Adjustable blade type water turbine crown leakage stop device

Abstract

The present application relates to a kind of adjustable blade type water turbine upper crown leak stop device, including multiple flexible blade type leak stop mechanism, flexible blade type leak stop mechanism includes flexible blade and adjustable electroactive polymer layer, flexible blade is set in runner upper crown gap and runner upper crown outlet position, the inside of flexible blade is provided with adjustable electroactive polymer layer, flexible blade type leak stop mechanism is provided with wireless flow sensor between, the power line of wireless flow sensor and adjustable electroactive polymer layer is connected servo voltage stabilizer feeder respectively, servo voltage stabilizer feeder is connected with lower computer, lower computer and wireless flow sensor are all connected with internet of things intelligent controller communication.This application sets up adjustable electroactive polymer layer, which can adjust posture through servo voltage stabilizer feeder, when water flow enters gap cavity from runner around along upper crown gap, flexible blade provides centrifugal force for water, under the action of centrifugal force, water in upper crown cavity is discharged to achieve leak stop effect.

Description

Technical Field

[0001] This invention relates to the field of hydropower engineering technology, specifically to a leak-stopping device for the crown of an adjustable blade-type water turbine. Background Technology

[0002] Hydropower turbine generator sets are the core components of hydropower stations and crucial equipment for maintaining power grid balance. Leakage losses during turbine operation are a significant factor affecting the efficiency of pump-turbine systems. Crown leakage is one of the most prevalent forms of leakage, significantly impacting the efficiency and safety of the entire turbine unit. It alters the internal flow field structure, leading to a substantial decrease in unit performance, changes in axial force, vibration, and noise, and in severe cases, structural damage. Currently, common methods for controlling crown leakage include labyrinth ring seals and crown gap seals. However, mechanical seals are prone to wear and require regular maintenance. References include CN202673542U (Turbine Top Cover Structure), CN201661405U (A Novel Leak-Stopping Ring on the Runner), CN115638072A (Leak-Stopping Method for Mixed-Flow Turbines), and CN113431724A (A Mixed-Flow Runner Device for Water Turbines).

[0003] Therefore, there is an urgent need for a crown-type leak-proof device that is not easily worn and can prevent leakage to meet the working requirements of hydro-generators. Summary of the Invention

[0004] To address the problems of wear and tear and the need for regular maintenance in existing labyrinth ring seal leak-proof devices, this invention provides an adjustable blade-type turbine crown leak-proof device. The device features a flexible blade-type leak-proof mechanism comprising flexible blades and an adjustable electroactive polymer layer. An IoT intelligent controller, based on flow data detected by a wireless flow velocity sensor, adjusts the power output of a servo voltage regulator via a lower-level computer to control the shape of the adjustable electroactive polymer layer. When water flows from around the turbine into the gap cavity along the crown gap, the flexible blade-type leak-proof mechanism achieves excellent leak-proof performance under centrifugal force.

[0005] To achieve the above objectives, the present invention proposes an adjustable blade-type turbine crown leak-stopping device, including a rotating shaft, a turbine crown, a wireless flow velocity sensor, a servo voltage regulator, and an Internet of Things intelligent controller. The top of the turbine crown is provided with multiple flexible blade-type leak-stopping mechanisms. Each flexible blade-type leak-stopping mechanism includes flexible blades and an adjustable electroactive polymer layer. The flexible blades are disposed in the gap of the turbine crown and at the outlet position of the turbine crown.

[0006] The flexible blade has multiple straight slots arranged in a longitudinal array on its side. An adjustable electroactive polymer layer is provided in the straight slots. An adjustable electroactive polymer layer is provided along the centerline of the flexible blade near the edge of the upper surface of the flexible blade.

[0007] A wireless flow rate sensor is installed between the flexible blade-type leak-stopping mechanism. The power lines of the wireless flow rate sensor and the adjustable electroactive polymer layer pass through the rotating shaft and are respectively connected to a servo voltage regulator. The servo voltage regulator is connected to a lower-level machine. Both the lower-level machine and the wireless flow rate sensor are connected to an Internet of Things (IoT) smart controller.

[0008] The IoT smart controller controls the morphology of the adjustable electroactive polymer layer by adjusting the power output of the servo voltage regulator through the lower-level computer based on the flow data detected by the wireless flow sensor.

[0009] Operating Principle: When the turbine rotates, a wireless flow velocity sensor detects the water velocity in the upper crown gap. The sensor transmits the detected parameters to an IoT smart controller. The IoT smart controller inputs control commands to a lower-level device based on the flow velocity and the turbine's rotation direction. The lower-level device drives a servo voltage regulator to output electrical energy. The adjustable electroactive polymer layer contracts to varying degrees depending on the output power of the servo voltage regulator. This causes the flexible blades to bend under the unbalanced tension, with the direction of the bend determined by the turbine's rotation and the degree of bend determined by the flow rate measured by the wireless flow velocity sensor. The flexible blades provide centrifugal force to the water, which displaces the water in the upper crown cavity, effectively preventing leakage.

[0010] Furthermore, multiple flexible blade-type leak-stopping mechanisms are arranged at equal angles along the circumference of the crown of the rotating wheel, and multiple wireless flow rate sensors are intersected with multiple flexible blades.

[0011] The presence of multiple wireless flow sensors improves detection accuracy. Furthermore, the array of wireless flow sensors along the circumference of the crown on the wheel ensures the balance of the crown's mass.

[0012] Furthermore, the flexible blade has a NACA airfoil, with an inlet angle of 90°, an outlet angle of 85°~95°, a blade wrap angle of -2°~2°, and a variable displacement of -10~10 cm at the blade edge.

[0013] Hydropower turbines require forward and reverse rotation during operation; therefore, the flexible blades must meet these requirements. This necessitates designing variable displacement at the inlet and outlet angles, blade wrap angle, and blade edge to ensure the flexible blades' bending direction changes with the turbine's rotation direction. Furthermore, the turbine operates under varying conditions, and its discharge rate varies accordingly. Therefore, the centrifugal force provided by the flexible blades must meet different discharge requirements. This necessitates a variable design for the flexible blade wrap angle to ensure the centrifugal force changes with leakage.

[0014] Furthermore, the radius of the crown on the rotor is R, the thickness of the flexible blade is 0.01 R ~ 0.05 R, the outer diameter of the blade edge of the flexible blade is 0.9R ± 0.1R, the inner diameter of the blade root of the flexible blade is 0.6R ± 0.1R, and the width of the flexible blade is 0.05R ± 0.01R.

[0015] The size of the flexible blades is related to the radius of the crown on the impeller, thus ensuring that the flexible blades have a good leak-proof effect under centrifugal force.

[0016] Furthermore, the number of flexible blade-type leak-stopping mechanisms is 2 to 4.

[0017] Furthermore, the flexible blade is a NACA airfoil structure made of flexible composite material, and the bottom of the flexible blade is fixed to the crown of the rotor by bolts;

[0018] The flexible composite material includes one or more combinations of aromatic polyamide fiber fabrics, ultra-high molecular weight polyethylene fiber fabrics, aliphatic polyester fiber fabrics, and aliphatic polyamide fiber fabrics.

[0019] The flexible blades are made of flexible composite materials and have good deformation performance.

[0020] Furthermore, the tunable electroactive polymer layer is a sheet structure made of tunable electroactive polymer, which includes an electrostrictive grafted elastomer electroactive polymer.

[0021] Furthermore, the IoT smart controller includes a wireless module and a host computer.

[0022] The beneficial effects of the present invention through the above technical solution are as follows:

[0023] (1) The present invention can achieve the effect of sealing the upper crown of the turbine, and compared with the existing labyrinth ring sealing ring, it has the advantages of being less prone to wear and not requiring regular maintenance and replacement. The top of the upper crown of the turbine is provided with multiple flexible blade-type sealing mechanisms. The flexible blade-type sealing mechanism includes flexible blades and adjustable electroactive polymer layers. The flexible blades are set in the gap of the upper crown of the turbine and the outlet position of the upper crown of the turbine. Multiple straight through slots are opened in a longitudinal array on the side of the flexible blades. The adjustable electroactive polymer layers are set in the straight through slots and along the centerline of the flexible blades near the edge of the upper surface of the flexible blades.

[0024] The adjustable electroactive polymer layer contracts to varying degrees depending on the output power of the servo voltage regulator. This causes the flexible blades to bend into an airfoil under the unbalanced tension, with the direction of the bend determined by the rotor's rotation and the degree of bend determined by the flow rate measured by the wireless flow sensor. The flexible blades provide centrifugal force to the water, which displaces the water in the upper crown cavity, effectively preventing leakage.

[0025] (2) This invention designs a complete control scheme for the electroactive polymer layer. First, a wireless flow velocity sensor is installed to detect the flow data. Then, the flow data is uploaded to the Internet of Things (IoT) intelligent controller via wireless communication. Based on the flow data detected by the wireless flow velocity sensor, the IoT intelligent controller adjusts the power output of the servo voltage regulator via a lower-level machine to control the shape of the adjustable electroactive polymer layer. This allows the flexible blade-type leak-stopping mechanism to match the forward and reverse rotation of the water turbine. Attached Figure Description

[0026] Figure 1 This is one of the structural schematic diagrams of an adjustable blade-type turbine crown leak-stopping device according to the present invention;

[0027] Figure 2 This is one of the schematic diagrams of the flexible blade-type leak-stopping mechanism of the adjustable blade-type turbine crown leak-stopping device of the present invention;

[0028] Figure 3 This is the second schematic diagram of the flexible blade-type leak-stopping mechanism of the adjustable blade-type turbine crown leak-stopping device of the present invention;

[0029] Figure 4 This is a second schematic diagram of the structure of an adjustable blade-type turbine crown leak-proof device according to the present invention;

[0030] Figure 5 This is a schematic diagram of the operation of an adjustable blade-type turbine crown leak-proof device according to the present invention;

[0031] Figure 6 This is an electrical flow diagram of an adjustable blade-type turbine crown leak-proof device according to the present invention.

[0032] Reference numerals: 1 is the upper crown of the rotor, 2 is the adjustable electroactive polymer layer, 3 is the flexible blade, 4 is the wireless flow sensor, 5 is the servo voltage regulator, 6 is the IoT intelligent controller, and 7 is the rotating shaft. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0034] Example 1

[0035] like Figure 1As shown, an adjustable blade-type turbine crown leak-stopping device includes a rotating shaft 7, a turbine crown 1, a wireless flow velocity sensor 4, a servo voltage regulator 5, and an Internet of Things intelligent controller 6. The top of the turbine crown 1 is provided with multiple flexible blade-type leak-stopping mechanisms. Each flexible blade-type leak-stopping mechanism includes flexible blades 3 and an adjustable electroactive polymer layer 2. The flexible blades 3 are disposed in the gap of the turbine crown 1 and at the outlet position of the turbine crown 1.

[0036] like Figure 2 As shown, the flexible blade 3 has multiple straight slots arranged in a longitudinal array on its side. An adjustable electroactive polymer layer 2 is disposed in the straight slots. An adjustable electroactive polymer layer 2 is disposed along the edge of the flexible blade 3 near the upper surface of the flexible blade 3.

[0037] A wireless flow rate sensor 4 is installed between the flexible blade-type leak-stopping mechanism. The power lines of the wireless flow rate sensor 4 and the adjustable electroactive polymer layer 2 pass through the rotating shaft 7 and are respectively connected to the servo voltage regulator 5. The servo voltage regulator 5 is connected to the lower-level machine. The lower-level machine and the wireless flow rate sensor 4 are both connected to the Internet of Things intelligent controller 6.

[0038] The IoT smart controller 6 controls the morphology of the adjustable electroactive polymer layer 2 by adjusting the power output of the servo voltage regulator 5 through the lower-level machine based on the flow data detected by the wireless flow sensor 4.

[0039] Preferably, the plurality of flexible blade-type leak-stopping mechanisms are arranged at equal angles along the circumference of the crown 1 of the rotating wheel, and the plurality of wireless flow rate sensors 4 are arranged intersectingly with the plurality of flexible blades 3.

[0040] Preferably, the flexible blade 3 has a NACA airfoil, an inlet angle of 90°, an outlet angle of 85°~95°, a blade wrap angle of -2°~2°, and a variable displacement of -10~10 cm at the blade edge.

[0041] like Figure 4 As shown, preferably, the radius of the crown 1 on the rotor is R, the thickness of the flexible blade 3 is 0.01 R ~ 0.05 R, the outer diameter of the blade edge of the flexible blade 3 is 0.9R ± 0.1R, the inner diameter of the blade root of the flexible blade 3 is 0.6R ± 0.1R, and the width of the flexible blade 3 is 0.05R ± 0.01R.

[0042] The inner diameter of the blade root is represented by the distance between the apex of the three circular arc segments of the flexible blade and the center of the crown 1 circle on the rotor.

[0043] Preferably, the number of flexible blade-type leak-stopping mechanisms is 2 to 4.

[0044] Preferably, the flexible blade 3 is a NACA airfoil structure made of flexible composite material, and the bottom of the flexible blade 3 is fixed to the crown 1 of the runner by bolts to prevent the flexible blade 3 from loosening due to the rotation of the turbine.

[0045] The flexible composite material includes one or more combinations of aromatic polyamide fiber fabrics, ultra-high molecular weight polyethylene fiber fabrics, aliphatic polyester fiber fabrics, and aliphatic polyamide fiber fabrics.

[0046] Preferably, the tunable electroactive polymer layer 2 is a sheet structure made of tunable electroactive polymer, which includes an electrostrictive grafted elastomer electroactive polymer.

[0047] Preferably, the IoT smart controller 6 includes a wireless module and a host computer.

[0048] The servo voltage regulator 5 is installed in the speed governor cabinet of the turbine generator layer, and is powered and controlled by the adjustable electroactive polymer layer 2 along the main axis of the turbine via cables.

[0049] The IoT smart controller 6 is installed in the power plant's central control room and intelligently determines the angle of the flexible blade 3 based on the unit's operating conditions.

[0050] In this embodiment, there are three flexible blade-type leak-stopping mechanisms. Correspondingly, there are also three flexible blades 3 and three wireless flow sensors 4.

[0051] like Figures 1-6 As shown,

[0052] During operation, the wireless flow sensor 4 detects the flow data of the crown 1 on the impeller and transmits it to the host computer via wireless communication. The host computer receives the flow data through the wireless module and then outputs control signals to the slave computer. The slave computer drives the servo voltage regulator 5 to work, which in turn causes the adjustable electroactive polymer layer 2 to deform, thus causing the flexible blade 3 to deform.

[0053] like Figure 5 As shown, Figure 5 (a) shows that when rotating clockwise, the flexible blade 3 deforms and completes the leak prevention operation under the action of centrifugal force in the counterclockwise direction.

[0054] like Figure 5 As shown, Figure 5 (b) shows that when rotating clockwise, the flexible blade 3 deforms and completes the leak prevention operation under the action of centrifugal force in the clockwise direction.

[0055] This invention relates to a leak-proof design for the upper crown gap structure of a water pump turbine runner. The flexible blade-type leak-proof mechanism is located directly below the top cover of the unit. When water flows from around the runner into the gap cavity along the upper crown 1, the flexible blades 3 provide centrifugal force to the water. Under the action of centrifugal force, the water in the upper crown cavity is discharged, achieving a good leak-proof effect.

[0056] This invention is applicable to the crown clearance structure of various water turbines, enabling accurate control of leakage and reducing the frequency of clearance seal maintenance. This improves the overall performance of the water turbine unit, resulting in energy savings and reduced consumption. The invention has a simple structure, reliable technology, and is easy to implement. It can be applied to various types of water turbines, including pump-turbines, mixed-flow turbines, and pump-turbines, and has broad application prospects.

[0057] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of the present invention should be included within the scope of the present invention.

Claims

1. An adjustable bladed turbine crown leak-proof device, comprising a shaft (7), a runner crown (1), a wireless flow velocity sensor (4), a servo voltage regulator (5), and an Internet of Things intelligent controller (6), characterized in that, The top of the upper crown (1) of the rotating wheel is provided with a plurality of flexible blade-type leak-stopping mechanisms. The flexible blade-type leak-stopping mechanism includes an adjustable electroactive polymer layer (2) and flexible blades (3). The flexible blades (3) are disposed in the gap of the upper crown (1) of the rotating wheel and at the outlet position of the upper crown (1). The flexible blade (3) has multiple straight slots arranged in a longitudinal array on its side. An adjustable electroactive polymer layer (2) is provided in the straight slots. An adjustable electroactive polymer layer (2) is provided along the edge of the flexible blade (3) near the upper surface of the flexible blade (3) along the centerline. A wireless flow rate sensor (4) is installed between the flexible blade-type leak-stopping mechanism. The power lines of the wireless flow rate sensor (4) and the adjustable electroactive polymer layer (2) pass through the rotating shaft (7) and are respectively connected to the servo voltage regulator (5). The servo voltage regulator (5) is connected to the lower computer. The lower computer and the wireless flow rate sensor (4) are both connected to the Internet of Things intelligent controller (6). The IoT smart controller (6) controls the morphology of the adjustable electroactive polymer layer (2) by adjusting the power output of the servo voltage regulator (5) through the lower-level machine based on the flow data detected by the wireless flow sensor (4).

2. The adjustable blade-type turbine crown leak-proof device according to claim 1, characterized in that, Multiple flexible blade-type leak-stopping mechanisms are arranged at equal angles along the circumference of the crown (1) of the rotating wheel, and multiple wireless flow sensors (4) are intersected with multiple flexible blades (3).

3. The adjustable blade-type turbine crown leak-proof device according to claim 1, characterized in that, The flexible blade (3) has an airfoil of NACA, an inlet angle of 90° and an outlet angle of 85°~95°, a blade wrap angle of -2°~2°, and a variable displacement of -10~10 cm at the blade edge.

4. The adjustable blade-type turbine crown leak-proof device according to claim 1, characterized in that, The radius of the crown (1) on the rotating wheel is R, the thickness of the flexible blade (3) is 0.01 R ~ 0.05 R, the outer diameter of the blade edge of the flexible blade (3) is 0.9R ± 0.1R, the inner diameter of the blade root of the flexible blade (3) is 0.6R ± 0.1R, and the width of the flexible blade (3) is 0.05R ± 0.01R.

5. The adjustable blade-type turbine crown leak-proof device according to claim 1, characterized in that, The number of flexible blade-type leak-stopping mechanisms is 2 to 4.

6. The adjustable blade-type turbine crown leak-proof device according to claim 3, characterized in that, The flexible blade (3) is a NACA airfoil structure made of flexible composite material, and the bottom of the flexible blade (3) is fixed to the crown (1) of the wheel by bolts; The flexible composite material includes one or more combinations of aromatic polyamide fiber fabrics, ultra-high molecular weight polyethylene fiber fabrics, aliphatic polyester fiber fabrics, and aliphatic polyamide fiber fabrics.

7. The adjustable blade-type turbine crown leak-proof device according to claim 1, characterized in that, The tunable electroactive polymer layer (2) is a sheet structure made of tunable electroactive polymer, which includes electrostrictive grafted elastomer electroactive polymer.

8. The adjustable blade-type turbine crown leak-proof device according to claim 1, characterized in that, The IoT smart controller (6) includes a wireless module and a host computer.

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