CN1786426A - Pulsing impact cooling blade for gas turbine engine - Google Patents

Abstract

There is disclosed an impulse cooling blade adapted for gas-turbine engine, inside which a cooling passage is divided into cooling cavities with periodic convergent and divergent sections or uniflow sections by curved and uniflow division plates. On the curved division plate are disposed chordwise impact holes for passing through the cooling gas. The comparison coefficient Nu/Cf of the impulse cooling blade is the ratio between the Nu sselt number Nu and the coefficient of resistance Cf.

Description

A kind of pulsatile impact cooled blade that is applicable to gas turbine engine

Technical field

The present invention relates to a kind of pulsatile impact cooled blade that is applicable to gas turbine engine, the cooling channel of this cooled blade constitutes the cooling chamber with periodic converging portion and extending section by the form of curved dividing plate or curved dividing plate and the combination of direct current dividing plate, and interchannel has tangential impact opening.

Background technique

Turbine blade in gas turbine engine is close to the firing chamber, and its ambient temperature of living in part is up to 2000K.In order to improve the thermal efficiency of gas turbine engine, the general employing improved turbine inlet temperature, and what bring is the increase of turbine part heat load thereupon.In addition, turbine blade (working blade) is in the middle of the very high centrifugal field work under the high rotating speed (changeing more than the scooter 15000rpm).In bad working environment like this, guarantee the work that blade is normal, reliable, long-term, just must effectively cool off turbine blade, keep best thermal stress state.The principle of cooling is to use minimum air conditioning quantity to guarantee the blade reliably working.Turbine cooling blade in using at present has a variety of, and its structure comparatively is typically the compound direct current of multi-cavity cooling channel, and what the dividing plate on its passage generally adopted is once-through type diaphragm structure (seeing also shown in Fig. 4 A).By dividing plate 5 passage is divided into a plurality of cooling chambers 6, cold air enters from blade root 2 ends, flows to blade tip 3 directions along cooling chamber 6 then, and a part flows out from blade tip 3, a part of hole by dividing plate 5 and blade tip 3 places is split seam 4 to trailing edge and is flowed, and splits seam 4 outflows through trailing edge.Defectives such as the boundary layer that the cooled gas of this structure forms can not fully be destroyed, and makes blade regional area heat exchange poor effect, and the blade flow resistance is bigger have a strong impact on the performance and the life-span of motor.

Summary of the invention

The purpose of this invention is to provide a kind of pulsatile impact cooled blade that is applicable to gas turbine engine, the cooling channel of its blade interior is separated to form the cooling chamber with periodic converging portion and extending section or direct current section by curved dividing plate and direct current dividing plate, the curved dividing plate of interchannel is provided with tangential impact opening, the boundary layer of cold air is constantly destroyed, thereby strengthened heat exchange; Reasonably porous design, periodic in addition the contraction and expansion makes cold air at tangential generation pulsatile impact.

The present invention is a kind of pulsatile impact cooled blade that is applicable to gas turbine engine, the cooling channel of its blade interior is separated to form the cooling chamber with periodic converging portion and extending section or direct current section by curved dividing plate and direct current dividing plate, and described curved dividing plate is provided with the tangential impact opening that passes through for cooling air; Described cooling chamber with periodic converging portion and extending section is to be separated to form by a curved dividing plate and two direct current dividing plates; Or be separated to form by two curved dividing plates and a direct current dividing plate; Cooling chamber with direct current section is to be separated to form by two curved dividing plates, or is separated to form by two direct current dividing plates.

Described pulsatile impact cooled blade, the dividing plate between its cooling chamber are curved dividing plate.

Described pulsatile impact cooled blade, what its curved dividing plate should satisfy is shaped as

$y=A\sin \left[\frac{2\mathrm{\π}}{\mathrm{\λ}}(x-\frac{\mathrm{\λ}}{4})\right]+A.......0\≤x\≤L,$ In the formula, y represents along tangential position coordinate, the x table

Show position coordinate radially, λ represents wavelength, and A represents amplitude, and L represents the leaf height of blade.

Described pulsatile impact cooled blade, its tangential impact opening are located at up and down and/or about the curved paddy of curved peak of described curved dividing plate, the angle of curved paddy

The advantage of pulsatile impact cooled blade of the present invention is: the curved dividing plate of (1) employing replaces the direct current dividing plate in original blade, constitutes periodic convergent flaring passage; (2) in curved dividing plate knuckle place's perforate, rational flow rate distribution.More than two kinds of improvement make cooled gas flow velocity in convergent flaring passage constantly change, turbulivity increases, and cooled gas by the aperture on the dividing plate when a passage jet enters another passage, because the shape of dividing plate, can form vortices in jet boundary, the time-dependent generation of these vortexs and the meeting that comes off produce oscillation effect, further increase the fluid turbulent degree, destroy boundary layer, strengthen heat exchange.Because the dividing plate small hole stream is directly taken away a part of heat, make cooling effect better simultaneously.

Description of drawings

Fig. 1 is the sectional structure chart of complex pulsatile impact cooled blade of the present invention.

Fig. 2 is the sectional structure chart of curved pulsatile impact cooled blade of the present invention.

Fig. 3 A is the curved diaphragm structure schematic representation that the hole is located at the below.

Fig. 3 B is the curved diaphragm structure schematic representation that the hole is located at the top.

Fig. 3 C is the curved diaphragm structure schematic representation that upper and lower all is provided with the hole.

Fig. 4 A is the turbine blade sectional view of conventional DC shelf-shaped.

Fig. 4 B is the A-A view of Fig. 4 A.

Among the figure: 1. impact opening 15. upper clamping holes 2. blade roots 3. blade tips 4. trailing edges are split seam 5. direct current dividing plates 6. cooling chambers on 12. times folder holes of 11. times impact openings of curved dividing plate, 13. angles 14.

Embodiment

The present invention is described in further detail below in conjunction with accompanying drawing.

See also shown in Figure 1ly, the present invention is a kind of pulsatile impact cooled blade that is applicable to gas turbine engine, and the internal cooling channel of this pulsatile impact cooled blade advances cooling air from blade root 2 ends, and splits seam 4 from blade tip 3 or trailing edge and go out cooling air.Wherein, the cooling channel is separated to form a plurality of cooling chambers 6 with periodic converging portion and extending section or direct current section by curved dividing plate 1 and direct current dividing plate 5.Cooling chamber 6 with periodic converging portion and extending section can be to be separated to form by a curved dividing plate 1 and two direct current dividing plates 5, also can be to be separated to form by two curved dividing plates 1 and a direct current dividing plate 5; Cooling chamber 6 with direct current section can be to be separated to form by two curved dividing plates 1, also can be to be separated to form by two direct current dividing plates 5.

See also shown in Fig. 1, Fig. 2, Fig. 4 A, Fig. 4 B, the structure of the internal cooling channel of conventional DC cooled blade is that the dividing plate between the passage adopts direct current dividing plate (as Fig. 4 A), the inner chamber at leading edge and middle part is divided into a plurality of passages (the passage I shown in Fig. 4 B, passage II, passage III, passage IV, passage V etc.) by the direct current dividing plate, has formed multi-cavity return flow type cooling system.The cooled gas of a passage flows in the turning runner that is made of the direct current dividing plate, changes flow direction, increases turbulivity.Trailing edge part also is divided into two passages by direct current dividing plate 5, from the cooled gas that passage IV enters, in this passage, carry out heat exchange after, from the gap inlet passage V of dividing plate and blade tip, and after in this passage, carrying out heat exchange, split seam 4 outflows through trailing edge.The result that such structure causes is that enough cold air coolings are arranged at vane tip and bottom, and the heat exchange effect is fine; But the blade middle part is in cold air intersection, the air conditioning quantity deficiency, and cooling effect is bad, and heat exchange is very poor, ruptures easily.Pulsatile impact cooled blade structure of the present invention, the most of zone of blade interior adopts staggered formation to have the flow pattern of periodic converging portion and extending section, flow out a plurality of tangential impact opening that cold air is provided with from curved dividing plate 1 (shown in Fig. 3 A, Fig. 3 B and Fig. 3 C), make cold air be separated into a plurality of tiny channel flow at internal cavity comparatively fully, and produce pulsatile impact.Gas flow direction in the passage constantly changes, and heat exchange is strengthened greatly.

The present invention has not only improved whole heat exchange effect from the thermal conduction study angle, and makes the overall thermal stress distribution even, and the pressure loss is also well below the blade of conventional DC dividing plate.

In the present invention, the pulsatile impact cooled blade is to adopt the moulding of gradation welding processing, can be by of the designing requirement of gas-turbine unit turbine blade to cooling power, with the cooling channel adopt method that different dividing plates separate cooling chambers 6 with the cooling channel of blade interior be designed to a kind of satisfy have curved dividing plate 1 feature cooling chamber 6 structures, what wherein, curved dividing plate 1 should satisfy is shaped as $y=A\sin \left[\frac{2\mathrm{\π}}{\mathrm{\λ}}(x-\frac{\mathrm{\λ}}{4})\right]+A.......0\≤x\≤L,$ In the formula, y

Expression is along tangential position coordinate, and x represents position coordinate radially, and λ represents wavelength, and A represents amplitude, and L represents the leaf height of blade.

Pulsatile impact cooled blade of the present invention through simplified model experiment and its heat-exchange performance of three-dimensional numerical value simulation test and flow resistance, has the analogy coefficient Nu/C of cooling channel of the blade interior of curved dividing plate 1 _fBe Nusselt number Nu and resistance coefficient C _fRatio, it is compared with the analogy coefficient of the cooling channel of the blade interior that only has direct current dividing plate 5 and has improved 10～50%.

Separate with dividing plate between passage and the passage, adopt curved dividing plate 1 (as Fig. 1), one end of curved dividing plate 1 is located at blade root 2 places of gas-entered passageway, the other end is located at blade tip 3 places, curved dividing plate 1 is provided with a plurality of tangential impact openings (promptly descending impact opening 11, time folder hole 12, last impact opening 14 and upper clamping hole 15 to be tangential impact opening), cold air flows out from the hole, turbine blade is separated into a plurality of air-flow paths, cooled gas enters from a passage, radially from the blade root to the blade tip, flow on one side, by hole dividing plate on impact another passage on one side.See also shown in Fig. 3 A, 3B and the 3C, according to the setting requirement of the coefficient of heat transfer, tangential impact opening is located at up and down and/or about the curved paddy of curved peak of described curved dividing plate 1, the angle of curved paddy $\mathrm{\α}=2\mathrm{arctg}\frac{\mathrm{\λ}}{4A}$ Be 35 °～155 °, angle α is preferable

Angle is 100 °.The wherein a kind of of tangential impact opening is provided with structure as shown in Figure 3A, only is located on the curved peak and curved paddy of curved dividing plate 1 lower end, is located at impact opening 11 under being of lower end, curved peak, is located at folder hole 12 under being of curved paddy lower end; The another kind of tangential impact opening is provided with structure shown in Fig. 3 B, only is located on the curved peak and curved paddy of curved dividing plate 1 upper end, and what be located at upper end, curved peak is to go up impact opening 14, and what be located at curved paddy upper end is upper clamping hole 15; Another of tangential impact opening is provided with structure shown in Fig. 3 C, can be located on the curved peak and curved paddy of curved dividing plate 1 upper and lower end, what be located at curved peak upper and lower end is to go up impact opening 14 and following impact opening 11, and what be located at curved paddy upper and lower end is upper clamping hole 15 and following folder hole 12.

Claims (5)

1, a kind of pulsatile impact cooled blade that is applicable to gas turbine engine, it is characterized in that: the cooling channel of blade interior is separated to form the cooling chamber (6) with periodic converging portion and extending section or direct current section by curved dividing plate (1) and direct current dividing plate (5), and described curved dividing plate (1) is provided with the tangential impact opening that passes through for cooling air;

Described cooling chamber (6) with periodic converging portion and extending section is to be separated to form by a curved dividing plate (1) and two direct current dividing plates (5); Or be separated to form by two curved dividing plates (1) and a direct current dividing plate (5);

Cooling chamber (6) with direct current section is to be separated to form by two curved dividing plates (1), or is separated to form by two direct current dividing plates (5).

2, pulsatile impact cooled blade according to claim 1 is characterized in that: the dividing plate between the described cooling chamber (6) is curved dividing plate (1).

3, pulsatile impact cooled blade according to claim 1 and 2 is characterized in that: what curved dividing plate (1) should satisfy is shaped as $y=A\sin \left[\frac{2\mathrm{\π}}{\mathrm{\λ}}(x-\frac{\mathrm{\λ}}{4})\right]+A.......0\≤x\≤L,$ In the formula, y represents that along tangential position coordinate, x represents position coordinate radially, and λ represents wavelength, and A represents amplitude, and L represents the leaf height of blade.

4, pulsatile impact cooled blade according to claim 1 and 2 is characterized in that: described tangential impact opening is located at up and down and/or about the curved paddy of curved peak of described curved dividing plate (1), the angle of curved paddy $\mathrm{\α}=2\mathrm{arctg}\frac{\mathrm{\λ}}{4A}$ It is 35 °～155 °.

5, pulsatile impact cooled blade according to claim 1 and 2 is characterized in that: the analogy coefficient Nu/C of cooling channel that has the blade interior of curved dividing plate (1) _fBe Nusselt number Nu and resistance coefficient C _fRatio, its analogy coefficient with the cooling channel of the blade interior of having only direct current dividing plate (5) is compared and has been improved 10～50%.

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