JP2011033037A - Thermoplastic final stage blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turbine blade having good buffer properties by remodeling a turbine blade including a buffer area 101 provided with a buffer layer 103. <P>SOLUTION: The buffer layer 103 includes a fiber matrix system 200. The fiber matrix system 200 includes a thermoplastic matrix 201. Reinforcement fiber 202 is embedded in the thermoplastic matrix 201. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a turbine blade. The invention also relates to a turbine, in particular a steam turbine. The invention further relates to a method for fabricating a turbine blade.

  Today, turbine blades made exclusively of steel are used in turbines, especially steam turbines. Particularly in large stationary steam turbines having a large diameter, the number of revolutions obtained for steel blades is limited by the high weight of the steel blades themselves. In order to significantly reduce the mass of the blade, it is also conceivable to use a blade made of fiber-reinforced material. In this case, the rotation speed can be increased.

  In stationary steam turbines with large diameters and thus large blade lengths, further undesirable vibrations need to be buffered. Therefore, today, vibration damping can be obtained via a buffer wire (Daempfungsdraehte) or a shroud (Deckbaender) additionally provided on the blade surface. Based on the geometry of the wing, the task of providing such a buffer wire or shroud on the wing is often very cumbersome, resulting in reduced efficiency and requiring a comprehensive manufacturing cost.

  Therefore, an object of the present invention is to provide a turbine blade having a shock absorbing characteristic.

  This object has been solved by the turbine blades, turbines, in particular steam turbines, and methods for making turbine blades as set out in the independent claims of the present invention.

  According to a first embodiment of the invention, a turbine blade is provided, wherein a partial region of the turbine blade or all turbine blades form or have a buffer region comprising a buffer layer. Yes. The buffer layer has a fiber matrix system. The fiber matrix system has a thermoplastic matrix in which reinforcing fibers are embedded.

  According to another embodiment of the present invention, a turbine having the turbine blade is provided.

  According to another embodiment of the present invention, a method for fabricating the turbine blade is provided. According to this method, reinforcing fibers are first embedded in a thermoplastic matrix to form a buffer matrix fiber matrix system. The buffer layer forms a buffer region of the turbine blade. The buffer region is a partial region of the turbine blade or the entire turbine blade.

  “Daempfungsbereich” refers to the region of a turbine blade that incorporates the damping characteristics of the turbine blade. The buffer region is provided in particular in the region of the turbine blade where generally higher shear loads or moment loads occur than in the other regions of the turbine blade, so that it is required to buffer in such a buffer region. ing. Furthermore, in the buffer region, greater vibrations can be buffered than in other regions of the turbine blade. The buffer region can be provided in a predetermined portion along the region where the turbine blade extends or along the entire length of the turbine blade. The buffer region can be provided in a predetermined region in the cross section of the turbine blade. Thus, for example, the outer region of the turbine blade has a buffer region, whereas the inner region of the turbine blade can form an arbitrary blade region. The buffer area is subject to buffering and is buffered in the buffer area, for example, high centrifugal force, high bending load, high shear load, high torsional load or adverse vibrations. All turbine blades form a buffer zone, especially for the turbine blades of the thermoplastic last stage blade. That is, all the turbine blades may be made of a plurality of buffer layers, and thus may consist of the buffer layers themselves.

  "" Lage "; layer", in particular a buffer layer and / or a fiber layer, refers to a buffer layer or layer of buffer material and a fiber layer or reinforcing fiber layer. One layer has a thickness of, for example, 0.1 mm to 1 mm, in particular 0.2 mm, 0.25 mm and / or 0.3 mm.

  “Faser-Matrix-System” refers to a fiber composite composed of a matrix and reinforcing fibers. The fiber matrix system may, for example, completely or partially constitute the buffer layer.

  "Verstaerkungsfaser" is a fiber that sends and transmits the force acting on the fiber matrix system further forward. This fiber has a high rigidity, especially in the direction of tension, compared to the matrix. In order to take advantage of the best stiffness properties of the reinforcing fibers, the force flow is designed to flow along the fibers.

  “Matrix” is a raw material in which reinforcing fibers are embedded. “Embedded” means that the reinforcing fibers are sterically fixed in the matrix, thereby enabling load introduction and load derivation. The matrix can further protect the reinforcing fibers against compression, for example when pressure is applied in a direction parallel to the fibers. Since the reinforcing fiber and the matrix are bonded or melted to each other, for example, load transmission is performed between the matrix and the reinforcing fiber, and thereby shear force can also be transmitted.

  “Thermoplastische Matrix” means the matrix material. The thermoplastic material or the thermoplastic matrix has particularly buffering properties. The matrix thermoplastic material has a low stiffness and a high cushioning value. As a result, the thermoplastic matrix has a buffering action, whereas the reinforcing fibers have a reinforcing action. The thermoplastic matrix is made of, for example, polyetheretherketone (PEEK), polyamide (PA), polypropylene (PP), polycarbonate (PC) or polyethylene (PE).

  The reinforcing fiber is made of, for example, synthetic fiber such as carbon fiber, aramid fiber, polyether fiber or polyethylene fiber. In addition to the organic reinforcing fibers, inorganic fibers such as glass fibers, natural fibers or metal fibers may be used.

  According to the present invention, a turbine blade made of a fiber composite material can be buffered as planned without causing instability due to a decrease in shape stability or rigidity of the turbine blade. By using a thermoplastic matrix material, the material itself provides the desired and adjusted advantageous possibility of buffering vibrations. In other words, vibration damping on the material side is improved by using a combination material consisting of thermoplastic resin and reinforcing fibers in the required damping area or on the entire turbine blade. Further, the buffer regions that are exposed to different loads can provide different combinations of different thermoplastic fiber matrix systems to adapt the turbine blades to the predefined load.

  In addition, the turbine blades are later deformed with the profile (cross-sectional shape) of the turbine blades by newly heating and melting the thermoplastic fiber matrix system based on the use of the thermoplastic fiber matrix system. can do. This allows later shaping or post-adjustment or fine-tuning for a given turbine blade profile or different load requirements. As a result, each blade can be caulked or deformed to the turbine blade ring.

  According to an advantageous embodiment of the invention, the buffer region has a fiber layer, which together with the buffer layer forms one laminated composite.

  ““ Schichtbverund ”; laminated composite” is, for example, a laminated material in which different layers, in particular a buffer layer and a fiber layer, are stacked one above the other. Laminate composites represent a layered configuration of buffer areas or a stack-type fabrication, or other areas of a turbine blade, such as other blade areas. A laminated composite material or a laminated composite material is composed of a plurality of layers or a different number of layers stacked one above the other. The layers or stacks are, for example, glued or secured together based on the material's offenporigkeit. For example, the laminate is resin impregnated to bond the layers together. Since the laminated composite material forms an integral structure of the constituent parts, forces acting on the constituent parts are transmitted through the laminated composite material. The laminated composite further has a uniformly extending surface of the component. In other words, the attachment part attached from the outside to the surface of the component part by adhesion is not included in the component part or the laminated composite of the turbine blade.

  "" Faserlage "" refers to a layer of fibers that does not have a thermoplastic material. The fiber layer may be made of different reinforcing fiber materials as described above, for example having a high rigidity or a higher rigidity than the buffer layer.

  According to an advantageous embodiment of the invention, the turbine blade further comprises a blade region, which comprises a plurality of fiber layers separate from the fiber layer. The plurality of other fiber layers form another laminated composite material. The blade region or regions may be adjacent to the turbine blade region or regions. The wing region may consist of another plurality of fiber layers that have a higher stiffness and loadability compared to the buffer region. The vibration is transmitted, for example, from the wing region to the buffer region, where the buffer region can buffer or absorb the vibration by means of a thermoplastic fiber matrix system. According to an embodiment of the present invention, a turbine blade having a plurality of blade regions adjacent to a plurality of buffer regions is provided, for example, along the extending direction of the turbine blade. Multiple buffer areas can be placed in pre-defined areas that have high loads or high buffer needs. The wing region is arranged in a region where vibration that does not cause a problem occurs or a region requiring high rigidity. This allows the turbine blades to individually compensate for their required load and thus meet the fine requirements for the blade profile with regard to cost and effectiveness.

  According to another advantageous embodiment, the reinforcing fibers are embedded in a thermoplastic matrix at an angle of 1 ° to 90 ° with each other. Depending on the complex load or load direction, the reinforcing fibers can be arranged at different angles from each other. The buffer layer or the fiber layer can be produced, for example, as a woven, sewn or knitted product with oriented reinforcing fibers. Depending on the alignment direction of the reinforcing fibers, the turbine blades can be adapted to a predefined load direction, so that the turbine blades can be adapted to the requirements relating to the predefined potential.

  According to an advantageous embodiment of the invention, the reinforcing fibers are embedded in the thermoplastic matrix parallel to each other. For example, in regions where turbine blades are exclusively subjected to tensile loads, it is sufficient to place the reinforcing fibers parallel to each other. Since complex weaving and alignment of the reinforcing fibers is not necessary, this region provides a manufacturing method at low manufacturing costs with reinforcing fibers arranged parallel to each other.

  According to another embodiment of the invention, at least one reinforcing fiber comprises a hybrid yarn. The hybrid yarn has a thermoplastic material and carbon fibers. Such a hybrid yarn is composed of, for example, a plurality of yarns twisted or twisted together, and the plurality of yarns form a single yarn. Some of these yarns are made of a thermoplastic material and the other is made of reinforcing fibers such as carbon fibers. Furthermore, the thermoplastic material may be configured as a yarn, and the hybrid yarn may be formed by melting the fiber yarn into the thermoplastic yarn. In this simple manner, the desired buffering of the turbine blades can be obtained by using thermoplastic yarns as reinforcing fibers.

  According to another embodiment, the buffer layer has a lower elastic stiffness and / or a higher buffer value than the fiber layer.

  "" Daempfungswert "; buffer value" refers to the buffer properties of the material. The buffer value “tan δ ′” is, for example, between 0 and 1.

  "" Steifigkeit "; rigidity" is expressed by E module or G module, for example. Thus, for example, the fibers have a stiffness of 130 GPa in the longitudinal direction and a stiffness of 8 GPa in the lateral direction. In a woven product of fibers, for example, a rigidity of 65 GPa is obtained in each main fiber direction. Each main fiber direction is aligned with each other at an angle α. The thermoplastic matrix has a rigidity of, for example, 0.5 to 10 GPa, and has better buffer properties than the reinforcing fiber.

  According to another embodiment, the damping region has a lower elastic stiffness and / or a higher damping value than the wing region.

  According to an advantageous embodiment, the turbine blade further has an envelope layer. The envelope layer surrounds the surface or surface area of the turbine blade so that the turbine blade is protected against external influences. The envelope layer comprises an unreinforced thermoplastic material, similar to the matrix material. Based on the high buffering action of the unreinforced thermoplastic material, the flexibility or elasticity of the thermoplastic material is greater than the elasticity of the fiber layer. When external particles impinge on the surface of the turbine blade, there is less erosion of the surface of thermoplastic material than the fiber layer of reinforcing fibers. Accordingly, the service life of the turbine blade is increased. This is because damage caused by collision of external particles is reduced. Moreover, corrosion is reduced because thermoplastic materials are generally more resistant to moisture than reinforcing fibers.

  According to an embodiment of the present invention, the turbine blade has another fiber matrix system with a thermoplastic matrix. This alternative fiber matrix system is located in the buffer and / or blade region so as to be exposed to external influences on the turbine blade. Another fiber matrix system with a thermoplastic matrix has reinforcing fibers extending in any main fiber direction as a fiber mat. By arbitrarily orienting the main fiber direction of the reinforcing fibers, the stiffness characteristics of another fiber matrix system are reduced, and good absorption characteristics and resistance to impact by external particles are increased. Another fiber matrix system may further extend over another region of the turbine blade, eg, over the blade region. Compared to an unreinforced thermoplastic matrix, another fiber matrix system with a fiber reinforced matrix has a high absorption capacity for impacting particles and also has a high rigidity, so The plastic fiber matrix system also contributes to the overall increase in turbine blade stiffness. Accordingly, a rigid material for the turbine blade is provided, and the liquid resistance and erosion resistance of the turbine blade surface are enhanced. In turbine blades, erosion due to droplets is a problem. An outer layer or surface of a wing blade made of unreinforced thermoplastic resin, or a subsequent layer or surface of a layer of thermoplastic matrix material, or a subsequent layer or surface of another fiber matrix system, An integral erosion layer is provided without the need for an additional sealing layer.

  According to another advantageous embodiment, a turbine, in particular a steam turbine, comprises the turbine blade. In particular, the steam turbine, in particular the first compression stage and the final turbine stage, has a large diameter. In the impeller of a steam turbine having a large diameter, high centrifugal forces, bending moments and torsional forces act. In this case, the turbine blade according to the invention is suitable in order to obtain sufficient rigidity with improved damping characteristics over conventional turbine blades. Thereby, turbine blades made of composite material are used in the steam turbine itself having a large diameter.

  According to an advantageous embodiment of the method of the invention, when embedding the reinforcing fibers in the plastic matrix, the thermoplastic matrix is melted so that the reinforcing fibers are crimped to the thermoplastic matrix. As a result, the thermoplastic material present in the matrix is melted, whereby an inexpensive production by a pressing method is obtained. There is no need for long-term penetration and curing steps as in conventional fiber composite layers.

According to another advantageous embodiment of the method according to the invention, the buffer region is deformed by further melting the thermoplastic matrix in order to adapt the buffer region to a predetermined shape of the turbine blade. Due to the meltability of such a fiber matrix system or thermoplastic matrix, the final shaping of the turbine blade can be obtained, for example by twisting the turbine blade, following the manufacturing process, for example the pressing process. This is particularly useful for special turbine requirements, especially torsion angles and other special turbine requirements. Furthermore, when a special problem with the vibration frequency occurs, it can be deformed or adjusted later. The buffer area is
By remelting, it can later be deformed or fine-tuned, for example in accordance with a changed or unpredictable vibration frequency.

  Since the fiber matrix system is remeltable, the wing can be repaired later. For example, additional thermoplastic material can be applied later to remove damage to the fiber matrix system. This also offers the possibility of repair. In other words, a thermoplastic resin can be applied locally to repair damage to the turbine blades.

  Embodiments of the invention related to different subject matter of the invention have been described. In particular, some embodiments are described in the claims relating to the means of the apparatus and in the claims relating to the means of other methods of the invention. However, in the present invention, unless otherwise specified, in addition to a combination of a plurality of features belonging to one form of the present invention, an embodiment in which a plurality of features belonging to different forms of the subject of the present invention are arbitrarily combined is also possible. Is possible.

  Other advantages and features of the invention are described in the following advantageous examples.

1 is a schematic view of a turbine blade having a buffer region according to one embodiment of the present invention. FIG. 1 is a plan view of a fiber matrix system in a buffer layer, according to one embodiment of the present invention. FIG. 1 is a schematic diagram of a fiber matrix system in a buffer layer, according to one embodiment of the present invention. FIG.

  In the drawings, identical or similar elements are marked with the same reference numerals. The drawings are schematic and not to scale.

  FIG. 1 shows an embodiment of a turbine blade 100 according to a first embodiment of the present invention. The turbine blade 100 has a buffer region 101 including a buffer layer 103. The buffer layer 103 has a fiber matrix system 200 (see FIG. 2). The fiber matrix system 200 includes a thermoplastic matrix 201 (see FIG. 2), and reinforcing fibers 202 (see FIG. 2) are embedded in the thermoplastic matrix 201.

  The turbine blade 100 has two blade regions 102 that surround a buffer region 101 as shown in FIG. The wing region 102 is formed of, for example, another laminated composite material 107, and the laminated composite material 107 includes a plurality of separate fiber layers 105. If these separate fiber layers 105 are made of reinforcing fibers 202 made of, for example, carbon fibers, or made of other reinforced composite fibers, then another laminated composite 107 has an outermost rigid wing region 102. Forming.

  The fiber layer 104 in the buffer region 101 moves smoothly into the wing region 102. In a smooth or constant transition line of the fiber layer 104 from the buffer region 101 to the wing region 102, the fiber layer 104 forms a continuous transition layer with another fiber layer 105. Also, the buffer region 101 can be formed as a semi-finished product, in which case the fiber layer 104 does not exceed the buffer region 101 or reach into the wing region 102. The fiber layer 104 is cut at the edge region of the buffer region 101, for example.

  The laminated composite material 106 including at least one buffer layer 103 and another fiber layer 104 forms the buffer region 101, and vibration damping is caused in the buffer region 101. Based on the layered configuration of the buffer layer 103, the buffer region 101 may be more flexible than the wing region 102, so that vibration damping is performed by the layer composite 106, that is, by the material itself.

  Further, the surroundings of the turbine blade 100 are surrounded by the envelope layer 108. This envelope layer 108 protects at least the buffer region 101 and additionally the wing region 102 against external influences. The envelope layer 108 is made of an unreinforced thermoplastic material, for example. The unreinforced thermoplastic material forms a flexible envelope 108 so that the impact of impurity particles hitting the turbine blades is buffered and bounced back by the flexible envelope 108. Since the thermoplastic envelope layer 108 is not rigid, the envelope layer 108 is slightly deformed when the impurity particles collide, so that the collision energy is absorbed and no cracks or other damage is generated. .

  The buffer region 101 or additionally the wing region 102 may also have another thermoplastic fiber matrix system 109. This fiber matrix system 109 protects the turbine blade 100 against external influences. The fiber matrix system 109 has a thermoplastic matrix 201 in which reinforcing fibers 202 are embedded. If the reinforcing fibers 202 are optionally provided within the thermoplastic matrix 201, this is referred to as a fiber mat. Since the fiber mat has a lower stiffness than a fiber matrix system with directional composite fibers, a higher flexibility or elasticity can be generated by another fiber matrix system 109. This protects against external impacts by impurity particles and against erosion of the turbine blade 100 surface.

  FIG. 2 shows a fiber matrix system 200 consisting of a thermoplastic matrix 201. Reinforcing fibers 202 are embedded in a thermoplastic matrix 201. As shown in FIG. 2, the reinforcing fibers 202 may be aligned in parallel. Thereby, the reinforcing fibers loaded by tension provide the high rigidity of the fiber matrix system 200. A high damping characteristic based on the low rigidity of the reinforcing fibers 202 is possible in the transverse direction perpendicular to the fiber direction of the reinforcing fibers 202.

  FIG. 3 illustrates another embodiment of a fiber matrix system 200 in which reinforcing fibers 202 are embedded within a thermoplastic matrix 201. In this embodiment, the reinforcing fiber 202 is embedded between other reinforcing fibers 202 at a predetermined angle α. In other words, the reinforcing fibers 202 are not arranged parallel to each other. By arranging the reinforcing fibers 202 in such a multi-directional manner, it is possible to obtain a high rigidity of the reinforcing fibers 202 in a plurality of predetermined directions. In this case, the shock-absorbing properties are caused in particular by the thermoplastic matrix 201. This provides a buffer region 101 that has reinforcing or rigid properties and also has buffering properties.

  In addition, “umfassend” does not exclude other members or steps, and does not exclude a plurality. Also, features or steps demonstrated by one of the above embodiments can be used in combination with other features or steps of other embodiments. Reference numerals recited in the claims are not limited to this.

  100 turbine blade, 101 buffer region, 102 blade region, 103 buffer layer, 104 fiber layer, 105 fiber layer, 106 laminated composite material, 107 laminated composite material, 108 envelope layer, 200 fiber matrix system, 201 thermoplastic matrix, 202 Reinforcing fiber

Claims (15)

In a turbine blade having a buffer region (101) with a buffer layer (103),
The buffer layer (103) comprises a fiber matrix system (200);
The turbine blade according to claim 1, wherein the fiber matrix system (200) has a thermoplastic matrix (201), and reinforcing fibers (202) are embedded in the thermoplastic matrix (201).   The buffer region (101) has a fiber layer (104), and the fiber layer (104) forms a laminated composite (106) with the buffer layer (103). Turbine blades.   The turbine blade further includes a blade region (102), and the blade region (102) includes a plurality of fiber layers (105) different from the fiber layer (104). The turbine blade according to claim 1 or 2, wherein the plurality of fiber layers (105) form another laminated composite (107).   4. The turbine according to claim 1, wherein the reinforcing fibers (202) are embedded in a thermoplastic matrix (201) at an angle (α) of 1 ° to 90 ° with each other. Wings.   The turbine blade according to any one of claims 1 to 3, wherein the reinforcing fibers (202) are embedded in the thermoplastic matrix (201) parallel to each other.   The at least one of the reinforcing fibers (202) has a hybrid yarn, and the hybrid yarn has a thermoplastic material and a carbon fiber material. Turbine wing.   The turbine blade according to any one of claims 2 to 6, wherein the buffer layer (103) has a lower elastic stiffness and / or a higher buffer value than the fiber layer (104).   The turbine blade according to any one of claims 3 to 7, wherein the buffer region (101) has a lower elastic stiffness and / or a higher buffer value than the blade region (102).   The turbine blade further has an envelope layer (108), which envelope layer (108) is a surface of the turbine blade (100) such that the turbine blade (100) is protected from external influences. The turbine blade according to any one of the preceding claims, wherein the envelope layer (108) comprises an unreinforced thermoplastic material.   The turbine blade further comprises a fiber matrix system (109) separate from the fiber matrix system (200), comprising a thermoplastic matrix (201), the separate fiber matrix system (109) The further fiber matrix system (109) is arranged in the buffer region (101) and / or in the blade region (102) such that it is exposed to external influences of the turbine blade (100), The turbine blade according to any one of the preceding claims, wherein the further fiber matrix system (109) comprises reinforcing fibers (202) provided as a fiber mat having an arbitrary main fiber orientation.   A turbine, in particular a steam turbine, comprising at least one turbine blade (100) according to any one of the preceding claims.   The turbine of claim 11, wherein the at least one turbine blade (100) is a turbine blade. In a method for fabricating a buffer region (101) of a turbine blade (100),
In order to form the fiber matrix system (200) of the buffer layer (103), the reinforcing fibers (202) are embedded in the thermoplastic matrix (201),
The buffer layer (103) forms a buffer region (101) of the turbine blade (100).
A method for fabricating a buffer region (101) of a turbine blade (100), characterized in that   When embedding the reinforcing fibers (202) in the thermoplastic matrix (201), the thermoplastic matrix (201) is melted, and the reinforcing fibers (202) are pressure-bonded to the thermoplastic matrix (201). Item 14. The method according to Item 13.   Deforming the buffer region (101) by further melting the thermoplastic matrix (201) to conform the buffer region (101) to a pre-defined shape of the turbine blade (100); 15. A method according to claim 13 or 14.

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