Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
  • F01D5/12—Blades
  • F01D5/28—Selecting particular materials; Particular measures relating thereto; Measures against erosion or corrosion
  • F01D5/288—Protective coatings for blades
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23R—GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS
  • F23R3/00—Continuous combustion chambers using liquid or gaseous fuel
  • F23R3/007—Continuous combustion chambers using liquid or gaseous fuel constructed mainly of ceramic components

Definitions

• the invention relates to a gas turbine system with a combustion chamber housing which is lined on the inside with solid ceramic stones, with a rotor provided with rotor blades and with a housing provided with guide vanes, in particular at least the first blades on the turbine side carrying a ceramic thermal barrier coating.
• Such a gas turbine is known for example from DE-OS 43 43 319.
• the combustion chamber housings in particular their flame tubes, are designed to be extremely heat-resistant in modern gas turbines.
• the inner walls can be covered with ceramic insulation layers or provided with a shield made of solid ceramic stones.
• the blades of the turbine part of the gas turbine systems are often provided with ceramic thermal barrier layers as thermal protective layers, which consist, for example, of yttrium oxide-stabilized zirconium oxide layers.
• the present invention is therefore based on the object of taking measures in a gas turbine of the type mentioned at the outset, on the one hand to protect the combustion chamber and the blades from thermal overload and on the other hand to extend the life of the turbine blades.
• the object is achieved in that the ceramic stones are provided on their surface with a coating.
• the ceramic stones have the advantage over heat shield plates made of other materials, for example super alloys, that higher material temperatures are possible and permissible. Only the stone fasteners need to be cooled. Because of the higher permissible material temperatures, for example, this leads to incomplete combustion of the combustion chamber lining
• Shovels act on these like projectiles and have a strong abrasive effect.
• the coating of the ceramic stones according to the invention effectively prevents the detachment of such particles from the surface of the ceramic stones. It seems particularly favorable here to coat the ceramic stones before installation in the combustion chamber housing. For this purpose, the coating must be such that good adhesion to the ceramic stones and good cohesion of the layer is ensured in order to avoid flaking off under thermal alternating stresses.
• the coating of the ceramic stones thus forms a layer for fixing the surface particles. This enables the use of ceramic thermal barrier layers on the blades in combination with solid ceramic stones as the combustion chamber lining.
• An embodiment of the invention provides that the coating consists of a metallic material and is applied in particular by means of vacuum plasma spraying (VPS).
• VPS vacuum plasma spraying
• Different corrosion protection layers which can be processed by VPS can be used for this purpose, e.g. B. the type M Cr A1Y, where M is Ni or Co.
• a combination coating consisting of a metallic bond coat as an adhesion promoter with an overlying ceramic cover layer could also be used.
• the ceramic cover layer can be partially applied by air plasma spraying.
• the slight difference in the thermal expansion coefficients between ceramic stones and a ceramic APS coating has a favorable effect on the resistance to alternating thermal stress.
• the execution of a ceramic layer as a thermal barrier layer has the additional advantage that the cooling air requirement of the combustion chamber lining is further reduced.
• Conventional thermal insulation layers such as Yr 2 0 3 - stabilized Zr0 2 or Si0 2 or Al 2 0 3 are conceivable as ceramic coatings.
• the invention can also be advantageously configured in that the ceramic cover layer is applied by means of the air plasma spraying process (APS).
• APS air plasma spraying process
• the APS procedure is a cheaper alternative to the VPS procedure.
• the multilayer coating of the ceramic stones can also be advantageous for thermal reasons or for reasons of better cohesion of the layer.
• both the binding layer and the outer coating can be designed as a graded layer, at that the thermal expansion behavior and the chemical composition change constantly over the layer thickness.
• FIG. 1 schematically shows a longitudinal section of part of a gas turbine
• Figure 2 schematically shows a section of the combustion chamber housing wall with distorted proportions in order to make the coating recognizable.
• FIG. 1 schematically shows a gas turbine system according to the invention in a longitudinal section with a housing 1, in which fixed guide blades 3, 4 are fastened, and a rotor 2, to which rotor blades 5, 6 are fastened.
• the fuel injected via the burners 14, 15 is burned with the air from the compressor 16.
• Compressor 16 is the input part of the gas turbine system in which incoming air (arrows 17, 18) is compressed before it flows into combustion chamber 7.
• a generator 20 for generating electrical energy is driven by means of the connecting shaft 19.
• FIG. 2 the surface area of the annular combustion chamber is shown in simplified cross-section.
• ceramic stones 10 are attached to the combustion chamber housing wall 11, which consists for example of metal.
• the ceramic stones 10 consist for example of silicon or aluminum oxide.
• a coating of the ceramic stones 10 is shown enlarged in two layers, of which the lower layer forms a binding layer (bond coat) 12, the upper layer forms a ceramic layer 13 which adheres particularly well to the binding layer 12.
• the layers 12 and 13 together form a solid layer covering the ceramic stones 10, which binds any particles detached from the surface of the ceramic stones 10. Such particles can therefore have no erosive effect on the thermal barrier layer of the turbine blades of the housing or of the rotor.
• the adhesion-promoting layer 12 preferably consists of a metal-chromium-aluminum-yttrium alloy (MCrAlY), while the heat insulation layer 13 preferably consists of yttrium oxide-stabilized zirconium oxide, SiO 2 or Al 2 O 3 .
• a single-layer coating 22 of a ceramic stone is shown as an example in area 21 of FIG. 2, the coating consisting of ceramic.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Combustion & Propulsion (AREA)
• Materials Engineering (AREA)
• Turbine Rotor Nozzle Sealing (AREA)
• Coating By Spraying Or Casting (AREA)
• Other Surface Treatments For Metallic Materials (AREA)
• Solid-Fuel Combustion (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7819815

Family Applications (1)

Country Status (6)

Families Citing this family (7)

Citations (10)

Family Cites Families (1)

• 1997
  • 1997-01-29 DE DE19704976A patent/DE19704976C2/de not_active Expired - Lifetime
• 1998
  • 1998-01-29 RU RU99118768/06A patent/RU2178530C2/ru active
  • 1998-01-29 UA UA99074363A patent/UA41485C2/uk unknown
  • 1998-01-29 JP JP53245998A patent/JP4294736B2/ja not_active Expired - Lifetime
  • 1998-01-29 WO PCT/DE1998/000324 patent/WO1998034068A1/de active IP Right Grant
  • 1998-01-29 DE DE59802328T patent/DE59802328D1/de not_active Expired - Lifetime
  • 1998-01-29 EP EP98909340A patent/EP0960308B1/de not_active Expired - Lifetime

Patent Citations (10)

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