Cooled, hollow, open turbine blade and gas turbine
By designing cooling channels at the blade roots of the turbine blades and supplying cooling air with the turbine roulette, the problem of creep load in the rear stage of the gas turbine is solved, the creep life is improved and the design improvement process is simplified.
Patent Information
- Application Number
- CN202480002943.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-11
- Publication Date
- 2025-08-08
AI Technical Summary
When open turbine blades are used in the rear stage of the gas turbine, the creep load problem is difficult to solve, and the development time for improved aerodynamic design is long and requires pre-testing in the thruster.
The cooling channel is designed at the blade root of the turbine blade, which extends from the lower side of the blade root into the cavity and is connected by the ribs, and the cooling air is supplied by the turbine roulette.
Improves the creep life of turbine blades, simplifies the design improvement process, and reduces development time and testing costs.
Smart Images
Figure CN120457267A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a hollow turbine blade which is designed to be open at one end and is additionally cooled, and to a gas turbine. Background Art
[0002] In gas turbines, open, hollow turbine blades are used in the later stages. Even the later stages of a gas turbine, i.e., the third or fourth stage, are typically subject to creep loads in the area of the blade airfoil. Increased thermal stresses, high blade weight, or casting defects can reduce creep life.
[0003] The problem of creep life can be reduced by an improved aerodynamic design of the blade airfoil. The development time of new designs capable of reducing creep loads is time consuming and must also be pre-tested in the propeller. Summary of the Invention
[0004] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems.
[0005] This object is achieved by a turbine blade according to claim 1 and a turbine according to claim 10 .
[0006] Further advantages are listed in the dependent claims, which can be combined with one another as desired in order to achieve further advantages.
[0007] The idea of the invention is to cool hollow and open turbine blades and in particular to cool them in and by means of the blade root. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figures 1 to 4 shows an embodiment of the present invention,
[0009] Figure 5 and Figure 6 Additional details are shown.
[0010] The description and drawings show exemplary embodiments only. DETAILED DESCRIPTION
[0011] Figure 1 A first turbine blade 1 ′ according to the invention is shown. The turbine blade 1 ′ has a blade root 4 ′. For installation in a turbine, more precisely in a wheel, the blade root 4 ′ has a fir-tree root design (not shown in detail). Other designs are also conceivable.
[0012] The blade platform 7 adjoins the blade root 4 ′.
[0013] Following the blade platform 7 , the blade airfoil 10 then extends with its contour up to the end 6 ′ of the turbine blade 1 ′.
[0014] In contrast to the blade platform 7 and the blade root 4 ′, the blade airfoil 10 is shown here in cross-section, ie in profile.
[0015] The turbine blade 1 ′ has an underside 5 ′ at the blade root 4 ′ and an opposite end 6 ′.
[0016] To save weight, the turbine blade 1 ′ is designed to be hollow and therefore has a cavity 16 ′.
[0017] In the cavity 16 ′, ribs 13 are preferably formed, which connect the suction side and the pressure side of the blade airfoil 10 to one another.
[0018] Two mutually connected channels 9 , 11 are formed in the cavity 16 ′ by the rib 13 that does not extend continuously to the blade root 4 ′. The channels are formed in a substantially U-shape.
[0019] In the flow direction 30 , the blade airfoil 10 is initially flowed over by the incoming flow at the incident edge 33 , wherein the flowing fluid then extends around the suction side and the pressure side and continues to flow after the delivery edge 36 .
[0020] The end 6 ′, ie the top of the turbine blade 1 ′, is designed to be open, ie the end 6 ′ is formed by the blade wall and at least one rib 13 .
[0021] According to the invention, at least one cooling channel 20 is provided in the blade root 4 ′, which cooling channel extends in the blade root 4 ′ from the underside 5 ′ of the blade root 4 ′ into the cavity 16 ′.
[0022] The cooling channel 20 is preferably arranged starting from the underside 5 ′ in the front third of the blade root 4 ′ in the flow direction 30 .
[0023] The cooling channel 20 extends obliquely. The rising angle of the cooling channel 20 is between 45° and 75°. This angle is determined relative to the bottom side 5'.
[0024] The cooling channel 20 opens into the cavity 16', flush with the rib 13. The opening of the cooling channel 20 can also be arranged flush with the front channel 9 or the rear channel 11.
[0025] Figure 2 Another embodiment of a turbine blade 1" is shown, wherein as a Figure 1 In addition, there are two cooling channels 21 , 22 , which preferably extend parallel to each other.
[0026] However, the rise angles of the two cooling channels 21 , 22 may preferably also be different.
[0027] The cooling channels 21 , 22 are preferably arranged starting from the underside 5 ″ in the front third of the blade root 4 ″ in the flow direction 30 .
[0028] The rising angle of the cooling channels 21 , 22 is between 45° and 75°.
[0029] The cooling channels 21, 22 open into the cavity 16', flush with the rib 13. The openings of the cooling channels 21, 22 can also be arranged flush with the front channel 9 and / or the rear channel 11.
[0030] Figure 3 Another embodiment of a turbine blade 1" is shown, wherein as a Figure 1 In addition, there are two ribs 14, 15, so that there are three channels 9', 11', 12 in the cavity 16", and a roughly W-shaped shape is formed.
[0031] The end portion 6 ″, ie the top portion of the turbine blade 1 ″′, is designed to be open, ie the end portion 6 ″ is formed by the blade wall and the ribs 14 , 15 .
[0032] The cooling channel 20 is preferably arranged starting from the underside 5 ′ in the front third of the blade root 4 ′ in the flow direction 30 .
[0033] The rising angle of the cooling channel 20 is between 45° and 75°.
[0034] The cooling channel 20 opens into the cavity 16 ″, here between the ribs 14 , 15 . The opening of the cooling channel 20 can also be arranged flush with the front channel 9 ′, the middle channel 11 ′ or the rear channel 12 , or flush with one of the ribs 14 , 15 .
[0035] Figure 4 Another embodiment of a turbine blade 1"" is shown, wherein as a Figure 2 The supplement has two ribs 14, 15, or from Figure 3 Initially there are two cooling channels 21 , 22 , so that in the cavity 16 ″ there are three channels 9 ′, 11 ′, 12 and an approximately W-shaped shape is formed.
[0036] The cooling channels 21 , 22 are preferably arranged starting from the underside 5 ″ in the front third of the blade root 4 ″ in the flow direction 30 .
[0037] The rising angle of the cooling channels 21 , 22 is between 45° and 75°.
[0038] However, the rising angles of the two cooling channels 21 , 22 may also be different.
[0039] The cooling channels 21 , 22 open into the cavity 16 ″ flush with the rib 15 . The openings of the cooling channels 21 , 22 can also be arranged flush with the front channel 9 ′, the middle channel 11 ′ or the rear channel 12 , or flush with one of the ribs 14 , 15 .
[0040] The number of ribs 13 , 14 , 15 and cooling channels 9 , 9 ′, 11 , 11 ′, 12 used can vary depending on the turbine blade and gas turbine.
[0041] The shapes of the ribs 13 , 14 , 15 are shown schematically only.
[0042] Cooling channels 20, 21, 22 ( Figures 1 to 4 ) is preferably between 3 mm and 6 mm in diameter. This diameter may vary depending on the size of the turbine blade and the number of cooling channels used.
[0043] Figure 5 and Figure 6 Shown Figures 1 to 4 Further details of the embodiment of the present invention. The lower side 5', 5" of the blade root 4', 4" preferably has a recess 28, the cooling channel 20 ( Figure 5 ) or cooling channels 21, 22 ( Figure 6 ) extends from the recess.
[0044] The cooling air for cooling the channels 20 , 21 , 22 is preferably supplied via turbine wheels.
[0045] In the installed state, the recess 28 essentially forms an air chamber for the cooling air supply.
[0046] The turbine blades 1 ′, 1 ″, 1 ″′, 1 ″″ preferably have no cooling air holes in the blade airfoil 10 .
[0047] The gas turbine has at least three stages, in particular four stages, in which the turbine blades described above are used. It can also have three stages of rotor blades and four stages of guide blades.
[0048] First, the third and / or fourth stage of rotor blades is cooled, in particular as described above.
Claims
1. Hollow, open turbine blades (1', 1", 1"', 1""), Especially the rotor blades, The turbine blade has at least: Blade root (4', 4"), Blade platform (7), Blade airfoil (10), Cavity (16', 16"), It is characterized in that At least one cooling channel (20, 21, 22) extends from the underside (5', 5") of the blade root (4', 4") through the blade root (4', 4") into the cavity (16', 16").
2. The turbine blade according to claim 1, The turbine blade has at least one rib (13) on the inside, In particular only one rib (13), The ribs respectively connect the suction side and the pressure side of the blade airfoil (10) to each other.
3. The turbine blade according to claim 1, The turbine blade has at least two ribs (14, 15) on the inside, Specifically only two ribs (14, 15), The ribs respectively connect the suction side and the pressure side of the blade airfoil (10) to each other.
4. The turbine blade according to claim 1, 2 or 3, in, The rising angle of the cooling channels (20, 21, 22) is between 45° and 75°.
5. Turbine blade according to one or more of the preceding claims 1, 2, 3 or 4, in, There is at least one cooling channel (20, 21, 22), in particular only one cooling channel (20).
6. Turbine blade according to one or more of the preceding claims 1, 2, 3 or 4, in, having at least two cooling channels (21, 22), In particular, there are only two cooling channels ( 21 , 22 ).
7. The turbine blade according to claim 6, in, The two cooling channels (21, 22) extend parallel to each other.
8. The turbine blade according to claim 6, in, The two cooling channels (21, 22) do not extend parallel to each other.
9. Turbine blade according to one or more of the preceding claims 1, 2, 3, 4, 5, 6, 7 or 8, in, The lower side (5', 5") has a recess (28), The cooling channel (20, 21, 22) extends from the recess through the blade root (4', 4").
10. Gas turbine, The gas turbine has at least three stages of guide blades and rotor blades in the hot gas path, Specifically, the four stages consist of guide vanes and rotor blades. in, The rotor blades of the third and / or fourth stage are cooled.
11. The gas turbine according to claim 10, in, The rotor blade is a hollow turbine blade according to one or more of the preceding claims 1 to 9 .