JP2008231929A - Cooling water inlet structure of heat exchanger for egr cooler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the cooling water inlet structure of a heat exchanger for an EGR cooler, uniformizing a cooling water flow in the heat exchanger by distributing cooling water inlets to two or more portions and also performing excellent heat exchange by eliminating a local overheated portion. <P>SOLUTION: The heat exchanger for the EGR cooler performs heat exchange in a manner that a tube assembly is enclosed in the shell of the heat exchanger, high-temperature EGR gas is introduced into the inside of each tube, and cooling water is introduced into the outside thereof. The heat exchanger is so configured that the cooling water inlets introducing the cooling water into the shell are provided to two or more portions, and a cooling water outlet discharging the cooling water from the inside of the shell is arranged at one portion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cooling water inlet structure for a heat exchanger for an EGR cooler in which the cooling water inlet in the heat exchanger for an EGR cooler having a plurality of flat tubes is divided into a plurality of portions so as not to stagnate the flow of the cooling water. Is.

  As shown in FIGS. 7 to 11, the EGR cooler heat exchanger 1 having a conventional flat tube has a flat tube 2 laminated with a substantially uniform clearance through a spacer (not shown) or a plurality of convex shapes on the surface. The flat tubes 2 on which the dowels 2a are projected are overlapped with the dowels, and the end portions of the flat tubes 2,... The tube assembly 4 is assembled, and the tube assembly 4 is accommodated in the shell 1a and fixed in a watertight and airtight manner and integrated.

In such an EGR cooler heat exchanger 1, an inlet 5 and an outlet 6 for cooling water are provided in one place, respectively, and the cooling water is introduced into the shell 1a so that each flat tube 2,. The EGR gas passing through each of the flat tubes 2, ..., 2 is cooled.
In order to improve the cooling effect, various types of cooling water that can pass through the inside of the shell 1a are formed at the positions where the cooling water inlet 5 and outlet 6 are installed. For example, as shown in FIGS. 7 and 8, the lower surface or side surface of the shell 1a is provided with an inlet 5 at one end, and the upper surface or side surface is provided with an outlet 6 at the end opposite to the end provided with the inlet 5. When the cooling water flows in parallel to the wall surface of the flat tube 2 and flows out in the parallel direction (Patent Documents 1 and 2), as shown in FIG. An inlet 5 is provided at the side end, and an outlet 6 is provided at the other end opposite to the end where the inlet 5 is provided. Cooling water flows in a direction perpendicular to the wall surface of the flat tube 2, and the vertical direction (Patent Document 1), and as shown in FIG. The inlet 5 is provided at an end portion, which is provided with an outlet 6 at the end opposite to the end provided with the inlet 5 of the upper surface of the shell 1a (Patent Documents 3 and 4) or the like.

And the arrangement | positioning position of these cooling water inlets 5 and outlets 6 and the state of the flow of cooling water by the relative direction of the inlet / outlet and the flat tube 2 are:
(1) When the cooling water in FIG. 7 flows from the lower surface and flows out from the upper surface in the vertical direction, the cooling water flowing in from the inlet 5 flows in as shown in FIG. Branching to flow along the wall surface of each flat tube 2,..., 2 arranged in the same direction so that the cooling water flows between the flat tubes 2,. .., 2 flows upward along the wall surface, converges toward the outlet 6 on the upper surface, and is discharged from the outlet 6 so that the surfaces of all the flat tubes 2,.
(2) When the cooling water of FIG. 8 flows in the lateral direction from one side of the side and out of the other side, as shown in FIG. 12, the cooling water flowing from the inlet 5 flows into the nearest flat tube 2. Proceed from the edge along the wall surface to the wall surface close to the opposite side of the shell, and another flow proceeds along the inner wall surface of the shell 1a, and between the flat tubes 2, ..., 2 and the inner wall surface of the shell 1a. And then converge toward the outlet 6 and are discharged from the outlet 6.
(3) When the cooling water in FIG. 9 flows in from the lower surface side and flows out to the upper surface side, as shown in FIG. 13, the cooling water flowing in from the inlet 5 hits the wall surface of the most recent flat tube 2 almost perpendicularly. Along the inner wall of the shell 1a from the edge of the flat tube 2 to the upper surface, and a certain amount of cooling water is bent into the gap formed between the flat tubes 2 along the way. The cooling water flows between the flat tubes 2, 2, 2, passes through the flat tubes 2, 2, 2 and then converges toward the outlet 6 on the upper surface side. Discharged.
(4) Further, as shown in FIG. 10, when cooling water flows in from the lateral direction and flows out upward, as shown in FIG. 14, the cooling water flowing from the inlet 5 flows into the nearest flat tube 2. The flow that branches forward along the wall surface, proceeds from the edge of the flat tube 2 toward the inner wall surface of the shell 1a on the opposite side along the wall surface, and branches along the inner wall surface of the shell 1a. A slight amount of cooling water is bent into the gap formed between the flat tubes 2 so that the cooling water flows between the flat tubes 2,. And then converge toward the outlet 6 on the upper surface side and are discharged from the outlet 6.

JP 2002-107091 A JP 2004-177060 A JP 2003-201923 A JP 2003-090693 A

[Problems of the prior art]
In the heat exchanger 1 for an EGR cooler having such a configuration, the flat tubes 2,... 2 are arranged according to the arrangement positions of the inlet 5 and the outlet 6 of the cooling water and the relative orientation of the inlet / outlet and the flat tube 2. The state of cooling differs depending on the distribution of cooling water inside the shell 1a.
For example, in the states (1) and (2) of the flow of the cooling water, as shown by circles in FIGS. The amount of water decreases, and heat exchange with the EGR gas flowing in the flat tube 2 in the peripheral portion becomes worse, and the cooling water between the flat tubes 2,..., 2 having a large heat exchange amount may boil. . In the cooling water flow state (3), as shown by circles in FIG. 13, the cooling water in the peripheral portion flowing along the inner wall surface of the shell 1a is centered between the flat tubes 2,. Compared with the cooling water in the part, the flow rate increases, and the cooling water may boil because the flow rate is small in the peripheral part. Further, in the flow state (4), as shown by circles in FIG. 14, the amount of water is large between the flat tubes 2, 2 near the inlet 5, and the flat tubes 2, 2 near the outlet 6. , 2, there is a problem that the amount of water decreases, and there is a possibility that the cooling water will boil around this area.
In addition, due to layout restrictions when mounted on a vehicle, the cooling water inlet pipe may be forced to be installed at a position where a place where water does not easily flow is likely to occur. It was.
For this reason, there has been a strong demand for improvement in heat exchangers such as EGR coolers, which have recently become hot in gas temperatures.

  The present invention has been made in view of the above problems in the prior art, and the technical problem specifically set in order to solve this problem is to disperse the cooling water inlets into a plurality of heat exchangers. Another object of the present invention is to provide a cooling water inlet structure of a heat exchanger for an EGR cooler that can make the flow of cooling water uniform in the inside and eliminate a local overheating portion and perform good heat exchange.

In order to identify the cooling water inlet structure of the heat exchanger for an EGR cooler in which the above-described problems in the present invention are effectively solved, all the matters recognized as necessary are covered and specifically configured as a problem solving means. It is shown below.
The first problem solving means for the cooling water inlet structure of the heat exchanger for the EGR cooler is that the tube assembly is built in the shell of the heat exchanger, the hot EGR gas is passed through each of the tubes, and the outside is cooled. A heat exchanger for an EGR cooler that exchanges heat through water is characterized by having two or more cooling water inlets for introducing cooling water into the shell and one cooling water outlet for discharging cooling water from the shell. To do.
The second problem solving means according to the cooling water inlet structure of the EGR cooler heat exchanger is characterized in that the same number of cooling water inlet pipes are fixed to the shell in accordance with the two or more cooling water inlets. And

  The third problem-solving means according to the cooling water inlet structure of the EGR cooler heat exchanger is the same as that described above. The cooling water inlet of the shell is connected to one inlet side connection end for connecting a hose for supplying cooling water, A cooling water inlet pipe adapter having a water supply side connection end that opens a water outlet in accordance with the cooling water inlet at a location or more, and that the water outlet of the water supply side connection end is fixed to the cooling water inlet of the shell. Features.

The fourth problem-solving means related to the cooling water inlet structure of the heat exchanger for EGR cooler is the same as the above, but the cooling water inlet pipe adapter has the same number of pipe-like outlet passages in accordance with two or more cooling water inlets of the shell. It is characterized by projecting.
Further, the fifth problem-solving means according to the cooling water inlet structure of the EGR cooler heat exchanger is the same as that of the cooling water inlet of the cooling water inlet pipe adapter at the periphery of the two or more cooling water inlets of the shell. It was formed in the shape which can be closely_contact | adhered according to the shell outer surface containing.

In the first problem solving means relating to the inlet structure of the heat exchanger for the EGR cooler, two or more cooling water inlets are provided, so that a plurality of stacked tubes are connected between the tubes and outside the outermost tubes. The cooling water introduced into the shell can be dispersed up to the side surface, and the cooling water can be efficiently and evenly passed through each formed flow path, and the flow inside the shell is stagnant. The boiling of the cooling water due to is eliminated, and heat exchange with the EGR gas flowing in the tube is good and efficient.
In the second problem solving means relating to the inlet structure of the heat exchanger for EGR cooler, the same number of cooling water inlet pipes are fixed to the shell in accordance with the cooling water inlets at a plurality of locations, so that the number of cooling water inlet pipes can be adjusted. Thus, piping from a cooling water supply source such as a cooling water tank, a radiator or another tank can be connected, and the cooling water can be supplied efficiently.

  In the third problem-solving means related to the inlet structure of the heat exchanger for EGR cooler, a cooling water inlet pipe adapter having one inlet side connecting end and a water supply side connecting end having two or more outlets opened is provided. By aligning the position of the water outlet opening at the water supply side connection end of the cooling water inlet pipe adapter and the cooling water inlet provided at two or more locations in the shell and fixing them to the shell, the periphery of the cooling water inlet is compactly gathered, Cooling water can be supplied to a plurality of locations by using only one pipe without using two or more pipes from the cooling water supply source.

In the fourth problem solving means relating to the inlet structure of the heat exchanger for EGR cooler, by connecting the pipe-shaped outlet passages protruding from the cooling water inlet pipe adapter to the cooling water inlets provided at two or more locations of the shell, Not only is a single pipe from the cooling water supply source, but a pipe-shaped outlet passage can be directly connected to the cooling water inlet provided in the shell, reducing the number of parts and simplifying the manufacturing process. Can do.
Further, in the fifth problem solving means relating to the inlet structure of the heat exchanger for the EGR cooler, the water supply side connection end surface of the cooling water inlet pipe adapter is aligned with the outer surface of the shell including the peripheral portions of the cooling water inlets at two or more locations of the shell. By forming it in a shape that can be closely attached, it is possible to supply cooling water into the shell via the cooling water inlet pipe adapter by sticking firmly to the outer surface of the shell, and the cooling water supply piping system is simple Therefore, the mounting space can be minimized, and the downsizing and the manufacturing process can be simplified.

Hereinafter, the best embodiment according to the present invention will be described in detail.
However, this embodiment is specifically described for better understanding of the gist of the invention, and does not limit the content of the invention unless otherwise specified.
The same components as those described in the prior art are denoted by the same reference numerals, and a specific description thereof is omitted.

[First Embodiment]
〔Constitution〕
The cooling water inlet structure of the heat exchanger for EGR cooler in the first embodiment has a shell 1a made of a thin plate made of stainless steel as shown in FIGS. 1 to 3, and the shell 1a has a plurality of flat tubes 2. ,..., 2 are accommodated by the end plates 3, 3, and the EGR gas is introduced into the flat tubes 2, 2, 2. It flows and absorbs the heat of EGR gas with cooling water. Two cooling water inlets 11 and 11 for introducing cooling water are provided on one end side of the lower surface of the shell 1a, and an end portion (hereinafter simply referred to as the other end) located on the opposite side of the cooling water introduction side of the upper surface of the shell 1a. The cooling water outlet 12 is provided at one location so that the cooling water can be discharged to the outside of the shell.
In the heat exchanger 10 for EGR cooler, the discharged EGR gas can be lowered to a predetermined temperature as a result of heat exchange.

The cooling water inlets 11, 11 provided in the shell 1 a of the EGR cooler heat exchanger 10 have a water supply side connection end 13 b having water outlets 13 a, 13 a opened in accordance with the cooling water inlets 11, 11. The cooling water inlet pipe adapter 13 having 13b is fixed to the shell 1a so that the positions of the cooling water inlets 11 and 11 and the outlets 13a and 13a of the water supply side connection ends 13b and 13b are aligned.
This cooling water inlet pipe adapter 13 has one water inlet side connection end 13c and water supply side connection ends 13b, 13b that open a plurality of outlets 13a, 13a. A cooling water inlet pipe 14 from a cooling water supply source such as a tank, a radiator or another tank is connected, and the water supply side connection ends 13b and 13b are connected to the cooling water inlets 11 and 11 provided in the shell 1a. Align and fix to the shell 1a.
A cooling water outlet pipe 15 is connected to the cooling water outlet 12.

[Function and effect]
In such a cooling water inlet structure of the heat exchanger for an EGR cooler in the first embodiment, the flow of the cooling water flowing in the shell 1a is made uniform by providing two cooling water inlets in the shell 1a. The boiling caused by the flow of the cooling water in the prior art is eliminated, and the heat exchange with the EGR gas flowing in the flat tubes 2,.
By connecting the cooling water inlet pipe 14 from the lateral direction to the inlet side connection end 13c of the cooling water inlet pipe adapter 13, the height can be suppressed, and the optimum cooling water inlet can be used even when the vertical space is limited. Can be secured.

[Another aspect of the first embodiment]
The first embodiment is specifically described to facilitate understanding of the gist of the invention, but does not limit the content of the invention, and does not limit another aspect not particularly described. It may be changed as appropriate. In this sense, some other embodiments that meet the gist of the invention are shown below.
In the first embodiment, the shell 1a is provided with the two cooling water inlets 11 and 11, and the cooling water inlet pipe adapter 13 is formed with the two water outlets 13a and 13a. However, the shell 1a has three cooling water inlets. As shown in FIG. 4, a cooling water inlet pipe adapter having three water outlets 13a, 13a, 13a adapted to the shape of the cooling water inlet may be formed.
Further, when two water outlets 13a, 13a are provided as the cooling water inlet pipe adapter 13, a surface that can be in close contact with the outer surface of the shell in accordance with the peripheral portions of the two cooling water inlets 11, 11 provided in the shell 1a. A water discharge side end surface 13e of the water supply side connection end 13d is formed, and a water outlet having a long hole 13f that is a space except for an end surface that becomes a close contact surface is provided inside the water discharge side end surface 13e. The connection end 13d may be directly adhered and fixed so as to cover the entire periphery of the cooling water inlets 11 and 11.

[Second Embodiment]
〔Constitution〕
The cooling water inlet structure of the heat exchanger for EGR cooler in the second embodiment is provided in the shell 1a when two cooling water inlet pipes 14 from the water supply source can be piped as shown in FIG. The cooling water inlet pipes 16 and 16 are fixed directly to the two cooling water inlets 11 and 11, and the cooling water inlet pipes 16 and 16 are connected to the cooling water inlet pipe 14 from the cooling water supply source, or Instead of the cooling water inlet pipes 16, 16, the cooling water inlet pipe 14 is directly connected to the cooling water inlets 11, 11.

[Function and effect]
In such a second embodiment, the distribution of the water supply in the shell 1a can be effectively made uniform from the optimum position of the cooling water supply, and heat exchange can be performed efficiently.

It is a cross-sectional explanatory drawing which shows the cooling water inlet structure of the heat exchanger for EGR coolers which concerns on the 1st embodiment of this invention. It is the perspective view seen from diagonally downward which shows the cooling water inlet structure which provided the cooling water inlet pipe adapter in the two cooling water inlets in the cooling water inlet structure of the heat exchanger for EGR same as the above. It is explanatory drawing which shows the cooling water inlet pipe adapter which has two water outlets utilized for the cooling water inlet structure of the heat exchanger for EGR coolers same as the above, (A) is a longitudinal cross-sectional view, (B) is from diagonally downward FIG. It is explanatory drawing which shows the cooling water inlet pipe adapter which has three water outlets utilized for the cooling water inlet structure of the heat exchanger for EGR coolers same as the above, (A) is a longitudinal cross-sectional view, (B) is from diagonally downward FIG. It is explanatory drawing which shows the cooling water inlet pipe adapter which formed the water discharge side end surface of the water supply side connection end according to the shell shape in the cooling water inlet structure of the heat exchanger for EGR coolers same as the above, (A) is a longitudinal sectional view, (B) is the perspective view seen from diagonally downward. It is the perspective view seen from diagonally downward which shows the state which connected the cooling water inlet pipe from the cooling water supply source of the heat exchanger for EGR coolers which concerns on the 2nd embodiment of this invention to two shells. It is a perspective partial section explanatory view showing the cooling water entrance-and-exit structure in which cooling water moves up and down in the conventional heat exchanger for EGR coolers. It is a perspective partial section explanatory view showing the cooling water entrance-and-exit structure in which cooling water moves in the transverse direction in the conventional heat exchanger for EGR cooler. It is a perspective partial section explanatory view showing the cooling water entrance-and-exit structure in which cooling water flows in from the lower part, and flows out upwards in the conventional heat exchanger for EGR coolers. It is a perspective partial cross-section explanatory drawing which shows the cooling water entrance-and-exit structure where a cooling water flows in from a side and flows out upwards in the conventional heat exchanger for EGR coolers. It is a cross-sectional explanatory drawing which shows the flow of the cooling water in the heat exchanger for EGR coolers shown in FIG. It is a cross-sectional explanatory drawing which shows the flow of the cooling water in the heat exchanger for EGR coolers shown in FIG. It is a cross-sectional explanatory drawing which shows the flow of the cooling water in the heat exchanger for EGR coolers shown in FIG. It is transverse cross-sectional explanatory drawing which shows the flow of the cooling water in the heat exchanger for EGR coolers shown in FIG.

Explanation of symbols

1,10 Heat exchanger for EGR cooler 1a Shell 2 Flat tube 2a Dowel 3 End plate 4 Tube assembly 5 Inlet 6 Outlet 11 Cooling water inlet 12 Cooling water outlet 13 Cooling water inlet pipe adapter 13a Outlet 13b, 13d Supply side connection end 13c Inlet side connection end 13e Outlet side end surface 13f Long holes 14, 16 Cooling water inlet pipe 15 Cooling water outlet pipe

Claims (5)

  In a heat exchanger for an EGR cooler in which a tube assembly is built in a shell of a heat exchanger, a high-temperature EGR gas is passed through each of the tubes, and cooling water is passed through the outside thereof, cooling water is introduced into the shell. An inlet structure of a heat exchanger for an EGR cooler, wherein two or more cooling water inlets are provided and one cooling water outlet for discharging the cooling water from the shell is provided.   The inlet structure of a heat exchanger for an EGR cooler according to claim 1, wherein the same number of cooling water inlet pipes are fixed to the shell in accordance with the two or more cooling water inlets.   The cooling water inlet of the shell has a cooling water inlet connecting end for connecting a hose that supplies cooling water, and a water supply connecting end that opens a water outlet in accordance with the two or more cooling water inlets. The inlet structure of the heat exchanger for an EGR cooler according to claim 1, wherein the water inlet pipe adapter is fixed so that a water outlet of the water supply side connection end is aligned with a cooling water inlet of the shell.   4. The heat exchanger for an EGR cooler according to claim 3, wherein the cooling water inlet pipe adapter is provided with the same number of pipe-shaped outlet passages in accordance with two or more cooling water inlets of the shell. 5. Entrance structure.   The water supply side connection end face of the cooling water inlet pipe adapter is formed in a shape that can be closely attached to a shell outer surface including peripheral portions of two or more cooling water inlets of the shell. The heat exchanger inlet structure for EGR coolers.

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