Hydraulic turbine set and main shaft axial thrust load shedding device thereof

Abstract

The invention discloses a hydraulic turbine set and a main shaft axial thrust load shedding device thereof, and relates to the technical field of hydraulic turbines, the main shaft axial thrust load shedding device comprises: a support arranged close to the main shaft end of a hydraulic turbine; the magnetizer is arranged at the end part of the main shaft; the electromagnet is arranged on the support, and the electromagnet and the magnetizer are distributed in an aligned mode; the excitation winding is arranged in the electromagnet; and the control device is electrically connected with the excitation winding, the control device is used for controlling the current of the excitation winding so that the electromagnet can generate the needed magnetic force, and the magnetic force is used for reducing the axial water thrust borne by the thrust pad. The device can effectively solve the problems of fatigue damage and the like of thrust bearing components (such as a thrust pad, an elastic oil tank and a runner plate) caused by temperature rise of the thrust pad and deterioration of lubricating conditions due to overlarge axial hydraulic thrust.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic turbine, more particularly, to a main shaft axial thrust load reduction device. In addition, the present application also relates to a hydraulic turbine unit comprising the main shaft axial thrust load reduction device. BACKGROUND

[0002] In the prior art, during the use of horizontal hydraulic turbine unit in hydropower station, the water flow generates an axial water thrust along the axis of the unit (horizontal direction) on the runner due to factors such as change of water flow direction, uneven pressure distribution or momentum exchange. The axial water thrust has a significant impact on the safe and stable operation of the unit, the service life and efficiency of the components, for example, when the axial water thrust is too large, the load of the thrust bearing will be far beyond the design value, the oil film between the thrust pad and the mirror plate may be damaged due to excessive pressure, and then the metal is directly contacted, which causes the temperature of the thrust pad to rise, and the temperature rise of the thrust pad will cause the performance of the lubricating oil to decrease (such as viscosity reduction, oxidation acceleration), further deteriorate the lubrication condition, and shorten the service life, and long-term overload will cause fatigue damage of the thrust bearing components (such as thrust pad, elastic oil tank, mirror plate), significantly shorten the service life, and increase the maintenance frequency and cost.

[0003] In view of the above, how to effectively solve the problems of temperature rise of the thrust pad, deterioration of the lubrication condition, and fatigue damage of the thrust bearing components caused by excessive axial water thrust is a problem that needs to be solved by the technical personnel in the field at present. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a main shaft axial thrust load reduction device, which can effectively solve the problems of temperature rise of the thrust pad, deterioration of the lubrication condition, and fatigue damage of the thrust bearing components (such as thrust pad, elastic oil tank, mirror plate) caused by excessive axial water thrust.

[0005] Another purpose of the present application is to provide a hydraulic turbine unit comprising the main shaft axial thrust load reduction device.

[0006] In order to achieve the above purpose, the present application provides the following technical solutions:

[0007] A main shaft axial thrust load reduction device, comprising:

[0008] a support arranged near the end of the main shaft of the hydraulic turbine;

[0009] a magnetically permeable body arranged at the end of the main shaft;

[0010] an electromagnet arranged on the support, and the electromagnet and the magnetically permeable body are aligned and distributed;

[0011] an excitation winding arranged in the electromagnet;

[0012] A control device electrically connected with the field winding, the control device being used to control the current of the field winding so that the electromagnet generates a required magnetic force, the magnetic force being used to reduce the axial water thrust borne by the thrust pad.

[0013] In an embodiment, the magnetic conductor is fixed on the end of the main shaft by a first fixing bolt.

[0014] In an embodiment, a mounting flange for fixing the electromagnet on the bracket is further included, the mounting flange being fixed on the bracket by a second fixing bolt.

[0015] In an embodiment, the electromagnet is fixed on the mounting flange by a third fixing bolt.

[0016] In an embodiment, the field winding is sealed in the electromagnet by an insulating glue.

[0017] In an embodiment, the electromagnet and the field winding are coaxially arranged.

[0018] In an embodiment, the bracket includes a bottom plate abuttingly arranged on the ground, a frame vertically arranged on the bottom plate, and a reinforcing rib, the electromagnet is vertically arranged on the frame, and the reinforcing rib is arranged on opposite sides of the frame and vertically arranged on the bottom plate.

[0019] In an embodiment, the bottom plate is circumferentially provided with at least four anchor bolts for fixing the bottom plate on the ground.

[0020] In an embodiment, a detection device for detecting the axial water thrust borne by the thrust pad is further included, the detection device being connected with the control device.

[0021] A hydraulic turbine unit including the main shaft axial thrust load reduction device according to any one of the preceding embodiments.

[0022] In use of the main shaft axial thrust load reduction device provided by the application, in the working process of the water turbine, when water flows through the runner of the water turbine, the water flow generates an axial water thrust along the axis of the unit (horizontal direction) due to factors such as change of water flow direction, uneven pressure distribution or momentum exchange, the axial water thrust is acted on the thrust pad by the mirror plate, and then is transmitted to the main shaft. At this time, the control device can control the current of the excitation winding to make the electromagnet generate the required magnetic force, the magnetic force is acted on the magnetically permeable body fixed with the main shaft, and the magnetic force and the axial water thrust are opposite in direction, so as to reduce the axial water thrust borne by the thrust pad, and then make the main shaft run more stably, avoid that the load of the thrust bearing is far more than the design value due to the excessive axial water thrust of the water turbine, and then the oil film between the thrust pad and the mirror plate is damaged due to excessive pressure, so that the metal is directly contacted, the temperature of the thrust pad is increased, the performance of the lubricating oil is reduced, the lubrication condition is deteriorated, the service life of the component is shortened, and the maintenance frequency and the maintenance cost are increased. The device can effectively reduce various problems caused by the excessive axial water thrust.

[0023] In summary, the main shaft axial thrust load reduction device provided by the application can effectively solve the problems such as temperature rise of the thrust pad, deterioration of the lubrication condition, and fatigue damage of the thrust bearing component (such as the thrust pad, the elastic oil tank and the mirror plate) caused by the excessive axial water thrust. In addition, the application also provides a water turbine unit comprising the above-mentioned main shaft axial thrust load reduction device. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of the provided drawings.

[0025] Figure 1 It is a side view of the main shaft axial thrust load reduction device provided by the application;

[0026] Figure 2 It is a structural schematic view of the main shaft axial thrust load reduction device;

[0027] Figure 3 It is a front view of Figure 2 ;

[0028] Figure 4 It is a rear view of Figure 2 .

[0029] Figures 1-4middle:

[0030] 1 is the bracket, 11 is the base plate, 12 is the frame, 13 is the reinforcing rib, 14 is the anchor bolt, 2 is the magnetic conductor, 3 is the electromagnet, 4 is the excitation winding, 5 is the first fixing bolt, 6 is the mounting flange, 7 is the second fixing bolt, and 8 is the third fixing bolt. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] The core of this invention is to provide a main shaft axial thrust reduction device, which can effectively solve the problems of increased thrust bearing temperature and deteriorated lubrication conditions caused by excessive axial water thrust, leading to fatigue damage in thrust bearing components (such as thrust bearings, elastic oil tanks, and mirror plates). Another core aspect of this invention is to provide a turbine unit including the above-mentioned main shaft axial thrust reduction device.

[0033] Please refer to Figure 1 This specific embodiment provides a spindle axial thrust reduction device, including:

[0034] Support 1 is installed near the end of the main shaft of the water turbine;

[0035] Magnetic conductor 2, which is located at the end of the main shaft;

[0036] Electromagnet 3 is mounted on support 1, and electromagnet 3 and magnetic conductor 2 are aligned and distributed.

[0037] Excitation winding 4 is located inside electromagnet 3;

[0038] The control device is electrically connected to the excitation winding 4. The control device is used to control the current of the excitation winding 4 so that the electromagnet 3 generates the required magnetic force. The magnetic force is used to reduce the axial water thrust borne by the thrust bearing.

[0039] It should be noted that the field winding 4 is a coil winding capable of generating a magnetic field, usually made of wire. When current passes through the field winding 4, it generates a magnetic field. The strength of this magnetic field is related to the number of turns of the field winding 4, the size of the current and the geometry of the winding. The electromagnet 3 refers to a device that can generate a strong magnetic field when energized, usually composed of a field winding 4 wound around a core. This core is part of the electromagnet 3, and the magnetic field strength of the electromagnet 3 can be adjusted by changing the current in the field winding 4. The magnetic conductor 2 is usually a material with high magnetic permeability, such as iron or other ferromagnetic materials, which can guide and concentrate the magnetic field, making the magnetic field more effective in a specific area. In a generator or motor, the magnetic conductor 2 can be part of the rotor, which works with the field winding 4 to ensure that the magnetic field can effectively pass through the air gap and act on the other side.

[0040] It should also be noted that the cooperation between the field winding 4, the electromagnet 3 and the magnetic conductor 2 includes the following steps: the field winding 4 generates a magnetic field after being energized; due to the presence of the electromagnet 3, the magnetic field generated by the field winding 4 is enhanced, and the magnetic field generated by the field winding 4 acts on the magnetic conductor 2, which is located at the end of the main shaft and can rotate synchronously with the main shaft. Moreover, the electromagnet 3 does not need to directly contact the magnetic conductor 2 and will not hinder the rotation of the magnetic conductor 2 and the main shaft. In addition, the magnetic force generated by the cooperation of the field winding 4 and the electromagnet 3 can reduce the axial water thrust borne by the thrust pad, which helps to avoid various problems caused by excessive axial water thrust.

[0041] For example, a support 1 can be installed on the ground near the tail end of the main shaft of the water turbine. By using this device, a magnetic force of about 7 tons opposite to the axial water thrust is added at the tail end of the main shaft, reducing the original 12-ton axial water thrust on the main shaft. The load on the thrust pad (i.e. the axial water thrust) is reduced to less than 50% of the original, and the heat generated by the axial water thrust is also reduced, resulting in a lower temperature of the thrust pad.

[0042] In actual application, the shape, structure, size, position, etc. of the support 1, the magnetic conductor 2, the electromagnet 3, the field winding 4 and the control device can be determined according to actual conditions and actual needs.

[0043] In the axial thrust load reduction device for main shaft provided by the application, during the operation of the water turbine, when the water flow passes through the runner of the water turbine, the axial water thrust along the axis of the unit (horizontal direction) is generated on the runner due to the change of water flow direction, uneven pressure distribution or momentum exchange, etc. The axial water thrust is applied to the thrust pad by the mirror plate, and then transmitted to the main shaft. At this time, the control device can control the current of the excitation winding 4 to make the electromagnet 3 generate the required magnetic force, which acts on the magnetically permeable body 2 fixed to the main shaft, and the magnetic force is opposite to the direction of the axial water thrust, so as to reduce the axial water thrust borne by the thrust pad, and then make the main shaft run more stably, avoid the load of the thrust bearing far exceeding the design value due to the excessive axial water thrust of the water turbine, and then destroy the oil film between the thrust pad and the mirror plate due to the excessive pressure, so that the metal is directly contacted, the temperature of the thrust pad is increased, the performance of the lubricating oil is reduced, the lubrication condition is deteriorated, the service life of the component is shortened, and the maintenance frequency and cost are increased. The device can effectively reduce various problems caused by excessive axial water thrust.

[0044] In summary, the axial thrust load reduction device for main shaft provided by the application can effectively solve the problems of temperature rise of the thrust pad, deterioration of the lubrication condition, and fatigue damage of the thrust bearing components (such as the thrust pad, the elastic oil tank and the mirror plate) caused by excessive axial water thrust.

[0045] In an embodiment, the magnetically permeable body 2 is fixed to the end of the main shaft by the first fixing bolt 5, so that the magnetically permeable body 2 is firmly arranged at the end of the main shaft, which does not affect the normal operation of the water turbine and the main shaft, and can cooperate with the excitation winding 4 and the electromagnet 3 to reduce the axial water thrust borne by the thrust pad.

[0046] In an embodiment, the mounting flange 6 for fixing the electromagnet 3 to the bracket 1 is further included, and the mounting flange 6 is fixed to the bracket 1 by the second fixing bolt 7, so as to effectively fix the electromagnet 3 through the mounting flange 6. The electromagnet 3 and the magnetically permeable body 2 are both cylindrical structures, and the central axes of the electromagnet 3 and the magnetically permeable body 2 are aligned with the central axis of the main shaft.

[0047] In an embodiment, the electromagnet 3 is fixed to the mounting flange 6 by the third fixing bolt 8. That is, the electromagnet 3 is detachably arranged on the bracket 1, if the electromagnet 3 is damaged, the damaged electromagnet 3 can be replaced by the dismounting operation, and the new electromagnet 3 and the magnetically permeable body 2 can continue to be used in cooperation, so as to reduce the maintenance cost of the device and improve the service life of the device.

[0048] In an embodiment, the excitation winding 4 is sealed in the electromagnet 3 by the insulating glue.

[0049] It should be noted that the insulating glue can effectively prevent the current leakage between the field winding 4 and the electromagnet 3, prevent short circuit or ground fault. Moreover, the sealing glue fills the gap between the field winding 4 and the electromagnet 3, forms an overall structure, and enhances the mechanical stability. This not only reduces the loosening or wear of the conductor caused by vibration, but also can resist mechanical impact during transportation or operation. Moreover, by sealing the field winding 4 with insulating glue, the failure caused by environmental factors or mechanical fatigue (such as short circuit, insulation aging) can be reduced, thereby reducing the maintenance frequency.

[0050] In an embodiment, the electromagnet 3 and the field winding 4 are coaxially arranged. That is, the field winding 4 can be arranged in a ring structure along the central axis of the electromagnet 3. The number and position of the field winding 4 can be determined according to actual conditions and actual needs in actual application.

[0051] In an embodiment, as shown in Figure 2 The bracket 1 includes a bottom plate 11 attached to the ground, a frame 12 vertically arranged on the bottom plate 11, and a reinforcing rib 13. The electromagnet 3 is vertically arranged on the frame 12, and the reinforcing rib 13 is arranged on the opposite sides of the frame 12 and vertically arranged on the bottom plate 11. The reinforcing rib 13 can enhance the connection effect of the frame 12 and the bottom plate 11, and improve the structural stability of the bracket 1.

[0052] In an embodiment, the bottom plate 11 is circumferentially provided with at least four anchor bolts 14, and the anchor bolts 14 are used to fix the bottom plate 11 to the ground.

[0053] It should be noted that the anchor bolt 14 is used to firmly fix the mechanical equipment or steel structure in the concrete foundation (i.e. the ground), to prevent displacement or collapse caused by external factors (such as earthquake, storm). Moreover, the anchor bolt 14 can transmit the load borne by the equipment or structure to the foundation, ensuring the safety of the foundation and the structure. Moreover, high-quality anchor bolts 14 are made of high-strength materials and are subjected to corrosion prevention treatment, which can maintain long service life in harsh environments. In addition, the design of the anchor bolt 14 helps to reduce the risk of loosening caused by vibration, thereby improving the seismic capacity and service life of the entire building system.

[0054] The position, number, type, etc. of the anchor bolt 14 can be determined according to actual conditions and actual needs in actual application.

[0055] In an embodiment, a detection device for detecting the axial water thrust borne by the thrust pad is further included, and the detection device is connected to the control device.

[0056] It should be noted that when this device is not in operation, the main shaft of the turbine will be subjected to axial water thrust during operation. When the control device controls the current of the excitation winding 4, the electromagnet 3 generates a suitable magnetic force. The magnetic force of the electromagnet 3 acts on the magnetic conductor 2 and is transmitted to the main shaft to reduce the axial water thrust on the thrust bearing, so that the main shaft runs more smoothly. This avoids the turbine unit from being overloaded by the thrust bearing due to excessive axial water thrust, which could cause the oil film between the thrust bearing and the mirror plate to be damaged due to excessive pressure, resulting in direct metal-to-metal contact and increased thrust bearing temperature. Increased thrust bearing temperature will reduce the performance of the lubricating oil (such as reduced viscosity and accelerated oxidation), further deteriorating lubrication conditions and shortening its life. In addition, long-term overload will cause fatigue damage to thrust bearing components (such as thrust bearing, elastic oil tank, mirror plate), significantly shortening their service life and increasing maintenance frequency and cost.

[0057] To further illustrate the spindle axial thrust reduction device provided by the present invention, examples can be provided.

[0058] 1. Install the fixed bracket 1, such as Figure 1 As shown, the tail end of the turbine's main shaft has the installation space for this device. This device is set on the ground at the tail end of the main shaft. Before fixing the bracket 1, the device can be positioned first, and then the anchor bolts 14 can be pre-embedded by drilling holes. For example, the anchor bolts 14 are M27*300 anchors, and there are 8 of them. They are made of high-strength concrete. After the anchor bolts 14 are installed, the bracket 1 is connected to the fixed base of the turbine unit through channel steel to ensure that the base plate 11 of the bracket 1 does not deform significantly when subjected to force.

[0059] 2. Install electromagnet 3 and magnetic conductor 2, such as Figure 2 and Figure 3 As shown, the magnetic conductor 2 replaces the original end cap and is fixed on the main shaft. The magnetic conductor 2 will rotate synchronously with the main shaft. For example, the four first fixing bolts 5 (such as M24 8.8 grade bolts) can withstand a tensile force of more than 50 tons, which is sufficient to withstand a magnetic force of 7 tons. The electromagnet 3 is installed on the bracket 1. By manually fine-tuning the electromagnet 3 and the magnetic conductor 2, the coaxiality and flatness of the electromagnet 3 and the magnetic conductor 2 are ensured to reach the optimal state.

[0060] 3. Magnetic field simulation: After the excitation winding 4 is loaded with the rated working current, the excitation winding 4 and the electromagnet 3 generate a magnetic field, which generates a magnetic force of 7 tons on the rotating magnetic conductor 2 (which is opposite to the direction of the axial water thrust).

[0061] 4. Install detection devices (such as eddy current displacement sensors). Eddy current displacement sensors are used to detect the axial displacement of the main shaft (which is closely related to the axial water thrust). A displacement sensor can also be added to the guide vane servo (the larger the opening of the guide vane servo of the turbine, the larger the water flow, and the smaller the opening, the smaller the water flow) to detect the opening of the guide vane servo. The signal is transmitted to the control device, which can coordinate the control according to the operating conditions of the turbine unit.

[0062] 5. The control device adopts a PLC (Programmable Logic Controller) + IGBT (Insulated Gate Bipolar Transistor) control mode. This PLC+IGBT control mode is an industrial automation technology solution that combines the intelligent program control of a programmable logic controller with the high-efficiency power switching characteristics of an IGBT. Its core is to drive the IGBT through the PLC output control signal to achieve precise adjustment of high-power loads. For example, using a 24V, 500W DC power supply, by detecting the axial displacement of the main shaft and the opening of the guide vane servo, the control device calculates the corresponding PWM signal through relevant programs and outputs the corresponding current to the excitation winding 4 via the IGBT. The excitation winding 4 and the electromagnet 3 generate a suitable magnetic attraction force to reduce the pressure on the thrust bearing, thereby reducing the heat generated by the thrust bearing, lowering its temperature, reducing unit vibration, and making the operation more stable.

[0063] In addition to the aforementioned main shaft axial thrust reduction device, the present invention also provides a turbine unit including the main shaft axial thrust reduction device disclosed in the above embodiments. For the structure of other parts of the turbine unit, please refer to the prior art, which will not be repeated here.

[0064] It should be noted that the first fixing bolt 5, the second fixing bolt 7, and the third fixing bolt 8 mentioned in this application are only distinguished by their different positions and do not have any order of precedence.

[0065] In addition, it should be noted that the orientation or positional relationship indicated by "vertical" and other terms in this application is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the purpose of simplifying the description and making it easier to understand, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0066] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Any combination of all embodiments provided by this invention is within the scope of protection of this invention and will not be elaborated upon here.

[0067] The foregoing has provided a detailed description of the turbine unit and its main shaft axial thrust reduction device provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A spindle axial thrust reduction device, characterized in that, include: The bracket (1) is installed near the end of the turbine's main shaft; A magnetic conductor (2) is disposed at the end of the main shaft; An electromagnet (3) is disposed on the support (1), and the electromagnet (3) and the magnetic conductor (2) are aligned and distributed. Excitation winding (4), which is located inside the electromagnet (3); A control device electrically connected to the excitation winding (4) is used to control the current of the excitation winding (4) so ​​that the electromagnet (3) generates the required magnetic force, which is used to reduce the axial water thrust borne by the thrust bearing.

2. The spindle axial thrust reduction device according to claim 1, characterized in that, The magnetic conductor (2) is fixed to the end of the main shaft by the first fixing bolt (5).

3. The spindle axial thrust reduction device according to claim 1, characterized in that, It also includes a mounting flange (6) for fixing the electromagnet (3) to the bracket (1), the mounting flange (6) being fixed to the bracket (1) by a second fixing bolt (7).

4. The spindle axial thrust reduction device according to claim 3, characterized in that, The electromagnet (3) is fixed to the mounting flange (6) by the third fixing bolt (8).

5. The spindle axial thrust reduction device according to any one of claims 1 to 4, characterized in that, The excitation winding (4) is sealed inside the electromagnet (3) with insulating glue.

6. The spindle axial thrust reduction device according to claim 5, characterized in that, The electromagnet (3) and the excitation winding (4) are coaxially arranged.

7. The spindle axial thrust reduction device according to any one of claims 1 to 4, characterized in that, The bracket (1) includes a base plate (11) that is attached to the ground, a frame (12) that is vertically mounted on the base plate (11), and a reinforcing rib (13). The electromagnet (3) is vertically mounted on the frame (12), and the reinforcing rib (13) is located on opposite sides of the frame (12) and is vertically mounted on the base plate (11).

8. The spindle axial thrust reduction device according to claim 7, characterized in that, The base plate (11) is provided with at least four anchor bolts (14) along the circumference, and the anchor bolts (14) are used to fix the base plate (11) to the ground.

9. The spindle axial thrust reduction device according to any one of claims 1 to 4, characterized in that, It also includes a detection device for detecting the axial water thrust borne by the thrust bearing, the detection device being connected to the control device.

10. A water turbine unit, characterized in that, Includes the spindle axial thrust reduction device as described in any one of claims 1 to 9.

Images