CN218669511U

CN218669511U - Reductant tank unit and selective catalytic reduction subsystem including the same

Info

Publication number: CN218669511U
Application number: CN202223251913.XU
Authority: CN
Inventors: K·皮泰曼妮
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2022-12-05
Filing date: 2022-12-05
Publication date: 2023-03-21
Anticipated expiration: 2032-12-05

Abstract

A reductant tank unit for a selective catalytic reduction subsystem of a vehicle exhaust aftertreatment system is disclosed, comprising a reductant tank (10) defining an interior space comprising a liquid volume space (V1) and an air volume space (V2), a supply module (20), an inlet connector (30) and a return connector (40), the inlet connector (30) defining an inlet passage (36) having an inlet tank port (32) opening to the air volume space (V2) and an inlet module port (34) opening to the supply module (20), the inlet tank port (32) being lower than the inlet module port (34); the return connector (40) defines a return channel (46) having a return tank port (42) open to the air volume space (V2) and a return module port (44) open to the supply module (20), the return tank port (42) being lower than the return module port (44).

Description

Reductant tank unit and selective catalytic reduction subsystem including the same

Technical Field

The utility model relates to a selective catalytic reduction subsystem's reductant jar unit for vehicle exhaust aftertreatment system to and including this reductant jar unit's selective catalytic reduction subsystem.

Background

Exhaust gas aftertreatment systems for vehicles are used to purify exhaust gas from internal combustion engines of vehicles before the exhaust gas is discharged into the atmosphere. Exhaust aftertreatment systems include a selective catalytic reduction (also referred to as "SCR") subsystem in which a reductant (e.g., an aqueous urea solution) is injected into the exhaust gas stream and interacts with the main pollutants and pollutants in the exhaust gasThe dyeing component-nitrogen oxide (NOx) is subjected to chemical reaction to generate N which does not pollute the environment ₂ And H ₂ And O, realizing the aim of reducing environmental pollution.

The SCR subsystem includes a reductant tank unit, which may be an integrated unit including a reductant tank and a supply module mounted on the reductant tank, and a dosing module mounted on an exhaust pipe through which exhaust from the vehicle flows. The reducing agent contained in the reducing agent tank is pumped into the supply module via an inlet connector between the reducing agent tank and the supply module and then supplied to the metering module through the high-pressure line for injection into the exhaust gas flow; the residual reductant in the path of the dosing module is returned to the supply module via a return line and then to the reductant tank via a return connection between the reductant tank and the supply module.

In currently configured integrated units, the inlet connector and the return connector are generally arranged in a Y-shaped configuration between the supply module and the reductant tank, the inlet tank port of the inlet connector opening to the reductant tank and the return tank port of the return connector opening to the reductant tank always being exposed to reductant within the reductant tank. As a result, a large amount of reducing agent always remains in these connectors (also referred to as elbow regions), in particular in the return connectors which slope downwards in the direction from the reducing agent tank to the supply module. For low pressure applications, more ice (frozen AdBlue) may be generated within the connector, thus requiring more defrost time to melt the ice during the next operation. Typically, the heat exchanger disposed within the reductant tank may not provide enough heat to thaw ice within the connector, or after the thaw time, some ice may still be present in the connector, resulting in a low efficiency of the SCR subsystem.

SUMMERY OF THE UTILITY MODEL

It is an object of the present application to reduce the amount of reducing agent remaining in the inlet connector and the return connector after operation.

This object is achieved by a reductant tank unit for use in a selective catalytic reduction subsystem of a vehicle exhaust aftertreatment system and an SCR subsystem comprising the reductant tank unit. The reductant tank unit includes a reductant tank for containing reductant, a supply module mounted on the reductant tank, an inlet connector via which reductant in the reductant tank is supplied to the supply module, and a return connector through which reductant in the supply module is returned to the reductant tank, the reductant tank defining an interior space including a liquid volume space and an air volume space, wherein: the inlet connector defines an inlet passage and includes an inlet tank port open to an air volume of the reductant tank and an inlet module port open to the supply module, the inlet tank port being horizontally lower than the inlet module port; and the return connector defines a return passage and includes a return tank port open to the air volume of the reductant tank and a return module port open to the supply module, the return tank port being horizontally lower than the return module port.

In one embodiment, the reductant tank includes a tank housing having an external recess in a top portion thereof, and the supply module is mounted in the external recess.

In one embodiment, the inlet channel defines an imaginary inlet centerline, the inlet connector being attached with a supply module in a form that the imaginary inlet centerline of the inlet channel at the inlet module port is obtuse with respect to vertical at an inlet inclination angle that is greater than 95 degrees; and/or the return channel defines an imaginary return centerline, the return connector being attached to the supply module with the imaginary return centerline of the return channel at the return module port being obtuse with respect to vertical at a return inclination angle greater than 95 degrees.

In one embodiment, the inlet cant angle is greater than 120 degrees and the return cant angle is greater than 120 degrees.

In one embodiment, the return tank port is located above the inlet tank port.

In one embodiment, the reductant tank unit further comprises a suction filter located at a bottom of the reductant tank and a suction tube within the reductant tank configured to direct reductant filtered by the suction filter into the inlet connector.

In one embodiment, the reductant tank unit further comprises a heat exchanger for circulating coolant from a vehicle engine therethrough, the heat exchanger comprising: a first heating portion proximate the return tank port and the inlet tank port, a second heating portion extending from the first heating portion to a bottom of the reductant tank, a third heating portion proximate the suction filter at the bottom of the reductant tank, and a fourth heating portion extending from the third heating portion to a top of the reductant tank.

In one embodiment, the second heating portion extends along the suction duct on one side thereof, either partially around the suction duct 60 in a C-shape or completely around the suction duct in a spiral form. In one embodiment the second heating portion has a tapered profile with a smaller heat exchange area near the first heating portion and a larger heat exchange area at the bottom of the reductant tank. In one embodiment the fourth heating portion also has a tapered profile and has a smaller heat exchange area near the top of the reductant tank and a larger heat exchange area near the bottom of the reductant tank.

In one embodiment, the reductant tank unit further comprises a sensor unit mounted on top of the reductant tank, the heat exchanger being attached to the sensor unit at opposite ends.

The selective catalytic reduction subsystem of the vehicle exhaust aftertreatment system of the present application includes the reductant tank unit described above, and a dosing module configured to receive reductant from the supply module of the reductant tank unit and inject the reductant into the exhaust of the vehicle.

In the reductant tank unit of the present application, the inlet tank port and the return tank port of the inlet connector and the return connector between the reductant tank and the supply module, respectively, open to the air volume space (top) of the interior space defined by the reductant tank, the inlet module port and the return module port of the inlet connector and the return connector, respectively, open to the supply module, being higher than the inlet tank port and the return tank port, respectively. This is very advantageous because the reductant in the inlet connector and the return connector automatically flows back to the reductant tank after operation, and neither of these connectors (their inlet tank port and return tank port) is exposed to the reductant liquid in the reductant tank. The amount of reducing agent remaining in the connector is significantly reduced and ice generation in low temperature applications is also reduced. This shortens the time required for defrosting, and sufficient heat can be supplied by the heat exchanger provided in the reducing agent tank.

Drawings

Advantages of the present disclosure will be readily understood by reference to the following detailed description when considered in connection with the accompanying drawings. It should be understood that the drawings are merely illustrative and are not drawn to scale.

FIG. 1 is a simplified schematic diagram of a reductant tank unit of an SCR subsystem for an exhaust aftertreatment system of a vehicle.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the following detailed description of the illustrated embodiments will be made with reference to the accompanying drawings.

Fig. 1 is a schematic diagram of a reductant tank unit according to the principles of the present disclosure. The reductant tank unit is part of a selective catalytic reduction (also referred to as "SCR") subsystem, which is itself part of a vehicle exhaust aftertreatment system. The reductant tank unit may be provided separately and configured to provide a reductant, such as an aqueous urea solution, to a dosing module (not shown) of the SCR subsystem. The dosing module is disposed or mounted on an exhaust pipe through which an exhaust gas flow discharged from an internal combustion engine of a vehicle flows, and is configured to dose and inject a reducing agent received from a reducing agent tank unit into the exhaust gas flow, thereby reducing a pollutant component NOx in the exhaust gas to a non-pollutant component, and discharging the non-pollutant component to the atmosphere.

Referring to fig. 1, the reducing agent tank unit of the present invention includes a reducing agent tank 10 and a supply module 20 installed outside (on the tank) the reducing agent tank 10. Supply module 20 may be secured to reductant tank 10 in any suitable manner, such as by means of a separately provided bracket or molded onto reductant tank 10, but this is not a focus of the present invention and will not be described in detail herein. There is shown an inlet connector 30 and a return connector 40 fluidly communicating the reductant tank 10 and the supply module 20.

The inlet connector 30 has an inlet tank port 32 and an inlet module port 34 that are open to the reductant tank 10 and the supply module 20, respectively, and the return connector 40 includes a return tank port 42 and a return module port 44 that are open to the reductant tank 10 and the supply module 20, respectively. The inlet connector 30 and the return connector 40 include an inlet passage 36 fluidly communicating the inlet tank port 32 and the inlet module port 34, and a return passage 46 fluidly communicating the return tank port 42 and the return module port 44, respectively.

As shown in fig. 1, the inlet tank port 32 is lower in height than the inlet module port 34, and the inlet passage 36 defines an imaginary inlet centerline 35 that forms an inlet inclination angle AI in the form of an obtuse angle with respect to the vertical at the inlet module port 34. Also, the height of the return tank port 42 is lower than the return module port 44, and the return channel 46 defines an imaginary return centerline 45 that forms an obtuse return angle of inclination AB with respect to vertical at the return module port 44. By way of example, the imaginary inlet and return centerlines 35 and 45 can be considered to be the centerlines of the inlet and return passages 36 and 46 of the inlet and return connectors 30 and 40, respectively. For simplicity, the inlet and return connectors 30 and 40 and their inlet and return passages 36 and 46 are depicted as imaginary inlet and return centerlines 35 and 45 in the illustration. It will be appreciated by those skilled in the art that the connector may have any suitable physical structure or configuration and that any suitable type of connector known in the art may be used.

It is advantageous to position the inlet tank port 32 lower than the inlet module port 34 and the return tank port 42 lower than the return module port 44. Due to the presence of the inclination angles AI and AB, the reducing agent in the inlet and return connectors 30 and 40 can automatically flow back to the reducing agent tank 10 under the influence of gravity, and substantially no reducing agent remains in the inlet and return passages 36 and 46 of the inlet and return connectors 30 and 40 after operation, so that very little or no ice is generated in the inlet and return connectors 30 and 40 even in low temperature applications. Thus, less defrost time will be required on the next operation. As an example, the entry and return inclination angles AI and AB in the form of obtuse angles may be greater than 95 degrees, preferably greater than 120 degrees, more preferably greater than 145 degrees or 150 degrees. The obtuse entry and return inclination angles AI and AB may be the same or different, as desired. In one example, the obtuse form of the backflow angle AB may be greater than the obtuse form of the inlet angle AI. As shown, the return connector 40 may be disposed above the inlet connector 30, particularly with the return tank port 42 located above the inlet tank port 32, and thus farther from the level of reductant in the reductant tank 10 than the inlet tank port 32.

Further, as shown in fig. 1, the reductant tank 10 defines an interior space including a liquid volume V1 filled with reductant and an air volume V2 filled with air. The liquid volume V1 may have a predetermined or nominal volume value or may be represented by a predetermined or nominal liquid level. The liquid volume V1 is smaller than the total volume value of the inner space in order to receive the reducing agent which is returned to the reducing agent tank 10 via the return connection 40. According to the principles of the present invention, the inlet tank port 32 and the return tank port 42 both open to the air volume space V2. This is also advantageous because with this arrangement, the inlet and

return tank ports

32 and 42 are above the level of reductant in the reductant tank 10, so the inlet and return connectors 30 and 40 (and in particular their tank ports 32 and 42) are not exposed to reductant in the reductant tank 10, especially during non-operating times, which reduces the amount of reductant remaining in the inlet and return connectors 30 and 40 after operation. Accordingly, this also reduces the amount of ice that may be produced, shortening the required defrost time.

In the example shown in fig. 1, the opening of the inlet and

return tank ports

32 and 42 of the inlet and return passages 36 and 46 of the inlet and return connectors 30 and 40 to the air volume V2 is achieved by disposing the supply module 20 on top of one side of the reductant tank 10. Specifically, the reducing agent tank 10 includes a tank case 15 defining the inner space, the tank case 15 being formed at a top thereof with an outer recess 25, the supply module 20 being mounted in the outer recess 25. Also shown in fig. 1 is a supply module filter 22 on top of the supply module 20.

The reductant tank 10 also includes a sensor unit 70 (including, but not limited to, a level sensor, a temperature sensor, a mass sensor, etc.) mounted on the top wall 12 of the tank housing 15 and a heat exchanger 80 within the reductant tank 10, the heat exchanger 80 being adapted to introduce coolant from the vehicle engine into the reductant tank 10 to thaw ice that may be produced or heat the reductant within the reductant tank 10. The heat exchanger 80 may be provided as a rigid coolant pipe, for example made of Al material due to its good thermal conductivity. The heat exchanger 80 may be attached to the sensor unit 70 at opposite ends. Thus, the heat exchanger 80 and the sensor unit 70 may be provided as an integrated unit. At the bottom of the reducing agent tank 10, a suction filter 50 is provided for filtering the reducing agent, when in operation, before it is sucked into the supply module 20 via the inlet connector 30. A suction tube 60 is also provided in fluid communication with the inlet passage 36 and extends from the inlet connector 30 to the suction filter 50 for directing filtered reductant into the inlet connector 30.

Referring to fig. 1, the heat exchanger 80 may include: a first heating section 82 located near the inlet and return

tank ports

32 and 42 of the inlet and return connectors 30 and 40 for defrosting ice that may be present in the connectors 30 and 40; a second heating portion 84 extending from the first heating portion 82 to the bottom of the reducing agent tank 10 along the suction pipe 60, mainly for heating the reducing agent in the suction pipe 60; and a third heating section 86 located near the bottom of the reductant tank 10, near the suction filter 50, which may be optional. The fourth heating portion 88 of the heat exchanger 80 extends from the third heating portion 86 back to the top of the reductant tank 10, such as the top wall 12.

Advantageously, as shown in FIG. 1, the second heated portion 84 of the heat exchanger 80 has a tapered profile that provides a relatively small heat exchange area near the first heated portion 82 located in the air volume V2 because there is air in the vicinity of the reductant in the region and a relatively large heat exchange area near the suction filter 50 at the bottom of the reductant tank 10. The second heating portion 84 may be provided on one side of the draft tube 60 or may extend around the draft tube 60 (e.g., in a spiral fashion) to provide as large a heat exchange area as possible. Alternatively, the second heating portion 84 may extend in a C-shaped configuration around only a portion of the suction tube 60 in the circumferential direction thereof, rather than extending completely around the suction tube 60, which enables the heat exchanger 80 to be removed without interference with the suction tube 60, for example for maintenance. It is contemplated that the fourth heating portion 88 may also have a tapered profile such that its heat exchange area decreases as it extends from bottom to top, similar to the second heating portion 84, for the same purpose.

Although not shown in fig. 1, one or more retaining members may be provided to support or retain components (e.g., tubes) forming the heat exchanger 80. The retaining member may be a clip for securing the heat exchanger 80 to the suction tube 60, a spring member suspended from the top wall 12 of the reductant tank 10, any form of bracket for securing the heat exchanger 80 to any wall of the reductant tank 10, or any other component within the reductant tank 10. The heat exchanger 80 may be fixed or suspended in any suitable manner known in the art. To facilitate securement, the second heated portion 84 of the heat exchanger 80 may extend substantially along the suction tube 60.

The invention has been described with reference to the examples shown in the drawings. However, the examples discussed herein are not intended to be exhaustive or to limit the invention to any particular form. The terminology used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations are possible in light of the above teaching, and the invention may be practiced otherwise than as specifically described.

Claims

1. A reductant tank unit for use in a selective catalytic reduction subsystem of a vehicle exhaust aftertreatment system, comprising a reductant tank (10) for containing reductant, a supply module (20) mounted on the reductant tank (10), an inlet connector (30) via which reductant in the reductant tank (10) is supplied to the supply module (20), and a return connector (40) through which reductant in the supply module (20) is returned to the reductant tank (10), the reductant tank (10) defining an interior space comprising a liquid volume space (V1) and an air volume space (V2), characterized in that:

the inlet connector (30) defines an inlet passage (36) and comprises an inlet tank port (32) opening to an air volume space (V2) of the reductant tank (10) and an inlet module port (34) opening to the supply module (20), the inlet tank port (32) being horizontally lower than the inlet module port (34); and is

The return connector (40) defines a return passage (46) and includes a return tank port (42) opening to an air volume (V2) of the reductant tank (10) and a return module port (44) opening to the supply module (20), the return tank port (42) being horizontally lower than the return module port (44).

2. The reductant tank unit according to claim 1, characterized in that the reductant tank (10) comprises a tank housing (15) having an external recess (25) in its top, and the supply module (20) is mounted in the external recess (25).

3. The reductant tank unit of claim 2,

the inlet channel (36) defining an imaginary inlet centre line (35), the inlet connector (30) being attached to a supply module (20) in such a way that the imaginary inlet centre line (35) of the inlet channel (36) at the inlet module port (34) is obtuse with respect to a vertical direction with an inlet inclination Angle (AI) of more than 95 degrees; and/or

The return channel (46) defines an imaginary return centre line (45), and the return connector (40) is attached to the supply module (20) in such a way that the imaginary return centre line (45) of the return channel (46) at the return module port (44) is obtuse with respect to a vertical direction with a return inclination Angle (AB) of more than 95 degrees.

4. The reductant tank unit according to claim 3, characterized in that the inlet Angle of Inclination (AI) is greater than 120 degrees and the return angle of inclination (AB) is greater than 120 degrees.

5. The reductant tank unit of claim 4 wherein the return tank port (42) is located above the inlet tank port (32).

6. The reductant tank unit according to any one of claims 1-5, further comprising a suction filter (50) located at a bottom of the reductant tank (10) and a suction tube (60) within the reductant tank (10) configured for directing reductant filtered by the suction filter (50) into the inlet connector (30).

7. The reductant tank unit of claim 6 further comprising a heat exchanger (80) for circulating coolant from a vehicle engine therethrough, the heat exchanger comprising: a first heating portion (82) proximate the return tank port (42) and the inlet tank port (32), a second heating portion (84) extending from the first heating portion (82) to a bottom of the reductant tank (10), a third heating portion (86) proximate the suction filter (50) at the bottom of the reductant tank (10), and a fourth heating portion (88) extending from the third heating portion (86) to a top of the reductant tank (10).

8. The reductant tank unit of claim 7, characterized by at least one of:

the second heating portion (84) extends along the suction duct (60) on one side thereof, or extends in a C-shape partially around the suction duct 60, or extends in a spiral form completely around the suction duct (60);

the second heating section (84) has a tapered profile with a smaller heat exchange area near the first heating section (82) and a larger heat exchange area at the bottom of the reductant tank (10); and

the fourth heating section (88) also has a tapered profile and has a smaller heat exchange area near the top of the reductant tank (10) and a larger heat exchange area near the bottom of the reductant tank (10).

9. The reductant tank unit of claim 8, further comprising a sensor unit (70) mounted at a top of the reductant tank (10), the heat exchanger (80) being attached to the sensor unit (70) at opposite ends.

10. A selective catalytic reduction subsystem of a vehicle exhaust aftertreatment system, comprising a reductant tank unit according to any of claims 1-9, and a dosing module, wherein the dosing module is configured to receive reductant from the supply module (20) of the reductant tank unit and to inject reductant into an exhaust gas of a vehicle.