Methods for varnish removal and prevention in an internal combustion engine
View Patent ↗Methods for removing and preventing the buildup of unwanted deposits and varnishes on combustion chamber surfaces, particularly injector-igniter components that are exposed to combustion events. A method of removing deposits from an injector-igniter comprises monitoring the current across a pair of electrodes in the injector-igniter, comparing the current with a predetermined threshold level, and performing a cleaning cycle if the current exceeds the threshold level. The cleaning cycle may comprise injecting oxidant through the injector-igniter and into the combustion chamber. The cleaning cycle may further comprise ionizing the oxidant with an electrical discharge having a first polarity and ionizing the oxidant a second time with an electrical discharge having a second polarity. In other cases the cleaning cycle comprises injecting hydrogen through the injector-igniter and into the combustion chamber. In still other cases the cleaning cycle may comprise injecting coolant onto the electrodes.
1. A method of removing deposits from an injector-igniter exposed to combustion events in a combustion chamber, the method comprising:
monitoring the current across a pair of electrodes in the injector-igniter;
comparing the current with a predetermined threshold level; and
performing a cleaning cycle if the current exceeds the threshold level.
2. The method of claim 1 , wherein the cleaning cycle comprises injecting oxidant through the injector-igniter and into the combustion chamber.
3. The method of claim 2 , wherein the cleaning cycle further comprises ionizing the oxidant with an electrical discharge having a first polarity.
4. The method of claim 3 , wherein the cleaning cycle further comprises ionizing the oxidant a second time with an electrical discharge having a second polarity.
5. The method of claim 1 , wherein the cleaning cycle comprises injecting hydrogen through the injector-igniter and into the combustion chamber.
6. The method of claim 5 , wherein the cleaning cycle further comprises ionizing the hydrogen.
7. The method of claim 1 , wherein the cleaning cycle comprises injecting coolant onto the electrodes.
8. The method of claim 7 , wherein the coolant is liquid.
9. The method of claim 7 , wherein the coolant is fuel.
10. A method of removing deposits from an injector-igniter exposed to combustion events in a combustion chamber, the method comprising:
establishing a predetermined current threshold;
monitoring the current across a pair of electrodes in the injector-igniter;
comparing the current with the predetermined current threshold; and
performing a cleaning cycle if the current exceeds the threshold level, wherein the cleaning cycle includes injecting a liquid coolant onto the electrodes.
11. The method of claim 10 , wherein the coolant is injected through a first channel of the injector-igniter.
12. The method of claim 11 wherein a fuel is injected through a second channel of the injector-igniter, wherein the second channel is separate from the first channel.
13. The method of claim 10 , wherein the coolant is fuel.
14. A method of preventing deposits from building up on an injector-igniter exposed to combustion cycles in a combustion chamber, the method comprising:
monitoring the number of combustion cycles that have occurred in the combustion chamber;
comparing the number of combustion cycles with a predetermined threshold number of cycles; and
performing a cleaning cycle if the number of combustion cycles exceeds the threshold number of cycles.
15. The method of claim 14 , wherein the cleaning cycle comprises injecting oxidant through the injector-igniter and into the combustion chamber.
16. The method of claim 15 , wherein the cleaning cycle further comprises ionizing the oxidant with an electrical discharge having a first polarity.
17. The method of claim 16 , wherein the cleaning cycle further comprises ionizing the oxidant a second time with an electrical discharge having a second polarity.
18. The method of claim 14 , wherein the cleaning cycle comprises injecting hydrogen through the injector-igniter and into the combustion chamber.
19. The method of claim 18 , wherein the cleaning cycle further comprises ionizing the hydrogen.
20. The method of claim 14 , wherein the cleaning cycle comprises injecting coolant onto the electrodes.