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EP-4739640-A2 - TURBINE ENGINE CMAS IN SITU MITIGATION

EP4739640A2EP 4739640 A2EP4739640 A2EP 4739640A2EP-4739640-A2

Abstract

In a method for using a gas turbine engine (720, 720A, 720B), the gas turbine engine has: a compressor section (840, 842); a combustor section (844) including a plurality of fuel nozzles (860); and a turbine section (846, 848) having one or more stages of blades (400). The method includes spraying a solution or suspension (23, 440) into the combustor section via the fuel nozzles or additional nozzles (26, 26A, 26B) of the gas turbine engine, if any. The solution or suspension has a binder selected from gadolinium and gadolinium compounds.

Inventors

  • THAYER, Henry, H.
  • Zaleski, Elisa M.
  • NEUSTADT, Nicole I.

Assignees

  • RTX Corporation

Dates

Publication Date
20260513
Application Date
20240708

Claims (20)

  1. 1. A method for using a gas turbine engine (720, 720A, 720B), the gas turbine engine comprising: a compressor section (840, 842); a combustor section (844) including a plurality of fuel nozzles (860); and a turbine section (846, 848) having one or more stages of blades (400), the method comprising: spraying a solution or suspension (23,440) into the combustor section via the fuel nozzles or additional nozzles (26, 26A, 26B) of the gas turbine engine, if any, the solution or suspension comprising a binder.
  2. 2. The method of claim 1 wherein: the binder comprises at least one metal or compound selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, indium, scandium, yttrium, zirconium, hafnium, titanium, and mixtures thereof as well as compounds of such metals.
  3. 3. The method of claim 1 wherein: the binder is selected from: gadolinium; and gadolinium compounds.
  4. 4. The method of claim 1 wherein: the spraying is of said solution as an aqueous gadolinium nitrate solution.
  5. 5. The method of claim 1 wherein: the spraying is of said suspension as a suspension of gadolinium or gadolinia in an aqueous and/or alcohol-based carrier.
  6. 6. The method of claim 1 wherein: the solution or suspension coats the one or more stages of blades.
  7. 7. The method of claim 1 wherein: the one or more stages of blades alternate with one or more stages of vanes.
  8. 8. The method of claim 1 wherein: the spraying is through the plurality of fuel nozzles.
  9. 9. The method of claim 1 wherein: the spraying is through a circumferentially distributed plurality of spray nozzles (26, 26A, 26B).
  10. 10. The method of claim 1 wherein: the spray nozzles are coaxial with respective associated fuel nozzles.
  11. 11. The method of claim 1 wherein: the gas turbine engine is a propulsion engine of an aircraft (700); and the spraying is from a reservoir (22, 24) contained within the aircraft.
  12. 12. The method of claim 1 wherein: the gas turbine engine is a propulsion engine of an aircraft (900); and the spraying is from an external reservoir (22, 24) connected to the aircraft via a hose (324).
  13. 13. The method of claim 12 wherein: the hose is a single hose connected to a single port (326) to treat multiple engines.
  14. 14. The method of claim 1 wherein: the spraying comprises blending the binder and a solvent or carrier and spraying the blend.
  15. 15. The method of claim 14 further comprising: after spraying the blend, a purge.
  16. 16. The method of claim 15 wherein: the purge is for not more than half a duration of the spraying.
  17. 17. The method of claim 1 further comprising: shutting down the engine; monitoring a temperature of the engine; and responsive to the monitoring showing temperature decrease to a predetermined level, commencing the spraying.
  18. 18. The method of claim 1 further comprising: driving rotation of a spool of the engine during the spraying.
  19. 19. The method of claim 18 wherein: the driving comprises directing air from an auxiliary power unit (APU) (730).
  20. 20. The method of claim 19 wherein: the driving is at a speed of 10.0-100.0 RPM.

Description

TURBINE ENGINE CMAS IN SITU MITIGATION CROSS-REFERENCE TO RELATED APPLICATION [0001] Benefit is claimed of U.S. Patent Application No. 63525256, filed July 6, 2023, and entitled “Turbine Engine CMAS In Situ Mitigation”, the disclosure of which is incorporated by reference herein in its entirety as if set forth at length. BACKGROUND [0002] The disclosure relates to gas turbine engines. More particularly, the disclosure relates to addressing calcium magnesium aluminosilicate (CMAS). [0003] Gas turbine engines (used in propulsion and power applications and broadly inclusive of turbojets, turboprops, turbofans, turboshafts, industrial gas turbines, and the like) have combustor and turbine sections that operate at high temperature (the “hot section” of the engine). [0004] Extremely fine dust, including calcium, magnesium, aluminum, and silicon oxides (CMAS), is a major problem for modern jet engines. It is mostly found in and above desert areas but can drift into other areas as well. CMAS is a problem because it is ingested by the engine and melts in the combustion chamber. The liquid CMAS deposits on the airfoils and walls (e.g., gaspath inner diameter (ID) and outer diameter (OD) surfaces) of the hot section of the engine and infiltrates the ceramic thermal barrier coatings that protect them. The ceramic coatings have either a columnar structure or controlled porosity that gives them strain tolerance to compensate for the different thermal expansion rates between the coating and the metallic substrate. The CMAS seeps into the gaps and porosity. When the engine is shut down, it cools, the CMAS can freeze, reducing or eliminating the strain tolerance of the coating. The resulting build-up of shear stresses as the metallic substate cools and contracts, and can cause the ceramic coating to spall after multiple cycles. [0005] There have been various proposals to apply supplemental coating(s) to spalled regions so as to extend service life. [0006] Examples are found in US Patent Publication 2022/0136095 Al (the ‘095 publication), May 5, 2022, “Reactive Phase Spray Formulation Coatings”, US Patent Publication 2021/0324201A1 (the ‘201 publication), October 21, 2021, “Consumable Coatings and Methods of Protecting A High Temperature Component from Dust Deposits”, and US Patent Publication 2021/0277523 Al (the ‘523 publication), September 9, 2021, “Coating Systems Including Infiltration Coatings and Reactive Phase Spray Formulation Coatings”. [0007] CMAS is not merely relevant to engines producing thrust for aircraft but also helicopter engines, armored land vehicle (wheeled or tracked) engines, ships, and the like. [0008] Separately, water injection has been used in gas turbine engines for purposes including increasing thrust and altering the emissions profile. Such engines have used various injection locations. US Patent 4395874 (the ‘874 patent), August 2, 1983, “Fuel Nozzles with Water Injection for Gas Turbine Engines” discloses a particular coaxial injection system. SUMMARY [0009] One aspect of the disclosure involves a method for using a gas turbine engine, the gas turbine engine comprising: a compressor section; a combustor section including a plurality of fuel nozzles; and a turbine section having one or more stages of blades. The method comprises: spraying a solution or suspension into the combustor section via the fuel nozzles or additional nozzles of the gas turbine engine, if any. The solution or suspension comprises a binder. [0010] In a further embodiment of any of the foregoing embodiments, additionally and/or alternatively, the binder comprises at least one metal or compound selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, indium, scandium, yttrium, zirconium, hafnium, titanium, and mixtures thereof as well as compounds of such metals. [0011] In a further embodiment of any of the foregoing embodiments, additionally and/or alternatively, the binder is selected from: gadolinium; and gadolinium compounds. [0012] In a further embodiment of any of the foregoing embodiments, additionally and/or alternatively, the spraying is of said solution as an aqueous gadolinium nitrate solution. [0013] In a further embodiment of any of the foregoing embodiments, additionally and/or alternatively, the spraying is of said suspension as a suspension of gadolinium or gadolinia in an aqueous and/or alcohol-based carrier. [0014] In a further embodiment of any of the foregoing embodiments, additionally and/or alternatively, the solution or suspension coats the one or more stages of blades (e.g., coats the blade and vane airfoils). [0015] In a further embodiment of any of the foregoing embodiments, additionally and/or alternatively, the one or more stages of blades alternate with one or more stages of vanes. [0016] In a further embodiment of any of the foregoing embodiments, additional