Thermal enhancer and hydrocarbon doser
A catalyst is positioned downstream of a thermal enhancer, such as a fuel-fired burner for example. A doser injects hydrocarbons into the thermal enhancer to maintain exhaust gas temperatures such that the catalyst is in an active condition and to raise exhaust gas temperatures to a level such that a diesel particulate filter can be regenerated.
1. An exhaust component assembly comprising:
a catalyst;
a fuel-fired burner to raise exhaust gas temperatures to activate the catalyst;
a doser that injects hydrocarbons into said fuel-fired burner to maintain exhaust gas temperatures such that said catalyst is in an active condition and to raise exhaust gas temperature to temperature levels sufficient to regenerate a diesel particulate filter or to perform another desired reaction on said catalyst; and
a controller that operates said fuel-fired burner in one of a plurality of operational modes to control exhaust gas temperatures, and wherein said plurality of operational modes includes at least a first mode comprising a burner only mode where said fuel-fired burner is active and said doser is inactive, a second mode comprising a burner and doser mode where said burner is active and said doser is supplying hydrocarbons to said exhaust gas, and a third mode comprising a doser only mode where said doser is supplying hydrocarbons to the exhaust gas and said burner is inactive, and wherein said controller only operates in said second mode subsequent to the catalyst reaching a light-off temperature due to activation of the fuel-fired burner until a predetermined condition is achieved, and wherein said controller initiates the third mode of operation by inactivating the fuel-fired burner once the predetermined condition is achieved.
2. The exhaust component assembly according to claim 1 wherein said catalyst comprises one of a diesel oxidation catalyst, a lean NOx catalyst, or a lean NOx trap and wherein said fuel-fired burner ignites exhaust gases to raise exhaust gas temperatures to a desired temperature level.
3. The exhaust component assembly according to claim 1 wherein the predetermined condition comprises at least one of a target temperature being achieved, the exhaust temperature exceeding a burner operating temperature, or the fuel-fired burner reaching a rich limit.
4. An exhaust component assembly comprising:
a catalyst;
a fuel-fired burner to raise exhaust gas temperatures to activate the catalyst;
a doser that injects hydrocarbons into said fuel-fired burner to maintain exhaust gas temperatures such that said catalyst is in an active condition and to raise exhaust gas temperature to temperature levels sufficient to regenerate a diesel particulate filter or to perform another desired reaction on said catalyst; and
a controller that operates said fuel-fired burner in one of a plurality of operational modes to control exhaust gas temperatures, and wherein said plurality of operational modes includes at least a first mode comprising a burner only mode where said fuel-fired burner is active and said doser is inactive, a second mode comprising a burner and doser mode where said burner is active and said doser is supplying hydrocarbons to said exhaust gas, and a third mode comprising a doser only mode where said doser is supplying hydrocarbons to the exhaust gas and said burner is inactive, and wherein said controller determines if an exhaust gas temperature is sufficient to achieve activation of said catalyst, and wherein if said exhaust gas temperature is not sufficient to achieve activation of said catalyst said controller operates in said first mode to activate only said fuel-fired burner until a light-off temperature of said catalyst is achieved, and wherein if said exhaust gas temperature is sufficient to achieve activation of said catalyst said controller operates in said third mode.
5. The exhaust component assembly according to claim 4 wherein, subsequent to said catalyst reaching a light-off temperature due to activation of said fuel-fired burner, said controller operates in said second mode with said fuel-fired burner being activated and said doser adding hydrocarbons to said exhaust gases until a target temperature is achieved, said exhaust temperature exceeds a burner operating temperature, or said fuel-fired burner reaches a rich limit.
6. An exhaust component assembly comprising:
a catalyst;
a fuel-fired burner to raise exhaust gas temperatures to activate the catalyst;
a doser that injects hydrocarbons into said fuel-fired burner to maintain exhaust gas temperatures such that said catalyst is in an active condition and to raise exhaust gas temperature to temperature levels sufficient to regenerate a diesel particulate filter or to perform another desired reaction on said catalyst; and
a controller that operates said fuel-fired burner in one of a plurality of operational modes to control exhaust gas temperatures, and wherein said plurality of operational modes includes at least a first mode comprising a burner only mode where said fuel-fired burner is active and said doser is inactive, a second mode comprising a burner and doser mode where said burner is active and said doser is supplying hydrocarbons to said exhaust gas, and a third mode comprising a doser only mode where said doser is supplying hydrocarbons to the exhaust gas and said burner is inactive, and wherein said controller operates in said third mode with said doser adding hydrocarbons to said exhaust gas as long as said catalyst is above light-off temperature and hydrocarbons do not continue downstream of said catalyst.
7. An exhaust component assembly comprising:
a catalyst;
a fuel-fired burner to raise exhaust gas temperatures to activate the catalyst;
a doser that injects hydrocarbons into said fuel-fired burner to maintain exhaust gas temperatures such that said catalyst is in an active condition and to raise exhaust gas temperature to temperature levels sufficient to regenerate a diesel particulate filter or to perform another desired reaction on said catalyst;
a controller that operates said fuel-fired burner in one of a plurality of operational modes to control exhaust gas temperatures, and wherein said plurality of operational modes includes at least a first mode comprising a burner only mode where said fuel-fired burner is active and said doser is inactive, a second mode comprising a burner and doser mode where said burner is active and said doser is supplying hydrocarbons to said exhaust gas, and a third mode comprising a doser only mode where said doser is supplying hydrocarbons to the exhaust gas and said burner is inactive; and
wherein said controller determines:
if an exhaust gas temperature is sufficient to achieve activation of said catalyst, and if said exhaust gas temperature is not sufficient to achieve activation of said catalyst said controller operates in said first mode to activate only said fuel-fired burner until a light-off temperature of said catalyst is achieved, and
wherein, subsequent to said catalyst reaching a light-off temperature due to activation of said fuel-fired burner, said controller operates in said second mode with said fuel-fired burner being activated and said doser adding hydrocarbons to said exhaust gases until a target temperature is achieved, said exhaust temperature exceeds a burner operating temperature, or said fuel-fired burner reaches a rich limit, and
wherein said controller operates in said third mode with said doser adding hydrocarbons to said exhaust gas as long as said catalyst is above light-off temperature and hydrocarbons do not continue downstream of said catalyst.
8. An exhaust component assembly comprising:
a catalyst;
a fuel-fired burner to raise said catalyst to a temperature at which said catalyst is active;
a diesel particulate filter that collects particulate matter from exhaust gases, wherein fuel-fired burner increases exhaust gas temperatures to regenerate said diesel particulate filter;
a doser that adds hydrocarbons to exhaust gases within said fuel-fired burner;
a controller that operates said fuel-fired burner in one of a plurality of operational modes to control exhaust gas temperatures for regeneration of said diesel particulate filter, and wherein said plurality of operational modes includes at least a first mode comprising a burner only mode where said fuel-fired burner is active and said doser is inactive, a second mode comprising a burner and doser mode where said burner is active and said doser is supplying hydrocarbons to said exhaust gas, and a third mode comprising a doser only mode where said doser is supplying hydrocarbons to the exhaust gas and said burner is inactive; and
wherein said controller determines:
if an exhaust gas temperature is sufficient to achieve activation of said catalyst, and wherein if said exhaust gas temperature is not sufficient to achieve activation of said catalyst said controller operates in said first mode to only activate said fuel-fired burner until a light-off temperature of said catalyst is achieved, and
wherein, subsequent to said catalyst reaches a light-off temperature due to activation of said fuel-fired burner, said controller operates in said second mode with said fuel-fired burner being activated and said doser adding hydrocarbons to said exhaust gases until a target temperature is achieved, said exhaust temperature exceeds a burner operating temperature, or said fuel-fired burner reaches a rich limit, and
wherein said controller operates in said third mode with said doser adding hydrocarbons to said exhaust gas as long as said catalyst is above light-off temperature and hydrocarbons do not continue downstream of said catalyst.
9. The exhaust component assembly according to claim 8 wherein said catalyst comprises one of a diesel oxidation catalyst, a lean NOx catalyst, or a lean NOx trap and wherein said catalyst is downstream of said fuel-fired burner.
10. A method of operating an exhaust treatment component comprising:
positioning a catalyst downstream of a fuel-fired burner;
associating a doser with the fuel-fired burner to inject an additive into the exhaust gas upstream of the catalyst;
determining if an exhaust gas temperature is sufficient to achieve activation of the catalyst;
initiating a first mode of operation by activating only the fuel-fired burner if the exhaust gas temperature is not sufficient to achieve activation of the catalyst while the doser remains inactive;
selectively injecting the additive with the doser to maintain exhaust gas temperatures such that the catalyst is in an active condition and to raise exhaust gas temperature to temperature levels such that a diesel particulate filter can be regenerated;
operating the fuel-fired burner in one of a plurality of operational modes to control exhaust gas temperatures, and wherein the plurality of operational modes includes at least the first mode of operation which comprises a burner only mode where the fuel-fired burner is active and the doser is inactive, a second mode of operation comprising a burner and doser mode where the burner is active and the doser is supplying the additive to said exhaust gas, and a third mode of operation comprising a doser only mode where the doser is supplying the additive to the exhaust gas and the fuel-fired burner is inactive; and
operating in the second mode, subsequent to the catalyst reaching a light-off temperature due to activation of the fuel-fired burner, with both the fuel-fired burner and doser being activated until a predetermined condition is achieved, and including initiating the third mode of operation by inactivating the fuel-fired burner once the predetermined condition is achieved.
11. The method according to claim 10 wherein the predetermined condition comprises at least one of a target temperature being achieved, the exhaust temperature exceeding a burner operating temperature, or the fuel-fired burner reaching a rich limit.
12. A method of operating an exhaust treatment component comprising:
positioning a catalyst downstream of a fuel-fired burner;
associating a doser with the fuel-fired burner to inject an additive into the exhaust gas upstream of the catalyst;
determining if an exhaust gas temperature is sufficient to achieve activation of the catalyst;
initiating a first mode of operation by activating only the fuel-fired burner if the exhaust gas temperature is not sufficient to achieve activation of the catalyst while the doser remains inactive;
selectively injecting the additive with the doser to maintain exhaust gas temperatures such that the catalyst is in an active condition and to raise exhaust gas temperature to temperature levels such that a diesel particulate filter can be regenerated;
operating the fuel-fired burner in one of a plurality of operational modes to control exhaust gas temperatures, and wherein the plurality of operational modes includes at least the first mode of operation which comprises a burner only mode where the fuel-fired burner is active and the doser is inactive, a second mode of operation comprising a burner and doser mode where the burner is active and the doser is supplying the additive to said exhaust gas, and a third mode of operation comprising a doser only mode where the doser is supplying the additive to the exhaust gas and the fuel-fired burner is inactive; and
operating in the first mode to only activate the fuel-fired burner until a light-off temperature of the catalyst is achieved.
13. A method of operating an exhaust treatment component comprising:
positioning a catalyst downstream of a fuel-fired burner;
associating a doser with the fuel-fired burner to inject an additive into the exhaust gas upstream of the catalyst;
determining if an exhaust gas temperature is sufficient to achieve activation of the catalyst;
initiating a first mode of operation by activating only the fuel-fired burner if the exhaust gas temperature is not sufficient to achieve activation of the catalyst while the doser remains inactive;
selectively injecting the additive with the doser to maintain exhaust gas temperatures such that the catalyst is in an active condition and to raise exhaust gas temperature to temperature levels such that a diesel particulate filter can be regenerated;
operating the fuel-fired burner in one of a plurality of operational modes to control exhaust gas temperatures, and wherein the plurality of operational modes includes at least the first mode of operation which comprises a burner only mode where the fuel-fired burner is active and the doser is inactive, a second mode of operation comprising a burner and doser mode where the burner is active and the doser is supplying the additive to said exhaust gas, and a third mode of operation comprising a doser only mode where the doser is supplying the additive to the exhaust gas and the fuel-fired burner is inactive; and
operating in the second mode, subsequent to the catalyst reaching a light-off temperature due to activation of the fuel-fired burner, with the fuel-fired burner being activated and the doser adding hydrocarbons to the exhaust gases until a target temperature is achieved, the exhaust temperature exceeds a burner operating temperature, or the fuel-fired burner reaches a rich limit.
14. A method of operating an exhaust treatment component comprising:
positioning a catalyst downstream of a fuel-fired burner;
associating a doser with the fuel-fired burner to inject an additive into the exhaust gas upstream of the catalyst;
determining if an exhaust gas temperature is sufficient to achieve activation of the catalyst;
initiating a first mode of operation by activating only the fuel-fired burner if the exhaust gas temperature is not sufficient to achieve activation of the catalyst while the doser remains inactive;
selectively injecting the additive with the doser to maintain exhaust gas temperatures such that the catalyst is in an active condition and to raise exhaust gas temperature to temperature levels such that a diesel particulate filter can be regenerated;
operating the fuel-fired burner in one of a plurality of operational modes to control exhaust gas temperatures, and wherein the plurality of operational modes includes at least the first mode of operation which comprises a burner only mode where the fuel-fired burner is active and the doser is inactive, a second mode of operation comprising a burner and doser mode where the burner is active and the doser is supplying the additive to said exhaust gas, and a third mode of operation comprising a doser only mode where the doser is supplying the additive to the exhaust gas and the fuel-fired burner is inactive; and
operating in the third mode with the doser adding hydrocarbons to the exhaust gas as long as said catalyst is above light-off temperature and hydrocarbons do not continue downstream of the catalyst.
15. A method of operating an exhaust treatment component comprising:
positioning a catalyst downstream of a fuel-fired burner;
associating a doser with the fuel-fired burner to inject an additive into the exhaust gas upstream of the catalyst;
determining if an exhaust gas temperature is sufficient to achieve activation of the catalyst;
initiating a first mode of operation by activating only the fuel-fired burner if the exhaust gas temperature is not sufficient to achieve activation of the catalyst while the doser remains inactive;
selectively injecting the additive with the doser to maintain exhaust gas temperatures such that the catalyst is in an active condition and to raise exhaust gas temperature to temperature levels such that a diesel particulate filter can be regenerated;
operating the fuel-fired burner in one of a plurality of operational modes to control exhaust gas temperatures, and wherein the plurality of operational modes includes at least the first mode of operation which comprises a burner only mode where the fuel-fired burner is active and the doser is inactive, a second mode of operation comprising a burner and doser mode where the burner is active and the doser is supplying the additive to said exhaust gas, and a third mode of operation comprising a doser only mode where the doser is supplying the additive to the exhaust gas and the fuel-fired burner is inactive; and
only initiating the second mode of operation in response to the fuel-fired burner alone increasing the exhaust gas temperature to a level sufficient to activate the catalyst.
16. An exhaust component assembly comprising:
a catalyst;
a fuel-fired burner to raise said catalyst temperature which said catalyst is active;
a diesel particulate filter that collects particulate matter from exhaust gases, wherein fuel-fired burner increases exhaust gas temperatures to regenerate said diesel particulate filter;
a doser that adds hydrocarbons to exhaust gases within said fuel-fired burner; and
a controller that operates said fuel-fired burner in one of a plurality of operational modes to control exhaust gas temperatures for regeneration of said diesel particulate filter, and wherein said plurality of operational modes includes at least a first mode comprising a burner only mode where said fuel-fired burner is active and said doser is inactive, a second mode comprising a burner and doser mode where said burner is active and said doser is supplying hydrocarbons to said exhaust gas, and a third mode comprising a doser only mode where said doser is supplying hydrocarbons to the exhaust gas and said burner is inactive, and wherein said controller only operates in said second mode subsequent to the catalyst reaching a light-off temperature due to activation of the fuel-fired burner until a predetermined condition is achieved, and wherein said controller initiates the third mode of operation by inactivating the fuel-fired burner once the predetermined condition is achieved.