JP2001027158A - Egr gas cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve EGR gas cooling performance by preventing decrease in heat transfer performance caused by adhering of bubble generated in coolant to a surface of a heat exchanger tube. SOLUTION: This system is made such that a heat transfer tube group 2 is securely arranged to a tube sheet secured near both end of a shell tube provided with a coolant inlet port 1-1 and a coolant outlet port 1-2 at either one or both ends, and end caps provided with an EGR gas inlet port and outlet port are secured on the outside of both end parts of the shell tube. In this case, the inside of the shell tube is partitioned to plural chambers by one or plural partition plates 5 provided over approximately overall length in a pipe axial direction, and each chamber is communicated through a notch provided at an end of the partition plate 5 placed with opposing to the coolant inlet port 1-1 and the coolant outlet port 1-2 and the coolant flowing into the shell tube from the coolant inlet port 1-2 flows through plural chambers. The flow velocity of the coolant in the shell tube is thereby increased and the coolant flows out from the coolant outlet port 1-2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for extracting a part of exhaust gas as an EGR gas from an exhaust system and cooling the EGR gas with a coolant for an engine, a refrigerant for an intercooler, a refrigerant for a car air conditioner or a cooling wind. It is about.

[0002]

2. Description of the Related Art A part of exhaust gas is taken out of an exhaust system,
To return to the intake system of the engine and add it to the mixture,
EGR (Exhaust Gas Recircula)
Tion: exhaust gas recirculation). EGR is NOx
(Nitrogen oxides) generation, pump loss reduction, heat radiation loss to the cooling fluid due to lowering of combustion gas temperature, increase in specific heat ratio due to changes in working gas amount and composition, and reduction in cycle efficiency Because many effects such as improvement can be obtained,
It is considered an effective way to improve the thermal efficiency of the engine.

However, when the temperature of the EGR gas increases, the fuel efficiency decreases due to the rise in the intake air temperature, and the durability of the EGR valve deteriorates due to the heat effect, which may lead to early breakage. It is recognized that a water-cooled structure is required. In order to avoid such a situation, a device that cools the EGR gas with a coolant for the engine or the like is used. As this device, a multi-tube heat exchanger is generally used.

FIG. 5 shows an example of a multi-tube heat exchanger used in this case . A shell-and-tube heat exchanger having a cooling medium inlet 11-1 and a cooling medium outlet 11-2 at both ends. Inside the heat transfer tube group 12, both end portions of the heat transfer tube group 12 are fixed to the tube sheet 13 by brazing or welding, while the tube sheet 13 is arranged with its outer peripheral portion fixed to the inner wall of the body tube 11 by brazing or welding, The body tube 1
An end cap 14a provided with an EGR gas inlet 14a-1 at one end thereof, and an end cap provided with an EGR gas outlet 14b-1 at the other end. 14b is fixed, and the engine coolant introduced through the coolant inlet 11-1
It is known that the EGR gas flowing inside the heat transfer tube group 12 is cooled (Japanese Utility Model Publication No. 57-30).
No. 9, etc.).

[0005]

However, in the case of the above-mentioned multi-tube heat exchanger in which the EGR gas is cooled by the coolant of the engine or the like, the flow rate of the coolant in the body tube 11 cannot be increased. There is a problem that the external heat transfer coefficient is low and the heat exchange performance is inferior. In addition, since the EGR gas has a high temperature, the gas in the coolant of the engine boils particularly on the EGR gas inlet 14a-1 side to form bubbles, which are formed on the outer surface of the heat transfer tube group 12 on the EGR gas inlet side. There is a problem that the heat transfer surface adheres and covers the heat transfer surface to further reduce the heat transfer performance.

The present invention has been made to solve the problems of a decrease in the flow velocity in the body tube due to a decrease in the flow rate of the extrapipe fluid and a decrease in heat exchange performance due to a decrease in the heat transfer surface due to the generation of bubbles. By dividing the inside of the body tube into a plurality of chambers, the flow rate of the cooling medium in the body tube is increased, and the function of easily removing and removing bubbles attached to the outer surface of the heat transfer tube group generated by boiling of the cooling liquid and the like is provided. It is an object of the present invention to provide an EGR gas cooling device provided with the same.

[0007]

According to the present invention, in order to solve the above-mentioned problems, the inside of the body tube is divided into a plurality of chambers by a partition plate, and the space through which the cooling medium flows is reduced so that the inside of the body tube can be cooled at a high speed. In the first embodiment, a heat transfer tube is attached to a tube sheet fixed near both ends of a body tube provided with a cooling medium inlet and a cooling medium outlet at one end or both ends. A multi-tube type EGR having a structure in which a group is fixedly arranged, and an end cap is fixed outside both ends of the body tube, and an inlet and an outlet for an EGR gas are provided in the end cap. In the gas cooling device, the inside of the body pipe is partitioned into a plurality of chambers by one or more partition plates disposed over substantially the entire length in the pipe axis direction, and each chamber is defined by the cooling medium inlet and the outlet. The said relative position The flow rate of the cooling medium in the body tube is increased by communicating the cooling medium flowing through the notch provided at the end of the cutting plate and flowing into the body tube from the cooling medium inlet through the plurality of chambers. The second embodiment is characterized in that it has a structure in which it is discharged from a cooling medium outlet, and in a multi-tube type EGR gas cooling device having the same structure as described above, both ends of the shell have the same width as the inner diameter of the body tube. One partition plate having a length substantially equal to the length between the tube sheets and having a cutout at an end opposite to the cooling medium inlet and the outlet is provided in the body tube in a tube axial direction. The inside of the body tube is partitioned into two chambers on the left and right sides substantially over the entire length, and the cooling medium flowing into the body tube from the cooling medium inflow port provided in one of the chambers passes through the notch and flows through the left and right chambers. By doing so, the flow rate of the cooling medium in the body tube is increased, Characterized in that no structure that flows from the cooling medium outlet port provided in the chamber, the third embodiment is a multi-tube type EG of the same structure as the
In the R gas cooling device, the width is shorter than the inner diameter of the body tube, has substantially the same length as the length between the tube sheets at both ends, and a notch is formed at an end opposite to the cooling medium inlet and the outlet. The two partition plates provided with are disposed in the body tube substantially over the entire length in the tube axis direction and are arranged in parallel at a predetermined interval from each other. The cooling medium flowing into the body tube from the cooling medium inlet provided in one of the outer chambers passes through the cutout portion and flows through each chamber, whereby the flow rate of the cooling medium in the body tube is increased, and The fourth embodiment is characterized in that it has a structure in which it flows out from a cooling medium outlet provided in an outer chamber of the multi-tube type EGR gas cooling device having the same structure as the above. Approximately the same width as the length between the tube sheets at both ends A cross-shaped partition plate having a notch at an end opposite to the cooling medium inlet and the outlet is arranged over substantially the entire length in the tube axis direction in the body tube, and Are divided into four chambers, and the cooling medium flowing into the body pipe from the cooling medium inlet provided in one of the chambers passes through the notch and flows through each chamber, whereby the flow rate of the cooling medium in the body pipe is increased. Is raised to flow out from a cooling medium outlet provided in another chamber, and in the first to fourth embodiments, the partition plate has a body tube and Preferably, it is brazed to the heat transfer tube group, and the end of the partition plate facing the notch is brazed or welded to the tube sheet.

In the present invention, the inside of the body tube is partitioned into a plurality of chambers, and the cooling medium is caused to flow through each chamber. The reason for this is that the flow rate of the cooling medium is increased by narrowing the space through which the cooling medium flows. This is because the heat exchange performance is improved, and bubbles attached to the outer surface of the heat transfer tube group generated by boiling of the coolant or the like are quickly and easily peeled off and removed before the large growth, thereby improving the heat transfer performance.

High-temperature EG flowing from the EGR gas inlet port
The R gas is first cooled by the cooling medium in the space on this side, but since the temperature of the EGR gas is high in this area, bubbles are generated in the cooling medium such as the engine coolant and the heat transfer tube on this side is formed. Attaches to outer surface. However, since the cooling medium introduced into the space flows in the narrow space in the axial direction, even if the flow rate of the cooling medium slightly decreases, its flow velocity is inevitably higher than that without the partition plate. . Therefore, it is possible to prevent a decrease in the flow velocity in the body tube due to a decrease in the flow rate of the cooling medium, and to increase the flow velocity of the cooling medium, so that the generation of bubbles is significantly reduced. Is removed from the heat transfer surface without large growth by the high-speed cooling medium, and as a result, large-scale boiling such as cooling liquid is almost eliminated. Further, by fixing the contact portion between the partition plate and the heat transfer tube by brazing or the like, heat is also transmitted to the partition plate, and the heat transfer area is further increased.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a multi-tube type EGR gas cooling device in which the inside of a body tube is partitioned into two chambers on the left and right sides.
(A) is a cross-sectional front view showing a partly omitted view, (b) is an enlarged vertical cross-sectional side view on the ii line in FIG. (A), and FIG. (A) is a cross-sectional front view showing a part of the cooling device,
(B) is an enlarged vertical sectional side view on the loro line of FIG.
(C) is a cross-sectional plan view showing a part of the EGR gas cooling device in which the inside of the body tube is divided into four chambers, and FIG. Cross-sectional front view, shown
(B) is an enlarged vertical cross-sectional side view on the haha line in FIG.
(C) is a cross-sectional plan view showing a part of the partition plate, and FIG. 4 is a perspective view showing a configuration of a partition plate used in the embodiment of FIG.
(A) is a figure which shows one Example of a partition plate, (b) is a figure which shows another Example, 1 is a body tube, 1-1 is a cooling medium inlet, 1-2 is a cooling medium outlet. 2 is a heat transfer tube group, 3 is a tube sheet, 4a and 4b are end caps, and 4a-1 is E
The GR gas inlet, 4b-1 is the EGR gas outlet, 5b
Is a partition plate, 5-1 is a cutout recess, 1A, 1B, 1C, 1D
Is a split room.

First, the EGR gas cooling device shown in FIG. 1 has a cooling medium inlet 1-1 and a cooling medium outlet 1-2 at one end.
Inside the body tube 1 provided with the heat transfer tube group 2, both ends are fixed to the tube sheet 3 by brazing or welding,
On the other hand, the tube sheet 3 is arranged such that its outer peripheral portion is fixed to both ends of the body tube 1 by brazing or welding, and an EGR gas inlet 4a-1 is provided at one end of the body tube 1. An end cap 4a having an end cap 4a fixed thereto, and an end cap 4b provided with an EGR gas outlet 4b-1 is fixed to the other end, and is disposed between the tube sheets 3 on both sides. The inside of the body tube 1 is divided into two chambers, a divided chamber 1A and a divided chamber 1B, from the center by one single partition plate 5. The partition plate 5 has the same effective width as the inner diameter of the body tube 1 except for the bent portions 5-2 provided on both side edges, and has substantially the same length as the length between the tube sheets 3 at both ends. A notch recess 5-1 is provided at one end. The partition plate 5 is disposed in the body tube 1 over substantially the entire length in the tube axis direction. Preferably, at least an end of the partition plate facing the cutout recess 5-1 is provided in the tube sheet 3 of the body tube 1. The bent portion 5-2 on both side edges is the body tube 1
The inside of the body tube 1 is partitioned into two left and right chambers extending in the longitudinal direction by brazing to the inner wall of the tube and further to the heat transfer tube group 2. The cooling medium inlet 1-1 and the cooling medium outlet 1-2 are provided on the side wall of the divided chamber 1A of the body tube 1 on the side opposite to the cutout recess 5-1 and on the side wall of the divided chamber 1B. It is provided to communicate with the room. Preferably, a corrugated portion 5-3 is provided at the center of the partition plate 5 as shown in the figure, so that the corrugated portion 5-3 can be brazed to a part of the heat transfer tube group 2. That is, this EG
In the case of the R gas cooling device, the dividing chamber 1A is connected to the inlet 1-1.
The cooling medium flowing into the inside flows into the EGR gas outlet 4 b-1 side in the chamber, and the notch recess 5-5 provided in the partition plate 5.
1, flows into the opposing divided chamber 1B, is changed direction, and flows through the divided chamber B into the EGR gas inlet 4a-.
It flows to the side 1 and flows out from the outlet 1-2.

In the EGR gas cooling device having the above structure,
The EGR gas flowing from the EGR gas inlet 4a-1 is cooled by a cooling medium such as an engine coolant while flowing through the heat transfer tube group 2 in the body tube 1 partitioned into two chambers. On the inlet side of the EGR gas, since the gas is in a high temperature state, bubbles may be generated in the cooling medium and adhere to the outer surface of the heat transfer tube group 2 on this side. However, in the case of this EGR gas cooling device, since the inside of the body tube 1 is partitioned into two chambers, the flow velocity of the cooling medium flowing in the divided chamber 1A and the inside of the divided chamber 1B in the body tube 1 is the same as the conventional single flow rate. It is twice as high as the room. Therefore, the generation of air bubbles is greatly reduced due to almost no boiling of the cooling liquid and the like, and even if the air bubbles adhere to the outer surface of the heat transfer tube group 2 in the body tube, the air bubbles are removed from the heat transfer tube surface by the high-speed cooling medium. It is peeled off.
The separated and removed air bubbles are cooled and condensed and disappear by being mixed in a high-speed cooling medium in the divided chamber 1A and the divided chamber 1B in the body tube 1, so that the heat transfer performance is reduced by the air bubbles. Can be eliminated. Also, by brazing the corrugated portion 5-3 provided at the center of the partition plate 5 and a part of the heat transfer tube group 2, heat is also transmitted to the partition plate 5 and the heat transfer area is increased. Exchange performance can be improved.

Next, the EGR gas cooling device shown in FIG. 2 will be described. Unlike the EGR gas cooling device shown in FIG. 1, a cylinder having a cooling medium inlet 1-1 and a cooling medium outlet 1-2 at both ends is provided. Inside the tube 1, both ends of the heat transfer tube group 2 are fixed to the tube sheet 3 by brazing or welding, while the outer periphery of the tube sheet 3 is fixed to the both ends of the body tube 1 by brazing or welding. An EGR gas inlet 4 is arranged at one end of the body tube 1.
a-1 is provided with an end cap 4a fixed thereto, and the other end is provided with an end cap 4b provided with an EGR gas outlet 4b-1.
2 arranged longitudinally between the tube sheets 3 on both sides
The inside of the body tube 1 is divided by a plurality of partition plates 5 into divided chambers 1A and 1B.
In addition, the two partition plates 5 have substantially the same length as the length between the tube sheets 3 at both ends in the same manner as described above. A notch concave portion 5-1 is provided in the portion, and the two partition plates 5 are disposed in the body tube 1 in opposite directions over substantially the entire length in the tube axis direction, and preferably at least the notch of the partition plate is provided. The end opposite to the recess 5-1 is brazed to the tube sheet 3 of the body tube 1, the bent portions 5-2 on both side edges are brazed to the inner wall of the body tube 1, and further to the heat transfer tube group 2. Body tube 1
The interior is partitioned into three chambers extending in the longitudinal direction. Then, for example, the cooling medium inflow port 1 is provided at an end side wall of the division chamber 1A.
-1 is provided on an end side wall of the divided chamber 1B on the side opposite to the cooling medium inlet 1-1 so that the cooling medium outlet 1-2 communicates with each of the divided chambers. Also in the case of this device, the same corrugated portion as described above may be provided on each partition plate 5, and the portion and the heat transfer tube may be brazed. That is, in the case of this EGR gas cooling device, the cooling medium flowing into the divided chamber 1A from the inflow port 1-1 flows through the EGR gas cooling chamber.
The gas flows to the outlet 4b-1 side, and then passes through the notch recess 5-1 provided in the partition plate 5, flows into the middle divided chamber 1C, is changed direction, and divides the inside of the divided chamber 1C. It flows in the opposite direction from the chamber 1A, passes through the notch recess 5-1 provided on the EGR gas inlet 4a-1 side of the next partition plate 5 on this side, and flows into the opposing divided chamber 1B. Then, the direction is changed again and flows in the divided room B in the opposite direction to the divided room 1C, and E
It is configured to flow out from a cooling medium outlet 1-2 provided on the GR gas outlet 4b-1 side.

In the case of the EGR gas cooling apparatus having the structure shown in FIG. 2, the inside of the body tube 1 is divided into three chambers of a divided chamber 1A, a divided chamber 1B and a divided chamber 1C, and the space through which the cooling medium flows is shown in FIG. It becomes narrower than the thing,
The flow velocity of the cooling medium flowing in A, in the divided chamber 1B, and in the divided chamber 1C is larger than that in FIG. Therefore, in the case of this device as well, the generation of air bubbles is greatly reduced due to almost no boiling of the coolant or the like, and the EG
Even if the bubbles adhere to the outer surface of the heat transfer tube group 2 on the R gas entry side, these bubbles are separated and removed from the heat transfer tube surface by the high-speed cooling medium as described above. Therefore, the problem of a decrease in heat transfer performance due to bubbles can be solved. Also in this EGR gas cooling device, heat is also transmitted to the two partition plates 5 by brazing the two partition plates 5 and a part of the heat transfer tube group 2 to further increase the heat transfer area. As a result, the heat exchange performance can be improved.

The multi-tube type EGR gas cooling device shown in FIG. 3 in which the inside of the body pipe is partitioned into four chambers is similar to the EGR gas cooling device shown in FIG. Inside the body tube 1 provided with the outlet 1-2, both ends of the heat transfer tube group 2 are fixed to the tube sheet 3 by brazing or welding, while the tube sheet 3 has its outer peripheral portion near the both ends of the body tube 1. An end cap 4a provided with an EGR gas inlet 4a-1 is fixed to one end of the body tube 1, and is fixed to the other end of the body tube 1. Outlet 4b-1 of EGR gas
The inside of the body tube 1 is formed by a partition plate 5 having a cross shape formed by combining two pieces in the longitudinal direction between the tube sheets 3 on both sides while the end cap 4b provided with is provided. It has a structure divided into four divided chambers 1A, 1B, 1C, and 1D, and the partition plate 5 has substantially the same length as the length between the tube sheets 3 at both ends as described above. A notch recess 5-1 is provided at the end,
The two partition plates 5 are arranged in a cross shape in the body tube 1 in opposite directions over the entire length in the tube axis direction.
-1 is brazed to the tube sheet 3 of the body tube 1, the bent portions 5-2 on both side edges are brazed to the inner wall of the body tube 1, and further to the heat transfer tube group 2, and the body tube is brazed. 1 is partitioned into four chambers extending in the longitudinal direction. And for example, divided room 1
The cooling medium inflow port 1-1 communicates with each of the divided chambers at the end side wall of A, and the cooling medium outflow port 1-2 communicates with the cooling medium inflow port 1-2 at the cooling medium inlet 1-1 side of the divided chamber 1D. It is provided as follows. Also in the case of this device, the same corrugated portion as described above may be provided on each partition plate 5, and the portion and the heat transfer tube may be brazed. That is, this four-chamber structure EGR
In the case of the gas cooling device, the cooling medium flowing into the divided chamber 1A from the inlet 1-1 flows through the chamber through the EGR gas outlet 4
It flows to the b-1 side, and then passes through the notch recess 5-1 provided in the partition plate 5 and flows into the horizontally adjacent divided room 1B, is changed direction, and the inside of the divided room 1B is divided into the divided room 1A. Flows in the opposite direction, passes through the notch 5-1 provided in the partition plate 5 on this side, flows into the upper adjacent divided room 1C, is changed direction again, and flows through the divided room 1C in the divided room 1B. Flows in the opposite direction, passes through the cutout recess 5-1 provided in the partition plate 5 on this side, flows into the division room 1D adjacent to the partition plate 5, and is provided on the EGR gas inlet 4a-1 side. The cooling medium flows out from the cooling medium outlet 1-2.

The cross-shaped partition plate 5 shown in FIG. 3 has, for example, a slit 5 extending from the notch recess 5-1 to the center in the longitudinal direction at the center in the width direction as shown in FIG.
-3 provided in the shape of a cross may be combined with each other so that the slits are fitted to each other, or three partition plate members 5a and 5b may be formed as shown in FIG. ′
a, 5'b and 5'c may be joined to each other by brazing or welding to form a predetermined cross shape.

In the case of the EGR gas cooling device having the structure shown in FIG. 3, the inside of the body tube 1 is divided into four chambers of a divided chamber 1A, a divided chamber 1B, a divided chamber 1C and a divided chamber 1D, and a space through which a cooling medium flows. Is smaller than that of the three-chamber structure shown in FIG. 2, so that the flow rate of the cooling medium flowing in each divided chamber in the body tube 1 becomes larger than that of FIG. Therefore, in the case of this apparatus as well, the generation of bubbles is greatly reduced due to almost no boiling of the coolant or the like, and even if the bubbles adhere to the outer surface of the heat transfer tube group 2 on the inlet side of the EGR gas, the bubbles remain in the same manner as described above. The high-speed cooling medium completely separates and removes the heat from the heat transfer tube surface, so that the problem of deterioration in heat transfer performance due to bubbles can be solved. Also in this EGR gas cooling device, heat is also transmitted to the two partition plates 5 by brazing the two partition plates 5 and a part of the heat transfer tube group 2 to further increase the heat transfer area. As a result, the heat exchange performance can be improved.

The EG of the present invention shown in FIGS.
In the R gas cooling device, the length of the partition plate is set to be substantially the same as the length between the tube sheets 3 because the length of the partition plate is shorter than the length between the tube sheets 3 when assembling the device. If the partition plate moves in the pipe axis direction in the pipe 1 and it takes time and effort for positioning, and the workability is poor, and if there is a large gap between the tube sheet and the end opposite to the notched concave part, the This is because the cooling medium leaks and the heat transfer performance is greatly impaired. When the length of the partition plate is set as described above, the position of the partition plate in the body tube 1 can be easily and quickly determined. High heat transfer performance can be maintained.

[0019]

As described above, the EGR gas cooling apparatus of the present invention can increase the flow rate of the cooling medium in the body pipe, so that the boiling of the cooling liquid and the like hardly occurs, and the generation of bubbles can be greatly reduced. Even if bubbles are generated, the high-speed cooling medium can easily and quickly separate and remove the heat from the heat transfer surface, so that the problem of deterioration of the heat transfer performance due to the bubbles can be solved. By fixing the contact portion by brazing or the like, heat is also transmitted to the partition plate and the heat transfer area increases, so that there is a great effect that the heat exchange rate can be significantly increased.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a multi-pipe type EGR gas cooling apparatus according to the present invention. FIG. 1 (a) is an E in which the inside of a body pipe is partitioned into two left and right chambers.
A cross-sectional front view showing a part of the GR gas cooling device by omitting it;
(B) is an enlarged vertical sectional side view on the yy line in FIG. (A).

FIG. 2 shows another embodiment of the multi-pipe type EGR gas cooling apparatus of the present invention, wherein (a) shows an EG in which a body pipe is partitioned into three chambers.
A cross-sectional front view showing a part of the R gas cooling device omitted;
(B) is an enlarged vertical sectional side view on the loro line of FIG.
(C) is a cross-sectional plan view showing a part of the above-mentioned device with a part omitted.

FIG. 3 shows another embodiment of the multi-pipe type EGR gas cooling apparatus of the present invention, wherein (a) shows an EG in which the inside of the body pipe is partitioned into four chambers.
A cross-sectional front view showing a part of the R gas cooling device omitted;
(B) is an enlarged vertical cross-sectional side view on the haha line in FIG.
(C) is a cross-sectional plan view showing a part of the above-mentioned device with a part omitted.

FIG. 4 is a perspective view showing a configuration of a partition plate used in the embodiment of FIG. 3; FIG.
(B) is a figure which shows another Example.

FIG. 5 is a partially cutaway plan view showing an example of a conventional multi-tube EGR gas cooling device to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body pipe 1-1 Cooling medium inflow port 1-2 Cooling medium outflow port 2 Heat transfer tube group 3 Tube sheet 4a, 4b End cap 4a-1 EGR gas inflow port 4b-1 EGR gas outflow port 5 Partition plate 5 -1 Notch recess 1A, 1B, 1C, 1D Division chamber

Continued on the front page F term (reference) 3G062 ED08 GA10 3L065 BA21 3L103 AA01 AA37 BB17 CC27 DD27 DD02 DD08 DD18 DD44

Claims (6)

[Claims] 1. A heat transfer tube group is fixedly arranged on a tube sheet fixed near both ends of a body tube provided with a cooling medium inlet and a cooling medium outlet at one or both ends, and furthermore, both ends of the body tube An end cap is fixed to the outside of the part,
Further, in the multi-tube type EGR gas cooling device having a structure in which an inlet and an outlet for an EGR gas are provided in the end cap, one or a plurality of the plurality of tubes are arranged in the body tube over substantially the entire length in the tube axis direction. Each partition is divided into a plurality of chambers, and each of the chambers is communicated through a notch provided at an end of the partition, which is positioned opposite to the cooling medium inlet and outlet. The cooling medium flowing into the body pipe from the medium inlet flows through the plurality of chambers, so that the flow rate of the cooling medium in the body pipe is increased and the cooling medium flows out of the cooling medium outlet. EGR gas cooling device. 2. A heat transfer tube group is fixedly arranged on a tube sheet fixed near both ends of a body tube provided with a cooling medium inlet and a cooling medium outlet at one end, and further outside the both ends of the body tube. In a multi-tube type EGR gas cooling device having a structure in which an inlet and an outlet for EGR gas are provided in the end cap, the end cap has the same width as the inner diameter of the body tube. A partition plate having a length substantially equal to the length between the tube sheets of the section and having a cutout at an end opposite to the cooling medium inlet and the outlet is provided in the body tube in the axial direction. The inside of the body tube is partitioned into two chambers on the left and right sides, and the cooling medium flowing into the body tube from the cooling medium inlet provided in one of the chambers passes through the cutout and passes through the left and right chambers. The flow rate of the cooling medium in the body tube is increased by flowing EG having a structure in which the cooling medium flows out from a cooling medium outlet provided in the other chamber.
R gas cooling device. 3. A heat transfer tube group is fixedly arranged on a tube sheet fixed near both ends of a body tube provided with a cooling medium inlet and a cooling medium outlet at both ends, and further, outside the both ends of the body tube. In a multi-tube EGR gas cooling device having a structure in which an inlet and an outlet for EGR gas are provided in the end cap, the end cap has a width shorter than the inner diameter of the body tube. Two partition plates having substantially the same length as the length between the tube sheets at both ends and provided with cutouts at ends opposite to the cooling medium inlet and the outlet are provided in the body tube in the axial direction. Are arranged substantially in parallel over the entire length and at a predetermined interval from each other, the inside of the body tube is partitioned into three chambers on the left and right sides and a central part, and the cooling medium inlet provided in one of the outer chambers The cooling medium flowing into the body pipe passes through the cutouts and passes through each chamber. An EGR gas cooling device characterized in that the flow rate of the cooling medium in the body tube is increased by flowing the air, and the cooling medium flows out from a cooling medium outlet provided in the other outer chamber. 4. A heat transfer tube group is fixedly arranged on a tube sheet fixed near both ends of a body tube provided with a cooling medium inlet and a cooling medium outlet at both ends, and further, outside the both ends of the body tube. In a multi-tube type EGR gas cooling device having a structure in which an inlet and an outlet for EGR gas are provided in the end cap, the end cap has the same width as the inner diameter of the body tube. A cross-shaped partition plate having a length substantially the same as the length between the tube sheets of the section and having a cutout at the end opposite to the cooling medium inlet and the outlet is provided in the body tube in the tube axial direction. The inside of the body pipe is partitioned substantially over the entire length, and the inside of the body pipe is partitioned into four chambers, and the cooling medium flowing into the body pipe from the cooling medium inlet provided in one of the chambers passes through the notch and flows through each chamber. By doing so, the flow rate of the cooling medium in the body tube is increased. EG having a structure in which the cooling medium flows out from a cooling medium outlet provided in another chamber.
R gas cooling device. 5. The partition plate is brazed to a body tube and / or a heat transfer tube group.
An EGR gas cooling device according to any one of the preceding claims. 6. The EGR according to claim 1, wherein an end of the partition plate facing the notch is brazed or welded to the tube sheet.
Gas cooling device.