A water-droplet-shaped Kagome truss filling structure for a combustor transition section

Abstract

A teardrop-shaped Kagome truss filling structure facing the transition section of the combustion chamber includes an inlet section shell, which is cooperatively connected with an impact orifice plate; the impact orifice plate is provided with an array of impact holes; the impact orifice plate, the outer wall of the impact section, and the bottom plate are cooperatively connected to form a jet space, and the bottom surface of the bottom plate is a heating surface; a teardrop-shaped Kagome lattice truss structure is inserted into the jet space; the impact orifice plate, the outer wall of the impact section, the bottom plate and the outlet section shell are cooperatively connected; the internal cavity of the outlet section shell is an air film cooling cavity, and the bottom surface is provided with an array of air film holes; the teardrop-shaped Kagome lattice truss structure is formed by teardrop-shaped Kagome truss units arranged in an array; each teardrop-shaped Kagome truss unit is connected by three rods, the angle between each two rods is fixed at 120°, and the inclination angle of the rod to the ground is fixed at 45°; the cross-section of each rod is the same teardrop shape; the present invention not only embodies the excellent mechanical properties and strong heat exchange performance of the Kagome truss structure, but also overcomes the problem of excessive flow resistance, and is easy to prepare and detachable.

Description

Technical Field

[0001] The invention belongs to the technical field of gas turbine combustion chambers, and in particular relates to a teardrop-shaped Kagome truss filling structure facing a transition section of a combustion chamber. Background Art

[0002] Gas turbines are important industrial equipment, widely used in many fields, including machinery, energy, aerospace, and more. Advanced high-power, heavy-duty gas turbines are gradually developing toward high temperature rise and low emissions. This means that for the same gas volume, the proportion of air involved in combustion must be significantly increased, while the amount of air involved in cooling must be significantly reduced. This poses a more severe challenge to cooling the combustion chamber flame tube wall. Impingement jet cooling is the cooling method with the highest cooling capacity under single-phase cooling media and is widely used in the transition section of the combustion chamber, primarily in the form of array impingement jet cooling. With advances in 3D printing technology and new materials, the design and development of the transition section of the combustion chamber has undergone significant changes, offering greater design freedom.

[0003] With the increase in thermal loads on equipment such as gas turbines, engine blades, and chips, a number of new cooling structures have emerged. The Kagome truss structure is a popular structure with high porosity, excellent mechanical properties, and good heat transfer performance. However, the common circular Kagome truss structure has a large flow resistance and is prone to blockage in high-temperature and high-pressure environments such as the transition section of the combustion chamber, which poses a risk. Currently, there are few optimized designs for the Kagome truss structure, but the drag reduction design of other spoilers can be used to optimize the truss. Compared with circular cross-section spoilers, teardrop-shaped cross-section spoilers have better flow and heat transfer characteristics, but no relevant literature has been published yet. Summary of the Invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a teardrop-shaped Kagome truss filling structure facing the transition section of the combustion chamber, which can not only reflect the excellent mechanical properties and strong heat exchange performance of the Kagome truss structure, but also overcome the problem of excessive flow resistance. It is easy to prepare and can be disassembled. At the same time, the number and structural parameters of the teardrop-shaped Kagome truss structure can be changed according to actual equipment requirements, thereby improving the adaptability of the cooling structure.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A teardrop-shaped Kagome truss filling structure facing the transition section of the combustion chamber includes an inlet section shell 1, which is cooperatively connected to an impact orifice plate 2; the impact orifice plate 2 is provided with an array of impact holes 3; the impact orifice plate 2, the impact section outer wall 4, and the bottom plate 5 are cooperatively connected to form a jet space 6, and the bottom surface of the bottom plate 5 is a heating surface; a teardrop-shaped Kagome lattice truss structure 7 is inserted into the jet space 6; the impact orifice plate 2, the impact section outer wall 4, and the bottom plate 5 are cooperatively connected to an outlet section shell 8; the internal cavity of the outlet section shell 8 is an air film cooling cavity 9, and the bottom surface is provided with an array of air film holes 10.

[0007] The teardrop-shaped Kagome lattice truss structure 7 is formed by teardrop-shaped Kagome truss units 701 arranged in a 5×5 array; each teardrop-shaped Kagome truss unit 701 is connected by three rods, the angle between every two rods is fixed at 120°, and the inclination angle between the rods and the ground is fixed at 45°; the cross-section of each rod is the same teardrop shape, its equivalent diameter d is 1mm~3mm, and the tail angle θ is 45~90°.

[0008] The teardrop-shaped Kagome lattice truss structure 7 is directly manufactured by 3D printing.

[0009] The array of impact holes 3 is composed of 5×6 impact holes, and the cross-sectional diameter of each impact hole is 10 mm.

[0010] The array air film holes 10 are arranged in a 6×9 array.

[0011] The heating surface of the bottom plate 5 provides different heat sources according to different working conditions.

[0012] The inlet section shell 1, impact orifice plate 2, impact section outer wall 4, bottom plate 5 and outlet section shell 8 are in a coordinated relationship, have excellent thermal conductivity, and are all 5 mm thick.

[0013] The impact orifice plate 2, the bottom plate 5 and the teardrop-shaped Kagome lattice truss structure 7 are in a coordinated relationship.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects:

[0015] Under the actual working conditions of high temperature and high pressure in the transition section of the combustion chamber, the overall cooling effect of the structure of the present invention is good, there is no local high temperature or local blockage, and there is no stress concentration, etc., which shows that the mechanical properties of the structure are excellent and firm, the structural strength is high, and the overall stability is high.

[0016] Under the actual operating conditions of high temperature and high pressure in the transition section of the combustion chamber, the comprehensive heat transfer factor of the teardrop-shaped Kagome lattice truss filling structure is 4.28% to 7.72% higher than that of the circular Kagome lattice truss filling structure, and the heat transfer performance of the teardrop-shaped Kagome truss is excellent; the pressure loss coefficient of the teardrop-shaped Kagome lattice truss filling structure is 0.93% to 3% lower than that of the circular Kagome lattice truss filling structure, indicating that the teardrop-shaped cross-section effectively reduces the flow resistance.

[0017] Under the actual working conditions of high temperature and high pressure in the transition section of the combustion chamber, the comprehensive heat transfer factor increases linearly with the equivalent diameter d of the teardrop-shaped Kagome truss unit 701.

[0018] Under the actual operating conditions of high temperature and high pressure in the transition section of the combustion chamber, the comprehensive heat transfer factor shows a linear decreasing relationship with the tail angle θ of the teardrop-shaped Kagome truss unit 701; the pressure loss coefficient is minimum when the tail angle θ = 60°, which is suitable for use in structures that require a significant reduction in flow resistance.

[0019] The inlet section shell 1, the impact orifice plate 2, the impact section outer wall 4, the bottom plate 5, the teardrop-shaped Kagome lattice truss structure 7 and the outlet section shell 8 have excellent thermal conductivity and enhance the heat exchange effect.

[0020] There is a matching relationship between the inlet section shell 1, the impact orifice plate 2, the impact section outer wall 4, the bottom plate 5 and the outlet section shell 8, which facilitates the disassembly and replacement for subsequent research, and can also adjust its structural shape according to the size of the equipment used.

[0021] The impact orifice plate 2, the bottom plate 5 and the teardrop-shaped Kagome lattice truss structure 7 are in a coordinated relationship, which not only facilitates assembly but also allows the number and structural parameters of the teardrop-shaped Kagome truss units 701 in the jet space 6 to be adjusted according to the size of the equipment used.

[0022] The teardrop-shaped Kagome lattice truss structure 7 is directly formed by 3D printing, which has a simple process flow, is lightweight, has low cost for small-scale production, and can be assembled in a modular manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0024] Figure 2 Schematic diagram (front view / top view) of the teardrop-shaped Kagome truss unit 701 of the present invention.

[0025] Figure 3 This is a flow and heat transfer comparison line diagram of the teardrop-shaped Kagome lattice truss filling structure and the circular Kagome lattice truss filling structure of the present invention.

[0026] Figure 4This is a line diagram showing the effect of the equivalent diameter d of the teardrop-shaped Kagome truss unit 701 on flow and heat transfer.

[0027] Figure 5 This is a line diagram showing the influence of the tail angle θ of the teardrop-shaped Kagome truss unit 701 on flow heat transfer in the present invention. DETAILED DESCRIPTION

[0028] The present invention will be described below with reference to the embodiments and accompanying drawings.

[0029] Reference Figure 1 A teardrop-shaped Kagome truss filling structure facing the transition section of the combustion chamber includes an inlet section shell 1, an impact orifice plate 2, an array impact hole 3, an impact section outer wall 4, a bottom plate 5, a jet space 6, a teardrop-shaped Kagome lattice truss structure 7, an outlet section shell 8, an air film cooling cavity 9, and an array air film hole 10; the inlet section shell 1 is cooperatively connected with the impact orifice plate 2; the impact orifice plate 2 is provided with an array impact hole 3; the impact orifice plate 2, the impact section outer wall 4, and the bottom plate 5 are cooperatively connected to form a jet space 6, and the bottom surface of the bottom plate 5 is a heating surface; a teardrop-shaped Kagome lattice truss structure 7 is inserted into the jet space 6; the impact orifice plate 2, the impact section outer wall 4, and the bottom plate 5 are cooperatively connected with the outlet section shell 8; the internal cavity of the outlet section shell 8 is an air film cooling cavity 9, and the bottom surface is provided with an array air film hole 10.

[0030] Reference Figure 2 The teardrop-shaped Kagome lattice truss structure 7 is formed by teardrop-shaped Kagome truss units 701 arranged in a 5×5 array. This structure has excellent thermal conductivity, provides support for the overall structure, and increases the contact area with the cooling fluid, improving cooling efficiency. Each teardrop-shaped Kagome truss unit 701 is connected by three rods, with the angle between each two rods fixed at 120°. This provides a large contact area with the high-speed cooling fluid and significantly disrupts the boundary layer. The rods are tilted at a fixed 45° angle to the ground, ensuring the stability of the teardrop-shaped Kagome truss unit 701. Each rod has a uniform teardrop-shaped cross-section, with an equivalent diameter d of 1mm to 3mm, ensuring machining accuracy while avoiding excessive internal fill rate. The tail angle θ ranges from 45° to 90°, ensuring molding accuracy during 3D printing and effectively demonstrating the trailing edge advantage. The teardrop-shaped Kagome lattice truss structure 7 is directly manufactured by 3D printing.

[0031] The array impact holes 3 is composed of 5×6 impact holes, and each impact hole has a cross-sectional diameter of 10 mm, which ensures that after the cold fluid passes through the impact holes, a jet impact effect is uniformly generated in the jet space 6 without clogging.

[0032] The array film holes 10 are arranged in a 6×9 array, which can evenly discharge the remaining low-temperature fluid in the film cooling cavity 9 and provide film cooling for the inner wall of the combustion chamber.

[0033] The inlet section shell 1, impact orifice plate 2, impact section outer wall 4, bottom plate 5 and outlet section shell 8 are in a coordinated relationship and have excellent thermal conductivity, which is convenient for disassembly and replacement in subsequent research. The structural shape can also be adjusted according to the size of the equipment used. The thickness is 5mm, which can better fit the actual situation of the transition section of the combustion chamber.

[0034] The impact orifice plate 2, the bottom plate 5 and the teardrop-shaped Kagome lattice truss structure 7 are in a coordinated relationship, which not only facilitates assembly, but also allows the number and structural parameters of the teardrop-shaped Kagome truss units 701 in the jet space 6 to be adjusted according to the size of the equipment used.

[0035] The working principle of the present invention is:

[0036] A heat source with a certain heat flux density is located on the bottom surface of the bottom plate 5 to maintain a constant high temperature. A cold fluid with a certain speed enters from the inlet of the inlet section shell 1, first passes through the array impact holes 3 on the impact orifice plate 2, and the flow velocity increases to achieve the effect of jet impact; then, in the jet space 6, it is disturbed by the water droplet-shaped Kagome lattice truss structure 7, and the original flow state of the fluid changes, generating more turbulence, and the development of the boundary layer is further destroyed; the flow characteristics of the fluid in the jet space 6 become more complex, and the heat exchange effect between the fluid and the impact orifice plate 2, the outer wall 4 of the impact section, the bottom plate 5 and the water droplet-shaped Kagome lattice truss structure 7 is significantly improved; then the fluid enters the outlet The segment shell 8 further cools the heat flow in the film cooling cavity 9 through the array film holes 10 on the bottom plate of the outlet segment shell to protect the combustion chamber; the gas that does not enter the array film holes 10 is discharged toward the outlet through the film cooling cavity 9; the teardrop-shaped Kagome lattice truss structure 7 serves as a turbulent flow structure in the jet space 6, which can not only reflect the excellent mechanical properties and strong heat transfer performance of the Kagome truss structure, but also overcome the problem of excessive flow resistance of the circular Kagome truss structure; the inlet segment shell 1, the impact orifice plate 2, the impact segment outer wall 4, the bottom plate 5, the teardrop-shaped Kagome lattice truss structure 7 and the outlet segment shell 8 have excellent thermal conductivity, thereby enhancing the heat transfer effect.

[0037] The bottom plate 5 heating surface can provide different heat sources according to different working conditions. The bottom plate 5 heating surface provides 6000W / m 2The heat flux density is adjusted, and the Reynolds number of the inlet airflow is controlled to be 5000-50000 to simulate the actual working conditions of high temperature and high pressure in the transition section of the combustion chamber. Under this working condition, the overall cooling effect of the structure is good, there is no local high temperature or local blockage, and there is no stress concentration. This shows that the mechanical properties of the structure are excellent and firm, the structural strength is high, and the overall stability is high.

[0038] Reference Figure 3 Under the actual working conditions of high temperature and high pressure in the transition section of the combustion chamber, the flow and heat transfer performance of the circular Kagome lattice truss filling structure with a cross-sectional diameter of 3mm is compared with that of the teardrop-shaped Kagome lattice truss filling structure with an equivalent diameter of d=3mm and a tail angle of θ=45°: the comprehensive heat transfer factor of the teardrop-shaped Kagome lattice truss filling structure is 4.28%~7.72% higher than that of the circular Kagome lattice truss filling structure, indicating that the heat transfer performance of the teardrop-shaped Kagome truss is excellent, even exceeding that of the circular Kagome truss under the same parameters; the pressure loss coefficient of the teardrop-shaped Kagome lattice truss filling structure is 0.93%~3% lower than that of the circular Kagome lattice truss filling structure, indicating that the teardrop-shaped cross-section effectively reduces the flow resistance.

[0039] Reference Figure 4 , under the actual working conditions of high temperature and high pressure in the transition section of the combustion chamber, the flow and heat transfer performance of the drop-shaped Kagome lattice truss filling structure with a tail angle of θ = 45° and equivalent diameters of d = 1, 2, and 3 mm is compared: the comprehensive heat transfer factor is the smallest when the equivalent diameter d = 1 mm, the second largest when d = 2 mm, and the largest when d = 3 mm, indicating that the comprehensive heat transfer factor is linearly increasing with the equivalent diameter d; the pressure loss coefficient is the smallest when the equivalent diameter d = 1 mm, the second largest when d = 3 mm, and the largest when d = 2 mm, indicating that the flow resistance is large when the equivalent diameter d = 2 mm, and it is not suitable as the first choice.

[0040] Reference Figure 5 Under the actual working conditions of high temperature and high pressure in the transition section of the combustion chamber, the flow and heat transfer performance of the teardrop-shaped Kagome lattice truss filling structure with an equivalent diameter of d = 3 mm and tail angles θ = 45°, 60°, and 90° are compared: the comprehensive heat transfer factor is the smallest when the tail angle θ = 90°, followed by θ = 60°, and the largest when θ = 45°, indicating that the comprehensive heat transfer factor has a linear decreasing relationship with the tail angle θ; the pressure loss coefficient is the smallest when the tail angle θ = 60°, and the difference between θ = 45° and θ = 90° is not much, indicating that the flow resistance is small when the tail angle θ = 60°, which is suitable for use in structures that require a large reduction in flow resistance.

Claims

1. A teardrop-shaped Kagome truss filling structure facing a combustion chamber transition section, comprising an inlet section shell (1), characterized in that: The inlet section shell (1) is connected with the impact orifice plate (2); the impact orifice plate (2) is provided with an array of impact holes (3); the impact orifice plate (2), the impact section outer wall (4), and the bottom plate (5) are connected with each other to form a jet space (6), and the bottom surface of the bottom plate (5) is a heating surface; a water drop-shaped Kagome lattice truss structure (7) is built into the jet space (6); the impact orifice plate (2), the impact section outer wall (4), and the bottom plate (5) are connected with the outlet section shell (8); the internal cavity of the outlet section shell (8) is an air film cooling cavity (9), and the bottom surface is provided with an array of air film holes (10); The teardrop-shaped Kagome lattice truss structure (7) is formed by teardrop-shaped Kagome truss units (701) arranged in a 5×5 array; each teardrop-shaped Kagome truss unit (701) is connected by three rods, and the angle between each two rods is fixed at 120°. The cross section of each rod is the same teardrop shape, and its equivalent diameter is d 1mm~3mm, tail angle θ 45~90°; The teardrop-shaped Kagome lattice truss structure (7) is directly manufactured by 3D printing.

2. The teardrop-shaped Kagome truss filling structure facing the combustion chamber transition section according to claim 1, characterized in that: The array of impact holes (3) consists of 5×6 impact holes, and each impact hole has a cross-sectional diameter of 10 mm.

3. The teardrop-shaped Kagome truss filling structure facing the combustion chamber transition section according to claim 1, characterized in that: The array air film holes (10) are arranged in a 6×9 array.

4. The teardrop-shaped Kagome truss filling structure facing the combustion chamber transition section according to claim 1, characterized in that: The heating surface of the bottom plate (5) provides different heat sources according to different working conditions.

5. The teardrop-shaped Kagome truss filling structure facing the combustion chamber transition section according to claim 1, characterized in that: The inlet section shell (1), the impact orifice plate (2), the impact section outer wall (4), the bottom plate (5) and the outlet section shell (8) are in a coordinated relationship, have excellent thermal conductivity, and are all 5 mm thick.

6. The teardrop-shaped Kagome truss filling structure facing the combustion chamber transition section according to claim 1, characterized in that: The impact orifice plate (2), the bottom plate (5) and the teardrop-shaped Kagome lattice truss structure (7) are in a coordinated relationship.

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