Sealing structure and centrifugal compressor
By designing a multi-layer carbon ring seal and a gas pressure control system in a centrifugal compressor, the problems of medium gas leakage and condition monitoring of the carbon ring seal were solved, and the stable operation of the sealing structure and timely fault detection were achieved.
Patent Information
- Application Number
- CN202520806385.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-26
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2035-04-26
AI Technical Summary
Carbon ring seals in centrifugal compressors suffer from media gas leakage problems, and it is difficult to monitor the operating status in real time, resulting in a failure to detect the decline in sealing performance in a timely manner.
Design a sealing structure including a multi-layer carbon ring seal and a gas pressure control system. By forming a high-pressure sealing chamber and an isolation gas chamber, it prevents the leakage of medium gas, and uses a gas pressure measuring element to monitor the sealing status in real time and provide timely alarm.
It effectively reduces media gas leakage, ensures stable operation of the sealing structure, and can promptly detect and handle potential faults, guaranteeing the normal operation of the centrifugal compressor.
Smart Images
Figure CN223953233U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to compressor sealing technical field, concretely relates to a sealing structure and centrifugal compressor. BACKGROUND
[0002] Carbon ring seal is a kind of flow resistance type non-contact sealing device, it reaches the purpose of leakage resistance by the fluid resistance effect in sealing gap, it belongs to a kind of floating ring seal, since it is usually made of graphite material, it is called carbon ring seal;Carbon ring seal is applied to the sealing field between rotor and stator of centrifugal compressor, expander, steam turbine etc.
[0003] Due to the sealing principle of carbon ring seal, a small amount of medium gas will inevitably pass through the carbon ring sealing part, which cannot fully meet the demand in some strict leakage scenarios;Meanwhile, the running state of carbon ring seal is not monitored, when the sealing performance of carbon ring seal is reduced due to wear or other conditions cause abnormality, it is difficult to find out in time, and the effective operation of centrifugal compressor cannot be guaranteed.
[0004] Therefore, it is an urgent problem to be solved at present to develop and design a sealing structure and centrifugal compressor which can effectively reduce the leakage of sealed medium, guarantee the effective operation of sealing structure and monitor the running state in real time. SUMMARY
[0005] For the problems existing in the prior art, the utility model provides a sealing structure and centrifugal compressor, first sealing part and second sealing part form first containing cavity, the gas pressure in first containing cavity is higher than medium side gas pressure, can effectively prevent the gas medium at medium side from leaking outward through first sealing part;Second sealing part and third sealing part form second containing cavity, third sealing part and fourth sealing part form third containing cavity, the gas pressure in third containing cavity is higher than the gas pressure in second containing cavity and slightly higher than atmospheric pressure, can prevent the gas in second containing cavity from entering third containing cavity through third sealing part, and make only a small amount of isolated gas leak from gearbox side;The sealing gas in first containing cavity, a small amount of isolated gas in third containing cavity pass through third sealing part into second containing cavity and then can be discharged into atmosphere or enter torch system, guarantee the effective operation of the utility model.
[0006] In order to realize the above-mentioned purpose, the technical scheme adopted by the utility model is as follows:
[0007] Firstly, the utility model provides a sealing structure, which comprises:
[0008] Shaft;
[0009] A sealing assembly is arranged on the shaft, one side of the sealing assembly is a medium side, and the other side of the sealing assembly is a gearbox side;
[0010] The sealing assembly comprises a first sealing part, a second sealing part, a third sealing part and a fourth sealing part distributed in the direction from the medium side to the gearbox side, and each of the sealing parts is arranged as a carbon ring seal.
[0011] The second sealing part comprises a plurality of carbon ring seals, and the number of carbon ring seals of the second sealing part is greater than that of the first sealing part.
[0012] A first containing cavity is arranged between the first sealing part and the second sealing part, the first containing cavity is filled with sealing gas, the sealing gas is of the same type as the gaseous medium on the medium side, and the gas pressure of the sealing gas is higher than that of the medium side; a second containing cavity is arranged between the second sealing part and the third sealing part, the second containing cavity is in communication with the atmosphere or a flare system; a third containing cavity is arranged between the third sealing part and the fourth sealing part, the third containing cavity is filled with isolation gas, and the gas pressure in the third containing cavity is higher than that in the second containing cavity.
[0013] The first containing cavity is in communication with a first connecting pipeline, the second containing cavity is in communication with a second connecting pipeline, and the third containing cavity is in communication with a third connecting pipeline, and a gas pressure measuring element is arranged in each of the first connecting pipeline, the second connecting pipeline and the third connecting pipeline.
[0014] As a preferred technical solution, the gas pressure measuring element is connected with a controller, and the controller is connected with an alarm element.
[0015] As a preferred technical solution, the first connecting pipeline and the third connecting pipeline are each connected with a gas pressure adjusting assembly, and the controller is connected with the gas pressure adjusting assembly.
[0016] As a preferred technical solution, the gas pressure measuring element is arranged as a gas pressure sensor.
[0017] And / or, the gas pressure adjusting assembly is arranged as a gas pump.
[0018] And / or, the controller is arranged as a PLC.
[0019] As a preferred technical solution, the gas pressure in the first containing cavity is 0.1-0.25 MPa higher than that on the medium side.
[0020] As a preferred technical solution, the purity of the sealing gas is ≥99%.
[0021] As a preferred technical solution, the isolation gas is arranged as nitrogen.
[0022] As a preferred technical solution, the number of the carbon ring seals of the second sealing part is more than the number of the carbon ring seals of the third sealing part.
[0023] As a preferred technical solution, the first sealing part comprises one carbon ring seal; the second sealing part comprises three carbon ring seals; and the third sealing part comprises one carbon ring seal.
[0024] In a second aspect, the utility model provides a centrifugal compressor, including gear box, impeller and preceding one kind of sealing structure, the shaft is located between gear box and impeller.
[0025] The utility model has the advantages of:
[0026] 1、The first sealing part and the second sealing part form a first containing cavity in the utility model, and the pure gas in the first containing cavity is the same as the medium side gas, and the gas pressure is higher than the medium side pressure, which can effectively prevent the gas medium on the medium side from leaking outward through the first sealing part, and avoid introducing impurities; The second sealing part and the third sealing part form a second containing cavity, and the third sealing part and the fourth sealing part form a third containing cavity, and the gas pressure in the third containing cavity is higher than the gas pressure in the second containing cavity and slightly higher than the atmospheric pressure, which can prevent the gas in the second containing cavity from entering the third containing cavity through the third sealing part, and at the same time, only a small amount of isolation gas will leak from the gear box side; The sealing gas in the first containing cavity enters the second containing cavity through the second sealing part and the third containing cavity, and a small amount of isolation gas in the third containing cavity enters the second containing cavity through the third sealing part, and then can be discharged into the atmosphere or into the flare system, ensuring the effective operation of the utility model.
[0027] 2、In the utility model, the pure gas in the first containing cavity is in a pressurized state, and under normal circumstances, the medium side pressure is greater than the second containing cavity evacuation pressure, when the number of carbon ring seals of the first sealing part and the second sealing part is the same, the pure gas in the first containing cavity tends to enter the second containing cavity through the second sealing part, in order to avoid the pure gas in the first containing cavity from leaking in large quantities or even failing to establish back pressure, the number of carbon ring seals of the second sealing part is higher than that of the first sealing part, so that the resistance of the pure gas in the first containing cavity through the second sealing part is significantly higher than that of the first sealing part, avoiding large leakage while ensuring stable back pressure.
[0028] 3、The utility model discloses a gas pressure measuring element is arranged in the connecting pipeline, can measure the gas pressure of first containing chamber, second containing chamber and third containing chamber in real time, when the utility model is normal work, the gas pressure in each connecting pipeline is in the preset range, when the utility model appears abnormal, such as the seal gas or the isolated gas of external connection breaks, the connecting pipeline appears breakage or blockage, the sealing performance drops and the like, the risk of medium side gas medium leakage can occur, at this time, the gas pressure or the gas pressure change in the connecting pipeline can exceed the preset range, and the controller can alarm through the alarm element, can promptly troubleshoot and carry out normal production again, guarantee the utility model continues normal work. BRIEF DESCRIPTION OF DRAWINGS
[0029] Figure 1 It is whole structure schematic diagram of one embodiment of the utility model one kind sealed structure;
[0030] Figure 2 It is Figure 1 The enlarged view of area A in the middle.
[0031] In the drawing: 1-axis, 21-first sealing part, 22-second sealing part, 23-third sealing part, 24-fourth sealing part, 3-medium side, 4-gearbox side, 5-first containing chamber, 51-first connecting pipeline, 6-second containing chamber, 61-second connecting pipeline, 7-third containing chamber, 71-third connecting pipeline. DETAILED DESCRIPTION
[0032] In order to facilitate the person skilled in the art to understand, the utility model is further explained below in combination with the drawings.
[0033] First, please refer to Figure 1 And Figure 2The utility model provides a kind of sealing structure one embodiment, including shaft 1 and sealing assembly, sealing assembly is located on shaft 1, one side of sealing assembly is medium side 3, the other side of sealing assembly is gear box side 4;Sealing assembly includes first sealing portion 21, second sealing portion 22, third sealing portion 23 and fourth sealing portion 24 in turn distributed along the direction from medium side 3 to gear box side 4, first sealing portion 21, second sealing portion 22, third sealing portion 23 and fourth sealing portion 24 are all by several carbon ring seal composition;First containing cavity 5 is equipped between first sealing portion 21 and second sealing portion 22, first containing cavity 5 is filled with sealing gas, the gas pressure of sealing gas in first containing cavity 5 is higher than the gas pressure of medium side 3, can effectively prevent the gas medium at medium side 3 from leaking outward through first sealing portion 21;Third containing cavity 7 is equipped between third sealing portion 23 and fourth sealing portion 24, third containing cavity 7 is filled with isolation gas, the gas pressure in third containing cavity 7 is higher than the gas pressure in second containing cavity 6, can prevent the gas in second containing cavity 6 from entering third containing cavity 7 through third sealing portion 23, while only a small amount of isolation gas is leaked in gear box side 4;Second containing cavity 6 is equipped between second sealing portion 22 and third sealing portion 23, second containing cavity 6 is communicated with atmosphere or torch system, after sealing gas in first containing cavity 5 passes through second sealing portion 22, a small amount of isolation gas in third containing cavity 7 passes through third sealing portion 23 and enters second containing cavity 6, it can be discharged into atmosphere or enter torch system, ensure that the gas medium in medium side 3 is zero leakage in gear box side 4, effectively ensure that the utility model continues normal operation.
[0034] It should be noted that the gas medium of medium side 3 refers to the main gas to be compressed or the gas to be obtained finally, and the sealing gas should be of the same type as the gas medium to avoid the gas containing impurities from entering the medium side 3 directly through the sealing assembly or indirectly through the external reflux pipeline, thereby polluting the gas medium of the medium side 3. In actual production, the gas medium of the medium side 3 is not pure and may contain multiple media, while the sealing gas needs to be of high purity to avoid polluting the gas medium of the medium side 3. Specifically, the gas medium of the medium side 3 and the sealing gas are both carbon dioxide, and the purity of the sealing gas is ≥99%. Correspondingly, the isolation gas is preferably nitrogen.
[0035] In this embodiment, please refer to Figure 1 and Figure 2, the second sealing part 22 comprises three carbon ring seals, the first sealing part 21 and the third sealing part 23 each comprise one carbon ring seal, the number of the carbon ring seals of the second sealing part 22 is more than that of the first sealing part 21 and the third sealing part 23 respectively, and the three carbon ring seals of the second sealing part 22 can avoid too much sealing gas from leaking through the second sealing part; in other embodiments, the number of the carbon ring seals contained in the first sealing part 21, the second sealing part 22 and the third sealing part 23 can also be other values, which can effectively ensure the sealing effect.
[0036] In actual production, in order to effectively prevent the gas medium at the medium side 3 from leaking outward through the first sealing part 21, the sealing gas should have a pressure to balance the pressure of the medium side 3; specifically, the gas pressure in the first containing cavity 5 is 0.1-0.25MPa higher than the gas pressure of the medium side 3, which can also prevent the sealing gas pressure from being too high to enter the medium side 3 too fast, thereby avoiding excessive influence on the normal operation of the medium side 3.
[0037] In the embodiment, please refer to Figure 1 and Figure 2 The first containing cavity 5 is communicated with a first connecting pipeline 51, the second containing cavity 6 is communicated with a second connecting pipeline 61, and the third containing cavity 7 is communicated with a third connecting pipeline 71, and a gas pressure measuring element is arranged in each of the first connecting pipeline 51, the second connecting pipeline 61 and the third connecting pipeline 71, which can measure the gas pressure in the first containing cavity 5, the second containing cavity 6 and the third containing cavity 7 in real time; specifically, the gas pressure measuring element is preferably a gas pressure sensor.
[0038] On the basis of the foregoing embodiment, the first connecting pipeline 51 and the third connecting pipeline 71 are connected with a gas source and a gas pressure adjusting assembly, and the gas pressure measuring element is connected with a controller, which can receive the measurement information of the gas pressure measuring element and compare it with a preset range; the controller is connected with the gas pressure adjusting assembly, and the controller can adjust the gas pressure in the first containing cavity 5 and the third containing cavity 7 by controlling the switch and working intensity of the gas pressure adjusting assembly; specifically, the gas pressure adjusting assembly is preferably a gas pump, and the controller is preferably a PLC.
[0039] Further, the utility model also should include alarm element, alarm element is connected with the controller, when the gas pressure in the connecting pipeline exceeds the preset range, the controller can alarm through alarm element, so that the staff can promptly troubleshoot, guarantee the stable operation of normal production; specifically, the alarm element can be one or more of warning light, buzzer.
[0040] The stable operation of the scheme depends on the normal establishment of the pressure of each connecting pipeline. When an abnormal situation occurs, the sealing abnormal situation can be found conveniently and quickly by monitoring the pressure of the connecting pipeline, and the abnormal position can be located according to the pressure change of different connecting pipelines, so that the abnormality can be found and eliminated in time, and the stable operation of the utility model is ensured through the joint action of the two. For example, when the pressure of the first connecting pipeline 51 abnormally decreases, and the pressure of the second connecting pipeline 61 increases, it can be preliminarily judged that the second sealing part 22 is abnormal.
[0041] Please refer to Figure 1 and Figure 2 The specific working principle of the utility model is as follows:
[0042] The gaseous medium of the medium side 3 decreases in pressure after passing through the first sealing part 21 and entering the first containing cavity 5;
[0043] Filling the first containing cavity 5 with sealing gas with a higher pressure than the gaseous medium of the medium side 3 can ensure that the gaseous medium of the medium side 3 does not leak outward;
[0044] After the sealing gas passes through the three carbon ring seals of the second sealing part 22, the pressure and flow rate of the sealing gas will sharply decrease, so that the sealing gas does not excessively leak from the second sealing part 22;
[0045] Filling the third containing cavity 7 with non-toxic isolation gas with a certain pressure makes the gear box side 4 have only a small amount of isolation gas leakage, so that the gaseous medium of the medium side 3 is zero leakage;
[0046] The sealing gas and a small amount of isolation gas enter the second containing cavity 6 and are directly discharged to the atmosphere or a flare system.
[0047] The utility model consumes a certain amount of sealing gas and a small amount of isolation gas, so that the gaseous medium of the medium side 3 is zero leakage, and other gases are not introduced into the gaseous medium of the medium side 3.
[0048] In the second aspect, the utility model provides a centrifugal compressor, including gear box, impeller and preceding one kind of sealing structure, shaft 1 is located between gear box and impeller, sealing structure can effectively prevent the gaseous medium leakage at impeller.
[0049] The above only is the preferred embodiment of the utility model, and is not used for limiting the utility model, for the person skilled in the art, the utility model can have various changes and changes; any modification, equivalent replacement, improvement etc. that is made within the spirit and principle of the utility model should be included in the protection scope of the utility model.
Claims
1. A seal structure, characterized by, The application relates to a sealing structure of a shaft. The sealing structure comprises a shaft (1), a sealing assembly arranged on the shaft (1), a medium side (3) of the sealing assembly, and a gearbox side (4) of the sealing assembly. The sealing assembly comprises a first sealing part (21), a second sealing part (22), a third sealing part (23) and a fourth sealing part (24) arranged in a direction from the medium side (3) to the gearbox side (4), wherein the sealing parts are all carbon ring seals. The second sealing part (22) comprises multiple carbon ring seals, and the number of the carbon ring seals of the second sealing part (22) is more than that of the first sealing part (21). A first accommodating cavity (5) is arranged between the first sealing part (21) and the second sealing part (22), the first accommodating cavity (5) is filled with sealing gas, the sealing gas is of the same type as the gas medium of the medium side (3), and the gas pressure of the sealing gas is higher than that of the medium side (3); a second accommodating cavity (6) is arranged between the second sealing part (22) and the third sealing part (23), the second accommodating cavity (6) is communicated with the atmosphere or a flare system; and a third accommodating cavity (7) is arranged between the third sealing part (23) and the fourth sealing part (24), the third accommodating cavity (7) is filled with isolation gas, and the gas pressure in the third accommodating cavity (7) is higher than that in the second accommodating cavity (6). The first connecting pipeline (51) is communicated with the first accommodating cavity (5), the second connecting pipeline (61) is communicated with the second accommodating cavity (6), and the third connecting pipeline (71) is communicated with the third accommodating cavity (7), wherein gas pressure measuring elements are arranged in the first connecting pipeline (51), the second connecting pipeline (61) and the third connecting pipeline (71). The gas pressure measuring elements are connected with a controller, and the controller is connected with an alarm element.
2. A seal structure according to claim 1, wherein The first connecting pipeline (51) and the third connecting pipeline (71) are both connected with a gas pressure adjusting assembly, and the controller is connected with the gas pressure adjusting assembly.
3. A seal structure according to claim 2, wherein The gas pressure measuring elements are gas pressure sensors.
4. A seal structure according to claim 3, wherein The gas pressure adjusting assembly is a gas pump. The controller is a PLC. The gas pressure in the first accommodating cavity (5) is 0.1-0.25 MPa higher than that of the medium side (3).
5. The seal of claim 1 wherein, The purity of the sealing gas is greater than or equal to 99%.
6. The sealed structure of claim 1, wherein The isolation gas is nitrogen.
7. The sealed structure of claim 1, wherein The number of the carbon ring seals of the second sealing part (22) is more than that of the third sealing part (23).
8. The sealed structure of claim 1, wherein The first sealing part (21) comprises one carbon ring seal, the second sealing part (22) comprises three carbon ring seals, and the third sealing part (23) comprises one carbon ring seal.
9. A sealed structure according to claim 1 or 8, wherein The application further relates to a gearbox, an impeller and a sealing structure as claimed in any one of claims 1-9, wherein the shaft (1) is arranged between the gearbox and the impeller.
10. A centrifugal compressor characterized by,