Turbine device for improving sealing performance of rim and aerodynamic performance of turbine

Abstract

The invention discloses a turbine device for improving the sealing performance of a rim and the aerodynamic performance of a turbine, which comprises a static-turntable cavity and a rotor hub end wall, and the rotor hub end wall is arranged above the static-turntable cavity; the static-rotating disc cavity comprises a static disc wall face, a jet flow groove is formed in the position, close to the wheel flange, of the static disc wall face, and the end wall of the rotor hub is a non-axisymmetric end wall. The vortex structure in the rim gap is broken through the jet flow groove, so that the rim sealing performance of the static-rotating disc cavity is improved, the vortex strength of an inlet of the downstream rotor is reduced, and a good air inlet condition is provided for the non-axisymmetric end wall of the downstream rotor to control secondary flow; the end wall of the rotor hub is arranged to be a non-axisymmetric end wall, so that the development of secondary flow of the hub in the flow direction is delayed, and the aerodynamic performance of the turbine is integrally enhanced. By means of the combined structure, the turbine aerodynamic performance can be improved while the sealing performance of the static-rotating disc cavity rim is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbine devices, and in particular to a turbine device capable of improving wheel rim sealing performance and turbine aerodynamic performance. Background Art

[0002] Increasing the gas temperature before the turbine is the most direct and effective means to improve the thrust-to-weight ratio. For every 100°C increase in the gas temperature before the turbine, the engine thrust increases by about 8%. The gas temperature before the turbine is still increasing at a rate of about 20-30°C / year, which has long exceeded the high temperature resistance limit of the turbine material, making the turbine working environment even worse, especially the high-speed rotating turbine wheel and rotor blade roots. Therefore, effective cooling and thermal protection measures are the key ways to increase the gas temperature before the turbine and ensure that the components are durable and resistant to high temperatures.

[0003] At present, the cooling gas is mainly drawn out from the compressor and transported to the turbine disc cavity, passing through the wheel disc, blades, sealing devices, etc. to cool the turbine disc cavity and blades. At the same time, the cooling gas entering the disc cavity can also prevent the mainstream high-temperature combustion gas from invading the inside of the turbine disc cavity through the sealing structure, causing the turbine disc temperature to be too high, which seriously affects the working safety and service life of the engine. In addition, the sealing gas will eventually enter the mainstream channel and interfere with the mainstream. Studies have shown that a 1% increase in gas intrusion may cause the life of the turbine disc to decrease by 50%. On the other hand, when the sealing cooling gas volume is reduced by 50%, the turbine efficiency can be increased by 0.5% and the fuel consumption rate can be reduced by 0.9%. Therefore, the rim flow will affect both the rim sealing performance and the mainstream aerodynamic performance of the turbine at the same time, and this effect is opposite.

[0004] However, the control strategy based on a single performance in the prior art cannot simultaneously improve the mainstream gas performance and sealing performance of the turbine. For example, the mainstream aerodynamic performance of the turbine can be improved through end wall design or shaping, but the effect on suppressing gas intrusion and improving the sealing performance is minimal. Structural designs that improve the sealing performance generally cause increased interference between the outflowing cold air and the mainstream, thereby reducing the mainstream aerodynamic performance of the turbine. Summary of the invention

[0005] The present invention provides a turbine device for improving the sealing performance of a wheel rim and the aerodynamic performance of a turbine, so as to solve the problem that the sealing performance and the aerodynamic performance of a turbine cannot be improved simultaneously in the prior art.

[0006] The present invention provides a turbine device for improving the rim sealing performance and turbine aerodynamic performance, comprising: a stationary-rotating disk cavity and a rotor hub end wall, wherein the rotor hub end wall is arranged above the stationary-rotating disk cavity; the stationary-rotating disk cavity comprises a stationary disk wall surface, wherein the stationary disk wall surface is provided with a jet groove near the rim, and the rotor hub end wall is a non-axisymmetric end wall.

[0007] Optionally, the turbine device also includes first-stage stator blades, first-stage rotor blades and second-stage stator blades, wherein the first-stage stator blades are located on one side of the rotor hub end wall, the first-stage rotor blades are located on the other side of the rotor hub end wall, and the second-stage stator blades are located on the side of the first-stage rotor blades away from the first-stage stator blades.

[0008] Optionally, the stationary-rotating disc cavity further includes a rotating disc wall, and the rotating disc wall is located on one side below the end wall of the rotor hub.

[0009] Optionally, the wall surface of the stationary disk and the wall surface of the rotating disk constitute an internal air flow channel of the disk cavity and an air flow channel in the gap of the disk cavity.

[0010] Optionally, the disk cavity formed by the stationary disk wall and the rotating disk wall is further provided with a disk cavity outlet and a cooling gas inlet.

[0011] Optionally, the circumferential position of the jet slot is located downstream of the trailing edge of the guide vane.

[0012] Optionally, the tangent direction of the jet groove is arc-shaped, and the circumferential range is 1 / 5 of the single channel of the guide vane.

[0013] Optionally, the radial height of the jet groove is 1 / 3 of the radial height of the air flow channel in the disc cavity gap.

[0014] Optionally, the jet groove is arranged on the wall surface of the static disk close to the high radius of the rim.

[0015] Optionally, the rotor hub end wall is a non-axisymmetric end wall that is concave on the suction surface side and convex on the pressure surface side.

[0016] A turbine device for improving the wheel rim sealing performance and turbine aerodynamic performance in the present invention has the following advantages: By setting a jet groove near the rim on the stator wall, the vortex structure in the rim gap can be broken, and by setting the rotor hub end wall as a non-axisymmetric end wall, a combined structure near the rim is formed, thereby improving the sealing efficiency of the stator-rotor cavity rim, that is, the sealing performance. At the same time, since the vortex structure in the rim gap is broken, the downstream rotor inlet vortex strength is reduced, providing good intake conditions for the control of the secondary flow by the downstream rotor non-axisymmetric end wall; by setting the rotor hub end wall as a non-axisymmetric end wall, the development of the hub secondary flow along the flow direction is delayed, so that the overall aerodynamic performance of the turbine is improved. This combined structure can improve the aerodynamic performance of the turbine while improving the sealing performance of the stator-rotor cavity rim. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only 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.

[0018] Figure 1 A schematic diagram of the overall structure of a turbine device for improving the wheel rim sealing performance and turbine aerodynamic performance provided by an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the structure of the central static-rotating disk cavity; Figure 3 A schematic diagram of the three-dimensional structure of the first-stage stator region including the jet groove of a turbine device for improving the wheel rim sealing performance and the turbine aerodynamic performance provided by an embodiment of the present invention; Figure 4 for Figure 2 Schematic diagram of the relative positions of the wall of the static disk and the jet slot; Figure 5 A schematic diagram of a non-axisymmetric end wall structure of a turbine device for improving the wheel rim sealing performance and turbine aerodynamic performance provided by an embodiment of the present invention; Figure 6 A schematic diagram of the circumferential distribution of the radius of the non-axisymmetric end wall (hub) of the hub provided in an embodiment of the present invention; Figure 7 A schematic diagram of the sealing efficiency in the radial direction of the disc cavity provided by an embodiment of the present invention (used to characterize the sealing performance); Figure 8 A curve diagram of entropy increase variation along the flow direction provided in an embodiment of the present invention (used to characterize the aerodynamic performance of the turbine mainstream).

[0019] Description of reference numerals: 1. First-stage stator blades; 2. First-stage rotor blades; 3. Second-stage stator blades; 4. Stator-rotating disk cavity; 5. Rotor hub end wall; 6. Stator disk wall; 7. Rotating disk wall; 8. Air flow channel inside the disk cavity; 9. Air flow channel in the gap of the disk cavity; 10. Disk cavity outlet; 11. Cooling gas inlet; 12. Jet slot. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0021] like Figure 1-Figure 8 As shown, an embodiment of the present invention provides a turbine device for improving the rim sealing performance and the turbine aerodynamic performance. The present invention provides a turbine device for improving the rim sealing performance and the turbine aerodynamic performance, comprising: a stator-rotating disk cavity 4 and a rotor hub end wall 5, the rotor hub end wall 5 is arranged above the stator-rotating disk cavity 4; the stator-rotating disk cavity 4 includes a stator wall 6, the stator wall 6 is provided with a jet groove 12 near the rim, and the rotor hub end wall 5 is a non-axisymmetric end wall.

[0022] The present invention proposes a turbine device for improving the rim sealing performance and the aerodynamic performance of the turbine. By setting a jet groove 12 on the stator disk wall 6 near the rim, the vortex structure in the rim gap can be broken, and by setting the rotor hub end wall 5 as a non-axisymmetric end wall, a combined structure near the rim is formed, so that the sealing efficiency of the stator-rotating disk cavity 4 is improved, that is, the sealing performance is improved. At the same time, since the vortex structure in the rim gap is broken, the downstream rotor inlet vortex strength is reduced, providing good intake conditions for the control of the secondary flow by the downstream rotor non-axisymmetric end wall; by setting the rotor hub end wall 5 as a non-axisymmetric end wall, the development of the hub secondary flow along the flow direction is delayed, so that the aerodynamic performance of the turbine is improved as a whole. This combined structure can improve the sealing efficiency of the stator-rotating disk cavity 4 while improving the aerodynamic performance of the turbine.

[0023] In an exemplary embodiment, the turbine device also includes first-stage stator blades 1, first-stage rotor blades 2 and second-stage stator blades 3, wherein the first-stage stator blades 1 are located on one side of the rotor hub end wall 5, the first-stage rotor blades 2 are located on the other side of the rotor hub end wall 5, and the second-stage stator blades 3 are located on the side of the first-stage rotor blades 2 away from the first-stage stator blades 1.

[0024] Specifically, the first-stage stator blades 1 and the first-stage rotor blades 2 interact with each other to form a high and low pressure alternately distributed in the circumferential direction in the main flow.

[0025] In an exemplary embodiment, the stationary-rotating disk cavity 4 further includes a rotating disk wall surface 7 , and the rotating disk wall surface 7 is located on one side below the rotor hub end wall 5 .

[0026] In the exemplary embodiment, the stationary disk wall 6 and the rotating disk wall 7 form an internal air flow channel 8 of the disk cavity, a disk cavity gap air flow channel 9, a disk cavity outlet 10 and a cooling gas inlet 11.

[0027] The total cooling air volume is 0.5% of the mainstream flow, of which 1 / 3 of the cooling airflow enters from the jet groove 12 at twice the rotor hub tangential speed, and 2 / 3 of the cooling airflow enters from the cooling gas inlet 11. Through CFD calculation, the jet groove 12 breaks the vortex structure existing in the disc cavity gap airflow channel 9, improving the sealing performance. Before and after the jet groove 12 is set, the sealing efficiency of the radial direction of the static-rotating disc cavity 4 is as follows: Figure 7 shown.

[0028] Specifically, computational fluid dynamics (CFD) is a discipline that predicts fluid flow, heat and mass transfer, chemical reactions and other physical phenomena. The calculation method of CFD is to discretize the continuous physical field using the finite volume method to simplify the partial differential equations into algebraic equations, and then use numerical methods to solve the algebraic equations to obtain the flow field solution.

[0029] The numerical calculation and boundary conditions in CFD calculation are: A 1 / 18 sector channel is taken as the calculation domain, and commercial CFD software is used for numerical simulation. The SST turbulence model is used in the unsteady calculation, and the interface is the transient rotor / static interface. The sweep of the moving blade through a channel is divided into 42 steps, and the physical time step is 60 / (2700×54×42), that is, 9.8×10-6s. The rotor blade row rotates around the Z axis at a speed of 2700r / min. The distribution of the total pressure along the span direction at the inlet is given, the total pressure at the mid-diameter is 139.6KPa, the total temperature is 328K, the turbulence of the inlet free flow is 6%, and the distribution of the static pressure along the span direction is given at the outlet section of the calculation domain. All wall surfaces (blades and upper and lower end walls) are adiabatic non-slip walls. The dynamic viscosity coefficient and thermal conductivity coefficient of the working gas are given by the Sutherland formula. The sealed cold air enters the static-rotating disk cavity 4 from the cooling gas inlet 11 and the jet groove 12 respectively.

[0030] Further, Figure 8 For the entropy increase curve along the flow direction, refer to Figure 8 , it can be seen that the rotor flow loss is reduced and the efficiency is improved. It should be noted that entropy increase represents loss.

[0031] In addition, when only the rotor hub end wall 5 is set as a non-axisymmetric end wall, and no jet groove 12 is set on the stator wall 6 near the wheel rim, Figure 8 It can be seen that the non-axisymmetric end wall slows down the development of secondary flow in the rotor domain, but enhances the vortex intensity caused by the sealed cold air outflow at the rotor inlet, so the rotor inlet loss is amplified, and overall the turbine efficiency is not improved.

[0032] In summary, the main reason for the poor control effect of the rotor hub end wall 5 is that the non-axisymmetric end wall causes the sealing gas vortex strength to increase. At the same time, the jet groove 12 is set, and the rotor hub end wall 5 is a non-axisymmetric end wall, so that the loss at the outlet of the static-rotating disk cavity 4 is reduced, and the loss in the rotor channel is also reduced compared with the original turbine device. Figure 8 As shown, the aerodynamic performance of the turbine is improved.

[0033] In this embodiment, in the area with high mainstream pressure, the mainstream high-temperature fuel gas enters the gas flow channel 8 inside the cavity from the cavity outlet 10 through the cavity gap gas flow channel 9, thereby causing fuel gas invasion. In addition, the cooling gas passes radially upward from the cooling gas inlet 11 through the cavity inner gas flow channel 8 and the cavity gap gas flow channel 9, and then enters the mainstream channel from the cavity outlet 10.

[0034] In the exemplary embodiment, the circumferential position of the injection slot 12 is located downstream of the trailing edge of the guide vane.

[0035] In an exemplary embodiment, the tangent direction of the jet groove 12 is in the shape of an arc, and the circumferential range is 1 / 5 of the single channel of the guide vane, and the radial height is 1 / 3 of the radial height of the disc cavity gap airflow channel 9.

[0036] Specifically, the jet tangential velocity can be changed by changing the air inlet angle and flow rate of the airflow at the jet slot 12 .

[0037] In an exemplary embodiment, the jet groove 12 is disposed on the stationary disk wall 6 at a position close to the high radius of the rim.

[0038] In an exemplary embodiment, the rotor hub end wall 5 is a non-axisymmetric end wall with a suction surface side being concave and a pressure surface side being convex.

[0039] Specifically, the rotor hub end wall 5 is shaped by the "trigonometric function method", and the circumferential shaping function of this method selects a sine function with a period of two pitches, as described in the following formula:

[0040] Where: y PS is the circumferential position of the pressure surface, y ss is the circumferential position of the suction surface, y represents the circumferential position coordinate, and α is the circumferential angle.

[0041] Considering that the airflow pressure field inside the cascade channel changes most dramatically and is also the main area for the generation and development of secondary flow and various vortices, the axial modeling function is applied between the leading edge and the trailing edge of the blade, thereby determining the modeling range of the three-dimensional surface of the non-axisymmetric end wall. The amplitude control function expression is determined based on the trigonometric function curve, as described in the following formula:

[0042] Where: z LE and z TE are the flow directions of the leading edge and the trailing edge, respectively, and H b is the blade height, C h is the amplitude coefficient, and z is the flow direction position coordinate.

[0043] Specifically, C hThe specific value of is 0.05, which is used to determine the peak (valley) value of the convex (concave) on the non-axisymmetric end wall surface. The local structural schematic diagram of the combined structure of the jet slot 12 and the non-axisymmetric end wall shape is shown in Figure 5 As shown, Figure 6 It is a schematic diagram of the circumferential distribution of the radius of the non-axisymmetric end wall (hub), where the radius of the reference rim (hub) is 0.33m.

[0044] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0045] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A turbine device for improving wheel rim sealing performance and turbine aerodynamic performance, characterized in that: include: A stationary-rotating disc cavity (4) and a rotor hub end wall (5), wherein the rotor hub end wall (5) is arranged above the stationary-rotating disc cavity (4); the stationary-rotating disc cavity (4) comprises a stationary disc wall surface (6), a jet groove (12) is arranged on the stationary disc wall surface (6) near the wheel rim, and the rotor hub end wall (5) is a non-axisymmetric end wall.

2. A turbine device for improving wheel rim sealing performance and turbine aerodynamic performance according to claim 1, characterized in that: The turbine device further comprises: A first-stage stator blade (1) located on one side of the rotor hub end wall (5); A first-stage rotor blade (2) located on the other side of the rotor hub end wall (5); The second-stage stator blades (3) are located on a side of the first-stage rotor blades (2) away from the first-stage stator blades (1).

3. A turbine device for improving wheel rim sealing performance and turbine aerodynamic performance according to claim 1, characterized in that: The stationary-rotating disc cavity (4) further comprises a rotating disc wall surface (7), wherein the rotating disc wall surface (7) is located on one side below the rotor hub end wall (5).

4. A turbine device for improving wheel rim sealing performance and turbine aerodynamic performance according to claim 3, characterized in that: The stationary disk wall surface (6) and the rotating disk wall surface (7) form an internal air flow channel (8) of the disk cavity and an air flow channel (9) in the disk cavity gap.

5. A turbine device for improving wheel rim sealing performance and turbine aerodynamic performance according to claim 3, characterized in that: The disc cavity formed by the stationary disc wall surface (6) and the rotating disc wall surface (7) is also provided with a disc cavity outlet (10) and a cooling gas inlet (11).

6. A turbine device for improving wheel rim sealing performance and turbine aerodynamic performance according to claim 3, characterized in that: The circumferential position of the jet groove (12) is located downstream of the trailing edge of the guide vane.

7. A turbine device for improving wheel rim sealing performance and turbine aerodynamic performance according to claim 4, characterized in that: The jet groove (12) is in the shape of an arc in the tangent direction, and has a circumferential range of 1 / 5 of a single channel of a guide vane.

8. A turbine device for improving wheel rim sealing performance and turbine aerodynamic performance according to claim 4, characterized in that: The radial height of the jet groove (12) is 1 / 3 of the radial height of the disc cavity gap airflow channel (9).

9. A turbine device for improving wheel rim sealing performance and turbine aerodynamic performance according to claim 1, characterized in that: The jet groove (12) is arranged on the wall surface (6) of the static disk at a position close to the high radius of the wheel rim.

10. A turbine device for improving wheel rim sealing performance and turbine aerodynamic performance according to claim 1, characterized in that: The rotor hub end wall (5) is a non-axisymmetric end wall with a suction surface side that is concave and a pressure surface side that is convex.

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