METHODS FOR VARNISH REMOVAL AND PREVENTION IN AN INTERNAL COMBUSTION ENGINE
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.