WO2008138815A1

WO2008138815A1 - Burner component for a gas turbine burner

Info

Publication number: WO2008138815A1
Application number: PCT/EP2008/055586
Authority: WO
Inventors: Andreas Böttcher; Jens Kleinfeld; Tobias Krieger; Claus Krusch; Elmar Pfeiffer
Original assignee: Siemens Aktiengesellschaft
Priority date: 2007-05-10
Filing date: 2008-05-07
Publication date: 2008-11-20
Also published as: EP1990580A1

Abstract

The invention relates to a burner component (1) for a gas turbine burner. Said burner component (1) is produced from a ferritic material which has a thermal conductivity of more than 18 J/(Kms), a specific thermal capacity of more than 510 J/(kgK) and a coefficient of thermal expansion of less than 14.8 (10-6/K) at 400°C.

Description

description

Burner component for a gas turbine burner

The present invention relates to a burner component for a gas turbine combustor. In addition, the invention relates to a gas turbine burner.

US 6,672,073 B2 discloses a gas turbine combustor having a number of fuel nozzles attached to a support having fuel supply channels. During operation of the burner in the gas turbine occur at the burner temperatures of up to about 400 ⁰ C. As a material for producing the carrier as well as the fuel nozzles, therefore, find high-temperature and corrosion-resistant nickel-based alloys such as the known under the name Hastelloy X alloy use.

Compared to the described prior art, it is an object of the present invention to provide an advantageous burner component, in particular a favorable Gasturbinenbrennerkom- component available. It is a further object of the present invention to provide an advantageous gas turbine combustor.

These objects are achieved by a burner component according to claim 1 and a gas turbine burner according to claim 9. The dependent claims contain advantageous embodiments of the invention.

A burner component according to the invention for a gas turbine nenbranner is made of a ferritic material, which at 400 ⁰ C a thermal conductivity of more than 18J / (Kms), a specific heat capacity of more than 51OkJ / (KgK) and a thermal expansion coefficient of less than 14, 8 (1 / K). While in the state of the art a material with a high strength at high temperatures is used as the material for burners or their components, in particular gas turbine burners or their components, the invention takes a different route. Instead of a material with high strength at high temperatures, a material is used which has a high thermal conductivity, a high specific heat capacity and a low coefficient of thermal expansion compared to the materials used hitherto.

A concrete example of ferritic materials, which have the mentioned thermal properties, are materials with the following constituents in the stated proportions by weight:

Carbon (C): 0.12% to 0.20%, Silicon (Si): 0.00% to 0.35%, Manganese (Mn): 0.40% to 0.90%, Phosphorus (P): 0.00% to 0.025%, sulfur (S): 0.00% to 0.015%, nitrogen (N): 0.00% to 0.012%, chromium (Cr): 0.00% to 0.30%, copper - fer (Cu): 0.00% to 0.30%, molybdenum (Mo): 0.25% to

0.35%, nickel (Ni): 0.00% to 0.30%, balance: iron (Fe). Such materials are known under the standard 16Mo3. Other examples of fundamentally suitable materials are grades of 15MiCuMoNb5S, 20MnMONi55, 34CrMiMo6S, C22.8S, GS-18NiMoCr37, GS-C25S, WStE255S, WStE285S, WStE315S, WStE355S grades.

The invention is based on the following finding:

Heretofore, for burner components, particularly for fuel nozzle carriers in a gas turbine combustor and the nozzles themselves, a high grade corrosion resistant nickel base alloy such as the Hastelloy X alloy mentioned above has been used. These alloys have a very high strength at the temperatures occurring at the burner. However, the materials have poor thermal properties, such as low thermal conductivity (λ) and low heat capacity (c _p ). In return, they have a high Thermal expansion coefficient (α) on. The thermal properties of the material lead to stresses in the material, which almost consume the advantage of high high-temperature strength.

The invention is based on the finding that, instead of a material with high high-temperature strength and relatively poor thermal properties, it is also possible to use a material which has more favorable thermal properties and, for that, a lower high-temperature strength.

With the material used in the burner component according to the invention, a material is used which has an increased thermal conductivity, an increased heat capacity and a reduced coefficient of thermal expansion compared to, for example, Hastelloy X. Due to the high thermal conductivity and the high heat capacity, lower temperature-induced component stresses occur in the material. Likewise, the lower coefficient of thermal expansion compared with the materials used hitherto also leads to lower component stresses in the temperatures prevailing during operation. Due to the lower component stresses compared to the materials used hitherto, the material may have lower high-temperature strength. Overall, the same, if not a longer service life of the burner component can be achieved in comparison to the materials used hitherto.

With the burner component according to the invention, a considerable reduction of the material costs compared to the materials used hitherto is possible, in particular when using

16Mo3. In addition, the processing costs for the burner component can be reduced because this material can be easily machined. Furthermore, materials with the mentioned good thermal properties and reduced high temperature resistance are more readily available than high-temperature superalloys. Another advantage of the material 16Mo3 in particular is the simplified weldability compared to the materials used hitherto. This creates niger Committee in producing the burner component by welding distortion, which in turn reduce the cost of production.

The fuel component may in particular comprise a carrier and at least one fuel nozzle attached to the carrier. The carrier is then equipped with a fuel distribution system with which the at least one fuel nozzle is supplied with fuel. The fuel distribution system of the burner component, in a specific embodiment of the invention, may have at least one, for example, a milled or eroded channel and a cover strip designed to cover the channel. The cover strip is then made of the same material as the carrier. Likewise, at least one fuel nozzle may be attached to the carrier, wherein the

Fuel nozzle is made of the same material as the carrier. The fact that the cover strip and / or the fuel nozzle are made of the same material as the carrier, thermal stresses between the individual components can be avoided.

Materials with the aforementioned advantageous material properties generally have no high-temperature corrosion resistance. Advantageously, the carrier and optionally the cover strip and optionally the fuel nozzle (s) are provided with an oxidation- and / or corrosion-inhibiting coating, for example with a coating comprising aluminum oxide (Al 2 O 3). The alumina may in this case be, in particular, alpha-alumina (CX-Al 2 O 3). The alpha alumina is characterized by a rhombohedral (trigonal) crystal structure and is also known as corundum and sapphire. It is generally insoluble in acids and in bases and is therefore particularly suitable as oxidation and / or corrosion protection.

A titanium nitride layer may be present between the alumina and the ferritic material of the burner component. Titanium nitride has a thermal conductivity of 29.1 J / (Kms) has a high thermal conductivity, which ensures that the coating does not chip off due to thermal shocks.

The application of the oxidation- and / or corrosion-inhibiting coating can be carried out, for example, by means of chemical vapor deposition (chemical vapor deposition, CVD).

A gas turbine burner according to the invention comprises a burner component according to the invention. A gas turbine burner according to the invention has the advantages described with reference to the burner component and can in particular be produced more cost-effectively than gas turbine burners made of the materials previously used.

Further features, properties and advantages of the present invention will become apparent from the following description of an embodiment with reference to the accompanying figures.

1 shows a burner component according to the invention in a schematic sectional view.

FIG. 2 shows a plan view of the burner component from FIG. 1.

3 shows the coating of the burner component in a highly schematic representation.

A burner component 1 according to the invention, which is designed for use in a gas turbine burner, is shown in FIGS. 1 and 2. While FIG. 1 shows a schematic cross-section through the burner component 1, FIG. 2 shows a plan view of the side of the burner component 1 at the top in FIG.

The burner component 1 comprises a carrier 3 with connections 5 for fuel nozzles 7, which are formed in the present embodiment as gas nozzles. Basically you can however, there may also be nozzles for liquid fuels such as oil.

When the burner component 1 is installed in a gas turbine burner, the nozzles 7 protrude into an air supply channel 9 of the burner, where they are mostly surrounded by swirl vanes 11. The swirl blades 11 are arranged so that nozzle openings 13 of the nozzles 7 are downstream of them with respect to the air flow through the air supply channel 9. As a result, the gas is injected into the swirling through the swirl vanes 11 airflow. The swirl vanes 11 and the air supply channels 9 are indicated by dashed lines in FIG.

The carrier 3 has a fuel distribution system, which serves in the present embodiment for the distribution of a gaseous fuel to the fuel nozzles 7. The fuel supply system therefore comprises in the present embodiment, a gas supply channel 15 which is supplied via a gas inlet port 17 with fuel gas. From the gas supply channel 15 go out gas lines 19, which extend through a portion of the carrier 3 and through the terminals 5. They open into gas ducts 21 of the nozzles 7 fastened to the connections 5. The gas ducts 21 of the nozzles 7 finally terminate in the nozzle openings 13.

The gas supply channel 15 is usually milled into the body of the carrier 3 and is therefore open at the top 23 of the carrier 3. It is therefore closed with a cover plate, which is formed in the present embodiment as a sheet metal strip 25.

Although not shown in FIGS. 1 and 2, there may be multiple fuel supply stages, each having its own supply channel. In general, all of these feed channels are milled into the carrier 3 and closed with metal strips or cover plates. It can then be associated with the different fuel supply levels corresponding to different nozzles. The carrier 3, the nozzles 7 and the cover plate 25 are made in the present embodiment of a 16Mo3 material. This has the following composition, wherein the percentages relate to parts by weight:

Carbon: 0.15%, silicon: 0.20%, manganese: 0.50%, chromium: 0.20%, molybdenum: 0.30%, nickel: 0.15%, balance: iron.

Although a specific composition of the 16Mo3 material is indicated in the present exemplary embodiment, in principle any admissible 16Mo3 composition is suitable. The chosen material is a ferritic material with a thermal conductivity of more than 18 J / (Kms) at 400 ⁰ C, a specific heat capacity of more than 510 J / (kgK) and a thermal expansion coefficient of less than (l / K). having. Other examples of fundamentally suitable materials are grades of 15MiCuMoNb5S, 20MnMONi55, 34CrMiMo6S, C22.8S, GS-18NiMoCr37, GS-C25S, WStE255S, WStE285S, WStE315S, WStE355S grades.

The material used for the carrier 3, the nozzles 7 and the cover plate 25 is provided with a corrosion and / or oxidation-inhibiting coating for corrosion and / or oxidation protection. In the present embodiment, the coating is two-ply. The coating is shown very schematically in FIG. The FIG shows a section through the carrier 3. There are the 16Mo3 material 27, a titanium nitride layer (TiN) 29 applied to this material and an alpha-aluminum oxide layer (CX-Al 2 O 3) 31 applied to the titanium nitride layer 29. For example, both layers can be applied to the carrier 3, the nozzle 7 or the cover plate 25 by means of chemical vapor deposition (CVD). In order to determine the corrosion resistance of the coated 16Mo3 material compared to Hastelloy X, three material samples were produced. The first material sample (Sample 1) consisted of uncoated Hastelloy X, the second sample of material (Sample 2) of uncoated 16Mo3, and the third sample of material (Sample 3) of 16Mo3 CVD coated with TiN / α-Al2O3. All three samples were exposed to 6% sulphurous acid (H2SO3) to test the corrosion resistance of the respective material. While sample 2 already showed considerable corrosion in the sulphurous acid after 30 seconds, no corrosion was observed either in sample 1 or in sample 3 even after 100 hours in the sulphurous acid. This shows that with the coating the 16Mo3 material has comparable good corrosion properties as Hastelloy X. By coating the 16Mo3 material, corrosion of the burner component during operation of the gas turbine can therefore be reliably avoided.

In order to estimate the load capacity of the material in gas turbine operation, comparative tests were carried out with Hastelloy X burner components and coated 16Mo3 burner components. The measurements were made at various measuring points of the burner component, which have different temperatures when starting and stopping a gas turbine. The voltages measured at the measuring points of the 16Mo3 torch component were always well below the voltages at the corresponding measuring points of the Hastelloy X torch component. Their values were between 50% and 75% of the stress in the Hastelloy X component. The reduced stresses allow the 16Mo3 torch component to last as long as the Hastelloy X torch component. However, in terms of manufacturing and processing costs, the 16Mo3 component is significantly cheaper than the component

Hastelloy X, even considering the coating process. The burner component according to the invention provides Therefore, a cost-effective alternative to the previously used burner components.

Claims

claims

1. burner component (1) for a gas turbine burner, characterized in that it is made of a ferritic material which at 400 ⁰ C, a thermal conductivity of more than 18 J / (Kms), a specific heat capacity of more than 510 J / (kgK) and a thermal expansion coefficient of less than 14.8 (10 ^{~ 6} / K).

2. Burner component (1) according to claim 1, characterized in that the ferritic material comprises the following constituents in the proportions by weight stated:

C 0.12 to 0.20% SSii 00, 0000% to 0.35%

Mn 0.40 to 0.90%

P 0, 00 to 0.025%

S 0.00 to 0.015%

N 0, 00 to 0,012% CCrr 00 ,, 0000% to 0,30%

Cu 0, 00 to 0.30%

Mo 0.25 to 0.35%

Ni 0, 00 to 0,30% RReesstt :: FFee ..

3. burner component (1), characterized in that it comprises a support (3) comprises and Wenig ^¬ least one fixed to the support fuel nozzle (7) and that a fuel distribution system (15, 19) designed for supplying the at least (a fuel nozzle 7 ) is present with fuel in the carrier (3).

4. Burner component (1) according to claim 3, characterized in that the fuel distribution system (15, 19) at least one channel (15) and a covering of the channel formed cover strip (25), wherein the cover strip (25) made of the same material as the carrier (3) is made.

5. Burner component (1) according to one of the preceding claims, characterized in that it is provided with a corrosion-inhibiting coating (29, 31).

6. Burner component (1) according to claim 5, characterized in that the corrosion-inhibiting coating (29, 31) comprises aluminum oxide (31).

7. burner component (1) according to claim 6, characterized in that the aluminum oxide (31) is CX-Al2O3.

8. Burner component (1) according to claim 6 or 7, characterized in that the corrosion-inhibiting coating (29, 31) comprises a titanium nitride layer (29) between the aluminum oxide (31) and the ferritic material (27).

9. gas turbine burner with a burner component (1) according to one of claims 1 to 8.