EP2196628A1 - Lead rotor holder - Google Patents

Abstract

The support (1) has volume-in sections that consist of different materials. Two volume regions (4, 6) are provided for high thermal load. The volume regions face a hot gas channel and/or a combustion chamber. The volume regions are connected in a form-fit manner. The volume regions consist of nodular-graphite cast iron. Fastening parts (2) are provided for fastening a guide vane. A ring segment seals the hot gas channel. A circular connection part is provided between the regions. An independent claim is also included for a method for producing a guide vane support.

Description

The invention relates to a guide vane carrier, in particular for a gas or steam turbine, which is manufactured in a casting process. It further relates to a method of manufacturing a vane carrier.

Gas or steam turbines are used in many areas to drive generators or work machines. In this case, the energy content of a fuel or superheated steam is used to generate a rotational movement of a turbine shaft. For this purpose, in the gas turbine, the fuel is burned in a combustion chamber, wherein compressed air is supplied by an air compressor. In the steam turbine, steam generated by a steam generator is supplied. The working medium under high pressure and high temperature is then passed through a downstream turbine unit, where it relaxes to perform work.

To generate the rotational movement of the turbine shaft, a number of rotor blades, which are usually combined into blade groups or rows of blades, are arranged thereon and drive the turbine shaft via a momentum transfer from the working medium. For guiding the flow of the working medium in the turbine unit also commonly associated between adjacent blade rows with the turbine housing and combined into rows of guide vanes are arranged.

The vanes are fixed in each case via a blade root, also referred to as a platform, on a guide vane carrier of the turbine unit. In stationary gas or steam turbine this vane support is usually conical or cylindrical in shape and consists of an upper and a lower segment, the z. B. are interconnected via flanges.

In the design of today's gas or steam turbines usually a particularly high efficiency is a design target in addition to the achievable performance. An increase in the efficiency can be achieved for thermodynamic reasons basically by increasing the temperature at which the working fluid flows into the turbine unit. In today's gas turbines temperatures of about 1200 ° C to 1500 ° C are sought and achieved.

At such high temperatures of the working medium, however, exposed to this components and components are exposed to high thermal loads. In order to be able to withstand these high temperatures, the guide vane carrier or its upper and lower segment is often manufactured as a one-piece casting made of heat-resistant steel. The cast steel allows a relatively simple production with good temperature resistance of the vane support.

The invention is based on the object of specifying a guide vane carrier and a method for producing a vane carrier, which, with particularly low production costs, permits a particularly good heat resistance and a particularly high degree of flexibility with regard to the choice of material.

With respect to the guide vane carrier, this object is achieved according to the invention in that the vane carrier is made of different materials by volume.

The invention is based on the consideration that a particularly good heat resistance of the guide blade carrier would be achieved if the comparatively strongly thermally loaded volume regions of the guide blade carrier would consist of a particularly temperature-resistant material such as heat-resistant steel. For large volume ranges of the vane carrier, the temperature resistance of such a high quality material is not required.

Namely, the guide vane carrier has a temperature profile which has comparatively small areas with high temperatures and a larger rear area with lower temperatures. High temperatures occur in the region of the entanglement of the vanes and the ring segments arranged between the vanes feet, since these components cause a local heat input in the region of their attachment. Based on the realization that a particularly heat-resistant material is not required outside of these areas, a reduction in production costs and a conservation of resources could be achieved by using a different material. This can be achieved by virtue of the fact that the guide vane carrier is made of different materials by volume.

In an advantageous embodiment, the most temperature-resistant of the materials is arranged in a volume range provided for a higher thermal load. This ensures that the guide blade carrier can not be damaged by penetration of working fluid from the hot gas or steam channel or by direct heat input at the attachment points of the vanes, since then a corresponding temperature-resistant material such as heat-resistant steel is provided here. Conversely, this means that in areas designed for lower thermal stress, a less temperature-resistant material is used. This allows savings in terms of material costs.

Advantageously, the intended for a higher thermal load volume range is a hot gas duct and / or a combustion chamber facing portion of the vane support. In fact, in a gas turbine, the highest temperatures occur at the outlet of the combustion chamber. Therefore, particularly temperature-resistant material should be arranged here in particular. Furthermore, the region of the guide blade carrier facing the hot gas channel, ie in the case of a cylindrical or conical guide blade carrier, is the one Inside, subjected to much higher temperatures than the outside. Therefore, particularly temperature-resistant materials should be used here.

During the casting of the guide vane carrier, the partially different materials of the vane carrier ideally already connect by pouring. However, in order to achieve a particularly high stability of the guide blade carrier, at least two volume regions are advantageously connected in a form-fitting manner. This can, for example, by introducing a corresponding contour in the areas, for example in the manner of a tongue and groove connection, a dovetail connection or the like. or additional connection segments e.g. be provided with appropriate connecting bolts between the areas. This ensures a particularly good cohesion of the different volume ranges of the vane carrier.

Advantageously, a volume range of the guide vane carrier made of cast iron with nodular graphite, also called spheroidal graphite iron. It is an iron-carbon alloy with a carbon content higher than 2.06%. Unlike steel, carbon is precipitated in the form of non-metallic graphite. Although spheroidal graphite cast iron has a lower thermal load than heat-resistant steel, it can be produced relatively inexpensively and is easy to process. In the case of a vane carrier consisting of regions of different materials, it can therefore be used in particular in the areas of the vane carrier designed for a lower thermal load, and thus a significantly more cost-effective production can be achieved without sacrificing the stability of the vane carrier.

With regard to the method, the invention is achieved by casting a first region of the vane carrier from a first material, and then a second volume region of the vane carrier from a first volume region different material is poured into the first volume range. By such a method, the guide blade carrier is partially flexible adaptable to the different thermal loads in the interior of the gas turbine and it can be used in a lower thermal stress areas cheaper materials, while in higher thermally stressed areas find relatively high-quality materials application. By the subsequent pouring of the further volume areas in a first volume range, a secure connection of the different areas can be achieved directly during the casting. Optionally, the already explained measures such as an additional positive connection can be provided by corresponding introduced grooves.

Advantageously, such a vane carrier is used in a gas or steam turbine and such a gas or steam turbine in a gas and steam turbine power plant.

The advantages achieved by the invention are in particular that a flexible adaptation of the guide vane carrier to the temperature profile present in a gas or steam turbine is possible by the design of a guide vane with partially different materials, without losing the integral design of the vane carrier and its advantages over a Abandon construction with several axial segments. As a result, the component is cost-optimized. The higher the thermal requirements for the gas or steam turbine rise, which is to be expected more and more in the future, the higher the cost savings through this method. Optimized use of the materials used also increases procurement flexibility.

FIG 1 bis 3

jeweils einen Längsschnitt durch die obere Hälfte eines Leitschaufelträgers,

FIG 4

einen Querschnitt durch die obere Hälfte eines Leitschaufelträgers,

FIG 5

wiederum einen Längsschnitt durch die obere Hälfte eines Leitschaufelträgers und

FIG 6 bis 9

einen Längsschnitt durch die obere Hälfte eines Leitschaufelträgers im Gießprozess, und

FIG 10

einen Halbschnitt durch eine Gasturbine.

An embodiment of the invention will be explained in more detail with reference to a drawing. Show:

1 to 3

each a longitudinal section through the upper half of a vane carrier,

FIG. 4

a cross section through the upper half of a vane carrier,

FIG. 5

again a longitudinal section through the upper half of a vane carrier and

FIGS. 6 to 9

a longitudinal section through the upper half of a vane carrier in the casting process, and

FIG. 10

a half section through a gas turbine.

Identical parts are provided with the same reference numerals in all figures.

FIG. 1 shows in detail a longitudinal section through a vane carrier 1. In stationary gas or steam turbine, the vane support 1 is usually conical or cylindrical in shape and consists of two segments, an upper and a lower segment, the z. B. are interconnected via flanges. Only the section through the upper segment is shown here.

The guide vane carrier 1 shown comprises a number of fastening elements 2 for the guide vanes and ring segments for sealing the hot gas channel. The lower one, ie in Fig. 1 shown below area of the fasteners 2 is the hot gas or steam channel facing region of the vane support 1 and is therefore subjected to higher temperatures than the upper, ie in Fig. 1 area shown above. When used in a gas turbine, the combustion chamber of the gas turbine is provided in the figure on the left side of the vane support 1, so that higher temperatures prevail here than in areas lying further to the right.

In order to simultaneously achieve a particularly high temperature resistance of the vane carrier with cost-effective manufacturability, the vane support 1 is partially made of different materials. In a first volume region 4, which comprises the outflow-side end of the hot gas or steam channel and possibly the combustion chamber remote areas of the hot gas channel, which are acted upon by comparatively lower temperatures, the guide vane carrier is made of cast iron with nodular graphite or ductile iron. In these areas, a comparatively high-quality cast steel is not required, since lower temperatures prevail here.

However, in order to take account of the high temperatures at the flow medium inlet, the guide blade carrier 1 is made of heat-resistant cast steel in a second volume region 6. This second volume region 6 is cast directly onto the first volume region 4, so that in this respect a dimensionally stable connection is formed. The second volume region 6 is provided at the inlet end of the hot gas or steam channel.

The contours of the volume ranges can now be adapted to the temperature profile prevailing on the guide blade carrier 1. In FIG. 2 is the second volume region 6, which is made of heat-resistant cast steel, further extended in the direction away from the working medium inlet areas. This may be desirable at particularly high temperatures present in a gas turbine (a line 8 shows here later in FIG. 4 shown cross section).

Another embodiment is in FIG. 3 shown. In order to increase the positive connection of the first volume region 4 with the second volume region 6, form-fitting connections, here in the form of dovetail connections 10, are provided between the volume regions. There may also be other types of connections, for example in the manner of a tongue and groove connection be provided. Corresponding recesses can for example be introduced after the casting of the first volume region 4 and are then filled directly during the casting of the second volume region 6. Thus, a firm connection is guaranteed even with an incomplete connection of both volume areas in the casting process.

FIG. 4 shows the guide blade carrier in cross-section, ie axial normal section, as shown by the line 8 in FIG. 2 marked. The FIG. 4 shows that the higher volume material second volume region 6 is not continued into the areas of the flanges 12, with which the lower and upper segments of the vane support 1 are connected, but only the thermally highly loaded, inner part lined. Accordingly, the first volume region 4 is arranged outside.

FIG. 5 shows a further embodiment of the vane support 1. The separation between the first volume region 4, which is designed for relatively lower temperatures and consists, for example, of ductile iron (GJS-400), and the second volume region 6 of a high-strength cast steel (G17CrMoV5-10 or GX12CrMoVNbN9-1), runs in the axis normal. Thus, the entire, the combustion chamber facing portion of the vane support 1 is also made on the outer sides of the highly heat-resistant material. In order to ensure a good positive connection of the two volume regions 4, 6, an annular connecting part 14 is also provided between the volume regions, which produces a positive connection. This can be fastened, for example, with bolts on the cast steel of the second volume region 6.

The FIG. 6 and 7 and FIGS. 8 and 9 show by way of example the step of the casting process of the vane carrier 1 FIG. 6 and 8th is first to see the first volume area 4 of a less heat-resistant material, which is poured in a rough contour. In this case, corresponding recesses for the second volume region 6 and other volume regions 16 left, in which a comparatively more heat-resistant material is poured.

Subsequently, the contour of the guide blade carrier 1 as a whole is further processed by mechanical post-processing, as in 7 and FIG. 9 seen. Here then the fastening devices 2 and further contours are introduced into the guide vane 1. The comparison of FIG. 6 and 7 With FIG. 8 respectively. FIG. 9 shows that it can be specifically addressed to the respective operating requirements in terms of heat resistance of the individual regions of the vane support 1 and possibly only small volume ranges of the highly heat-resistant and expensive material must be made, which allows a resource-saving and less expensive production of the vane support 1, without thereby having to compromise in terms of operational safety and durability, for example, a gas or steam turbine to accept.

A gas turbine 101, as in FIG. 10 has a compressor 102 for combustion air, a combustion chamber 104 and a turbine unit 106 for driving the compressor 102 and a generator, not shown, or a working machine. For this purpose, the turbine unit 106 and the compressor 102 are arranged on a common turbine shaft 108, also referred to as turbine rotor, to which the generator or the working machine is also connected, and which is rotatably mounted about its central axis 109. The combustor 104, which is in the form of an annular combustor, is equipped with a number of burners 110 for combustion of a liquid or gaseous fuel.

The turbine unit 106 has a number of rotatable blades 112 connected to the turbine shaft 108. The blades 112 are annularly disposed on the turbine shaft 108 and thus form a number of blade rows. Furthermore, the turbine unit 106 includes a number fixed stator vanes 114 also annularly attached to a vane support 1 of the turbine unit 106 to form rows of vanes. The blades 112 serve to drive the turbine shaft 108 by momentum transfer from the turbine unit 106 flowing through the working medium M. The vanes 114, however, serve to guide the flow of the working medium M between two seen in the flow direction of the working medium M consecutive blade rows or blade rings. A successive pair of a ring of vanes 114 or a row of vanes and a ring of blades 112 or a blade row is also referred to as a turbine stage.

Each vane 114 has a platform 118 which is arranged to fix the respective vane 114 to a vane support 1 of the turbine unit 106 as a wall element. The platform 118 is a thermally comparatively heavily loaded component, which forms the outer boundary of a hot gas channel for the turbine unit 106 flowing through the working medium M. Each blade 112 is fastened to the turbine shaft 108 in an analogous manner via a platform 119, also referred to as a blade root.

Between the spaced-apart platforms 118 of the guide vanes 114 of two adjacent rows of guide vanes, a ring segment 121 is respectively arranged on a guide vane carrier 1 of the turbine unit 106. The outer surface of each ring segment 121 is also exposed to the hot, the turbine unit 106 flowing through the working medium M and spaced in the radial direction from the outer end of the opposed blades 112 through a gap. The arranged between adjacent rows of stator ring segments 121 serve in particular as cover that protect the inner housing in the guide blade carrier 1 or other housing-mounting components from thermal overload by the turbine 106 flowing through the hot working medium M.

The combustion chamber 104 is configured in the exemplary embodiment as a so-called annular combustion chamber, in which a plurality of burners 110 arranged around the turbine shaft 108 in the circumferential direction open into a common combustion chamber space. For this purpose, the combustion chamber 104 is configured in its entirety as an annular structure, which is positioned around the turbine shaft 108 around.

By using a vane support 1 of the above-mentioned embodiment, a significant cost reduction in the production of the gas turbine 101 or a steam turbine can be achieved with simultaneously high operational safety and service life. By reducing the range of application of the higher-grade material to the areas of the guide blade carrier 1, in which the high thermal and mechanical loads really occur, the majority of the guide blade carrier 1 can be made of a much cheaper base material.

Claims (8)

Guide vane carrier (1), in particular for a gas or steam turbine (101), which is manufactured in a casting process, wherein the guide vane carrier (1) volume-wise consists of different materials. Guide vane carrier (1) according to claim 1,
in which the most temperature-resistant of the materials in a provided for a higher thermal load volume range (4, 6) is arranged. Guide vane carrier (1) according to claim 2,
in which the volume range provided for a higher thermal load is a volume region (4, 6) of the guide blade carrier (1) facing a hot gas channel and / or a combustion chamber (104). Guide vane carrier (1) according to one of claims 1 to 3, at least two volume regions (4, 6) are positively connected. Guide vane carrier (1) according to one of claims 1 to 4, wherein a volume region (4, 6) of the vane carrier (1) consists of ductile iron cast iron. Method for producing a vane carrier (1), in which a first volume region (4) of the vane carrier (1) is cast from a first material, with a second volume region (6) of the vane carrier (1) then being formed from a first volume region (4) different material in the first volume range (4) is poured. A gas or steam turbine (101) comprising a vane support (1) according to any one of claims 1 to 5 and / or a vane support (1) made by the process of claim 6. Gas and steam turbine power plant with a gas or steam turbine (101) according to claim 7.

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