Turbine interstage guider

Abstract

The invention relates to a turbine interstage guider, which belongs to the field of turbine engines and comprises a guider body, a composite swept-curved blade is arranged in an airflow channel of the guider body, and the axial chord length of the root section of the blade is longer than the axial chord length of the middle section of the blade and shorter than the axial chord length of the tip section of the blade. The blades comprise first blades, second blades and third blades which are consistent in structure, the second blades and the third blades are evenly distributed in the airflow channel, the first blades are evenly distributed on the portion, located between the second blades and the third blades, of the airflow channel, and the axial chord length of the second blades is larger than that of the first blades; the tail edge radiuses of the second blade and the first blade are the same. By means of the spatial arrangement of the first blade, the second blade and the third blade and the full-three-dimensional composite swept-curved feature modeling, the weight of the turbine is reduced, flow separation of the blades can be effectively controlled, the total pressure loss of the transition section is reduced, and the aerodynamic efficiency of the turbine is improved.

Description

Technical Field

[0001] The invention belongs to the field of turbine engines, and in particular relates to a turbine interstage guide vane. Background Art

[0002] In modern high-performance aviation turbine engines, in order to reduce fuel consumption and reduce the total weight of the engine, a turbine transition section as short as possible is usually used to achieve the transition of the airflow from the gas turbine to the power turbine. The significance of the integrated transition section design technology lies in the integrated design of the transition section between the gas turbine and the power turbine and the first-stage guide vane of the power turbine, that is, the transition section itself is also the guide vane of the power turbine, which not only reduces the total weight of the engine, but also saves space. The main function of the integrated transition section is to transfer the radial force generated by the gas turbine and power turbine rotors to the turbine support casing, and to convert the enthalpy of the low-pressure turbine outlet gas into kinetic energy.

[0003] Compared with ordinary transition sections, the integrated transition section not only has obvious structural differences, but also has significant differences in flow mechanisms. The combined effect of the expansion of the outer ring, the upstream rotor wake, and the change in flow curvature also makes it easier for the boundary layer to separate inside the ring, thereby increasing flow losses. Studies have shown that large blades have a significant impact on adjacent small blades. At present, some existing engines use integrated transition sections with a large number of large blades and thick thickness, and the linear shape and spatial position of large and small blades are arranged differently, which not only increases the weight of the turbine, but also leads to separation of the flow field between the large blades and the adjacent small blades, large total pressure loss in the transition section, and low aerodynamic efficiency of the turbine stage. Summary of the invention

[0004] In view of the above problems, the present invention provides a turbine interstage guide, comprising a guide body, a composite swept blade is arranged in the air flow channel of the guide body, the axial chord length of the root section of the blade is longer than the axial chord length of the middle section of the blade, and shorter than the axial chord length of the tip section of the blade, the blade comprises a first blade, a second blade and a third blade with the same structure, the second blade and the third blade are evenly distributed in the air flow channel, the first blade is evenly distributed in the portion of the air flow channel between the second blade and the third blade, the axial chord length of the second blade is longer than the axial chord length of the first blade, the trailing edge radius of the second blade is the same as that of the first blade, and the leading edge and trailing edge radii of the first blade are both smaller than the leading edge radius of the second blade.

[0005] Furthermore, the turning angles of the root, middle and tip sections of the second blade are 20-30°, 30-50° and 75-85° respectively.

[0006] Furthermore, the leading edge radius of the second blade is 4-5 mm, and the trailing edge radius is 1-1.5 mm.

[0007] Further, a first throat is provided in the flow passage between the pressure surface of the second blade root section and the suction surface of the adjacent first blade root section, the inlet position of the first throat is located at the trailing edge of the second blade root section, a second throat is provided in the flow passage between the suction surface of the second blade root section and the pressure surface of the adjacent first blade root section, the inlet position of the second throat is located at the trailing edge of the first blade root section, and the outlet position of the first throat is adjacent to the inlet position of the second throat.

[0008] Further, the inlet width of the first throat is the same as the inlet width of the second throat, the inlet width of the second throat is greater than the outlet width of the second throat, and the outlet width of the second throat is greater than the outlet width of the first throat.

[0009] Furthermore, a third throat is provided in the flow passage between the pressure surface of the middle section of the second blade and the suction surface of the middle section of the adjacent first blade, and the inlet position of the third throat is located at the trailing edge of the middle section of the second blade; a fourth throat is provided in the flow passage between the suction surface of the middle section of the second blade and the pressure surface of the middle section of the adjacent first blade, and the inlet position of the fourth throat is located at the trailing edge of the middle section of the first blade; the outlet position of the fourth throat is adjacent to the leading edge of the middle section of the second blade, and the outlet position of the third throat is located at the trailing edge of the middle section of the second blade.

[0010] Further, the inlet width of the third throat is greater than the outlet width of the third throat, the outlet width of the third throat is the same as the inlet width of the fourth throat, and the inlet width of the fourth throat is greater than the outlet width of the fourth throat.

[0011] Further, a fifth throat is provided in the flow passage between the pressure surface of the second blade tip cross section and the suction surface of the adjacent first blade tip cross section, the inlet position of the fifth throat is located at the trailing edge of the second blade tip cross section, and the outlet position of the fifth throat is located at the trailing edge of the second blade tip cross section, and a sixth throat is provided in the flow passage between the suction surface of the second blade tip cross section and the pressure surface of the adjacent first blade tip cross section, the inlet position of the sixth throat is located at the trailing edge of the first blade tip cross section, and the outlet position of the sixth throat is located at the trailing edge of the second blade tip cross section.

[0012] Further, the inlet width of the sixth throat is greater than the inlet width of the fifth throat, the inlet width of the fifth throat is greater than the outlet width of the fifth throat, and the outlet width of the fifth throat is the same as the outlet width of the sixth throat.

[0013] Furthermore, the turning angles of the root, middle and tip sections of the first blade are 30-40°, 30-40° and 100-130° respectively.

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

[0015] 1) The present invention utilizes the spatial arrangement of the first blade, the second blade, and the third blade and the full three-dimensional composite curved and swept feature modeling to reduce the weight of the turbine and effectively control the flow separation of the blades, thereby not only reducing the total pressure loss in the transition section but also improving the aerodynamic efficiency of the turbine.

[0016] 2) The blades in the present invention are shaped through full three-dimensional composite bending and sweeping features, and the axial chord lengths of the root, middle and tip sections of the blades are inconsistent, so the stacking line is not a radial straight line, and the leading edge radius of the second blade is greater than the trailing edge radius, and the trailing edge radii of the first blade and the second blade are the same. Therefore, the blade profiles of the second blade and the first blade change dramatically, can adapt to uneven incoming flow conditions, effectively control the flow separation of the blades, enhance the flow capacity of the turbine stage, and improve the performance of the turbine.

[0017] 3) The change in the throat position of the flow passage between the second blade and the adjacent first blade in the present invention can reduce the peak Mach number in the flow passage between the first blade and the second blade, weaken or even eliminate the shock wave, and also weaken or even eliminate the flow separation between the pressure side of the first blade and the suction side of the second blade, thereby reducing energy loss and improving turbine performance.

[0018] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic structural diagram of a turbine interstage guide device according to Embodiment 1 of the present invention is shown;

[0021] Figure 2 A schematic diagram showing a comparison between a second blade root cross section and an adjacent first blade root cross section is shown;

[0022] Figure 3 A schematic diagram showing a comparison between a middle section of a second blade and a middle section of an adjacent first blade is shown;

[0023] Figure 4A schematic diagram showing a comparison between a cross section of a second blade tip and a cross section of an adjacent first blade tip is shown;

[0024] Figure 5 A schematic diagram of the blade profile stacking of the second blade is shown;

[0025] Figure 6 A schematic diagram of the stacking line of the blade is shown;

[0026] Figure 7 A schematic diagram of the circumferential shape definition of a blade is shown;

[0027] Figure 8 A schematic diagram of blade profile stacking of a first blade is shown;

[0028] Fig. 9 The mid-section Mach number distribution cloud diagram of the first blade and the second blade is shown;

[0029] Fig.10 A schematic diagram of the structure of the pipeline is shown;

[0030] Fig.11 A three-dimensional stereogram of the first embodiment of the present invention is shown;

[0031] Fig.12 A schematic diagram of the turning angle of the root section of the second blade is shown;

[0032] Fig.13 A schematic diagram of the turning angle of the middle section of the second blade is shown;

[0033] Fig.14 A schematic diagram of the turning angle of the second blade tip cross section is shown;

[0034] Fig.15 A schematic diagram of the turning angle of the first blade root section is shown;

[0035] Fig.16 A schematic diagram of the turning angle of the middle section of the first blade is shown;

[0036] Fig.17 A schematic diagram of the turning angle of the first blade tip cross section is shown.

[0037] Figure numerals: 1. guide body; 11. outer ring; 12. inner ring; 13. air flow channel; 14. first blade; 141. first blade root section; 142. first blade middle section; 143. first blade tip section; 15. second blade; 151. pipeline; 152. second blade root section; 153. second blade middle section; 154. second blade tip section; 16. third blade; 17. flow channel; 171. first throat; 172. second throat; 173. third throat; 174. fourth throat; 175. fifth throat; 176. sixth throat; 2. leading edge; 3. pressure surface; 4. trailing edge; 5. suction surface. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Embodiment 1

[0040] Figure 1 FIG. 2 shows a schematic diagram of a structure according to an embodiment of the present invention. Figure 1 As shown, a turbine interstage guide vane comprises a guide vane body 1, wherein a three-dimensional composite curved blade is arranged in an air flow passage 13 of the guide vane body 1, wherein an axial chord length of a root section of the blade is longer than an axial chord length of a middle section of the blade and shorter than an axial chord length of a tip section of the blade, wherein the blade comprises a first blade 14, a second blade 15 and a third blade 16 of the same structure, wherein the second blade 15 and the third blade 16 are evenly distributed in the air flow passage 13, wherein the first blade 14 is evenly distributed at a portion of the air flow passage 13 between the second blade 15 and the third blade 16, wherein an axial chord length of the second blade 15 is longer than an axial chord length of the first blade 14, wherein the trailing edge 4 radii of the second blade 15 and the first blade 14 are the same, and the leading edge 2 and trailing edge 4 radii of the first blade 14 are both smaller than the leading edge 2 radius of the second blade 15.

[0041] The turbine interstage guide vane utilizes the spatial arrangement of the first blade 14, the second blade 15 and the third blade 16 and the full three-dimensional composite curved feature modeling to reduce the weight of the turbine. On this basis, the lengths of the root, middle and tip sections of the blades are different, and the radii of the leading edge 2 and the trailing edge 4 of the blades are different, resulting in more drastic changes in the blade profile, thereby effectively controlling the flow separation of the blades, which not only reduces the total pressure loss in the transition section, but also improves the aerodynamic efficiency of the turbine.

[0042] Specifically, the full three-dimensional composite bending and sweeping feature is a prior art, so it will not be described in detail here.

[0043] Fig.11 1 shows a three-dimensional stereogram of an embodiment of the present invention. Fig.11 As shown, specifically, the guide body 1 is provided with an inner ring 12 , blades, and an outer ring 11 in sequence and diffused outwardly along the axial direction. The distance between the inner ring 12 and the outer ring 11 is an air flow channel 13 , and the blades are arranged in the air flow channel 13 .

[0044] Figure 5 A schematic diagram of the blade profile stacking of the second blade 15 is shown; Figure 6 A schematic diagram of the stacking line of the blades is shown; Figure 7 A schematic diagram of the circumferential shape definition of a blade is shown; Figure 8 FIG. 4 shows a schematic diagram of the blade profile stacking of the first blade 14. Figures 5 to 8 As shown, in some embodiments, the stacking lines of the blades are not on a radial straight line, the axial chord length of the root section of the blade is longer than the axial chord length of the middle section of the blade, and shorter than the axial chord length of the tip section of the blade. Then, the blade profile changes dramatically from the root to the tip section, which can better adapt to uneven incoming flow conditions, effectively control the flow separation of the blades, enhance the flow capacity of the turbine, and improve the performance of the turbine.

[0045] In some embodiments, the axial chord length of the second blade 15 is 80-87 mm, which can better adapt to uneven incoming flow conditions, including uneven incoming flow pressure, airflow angle, etc., and effectively control the flow separation of the blade.

[0046] In some embodiments, the axial chord length of the first blade 14 is 70 to 80 mm, and the axial chord length of the first blade 14 is shorter than the axial chord length of the second blade 15. The second blade 15 and the third blade 16 can envelop the blade profile of the first blade 14. On this basis, the trailing edge 4 radius of the second blade 15 is the same as that of the first blade 14, and the leading edge 2 radius of the second blade 15 is greater than the trailing edge 4 radius of the second blade 15. The blade profile changes more dramatically, can better adapt to uneven incoming flow conditions, and has strong adaptability.

[0047] In some embodiments, the thickness of the second blade 15 is 20-22 mm, which can not only envelop the first blade 14 but also facilitate the installation of the oil pipe.

[0048] In some embodiments, the first blade 14 has a thickness of 8.5 to 12.5 mm, can be enveloped by the second blade 15 and the third blade 16 , and can meet the distribution requirements of the second blade 15 , the third blade 16 , and the first blade 14 on the airflow channel 13 .

[0049] In some embodiments, the second blades 15 and the third blades 16 are evenly distributed in the airflow channel 13, and the first blades 14 are evenly distributed at the position of the airflow channel 13 between the second blades 15 and the third blades 16; the arrangement of the first blades 14, the second blades 15 and the third blades 16 in the airflow channel 13 can ensure reasonable distribution of the blades, better flow field distribution and less aerodynamic loss when the inlet Mach number is high and the inlet flow conditions are uneven; since there are only two thick blades in the blades, the weight of the engine is reduced.

[0050] In some embodiments, the blade shape of the root section of the second blade 15 is a mallet shape; it can better adapt to uneven incoming flow conditions, including uneven incoming flow pressure, airflow, etc., effectively control the flow separation of the blades, enhance the flow capacity of the turbine, and improve the performance of the turbine stage.

[0051] In some embodiments, the blade shape of the tip cross section of the second blade 15 is tadpole-shaped; it can better adapt to uneven incoming flow conditions, including uneven incoming flow pressure, airflow, etc., effectively control the flow separation of the blades, enhance the flow capacity of the turbine, and improve the performance of the turbine stage.

[0052] Fig.12 A schematic diagram of the turning angle of the second blade root section 152 is shown; Fig.13 A schematic diagram of the turning angle of the middle section 153 of the second blade is shown; Fig.14 FIG. 2 shows a schematic diagram of the turning angle of the second blade tip section 154. Figures 12-14 As shown, in some embodiments, the turning angles of the root, middle and tip sections of the second blade 15 are 20-30°, 30-50° and 75-85° respectively; the turning angles determine the blade shapes of the root, middle and tip sections of the second blade 15, and also determine the overall blade shape of the second blade 15. On the basis that the radius of the leading edge 2 of the second blade 15 is greater than the radius of the trailing edge 4 of the second blade 15, the first blade 14, the second blade 15 and the third blade 16 can better adapt to the uneven incoming flow conditions, which not only enhances the flow capacity of the turbine, but also improves the performance of the turbine.

[0053] In some embodiments, the radius of the leading edge 2 of the second blade 15 is 4-5 mm, and the radius of the trailing edge 4 is 1-1.5 mm; the radius of the leading edge 2 and the trailing edge 4 of the second blade 15 is quite different, so that the blade shape changes greatly, so that it can better adapt to uneven incoming flow conditions, effectively control the flow separation of the blades, enhance the flow capacity of the turbine, and improve the performance of the turbine.

[0054] In some embodiments, the radius of the leading edge 2 of the first blade 14 is smaller than the radius of the leading edge 2 of the second blade 15 , which not only facilitates distinguishing the second blade 15 from the first blade 14 , but also provides reasonable conditions for the reasonable distribution of the second blade 15 , the third blade 16 , and the first blade 14 in the airflow channel 13 .

[0055] In some embodiments, the radii of the leading edge 2 and the trailing edge 4 of the first blade 14 are 1-1.3 mm and 1-1.5 mm respectively; the radii of the trailing edges 4 of the first blade 14 and the second blade 15 are both 1-1.5 mm, and the radius of the leading edge 2 of the first blade 14 is 1-1.3 mm, which provides conditions for distinguishing the thickness of the second blade 15 and the first blade 14, and also provides conditions for distinguishing their respective blade shapes.

[0056] Figure 2 FIG. 1 shows a schematic diagram comparing a second blade root section 152 with an adjacent first blade root section 141. Figure 2 As shown, in some embodiments, a first throat 171 is provided in the flow channel 17 between the pressure surface 3 of the second blade root section 152 and the suction surface 5 of the adjacent first blade root section 141, and an inlet position of the first throat 171 is located at the trailing edge 4 of the second blade root section 152, and a second throat 172 is provided in the flow channel 17 between the suction surface 5 of the second blade root section 152 and the pressure surface 3 of the adjacent first blade root section 141, and an inlet position of the second throat 172 is located at the trailing edge 4 of the first blade root section 141, and an outlet position of the first throat 171 is adjacent to an inlet position of the second throat 172; the different positions of the first throat 171 and the second throat 172 can reduce the peak Mach number in the flow channel 17, weaken or even eliminate shock waves, weaken or even eliminate flow separation on the pressure surface 3 side of the first blade root section 141 and the suction surface 5 side of the second blade root section 152, reduce energy loss, and improve turbine performance.

[0057] Fig.10 Schematic diagram of the structure of pipeline 151 is shown. Fig.10 As shown, in some embodiments, a pipe 151 is provided in the second blade 15; the pipe 151 is used for installing an oil pipe.

[0058] In some embodiments, the inlet width of the first throat 171 is the same as the inlet width of the second throat 172, the inlet width of the second throat 172 is greater than the outlet width of the second throat 172, and the outlet width of the second throat 172 is greater than the outlet width of the first throat 171; the widths of the first throat 171 and the second throat 172 are gradually reduced, and the inlet position of the first throat 171 is the same as the inlet position of the second throat 172. Such a design can reduce the peak Mach number in the flow channel 17, weaken or even eliminate shock waves, and can also weaken or even eliminate the flow separation on the pressure surface 3 side of the first blade 14 and the suction surface 5 side of the second blade 15, reduce energy loss, and improve turbine performance.

[0059] Specifically, the inlet widths of the first throat 171 and the second throat 172 are both a1, the outlet width of the first throat 171 is a2, and the outlet width of the second throat 172 is a3, then a1>a3>a2.

[0060] Figure 3 FIG. 1 shows a schematic diagram comparing a second blade middle section 153 with an adjacent first blade middle section 142. Figure 3 As shown, in some embodiments, a third throat 173 is provided in the flow passage 17 between the pressure surface 3 of the second blade middle section 153 and the suction surface 5 of the adjacent first blade middle section 142, and the inlet position of the third throat 173 is located at the trailing edge 4 of the second blade middle section 153, and a fourth throat 174 is provided in the flow passage 17 between the suction surface 5 of the second blade middle section 153 and the pressure surface 3 of the adjacent first blade middle section 142, and the inlet position of the fourth throat 174 is located at the trailing edge 4 of the first blade middle section 142, and the outlet position of the fourth throat 174 is adjacent to the leading edge 2 of the second blade middle section 153, and the outlet position of the third throat 173 is close to the trailing edge 4 of the second blade middle section 153; Fig. 9 The mid-section Mach number distribution cloud diagram of the first blade 14 and the second blade 15 is shown; Fig. 9 As shown, the position of the second throat 172 is different from that of the third throat 173, which can reduce the peak Mach number in the flow channel 17, weaken or even eliminate the shock wave, weaken or even eliminate the flow separation on the pressure surface 3 side of the middle section 142 of the first blade and the suction surface 5 side of the middle section 153 of the second blade, reduce energy loss, and improve turbine performance.

[0061] In some embodiments, the inlet width of the third throat 173 is greater than the outlet width of the third throat 173, the outlet width of the third throat 173 is the same as the inlet width of the fourth throat 174, and the inlet width of the fourth throat 174 is greater than the outlet width of the fourth throat 174; the widths of the third throat 173 and the fourth throat 174 are gradually reduced, and the outlet width of the third throat 173 is the same as the inlet width of the fourth throat 174. Such a design can reduce the peak Mach number in the flow channel 17, weaken or even eliminate shock waves, and can also weaken or even eliminate the flow separation on the pressure surface 3 side of the first blade 14 and the suction surface 5 side of the second blade 15, reduce energy loss, and improve turbine performance.

[0062] Specifically, the inlet width of the third throat 173 is a5, the inlet widths of the third throat 173 and the fourth throat 174 are both a4, and the outlet width of the fourth throat 174 is a6, then a5>a4>a6.

[0063] Figure 4 FIG. 1 shows a schematic diagram comparing the second blade tip section 154 and the adjacent first blade tip section 143. Figure 4 As shown, in some embodiments, the flow channel 17 between the pressure surface 3 of the second blade tip section 154 and the suction surface 5 of the adjacent first blade tip section 143 is provided with a fifth throat 175, the inlet position of the fifth throat 175 is located at the trailing edge 4 of the second blade tip section 154, the outlet position of the fifth throat 175 is located at the trailing edge 4 of the second blade tip section 154, and the flow channel 17 between the suction surface 5 of the second blade tip section 154 and the pressure surface 3 of the adjacent first blade tip section 143 is provided with a fifth throat 175. Six throats 176, the inlet position of the sixth throat 176 is located at the trailing edge 4 of the first blade tip section 143, and the outlet position of the sixth throat 176 is located at the trailing edge 4 of the second blade tip section 154; the position of the fifth throat 175 is different from the position of the sixth throat 176, which can reduce the peak Mach number in the flow channel 17, weaken or even eliminate the shock wave, weaken or even eliminate the flow separation on the pressure surface 3 side of the first blade middle section 142 and the suction surface 5 side of the second blade middle section 153, reduce energy loss, and improve turbine performance.

[0064] In some embodiments, the inlet width of the sixth throat 176 is greater than the inlet width of the fifth throat 175, the inlet width of the fifth throat 175 is greater than the outlet width of the fifth throat 175, and the outlet width of the fifth throat 175 is the same as the outlet width of the sixth throat 176; the widths of the fifth throat 175 and the sixth throat 176 are gradually reduced, and the outlet width of the fifth throat 175 is the same as the outlet width of the sixth throat 176. Such a design can reduce the peak Mach number in the flow channel 17, weaken or even eliminate shock waves, and can also weaken or even eliminate the flow separation on the pressure surface 3 side of the first blade 14 and the suction surface 5 side of the second blade 15, reduce energy loss, and improve turbine performance.

[0065] Specifically, the outlet widths of the fifth throat 175 and the sixth throat 176 are both a7, the inlet width of the sixth throat 176 is a8, and the inlet width of the fifth throat 175 is a9, then a8>a9>a7.

[0066] Fig.15 A schematic diagram of the turning angle of the first blade root section 141 is shown; Fig.16 A schematic diagram of the turning angle of the middle section 142 of the first blade is shown; Fig.17 FIG. 1 shows a schematic diagram of the turning angle of the first blade tip section 143. Figures 15 to 17 As shown, in some embodiments, the turning angles of the root, middle and tip sections of the first blade 14 are 30-40°, 30-40° and 100-130° respectively; the turning angles determine the blade shapes of the root, middle and tip sections of the first blade 14, and also determine the overall blade shape of the first blade 14. On the basis that the radius of the leading edge 2 of the second blade 15 is greater than the radius of the trailing edge 4 of the first blade 14, the first blade 14, the second blade 15 and the third blade 16 can better adapt to the uneven incoming flow conditions, which not only enhances the flow capacity of the turbine, but also improves the performance of the turbine.

[0067] In some embodiments, the tip cross-section blade profile of the first blade 14 is a sickle shape. On this basis, the cooperation between the first blade 14 and the second blade 15 or the third blade 16 can better adapt to uneven incoming flow conditions, including uneven incoming flow pressure, airflow, etc., effectively control the flow separation of the blades, enhance the flow capacity of the turbine, and improve the performance of the turbine stage.

[0068] The working principle of the turbine interstage guide vane is as follows:

[0069] The weight of the turbine is reduced by utilizing the spatial arrangement of the first blade 14, the second blade 15 and the third blade 16 and by using the full three-dimensional composite curved feature modeling. On this basis, the lengths of the root, middle and tip sections of the blades are different, and the radii of the leading edge 2 and the trailing edge 4 of the blades are different, resulting in more drastic changes in the blade profile, thereby effectively controlling the flow separation of the blades, which not only reduces the total pressure loss in the transition section, but also improves the aerodynamic efficiency of the turbine.

[0070] Among them, the first blade 14 and the second blade 15 have different thicknesses, different curvatures, different leading edge radii, the same trailing edge radii, different chord lengths of the root, middle and tip sections, and different blade shapes. On this basis, the inlet widths of the first throat 171 and the second throat 172 are the same, the inlet width of the second throat 172 is greater than the outlet width of the second throat 172, the outlet width of the second throat 172 is greater than the outlet width of the first throat 171, the inlet width of the third throat 173 is greater than the outlet width of the third throat 173, the outlet width of the third throat 173 is the same as the inlet width of the fourth throat 174, the inlet width of the fourth throat 174 is greater than the outlet width of the fourth throat 174, and the inlet width of the sixth throat 176 is greater than the inlet width of the fifth throat 175 , the inlet width of the fifth throat 175 is greater than the outlet width of the fifth throat 175, and the outlet width of the fifth throat 175 is the same as the outlet width of the sixth throat 176. Therefore, when the airflow flows through the first throat 171, the second throat 172, the third throat 173, the fourth throat 174, the fifth throat 175 and the sixth throat 176 at the same time, the inlet position to the outlet position of the first throat 171, the second throat 172, the third throat 173, the fourth throat 174, the fifth throat 175 and the sixth throat 176 can reduce the peak Mach number in the flow channel 17, weaken or even eliminate the shock wave, weaken or even eliminate the flow separation between the pressure surface 3 of the first blade 14 and the suction surface 5 of the second blade 15 or the third blade 16, reduce energy loss, and improve turbine performance.

[0071] Specifically, the direction of the airflow when flowing through the first throat 171 , the second throat 172 , the third throat 173 , the fourth throat 174 , the fifth throat 175 and the sixth throat 176 is consistent.

[0072] Embodiment 2

[0073] Based on Example 1, the turning angles of the root, middle and tip sections of the second blade 15 are 26°, 42° and 80° respectively; the turning angles of the root, middle and tip sections of the first blade 14 are 36°, 35° and 115° respectively; the axial chord length of the second blade 15 is 83mm; the axial chord length of the first blade 14 is 76mm; the thickness of the second blade 15 is 21mm; the thickness of the first blade 14 is 10mm.

[0074] In this embodiment, the blade profiles of the second blade 15, the third blade 16 and the first blade 14 all change dramatically, thereby effectively controlling the flow separation of the blades, which not only reduces the total pressure loss in the transition section, but also improves the aerodynamic efficiency of the turbine.

[0075] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A turbine interstage guide vane, comprising a guide vane body (1), characterized in that: A composite curved blade is arranged in the air flow passage (13) of the guide body (1), the axial chord length of the root section of the blade is longer than the axial chord length of the middle section of the blade, and shorter than the axial chord length of the tip section of the blade, the blade comprises a first blade (14), a second blade (15) and a third blade (16) of identical structure, the second blade (15) and the third blade (16) are evenly distributed in the air flow passage (13), the first blade (14) is evenly distributed in the portion of the air flow passage (13) between the second blade (15) and the third blade (16), the axial chord length of the second blade (15) is longer than the axial chord length of the first blade (14), the trailing edge (4) radius of the second blade (15) and the first blade (14) is the same, the leading edge (2) and trailing edge (4) radii of the first blade (14) are both smaller than the leading edge (2) radius of the second blade (15).

2. A turbine interstage guide vane according to claim 1, characterized in that: The turning angles of the root, middle and tip sections of the second blade (15) are 20-30°, 30-50° and 75-85° respectively.

3. A turbine interstage guide vane according to claim 1, characterized in that: The radius of the leading edge (2) of the second blade (15) is 4 to 5 mm, and the radius of the trailing edge (4) is 1 to 1.5 mm.

4. A turbine interstage guide vane according to claim 1, characterized in that: A first throat (171) is provided in the flow passage (17) between the pressure surface (3) of the second blade root section (152) and the suction surface (5) of the adjacent first blade root section (141); an inlet position of the first throat (171) is located at the trailing edge (4) of the second blade root section (152); a second throat (172) is provided in the flow passage (17) between the suction surface (5) of the second blade root section (152) and the pressure surface (3) of the adjacent first blade root section (141); an outlet position of the first throat (171) is adjacent to an inlet position of the second throat (172).

5. A turbine interstage guide vane according to claim 4, characterized in that: The inlet width of the first throat (171) is the same as the inlet width of the second throat (172), the inlet width of the second throat (172) is greater than the outlet width of the second throat (172), and the outlet width of the second throat (172) is greater than the outlet width of the first throat (171).

6. The turbine interstage guide vane according to claim 1, characterized in that: A third throat (173) is provided in the flow passage (17) between the pressure surface (3) of the second blade middle section (153) and the suction surface (5) of the adjacent first blade middle section (142), and the inlet position of the third throat (173) is located at the trailing edge (4) of the second blade middle section (153); a fourth throat (174) is provided in the flow passage (17) between the suction surface (5) of the second blade middle section (153) and the pressure surface (3) of the adjacent first blade middle section (142), and the inlet position of the fourth throat (174) is located at the trailing edge (4) of the first blade middle section (142); the outlet position of the fourth throat (174) is adjacent to the leading edge (2) of the second blade middle section (153), and the outlet position of the third throat (173) is located at the trailing edge (4) of the second blade middle section (153).

7. A turbine interstage guide vane according to claim 6, characterized in that: The inlet width of the third throat (173) is greater than the outlet width of the third throat (173), the outlet width of the third throat (173) is the same as the inlet width of the fourth throat (174), and the inlet width of the fourth throat (174) is greater than the outlet width of the fourth throat (174).

8. The turbine interstage guide vane according to claim 1, characterized in that: A fifth throat (175) is provided in the flow passage (17) between the pressure surface (3) of the second blade tip section (154) and the suction surface (5) of the adjacent first blade tip section (143); the inlet position of the fifth throat (175) is located at the trailing edge (4) of the second blade tip section (154); and the outlet position of the fifth throat (175) is located at the trailing edge (4) of the second blade tip section (154); a sixth throat (176) is provided in the flow passage (17) between the suction surface (5) of the second blade tip section (154) and the pressure surface (3) of the adjacent first blade tip section (143); the inlet position of the sixth throat (176) is located at the trailing edge (4) of the first blade tip section (143); and the outlet position of the sixth throat (176) is located at the trailing edge (4) of the second blade tip section (154).

9. A turbine interstage guide vane according to claim 8, characterized in that: The inlet width of the sixth throat (176) is greater than the inlet width of the fifth throat (175), the inlet width of the fifth throat (175) is greater than the outlet width of the fifth throat (175), and the outlet width of the fifth throat (175) is the same as the outlet width of the sixth throat (176).

10. A turbine interstage guide vane according to any one of claims 1 to 9, characterized in that: The turning angles of the root, middle and tip sections of the first blade (14) are 30-40°, 30-40° and 100-130° respectively.

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