Sealing gas discharging system of carbon dioxide centrifugal compressor
By designing a sealed gas emission system for carbon dioxide centrifugal compressors, the leakage gas is recovered and reduced, and the problems of large leakage gases and oil fume pollution in the existing technology are solved, and the stability and environmental quality of the system are improved.
Patent Information
- Application Number
- CN202510454205.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2025-06-24
AI Technical Summary
During use, the existing sealed gas emission system of the carbon dioxide centrifugal compressor, the first-stage leaking air of the high-pressure cylinder flows to the low-stage cylinder, resulting in a large amount of leakage air in the low-stage leaking air. The excessive pressure of the third-stage leaking air causes the oil smoke in the bearing box to be brought out, polluting the environment and posing a fire hazard.
A sealed gas emission system for carbon dioxide centrifugal compressors was designed. The first-stage leaked air through the high and low-pressure cylinders was returned to a section of the inlet, and the second-stage leaked air was pushed to a section of the inlet through the injector. The high point of the third-stage sealed leaked air exhaust line was emptied to reduce the pressure of the low-pressure cylinder and avoid the ejection of oil smoke.
By recycling and reducing leaked gases, the pressure of the low-pressure cylinder is reduced, oil fume polluted the environment and fire hazards are avoided, and the stability and environmental quality of the system are improved.
Smart Images
Figure CN120194037A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of carbon dioxide centrifugal compressors, and particularly to a carbon dioxide centrifugal compressor seal gas discharge system. Background Art
[0002] Carbon dioxide centrifugal compressors are essential equipment in nitrogen fertilizer plants. The operating environment of the equipment usually requires fire and explosion prevention, and the occurrence of ignition points is prohibited. The existing carbon dioxide centrifugal compressor seal gas discharge system includes the discharge of the primary seal leakage gas of the high-pressure and low-pressure cylinders of the compressor, the discharge of the secondary seal leakage gas, and the discharge of the tertiary seal leakage gas.
[0003] However, during its use, due to the flow of the primary leakage gas in the high-pressure cylinder to the low-pressure cylinder, a large amount of gas enters the low-pressure cylinder, resulting in a large amount of leakage gas in the low-pressure cylinder. The excessive pressure of the tertiary seal leakage gas causes the oil fume in the bearing box to be carried out, which not only pollutes the environment but also poses a fire hazard. Summary of the Invention
[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a carbon dioxide centrifugal compressor seal gas discharge system.
[0005] To achieve the above object, the present invention provides the following technical solution: A carbon dioxide centrifugal compressor seal gas discharge system includes a compressor high-pressure cylinder and a compressor low-pressure cylinder. The compressor low-pressure cylinder is rotationally connected to a compressor first stage and a compressor second stage; the compressor high-pressure cylinder is rotationally connected to a compressor third stage and a compressor fourth stage. The compressor first stage is sequentially connected with a flange A1, a flange A2, and a flange A3; the compressor second stage is sequentially connected with a flange B3, a flange B2, and a flange B1; the compressor third stage is sequentially connected with a flange A4, a flange A5, and a flange A6, and the compressor fourth stage is sequentially connected with a flange B6, a flange B5, and a flange B4. The flange A3 and the flange B3 of the compressor low-pressure cylinder are connected and used as the discharge pipeline for the primary seal leakage gas of the low-pressure cylinder; the flange A2 and the flange B2 of the low-pressure cylinder are connected and used as the discharge pipeline for the secondary seal leakage gas of the low-pressure cylinder, and the flange A1 and the flange B1 of the low-pressure cylinder are connected and used as the discharge pipeline for the tertiary seal leakage gas of the low-pressure cylinder; the flange A6 and the flange B6 of the high-pressure cylinder are connected and used as the discharge pipeline for the primary seal leakage gas of the high-pressure cylinder, the flange A5 and the flange B5 of the high-pressure cylinder are connected and used as the discharge pipeline for the secondary seal leakage gas of the high-pressure cylinder, and the flange A4 and the flange B4 of the high-pressure cylinder are connected and used as the discharge pipeline for the tertiary seal leakage gas of the high-pressure cylinder; the discharge pipeline for the primary seal leakage gas of the low-pressure cylinder and the discharge pipeline for the primary seal leakage gas of the high-pressure cylinder send the seal leakage gas back to the inlet of the compressor first stage. The discharge pipeline for the secondary seal leakage gas of the low-pressure cylinder and the discharge pipeline for the secondary seal leakage gas of the high-pressure cylinder are connected and send the seal leakage gas back to the inlet of the compressor first stage through an ejector. The discharge pipelines for the tertiary seal leakage gas of the low-pressure cylinder and the high-pressure cylinder are vented.
[0006] As a further preference of the present invention, the inlet of the third stage of the compressor and the inlet of the fourth stage of the compressor are connected by a balance pipe. By providing the balance pipe, the inlet pressure of the fourth stage of the compressor is reduced, and the unilateral force is reduced.
[0007] As a further preference of the present invention, the low-pressure cylinder of the compressor is rotationally connected to the first stage and the second stage of the compressor through bearings, and the high-pressure cylinder of the compressor is rotationally connected to the third stage and the fourth stage of the compressor through bearings. A seal is provided at the bearing connection, and an isolation gas is used as a gas seal between the seal and the bearing to prevent process gas from being contaminated by bearing lubricating oil.
[0008] As a further preference of the present invention, the hot gas at the outlet of the first stage of the compressor is supplied to the ejector after the leakage gas discharge pipelines of the secondary seals of the low-pressure cylinder and the high-pressure cylinder are connected.
[0009] As a further preference of the present invention, the hot gas at the outlet of the second stage of the compressor is supplied and refluxed to the inlet of the third stage of the compressor, and the hot gas at the outlet of the third stage of the compressor is supplied and refluxed to the inlet of the fourth stage of the compressor.
[0010] The above hot gas prevents carbon dioxide from forming dry ice during throttling and pressure reduction, blocking the pipeline.
[0011] As a further preference of the present invention, valves are provided at the bottoms of the first stage, the second stage, the third stage and the fourth stage of the compressor. Through the valve setting, condensate drainage is carried out to drain the inner cavity of the compressor completely, avoiding blockage.
[0012] As a further preference of the present invention, the leakage gas discharge pipelines of the tertiary seals of the low-pressure cylinder and the high-pressure cylinder are vented at a high position to avoid pipeline blockage.
[0013] Technical effects and advantages of the invention:
[0014] Through the setting that the primary leakage gas of the high and low-pressure cylinders returns to the inlet of the first stage, the secondary leakage gas is pushed to the inlet of the first stage by the ejector after being balanced between the high and low-pressure cylinders, and the high points of the tertiary seal leakage gas discharge pipelines are vented. While the amount of gas entering the secondary stage is reduced, the pressure of the low-pressure cylinder is reduced, avoiding the problem of a large amount of oil fume spraying out of the bearing box due to the too high discharge pressure of the low-pressure cylinder, resulting in environmental pollution and waste of resources. This makes the system design more perfect, improves the environmental quality and saves resources; at the same time, the fire hazard is solved, providing a more stable operation guarantee for users. Brief description of the drawings
[0015] Figure 1 It is a schematic structural diagram of a carbon dioxide centrifugal compressor seal gas discharge system of the present invention.
[0016] Figure 2 It is a schematic structural diagram of the reflux of the secondary seal leakage gas discharge pipeline in the present invention.
[0017] Figure 3 This is a schematic structural diagram of the low-pressure cylinder of the compressor in the present invention.
[0018] Figure 4 This is a schematic structural diagram of the high-pressure cylinder of the compressor in the present invention.
[0019] The reference numerals are: 1. Low-pressure cylinder first-stage seal leakage gas discharge pipeline; 2. Low-pressure cylinder second-stage seal leakage gas discharge pipeline; 3. High-pressure cylinder second-stage seal leakage gas discharge pipeline; 4. Low-pressure cylinder third-stage seal leakage gas discharge pipeline; 5. High-pressure cylinder first-stage seal leakage gas discharge pipeline; 6. High-pressure cylinder third-stage seal leakage gas discharge pipeline; 7. Ejector; 8. Compressor low-pressure cylinder; 9. Compressor first stage; 10. Compressor second stage; 11. Compressor high-pressure cylinder; 12. Compressor third stage; 13. Compressor fourth stage; 14. Balance pipe. Detailed implementation manners
[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0021] Refer to the attached Figures 1-4As shown in the figure, a carbon dioxide centrifugal compressor seal gas discharge system includes a compressor high-pressure cylinder 11 and a compressor low-pressure cylinder 8. The compressor low-pressure cylinder 8 is rotationally connected to a first-stage compressor 9 and a second-stage compressor 10; the compressor high-pressure cylinder 11 is rotationally connected to a third-stage compressor 12 and a fourth-stage compressor 13. The first-stage compressor 9 is sequentially connected with a flange A1, a flange A2, and a flange A3; the second-stage compressor 10 is sequentially connected with a flange B3, a flange B2, and a flange B1; the third-stage compressor 12 is sequentially connected with a flange A4, a flange A5, and a flange A6, and the fourth-stage compressor 13 is sequentially connected with a flange B6, a flange B5, and a flange B4. The flange A3 and the flange B3 of the compressor low-pressure cylinder 8 are connected and used as the first-stage seal leakage gas discharge pipeline 1 of the low-pressure cylinder; the flange A2 and the flange B2 of the low-pressure cylinder are connected and used as the second-stage seal leakage gas discharge pipeline 2 of the low-pressure cylinder, and the flange A1 and the flange B1 of the low-pressure cylinder are connected and used as the third-stage seal leakage gas discharge pipeline 4 of the low-pressure cylinder. The flange A6 and the flange B6 of the high-pressure cylinder are connected and used as the first-stage seal leakage gas discharge pipeline 5 of the high-pressure cylinder, the flange A5 and the flange B5 of the high-pressure cylinder are connected and used as the second-stage seal leakage gas discharge pipeline 3 of the high-pressure cylinder, and the flange A4 and the flange B4 of the high-pressure cylinder are connected and used as the third-stage seal leakage gas discharge pipeline 6 of the high-pressure cylinder. The first-stage seal leakage gas discharge pipeline 1 of the low-pressure cylinder and the first-stage seal leakage gas discharge pipeline 5 of the high-pressure cylinder send the seal leakage gas back to the inlet of the first-stage compressor 9. The second-stage seal leakage gas discharge pipeline 2 of the low-pressure cylinder and the second-stage seal leakage gas discharge pipeline 3 of the high-pressure cylinder are connected and the seal leakage gas is sent back to the inlet of the first-stage compressor 9 through an ejector 7. The third-stage seal leakage gas discharge pipeline 4 of the low-pressure cylinder and the third-stage seal leakage gas discharge pipeline 6 of the high-pressure cylinder are vented.
[0022] As Figure 1 and 4 shown, in the invention embodiment, the inlets of the third-stage compressor 12 and the fourth-stage compressor 13 are connected with a balance pipe 14. By arranging the balance pipe 14, the inlet pressure of the fourth-stage compressor 13 is reduced, and the unilateral force is reduced.
[0023] As Figure 1 shown, in the invention embodiment, the compressor low-pressure cylinder 8 is rotationally connected to the first-stage compressor 9 and the second-stage compressor 10 through bearings. The compressor high-pressure cylinder 11 is rotationally connected to the third-stage compressor 12 and the fourth-stage compressor 13 through bearings. Seals are provided at the bearing connections, and isolation gas is used as a gas seal between the seals and the bearings to prevent process gas from being contaminated by bearing lubricating oil.
[0024] As Figure 2 shown, in the invention embodiment, the hot gas at the outlet of the first-stage compressor 9 is supplied to the ejector 7 where the second-stage seal leakage gas discharge pipeline 2 of the low-pressure cylinder and the second-stage seal leakage gas discharge pipeline 3 of the high-pressure cylinder are connected.
[0025] As Figure 4As shown, in the embodiment of the invention, the hot gas discharged from the outlet of the second stage 10 of the compressor is supplied and refluxed to the inlet of the third stage 12 of the compressor, and the hot gas discharged from the outlet of the third stage 12 of the compressor is supplied and refluxed to the inlet of the fourth stage 13 of the compressor. The above hot gas prevents carbon dioxide from forming dry ice during throttling and depressurization, thus blocking the pipeline.
[0026] As Figure 1 , 3 and as shown in Figure 4, in the embodiment of the invention, valves are provided at the bottoms of the first stage 9, the second stage 10, the third stage 12 and the fourth stage 13 of the compressor. The valves are used for condensate drainage to drain the inner cavity of the compressor completely, thus avoiding blockage.
[0027] As Figure 2 shown, in the embodiment of the invention, the low-pressure cylinder third-stage seal leakage gas discharge pipeline 4 and the high-pressure cylinder third-stage seal leakage gas discharge pipeline 6 are vented at a high position to avoid pipeline blockage.
[0028] During the working process of the present invention, the low-pressure cylinder first-stage seal leakage gas discharge pipeline 1 and the high-pressure cylinder first-stage seal leakage gas discharge pipeline 5 respectively send the seal leakage gas back to the inlet pipeline of the first stage 9 of the compressor. The low-pressure cylinder second-stage seal leakage gas discharge pipeline 2 and the high-pressure cylinder second-stage seal leakage gas discharge pipeline 3 are connected and then send the seal leakage gas back to the inlet pipeline of the first stage 9 of the compressor through an ejector 7. Driven by the power gas, a large amount of leakage gas is recovered. The high-pressure cylinder second-stage seal leakage gas discharge pipeline 3 and the high-pressure cylinder third-stage seal leakage gas discharge pipeline 6 respectively vent the seal leakage gas directly.
[0029] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A carbon dioxide centrifugal compressor sealing gas discharge system, comprising a compressor high-pressure cylinder and a compressor low-pressure cylinder, wherein the compressor low-pressure cylinder is rotatably connected to the compressor section 1 and the compressor section 2; the compressor high-pressure cylinder is rotatably connected to the compressor section 3 and the compressor section 4, the compressor section 1 is sequentially connected to the A1 flange, the A2 flange, and the A3 flange; the compressor section 2 is sequentially connected to the B3 flange, the B2 flange, and the B1 flange; the compressor section 3 is sequentially connected to the A4 flange, the A5 flange, and the A6 flange, and the compressor section 4 is sequentially connected to the B6 flange, the B5 flange, and the B4 flange, wherein: The A3 flange and B3 flange of the compressor low-pressure cylinder are connected to serve as the primary seal leakage gas discharge pipeline of the low-pressure cylinder; the A2 flange and B2 flange of the low-pressure cylinder are connected to serve as the secondary seal leakage gas discharge pipeline of the low-pressure cylinder; the A1 flange and B1 flange of the low-pressure cylinder are connected to serve as the tertiary seal leakage gas discharge pipeline of the low-pressure cylinder; the A6 flange and B6 flange of the high-pressure cylinder are connected to serve as the primary seal leakage gas discharge pipeline of the high-pressure cylinder; the A5 flange and B5 flange of the high-pressure cylinder are connected to serve as the secondary seal leakage gas discharge pipeline of the high-pressure cylinder; the A4 flange and B4 flange of the high-pressure cylinder are connected to serve as the tertiary seal leakage gas discharge pipeline of the high-pressure cylinder; The first-level seal leakage gas discharge pipeline of the low-pressure cylinder and the first-level seal leakage gas discharge pipeline of the high-pressure cylinder send the seal leakage gas back to the inlet of the first section of the compressor. After the second-level seal leakage gas discharge pipeline of the low-pressure cylinder and the second-level seal leakage gas discharge pipeline of the high-pressure cylinder are connected, the seal leakage gas is returned to the inlet of the first section of the compressor through the ejector. The third-level seal leakage gas discharge pipeline of the low-pressure cylinder and the third-level seal leakage gas discharge pipeline of the high-pressure cylinder are vented.
2. A carbon dioxide centrifugal compressor sealing gas exhaust system according to claim 1, characterized in that: the inlet of the third stage of the compressor and the inlet of the fourth stage of the compressor are connected by a balance pipe.
3. A carbon dioxide centrifugal compressor sealing gas discharge system according to claim 1, characterized in that: the compressor low-pressure cylinder is rotatably connected to the compressor stage one and the compressor stage two through a bearing, the compressor high-pressure cylinder is rotatably connected to the compressor stage three and the compressor stage four through a bearing, a seal is provided at the bearing connection, and isolation gas is communicated between the seal and the bearing.
4. A carbon dioxide centrifugal compressor sealing gas exhaust system according to claim 1, characterized in that: the outlet hot gas of the compressor stage 1 is supplied to the ejector after the low-pressure cylinder secondary sealing leakage gas exhaust pipeline and the high-pressure cylinder secondary sealing leakage gas exhaust pipeline are connected.
5. A carbon dioxide centrifugal compressor sealing gas exhaust system according to claim 1, characterized in that: the outlet hot gas supply of the second stage of the compressor is refluxed to the inlet of the third stage of the compressor, and the outlet hot gas supply of the third stage of the compressor is refluxed to the inlet of the fourth stage of the compressor.
6. A carbon dioxide centrifugal compressor sealing gas exhaust system according to claim 1, characterized in that valves are provided at the bottom of compressor stage one, compressor stage two, compressor stage three and compressor stage four.
7. A carbon dioxide centrifugal compressor sealing gas discharge system according to claim 1, characterized in that: the low-pressure cylinder three-stage sealing leakage gas discharge pipeline and the high-pressure cylinder three-stage sealing leakage gas discharge pipeline are vented at a high position.