An EGRC pre-cooler

Abstract

The present invention discloses an EGRC pre-cooler, which comprises a housing. The housing is provided with a first cavity, a second cavity and a third cavity. The second cavity is provided with a cavity wall. A plurality of heat exchange tubes penetrating through the second cavity are arranged in the second cavity. The two ends of the heat exchange tubes are respectively communicated with the first cavity and the third cavity. Both the first cavity and the third cavity are single-sided open cavities. The opening surface of the first cavity is covered with a first cover plate, and a water inlet pipe is arranged on the first cover plate. The opening surface of the third cavity is covered with a second cover plate, and a water outlet pipe is arranged on the second cover plate. An air inlet is formed in a side surface of the second cavity parallel to the heat exchange tubes, and a connector is arranged at the air inlet end of the air inlet. An air outlet is formed in a side surface of the second cavity far away from the air inlet, and a flange end plate is arranged at the air outlet end of the air outlet. The beneficial effects of the present invention are as follows: the heat exchange speed is fast and the efficiency is high, realizing the rapid cooling of waste gas; it can prevent the temperature entering the EGRC from being too high, resulting in deformation, cracking and further damage of the EGRC.

Description

Technical Field

[0001] The present invention relates to the technical field of EGR coolers, and specifically to an EGR C pre-cooler. Background Art

[0002] In order to reduce the content of nitrogen oxides (NOX) in automobile exhaust gas, a part of the exhaust gas needs to be returned to the engine cylinder (i.e., the exhaust gas recirculation technology). The temperature of the exhaust gas is as high as 800 degrees. Before entering the engine intake system, it must be cooled down. Thus, the exhaust gas recirculation cooler (EGRC) came into being. The EGRC is a device installed in the automobile EGR system for cooling the reflux exhaust gas and cooling part of the exhaust gas returned to the engine cylinder. In the existing EGRC, there is no pre-cooling structure at the exhaust gas inlet end, and the exhaust gas cannot be cooled. The temperature of the exhaust gas entering the EGRC is too high, which easily causes damage to the EGRC. Especially for heavy-duty EGRC, its intake temperature is generally 750 - 850˚C, which causes very large thermal stress on the end plate and the internal heat exchange tubes of the EGRC, making the end plate and the heat exchange tubes prone to deformation and cracking, resulting in the failure of the EGRC. Summary of the Invention

[0003] The purpose of the present invention is to provide an EGR C pre-cooler to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: An EGR C pre-cooler includes a housing. The housing is provided with a first cavity, a second cavity, and a third cavity. The first cavity and the third cavity are respectively arranged on opposite sides of the second cavity. The second cavity is surrounded by a cavity wall. A plurality of heat exchange tubes passing through the second cavity are arranged in the second cavity. The two ends of the heat exchange tubes are respectively communicated with the first cavity and the third cavity. Both the first cavity and the third cavity are single-sided open cavities. The opening surfaces of the first cavity and the third cavity are both arranged on the side away from the second cavity. A first cover plate is provided on the opening surface of the first cavity. A water inlet pipe is provided on the first cover plate. A second cover plate is provided on the opening surface of the third cavity. A water outlet pipe is provided on the second cover plate. An air inlet is provided on a side surface of the second cavity parallel to the heat exchange tubes. A connector is provided at the air inlet end of the air inlet. An air outlet is provided on the side surface of the second cavity away from the air inlet. A flange end plate is provided at the air outlet end of the air outlet.

[0005] Further preferably, a threaded portion is provided in the middle of the heat exchange tube, which can increase the contact area between the exhaust gas and the heat exchange tube and improve the cooling effect of the exhaust gas; smooth surfaces are provided at both ends of the heat exchange tube to facilitate the installation of the heat exchange tube.

[0006] Further preferably, the heat exchange tube is a cylindrical pipe. Both smooth surfaces at both ends of the heat exchange tube are connected to the cavity wall by soldering with solder paste to ensure the sealing effect of the second cavity.

[0007] Further preferably, multiple heat exchange tubes are uniformly and staggeredly installed on the cavity wall to improve the cooling effect of the exhaust gas; the cavity wall is provided with first mounting holes for installing the heat exchange tubes, which is convenient for the installation of the heat exchange tubes.

[0008] Further preferably, the first cavity and the third cavity have the same height and are both greater than the height of the second cavity. The upper and lower ends of the first cavity and the third cavity are respectively wrapped around the upper and lower sides of the cavity wall of the second cavity, and a connecting wall is provided therebetween. The upper and lower ends of the connecting wall are respectively connected to the housing and the cavity wall, so that the cooling water can wrap the upper, lower, left and right four sides of the second cavity, improving the cooling effect of the exhaust gas in the second cavity.

[0009] Further preferably, a plurality of water guide holes are provided on the connecting wall, and the water guide holes communicate the first cavity and the third cavity, so that the cooling water in the first cavity can directly flow into the third cavity, improving the flow rate of the cooling water.

[0010] Further preferably, a groove is provided on the flange end plate, and the groove is arranged around the edge of the air outlet, which is convenient for the installation of the sealing ring and improves the sealing effect between the pre-cooler and the EGRC; a plurality of second connection holes are provided on the edge of the flange end plate, which is convenient for the connection between the pre-cooler and the EGRC.

[0011] Further preferably, first connection holes are provided on the sides of the water inlet pipe and the water outlet pipe, which is convenient for the connection between the water inlet pipe and the water outlet pipe and the corresponding pipes; a second mounting hole is provided on the water outlet pipe for installing a temperature sensor; the second mounting hole communicates with the pipe of the water outlet pipe, and the water outlet pipe is arranged at the bottom end of the second cover plate, which is convenient for the cooling water in the third cavity to flow out.

[0012] Further preferably, the air inlet is circular, and the position of the housing close to the air inlet is provided with an inclined surface structure, which can expand the flow area of the exhaust gas entering the second cavity, slow down the flow rate of the exhaust gas, and improve the cooling effect of the exhaust gas.

[0013] Further preferably, the housing, the cavity wall, the connecting head and the flange end plate are of an integrally formed structure, which is convenient for the processing of the pre-cooler, improves the processing efficiency and reduces the manufacturing cost.

[0014] Compared with the prior art, the EGRC pre-cooler of the present invention has the following beneficial effects:

[0015] 1. The cooling water is introduced into the first cavity through the water inlet pipe. The cooling water flows into the heat exchange tubes and the third cavity through the first cavity, and finally flows out through the water outlet pipe, so as to take away the heat generated by the exhaust gas in the second cavity and realize the cooling of the exhaust gas.

[0016] 2. The external surface area of the heat exchange tube can be increased through the threaded part, thereby increasing the contact area between the exhaust gas and the heat exchange tube, improving the heat exchange capacity of the heat exchange tube, enhancing the heat exchange speed, improving the heat exchange efficiency, and enabling the rapid cooling of the exhaust gas;

[0017] 3. By wrapping the first cavity and the third cavity around the upper, lower, left, and right four sides of the second cavity, the cooling water surrounds the second cavity, improving the heat exchange of the second cavity, enhancing the cooling effect of the exhaust gas, and accelerating the cooling of the exhaust gas;

[0018] 4. Through the water guiding holes, the cooling water in the first cavity can directly flow into the third cavity, further increasing the cooling speed of the exhaust gas and improving the cooling efficiency of the pre-cooler;

[0019] 5. This pre-cooler can reduce the intake temperature of the air entering the EGRC by about 100 °C, realizing the pre-cooling of the exhaust gas, and preventing the EGRC from being deformed, cracked, and damaged due to the too high temperature entering the EGRC;

[0020] 6. The structure of this pre-cooler is simple and compact, facilitating installation at the exhaust gas inlet end of the EGRC. Brief Description of the Drawings

[0021] Figure 1 It is a schematic cross-sectional structure view of the EGRC pre-cooler disclosed in the embodiment of the present invention;

[0022] Figure 2 It is a schematic perspective structure view of one perspective of the EGRC pre-cooler disclosed in the embodiment of the present invention;

[0023] Figure 3 It is a schematic perspective structure view of another perspective of the EGRC pre-cooler disclosed in the embodiment of the present invention;

[0024] Figure 4 It is a schematic front view structure view of the EGRC pre-cooler disclosed in the embodiment of the present invention;

[0025] Figure 5 It is a schematic rear view structure view of the EGRC pre-cooler disclosed in the embodiment of the present invention;

[0026] Figure 6 It is a schematic overall perspective structure view composed of the housing, cavity wall, connection head, and flange end plate disclosed in the embodiment of the present invention;

[0027] Figure 7 It is a schematic overall right view structure view composed of the housing, cavity wall, connection head, and flange end plate disclosed in the embodiment of the present invention;

[0028] Figure 8Schematic structural diagram of the overall assembly after the heat exchange tube is assembled with the housing, cavity wall, connector and flange end plate disclosed in the embodiment of the present invention;

[0029] Figure 9 Axonometric structural diagram of the heat exchange tube disclosed in the embodiment of the present invention.

[0030] Reference numerals: 1 - housing, 2 - first cavity, 3 - second cavity, 4 - third cavity, 5 - cavity wall, 6 - heat exchange tube, 61 - threaded part, 62 - smooth part, 7 - first cover plate, 8 - second cover plate, 9 - water inlet pipe, 91 - water inlet, 10 - water outlet pipe, 101 - water outlet, 11 - air inlet, 12 - connector, 13 - air outlet, 14 - flange end plate, 15 - groove, 16 - connecting wall, 17 - water guiding hole, 18 - first connecting hole, 19 - first mounting hole, 20 - second mounting hole, 21 - second connecting hole. Detailed implementation manners

[0031] The following are specific embodiments of the present invention and in combination with the accompanying drawings, the technical solutions of the present invention are further described, but the present invention is not limited to these embodiments.

[0032] As Figures 1-9As shown in the figure, an EGRC pre-cooler includes a housing 1, which is provided with a first cavity 2, a second cavity 3 and a third cavity 4. The first cavity 2 and the third cavity 4 are respectively arranged on opposite sides of the second cavity 3. Among them, the housing 1 is installed at the intake end of the heavy-duty EGRC, and the exhaust gas passes through this pre-cooler before entering the EGRC. The first cavity 2 and the third cavity 4 are cooling water cavities, and the second cavity 3 is an exhaust gas flow cavity. The second cavity 3 is provided with a cavity wall 5, and a plurality of heat exchange tubes 6 penetrating the second cavity 3 are arranged in the second cavity 3. The two ends of the heat exchange tube 6 are respectively communicated with the first cavity 2 and the third cavity 4. Through the heat exchange tube 6, the exhaust gas in the second cavity 3 can be cooled. The exhaust gas flows past the outer side of the heat exchange tube 6, and the cooling water flows through the pipeline of the heat exchange tube 6, so as to take away the heat of the exhaust gas in the second cavity 3 and realize the pre-cooling of the exhaust gas. Both the first cavity 2 and the third cavity 4 are single-sided open cavities, and the opening surfaces of the first cavity 2 and the third cavity 4 are both arranged on the side far from the second cavity 3. The opening surface of the first cavity 2 is covered with a first cover plate 7, and the first cover plate 7 is used for sealing the opening of the first cavity 2. A water inlet pipe 9 is arranged on the first cover plate 7 for introducing the cooling water into the first cavity 2. The cooling water flows into the heat exchange tube 6 and the third cavity 4 through the first cavity 2, and finally flows out through the water outlet pipe 10, so as to take away the heat generated by the exhaust gas in the second cavity 3 and realize the cooling of the exhaust gas; the opening surface of the third cavity 4 is covered with a second cover plate 8, and the second cover plate 8 is used for sealing the opening of the third cavity 4. A water outlet pipe 10 is arranged on the second cover plate 8 to facilitate the outflow of the cooling water in the third cavity 2, realize the circulation of the cooling water and take away the heat. In this application, this pre-cooler can reduce the intake temperature of the gas entering the EGRC by about 100°C, realize the pre-cooling of the exhaust gas, and prevent the EGRC from being deformed, cracked and damaged due to too high temperature entering the EGRC.

[0033] In this application, an air inlet 11 is opened on a side of the second cavity 3 parallel to the heat exchange tube 6 for the inflow of the exhaust gas. A connector 12 is arranged at the intake end of the air inlet 11 to realize the connection between this pre-cooler and the exhaust gas pipeline; an air outlet 13 is opened on the side of the second cavity 3 far from the air inlet 11 for the exhaust gas to flow out and flow into the exhaust gas pipeline of the EGRC. A flange end plate 14 is arranged at the outlet end of the air outlet 13 to realize the connection between this pre-cooler and the end plate of the EGRC. Among them, a groove 15 is arranged on the flange end plate 14, and the groove 15 is arranged around the edge of the air outlet 13. The groove 15 is used for embedding the sealing ring to ensure the sealing at the connection between this pre-cooler and the EGRC and prevent the exhaust gas from leaking through the connection between the pre-cooler and the EGRC; a plurality of second connection holes 21 are arranged on the edge of the flange end plate 14, and the connection between this pre-cooler and the EGRC can be realized by screwing through the second connection holes 21, and the connection is convenient and easy.

[0034] In this application, a threaded portion 61 is provided in the middle of the heat exchange tube 6, which can increase the outer surface area of the heat exchange tube 6, thereby increasing the contact area between the exhaust gas and the heat exchange tube 6, improving the heat exchange capacity of the heat exchange tube 6, increasing the heat exchange speed, improving the heat exchange efficiency, and enabling the rapid cooling of the exhaust gas; smooth portions 62 are provided at both ends of the heat exchange tube 6 to facilitate the connection of the heat exchange tube 6 to the cavity wall 5. A first mounting hole 19 for mounting the heat exchange tube 6 is provided on the cavity wall 5. The smooth portions 62 at both ends of the heat exchange tube 6 are in clearance fit with the cavity wall 5, and then brazing paste is applied for brazing and sealing, that is, the smooth portion 62 and the first mounting hole 19 are connected by brazing to ensure the sealing effect of the first cavity 2, the second cavity 3, and the third cavity 4, and prevent the cooling water from entering the second cavity 3 through the gap between the heat exchange tube 6 and the cavity wall 5. Among them, the heat exchange tube 6 is a cylindrical pipe, which is convenient for the processing of the heat exchange tube 6; multiple heat exchange tubes 6 are evenly and staggeredly mounted on the cavity wall 5. In this application, multiple heat exchange tubes 6 are arranged in multiple horizontal rows, and each row has multiple heat exchange tubes 6 arranged longitudinally, and the heat exchange tubes 6 in adjacent rows are staggeredly arranged, so that the exhaust gas flowing through the heat exchange tube 6 can be cooled by multiple heat exchange tubes 6, realizing the rapid cooling of the exhaust gas.

[0035] In this application, the first cavity 2 and the third cavity 4 have the same height and are both greater than the height of the second cavity 3. The upper and lower ends of the first cavity 2 and the third cavity 4 are both wrapped around the upper and lower sides of the cavity wall 5 of the second cavity 3, and a connecting wall 16 is provided therebetween. The upper and lower ends of the connecting wall 16 are respectively connected to the housing 1 and the cavity wall 5. By wrapping the upper and lower ends of the first cavity 2 and the third cavity 4 around the upper and lower sides of the cavity wall 5 of the second cavity 3, the cooling water surrounds the second cavity 3, improving the heat exchange of the second cavity 3, improving the cooling effect of the exhaust gas, and accelerating the cooling of the exhaust gas.

[0036] In this application, a plurality of water guiding holes 17 can also be provided on the connecting wall 16. The water guiding holes 17 communicate the first cavity 2 and the third cavity 4, facilitating the direct connection between the first cavity 2 and the third cavity 4, so that the cooling water entering the first cavity 2 through the water inlet pipe 9 can directly flow into the third cavity 4, enabling the cooling water to be present on the upper, lower, left, and right four sides of the second cavity 3, which can improve the cooling speed of the exhaust gas in the second cavity 3. At the same time, the water guiding holes 17 increase the flow rate of the cooling water, further improving the cooling speed of the exhaust gas and the cooling efficiency of the pre-cooler.

[0037] In this application, first connection holes 18 are provided on the sides of the water inlet pipe 9 and the water outlet pipe 10 to facilitate the connection of the water inlet pipe 9 and the water outlet pipe 10 to the external pipeline; a second mounting hole 20 is provided on the water outlet pipe 10. The second mounting hole 20 is used for mounting a temperature sensor, and the second mounting hole 20 communicates with the pipeline of the water outlet pipe 10, enabling the temperature sensor to directly contact the cooling water flowing out of the third cavity 4, realizing the detection of the water temperature, and the temperature measurement result is more accurate; the water outlet pipe 10 is arranged at the bottom end of the second cover plate 8 to facilitate the outflow of the cooling water in the third cavity 4.

[0038] In this application, the air inlet 11 is circular, which is convenient for the connection of the air inlet pipe; the position of the housing 1 close to the air inlet 11 is provided with an inclined surface structure, which can expand the flow area of the waste gas, slow down the impact force of the waste gas on the heat exchange tube 6, reduce the flow velocity of the waste gas, increase the cooling time of the waste gas, and improve the cooling effect of the waste gas.

[0039] In this application, the housing 1, the cavity wall 5, the connector 12 and the flange end plate 14 are of an integrally formed structure, which reduces the processing of the components of the pre-cooler, reduces the assembly process, improves the assembly efficiency of the pre-cooler, and reduces the production cost; at the same time, the integrally structured housing 1, cavity wall 5, connector 12 and flange end plate 14 have high structural strength and good sealing performance.

[0040] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An EGRC pre-cooler, characterized in that: It includes a housing (1), the housing (1) is provided with a first cavity (2), a second cavity (3) and a third cavity (4), the first cavity (2) and the third cavity (4) are respectively arranged on opposite sides of the second cavity (3), the second cavity (3) is wrapped with a cavity wall (5), and a plurality of heat exchange tubes (6) penetrating through the second cavity (3) are arranged in the second cavity (3). The two ends of the heat exchange tube (6) are respectively communicated with the first cavity (2) and the third cavity (4). Both the first cavity (2) and the third cavity (4) are single-sided open cavities, and the opening surfaces of the first cavity (2) and the third cavity (4) are both arranged on the side away from the second cavity (3). The opening surface of the first cavity (2) is covered with a first cover plate (7), and a water inlet pipe (9) is arranged on the first cover plate (7). The opening surface of the third cavity (4) is covered with a second cover plate (8), and a water outlet pipe (10) is arranged on the second cover plate (8). An air inlet (11) is opened on one side of the second cavity (3) parallel to the heat exchange tube (6), and a connector (12) is arranged at the air inlet end of the air inlet (11). An air outlet (13) is opened on the side of the second cavity (3) away from the air inlet (11), and a flange end plate (14) is arranged at the air outlet end of the air outlet (13). A threaded portion (61) is arranged in the middle of the heat exchange tube (6), and smooth surfaces (62) are arranged at both ends of the heat exchange tube (6). The heights of the first cavity (2) and the third cavity (4) are the same and both are greater than the height of the second cavity (3). The upper and lower ends of the first cavity (2) and the third cavity (4) are respectively wrapped on the upper and lower sides of the cavity wall (5) of the second cavity (3), and a connecting wall (16) is arranged between them. The upper and lower ends of the connecting wall (16) are respectively connected to the housing (1) and the cavity wall (5), and a plurality of water guide holes (17) are arranged on the connecting wall (16). The water guide holes (17) communicate the first cavity (2) and the third cavity (4).

2. An EGRC pre-cooler according to claim 1, characterized in that: The heat exchange tube (6) is a cylindrical pipe, and the smooth surfaces (62) at both ends of the heat exchange tube (6) are both connected to the cavity wall (5) by soldering with solder paste.

3. An EGRC pre-cooler according to claim 2, characterized in that: A plurality of the heat exchange tubes (6) are evenly and staggeredly installed on the cavity wall (5), and a first installation hole (19) for installing the heat exchange tube (6) is arranged on the cavity wall (5).

4. An EGRC pre-cooler according to claim 1, characterized in that: A groove (15) is arranged on the flange end plate (14), the groove (15) is arranged around the edge of the air outlet (13), and a plurality of second connection holes (21) are arranged on the edge of the flange end plate (14).

5. An EGRC pre-cooler according to claim 1, characterized in that: The sides of the inlet pipe (9) and the outlet pipe (10) are both provided with first connection holes (18). The outlet pipe (10) is provided with a second installation hole (20), and the second installation hole (20) communicates with the pipeline of the outlet pipe (10). The outlet pipe (10) is arranged at the bottom end of the second cover plate (8).

6. An EGRC pre-cooler according to claim 1, characterized in that: the air inlet (11) is circular, and the position of the housing (1) close to the air inlet (11) is arranged in an inclined surface structure.

7. An EGRC pre-cooler according to claim 1, characterized in that: the housing (1), the cavity wall (5), the connector (12) and the flange end plate (14) are of an integrally formed structure.

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