Water-turbine generator set bearing oil mist sealing device and system and control method thereof

Abstract

The invention discloses a water-turbine generator set bearing oil mist sealing device and system and a control method thereof.The water-turbine generator set bearing oil mist sealing device comprises a sealing cover, an oil baffle is installed in the sealing cover, an oil return hole is formed in the oil baffle, the sealing cover comprises an upper sealing cover body and a lower sealing cover body, and the inner circumferential side of the upper sealing cover body is used for being fixedly connected with a thrust block; the lower side of the lower sealing cover is used for being installed and fixed to a lower rack of the water-turbine generator set, one end of the upper side is rotationally and hermetically connected with the outer circumference of the upper sealing cover, and the other end of the upper side is close to the outer circumference of the thrust block. Oil mist generated in the oil cavity can enter the oil gas deposition cavity from a gap between the oil baffle plate and the thrust block, part of the oil mist is deposited in the oil gas deposition cavity, the other part of the oil mist can enter the negative pressure buffer cavity from a gap between the lower sealing cover and the thrust block, then the oil mist passes through the labyrinth type flow channel, oil mist particles collide and are deposited in the labyrinth type flow channel, and the oil mist particles enter the negative pressure buffer cavity. The oil mist is deposited for multiple times, so that the oil mist pumped away from the negative pressure hole is reduced, and the extra consumption of lubricating oil is reduced.

Description

Technical Field

[0001] This invention relates to the field of hydro-generator technology, and in particular to a hydro-generator bearing oil mist sealing device, system and control method. Background Technology

[0002] The thrust bearing of a hydro-generator unit is a core load-bearing component, bearing the entire weight of the rotor and the thrust of the water. During operation, frictional heat and oil flow disturbance are the basis for oil mist generation. Located below the generator stator and rotor, the thrust bearing allows oil mist to diffuse to key electrical components such as the generator windings, stator core, slip rings, carbon brushes, and cable joints, threatening the safety of the unit's electrical system.

[0003] In the prior art, for example, Chinese patent document CN118912209A, published on November 8, 2024, discloses an oil mist sealing device for a hydro-generator set, including an upper sealing cover and a lower sealing cover; the upper and lower sealing covers are coaxially mounted on the outside of the main shaft of the hydro-generator; the upper and lower sealing covers are detachably connected; the upper sealing cover is provided with wool felt, the inner ring surface of which contacts the main shaft; the upper sealing cover is also provided with a contact-type follower sealing ring I that contacts the main shaft; a negative pressure buffer chamber is formed between the main shaft and the upper sealing cover; the wool felt, the contact-type follower seal I, and the negative pressure buffer chamber are arranged sequentially from top to bottom; the lower sealing cover is provided with a contact-type follower sealing ring I that contacts the main shaft. The system consists of a contact-type follower seal ring II, a contact-type follower seal ring III, and a positioning seal ring; an oil mist collection chamber is formed between the lower sealing cover and the main shaft; an oil stabilizing plate is also provided on the lower sealing cover, located between the positioning seal ring and the oil groove cover plate; the oil stabilizing plate has an oil return hole; its features are: the combination of three contact-type follower seals and the oil groove cover plate forms an oil mist collection chamber and a negative pressure buffer chamber, plus the final wool felt sealing layer, which can achieve zero leakage of lubricating oil mist overflow from the lower oil guide groove; its disadvantage is: although the air in the oil collection chamber is extracted by the oil inlet pipe, which can prevent oil mist overflow, a large amount of oil mist is drawn away from the oil inlet pipe, causing excessively rapid additional consumption of lubricating oil. Summary of the Invention

[0004] The purpose of this invention is to provide an oil mist sealing device, system and control method for the bearings of hydro-generator sets, in order to solve the problem in the prior art where the oil collection chamber is in a negative pressure state for a long time, resulting in a large amount of oil mist being discharged from the oil inlet pipe and causing excessively rapid additional consumption of lubricating oil.

[0005] To achieve the above objectives, this application provides an oil mist sealing device for a hydro-generator bearing, including a sealing cover, an oil baffle plate installed inside the sealing cover, and an oil return hole provided on the oil baffle plate. The sealing cover includes an upper sealing cover and a lower sealing cover. The inner circumference of the upper sealing cover is used for connection and fixation with a thrust head, and the lower side of the lower sealing cover is used for installation and fixation with the lower frame of the hydro-generator. One end of the upper side is rotatably sealed to the outer circumference of the upper sealing cover, and the other end of the upper side is close to the outer circumference of the thrust head. The oil baffle plate is installed inside the lower sealing cover. A negative pressure buffer chamber, a labyrinth-shaped flow channel, and an oil mist collection chamber are arranged sequentially from the inside to the outside between the upper sealing cover and the lower sealing cover. A negative pressure hole communicating with the oil mist collection chamber is provided on the lower sealing cover. An oil and gas deposition chamber is formed between the upper side of the oil baffle plate and the lower sealing cover.

[0006] The upper sealing cover includes an upper annular plate, the inner circumference of which is used to connect and fix with the thrust head, and the outer circumference of which extends radially outward. The lower sealing cover includes a support ring, a transverse extension ring, and a longitudinal extension ring. The lower end of the support ring is used to install and fix it on the lower frame of the lower turbine generator set. The outer circumference of the transverse extension ring is fixed to the upper end of the support ring, and the inner circumference is close to the outer circumference of the thrust head. The lower end of the longitudinal extension ring is connected and fixed to the support ring or the transverse extension ring, and the upper end is rotatably sealed to the upper sealing cover. The negative pressure buffer chamber, the labyrinth-shaped flow channel, and the oil mist collection chamber are located between the upper annular plate and the transverse extension ring.

[0007] The lower side of the upper annular plate is provided with a plurality of concentric first convex rings, and the upper side of the transverse extension ring is provided with a plurality of concentric second convex rings. The first convex rings and the second convex rings are interleaved and inserted, and the first convex rings and the second convex rings do not contact each other to form the labyrinth-shaped flow channel. Between the upper annular plate and the transverse extension ring, the negative pressure buffer cavity is formed in the inner region of the labyrinth-shaped flow channel, and the oil mist collection cavity is formed in the outer region of the labyrinth-shaped flow channel.

[0008] The inner wall of the support ring is provided with a flange, and the oil baffle is installed on the flange by bolts.

[0009] The lower sealing cover has a primary filter installed inside the oil mist collection chamber.

[0010] The lower sealing cover is provided with at least one mounting ring, the lower end of the primary filter screen is mounted on the mounting ring, and the upper end of the primary filter screen is close to the upper sealing cover.

[0011] A connecting pipe is connected between the lower sealing cover and the oil baffle plate. One end of the connecting pipe connected to the lower sealing cover is connected to the oil mist collection chamber and is located inside the primary filter screen. A one-way valve is installed on the connecting pipe.

[0012] The one-way valve includes a main body and an air supply pipe connected to the outer wall of the main body. The main body has an air guiding structure inside, so that the airflow entering from the air supply pipe flows out to the lower end of the main body. A support platform is provided on the inner wall of the main body above the air guiding structure. A spring is installed on the support platform, and a ball is elastically supported on the top of the spring. The ball abuts against a conical annular ring, which is fixedly installed in the main body. The air supply pipe is connected to an outlet pipe, which extends out from the lower sealing cover. In use, the outlet pipe is connected to a pressure source.

[0013] The lower sealing cover is equipped with a first contact-type follow-up sealing ring and a positioning sealing ring at one end near the outer circumference of the thrust head.

[0014] A second contact-type follower sealing ring is installed at one end of the lower sealing cover that is circumferentially sealed to the upper sealing cover.

[0015] A support plate is bolted to the upper side of the upper sealing cover, and the support plate is fixedly installed on the thrust head.

[0016] The upper sealing cover, lower sealing cover, and oil baffle are all composed of multiple fan-shaped structures spliced ​​together.

[0017] The upper and lower sealing covers have ear plates on their respective connecting sides, and the ear plates on both sides are connected by bolts. Adjacent fan-shaped structures are sealed by a sealing structure.

[0018] A hydro-generator bearing oil mist sealing system includes a hydro-generator bearing oil mist sealing device and an oil mist absorption and treatment device. A negative pressure port is connected to the oil mist absorption and treatment device via a negative pressure pipe. One end of the outlet pipe, located outside the lower sealing cover, is connected to a pressure source, and a solenoid valve is installed on the outlet pipe. A vibration sensor is deployed on the upper sealing cover to collect vibration spectrum data. A temperature sensor is deployed on the lower sealing cover to collect temperature gradient data. A micro differential pressure flow meter is installed in the negative pressure buffer chamber to collect air pressure change data. The oil mist absorption and treatment device, solenoid valve, vibration sensor, temperature sensor, and micro differential pressure flow meter are electrically connected to the control system for control.

[0019] The control method for the bearing oil mist sealing system of a hydro-generator set includes the following steps: S1. Collect vibration spectrum data, oil temperature gradient data, and air pressure change data of the hydro-generator unit, and perform noise reduction, feature extraction, and data fusion processing on the vibration spectrum, temperature gradient, and air pressure change data. S2. Based on the Long Short-Term Memory network model, the temporal correlation of vibration, temperature, and air pressure is integrated to predict the probability distribution of bearing oil mist concentration. S3. Based on the predicted probability distribution, control signals are generated to achieve dynamic adjustment of the operation of the oil mist absorption treatment device and control of the solenoid valve.

[0020] In S1: The collected vibration signal data is subjected to noise reduction processing using a bandpass filter, specifically as follows: ; In the formula: For the vibration signal after filtering The value at time; This is the Butterworth filter kernel function; The original vibration signal at time The value, that is, the original signal on the time axis. The shift of time.

[0021] Feature extraction is performed on the preprocessed vibration spectrum, as well as the temperature gradient and air pressure change data, as follows: The vibration spectrum is converted to the time-frequency domain using Fast Fourier Transform, and the dominant frequency amplitude is extracted. : ; For temperature gradients, calculate the spatial gradient. and take the modulus value As input features; For changes in air pressure, calculate the first derivative. ; The extracted feature vectors are converted into time series input. ; In the formula: For temperature Spatial coordinates The partial derivative of the value represents the temperature at which the temperature changes. Rate of change in direction; For temperature Spatial coordinates The partial derivative of the value represents the temperature at which the temperature changes. Rate of change in direction.

[0022] In S2: The model's input is the preprocessed feature sequence. ,in Historical data over a period of time; Forgetting gates: used to control the proportion of historical memories retained, specifically represented as: ; In the formula: Output for the forget gate; This is the weight matrix; It is the bias vector; The state was hidden in the previous moment; Use the Sigmoid activation function; Input gate: Used to control the updating of new information, specifically represented as: ; ; In the formula: For input gate output; Candidate memory cell state; Here is the weight matrix of the input gate; The bias vector for the input gate; It is the weight matrix used to calculate the state of candidate units; This is the bias vector used to calculate the state of the candidate cell.

[0023] Memory unit update; merging historical and current information, specifically represented as: ; In the formula: This represents the current state of the memory cell. This represents element-wise multiplication; Output gate: Generates the current hidden state, specifically represented as: ; ; In the formula: For output gate; Currently hidden; In the prediction output layer, the hidden state Mapping to oil mist concentration prediction via a fully connected layer is represented as follows: ; In the formula: This is the predicted vector for oil mist concentration over a future period of time; This is the weight matrix; This is the bias vector of the fully connected layer; The probability density of oil mist concentration for the next 90 seconds is generated using the softmax function: ; In the formula, Let be the probability density of oil mist concentration at the k-th second; The original value for the predicted oil mist concentration at second k; This is the predicted raw value of the oil mist concentration at second j.

[0024] In S3: Define different levels of risk thresholds: Real-time calculation of cumulative risk probability Specifically, it is expressed as: ; The final control strategy for the oil mist absorption and treatment device is as follows:

[0025] When the oil mist absorption and treatment device is in a dormant state, the solenoid valve on the control outlet pipe is opened for a period of time.

[0026] Compared with the prior art, the above-conceptual technical solution conceived in this application has the following beneficial effects: 1. The oil baffle of this invention is used to prevent lubricating oil from splashing in the oil chamber. The negative pressure hole is used to connect to negative pressure, so that a certain negative pressure is generated in the oil mist sealing device. The oil mist generated in the oil chamber will enter the oil gas deposition chamber through the gap between the oil baffle and the thrust head. Some of the oil mist will be deposited in the oil gas deposition chamber, and another part of the oil mist will enter the negative pressure buffer chamber through the gap between the lower sealing cover and the thrust head. Then, it passes through the labyrinth-shaped flow channel. The oil mist particles collide in the labyrinth-shaped flow channel, and most of the oil mist is deposited in the labyrinth-shaped flow channel. Finally, a small part of the oil mist enters the oil mist collection chamber and is then drawn away through the negative pressure hole. The oil mist undergoes multiple depositions, reducing the oil mist drawn away from the negative pressure hole and reducing the extra consumption of lubricating oil.

[0027] 2. The lower sealing cover of this invention has a primary filter screen installed inside the oil mist collection chamber, which further filters the oil mist in the oil mist collection chamber. When the oil mist passes through the primary filter screen, the oil mist particles adhere to the screen and eventually deposit inside the oil mist collection chamber. The lubricating oil deposited in the labyrinthine flow channel also moves towards the oil mist collection chamber with the airflow, with approximately 90% or more of the oil mist particles deposited there. After a period of operation, a one-way valve is opened, allowing the lubricating oil in the oil mist collection chamber to return to the oil chamber, further reducing lubricating oil consumption.

[0028] 3. The present invention also proposes an oil mist sealing system for the bearings of a hydro-generator set, which realizes automatic control of the oil mist absorption and treatment device and the solenoid valve.

[0029] 4. This invention also proposes a control method for the bearing oil mist sealing system of a hydro-generator set. By using a Long Short-Time Memory Network (LSTM) model, the temporal correlation of vibration, temperature, and air pressure is integrated to predict the probability distribution of bearing oil mist concentration. Based on the predicted probability distribution, a control signal is generated to realize the dynamic adjustment of the operation of the oil mist absorption and treatment device. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0031] Figure 1This is a diagram showing the usage state of the oil mist sealing device of the present invention.

[0032] Figure 2 This is a cross-sectional structural diagram of the one-way valve in this invention.

[0033] Figure 3 This is a cross-sectional structural diagram of the oil mist sealing device of the present invention.

[0034] Figure 4 This is a block diagram of the control system of the present invention.

[0035] Figure label: Thrust head 1, lower frame 2, negative pressure buffer chamber 3, labyrinth-shaped flow channel 4, oil mist collection chamber 5, oil and gas deposition chamber 6; Upper sealing cover 10, upper annular plate 11, first convex ring 12, ear plate 13; Lower sealing cover 20, support ring 21, transverse extension ring 22, mounting ring 221, primary filter screen 222, longitudinal extension ring 23, second convex ring 24, flange 25, first contact follower sealing ring 26, positioning sealing ring 27, second contact follower sealing ring 28, negative pressure hole 29. Oil baffle 30, oil return hole 31; Connecting pipe 40, one-way valve 41, main body 411, air supply pipe 412, air guiding structure 413, support platform 414, spring 415, ball 416, conical hole ring 417, outlet pipe 42. Negative pressure pipe 50, support plate 60; Oil mist absorption and treatment device 70; Control system 80, vibration sensor 81, temperature sensor 82, micro differential pressure flow meter 83. Detailed Implementation

[0036] To more clearly illustrate the purpose, technical solution, and beneficial effects of this application, a further detailed description of this application is provided below in conjunction with illustrations and specific embodiments. It should be specifically noted that the specific embodiments described below are only for illustrating the technical content of this application and do not constitute a limitation on the scope of protection of this application.

[0037] Regarding the explanation of terminology: In this application, "and / or" is used to describe the relationship between related objects, covering three possible situations: taking "A and / or B" as an example, it can indicate the situation where only A exists, A and B exist simultaneously, or only B exists; the symbol " / " indicates the "or" relationship between related objects, such as "A / B" which refers to A or B.

[0038] Regarding the description of the embodiments: The terms "exemplary" and "for example" appearing in this application are only used to illustrate the technical solutions through specific examples. It should be particularly emphasized that any implementation method or design scheme marked as "exemplary" or "for example" should not be construed as having an advantage over other solutions. Such expressions are only used to present the technical concepts more intuitively.

[0039] Example 1: See Figure 1 , 3 As shown, the present invention provides an oil mist sealing device for a hydro-generator bearing, including a sealing cover, an oil baffle plate 30 installed inside the sealing cover, and an oil return hole 31 provided on the oil baffle plate 30. The sealing cover includes an upper sealing cover 10 and a lower sealing cover 20. The inner circumference of the upper sealing cover 10 is used to connect and fix it to the thrust head 1, and the lower side of the lower sealing cover 20 is used to install and fix it to the lower frame 2 of the hydro-generator. One end of the upper side is rotatably sealed to the outer circumference of the upper sealing cover 10, and the other end of the upper side is close to the outer circumference of the thrust head 1. The oil baffle plate 30 is installed inside the lower sealing cover 20. A negative pressure buffer chamber 3, a labyrinth-shaped flow channel 4, and an oil mist collection chamber 5 are arranged sequentially from the inside to the outside between the upper sealing cover 10 and the lower sealing cover 20. A negative pressure hole 29 communicating with the oil mist collection chamber 5 is provided on the lower sealing cover 20. An oil and gas deposition chamber 6 is formed between the upper side of the oil baffle plate 30 and the lower sealing cover 20.

[0040] The oil baffle 30 is used to prevent lubricating oil from splashing in the oil chamber, and the negative pressure hole 29 is used to connect negative pressure, so that a certain negative pressure is generated in the oil mist sealing device. The oil mist generated in the oil chamber will enter the oil vapor deposition chamber 6 through the gap between the oil baffle 30 and the thrust head 1. Some of the oil mist will be deposited in the oil vapor deposition chamber 6, and another part of the oil mist will enter the negative pressure buffer chamber 3 through the gap between the lower sealing cover 20 and the thrust head 1. Then, it passes through the labyrinth-shaped flow channel 4. The oil mist particles collide in the labyrinth-shaped flow channel 4, and most of the oil mist is deposited in the labyrinth-shaped flow channel 4. Finally, a small part of the oil mist enters the oil mist collection chamber 5 and is then drawn away through the negative pressure hole 29. After multiple depositions, the amount of oil mist drawn away from the negative pressure hole 29 is reduced, thus reducing the extra consumption of lubricating oil.

[0041] In this embodiment, see Figure 1The upper sealing cover 10 includes an upper annular plate 11, the inner circumference of which is used to connect and fix with the thrust head 1, and the outer circumference of the upper annular plate 11 extends outward radially. The lower sealing cover 20 includes a support ring 21, a transverse extension ring 22, and a longitudinal extension ring 23. The lower end of the support ring 21 is used to install and fix it on the lower frame 2 of the lower turbine generator set. The outer circumference of the transverse extension ring 22 is fixed to the upper end of the support ring 21, and the inner circumference is close to the outer circumference of the thrust head 1. The lower end of the longitudinal extension ring 23 is connected and fixed to the support ring 21 or the transverse extension ring 22, and the upper end is rotatably sealed to the upper sealing cover 10. The negative pressure buffer chamber 3, the labyrinth-shaped flow channel 4, and the oil mist collection chamber 5 are located between the upper annular plate 11 and the transverse extension ring 22.

[0042] Furthermore, a plurality of concentric first convex rings 12 are provided on the lower side of the upper annular plate 11, and a plurality of concentric second convex rings 24 are provided on the upper side of the transverse extension ring 22. The first convex rings 12 and the second convex rings 24 are interleaved and inserted, and the first convex rings 12 and the second convex rings 24 do not contact each other to form the labyrinth-shaped flow channel 4. Between the upper annular plate 11 and the transverse extension ring 22, the negative pressure buffer chamber 3 is formed in the inner region of the labyrinth-shaped flow channel 4, and the oil mist collection chamber 5 is formed in the outer region of the labyrinth-shaped flow channel 4.

[0043] See Figure 1 The inner wall of the support ring 21 is provided with a flange 25, and the oil baffle 30 is installed on the flange 25 by bolts.

[0044] To reduce oil mist overflow, see Figure 1 The lower sealing cover 20 is equipped with a first contact-type follow-up sealing ring 26 and a positioning sealing ring 27 at one end near the outer circumference of the thrust head 1.

[0045] Furthermore, a second contact-type follower sealing ring 28 is installed at one end of the lower sealing cover 20 that is circumferentially connected to the upper sealing cover 10.

[0046] For easy installation of the upper sealing cap 10, see [link / reference]. Figure 1 A support plate 60 is bolted to the upper side of the upper sealing cover 10, and the support plate 60 is welded and fixedly installed on the thrust head 1.

[0047] For ease of installation, the upper sealing cover 10, the lower sealing cover 20, and the oil baffle 30 are all composed of multiple fan-shaped structures spliced ​​together. For example, 4, 5, or 6 pieces, with multiple fan-shaped structures spliced ​​together to form a circle.

[0048] Specifically, the upper sealing cover 10 and the lower sealing cover 20 each have an ear plate 13 on one side of their fan-shaped structure mating. The ear plates 13 on both sides are connected by bolts, and adjacent fan-shaped structures are sealed by a sealing structure. The sealing structure includes sealant or a gasket.

[0049] Example 2: Based on Example 1, see Figure 1 , 3 The lower sealing cover 20 has a primary filter 222 installed inside the oil mist collection chamber 5, which further filters the oil mist in the oil mist collection chamber 5. In this embodiment, the primary filter 222 is made of sintered stainless steel. When the oil mist passes through the primary filter 222, the oil mist particles adhere to the primary filter 222 and eventually deposit inside the oil mist collection chamber 5.

[0050] See Figure 1 , 3 The lower sealing cover 20 is provided with at least one mounting ring 221. The lower end of the annular primary filter screen 222 is mounted on the mounting ring 221, and the upper end of the primary filter screen 222 is close to the upper sealing cover 10. This structure enables the installation of the primary filter screen 222. When one mounting ring 221 is provided, the primary filter screen 222 can be mounted on the mounting ring 221 by screws or rivets; when two mounting rings 221 are provided, the lower end of the primary filter screen 222 can be secured between the two mounting rings 221.

[0051] Further, see Figure 1 , 3 A connecting pipe 40 is connected between the lower sealing cover 20 and the oil baffle plate 30. One end of the connecting pipe 40 connected to the lower sealing cover 20 is connected to the oil mist collection chamber 5 and is located inside the primary filter screen 222. A one-way valve 41 is installed on the connecting pipe 40. Through the above structure, the lubricating oil deposited in the oil mist collection chamber 5 is discharged.

[0052] When the oil mist collection chamber 5 is under negative pressure, the oil mist generated in the oil chamber will enter the oil vapor deposition chamber 6 through the gap between the oil baffle 30 and the thrust head 1. Some of the oil mist will be deposited in the oil vapor deposition chamber 6, while the rest will enter the negative pressure buffer chamber 3 through the gap between the lower sealing cover 20 and the thrust head 1. After passing through the labyrinth-shaped flow channel 4, the oil mist particles collide in the labyrinth-shaped flow channel 4, and most of the oil mist will be deposited in the labyrinth-shaped flow channel 4. Finally, a small portion of the oil mist will enter the oil mist collection chamber 5. The oil mist particles entering the oil mist collection chamber 5 will be filtered by the primary filter screen 222 and deposited in the oil mist collection chamber 5. The lubricating oil deposited in the labyrinth-shaped flow channel 4 will also move into the oil mist collection chamber 5 with the airflow. Approximately 90% or more of the oil mist particles will be deposited in the oil mist collection chamber 5. After running for a period of time, the control check valve 41 will open, allowing the lubricating oil in the oil mist collection chamber 5 to return to the oil chamber.

[0053] In this embodiment, see Figure 2The one-way valve 41 includes a main body 411 and an air supply pipe 412 connected to the outer wall of the main body 411. The main body 411 has an air guiding structure 413 inside, so that the airflow entering from the air supply pipe 412 flows out to the lower end of the main body 411. The inner wall of the main body 411 has a support platform 414 located on the upper side of the air guiding structure 413. A spring 415 is installed on the support platform 414. A ball 416 is elastically supported on the top of the spring 415. The ball 416 abuts against a conical hole ring 417. The conical hole ring 417 is installed and fixed inside the main body 411. The air supply pipe 412 is connected to an outlet pipe 42, which extends from the lower sealing cover 20. In use, the outlet pipe 42 is connected to a pressure source, which includes filtered and dried compressed air or inert gas.

[0054] Taking compressed air as an example, when compressed air enters from the air supply pipe 412, it is guided by the air guide structure 413, causing the compressed air to flow downwards. This results in a decrease in air pressure on the upper side of the air guide structure 413 within the main pipe body 411. The air pressure on the upper side of the ball 416 pushes the ball 416 downwards, compressing the spring 415. This opens up the upper and lower ends of the main pipe body 411, allowing the lubricating oil deposited in the oil mist collection chamber 5 to pass through the main pipe body 411 and return to the lower oil chamber. When the pressure source stops, the ball 416 moves upwards under the elastic force of the spring 415, closing the conical hole in the middle of the conical annular ring 417.

[0055] Example 3: Based on Example 2, see Figure 3 , 4 A hydro-generator bearing oil mist sealing system includes a hydro-generator bearing oil mist sealing device and an oil mist absorption and treatment device 70. A negative pressure port 29 is connected to the oil mist absorption and treatment device 70 via a negative pressure pipe 50. One end of an outlet pipe 42 located outside the lower sealing cover 20 is connected to a pressure source, and a solenoid valve is installed on the outlet pipe 42. A vibration sensor 81 is deployed on the upper sealing cover 10 to collect vibration spectrum data; a temperature sensor 82 is deployed on the lower sealing cover 20 to collect temperature gradient data; a micro-differential pressure flow meter 83 is installed in the negative pressure buffer chamber 3 to collect air pressure change data. The oil mist absorption and treatment device 70, solenoid valve, vibration sensor 81, temperature sensor 82, and micro-differential pressure flow meter 83 are electrically connected to a control system 80 for control. This structure enables automatic control of the oil mist absorption and treatment device 70 and the solenoid valve.

[0056] In this embodiment, the vibration sensor 81 is a MEMS vibration sensor; the temperature sensor 82 is an infrared thermal imaging array sensor, and the temperature sensor 82 is used to detect the oil temperature.

[0057] Example 4: Based on Example 3, this application also proposes a control method for the aforementioned oil mist sealing system for a hydro-generator bearing, comprising the following steps: S1. Collect vibration spectrum data, oil temperature gradient data, and air pressure change data of the hydro-generator unit, and perform noise reduction, feature extraction, and data fusion processing on the vibration spectrum, temperature gradient, and air pressure change data. S2. Based on the Long Short-Term Memory (LSTM) network model, the temporal correlation of vibration, temperature, and air pressure is fused to predict the probability distribution of bearing oil mist concentration. S3. Based on the predicted probability distribution, a control signal is generated to realize the dynamic adjustment of the operation of the oil mist absorption treatment device 70 and the control of the solenoid valve.

[0058] Specifically, in S1: The collected vibration signal data is subjected to noise reduction processing using a bandpass filter, specifically as follows: ; In the formula: For the vibration signal after filtering The value at time; This is the Butterworth filter kernel function; The original vibration signal at time The value, that is, the original signal on the time axis. The shift of time.

[0059] Feature extraction is performed on the preprocessed vibration spectrum, as well as the temperature gradient and air pressure change data, as follows: The vibration spectrum is converted to the time-frequency domain using Fast Fourier Transform, and the dominant frequency amplitude is extracted. : ; For temperature gradients, calculate the spatial gradient. and take the modulus value As input features; For changes in air pressure, calculate the first derivative. ; The extracted feature vectors are converted into time series input. ; In the formula: For temperature Spatial coordinates The partial derivative of the value represents the temperature at which the temperature changes. Rate of change in direction; For temperature Spatial coordinates The partial derivative of the value represents the temperature at which the temperature changes. Rate of change in direction.

[0060] In S2: The model's input is the preprocessed feature sequence. ,in Take 60 seconds of historical data; Forgetting gates: used to control the proportion of historical memories retained, specifically represented as: ; In the formula: Output for the forget gate; This is the weight matrix; It is the bias vector; The state was hidden in the previous moment; Use the Sigmoid activation function; Input gate: Used to control the updating of new information, specifically represented as: ; ; In the formula: For input gate output; Candidate memory cell state; Here is the weight matrix of the input gate; The bias vector for the input gate; It is the weight matrix used to calculate the state of candidate units; This is the bias vector used to calculate the state of the candidate cell.

[0061] Memory unit update; merging historical and current information, specifically represented as: ; In the formula: This represents the current state of the memory cell. This represents element-wise multiplication; Output gate: Generates the current hidden state, specifically represented as: ; ; In the formula: For output gate; Currently hidden; In the prediction output layer, the hidden state Mapping to oil mist concentration prediction via a fully connected layer is represented as follows: ; In the formula: This is the predicted vector for oil mist concentration over a future period of time; This is the weight matrix; This is the bias vector for the fully connected layer.

[0062] The probability density of oil mist concentration for the next 90 seconds is generated using the softmax function: ; In the formula, Let be the probability density of oil mist concentration at the k-th second; The original value for the predicted oil mist concentration at second k; This is the predicted raw value of the oil mist concentration at second j.

[0063] In S3: Define different levels of risk thresholds: Real-time calculation of cumulative risk probability Specifically, it is expressed as: ; The final control strategy for the oil mist absorption and treatment device 70 is as follows:

[0064] When the oil mist absorption and treatment device 70 is in a dormant state, the solenoid valve on the control outlet pipe 42 is opened for a period of time.

[0065] The oil mist absorption and treatment device 70 uses a permanent magnet synchronous variable frequency fan, the speed of which is dynamically adjusted by the predicted value of oil mist concentration obtained by the oil mist monitoring method. The oil mist absorption and treatment device is equipped with a two-stage gradient adsorption structure. A cyclone separator is used for primary cooling and separation of the drawn oil mist, and a coarse and fine filter screen is used for secondary adsorption treatment of the oil mist. An oil collection tank is set up to recover the oil.

[0066] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims. Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A bearing oil mist sealing device for a hydro-generator set, comprising a sealing cover, an oil baffle plate (30) installed inside the sealing cover, and an oil return hole (31) provided on the oil baffle plate (30), characterized in that: The sealing cover includes an upper sealing cover (10) and a lower sealing cover (20). The inner circumference of the upper sealing cover (10) is used to connect and fix with the thrust head (1). The lower side of the lower sealing cover (20) is used to install and fix with the lower frame (2) of the turbine generator set. One end of the upper side is rotated and sealed to the outer circumference of the upper sealing cover (10). The other end of the upper side is close to the outer circumference of the thrust head (1). The oil baffle (30) is installed inside the lower sealing cover (20). A negative pressure buffer chamber (3), a labyrinth-shaped flow channel (4) and an oil mist collection chamber (5) are arranged sequentially from the inside to the outside between the upper sealing cover (10) and the lower sealing cover (20). A negative pressure hole (29) communicating with the oil mist collection chamber (5) is provided on the lower sealing cover (20). An oil and gas deposition chamber (6) is formed between the upper side of the oil baffle (30) and the lower sealing cover (20).

2. The oil mist sealing device for a hydro-generator bearing according to claim 1, characterized in that: The upper sealing cover (10) includes an upper annular plate (11), the inner circumference of which is used to connect and fix with the thrust head (1), and the outer circumference of which extends outward radially; the lower sealing cover (20) includes a support ring (21), a transverse extension ring (22) and a longitudinal extension ring (23), the lower end of which is used to be installed and fixed on the lower frame (2) of the lower turbine generator set, the outer circumference of which is fixed to the upper end of the support ring (21), the inner circumference of which is close to the outer circumference of the thrust head (1), the lower end of which is connected and fixed to the support ring (21) or the transverse extension ring (22), and the upper end of which is rotatably sealed to the upper sealing cover (10); the negative pressure buffer chamber (3), the labyrinth-shaped flow channel (4) and the oil mist collection chamber (5) are located between the upper annular plate (11) and the transverse extension ring (22).

3. The oil mist sealing device for a hydro-generator bearing according to claim 2, characterized in that: The lower side of the upper annular plate (11) is provided with a plurality of concentric first convex rings (12), and the upper side of the transverse extension ring (22) is provided with a plurality of concentric second convex rings (24). The first convex rings (12) and the second convex rings (24) are interleaved and inserted, and the first convex rings (12) and the second convex rings (24) do not contact each other to form the labyrinth-shaped flow channel (4). Between the upper annular plate (11) and the transverse extension ring (22), the negative pressure buffer chamber (3) is formed in the inner region of the labyrinth-shaped flow channel (4), and the oil mist collection chamber (5) is formed in the outer region of the labyrinth-shaped flow channel (4).

4. The oil mist sealing device for a hydro-generator bearing according to claim 2, characterized in that: The inner wall of the support ring (21) is provided with a flange (25), and the oil baffle (30) is installed on the flange (25) by bolts.

5. A hydro-generator bearing oil mist sealing device according to claim 1 or 2, characterized in that: The lower sealing cover (20) has a primary filter (222) installed inside the oil mist collection chamber (5).

6. The oil mist sealing device for a hydro-generator bearing according to claim 5, characterized in that: At least one mounting ring (221) is provided on the lower sealing cover (20), the lower end of the primary filter screen (222) is mounted on the mounting ring (221), and the upper end of the primary filter screen (222) is close to the upper sealing cover (10).

7. The oil mist sealing device for a hydro-generator bearing according to claim 5, characterized in that: A connecting pipe (40) is connected between the lower sealing cover (20) and the oil baffle (30). One end of the connecting pipe (40) connected to the lower sealing cover (20) is connected to the oil mist collection chamber (5) and is located inside the primary filter screen (222) connected to the connecting pipe (40). A one-way valve (41) is installed on the connecting pipe (40).

8. The oil mist sealing device for a hydro-generator bearing according to claim 7, characterized in that: The one-way valve (41) includes a main body (411) and an air supply pipe (412) connected to the outer wall of the main body (411). The main body (411) is provided with an air guiding structure (413) so that the airflow entering from the air supply pipe (412) flows out to the lower end of the main body (411). The inner wall of the main body (411) is provided with a support platform (414) located on the upper side of the air guiding structure (413). A spring (415) is installed on the support platform (414). A ball (416) is elastically supported on the top of the spring (415). The ball (416) abuts against a conical hole ring (417). The conical hole ring (417) is installed and fixed inside the main body (411). The air supply pipe (412) is connected to an outlet pipe (42). The outlet pipe (42) extends out from the lower sealing cover (20). When in use, the outlet pipe (42) is connected to a pressure source.

9. A hydro-generator bearing oil mist sealing device according to claim 1 or 2, characterized in that: The lower sealing cover (20) is equipped with a first contact type follower sealing ring (26) and a positioning sealing ring (27) at one end near the outer circumference of the thrust head (1).

10. A hydro-generator set bearing oil mist sealing device according to claim 1 or 2, characterized in that: A second contact-type follower sealing ring (28) is installed at one end of the lower sealing cover (20) that is circumferentially sealed to the upper sealing cover (10).

11. A hydro-generator bearing oil mist sealing device according to claim 1 or 2, characterized in that: The upper sealing cover (10) is bolted to a support plate (60), which is fixedly mounted on the thrust head (1).

12. A hydro-generator bearing oil mist sealing device according to claim 1 or 2, characterized in that: The upper sealing cover (10), the lower sealing cover (20), and the oil baffle (30) are all made of multiple fan-shaped structures spliced ​​together.

13. The oil mist sealing device for a hydro-generator bearing according to claim 12, characterized in that: The upper sealing cover (10) and the lower sealing cover (20) are respectively provided with ear plates (13) on the side of the fan-shaped structure docking. The two ear plates (13) are connected by bolts, and the adjacent fan-shaped structures are sealed by a sealing structure.

14. A bearing oil mist sealing system for a hydro-generator set, characterized in that: The device includes a water turbine generator bearing oil mist sealing device as described in claim 8, and further includes an oil mist absorption treatment device (70). The negative pressure hole (29) is connected to the oil mist absorption treatment device (70) through a negative pressure pipe (50). One end of the outlet pipe (42) located outside the lower sealing cover (20) is connected to a pressure source. An electromagnetic valve is installed on the outlet pipe (42). A vibration sensor (81) is deployed on the upper sealing cover (10) to collect vibration spectrum data. A temperature sensor (82) is deployed on the lower sealing cover (20) to collect temperature gradient data. A micro differential pressure flow meter (83) is installed in the negative pressure buffer chamber (3) to collect air pressure change data. The oil mist absorption treatment device (70), electromagnetic valve, vibration sensor (81), temperature sensor (82), and micro differential pressure flow meter (83) are electrically connected to the control system (80) for control.

15. A control method for a hydro-generator set bearing oil mist sealing system as described in claim 14, characterized in that, Includes the following steps: S1. Collect vibration spectrum data, oil temperature gradient data, and air pressure change data of the hydro-generator unit, and perform noise reduction, feature extraction, and data fusion processing on the vibration spectrum, temperature gradient, and air pressure change data. S2. Based on the Long Short-Term Memory network model, the temporal correlation of vibration, temperature, and air pressure is integrated to predict the probability distribution of bearing oil mist concentration. S3. Based on the predicted probability distribution, a control signal is generated to realize the dynamic adjustment of the operation of the oil mist absorption treatment device (70) and the control of the solenoid valve.

16. A control method, characterized in that, In S1: The collected vibration signal data is subjected to noise reduction processing using a bandpass filter, specifically as follows: ； In the formula: For the vibration signal after filtering The value at time; This is the Butterworth filter kernel function; The original vibration signal at time The value, that is, the original signal on the time axis. The translation of time; Feature extraction is performed on the preprocessed vibration spectrum, as well as the temperature gradient and air pressure change data, as follows: The vibration spectrum is converted to the time-frequency domain using Fast Fourier Transform, and the dominant frequency amplitude is extracted. : ； For temperature gradients, calculate the spatial gradient. and take the modulus value As input features; For changes in air pressure, calculate the first derivative. ; The extracted feature vectors are converted into time series input. ; In the formula: For temperature Spatial coordinates The partial derivative of the value represents the temperature at which the temperature changes. Rate of change in direction; For temperature Spatial coordinates The partial derivative of the value represents the temperature at which the temperature changes. Rate of change in direction.

17. A control method, characterized in that, In S2: The model's input is the preprocessed feature sequence. ,in Historical data over a period of time; Forgetting gates: used to control the proportion of historical memories retained, specifically represented as: ； In the formula: Output for the forget gate; This is the weight matrix; It is the bias vector; The state was hidden in the previous moment; Use the Sigmoid activation function; Input gate: Used to control the updating of new information, specifically represented as: ； ； In the formula: For input gate output; Candidate memory cell state; Here is the weight matrix of the input gate; The bias vector for the input gate; It is the weight matrix used to calculate the state of candidate units; This is the bias vector used to calculate the state of the candidate cell; Memory unit update; merging historical and current information, specifically represented as: ； In the formula: This represents the current state of the memory cell. This represents element-wise multiplication; Output gate: Generates the current hidden state, specifically represented as: ； ； In the formula: For output gate; Currently hidden; In the prediction output layer, the hidden state Mapping to oil mist concentration prediction via a fully connected layer is represented as follows: ； In the formula: This is the predicted vector for oil mist concentration over a future period of time; This is the weight matrix; This is the bias vector of the fully connected layer; The probability density of oil mist concentration for the next 90 seconds is generated using the softmax function: ； In the formula, Let be the probability density of oil mist concentration at the k-th second; The original value for the predicted oil mist concentration at second k; This is the predicted raw value of the oil mist concentration at second j.

18. A control method, characterized in that, In S3: Define different levels of risk thresholds: Real-time calculation of cumulative risk probability Specifically, it is expressed as: ； The final control strategy for the oil mist absorption and treatment device (70) is as follows: When the oil mist absorption treatment device (70) is in a dormant state, the solenoid valve on the control outlet pipe (42) is opened for a period of time.

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