Centripetal turbine with high-efficiency internal cooling structure

Abstract

This invention provides a radial turbine with a highly efficient internal cooling structure, relating to the field of radial turbine cooling technology. It includes a disk and blades. The disk has a disk back surface and a mounting surface arranged opposite each other in its axial direction. The blade root is connected to the mounting surface, forming a connection. The radial turbine has a cooling channel comprising an inlet section, a transition section, and a flow-diverting section connected sequentially. The inlet section extends from the disk back surface toward the mounting surface and to the connection. The transition section extends toward the leading edge of the blade and is inclined toward the blade tip. The flow-diverting section extends from the leading edge of the blade toward the trailing edge to the trailing edge of an adjacent blade. The flow-diverting section includes a first flow path and a second flow path spaced apart along the height direction of the blade. This invention can achieve cooling of various key components of the radial turbine, reduce the temperature at high-temperature and high-stress locations, and extend the service life of the radial turbine.

Description

Technical Field

[0001] This invention relates to the field of radial turbine cooling technology, and more particularly to a radial turbine with a highly efficient internal cooling structure. Background Technology

[0002] Centripetal turbines have advantages such as compact structure, small size, light weight, high energy density and high overall system efficiency. They are mainly used in distributed energy and micro gas turbines, airborne power generation systems using closed Brayton cycles, automotive turbochargers, cryogenic engineering expanders and auxiliary power units.

[0003] In pursuit of higher thermodynamic cycle efficiency, the turbine inlet temperature in related technologies is constantly increasing, to the point that the thermodynamic coupling challenge faced by centripetal turbines is approaching the physical limits of their materials. Therefore, it is urgent to design a centripetal turbine with a cooling structure to meet the requirements of actual working conditions. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, embodiments of the present invention propose a radial turbine with a highly efficient internal cooling structure. This radial turbine with a highly efficient internal cooling structure can cool various key parts of the radial turbine, reduce the temperature at high-temperature and high-stress locations, and extend the service life of the radial turbine.

[0006] According to an embodiment of the present invention, a radial turbine with a highly efficient internal cooling structure includes a disk and blades. The disk has a disk back surface and a mounting surface arranged opposite each other in its axial direction. The blade root is connected to the mounting surface and forms a connection. The radial turbine has a cooling channel, which includes an inlet section, a transition section, and a flow branching section connected in sequence. The inlet section extends from the disk back surface toward the mounting surface and extends to the connection. The transition section extends toward the leading edge of the blade and is inclined toward the blade tip. The flow branching section extends along the leading edge of the blade toward the trailing edge to a position adjacent to the trailing edge of the blade. The flow branching section includes a first flow path and a second flow path spaced apart along the height direction of the blade.

[0007] According to an embodiment of the present invention, a radial turbine with a highly efficient internal cooling structure allows the cooling medium to enter the inlet section of the cooling channel from the back of the turbine disk, and then enter the transition section inside the blade. The cooling medium then flows into a first flow path and a second flow path, respectively. In the transition section, the cooling medium can exchange heat with the region adjacent to the leading edge of the blade. The first and second flow paths are arranged along the height direction of the blade, enabling the cooling medium to exchange heat with both the high and low spanwise positions of the blade, cooling the blade tip and root. Simultaneously, the flow branching section extends to the trailing edge of the blade, meaning the outlets of the first and second flow paths are located near the trailing edge of the blade, facilitating heat exchange between the cooling medium and the trailing edge. Therefore, this structural design allows for a reasonable and comprehensive consideration of the mutual influence between various cooling components, achieving simultaneous and efficient cooling of the blade's leading edge, tip, root, and trailing edge. Thus, compared to related technologies, the present invention can achieve cooling of all key components of the radial turbine, reduce temperatures at high-temperature and high-stress locations, and extend the service life of the radial turbine.

[0008] In some embodiments, the first flow path is connected to the end of the transition section opposite to the inlet section, and the inlet of the second flow path is located between the inlet of the transition section and the inlet of the first flow path in the height direction of the blade.

[0009] In some embodiments, the outlet of at least one of the first flow path and the second flow path is formed on the pressure surface of the blade.

[0010] In some embodiments, the first flow path includes a first segment, a tapering segment, and a first slit segment arranged sequentially and connected along the leading edge of the blade toward the trailing edge. The end of the first segment opposite to the tapering segment is connected to the transition segment, and the end of the first slit segment opposite to the tapering segment is formed on the pressure surface of the blade.

[0011] In some embodiments, the tapering segment is a single segment, and the first split segment is a single segment corresponding one-to-one with the tapering segment; or...

[0012] The tapering section consists of at least two segments arranged at intervals along the height direction of the blade, and the first slit segment consists of at least two segments, each corresponding to one of the tapering sections.

[0013] In some embodiments, the centripetal turbine further includes a baffle column disposed on the tapering section, and there are multiple baffle columns arranged at intervals in the tapering section.

[0014] In some embodiments, the second flow path includes a variable diameter section, a second section, and a second slit section arranged sequentially along the direction from the leading edge to the trailing edge of the blade. The end of the variable diameter section opposite to the second section is connected to the transition section. The cross-sectional area of ​​the variable diameter section gradually decreases and then gradually increases along the direction from the variable diameter section toward the second section. The end of the second slit section opposite to the second section is formed on the pressure surface of the blade.

[0015] In some embodiments, the centripetal turbine further includes a baffle rib, and at least one of the first flow path and the second flow path is provided with a baffle rib; There are multiple turbulence ribs, which are arranged at intervals along the extension direction of the corresponding flow path, and the extension direction of the corresponding flow path is the direction from the leading edge of the blade to the trailing edge.

[0016] In some embodiments, on the projection plane formed by the extension direction of the blade and the height direction of the blade, the projection of the turbulence rib forms an angle α with the airflow direction of the corresponding flow path, and α is 60°-90°.

[0017] In some embodiments, the height of any of the baffle ribs is l, and the distance between any two adjacent baffle ribs is s, where 0.8l≤s≤1.5l.

[0018] In some embodiments, the blade has an impact cavity and is provided with an impact hole and a first film air hole communicating with the impact cavity. The impact cavity is adjacent to the leading edge of the blade and is arranged with the cooling channel in a direction from the leading edge of the blade toward the trailing edge. The end of the impact hole opposite to the impact cavity is connected to the transition section, and the end of the first film air hole opposite to the impact cavity is formed on the leading edge of the blade.

[0019] In some embodiments, the impact cavity extends along the height direction of the blade, and the shortest distance between any position of the central axis of the impact cavity and the leading edge of the blade is equal.

[0020] In some embodiments, the inlet of the impact hole is located between the inlet of the first flow path and the inlet of the second flow path in the height direction of the blade; There are multiple first air film pores, which are arranged at intervals along the leading edge of the blade.

[0021] In some embodiments, the blade tip has a groove recessed toward the blade root, and the blade is further provided with a second air film hole, the second air film hole extending along a direction from the inner wall surface of the diversion section toward the blade tip and extending to the wall surface of the groove.

[0022] In some embodiments, the groove extends in a direction from the leading edge of the blade toward the trailing edge, and the second air film holes are multiple and spaced apart along the extending direction of the groove.

[0023] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the connection structure between the blades and the disk in a radial turbine with a highly efficient internal cooling structure according to an embodiment of the present invention (the blades and the disk are partially cut in half in the figure).

[0025] Figure 2 This is a front view of the connection structure between the blades and the disk portion of a radial turbine with a highly efficient internal cooling structure according to an embodiment of the present invention.

[0026] Figure 3 yes Figure 2 Top view.

[0027] Figure 4 yes Figure 2 Side view.

[0028] Figure 5 This is a perspective view of the connection structure between the blades and the disk portion of a radial turbine with a highly efficient internal cooling structure according to an embodiment of the present invention.

[0029] Figure 6 This is a schematic diagram of the connection structure of the cooling channel, impact hole, impact chamber and second film cooling hole in a radial turbine with a high-efficiency internal cooling structure according to an embodiment of the present invention.

[0030] Figure label: 1. Wheel; 11. Back of the wheel; 12. Mounting surface; 2. Blade; 21. Blade root; 22. Blade leading edge; 23. Blade tip; 231. Groove; 24. Blade trailing edge; 25. Blade pressure surface; 26. Impact chamber; 27. Impact hole; 28. First film air hole; 29. ​​Second film air hole; 3. Cooling channel; 31. Inlet section; 32. Transition section; 33. Flow branching section; 331. First flow path; 3311. First section; 3312. Gradient section; 3313. First split section; 332. Second flow path; 3321. Variable diameter section; 3322. Second section; 3323. Second split section; 4. Baffle column; 5. Blowout ribs. Detailed Implementation

[0031] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0032] like Figures 1 to 5 As shown, a centripetal turbine with a highly efficient internal cooling structure according to an embodiment of the present invention includes a disk 1 and blades 2. The disk 1 has a disk back surface 11 and a mounting surface 12 arranged opposite to each other in its axial direction. The blade root 21 is connected to the mounting surface 12 and forms a connection. The centripetal turbine has a cooling channel 3, which includes an inlet section 31, a transition section 32 and a flow branching section 33 connected in sequence. The inlet section 31 extends from the disk back surface 11 toward the mounting surface 12 and extends to the connection. That is, the inlet section 31 is located inside the disk 1 and the outlet of the inlet section 31 is located at the connection formed by the blade root 21 and the mounting surface 12. The transition section 32 extends toward the leading edge 22 of the blade and is inclined toward the blade tip 23. The flow branching section 33 extends along the leading edge 22 of the blade toward the trailing edge to the adjacent trailing edge 24 of the blade. The flow branching section 33 includes a first flow path 331 and a second flow path 332 arranged at intervals along the height direction of the blade 2.

[0033] According to an embodiment of the present invention, a radial turbine with a highly efficient internal cooling structure allows the cooling medium to enter the inlet section 31 of the cooling channel 3 from the back side 11 of the disk 1, and then into the transition section 32 inside the blade 2. Afterward, the cooling medium can flow into the first flow path 331 and the second flow path 332 respectively. In the transition section 32, the cooling medium can exchange heat with the region adjacent to the leading edge 22 of the blade. The first flow path 331 and the second flow path 332 are arranged along the height direction of the blade 2, allowing the cooling medium to exchange heat with both the high and low spanwise positions of the blade 2, thus cooling the blade tip 23. At the blade root, the flow splitting section 33 also extends to the trailing edge 24 adjacent to the blade, that is, the outlet of the first flow path 331 and the outlet of the second flow path 332 are arranged near the trailing edge 24 of the blade, so that the cooling working fluid can exchange heat with the trailing edge 24 of the blade. Therefore, by adopting the above structural design, the mutual influence between various cooling parts can be reasonably considered, and the simultaneous and efficient cooling of the leading edge 22, blade tip, blade root and trailing edge of the blade can be achieved. Therefore, compared with related technologies, the present invention can achieve cooling of various key parts of the radial turbine, reduce the temperature of high temperature and high stress positions, and extend the service life of the radial turbine.

[0034] Specifically, the radial turbine may further include a volute (not shown in the figure), which has a receiving cavity. Both the disk 1 and the blades 2 are located within the receiving cavity and are rotatable relative to it. The axial direction of the disk 1 is aligned with the direction of their pivot axes. Multiple blades 2 may be arranged at circumferential intervals along the disk 1. The inlet of the inlet section 31 is formed on the back surface 11 of the disk, meaning a cooling fluid inlet is provided on the back surface of the disk. The transition section 32 and the flow branching section 33 are located inside the blades 2. The first flow path 331 and the second flow path 332 can jointly cover the blade body of the blade 2, meaning they cover both the high spanwise and low spanwise positions of the blade 2.

[0035] It should be noted that the height of the blade 2 span is defined according to the height direction of the blade 2. "Span" is the direction from the leaf root 21 to the leaf tip 23 of the blade. "High span position" is the position close to the leaf tip 23 of the blade, while "low span position" is the position close to the leaf root 21 of the blade.

[0036] like Figures 3 to 5 As shown, in some embodiments, the first flow path 331 is connected to the end of the transition section 32 away from the inlet section 31, and the inlet of the second flow path 332 is located between the inlet of the transition section 32 and the inlet of the first flow path 331 in the height direction of the blade 2. That is, the first flow path 331 can be closer to the blade tip 23 than the second flow path 332.

[0037] Understandably, after the cooling medium impacts the wall of the transition section 32, a portion of the cooling medium can flow into the first flow path 331 under the action of centrifugal force, and exchange heat with the leading edge 22 of the blade, the high spanwise position of the blade 2, and the trailing edge 24 of the blade in sequence. Meanwhile, another portion of the cooling medium can enter the second flow path 332 and fully exchange heat with the low spanwise position of the blade 2 and the trailing edge 24 of the blade, thereby constructing a dual-flow-path cooling structure. This allows the cooling medium to efficiently cool the leading edge, blade tip, blade root, and trailing edge simultaneously, achieving full heat exchange with each high-temperature and high-stress location.

[0038] For example, as shown in the figure, the transition section 32 may have two bends inside the blade 2. The first bend (the bend near the inlet section 31) is connected to the inlet of the second flow path 332, and the second bend (the bend near the leading edge 22 of the blade) is connected to the inlet of the first flow path 331. The first bend may be a 90° bend from the blade root 21 toward the leading edge, and the second bend may be a 90° bend from the leading edge 22 of the blade toward the blade tip.

[0039] It should be noted that the aforementioned "high temperature and high stress locations" include the mounting surface 12 of the wheel 1, as well as the leading edge 22 of the blade, the blade tip, the blade root, and the trailing edge, which are prone to localized high temperatures.

[0040] like Figures 3 to 5 As shown, in some embodiments, the outlet of at least one of the first flow path 331 and the second flow path 332 is formed on the pressure surface 25 of the blade, that is, the outlet of the first flow path 331 is formed on the pressure surface 25 of the blade; or, the outlet of the second flow path 332 is formed on the pressure surface 25 of the blade; or, the outlet of each of the first flow path 331 and the second flow path 332 is formed on the pressure surface 25 of the blade, in other words, the cooling channel 3 has a tail-edge pressure-side cooling medium outlet.

[0041] Understandably, compared to the trailing edge center slotted outflow form of related technologies, which leads to severe aerodynamic efficiency loss of the radial turbine, the present invention adopts a trailing edge pressure side cooling working fluid outflow form. This not only effectively reduces the aerodynamic loss of the radial turbine, but also, after the cooling working fluid flows out through the trailing edge pressure side outlet, under the pressure of the mainstream high-temperature gas, the cooling working fluid flowing out through the trailing edge pressure side outlet will flow closely to the trailing edge position towards the suction side, so as to play a thermal protection role for the high-temperature area of ​​the trailing edge pressure side. At the same time, the trailing edge pressure side cooling working fluid outlet setting can also prevent the backflow of high-temperature gas at the trailing edge.

[0042] It should be noted that the "mainstream high-temperature gas" mentioned above refers to the high-temperature gas flowing through the stationary and moving blades.

[0043] like Figure 5 and Figure 6 As shown, in some embodiments, the first flow path 331 includes a first segment 3311, a tapering segment 3312, and a first slit segment 3313 arranged sequentially and connected along the leading edge 22 of the blade toward the trailing edge. One end of the first segment 3311 away from the tapering segment 3312 is connected to the transition segment 32. One end of the first slit segment 3313 away from the tapering segment 3312 is formed on the pressure surface 25 of the blade to form a trailing edge pressure side cooling medium outlet. At this time, the trailing edge pressure side cooling medium outlet is the pressure side slit outlet near the trailing edge.

[0044] Understandably, the tapered flow channel structure of the tapered section 3312 can accelerate the low-speed cooling medium reaching the trailing edge 24 of the blade to obtain a high-velocity cooling medium. The high-velocity cooling medium can prevent the backflow of the mainstream high-temperature gas. At the same time, the pressure side slit outlet design near the trailing edge can completely preserve the trailing edge structure of the radial turbine, greatly reducing aerodynamic losses.

[0045] Specifically, the cross-sectional area of ​​the first segment 3311 can gradually increase along the direction from the first segment 3311 toward the tapering segment 3312, the maximum cross-sectional area of ​​the tapering segment 3312 can be equal to the maximum cross-sectional area of ​​the first segment 3311, and the cross-sectional area of ​​the tapering segment 3312 can gradually decrease along the direction from the first segment 3311 toward the tapering segment 3312.

[0046] like Figure 5 and Figure 6 As shown, in some embodiments, the tapered segment 3312 is a single segment, and the first split segment 3313 is a single segment that corresponds one-to-one with the tapered segment 3312.

[0047] Alternatively, there may be at least two tapered sections 3312 arranged at intervals along the height direction of the blade 2, and at least two first slit sections 3313 corresponding one-to-one with the tapered sections 3312. The number of tapered sections 3312 should not be too many, as stress concentration and manufacturing requirements need to be considered. At the same time, the number of tapered sections should not be too few, as centrifugal force needs to be considered to prevent the cooling medium from accumulating at the blade tip 23. In addition, the spacing between any two adjacent tapered sections 3312 should be designed to take into account the actual cooling effect on the surface of the blade 2.

[0048] like Figure 5 and Figure 6 As shown, in some embodiments, the centripetal turbine also includes a turbulence column 4, which is disposed in the tapering section 3312. There are multiple turbulence columns 4, which are arranged at intervals in the tapering section 3312, so that the cooling medium accelerated by the tapering section 3312 impacts the turbulence column 4 to form turbulence, thereby enhancing the heat exchange effect between the cooling medium and the wall. At the same time, the tapering structure of the tapering section 3312 can locally accelerate the cooling medium that reaches the trailing edge 24 of the blade, ensuring that after the cooling medium flows out from the trailing edge 24 of the blade, it can still cover the trailing edge 24 of the blade under the pressure of the mainstream high-temperature gas, so as to achieve a good cooling effect on the high-temperature position of the trailing edge 24 of the blade, that is, to enhance the heat exchange capacity of the first slit section 3313.

[0049] For example, as shown in the figure, the diameter of the turbulence column 4 is approximately 0.5 mm.

[0050] like Figure 5 and Figure 6 As shown, in some embodiments, the second flow path 332 includes a variable diameter section 3321, a second section 3322, and a second slit section 3323 arranged sequentially and connected along the leading edge 22 of the blade toward the trailing edge.

[0051] The end of the variable diameter section 3321 that is away from the second section 3322 is connected to the transition section 32. The cross-sectional area of ​​the variable diameter section 3321 gradually decreases and then gradually increases along the direction from the variable diameter section 3321 toward the second section 3322. In other words, the variable diameter section 3321 is a variable diameter acceleration section that first gradually shrinks and then gradually expands. The end of the second slit section 3323 that is away from the second section 3322 is formed on the pressure surface 25 of the blade. Similarly, the second slit section 3323 also forms a pressure side slit outlet near the trailing edge.

[0052] Understandably, the variable diameter section 3321 can accelerate the cooling medium flowing from the transition section 32 into the second flow path 332, so as to ensure that the cooling medium still has a high speed and pressure when it reaches the second slit section 3323. At the same time, the design of the second slit section 3323 can also completely retain the trailing edge structure of the radial turbine, greatly reducing aerodynamic losses.

[0053] Specifically, the cross-sectional area of ​​the second segment 3322 can gradually increase in the direction from the variable diameter segment 3321 toward the second segment 3322, and the maximum cross-sectional area of ​​the portion of the variable diameter segment 3321 adjacent to the second segment 3322 is equal to the minimum cross-sectional area of ​​the second segment 3322.

[0054] For example, as shown in the figure, the inlet width of the variable diameter section 3321 in the second flow path 332 is 4 mm, and the length is approximately 3.1 mm. The inlet cross-section is rectangular, and the minimum distance between the upper and lower cross-sections in the second flow path 332 is only 3.5 mm. The width of the first flow path 331 is 1.8 mm. The cross-sectional area of ​​each of the first split section 3313 and the second split section 3323 can be rectangular, with a width of approximately 0.5 mm and a length given according to the outlet of the corresponding flow path, not exceeding a maximum of 7 mm.

[0055] like Figure 5 and Figure 6 As shown, in some embodiments, the centripetal turbine further includes a baffle 5. At least one of the first flow path 331 and the second flow path 332 is provided with the baffle 5, that is, the first flow path 331 is provided with the baffle 5; or, the second flow path 332 is provided with the baffle 5; or, both the first flow path 331 and the second flow path 332 are provided with the baffle 5. The baffle 5 may extend in the direction from the blade root 21 toward the blade tip.

[0056] There are multiple turbulence ribs 5, which are arranged at intervals along the extension direction of the corresponding flow path, and the extension direction of the corresponding flow path is the direction from the leading edge 22 of the blade to the trailing edge.

[0057] Understandably, the turbulence rib 5 is beneficial to enhancing the heat exchange capacity between the local area and the cooling medium. When the cooling medium flows along the chord of the blade 2 under the action of strong centrifugal force, the cooling medium impacts the side wall of the turbulence rib 5, forming turbulence. The flow velocity and pressure of the cooling medium decrease at the same time, and at this time, it fully exchanges heat with the wall of the turbulence rib 5, effectively reducing the temperature of the blade 2 in this area.

[0058] Specifically, in the first flow path 331, the portion of the first segment 3311 adjacent to the tapering segment 3312 may be provided with a flow-deflecting rib 5. In the second flow path 332, the portion of the second segment 3322 adjacent to the second split segment 3323 may be provided with a flow-deflecting rib 5.

[0059] For example, as shown in the figure, the depth of the baffle 5 is about 0.5 mm, the length is about 0.7 mm, and the width depends on the width of the internal cooling channel 3.

[0060] like Figure 5 and Figure 6As shown, in some embodiments, on the projection surface formed by the extension direction of the blade 2 and the height direction of the blade 2, the projection of the deflector rib 5 forms an angle α with the airflow direction of the corresponding flow path, and α is 60°-90°. For example, α can be 60°, 65°, 70°, 75°, 80°, 85°, 90°, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0061] like Figure 5 and Figure 6 As shown, in some embodiments, the height of any one of the baffle ribs 5 is l, and the distance between any two adjacent baffle ribs 5 is s, where 0.8l ≤ s ≤ 1.5l. That is, the distance between any two adjacent baffle ribs 5 is approximately between 80% and 150% of the height of the baffle rib 5. For example, the distance between any two adjacent baffle ribs 5 is in the range of 0.3mm to 1mm.

[0062] Understandably, designing the turbulence rib 5 structure with the above parameters can further improve the heat exchange effect between the cooling medium and the wall of the corresponding flow path.

[0063] like Figure 5 and Figure 6 As shown, in some embodiments, the blade 2 has an impact cavity 26 and is provided with an impact hole 27 and a first film air hole 28 communicating with the impact cavity 26. The impact cavity 26 is adjacent to the leading edge 22 of the blade and is arranged with the cooling channel 3 in the direction from the leading edge 22 of the blade toward the trailing edge. The end of the impact hole 27 away from the impact cavity 26 is connected to the transition section 32. The end of the first film air hole 28 away from the impact cavity 26 is formed on the leading edge 22 of the blade. That is, the first film air hole 28 is a leading edge film air hole.

[0064] Understandably, the above structure forms a combined cooling strategy of leading-edge film cooling and impact cooling. The cooling medium enters through the cooling medium inlet on the back of the disc and flows to the leading edge 22 of the blade under the action of centrifugal force. Part of the cooling medium enters the impact chamber 26 through the impact hole 27. The cooling medium forms turbulence in the impact chamber 26, which enhances its convective heat transfer with the high-temperature wall. Then, under the combined action of strong centrifugal force and pressure, the cooling medium in the impact chamber 26 is ejected through the first film cooling hole 28. The ejected cooling medium also has a certain covering and protective effect on the leading edge 22 of the blade.

[0065] Specifically, the impact cavity 26 can extend along the height direction of the blade 2. The impact cavity 26 and the cooling channel 3 can be arranged at intervals along the direction from the leading edge 22 of the blade toward the trailing edge. The impact hole 27 can be located between the impact cavity 26 and the cooling channel 3. The extension direction of the impact hole 27 can be along the direction from the leading edge 22 of the blade toward the trailing edge.

[0066] like Figure 5 and Figure 6 As shown, in some embodiments, the impact cavity 26 extends along the height direction of the blade 2, and the shortest distance between any position of the central axis of the impact cavity 26 and the leading edge 22 of the blade is equal. In other words, the impact cavity 26 is conformed to the leading edge 22 of the blade to further improve the heat transfer uniformity at all points of the leading edge 22 of the blade.

[0067] For example, as shown in the figure, the diameter of the impact hole 27 is about 0.6 mm, the length of the impact cavity 26 is about 5.8 mm, and the width is about 2 mm. The wall of the impact cavity 26 away from the leading edge 22 of the blade can be rectangular, and the wall adjacent to the leading edge 22 of the blade can be similar in shape to the leading edge 22 of the blade.

[0068] like Figure 5 and Figure 6 As shown, in some embodiments, the inlet of the impact hole 27 is located between the inlet of the first flow path 331 and the inlet of the second flow path 332 in the height direction of the blade 2, so that the cooling working fluid can be divided into three paths through the transition section 32 and enter the second flow path 332, the impact chamber 26 and the first flow path 331 respectively.

[0069] There are multiple first air film pores 28, which are arranged at intervals along the leading edge 22 of the blade to ensure uniform heat exchange to the leading edge 22 of the blade and improve the heat exchange effect.

[0070] like Figure 5 and Figure 6 As shown, in some embodiments, the blade tip 23 has a groove 231 recessed toward the blade root 21, and the blade 2 is also provided with a second air film hole 29. The second air film hole 29 extends from the inner wall surface of the flow divider section 33 toward the blade tip 23 and extends to the wall surface of the groove 231. That is, the second air film hole 29 is a blade tip air film hole. Specifically, the second air film hole 29 extends from the inner wall surface of the first section 3311 in the first flow path 331 toward the blade tip 23.

[0071] Understandably, the above structure forms a film cooling strategy with the blade tip groove 231 superimposed on it. Affected by the blade tip gap flow, the mainstream high-temperature gas flows from the pressure surface to the suction surface through the blade tip gap. The high-temperature gas scours the blade tip 23 position, causing local high temperature. By setting the groove 231 and arranging the second film cooling hole 29, thermal protection can be provided to the high-temperature position at the blade tip. At the same time, the cooling medium sprayed from the second film cooling hole 29 scours the high spanwise region near the blade tip along the chord of the blade 2, which has a cooling and protective effect on the groove 231. Subsequently, under the entrainment effect of the blade tip gap flow, the cooling medium inside the groove 231 moves from the pressure surface 25 of the blade to the suction surface, and at the same time has a cooling effect on the shoulders on both sides of the groove 231.

[0072] like Figure 5 and Figure 6 As shown, in some embodiments, the groove 231 extends from the leading edge 22 of the blade toward the trailing edge, and the second air film holes 29 are multiple and arranged at intervals along the extending direction of the groove 231, so as to ensure uniform heat exchange to the blade tip 23 and improve the heat exchange effect.

[0073] Specifically, since the blades 2 of the radial turbine are relatively thin, and the trailing edge of the blade tip region is even thinner, the groove 231 can be arranged near the leading edge 22 of the blade, provided that the processing and manufacturing accuracy is met.

[0074] For example, as shown in the figure, the diameter of the cooling medium inlet on the back of the plate is about 5 mm, the diameter of the first air film hole 28 is about 0.6 mm, the width of the groove 231 is about 0.8 mm, the depth is about 0.7 mm, the length is about 32 mm, and the diameter of the second air film hole 29 is about 0.6 mm.

[0075] The working process of this radial turbine with its highly efficient internal cooling structure will now be explained in detail below: The cooling medium enters the cooling channel 3 of the radial turbine from the cooling medium inlet on the back of the disk. After passing through the transition section 32 of the cooling channel 3, part of the cooling medium enters the second flow path 332 to cool the low spanwise position of the blade 2. It flows through the turbulence column 4 in the second flow path 332 and undergoes sufficient heat exchange. Then it flows out through the second slit section 3323 and covers the high-temperature area of ​​the trailing edge of the low spanwise position of the blade 2. The remaining part of the cooling medium enters the first flow path 331, and a small part of the cooling medium enters the impact chamber 26 through the impact hole 27, forming turbulence. Under the action of strong centrifugal force and pressure, The coolant is ejected through the first film cooling hole 28, and the remaining coolant continues to flow along the first flow path 331. Under the action of centrifugal force, a small portion of the coolant flows out through the second film cooling hole 29 and cools the groove 231. Under the pressure of the blade tip gap flow, it flows towards the suction side. The remaining coolant is fully heat-exchanged by the turbulence ribs 5 and turbulence columns 4 of the first flow path 331 and then accelerates to flow out through the first slit section 3313. As a result, the centrifugal turbine with a highly efficient internal cooling structure greatly reduces the highest and average surface temperature of the blade 2 and enhances the surface temperature uniformity of the blade 2.

[0076] Therefore, compared with related technologies, the present invention has the following advantages: 1) The cooling channel 3 structure of the present invention enables the cooling medium to efficiently cool the leading edge 22, blade tip, blade root and trailing edge of the blade simultaneously under the action of strong centrifugal force. The dual flow path design ensures that the cooling medium can fully exchange heat at the high temperature and high stress position of the blade root in the second flow path 332, and also ensures that an appropriate amount of cooling medium is supplied to the leading edge 22 and blade tip of the blade, so that the cooling medium still has sufficient pressure and velocity when it reaches the trailing edge 24 outlet of the blade. Under the action of the mainstream high temperature and high pressure gas, the trailing edge 24 of the blade can be effectively thermally protected. 2) The present invention optimizes the cooling arrangement of the leading edge 22 of the blade. By applying a combination of air film cooling and impingement cooling to the leading edge 22 of the blade, the leading edge 22 of the blade can obtain a good heat exchange effect. 3) The present invention optimizes the blade tip cooling structure. A combination of groove 231 and air film hole is added to the chord position in the first flow path 331 to provide thermal protection for the blade tip, which can make the blade tip 23 of the blade obtain a good heat exchange effect. 4) This invention optimizes the trailing edge 24 outlet structure of the blade and designs a cooling working fluid outlet on the pressure side of the trailing edge. While ensuring that the cooling working fluid outflow from the trailing edge covers the air film at the trailing edge, it can also improve the turbine aerodynamic efficiency and prevent backflow. 5) The present invention lays turbulence ribs 5 and turbulence columns 4 at a certain spacing and depth in the cooling channel 3, so as to improve the heat exchange effect of the cooling channel 3 while ensuring the flow rate and pressure of the cooling working fluid.

[0077] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0078] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least one, such as two, three, etc., unless otherwise explicitly specified.

[0079] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0080] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0081] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0082] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A radial turbine with a highly efficient internal cooling structure, characterized in that, include: A wheel, the wheel having a back surface and a mounting surface arranged opposite each other in its axial direction; The blade has its root connected to the mounting surface, forming a connection. The radial turbine has a cooling channel, which includes an inlet section, a transition section and a branch section connected in sequence. The inlet section extends from the back of the disk toward the mounting surface and to the connection point. The transition section extends toward the leading edge of the blade and is inclined toward the blade tip. The branch section extends along the leading edge of the blade toward the trailing edge to a position adjacent to the trailing edge of the blade. The flow divider section includes a first flow path and a second flow path arranged at intervals along the height direction of the blade.

2. The radial turbine with a high-efficiency internal cooling structure according to claim 1, characterized in that, The first flow path is connected to the end of the transition section away from the inlet section, and the inlet of the second flow path is located between the inlet of the transition section and the inlet of the first flow path in the height direction of the blade.

3. The radial turbine with a high-efficiency internal cooling structure according to claim 1, characterized in that, The outlet of at least one of the first flow path and the second flow path is formed on the pressure surface of the blade.

4. The radial turbine with a high-efficiency internal cooling structure according to claim 1, characterized in that, The first flow path includes a first segment, a tapering segment, and a first slit segment arranged sequentially and connected along the leading edge of the blade toward the trailing edge. The end of the first segment away from the tapering segment is connected to the transition segment, and the end of the first slit segment away from the tapering segment is formed on the pressure surface of the blade.

5. The radial turbine with a high-efficiency internal cooling structure according to claim 3, characterized in that, The tapering segment is a single unit, and the first split segment is a single unit, corresponding one-to-one with the tapering segment; or... The tapering section consists of at least two segments arranged at intervals along the height direction of the blade, and the first slit segment consists of at least two segments, each corresponding to one of the tapering sections.

6. The radial turbine with a high-efficiency internal cooling structure according to claim 1, characterized in that, The second flow path includes a variable diameter section, a second section, and a second slit section arranged sequentially and connected along the direction from the leading edge to the trailing edge of the blade; The end of the variable diameter section opposite to the second section is connected to the transition section. The cross-sectional area of ​​the variable diameter section gradually decreases and then gradually increases along the direction from the variable diameter section toward the second section. The end of the second slit section opposite to the second section is formed on the pressure surface of the blade.

7. The radial turbine with a high-efficiency internal cooling structure according to claim 1, characterized in that, It also includes a flow-deflecting rib, wherein at least one of the first flow path and the second flow path is provided with a flow-deflecting rib; There are multiple turbulence ribs, which are arranged at intervals along the extension direction of the corresponding flow path, and the extension direction of the corresponding flow path is the direction from the leading edge of the blade to the trailing edge.

8. The radial turbine with a high-efficiency internal cooling structure according to claim 1, characterized in that, The blade has an impact cavity and is provided with an impact hole and a first air film hole that communicate with the impact cavity. The impact cavity is adjacent to the leading edge of the blade and is arranged with the cooling channel in a direction from the leading edge of the blade toward the trailing edge. The end of the impact hole facing away from the impact cavity communicates with the transition section. The end of the first air film hole facing away from the impact cavity is formed on the leading edge of the blade.

9. The radial turbine with a high-efficiency internal cooling structure according to claim 7, characterized in that, The impact cavity extends along the height direction of the blade, and the shortest distance between any position of the central axis of the impact cavity and the leading edge of the blade is equal.

10. The radial turbine with a high-efficiency internal cooling structure according to claim 1, characterized in that, The blade tip has a groove recessed toward the blade root, and the blade is also provided with a second air film hole, which extends from the inner wall surface of the diversion section toward the blade tip and extends to the wall surface of the groove.

Images