Claims:CLAIMS
We Claim:
1. A system (10) to reduce temperature of an exhaust gas in a vehicle , said system (10) comprising :
- an inlet manifold (12) connected upstream an engine (13);
- an exhaust manifold (14) connected downstream said engine (13); a turbocharger (15) connected to said inlet manifold (12) and said exhaust manifold (14);
characterized in:
- a first channel (16) , a second channel (18), a heat exchanger (20) positioned in said exhaust manifold (14);
- one end of said first channel (16) connected to inlet manifold (12) downstream a compressor (22) of said turbocharger (15) and other end to said heat exchanger (20);
- one end of said second channel (18) connected to said heat exchanger (20) in said exhaust manifold (14), another end connected to said inlet manifold (12) downstream said first channel (16), such that said first and second channels (16,18) and said heat exchanger (20) forms a closed loop.
2. The system (10) as claimed in claim 1, wherein said first channel (16) comprises a first valve (24) adapted to allow compressed air from said compressor (22) of said turbocharger (15) towards said exhaust manifold (14).
3. The system (10) as claimed in claim 1, wherein said exhaust gas flows over said heat exchanger (20) in said exhaust manifold (14), such that, said compressed air flowing in said heat exchanger (20) absorbs heat of said exhaust gas.
4. The system (10) as claimed in claim 1, wherein said second channel (18) comprises a second valve (26) adapted to allow said heated compressed air from said heat exchanger (20) back to said inlet manifold (12).
5. The system (10) as claimed in claims 2 and 4, wherein said first valve (24) and said second valve (26) are controlled by an electronic control unit (28).
, Description: Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to a system to reduce temperature of an exhaust gas in a vehicle.

Background of the invention
[0002] By cooling exhaust gases, more percent of exhausted NOX pollutants will be decreased. In other side, by decreasing the restored gases temperature, durability of exhaust gas valves and other parts, which are depended on exhaust gas, will be increased. Some exhaust gas treatment systems, which are used in the vehicles, are very sensitive to high temperature operations. Segment as load carriers with small engine capacity reach higher exhaust temperatures at some operating points, which makes it a vital parameter when deciding the EGT strategy.

[0003] Prior art patent application US 20100107631 discloses a method of using compressed intake air to clean engine exhaust gas recirculation coolers. System includes an EGR valve for selectively diverting a portion of exhaust gas through an EGR conduit to an intake side of the internal combustion engine. Compressed intake air delivery system including a compressed air conduit, the compressed intake air delivery system being configured to selectively divert a portion of compressed intake air compressed by the turbocharger through the EGR cooler to remove soot particles deposited in the EGR cooler.
Brief description of the accompanying drawing
[0004] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:

[0005] FIG. 1 illustrates a system to reduce temperature of an exhaust gas in a vehicle in accordance to one embodiment of the invention.

Detailed description of the embodiments
[0006] FIG. 1 illustrates a system to reduce temperature of an exhaust gas in a vehicle in accordance with one embodiment of the invention. The system 10 comprises an inlet manifold 12 connected upstream an engine 13. The system 10 further comprises an exhaust manifold 14 connected downstream the engine 13 and a turbocharger 15 connected to the inlet manifold 12 and the exhaust manifold 14. The system comprises a first channel 16, a second channel 18, a heat exchanger 20 positioned in the exhaust manifold 14. One end of the first channel 16 connected to inlet manifold 12 downstream a compressor 22 of the turbocharger 15 and other end to the heat exchanger 20. One end of the second channel 18 is connected to the heat exchanger 20 in the exhaust manifold 14, and another end connected to the inlet manifold 12 downstream the first channel 16, such that the first and second channels (16,18) and the heat exchanger 20 forms a closed loop.

[0007] Further the construction of the system 10 and the components of the system 10 is explained as follows. An inlet air from the atmosphere is drawn into the inlet manifold 12 by operating an accelerator pedal of the vehicle. The inlet air in the inlet manifold 12 is compressed using the compressor 22 and is then directed into the engine 13 via an inter-cooler 30. The inter-cooler 30 is connected between the compressor 22 (downstream to second channel 18) and the engine 13. The exhaust gas from the engine 13 enters the exhaust manifold 14 and undergoes the exhaust gas treatment process before releasing into the atmosphere, as known to the person skilled in the art. The first and the second channels (16, 18) are of flexible pipe like the one structures connected between the inlet manifold 12 and the heat exchanger 20 of the exhaust manifold 14. The second channel 18 is made of a material, such that, the material dissipates the heat quickly.
According to one embodiment of the invention, the second channel 18 is made of a metal comprising aluminum or copper or silver or the like.

[0008] The first channel 16 comprises a first valve 24 and the second channel 18 comprises a second valve 26. The first and second valves (24, 26) are controlled by an electronic control unit 28. The first valve 24 is adapted to allow the compressed air into the heat exchanger 20 when operated by the electronic control unit 28. The second valve 26 is adapted to allow the heated compressed air from the heat exchanger 20 of the exhaust manifold 14 towards the inlet manifold 12. The second valve 26 is a unidirectional valve. The heat exchanger 20 is positioned downstream to a turbine of the turbocharger. The heat exchanger 20 in the exhaust manifold 14 operates in a conventional way as known to a person skilled in the art. The heat exchanger 20 transfers the heat from one medium to other medium or from one fluid to other fluid. The heat exchanger 20 can be of a shell type, a tube type, a plate type, or the like.

[0009] The working of the above system is explained as follows. The inlet air from the inlet manifold 12 is compressed in the compressor 22 of the turbocharger 15. The electronic control unit 28 opens the first valve 24 present in the first channel 16 and a portion of the compressed air that is flowing towards the inter cooler 30 from the compressor 22, is directed towards the heat exchanger. By the time the compressed air reaches the heat exchanger 20, the exhaust gas from the engine 13 is released as an output and the released exhaust gas flows over the heat exchanger 20 present in the exhaust manifold 14. The temperature of the exhaust gas will be approximately in the range of 500 degrees to 700 degrees. This heat of the exhaust gas is absorbed by the compressed air flowing in the heat exchanger 20. By the time the exhaust gas flows completely over the heat exchanger 20, the heat of the exhaust gas is reduced due to the above disclosed absorption process. The heated compressed air is directed back to the inlet manifold 12 through the second channel 18 and via the second valve 26. According to one embodiment, the second valve 26 is electronically controlled, i.e., the electronic control unit 28 opens the second valve 26 upon detecting the flow of the heated compressed air in the second channel 18. According to one embodiment of the invention, the second valve 26 is the unidirectional mechanical valve that opens by the force of the heated compressed air.

[0010] Due to the material of the second channel 18, the heat of the compressed air flowing from the heat exchanger 20 is dissipated. The temperature of the heated compressed air flowing the second channel 18 is reduced before reaching the inlet manifold 12. Then from the second channel 18, the compressed air temperature is further reduced by the inter cooler 30 before entering into the engine 13. Thus, the system reduces the heat of the exhaust gas in the exhaust manifold 14 by using two channels (16, 18) and the heat exchanger 20.

[0011] With the above system and the method disclosed, the heat/temperature of the exhaust gas is reduced before undergoing the exhaust gas treatments. The load on the inter cooler 30 is reduced, as the material of the second channel 18 helps in dissipating the heat of the compressed air flowing from the heat exchanger 20. The electronic control unit 28 operates the first valve 24 (opens or closes) based on the requirement, thus increasing the exhaust gas treatment efficiency.

[0012] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.