JP7714568B2 - EGR cooler and vehicle waste heat recovery device - Google Patents

Description

This disclosure relates to an EGR cooler and a vehicle waste heat recovery device.

An EGR cooler that cools exhaust gases from automobiles and other vehicles is known, as disclosed in Patent Document 1, etc.

Japanese Patent Application Publication No. 2008-128611

The EGR cooler described in Patent Document 1 improves cooling efficiency by circulating cooling water evenly at the inlet of the cooling water on the outer surface side of the flat tubes through which exhaust gas passes.
Although the structure of Patent Document 1 can improve the cooling efficiency near the inlet of the cooling water, there is still room for improvement in terms of improving the cooling efficiency of the entire EGR cooler.

This disclosure therefore provides an EGR cooler and a vehicle waste heat recovery device with improved overall cooling efficiency.

An EGR cooler according to one aspect of the present disclosure includes:
The exhaust gas evaporator has a plurality of tubes through which exhaust gas flows, and a casing that houses the tubes.
An EGR cooler that performs heat exchange between the exhaust gas and the cooling water through the tubes by flowing cooling water inside the casing,
The EGR cooler is
a gas inlet for introducing the exhaust gas into the tube;
a gas outlet for discharging the exhaust gas from the tube;
a water inlet portion for introducing the cooling water into the casing;
a water outlet portion for discharging the cooling water from the casing,
The water outlet portion is
a main body portion forming a water outlet passage through which the cooling water passes;
and a blocking portion extending from the main body portion closer to the water inlet portion than the water outlet passage in a direction away from the water inlet portion.

A vehicle waste heat recovery device according to one aspect of the present disclosure includes:
The exhaust gas evaporator has a plurality of tubes through which exhaust gas flows, and a casing that houses the tubes.
A waste heat recovery device for a vehicle, in which heat exchange is performed between the exhaust gas and the cooling water through the tube by flowing cooling water inside the casing,
The vehicle waste heat recovery device includes:
a gas inlet for introducing the exhaust gas into the tube;
a gas outlet for discharging the exhaust gas from the tube;
a water inlet portion for introducing the cooling water into the casing;
a water outlet portion for discharging the cooling water from the casing,
The water outlet portion is
a main body portion forming a water outlet passage through which the cooling water passes;
and a blocking portion extending from the main body portion closer to the water inlet portion than the water outlet passage in a direction away from the water inlet portion.

The present disclosure provides an EGR cooler and a vehicle waste heat recovery device with improved overall cooling efficiency.

FIG. 1 is a perspective view of an EGR cooler according to an embodiment of the present disclosure. FIG. 2 is an exploded perspective view of the EGR cooler. FIG. 2 is a cross-sectional view of the EGR cooler as viewed from above. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3. 4 is a cross-sectional view taken along the line VV in FIG. 3. FIG. 6 is an enlarged view of a portion VI in FIG. 5 . FIG. FIG. 10 is a top view showing an adapter of an EGR cooler according to a first modified example of the present disclosure. FIG. 10 is a top view showing an adapter of an EGR cooler according to a second modified example of the present disclosure.

Embodiments of the present disclosure will be described below with reference to the drawings. For the sake of convenience, descriptions of components with the same reference numbers as components already described in the description of the embodiments will be omitted. Furthermore, for the sake of convenience, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component.

Furthermore, in the description of this embodiment, for the sake of convenience, reference will be made to the "left-right direction," "front-rear direction," and "up-down direction" as appropriate. Here, the "up-down direction" includes the "upward direction" and the "downward direction." The "front-rear direction" includes the "forward direction" and the "rearward direction." The "left-right direction" includes the "leftward direction" and the "rightward direction." In the figures described below, the symbol U indicates the upward direction. The symbol D indicates the downward direction. The symbol F indicates the forward direction. The symbol B indicates the rearward direction. The symbol L indicates the leftward direction. The symbol R indicates the rightward direction. Note that these directions do not necessarily coincide with the respective directions set for the vehicle when the EGR cooler is installed on the vehicle.

1 is a perspective view of an EGR cooler 1 according to an embodiment of the present disclosure. As shown in FIG. 1, the EGR cooler 1 has a heat exchanger 10, a gas inlet 20 for introducing exhaust gas into the heat exchanger 10, a gas outlet 30 for discharging exhaust gas from the heat exchanger 10, a water inlet 40 for introducing cooling water into the heat exchanger 10, and a water outlet 50 (see FIG. 2) for discharging cooling water from the heat exchanger 10.

1, hot exhaust gas flows into the heat exchange section 10 from the front through the gas inlet 20, where it exchanges heat with the cooling water inside the heat exchange section 10, and the cooled exhaust gas is discharged rearward from the heat exchange section 10 through the gas outlet 30. Cold cooling water also flows into the heat exchange section 10 from below through the water inlet 40 at the rear of the heat exchange section 10, where it exchanges heat with the exhaust gas inside the heat exchange section 10, and the heated cooling water is discharged downward through the water outlet 50 at the front of the heat exchange section 10. The illustrated EGR cooler 1 is a so-called counterflow type EGR cooler, where the flow directions of the exhaust gas and the cooling water are opposite each other in the heat exchange section 10.

Figure 2 is an exploded perspective view of the EGR cooler 1. As shown in Figure 2, the heat exchange section 10 has multiple tubes 11 and a casing 12 that houses these tubes 11. The tubes 11 are flat, hollow, plate-like members that are long in the front-to-rear direction. Exhaust gas flows inside the tubes 11. Cooling water flows through the spaces between the tubes 11 inside the casing 12. Fins 17 are provided inside the tubes 11 to aid in heat exchange between the exhaust gas and the cooling water. Dimples 13 are provided on the outer surface of the tubes 11 to induce turbulence in the cooling water and promote heat exchange.

The casing 12 is a rectangular cylindrical member that is long in the front-to-rear direction. A front end plate 14 is attached to the front end of the casing 12. A rear end plate 15 is attached to the rear end of the casing 12. The gas inlet section 20 is attached to the casing 12 via the front end plate 14. The gas outlet section 30 is attached to the casing 12 via the rear end plate 15. The tubes 11 are attached to these front end plate 14 and rear end plate 15.

Figure 3 is a cross-sectional view of the EGR cooler 1 as seen from above. Figure 4 is a cross-sectional view taken along the line IV-IV in Figure 3. As shown in Figures 3 and 4, multiple tubes 11 are arranged in the left-right direction within the casing 12. Openings 14a are provided in the front end plate 14 at positions corresponding to the openings of the tubes 11, allowing exhaust gas to be taken into the tubes 11. Openings are provided in the rear end plate 15 at positions corresponding to the openings of the tubes 11, allowing exhaust gas to be discharged from the tubes 11. The spaces between the openings 14a in the front end plate 14 and the openings in the rear end plate 15 are closed, forming sealed spaces between the casing 12, the tubes 11, the front end plate 14, and the rear end plate 15. Cooling water flows within these sealed spaces.

Figure 5 is a cross-sectional view taken along the V-V line in Figure 3. In this embodiment, a water inlet section 40 and a water outlet section 50 are provided on the underside of the casing 12. Figure 6 is an enlarged view of section VI in Figure 5. As shown in Figure 6, in this embodiment, the water outlet section 50 is formed as an adapter 51 attached to the casing 12. This adapter 51 includes a main body section 53 that forms a water outlet passage 52 through which cooling water passes, and a blocking section 54 that extends from the main body section 53 closer to the water inlet section 40 than the water outlet passage 52 in a direction away from the water inlet section 40.

Generally, fluids tend to flow in the shortest distance from the inlet to the outlet. Therefore, unlike the present embodiment, if there is no blocking section and the cooling water flows linearly from the water inlet to the water outlet, the cooling water is likely to stagnate near the upper front region of the casing. If the cooling water stagnates, heat exchange between the cooling water and the exhaust gas in that region is difficult to progress, making it difficult to improve the cooling efficiency of the EGR cooler as a whole.
However, in the EGR cooler 1 according to this embodiment, the water outlet 50 is provided with a blocking portion 54 extending in a direction away from the water inlet 40 from the main body 53, which is closer to the water inlet 40 than the water outlet passage 52. Therefore, the blocking portion 54 blocks the flow of cooling water that attempts to flow directly from the water inlet 40 to the water outlet 50.
As shown in FIG. 6 , the cooling water Y1 blocked by the blocking portion 54 flows around the blocking portion 54 to a position forward of the water outlet passage 52, hits the front end plate 14 and changes direction downward, hits the underside of the casing 12 and changes direction forward, and then is discharged to the outside through the water outlet passage 52. The cooling water Y1 flowing around the blocking portion 54 in this manner entrains cooling water Y2 near the upper front region A within the casing 12. Therefore, the provision of the blocking portion 54 allows the cooling water to flow widely within the casing 12. This allows the cooling water to flow also in the upper front region A, which is far from the water inlet portion 40 and the water outlet portion 50 within the casing 12 and is a "region where cooling water tends to stagnate." This makes it possible to cool exhaust gases using areas that previously contributed little to heat exchange, thereby improving the cooling efficiency of the EGR cooler 1 as a whole.

In the EGR cooler 1 of this embodiment, the water outlet portion 50 is provided at a position closer to the gas inlet portion 20 than the water inlet portion 40, and the blocking portion 54 extends toward the gas inlet portion 20. In other words, the EGR cooler 1 of this embodiment is a counterflow type.
In such a counterflow type EGR cooler 1, uncooled hot exhaust gas is blown onto the tubes 11 near the gas inlet 20. Therefore, the tubes 11 near the gas inlet 20 are likely to become hot. In the EGR cooler 1 of this embodiment, the blocking portion 54 extending toward the gas inlet 20 allows the cooling water to flow around to the vicinity of the gas inlet 20, thereby cooling the portion of the tubes 11 that is likely to become hot. Therefore, this embodiment is suitable for a counterflow type EGR cooler 1.

Figure 7 is an oblique view of the adapter 51. As shown in Figure 7, the upper surface 53a of the main body 53 of the adapter 51 is provided with a standing wall portion 55 and an extension wall portion 56 that extend upward. The standing wall portion 55 is a portion that extends in the left-right direction. The extension wall portion 56 is a portion that extends forward from the right and left ends of the standing wall portion 55. The standing wall portion 55 blocks cooling water from flowing from the water inlet portion 40 along the underside of the casing 12, diverting the flow upward. The extension wall portion 56 prevents cooling water flowing from rear to front from flowing into the water outlet passage 52 from the left and right sides of the standing wall portion 55.

A blocking portion 54 is provided on the upper surfaces of the vertical wall portion 55 and the extension wall portion 56. The blocking portion 54 is plate-shaped and extends in the front-to-rear and left-to-right directions. The blocking portion 54 is a roughly rectangular portion that is long in the left-to-right direction. Of the front end (tip) of the blocking portion 54, the left-to-right central portion 54a extends the furthest toward the side opposite the water inlet portion 40, and both left-to-right end portions 54b are shorter than the central portion 54a. The front end of the blocking portion 54 extends to a position that covers at least a portion of the water outlet passage 52.

As shown in Figure 7, in the EGR cooler 1 of this embodiment, the water outlet section 50 has a vertical wall section 55 that protrudes toward the inside of the casing 12 from the main body section 53 that is closer to the water inlet section 40 than the water outlet passage 52, and a blocking section 54 that extends from the tip of the vertical wall section 55 in a direction away from the water inlet section 40.
With this configuration, the vertical wall portion 55 and the blocking portion 54 allow the cooling water to flow to areas far from the water outlet portion 50, and the cooling water can flow more widely throughout the entire casing 12. This makes it possible to realize an EGR cooler 1 with better cooling efficiency.

7 , in the EGR cooler 1 of this embodiment, the water outlet portion 50 has a standing wall portion 55 and an extension wall portion 56. The standing wall portion 55 protrudes toward the inside of the casing 12 from the main body portion 53 on a side closer to the water inlet portion 40 than the water outlet passage 52, and extends so as to block the space between the water inlet portion 40 and the water outlet passage 52. The extension wall portions 56 extend from both ends of the standing wall portion 55 in directions away from the water inlet portion 40.
With this configuration, the blocking portion 54 allows the cooling water to flow in a direction away from the lower surface of the casing 12, and the extension wall portion 56 allows the cooling water to flow in a direction away from the water outlet portion 50. This allows the cooling water to circulate over a wider area, and allows the cooling water to flow more widely throughout the casing 12. This makes it possible to realize an EGR cooler 1 with better cooling efficiency.

Furthermore, as shown in Figures 6 and 7, in the EGR cooler 1 of this embodiment, the blocking portion 54 is provided inside the casing 12. Compared to when the blocking portion 54 is provided outside the casing 12, the EGR cooler 1 can be made smaller.

As shown in FIGS. 6 and 7 , in the EGR cooler 1 of this embodiment, the blocking portion 54 extends into the space between the inner surface of the casing 12 and the tube 11 .
With this configuration, the cooling water flowing from the water inlet 40 along the underside of the casing 12 can be directed toward the tubes 11 performing heat exchange, thereby further improving cooling efficiency.

7, in the EGR cooler 1 of this embodiment, the casing 12 is formed with a mounting hole 16 (see FIG. 6), and the main body 53 is mounted in the mounting hole 16. The EGR cooler 1 can be easily assembled by separately preparing an adapter 51 having a complex shape including a blocking portion 54 and mounting this adapter 51 to the casing 12.
Unlike the present embodiment, the water outlet 50 including the blocking portion 54 may be integrally formed with the casing 12. For example, if the casing 12 is made of a metal such as aluminum, stainless steel, or copper, the water outlet 50 can be formed integrally with the casing 12 by drilling, pressing, or the like.

7, in the EGR cooler 1 of this embodiment, the blocking portion 54 extends to face the water outlet passage 52. At the tip of the blocking portion 54, a central portion 54a corresponding to the water outlet passage 52 extends further toward the opposite side from the water inlet portion 40 than an end portion 54b.
3, the flow rate of cooling water flowing through the central region in the left-right direction within the casing 12 is generally greater than the flow rate of cooling water flowing through the left and right regions. The central portion 54a at the tip of the blocking portion 54 extends the longest on the side opposite the water inlet portion 40, making it difficult for cooling water to flow in the central region and easy for cooling water to flow in the left and right regions, thereby making the flow of cooling water within the casing 12 more uniform.

The shape of the adapter 51 is not limited to the shape described in the above embodiment. Fig. 8 is a top view showing an adapter 151 of an EGR cooler according to a first modified example of the present disclosure. Fig. 9 is a top view showing an adapter 251 of an EGR cooler according to a second modified example of the present disclosure.
8, the blocking portion 154 of the adapter 151 may have a shape that combines a rectangle and a semicircle when viewed from above. A standing wall portion 155 is provided at the top of the figure, and the blocking portion 154 extends from the standing wall portion 155 toward the gas inlet portion 20 (downward in the figure). In this case, too, the central portion 154a in the left-right direction of the tip of the blocking portion 154 extends further toward the gas inlet portion 20 than both end portions 154b.
9, the blocking portion 254 of the adapter 251 may be trapezoidal in top view. A standing wall portion 255 is provided at the top of the figure, and the blocking portion 254 extends from the standing wall portion 255 toward the gas inlet portion 20 (downward in the figure). In this case, too, the central portion 254a in the left-right direction of the tip of the blocking portion 254 extends further toward the gas inlet portion 20 than the end portion 254b.

In the above-described embodiment, an example in which the present disclosure is applied to an EGR cooler has been described, but the present disclosure may also be applied to a vehicle waste heat recovery device. A vehicle waste heat recovery device is a component that is also called a heat collector and is installed in a vehicle. A vehicle waste heat recovery device performs heat exchange between exhaust gas and coolant, and is used to warm the engine with the heated coolant to improve fuel efficiency. Such a vehicle waste heat recovery device also includes tubes, a casing, etc., and can be configured in a similar manner to the configuration described above.

This application incorporates, as appropriate, the contents disclosed in the Japanese patent application (Patent Application No. 2020-183825) filed on November 2, 2020.

REFERENCE SIGNS LIST 1 EGR cooler 10 heat exchange section 11 tube 12 casing 13 dimple 14 front end plate 15 rear end plate 16 mounting hole 20 gas inlet section 30 gas outlet section 40 water inlet section 50 water outlet section 51 adapter 52 water outlet passage 53 main body section 54 blocking section 55 standing wall section 56 extension wall section A front upper region

Claims (8)

The exhaust gas evaporator has a plurality of tubes through which exhaust gas flows, and a casing that houses the tubes.
An EGR cooler that performs heat exchange between the exhaust gas and the cooling water through the tubes by flowing cooling water inside the casing,
The EGR cooler is
a gas inlet for introducing the exhaust gas into the tube;
a gas outlet for discharging the exhaust gas from the tube;
a water inlet portion for introducing the cooling water into the casing;
a water outlet portion for discharging the cooling water from the casing,
The water outlet portion is
a main body portion forming a water outlet passage through which the cooling water passes;
a blocking portion extending from the main body portion closer to the water inlet portion than the water outlet passage in a direction away from the water inlet portion ,
The blocking portion extends to face the water outlet passage,
An EGR cooler , wherein a tip end of the blocking portion has a central portion corresponding to the water outlet passage that extends further toward the opposite side from the water inlet portion than the end portion . the water outlet portion is provided at a position closer to the gas inlet portion than the water inlet portion,
The EGR cooler of claim 1 , wherein the blocking portion extends toward the gas inlet portion. The water outlet portion is
a standing wall portion protruding toward the inside of the casing from the main body portion on a side closer to the water inlet portion than the water outlet passage;
The EGR cooler according to claim 1 , further comprising: the blocking portion extending from a tip of the standing wall portion in a direction away from the water inlet portion. The water outlet portion is
a standing wall portion that protrudes toward the inside of the casing from the main body portion on a side closer to the water inlet portion than the water outlet passage and extends so as to block the gap between the water inlet portion and the water outlet passage;
The EGR cooler according to claim 1 , further comprising: extension wall portions extending from both ends of the standing wall portion in a direction away from the water inlet portion. The EGR cooler of claim 1, wherein the blocking portion is provided inside the casing. The EGR cooler of claim 1, wherein the blocking portion extends into the space between the inner surface of the casing and the tube. The casing has a mounting hole formed therein,
The EGR cooler according to claim 1 , wherein the main body is attached to the attachment hole . The exhaust gas evaporator has a plurality of tubes through which exhaust gas flows, and a casing that houses the tubes.
A waste heat recovery device for a vehicle, in which heat exchange is performed between the exhaust gas and the cooling water through the tube by flowing cooling water inside the casing,
The vehicle waste heat recovery device includes:
a gas inlet for introducing the exhaust gas into the tube;
a gas outlet for discharging the exhaust gas from the tube;
a water inlet portion for introducing the cooling water into the casing;
a water outlet portion for discharging the cooling water from the casing,
The water outlet portion is
a main body portion forming a water outlet passage through which the cooling water passes;
a blocking portion extending from the main body portion closer to the water inlet portion than the water outlet passage in a direction away from the water inlet portion ,
The blocking portion extends to face the water outlet passage,
a central portion of the tip of the blocking portion corresponding to the water outlet passage extends further toward the opposite side of the water inlet portion than the end portion;