An oil sump cover to prevent oil mist leakage from large thrust bearings

Abstract

This invention discloses an oil tank cover for preventing oil mist leakage from large thrust bearings in hydropower stations. The cover includes an oil tank cover body, a sealing assembly mounted on the oil tank cover body, and a cooling assembly mounted on the lower surface of the oil tank cover body. The sealing assembly includes a first sealing chamber, with sealing teeth at the ends of the sidewalls of the first sealing chamber. The sidewalls of the first sealing chamber are sealed to the outer circumferential surface of the thrust head of the thrust bearing via the sealing teeth, forming a first sealing cavity. High-pressure gas flows through the first sealing cavity. The cooling assembly includes a condenser pipe, which is connected to the lower surface of the oil tank cover body. Coolant flows through the condenser pipe, with one end connected to the inlet of a cooler and the other end connected to the outlet of the cooler. This application effectively solves the problem of oil spillage and oil mist leakage from hydropower station unit bearings by using a dual approach of low-temperature condensation of oil mist and high-pressure prevention of oil mist escape, through the installation of a sealing assembly and a cooling assembly on the oil tank cover body.

Description

Technical Field

[0001] This invention belongs to the technical field of power plant bearing oil tank cover, specifically relating to an oil tank cover that prevents oil mist leakage from large thrust bearings in hydropower stations. Background Technology

[0002] For most hydropower station bearings, oil splashing and oil mist escape are unavoidable phenomena. The reasons for this include: 1. The physical properties of the lubricating oil itself. Extracted from petroleum and processed, it becomes a mixture with multiple boiling points, which atomizes with air at certain temperatures. 2. During operation, the bearing oil film bears the weight of rotating components, continuously generating high temperatures. These high temperatures reduce the viscosity and quality of the lubricating oil. Furthermore, the centrifugal force during operation causes the lubricating oil to rotate at high speed, resulting in liquid splashing, atomization, and impact. Therefore, oil mist is inevitably generated and escapes from the bearing oil tank through internal or external oil splashing. Oil mist leakage leads to persistently high bearing temperatures, severely polluting the generator's internal environment, reducing generator stator life, causing oil level drops in the oil pan, threatening the safe and stable operation of the unit, and polluting the power station environment and the downstream river ecosystem.

[0003] In response, engineers have explored several methods to address oil mist emission through practical engineering experience. These include optimizing the oil tank structure and oil cooling circulation system from a design perspective, and designing oil tank covers with better sealing performance. These methods help reduce the amount of oil mist escaping and improve the safety and stability of unit operation. However, over time, the seals will gradually fail, and oil mist will continue to escape. Summary of the Invention

[0004] The purpose of this invention is to provide an oil tank cover for preventing oil mist leakage from large thrust bearings in hydropower stations, thereby solving the problem of oil mist leakage pollution during the operation of hydropower station units in the prior art.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] An oil tank cover for preventing oil mist leakage from a large thrust bearing in a hydropower station includes an oil tank cover body, a sealing assembly disposed on the oil tank cover body, and a cooling assembly disposed on the lower surface of the oil tank cover body.

[0007] The sealing assembly includes a first sealing chamber, the end of the side wall of the first sealing chamber is provided with sealing teeth, the side wall of the first sealing chamber is sealed to the outer peripheral surface of the thrust head of the thrust bearing through the sealing teeth, and forms a first sealing cavity; high-pressure gas is passed through the first sealing cavity.

[0008] The cooling assembly includes a condenser tube, which passes through the lower surface of the oil tank cover body. Coolant flows through the condenser tube, with one end connected to the inlet of the cooler and the other end connected to the outlet of the cooler.

[0009] During the operation of a hydroelectric power station unit, the oil film is subjected to continuous heat generated by high pressure and centrifugal force from the high-speed rotation of the main shaft. As the unit operates, the lubricating oil begins to atomize and accumulates in the area above the thrust bearing oil tank. When the oil mist comes into contact with the cooling components, its temperature drops rapidly, condenses into oil droplets, and falls back into the oil tank.

[0010] Since the cooling area of ​​the cooling layer is fixed, i.e., the cooling capacity is fixed, some oil mist that cannot be completely cooled will escape from the gap between the oil tank cover body and the thrust head. In this application, a first sealing chamber is provided in the oil tank cover body, and high-pressure gas is continuously introduced into the first sealing chamber. The pressure of the high-pressure gas in the first sealing chamber is much greater than the pressure of the escaping oil mist. Based on the principle of pressure difference, further leakage of oil mist is effectively suppressed.

[0011] In this application, by setting a sealing component and a cooling component on the oil tank cover body, and utilizing the dual measures of low-temperature condensation of oil mist and high pressure to prevent oil mist from escaping, the problem of oil splashing and oil mist escaping from the bearings of hydropower station units is effectively solved.

[0012] In a further improvement, the sealing assembly also includes a second sealing chamber, which is located above the first sealing chamber. The end of the side wall of the second sealing chamber is provided with sealing teeth. The side wall of the second sealing chamber is sealed to the side of the thrust head of the thrust bearing through the sealing teeth, and forms a second sealing cavity. High-pressure gas is passed through the second sealing cavity.

[0013] As the unit operates for extended periods, the sealing teeth at the end of the sidewall of the first sealing chamber will wear down, increasing the gap between the sidewall of the first sealing chamber and the outer circumference of the thrust head. This causes some oil mist that cannot be completely cooled to escape from the cover gap. To address this, this application provides a second sealing chamber above the first sealing chamber, which also contains high-pressure gas. When oil mist escaping from the first sealing chamber attempts to enter the second sealing chamber, it encounters the high-pressure gas in the second sealing chamber and is again blocked from escaping due to the pressure difference.

[0014] Although the sealing teeth at the end of the side wall of the second sealing chamber will also wear down, the amount of oil mist entering the first sealing chamber is already relatively small. After being blocked by the high-pressure gas in the second sealing chamber, the amount of oil mist escaping is greatly reduced.

[0015] A further improvement is made: the sidewall ends of the first and second sealing chambers are uniformly grooved circumferentially, with a portion of the sealing teeth embedded in the grooves. As the unit operates for extended periods, the sealing teeth will wear down, requiring replacement when the wear becomes excessive. However, replacing the entire oil tank cover body is too costly. Therefore, the sealing teeth are assembled with the oil tank cover body for use, requiring only the sealing teeth to be replaced each time, significantly reducing costs and extending the service life of the oil tank cover body.

[0016] In a further improvement, the oil tank cover body includes an inner cover plate and an outer cover plate, both of which are annular plates. The inner cover plate and the outer cover plate are detachably sealed together. The inner edge of the inner cover plate is sealed to the outer circumferential surface of the thrust head of the thrust bearing. The first sealing chamber and the second sealing chamber are disposed on the inner cover plate.

[0017] Because the oil tank cover is quite large, it is divided into an inner cover plate and an outer cover plate. The inner cover plate and the outer cover plate are detachably sealed together, which facilitates installation and prevents oil mist from escaping.

[0018] The condenser includes multiple concentrically arranged first condenser tubes and multiple concentrically arranged second condenser tubes. The first condenser tubes are located on the lower surface of the inner cover plate; the second condenser tubes are located on the lower surface of the outer cover plate. One end of each of the first condenser tubes is connected to a first input pipe, and the other end of each of the first condenser tubes is connected to a first output pipe. One end of each of the second condenser tubes is connected to a second input pipe, and the other end of each of the second condenser tubes is connected to a second output pipe. Different condenser tubes are arranged on the bottom surfaces of the inner and outer cover plates, and the first and second condenser tubes are not connected, which facilitates installation and shortens the length of each condenser tube compared to a single integrated design, thus increasing the condensation effect.

[0019] In a further improvement, a first condensation chamber is provided on the bottom surface of the inner cover plate, and a first condensation pipe is coiled in the first condensation chamber along the radial direction of the inner cover plate; a second condensation chamber is provided on the bottom surface of the outer cover plate, and a second condensation pipe is coiled in the second condensation chamber along the radial direction of the outer cover plate.

[0020] There is a gap between two adjacent coils of condenser tubes on the bottom surface of the oil tank cover. After the oil mist cools, it is easy to stick to the gap and the outer wall of the condenser tube. Over time, this greatly reduces the cooling effect of the cooling components, and the stuck oil stains are not easy to clean.

[0021] In this application, by setting up a first condensing chamber and a second condensing chamber, the condensing tube edge is set in the corresponding condensing chamber, which facilitates the installation of the condensing tube. The condensing tube edge is in contact with the bottom surface of the condensing chamber. The condensing chamber has good thermal conductivity, which ensures good cooling effect. In addition, the bottom surface of the condensing chamber is flat, which facilitates regular cleaning of the adhered oil stains.

[0022] Further improvements include the bottom plates of the first and second condensing chambers having V-shaped radial end faces, meaning the bottom plates are lower in the middle and higher at both ends. The lubricating oil film condensed on the bottom plates flows towards the middle under gravity, converging into large oil droplets that easily fall into the oil trough, greatly reducing oil adhesion on the bottom plates and ensuring cooling effect.

[0023] Further improvements include the use of aluminum alloy for the base plates of both the first and second condensing chambers. This material is lightweight, corrosion-resistant, and has excellent thermal conductivity.

[0024] The beneficial effects achieved by this invention are as follows:

[0025] 1. In this application, by setting a sealing component and a cooling component on the oil tank cover body, the dual measures of low-temperature condensation of oil mist and high pressure to prevent oil mist from escaping are used to effectively solve the problem of oil splashing and oil mist escaping from the bearings of hydropower station units, and to avoid oil mist leakage from polluting the generator and the power station environment, threatening the safe and stable operation of the unit and the ecological environment safety of the downstream river.

[0026] 2. In this application, a second sealing chamber is provided above the first sealing chamber. High-pressure gas also flows through the second sealing chamber. When oil mist escaping from the first sealing chamber attempts to enter the second sealing chamber, it encounters the high-pressure gas in the second sealing chamber and is blocked from escaping again based on the pressure difference principle. Even if the sealing teeth are worn, the escape of oil mist can be greatly reduced. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the oil tank cover for preventing oil mist leakage from large thrust bearings in hydropower stations, as described in this invention.

[0028] Figure 2 for Figure 1 A magnified view of part A in the middle;

[0029] Figure 3 This is a schematic diagram of the condenser tube arrangement. Implementation

[0030] The present invention will now be further described with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the protection of the present invention.

[0031] like Figure 1 , 2 As shown, an oil tank cover structure for preventing oil mist leakage from a large thrust bearing in a hydropower station includes an oil tank cover body 1, a high-pressure sealing assembly disposed on the oil tank cover body, and a cooling assembly disposed on the lower surface of the oil tank cover body.

[0032] The sealing assembly includes a first sealing chamber 2, and the end of the side wall of the first sealing chamber is provided with sealing teeth. The side wall of the first sealing chamber is sealed to the outer peripheral surface of the thrust head 4 of the thrust bearing through the sealing teeth, and forms a first sealing cavity 21. High-pressure gas is passed through the first sealing cavity.

[0033] The cooling assembly includes a condenser tube, which passes through the lower surface of the oil tank cover body. Coolant flows through the condenser tube, with one end connected to the inlet of the cooler and the other end connected to the outlet of the cooler.

[0034] In this embodiment, the sealing assembly further includes a second sealing chamber 3, located above the first sealing chamber 2. The end of the side wall of the second sealing chamber 3 is provided with sealing teeth. The side wall of the second sealing chamber is sealed to the side of the thrust head 4 of the thrust bearing via the sealing teeth, forming a second sealing cavity 31. High-pressure gas flows through the second sealing cavity 31. As the unit operates for a long time, the sealing teeth at the end of the side wall of the first sealing chamber will wear down, increasing the gap between the side wall of the first sealing chamber and the outer circumference of the thrust head. This causes some oil mist that cannot be completely cooled to escape from the cover gap. To address this, in this application, a second sealing chamber is provided above the first sealing chamber, and high-pressure gas also flows through the second sealing cavity. When oil mist escaping from the first sealing chamber tries to enter the second sealing chamber, it encounters the high-pressure gas in the second sealing cavity and is again blocked from escaping based on the pressure difference principle.

[0035] The first sealing chamber 2 and the second sealing chamber 3 are connected to the same high-pressure gas pipeline 20 via a tee. The high-pressure gas pipeline 20 is equipped with a pressure regulating valve to adjust the gas pressure in the first sealing chamber 2 and the second sealing chamber 3 as needed, so as to achieve better high-pressure sealing.

[0036] In this embodiment, the side wall ends of the first sealing chamber 2 and the side wall ends of the second sealing chamber 2 are circumferentially grooved, and a portion of the sealing teeth 22 are embedded in the grooves, such as... Figure 2 As shown, with prolonged operation of the unit, the sealing teeth will wear down. When the wear is excessive, replacement is necessary. However, replacing the entire oil tank cover body is too costly. Therefore, the sealing teeth are assembled with the oil tank cover body for use. Only the sealing teeth need to be replaced each time, which greatly reduces costs and extends the service life of the oil tank cover body.

[0037] In this embodiment, the oil tank cover body 1 includes an inner cover plate 11 and an outer cover plate 12, both of which are annular plates. The inner cover plate and the outer cover plate are detachably sealed together. The inner edge of the inner cover plate is sealed to the outer circumferential surface of the thrust head of the thrust bearing. The inner cover plate 11 and the outer cover plate 12 are connected by bolts, and an elastic sealing gasket is provided in the connection seam.

[0038] The first sealed chamber 2 and the second sealed chamber 2 are disposed on the inner cover plate 11;

[0039] The condenser tubes include multiple concentrically arranged first condenser tubes 8 and multiple concentrically arranged second condenser tubes 9. The first condenser tubes 8 are located on the lower surface of the inner cover plate 11; the second condenser tubes 9 are located on the lower surface of the outer cover plate 12. Figure 3 As shown in the figure, the arrows indicate the direction of coolant flow.

[0040] One end of all the first condenser tubes 8 is connected to the first input pipe 81, and the other end of all the first condenser tubes 8 is connected to the first output pipe 82; one end of all the second condenser tubes 9 is connected to the second input pipe 91, and the other end of all the second condenser tubes 9 is connected to the second output pipe 92; the first input pipe 81 and the second input pipe 91 are connected to the outlet of the cooler through a three-way pipe; the first output pipe 82 and the second output pipe 92 are connected to the inlet of the cooler through a three-way pipe, forming a circulation system, so that the heated coolant can be cooled down in time and recycled without waste.

[0041] In this embodiment, a first condensing chamber 5 is provided on the bottom surface of the inner cover plate 11, and a first condensing pipe 8 is coiled in the first condensing chamber along the radial direction of the inner cover plate 11; a second condensing chamber 6 is provided on the bottom surface of the outer cover plate 12, and a second condensing pipe is coiled in the second condensing chamber 6 along the radial direction of the inner cover plate 12.

[0042] In this embodiment, the bottom plates of the first and second condensing chambers 5 are both V-shaped. That is, the bottom plate is lower in the middle and higher at both ends. The lubricating oil film condensed on the bottom plate flows towards the middle under the action of gravity, and gathers into large oil droplets that easily fall into the oil tank, greatly reducing the adhesion of oil on the bottom plate and ensuring the cooling effect.

[0043] In this embodiment, the bottom plates of both the first and second condensing chambers are made of aluminum alloy.

[0044] During operation, the lubricating oil begins to atomize due to centrifugal force and increased temperature, and gathers towards the area above the thrust bearing oil tank. When the oil mist comes into contact with the base plate of the cooling component made of aluminum alloy, the temperature of the oil mist drops rapidly, flows along the slope of the base plate towards the center, and converges into large oil droplets before falling back into the oil tank. When the sealing teeth have not worn due to long-term operation, they have strong sealing performance and can effectively prevent oil mist from escaping from the oil sump cover plate body.

[0045] When the sealing teeth wear down due to prolonged operation, an uncompensated gap will appear between the oil tank cover body 1 and the moving and stationary parts of the thrust head 4. If this gap is not too large, some oil mist that has not been cooled and condensed will escape outward from the gap. At this time, the high-pressure gas in the first sealing chamber 21 can effectively prevent the oil mist from escaping by utilizing the pressure difference. At this point, almost all the oil mist is blocked below the oil tank cover body and cannot escape.

[0046] When the sealing teeth are severely worn and the gap between the oil tank cover and the thrust head is too large, even after condensation by the cooling components and the high-pressure sealing chamber of the first sealing chamber 2, it is still impossible to completely prevent oil mist from escaping. In this case, the high-pressure gas in the second sealing chamber 3 will be the last barrier to prevent oil mist from escaping, effectively blocking the oil mist in the thrust bearing oil tank, avoiding oil mist leakage from polluting the generator and power station environment, improving the safe and stable operation of the unit, and ensuring the ecological safety of the downstream river.

[0047] A model was created for the oil tank cover structure in the application. A gas sensor was installed at the connection between the oil tank cover body and the thrust head to simulate the amount of oil mist leakage under different conditions, as shown in Table 1 below.

[0048] Table 1: Oil mist leakage under different conditions

[0049]

[0050] Under different operating conditions, when the unit first starts running, the sealing teeth are not yet worn, so there is no oil mist leakage. As the unit operates for a longer period of time, the wear of the sealing teeth increases, which increases the gap between the side wall of the sealing chamber and the outer peripheral surface of the thrust head, resulting in an increase in oil mist leakage.

[0051] The simulation data in Table 1 clearly shows that by setting up the condensation assembly, the first sealing chamber, and the second sealing chamber, the amount of lubricating oil leakage was effectively controlled. Since this is a simulation experiment, the impact of lubricating oil evaporation in other parts of the unit can be set to zero; therefore, the data in Table 1 is highly persuasive.

[0052] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A water power station large thrust bearing oil mist leakage prevention oil tank cover, characterized in that, The oil tank cover body, the sealing assembly arranged on the oil tank cover body, and the cooling assembly arranged on the lower surface of the oil tank cover body are provided; The sealing assembly comprises a first sealing cabin, the end of the side wall of the first sealing cabin is provided with a sealing tooth, the side wall of the first sealing cabin is sealingly connected with the outer circumferential surface of the thrust head of the thrust bearing through the sealing tooth, and a first sealing cavity is formed; high-pressure gas flows through the first sealing cavity; The cooling assembly comprises a condenser pipe, the lower surface of the oil tank cover body passes through the condenser pipe, cooling liquid flows through the condenser pipe, one end of the condenser pipe is in communication with the liquid inlet of the cooling machine, and the other end is in communication with the liquid outlet of the cooling machine; The sealing assembly further comprises a second sealing cabin, the second sealing cabin is located above the first sealing cabin, the end of the side wall of the second sealing cabin is provided with a sealing tooth, the side wall of the second sealing cabin is sealingly connected with the side surface of the thrust head of the thrust bearing through the sealing tooth, and a second sealing cavity is formed; high-pressure gas flows through the second sealing cavity; The oil tank cover body comprises an inner cover plate and an outer cover plate which are both annular plates, the inner cover plate and the outer cover plate are detachably sealingly connected, and the inner edge of the inner cover plate is sealingly connected with the outer circumferential surface of the thrust head of the thrust bearing; The first sealing cabin and the second sealing cabin are arranged on the inner cover plate; The condenser pipe comprises a plurality of concentrically arranged first condenser pipes and a plurality of concentrically arranged second condenser pipes, the first condenser pipes are arranged on the lower surface of the inner cover plate, and the second condenser pipes are arranged on the lower surface of the outer cover plate; One end of all the first condenser pipes is in communication with a first input pipe, and the other end of all the first condenser pipes is in communication with a first output pipe; One end of all the second condenser pipes is in communication with a second input pipe, and the other end of all the second condenser pipes is in communication with a second output pipe; The first condenser pipes and the second condenser pipes are not in communication.

2. The oil tank cover for preventing water power station large thrust bearing oil mist leakage according to claim 1, characterized in that, The end of the side wall of the first sealing cabin and the end of the side wall of the second sealing cabin are both provided with a groove in the circumferential direction, and a part of the sealing tooth is embedded in the groove.

3. The oil tank cover for preventing water power station large thrust bearing oil mist leakage according to claim 1, characterized in that, The bottom surface of the inner cover plate is provided with a first condensing bin, and the first condenser pipes are arranged in the first condensing bin in the radial direction of the inner cover plate; the bottom surface of the outer cover plate is provided with a second condensing bin, and the second condenser pipes are arranged in the second condensing bin in the radial direction of the outer cover plate.

4. The oil tank cover for preventing water power station large thrust bearing oil mist leakage according to claim 3, characterized in that, The end faces of the bottom plates of the first condensing bin and the second condensing bin are both in the shape of a v.

5. The oil tank cover for preventing water power station large thrust bearing oil mist leakage according to claim 3, characterized in that, The bottom plates of the first condensing bin and the second condensing bin are both made of aluminum alloy.

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