CN116291763A - Geometric structure for reducing temperature of back wind surface of stepped inclined grate - Google Patents
Geometric structure for reducing temperature of back wind surface of stepped inclined grate Download PDFInfo
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- CN116291763A CN116291763A CN202310305737.3A CN202310305737A CN116291763A CN 116291763 A CN116291763 A CN 116291763A CN 202310305737 A CN202310305737 A CN 202310305737A CN 116291763 A CN116291763 A CN 116291763A
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- 244000126211 Hericium coralloides Species 0.000 claims description 12
- 230000002265 prevention Effects 0.000 abstract description 3
- 238000005516 engineering process Methods 0.000 description 9
- 238000002156 mixing Methods 0.000 description 8
- 239000012530 fluid Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 230000000737 periodic effect Effects 0.000 description 5
- 238000007789 sealing Methods 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000003116 impacting effect Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
- F01D11/08—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator
- F01D11/14—Adjusting or regulating tip-clearance, i.e. distance between rotor-blade tips and stator casing
- F01D11/20—Actively adjusting tip-clearance
- F01D11/24—Actively adjusting tip-clearance by selectively cooling-heating stator or rotor components
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Air-Flow Control Members (AREA)
Abstract
The invention belongs to the technical field of leakage prevention of aeroengines, and particularly relates to a geometric structure for reducing the temperature of a back wind surface of a stepped inclined grate, which comprises a stator inner wall surface, an inclined grate, a grate disc, tooth top gaps, a back wind surface, a high-temperature air-entraining channel, a high-temperature area of the back wind wall surface, a hinge, a poking piece and a channel inlet.
Description
Technical Field
The invention belongs to the field of leakage prevention of aeroengines, and particularly relates to a geometric structure for reducing the back wind surface temperature of a stepped inclined grate.
Background
At present, the comb teeth are important devices for preventing gas leakage of an aeroengine compressor and a turbine blade tip, and because the blade tips cannot be in contact with the outer casing and keep a certain gap, the gas can leak out of the gap, the efficiency of the engine is affected, and the comb teeth can effectively reduce the leakage; the various geometries of the grate, the inlet pressure and the temperature can influence the sealing efficiency of the grate.
As shown in fig. 1 a, the geometry of the stepped comb teeth is 5 teeth, 4 steps, and a shorter air inlet channel is also arranged at the inlet, wherein each geometrical parameter t is tooth top width, H is tooth height, a is front inclination angle, β is back inclination angle, e is step length, B is tooth spacing, d is step height, and C is tooth top gap, and the purpose of changing C/t is achieved by changing tooth top gap C while tooth top width t is unchanged.
FIG. 2 is an enlarged partial total temperature map of the final stage teeth and shows traces, and it can be found that there is a section of high temperature region of the leeward wall surface on the leeward surface which is impacted, and three causes are analyzed, one causes are that the temperature close to the wall surface is increased due to the friction effect of rotation, and the wall surface temperature is higher as the rotating speed is higher; secondly, the influence of the main flow vertically and downwards impacting the leeward surface due to the influence of the ladder geometry; thirdly, because the position where the two large-size vortexes meet is the position where the large-size vortexes are opposite in direction, the mixing effect is stronger, so that the kinetic energy is mutually reduced, the converted heat energy is more than that of other positions, and the rotating wall surface can be continuously heated more strongly than the other positions when passing through the section downwards along the journey; the local high temperature area of the leeward wall surface can cause thermal stress at the position of the leeward wall surface, so that the service life of related parts can be influenced, and the safety and stability of the whole structure are not facilitated.
The invention aims to solve the problems in the background art and provides a geometric structure for reducing the temperature of the lee surface of a stepped inclined grate.
Disclosure of Invention
In order to solve the defects in the prior art and achieve the technical purposes, the invention discloses a geometric structure for reducing the temperature of the back wind surface of a stepped inclined grate, which is realized by adopting the following technical scheme:
the utility model provides a reduce geometric structure of step formula inclined grate back of body wind face temperature, includes install inclined grate tooth, the stator that distributes with the step mode on the grate disc, stator inner wall personally submits step formula level and decurrent, its characterized in that: the leeward surface of the inclined grate is circumferentially provided with a plurality of high-temperature air-entraining channels, the tail end of each high-temperature air-entraining channel close to the axis is provided with a channel inlet, the tail end of each high-temperature air-entraining channel far away from the axis is provided with a channel outlet, and high-temperature air flow enters from the channel inlet and is discharged from the channel outlet; the channel outlet is hinged with a plectrum, and the plectrum switches the channel outlet.
As a further development of the technology, the high-temperature bleed air channel is a tapering channel from the channel inlet to the channel outlet.
As a further improvement of the technology, the shrinkage area ratio of the high-temperature air entraining channel is 3:1.
As a further improvement of the technology, the channel inlet is positioned at the position of the high-temperature area on the leeward wall surface.
As a further improvement of the technology, the opening and closing movement angle of the poking piece is 0-180 o The length of the poking piece is 0.3mm, and the tail end of the poking piece is of a pointed structure.
As a further improvement of the technology, the channel inlet is subjected to fillet treatment, and the fillet radius is 0.1mm-0.2mm.
As a further improvement of the technology, 12 high-temperature air-entraining channels are circumferentially arranged at the lee surface of the inclined comb teeth of the comb tooth disc, and each 30 degrees of air-entraining channels are arranged.
As a further improvement of the technology, the high-temperature air entraining channel reaches the tooth top gap upwards and bends towards the downstream direction of the main flow, and the angle between the channel outlet and the tooth back wind surface is less than or equal to 90 degrees.
As a further improvement of the technology, the channel inlet and the channel outlet are round, and the diameter is 0.05mm.
Compared with the traditional aeroengine leakage prevention technology, the invention has the following advantages:
1. the high-temperature air-entraining channel can damage the structure of the large-size vortex below, redundant kinetic energy can not be converted into heat energy through friction and blending to be consumed, and the heat energy can enter the high-temperature air-entraining channel, so that the blending strength of a leeward surface is reduced, and the temperature is lowered.
2. The fluid in the high-temperature air-entraining channel is subsonic fluid, so that the fluid entering the tapered high-temperature air-entraining channel is accelerated, the impact force of the channel outlet on the plectrum is enhanced, the movement of the plectrum is more severe, the mixing force of the main flow is enhanced on the other hand with higher flow velocity, the leakage quantity of the grate is reduced, and the method is helpful for the working performance of the whole grate structure.
3. The structure significance of the hinged plectrum is that the vibration effect amplitude of the plectrum is larger, the plectrum is less prone to fatigue fracture, the service life is prolonged, the limitation on the material of the plectrum is much less, the material selection difficulty of the plectrum is lower, and the range is larger.
4. For the plectrum itself, mainly the impact of leaning on the fluid drives it to carry out periodic opening and shutting motion, and this motion helps to form the disturbance to the mainstream, has avoided the temperature rise that the direct impact of mainstream brought to the leeward face in the above-mentioned leeward wall high temperature region cause to and promoted the blending of mainstream and passageway drainage, further reduces the leakage volume of comb tooth, promotes the sealing performance of comb tooth.
5. The high-temperature air-entraining channels are evenly distributed on the comb teeth sealing disc, and the structure is installed at intervals of certain same angle, so that the whole comb teeth disc has axisymmetry, and the periodic stability of flow state is facilitated.
Drawings
FIG. 1 is a schematic diagram of stepped inclined grate geometry and grate disk position.
FIG. 2 is an enlarged local total temperature trace plot of the last stage tooth.
Figure 3 is a schematic overall geometry of the novel structure of the present invention.
Fig. 4 is an enlarged partial schematic view of the paddle at the exit of the channel.
Fig. 5 is a schematic view of the periodic movement of the paddle.
FIG. 6 is a schematic view of the high temperature zone of the lee wall of the tunnel inlet.
FIG. 7 is a schematic diagram of a mounting of a grate disk cooling geometry array.
FIG. 8 is an enlarged schematic view of a cooling geometry array mounting portion.
Reference numerals in the figures: 1. the inner wall surface of the stator; 2. inclined comb teeth; 3. comb tooth disc; 4. tooth top gap; 5. a lee surface; 6. a high temperature bleed passage; 7. a leeward wall surface high temperature region; 8. a hinge; 9. a pulling piece; 10. a channel inlet; 11. high-temperature air-entraining incoming flow direction; 12. a shifting sheet motion trail; 13. a channel outlet; 14. sharp corners; 15. round corners; 16. the mounting position of the comb tooth disc cooling structure array; 17 comb disk positions.
Description of the embodiments
The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples or figures are illustrative of the invention and are not intended to limit the scope of the invention.
The outline of the square outer frame as in fig. 4, 5, 6, 8 is not a schematic structure, but is a schematic partially enlarged range.
As shown in fig. 1, 2 and 3, the comb disc 3 is positioned at a mounting position 17 in the aeroengine, as shown in fig. 1 b, the comb disc 3 comprises inclined comb teeth 2 and stators which are mounted on the comb disc 3 and distributed in a step mode, the inner wall surface 1 of each stator is downward in a step level, as shown in fig. 1 and 2, a plurality of high-temperature air-entraining channels 6 are circumferentially arranged at the leeward surface 5, the high-temperature air-entraining channels 6 are provided with channel inlets 10 at the tail ends close to the axis, the tail ends of the high-temperature air-entraining channels 6 far from the axis are provided with channel outlets 13, and high-temperature air flows enter from the channel inlets 10 and are discharged from the channel outlets 13; the channel outlet 13 is hinged with a plectrum 9, and the plectrum 9 switches the channel outlet 13.
As shown in fig. 3, the high temperature bleed air channel 6 is a tapering channel from the channel inlet 10 to the channel outlet 13.
As shown in fig. 3, the shrinkage area ratio of the high temperature bleed air channel 6 is 3:1.
As shown in fig. 3, the channel inlet 10 is located at the position of the leeward high temperature region 7.
As shown in fig. 4 and 5, the opening and closing movement angle of the poking piece 9 is 0-180 o The length of the poking piece 9 is 0.3mm, and the tail end of the poking piece 9 is of a sharp corner 14 structure.
As shown in FIG. 6, the channel inlet 10 is treated with a round corner 15, and the radius of the round corner 15 is 0.1mm-0.2mm.
As shown in fig. 3, 12 high-temperature air-entraining channels 6 are circumferentially arranged at the lee surface 5 of the inclined comb teeth 2 of the comb tooth disc 3, one at every 30 degrees.
As shown in fig. 4 and 5, the high-temperature bleed air duct 6 reaches the tooth top gap 4 upward, curves toward the duct outlet 13, and the duct outlet 13 is at an angle of 90 degrees or less with the leeward side 5. The incoming flow direction 11 of the high-temperature bleed air impacts the plectrum 9 to enable the movement track to be a plectrum movement track 12.
As shown in FIG. 3, the channel inlets and outlets are rounded corners 15, and the diameter is 0.05mm.
As shown in fig. 4 and 5, the movable plectrum 9 adopts a hinge 8 formed by a hinge mode to link with the comb teeth, so that the opening and closing movement angle of the plectrum 9 reaches 180 degrees o And the materials of the hinge 8 and the plectrum 9 can meet the working condition of the temperature of the comb 700K, so that the hinge 8 and the plectrum 9 can bear long-term impact at the temperature and the movement can reach the expected service life, and the frequent abrasion and maintenance are avoided.
As shown in FIG. 6, a rounded corner 15 of a proper radius is used at the channel inlet 10 to reduce the kinetic energy attenuation of the incoming flow to the channel at this point to reduce the temperature rise.
As shown in fig. 1, the inner wall surface 1 of the stator of the comb is stepped downward, and only a part of the whole comb structure is selected as an illustration in the figure, and the comb disc 3 is cylindrical.
As shown in fig. 1, 2 and 6, in some embodiments, a section of high-temperature air-entraining channel 6 is manufactured from a high-temperature area 7 on the leeward wall surface upwards to a position on the leeward surface 5, the high-temperature air-entraining channel 6 adopts a taper shape, the flow area from the high-temperature air-entraining channel 6 to a channel outlet 13 is minimized, the flow rate in the channel is fastest at the moment, the impact force of the outlet on the plectrum 9 is enhanced, the movement of the plectrum 9 is more intense, the blending force of the main flow is enhanced on the other side with higher flow rate, the leakage amount between the comb teeth and the inner wall surface 1 of the stator is reduced, and the working performance of the whole comb tooth structure is also facilitated.
As shown in fig. 3, 4 and 5, in some embodiments, a paddle 9 that can move to achieve the purpose of opening and closing is installed on the high temperature area 7 of the leeward wall surface, and the moving part is connected by a hinge 8.
As shown in fig. 2, 3, 4 and 5, in some embodiments, when the fluid in the channel impacts on the pulling plate 9, the pulling plate 9 is opened outwards according to the flow state, the air flow in the channel flows out of the channel 13 to impact and mix with the main flow, and breaks the stable structure of two large-size eddies shown in fig. 2, so that the flow of the channel is disturbed, the inlet of the channel fluid is not broken due to the breaking of the large-size eddies below, at the moment, the streamline of the main flow deflects downwards to be closer to the pulling plate 9, and an impact phenomenon occurs, backflow occurs in the channel, so that the pulling plate 9 is closed again, and in a period formed by the process, the pulling plate 9 is opened and closed, the mixing effect is also promoted, and in a state of the pulling plate 9, the two large-size eddies formed at the lee surface 5 are broken again, so that a regular structure capable of continuously breaking the heating process of the lee surface 5 is formed.
As shown in fig. 7 and 8, for the whole, the temperature reducing structures of the comb tooth discs on the comb tooth disc 3 are distributed in an equidistant distribution mode, every 30 degrees is one, 12 comb teeth of each stage are installed in total, so that the whole comb tooth disc 3 has axisymmetry, and the periodic stability of flow state is facilitated.
The diameter of the channel inlet and outlet is 0.05mm, as shown in fig. 5, the hinge 8 can freely move by 180 degrees, but the actual moving range is possibly smaller than 90 degrees, because the angle between the channel outlet 13 and the leeward side 5 is smaller than or equal to 90 degrees, the jet angle at the channel outlet 13 and the design angle of the wall surface are smaller, so that the maximum angle of the impact plectrum 9 is also smaller, the normal opening and closing movement of the plectrum 9 is ensured, if the angle between the channel outlet 13 and the leeward side 5 is larger than or equal to 90 degrees, the condition that the plectrum 9 cannot be closed after being turned up by 180 degrees can be caused, the length of the plectrum 9 is 0.3mm, and the tail end of the plectrum 9 has a pointed structure to reduce the blocking effect on incoming flow during closing, so that the follow-up opening is facilitated.
To sum up: the high-temperature air-entraining channel 6 in the invention is beneficial to enhancing the mixing strength of the main flow of the leeward side 5 and the jet flow of the high-temperature air-entraining channel 6, and reducing the temperature; the opening and closing movement effect of the poking plate 9 caused by jet impact of the high-temperature air entraining channel 6 is beneficial to disturbing the main flow, so that the leakage quantity of the comb teeth is further reduced, and the sealing performance of the comb teeth is improved; circumferential equidistant installation is carried out on the comb tooth disc with axisymmetry, so that the periodic stability of flow state is facilitated, the safety and stability of the whole structure are improved, and the efficiency of the engine is improved.
Claims (9)
1. The utility model provides a reduce geometric structure of step formula inclined grate back of body wind face temperature, includes install inclined grate tooth, the stator that distributes with the step mode on the grate disc, stator inner wall personally submits step formula level and decurrent, its characterized in that: the leeward surface of the inclined grate is circumferentially provided with a plurality of high-temperature air-entraining channels, the tail end of the high-temperature air-entraining channel close to the axis is provided with a channel inlet, the tail end of the high-temperature air-entraining channel far away from the axis is provided with a channel outlet, and high-temperature air flow enters from the channel inlet and is discharged from the channel outlet; the channel outlet is hinged with a plectrum, and the plectrum switches the channel outlet.
2. A stepped-inclined-grate back-wind-surface temperature reducing geometry as defined in claim 1, wherein: the high temperature bleed air channel is a tapered channel from the channel inlet to the channel outlet.
3. A stepped-inclined-grate back-wind-surface temperature reducing geometry as defined in claim 2, wherein: the shrinkage area ratio of the high-temperature air entraining channels is 3:1.
4. A stepped-inclined-grate back-wind-surface temperature reducing geometry as defined in claim 1, wherein: the channel inlet is positioned at the position of the high-temperature area on the leeward wall surface.
5. A stepped-inclined-grate back-wind-surface temperature reducing geometry as defined in claim 1, wherein: the opening and closing movable angle of the poking piece is 0-180 DEG o The length of the poking piece is 0.3mm, and the tail end of the poking piece is of a pointed structure.
6. The geometry for reducing the back-wind temperature of a stepped inclined grate in accordance with claim 4, wherein: and the inlet of the channel is subjected to fillet treatment, and the fillet radius is 0.1mm-0.2mm.
7. A stepped-inclined-grate back-wind-surface temperature reducing geometry as defined in claim 1, wherein: 12 high-temperature air-entraining channels are circumferentially arranged at the lee surface of the inclined comb teeth of the comb tooth disc, and each 30 degrees of high-temperature air-entraining channels are arranged.
8. The geometry for reducing the back-wind temperature of a stepped inclined grate in accordance with claim 7, wherein: the high-temperature air entraining channel reaches the tooth top gap upwards and bends towards the downstream direction of the main flow, and the angle between the channel outlet and the tooth back wind surface is less than or equal to 90 degrees.
9. A stepped-inclined-grate back-wind-surface temperature reducing geometry as defined in claim 1, wherein: the cross sections of the channel inlet and the channel outlet are circular, and the diameter is 0.05mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310305737.3A CN116291763B (en) | 2023-03-27 | 2023-03-27 | Geometric structure for reducing temperature of back wind surface of stepped inclined grate |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310305737.3A CN116291763B (en) | 2023-03-27 | 2023-03-27 | Geometric structure for reducing temperature of back wind surface of stepped inclined grate |
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| Publication Number | Publication Date |
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| CN116291763A true CN116291763A (en) | 2023-06-23 |
| CN116291763B CN116291763B (en) | 2024-02-13 |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5351732A (en) * | 1990-12-22 | 1994-10-04 | Rolls-Royce Plc | Gas turbine engine clearance control |
| US20110229306A1 (en) * | 2010-03-17 | 2011-09-22 | Rolls-Royce Plc | Rotor blade tip clearance control |
| US20160138471A1 (en) * | 2014-09-05 | 2016-05-19 | Rolls-Royce Deutschland Ltd & Co Kg | Air guiding device and turbo engine with air guiding device |
| CN115749969A (en) * | 2022-11-07 | 2023-03-07 | 西北工业大学 | Rotor blade with self-air-entraining front edge and self-adaptive air-jet blade top |
-
2023
- 2023-03-27 CN CN202310305737.3A patent/CN116291763B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5351732A (en) * | 1990-12-22 | 1994-10-04 | Rolls-Royce Plc | Gas turbine engine clearance control |
| US20110229306A1 (en) * | 2010-03-17 | 2011-09-22 | Rolls-Royce Plc | Rotor blade tip clearance control |
| US20160138471A1 (en) * | 2014-09-05 | 2016-05-19 | Rolls-Royce Deutschland Ltd & Co Kg | Air guiding device and turbo engine with air guiding device |
| CN115749969A (en) * | 2022-11-07 | 2023-03-07 | 西北工业大学 | Rotor blade with self-air-entraining front edge and self-adaptive air-jet blade top |
Non-Patent Citations (1)
| Title |
|---|
| 雷昭等: ""高转速下台阶篦齿流动特性的实验与计算", 推进技术, vol. 38, no. 11, pages 2587 - 2596 * |
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| CN116291763B (en) | 2024-02-13 |
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