RU2478796C1 - Manufacturing method of integrated blisk with cooled moving blades, integrated blisk and cooled blade for gas turbine engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: individual cooled blades from monocrystalline alloy is attached to a disc part from granulated alloy into a solid part by hot isostatic pressing (HIP) in the zone where long-term strengths of those alloys are similar at one and the same temperature in a continuous operating mode. Shaped part, path flange and some part of the root with a cooling air supply branch pipe via a shaped channel to any of the blades are located outside the HIP influence zone; blade roots are aligned with the disc, and mainly end-to-end. Zone of similar long-term strength of both alloys is pre-determined as per long-term strength curves of alloys. Cooled blade includes the air cooling system comprising the air supply device to the blade in the form of an inlet branch pipe or holes in the root, air distribution channels to the shaped part and in the blade shaped part itself, which are located above a certain zone equal approximately to long-term strength of alloys of blades and disc part.

EFFECT: increasing strength, service life and reducing the weight of the turbine impeller for full-size high-temperature gas turbine engines, including high-temperature gas turbine engines with long service life, which are used in aviation, space and ground facilities, and in industrial power engineering.

6 cl, 8 dwg

Description

The invention relates to the field of engine building, more specifically to axial turbines and compressors of gas turbine engines, and in particular to a method for the manufacture of bimetallic blisk with cooled blades, including high-temperature gas turbine engines with a long resource.

The integral impeller of a turbine is known to have uncooled single-crystal blades, cast simultaneously and together with one or two (outer and inner) rings, the so-called “blings” (EP 1728971 from 05.31.2005, publ. 2006). In this case, the casting form of rings with blades is perpendicular to the growth of crystals from seeds in all blades at the same time. The bling thus obtained is connected to a disk of another metal alloy by diffusion welding at high temperature and pressure or by isostatic pressing into an integral impeller. This design is intended only for small engines with uncooled blades and a disk rim.

It is also known that the impeller is manufactured by mechanical assembly of separately cast cooled blades with a separately manufactured disk using lock joints, for example, the "Christmas tree lock" type (Manushin E.A., Surovtsev I.G. Design and strength analysis of gas turbine engines and combined installations. M .: Mechanical Engineering. 1990. S.93-98). The blades are cooled by air, for the supply of which there are channels in the profile part of the blade and in the castle connection itself. The castle joint partially dampens the vibrations of the blades. This design of the impeller due to the configuration of the locking part has many places of stress concentration, which limits the resource, leads to a heavier disk. Impellers with detachable joints of the disk and blades often do not allow to place the number of blades necessary for gas-dynamic efficiency due to the limitation, which is the strength of the locking joint. In addition, the operation of manufacturing the teeth for the locking connection (broaching operation) is expensive.

A manufacturing method and integral blisk with cooled blades suitable for a wide class of turbines, including high-temperature turbines with a long resource, were not found in information sources. Integral glare refers to the impeller of a turbine - the disk part and blades as a single part.

The problem of connecting the cooled blades to the disk part, in particular for high-temperature long-life turbines, into a single detail is that the process of connecting these components at high temperatures and pressure by the method of, for example, hot isostatic pressing (GUI), which allows you to firmly connect these components ( blades and disk part), does not allow to keep cooling channels in the blades.

The basis of the invention is the task of increasing the resource and facilitating the design of the impeller of high-temperature turbines of gas turbine engines, including those intended for long-term operation, by eliminating the locking part and connecting the cooled blades to the disk part in a single integral blisk detail.

The technical result is a solid connection of the cooled blades and the disk part into a single part of the integral blisk without changing their configuration, in particular the preservation of the cooling channels in the blades.

Another technical result is to reduce the mass of the impeller of the turbine.

The problem is solved in that in a method of manufacturing an integrated blisk with cooled working blades for a gas turbine engine, in which individual cooled blades equipped with a system of channels for air cooling made of one metal alloy are connected to a disk part made of another metal alloy according to the invention , pre-determine a zone of approximately equal long-term strength of the alloys, part of the legs, under the region of a certain zone located on it, approximately of equal long-term strength, and the disk part is encapsulated and placed in the apparatus in the area of the ISU exposure, and the profile part, the path shelf, part of the leg above the zone of approximately equal long-term strength of the alloys with the cooling system of the blades are located outside the zone of the ISU exposure, after which the ISU process is performed until the connection of the blades with the disk part into a single part in an area of approximately equal long-term strength of both alloys.

Cooled working blades are made with elongated legs quadrangular in cross section and a system of cooling channels located above a certain area of approximately equal long-term strength of the two alloys to be joined, inserted into the holes of the process ring with the processed parts of the legs, soldered to it and ground along its inner diameter, the disk blank is made of granular alloy, grind and process on a smooth outer diameter with granules of its own alloy, the resulting process ring with blades and installed on the machined outer surface of the disk with an interference fit, after which, by welding the end caps to the process ring, they form a capsule around the disk and blade legs so that a zone of approximately equal long-term strength of both joined alloys is located inside the capsule, place the capsule in a gas bath so that only the capsule with the contents was in the zone of the technological process, the GUI process is carried out, after which the capsule elements and the technological ring are removed by machining and etching By using the method, they make out the radii on the disk at the junction of the disk part with the blades, for example, by electrochemistry, and carry out the final mechanical and finishing heat treatment.

The zone of approximately equal long-term strength of both alloys is determined by calculation or modeling along the curves of long-term strength.

The problem is also solved by the fact that the integrated blisk with cooled blades for a gas turbine engine, the blades of which from one metal alloy, including single-crystal, are connected in one piece with a disk part from another metal alloy, including granular, by hot isostatic pressing (GUI ) according to the above manufacturing method.

The task, in addition, is also solved by the fact that the cooled working blade for the integral blisk of the turbine contains an air cooling system, including a device for supplying air to the blade in the form of an inlet pipe or holes in the leg, air distribution channels in the profile part and in the profile part of the blade located above a certain zone of connection of the blades and the disk part, and the air supply tube to the supply device, located between the main disk part of the blisk and the cover discs and connected nnym to the air supply device.

The invention is further illustrated by a description and an example of a specific implementation and drawings, which show:

Fig. 1 - diagram of an integrated blisk with cooled blades and with air supply to the blade through holes in the leg above the zone of connection with the disk part,

Fig. 2 is a schematic diagram of a blade cooling system with a supply of cooling air through a special pipe and a profiled channel, which are located above the zone of connection of the blades with the disk part,

Fig. 3 - solid-state model of the cooled working blades (Fig. 2) to the zone of connection (6) with the disk part,

Fig. 4 - technological ring,

Fig. 5 - assembly of the blades and disk in the capsule,

Fig. 6 - the resulting integral blisk with cooled blades according to the invention,

Fig. 7 - temperature dependence of the long-term strength of both alloys for a given duration of the design mode,

Fig. 8 - illustration of the calculation of blisk, Mises stress [MPa], the location of the investigated blisk zones, shown in table 2.

A method of manufacturing an integral blisk with cooled blades according to the invention is as follows.

In an example of a method for manufacturing an integral blisk with cooled blades for the impeller of a high-temperature turbine of a gas turbine engine (Fig. 6), including a long resource, in which individual blades are made of one single-crystal alloy ZhS32 <001>, and the disk part is made of another granular metal alloy EP741NP, connect in a single part according to the invention as follows.

A zone of approximately equal long-term strength of alloys is preliminarily calculated, for example, by the Laoson-Miller long-term strength curves or as shown in Fig. 7, where a region of approximately equal long-term strength of a pair of alloys joined into a single part is previously determined by the long-term strength curves of both alloys, rebuilt as dependences of the long-term strength limits of each alloy on temperature for the duration of the most damaging operating mode (Fig. 7), according to which at the intersection of these curves (t item A) a temperature value is set at which the values of the long-term strength of both alloys are the same, then, in accordance with the temperature condition of the wheel in the specified operating mode, the temperature zone of the found value is set, which is optimal for connecting the blades to the disk part of the wheel, t. e. zone of approximately equal long-term strength of both alloys.

The cooled blade 11 (Fig. 3) has an air cooling system that includes a device for supplying air to the blade in the form of an inlet pipe 5 (Fig. 2) or holes in the leg 17 (Fig. 1) located above the connection zone of 6 blades with the disk part , air distribution channels in the profile part 1 of the blade 11, located above the path shelf 2 (not shown in the figure), and the outlet 18 in the profile part 1 of the blade. Tubes 8 for supplying air to the supply device are located between the disk part 7 of the blisk and the cover 10 disk. Fig. 2 shows tubes 8 connected to the above branch pipe 5.

The blades 11 are molded with legs 4 quadrangular in cross section, elongated for embedding into the disk part, which are processed to be connected to the disk part 7. The processed legs are inserted into the metal technological ring 13 into the holes 14, which are made under the blade legs, and soldered to the technological ring 13. Technological ring 13 can be made, for example, of steel 20.

Then the technological 13 ring with the blades 1 soldered into it is ground along the inner diameter.

The blank of the disk part, for example, of a granular alloy, is processed (ground) along the surface 6 of the connection with the blades, i.e. on the outer diameter and then treated with granules, for example, their own alloy with a thin layer.

Based on the results of calculations and optimization of the ISU modes and equipment design, a computer model is created that allows three-dimensional prototyping, computer assembly to form the capsule 15.

The technological ring 13 (Fig. 4) with blades is installed on the machined outer surface of the disk part, after which, welding the end caps 16 designed according to the computer model, form the capsule 15 (Fig. 5) according to the computer model.

The disk part 7 and part of the legs of the blades 4 are encapsulated so that zone 6 of approximately equal long-term strength of both joined alloys is located inside the capsule 15.

Then, a capsule 15 is placed in the apparatus (gas-bath) in the area of influence of the ISU, and the profile part 1 of the blades, the path shelf 2, part of the legs 4 and the cooling system — the nozzle 5 is placed outside the zone of influence, after which the ISU process is applied until the blades are connected to the disk part into a single part in an area of approximately equal long-term strength of both alloys.

After that, the elements of the capsule 15 and 16 and the process ring 13 are removed by machining and etching, the radii are formed on the disk part at the junction of the disk part with the blades, for example, by electrochemistry, and the final mechanical and finishing heat treatment is performed.

Operations preceding the gas-conditioning process are carried out by methods traditional for GUI technology.

In the finished product, geometric dimensions and properties are controlled.

The result is an integral blisk with a system for cooling the blades (Fig. 6)

Details of the tube 8 and the cover disk 10 are set to the finished blisk during the assembly of the turbine.

The following table 1 and table 2 shows the comparison of the impeller of the turbine according to the invention and the prototype:

And the "classic" collapsible (lock) impeller: blades from ZhS32 <001> alloy and a disk from EP741NP alloy are connected by a herringbone trident lock.

Into an integral blisk containing cooled blades, including single-crystal, with a special (rational) construction of a shank and a disk from another, in particular, granular alloy, connected by the ISU method in an optimal place from the point of view of operating conditions.

With an integral blisk containing cooled blades, including single-crystal, with a special (rational) construction of a shank and a disk from another, in particular, granular alloy, connected by the ISU method in an optimum place from the point of view of operating conditions with weight optimization.

Table 1 Weight Optimization disk EP741NP, blades ZhS32 <001> BUT AT FROM Disc weight kg 17.37 08/13 9.89 Weight of the blade, kg 0.071 0.079 0.079 Mass of 53 blades, kg 3.758 4.164 4.164 Wheel weight kg 21.13 17.25 14.05

Table 1 shows the reduction in wheel weight compared to the original locking structure (A) - by 18.4% for the design of integrated blisk B and> 33% for the design of optimized integrated blisk C.

table 2 Temperatures ТºС, von Mises stress σ _Mis , MPa and local reserves of long-term static strength K _m (σ _Mis ) for 300 hours of work in the studied ("dangerous") areas of blisk No. Zone TºC σ _Mis , MPa K _m (σ _Mis ) Connection Zone: I disk 575.1 747.35 1.66 II ZhS32 blade 574.5 695.03 1.63 Disk part: III fillet slot 565.9 759.49 1.66 IV hub 609.8 754.75 1.50 Shoulder blade V under the nozzle 608.1 595.28 1.742

The zones in table 2 are presented in Fig. 8 in accordance with the numbering.

As can be seen from table 2, the obtained reserves of long-term static strength are significantly higher than the permissible values [K _m ] = 1.1 for the blades and [K _m ] = 1.25 for the disk part. This allows you to several times increase the resource of the wheel.

Invention allows

- create composite structures with built-in blades (including single-crystal ones) that work under optimal temperature and power conditions for each of the materials and have sufficient strength and reliability of the joint zone;

- eliminate such complex structural joints as locking, flanged, as well as welded and soldered, and the problems associated with the use of these joints to ensure strength reliability;

- to reduce the weight of the impeller by more than 30% compared with the prototype - a castle design with the dimension of integral blisk, which leads to a decrease in the inertia of the rotor, improving its dynamic characteristics, i.e. reduce pick-up time, facilitate starting. The reduction in the mass of the wheel and the blades as a whole can be used to detune from the resonant modes of the rotor blades;

- increase the wheel resource by several times due to the exclusion of stress concentrators in the castle joints;

- solve the problem of placing the blades on the disk, i.e. to optimize the density of the lattice in terms of gas-dynamic efficiency, which can lead to an increase in efficiency and, consequently, to a gain in fuel efficiency;

- determine the optimal from the point of view of the properties and working conditions of the part, the position of the zone of connection of the blades with the disk;

- provide a supply of cooling air to the blades;

- to eliminate the expensive complex operation broach in the manufacture of the castle joints of the blades with the disk.

In addition, the use of an integrated blisk with a rational design of the shanks of cooled blades, including single-crystal blades, for connecting them by hot isostatic pressing with a disk of another metal alloy, can increase the speed or temperature of the gas in front of the turbine, which will lead to an increase in power (thrust ), a decrease in specific fuel consumption.

The invention can be used mainly for the manufacture of bimetallic shines of full-size high-temperature gas turbine engines, including high-temperature gas turbine engines of a large resource, used in aviation, space, ground technology, industrial energy, but not limited to.

Claims (6)

1. A method of manufacturing an integral blisk with cooled blades for a gas turbine engine, comprising making a metal disk part of the blisk from a granular alloy, and cooled blades having a profile part, a path shelf and a leg with an air cooling system, from a single crystal alloy, and connecting them together in this case, previously for each of the blades and the disk, zones are determined in which, at the same temperature in the long-term operating mode of operation, the strengths of their alloys are the same, e portion which the blade roots, which are located in said zone, and a disk portion is encapsulated, the capsule is disposed in gazostat and by hot isostatic pressing is performed with a disk blade connection part in a single piece in the zone having the same long-term strength of both alloys. 2. The method according to claim 1, characterized in that the cooled blades are made with elongated legs quadrangular in cross section and a cooling system with cooling channels located above the zone of the same long-term strength of the alloys, and a capsule is formed around the disk part and the legs of the blades, the zone of equal long-term strength of both joined alloys inside the capsule, and the elongated parts of the legs are inserted into the holes of the process ring, soldered to it and ground over the inner diameter, the disk part l, they are ground and processed over a smooth outer diameter with granules of an alloy similar to the alloy from which it is made, the resulting process ring with blades is mounted on the machined outer surface of the disk part, then the end caps are welded to the process ring, the GUI process is carried out, after which the capsule elements are removed and the technological ring by machining and etching, form the radii on the disk part at the junction with the blades and conduct the final mechanical and fi ishnuyu heat treatment. 3. The method according to claim 2, characterized in that they form the radii on the disk part at the junction with the blades by means of electrochemical processing. 4. The method of claim 1, characterized in that the zone of the same long-term strength of the alloys of the blade and the disk is determined by modeling along the curves of the long-term strength of the alloys. 5. Integral blisk with cooled blades for a gas turbine engine made by the method according to claim 1. 6. Cooled blade integral blisk of a gas turbine engine containing a profile part, a path shelf, a leg and an air cooling system, consisting of a device for supplying air to the blade in the form of an inlet pipe or holes in the leg, air distribution channels in the profile part and channels in the profile part of the blade located above the zone of the blade made of an alloy with long-term strength of the same long-term strength of the alloy of the zone of the disk, intended for connection to it, and tubes for supplying air to the mouth oystvu air.

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