JP2001248980A - Multitubular heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multitubular heat exchanger capable of making an amount of a high temperature gas flowing to many heat transfer tubes substantially uniform even by incorporating the heat transfer tubes and having a high cooling performance. SOLUTION: The multitubular heat exchanger 21 comprises a substantially cylindrical shell body 22, a plurality of heat transfer tubes 23 disposed in the body 22, and a fixed tube plate 24 disposed at least near one end of the body 22. In this case, the vicinities of the ends of the tubes 23 are fixed to the plate 24. A straightening chamber 27A is formed near the tube 14. The chamber 27A is formed in a substantially-tapered section. One or more fluid straightening members 25 are disposed at an inner side of the chamber 27A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-tube heat exchanger for exchanging heat by passing high-speed high-temperature gas (gas) through a heat transfer tube and cooling water (liquid) through a body. In particular, the present invention relates to a multi-tube heat exchanger in which a plurality of heat transfer tubes are arranged, and is suitable for an exhaust cooler that cools exhaust gas of an internal combustion engine with cooling water (a high heat exchange capability is required). Invention.

[0002]

2. Description of the Related Art Conventionally, as a multi-tube heat exchanger, FIG.
Those shown in FIG. 2 are used. The multi-tubular heat exchanger 11 includes a substantially cylindrical body portion 12 and a plurality of heat transfer tubes 13 disposed inside the body portion 12, and fixed tube plates are provided near both ends of the body portion 12, respectively. 14, 14 are arranged,
The configuration is such that the vicinity of both ends of the heat transfer tube 13 is fixed to the fixed tube plate 14. At both ends of the body 12, an inlet nozzle 1 for cooling water is provided.
5 and the outlet nozzle 16 are formed so as to be used in countercurrent / cocurrent (countercurrent in the illustrated example). And fixed tube sheet 1
4, a gas introduction rectification chamber 17A and a gas derivation rectification chamber 17B each having a substantially tapered cross section are formed, and a gas introduction pipe 18A is provided near the end of the gas introduction rectification chamber 17A.
A gas outlet pipe 18B is provided near the end of the gas outlet straightening chamber 17B.
Are arranged respectively. In addition, the gas introduction pipe 18A
And a flange portion 19 near the end of the gas outlet pipe 18B.
Are formed respectively.

[0003]

The multi-tubular heat exchanger 1
No. 1 has a large heat transfer area, so that it is easy to obtain a large heat exchange capacity. However, in order to increase the heat transfer area, the heat transfer tubes 13
If the number is increased, the area of the fixed tube sheet 14 increases, and the difference from the cross-sectional area of the gas introduction tube 18A increases. At this time, even if the number of the heat transfer tubes 13 is increased, increasing the distance between the fixed tube sheet 14 and the end of the gas introduction tube 18A is difficult when the multi-tube heat exchanger is enlarged and installed. It is not desirable because it requires a large space. Therefore, the fixed tube sheet 14
It is desirable to make the distance between the gas and the end of the gas introduction pipe 18A as short as possible.

However, in a multi-tube heat exchanger having a large number of heat transfer tubes 13, when the distance between the fixed tube plate 14 and the end of the gas introduction tube 18A is shortened, a sudden change in the cross-sectional area in the gas flow path occurs. Occurs. Since the high-temperature gas flowing into the gas introduction rectifying chamber 17A is very high-speed, it is not sufficiently dispersed until reaching the fixed tube plate 14, and the high-temperature gas does not easily flow into the heat transfer tubes 13 arranged outside. Therefore, in a heat exchanger containing a large number of heat transfer tubes, the amount of gas flowing in varies between the heat transfer tubes arranged near the center and the heat transfer tubes arranged at the outermost side, resulting in poor cooling efficiency. Was. At the same time, there is a problem that the carbon component in the exhaust gas is liable to deposit on the inner wall of the heat transfer tube that is disposed outside where the flow rate of the flowing gas is low. The deposition of the carbon component further reduces the cooling effect and increases the airflow resistance.

SUMMARY OF THE INVENTION In view of the above, the present invention provides a multi-tube type having a high cooling performance, in which a large amount of high-temperature gas flowing into each heat transfer tube can be made substantially uniform while a large number of heat transfer tubes are incorporated. It is intended to provide a heat exchanger.

[0006]

The present invention solves the above-mentioned problems by the following constitutions.

[0007] A substantially tubular body and a plurality of heat transfer tubes arranged inside the body are provided. A fixed tube plate is provided near at least one end of the body. In a multi-tube heat exchanger configured to be fixed to a fixed tube sheet, a rectification chamber is formed near the fixed tube sheet, and the rectification chamber is formed to have a substantially tapered cross section. A fluid distribution member is provided.

[0008] The above configuration is particularly effective when used in a multi-tube heat exchanger in which the outer peripheral wall of the rectifying chamber has an angle of 25 ° or more with respect to the center axis of the fixed tube sheet. Yes,
preferable.

Further, the fluid distribution member includes at least a pair of distribution plate portions, and the distribution plate portion is disposed at an angle smaller than the outer peripheral wall of the flow regulating chamber with respect to the central axis. This is preferable because the flow of the fluid into each heat transfer tube becomes more uniform.

Further, the heat transfer tube is formed in a substantially flat cross-sectional shape, is provided with heat transfer fins therein, and is disposed so as to be substantially parallel to each other. It is preferable that each of the plate portions is arranged so that the longitudinal portion of the plate portion is substantially parallel to the longitudinal direction of the heat transfer tube end face, whereby a larger heat exchange can be obtained.

Further, the flow dividing plate portion may be formed integrally by connecting the adjacent ends with a plate-like connecting portion, and the connecting portion may be arranged substantially parallel to the end surface of the heat transfer tube. This is preferable because the manufacturing cost is low.

[0012] In addition, in the case of the above-mentioned configuration, it is preferable that the connection portion is formed with a hole, since the fluid flows into each heat transfer tube more uniformly.

Further, it is preferable that the hole is formed in a substantially flat circular shape and the longitudinal portion is formed substantially parallel to the longitudinal direction of the end surface of the heat transfer tube, so that a larger heat exchange can be obtained.

Further, it is preferable that a plurality of holes be formed, since the flow of fluid into each heat transfer tube becomes more uniform.

In the above configuration, if the body is formed to have a substantially rectangular cross section and the width of the heat transfer tubes is all equal, the same heat transfer tubes can be used, and the number of parts can be reduced. This is preferable because it can be reduced.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

(1) A multi-tube heat exchanger (hereinafter simply referred to as a “heat exchanger”) according to an embodiment of the present invention is shown in FIGS.
Shown in

The heat exchanger 21 has a tubular body 22 having a substantially rectangular cross section and a plurality of heat transfer tubes 2 arranged inside the body 22.
3 and fixed tube sheets 24, 24 are disposed near both ends of the body 22, respectively. In each fixed tube sheet 24,
A hole 24a through which the heat transfer tube 23 is inserted is formed.
In this configuration, the vicinity of the end of the heat transfer tube 23 is fixed to the fixed tube plate 24. Near the both ends of the body 22, an inlet nozzle 1 for cooling water is provided.
The outlet 6 and the outlet nozzle 18 are formed so that they can be used in countercurrent / cocurrent (in the illustrated example, cocurrent). And fixed tube sheet 2
4, a gas introduction rectification chamber 27A and a gas derivation rectification chamber 27B each having a substantially tapered cross section are formed, and a gas introduction pipe 18A is provided near an end of the gas introduction rectification chamber 27A.
A gas outlet pipe 18B is provided near the end of the gas outlet rectifying chamber 27B.
Are the arrangements respectively arranged. The fluid flow dividing member 25 is disposed inside the gas introduction rectifying chamber 27A. The gas introduction pipe 18A and the gas discharge pipe 18
A flange 19 is formed at the end of B as in the prior art.

The heat transfer tube 23 is composed of a heat transfer tube main body 26 having a substantially flat circular cross section and a heat transfer fin 30, and the heat transfer fin 30 is disposed inside the heat transfer tube main body 26. As shown in FIG. 4, the heat transfer fins 30 are formed by forming a plate-like object into a substantially corrugated shape.
It is a configuration brazed to the inner wall.

Each of the gas introduction and rectification chamber 27A and the gas derivation and rectification chamber 27B has a configuration in which the outer peripheral wall has an angle of 25 ° or more with respect to the center axis of the fixed tube sheet 24. As shown in FIGS. 3 and 5, the fluid distribution member 25 has a substantially rectangular plate shape, and a pair of distribution plate portions 25 arranged such that the longitudinal portions thereof are substantially parallel to the longitudinal direction of the end surface of the heat transfer tube 23.
a, 25a and a plate-like connecting portion 25b for connecting between adjacent ends of the flow dividing plate portions 25a, 25a. The ends (upper and lower ends in FIG. 5) of the connecting portion 25b are fixed to the rectifying chamber 27A. The flow dividing plate 25a is configured to have a smaller angle with respect to the central axis than the outer peripheral wall of the gas introduction rectification chamber 27A. In the connecting portion 25b, three holes 25c having a substantially flat circular shape and a longitudinal portion formed substantially in parallel with the longitudinal direction on the end surface of the heat transfer tube 23 are arranged substantially parallel to each other. The configuration is such that high-temperature gas flows between the rectification chamber 27A and the flow dividing plate 25a and from each hole 25c.

The thicknesses of the heat transfer tube main body 26, the heat transfer fins 30, and the fixed tube plate 24 vary depending on the material and the service life. For example, in the case of stainless steel, the first member is 0.1 mm.
1 to 1.0 mm (preferably 0.3 to 0.8 mm), the former second: 0.01 to 0.8 mm (preferably 0.05 to 0.8 mm)
0.5 mm), the latter: 0.5-3 mm (preferably 1-2)
mm). The heat transfer tube main body 26 has a length of 15 to 4
5 mm (preferably 20 to 40 mm), 3.5 to 5 mm (preferably 4 to 4.5 mm), and the pitch of the heat transfer fins 30 is 2 to 5.5 mm (preferably 2.5 to 5 mm). .

With the above structure, the high-temperature gas discharged from the gas introduction pipe 18A is dispersed in the gas introduction rectification chamber 27A by the fluid distribution member 25, so that the heat transfer pipe 23 disposed outside is also dispersed. The high-temperature gas flows easily, and the amount of the high-temperature gas flowing into each heat transfer tube 23 can be made substantially uniform.

(2) Next, a method of manufacturing the heat exchanger 21 of the present embodiment will be described.

First, the heat transfer fins 30 are formed by a conventional method such as drawing. Then, after a wax material is attached to each top of the heat transfer fins 30 and inserted into the heat transfer tube main body 26, the heat transfer tube main body 26 is compression-molded so that the heat transfer fins 30 are
6 and passed through a heating furnace for brazing, and each heat transfer tube 23
To form

Next, each heat transfer tube 23 is inserted and joined to a fixing hole 24a formed in the fixed tube plate 24. In this case, TIG (Tungsten Insert Gas) welding or laser welding is desirable, in which the oxidation of the brazing material is small and the joining strength is easy to secure, but other arc welding, resistance welding, and heat-resistant adhesive Bonding may be used.

Next, after a brazing material is applied to the outer periphery of the fixed tube sheet 24, the brazing material is partially inserted into the rectangular cylinder forming the body to form rectification chambers (gas introduction rectification chamber 27A and gas outlet rectification chamber 27B). The gas inlet pipe 18A and the gas outlet pipe 18B, each of which is integrally formed with the flange portion 19, are inserted into the small diameter side of the pyramid cylindrical body to be inserted into the brazing heating furnace. . In addition, the fluid distribution member 25 is previously joined in the gas introduction rectification chamber 27A.

At this time, when the material of the heat exchanger is stainless steel, for example, copper wax or nickel copper wax is usually used.

In the above-described embodiment, the fluid dividing member 25 has a structure in which the hole 25c is formed in the connecting portion 25b, but is not limited to this, and a structure in which the hole 25c is not arranged. Can also be used. Also,
Although the number of the holes 25c is also three in the above embodiment,
Singularity is also possible. However, from the viewpoint of the dispersibility of the high-temperature gas in each heat transfer tube 23, it is preferable that the holes 25c be formed, and it is more preferable that a plurality of holes 25c be formed. In order to improve the dispersibility of the high-temperature gas, the hole 25c is preferably formed near the center of the connecting portion 25b.

In the above embodiment, the fluid diverting member 25 has a substantially flat circular hole 25c whose longitudinal portion is formed substantially parallel to the longitudinal direction of the end surface of the heat transfer tube 23. However, the present invention is not limited to this. For example, the hole may be formed in a substantially flat circular shape whose longitudinal portion is substantially perpendicular to the longitudinal direction of the heat transfer tube 23 end face, or in a substantially circular shape. However, it is preferable that the shape of the hole is a substantially flat circular shape in which the longitudinal portion is formed substantially parallel to the longitudinal direction on the end surface of the heat transfer tube 23 because a high heat exchange ability can be obtained.

Further, in the above embodiment, the fluid dividing member 25 has the substantially rectangular connecting portion 25b having both ends in the longitudinal direction fixed to the gas introduction rectifying chamber 27A, and having the dividing plates 25a at both ends in the short direction. It is a configuration that is formed, but the configuration of the fluid distribution member is not limited to this, it is also possible to fix both ends in the short direction to the gas introduction rectification chamber and form inclined parts at both ends in the long direction It is.

Further, in the above embodiment, the fluid dividing member 25 is arranged such that the dividing plate portion 25a has a smaller angle with respect to the central axis than the central axis of the outer peripheral wall of the gas introduction rectifying chamber 27A. Have been. For example, previous arrival 7
When the angle is 0 °, the rear arrival is 60 °. However, the present invention is not limited to this.
7A is arranged substantially parallel to the outer peripheral wall,
The gas introduction rectifying chamber 27A may be arranged so as to have a larger angle with respect to the central axis than the central axis of the outer peripheral wall of the gas introduction rectifying chamber 27A. However, in consideration of the amount of high-temperature gas flowing into the heat transfer tube 23 near the outside, the angle of the flow dividing plate portion 25a is preferably smaller than the angle with respect to the central axis of the gas introduction rectifying chamber 27A. . However, for example, it is also possible to form a hole in the flow dividing plate portion, if such a configuration, the flow rate of high-temperature gas into the heat transfer tube near the outside increases, the installation angle of the flow dividing plate portion, It is not limited to the above.

In the above-described embodiment, a heat transfer tube 23 in which a separate substantially wave-shaped heat transfer fin 26 is disposed inside a heat transfer tube main body 26 formed of a cylindrical object having a substantially flat circular cross section is used. However, the present invention is not limited to this, and it is also possible to use one in which the heat transfer tube main body and the heat transfer fin are integrally formed. Further, the shape of the heat transfer tube main body 26 is not limited to a substantially flat circular cross section.
Those having a substantially flat rectangular cross section can also be used.

In the above embodiment, the body 22 has a cylindrical shape with a substantially rectangular cross section.
Of course, the shape of 2 is not limited to this, and any cylindrical shape such as a substantially circular cross-section and a substantially elliptical cross-section can be used. However, if the body 22 is formed to have a substantially rectangular cross section, the same heat transfer tube can be used,
This is preferable because the number of parts can be reduced.

(3) Next, a heat exchanger 31 according to another embodiment of the present invention will be described. The heat exchanger 31 has the same configuration as the above-described heat exchanger 21 except for the shape of the fluid distribution member, and a description thereof will be omitted.

The fluid distribution member 3 used in the heat exchanger 31
5 includes two flow dividing plate portions 35A as shown in FIGS.
It consists of The split plate portions 35A, 35A
In the gas introduction rectification chamber 27A independently, the longitudinal portion of the flow dividing plate portion 35A is formed in the longitudinal direction of the end surface of the heat transfer tube 23, that is, in FIG. They are arranged so as to be substantially parallel. As shown in FIG. 6, the flow dividing plate portion 35A has a smaller angle with respect to the central axis than the outer peripheral wall of the gas introduction rectification chamber 27A, similarly to the flow dividing plate portion 25a in the above-described embodiment. is there.

In the above-described embodiment, the flow dividing plate 35A has a substantially rectangular plate shape, and is arranged such that the longitudinal portion of the flow dividing plate 35A is substantially parallel to the longitudinal direction in the cross section of the heat transfer tube 23. However, the present invention is not limited to this example. However, it is preferable to dispose the longitudinal portion of the flow dividing plate portion 35A so as to be substantially parallel to the longitudinal direction in the cross section of the heat transfer tube 23 because high heat exchange ability can be obtained.

In the above embodiment, the fluid dividing member 3
5, two split plate portions 35A are used,
However, the present invention is not limited to this. For example, a conical or pyramid-shaped cylindrical body with a cut-out head can be used. Further, the number of the flow dividing plate portions 35 is also two in the above embodiment, but is not limited thereto.
It is possible to arrange one or a plurality. However, from the viewpoint of the dispersibility of the high-temperature gas, it is preferable to arrange a plurality of them.

Further, in the above embodiment, the flow dividing plate portion 35A is arranged so as to have an angle smaller than the central axis of the outer peripheral wall of the gas introduction rectifying chamber 27A with respect to the central axis. The gas introduction rectification chamber 27A is disposed so as to be substantially parallel to the outer peripheral wall of the gas introduction rectification chamber 27A, and is larger than the angle with respect to the central axis of the outer peripheral wall of the gas introduction rectification chamber 27A. It is also possible to arrange so as to have an angle. However, considering the amount of high-temperature gas flowing into the heat transfer tube 23 near the outside, the flow dividing plate portion 35A may have a smaller angle with respect to the central axis than the central axis of the gas introduction rectification chamber 27A. preferable. However, for example, it is also possible to dispose a fluid distribution member having a hole formed therein, and if such a configuration is adopted, the amount of high-temperature gas flowing into the heat transfer tube near the outside increases, so that the installation angle of the distribution plate portion is increased. Is not limited to the above.

In this fluid distribution member 35, the two flow dividing plates 35A are individually disposed. However, as in the above-described embodiment, the fluid distribution member 25a is connected to the connecting portion 25b.
The fluid diverting member 25 integrally formed by being connected by
This is preferable from the viewpoint of manufacturing cost.

In the heat exchanger having the above-described structure, the center of the fixed tube plate and the center of the end of the gas introduction tube are formed to be substantially coaxial with each other. However, the present invention is not limited to this. The present invention is also applicable to a configuration in which the center of the end of the introduction tube is formed eccentrically from the center of the fixed tube sheet.

Further, in the above embodiment, as a heat exchanger to which the structure of the present invention is applied, a multi-tube heat exchange structure in which a heat transfer tube is formed to have a substantially flat circular cross section and heat transfer fins are arranged inside. Although the heat exchanger is exemplified, the applicable multi-tube heat exchanger is not limited to this, and for example, a conventional example (FIG. 1)
As in 2), the heat transfer tube can be applied to a tube having a substantially cylindrical shape, etc. Further, a rectifying chamber is formed only at one end and is divided by a partition plate so that the inlet and outlet of the hot gas are on the same side. The present invention is applicable to any type of multi-tube heat exchanger such as an exchanger.

In the above embodiment, the high-temperature gas is used as the fluid to be cooled, and the cooling water is used as the cooling fluid. However, the fluid to be cooled and the cooling fluid are not limited to those described above. Of course, it is possible to use the cooling fluid and the cooling fluid when both are gas.

[0043]

The heat exchanger according to the present invention has a structure in which a fluid diverting member is disposed inside the rectifying chamber, and the fluid diverting member disperses the high-temperature gas flowing into the rectifying chamber, so that it is fixed. Even in a heat exchanger where the distance between the fixed tube sheet and the hot gas inlet tube is shorter than the distance from the center of the tube sheet to the outermost heat transfer tube, the amount of gas flowing into each heat transfer tube Can be kept substantially uniform, and good cooling efficiency can be obtained.

Further, the fluid distribution member has at least a pair of distribution plate portions, and the distribution plate portion is arranged at an angle smaller than the outer peripheral wall of the flow regulating chamber with respect to the central axis. This is preferable because the flow of the fluid into each heat transfer tube becomes more uniform.

Further, the heat transfer tube is formed to have a substantially flat cross section, is provided with heat transfer fins therein, and is disposed so as to be substantially parallel to each other. It is preferable that each of the plate portions is arranged so that the longitudinal portion of the plate portion is substantially parallel to the longitudinal direction of the heat transfer tube end face, whereby a larger heat exchange can be obtained.

Furthermore, the flow dividing plate portion may be formed integrally by connecting the adjacent ends with a plate-shaped connecting portion, and the connecting portion may be arranged substantially parallel to the end surface of the heat transfer tube. This is preferable because the manufacturing cost is low.

In addition, in the case of the above configuration, it is preferable that a hole is formed in the connecting portion, since the fluid flows into each heat transfer tube more uniformly.

Further, it is preferable that the hole is formed in a substantially flat circular shape and the longitudinal portion is formed substantially parallel to the longitudinal direction on the end surface of the heat transfer tube, so that a larger heat exchange can be obtained.

Further, it is preferable that a plurality of holes be formed, since the flow of fluid into each heat transfer tube becomes more uniform.

In the above configuration, if the body is formed to have a substantially rectangular cross section and the width of the heat transfer tubes is all equal, the same heat transfer tube can be used, and the number of parts can be reduced. This is preferable because it can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a conventional heat exchanger.

FIG. 2 is an enlarged sectional view taken along a line 2-2 in FIG. 1;

FIG. 3 is a schematic cross-sectional view of a heat exchanger according to an embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view taken along a line 4-4 in FIG. 3;

FIG. 5 is an enlarged end view taken along a line 5-5 in FIG. 3;

FIG. 6 is a partially enlarged cross-sectional view schematically showing a heat exchanger according to another embodiment of the present invention.

FIG. 7 is an enlarged end view taken along the line 7-7 in FIG. 6;

[Explanation of symbols]

 11, 21, 31 Multi-tubular heat exchanger 12, 22 Body 13, 23 Heat transfer tube 14, 24 Fixed tube plate 15 Inlet nozzle 16 Outlet nozzle 17A, 27A Gas introduction rectification room 17B, 27B Gas extraction rectification room 18A Gas introduction Pipe 18B Gas outlet pipe 19 Flange part 25, 35 Fluid distribution member 25a Main body part 25b Inclined part 25c Hole 26 Heat transfer fin

Claims (9)

[Claims] 1. A heat transfer tube comprising: a substantially cylindrical body; and a plurality of heat transfer tubes disposed inside the body, wherein a fixed tube plate is disposed near at least one end of the body. In the multi-tube heat exchanger having a configuration in which the vicinity of the end is fixed to the fixed tube sheet, a rectification chamber is formed near the fixed tube sheet, and the rectification chamber is formed to have a substantially tapered cross section. A multi-tube heat exchanger, wherein a fluid distribution member is disposed inside the rectifying chamber. 2. The multi-tube heat exchanger according to claim 1, wherein an outer peripheral wall of the rectifying chamber has an angle of 25 ° or more with respect to a center axis of the fixed tube sheet. 3. The fluid distribution member includes at least a pair of distribution plate portions, and the distribution plate portion is disposed at a smaller angle with respect to the central axis than an outer peripheral wall of the rectification chamber. The multi-tubular heat exchanger according to claim 2, wherein: 4. The heat transfer tube is formed in a substantially flat cross-sectional shape, has a heat transfer fin therein, and is disposed so as to be substantially parallel to each other. 4. The multi-tube heat exchanger according to claim 3, wherein a longitudinal portion of the flow dividing plate portion is disposed so as to be substantially parallel to a longitudinal direction of the heat transfer tube end face. 5. 5. The method according to claim 1, wherein the flow dividing plate portion is connected and integrated by a plate-like connecting portion between adjacent ends, and the connecting portion is disposed substantially parallel to the heat transfer tube end face. The multi-tube heat exchanger according to claim 3 or 4, wherein: 6. The multi-tubular heat exchanger according to claim 5, wherein a hole is formed in the connecting portion. 7. The multi-tubular heat exchanger according to claim 6, wherein the hole has a substantially flat circular shape, and a longitudinal portion is formed substantially parallel to a longitudinal direction of the end surface of the heat transfer tube. vessel. 8. The multi-tube heat exchanger according to claim 7, wherein a plurality of said holes are formed. 9. The multi-tube according to claim 4, wherein said body is formed in a substantially rectangular cross section, and said heat transfer tubes are all formed to have the same width. Type heat exchanger.