Impact type water-turbine generator set turning system and using method thereof

Abstract

The invention discloses an impact type water-turbine generator set barring system and a using method thereof, and belongs to the field of installation, debugging and overhauling of large impact type water-turbine generator sets. The barring system comprises a barring device, a water turbine runner protection cover and a water turbine runner overhauling platform, and the barring device is composed of a flexible coupler, a speed reducer, a motor and a supporting seat; the driving point is located on a turbine runner of the turbine runner chamber. During turning, the turning wheel protection cover is assembled on the turning wheel, the turning device and the protection cover are connected through the flexible coupler, and the motor is started to drive the turning wheel to rotate through the speed reducer. According to the scheme, parts such as a generator outer cover and a collecting ring do not need to be disassembled and assembled, accurate centering is avoided through the flexible coupler, the synchronization problem is avoided through single-motor driving, the unit installation debugging and maintenance efficiency is greatly improved, the device installation process is simplified, and the device is suitable for efficient turning operation of the impact type unit.

Description

Technical Field

[0001] The present invention relates to the technical field of installation, commissioning and maintenance of large-scale impulse turbine generator sets, and in particular to a turning system of an impulse turbine generator set and a method for using the same. Background Art

[0002] Large-scale Pelton turbine generator sets, as the core equipment of high-head hydropower stations, play a crucial role in hydropower development. With the development of high-head hydropower stations, the efficiency of their installation, commissioning, and maintenance has become a key factor restricting the industry's development. The technical level of the turning process, a core step in the installation, commissioning, and maintenance process, directly impacts the unit's operating accuracy and maintenance cycle.

[0003] At present, the cranking method of large-scale Pelton turbine generator sets in China generally follows the cranking method and system of conventional Francis units. This method has the following main problems: From the cranking position, existing cranking operations are all performed on the generator side, and there are two specific implementation methods: First, a specialized turning tool consisting of an electric motor, reduction gear set, and turning bracket must be installed on the top shaft of the generator. While this method enables electric drive, the specialized device is complex and requires strict alignment during installation, which not only increases the difficulty but also prolongs the construction time. Furthermore, the turning process requires the removal of components such as the generator housing, collector rings, their cooling system, and the upper cover. Removal and reinstallation of these components is not only labor-intensive and time-consuming, but can also lead to component wear due to repeated disassembly and assembly, compromising the unit's sealing and operational stability.

[0004] The second method involves manually turning the generator rotor using mechanical turning posts evenly spaced around the circumference of the generator rotor bracket. Using the vertical lifting force of a factory crane, the fixed pulley redirects the force, generating a tangential pulling force to drive the unit. While relatively simple, this method relies on a crane, which is subject to significant limitations imposed by the factory's lifting equipment. Furthermore, manual operation is labor-intensive, resulting in low turning efficiency. Furthermore, the generator-side components must be disassembled, creating the same heavy assembly and disassembly workload as the electric mechanical turning method.

[0005] In summary, the existing cranking methods and systems in the application of impulse turbine generator sets have defects such as large disassembly and assembly workload, complex device installation, high alignment requirements, low drive efficiency, and poor system compatibility, which seriously restrict the installation, commissioning and maintenance efficiency of the units. There is an urgent need for a new cranking method and system tailored to the characteristics of impulse turbines. Summary of the Invention

[0006] The present invention aims to overcome the above-mentioned shortcomings of the prior art and provides a winch system for an impulse turbine generator set and a method for using the same.

[0007] The technical solution adopted in the present invention is as follows: A turning system of an impulse turbine generator set, comprising: Turning device: The turning device includes a flexible coupling, a reducer, an electric motor and a support seat; Turbine runner protection cover: one end of the flexible coupling is connected to the turbine runner protection cover, and the other end is connected to the reducer. The turbine runner protection cover is concentrically assembled on the bottom of the turbine runner; Turbine runner maintenance platform: The turbine runner maintenance platform is set in the turbine runner room. The support base is installed on the turbine runner maintenance platform to support the turning device. The electric motor is connected to the flexible coupling through the reducer. The turning device, turbine runner protection cover and turbine runner maintenance platform constitute the turning system.

[0008] Furthermore, the flexible coupling is an elastic coupling, which is used to compensate for the coaxiality deviation between the turning device and the axis of the hydro-generator set.

[0009] Furthermore, the electric motor is a single motor drive structure, and the reducer is a gear reducer, which is used to achieve deceleration and torque increase.

[0010] Furthermore, the turbine runner maintenance platform is a detachable platform, which is fixedly installed at a predetermined position of the turbine runner chamber and is used to support the support seat.

[0011] Furthermore, the flexible coupling and the turbine runner protection cover are connected by flange connection or key connection.

[0012] Furthermore, a reserved bolt hole is provided in the middle of the turbine runner for bolt connection of the runner protection cover.

[0013] Furthermore, a method for using a cranking system of an impulse turbine generator set comprises the following steps: S1: Assemble the turbine runner protection cover on the turbine runner; S2: Connect the flexible coupling of the turning gear to the turbine runner protection cover, and fix the support base on the turbine runner maintenance platform; S3: Start the electric motor, reduce speed and increase torque through the reducer, and then drive the turbine runner to rotate through the flexible coupling to realize the unit turning.

[0014] Furthermore, the speed of the motor is adjusted through a control system to meet different turning accuracy requirements.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: The method and system for turning the Pelton turbine generator set provided by the present invention significantly improve the efficiency of unit installation, commissioning, and maintenance through innovative structural design and drive logic optimization. The beneficial effects are as follows: First, the no-disassembly feature significantly reduces workload. The turning system's drive point is lowered to the turbine runner chamber, eliminating the need to disassemble components such as the generator housing, collector rings, their cooling system, and the upper cover. This eliminates the traditional disassembly and assembly steps, shortening maintenance cycles and reducing the risk of component wear caused by frequent disassembly and assembly, thereby improving the unit's sealing and operational stability.

[0016] Secondly, the flexible coupling eliminates the need for precise alignment. Using an elastic coupling to compensate for coaxiality deviations shortens installation time. It also absorbs motor vibration through elastic deformation, suppressing the transmission of shaft vibration and improving the stability of the turning process.

[0017] Furthermore, single-motor drive simplifies the system structure. Abandoning the traditional multi-motor synchronous drive mode, a single motor is used in conjunction with a gear reducer. This eliminates the need for complex synchronous control, reduces the failure rate, and its low-speed torque-increasing characteristics directly match the turning requirements, shortening the transmission path and significantly reducing energy loss.

[0018] In summary, the present invention systematically solves the problems of cumbersome disassembly and assembly, difficult centering, and low efficiency of the traditional turning method through innovations such as drive point reconstruction, flexible transmission, and single motor integration. The overall efficiency is improved, providing a reliable solution for the efficient operation and maintenance of large-scale impact units. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Markings in the figure: 1-turbine runner, 2-turbine runner protection cover, 3-flexible coupling, 4-speed reducer, 5-electric motor, 6-support base, 7-turbine runner maintenance platform, 8-turning device. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to the accompanying drawings.

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0023] In this embodiment, if Figure 1 As shown, a cranking system of an impulse turbine generator set includes: Turning device: The turning device includes a flexible coupling, a reducer, an electric motor and a support seat; Turbine runner protection cover: one end of the flexible coupling is connected to the turbine runner protection cover, and the other end is connected to the reducer. The turbine runner protection cover is concentrically assembled on the bottom of the turbine runner; Turbine runner maintenance platform: The turbine runner maintenance platform is set in the turbine runner room. The support base is installed on the turbine runner maintenance platform to support the turning device. The electric motor is connected to the flexible coupling through the reducer. The turning device, turbine runner protection cover and turbine runner maintenance platform constitute the turning system.

[0024] Specifically: The turning device consists of a flexible coupling, a gear reducer, an electric motor, and a support base. The flexible coupling is a plum blossom-shaped elastic coupling, one end of which is bolted to the turbine runner protection cover via a flange, and the other end is fixed to the reducer input shaft via a keyway. The motor output shaft is directly connected to the reducer input end, and the support base is a frame structure made of welded steel sections, fixed to the turbine runner maintenance platform via anchor bolts.

[0025] Turbine runner protection cover: It is disc-shaped and concentrically assembled at the bottom center of the turbine runner. The center of the protection cover is provided with a positioning boss that matches the center body of the runner. There are 8 bolt holes evenly distributed on the edge, and it is fixed to the runner with M24 bolts.

[0026] Turbine runner maintenance platform: It is a detachable steel structure platform, fixed by U-shaped bolts embedded in the bottom of the runner chamber. Horizontal adjustment bolts are set on the platform surface to ensure the horizontality of the support base installation plane.

[0027] Start the motor, and the power is decelerated and torque-increased by the gear reducer, and then transmitted to the turbine runner protection cover through the flexible coupling, driving the turbine runner to rotate at a low speed around the axis of the unit, realizing turning.

[0028] Principle of downward shifting of the driving point: The turbine runner of the impulse turbine unit is located below the unit, and the driving point is set directly in the runner chamber. The force transmission path is short (only through the protective cover → runner), avoiding the energy loss and shaft deformation caused by the traditional generator-side drive that needs to transmit torque through a long shaft system.

[0029] Advantages of no disassembly and assembly: The turning system is independently set in the runner room, and there is no need to disassemble the generator cover, slip ring and other components, which reduces the workload of disassembly and assembly and shortens the maintenance cycle.

[0030] Example 2 The flexible coupling is an elastic coupling used to compensate for the coaxiality deviation between the turning gear and the axis of the hydro-generator set.

[0031] The flexible coupling utilizes a diaphragm-type elastic coupling, consisting of two flanges and an intermediate diaphragm assembly. The diaphragm assembly is composed of several stainless steel sheets interlaced and bolted together, allowing for axial deviations of ±2mm, radial deviations of ±1.5mm, and angular deviations of ±1.5°. One end of the coupling is connected to the protective cover flange with 12 M16 bolts, while the other end is connected to the reducer input flange with 8 M12 bolts.

[0032] When there is a coaxial deviation between the turning device and the axis of the unit, the diaphragm group absorbs the deviation through elastic deformation, and the torque of the motor is flexibly transmitted to the protective cover through the diaphragm group, driving the wheel to rotate while suppressing vibration transmission.

[0033] Centering fault tolerance principle: Traditional turning devices must ensure coaxiality ≤0.05mm, otherwise it is easy to cause bearing wear or coupling damage; this embodiment relaxes the installation centering accuracy requirement to ≤0.5mm through the deviation compensation capability of the elastic coupling, reducing installation difficulty and saving debugging time.

[0034] Vibration suppression: The elastic diaphragm can absorb the high-frequency vibration of the motor, prevent the vibration from being transmitted to the unit shaft system, and improve the stability of the cranking process.

[0035] Furthermore, the electric motor is a single motor drive structure, and the reducer is a gear reducer, which is used to achieve deceleration and torque increase.

[0036] The motor is connected to the input of the gear reducer via an elastic sleeve pin coupling. The reducer is a two-stage cylindrical gear reducer with a transmission ratio of 10:1. The output is secured to the flexible coupling via a keyway. A shock-absorbing pad is installed inside the support base to reduce the impact of motor vibration on the platform.

[0037] The motor runs at rated speed. After being decelerated by the reducer, the output speed is reduced and the torque is increased. The flexible coupling drives the runner to rotate slowly, meeting the low-speed and high-torque working conditions required for the turning gear.

[0038] Single-motor simplified logic: Traditional multi-motor drives require a synchronous controller to coordinate speeds, which carries the risk of motor overload due to uneven loads. This embodiment uses a single motor for direct drive, eliminating the need for synchronous control, resulting in a simplified structure, improved reliability, and reduced failure rates.

[0039] High efficiency of gear transmission: Cylindrical gear reducer has high transmission efficiency and reduces energy loss compared with other transmission forms such as worm gear, making it suitable for long-term turning operations.

[0040] Furthermore, the turbine runner maintenance platform is a detachable platform, which is fixedly installed at a predetermined position of the turbine runner chamber and is used to support the support seat.

[0041] The turbine runner inspection platform is welded from steel sections into a rectangular frame, topped with a non-slip steel plate. Adjustable legs (with threaded sleeves and lock nuts) are installed at the frame's four corners. The platform is secured to the embedded steel plate at the bottom of the runner chamber with four sets of U-bolts. To dismantle the platform, simply loosen the U-bolts and nuts, and the entire platform can be removed.

[0042] During installation, move the platform to the predetermined position in the runner room, adjust the levelness through the adjustable legs, and tighten the U-bolts to secure it; after turning, remove the U-bolts and move the platform away without affecting other maintenance work in the runner room.

[0043] The logic of the detachable design: The space in the impingement unit's impeller chamber is small, and the traditional fixed platform takes up permanent space, affecting the maintenance of other components. The detachable platform is only installed during cranking and removed after use, improving space utilization while avoiding rust problems caused by the platform being immersed in a humid environment for a long time.

[0044] Quick installation: The platform is connected by standardized U-bolts, and the installation / disassembly time can be controlled within 30 minutes, saving labor hours compared to traditional welded platforms.

[0045] Furthermore, the flexible coupling and the turbine runner protection cover are connected by flange connection or key connection.

[0046] Flange connection reliability: High-strength bolt connections can withstand large axial forces and torques, are suitable for dynamic loads during cranking, avoid the problem of easy loosening of traditional pin connections, and ensure the stability of power transmission.

[0047] Key connection economy: The flat key has a simple structure, low cost, and is easy to disassemble and maintain. It is suitable for scenarios where the coupling position needs to be frequently adjusted. Compared with the spline connection, the processing cost is lower.

[0048] Furthermore, a reserved bolt hole is provided in the middle of the turbine runner for bolt connection of the runner protection cover.

[0049] When installing the protective cover, insert the center positioning boss of the protective cover into the groove of the center body of the runner to ensure concentricity and ensure a firm connection.

[0050] Concentric assembly principle: The cooperation between the positioning boss and the groove can ensure the coaxiality of the protective cover and the runner, ensure uniform torque transmission during turning, and avoid runner swing or bearing eccentricity caused by eccentricity.

[0051] Bolt connection stability: The reserved bolt hole design avoids additional processing on the runner, maintaining the structural integrity of the runner. At the same time, the bolt connection can withstand large shear forces, ensuring that the protective cover does not undergo circumferential displacement during the turning process.

[0052] Furthermore, a method for using a cranking system of an impulse turbine generator set comprises the following steps: S1: Assemble the turbine runner protection cover on the turbine runner; S2: Connect the flexible coupling of the turning gear to the turbine runner protection cover, and fix the support base on the turbine runner maintenance platform; S3: Start the electric motor, reduce speed and increase torque through the reducer, and then drive the turbine runner to rotate through the flexible coupling to realize the unit turning.

[0053] No-disassembly mechanism: The entire cranking process does not require touching any parts on the generator side. The generator cover, slip ring, etc. remain in their original state, avoiding the risk of seal aging or component damage caused by disassembly in traditional methods.

[0054] Efficient transmission path: Power is driven directly from the runner, which reduces intermediate links such as the main shaft and coupling compared to traditional generator-side drive, improves transmission efficiency and shortens cranking time.

[0055] Furthermore, the speed of the motor is adjusted through a control system to meet different turning accuracy requirements.

[0056] The motor speed can be adjusted steplessly by changing the power supply frequency. Compared with the traditional mechanical speed change mechanism, it has a faster response speed and can realize soft start, reducing the impact of starting impact current on the power grid.

[0057] The above description is only a preferred embodiment of the invention and is not intended to limit the invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the invention should be included in the scope of protection of the invention.

Claims

1. A turning system for an impulse turbine generator set, characterized in that: include: The turning device includes a flexible coupling, a reducer, an electric motor and a support seat; Turbine runner protection cover: one end of the flexible coupling is connected to the turbine runner protection cover, and the other end is connected to the reducer. The turbine runner protection cover is concentrically assembled on the bottom of the turbine runner; Turbine runner maintenance platform: The turbine runner maintenance platform is arranged in the turbine runner room, and the support base is installed on the turbine runner maintenance platform to support the winching device. The electric motor is connected to the flexible coupling through the reducer. The winching device, turbine runner protection cover and turbine runner maintenance platform constitute a winching system.

2. The turning system of a Pelton turbine generator set according to claim 1, characterized in that: The flexible coupling is an elastic coupling used to compensate for the coaxiality deviation between the turning device and the axis of the hydro-generator set.

3. The turning system of a Pelton turbine generator set according to claim 1, characterized in that: The electric motor is a single motor drive structure, and the reducer is a gear reducer for achieving speed reduction and torque increase.

4. The turning system of a Pelton turbine generator set according to claim 1, characterized in that: The water turbine runner maintenance platform is a detachable platform, which is fixedly installed at a predetermined position of the water turbine runner chamber and is used to support the support seat.

5. The turning system of a Pelton turbine generator set according to claim 1, characterized in that: The flexible coupling is connected to the turbine runner protection cover by flange connection or key connection.

6. The turning system of the Pelton turbine generator set according to claim 5, characterized in that: A reserved bolt hole is provided in the middle of the turbine runner for bolt connection of the runner protection cover.

7. A method for using a turning system of a Pelton turbine generator set, applied to a turning system of a Pelton turbine generator set according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: Assembling the turbine runner protective cover on the turbine runner; S2: Connecting the flexible coupling of the turning gear to the turbine runner protection cover, and fixing the support base on the turbine runner maintenance platform; S3: Start the electric motor, reduce speed and increase torque through the reducer, and then drive the turbine runner to rotate through the flexible coupling to achieve unit turning.

8. The method for using the turning system of a Pelton turbine generator set according to claim 7, characterized in that: The rotation speed of the motor is adjusted by a control system to meet different turning accuracy requirements.

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