Electrically heated particulate filter
View Patent ↗A control system comprises a particulate matter (PM) filter, an electric heater, a first heating module, and a second heating module. The PM filter includes M zones that filter PM from exhaust gas. The electric heater includes M segments corresponding to the M zones that heat exhaust gas input to selected ones of the M zones when activated. The first heating module activates N of the M segments to heat exhaust gas input to N of the M zones to regenerate the N zones. The second heating module operates in one of a first mode and a second mode to regenerate other ones of the M zones after the N zones are regenerated. The first mode includes adjusting an air-fuel ratio of the exhaust gas. The second mode includes activating other ones of the M segments to heat exhaust gas input to other ones of the M zones.
1. A control 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 and wherein M is an integer greater than one;
an electric heater that includes M segments corresponding to the M zones that heat exhaust gas input to selected ones of the M zones when activated;
a first heating module that activates N of the M segments to heat exhaust gas input to N of the M zones to regenerate the N zones, wherein N is an integer less than M; and
a second heating module that is configured to operate in a first mode and a second mode to regenerate other ones of the M zones after the N zones are regenerated,
wherein the first mode includes adjusting an air-fuel ratio of the exhaust gas to heat exhaust gas input to the M zones, and wherein the second mode includes activating other ones of the M segments to heat exhaust gas input to other ones of the M zones.
2. The control system of claim 1 , wherein the second heating module operates in the first mode when a flow rate of the exhaust gas is greater than a predetermined flow rate.
3. The control system of claim 2 , wherein the second heating module operates in the second mode when the flow rate is less than or equal to the predetermined flow rate.
4. The control system of claim 1 , wherein the first mode includes heating the exhaust gas to a predetermined temperature.
5. The control system of claim 4 , wherein the predetermined temperature causes PM in the other ones of the M zones to combust.
6. The control system of claim 4 , wherein the predetermined temperature is greater than 650° C.
7. The control system of claim 4 , wherein the predetermined temperature is greater than 700° C.
8. The control system of claim 1 , wherein the first mode includes adjusting the air-fuel ratio by injecting fuel into at least one of a cylinder of an engine and an exhaust system.
9. The control system of claim 1 , wherein the first heating module activates the N segments until PM in the N zones combusts.
10. The control system of claim 1 , wherein the N zones include an axially centered portion of the PM filter, and wherein the others of the M zones include portions of the PM filter surrounding the N zones.
11. 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 and wherein M is an integer greater than one;
providing an electric heater that includes M segments corresponding to the M zones that heat exhaust gas input to selected ones of the M zones when activated;
activating N of the M segments to heat exhaust gas input to N of the M zones to regenerate the N zones, wherein N is an integer less than M; and
operating in a first mode and a second mode to regenerate other ones of the M zones after the N zones are regenerated,
wherein the first mode includes adjusting an air-fuel ratio of the exhaust gas to heat exhaust gas input to the M zones, and wherein the second mode includes activating other ones of the M segments to heat exhaust gas input to other ones of the M zones.
12. The method of claim 11 , further comprising operating in the first mode when a flow rate of the exhaust gas is greater than a predetermined flow rate.
13. The method of claim 12 , further comprising operating in the second mode when the flow rate is less than or equal to the predetermined flow rate.
14. The method of claim 11 , wherein operating in the first mode includes heating the exhaust gas to a predetermined temperature.
15. The method of claim 14 , wherein the predetermined temperature causes PM in the other ones of the M zones to combust.
16. The method of claim 14 , wherein the predetermined temperature is greater than 650° C.
17. The method of claim 14 , wherein the predetermined temperature is greater than 700° C.
18. The method of claim 11 , wherein operating in the first mode includes adjusting the air-fuel ratio by injecting fuel into at least one of a cylinder of an engine and an exhaust system.
19. The method of claim 11 , further comprising activating the N segments until PM in the N zones combusts.
20. The method of claim 11 , wherein the N zones include an axially centered portion of the PM filter, and wherein the others of the M zones include portions of the PM filter surrounding the N zones.