Cooling blade with rib column lattice structure and preparation method of cooling blade

Abstract

The invention discloses a rib column lattice structure cooling blade and a preparation method thereof. The rib column lattice structure cooling blade comprises a cavity wall surface, and a front edge lattice structure, a middle lattice structure and a tail edge lattice structure which are arranged on the inner side of the cavity wall surface, the front edge dot matrix structure, the middle dot matrix structure and the tail edge dot matrix structure are arranged in parallel, and the middle dot matrix structure is arranged between the front edge dot matrix structure and the tail edge dot matrix structure; the front edge lattice structure comprises a plurality of lamellar ribs parallel to the airflow direction; the middle lattice structure comprises a plurality of oval flat ribs perpendicular to the airflow direction. The trailing edge lattice structure comprises a plurality of porous circular columns; the cavity wall surface, the front edge lattice structure, the middle lattice structure and the tail edge lattice structure are integrally formed; according to the cooling blade with the rib-column lattice structure, on the basis that the heat transfer area is greatly increased through the lattice structure, the lattice rods are designed into different rib and column shapes according to the airflow rules of different areas, and the airflow resistance is reduced.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and more specifically, to a ribbed lattice structure cooling blade and its preparation method. Background Art

[0002] The high-temperature resistance of turbine blades determines the efficiency of aero-engines and gas turbines, making them core components. Currently, the turbine inlet temperature of advanced aero-engines and gas turbines exceeds the melting point of the blades. To ensure stable long-term operation under extreme high-temperature and high-pressure environments, internal cooling of the inlet blades is essential. Depending on the heat flux density and internal cavity structure of the leading edge, middle, and trailing edge regions, internal cooling methods mainly include leading-edge impingement cooling, middle rib channel cooling, and trailing-edge spoiler column cooling.

[0003] Leading-edge impingement cooling is mainly achieved by high-speed airflow impacting the wall surface. Impingement cooling can disrupt the boundary layer near the wall surface, resulting in high heat transfer intensity. However, it also has drawbacks such as the impinging airflow being easily pushed by lateral airflow, small cooling heat transfer area, and uneven cooling. Central rib channel cooling is mainly achieved by separating and re-attaching the boundary layer as the airflow flows past the near-wall ribs, thinning the boundary layer and increasing mainstream disturbance. Central rib channel cooling can increase the heat transfer area, but at the corners where the ribs connect to the wall surface, cooling dead zones are very likely to occur. In addition, the airflow disturbance effect is poor in the middle region of the inner cavity far from the wall surface, reducing the cooling effect. Trailing-edge turbulence column cooling mainly uses columns connecting the two side walls to enhance airflow circulation and strengthen heat transfer, resulting in high heat transfer efficiency. However, the turbulence columns significantly increase the flow resistance of the airflow and increase the power consumption of the compressor.

[0004] To address the various problems associated with leading-edge impact cooling, central rib channel cooling, and trailing-edge turbulence column cooling, currently published improvement methods include: using concave impact cooling or combined impact-swirl cooling to improve impact cooling efficiency; using intermittent ribs, V-shaped ribs, W-shaped ribs, S-shaped ribs, cross-shaped ribs, arranged column ribs, grid structures, or lattice structures to improve rib channel cooling efficiency; and using teardrop-shaped columns, dumbbell-shaped columns, or alternating staggered columns to improve turbulence column cooling efficiency. While these methods can improve enhanced heat transfer cooling efficiency to some extent, they often increase airflow resistance, making it difficult to effectively balance high enhanced heat transfer capacity with low flow resistance. Summary of the Invention

[0005] To address at least one of the aforementioned technical problems, this invention proposes a ribbed lattice structure cooling blade and its preparation method.

[0006] The first aspect of the present invention provides a ribbed lattice structure cooling blade, comprising: a cavity wall and a leading edge lattice structure, a middle lattice structure and a trailing edge lattice structure disposed on the inner side of the cavity wall;

[0007] The leading edge lattice structure, the middle lattice structure, and the trailing edge lattice structure are arranged side by side, and the middle lattice structure is disposed between the leading edge lattice structure and the trailing edge lattice structure.

[0008] The leading edge lattice structure includes multiple lamellar ribs parallel to the airflow direction;

[0009] The central dot matrix structure includes multiple elliptical flat ribs perpendicular to the airflow direction.

[0010] The trailing edge lattice structure includes multiple porous circular pillars;

[0011] The cavity wall, leading edge lattice structure, middle lattice structure and trailing edge lattice structure are integrally formed.

[0012] In a preferred embodiment of the present invention, the leading edge lattice structure is a BCC structure, the unit cell side length of the leading edge lattice structure is 5-10 mm, the width of the lamellar ribs is 1-3 mm, and the thickness is 0.2-0.5 mm.

[0013] In a preferred embodiment of the present invention, the central lattice structure is an FCC structure, the unit cell side length of the central lattice structure is 4-8mm, the major semi-axis of the elliptical flat rib is 2-4mm, the minor semi-axis is 0.5-1mm, and the thickness is 1-2mm.

[0014] In a preferred embodiment of the present invention, the trailing edge lattice structure is a BCC-Z structure, the unit cell side length of the trailing edge lattice structure is 2-5 mm, the diameter of the porous cylindrical column is 0.5-1 mm, the diameter of the pores is 50-100 μm, and the porosity is 40-60%.

[0015] In a preferred embodiment of the present invention, the cooling blades have a gradient decreasing from bottom to top dimensions.

[0016] In a preferred embodiment of the present invention, the materials of the leading edge lattice structure, the middle lattice structure and the trailing edge lattice structure are either high-temperature alloys or titanium alloys, and the cavity wall is made of a high-temperature alloy.

[0017] In a preferred embodiment of the present invention, the surface roughness of the leading edge lattice structure, the middle lattice structure and the trailing edge lattice structure is 10-50 μm.

[0018] A second aspect of the present invention provides a method for preparing a ribbed lattice structure cooling blade, applicable to ribbed lattice structure cooling blades, comprising the following steps:

[0019] S1. Construct a three-dimensional model of the blade including the leading edge lattice structure, the middle lattice structure, and the trailing edge lattice structure. Divide the three-dimensional model into a main structure model and a trailing edge lattice structure model. Layer the main structure model and the trailing edge lattice structure model with a layer thickness of 20-40μm. For each layer of the main structure model and the trailing edge lattice structure model, perform path planning with scanning intervals of 70-90μm and 10-20μm, respectively, to obtain the printing path of the main structure and the printing path of the trailing edge lattice structure.

[0020] S2, the main structure of the cooling blade and a layer of porous trailing edge lattice structure are formed on the powder bed fusion additive manufacturing equipment according to the main body printing path;

[0021] S3, after the main structure and the trailing edge lattice structure are formed, the substrate is moved down by one layer thickness.

[0022] S4. Repeat steps S2 and S3 until a complete blade with the leading edge lattice structure, the middle lattice structure, the trailing edge lattice structure, and the cavity wall is formed.

[0023] In a preferred embodiment of the present invention, the laser power for forming the main structure in step S2 is 200-500W, and the scanning speed is 700-1000mm / s.

[0024] In a preferred embodiment of the present invention, the laser power for forming the porous trailing edge lattice structure in step S2 is 100W-300W, and the scanning speed is 5000-8000mm / s.

[0025] The technical solution of the present invention has the following advantages compared with the prior art:

[0026] (1) The rib-column lattice structure cooling blade of this application, based on the significant increase of heat transfer area through the lattice structure, designs the lattice rods into different rib and column shapes according to the airflow pattern of different regions, thereby reducing airflow resistance.

[0027] (2) The lattice structure in the ribbed lattice structure cooling blade can improve cooling efficiency and reduce airflow resistance, while also buffering vibration and thermal shock during blade service, thus improving blade service life.

[0028] (3) The method of preparing the rib lattice structure cooling blade adopts additive manufacturing technology. The dense structure and porous structure of the rib lattice structure cooling blade are integrated by the strategy of regional scanning, which significantly shortens the process flow. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, some of the drawings in the following description are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the cooling blade structure of the rib lattice structure according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the leading edge lattice structure, the middle lattice structure, and the trailing edge lattice structure according to an embodiment of the present invention.

[0032] In the figure: 1. Leading edge lattice structure, 2. Middle lattice structure, 3. Trailing edge lattice structure, 4. Cavity wall. DETAILED DESCRIPTION

[0033] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0034] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0035] Example 1

[0036] Example 1: See Figures 1-2 As shown, this invention proposes a ribbed lattice structure cooling blade, including a leading edge lattice structure 1, a middle lattice structure 2, a trailing edge lattice structure 3, and a cavity wall 4. The leading edge lattice structure 1 is a BCC structure, composed of lamellar ribs parallel to the airflow direction; the middle lattice structure 2 is an FCC structure, composed of elliptical flat ribs perpendicular to the airflow direction; the trailing edge lattice structure 3 is a BCC-Z structure, composed of porous circular pillars; the cavity wall 4 is connected to the leading edge lattice structure 1, the middle lattice structure 2, and the trailing edge lattice structure 3.

[0037] Specifically, BCC and FCC structures refer to body-centered cubic and face-centered cubic structures, respectively. The BCC-Z structure refers to adding vertical connecting rods to a body-centered cubic structure. The side length of a unit cell is the side length of a crystal lattice, which can be understood as the spacing between two crystal lattices when the lattice is arranged.

[0038] Furthermore, the unit cell side length of the leading edge lattice structure 1 is 5-10 mm, the width of the lamellar ribs is 1-3 mm, and the thickness is 0.2-0.5 mm.

[0039] Optionally, the unit cell side length of the leading edge lattice structure 1 is 5mm, 6mm, 7mm, 8mm, 9mm, or 10mm, and the width of the lamellar ribs is 1mm, 2mm, or 3mm; the thickness is 0.2mm, 0.3mm, 0.4mm, or 0.5mm.

[0040] Furthermore, the unit cell of the central lattice structure 2 has a side length of 4-8 mm, the long semi-axis of the elliptical flat rib has a length of 2-4 mm, the short semi-axis has a length of 0.5-1 mm, and the thickness has a length of 1-2 mm.

[0041] Optionally, the unit cell side length of the central lattice structure 2 is 4mm, 5mm, 6mm, 7mm, or 8mm; the major semi-axis of the elliptical flat rib is 2mm, 3mm, or 4mm; the minor semi-axis is 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm; the thickness is 1mm, 1.5mm, or 2mm.

[0042] Furthermore, the unit cell side length of the trailing edge lattice structure 3 is 2-5 mm, the diameter of the porous cylindrical column is 0.5-1 mm, the diameter of the pores is 50-100 μm, and the porosity is 40-60%.

[0043] Optionally, the unit cell side length of the trailing edge lattice structure 3 is 2 mm, 3 mm, 4 mm, or 5 mm; the diameter of the porous cylindrical column is 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm; the diameter of the pores is 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, or 100 μm; and the porosity is 40%, 45%, 50%, 55%, or 60%.

[0044] Furthermore, the size of the unit cells of the leading edge lattice structure 1, the middle lattice structure 2, and the trailing edge lattice structure 3 decreases in a gradient from the bottom to the top of the blade.

[0045] Furthermore, the materials of the leading edge lattice structure 1, the middle lattice structure 2, and the trailing edge lattice structure 3 are either high-temperature alloys or titanium alloys, and the cavity wall 4 is made of a high-temperature alloy.

[0046] Furthermore, the surface roughness of the leading edge lattice structure 1, the middle lattice structure 2, and the trailing edge lattice structure 3 is 10-50 μm.

[0047] Optionally, the surface roughness is 10 μm, 20 μm, 30 μm, 40 μm, or 50 μm.

[0048] Example 2: The second aspect of the present invention provides a method for preparing a ribbed lattice structure cooling blade, including constructing a three-dimensional model of a CMSX-4 blade including a leading edge lattice structure 1, a middle lattice structure 2 and a trailing edge lattice structure 3, and dividing the three-dimensional model into a main structure model and a trailing edge lattice structure 3 model. The main structure model and the trailing edge lattice structure 3 model are layered with a thickness of 30 μm. For each layer of the main structure model and the trailing edge lattice structure 3 model, path planning is performed with scanning intervals of 80 μm and 10 μm, respectively, to obtain the printing paths for the main structure and the trailing edge lattice structure 3. On a powder bed fusion additive manufacturing equipment, following the main printing path, one layer of the main structure is formed under parameters of 300W laser power and 800mm / s scanning speed. A layer of porous trailing edge lattice structure 3 is formed under parameters of 200W laser power and 5000mm / s scanning speed. After one layer of the main structure and the trailing edge lattice structure 3 are formed, the substrate is lowered by 30 μm. The above process of forming one layer of the main structure and one layer of porous trailing edge lattice structure 3, and lowering the substrate, is repeated until a complete CMSX-4 blade with a leading edge lattice structure 1, a middle lattice structure 2, a trailing edge lattice structure 3, and a cavity wall surface 4 is formed.

[0049] Example 3:

[0050] A three-dimensional model of the M247 blade, including leading edge lattice structure 1, middle lattice structure 2 and trailing edge lattice structure 3, was constructed. The three-dimensional model was divided into a main structure model and a trailing edge lattice structure 3 model. The main structure model and the trailing edge lattice structure 3 model are layered with a thickness of 30 μm. For each layer of the main structure model and the trailing edge lattice structure 3 model, path planning is performed with scanning intervals of 80 μm and 15 μm, respectively, to obtain the printing paths for the main structure and the trailing edge lattice structure 3. On a powder bed fusion additive manufacturing equipment, following the main printing path, one layer of the main structure is formed under parameters of 350W laser power and 800mm / s scanning speed. A layer of porous trailing edge lattice structure 3 is formed under parameters of 200W laser power and 6000mm / s scanning speed. After one layer of the main structure and the trailing edge lattice structure 3 are formed, the substrate is lowered by 30 μm. The above process of forming one layer of the main structure and one layer of porous trailing edge lattice structure 3, and lowering the substrate, is repeated until a complete M247 blade with a leading edge lattice structure 1, a middle lattice structure 2, a trailing edge lattice structure 3, and a cavity wall surface 4 is formed.

[0051] Example 4:

[0052] A three-dimensional model of the DD32 blade, including leading edge lattice structure 1, middle lattice structure 2 and trailing edge lattice structure 3, was constructed. The three-dimensional model was divided into a main structure model and a trailing edge lattice structure 3 model. The main structure model and the trailing edge lattice structure 3 model are layered with a thickness of 20 μm. For each layer of the main structure model and the trailing edge lattice structure 3 model, path planning is performed with scanning intervals of 70 μm and 10 μm, respectively, to obtain the printing paths for the main structure and the trailing edge lattice structure 3. On a powder bed fusion additive manufacturing equipment, following the main printing path, one layer of the main structure is formed under parameters of 200W laser power and 900 mm / s scanning speed. A layer of porous trailing edge lattice structure 3 is formed under parameters of 150W laser power and 5500 mm / s scanning speed. After one layer of the main structure and the trailing edge lattice structure 3 are formed, the substrate is lowered by 20 μm. The above process of forming one layer of the main structure and one layer of porous trailing edge lattice structure 3, and lowering the substrate, is repeated until a complete DD32 blade with a leading edge lattice structure 1, a middle lattice structure 2, a trailing edge lattice structure 3, and a cavity wall surface 4 is formed.

[0053] In summary, the rib-column lattice structure cooling blades of this application, while significantly increasing the heat transfer area through the lattice structure, also reduce airflow resistance by designing the lattice rods into different rib and column shapes according to the airflow patterns in different regions.

[0054] The lattice structure in the ribbed lattice structure cooling blades not only improves cooling efficiency and reduces airflow resistance, but also buffers vibration and thermal shock during blade service, thereby extending the blade's service life.

[0055] The method for fabricating ribbed lattice structure cooling blades employs additive manufacturing technology. By using a regional scanning strategy, the dense and porous structures of the ribbed lattice structure cooling blades are integrally formed, significantly shortening the process flow.

[0056] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to the above embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0058] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cooling blade with a rib lattice structure, comprising: The cavity wall and the leading edge lattice structure, the middle lattice structure and the trailing edge lattice structure arranged on the inner side of the cavity wall; characterized in that, The leading edge lattice structure, the middle lattice structure and the trailing edge lattice structure are arranged in parallel, and the middle lattice structure is arranged between the leading edge lattice structure and the trailing edge lattice structure; The leading edge lattice structure includes a plurality of lamellar ribs parallel to the airflow direction; The middle lattice structure includes a plurality of elliptical flat ribs perpendicular to the airflow direction; The trailing edge lattice structure includes a plurality of porous circular columns; The cavity wall, the leading edge lattice structure, the middle lattice structure and the trailing edge lattice structure are integrally formed.

2. The rib lattice structure cooling blade according to claim 1, characterized in that: The leading edge lattice structure is a BCC structure, the unit cell side length of the leading edge lattice structure is 5-10 mm, the width of the lamellar rib is 1-3 mm, and the thickness is 0.2-0.5 mm.

3. The cooling blade with a rib lattice structure according to claim 1, characterized in that: The central lattice structure is an FCC structure, the unit cell side length of the central lattice structure is 4-8 mm, the major semi-axis of the elliptical flat rib is 2-4 mm, the minor semi-axis is 0.5-1 mm, and the thickness is 1-2 mm.

4. The cooling blade with a rib lattice structure according to claim 1, characterized in that: The trailing edge lattice structure is a BCC-Z structure, the unit cell side length of the trailing edge lattice structure is 2-5 mm, the diameter of the porous circular column is 0.5-1 mm, the diameter of the hole is 50-100 μm, and the porosity is 40-60%.

5. The cooling blade with a rib lattice structure according to claim 4, characterized in that: The size of the cooling blade decreases gradually from the bottom to the top.

6. The cooling blade with a rib lattice structure according to claim 1, characterized in that: The material of the leading edge lattice structure, the middle lattice structure and the trailing edge lattice structure is one of a high-temperature alloy or a titanium alloy, and the cavity wall is a high-temperature alloy.

7. The cooling blade with a rib lattice structure according to claim 1, characterized in that: The surface roughness of the leading edge lattice structure, the middle lattice structure and the trailing edge lattice structure is 10-50 μm.

8. A method for preparing a cooling blade with a rib column lattice structure, applied to a cooling blade with a rib column lattice structure as claimed in any one of claims 1 to 7, characterized in that: The steps include: S1, constructing a three-dimensional model of a blade including the leading edge lattice structure, the middle lattice structure and the trailing edge lattice structure, dividing the three-dimensional model into a main structure model and a trailing edge lattice structure model, layering the main structure model and the trailing edge lattice structure model according to a layer thickness of 20-40 μm, performing path planning for each layer of the main structure model and the trailing edge lattice structure model according to scanning intervals of 70-90 μm and 10-20 μm, respectively, to obtain a main structure printing path and a trailing edge lattice structure printing path; S2, completing the formation of the main structure of the cooling blade and a layer of porous trailing edge lattice structure according to the main printing path on a powder bed fusion additive manufacturing device; S3, after a layer of the main structure and the trailing edge lattice structure is formed, the substrate is moved downward by a layer thickness. S4, repeating the above steps S2 and S3 until the complete blade with the leading edge lattice structure, the middle lattice structure, the trailing edge lattice structure and the cavity wall is formed.

9. The method for preparing a cooling blade with a rib lattice structure according to claim 8, characterized in that: In step S2, the laser power for forming the main structure is 200-500W, and the scanning speed is 700-1000mm / s.

10. The method for preparing a cooling blade with a rib lattice structure according to claim 8, characterized in that: In step S2, the laser power for forming the porous trailing edge lattice structure is 100W-300W, and the scanning speed is 5000-8000mm / s.

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