Exhaust gas cooling device

Abstract

The invention relates to an exhaust gas cooling device for an internal combustion engine, having a housing connectable to an exhaust line of the internal combustion engine, and having a Venturi assembly coupled to the housing for introduction of exhaust gas and ambient air, and having an outlet line discharging an exhaust gas-ambient air mixture into the environment, the housing having a symmetry axis, wherein the Venturi assembly has a Venturi channel fluidically couplable to the exhaust line and an inlet opening for ambient air delimited by the Venturi channel and the exhaust line; the Venturi channel for conducting an exhaust gas-ambient air mixture and opening into a mixing chamber through the inlet opening; the Venturi channel having an outlet opening and the outlet line having an inflow opening, wherein the outlet opening and the inflow opening are spaced apart from each other, the Venturi channel and the outlet line opening into the housing through the inflow opening.

Description

Technical Field

[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. Background Technology

[0002] The exhaust gas cooling device has a housing with a symmetrical axis that can be connected to an exhaust gas line for an internal combustion engine or a battery, a Venturi assembly coupled to the housing for introducing exhaust gas and ambient air, and an outlet line for discharging the exhaust gas-ambient air mixture into the environment. The Venturi assembly has a Venturi channel that can be fluidly connected to the exhaust gas line and an inlet opening for ambient air, the inlet opening being defined by the Venturi channel and the exhaust gas line. The Venturi channel is used to guide the exhaust gas-ambient air mixture and leads to a mixing chamber through the inlet opening.

[0003] An exhaust gas cooling device is known from US 8,549,850 B2, which has a Venturi arrangement for supplying ambient air. The exhaust gas cooling device has multiple exhaust gas inlet channels and downstream Venturi ducts. Additionally, multiple inlet openings for ambient air are provided. The acquired exhaust gas and ambient air are mixed through the Venturi ducts and delivered to the environment. Summary of the Invention

[0004] The purpose of this invention is to configure and arrange exhaust gas cooling devices to ensure an improved mixing method for the exhaust gas-ambient air mixture.

[0005] The objective achieved according to the invention is that the Venturi channel has an outlet opening and the outlet line has an inflow opening, wherein the outlet opening and the inflow opening are spaced apart from each other, and the Venturi channel and the outlet line lead to the housing through their inflow openings. The outlet line is used to guide the exhaust gas-ambient air mixture from inside the housing to another exhaust gas line or to the environment. In this way, it is possible to guide the exhaust gas-ambient air mixture over a longer period of time and along a longer path inside the housing, thereby improving the mixing before the exhaust gas-ambient air mixture is guided to the environment through the outlet line.

[0006] For this purpose, it may also be advantageous for the shell to define a mixing chamber by chamber walls, wherein the outlet opening of the Venturi channel has an outlet cross-section Qv, and the mixing chamber for discharging the exhaust gas-ambient air mixture from the Venturi channel forms a flow cross-section Qm, where Qm ≥ f Qv, and 2 ≤ f ≤ 12, particularly f = 6, f = 7, or f = 8. As the flow cross-section widens upon entering the shell or mixing chamber, the flow velocity decreases, resulting in a longer residence time within the shell.

[0007] Furthermore, it may be advantageous to arrange the outlet opening of the Venturi channel and the inlet opening of the outlet line as misaligned. This misalignment, or offset achieved through various alignments of the openings, increases the distance the exhaust gas-ambient air mixture travels within the housing. Alignment, offset, or orientation involves the respective central axes of the outlet and inlet openings, or the flow vectors defined by those central axes, such as gas outlet A and gas inlet E. Misalignment, where the flow vectors have different orientations, can also be achieved.

[0008] It may also be advantageous to align the outlet opening of the Venturi channel with the inlet opening of the outlet line, wherein a deflection element is placed between the outlet and inlet openings to achieve deflection in direction Rq, the directional component of which is perpendicular to the direction of the gas outlet A of the outlet opening. Despite the aforementioned alignment, this is accompanied by an increase in the flow path within the mixing chamber.

[0009] Advantageously, the outlet opening of the Venturi channel creates a gas outlet A guided radially toward the axis of symmetry, wherein the outlet line with the inlet opening creates a gas inlet E guided parallel to the axis of symmetry. This ensures at least a 90° deflection of the airflow and an increase in the associated flow path.

[0010] What may be particularly important for this invention is that the mixing chamber at least partially has a circular cross-sectional shape Q relative to the axis of symmetry, or has a vortex device disposed on the chamber wall, wherein when the airflow impacts the circular chamber wall or the vortex device, the gas outlet A generates at least one double vortex in the mixing chamber, which is guided in opposite directions relative to the axis of symmetry. The at least one double vortex also prolongs the flow path and thus prolongs the residence time. The circular shape of the chamber wall may include a circle, an ellipse, or other circular shapes. Fin-shaped or airfoil-shaped vortex devices may also be formed by or be part of the chamber wall. If a corresponding vortex device is provided on the chamber wall, the cross-sectional shape Q of the mixing chamber may also be square.

[0011] In combination with the configuration and arrangement according to the invention, it may be advantageous for the Venturi channel to form a mixing stage Mv with volume Vv, and the mixing chamber to form a mixing stage Mm with volume Vm, and the outlet line to form a mixing stage Ma with volume Va, wherein for the ratio of Vm to Vv S1: 25 ≥ S1 ≥ 2, particularly 16 ≥ S1 ≥ 12, and / or for the ratio of Vm to Va S2: 25 ≥ S2 ≥ 2, particularly 16 ≥ S2 ≥ 12. The relative size of the mixing chamber is also decisive for the length of the flow path available to the airflow inside a mixing chamber that is otherwise enclosed. A relatively large mixing chamber ensures a relatively large or long flow path.

[0012] It may also be advantageous to provide sound-absorbing devices in the interior of the mixing chamber and / or upstream of the venturi components.

[0013] Additionally, it may be advantageous to provide further vortex or deflection devices inside the mixing chamber. This further improves the mixing process.

[0014] Additionally, it may be advantageous to install a baffle upstream of the inlet opening for ambient air or at the ambient air inlet for intercepting ambient air or airflow, so as to actively increase the supply of ambient air.

[0015] Ambient air can also be supplied directly through an inlet opening for ambient air. In this case, the inlet opening is open to the environment. The ambient air inlet does not necessarily need to be installed through the housing.

[0016] In addition, it may be advantageous to provide a bypass arrangement with a bypass line through which exhaust gas can be guided through a cooling device.

[0017] Furthermore, it may be advantageous that the Venturi passage and the outlet line with the inlet opening lead to the same mixing chamber of the housing. Cooling of the exhaust gas-ambient air mixture takes place in the mixing chamber, particularly by transferring heat to the chamber walls. The exhaust gas-ambient air mixture can be directed immediately after cooling, or it can be directed out of the mixing chamber through the inlet opening of the outlet line.

[0018] For this purpose, it may be advantageous to have a mixing chamber without partition walls or shell partition walls. This ensures optimal flow of the exhaust gas-ambient air mixture within a single mixing chamber. It also avoids pressure losses associated with partition walls or shell partition walls. A partition wall or shell partition wall is considered a wall inside the mixing chamber that has one or more through openings or perforations. Such a wall divides the mixing chamber into two fluidly connected parts.

[0019] For this purpose, it may be advantageous to connect the inlet opening to the environment via an ambient air passage and an ambient air inlet guided through the housing, wherein the ambient air inlet is aligned radially with the axis of symmetry. Therefore, the incoming ambient air experiences a radial component, which is at least partially deflected in the circumferential direction by the cylindrical ambient air passage along the axis of symmetry. The ambient air thus experiences directional components in both the circumferential and axial directions along the axis of symmetry. This ensures the initial mixing of exhaust gas and ambient air in the Venturi passage. Attached Figure Description

[0020] Further advantages and details of the invention are described in the claims and specification, and are illustrated in the drawings. In the drawings:

[0021] Figure 1a Shown from Figure 2 BB (cross-sectional view);

[0022] Figure 1b A cross-sectional view of an alternative embodiment is shown;

[0023] Figure 2 Shown from Figure 3 Sectional view AA;

[0024] Figure 3 A schematic diagram is shown;

[0025] Figure 4 Various cross-sectional forms are shown;

[0026] Figure 5 A schematic diagram of another embodiment is shown. Detailed Implementation

[0027] Figure 1a The exhaust gas cooling device 1, shown in cross-sectional view BB, is connected to an exhaust gas line 1.1 for exhaust gas 1.2. The exhaust gas line 1.1 is the outlet pipe of the exhaust gas purification system 8.2, such as a catalytic converter housing. The exhaust gas cooling device 1 has a housing 3.6 with chamber walls 3.4 defining a mixing chamber 3.1. Inside the housing 3.6, a Venturi assembly 5 is provided with a Venturi channel 5.1, which is fluidly connected to the exhaust gas line 1.1 via an inlet opening 5.4 for exhaust gas, i.e., is blown in. Additionally, the Venturi assembly 5 has an inlet opening 5.2 for ambient air 9, defined on one side by the exhaust gas line 1.1 and on the other by the Venturi channel 5.1. The inlet opening 5.2 for ambient air 9 connects to an ambient air passage 3.2, which circumferentially surrounds the Venturi channel 5.1. The ambient air passage 3.2 is connected to the environment via an air inlet 3.3 guided through the housing 3.6, such that ambient air 9 is guided to the inlet opening 5.2 through the ambient air inlet 3.3 and the ambient air passage 3.2. The ambient air inlet 3.3 may have a baffle (not shown here) for capturing ambient air.

[0028] Therefore, the Venturi channel 5.1 guides the exhaust gas-ambient air mixture in the direction of the axis of symmetry 3.5 of the housing 3.6 or mixing chamber 3.1, wherein the Venturi channel 5.1 has a 90° bend at its end, such that gas outlet A is achieved through the outlet opening 5.3 of the Venturi channel 5.1 in the radial direction of the axis of symmetry 3.5. Figure 2 As shown, the exhaust gas-ambient air mixture exiting the outlet opening 5.3 encounters the upper chamber wall 3.4 or the vortex device 7 located there, therefore, due to Figure 2 The circular cross-sectional shape Q shown in the figure forms a reverse double vortex of the exhaust gas-ambient air mixture.

[0029] The housing 3.6 also has an outlet line 2 with an inlet opening 2.1 through which the exhaust gas-ambient air mixture is guided outward from the housing 3.6 or the mixing chamber 3.1 or into the environment. The inlet opening 2.1 ensures that the gas inlet E of the exhaust gas-ambient air mixture extends in the axial direction. By means of the misalignment or different and offset orientation of the gas outlet A and the gas inlet E, a sufficiently long flow path is ensured inside the mixing chamber 3.1. Thus, the outlet opening 5.3 of the Venturi channel has an outlet cross-section Qv that is significantly smaller than the flow cross-section Qm, which is designed for the exhaust gas-ambient air mixture passing through the mixing chamber 3.1. This results in a corresponding delay in the flow velocity of the exhaust gas-ambient air mixture, and thus increases the residence time inside the mixing chamber 3.1.

[0030] Inside the mixing chamber 3.1, an additional deflector 7.1 is provided to deflect the airflow as it flows toward the inflow opening 2.1. Upstream of the Venturi assembly 5, a sound-absorbing device 6 is provided, which the exhaust gas 1.2 collides with immediately after leaving the exhaust gas purification system 8.2.

[0031] The exhaust gas cooling device 1 has a total of three mixing stages: mixing stage Mv in the Venturi channel 5.1 with volume Vv, mixing stage Mm in the mixing chamber 3.1 with volume Vm, and mixing stage Ma in the outlet pipeline 2 with volume Va. The volume Vm of mixing stage Mm is 14 times larger than the volumes Vv and Va of the other two mixing stages Mv and Ma, respectively.

[0032] According to Figure 1b In an exemplary embodiment, the gas outlet A and gas inlet E are oriented in the same direction. Furthermore, the outlet opening 5.3 of the Venturi channel and the inlet opening 2.1 of the outlet line 2 are oriented in the same direction. To prevent gas from being directly blown into the inlet opening 2.1 through the Venturi channel 5.1, a deflector element 4 is provided, through which the airflow is radially guided outward into the mixing chamber 3.1 to complete a sufficiently long flow path to ensure the desired mixing of the exhaust gas and ambient air mixture. Gas outlet A is deflected by the deflector element 4 in direction Rq, which has a directional component radially to the axis of symmetry 3.5.

[0033] according to Figure 1a , 1b In an exemplary embodiment, the mixing chamber 3.1 does not have a partition wall or a shell partition wall. In an alternative exemplary embodiment (not shown), the mixing chamber 3.1 may have at least one partition wall or a shell partition wall, which is provided with one or more through openings or perforations. Thus, the mixing chamber is divided into two flow-connected mixing chambers.

[0034] Figure 3The exhaust gas cooling device 1 is shown downstream of the exhaust gas purification system 8.2. The exhaust gas purification system 8.2 is connected to the internal combustion engine 8 via exhaust gas pipeline segment 8.1. The exhaust gas 1.2, cooled to this extent, leaves the exhaust system through outlet pipeline 2.

[0035] Figure 2 Shown from Figure 3 A cross-sectional view AA. It also shows the cross-sectional view used according to Figure 1a Part BB of an exemplary embodiment.

[0036] Ambient air 9 is guided through ambient air inlet 3.3 to ambient air passage 3.2, which circumferentially surrounds venturi passage 5.1, allowing ambient air 9 to enter venturi passage 5.1 through inlet opening 5.2 between venturi passage 5.1 and exhaust gas line 1.1. The exhaust gas-ambient air mixture then exits venturi passage 5.1 radially upwards and reaches the concave chamber wall 3.4 or optionally a vortex device 7 placed there, thereby forming a reverse double vortex. This correspondingly ensures a corresponding flow path for the exhaust gas-ambient air mixture within mixing chamber 3.1 before it is discharged outwards or to the environment through inlet opening 2.1 of outlet line 2.

[0037] In the region where the exhaust gas-ambient air mixture from the Venturi channel 5.1 impacts the chamber wall 3.4, the concave shape of the aforementioned chamber wall 3.4 ensures the formation of a double vortex. This concavity is achieved through a corresponding circular or elliptical cross-sectional shape Q of the chamber wall 3.4, such as... Figure 4 As shown in the diagram. Of course, other cross-sectional shapes are also possible, which can ensure the formation of corresponding double or single vortices when the airflow impacts, thus increasing the residence time of the entire flow path, i.e., the airflow within the mixing chamber 3.1. For example... Figure 4 The square cross-sectional shape Q shown also requires a corresponding vortex device on the chamber wall.

[0038] The inlet opening 5.2 is connected to the environment or ambient air 9 via an ambient air passage 3.2 and an air inlet 3.3 that are led through the housing 3.6. The ambient air inlet 3.3 is aligned radially with the axis of symmetry 3.5. It is at least partially deflected circumferentially towards the axis of symmetry 3.5 by a cylindrical ambient air duct 3.2 and enters the inlet opening 5.2 for ambient air 9, having at least a directional component in the axial direction of the axis of symmetry 3.5 or parallel to the exhaust gas 1.2.

[0039] Figure 5The embodiment of the exhaust gas cooling device 1 shown is directly downstream of a hot gas source 8, such as an internal combustion engine or a fuel cell. Additionally, the exhaust gas cooling device 1 has a bypass arrangement 8.3 with a bypass line 8.4 through which exhaust gas can be guided through the exhaust gas cooling device 1.

Claims

1. An exhaust gas cooling device (1) for a hot gas source (8), the exhaust gas cooling device having a housing (3.6) capable of connecting to an exhaust gas line (1.1) of the hot gas source (8), a Venturi assembly (5) connected to the housing (3.6) for introducing exhaust gas (1.2) and ambient air (9), and an outlet line (2) for discharging the exhaust gas-ambient air mixture into the environment, the housing (3.6) having an axis of symmetry (3.5), wherein the Venturi assembly (5) has a Venturi channel (5.1) capable of fluidly connecting to the exhaust gas line (1.1) and an inlet opening (5.2) for ambient air, the inlet opening being defined by the Venturi channel (5.1) and the exhaust gas line (1.1), wherein the Venturi channel (5.1) is used to guide the exhaust gas-ambient air mixture and opens through the inlet opening (5.2) to a mixing chamber (3.1), Its features are: The Venturi channel (5.1) has an outlet opening (5.3) and the outlet line (2) has an inflow opening (2.1), wherein the outlet opening (5.3) and the inflow opening (2.1) are spaced apart from each other, wherein the Venturi channel (5.1) and the outlet line (2) lead to the housing (3.6) through the inflow opening (2.1), and the Venturi channel (5.1) and the outlet line (2) lead to the same mixing chamber (3.1) of the housing (3.6) through the inflow opening (2.1); the outlet opening (5.3) of the Venturi channel (5.1) produces a gas outlet A guided in the radial direction of the axis of symmetry (3.5), or the gas outlet A is deflected in the direction Rq by a deflecting element (4), the direction Rq having a directional component radial to the axis of symmetry (3.5).

2. The exhaust gas cooling device (1) according to claim 1, Its features are: The housing (3.6) defines the mixing chamber (3.1) by a chamber wall (3.4), wherein the outlet opening (5.3) of the Venturi channel (5.1) has an outlet cross-section Qv, and the mixing chamber (3.1) is used to form a flow cross-section Qm of ≥f Qv for the exhaust gas-ambient air mixture exiting the Venturi channel (5.1), where 2≤f≤10.

3. The exhaust gas cooling device (1) according to claim 1 or 2, Its features are: The outlet opening (5.3) of the Venturi channel (5.1) and the inflow opening (2.1) of the outlet pipeline (2) are arranged to be misaligned.

4. The exhaust gas cooling device (1) according to claim 1 or 2, Its features are: The outlet opening (5.3) of the Venturi channel (5.1) and the inflow opening (2.1) of the outlet pipeline (2) are positioned aligned, wherein a deflection element (4) is provided between the outlet opening (5.3) and the inflow opening (2.1) to cause deflection in the direction Rq, the directional component of the direction Rq being perpendicular to the direction of the gas outlet A of the outlet opening (5.3).

5. The waste gas cooling device (1) according to claim 1, Its features are: The outlet line (2) having the inflow opening (2.1) produces a gas inlet E guided parallel to the axis of symmetry (3.5).

6. The exhaust gas cooling device (1) according to claim 2, Its features are: The mixing chamber (3.1) has at least a partially circular cross-sectional shape Q relative to the axis of symmetry (3.5), or a vortex device (7) is provided on the chamber wall (3.4), wherein when the airflow impacts the circular chamber wall (3.4) or the vortex device (7), the gas outlet A generates at least one double vortex in the mixing chamber (3.1), the double vortex being guided in opposite directions relative to the axis of symmetry (3.5).

7. The exhaust gas cooling device (1) according to claim 1, Its features are: The Venturi channel (5.1) forms a mixing stage Mv with volume Vv, the mixing chamber (3.1) forms a mixing stage Mm with volume Vm, and the outlet pipeline (2) forms a mixing stage Ma with volume Va, wherein for the ratio of Vm to Vv S1: 25 ≥ S1 ≥ 2 and / or For the ratio of Vm to Va, S2: 25 ≥ S2 ≥ 2.

8. The exhaust gas cooling device (1) according to claim 1, Its features are: A sound-absorbing device (6) is provided inside the mixing chamber (3.1) and / or upstream of the Venturi assembly (5).

9. The exhaust gas cooling device (1) according to claim 1, Its features are: The mixing chamber (3.1) is equipped with an additional eddy current or deflection device (7.1).

10. The exhaust gas cooling device (1) according to claim 1, Its features are: A baffle (3.7) is provided upstream of the inlet opening (5.2) for ambient air to trap ambient air (9).

11. The exhaust gas cooling device (1) according to claim 1, Its features are: A bypass arrangement (8.3) with a bypass pipeline (8.4) is provided.

12. The exhaust gas cooling device (1) according to claim 1, Its features are: The mixing chamber (3.1) has no partition wall or shell partition wall.

13. The waste gas cooling device (1) according to claim 1, Its features are: The inlet opening (5.2) is connected to the environment via an ambient air passage (3.2) and an ambient air inlet (3.3) guided through the housing (3.6), wherein the ambient air inlet (3.3) is aligned radially with respect to the axis of symmetry (3.5).

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