A steam turbine capable of online dehydration and equipped with shaft seals

Abstract

This utility model provides a steam turbine with online dehydration and a shaft seal, belonging to the field of steam turbine sealing technology. It includes a bearing housing, a steam turbine shaft, a steam source, and a pressure nitrogen channel. The bearing housing has a receiving cavity with a liquid outlet at the bottom and a top oil filling port at the top. A shaft seal cavity is located between the steam source and the bearing housing, and the pressure nitrogen channel communicates with the shaft seal cavity. By passing nitrogen gas through the shaft seal cavity, steam can be effectively prevented from penetrating axially towards the bearing housing, thereby protecting the purity and lubrication performance of the lubricating oil and ensuring the long-term stable operation of the bearing system. Furthermore, the design of the top oil filling port and liquid outlet of the bearing housing ensures that the bearing housing always maintains an appropriate oil level and sufficient high-quality lubricating oil, thus guaranteeing reliable lubrication, cooling, and normal operation of the steam turbine rotor system and extending the equipment's service life.

Description

Technical Field

[0001] This utility model belongs to the field of steam turbine sealing technology, and relates to a steam turbine that can be dehydrated online and has a shaft seal. Background Technology

[0002] Steam turbines, as core power equipment that converts thermal energy into mechanical energy, are widely used in industries such as power, petrochemicals, and metallurgy. During actual operation, the lubricating oil in the bearing housing of steam turbines is easily affected by external moisture or steam intrusion. Especially in high-temperature and high-pressure steam environments, steam may leak along the axial direction of the steam turbine to the bearing housing side, causing water to mix into the lubricating oil, resulting in oil emulsification, decreased lubrication performance, and further aggravated bearing wear. In severe cases, it may lead to excessive unit vibration or even shutdown accidents.

[0003] In summary, although some existing technical solutions solve the sealing problem by using shaft seal structures such as labyrinth steam seals or carbon ring seals, they still cannot achieve complete isolation. At the same time, there is still considerable room for improvement in the issue of replacing the lubricating oil in the bearing housing. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing a steam turbine capable of online dehydration and equipped with a shaft seal, comprising:

[0005] The bearing housing has a receiving cavity, the bottom of which has a liquid outlet communicating with the outside, and the top of which has a top oil filling port communicating with the outside.

[0006] A steam turbine shaft, one end of which is rotatably housed within the receiving cavity;

[0007] A steam source is provided with a shaft sealing cavity between itself and the bearing housing, and the turbine shaft is rotatably accommodated in the shaft sealing cavity;

[0008] A pressure nitrogen channel, which is connected to the shaft seal cavity, is used to supply nitrogen gas to the shaft seal cavity.

[0009] In the aforementioned steam turbine capable of online dehydration and equipped with a shaft seal, a steam seal and an oil seal are also provided on the outer periphery of the turbine shaft. The steam seal is located at one end near the steam source, and the oil seal is located at one end near the bearing housing. The pressure nitrogen channel is connected to the shaft seal cavity between the steam seal and the oil seal.

[0010] In the aforementioned steam turbine capable of online dehydration and equipped with shaft seals, both the steam seal and the oil seal are configured as comb-tooth seals.

[0011] In the aforementioned steam turbine capable of online dehydration and equipped with shaft seals, a breather valve is also provided on the top of the bearing housing, and the breather valve connects the receiving cavity to the outside.

[0012] In the aforementioned steam turbine capable of online dehydration and equipped with shaft seals, the pressure nitrogen passage is also equipped with a regulating valve.

[0013] In the aforementioned steam turbine capable of online dehydration and equipped with a shaft seal, a pressure gauge is also provided on the pressure nitrogen passage between the regulating valve and the shaft seal chamber.

[0014] In the aforementioned steam turbine capable of online dehydration and equipped with shaft seals, the pressure of the pressure nitrogen channel is set to 0.2-0.3 MPa.

[0015] In the aforementioned steam turbine capable of online dehydration and equipped with shaft seals, a switching valve is also provided at the liquid outlet.

[0016] The aforementioned steam turbine capable of online dehydration and equipped with shaft seals also includes a visible oil cup, and the liquid outlet is connected to the outside via the visible oil cup and a switching valve.

[0017] In the aforementioned steam turbine capable of online dehydration and equipped with a shaft seal, a connecting valve is also provided between the visible oil cup and the liquid outlet.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] 1. By using nitrogen gas to seal the shaft seal cavity, steam can be effectively blocked from penetrating axially towards the bearing housing, thereby protecting the purity and lubrication performance of the lubricating oil and ensuring the long-term stable operation of the bearing system. In addition, the design of the oil filling port and liquid discharge port on the top of the bearing housing can ensure that the bearing housing always maintains an appropriate oil level and sufficient high-quality lubricating oil, thereby ensuring reliable lubrication, cooling and normal operation of the turbine rotor system and extending the service life of the equipment.

[0020] 2. The comb-tooth seal adopts a labyrinthine structural design, forming multiple narrow throttling gaps with the turbine shaft surface. When gas or liquid attempts to leak outward, it must pass through multiple tiny gaps formed between the comb teeth and the shaft surface in sequence, gradually weakening the pressure and kinetic energy of the leaking medium. This greatly suppresses the overall leakage flow and leakage rate. At the same time, the comb-tooth seal is non-contact, which means it will not directly rub against the turbine shaft, thus reducing wear and extending service life.

[0021] 3. This structural design not only facilitates real-time monitoring of lubricating oil quality during daily maintenance, but also enables online detection and partial replacement of oil without disassembling the equipment, effectively improving the convenience of equipment maintenance and the reliability of operation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model.

[0023] Figure 2 This is a schematic diagram of the bearing housing of this utility model.

[0024] In the picture:

[0025] 1. Bearing housing; 11. Receiving cavity; 12. Liquid outlet; 13. Top oil filler port; 14. Breather valve; 15. Switch valve; 16. Visible oil cup; 17. Connecting valve; 2. Steam turbine shaft; 3. Steam source; 4. Shaft seal cavity; 5. Pressure nitrogen channel; 51. Regulating valve; 52. Pressure gauge; 6. Steam seal; 7. Oil seal. Detailed Implementation

[0026] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0027] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0028] Furthermore, in this utility model, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, features defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly and specifically defined.

[0029] In this utility model, unless otherwise explicitly specified and limited, the terms "connection" and "fixation" should be interpreted broadly. For example, "fixation" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0030] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0031] The specific embodiments described herein are merely illustrative examples of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or adopt similar methods to replace them, but without departing from the patent of this utility model or exceeding the scope defined by the appended claims.

[0032] like Figures 1-2 As shown, a steam turbine capable of online dehydration and equipped with a shaft seal includes: a bearing housing 1, a steam turbine shaft 2, a steam source 3, and a pressure nitrogen channel 5.

[0033] The bearing housing 1 is provided with a receiving cavity 11, the bottom of the receiving cavity 11 is provided with a liquid outlet 12 communicating with the outside, and the top of the receiving cavity 11 is provided with a top oil filling port 13 communicating with the outside.

[0034] One end of the turbine shaft 2 is rotatably housed within the receiving cavity 11.

[0035] A shaft sealing cavity 4 is provided between the steam source 3 and the bearing housing 1, and the turbine shaft 2 is rotatably accommodated in the shaft sealing cavity 4.

[0036] The pressure nitrogen channel 5 is connected to the shaft seal cavity 4 and is used to supply nitrogen gas to the shaft seal cavity 4.

[0037] Specifically, the high-temperature and high-pressure steam generated by the steam source 3 is used as the working medium and is guided to the shaft seal cavity 4 area of ​​the steam turbine. When the steam enters the shaft seal cavity 4, it comes into contact with the impeller installed on the steam turbine shaft 2, pushing the impeller to generate a rotational torque, thereby driving the entire steam turbine shaft 2 to rotate continuously at high speed. One end of the steam turbine shaft 2 is rotatably housed in the receiving cavity 11 of the bearing housing 1. The bearing housing 1 is used to support the rotation of the steam turbine shaft 2. The nitrogen gas introduced into the shaft seal cavity 4 by the pressure nitrogen channel 5 can prevent steam from entering the bearing housing 1, thereby causing the lubricating oil in the bearing housing 1 to emulsify and deteriorate. At the same time, the liquid outlet 12 on the bearing housing 1 can discharge the emulsified and deteriorated lubricating oil, while the oil filling port 13 at the top of the bearing housing 1 can replenish the missing lubricating oil, ensuring that there is sufficient high-quality lubricating oil in the bearing housing 1.

[0038] In this embodiment, nitrogen gas is used to effectively block the axial penetration of steam into the bearing housing 1 by the shaft seal cavity 4, thereby protecting the purity and lubrication performance of the lubricating oil and ensuring the long-term stable operation of the bearing system. In addition, the design of the oil filling port 13 and liquid discharge port 12 on the top of the bearing housing 1 can ensure that the bearing housing 1 always maintains an appropriate oil level and sufficient high-quality lubricating oil, thereby ensuring reliable lubrication, cooling and normal operation of the turbine rotor system and extending the service life of the equipment.

[0039] like Figures 1-2 As shown, based on the above embodiment, a steam seal 6 and an oil seal 7 are also provided on the outer periphery of the turbine shaft 2. The steam seal 6 is located at one end near the steam source 3, and the oil seal 7 is located at one end near the bearing housing 1. The pressure nitrogen channel 5 is connected to the shaft sealing cavity 4 between the steam seal 6 and the oil seal 7.

[0040] Specifically, the steam seal 6 is located on the shaft section near the inlet end of the steam source 3. Its main function is to initially curb the leakage of steam from the high-pressure steam zone, reduce the amount of steam entering the shaft seal area, and provide pre-seal protection for subsequent sealing. The oil seal 7 is arranged on the side near the bearing housing 1. The function of the oil seal 7 is to prevent any residual steam or sealing gas (such as nitrogen) from further penetrating towards the bearing housing 1, while preventing the lubricating oil in the bearing housing 1 from leaking outward.

[0041] In this embodiment, the steam seal 6 and the oil seal 7 are located at both ends of the shaft sealing cavity 4, working together to form multiple physical and pneumatic barriers. With the continuous supply of pressurized nitrogen, this not only significantly reduces the risk of steam leakage, but also fundamentally eliminates the possibility of steam intrusion into the bearing housing 1, leading to emulsification and deterioration of the lubricating oil. This ensures the lubrication performance, operational stability, and long-term safe operation of the bearing system.

[0042] like Figures 1-2 As shown, based on the above embodiments, both the steam seal 6 and the oil seal 7 are configured as comb-tooth seals.

[0043] In this embodiment, the comb seal adopts a labyrinthine structural design, forming multiple narrow throttling gaps with the surface of the turbine shaft 2. When gas or liquid attempts to leak outward, it must pass through multiple tiny gaps formed between the comb teeth and the shaft surface in sequence, gradually weakening the pressure and kinetic energy of the leaking medium, thereby greatly suppressing the overall leakage flow and leakage rate. At the same time, the comb seal is non-contact, so it does not directly rub against the turbine shaft 2, thus reducing wear and extending service life.

[0044] like Figures 1-2 As shown, based on the above embodiment, a breather valve 14 is also provided on the top of the bearing housing 1, and the breather valve 14 connects the receiving cavity 11 to the outside.

[0045] In this embodiment, the breather valve 14 allows air exchange between the inside and outside of the bearing housing 1 to balance the pressure, prevent seal damage caused by pressure differences or reduce the possibility of lubricating oil leakage from other parts, and also prevent other external impurities from entering the bearing housing 1. It plays an indispensable role in ensuring the sealing integrity of the bearing housing 1, maintaining the stability of the lubrication system and extending the equipment maintenance cycle.

[0046] like Figures 1-2 As shown, based on the above embodiment, the pressure nitrogen channel 5 is also provided with a regulating valve 51.

[0047] Specifically, during turbine operation, the shaft seal chamber 4 needs to maintain a nitrogen pressure slightly higher than the steam side pressure and the lubricating oil side pressure to form an effective "gas seal barrier" 6 to prevent steam or lubricating oil leakage, while the regulating valve 51 can adjust the nitrogen pressure according to the steam side pressure and the lubricating oil side pressure.

[0048] In this embodiment, the nitrogen pressure is intelligently controlled by the regulating valve 51, so that the nitrogen pressure in the shaft seal cavity 4 is always in the optimal range of "slightly higher than the two sides". This not only builds a stable and reliable bidirectional gas seal barrier, effectively preventing steam from entering the bearing housing 1 and causing lubricating oil emulsification, but also avoids lubricating oil leakage and pollution of equipment and environment.

[0049] like Figures 1-2 As shown, based on the above embodiment, a pressure gauge 52 is also provided on the pressure nitrogen channel 5 between the regulating valve 51 and the shaft sealing cavity 4.

[0050] In this embodiment, the pressure gauge 52 on the pressure nitrogen channel 5 can directly display the actual pressure value of the nitrogen gas entering the shaft seal cavity 4. The regulating valve 51 can be adjusted by the value on the pressure gauge 52 so that the nitrogen gas pressure in the shaft seal cavity 4 is always in the optimal range that is slightly higher than the two sides.

[0051] like Figures 1-2 As shown, based on the above embodiment, the pressure of the pressure nitrogen channel 5 is set to 0.2-0.3 MPa.

[0052] Specifically, the pressure of the pressure nitrogen channel 5 is set to 0.2–0.3 MPa. Precisely controlling the working pressure of the pressure nitrogen channel 5 between 0.2 and 0.3 MPa ensures that nitrogen gas is continuously and evenly provided for protection, maintaining a clean and dry operating environment inside the chamber, while avoiding equipment damage and energy waste caused by excessive pressure, thus achieving safe, reliable, and efficient operation and maintenance.

[0053] like Figures 1-2As shown, based on the above embodiment, a switch valve 15 is also provided at the liquid outlet 12.

[0054] In this embodiment, if steam still enters the bearing housing 1, causing the lubricating oil in the bearing housing 1 to emulsify, the lubricating oil containing water vapor will sink to the bottom of the bearing housing 1 due to its own density. At this time, the switch valve 15 is opened, and the lubricating oil containing water vapor will be discharged from the bearing housing 1 through the liquid outlet 12, thereby ensuring the purity of the lubricating oil inside the bearing housing 1.

[0055] like Figures 1-2 As shown, based on the above embodiment, a visible oil cup 16 is also included, and the liquid outlet 12 passes through the visible oil cup 16 and the switch valve 15 in sequence to the outside.

[0056] Specifically, the liquid outlet 12 is connected in sequence to a visible oil cup 16 and a switch valve 15. The lubricating oil in the bearing housing 1 first enters the visible oil cup 16 through the liquid outlet 12. The lubricating oil can be observed through the visible oil cup 16 to see if it has emulsified or deteriorated. If it has deteriorated, the switch valve 15 is opened to discharge a portion of the lubricating oil and then the observation is continued until the lubricating oil in the visible oil cup 16 becomes pure. Then, the missing lubricating oil is replenished through the top filler port 13.

[0057] In this embodiment, the structural design not only facilitates real-time monitoring of lubricating oil quality during routine maintenance, but also enables online detection and partial replacement of the oil without disassembling the equipment, effectively improving the convenience of equipment maintenance and the reliability of operation.

[0058] like Figures 1-2 As shown, based on the above embodiment, a connecting valve 17 is also provided between the visible oil cup 16 and the liquid outlet 12.

[0059] Specifically, after opening the connecting valve 17, some of the lubricating oil in the bearing housing 1 enters the visible oil cup 16, and then the connecting valve 17 is closed, if the lubricating oil in the visible oil cup 16 emulsifies and deteriorates, the switch valve 15 is opened to allow the lubricating oil in the oil cup to be discharged. This process is repeated several times until the lubricating oil in the visible oil cup 16 becomes pure, and then the missing lubricating oil is replenished through the top filler port 13.

[0060] In this embodiment, the lubricating oil can be checked multiple times by the connecting valve 17 to reduce the waste of lubricating oil. This design only requires the discharge of a very small amount of oil sample to complete the test, avoiding excessive oil discharge.

Claims

1. A steam turbine which can be dehydrated on-line and which has shaft seals, characterized in that include: The bearing housing has a receiving cavity, the bottom of which has a liquid outlet communicating with the outside, and the top of which has a top oil filling port communicating with the outside. A turbine shaft, one end of which is rotatably housed within the receiving cavity; A steam source is provided with a shaft sealing cavity between itself and the bearing housing, and the turbine shaft is rotatably accommodated in the shaft sealing cavity; A pressure nitrogen channel, which is connected to the shaft seal cavity, is used to supply nitrogen gas to the shaft seal cavity.

2. A steam turbine which can be dehydrated on-line and which has shaft seals, according to claim 1, characterized in that: The turbine shaft is also provided with a steam seal and an oil seal. The steam seal is located at one end near the steam source, and the oil seal is located at one end near the bearing housing. The pressure nitrogen channel is connected to the shaft sealing cavity between the steam seal and the oil seal.

3. A steam turbine capable of online dehydration and equipped with a shaft seal as described in claim 2, characterized in that: Both the steam seal and the oil seal are configured as comb-tooth seals.

4. A steam turbine which can be dehydrated on-line and which has shaft seals, according to claim 1, characterized in that: The bearing housing is also equipped with a breather valve on its top, which connects the housing cavity to the outside.

5. A steam turbine which can be dehydrated on-line and which has shaft seals, according to claim 1, characterized in that: The pressure nitrogen channel is also equipped with a regulating valve.

6. A steam turbine which can be dehydrated on-line and which has shaft seals, according to claim 5, characterized in that: A pressure gauge is also provided on the pressure nitrogen channel between the regulating valve and the shaft seal cavity.

7. A steam turbine capable of online dehydration and equipped with a shaft seal as described in claim 6, characterized in that: The pressure of the pressure nitrogen channel is set to 0.2-0.3 MPa.

8. A steam turbine which can be dehydrated on-line and which has shaft seals, according to claim 1, characterized in that: A switch valve is also installed at the liquid outlet.

9. A steam turbine which can be dehydrated on-line and which has shaft seals, according to claim 8, characterized in that: It also includes a visible oil cup, and the liquid outlet passes through the visible oil cup and the switch valve in sequence to the outside.

10. A steam turbine which can be dehydrated on-line and which has shaft seals, according to claim 9, characterized in that: A connecting valve is also provided between the visible oil cup and the liquid outlet.

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