Sealing gas discharging system of carbon dioxide centrifugal compressor
By installing a leakage gas discharge pipeline and an injector in the carbon dioxide centrifugal compressor, the problem of leakage gas flowing from the high-pressure cylinder to the low-pressure cylinder was solved, resulting in reduced pressure in the low-pressure cylinder and reduced oil fumes, thus ensuring stable system operation and environmental protection.
Patent Information
- Application Number
- CN202520682036.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2035-04-11
AI Technical Summary
In the existing carbon dioxide centrifugal compressor sealing gas emission system, leakage gas from the high-pressure cylinder first stage flows to the low-pressure cylinder, resulting in a large leakage volume and excessively high pressure in the low-pressure cylinder. This causes oil fumes to be ejected from the bearing housing, polluting the environment and posing a fire hazard.
A novel sealed gas discharge system was designed. This system involves setting up a leakage gas discharge pipeline between the low-pressure cylinder and the high-pressure cylinder, using an ejector to send the secondary leakage gas back to the first inlet of the compressor, and directly venting the tertiary leakage gas. The system also incorporates a balance pipe to reduce the pressure at the fourth inlet of the compressor, uses an air seal to prevent lubricating oil contamination, and installs valves to prevent blockage.
It effectively reduces the leakage of air from the low-pressure cylinder, lowers the pressure, avoids oil fume emission and fire hazards, improves system stability and environmental quality, and saves resources.
Smart Images
Figure CN223894496U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of carbon dioxide centrifugal compressor technology, and in particular to a carbon dioxide centrifugal compressor sealing gas discharge system. Background Technology
[0002] Carbon dioxide centrifugal compressors are essential equipment in nitrogen fertilizer plants. The operating environment of these compressors typically requires fire and explosion protection, and ignition points must be prohibited. Existing carbon dioxide centrifugal compressor sealing gas discharge systems include primary sealing gas discharge for high and low pressure cylinders, secondary sealing gas discharge for secondary sealing gas, and tertiary sealing gas discharge for tertiary sealing gas.
[0003] However, during its use, leakage from the first stage of the high-pressure cylinder often flows into the low-pressure cylinder, causing a large amount of gas to enter the low-pressure cylinder. This results in a large amount of leakage from the low-pressure cylinder. The excessively high pressure of the leakage from the third-stage seal causes oil fumes to be carried out of the bearing housing, which not only pollutes the environment but also poses a fire hazard. Utility Model Content
[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a carbon dioxide centrifugal compressor sealing gas emission system.
[0005] To achieve the above objectives, this utility model provides the following technical solution: 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 a compressor section 1 and a compressor section 2; the compressor high-pressure cylinder is rotatably connected to a compressor section 3 and a compressor section 4, wherein compressor section 1 is sequentially connected to flanges A1, A2, and A3; compressor section 2 is sequentially connected to flanges B3, B2, and B1; compressor section 3 is sequentially connected to flanges A4, A5, and A6; and compressor section 4 is sequentially connected to flanges B6, B5, and B4. The connection between flanges A3 and B3 of the compressor low-pressure cylinder serves as the primary sealing leakage gas discharge pipeline for the low-pressure cylinder; the connection between flanges A2 and B2 of the low-pressure cylinder serves as the secondary sealing leakage gas discharge pipeline for the low-pressure cylinder. The discharge pipelines are as follows: the low-pressure cylinder A1 flange and B1 flange are connected to form the low-pressure cylinder third-stage seal leakage gas discharge pipeline; the high-pressure cylinder A6 flange and B6 flange are connected to form the high-pressure cylinder first-stage seal leakage gas discharge pipeline; the high-pressure cylinder A5 flange and B5 flange are connected to form the high-pressure cylinder second-stage seal leakage gas discharge pipeline; the high-pressure cylinder A4 flange and B4 flange are connected to form the high-pressure cylinder third-stage seal leakage gas discharge pipeline; the low-pressure cylinder first-stage seal leakage gas discharge pipeline and the high-pressure cylinder first-stage seal leakage gas discharge pipeline send the seal leakage gas back to the inlet of the compressor stage 1; the low-pressure cylinder second-stage seal leakage gas discharge pipeline and the high-pressure cylinder second-stage seal leakage gas discharge pipeline are connected to send the seal leakage gas back to the inlet of the compressor stage 1 through an ejector; the low-pressure cylinder third-stage seal leakage gas discharge pipeline and the high-pressure cylinder third-stage seal leakage gas discharge pipeline are vented.
[0006] As a further preferred embodiment of this utility model, 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. The balance pipe reduces the inlet pressure of the fourth stage of the compressor and reduces the force on one side.
[0007] As a further preferred embodiment of this utility model, the low-pressure cylinder of the compressor is rotatably connected to the first and second sections of the compressor via bearings, and the high-pressure cylinder of the compressor is rotatably connected to the third and fourth sections of the compressor via bearings. A seal is provided at the bearing connection, and an isolation gas is passed between the seal and the bearing as an air seal to prevent the process gas from being contaminated by the bearing lubricating oil.
[0008] As a further preferred embodiment of this invention, the hot gas outlet of the compressor is supplied to the injector after the low-pressure cylinder secondary seal leakage gas discharge pipeline and the high-pressure cylinder secondary seal leakage gas discharge pipeline are connected.
[0009] As a further preferred embodiment of this invention, the hot gas outlet of the second stage compressor is supplied to the inlet of the third stage compressor, and the hot gas outlet of the third stage compressor is supplied to the inlet of the fourth stage compressor.
[0010] The aforementioned hot gas prevents carbon dioxide from forming dry ice during throttling and pressure reduction, which could clog the pipeline.
[0011] As a further preferred embodiment of this utility model, valves are provided at the bottom of the first, second, third and fourth compressor sections. These valves are used to drain condensate, thereby emptying the compressor cavity and preventing blockage.
[0012] As a further preferred embodiment of this invention, 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 high levels to avoid pipeline blockage.
[0013] Technical effects and advantages of the utility model:
[0014] The system incorporates a three-stage leak-proof design: first-stage leakage gas from the high and low pressure cylinders returns to the first-stage inlet; second-stage leakage gas, after being balanced between the high and low pressure cylinders, is pushed to the first-stage inlet by the ejector; and third-stage leak-proof gas is vented at a high point in the discharge pipeline. This design reduces the amount of gas entering the second stage and lowers the pressure in the low-pressure cylinder. It prevents excessively high discharge pressure in the low-pressure cylinder from causing large amounts of oil fumes to be emitted from the bearing housing, thus avoiding environmental pollution and resource waste. This design improves the system's design, enhances environmental quality, and conserves resources. Furthermore, it eliminates fire hazards and provides users with a more stable operating guarantee. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of a carbon dioxide centrifugal compressor sealing gas emission system according to the present invention.
[0016] Figure 2This is a schematic diagram of the backflow structure of the secondary sealed leakage gas discharge pipeline in this utility model.
[0017] Figure 3 This is a schematic diagram of the low-pressure cylinder of the compressor in this utility model.
[0018] Figure 4 This is a schematic diagram of the high-pressure cylinder of the compressor in this utility model.
[0019] The attached diagram is labeled as follows: 1. Low-pressure cylinder primary seal leakage gas discharge line; 2. Low-pressure cylinder secondary seal leakage gas discharge line; 3. High-pressure cylinder secondary seal leakage gas discharge line; 4. Low-pressure cylinder tertiary seal leakage gas discharge line; 5. High-pressure cylinder primary seal leakage gas discharge line; 6. High-pressure cylinder tertiary seal leakage gas discharge line; 7. Injector; 8. Compressor low-pressure cylinder; 9. Compressor stage 1; 10. Compressor stage 2; 11. Compressor high-pressure cylinder; 12. Compressor stage 3; 13. Compressor stage 4; 14. Balance pipe. Detailed Implementation
[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0021] See appendix Figure 1-4As shown, a carbon dioxide centrifugal compressor sealing gas discharge system includes a compressor high-pressure cylinder 11 and a compressor low-pressure cylinder 8. The compressor low-pressure cylinder 8 is rotatably connected to a compressor stage 9 and a compressor stage 10. The compressor high-pressure cylinder 11 is rotatably connected to a compressor stage 12 and a compressor stage 13. Compressor stage 9 is sequentially connected to flanges A1, A2, and A3; compressor stage 10 is sequentially connected to flanges B3, B2, and B1; compressor stage 12 is sequentially connected to flanges A4, A5, and A6; and compressor stage 13 is sequentially connected to flanges B6, B5, and B4. The connection between flanges A3 and B3 of the compressor low-pressure cylinder 8 serves as the primary sealing gas discharge pipeline 1; the connection between flanges A2 and B2 of the low-pressure cylinder serves as the secondary sealing gas discharge pipeline 2. The connection between flanges A1 and B1 of the low-pressure cylinder serves as the third-stage sealing leakage gas discharge line 4 for the low-pressure cylinder. The connection between flanges A6 and B6 of the high-pressure cylinder serves as the first-stage sealing leakage gas discharge line 5 for the high-pressure cylinder. The connection between flanges A5 and B5 of the high-pressure cylinder serves as the second-stage sealing leakage gas discharge line 3 for the high-pressure cylinder. The connection between flanges A4 and B4 of the high-pressure cylinder serves as the third-stage sealing leakage gas discharge line 6 for the high-pressure cylinder. The first-stage sealing leakage gas discharge lines 1 and 5 of the low-pressure cylinder send the sealing leakage gas back to the inlet of the first stage 9 of the compressor. The second-stage sealing leakage gas discharge lines 2 and 3 of the low-pressure cylinder send the sealing leakage gas back to the inlet of the first stage 9 of the compressor through the ejector 7. The third-stage sealing leakage gas discharge lines 4 and 6 of the low-pressure cylinder vent the gas.
[0022] like Figure 1 and 4 As shown, in the embodiment of the utility model, the inlet of the compressor section 12 and the inlet of the compressor section 13 are connected by a balance pipe 14. The balance pipe 14 reduces the inlet pressure of the compressor section 13 and reduces the force on one side.
[0023] like Figure 1 As shown, in the embodiment of the utility model, the low-pressure cylinder 8 of the compressor is rotatably connected to the first stage 9 and the second stage 10 of the compressor via bearings, and the high-pressure cylinder 11 of the compressor is rotatably connected to the third stage 12 and the fourth stage 13 of the compressor via bearings. A seal is provided at the bearing connection, and the seal and the bearing are sealed by an isolation gas to prevent the process gas from being contaminated by the bearing lubricating oil.
[0024] like Figure 2 As shown, in the embodiment of the utility model, the hot gas from the outlet of the compressor section 9 is supplied to the injector 7, which is connected to the low-pressure cylinder secondary seal leakage gas discharge pipeline 2 and the high-pressure cylinder secondary seal leakage gas discharge pipeline 3.
[0025] like Figure 4As shown, in the utility model embodiment, the hot gas outlet of compressor section 10 is supplied back to the inlet of compressor section 12, and the hot gas outlet of compressor section 12 is supplied back to the inlet of compressor section 13. The above-mentioned hot gas prevents carbon dioxide from forming dry ice during throttling and pressure reduction, thus avoiding blockage of the pipeline.
[0026] like Figure 1 , 3 As shown in Figure 4, in the utility model embodiment, the bottom of the compressor section 9, compressor section 10, compressor section 12 and compressor section 13 are provided with valves. The valves are used to drain condensate and clean the compressor cavity to avoid blockage.
[0027] like Figure 2 As shown in the utility model embodiment, the low-pressure cylinder three-stage seal leakage gas discharge pipeline 4 and the high-pressure cylinder three-stage seal leakage gas discharge pipeline 6 are vented at high levels to avoid pipeline blockage.
[0028] During the operation of this utility model, the low-pressure cylinder primary sealing leakage gas discharge line 1 and the high-pressure cylinder primary sealing leakage gas discharge line 5 respectively send the sealing leakage gas back to the compressor section 9 inlet line. The low-pressure cylinder secondary sealing leakage gas discharge line 2 and the high-pressure cylinder secondary sealing leakage gas discharge line 3 are connected and send the sealing leakage gas back to the compressor section 9 inlet line through the ejector 7. Driven by the power gas, a large amount of leakage gas is recovered. The high-pressure cylinder secondary sealing leakage gas discharge line 3 and the high-pressure cylinder tertiary sealing leakage gas discharge line 6 respectively directly vent the sealing leakage gas.
[0029] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A sealing gas discharge system for a carbon dioxide centrifugal compressor, comprising a high-pressure cylinder and a low-pressure cylinder of the compressor, wherein the low-pressure cylinder is rotatably connected to a first compressor section and a second compressor section; the high-pressure cylinder is rotatably connected to a third compressor section and a fourth compressor section; the first compressor section is sequentially connected to flanges A1, A2, and A3; the second compressor section is sequentially connected to flanges B3, B2, and B1; the third compressor section is sequentially connected to flanges A4, A5, and A6; and the fourth compressor section is sequentially connected to flanges B6, B5, and B4, characterized in that: The connection between flanges A3 and B3 of the low-pressure cylinder serves as the primary sealing leakage gas discharge line for the low-pressure cylinder; the connection between flanges A2 and B2 serves as the secondary sealing leakage gas discharge line for the low-pressure cylinder; the connection between flanges A1 and B1 serves as the tertiary sealing leakage gas discharge line for the low-pressure cylinder; the connection between flanges A6 and B6 of the high-pressure cylinder serves as the primary sealing leakage gas discharge line for the high-pressure cylinder; the connection between flanges A5 and B5 of the high-pressure cylinder serves as the secondary sealing leakage gas discharge line for the high-pressure cylinder; and the connection between flanges A4 and B4 of the high-pressure cylinder serves as the tertiary sealing leakage gas discharge line for the high-pressure cylinder. The low-pressure cylinder primary seal leakage gas discharge line and the high-pressure cylinder primary seal leakage gas discharge line send the seal leakage gas back to the inlet of the compressor stage 1. The low-pressure cylinder secondary seal leakage gas discharge line and the high-pressure cylinder secondary seal leakage gas discharge line are connected and send the seal leakage gas back to the inlet of the compressor stage 1 through the ejector. The low-pressure cylinder tertiary seal leakage gas discharge line and the high-pressure cylinder tertiary seal leakage gas discharge line are vented.
2. The carbon dioxide centrifugal compressor sealing gas discharge system according to claim 1, characterized in that: the inlet of the third section of the compressor and the inlet of the fourth section 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 low-pressure cylinder of the compressor is rotatably connected to the first and second sections of the compressor via bearings, the high-pressure cylinder of the compressor is rotatably connected to the third and fourth sections of the compressor via bearings, a seal is provided at the bearing connection, and an isolation gas is supplied between the seal and the bearing.
4. A carbon dioxide centrifugal compressor sealing gas discharge system according to claim 1, characterized in that: the outlet hot gas of the first stage of the compressor is supplied to the injector after the low-pressure cylinder secondary sealing leakage gas discharge pipeline and the high-pressure cylinder secondary sealing leakage gas discharge pipeline are connected.
5. A carbon dioxide centrifugal compressor sealing gas discharge system according to claim 1, characterized in that: the hot gas outlet of the second stage of the compressor is supplied back to the inlet of the third stage of the compressor, and the hot gas outlet of the third stage of the compressor is supplied back to the inlet of the fourth stage of the compressor.
6. A carbon dioxide centrifugal compressor sealing gas discharge system according to claim 1, characterized in that: valves are provided at the bottom of compressor section one, compressor section two, compressor section three and compressor section 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 high level.