Pump turbine guide vane with dynamically adjustable molded line and molded line adjusting method

Abstract

The invention discloses a pump turbine guide vane with a dynamically adjustable molded line and a molded line adjusting method, and belongs to the technical field of hydraulic machine.The guide vane comprises a guide vane shaft and a guide vane body which are integrally formed, and the guide vane body is divided into an oval structure side and a dynamic molded line structure side; the dynamic molded line structure is composed of a first molded surface, a second molded surface, a third molded surface and an elastic metal skin covering the surfaces of the first molded surface, the second molded surface and the third molded surface, and the piston mechanism is driven through an independent oil way system arranged in the guide vane to achieve dynamic deformation adjustment of the elastic skin. During adjustment, the piston rod is pushed by injecting pressure oil into the main oil way, continuous deformation of the molded line is controlled in combination with a spring feedback mechanism, and the differentiated requirements of working conditions of a water turbine and a water pump for the guide vane molded line are met. The problem that a fixed molded line guide vane easily induces eddy current and pressure pulsation under the variable working condition is solved, flow state distribution is optimized through regional oil pressure control, and the hydraulic loss and the silt abrasion risk are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic machinery, and particularly relates to a guide vane of a pump-turbine with dynamically adjustable profile lines, and also relates to a method for adjusting the profile lines of the guide vane of the pump-turbine with dynamically adjustable profile lines. Background Art

[0002] The guide vane of a pump-turbine is a key component for regulating the flow rate of a turbine and the main actuator for safe shutdown of the unit after overspeed. Since the pump-turbine needs to meet two-way operation, different requirements should be imposed on the profile lines at the high-pressure end and the low-pressure end of the guide vane to better guide the water flow along the flow direction. The vaneless area between the low-pressure end of the guide vane and the high-pressure side of the runner blade is the core area causing pressure pulsation in the turbine, and there is a mutual promotion relationship between pressure pulsation and unit vibration. The geometric shapes at the high-pressure end and the low-pressure end of the guide vane are closely related to the formation of Karman vortices, and the profile line on the guide vane surface is also crucial for guiding the water flow into the runner and reducing hydraulic losses. Although there are various types of current guide vane profile lines, and even bionic structures based on humpback whales, they are all non-adjustable fixed profile lines. However, the operating conditions of the pump-turbine are complex and variable, and the fixed profile lines are difficult to meet the requirements of various conditions. As a result, since the guide vane profile lines remain the same under different conditions, once in a non-optimal opening, Karman vortices will form in the wake flow of the guide vane and inter-blade vortices will form due to flow separation on the guide vane surface. The action of the vortices transmitted to the vaneless area will exacerbate the pressure pulsation of the turbine and reduce the service life of the unit. Moreover, the turbine operating condition and the reverse pump operating condition have different requirements for the profile line at the inlet flow of the guide vane and cannot be coordinated. Therefore, a guide vane of a pump-turbine with dynamically adjustable profile lines is hereby invented. Summary of the Invention

[0003] The first object of the invention is to provide a guide vane of a pump-turbine with dynamically adjustable profile lines, which solves the technical problem that the guide vane profile line in the prior art is non-adjustable.

[0004] The second object of the invention is to provide a method for adjusting the profile lines of the guide vane of the pump-turbine with dynamically adjustable profile lines.

[0005] The first technical solution adopted by the invention is that the guide vane of the pump-turbine with dynamically adjustable profile lines includes an integrally formed guide vane shaft and a guide vane body. The cross-section of the guide vane body is elliptical, and the longitudinal section of the guide vane body is rectangular; taking the minor axis of the guide vane body as the center line, one side is an elliptical structure and the other side is a dynamic profile line structure; the dynamic profile line structure includes a first profile surface, a second profile surface and a third profile surface which are vertically arranged and connected in sequence. The first profile surface and the third profile surface are oppositely arranged, and the included angle formed between the first profile surface and the third profile surface is an acute angle. The first surface, the second surface, and the third surface are connected with an elastic metal skin by fasteners, and the first surface, the second surface, the third surface, and the elastic metal skin are connected by an adjusting mechanism; several oil passages are provided in the guide vane shaft and the guide vane body, and the several oil passages are communicated with the adjusting mechanism.

[0006] The features of the first technical solution of the present invention are further as follows: Several oil cavity walls are provided on both the first surface and the third surface, the oil cavity walls are communicated with the several oil passages, pistons are slidably connected inside the oil cavity walls, a surface piston rod is fixedly connected to the side of the piston facing away from the oil passages, and a restoring spring is sleeved circumferentially on the surface piston rod; The surfaces of the first surface and the third surface are connected with a surface oil cavity spring plate by fasteners, the surface piston rod penetrates through the surface oil cavity spring plate and abuts against the elastic metal skin, one end of the restoring spring abuts against the piston, and the other end of the restoring spring abuts against the surface oil cavity spring plate.

[0007] Several oil cavity walls are provided on the second surface, the oil cavity walls are communicated with the several oil passages, pistons are slidably connected inside the oil cavity walls, a tail piston rod is fixedly connected to the side of the piston facing away from the oil passages, and a restoring spring is sleeved circumferentially on the tail piston rod; The surface of the second surface is connected with a tail oil cavity spring plate by fasteners, a tail piston rod bolt hole is provided at the end of the tail piston rod, a metal elastic skin bolt hole corresponding to the tail piston rod bolt hole is provided on the surface of the elastic metal skin, the tail piston rod penetrates through the tail oil cavity spring plate and is threadedly connected with the elastic metal skin, one end of the restoring spring abuts against the piston, and the other end of the restoring spring abuts against the tail oil cavity spring plate.

[0008] The length of the tail piston rod is greater than the length of the surface piston rod, a chute is provided inside the guide vane body, and both ends of the elastic metal skin slide along the chute.

[0009] The several oil passages include a first main oil passage, a second main oil passage, and a third main oil passage opened along the axis of the guide vane shaft; further included are a first branch oil passage communicating with the oil cavity wall of the first surface, a second branch oil passage communicating with the oil cavity wall of the second surface, and a third branch oil passage communicating with the oil cavity wall of the third surface; the first main oil passage is communicated with the first branch oil passage, the second main oil passage is communicated with the second branch oil passage, and the third main oil passage is communicated with the third branch oil passage.

[0010] The elastic metal skin is made of any one of aluminum, magnesium, titanium alloy or composite material.

[0011] The second technical solution adopted by the present invention is a method for adjusting the profile of a guide vane of a pump-turbine with dynamically adjustable profile. The guide vane of the pump-turbine with dynamically adjustable profile as described above is specifically implemented according to the following steps: Inject pressure oil into the first main oil circuit and the third main oil circuit. The pressure oil enters the oil cavity walls of the first profile and the third profile along the first branch oil circuit and the third branch oil circuit. The piston is subjected to hydraulic action, and the surface piston rod pushes the elastic metal skin to elastically deform, and the restoring spring is compressed to store elastic potential energy until the oil pressure is balanced with the elastic force, and the profile remains in the current state; when the working condition changes, the oil pressure of the pressure oil is reduced, the restoring spring elongates, and the profile of the guide vane is adjusted again to achieve profile adjustment.

[0012] The characteristics of the second technical solution of the present invention also lie in: Inject pressure oil into the second main oil circuit. The pressure oil enters the oil cavity wall of the second profile along the second branch oil circuit. The piston is subjected to hydraulic action, and the tail piston rod pushes the elastic metal skin to move. The restoring spring is compressed to store elastic potential energy until the oil pressure is balanced with the elastic force, and the length of the guide vane remains in the current state; when the working condition changes, the oil pressure of the pressure oil is reduced, the restoring spring elongates, and the length of the guide vane is adjusted again.

[0013] Compared with the prior art, the beneficial effects of the present invention are: The guide vane of the present invention is not only dynamically adjustable in profile, but also adjustable in length, and can meet the requirements of the pump-turbine under different working conditions. When the present invention is in use, according to the operating conditions of the unit, the oil pressure of the pipeline is artificially adjusted to change the profile of the front and back surfaces and the tail of the guide vane, realizing the dynamic adjustment of the guide vane profile to match the working conditions of the water turbine, achieving the purpose of suppressing the inter-vane vortex and the trailing vortex of the guide vane and reducing the pressure pulsation and energy loss. Moreover, since the profile is continuously and dynamically adjusted, the fine controllability of the profile adjustment is ensured. Brief Description of the Drawings

[0014] Figure 1 is a schematic structural diagram of a guide vane of a pump-turbine with dynamically adjustable profile according to the present invention; Figure 2 is Figure 1 a sectional view of Figure 3 is Figure 1 a top view of Figure 4 is Figure 2 a partial view at A in Figure 5 is Figure 2 a partial view at B in Figure 6 is Figure 3 a partial view at E in Figure 7It is a schematic structural diagram of the metal elastic skin in the guide vane of a pump-turbine with dynamically adjustable profile lines according to the present invention; Figure 8 It is an assembly schematic diagram of the oil cavity spring plate and the guide vane body in the guide vane of a pump-turbine with dynamically adjustable profile lines according to the present invention; Figure 9 It is Figure 2 a partial view at C in Figure 10 It is a schematic structural diagram of the oil cavity pressure oil plate in the guide vane of a pump-turbine with dynamically adjustable profile lines according to the present invention; Figure 11 It is an assembly schematic diagram of the oil cavity wall and the oil circuit in the guide vane of a pump-turbine with dynamically adjustable profile lines according to the present invention; Figure 12 It is an assembly schematic diagram of the piston and the oil cavity wall in the guide vane of a pump-turbine with dynamically adjustable profile lines according to the present invention; Figure 13 It is a schematic structural diagram of the oil cavity wall in the guide vane of a pump-turbine with dynamically adjustable profile lines according to the present invention; Figure 14 It is a schematic structural diagram of the piston in the guide vane of a pump-turbine with dynamically adjustable profile lines according to the present invention.

[0015] In the figure, 1. guide vane shaft, 2. elastic metal skin, 3. first main oil circuit, 4. second main oil circuit, 5. third main oil circuit, 6. first branch oil circuit, 7. second branch oil circuit, 8. third branch oil circuit, 9. metal elastic skin bolt hole, 10. chute, 11. tail oil cavity spring plate, 12. surface oil cavity spring plate, 13. surface piston rod, 14. oil cavity wall, 15. tail piston rod, 16. tail piston rod bolt hole, 17. restoring spring, 18. piston. Detailed implementation manners

[0016] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0017] Embodiment 1 As Figures 1-3 、 Figure 7As shown in the figure, the guide vane of the pump-turbine with dynamically adjustable blade profile disclosed in this embodiment includes an integrally formed guide vane shaft 1 and a guide vane body. The cross-section of the guide vane body is oval, and the longitudinal section of the guide vane body is rectangular. Taking the minor axis of the guide vane body as the center line, one side is an elliptical structure, and the other side is a dynamic blade profile structure. The dynamic blade profile structure includes a first profile, a second profile, and a third profile that are vertically arranged and connected in sequence. The first profile and the third profile are arranged opposite to each other, and the included angle formed between the first profile and the third profile is an acute angle. The first profile, the second profile, and the third profile are connected with an elastic metal skin 2 through fasteners, and the first profile, the second profile, the third profile, and the elastic metal skin 2 are connected through an adjusting mechanism. A plurality of oil channels are opened in the guide vane shaft 1 and the guide vane body, and the plurality of oil channels are communicated with the adjusting mechanism.

[0018] Among them, the elastic metal skin 2 is made of any one of aluminum, magnesium, titanium alloy or composite material.

[0019] In this embodiment, the guide vane is integrally formed by the guide vane shaft 1 and the guide vane body. The cross-section of the guide vane body is oval and the longitudinal section is rectangular. It is divided into a static elliptical structure and a dynamic blade profile structure with the minor axis as the boundary. The dynamic blade profile structure includes an acute angle area formed by the first profile, the second profile, and the third profile, and the adjusting mechanism is covered by the elastic metal skin 2. A plurality of oil channels are arranged inside the guide vane shaft 1 and the guide vane body, and the dynamic adjustment of the skin blade profile is realized by driving the adjusting mechanism through oil pressure.

[0020] The adjustment of the guide vane blade profile is mainly located in three positions: the third profile (front), the first profile (back), and the second profile (tail). When controllably adjusting the guide vane blade profile, it is necessary to determine the position of the guide vane blade profile to be adjusted according to the specific working conditions of the water turbine. For a pump-turbine, when operating bidirectionally, different requirements are imposed on the guide vane blade profile, and it is necessary to determine the adjustment scheme to inject pressure oil. The elastic metal skin 2 is made of aluminum, magnesium, titanium alloy or composite material, and its high elasticity and fatigue resistance characteristics ensure the structural stability under repeated deformation conditions, while meeting the corrosion resistance requirements of different fluid medium environments.

[0021] Embodiment 2 As Figures 8-10 As shown in FIGS. 12 - 14, on the basis of Embodiment 1, a plurality of oil cavity walls 14 are opened on both the first profile and the third profile. The oil cavity walls 14 are communicated with the plurality of oil channels. A piston 18 is slidably connected inside the oil cavity walls 14. A surface piston rod 13 is fixedly connected to the side of the piston 18 facing away from the oil channels. A restoring spring 17 is sleeved circumferentially on the surface piston rod 13. The surfaces of the first profile and the third profile are connected with a surface oil cavity spring plate 12 through fasteners. The surface piston rod 13 passes through the surface oil cavity spring plate 12 and abuts against the elastic metal skin 2. One end of the restoring spring 17 abuts against the piston 18, and the other end of the restoring spring 17 abuts against the surface oil cavity spring plate 12.

[0022] In this embodiment, a piston 18 is provided inside the oil cavity walls 14 of the first and third profiled surfaces. The surface piston rod 13 cooperates with the return spring 17, and the piston rod is pushed by the change of the oil circuit pressure to press the elastic metal skin 2. The surface oil cavity spring plate 12 is fixed to the profiled surface to form an oil cavity sealing structure, and the spring force and the oil pressure jointly control the deformation amplitude of the skin.

[0023] The outer surface of the elastic metal skin 2 is in direct contact with the water flow, and the inner surface is in contact with the surface piston rod 13. The surface piston rod 13 can push the elastic metal skin 2 to elastically deform, so as to achieve the purpose of changing the guide vane profile; the surface oil cavity spring plate 12 is connected to the guide vane body by bolts; in order to ensure uniform force on the elastic metal skin 2, a three-layer piston 18 is designed, and the oil circuits are connected in parallel between each layer without affecting each other, and the oil pressure value can be manually controlled to achieve fine adjustment of the guide vane profile.

[0024] Embodiment 3 On the basis of Embodiment 2, a plurality of oil cavity walls 14 are provided on the second profiled surface. The oil cavity walls 14 are communicated with a plurality of oil circuits. A piston 18 is slidably connected inside the oil cavity walls 14. A tail piston rod 15 is fixedly connected to the side of the piston 18 facing away from the oil circuit. A return spring 17 is sleeved circumferentially on the tail piston rod 15; The surface of the second profiled surface is connected with a tail oil cavity spring plate 11 through a fastener. A tail piston rod bolt hole 16 is provided at the end of the tail piston rod 15. A metal elastic skin bolt hole 9 corresponding to the tail piston rod bolt hole 16 is provided on the surface of the elastic metal skin 2. The tail piston rod 15 passes through the tail oil cavity spring plate 11 and is threadedly connected to the elastic metal skin 2. One end of the return spring 17 abuts against the piston 18, and the other end of the return spring 17 abuts against the tail oil cavity spring plate 11.

[0025] The piston 18 inside the oil cavity wall 14 of the second profiled surface is connected to the tail piston rod 15, and the tail oil cavity spring plate 11 is fixedly connected to the elastic metal skin 2 through the bolt hole 16. The length of the tail piston rod is greater than that of the surface piston rod to ensure uniform tension of the skin during sliding, and the return spring 17 provides a reset support.

[0026] Furthermore, the length of the tail piston rod 15 is greater than that of the surface piston rod 13. A chute 10 is provided inside the guide vane body. Both ends of the elastic metal skin 2 slide along the chute 10.

[0027] In this embodiment, the length difference between the tail piston rod 15 and the surface piston rod 13 cooperates with the chute 10 inside the guide vane body, so that the friction resistance is reduced when both ends of the elastic metal skin 2 slide along the chute 10, and the continuous and smooth adjustment of the profile is realized; The tail piston rod 15 pushes the elastic metal skin 2 to move along the slide groove 10 after being acted upon by the pressure oil to change the length of the guide vane, or shortens the guide vane under the restoring force of the restoring spring 17 after recovering the pressure oil, thereby achieving the requirement of changing the length of the guide vane.

[0028] Example 4 like Figures 4-6 and Figure 11 As shown, on the basis of Example 3, the plurality of oil circuits include a first main oil circuit 3, a second main oil circuit 4, and a third main oil circuit 5 opened along the axis of the guide vane shaft 1; and also include a first branch flow path 6 connected to the first profile oil cavity wall 14, a second branch flow path 7 connected to the second profile oil cavity wall 14, and a third branch flow path 8 connected to the third profile oil cavity wall 14; the first main oil circuit 3 is connected to the first branch flow path 6, the second main oil circuit 4 is connected to the second branch flow path 7, and the third main oil circuit 5 is connected to the third branch flow path 8.

[0029] In this embodiment, the first main oil circuit 3, the second main oil circuit 4, and the third main oil circuit 5 can be fed with pressurized oil individually to adjust the profile of a certain position, and can also be fed with pressurized oil simultaneously to adjust the overall profile of the guide vane.

[0030] Example 5 On the basis of Example 4, the working condition of the turbine is less than 30% Qr. At this time, the end of the elastic metal skin 2 is used as the tail of the guide vane. Since the flow rate is extremely small and the guide vane opening is also very small, the water flow is bound to increase the circumferential velocity component. At this time, the front profile of the guide vane should be adjusted to be straight, and the curvature of the back profile of the guide vane should be increased. Therefore, the pressure oil should be injected into the first main oil circuit 3, and the pressure oil of the third main oil circuit 5 should be recovered. The surface piston rod 13 moves closer to the guide vane body under the action of the restoring force of the restoring spring 17, and the piston 18 compresses The spring stores elastic potential energy; then consider the working condition of greater than 30% Qr and less than 70% Qr. At this time, the working flow is medium to small. After the flow around the guide vane, Karman vortex is easy to occur at the tail of the guide vane. The Karman vortex is related to the width of the tail of the guide vane. The width of the tail of the guide vane can be shortened by extending the length of the guide vane; finally, consider the working condition of greater than 70% Qr and less than 100% Qr. At this time, the flow condition is close to the design condition, and the guide vane opening is large. The curvature of the guide vane on both sides should be reduced to make the guide vane profile thinner and the channel between the guide vanes larger, which can reduce hydraulic losses; Example 6 On the basis of Embodiment 5, considering the working conditions of the water pump, at this time, this end of the elastic metal skin 2 will serve as the head of the guide vane. To uniformly guide the water flow into the guide vane, when pumping water under the working conditions where the flow rate is greater than 70%Qr and less than 100%Qr, it is necessary to widen the head profile line. At this time, it is necessary to shorten the length of the guide vane and increase the width of the guide vane. Therefore, the pressure oil should be introduced into the first main oil passage 3 and the third main oil passage 5, and the pressure oil inside the second main oil passage 4 should be recovered. Under other small-flow working conditions, the flow pattern at the water pump outlet is relatively chaotic, and a narrow and long flow passage is required to constrain and regularize the flow pattern so as to better convert the dynamic pressure into static pressure. Therefore, at this time, the guide vane should be elongated and the bilateral curvature of the guide vane should be increased, that is, the guide vane is fully extended. At this time, it is necessary to inject pressure oil into the first main oil passage 3, the second main oil passage 4, and the third main oil passage 5 at the same time.

[0031] It should be noted particularly that: The stroke of the piston 18 determines the different curvatures of the guide vane profile line, and the stroke is continuously variable. Therefore, theoretically, there are countless adjustment combination methods; the specific adjustment scheme of the guide vane profile line should be determined according to different water turbine models under the specific working conditions in service. The ultimate goal is to reduce the pressure pulsation and mechanical vibration of the unit. Therefore, the adjustment scheme given in the embodiment is not the only one.

[0032] Combined with Embodiments 1-6, the present invention also discloses a method for adjusting the profile line of a guide vane of a pump-turbine with a dynamically adjustable profile line. Using the above-mentioned guide vane of a pump-turbine with a dynamically adjustable profile line, it is specifically implemented according to the following steps: Inject pressure oil into the first main oil passage and the third main oil passage. The pressure oil enters the oil cavity walls 14 of the first profile surface and the third profile surface along the first branch oil passage and the third branch oil passage. The piston 18 is subjected to the hydraulic action, and the piston rod 13 on the surface pushes the elastic metal skin 2 to elastically deform, and the restoring spring 17 is compressed to store elastic potential energy until the oil pressure is balanced with the elastic force, and the profile line remains in the current state; when the working condition changes, the oil pressure of the pressure oil is reduced, the restoring spring 17 elongates, and the guide vane profile line is adjusted again to achieve profile line adjustment.

[0033] Furthermore, inject pressure oil into the second main oil passage. The pressure oil enters the oil cavity wall 14 of the second profile surface along the second branch oil passage. The piston 18 is subjected to the hydraulic action, and the piston rod 15 at the tail pushes the elastic metal skin 2 to move, and the restoring spring 17 is compressed to store elastic potential energy until the oil pressure is balanced with the elastic force, and the length of the guide vane remains in the current state; when the working condition changes, the oil pressure of the pressure oil is reduced, the restoring spring 17 elongates, and the length of the guide vane is adjusted again.

[0034] The present invention controls the movement of the piston 18 through hydraulic operation to push and pull the elastic metal skin 2 to elastically deform, so as to achieve the purpose of dynamically adjusting the guide vane profile. It can be used to solve the problems in the prior art that the guide vane profile cannot be dynamically adjusted, resulting in the formation of von Kármán vortices in the wake flow of the guide vane and interblade vortices in the separated flow on the guide vane surface when in different working conditions due to the same guide vane profile. Once in a non-optimal opening, the action of the vortices transmitted to the vaneless area will exacerbate the pressure pulsation of the water turbine and reduce the service life of the unit. Moreover, the water turbine operating conditions and the reverse pump operating conditions have different requirements for the profile at the inlet of the guide vane and cannot be coordinated. The guide vane profile and length of the present invention can be dynamically adjusted, which can meet the requirements of the pump-turbine under different working conditions, effectively reduce the pressure pulsation and unit vibration. The dynamic adjustment of the guide vane profile is a targeted means to suppress the generation of guide vane vortices under different working conditions, which will greatly reduce the energy loss and improve the efficiency.

[0035] Finally, it should also be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0036] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0037] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The guide vane of a pump-turbine with dynamically adjustable profile is characterized in that: The invention comprises an integrally formed guide vane shaft (1) and a guide vane body, wherein the cross section of the guide vane body is elliptical and the longitudinal section of the guide vane body is rectangular; with the short axis of the guide vane body as the center line, one side is an elliptical structure and the other side is a dynamic profile structure; the dynamic profile structure comprises a first profile surface, a second profile surface and a third profile surface which are vertically arranged and sequentially connected, the first profile surface and the third profile surface are arranged opposite to each other, and the angle formed between the first profile surface and the third profile surface is an acute angle; The first profile, the second profile and the third profile are connected with an elastic metal skin (2) via fasteners, and the first profile, the second profile and the third profile and the elastic metal skin (2) are connected via an adjustment mechanism; a plurality of oil paths are provided in the guide vane shaft (1) and the guide vane body, and the plurality of oil paths are connected to the adjustment mechanism.

2. The pump-turbine guide vane with dynamically adjustable profile according to claim 1, characterized in that: The first molded surface and the third molded surface are both provided with a plurality of oil chamber walls (14), the oil chamber walls (14) are in communication with a plurality of oil passages, a piston (18) is slidably connected in the oil chamber walls (14), a surface piston rod (13) is fixedly connected to a side of the piston (18) facing away from the oil passage, and a restoring spring (17) is circumferentially sleeved on the surface piston rod (13); The surfaces of the first profile and the third profile are connected with a surface oil chamber spring plate (12) via fasteners; a surface piston rod (13) penetrates the surface oil chamber spring plate (12) and abuts against the elastic metal skin (2); one end of a restoring spring (17) abuts against the piston (18); and the other end of the restoring spring (17) abuts against the surface oil chamber spring plate (12).

3. The pump-turbine guide vane with dynamically adjustable profile according to claim 2, characterized in that: The second mold surface is provided with a plurality of oil chamber walls (14), the oil chamber walls (14) being in communication with a plurality of oil passages, a piston (18) being slidably connected in the oil chamber wall (14), a tail piston rod (15) being fixedly connected to a side of the piston (18) facing away from the oil passage, and a restoring spring (17) being sleeved circumferentially on the tail piston rod (15); The surface of the second profile is connected to a tail oil chamber spring plate (11) via a fastener, a tail piston rod bolt hole (16) is provided at the end of the tail piston rod (15), a metal elastic skin bolt hole (9) corresponding to the tail piston rod bolt hole (16) is opened on the surface of the elastic metal skin (2), the tail piston rod (15) passes through the tail oil chamber spring plate (11) and is bolted to the elastic metal skin (2), one end of the restoring spring (17) abuts against the piston (18), and the other end of the restoring spring (17) abuts against the tail oil chamber spring plate (11).

4. The pump-turbine guide vane with dynamically adjustable profile according to claim 3, characterized in that: The length of the tail piston rod (15) is greater than the length of the surface piston rod (13), a slide groove (10) is provided in the guide vane body, and both ends of the elastic metal skin (2) slide along the slide groove (10).

5. The pump-turbine guide vane with dynamically adjustable profile according to claim 4, characterized in that: The plurality of oil passages include a first main oil passage (3), a second main oil passage (4), and a third main oil passage (5) which are opened along the axis of the guide vane shaft (1); and also include a first branch passage (6) connected to the first profile oil cavity wall (14), a second branch passage (7) connected to the second profile oil cavity wall (14), and a third branch passage (8) connected to the third profile oil cavity wall (14); the first main oil passage (3) is connected to the first branch passage (6), the second main oil passage (4) is connected to the second branch passage (7), and the third main oil passage (5) is connected to the third branch passage (8).

6. The pump-turbine guide vane with dynamically adjustable profile according to any one of claims 1 to 5, characterized in that: The elastic metal skin (2) is made of any one of aluminum, magnesium, titanium alloy or composite material.

7. A method for adjusting the profile of a pump-turbine guide vane with a dynamically adjustable profile, using the pump-turbine guide vane with a dynamically adjustable profile as claimed in claim 5, characterized in that: Specifically, the process is implemented according to the following steps: injecting pressurized oil into the first main oil circuit and the third main oil circuit, and the pressurized oil enters the oil cavity wall (14) of the first mold surface and the third mold surface along the first branch flow path and the third branch flow path, the piston (18) is subjected to hydraulic pressure, the surface piston rod (13) pushes the elastic metal skin (2) to elastically deform, and the restoring spring (17) is compressed to store elastic potential energy until the oil pressure and the elastic force are balanced and the mold line remains in the current state; when the working condition changes, the pressure of the pressurized oil is reduced, the restoring spring (17) is extended, and the guide vane mold line is adjusted again to achieve mold line adjustment.

8. The method for adjusting the profile of a pump-turbine guide vane with dynamically adjustable profile according to claim 7, characterized in that: Pressurized oil is injected into the second main oil circuit, and the pressurized oil enters the oil chamber wall (14) of the second profile along the second branch flow path. The piston (18) is acted upon by hydraulic pressure, and the tail piston rod (15) pushes the elastic metal skin (2) to move, and the restoring spring (17) is compressed to store elastic potential energy until the oil pressure and the elastic force are balanced, and the length of the guide vane is maintained at the current state. When the working condition changes, the pressure of the pressurized oil is reduced, the restoring spring (17) is extended, and the length of the guide vane is adjusted again.

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