COOLING SYSTEM FOR ENGINE AFTERTREATMENT SYSTEM

Abstract

A cooling system for an engine aftertreatment system at least partially located in an engine compartment including a pressurized air source and an air conduit. The pressurized air source is configured to generate a cooling airflow. The air conduit is connected to the pressurized air source. The air conduit is configured to provide the cooling airflow to the engine aftertreatment system.

Description

TECHNICAL FIELD

The present disclosure relates to an engine aftertreatment system, and more particularly to a system for cooling the engine aftertreatment system.

BACKGROUND

Selective Catalytic Reduction (SCR) systems may be included in an engine aftertreatment system for a power system to remove or reduce nitrous oxide (NOx or NO) emissions coming from an engine. The SCR systems may include the introduction of a reductant, such as urea, to the exhaust stream. The engine aftertreatment system includes a reductant line, and a valve located in an engine compartment, which may get overheated during the operation of the engine. Thermal management of the reductant may be needed for proper operation of the SCR system.

In light of the above, there is a need to provide cooling to the engine aftertreatment system and its associated components which are located in the engine compartment.

U.S. Pat. No. 6,647,971 discloses a cooling system for an exhaust gas recirculation system including a valve. A motor opens the valve allowing hot fluid exhaust gas to flow into the valve. Cooling fluid continuously flows in and is circulated around the valve, reducing the amount of heat transfer from the hot fluid to the other components in the exhaust gas recirculation system.

SUMMARY OF THE DISCLOSURE

In one aspect, the present disclosure provides a cooling system for an engine aftertreatment system at least partially located in an engine compartment. The cooling system includes a pressurized air source and an air conduit. The pressurized air source generates a cooling airflow. The air conduit is connected to the pressurized air source. The air conduit provides the cooling airflow to the engine aftertreatment system.

In another aspect, the present disclosure provides a method for cooling an engine aftertreatment system at least partially located in an engine compartment. The method generates a cooling airflow by a pressurized air source. Subsequently, the method provides the cooling airflow to the engine aftertreatment system by an air conduit connected to the pressurized air source.

Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a power system including an engine, and an engine aftertreatment system, according to an aspect of the disclosure;

FIG. 2 is a diagrammatic view of a power system including an engine, and an engine aftertreatment system, according to another aspect of the disclosure; and

FIG. 3 is a process flow diagram for a cooling sequence for the engine aftertreatment system.

DETAILED DESCRIPTION

As seen in FIG. 1, a power system 10 includes an engine 12, and an engine aftertreatment system 14 to treat an exhaust stream 13 produced by the engine 12. The engine 12 may include other features which are not shown, for example, but not limited to, a fuel supply system, an air system, insulating systems, peripheries, drivetrain components, turbochargers, electronics, sensors and the like. Moreover, the engine 12 may be, without any limitation, an internal combustion engine, a gasoline or diesel engine, a natural gas engine, and the like. The engine 12 may further include a number of cylinders arranged in any suitable configuration, for example, in-line arrangement, “V” arrangement, radial arrangement, or the like. The engine 12 may be used to power any machine or other device, including on-highway trucks or vehicles, off-highway trucks or machines, earth moving equipment, generators, aerospace applications, locomotive applications, marine applications, pumps, stationary equipment, or other engine powered applications. Based on the application, the size of the engine 12 may vary without deviating from the scope of the present disclosure.

During operation of the engine 12, the exhaust stream 13 from the engine 12 may enter into the engine aftertreatment system 14. In an embodiment, the engine aftertreatment system 14 includes a Selective Catalytic Reduction (SCR) system 18, pre-SCR components 16, post-SCR components 20, and an exhaust pipe 22. The exhaust stream 13 exits from the engine 12 and passes through the pre-SCR components 16, then passes through the SCR system 18, and then passes through the post-SCR components 20 via the exhaust pipe 22.

The pre-SCR and post-SCR components 16 and 20 may include devices such as regeneration devices, heat sources, oxidation catalysts, diesel oxidation catalysts (DOCs), diesel particulate filters (DPFs), additional SCR systems, lean NOx traps (LNTs), mufflers, or other devices needed to treat the exhaust stream 13 before and after the SCR system 18; and before exiting the power system 10. In various other embodiments, the pre-SCR and post-SCR components 16 and 20 may or may not be needed.

In an embodiment, the SCR system 18 may include a reductant system 24, mixer 26, and an SCR device 28. The reductant system 24 introduces or supplies a reductant 30 into the exhaust stream 13. The mixer 26 may be included to mix the reductant 30 in the exhaust stream 13 and introduce the mixture to the SCR device 28. The reductant 30 may be urea, ammonia, diesel fuel, other hydrocarbon, or chemical used by the SCR device 28 to reduce or otherwise remove NOx or NO emissions from the exhaust stream 13. The SCR device 28 may include a catalyst facilitating the reaction, reduction, or removal of NOx emissions from the exhaust stream 13 as it passes through the SCR device 28.

Moreover, the reductant system 24 is shown to include a reductant source 32, a pump 34, a valve 36, an injector 38, and a reductant line 40. The reductant source 32 may be a tank, vessel, absorbing material, or other device capable of storing and releasing the reductant 30. The reductant line 40 transports the reductant 30 from the reductant source 32 to the exhaust stream 13 of the engine 12 via the injector 38.

The pump 34 is an extraction device capable of passing the reductant 30 from the reductant source 32, generating a reductant flow 31. The valve 36 may be included to help regulate or control the delivery of the reductant 30. The injector 38 is a device capable of creating a reductant spray or otherwise introducing the reductant 30 in the exhaust stream 13. The injector 38 may be designed to introduce the reductant 30 in the exhaust stream 13 with or without the aid of compressed air.

As shown in the FIG. 1, the engine 12 and the engine aftertreatment system 14 may be contained or located inside an engine compartment 42. The engine compartment 42 may define an engine compartment interior space 44 inside. The engine compartment 42 may be the machine's hood or engine's enclosure. The engine compartment 42 may include vents for ventilation and other components (not shown). Components shown to be inside the engine compartment 42 may alternatively be located outside the engine compartment 42 and components shown to be outside the engine compartment 42 may alternatively be located inside the engine compartment 42. The reductant source 32 may be located outside or otherwise thermally insulated from the engine compartment 42.

In an embodiment of the present disclosure, a cooling system 46 is provided for the engine aftertreatment system 14. The cooling system 46 may include a pressurized air source 48 and an air conduit 50. The air conduit 50 may be connected to the pressurized air source 48. As shown in the FIG. 1, the air conduit 50 may be partially located inside the engine compartment 42; such that the air conduit 50 may surround the reductant line 40.

In an embodiment, the pressurized air source 48 may include a fan 52. The fan 52 may pull in air from ambient environment and generate a cooling airflow 54. The fan 52 may be configured to provide the cooling airflow 54 to the engine aftertreatment system 14 through the air conduit 50.

In an embodiment, the pressurized air source 48 may include more than one fan 52. It will be apparent to a person skilled in the art that the fan 52 may include an axial fan configured to pull the ambient air through inlet vents 56 provided in the cooling system 46. Further, one or more outlet vents 58 may be provided to move the generated cooling airflow 54 at very high speed. Moreover, the cooling system 46 may include a wire mesh filter to keep the dust and foreign particulate outside the cooling system 46.

In another embodiment of the present disclosure, the cooling system 46 may be coupled to a heat exchanging system 60. As shown in the FIG. 2, the heat exchanging system 60 may embody another cooling system associated with the engine 12, or may embody another heat exchanging system in the power system 10. Further, the heat exchanging system 60, as shown, may include a radiator 62, radiator inlet line 64, and radiator outlet line 66.

In an embodiment, the fan 52 may also be used to provide the cooling airflow 54 to the radiator 62. Moreover, the fan 52 may either be located within or outside the engine compartment 42, without deviating from the scope of the disclosure.

FIG. 3 is a process flow diagram of a cooling sequence 300 for the engine aftertreatment system 14. At step 302, the pressurized air source 48 generates the cooling airflow 54.

Further, at step 304 the cooling airflow 54 is provided to the engine aftertreatment system 14 by the air conduit 50. The air conduit 50 is connected to the pressurized air source 48.

In one embodiment, the cooling airflow 54 may be provided to the reductant line 40 of the engine aftertreatment system 14, by the air conduit 50 that surrounds the reductant line 40. Hence, the cooling airflow 54 may be used to cool the reductant 30 flowing through the reductant line 40. In another embodiment, the cooling airflow 54 may be provided to the valve 36 which is located on the reductant line 40. Hence, the cooling airflow 54 may also facilitate in cooling the valve 36.

INDUSTRIAL APPLICABILITY

During operation of the engine 12, a large amount of heat may be generated. This may lead to an increase in temperature within the engine compartment 42. The rise in temperature may correspondingly cause components located within the engine compartment interior space 44 to get overheated. For example, the valve 36 and the reductant line 40 may be overheated due to high temperatures in the engine compartment 42, causing the reductant 30 in the reductant line 40 to get heated. As a result, the reductant 30 may not be able to effectively absorb the diesel particulate emission in the engine aftertreatment system 14.

Typical solutions use a combination of techniques such as, but not limited to shielding, deflecting, and/or forced ventilation to cool the components within the engine compartment 42. However, these cooling methods did not meet the exact cooling need or reduce heat transfer from the hot environment in the engine compartment interior space 44 to the reductant 30 being delivered by the reductant line 40.

The cooling system 46 described above provides the cooling airflow 54 generated by the pressurized air source 48 to the air conduit 50, in order to cool the reductant line 40. The cooling system 46 may also facilitate in cooling of the valve 36 associated with the reductant line 40. In one embodiment, a simple nested assembly of the air conduit 50, wherein the air conduit 50 may be attached at one end to the pressurized air source 48, and connected at another end to the valve 36; may facilitate in effectively cooling the reductant line 40 as well as the valve 36.

Moreover, as described earlier, the pressurized air source 48 may include the fan 52. In one embodiment, the fan 52 may also be used to provide the cooling airflow 54 to the engine 12. Hence, by using the same fan 52 to cool the engine 12 and the reductant line 40, the use of an additional separate fan assembly may be avoided. By cutting down on the use of the additional separate fan assembly, complexity and cost of the same may be saved by using the cooling system 46.

Additionally, when the fan 52 is located outside the engine compartment 42, walls of the engine compartment 42 may act as a bulkhead between the fan 52 and the components lying within the engine compartment interior space 44. This may assist in creating an area of high pressure in order to facilitate in generating the cooling airflow 54.

A person of ordinary skill in that will appreciate that although the use of the cooling system 46 has been explained in conjunction with cooling of the reductant line 40 of the engine aftertreatment system 14, the cooling system 46 may also be used to cool any other component at least partially located within the engine compartment 42, without deviating from the scope and spirit of the disclosure.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

Claims

1. A cooling system for an engine aftertreatment system at least partially located inside an engine compartment, the system comprising:

a pressurized air source configured to generate a cooling airflow; and

an air conduit connected to the pressurized air source and configured to provide the cooling airflow to the engine aftertreatment system.

2. The cooling system of claim 1, wherein the air conduit is located at least partially inside the engine compartment.

3. The cooling system of claim 1, wherein the engine aftertreatment system includes a reductant line connected to a reductant source.

4. The cooling system of claim 3, wherein the air conduit surrounds the reductant line.

5. The cooling system of claim 3, wherein the engine aftertreatment system further includes a valve provided on the reductant line.

6. The cooling system of claim 5, wherein the air conduit deliver the cooling airflow to the valve.

7. The cooling system of claim 3, wherein the reductant source is located outside the engine compartment.

8. The cooling system of claim 1, wherein the pressurized air source includes a fan.

9. A power system comprising:

an engine contained inside an engine compartment;

an engine aftertreatment system associated with the engine; and

a cooling system for the engine aftertreatment system, the system including: a pressurized air source configured to generate a cooling airflow; and an air conduit connected to the pressurized air source and configured to provide the cooling airflow to the engine aftertreatment system.

10. The power system of claim 9, wherein the air conduit is located at least partially inside the engine compartment.

11. The power system of claim 9, wherein the engine aftertreatment system includes a reductant line connected to a reductant source.

12. The power system of claim 11, wherein the air conduit surrounds the reductant line.

13. The power system of claim 11, wherein the engine aftertreatment system further includes a valve provided on the reductant line.

14. The power system of claim 13, wherein the air conduit delivers the cooling airflow to the valve.

15. The power system of claim 13, wherein the pressurized air source delivers the cooling airflow to a radiator associated with the engine.

16. A method for cooling an engine aftertreatment system at least partially located inside an engine compartment, the method comprising:

generating a cooling airflow by a pressurized air source; and

providing the cooling airflow to the engine aftertreatment system by an air conduit connected to the pressurized air source.

17. The method of claim 16, wherein the cooling airflow is further provided to a reductant line.

18. The method of claim 17, wherein the cooling airflow is further provided to a valve connected to the reductant line.