Reduced volume electrically heated particulate filter
View Patent ↗A control system comprises an exhaust treatment system, an electric heating module, and an exhaust heating module. The exhaust treatment system comprises a particulate matter (PM) filter and an electric heater. The PM filter includes M zones that receive exhaust gas of an engine and filter PM from the exhaust gas. The electric heater heats exhaust gas input to N of the M zones, wherein M is an integer greater than one and N is an integer less than M. The electric heating module activates the electric heater to heat exhaust gas input to the N zones to regenerate the N zones. The exhaust heating module heats exhaust gas input to the M zones by controlling an air-fuel ratio of the exhaust gas after the N zones regenerate.
1. An exhaust treatment system comprising:
a particulate matter (PM) filter that receives exhaust gas of an engine and filters PM from the exhaust gas, wherein the PM filter includes M zones;
an electric heater arranged to cover a first one of the M zones but not other ones of the M zones, wherein the electric heater heats exhaust gas that is input to the first one of the M zones but not the other ones of the M zones, and wherein M is an integer greater than one; and
a control module configured to i) adjust an exhaust temperature to a first predetermined temperature and activates the electric heater to initiate regeneration in the first one of the M zones, ii) deactivate the electric heater, and iii) after deactivating the electric heater, adjust the exhaust temperature to a second predetermined temperature that is greater than the first predetermined temperature to initiate regeneration in the other ones of the M zones,
wherein the first one of the M zones includes an axially centered portion of the PM filter, and wherein the other ones of the M zones include a remaining portion of the PM filter surrounding the first one of the M zones.
2. The exhaust treatment system of claim 1 , wherein the control module is configured to activate the electric heater for a predetermined period.
3. The exhaust treatment system of claim 1 , wherein the control module is configured to activate the electric heater until PM in the first one of the M zones reaches a third predetermined temperature.
4. The exhaust treatment system of claim 1 , wherein the second predetermined temperature causes PM in the other ones of the M zones to combust.
5. The exhaust treatment system of claim 1 , wherein the second predetermined temperature is greater than 650° C.
6. A method comprising:
providing a particulate matter (PM) filter that receives exhaust gas of an engine and filters PM from the exhaust gas, wherein the PM filter includes M zones;
arranging an electric heater to cover a first one of the M zones but not other ones of the M zones,
wherein the electric heater is arranged to heat exhaust gas that is input to N the first one of the M zones but not the other ones of the M zones, and wherein M is an integer greater than one;
adjusting an exhaust temperature to a first predetermined temperature;
activating the electric heater to initiate regeneration in the first one of the M zones;
deactivating the electric heater; and
after deactivating the electric heater, adjusting the exhaust temperature to a second predetermined temperature that is greater than the first predetermined temperature to initiate regeneration in the other ones of the M zones,
wherein the first one of the M zones includes an axially centered portion of the PM filter, and wherein the other ones of the M zones include a remaining portion of the PM filter surrounding the first one of the M zones.
7. The method of claim 6 , further comprising activating the electric heater for a predetermined period.
8. The method of claim 6 , further comprising activating the electric heater until PM in the first one of the M zones reaches a predetermined temperature.
9. The method of claim 6 , wherein the second predetermined temperature causes PM in the other ones of the M zones to combust.
10. The method of claim 6 , wherein the second predetermined temperature is greater than 650° C.