Claims:1. An exhaust gas system (10) in a vehicle, said exhaust gas system (10)
comprising :
- a diesel oxidation catalyst (DOC) (12) connected in an exhaust pipe (14)
downstream 5 to an engine (16);
- an exhaust gas recirculation (EGR) cooler (18) adapted to cool an exhaust
gas coming from said engine (16);
- an exhaust valve (20) located in said exhaust pipe (14) , said exhaust
valve (20) is controlled by a control unit (22);
10 characterized in that:
- a first flow path (24) comprising at least one valve (26), connected
between said DOC (12) and an inlet (28) of said EGR cooler (18);
- a second flow path (30) connected between an outlet (32) of said EGR
cooler (18) and said exhaust pipe (14).
2. The exhaust gas system (10) as claimed in claim 1, wherein said first flow
path (24) comprises a first valve (26(a)) and a second valve (26(b)), said first
valve (26(a)) is positioned in proximity to said DOC (12) and said second
valve (26(b)) is positioned in proximity to said inlet (28) of said EGR cooler
20 (18).
3. The exhaust gas system (10) as claimed in claim 1, comprises a temperature
sensor (38) adapted to detect a temperature of said EGR cooler (18) .
4. The exhaust gas system (10) as claimed in claim 1, wherein said control unit
(22) detects clogging of said EGR cooler (18) based on said detected
temperature.
5. The exhaust gas system (10) as claimed in claim 3, wherein said control unit
30 (22) adapted to operate said exhaust valve (20) and said at least one valve
(26) present in said first flow path (24), based on said detected temperature
of said EGR cooler (18).
6. The exhaust gas system (10) as claimed in claim 4, wherein said control unit
(22) adapted to partially open said exhaust valve (20) and 5 fully open said at
least one valve (26) ,when said detected temperature is more than a
predefined temperature.
7. The exhaust gas system (10) as claimed in claim 1, wherein said at least one
10 valve (26) of said first flow path (24) is a uni-directional valve.
8. The exhaust gas system (10) as claimed in claim 1, wherein said first flow
path (24) and said second flow path (30) are made of heat resistant material.
9. The exhaust gas system (10) as claimed in claim 1, wherein said clogging of
said EGR cooler (18) is removed by directing an exhaust gas from said engine
(16) through said first flow path (24).
10. A method of unclogging an exhaust gas regeneration (EGR) cooler (18) in a
20 vehicle, said method comprising :
- increasing a quantity of fuel injecting into an engine (16) during a
combustion cycle;
- increasing a temperature of an exhaust gas existing said engine (16) due
25 to said increased fuel injection;
characterized in that:
- operating an exhaust valve (20) present in an exhaust pipe (14) and at
least one valve (26) present in a first flow path (24) connecting said EGR
cooler (18) and said engine (16);
- directing said exhaust gas with increased temperature towards said EGR
cooler (18) for unclogging said EGR cooler (18) during a regeneration
mode. , Description:The exhaust gas system 10 comprises a diesel oxidation catalyst (DOC) 12 connected in
an exhaust pipe 14 downstream to an engine 16. The system 10 further comprises an
exhaust gas recirculation (EGR) cooler 18 adapted to cool an exhaust gas coming from
said engine 16. The system 10 comprises an exhaust valve 20 located in said exhaust pipe
10 14. The exhaust valve is controlled by a control unit 22. The system 10 comprises a first
flow path 24 comprising at least one valve 26. The first flow path 24 is connected
between the DOC 12 and an inlet 28 of the EGR cooler 18. The system 10 comprises a
second flow path 30 connected between an outlet 32 of the EGR cooler 18 and the
exhaust pipe 14.