Design method for cooling structure of moving blade airfoil with circular microtube array

Abstract

The present invention provides a design method for a cooling structure with a circular microtube array on the moving blade airfoil. By constructing the external shape and internal cooling structure of the turbine moving blade airfoil, the position to be strengthened and cooled on the turbine moving blade airfoil is determined. A whole three-dimensional model of the turbine moving blade with a cooling structure having a circular microtube array on the moving blade airfoil is constructed, and the reduced amount of cooling air for the turbine moving blade airfoil is preset; the cooling parameters of the turbine moving blade airfoil, the cooling structure, and the circular microtube array are adjusted; a whole three-dimensional model of the turbine moving blade with a circular microtube array cooling structure after the airfoil is thinned is constructed, and a full three-dimensional fluid-thermal coupling calculation of the turbine moving blade airfoil is carried out. If the temperature parameters of the turbine moving blade airfoil meet the predetermined temperature standard, the design is completed. The technical solution of the present invention can solve the problems that the temperature distribution of the gas turbine high-pressure turbine moving blade airfoil is uneven due to the limitation of the structural size space and the cooling air consumption, resulting in failures such as blade ablation and cracks, and avoid the blade failure caused by the blade over-temperature operation and inability to work.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas turbine design, and particularly relates to a design method for a cooling structure with a circular microtube array on the blade body of a moving blade. Background Art

[0002] With the continuous improvement of the performance indicators of gas turbines and the continuous expansion of their operating boundaries, the turbine inlet temperature has been increasing, posing higher requirements for the temperature resistance level of the turbine blade materials and the design of cooling structures under high-load conditions for long-term continuous operation.

[0003] During the operation of in-service engines and the development of new engines, there are areas on the turbine blades that are difficult to cool. In particular, positions such as the end walls and blade tips with relatively small dimensional spaces and relatively complex flows are extremely prone to forming cooling "blind spots" or even "dead zones". The metal temperatures at these positions are all close to the heat resistance limit of the blade alloy. Similar phenomena have also been reported by foreign researchers during the design and testing of gas turbines. The surface temperature distributions of turbine moving blades obtained by Siemens and other companies through transient liquid crystal measurements and numerical calculations show that obvious local high-temperature areas appear at the blade body, end walls, and blade tips. These difficult-to-cool local high-temperature areas are extremely prone to causing local ablation of the turbine blades, bringing great difficulties to the cooling design of the turbine blades. In addition, with the expansion of the engine operating environment and the improvement of performance requirements, the turbine inlet temperature continues to increase, further increasing the design difficulty of the turbine blade cooling structure.

[0004] Therefore, in the case where traditional large-scale cooling structures are difficult to meet the cooling requirements of "blind spots" and "dead zones", innovating and developing efficient cooling structures for turbine blades to further improve the cooling effect without increasing the cooling air consumption has important scientific significance and practical value for the development of advanced high-performance gas turbine engines. Summary of the Invention

[0005] An embodiment of the present invention provides a design method for a cooling structure with a circular microtube array on the blade body of a moving blade, which can solve the problems that the blade body of the high-pressure turbine moving blade of a gas turbine is restricted by the structural dimension space and the cooling air consumption, resulting in uneven temperature distribution on the blade body, causing faults such as blade ablation and cracks, and avoiding over-temperature operation of the blade, which may lead to blade failure and inability to work.

[0006] In an embodiment of the present invention, a design method for a cooling structure with a circular microtube array on the blade body of a moving blade is provided, including:

[0007] S101. According to the outer shape of the blade body of the turbine moving blade, determine the cooling structure of the blade body of the turbine moving blade without a microtube array cooling channel, perform a full three-dimensional fluid-thermal coupling calculation and analysis on the turbine moving blade, and determine the temperature field distribution and data information of the blade body of the moving blade as the comparison basis for subsequent analysis and the design of the cooling structure with a circular microtube array.

[0008] S102. Determine the position of the high-temperature area in the blade body of the turbine moving blade where the enhanced cooling structure is to be arranged;

[0009] S103. Given the cooling structure parameters of the turbine moving blade body with a circular microtube array according to the surface structure of the moving blade body and in combination with the dimensional parameters of the moving blade body including at least the blade body wall thickness, leading-edge film structure, and trailing-edge exhaust structure;

[0010] S104. Construct a three-dimensional model of the turbine moving blade with a circular microtube array cooling structure, and infer the reduction amount of the cooling air in the blade body of the turbine moving blade and the cooling air consumption of the blade body of the turbine moving blade with the circular microtube array cooling structure;

[0011] S105. Based on the overall three-dimensional model of the turbine moving blade with a circular microtube array cooling structure, divide the grids of the fluid domain and the solid domain required for the full three-dimensional calculation, and conduct a full three-dimensional fluid-thermal coupling calculation and analysis to obtain the temperature field distribution and temperature data of the blade body of the moving blade;

[0012] S106. Determine the amount of thinning of the outer shape of the blade body of the turbine moving blade based on the ratio of the cooling air consumption to the originally given cooling air consumption;

[0013] S107. Based on the reduction ratio of the internal cooling channel area of the blade body of the turbine moving blade and the thickness of the outer shape of the blade body, reconstruct the cooling structure of the blade body of the turbine moving blade, and use a three-dimensional modeling tool to establish a three-dimensional model of the blade body of the turbine moving blade and the cooling channel after adjusting the blade profile;

[0014] S108. According to the three-dimensional model of the blade body of the turbine moving blade after adjusting the blade profile and the reduction ratio of the internal cooling channel area of the blade body of the moving blade, adjust the positions of the micro circular tubes at the root section and the top section, the diameter of each circular microtube, the diameter of each circular microtube, the spacing between the circular microtubes, and the number of circular microtubes;

[0015] S109. Construct a three-dimensional model of the turbine moving blade with a circular microtube array cooling structure after thinning the blade body, conduct a full three-dimensional fluid-thermal coupling calculation and analysis of the blade body of the turbine moving blade to obtain the temperature field distribution and temperature data of the blade body of the moving blade; if the temperature parameters of the blade body of the turbine moving blade meet the predetermined temperature standard, the design process ends; otherwise, adjust the amount of thinning of the outer shape of the blade body of the turbine moving blade and the cooling structure parameters of the circular microtube array, and repeat S106 - S108 until the temperature parameters of the blade body of the turbine moving blade reach the predetermined standard.

[0016] Further, given the cooling structure parameters of the turbine moving blade body with a circular microtube array according to the surface structure of the moving blade body and in combination with the dimensional parameters of the moving blade body including at least the blade body wall thickness, leading-edge film structure, and trailing-edge exhaust structure, including:

[0017] Based on the specific positions on the blade body of the turbine rotor blade that require enhanced cooling, the cooling structure parameters of the circular microtube array on the blade body of the turbine rotor blade are given; among them, at the root section, the distance H from the position of each circular microtube along the midline direction of the blade body wall thickness to the leading edge point of the midline of the blade body wall thickness h,i , the diameter φ of each circular microtube h,i , the spacing L between circular microtubes h,i , the number N of circular microtubes; at the tip section, the distance H from the position of each circular microtube along the midline direction of the blade body thickness to the leading edge point of the midline of the blade body thickness t,i , the diameter φ of each circular microtube t,i , the spacing L between circular microtubes t,i and the number N of circular microtubes.

[0018] Furthermore, based on the ratio of the cooling air consumption to the originally given cooling air consumption, the amount of reduction in the outer shape of the blade body of the turbine rotor blade is determined, including:

[0019] The ratio of the cooling air consumption to the originally given cooling air consumption, that is, the reduction ratio of the internal cooling channel area of the blade body of the turbine rotor blade; on the basis of the original internal cooling channel of the blade body of the turbine rotor blade, a new internal cooling channel of the blade body of the turbine rotor blade is obtained by shrinking, keeping the wall thickness of the blade body unchanged, and offsetting the wall thickness of the blade body outward from the new internal cooling channel of the blade body of the turbine rotor blade, the thickness of the outer shape of the blade body after adjusting the internal cooling channel can be obtained, and the difference between the thickness of the outer shape of the blade body after adjusting the internal cooling channel and that before adjustment is the amount of reduction in the outer shape of the blade body.

[0020] Furthermore, based on the overall three-dimensional model of the turbine rotor blade with a circular microtube array cooling structure, the fluid domain and solid domain meshes required for full three-dimensional calculation are divided to obtain the temperature field distribution and temperature data of the blade body, including:

[0021] The temperature field distribution and temperature data of the blade body of the turbine rotor blade are compared and analyzed with the temperature field distribution and data information of the blade body of the turbine rotor blade. If the obtained temperature parameters of the blade body of the turbine rotor blade meet the predetermined temperature standard, then S106 is executed; otherwise, at least one or more of increasing the number of microtube rows or increasing the diameter of the microtubes are used to adjust the cooling structure parameters of the circular microtube array, and S104 - S105 are repeatedly executed until the temperature parameters of the blade body of the turbine rotor blade reach the predetermined temperature standard.

[0022] Furthermore, the predetermined temperature standard includes:

[0023] If the highest temperature of the blade body of the turbine rotor blade is higher than the temperature resistance level of the metal material used, the predetermined temperature standard is: the highest temperature of the blade body of the turbine rotor blade is lower than the temperature resistance level of the metal material used;

[0024] If the maximum temperature of the turbine moving blade airfoil is lower than the temperature resistance level of the metal material used, the predetermined temperature standard is: the maximum temperature of the turbine moving blade airfoil is reduced by no less than 20 °C.

[0025] Furthermore, for the cooling of the circular microtube array structure, the diameter of the circular tubes ranges from 0.1 mm to 1 mm. The microtube row structure can increase the heat transfer area of the cooling channels and increase the convective heat transfer coefficient. At the same time, in combination with the leading-edge film cooling of the turbine moving blade airfoil, full coverage of the cooling of the high-pressure turbine moving blade airfoil is achieved.

[0026] Furthermore, the method includes:

[0027] The cooling structure of the circular microtube array is arranged inside the metal wall of the airfoil to reduce the thickness of the airfoil profile of the moving blade.

[0028] Furthermore, the method includes:

[0029] The circular microtube array cooling structure covers all positions of the moving blade airfoil except the leading edge, achieving full coverage of the cooling of the high-pressure turbine moving blade airfoil and making the temperature distribution of the turbine moving blade airfoil uniform.

[0030] Furthermore, determining the positions of the high-temperature zones in the turbine moving blade airfoil where the enhanced cooling structure is to be arranged includes:

[0031] Based on the temperature field distribution and temperature data of the moving blade airfoil, judge the positions of the high-temperature zones of the turbine moving blade airfoil, which are the specific positions that need to be focused on for enhanced cooling of the turbine moving blade airfoil. Subsequently, the cooling structure of the circular microtube array will be arranged in these high-temperature zones.

[0032] Furthermore, the 3D modeling software for the computational domain uses UG NX software, the full 3D fluid-thermal coupling calculation and analysis software uses CFX and Fluent software, and the mesh generation uses ICEM CFD software.

[0033] The beneficial effects brought by the present invention are as follows:

[0034] As can be seen from the above solution, the embodiment of the present invention provides a design method for a cooling structure with a circular microtube array on the moving blade airfoil. By constructing the outer shape and internal cooling structure of the turbine moving blade airfoil, the positions that need to be strengthened for cooling on the turbine moving blade airfoil are determined. Given the cooling structure parameters of the circular microtube array on the turbine moving blade airfoil, a three-dimensional model of the entire turbine moving blade with a cooling structure of a circular microtube array on the airfoil is constructed, and the reduced amount of cooling air for the turbine moving blade airfoil is preset; a full three-dimensional fluid-thermal coupling calculation and analysis of the turbine moving blade airfoil is carried out to determine the thinning amount of the outer shape of the turbine moving blade airfoil, and the cooling parameters of the turbine moving blade airfoil, cooling structure, and circular microtube array are adjusted; a three-dimensional model of the turbine moving blade with a circular microtube array cooling structure after the airfoil is thinned is constructed, and a full three-dimensional fluid-thermal coupling calculation and analysis of the turbine moving blade airfoil is carried out to obtain the temperature field distribution information of the turbine moving blade airfoil. If the temperature parameters of the turbine moving blade airfoil meet the predetermined temperature standard, the design of the microtube array cooling structure with a circular bulge on the turbine moving blade airfoil is completed. The technical solution of the present invention can solve the problems that the temperature distribution of the high-pressure turbine moving blade of a gas turbine is uneven due to the limitations of the structural size space and the cooling air consumption, resulting in faults such as blade ablation and cracks, and avoid the over-temperature operation of the blade, which may cause the blade to fail and cannot work. Description of the Drawings

[0035] Figure 1 It shows a flowchart of a design method for a cooling structure with a circular microtube array on the moving blade airfoil according to an embodiment of the present invention. Detailed Embodiments

[0036] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] In order to solve the problems that the high-pressure turbine moving blade of a gas turbine is restricted by the structural size space and the cooling air consumption, resulting in uneven temperature distribution on the airfoil, and causing faults such as blade ablation and cracks, a circular microtube array turbine cooling structure design method suitable for the high-pressure turbine moving blade of a gas turbine, with excellent cooling effect and low cooling air consumption, etc., is provided to avoid the problem that the over-temperature operation of the blade causes the blade to fail and cannot work.

[0038] As Figure 1 shown, Figure 1 It shows a flowchart of a design method for a cooling structure with a circular microtube array on the moving blade airfoil according to an embodiment of the present invention.

[0039] In the figure, a design method for a cooling structure with a circular microtube array on the moving blade airfoil includes:

[0040] S101. According to the shape of the moving blade airfoil of the turbine, determine the cooling structure of the moving blade airfoil of the turbine without the microtube array cooling channel, conduct a full three-dimensional fluid-thermal coupling calculation and analysis on the moving blade of the turbine, determine the temperature field distribution and data information of the moving blade airfoil, and use it as the comparison basis for subsequent analysis and after adopting the circular microtube array cooling structure design.

[0041] In the embodiment of the present invention, construct the shape of the moving blade airfoil of the turbine. Based on the airfoil profile obtained from the aerodynamic design of the turbine, use a three-dimensional modeling tool to carry out the design of the structure of the moving blade airfoil, and construct the three-dimensional shape of the moving blade airfoil of the turbine. Design the cooling structure of the moving blade airfoil without the microtube array cooling channel. Based on the three-dimensional shape of the moving blade airfoil, carry out the design of the cooling structure of the moving blade airfoil (the circular microtube array cooling structure is not carried out on the moving blade airfoil temporarily), and obtain the three-dimensional model of the moving blade of the turbine with the cooling structure on the airfoil (without the circular microtube array cooling structure).

[0042] Conduct a full three-dimensional fluid-thermal coupling calculation and analysis on the moving blade of the turbine. According to the inlet and outlet boundary conditions of the moving blade of the turbine, import the three-dimensional model of the moving blade constructed in the second step into the mesh generation program, divide the full three-dimensional calculation mesh, and then use the full three-dimensional fluid-thermal coupling calculation and analysis program to carry out the full three-dimensional fluid-thermal coupling calculation and analysis on the moving blade of the turbine, obtain the temperature distribution and data of the moving blade airfoil, use it as the comparison basis for subsequent analysis and after adopting the circular microtube array cooling design, and obtain the temperature distribution data of the moving blade airfoil.

[0043] S102. Determine the positions of the high-temperature areas in the moving blade airfoil of the turbine where the enhanced cooling structure is to be arranged.

[0044] In the embodiment of the present invention, based on the temperature field distribution and temperature data of the moving blade airfoil, judge the positions of the high-temperature areas of the moving blade airfoil of the turbine, which are the specific positions that need to be strengthened in cooling for the moving blade airfoil of the turbine. Subsequently, circular microtube array cooling structures will be mainly arranged in these high-temperature areas.

[0045] S103. According to the surface structure of the moving blade airfoil, combined with the dimensional parameters of the moving blade airfoil including at least the airfoil wall thickness, leading-edge film cooling structure, and trailing-edge exhaust structure, specify the cooling structure parameters of the moving blade airfoil of the turbine with a circular microtube array.

[0046] In an embodiment of the present invention, based on determining the specific positions on the blade body of the turbine moving blade that require enhanced cooling, according to the structural characteristics of the slender blade body thickness of the turbine moving blade, combined with structural dimension parameters such as the blade body wall thickness, leading-edge film cooling, and trailing-edge exhaust of the turbine moving blade, the cooling structure parameters of the circular microtube array on the blade body of the moving blade are given: the number of circular microtubes; at the root section, the position of each circular microtube along the midline direction of the blade body wall thickness (the distance from the leading-edge point of the blade body wall thickness midline), the diameter of each circular microtube, and the spacing between circular microtubes; at the tip section, the position of each circular microtube along the midline direction of the blade body thickness (the distance from the leading-edge point of the blade body thickness midline), and the diameter of each circular microtube.

[0047] In an embodiment of the present invention, based on the specific positions on the blade body of the turbine moving blade that require enhanced cooling, the cooling structure parameters of the circular microtube array on the blade body of the turbine moving blade are given; among them, at the root section, the distance H from the position of each circular microtube along the midline direction of the blade body wall thickness to the leading-edge point of the blade body wall thickness midline h,i , the diameter φ of each circular microtube h,i , the spacing L between circular microtubes h,i , and the number N of circular microtubes; at the tip section, the distance H from the position of each circular microtube along the midline direction of the blade body thickness to the leading-edge point of the blade body thickness midline t,i , the diameter φ of each circular microtube t,i , the spacing L between circular microtubes t,i and the number N of circular microtubes.

[0048] S104. Construct a three-dimensional model of the turbine moving blade with a circular microtube array cooling structure, and infer the reduction in the cooling air volume of the blade body of the turbine moving blade and the cooling air consumption of the blade body of the turbine moving blade after adopting the circular microtube array cooling structure.

[0049] In an embodiment of the present invention, based on the three-dimensional model of the turbine moving blade with a cooling structure on the blade body (without a circular microtube array cooling structure), using the given cooling structure parameters of the circular microtube array on the blade body of the turbine moving blade, adopting a three-dimensional modeling tool, using the hybrid function, mixing the circular microtube arrays at the root section and the tip section, constructing a circular microtube row on the blade body of the turbine moving blade, and obtaining the overall three-dimensional model of the turbine moving blade with a circular microtube array cooling structure; according to the given cooling structure parameters of the circular microtube array on the blade body of the turbine moving blade, evaluating its heat transfer and cooling effect, and accordingly, preliminarily inferring the reduction in the cooling air volume of the blade body of the turbine moving blade and the cooling air consumption of the blade body of the turbine moving blade after adopting the circular microtube array cooling structure.

[0050] S105. Based on the overall three-dimensional model of the turbine moving blade with a circular microtube array cooling structure, divide the grids of the fluid domain and the solid domain required for the full three-dimensional calculation, and carry out the full three-dimensional fluid-thermal coupling calculation and analysis to obtain the temperature field distribution and temperature data of the blade body of the moving blade.

[0051] According to the given reduction in cooling air, combined with the remaining inlet and outlet boundary conditions of the turbine rotor blade, import the three-dimensional model of the rotor blade body constructed in Step Six into the mesh generation program to generate a full three-dimensional computational mesh. Then, use the full three-dimensional fluid-thermal coupling calculation and analysis program to conduct a full three-dimensional fluid-thermal coupling calculation and analysis of the turbine rotor blade body to obtain the temperature distribution and related temperature data of the rotor blade body.

[0052] Compare and analyze the temperature field distribution and temperature data of the turbine rotor blade body with the temperature field distribution and data information of the rotor blade body. If the obtained temperature parameters of the turbine rotor blade body meet the predetermined temperature standard, execute S106; otherwise, at least adjust the cooling structure parameters of the circular microtube array by increasing the number of microtube rows or increasing the diameter of the microtubes, and repeat S104 - S105 until the temperature parameters of the turbine rotor blade body reach the predetermined temperature standard.

[0053] Among them, the predetermined temperature standard includes:

[0054] If the highest temperature of the turbine rotor blade body is higher than the heat-resistant grade of the metal material used, the predetermined temperature standard is: the highest temperature of the turbine rotor blade body is lower than the heat-resistant grade of the metal material used;

[0055] If the highest temperature of the turbine rotor blade body is lower than the heat-resistant grade of the metal material used, the predetermined temperature standard is: the highest temperature of the turbine rotor blade body is reduced by no less than 20°C.

[0056] S106. Determine the amount of profile thinning of the turbine rotor blade body based on the ratio of the cooling air consumption to the original given cooling air consumption.

[0057] In the embodiment of the present invention, according to the determined ratio of the cooling air consumption to the original given cooling air consumption, this ratio is the reduction ratio of the internal cooling channel area of the turbine rotor blade body. Based on this ratio, on the basis of the original internal cooling channel of the turbine rotor blade body, a new internal cooling channel of the turbine rotor blade body is reduced, keeping the wall thickness of the rotor blade body unchanged. By offsetting the wall thickness of the rotor blade body outward from the new internal cooling channel of the turbine rotor blade body, the profile thickness of the blade body after adjusting the internal cooling channel can be obtained, and the difference between the profile thickness of the blade body after adjusting the internal cooling channel and that before adjustment is the amount of profile thinning.

[0058] S107. Reconstruct the cooling structure of the turbine rotor blade body based on the reduction ratio of the internal cooling channel area of the turbine rotor blade body and the profile thickness of the blade body, and use a three-dimensional modeling tool to establish a three-dimensional model of the turbine rotor blade body and the cooling channel after adjusting the blade profile.

[0059] In an embodiment of the present invention, based on the constructed cooling structure of the moving blade airfoil, according to the determined reduction ratio of the internal cooling channel area of the turbine moving blade airfoil and the airfoil outer profile thickness, the cooling structure of the turbine moving blade airfoil is reconstructed, and a three-dimensional model of the turbine moving blade airfoil and the cooling channel after adjusting the airfoil is established using a three-dimensional modeling tool.

[0060] S108. According to the three-dimensional model of the turbine moving blade airfoil after adjusting the airfoil and the reduction ratio of the internal cooling channel area of the moving blade airfoil, adjust the positions of the micro circular tubes at the root section and the top section, the diameter of each circular micro tube, the diameter of each circular micro tube, the spacing between the circular micro tubes, and the number of circular micro tubes.

[0061] S109. Construct a three-dimensional model of the turbine moving blade with a circular micro tube array cooling structure after thinning the airfoil, conduct a full three-dimensional fluid-thermal coupling calculation and analysis of the turbine moving blade airfoil, and obtain the temperature field distribution and temperature data of the moving blade airfoil; if the temperature parameters of the turbine moving blade airfoil meet the predetermined temperature standard, the design process ends; otherwise, adjust the thinning amount of the turbine moving blade airfoil outer profile and the parameters of the circular micro tube array cooling structure, and repeat S106 - S108 until the temperature parameters of the turbine moving blade airfoil reach the predetermined standard.

[0062] In an embodiment of the present invention, according to the given cooling air consumption, combined with the other inlet and outlet boundary conditions of the turbine moving blade, the constructed overall three-dimensional model of the turbine moving blade with a circular micro tube array cooling structure after thinning the airfoil is imported into the mesh generation program to generate the grids of the fluid domain and the solid domain required for the full three-dimensional calculation, and then using the full three-dimensional fluid-thermal coupling calculation and analysis program, conduct a full three-dimensional fluid-thermal coupling calculation and analysis of the turbine moving blade airfoil, and obtain the temperature field distribution and temperature data of the moving blade airfoil.

[0063] In one embodiment of the present invention, for the cooling of the circular micro tube array cooling structure, the diameter of the circular tube is in the range of 0.1 mm to 1 mm. The micro tube row structure can increase the heat transfer area of the cooling channel and increase the convective heat transfer coefficient; at the same time, in cooperation with the leading edge film cooling of the turbine moving blade airfoil, it realizes the full coverage of the cooling of the high-pressure turbine moving blade airfoil and meets the airfoil cooling requirements.

[0064] In another embodiment of the present invention, the cooling structure of the circular micro tube array is arranged inside the metal wall of the airfoil to thin the thickness of the airfoil profile of the moving blade.

[0065] The cooling of the circular micro tube array cooling structure is arranged inside the metal wall of the airfoil, realizing efficient primary cooling of the airfoil. The internal cooling demand of the airfoil will be reduced, and the original internal cooling cavity can be reduced, that is, the thickness of the airfoil profile can be thinned. This is not only beneficial to improving the aerodynamic performance of the moving blade, but also can reduce the heat receiving area of the airfoil, which is conducive to further reducing the cooling demand and comprehensively reducing the consumption of cooling air.

[0066] In another embodiment of the present invention, the circular microtube array cooling structure covers all positions of the moving blade airfoil except the leading edge, achieving full coverage of the cooling of the high-pressure turbine moving blade airfoil and making the temperature distribution of the turbine moving blade airfoil uniform.

[0067] Cooled by the circular microtube array cooling structure, which covers all positions of the airfoil except the leading edge with a microtube array of smaller scale, not only can full coverage of the cooling of the high-pressure turbine moving blade airfoil be achieved, but also the temperature distribution of the airfoil is more uniform, and the problem of large thermal stress caused by non-uniform temperature in the traditional airfoil film cooling plus convective cooling will no longer exist.

[0068] Cooled by the circular microtube array cooling structure, making full use of the advantages of excellent cooling effect and large heat transfer area of the microtube array, and cooperating with the convective heat transfer in the internal cavity to meet the cooling requirements of the airfoil. Therefore, part of the film cooling in the middle and rear parts of the blade row can be cancelled. For the circular microtube array cooling of the turbine moving blade airfoil, by reducing the diameter of the circular tubes in the microtube array, the cooling air can be transported to any position of the moving blade airfoil, so as to achieve precise customized transportation of the cooling requirements of the airfoil and can cool the high-temperature area of the airfoil targeted.

[0069] In the embodiment of the present invention, for the circular microtube array cooling of the turbine moving blade airfoil, the parametric design of the circular microtube array cooling of the moving blade airfoil can be realized only through a small number of parameters, which is beneficial to quickly carry out optimization and adjustment to obtain the best cooling scheme. For the circular microtube array cooling of the turbine moving blade airfoil, the partial film hole cooling structure of the moving blade airfoil is cancelled, which is beneficial to weakening the influence of the airfoil film cooling on the mainstream, reducing the mixing loss and improving the turbine efficiency.

[0070] For the circular microtube array cooling of the turbine moving blade airfoil, making full use of the excellent cooling effect of the circular microtube array structure, reducing the amount of cooling air used for the airfoil is beneficial to improving the performance of the turbine and the entire gas turbine unit and increasing the unit efficiency. Among them, for the circular microtube array cooling of the turbine moving blade airfoil, the thickness of the moving blade airfoil is thinned, and the cooling tube array channels are arranged inside the blade wall thickness, which can reduce the weight of the moving blade by about 8%.

[0071] A design method for the circular microtube array cooling of the moving blade airfoil proposed by the present invention is universal, not only limited to the design of the high-pressure turbine moving blade of the gas turbine, but also applicable to the design of the high-pressure turbine moving blade of the aeroengine.

[0072] In another embodiment of the present invention, the 3D modeling software for the computational domain is UG NX software, the full 3D fluid-thermal coupling calculation and analysis software is CFX and Fluent software, and the mesh generation is carried out by ICEM CFD software.

[0073] In the embodiments of the present invention, based on making full use of the conventional full three-dimensional fluid-thermal coupling calculation method for turbine moving blades, according to the structural characteristics of the blade body of the high-pressure turbine moving blade of a gas turbine, and focusing on the high-temperature area of the blade body of the high-pressure turbine moving blade, the cooling structure design of the blade body of the moving blade and the temperature field calculation process are reorganized, and a circular microtube array cooling design method suitable for the blade body of the high-pressure turbine moving blade of a gas turbine is proposed, obtaining an efficient cooling structure design method for the blade body of the high-pressure turbine moving blade, and solving the problem that it is difficult to cool the blade body of the high-pressure turbine moving blade of a gas turbine.

[0074] Through microtube rows with a smaller diameter (0.1 mm to 1 mm), the heat transfer area and convective heat transfer coefficient of the cooling channels are increased several times, thereby achieving super cooling of the blade body. It can not only achieve full coverage of the cooling of the blade body of the high-pressure turbine moving blade, but also fully meet the cooling requirements of the blade body. Therefore, it effectively solves the problems of "blind areas" and "dead zones" that are difficult to cool due to the limitation of the space structure in traditional film cooling and large-scale cooling, and further can effectively solve the problems of blade body overheating and even ablation. The cooling air is transported to any position of the blade body of the moving blade through the small-scale circular microtube array cooling structure, thereby realizing the precise customized transportation of the cooling requirements of the blade body, and thus can focus on cooling the high-temperature area of the blade body targeted, meeting the local cooling and temperature reduction requirements of the blade body of the moving blade.

[0075] The technical solution of the present invention can give full play to the better cooling effect of the microtube array, cancel the film hole cooling structure in the middle and rear sections of the blade body of the moving blade, thereby weakening the influence of the film cooling of the blade body on the mainstream, being beneficial to reducing the cold and hot mixing loss of the blade body of the turbine moving blade, and improving the turbine efficiency. Making full use of the excellent cooling effect of the circular microtube array structure can reduce the cooling air consumption of the blade body, being beneficial to improving the performance of the turbine and the entire gas turbine unit, and improving the unit efficiency. The designed blade body profile of the moving blade is relatively thin, and microtubes are arranged inside the wall thickness, which is beneficial to reducing the weight of the moving blade and improving the power-to-weight ratio of the engine.

[0076] It can be understood that in the embodiments of the present invention, a circular microtube array cooling design method for the blade body of a moving blade proposed by the present invention has universality, not only limited to the design of the high-pressure turbine moving blade of a gas turbine, but also applicable to the design of the high-pressure turbine moving blade of an aeroengine.

[0077] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for designing a cooling structure of a moving blade with a circular micro-tube array, characterized in that: The design method comprises: S101. Determine the cooling structure of the turbine blade body without a micro-tube array cooling channel according to the appearance of the turbine blade body, perform full three-dimensional fluid-heat coupling calculation and analysis on the turbine blade, and determine the temperature field distribution and data information of the blade body, which will serve as a comparison basis for subsequent analysis and design using a circular micro-tube array cooling structure; S102, determining the position of the high temperature area in the turbine rotor blade where the enhanced cooling structure is to be arranged; S103, according to the surface structure of the rotor blade, combined with the dimension parameters of the rotor blade including at least the blade wall thickness, the leading edge air film structure, and the trailing edge exhaust structure, the cooling structure parameters of the turbine rotor blade with a circular micro-tube array are given; S104, constructing a three-dimensional model of a turbine blade with a circular micro-tube array cooling structure, and inferring the reduction in cooling air for the turbine blade body and the amount of cooling air for the turbine blade body after the circular micro-tube array cooling structure is installed; S105. Based on the overall three-dimensional model of the turbine rotor blade with a circular micro-tube array cooling structure, the fluid domain and solid domain grids required for full three-dimensional calculation are divided, and full three-dimensional fluid-heat coupling calculation and analysis are carried out to obtain the temperature field distribution and temperature data of the rotor blade body; S106, determining an amount of thinning of a turbine blade body based on a ratio of the cooling air usage to an originally given cooling air usage; S107, based on the reduction ratio of the cooling channel area inside the turbine rotor blade body and the thickness of the blade body, reconstruct the cooling structure of the turbine rotor blade body, and use a three-dimensional modeling tool to establish a three-dimensional model of the turbine rotor blade body and the cooling channel after the blade shape is adjusted; S108, adjusting the positions of the micro circular tubes in the root section and the top section, the diameter of each micro circular tube, the spacing between the micro circular tubes, and the number of the micro circular tubes according to the three-dimensional model of the turbine rotor blade body after the blade profile is adjusted and the reduction ratio of the cooling channel area inside the rotor blade body; S109. Construct a three-dimensional model of the turbine rotor blade with a circular micro-tube array cooling structure after blade body thinning, perform full three-dimensional heat-flow coupling calculation and analysis on the turbine rotor blade body, and obtain the temperature field distribution and temperature data of the rotor blade body; if the temperature parameters of the turbine rotor blade body meet the predetermined temperature standard, the design process ends; otherwise, adjust the thinning amount of the turbine rotor blade body and the parameters of the circular micro-tube array cooling structure, and repeat S106 to S108 until the temperature parameters of the turbine rotor blade body reach the predetermined standard.

2. The method for designing a cooling structure of a moving blade with a circular micro-tube array according to claim 1, characterized in that: According to the surface structure of the moving blade body, combined with the size parameters of the moving blade body including at least the blade body wall thickness, the leading edge air film structure, and the trailing edge exhaust structure, the cooling structure parameters of the turbine moving blade body with a circular micro-tube array are given, including: Based on the specific position of the turbine blade body that needs enhanced cooling, the cooling structure parameters of the turbine blade body with circular micro-tube array are given; among them, in the root section, the distance H from the position of each circular micro-tube along the center line of the blade body wall thickness to the leading edge point of the center line of the blade body wall thickness is h,i 、Each circular microtube diameter φ h,i 、Circular microtube spacing L h,i , the number of circular microtubes N; in the top section, the distance from the position of each circular microtube along the midline of the blade thickness to the leading edge point of the midline of the blade thickness H t,i 、Each circular microtube diameter φ t,i 、Circular microtube spacing L t,i and the number of circular microtubules N.

3. The method for designing a cooling structure of a moving blade with a circular micro-tube array according to claim 1, characterized in that: Based on the ratio of cooling air usage to the original given cooling air usage, determine the thinning amount of the turbine blade body, including: The ratio of the cooling air usage to the original given cooling air usage is the reduction ratio of the cooling channel area inside the turbine blade body; on the basis of the original turbine blade body internal cooling channel, a new turbine blade body internal cooling channel is obtained by reducing the channel while keeping the blade body wall thickness unchanged; the new turbine blade body internal cooling channel is offset outwardly to obtain the blade body outer thickness after adjusting the internal cooling channel; the difference between the blade body outer thickness after adjusting the internal cooling channel and the thickness before adjustment is the blade body outer thickness reduction amount.

4. The method for designing a cooling structure of a moving blade with a circular micro-tube array according to claim 1, characterized in that: Based on the overall three-dimensional model of the turbine rotor blade with a circular micro-tube array cooling structure, the fluid domain and solid domain grids required for full three-dimensional calculation are divided, and full three-dimensional fluid-heat coupling calculation and analysis are carried out to obtain the temperature field distribution and temperature data of the rotor blade body, including: The temperature field distribution and temperature data of the turbine blade body are compared and analyzed with the temperature field distribution and data information of the turbine blade body without the micro-tube array cooling channel. If the obtained temperature parameters of the turbine blade body meet the predetermined temperature standard, S106 is executed; otherwise, the circular micro-tube array cooling structure parameters are adjusted by at least increasing the number of micro-tube rows or increasing the diameter of the micro-tubes, and S104 to S105 are repeatedly executed until the temperature parameters of the turbine blade body reach the predetermined temperature standard.

5. The method for designing a cooling structure of a moving blade with a circular micro-tube array according to claim 4, characterized in that: The predetermined temperature standard includes: If the maximum temperature of the turbine blade body is higher than the temperature resistance grade of the metal material used, the predetermined temperature standard is: the maximum temperature of the turbine blade body is lower than the temperature resistance grade of the metal material used; If the maximum temperature of the turbine rotor blade body is lower than the temperature resistance grade of the metal material used, the predetermined temperature standard is: the maximum temperature of the turbine rotor blade body is reduced by not less than 20°C.

6. The method for designing a cooling structure of a moving blade with a circular micro-tube array according to claim 1, characterized in that: The circular micro-tube array cooling structure has a circular tube diameter between 0.1 mm and 1 mm. The micro-tube array structure can increase the heat exchange area of ​​the cooling channel and increase the convective heat transfer coefficient. At the same time, it cooperates with the leading edge air film cooling of the turbine blade body to achieve full coverage of the high-pressure turbine blade body cooling.

7. The method for designing a cooling structure of a moving blade with a circular micro-tube array according to claim 1, characterized in that: The method comprises: The circular micro-tube array cooling structure is arranged inside the metal wall of the blade body to reduce the thickness of the blade body profile of the moving blade.

8. The method for designing a cooling structure of a moving blade with a circular micro-tube array according to claim 1, characterized in that: The method comprises: The circular micro-tube array cooling structure is distributed all over the moving blade body except the leading edge, thereby achieving full coverage of the cooling of the high-pressure turbine moving blade body, so that the temperature of the turbine moving blade body is evenly distributed.

9. The method for designing a cooling structure of a moving blade with a circular micro-tube array according to claim 1, characterized in that: Determining the location of the high temperature area in the turbine rotor blade where the enhanced cooling structure is to be arranged includes: Based on the temperature field distribution and temperature data of the moving blade body, the location of the high-temperature area of ​​the turbine moving blade body is determined, that is, the specific location of the turbine moving blade body that needs to be focused on and enhanced cooling. Subsequently, a circular micro-tube array cooling structure will be arranged in these high-temperature areas.

10. The method for designing a cooling structure of a moving blade with a circular micro-tube array according to claim 1, characterized in that: The 3D modeling software of the computational domain adopts UG NX software, the full 3D fluid-heat coupling calculation and analysis software adopts CFX and Fluent software, and the meshing adopts ICEM CFD software.

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