Exhaust gas cooling device

Abstract

The invention relates to an exhaust gas cooling device (1) for an internal combustion engine, comprising: a housing (3.6) configured to be connected to an exhaust gas line (1.1) of the internal combustion engine (8), having an axis of symmetry (3.5); and a venturi assembly (5) connected to the housing (3.6) for introducing exhaust gas (1.2) and ambient air (9); the venturi assembly (5) comprises a venturi tube (5.1) configured to be in fluid connection with the exhaust gas pipeline (1.1), and an inlet (5.2) of ambient air defined by the venturi tube (5.1) and the exhaust gas pipeline (1.1), the inlet (5.2) being in fluid connection with an ambient air channel (3.2), and wherein the inlet (5.2) of the ambient air is in fluid connection with the venturi tube (5.1). The venturi tube (5.1) is configured to guide the exhaust gas / ambient air mixture and to lead to a mixing chamber (3.1) through an inlet (5.2), the venturi tube (5.1) comprises an outlet (5.3), the outlet pipeline (2) comprises an inlet (2.1), the outlet (5.3) and the inlet (2.1) are arranged at intervals, the venturi tube (5.1) and the outlet pipeline (2) comprising the inlet (2.1) lead to the housing (3.6), and the venturi tube (5.1) is configured to guide the exhaust gas / ambient air mixture to the mixing chamber (3.1) through the inlet (5.2). A communication pipe (2.3) is provided, by means of which the ambient air channel (3.2) is connected to the outlet line (2) for gas exchange.

Description

[0001] The present invention relates to an exhaust gas cooling device for a hot gas source (such as an internal combustion engine or a fuel cell), which includes a shell that can be connected to the exhaust gas pipeline of the internal combustion engine or a battery, the shell defining a mixing chamber and having a symmetry axis; and a Venturi component connected to the shell for introducing exhaust gas and ambient air into the mixing chamber; it also includes an outlet pipeline for discharging the exhaust gas / ambient air mixture into the environment; wherein the Venturi component includes a Venturi tube that can be fluidly connected to the exhaust gas pipeline, and an ambient air inlet defined by the Venturi tube and the exhaust gas pipeline, the inlet being fluidly connected to the ambient air channel, wherein the Venturi tube is configured to guide the exhaust gas-ambient air mixture and lead to the mixing chamber of the shell through the outlet.

[0002] From US 8,549,850 B2, an exhaust gas cooling device is known, which has a Venturi device for supplying ambient air. The exhaust gas cooling device comprises several exhaust gas inlet pipes and a Venturi tube located downstream. In addition, several ambient air inlets are provided. The exhaust gas and the sucked-in ambient air are mixed through the Venturi tube and discharged to the surrounding environment.

[0003] WO 03069 136A1 discloses a particle cleaning unit for a vehicle exhaust system. The particle cleaning unit comprises a housing having a venturi assembly for tangentially introducing exhaust gas and mixing with ambient air. The exhaust gas is accelerated in the circumferential direction in the housing and is led out of the housing in a central manner through an outlet pipe.

[0004] US Pat. No. 4,209,493 B discloses an exhaust gas aftertreatment component having a housing wall and a resonance chamber arranged between the housing wall and the catalytic converter.

[0005] US Pat. No. 4,579,194 B discloses an exhaust gas aftertreatment component which has a plurality of chambers in a housing, one of which is provided with an ambient air supply line.

[0006] JP S49-84505 A discloses an exhaust gas aftertreatment component having a plurality of chambers in a housing, one of which is designed as a resonance chamber.

[0007] The invention is based on the problem of designing and arranging an exhaust gas cooling device in order to provide an improved mixing of the exhaust gas / ambient air mixture.

[0008] According to the invention, this problem is solved in the following way: the outlet line comprises an inlet, wherein the inlet and the outlet of the venturi are arranged at intervals and open to the housing, wherein a connecting pipe is provided, through which the ambient air channel is directly connected to the outlet line for gas exchange. The outlet line is used to guide the exhaust gas / ambient air mixture from the interior of the housing to another exhaust gas duct or the environment. The inlet can be designed as an annular gap. This ensures that the exhaust gas / ambient air mixture is guided in the housing for a longer residence time and a longer flow distance, thereby improving the mixing effect before being guided to the environment through the outlet line. The connecting pipe is connected to the ambient air channel upstream of the ambient air inlet. In addition, the connecting pipe is connected to the outlet line downstream of the inlet. The connecting pipe ensures that ambient air is additionally mixed into the outlet line, thereby further reducing the temperature of the exhaust gas-ambient air mixture in the outlet line. In other words, the connecting pipe acts as a bypass line for fresh air and directly conveys fresh air to the outlet line.

[0009] It may also be advantageous if the housing delimits a mixing chamber by means of a chamber wall, wherein the outlet of the venturi has an outlet cross section Qv and the mixing chamber forms a flow cross section Qm for the exhaust gas / ambient air mixture flowing out of the venturi, wherein Qm ≥ f Qv, wherein 2 ≤ f ≤ 12, in particular when f = 6, f = 7 or f = 8. Due to the increased flow cross section when entering the housing and / or the mixing chamber, the flow velocity is reduced, resulting in a longer residence time in the housing.

[0010] It may also be advantageous if the outlet of the venturi and the inlet of the outlet line are arranged offset. This offset or displacement, achieved by different orientations of the openings, increases the path that the exhaust gas / ambient air mixture has to travel within the housing. This alignment and / or displacement or orientation refers to the respective center axes of the outlet and inlet, or to the flow vectors defined by the respective center axes, such as gas outlet A and gas inlet E. This offset can also be achieved by different orientations of the flow vectors.

[0011] It may also be advantageous if the outlet of the Venturi tube and the inlet of the outlet line are arranged in alignment, wherein a flow guide element is arranged between the outlet and the inlet, which deflects the gas flow in a direction Rq which contains a directional component perpendicular to the direction of the gas outlet A of the outlet. Despite the above alignment, this is also accompanied by an increase in the flow path in the mixing chamber.

[0012] Furthermore, no matter which alignment is adopted, it is very advantageous if the outlet of the venturi tube and the inlet of the outlet pipeline are arranged in the same mixing chamber.

[0013] This arrangement may be advantageous if the outlet of the venturi tube creates a radial gas outlet A relative to the symmetry axis, while the outlet line together with the inlet creates a parallel gas inlet E to the symmetry axis. This ensures a deflection of the gas flow of at least 90° and thus increases the flow path.

[0014] For the present invention, it may be particularly important if the mixing chamber has a circular cross-sectional shape Q at least partially relative to the axis of symmetry, or a swirl device is provided on the chamber wall, wherein when the gas flow hits the circular chamber wall or the swirl device, the gas outlet A generates at least one double vortex in the mixing chamber in the opposite direction relative to the axis of symmetry. On the one hand, at least one double vortex prolongs the flow path and thus prolongs the residence time. On the other hand, improved mixing is achieved due to the vortex parts of the generated double vortex being in opposite directions relative to each other. When these vortex parts converge or collide, a very good mixing effect can be achieved. The circular shape of the chamber wall can include circular, elliptical or other circular shapes. Fin-shaped or wing-shaped swirl devices can also be formed by the chamber wall, or they can be integrated with the chamber wall. If corresponding swirl devices are provided on the chamber wall, the mixing chamber can also have an angular cross-sectional shape Q. Maximum mixing of exhaust gas and ambient air is important for preventing hot air masses from escaping from the outlet duct.

[0015] With regard to the mixing chamber, it may be advantageous to have:

[0016] a) the outlet produces a gas outlet in a direction R radial to the axis of symmetry, or

[0017] b) A flow guide element is provided, by which the gas outlet flowing out of the outlet is deflected into a direction Rq, which direction Rq contains a directional component R radial to the axis of symmetry.

[0018] The direction Rq may also be a radial direction R without any axial component. Thus, the exhaust gas / ambient air mixture is directed radially from the venturi to the chamber wall, where it flows in the circumferential direction of the chamber wall due to the circular shape of the housing or due to the curved chamber wall. This results in a heat exchange with the chamber wall, which results in a further cooling of the exhaust gas / ambient air mixture.

[0019] Further, according to the design and arrangement of the present invention, if the venturi tube forms a mixing stage Mv with a volume Vv, and the mixing chamber forms a mixing stage Mm with a volume Vm, and the outlet pipeline forms a mixing stage Ma with a volume Va, wherein for a ratio S1 of Vm to Vv, it satisfies:

[0020] 25≥S1≥2, in particular 16≥S1≥12, and / or

[0021] For the ratio S2 of Vm to Va, it satisfies:

[0022] 25≥S2≥2, especially 16≥S2≥12,

[0023] The relative size of the mixing chamber also determines the achievable flow path length of the gas flow within the otherwise closed mixing chamber. A relatively large mixing chamber ensures a relatively large or long flow path.

[0024] It may also be advantageous if a silencer is provided inside the mixing chamber and / or upstream of the Venturi assembly.

[0025] Furthermore, it may also be advantageous to provide eddy currents or flow guides in the mixing chamber, thereby further improving the mixing effect.

[0026] It may also be advantageous if baffles are provided upstream of or at the ambient air inlet to capture ambient air or relative wind / air flow, thereby actively increasing the amount of ambient air supplied.

[0027] Ambient air can also be supplied directly via an ambient air inlet. In this case, the inlet leads to the surrounding environment. An ambient air inlet which must pass through the housing is not required.

[0028] Furthermore, a bypass device is provided which comprises a bypass line, via which the exhaust gas can be conducted to a bypass outlet, bypassing the cooling device.

[0029] Furthermore, it may be advantageous if the venturi and the outlet line including the inlet lead into the same mixing chamber of the housing. The exhaust gas / ambient air mixture is cooled in the mixing chamber, in particular by transferring heat to the chamber wall. The exhaust gas / ambient air mixture can be discharged from the mixing chamber through the inlet of the outlet line immediately after cooling or after flowing through the mixing chamber.

[0030] For this purpose, it may be advantageous if the mixing chamber does not contain partitions or housing partitions. This ensures an optimal flow of the exhaust gas / ambient air mixture within the individual mixing chambers. Pressure losses associated with partitions or housing partitions are avoided. Partitions or housing partitions are considered to be walls in the mixing chamber which are provided with one or more openings or perforations. These walls divide the mixing chamber into two partial mixing chambers which are in fluid communication.

[0031] For this purpose, it may be advantageous if the inlet communicates with the environment via an ambient air channel and an ambient air inlet through the housing, wherein the ambient air inlet is arranged radially with respect to the axis of symmetry. This causes the incoming ambient air to have a radial directional component, which directional component can be at least partially deflected by the cylindrical ambient air channel into a circumferential direction with respect to the axis of symmetry. The ambient air thus has a circumferential and an axial directional component with respect to the axis of symmetry. This ensures that an initial mixing of the exhaust gas and the ambient air is achieved in the venturi.

[0032] Further advantages and details of the invention are given in the claims and the description and are shown in the drawings. It shows:

[0033] Figure 1a yes Figure 2 BB line cross-sectional view;

[0034] Figure 1b is a cross-sectional view of another embodiment;

[0035] Figure 2 yes Figure 3 AA line section view;

[0036] Figure 3 It is a schematic diagram;

[0037] Figure 4 are different cross-sectional shapes;

[0038] Figure 5 is a schematic diagram of another implementation.

[0039] like Figure 1a In the BB cross-sectional view shown, an exhaust gas cooling device 1 is connected to an exhaust gas line 1.1 for exhaust gas 1.2. The exhaust gas line 1.1 is an outlet or outlet pipe of an exhaust gas purification system 8.2 (such as a catalytic converter housing). The exhaust gas cooling device 1 includes a housing 3.6 and a cavity wall 3.4, which define a mixing chamber 3.1. A venturi assembly 5 and its venturi tube 5.1 are arranged in the housing 3.6, and the venturi tube is fluidically connected to the exhaust gas line 1.1 via an exhaust gas inlet 5.4, that is, it is blown into. In addition, the venturi assembly 5 includes an inlet 5.2 for ambient air 9, which is defined on the one hand by the exhaust gas line 1.1 and on the other hand by the venturi tube 5.1. The inlet 5.2 for ambient air 9 is connected to an ambient air channel 3.2, which circumferentially surrounds the venturi tube 5.1. The ambient air channel 3.2 is in turn connected to the environment via the air inlet 3.3 passing through the housing 3.6, so that the ambient air 9 is guided to the inlet 5.2 via the ambient air inlet 3.3 and the ambient air channel 3.2. Figure 3 As shown, the ambient air inlet 3.3 may include a guide plate 3.7 for capturing ambient air 9. The ambient air channel 3.2 and the outlet pipeline 2 are fluidly connected via a connecting pipe 2.3. The ambient air 9 entering through the air inlet 3.3 is at least partially delivered to the connecting pipe 2.3 according to the current pressure conditions, and further delivered to the downstream of the outlet pipeline 2.

[0040] Thus, the venturi tube 5.1 guides the exhaust gas / ambient air mixture in the direction of the symmetry axis 3.5 of the housing 3.6 or the mixing chamber 3.1, wherein the venturi tube 5.1 has a 90° bend at the end, so that a gas outlet A is formed through the outlet 5.3 of the venturi tube 5.1 in the radial direction R relative to the symmetry axis 3.5. Figure 2 As shown, the exhaust gas / ambient air mixture flowing out of the outlet 5.3 hits the upper chamber wall 3.4 or the cyclone device 7 arranged there, so that due to Figure 2 The circular cross-sectional shape Q shown forms a counter-rotating double vortex of the exhaust gas / ambient air mixture. In this case, the direction Rq corresponds to the radial direction R.

[0041] The housing 3.6 further comprises an outlet line 2 with an inlet 2.1, through which the exhaust gas / ambient air mixture is led from the housing 3.6 or the mixing chamber 3.1 to the outside or the environment. The inlet 2.1 ensures that the gas inlet E for the exhaust gas / ambient air mixture runs in the axial direction. The staggered or different orientation of the gas outlet A and the gas inlet E and the offset orientation ensure a correspondingly longer flow path in the mixing chamber 3.1. In this case, the outlet 5.3 of the venturi has an outlet cross section Qv, which is significantly smaller than the flow cross section Qm provided for the exhaust gas / ambient air mixture through the mixing chamber 3.1. This leads to a corresponding delay in the flow velocity of the exhaust gas / ambient air mixture, thereby increasing the residence time in the mixing chamber 3.1.

[0042] An additional flow guiding device 7.1 is also provided in the mixing chamber 3.1 for guiding the air flow toward the inlet 2.1.

[0043] Arranged upstream of the Venturi assembly 5 is a silencer 6 , against which the exhaust gas 1 . 2 impinges immediately after leaving the exhaust gas purification system 8 . 2 .

[0044] The exhaust gas cooling device 1 comprises three mixing stages: a mixing stage Mv of the venturi 5.1 with a volume Vv, a mixing stage Mm of the mixing chamber 3.1 with a volume Vm, and a mixing stage Ma of the outlet line 2 with a volume Va. The volume Vm of the mixing stage Mm is approximately 14 times the volume Vv, Va of the other two mixing stages Mv, Ma by a factor S1, S2.

[0045] exist Figure 1b In the embodiment shown, the gas outlet A and the gas inlet E have the same orientation. Furthermore, the outlet 5.3 of the venturi and the inlet 2.1 of the outlet line 2 are aligned. In order to prevent direct blowing into the inlet 2.1 through the venturi 5.1, a flow guide element 4 is provided, by which the gas flow is guided radially outwards to the mixing chamber 3.1 in order to complete a sufficiently long flow path there to ensure the desired mixing of the exhaust gas / ambient air mixture. The gas flow out of the outlet 5.3 of the venturi or the gas outlet A is deflected by the flow guide element 4 into a direction Rq, which contains a radial component R relative to the axis of symmetry 3.5. In addition, it also contains a relatively small axial component parallel to the axis of symmetry 3.5.

[0046] according to Figure 1a , 1bIn the embodiment shown, the mixing chamber 3.1 does not contain a partition / intermediate wall or a housing partition. In an alternative embodiment not shown, the mixing chamber 3.1 can have at least one partition or housing partition provided with one or more passage openings or perforations. Thus, the mixing chamber 3.1 is divided into two partial mixing chambers with fluid communication.

[0047] Figure 3 The exhaust gas cooling device 1 is shown with an ambient air inlet 3.3, which is located downstream of an exhaust gas purification system 8.2. The exhaust gas purification system 8.2 is in turn connected to the internal combustion engine 8 via an exhaust gas line section 8.1. The cooled exhaust gas 1.2 leaves the exhaust system via an outlet line 2.

[0048] Figure 2 Shows Figure 3 AA cross-sectional view. Also shown is Figure 1a A cross-sectional view taken along line BB of the illustrated embodiment.

[0049] The ambient air 9 is guided via the ambient air inlet 3.3 to the ambient air channel 3.2, which circumferentially surrounds the Venturi 5.1, so that the ambient air 9 can enter the Venturi 5.1 via the inlet 5.2 between the Venturi 5.1 and the exhaust gas line 1.1. The exhaust gas / ambient air mixture then leaves the Venturi 5.1 radially upwards along a directional component R and strikes the concave chamber wall 3.4 or the swirl device 7 optionally / alternatively arranged therein, thereby forming an opposing double vortex, which in turn ensures that the exhaust gas / ambient air mixture has a corresponding flow path within the mixing chamber 3.1 before being discharged to the outside or the environment via the inlet 2.1 of the outlet line 2.

[0050] In the area where the exhaust gas / ambient air mixture strikes the chamber wall 3.4 from the venturi 5.1, the concave shape of the chamber wall 3.4 ensures the formation of a double vortex. Figure 4 As shown, the concave shape is achieved by a corresponding circular or elliptical cross-sectional shape Q of the chamber wall 3.4. Of course, other cross-sectional shapes can also be used, which ensure the formation of corresponding double vortices or single vortices when the airflow hits, thereby increasing the overall flow path and residence time of the airflow in the mixing chamber 3.1. Figure 4 The angular cross-sectional shape Q shown requires corresponding swirl means 7, 7.1 to be provided on the chamber wall 3.4.

[0051] The inlet 5.2 is connected to the environment or ambient air 9 via the ambient air channel 3.2 and the air inlet 3.3 passing through the housing 3.6. The ambient air inlet 3.3 is arranged radially with respect to the axis of symmetry 3.5. It is at least partially deflected by the cylindrical ambient air channel 3.2 into a circumferential direction with respect to the axis of symmetry 3.5 and enters the inlet 5.2 of the ambient air 9 with at least one axial direction component with respect to the axis of symmetry 3.5 or in a direction parallel to the exhaust gas 1.2. The ambient air channel 3.2 and the outlet line 2 are fluidically connected via a connecting pipe 2.3. For this purpose, the connecting pipe 2.3 is connected to the ambient air channel 3.2 upstream of the ambient air inlet 5.2. The connecting pipe 2.3 is connected to the outlet line 2 downstream of the inlet 2.1. This means that the ambient air 9 entering through the air inlet 3.3 can be at least partially conveyed to the connecting pipe 2.3 and further conveyed downstream to the outlet line 2.

[0052] according to Figure 5 The embodiment of the exhaust gas cooling device 1 shown is arranged directly downstream of a hot gas source 8, such as an internal combustion engine or a fuel cell. In addition, the exhaust gas cooling device 1 comprises a bypass device 8.3 with a bypass line 8.4 and a bypass outlet 8.5, through which the exhaust gas can bypass the exhaust gas cooling device 1 and be discharged directly into the environment.

[0053] Reference numerals list

[0054] 1 Exhaust gas cooling device

[0055] 1.1 Exhaust gas pipeline, hot gas pipeline

[0056] 1.2 Exhaust gas

[0057] 2Export pipe

[0058] 2.1 Inflow opening and inlet

[0059] 2.3 Connecting pipe

[0060] 3.1 Mixing chamber

[0061] 3.2 Ambient air channel

[0062] 3.3 Ambient air inlet

[0063] 3.4 Cavity wall

[0064] 3.5 Axis of symmetry

[0065] 3.6 Shell

[0066] 3.7 Guide plate

[0067] 4. Flow guide element

[0068] 5 Venturi Components

[0069] 5.1 Venturi tube

[0070] 5.2 Ambient air inlet

[0071] 5.3 Venturi tube outlet

[0072] 5.4 Exhaust gas inlet and exhaust gas pipeline

[0073] 6. Silencer

[0074] 7. Cyclone device

[0075] 7.1 Other eddy current or flow guide devices

[0076] 8 Internal combustion engine, fuel cell, hot gas source

[0077] 8.1 Exhaust pipe section

[0078] 8.2 Exhaust gas purification system

[0079] 8.3 Bypass device

[0080] 8.4 Bypass Pipeline

[0081] 8.5 Bypass outlet

[0082] 9. Ambient air

[0083] Other terms

[0084] AGas outlet

[0085] E Gas Inlet

[0086] Ma Mixed

[0087] Mm mixed grade

[0088] Mv mixed grade

[0089] Q Cross-sectional shape

[0090] Qm flow cross section

[0091] Qv outlet cross section

[0092] R radial component

[0093] Rq direction

[0094] S1 ratio, coefficient

[0095] S2 ratio, coefficient

[0096] Va Volume

[0097] Vm volume

[0098] Vv Volume

Claims

1. An exhaust gas cooling device (1) for a hot gas source (8), comprising: a housing (3.6) configured to be connected to an exhaust gas line (1.1) of the hot gas source (8), having an axis of symmetry (3.5) and defining a mixing chamber (3.1) having a cavity wall (3.4); and a venturi assembly (5) connected to the housing (3.6) for introducing the exhaust gas (1.2) and ambient air (9) into the mixing chamber (3.1); and an outlet line (2) for discharging the exhaust gas / ambient air mixture into the environment, The venturi assembly (5) comprises a venturi tube (5.1) configured to be fluidically connected to the exhaust gas line (1.1), and an inlet (5.2) for ambient air defined by the venturi tube (5.1) and the exhaust gas line (1.1), the inlet (5.2) being fluidically connected to the ambient air channel (3.2), wherein the venturi tube (5.1) is configured to guide the exhaust gas / ambient air mixture through an outlet (5.3) to a mixing chamber (3.1) of the housing (3.6), It is characterized in that The outlet pipeline (2) comprises an inlet (2.1), wherein the outlet (5.3) of the venturi tube (5.1) is spaced apart from the inlet (2.1) and leads to the mixing chamber (3.1), A connecting pipe (2.3) is provided, through which the ambient air channel (3.2) is connected to the outlet pipeline (2) for gas exchange.

2. The exhaust gas cooling device (1) according to claim 1, characterized in that The housing (3.6) defines the mixing chamber (3.1) through a cavity wall (3.4), wherein the outlet (5.3) of the Venturi tube (5.1) has an outlet cross section Qv, and the mixing chamber (3.1) forms a flow cross section Qm for the exhaust gas / ambient air mixture flowing out of the Venturi tube (5.1), Among them, Qm ≥ f Qv, Among them, 2≤f≤10.

3. The exhaust gas cooling device (1) according to claim 1 or 2, characterized in that: The outlet (5.3) of the Venturi tube (5.1) and the inlet (2.1) of the outlet pipeline (2) are arranged in a staggered manner.

4. The exhaust gas cooling device (1) according to claim 1 or 2, characterized in that: The outlet (5.3) of the venturi tube (5.1) is aligned with the inlet (2.1) of the outlet pipeline (2), A flow-guiding element (4) is provided between the outlet (5.3) and the inlet (2.1), and the flow-guiding element (4) realizes deflection in a direction Rq, wherein the direction Rq includes a directional component R perpendicular to a gas outlet direction A of the outlet (5.3).

5. The exhaust gas cooling device (1) according to any one of claims 1 to 3, characterized in that: The outlet (5.3) of the Venturi tube (5.1) produces a gas outlet A radial to the axis of symmetry (3.5), wherein the outlet line (2) together with the inlet (2.1) produces a gas inlet E parallel to the axis of symmetry (3.5).

6. Exhaust gas cooling device (1) according to any one of the preceding claims, characterized in that The mixing chamber (3.1) at least partially has a circular cross-sectional shape Q relative to the axis of symmetry (3.5), or a swirl device (7) is provided on the chamber wall (3.4), When the airflow impacts the circular cavity wall (3.4) or the swirl device (7), the gas outlet A generates double vortices in at least opposite directions relative to the symmetry axis (3.5) in the mixing chamber (3.1).

7. Exhaust gas cooling device (1) according to any one of the preceding claims, characterized in that a) the outlet (5.3) produces a gas outlet in a direction R radial to the axis of symmetry (3.5), or b) A flow guide element (4) is provided, by which the gas outlet flowing out of the outlet (5.3) is deflected to a direction Rq, which direction Rq contains a radial direction component R relative to the symmetry axis (3.5).

8. Exhaust gas cooling device (1) according to any one of the preceding claims, characterized in that The venturi (5.1) forms a mixing stage Mv having a volume Vv; and The mixing chamber (3.1) forms a mixing stage Mm having a volume Vm; and The outlet line (2) forms a mixing stage Ma having a volume Va, Among them, for the ratio S1 of Vm to Vv, it satisfies: 25≥S1≥2; and / or For the ratio S2 of Vm to Va, it satisfies: 25≥S2≥2。 9. Exhaust gas cooling device (1) according to any one of the preceding claims, characterized in that A silencer (6) is arranged inside the mixing chamber (3.1) and / or upstream of the Venturi assembly (5).

10. The exhaust gas cooling device (1) according to any one of claims 6 to 9, characterized in that An additional swirl or flow guiding device (7.1) is arranged inside the mixing chamber (3.1).

11. Exhaust gas cooling device (1) according to any one of the preceding claims, characterized in that A guide plate (3.7) for capturing ambient air (9) is arranged upstream of the ambient air inlet (5.2).

12. Exhaust gas cooling device (1) according to any one of the preceding claims, characterized in that A bypass device (8.3) comprising a bypass line (8.4) is provided, through which the exhaust gas can be guided to a bypass outlet (8.5) bypassing the cooling device (1).

13. Exhaust gas cooling device (1) according to any one of the preceding claims, characterized in that The venturi tube (5.1) and the outlet line (2) including the inlet (2.1) open into the same mixing chamber (3.1) of the housing (3.6).

14. Exhaust gas cooling device (1) according to any of the preceding claims, characterized in that The mixing chamber (3.1) contains no partitions or housing partitions.

15. Exhaust gas cooling device (1) according to any one of the preceding claims, characterized in that The inlet (5.2) is connected to the environment through an ambient air channel (3.2) and an ambient air inlet (3.3) passing through the housing (3.6), The ambient air inlet (3.3) is arranged radially relative to the symmetry axis (3.5).

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