# US 2021/0277838 A1 · System and method for fuel nozzle cleaning during engine operation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0277838 A1 - Document ID: US20210277838A1 - Status: Published application - Kind: A1 - Application number: 16/809,797 - Filed: 2020-03-05 - Published: 2021-09-09 - Earliest claimed: 2020-03-05 - Assignees: General Electric Company - Applicants: General Electric Company - Inventors: Nayan Vinodbhai Patel; Michael Scott McCambridge; Eric John Kress; Kevin Richard Graziano; Brendon Matthew Leeker - Web page: https://patentgrep.com/patent/US20210277838A1 ## CPC - F02C 9/32: characterised by throttling of fuel (F02C9/38 takes precedence) - F01D 25/002: {Cleaning of turbomachines} - F02M 65/008: {of injectors only} - F23D 11/38: Nozzles; Cleaning devices therefor - F23N 1/002: {using electronic means (F23N1/04 - F23N1/10 take precedence)} - F05D 2220/323: for aircraft propulsion, e.g. jet engines - F23D 2209/30: Purging - F23K 2300/203: Purging - F23N 2225/04: pressure - F23N 2225/08: temperature - F23N 2227/06: Postpurge - F23R 2900/00019: Repairing or maintaining combustion chamber liners or subparts - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - F23D: BURNERS - F23N: REGULATING OR CONTROLLING COMBUSTION (control devices specially adapted for combustion apparatus in which combustion takes place in a fluidised bed of fuel or other particles F23C10/28; condition responsive controls for regulating combustion in domestic stoves with open fires for solid fuel F24B1/187) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - F23K: FEEDING FUEL TO COMBUSTION APPARATUS (fuel feeders specially adapted for fluidised bed combustion apparatus F23C10/22) - F23R: GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS (fluidised bed combustion apparatus specially adapted for operation at superatmospheric pressures F23C10/16) ## Abstract A method and system for cleaning a fuel nozzle during engine operation is provided. Operations include operating the compressor section to provide the flow of oxidizer at a first oxidizer flow condition to the combustion chamber, wherein the first oxidizer flow condition comprises an environmental parameter; operating the fuel system at a first fuel flow condition to produce a fuel-oxidizer ratio at the combustion chamber; comparing the environmental parameter to a first environmental parameter threshold; and transitioning the fuel system to a second fuel flow condition corresponding to a cleaning condition at the fuel nozzle if the environmental parameter is equal to or greater than the first environmental threshold. ## Claims ### Claim 1 A heat engine, the heat engine comprising: a compressor section configured to provide a flow of oxidizer to a combustion chamber; a fuel nozzle comprising a plurality of fuel injection openings, wherein the fuel nozzle is configured to provide a first fuel flow to the combustion chamber through one or more of the fuel injector openings and a second fuel flow to the combustion chamber through one or more of the fuel injector openings different from the first fuel flow; a fuel system configured to provide a first fuel flow through the fuel nozzle variably and separate from a second fuel flow through the fuel nozzle; and a controller configured to execute operations, the operations comprising: operating the compressor section to provide the flow of oxidizer at a first oxidizer flow condition to the combustion chamber, wherein the first oxidizer flow condition comprises an environmental parameter; operating the fuel system at a first fuel flow condition to produce a fuel-oxidizer ratio at the combustion chamber; comparing the environmental parameter to a first environmental parameter threshold; and transitioning the fuel system to a second fuel flow condition corresponding to a cleaning condition at the fuel nozzle if the environmental parameter is equal to or greater than the first environmental threshold. ### Claim 2 (depends on 1) The heat engine of claim 1, wherein the environmental parameter comprises a temperature parameter and a pressure parameter. ### Claim 3 (depends on 2) The heat engine of claim 2, wherein the environmental parameter corresponds to a location at the heat engine downstream of the compressor section and upstream of the combustion chamber. ### Claim 4 (depends on 2) The heat engine of claim 2, comparing the environmental parameter to a second environmental parameter threshold and transitioning the fuel system to a second fuel flow condition corresponding to the cleaning condition at the fuel nozzle if the environmental parameter is less than or equal to the second environmental parameter threshold. ### Claim 5 (depends on 4) The heat engine of claim 4, wherein the first environmental parameter threshold corresponds to one or more of a temperature of the flow of oxidizer of 550 F or greater or a pressure of 135 psi or greater downstream of the compressor section and upstream of the combustion chamber. ### Claim 6 (depends on 5) The heat engine of claim 5, wherein the second environmental parameter threshold corresponds to one or more of the temperature of the flow of oxidizer of 1250 F or less or the pressure of 315 psi or less downstream of the compressor section and upstream of the combustion chamber. ### Claim 7 (depends on 1) The heat engine of claim 1, the operations comprising: comparing a health parameter to a health parameter threshold, wherein the health parameter corresponds to one or more of a combustor component temperature, a combustion thermal gradient, a combustor stability parameter, or an emissions parameter. ### Claim 8 (depends on 7) The heat engine of claim 7, wherein transitioning the fuel system to the second fuel flow condition corresponding to a cleaning condition occurs if the health parameter is within the health parameter threshold. ### Claim 9 (depends on 7) The heat engine of claim 7, wherein the emissions parameter corresponds to an emissions output versus flight mode, wherein the flight mode corresponds to an emissions environment. ### Claim 10 (depends on 1) The heat engine of claim 1, wherein the cleaning condition comprises: operating the fuel system at a second fuel flow condition. ### Claim 11 (depends on 10) The heat engine of claim 10, wherein the cleaning condition comprises: flowing, through the fuel nozzle, a purge fluid through the fuel nozzle. ### Claim 12 (depends on 11) The heat engine of claim 11, wherein flowing the purge fluid comprises continuously flowing for a predetermined period of time of at least a portion of the flow of oxidizer to remove fuel deposits from the fuel nozzle. ### Claim 13 (depends on 10) The heat engine of claim 10, wherein operating the fuel system at the second fuel flow condition comprises reducing the second fuel flow to zero and increasing the first fuel flow to equal the fuel-oxidizer ratio at the combustion chamber at the first fuel flow condition. ### Claim 14 (depends on 11) The heat engine of claim 11, wherein flowing the purge fluid comprises: operating the fuel system at a third fuel flow condition after operating the fuel system at the second fuel flow condition, wherein the third fuel flow condition and the first oxidizer flow condition together provide the fuel-oxidizer ratio at the combustion chamber as the first fuel flow condition and the first oxidizer flow condition. ### Claim 15 (depends on 1) The heat engine of claim 1, wherein the first fuel flow condition corresponds to a cruise operating condition. ### Claim 16 (depends on 1) The heat engine of claim 1, wherein the first oxidizer flow condition corresponds to a steady state inlet condition of oxidizer into the compressor section. ### Claim 17 (depends on 16) The heat engine of claim 16, wherein the steady state inlet condition corresponds to an idle operating condition, a part-power operating condition, or a full-power operating condition. ### Claim 18 (depends on 1) The heat engine of claim 1, the operations comprising: operating the compressor section to provide the flow of oxidizer at an initial oxidizer flow condition, wherein the initial oxidizer flow condition precedes the first oxidizer flow condition. ### Claim 19 (depends on 18) The heat engine of claim 18, wherein the initial oxidizer flow condition corresponds to a transient inlet condition of the flow of oxidizer into the compressor section. ### Claim 20 (depends on 1) The heat engine of claim 1, wherein the plurality of fuel injection openings comprises a main fuel injector and a pilot fuel injector.