RU2735972C1 - Turbojet turbine stage blades air-liquid cooling system - Google Patents

Abstract

FIELD: turbines or turbomachines.SUBSTANCE: invention relates to the field of aircraft engine building of gas turbines, namely to turbojet engines turbines cooling, in particular to the straightening blades cooling device, turbine blades and impeller intended mainly for operation in the field of high temperatures, maximum engine rpm and afterburner. Outboard air (21), which is cleaned from foreign impurities by centrifugal filter (20) and filter of fine cleaning of outboard air (17), is supplied via air duct (13) and air duct (22) into housing (26). Further, cleaned air is forced through channels (31, 32, 33, 38, 40, 41) through holes in annular flanges with sealing seals of first, second stages of turbine (50, 51, 52, 53, 54, 55) and arrives in straightening vanes (6, 8). When engine rpm increases from cruise to maximum and afterburner is added to impeller and turbine vanes, coolant is fed proportionately to pressure pump by coolant with reverse motor (15).EFFECT: improved cooling of turbojet engines turbines at various operation modes.1 cl, 2 dwg

Description

The invention relates to the field of an aircraft engine of the structure of gas turbines, namely to cooling the turbines of turbojet engines, in particular to cooling the blades of the straightening apparatus, turbine blades and impeller, intended mainly for operation in the area of high temperatures.

The objective of the invention is to increase the engine power, efficiency and economy of the turbine during its operation at variable and maximum modes, to provide cooling of the rectifier blades, turbine blades and impeller, outboard air and increase the engine service life.

List of references

1.A.S. 1152289 SSR, IPC F01D 5/18. Cooled blade of a gas turbine / V.M. Bregman, V.A. Malkov (USSR) - application 833532826/06, 01/07/1983.

2. Stationary gas turbine installations / L.V. Arseniev, V.G. Tyryshkin, I.A. Bogov and others: Ed. L.V. Arsenyev and V.G. Tyryshkin. - L .: Mechanical engineering. Leningrad. branch 1989 .-- 543 p.

3. A.M. Drokonov. Optimization of the cooling air consumption in the gas turbine engine. // Improvement of transport machines [Text] + [Electronic resource]: collection of articles. scientific. tr. / ed. V.V. Rogalev. - Bryansk: BSTU, 2018 - p. 147 ... 151.

4. Gas turbine installations. Design and calculation: Reference book / Under total. ed. L.V. Arsenyev and V.G. Tyryshkin. - L .: Mechanical engineering. Leningrad. branch 1978 .-- 232 p.

5. Patent 2268763, IPC F01D 5/18. Gas turbine component / J. Ferber, P.V. Laletin; patent holder "Alstom Technology LTD (SN)" - No. 2014103219/06; declared 01/30/2014; publ. 08/10/2015, bul. No. 22.

6. US patent N 4807433, NCI 60-39.29, publ. 1989 year

7. Application of the shape memory effect in modern mechanical engineering. S. Tikhonov, A.P. Gerasimov, I.I. Prokhorov. - M .: Mechanical Engineering, 1981 .-- 80 p.

Sources of information

1. US patent N 4275990, NKI 416-95, publ. 1981 year

Various designs of gas turbines of turbojet engines are known, in which the cooling air passes through the nozzle and working grids, and the gas can have a temperature close to or even higher than the melting point of the blade material. Internal cooling of turbine blades is realized in the form of an open and closed system. It should be borne in mind that the extraction of even 1% of air from the compressor for cooling the flow path of the turbine with a gas temperature of 1300 to 1500 degrees Celsius leads to an increase in the unit's fuel consumption of approximately 0.6%, which reduces the efficiency of the turbine.

Known cooled gas turbine blade, containing a hollow feather, the inlet part of which has in the edge zone, on the back and trough holes and placed in the cavity of the feather transverse partitions, dividing the blade into a number of separate cavities connected to the source of the cooling medium. In this case, in the cavity of the inlet part, longitudinal partitions are additionally installed, forming channels with the back and the trough, isolated from the said cavity, and connecting holes on the back and the trough with one of the subsequent cavities of the row.

The disadvantage of this cooled gas turbine blade is the impossibility of regulating the supply of cooling air, which reduces the efficiency of the turbine in transient conditions. The disadvantage of this device is the impossibility of automatic regulation of the cooling air supply to the blade and the transition from film to filmless cooling of the blade edges, which reduces the efficiency of the turbine in transient modes of its operation.

Known cooled hollow blade with radial channels for cooling with compressed air (US patent No. 5947687). The disadvantage of the known blade is the difficulty in manufacturing due to warpage, displacement of the rod, which forms the inner cavity when casting the blade, as well as the difficulty of etching the rod only through the cavity in the locking part of the blade.

Closest to the claimed design is a cooled gas turbine blade containing a hollow blade with radial channels in the inner cavity and with a plug (RU patent No. 2106499). The disadvantage of the design, taken as a prototype, is the difficulty in manufacturing, insufficient reliability of the turbomachine blade. The closest in technical essence and the achieved result is a cooled turbine containing nozzle blades, each of which is made in the form of a structural element bounded by the upper and lower shelves, and the space between them, bounded by the concave and convex walls of the blade airfoil, in the form of located along its axis the distributing header of the leading edge and the dispensing cavity with a transit deflector forming cooling channels along the inner surfaces of the feather walls, connected with the turbine flow path, the distributing header of the leading edge is connected at the inlet with the air cavity of the combustion chamber, and at the outlet through the perforations in the leading edge of the blade with the flow path of the turbine, a heat exchanger connected at the inlet with the air cavity of the combustion chamber, and at the outlet in series with the air manifold, the transit deflector of the dispensing cavity, the transit air duct, the swirling nozzle, the working cooling channels wheels and turbine rotor blades. RU No. 2196239, IPC ⁷ F02C 7/12, published 10.01.2001

The disadvantage of such a cooled turbine is that the transit of cooling air to the swirl nozzle and the cooling of the nozzle blade of the high-pressure turbine is carried out jointly through a common deflector, which, on the one hand, leads to heating of the cooling air going to the swirl nozzle, and on the other hand, to the dependence of the amount of cooling air going to the swirl nozzle apparatus and the amount of cooling air taken to cool the high-pressure turbine nozzle blade from each other, thereby reducing the cooling efficiency of both the high-pressure turbine nozzle blade itself and the turbine rotor blade, increasing thus the required level of cooling air consumption, which leads to a deterioration in the efficiency of the engine as a whole.

It is possible to increase the efficiency of the turbine and the listed types of cooling of the blades using pre-cooled air, for example, in special heat exchangers located in the second circuit of the turbofan engine (AL-31) However, the installation of heat exchangers in the second circuit worsens its hydraulic characteristics and, as a result, increases the specific fuel consumption. In addition, the supply of cold air to heated surfaces can cause significant thermal stresses due to large temperature differences., Taken from the engine compressor, significantly increases the specific fuel consumption due to the fact that part of the cycle work is spent on compressing the cooling air, and the work this air does less than it could do when passing through the flow path of the turbine, since it loses part of its energy when flowing through the cooling channels. An increase in the degree of pressure increase in modern gas turbine engines leads to an increase in the temperature of the cooling air and a decrease in the temperature head. Roughly, it can be considered that depending on the efficiency of the engine air bleed units for cooling the turbine, the specific fuel consumption increases by 0.5-0.7. The air intake for cooling the turbine on modern engines is G _cool 10 ... 12%, which leads to a significant increase in specific fuel consumption.

Another disadvantage of the method of cooling the turbine with air taken from the compressor or secondary air from the combustion chamber is that this air contains a significant amount of foreign particles from the production of compressor seals, soot, coke from incomplete combustion of fuel, as well as dust entering the inlet into the engine compressor. The ingress of foreign particles into the blades and their adhesion to the walls, reducing the diameter of the cooling holes of the straightener and turbine blades, significantly reduces the heat transfer from the wall to the air due to the growth of the temperature gradient in the blade wall, which increases the blade temperature. It should be noted that this phenomenon is especially characteristic of helicopter engines and to a lesser extent manifests itself in aircraft power plants. The influence of deposits is aggravated with long engine resources.

The technical result of the invention is to increase power, service life and improve engine performance.

The technical result is achieved by the fact that the air for cooling the turbine blades and the impeller is taken from outside the aircraft; centrifugal compressors are built into the impellers of the first and second turbine stages, into which filtered outboard air enters. Before entering the straightening and turbine blades of the turbine, the air is compressed by the centrifugal compressor blades and the blades for increasing the pressure of the cooling air-liquid mixture, and by the straightening blades of the cooling air-liquid mixture. Cooling purified air cools all elements of the turbine. When the engine is running at maximum speed and with the afterburner on, an additional cooling liquid (water) is supplied to the centrifugal compressor of the turbines.

The invention is illustrated by graphic materials, where:

FIG. 1. Cooling system for air-liquid blades of turbine stages of a turbojet engine.

1. Rotor shaft;

2. Housing 1 of the impeller, the first stage of the turbine blades;

3. Casing 2 of the impeller of the first stage of the turbine blades;

4. Blades of the centrifugal compressor of the first stage of the turbine;

5. Annular combustion chamber;

6. Straightening blades of the first stage of the turbine;

7. Blades of the first stage of the turbine;

8. Straightening blades of the second stage of the turbine;

9. Blades of the second stage of the turbine;

10. Fairing body;

11. Engine mounting unit;

12. Coolant (water) pipeline;

13. Air inlet;

14. Purified air;

15. Coolant (water) injection pump with reversible electric motor;

16. Coolant (water) reservoir;

17. Filter for fine cleaning of outboard air;

18. Air inlet;

19. Outlet of polluted air;

20. Centrifugal filter;

21. Outboard air;

22. Air inlet;

23. Blades of the centrifugal compressor of the second stage of the turbine;

24. Housing 1 of the impeller, the second stage of the turbine blades;

25. Casing 2 of the impeller, the second stage of the turbine blades;

26. Housing for outside cooling air;

27. Rack for mounting the coolant (water) nozzle;

28. Coolant (water) nozzle;

29. Cooling air-liquid mixture.

FIG. 2. Cooling system of air-liquid blades of turbine stages of a turbojet engine.

3. Casing 2 of the impeller of the first stage of the turbine blades;

4. Blade of the centrifugal compressor of the first stage of the turbine;

6. Blade of the straightening apparatus of the blade of the first stage of the turbine;

7. Blades of the second stage of the turbine;

8. Straightening blades of the second stage of the turbine;

23. Blades of the centrifugal compressor of the second stage of the turbine;

24. Housing 1 of the impeller, the second stage of the turbine blades;

25. Casing 2 of the impeller, the second stage of the turbine blades;

29. Cooling air-liquid mixture;

30. Straightening blade of the cooling air-liquid mixture (water) of the first stage of the compressor;

31. End channel of the cooling air-liquid mixture (water) of the first stage turbine blades;

32. Middle channel of the cooling air-liquid mixture (water) of the turbine first stage blades;

33. End channel of the cooling air-liquid mixture (water) of the first stage turbine blades;

34. Blade for increasing the pressure of the cooling air-liquid mixture (water) of the first stage of the turbine;

35. Annular shelf with bandage seals of the first stage of the turbine;

36. Outlet of the cooling air-liquid mixture (water) from the blades of the straightening apparatus of the second stage of the turbine;

37. Straightening blade of the cooling air-liquid mixture (water) of the second stage of the compressor;

38. End channel of the cooling air-liquid mixture (water) of the blades of the second stage of the turbine;

39. Blade for increasing the pressure of the cooling air-liquid mixture (water) of the second stage of the turbine;

40. The middle channel of the cooling air-liquid mixture (water) of the blades of the second stage of the turbine;

41. End channel of the cooling air-liquid mixture (water) of the blades of the second stage of the turbine;

42. Annular shelf with bandage seals for the second stage of the turbine;

43. Outlet of the cooling air-liquid mixture (water) from the blades of the second stage of the turbine;

44. Outlet of the cooling air-liquid mixture (water) from the blades of the first stage of the turbine;

45. The movement of the cooling air-liquid mixture (water) of the straightening blades of the first stage of the turbine;

46. The cavity of the cooling air-liquid mixture of the straightening blades of the first stage of the turbine;

47. Outlet of the cooling air-liquid mixture (water) from the blades of the straightening apparatus of the first stage of the turbine;

48. The movement of the cooling air-liquid mixture (water) of the straightening blades of the second stage of the turbine;

49. The cavity of the cooling air-liquid mixture of the straightening blades of the second stage of the turbine;

50, 51, 52. Holes in the annular flange with shroud seals of the first stage of the turbine;

53, 54, 55. Holes in the annular shelf with bandage seals of the second stage of the turbine.

The operation of the cooling system of the air-liquid blades of the turbine stages of a turbojet engine is carried out as follows: When the impellers of the first and second stages of the turbine rotate (which consist of: the first stage of the turbine - from the housing 1 of the impeller, the first stage of turbine blades 2 and the housing 2 of the impeller of the first stage turbine blades 3, between which the centrifugal compressor blades of the first stage of the turbine 4 are installed and fixed, which form the centrifugal compressor of the first stage, the second stage of the turbine - from the impeller housing 1, the second stage of the turbine blades 24, the impeller housing 2, the second stage of the turbine blades 25, between which are installed and fixed blades of the centrifugal compressor of the second stage of the turbine 23, which form the centrifugal compressor of the second stage), due to the occurrence of centrifugal forces in the centrifugal compressors of the first and second stages of the turbine, the cooling outside air 21 is sucked in, which passes through a centrifugal filter 20, where large air particles are removed to the atmosphere through the polluted air pipe 19, through the air pipe 18, the air enters the outboard air fine filter 17 for final air purification, then the air enters through the air pipe 13 and the air pipe 22 to building 26.

From housing 26, air enters the centrifugal compressor of the first stage of the turbine, increasing its pressure and moving through the channels:

- the end channel of the cooling air-liquid mixture (water) of the blades of the first stage of the turbine 31;

- the middle channel of the cooling air-liquid mixture (water) of the blades of the first stage of the turbine 32 .;

- the end channel of the cooling air-liquid mixture (water) of the blades of the first stage of the turbine 33;

Passing through the channels 31, 32, 33, the inner cavity of the blades of the first stage of the turbine 7 is cooled, the air released under pressure from the outlet openings of the cooling air-liquid mixture (water) from the blades of the first stage of the turbine 44 prevents the temperature of the blades of the first stage of the turbine 7 from increasing.

The air passing through the channels 31, 32, 33 enters through the holes 50, 51, 52 into the annular shelf with the shroud seals of the first stage of the turbine 35, onto the blades of increasing the pressure of the cooling air-liquid mixture (water) of the first stage of the turbine 34 and the straightening blades of the cooling air - liquid mixture (water) of the first stage of the compressor 30.

The blades for increasing the pressure of the cooling air-liquid mixture (water) of the first stage of the turbine 34 and the straightening blades of the cooling air-liquid mixture (water) of the first stage of the compressor 30, when rotating, perform the work of an axial compressor, increasing the air pressure.

Further, pressurized air enters the cavities of the cooling air-liquid mixture of the straightening blades of the first stage of the turbine 46, cooling the inner cavity of the straightening blades of the turbine 6. The air released under pressure from the outlet openings of the cooling air-liquid mixture (water) 47 prevents an increase in the temperature of the blades of the straightening apparatus of the blades the first stage of the turbine 6.

Also, from the housing 26, air enters the centrifugal compressor of the second stage of the turbine, increasing its pressure and moving through the channels:

- the end channel of the cooling air-liquid mixture (water) of the blades of the first stage of the turbine 38;

- the middle channel of the cooling air-liquid mixture (water) of the blades of the first stage of the turbine 40;

- the end channel of the cooling air-liquid mixture (water) of the blades of the first stage of the turbine 41.

Passing through the channels 38, 40, 41, the inner cavity of the blade of the second stage of the turbine 9 is cooled, the air released under pressure from the outlet openings of the cooling air-liquid mixture (water) from the blades of the first stage of the turbine 43 prevents the temperature of the blades of the second stage of the turbine 9 from increasing.

The air passing through the channels 38, 40, 41 enters through the holes 53, 54, 55 into the annular shelf with the shroud seals of the second stage of the turbine 42, onto the blades for increasing the pressure of the cooling air-liquid mixture (water) of the second stage of the turbine 39 and straightening blades of the cooling air - the liquid mixture (water) of the first stage of the compressor 37.

The blades for increasing the pressure of the cooling air-liquid mixture (water) of the second stage of the turbine 39 and the straightening blades of the cooling air-liquid mixture (water) of the first stage of the compressor 37, when rotating, perform the work of an axial compressor, increasing the air pressure.

Further, the air under pressure enters the cavities of the cooling air-liquid mixture of the straightening blades of the second stage of the turbine 48, cooling the inner cavity of the straightening blades of the turbine 8. The air released under pressure from the outlet openings of the cooling air-liquid mixture (water) 36 prevents an increase in the temperature of the blades of the straightening apparatus of the blades second stage turbine 8.

Cooling outboard air 21 passing between the casing 1 of the impeller, the first stage of the turbine blades 2 and the casing 2 of the impeller of the first stage of the turbine blades 3 and the centrifugal compressor blades of the first stage of the turbine 4 - cools the impeller of the first stage of the turbine.

Cooling outboard air 21 passing between the casing 1 of the impeller and the second stage of the turbine blades 24 and the casing 2 of the impeller, the second stage of the turbine blades 25 with the blades of the centrifugal compressor of the second stage of the turbine 23 - cools the impeller of the second stage of the turbine.

With an increase in engine speed from cruising to maximum and afterburner engagement from the coolant (water) reservoir 16, the liquid enters the coolant (water) injection pump with a reversible electric motor 15 (The amount of coolant is regulated by a reversible electric motor providing favorable conditions for the operation of the turbine blades), the coolant (water) pipe 12, enters the coolant (water) nozzle 28, being sprayed, mixed with the cooling air flow, forming an air-liquid mixture, which, under pressure, enters the turbine blades ensuring normal engine operation when the engine speed changes to maximum and the afterburner is turned on ...

The proposed technical solution is not known from available sources of information about the cooling system of the air-liquid blades of the turbine stages and the impeller of a turbojet engine, from which it follows that it can be practically implemented in production, that is, contributes to the criteria of patentability.

Claims (1)

The system of air-liquid cooling of the turbine stage blades of a turbojet engine, which has cooled straightening vanes and impeller turbine blades, including the supply of cooling air and coolant to the impeller cooling system and changing its flow rate according to the operating modes of the turbojet engine, characterized in that for cooling the blades of the straightening apparatus of the blades of the first stage of the turbine (6), the straightening blades of the second stage of the turbine (8) and the blades of the first stage of the turbine (7), the blades of the second stage of the turbine (9) and the impellers of the first, second stage of the turbine, cooling outside air (21) is used cleaned of impurities by a centrifugal filter (20) and a fine filter of outside air (17) and centrifugal compressors consisting of the first stage of the turbine - from the impeller housing of the first stage of turbine blades (2) and the impeller housing of the first stage of turbine blades (3 ), between which and z The blades of the centrifugal compressor of the first stage of the turbine (4) are fixed, which form the centrifugal compressor of the first stage, the second stage of the turbine - from the impeller housing of the second stage of the turbine blades (24), the impeller housing of the second stage of the turbine blades (25), between which are installed and fixed second stage centrifugal compressor blades of the turbine (23), which form the second stage centrifugal compressor; in the centrifugal compressors of the first and second stages of the turbine, the cooling outside air (21) is sucked in, then the air enters through the air pipe (13) and the air pipe (22) into the housing (26), from which the air enters the centrifugal compressor of the first, second stages of the turbine , with increased pressure through the channels (31, 32, 33, 38, 40, 41) moves through the holes in the annular shelves with the shroud seals of the first, second stage of the turbine (50, 51, 52, 53, 54, 55), to the boost blades pressure of the cooling air-liquid mixture of the first, second stage of the turbine (34, 39) to the straightening blades of the cooling air-liquid mixture of the first and second stages of the compressor (30, 37) and enters the blades of the straightening apparatus of the first, second stage of the turbine (6, 8) ; when the cooling air moves through the channels (31, 32, 33, 38, 40, 41), cooling occurs inside the turbine blades (7, 9), when the cooling air escapes from the outlet openings of the cooling air-liquid mixture from the blades of the first, second stage of the turbine ( 44, 43), cooling occurs from the outer side of the turbine blades (7, 9); when air moves through the cavities of the cooling air-liquid mixture of the straightening blades of the first, second stages of the turbine (46, 49), the inner sides of the blades of the straightening blades (6, 8) are cooled, when the cooling air leaves the outlet openings of the cooling air-liquid mixture from the blades ( 47, 36), cooling occurs from the outside of the straightening blades (6, 8); when the cooling air moves inside the impellers, they are cooled; when the engine speed increases from cruising to maximum and the afterburner is turned on from the coolant reservoir (16), the liquid enters the coolant injection pump with a reversible electric motor (15), through the pipeline the coolant (12) enters the coolant nozzle (28), being atomized, it mixes with the flow of cooling air, forming an air-liquid mixture, which under pressure enters the turbine blades.

Images