Negative pressure helium oil injection screw compressor with positive pressure helium protection seal
By using a positive pressure helium protection sealing mechanism at the sealing point of the negative pressure helium oil injection screw compressor, a positive pressure helium atmosphere is formed, and the air leakage problem caused by seal failure in the negative pressure section is solved, which significantly improves the seal reliability and failure protection of the system.
Patent Information
- Application Number
- CN202422016368.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2025-06-06
- Estimated Expiration
- 2034-08-20
AI Technical Summary
Since the internal pressure of the negative pressure helium oil injection screw compressor is lower than the atmospheric pressure, the negative pressure section of the negative pressure helium oil injection screw compressor is likely to cause reverse leakage of atmospheric air when the seal fails, contaminating the entire helium closed circulation system.
A positive pressure helium protection sealing mechanism is adopted. By setting a positive pressure helium protection gas tank and a positive pressure sealing structure at the sealing point of the negative pressure helium intake pipeline, a positive pressure helium atmosphere is formed to prevent leakage of the external atmosphere.
Even if the seal or pressure transmitter seal fails, it can effectively prevent air leakage, avoid contamination of the entire closed helium circulation system, and improve the system's seal reliability and failure protection.
Smart Images
Figure CN222950068U_ABST
Abstract
Description
Technical field:
[0001] The utility model belongs to the technical field of screw compressors, and particularly relates to a negative-pressure helium oil-injected screw compressor with a positive-pressure helium protective seal. Background technology:
[0002] With the development of cutting-edge science and technology such as superconductivity, aerospace, and controlled nuclear fusion, as well as the demand for large scientific facilities such as free electron lasers, large hadron colliders, spallation neutron sources, superconducting accelerators, and synchrotron radiation sources, large cryogenic systems using helium as a working fluid are increasingly being used. One of the core equipment of large cryogenic systems is the helium oil-injected screw compressor. At the same time, helium oil-injected screw compressors are also used in large hydrogen-helium liquefaction systems, natural gas helium extraction, and fourth-generation nuclear island helium turbine shaft seal systems. Conventional helium oil-injected screw compressors are generally used in closed-loop systems. Relative to atmospheric pressure, they can be divided into positive pressure units (intake pressure is greater than or equal to atmospheric pressure) and negative pressure units (intake pressure is less than atmospheric pressure) according to the intake pressure value.
[0003] For helium oil-injected screw compressors with negative inlet pressure, there is a negative pressure part in the system section, that is, the internal pressure of this part of the pipeline system is always lower than the atmospheric pressure. Helium has a small molecular weight and is very easy to leak, so the design of each sealing point of the unit is also the difficulty and focus of the helium oil-injected screw compressor. The sealing design of the negative pressure section and the positive pressure section of the conventional negative pressure helium oil-injected screw compressor is consistent, which is the same as the sealing design of the positive pressure helium oil-injected screw compressor. For the positive pressure sealing section, since the internal pressure is higher than the atmospheric pressure, if there is a slight leak or serious failure at each sealing point, the helium inside the unit will only leak into the atmosphere in one direction; but for the negative pressure sealing section, if a conventional sealing form is used, since the internal pressure of the negative pressure section of the unit is lower than the atmospheric pressure, if there is a slight leak or serious failure at each sealing point, the air in the atmosphere will leak back to the negative pressure pipeline of the helium unit, so that the air is mixed into the entire helium closed circulation system, resulting in pollution of the entire helium unit and even the entire helium closed circulation system, seriously affecting the operation of the entire device.
[0004] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to a person skilled in the art. Utility model content:
[0005] The utility model aims to provide a negative pressure helium oil-injected screw compressor with a positive pressure helium protective seal, thereby overcoming the defects in the above-mentioned prior art.
[0006] To achieve the above-mentioned purpose, the utility model provides a negative-pressure helium-injected screw compressor with positive-pressure helium protection seal, comprising a negative-pressure helium inlet pipeline, a compressor main engine, a driving motor, a positive-pressure helium output pipeline, and a positive-pressure helium protection sealing mechanism, wherein the negative-pressure helium inlet pipeline and the positive-pressure helium output pipeline are respectively connected to the air inlet and the air outlet of the compressor main engine, and the driving motor is connected to the compressor main engine; an air inlet filter and an air inlet valve are arranged on the negative-pressure helium inlet pipeline, and an oil-gas separator and an air-cooled cooler are arranged on the positive-pressure helium output pipeline; the positive-pressure helium protection sealing mechanism comprises a positive-pressure helium protection gas tank and a positive-pressure sealing structure, and positive-pressure sealing structures are arranged on the sealing points of each flange connection on the negative-pressure helium inlet pipeline, and the positive-pressure sealing structure is connected to the positive-pressure helium protection gas tank, so that a positive-pressure helium atmosphere is formed at the sealing points of each flange connection to prevent external atmosphere from leaking into the negative-pressure helium inlet pipeline.
[0007] Preferably, in the technical solution, the positive pressure sealing structure includes an inner O-ring, an outer O-ring, an inner ring groove, an outer ring groove, a V-shaped ring groove, and a positive pressure helium interface. The sealing point is two matching flanges, and an inner ring groove, an outer ring groove, and a V-shaped ring groove are arranged on the sealing surface of one of the flanges. The inner ring groove is located on the negative pressure helium side inside the flange, and the outer ring groove is located on the atmospheric environment side outside the flange. The V-shaped ring groove is located between the inner ring groove and the outer ring groove. The inner O-ring is arranged in the inner ring groove, and the outer O-ring is arranged in the outer ring groove. A positive pressure helium interface is arranged on the outer circle of the flange, the V-shaped ring groove is connected to the positive pressure helium interface, the positive pressure helium interface is connected to the positive pressure helium protection gas tank, and the V-shaped ring groove is filled with positive pressure helium to form a sealing structure of "double O-rings + positive pressure helium atmosphere" at the sealing surface of the matching flange.
[0008] Preferably, in the technical solution, the positive-pressure helium protection sealing mechanism also includes a gas tank pressure transmitter and a helium replenishing circuit. The gas tank pressure transmitter is arranged on the positive-pressure helium protection gas tank, the helium replenishing circuit is arranged between the positive-pressure helium protection gas tank and the positive-pressure helium output pipeline, the helium replenishing circuit is provided with a throttling orifice plate and a solenoid valve, and the connecting part between the helium replenishing circuit and the positive-pressure helium output pipeline is located after the outlet of the air-cooled cooler; the helium pressure in the positive-pressure helium protection gas tank is detected by the gas tank pressure transmitter, and the helium is replenished in time.
[0009] Preferably, in the technical solution, a unit air intake pressure transmitter and a main engine air intake pressure transmitter are arranged in the positive-pressure helium protective gas tank, the unit air intake pressure transmitter and the main engine air intake pressure transmitter are located in the positive-pressure helium atmosphere, the unit air intake pressure transmitter and the main engine air intake pressure transmitter are connected to the negative-pressure helium air intake pipeline through pressure-leading pipelines, respectively, and the pressure-leading pipelines are connected to the negative-pressure helium air intake pipelines and the positive-pressure helium protective gas tanks at the joints by welding; wherein the pressure-leading pipeline of the unit air intake pressure transmitter is located in front of the air intake filter, and the pressure-leading pipeline of the main engine air intake pressure transmitter is located behind the air intake valve.
[0010] Preferably, in the technical solution, the negative pressure helium oil-injected screw compressor with a positive pressure helium protective seal also includes a lubricating oil return pipeline, the oil-gas separator is connected to the compressor host through the lubricating oil return pipeline, and an oil cooler and an oil filter are provided on the lubricating oil return pipeline.
[0011] Compared with the prior art, the utility model has the following beneficial effects:
[0012] The positive pressure helium protection sealing mechanism can effectively prevent air from leaking into the screw compressor system even if the seal or pressure transmitter itself fails, thereby avoiding contamination of the entire closed helium circulation system, greatly improving the system's sealing reliability and failure protection. The positive pressure helium protection gas tank has an independent positive pressure helium protection sealing structure design for each sealing gasket on the negative pressure helium inlet pipeline, greatly improving the reliability of the negative pressure seal. Description of the drawings:
[0013] Figure 1 This is a schematic diagram of the structure of a negative pressure helium oil-injected screw compressor with a positive pressure helium protective seal according to the utility model;
[0014] Figure 2 This is a schematic diagram of the positive pressure sealing structure of the utility model. Specific implementation method:
[0015] The specific implementation modes of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.
[0016] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.
[0017] like Figure 1As shown, a negative pressure helium oil-injected screw compressor with positive pressure helium protection seal comprises a negative pressure helium inlet pipeline, a compressor main unit 3, a drive motor 4, a positive pressure helium output pipeline, a positive pressure helium protection seal mechanism, and a lubricating oil recycling pipeline, wherein the negative pressure helium inlet pipeline and the positive pressure helium output pipeline are respectively connected to the air inlet and the air outlet of the compressor main unit 3, and the drive motor 4 is connected to the compressor main unit 3; an air inlet filter 1 and an air inlet valve 2 are arranged on the negative pressure helium inlet pipeline, an oil-gas separator 5 and an air-cooled cooler 7 are arranged on the positive pressure helium output pipeline, a minimum pressure valve 6 is arranged at the outlet of the oil-gas separator 5, and the minimum pressure valve 6 is connected to the positive pressure helium output pipeline; the positive pressure helium The gas protection sealing mechanism comprises a positive pressure helium protection gas tank 12, a positive pressure sealing structure, a gas tank pressure transmitter 13, and a helium replenishing circuit. The sealing points ①-⑦ of each flange connection on the negative pressure helium inlet pipeline are all provided with a positive pressure sealing structure; the gas tank pressure transmitter 13 is arranged on the positive pressure helium protection gas tank 12, the helium replenishing circuit is arranged between the positive pressure helium protection gas tank 12 and the positive pressure helium output pipeline, the helium replenishing circuit is provided with a throttling orifice plate 14 and a solenoid valve 15, and the connection part between the helium replenishing circuit and the positive pressure helium output pipeline is located after the outlet of the air-cooled cooler 7; the helium pressure in the positive pressure helium protection gas tank 12 is detected by the gas tank pressure transmitter 13, and the helium is replenished in time. The positive pressure helium protection gas tank 12 is provided with a unit intake pressure transmitter 11 and a main engine intake pressure transmitter 10. The unit intake pressure transmitter 11 and the main engine intake pressure transmitter 10 are located in a positive pressure helium atmosphere. The unit intake pressure transmitter 11 and the main engine intake pressure transmitter 10 are connected to the negative pressure helium intake pipeline through a pressure lead pipeline respectively. The connection between the pressure lead pipeline and the negative pressure helium intake pipeline and the positive pressure helium protection gas tank is ⑧- All are connected by welding; the pressure-inducing pipeline of the unit air intake pressure transmitter 11 is located in front of the air intake filter 1, and the pressure-inducing pipeline of the host air intake pressure transmitter 10 is located behind the air intake valve 2. The oil-gas separator 5 is connected to the compressor host 3 through the lubricating oil return pipeline, and the lubricating oil return pipeline is provided with an oil cooler 8 and an oil filter 9. The air cooler 7 and the oil cooler 8 are both connected to the cooling water pipeline.
[0018] like Figure 2As shown, the positive pressure sealing structure includes an inner O-ring 18, an outer O-ring 19, an inner ring groove 20, an outer ring groove 21, a V-shaped ring groove 22, and a positive pressure helium interface 23. The sealing points ①-⑦ are two matching flanges 16 and 17. An inner ring groove 20, an outer ring groove 21, and a V-shaped ring groove 22 are arranged on the sealing surface of one flange 17. The inner ring groove 20 is located on the negative pressure helium side of the flange 17, the outer ring groove 21 is located on the atmospheric environment side of the flange 17, and the V-shaped ring groove 22 is located between the inner ring groove 20 and the outer ring groove 21. Between the ring grooves 21, the inner O-ring 18 is arranged in the inner ring groove 20, and the outer O-ring 19 is arranged in the outer ring groove 21. A positive-pressure helium interface 23 is arranged on the outer circle of the flange 17, and the V-shaped ring groove 22 is connected to the positive-pressure helium interface 23. The positive-pressure helium interface 23 is connected to the positive-pressure helium protection gas tank 12. The V-shaped ring groove 22 is filled with positive-pressure helium, and a sealing structure of "double O-rings + positive-pressure helium atmosphere" is formed at the sealing surfaces of the matching flanges 16 and 17 to prevent external atmosphere from leaking into the negative-pressure helium inlet pipeline.
[0019] During operation, negative pressure (lower than atmospheric pressure) helium enters the compressor main unit 3 through the air intake filter 1 and the air intake valve 2, and mixes with the injected lubricating oil. The drive motor 4 drives the compressor main unit 3 to compress the oil-gas mixture. The compressed positive pressure oil-gas mixture is separated by the oil-gas separator 5. The separated compressed helium is sent to the air-cooled cooler 7 for cooling after passing through the minimum pressure valve 6, and then supplied to the outside; the oil separated by the oil-gas separator 5 is sent to the oil-cooled cooler 8 for cooling, and after cooling, it is filtered by the oil filter 9. The filtered lubricating oil is sprayed into the compressor main unit 3, thus completing the cycle.
[0020] The positive pressure helium gas protection tank 12 contains helium gas at a pressure of 1.5 bar (higher than atmospheric pressure), and the helium gas comes from the positive pressure helium gas output pipeline (after cooling). When the pressure in the positive pressure helium gas protection tank 12 is lower than 1.3 bar (the pressure value can be adjusted, but must be higher than atmospheric pressure), the solenoid valve 15 is powered on to open, and the positive pressure helium gas output pipeline replenishes helium gas to the positive pressure helium gas protection tank 12 through the solenoid valve 15 and the throttle orifice plate 14. When the pressure in the positive pressure helium gas protection tank 12 is higher than 1.8 bar (the pressure value can be adjusted), the solenoid valve 15 is closed, and the gas replenishment ends, thereby maintaining a certain purity and pressure of the helium gas in the positive pressure helium gas protection tank 12.
[0021] The positive pressure helium protection sealing mechanism can effectively prevent air from leaking into the screw compressor system even if the seal or pressure transmitter itself fails, thereby avoiding contamination of the entire closed helium circulation system, greatly improving the system's sealing reliability and failure protection. The positive pressure helium protection gas tank has an independent positive pressure helium protection sealing structure design for each sealing gasket on the negative pressure helium inlet pipeline, greatly improving the reliability of the negative pressure seal.
[0022] The foregoing description of specific exemplary embodiments of the utility model is for the purpose of illustration and illustration. These descriptions are not intended to limit the utility model to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the utility model and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the utility model and various different options and changes. The scope of the utility model is intended to be defined by the claims and their equivalents.
Claims
1. A negative pressure helium oil-injected screw compressor with positive pressure helium protection seal, comprising a negative pressure helium inlet pipeline, a compressor mainframe, a drive motor, a positive pressure helium output pipeline, and a positive pressure helium protection seal mechanism, wherein the negative pressure helium inlet pipeline and the positive pressure helium output pipeline are respectively connected to the air inlet and the air outlet of the compressor mainframe, and the drive motor is connected to the compressor mainframe; an air inlet filter and an air inlet valve are arranged on the negative pressure helium inlet pipeline, and an oil-gas separator and an air-cooled cooler are arranged on the positive pressure helium output pipeline; characterized in that: The positive-pressure helium protection sealing mechanism comprises a positive-pressure helium protection gas tank and a positive-pressure sealing structure. The positive-pressure sealing structure is arranged at each flange-connected sealing point on the negative-pressure helium inlet pipeline. The positive-pressure sealing structure is connected to the positive-pressure helium protection gas tank to form a positive-pressure helium atmosphere at each flange-connected sealing point.
2. The negative pressure helium oil-injected screw compressor with positive pressure helium protective seal according to claim 1, characterized in that: The positive pressure sealing structure includes an inner O-ring, an outer O-ring, an inner ring groove, an outer ring groove, a V-shaped ring groove, and a positive pressure helium interface. The sealing point is two matching flanges, one of which is provided with an inner ring groove, an outer ring groove, and a V-shaped ring groove on its sealing surface. The inner ring groove is located on the negative pressure helium side inside the flange, and the outer ring groove is located on the atmospheric environment side outside the flange. The V-shaped ring groove is located between the inner ring groove and the outer ring groove. The inner O-ring is arranged in the inner ring groove, and the outer O-ring is arranged in the outer ring groove. A positive pressure helium interface is arranged on the outer circle of the flange, the V-shaped ring groove is connected to the positive pressure helium interface, the positive pressure helium interface is connected to the positive pressure helium protection gas tank, and the V-shaped ring groove is filled with positive pressure helium to form a sealing structure of "double O-rings + positive pressure helium atmosphere" at the sealing surface of the matching flange.
3. The negative pressure helium oil-injected screw compressor with positive pressure helium protective seal according to claim 1, characterized in that: The positive-pressure helium protection sealing mechanism also includes a gas tank pressure transmitter and a helium replenishment circuit. The gas tank pressure transmitter is arranged on the positive-pressure helium protection gas tank. The helium replenishment circuit is arranged between the positive-pressure helium protection gas tank and the positive-pressure helium output pipeline. A throttling orifice plate and a solenoid valve are arranged on the helium replenishment circuit. The connection part between the helium replenishment circuit and the positive-pressure helium output pipeline is located after the outlet of the air-cooled cooler.
4. The negative pressure helium oil-injected screw compressor with positive pressure helium protective seal according to claim 1, characterized in that: The positive-pressure helium protective gas tank is equipped with a unit intake pressure transmitter and a main engine intake pressure transmitter. The unit intake pressure transmitter and the main engine intake pressure transmitter are located in a positive-pressure helium atmosphere. The unit intake pressure transmitter and the main engine intake pressure transmitter are connected to the negative-pressure helium intake pipeline through pressure-leading pipelines respectively. The pressure-leading pipelines are connected to the negative-pressure helium intake pipelines and the positive-pressure helium protective gas tanks by welding. The pressure-leading pipeline of the unit intake pressure transmitter is located in front of the intake filter, and the pressure-leading pipeline of the main engine intake pressure transmitter is located behind the intake valve.
5. The negative pressure helium oil-injected screw compressor with positive pressure helium protective seal according to claim 1, characterized in that: The negative pressure helium oil-injected screw compressor with positive pressure helium protective seal also includes a lubricating oil return pipeline, the oil-gas separator is connected to the compressor host through the lubricating oil return pipeline, and an oil cooler and an oil filter are arranged on the lubricating oil return pipeline.