe is halved is provided on the outer side of the second side bar 10. The gas leak detection tube 15 extends in the stacking direction of the plates 5 and is connected to gas leak detection means (not shown). The gas leakage detection pipe 15 forms a detection flow path 16 for detecting gas leakage. For example, a pressure gauge is used as the gas leakage detection means.

  Two gas leak detection pipes 15 are provided on both sides of the core portion 3 (see, for example, FIG. 1), two for primary gas detection and the other two for secondary gas detection. ing. That is, as shown in FIG. 4, the lower left and upper right gas leak detection pipes 15 are for primary gas detection, and as shown in FIG. 5, the lower right and upper left gas leak detection pipes 15 are secondary gas detection. It is for detection.

  The second space 13 formed by the second sidebar 10 is maintained at a pressure lower than the pressure of the heat exchange channel 11 and the pressure outside the heat exchanger 1A. Thereby, even when gas leaks from the first sidebar 9 or when gas leaks from the second sidebar 10, the pressure increase in the second space 13 and thus the detection flow path 16 is detected. By doing so, gas leakage can be detected.

The plate fin heat exchanger 1A having the above configuration is used as follows.
Hereinafter, the case where it is used for an intermediate heat exchanger of a high temperature gas furnace will be described as an example.
The primary gas G1 such as helium gas that has been heated to a high temperature by the high-temperature gas furnace flows from the intermediate ring 2a connected to the header (not shown) into the heat exchange channels 11a and 11c of the core portion 3. On the other hand, the secondary gas G2, such as helium gas, which is relatively low in temperature, flows from the intermediate ring 2c into the heat exchange channel 11b of the core portion 3. In the core part 3, the primary gas G1 and the secondary gas G2 flow through the heat exchange flow paths 11 adjacent to each other in the stacking direction, and sensible heat is transported from the high temperature primary gas G1 to the low temperature secondary gas G2. The heated secondary gas G2 flows out from the intermediate ring 2d, and boiles water in the boiler located downstream via the header to drive the steam turbine. The primary gas G1 cooled in the core part 3 flows out from the intermediate ring 2b, and is led again to the reactor of the high temperature gas furnace through the header.

When the radioactively contaminated primary gas G1 leaks from the first sidebar 9, it is detected as follows.
When the primary gas G1 leaks from the first sidebar 9, the leaked primary gas G1 flows into the second space 13. Since the second space 13 is set to a pressure lower than that of the heat exchange channel 11 through which the primary gas G1 flows, when the primary gas G1 flows into the second space 13, the pressure of the second space 13 and thus the detection channel. 16 pressure increases. Then, the indicated value of the pressure sensor provided on the downstream side of the gas leakage detection pipe 15 for detecting the primary gas is increased, thereby detecting that gas leakage has occurred.
Similarly, when the secondary gas G2 leaks, the pressure increase in the second space 13 and the detection flow path 16 is detected by the pressure sensor to detect the gas leak.
In addition, since the second space 13 is set to a pressure lower than the pressure outside the plate fin heat exchanger 1A, gas leakage from the second side bar 10 into the second space 13 can also be detected. it can.

According to the plate fin heat exchanger 1A according to the present embodiment, the following operational effects can be obtained.
The plate 5, the first side bar 9, and the second side bar 10 positioned above and below form a second space 13 outside the heat exchange channel 11, and a gas leak detection tube 15 is connected to the second space 13. Therefore, it is possible to detect gas leakage before the primary gas G1 and the secondary gas G2 are mixed.
Moreover, since the pressure in the second space 13 is set to a pressure lower than the heat exchange channel 11 and the external pressure, the gas leak can be easily detected by the pressure increase in the second space 13 or the gas leak detection tube. Can do.
Further, even when the radioactively contaminated primary gas G1 leaks from the core 3, the inside of the second space 13 before mixing with the secondary gas G2 or before leaking to the outside of the plate fin heat exchanger 1A. The gas leaked in can be stopped and the sealing performance can be enhanced.

This embodiment can be modified as follows.
As shown in FIG. 6, a gas leak detection sensor 18 may be provided in the second space 13. As the gas leakage detection sensor 18, a change in temperature is detected using a thermography, a thermocouple, an optical fiber, or the like. Also. An AE (acoustic emission) sensor may be used to detect sound generated at the time of leakage. If such a gas leak detection sensor 18 is used, the gas leak detection tube 15 can be omitted.

  In addition, as shown in FIG. 6, instead of the second side bar 9 sandwiched between the plates 5, an outer wall portion 20 provided so as to cover the entire side surface of the core portion 3 may be used. The use of the integrated outer wall 20 as described above has an advantage that the manufacture becomes easy.

  Further, the first side bar 9 and / or the second side bar 10 and the plate 5 may be joined by solid phase joining. If joining by solid phase joining, even if welding is performed in the vicinity, there is no brazing part, and therefore no cracking of the brazing part occurs. Preferably, the second side bar 10 and the plate 5 that are likely to be in the vicinity of the welded portion are solid-phase bonded.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 7 shows a plate fin heat exchanger 1B according to the second embodiment of the present invention.
As in the first embodiment, the core portion 3 has a configuration in which a plurality of plates and fins are alternately stacked and fixed by brazing. In addition, about a side bar, it is good also as using 1st and 2nd side bar 9 and 10 (refer FIG. 2) like 1st embodiment, and the flow path for heat exchange by one side bar. It is good also as forming.

  The plate fin heat exchanger 1 </ b> B has an upper end plate 25 brazed to the upper portion of the core portion 3 and a lower end plate 27 brazed to the lower portion of the core portion 3. These end plates 25 and 27 have the same shape, and as shown in FIG. 8, projecting pieces 25a and 27a projecting diagonally are provided at the four corners. The tips of the protruding pieces 25a, 27a are welded to a header (not shown).

  On the side surface of the core portion 3, a side plate 29 fixed by being brazed to the side edges of the upper end plate 25 and the lower end plate 27 is provided. The side plate 29 forms an intermediate ring (protruding portion) 30 together with the protruding piece 25 a of the upper end plate 25 and the protruding piece 27 a of the lower end plate 27. The side plate 29 is provided not only on the front surface shown in FIG. 7 but also on the right side surface, the left side surface, and the back surface so as to cover all the side surfaces of the core portion 3.

Next, a method for manufacturing the plate fin heat exchanger 1B having the above-described configuration will be described.
First, as shown in FIG. 9, the upper end plate 25 and the lower end plate 27 are arranged above and below the core portion 3 in which the plates, fins, and side bars are stacked. And it brazes by installing in a vacuum heating furnace and heating under vacuum. In brazing, brazing is surely performed by applying a pressing force in the laminating direction of the plates.
After that, the side plates 29 are installed on the four side surfaces of the core portion 3 and brazed again in the vacuum heating furnace.
Thus, the plate fin heat exchanger 1B in which all joints are manufactured by brazing is welded to a header (not shown). This welding is performed at the tip of the intermediate ring 30 and is performed at a position separated from the core portion 3.

According to this embodiment, there exist the following effects.
An intermediate ring 30 to which the header is fixed is formed by the protruding pieces 25a and 27a of the upper and lower end plates 25 and 27 and the side plate 29, and the tip of the header is fixed to the tip of the intermediate ring 30 by welding. Therefore, welding is performed at a position away from the core portion 3 where there are many brazing portions for partitioning the heat exchange flow path. Therefore, the crack of the brazing part by welding can be avoided as much as possible, and a plate fin type heat exchanger with high airtightness can be provided.

  In addition, when a plurality of plate fin heat exchangers are connected via a header to achieve a large-scale heat exchanger group such as an intermediate heat exchanger of a high-temperature gas furnace, such a heat exchanger group In order to braze the whole, a vacuum furnace having a size capable of accommodating the entire heat exchanger group is required. However, this is not practical because its size is too large. In the present embodiment, by adopting the intermediate ring 30 for moving the welding portion away from the core portion 3, the headers can be connected by welding after the respective plate fin heat exchangers 1B are formed by brazing. . Therefore, a large-scale heat exchanger group can be configured by preparing a plurality of plate fin heat exchangers and connecting these plate fin heat exchangers via a header by welding. .

[Third embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS.
FIG. 10 shows a plate fin heat exchanger 1C according to the present embodiment.
The plate fin heat exchanger 1 </ b> C according to this embodiment is different from the other embodiments in that the header 32 is integrated. That is, headers 32 are provided at the four opposing corners of the core portion 3 of the plate fin heat exchanger 1C. The header flow path 32 a formed in the header 32 is formed in the stacking direction of the core portion 3.
The core part 3 is configured by laminating plates, fins, and side bars.

FIG. 11 shows each component of the plate fin heat exchanger 1C of FIG. In addition, illustration is abbreviate | omitted about the fin installed in plate shape.
FIG. 11A shows the plate 33. As for the plate 33, a plate exists in the core part 3 where the fins are arranged, and header holes 40 are provided at four corners.
FIG. 11B shows the first spacer 34 that forms the flow path of the primary gas G1. In the first spacer 34, the primary gas G <b> 1 flows diagonally by the heat exchange flow path forming wall 34 a. Further, a header wall 34b is provided at a position corresponding to the header hole 40. In addition, the core part 3 in which a fin is installed is hollow.
FIG. 11C shows a second spacer 36 that forms a flow path for the secondary gas G2. The second spacer 36 is configured such that the secondary gas G2 flows in a diagonal direction intersecting the primary gas G1 by the heat exchange flow path forming wall portion 36a. A header wall 36b is provided at a position corresponding to the header hole 40. In addition, the core part 3 in which a fin is installed is hollow.
FIG. 11D shows end plates 38 arranged above and below the core portion 3. The end plate 38 is formed with a header hole 38a only at a position corresponding to the header to be connected.

The plate 33, the first spacer 34, the second spacer 36, and the end plate 38 are stacked as follows.
In the lowest position, an end plate 38 is installed as a bottom plate. On top of this, the plate 33, the first spacer 34 and the fin, the plate 33, the second spacer and the fin are installed in this order. Further, similarly, the plate 33, the first spacer 34 and the fin, the plate 33, the second spacer and the fin are installed in this order. This is repeated a plurality of times, and after laminating to a desired layer, the end plate 38 is installed as a top plate at the uppermost position.
The direction of the end plate 38 is changed between the bottom plate and the top plate. That is, when the header hole 38a is positioned on the right side of the bottom plate as shown in FIG. 11D, the top plate is reversed so that the header hole 38a is positioned on the left side of the drawing. By arranging the bottom plate and the top plate in this way, as shown in FIG. 10, the primary gas G1 flowing in from the lower side of the left front header 32 flows upward from the header 32 positioned on the diagonal right side. The secondary gas G2 flowing in from the lower side of the right front header 32 flows upward from the header 32 located at the back of the left hand on the diagonal line.
After laminating the plate 33, the first spacer 34, the second spacer 36, and the end plate 38 in this way, it is placed in a vacuum heating furnace and brazed while being pressurized in the laminating direction. Thereby, the plate fin type heat exchanger 1C provided integrally with the header 32 is obtained.

  When connecting a plurality of plate fin heat exchangers 1C obtained in this way, welding is performed after piping is installed above (or below) the header 32. In this case, the end plate 38 is welded. However, if the thickness of the end plate is set to a thickness that does not cause the heat effect of the welding (for example, 3 cm or more), the brazed portion is cracked. Will not enter.

According to this embodiment, there exist the following effects.
Since the header 32 is integrally formed by laminating the plate 33, the first spacer 34, and the second spacer 36, a process of fixing the header to the core portion 3 later becomes unnecessary. Thereby, a significant cost reduction is realized.

  In this embodiment, the heat exchange flow path forming walls 34a and 36a of the first spacer 34 and the second spacer 36 are configured by one wall, but as shown in the first embodiment, the sidebar May be configured as a double wall portion.

Further, the present embodiment may be modified as shown in FIG.
In the embodiment shown in FIG. 10, all the headers 32 of the header 32 through which the primary gas G1 flows and the header 32 through which the secondary gas G2 flows are integrated with the core part 3, but only the secondary gas G2 is used in this embodiment. The header 32 integrated with the core part 3 as shown is used, and for the primary gas G1, the intermediate ring 40 brazed to the side surface of the core part 3 as shown in the first embodiment is used. It is good as well. That is, the intermediate ring 40 is fixed by the second brazing after the plate 33, the spacers 34 and 36 and the end plate 38 are laminated and brazed. The intermediate ring 40 may be brazed together with the plate 33, the spacers 34 and 36 and the end plate 38 at the same time.

According to such a configuration, even if the second brazing for joining the intermediate ring 40 fails and gas leaks from the joint between the intermediate ring 40 and the core part 3, the primary gas G1 and the secondary gas There is an advantage that the gas G2 is not mixed.
That is, as shown in FIG. 13, the radioactively contaminated primary gas G <b> 1 flows into the core portion 3 through the intermediate ring 40. Even if this primary gas G1 leaks from the connection portion between the intermediate ring 40 and the core portion 3, it only leaks to the outside (see arrow F in FIG. 13) and is mixed with the secondary gas G2 flowing through the header 32. Never do. Therefore, it is possible to prevent the secondary gas G2 from being radioactively contaminated. In this case, it is more preferable that the external atmosphere is the primary gas G1, and the primary gas G1 is allowed to leak.

  Furthermore, the intermediate ring 40 may be removed from the plate fin heat exchanger 1D shown in FIG. In this case, the primary gas G1 is guided to the outside (surrounding) of the plate fin heat exchanger 1D, and the primary gas G1 outside is directly guided to the core portion 3. With such a configuration, the step of brazing the intermediate ring 40 can be omitted, so that the cost can be reduced.

  In addition, although each embodiment mentioned above demonstrated as an example the intermediate heat exchanger of a high temperature gas furnace, this invention is not limited to this use, You may use for the heat exchanger of another use. In particular, it is suitable for use in heat exchangers that require hermeticity.

It is the perspective view which showed the plate fin type heat exchanger concerning 1st embodiment of this invention. It is a fragmentary sectional view of the core part in the cutting line II of FIG. It is a fragmentary sectional view of the core part in the cutting line III of FIG. It is the top view which showed the flow path and second space through which primary gas flows. It is the top view which showed the flow path and secondary space through which secondary gas flows. It is a partial sectional view of a core part, showing a modification of the first embodiment. It is the perspective view which showed the plate fin type heat exchanger concerning 2nd embodiment of this invention. It is the top view which showed the upper and lower end plates of the plate fin type heat exchanger of FIG. It is the plate fin type heat exchanger of FIG. 7, Comprising: It is the perspective view which showed the state before joining a side plate. It is the perspective view which showed the plate fin type heat exchanger concerning 3rd embodiment of this invention. Each component of plate fin type heat exchanger 1C of Drawing 10 is shown, (a) is a top view of a plate, (b) is a top view of the 1st spacer, (c) is a top view of the 2nd spacer. (D) is a top view of an end plate. It is the perspective view which showed the modification of FIG. It is the top view which showed the flow of the primary gas of FIG.

Explanation of symbols

1A, 1B, 1C Plate fin type heat exchanger 3 Core portion 5 Plate 7 Fin 9 First side bar (first wall)
10 Second sidebar (second wall)
11 Heat exchange flow path 13 Second space 16 Detection flow path 25 Top plate 27 Bottom plate 29 Side plate 32 Header 34 First spacer 36 Second spacer G1 Primary gas G2 Secondary gas

Claims (6)

In the plate fin type heat exchanger in which a plurality of plates and fins are alternately stacked,
A first wall that is installed on the side of the plate and forms a heat exchange channel with the plate through which a heat exchange fluid flows;
A second wall that is installed on the side of the plate and outside the first wall, and forms a second space independent of the heat exchange channel and the outside together with the plate and the first wall;
The plate fin type heat exchanger characterized by the above-mentioned. The plate fin type heat exchanger according to claim 1, wherein a flow path for detection for detecting fluid flowing into the second space is provided on the second wall. A core portion in which a plurality of plates and fins are alternately laminated and fixed by brazing;
An upper end plate having a protruding piece fixed to the upper surface of the core portion by brazing and having a tip fixed by welding to a header that guides fluid flowing into and out of the core portion;
A lower end plate having a protruding piece that is fixed to the lower surface of the core portion by brazing and whose tip is fixed by welding to a header that guides fluid flowing into and out of the core portion;
A side plate that covers the side surface of the core portion, is fixed to the side edges of the upper end plate and the lower end plate by brazing, and forms a protruding portion that is connected to the header together with the protruding pieces,
A plate fin heat exchanger. A plate having a header hole for the header for guiding the heat exchange fluid;
A header wall portion provided on the plate and provided at a position corresponding to the header hole portion, and a heat exchange flow path forming wall portion that forms a heat exchange flow path through which the heat exchange fluid flows. A provided spacer;
A fin disposed on the plate and disposed in the heat exchange channel,
The plate, the spacer and the fin are formed by repeatedly laminating,
By stacking the plate and the spacer, the header hole portion of the plate and the header wall portion of the spacer are connected, and the header flow path is formed in the stacking direction. Plate fin type heat exchanger. A plurality of plates and fins are alternately stacked to form a core part,
On the upper surface of the core portion, an upper end plate having a protruding piece whose tip is fixed by welding to a header that guides fluid flowing into and out of the core portion,
A lower end plate having a projecting piece whose tip is fixed by welding to the lower surface of the core portion and a header that guides fluid flowing into and out of the core portion;
The core part, the upper end plate and the lower end plate are heated and joined by brazing,
While covering the side surface of the core portion, on the side edges of the upper end plate and the lower end plate, a side plate that forms a protruding portion connected to the header together with the protruding pieces is installed.
The brazed core part, the upper end plate and the lower end plate, and the side plate are heated and joined by brazing,
A method for manufacturing a plate fin heat exchanger. On the plate in which the header hole for the header for guiding the heat exchange fluid is formed,
A spacer provided with a header wall provided at a position corresponding to the header hole and a heat exchange channel forming wall that forms a heat exchange channel through which the heat exchange fluid flows;
A fin disposed in the heat exchange channel,
These plates, the spacers and the fins are repeatedly laminated to form a laminate,
The laminated body is joined by brazing by heating, and the plate and the spacer are laminated and joined to connect the header hole of the plate and the header wall of the spacer. The manufacturing method of the plate fin type heat exchanger characterized by forming the flow path for headers in the lamination direction.

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