Turbine blade cooling effect test switching section
By adopting a spiral baffle and double-shell design in the transition section of the turbine blade cooling effect test, the problem of uneven circumferential heat transfer of the cooling medium in the annular cavity was solved, realizing uniform flow and efficient heat transfer of the cooling medium, and improving the safety and economy of the test piece.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-13
- Publication Date
- 2026-05-01
AI Technical Summary
The cooling medium in the existing turbine blade cooling efficiency test transition section has uneven circumferential heat transfer within the annular cavity, which poses risks of excessive thermal stress and local overheating. In addition, the design is complex, costly, and difficult to assemble.
The cooling medium flow channel is divided by a spiral baffle to form a spiral channel. The cooling medium flows in the opposite direction to the gas flow. Through the spiral baffle and double shell design, uniform flow of the cooling medium and efficient heat exchange are achieved.
The cooling effect of the transition section in the turbine blade cooling effect test was improved, thermal stress was reduced, the weight and cost of the test piece were reduced, and the safety, reliability and economy of the test piece were ensured.
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Figure CN121954448A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of turbine blade cooling technology, specifically a turbine blade cooling effect test transition section. Background Technology
[0002] Most existing designs for the transition section of turbine blade cooling effect test specimens do not consider the cooling of the transition section. When the test parameter temperature is not too high, the material can withstand the gas temperature while ensuring the safety and reliability of the test specimen. However, when the test gas temperature exceeds the allowable temperature range of the test specimen material, cooling protection for the transition section needs to be considered. Existing high-temperature cooling effect test transition section designs generally use a double-layer structure with a cooling medium between the inner and outer layers for cooling. However, existing double-layer structures have problems such as uneven cooling and poor cooling effect.
[0003] Aero gas turbines operate under extremely harsh conditions, characterized by high temperature, high pressure, and high speed. They are subjected to significant aerodynamic forces, thermal stress, inertial forces, and vibrations. The operating environment temperature of gas turbine blades is far higher than their metal service temperature, necessitating cooling protection through refrigerated air; therefore, air-cooled blades are the most common type. Blade cooling effect testing is a crucial step in the development of air-cooled blades. This testing reveals the cooling characteristics of the turbine's air-cooled blades and the distribution of wall temperature under engine design conditions. This allows for the verification and correction of theoretical calculations, evaluation of the rationality of blade cooling structure design, and selection of appropriate cooling structures. Furthermore, it plays a vital role in accumulating databases and refining the turbine cooling design system. In the past, due to limitations in testing conditions, most tests could only provide medium-temperature and medium-pressure environments. It was necessary to model the parameters under engine conditions using similarity principles to obtain airflow and temperature fields similar to those of a real turbine. However, when the engine cycle parameters are high, this modeling process can lead to relatively large testing errors. Therefore, with the improvement of testing capabilities, it is essential to obtain the cooling effect characteristics and wall temperature distribution of engine turbine blades through high-temperature and high-pressure cooling effect tests or full-temperature and full-pressure cooling effect tests for turbine blades with high inlet temperatures. This leads to the development of cooling effect test transition sections with cooling.
[0004] In existing high-temperature cooling effect test specimens with double-layer cooling structures, the structural strength is generally improved by setting reinforcing ribs or turbulence ribs in the inner layer or adding heat dissipation fins on the wall surface. However, baffles are generally not designed. The cooling medium flows forward in the annular cavity, resulting in significant non-uniformity of circumferential heat transfer. There may be risks of excessive thermal stress and local overheating in the test transition section. If axial baffles are designed to divide the cooling medium flow channel circumferentially into different flow channels, multiple cooling conduits need to be designed, with one channel corresponding to two cooling conduits. Although the problem of non-uniform cooling is solved by dividing the cooling medium flow channel into multiple cooling channels, the design of the test specimen is relatively complex, the layout of the cooling pipes is inconvenient, and the test bench is required to have multiple cooling flow paths. The test specimen is also relatively bulky, difficult to assemble, and has high processing costs. Summary of the Invention
[0005] The purpose of this invention is to provide a turbine blade cooling effect test transition section, which solves the problem of large non-uniformity of circumferential heat transfer when the cooling medium flows forward in the annular cavity during the high-temperature cooling effect test of turbine blades, reduces the heat transfer dead angle of the entire transition section, and improves the cooling effect of the turbine blade cooling effect test transition section.
[0006] The objective of this invention can be achieved through the following technical solutions: A turbine blade cooling efficiency test transition section includes an inlet flange, a front end wall, an outer shell of the transition section, an inner shell of the transition section, a spiral baffle, a rear end wall, and cooling ducts. One side of the inlet flange is used to connect a gas input component. The outer shell of the transition section is fitted over the inner shell of the transition section, and a reserved cooling medium flow channel is formed between the two. The two end faces of the cooling medium flow channel are sealed by the front end wall and the rear end wall, which are respectively connected. The spiral baffle is set between the inner shell and the outer shell of the transition section, and the spiral direction of the spiral baffle is the same as the fluid flow direction of the cooling medium flow channel. The front end wall is connected to the other side of the inlet flange. A hollow gas flow channel is formed inside the inner shell of the transition section. Cooling ducts are connected to both ends of the outer shell of the transition section. The cooling ducts at both ends are used to introduce and exit the cooling medium flow channel, respectively.
[0007] Furthermore, the spiral baffle is formed by sweeping the cross section along two spiral lines. There are two spiral lines, which are respectively set to spiral upward along the inner wall surface of the outer shell of the transition section and the outer wall surface of the inner shell of the transition section. The cross section length is greater than the gap value between the inner wall surface of the outer shell of the transition section and the outer wall surface of the inner shell of the transition section. The pitch of the two spiral lines is determined according to the cooling medium flow channel. The starting point and ending point of the two spiral lines are both set on the intersection line of the inner wall surface of the outer shell of the transition section and the center plane, and the intersection line of the outer wall surface of the inner shell of the transition section and the center plane, respectively. The two spiral lines coincide with the inner wall surface of the outer shell of the transition section and the outer wall surface of the inner shell of the transition section.
[0008] Furthermore, the cross-section is rectangular.
[0009] Furthermore, the cooling medium flows in the opposite direction to the gas flow.
[0010] Furthermore, both the outer shell and the inner shell of the transition section are trumpet-shaped, and the distance between them is equal.
[0011] Furthermore, the outer shell of the transition section has an inlet for cooling medium directly below the end near the small horn-shaped opening, and an outlet for cooling medium directly above the end near the large horn-shaped opening.
[0012] Furthermore, the cross-sectional profile of the small end of the trumpet-shaped opening is fan-shaped.
[0013] Furthermore, the cooling conduit includes an inlet cooling conduit and an outlet cooling conduit. The inlet cooling conduit is connected directly below the smaller end of the flared end, and the outlet cooling conduit is connected directly above the larger end of the flared end.
[0014] Furthermore, the cooling medium flow channel includes a secondary flow channel and a spiral flow channel. There are two secondary flow channels, which are respectively connected to the two ends of the spiral flow channel. The middle part of the spiral baffle, the outer shell of the transition section, and the inner shell of the transition section form a spiral flow channel. The two ends of the spiral baffle and the front wall and the rear wall form secondary flow channels. The ends of the secondary flow channels and the spiral flow channels are all connected to the adjacent cooling duct.
[0015] Furthermore, the outer shell of the transition section, the inner shell of the transition section, and the spiral partition are integrally formed.
[0016] The beneficial effects of this invention are: This invention achieves efficient and uniform cooling of the inner shell of the transition section by forming a double-layer cooling spiral channel through the front wall, the outer shell of the transition section, the inner shell of the transition section, the spiral partition, and the rear wall. While ensuring that the inner shell of the transition section does not exceed the temperature limit, it also improves the structural strength of the inner shell of the transition section, reduces thermal stress, and improves the safety and reliability of the transition section in the cooling effect test. At the same time, it can also reduce the wall thickness of the inner shell of the transition section to a certain extent, reducing weight and improving economy.
[0017] The cooling effect test transition section of this invention has uniform temperature, is safe and economical. Its key configuration lies in the design of the double-layer shell and the spiral baffle. By rationally arranging the spiral baffle, the cooling medium flow channel is divided into several spiral channels, realizing efficient heat exchange in the spiral channels, greatly eliminating the heat exchange dead zone in the cooling medium flow channel, and ensuring the uniformity of heat exchange.
[0018] The cooling effect test transition section has a double-layer cooling structure with spiral baffles to form a spiral channel, which enhances the heat exchange effect and reduces the dead zone of heat exchange.
[0019] The structural dimensions of the spiral baffle are selected, and the wall thickness is chosen while taking into account the structural strength requirements and the weight of the transition section. The pitch is selected while considering the axial length of the transition section and the heat exchange effect of the spiral channel. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of a turbine blade cooling effect test transition section in an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of a turbine blade cooling effect test transition section in an embodiment of the present invention; Figure 3 This is a side view schematic diagram of a turbine blade cooling effect test transition section in an embodiment of the present invention; Figure 4 This is a schematic diagram of the flow direction of the cooling medium in the flow channel in an embodiment of the present invention.
[0022] In the diagram: 1. Inlet flange; 2. Front end wall; 3. Outer shell of transition section; 301. Secondary flow channel; 302. Spiral flow channel; 4. Inner shell of transition section; 5. Spiral baffle; 6. Rear end wall; 7. Cooling duct; 701. Outlet cooling duct; 702. Inlet cooling duct; 101. Gas flow channel; 202. Cooling medium flow channel. Detailed Implementation
[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0024] like Figure 2 As shown, a turbine blade cooling effect test transition section includes, as follows: Figure 2The diagram shows an inlet flange 1, a front wall 2, an outer shell 3 of the transition section, an inner shell 4 of the transition section, a spiral baffle 5, a rear wall 6, and a cooling conduit 7. One side of the inlet flange 1 is used to connect to a gas input component. The outer shell 3 of the transition section is fitted over the inner shell 4 of the transition section, forming a reserved cooling medium flow channel 202 between them. The two end faces of the cooling medium flow channel 202 are sealed by the front wall 2 and the rear wall 6, respectively. The spiral baffle 5 is disposed between the inner shell 4 and the outer shell 3 of the transition section. As shown in Figure 1, the direction indicated by the arrow in the figure is the cooling medium flow method. The spiral direction of the spiral baffle 5 is the same as the fluid flow direction of the cooling medium flow channel 202. The front wall 2 is connected to the other side of the inlet flange 1. A hollow gas flow channel 101 is formed inside the inner shell 4 of the transition section. The cooling conduit 7 is connected to both ends of the outer shell 3 of the transition section. The cooling conduit 7 at both ends is used to introduce and exit the cooling medium into the cooling medium flow channel 202, respectively.
[0025] Its working principle is as follows: (See reference) Figure 2 As shown, the turbine blade cooling effect test transition section is installed before or after the test section of the high-temperature cooling effect test piece. It is used to provide a suitable gas passage, a front or rear installation interface for the test piece, and a test temperature and pressure test installation interface. The inlet flange 1 is used to connect the interface of the test piece or the gas input component on the test bench (usually the combustion chamber outlet on the test bench). Taking the combustion chamber as an example, the front wall 2, the rear wall 6, the spiral baffle 5, the outer shell 3 of the transition section, and the inner shell 4 of the transition section constitute the main body of the transition section. The interior of the inner shell 4 of the transition section is the gas flow channel 101, which is used to convert the circular outlet channel of the combustion chamber into the test section blade. The required fan-shaped inlet channel provides stable and smooth combustion gas in a specified direction. The size of the circular channel is generally determined by the combustion chamber outlet interface on the test bench, while the size of the fan-shaped channel is generally determined by the upper and lower flow channels of the test blade and the number of blades. The cooling medium flow channel 202 is located between the outer shell 3 and the inner shell 4 of the transition section, which is used to cool the outer shell 3 of the transition section and keep it at a reasonable temperature level. The spiral baffle 5 is used to divide the cooling medium flow channel 202, forming a specific cooling spiral flow channel 302 structure, which organizes the smooth flow of the cooling medium in the cooling medium flow channel 202.
[0026] The heat exchange process within the cooling medium flow channel 202: First, the transition section with a double-layer structure can be considered, to some extent, as a shell-and-tube heat exchanger, such as... Figure 2 and Figure 3As shown, within the gas flow channel 101, the gas flows from left to right. During the experiment, the heat exchange on the gas side of the inner wall of the inner shell 4 of the transition section was determined based on the experimental conditions. To enhance the heat exchange of the cooling medium within the cooling medium flow channel 202, a counter-flow pattern was adopted to increase the average temperature difference during the heat exchange process, i.e., the flow direction of the cooling medium is opposite to that of the gas. During the flow, because the spiral channel is relatively narrow, the cooling medium and the outer wall of the inner shell 4 of the transition section can exchange heat sufficiently and uniformly. During the circumferential flow, due to the influence of centrifugal force, secondary flow and near-wall vortices will occur in the spiral channel, further increasing the turbulence of the cooling medium and increasing the heat transfer coefficient of the cooling medium.
[0027] The transition section of the present invention can be used both before the inlet of the cooling effect test section and after the outlet of the cooling effect test section as the exhaust section of the test piece.
[0028] In some embodiments, the spiral baffle 5 is formed by sweeping the cross section along two spiral lines. There are two spiral lines, which are respectively arranged to spiral upward along the inner wall surface of the outer shell 3 of the transition section and the outer wall surface of the inner shell 4 of the transition section. The length of the cross section is greater than the gap value between the inner wall surface of the outer shell 3 of the transition section and the outer wall surface of the inner shell 4 of the transition section. The pitch of the two spiral lines is determined according to the cooling medium flow channel 202. The starting point and the ending point of the two spiral lines are both located on the intersection line of the inner wall surface of the outer shell 3 of the transition section and the center plane and the intersection line of the outer wall surface of the inner shell 4 of the transition section and the center plane. The two spiral lines coincide with the inner wall surface of the outer shell 3 of the transition section and the outer wall surface of the inner shell 4 of the transition section, respectively.
[0029] like Figure 2 As shown, the spiral baffle 5 is formed by sweeping the cross section along two spiral lines to divide the cooling medium flow channel 202, and is obtained by trimming the outer shell 3 and inner shell 4 of the transition section. The thickness of the baffle is usually 4 to 8 mm. The rectangle used for sweeping must ensure that the sweeping body before trimming can completely divide the entire cooling medium flow channel 202. The pitch and number of turns of the spiral are determined by the length of the transition section in the axial direction. The starting point and ending point of the spiral are arranged directly below the transition section. The pitch is generally set considering the flow velocity of the cooling medium in the divided channel. When it is necessary to enhance the heat exchange of the cooling medium, the pitch can be appropriately reduced, but it should not be too small, otherwise it will increase the flow resistance.
[0030] In some embodiments, the cross-section is rectangular, resulting in a very large cooling area. The shape of the spiral baffle 5 can also be improved, for example, by sweeping the cross-section along a spiral line. The cross-section can also be changed to other shapes as needed, such as elliptical or hyperbolic, all in order to achieve uniform heat exchange, ensure the structural strength of the test piece, and take into account factors such as weight and cost.
[0031] In some embodiments, such as Figure 3 As shown, the cooling medium flows in the opposite direction to the gas flow. Specifically, the cooling medium (usually water or air) flows in from the inlet cooling duct 702, first impacting the lower right corner of the outer wall of the inner shell 4 of the transition section, then flowing spirally to the left in a circumferential direction, and finally flowing out from the outlet cooling duct 701. In some embodiments, both the outer shell 3 and the inner shell 4 of the transition section are trumpet-shaped, and the distance between them is equal. This not only simulates the fan-shaped inlet channel required for the test section blades but also increases the cooling area.
[0032] In some embodiments, the outer shell 3 of the transition section has a cooling medium inlet located directly below the end near the small flared opening, and an outlet located directly above the end near the large flared opening. This increases the contact time between the cooling medium and the outer shell 3 and the inner shell 4 of the transition section, thereby improving cooling efficiency. In some embodiments, such as Figure 1 As shown, the cross-sectional profile of one end of the horn-shaped inlet is annular. This is intended to realistically simulate the fan-shaped inlet channel required for the test section blades, and can also be designed according to the actual inlet channel shape.
[0033] In some embodiments, such as Figure 2 As shown, the cooling conduit 7 includes an inlet cooling conduit 702 and an outlet cooling conduit 701. The inlet cooling conduit 702 is connected directly below the smaller end of the flared end, and the outlet cooling conduit 701 is connected directly above the larger end of the flared end. It is generally positioned for easy flow, thus facilitating the diversion of externally supplied cooling medium to the outlet cooling conduit 701 within the transition section.
[0034] In some embodiments, the cooling medium flow channel 202 includes a secondary flow channel 301 and a spiral flow channel 302. There are two secondary flow channels 301, which are respectively connected to the two ends of the spiral flow channel 302. The spiral flow channel 302 is formed by the middle part of the spiral baffle 5, the outer shell 3 of the transition section, and the inner shell 4 of the transition section. The secondary flow channel 301 is formed between the two ends of the spiral baffle 5 and the front wall 2 and the rear wall 6. The ends of the secondary flow channel 301 and the spiral flow channel 302 are connected to the adjacent cooling duct 7.
[0035] like Figure 4As shown in the figure, the arrows indicate the direction of the cooling medium flow convergence. By reasonably arranging the spiral baffles 5, the flow of the cooling medium in the spiral channel is almost free of dead zones. When the cooling medium in the spiral channel 302 flows to the top of the spiral channel, part of the cooling medium flows out from the outlet cooling pipe 701, and part of the cooling medium continues to flow circumferentially due to inertia, that is, it flows into the secondary channel 301 to cool the inner shell 4 of the transition section at the lower left. Moreover, the secondary channel 301 is also affected by the suction effect of the cooling medium flow in the spiral channel 302, which also has a positive effect on the flow of the cooling medium in the secondary channel 301. The temperature gradient of the inner shell 4 of the transition section is greatly reduced through uniform cooling.
[0036] In some embodiments, the outer shell 3, inner shell 4, and spiral partition 5 of the transition section are integrally formed. The material must be a high-temperature alloy; alternatively, the inner and outer shells of the transition section can be processed separately, with the outer shell 3 halved on both sides and then welded together with the rest of the transition section. If processed separately, the inner shell 4 is made of a high-temperature alloy, and the outer shell 3 is made of ordinary stainless steel. Furthermore, the front end wall 2 and rear end wall 6 can be added and integrally formed together.
[0037] Compared with existing medium- and high-temperature cooling effect test specimen designs, this invention has a highly efficient cooling structure, generally eliminating the need for additional cooling conduits 7, making it very user-friendly for test specimen installation and debugging; it also solves the problem of uneven cooling of the inner shell, greatly reducing the thermal stress of the test specimen, while reducing the wall thickness of the inner shell, ensuring the safety and reliability of the test specimen, and reducing the weight and cost of the test specimen.
[0038] It should be noted that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein.
[0039] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0040] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.
Claims
1. A turbine blade cooling effect test transition section, characterized in that, The system includes an inlet flange (1), a front end wall (2), an outer shell of the transition section (3), an inner shell of the transition section (4), a spiral baffle (5), a rear end wall (6), and a cooling duct (7). One side of the inlet flange (1) is used to connect to a gas input component. The outer shell of the transition section (3) is fitted over the inner shell of the transition section (4), and a reserved cooling medium flow channel (202) is formed between the two. The two end faces of the cooling medium flow channel (202) are sealed by the front end wall (2) and the rear end wall (6) connected respectively. The spiral baffle (5) The spiral baffle (5) is located between the inner shell (4) and the outer shell (3) of the transition section. The spiral direction of the spiral baffle (5) is the same as the fluid flow direction of the cooling medium flow channel (202). The front end wall (2) is connected to the other side of the inlet flange (1). A hollow gas flow channel (101) is formed inside the inner shell (4) of the transition section. The cooling conduits (7) are connected to both ends of the outer shell (3) of the transition section. The cooling conduits (7) at both ends are used to introduce and lead the cooling medium into and out of the cooling medium flow channel (202), respectively.
2. The turbine blade cooling effect test transition section according to claim 1, characterized in that, The spiral baffle (5) is formed by sweeping the cross section along two spiral lines. There are two spiral lines, which are respectively set to spiral up along the inner wall surface of the outer shell (3) of the transition section and the outer wall surface of the inner shell (4) of the transition section. The length of the cross section is greater than the gap value between the inner wall surface of the outer shell (3) of the transition section and the outer wall surface of the inner shell (4) of the transition section. The pitch of the two spiral lines is determined according to the cooling medium flow channel (202). The starting point and the ending point of the two spiral lines are both set on the intersection line of the inner wall surface of the outer shell (3) of the transition section and the center plane and the intersection line of the outer wall surface of the inner shell (4) of the transition section and the center plane. The two spiral lines coincide with the inner wall surface of the outer shell (3) of the transition section and the outer wall surface of the inner shell (4) of the transition section, respectively.
3. The turbine blade cooling effect test transition section according to claim 2, characterized in that, The cross-section is rectangular.
4. The turbine blade cooling effect test transition section according to claim 1, characterized in that, The cooling medium flows in the opposite direction to the gas flow.
5. The turbine blade cooling effect test transition section according to claim 1, characterized in that, Both the outer shell (3) and the inner shell (4) of the transition section are horn-shaped, and the distance between them is equal.
6. The turbine blade cooling effect test transition section according to claim 5, characterized in that, The outer shell (3) of the transition section has an inlet for cooling medium directly below the end near the small horn-shaped opening, and an outlet for cooling medium directly above the end near the large horn-shaped opening.
7. The turbine blade cooling effect test transition section according to claim 5, characterized in that, The cross-sectional profile of the small end of the trumpet-shaped opening is annular.
8. The turbine blade cooling effect test transition section according to claim 5, characterized in that, The cooling conduit (7) includes an inlet cooling conduit (702) and an outlet cooling conduit (701). The inlet cooling conduit (702) is connected directly below the small end of the horn-shaped opening, and the outlet cooling conduit (701) is connected directly above the large end of the horn-shaped opening.
9. The turbine blade cooling effect test transition section according to claim 1, characterized in that, The cooling medium flow channel (202) includes a secondary flow channel (301) and a spiral flow channel (302). There are two secondary flow channels (301) and they are connected to the two ends of the spiral flow channel (302). The middle part of the spiral baffle (5) forms the spiral flow channel (302) with the outer shell (3) of the transition section and the inner shell (4) of the transition section. The two ends of the spiral baffle (5) form the secondary flow channel (301) between the front wall (2) and the rear wall (6). The ends of the secondary flow channel (301) and the spiral flow channel (302) are connected to the adjacent cooling duct (7).
10. A turbine blade cooling effect test transition section according to claim 1, characterized in that, The outer shell (3), inner shell (4), and spiral partition (5) of the transition section are integrally formed.