Oil-lubricated helium compressor with self-protection function

Abstract

The application belongs to the technical field of scroll helium compressors, and particularly relates to an oil-lubricated helium compressor with a self-protection function, which comprises a scroll compression package, the scroll compression package comprising a driving motor, a bearing, an oil discharge port and a scroll disc; the driving motor is arranged in the interior of the scroll compression package and divides the interior of the scroll compression package into an oil-gas cavity and an oil cavity, the oil-gas cavity is located in the space between the driving motor and the top of the scroll compression package, and the oil cavity is located in the bottom space of the scroll compression package; the bearing penetrates through the driving motor, one end of the bearing is connected with the scroll disc, the other end of the bearing faces the bottom of the scroll compression package, the bottom of the bearing is provided with a rotating shaft oil suction port, and at least one oil discharge port is formed in the side wall of the oil cavity of the scroll compression package; the rotating shaft oil suction port has a preset interval to the bottom of the shell of the scroll compression package, and the oil discharge port is located between below the driving motor and above the oil discharge port. The application establishes a constraint condition for the position of the oil discharge port at the bottom of the scroll compression package, and combines a temperature measuring device to improve the reliability and service life of the scroll compression package.

Description

Technical Field

[0001] This invention belongs to the technical field of scroll helium compressors, and more specifically, relates to an oil-lubricated helium compressor with self-protection function. Background Technology

[0002] In a helium refrigeration system, cooling is achieved through the compression and expansion cycle of a gas using a helium refrigerator. The helium refrigerator includes a compressor, a heat exchanger, and a helium storage tank. Specifically, the helium gas is compressed by the compressor, increasing both its pressure and temperature. Then, the high-pressure, high-temperature helium gas is cooled by the heat exchanger, followed by a rapid drop in pressure and temperature via an expansion valve. Finally, the low-temperature, low-pressure helium gas is used again to recover heat and reheat through the heat exchanger, completing a full refrigeration cycle.

[0003] Helium refrigeration compressors typically employ helium scroll compressors. During helium compression, these compressors require a large amount of lubricating oil to be injected into the scroll plate, increasing the power consumption of the drive motor. Compared to ordinary air conditioning scroll compressors, the rated power consumption of the drive motor in a helium scroll compressor increases by 30% to 50%, resulting in a significant increase in heat generation. Existing helium scroll compressors suffer from the following problems: the high-temperature, high-pressure oil-gas mixture compressed by the scroll plate is directly discharged outside the compressor casing, leaving the casing cavity pressureless. Some compressors require an external lubrication system (pipelines, oil pump, and oil reservoir) to lubricate the bearings and ensure compressor lifespan. A failure in this system can damage the compressor due to poor lubrication. External lubrication systems also increase space requirements and maintenance costs. Other compressors pre-store a certain amount of lubricating oil at the bottom of the compressor casing and pump it into the bearings. However, this system cannot continuously supply lubricating oil to the bearings when the pre-stored oil is depleted, also leading to compressor damage. Compressor failures result in significant economic losses, thus necessitating a helium compressor that can address existing problems and improve the reliability and lifespan of helium compressors. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes an oil-lubricated helium compressor with self-protection function. By establishing constraints on the position of the oil outlet at the bottom of the scroll compressor and using a temperature measuring device, the reliability and lifespan of helium compression using the scroll compressor, especially the high-pressure chamber scroll compressor, are improved.

[0005] To achieve the technical objectives of this invention, the following technical solutions will be adopted:

[0006] A self-protecting oil-lubricated helium compressor includes a scroll compressor, which comprises a drive motor, bearings, an oil drain port, and a scroll plate. The drive motor is located inside the scroll compressor and divides the interior of the scroll compressor into an oil-gas chamber and an oil chamber. The oil-gas chamber is located in the space between the drive motor and the top of the scroll compressor, and the oil chamber is located in the bottom space of the scroll compressor. There is a gap between the drive motor and the inner wall of the scroll compressor.

[0007] The bearing passes through the drive motor, with one end closed and connected to the scroll plate, and the other end facing the bottom of the scroll press. The bottom of the bearing is provided with a shaft oil suction port, and the oil chamber side wall of the scroll press has at least one oil discharge port. The oil-gas chamber side wall of the scroll press has an air outlet.

[0008] The scroll plate includes a fixed scroll plate and a moving scroll plate. The fixed scroll plate is fixed to the inner wall of the scroll pressurizer, and the moving scroll plate is connected to the bearing. The fixed and moving scroll plates are eccentrically arranged and installed facing each other. The scroll profiles of the fixed and moving scroll plates have a phase angle difference. The meshing line and sidewall surfaces of the fixed and moving scroll plates form multiple compressed oil-gas mixture volumetric cavities. A channel communicating with the volumetric cavities is provided at the top of the scroll pressurizer. The oil-gas mixture enters the volumetric cavity of the scroll plate through the channel at the top of the scroll pressurizer. The bearing drives the moving scroll plate to rotate relative to the fixed scroll plate, compressing the oil-gas mixture in the volumetric cavity of the scroll plate.

[0009] The scroll plate has an exhaust passage and an oil discharge passage. The exhaust passage and the oil discharge passage are two collinear openings on the side walls of the fixed scroll plate and the moving scroll plate, arranged from the middle to the outer edge. After the fixed scroll plate and the moving scroll plate rotate and compress to a certain extent, the two openings on the side walls of the fixed scroll plate and the moving scroll plate are aligned. The high-temperature and high-pressure oil-gas mixture after compression enters the scroll pressure tank through the exhaust passage and the oil discharge passage. The high-temperature and high-pressure oil-gas mixture is located in the oil-gas chamber of the scroll pressure tank and is discharged through the exhaust port under high pressure. The high-temperature and high-pressure lubricating oil is deposited at the bottom of the scroll pressure tank along the gap between the drive motor and the inner wall of the scroll pressure tank. The internal pressure of the bearing is lower than the external pressure. Under the action of pressure, the high-temperature and high-pressure lubricating oil enters the bearing through the oil suction port of the rotating shaft for lubrication. When the lubricating oil level at the bottom of the scroll pressure tank is higher than the height of the oil discharge port, the lubricating oil is discharged from the oil discharge port under high pressure.

[0010] There is a preset distance between the oil suction port of the rotating shaft and the bottom of the housing of the vortex press, and the oil discharge port is located between the bottom of the drive motor and the top of the oil discharge port, so that the oil suction port of the rotating shaft always has lubricating oil.

[0011] Furthermore, the height from the bottom of the drive motor to the bottom of the scroll press is H1, the height from the oil outlet to the bottom of the scroll press is H3, and the height from the bottom of the shaft oil inlet to the bottom of the scroll press is H4, where H4 < H3 < H1.

[0012] Furthermore, the oil chamber of the vortex press contains lubricating oil, and the optimal level of the lubricating oil is determined by the height of H3:

[0013] Furthermore, the reliability of the bearing is determined by the height H3 from the oil drain port to the bottom of the scroll compressor:

[0014] Furthermore, within the preferred height range of H3, multiple oil drain ports are provided on the side wall of the oil cavity of the vortex pressure pack, and the multiple oil drain ports are arranged in parallel.

[0015] Furthermore, the vortex press also includes an oil and gas pipe, one end of which is inserted into the vortex press and communicates with the compression chamber of the vortex disk, while the other end extends out of the vortex press.

[0016] Furthermore, the oil-lubricated helium compressor with self-protection function also includes a buffer tank, a heat exchanger assembly, an oil-gas separator, and an adsorber.

[0017] The oil and gas pipes are connected to the buffer tank and the heat exchanger assembly respectively through pipelines, and the connecting pipelines between the oil and gas pipes and the buffer tank and the heat exchanger assembly are interconnected; the side wall of the oil and gas chamber of the vortex pressure pack is provided with an air outlet, and the air outlet is connected to the heat exchanger assembly through a pipeline. The heat exchanger assembly is connected to the oil and gas separator through a pipeline. The oil and gas separator is connected to the adsorber. One end of the external low-temperature refrigeration equipment is connected to the adsorber, and the other end is connected to the buffer tank.

[0018] Furthermore, the oil-gas separator is connected to the buffer tank and the oil-gas pipeline respectively via two pipelines; a check valve and a solenoid valve are installed in parallel on the pipeline connecting the oil-gas separator and the buffer tank.

[0019] Furthermore, the oil-lubricated helium compressor with self-protection function also includes a temperature sensor, which is installed on the connecting pipe between the outlet and the heat exchanger assembly.

[0020] Furthermore, the high-temperature and high-pressure lubricating oil in the oil chamber of the vortex pressurizer enters the heat exchanger assembly through the oil outlet and is cooled. After being mixed with helium gas from the buffer tank to the oil-gas pipeline, it enters the oil-gas pipeline. The mixed oil and gas in the oil-gas chamber of the vortex pressurizer enters the heat exchanger assembly through the gas outlet and is cooled. After being cooled, it enters the oil-gas separator. The lubricating oil separated by the oil-gas separator enters the buffer tank to the oil-gas pipeline and is mixed. The helium gas of the residual lubricating oil separated by the oil-gas separator enters the adsorber for purification and is then transported to the external cryogenic refrigeration equipment. After being expanded by the external cryogenic refrigeration equipment, it returns to the buffer tank.

[0021] The beneficial effects of this invention are:

[0022] First, the bearing bottom of the vortex press of the present invention is provided with a rotating shaft oil suction port, and there is a preset distance between the rotating shaft oil suction port and the bottom of the shell of the vortex press. The oil discharge port is located between the bottom of the drive motor and the top of the oil discharge port. By establishing a constraint condition on the position of the oil discharge port at the bottom of the vortex press, and in conjunction with a temperature measuring device, the reliability and life of compressing helium using the vortex press, especially the high-pressure chamber vortex press, are improved.

[0023] Second, in the preferred implementation, the height from the bottom of the drive motor to the bottom of the scroll compressor is H1, the height from the oil outlet to the bottom of the scroll compressor is H3, and the height from the bottom of the shaft oil inlet to the bottom of the scroll compressor is H4. This is defined by... This ensures that the lubricating oil in the vortex pressure chamber is at the optimal level;

[0024] Third, in the preferred implementation method, by defining The bearings of the vortex press can ensure that they can draw in a sufficient amount of lubricating oil to meet the requirements for long-term reliable operation.

[0025] Fourth, in the preferred implementation, the temperature sensor is installed on the connecting pipe between the outlet and the heat exchanger assembly. When the lubricating oil inside the scroll compressor is insufficient, and the lubricating oil level at the bottom of the scroll compressor is lower than H3 but higher than H4, the scroll compressor can operate normally, but the lubricating oil cannot be cooled by external oil circulation. The scroll compressor will rapidly increase its operating temperature, and the exhaust temperature of the helium in the scroll compressor exhaust pipe will also increase. When the temperature sensor detects that the exhaust temperature has reached the set value, the system stops working to prevent the internal lubricating oil interface of the scroll compressor from falling below the height of the scroll compressor bearing oil suction port, causing internal lubrication failure and compressor burnout. This ensures that the helium compressor can ensure smooth oil suction at the shaft oil suction port during both normal and abnormal processes, and that the scroll compressor can operate normally. Furthermore, when the liquid level in the scroll compressor drops to an abnormal state, the system can be stopped in time to protect the service life of the scroll compressor.

[0026] Fifth, in the preferred implementation, the mixed oil and gas entering the scroll plate of the present invention is in a low temperature and low pressure state, which can cool and lubricate the scroll plate, reduce the temperature generated during the compression process, and keep the compression temperature within the allowable limit. The heat generated by the compression of the scroll plate is absorbed by the lubricating oil and the temperature rises, which creates a pressure difference with the mixed oil and gas entering the scroll plate. The high and low pressure difference of the lubricating oil drives the lubricating oil to circulate, eliminating the need to add an oil pump drive, saving the component layout space of the helium compressor, and reducing the component cost.

[0027] Sixth, in a preferred embodiment, the buffer tank and the oil-gas separator of the present invention are connected by a helium bypass pipeline, and a one-way valve and a solenoid valve are installed in parallel on the helium bypass pipeline. The one-way valve and the solenoid valve play a role in pressure control and pressure balancing of the helium compressor system. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of an oil-lubricated helium compressor with self-protection function according to an embodiment of the present invention;

[0029] Figure 2 This is a cross-sectional view of the scroll disk according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the structure of the vortex press according to an embodiment of the present invention.

[0031] Wherein, A-Lubricating oil level; 1-Vortex pressure pack; 10-Vortex disk; 100-Fixed vortex disk; 101-Moving vortex disk; 102-Volume cavity; 11-Bearing; 12-Motor coil; 13-Rotor; 14-Oil-gas pipe; 15-Temperature sensor; 16-Exhaust pipe; 17-Oil outlet; 18-Rotor shaft oil suction port; 2-Buffer tank; 20-Inlet pipe; 3-Heat exchanger assembly; 30-Throttle; 31-Filter; 32-First oil inlet pipe; 4-Oil separator; 40-Second oil inlet pipe; 5-Adsorber. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solutions of this application, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] The directional terms such as above, below, left, right, front, and back used in this application are based on the positional relationships shown in the attached drawings. Different attached drawings may result in different positional relationships, therefore they should not be interpreted as limitations on the scope of protection.

[0034] In this application, the terms "installation," "connection," "interlocking," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, or a connection that allows communication between components. They can also refer to a direct connection or an indirect connection through an intermediate medium. They can refer to the internal connection of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0035] See the attached instruction manual. Figure 1-2The oil-lubricated helium compressor with self-protection function in this embodiment includes a scroll compressor 1, a buffer tank 2, a heat exchanger assembly 3, an oil-gas separator 4, an adsorber 5, auxiliary pipelines, and control valves. The scroll compressor 1 includes a scroll plate 10, a bearing 11, a motor coil 12, a rotor 13, an oil-gas pipe 14, a temperature sensor 15, an exhaust pipe 16, an oil outlet 17, a shaft oil inlet 18, a stator, and a housing. The buffer tank 2 includes an inlet pipe 20. The heat exchanger assembly 3 includes a throttle 30, a filter 31, and a first oil inlet pipe 32.

[0036] The scroll disk 10 includes a fixed scroll disk 100 and a moving scroll disk 101. The fixed scroll disk 100 and the moving scroll disk 101 are eccentrically arranged and installed facing each other. The phase angle difference between the scroll profiles of the fixed scroll disk 100 and the moving scroll disk 101 is 180°. The meshing line and side wall surface of the fixed scroll disk 100 and the moving scroll disk 101 form a plurality of volume cavities 102. The plurality of volume cavities 102 are used to compress the oil-gas mixture. The scroll disk 10 has an exhaust passage and an oil discharge passage. The exhaust passage is used to discharge the intermediate pressure of the volume chamber 102, and the oil discharge passage is used to discharge the high-temperature oil-gas mixture after compression in the volume chamber 102. The side walls of the fixed scroll disk 100 and the moving scroll disk 101 are provided with two openings with collinear central axes arranged from the middle to the outer edge. When the fixed scroll disk 100 and the moving scroll disk 101 are swirling and compressing, the two openings on the side walls of the fixed scroll disk 100 and the moving scroll disk 101 are aligned and form the exhaust passage and the oil discharge passage respectively. That is, the exhaust passage and the oil discharge passage extend from the center of the scroll disk 10 to its outer edge and penetrate the fixed scroll disk 100 and the moving scroll disk 101 respectively.

[0037] The fixed scroll 100 is fixed to the inner wall of the scroll press 1 housing, and the moving scroll 101 is connected to the bearing 11, which drives the moving scroll 101 to rotate. The motor coil 12, rotor 13 and stator constitute the drive motor of the scroll press 1. The drive motor divides the interior of the scroll press 1 into an interconnected oil chamber and an oil-gas chamber. The oil chamber is located at the bottom of the oil-gas chamber, so that the oil settles at the bottom of the inner cavity of the scroll press 1 housing, while the oil-gas floats at the top of the inner cavity of the scroll press 1 housing. The drive motor and the inner wall of the scroll press 1 have a gap for the lubricating oil to flow to the bottom of the scroll press 1.

[0038] The bearing 11 passes through the rotor 13, with one end closed and connected to the moving scroll 101 of the scroll plate 10, and the other end facing the bottom of the casing of the scroll press 1. The bottom of the bearing 11 is provided with a shaft oil suction port 18, and there is a preset distance between the shaft oil suction port 18 and the bottom of the casing of the scroll press 1. The interior of the bearing 11 has a channel connecting the bearing 11 and the shaft oil suction port 18. This channel is used to deliver the lubricating oil sucked in by the shaft oil suction port 18 to the bearing 11 for lubrication.

[0039] One end of the oil-gas pipe 14 is inserted into the shell of the vortex pressure tank 1 and communicates with multiple volume chambers 102 of the vortex disk 10. The other end extends out of the shell of the vortex pressure tank 1 and is connected to the buffer tank 2 and the heat exchanger assembly 3 through the air inlet pipe 20 and the first oil inlet pipe 32, respectively. An oil drain port 17 is provided on the side wall of the oil chamber of the vortex pressure tank 1. The oil drain port 17 is connected to the heat exchanger assembly 3 through an oil pipe and then connected to the oil-gas pipe 14 through the connection end of the first oil inlet pipe 32. A filter 31 and a throttle 30 are installed sequentially from the end of the heat exchanger assembly 3 to the oil-gas pipe 14. After being cooled and filtered by the heat exchanger assembly 3 and the filter 31, the lubricating oil mixes with the gas entering the intake pipe 20 from the buffer tank 2 and then enters the oil-gas pipe 14, and then enters the multiple volume chambers 102 of the scroll plate 10. The oil-gas mixture in the multiple volume chambers 102 is compressed by the rotating scroll plate 101 relative to the stationary scroll plate 100. The oil-gas mixture changes from low temperature and low pressure to high temperature and high pressure. The high temperature and high pressure oil-gas mixture enters the shell of the scroll pressure pack 1 through the exhaust passage and oil discharge passage of the scroll plate 10.

[0040] An outlet is provided on the side wall of the oil-gas chamber of the vortex press 1. The outlet is connected to the heat exchanger assembly 3 through an exhaust pipe 16. A temperature sensor 15 is installed on the exhaust pipe 16. The temperature sensor 15 is used to determine the temperature of the outlet helium to determine the cooling status of the vortex press 1. The high-temperature and high-pressure oil-gas mixture compressed by the vortex disk 10 enters the exhaust pipe 16 through the outlet of the oil-gas chamber of the vortex press 1, and then enters the heat exchanger assembly 3. The high-temperature and high-pressure lubricating oil compressed by the vortex disk 10 flows along the gap between the drive motor and the inner wall of the vortex press 1 to the bottom of the shell of the vortex press 1 and deposits. Then, it enters the heat exchanger assembly 3 through the exhaust pipe 16 to dissipate heat and enters the oil-gas separator 4 through the pipeline.

[0041] Since the mixed oil and gas entering the scroll plate 10 is in a low temperature and low pressure state, it can cool and lubricate the scroll plate 10, reduce the temperature generated during the compression process, and keep the compression temperature within the allowable limits. Because the top of the bearing 11 is sealed (the bearing 11 is filled with lubricating oil before installation to prevent air bubbles from being present, so that when the lubricating oil is consumed, the oil suction port 18 on the shaft below the bearing 11 can replenish the lubricating oil in time), and the bottom of the oil inlet is equipped with the oil suction port 18 on the shaft, the oil-gas mixture compressed by the scroll plate 10 is in a high temperature and high pressure state. The high temperature lubricating oil flows out from the scroll plate 10 and flows along the inner wall of the scroll pressure pack 1 to the bottom of the shell to deposit, so that the external pressure of the bearing 11 is greater than the internal pressure of the bearing 11. Under the action of high pressure, the lubricating oil enters the bearing 11 through the oil suction port 18 to lubricate the bearing 11. When the level of the lubricating oil exceeds the oil drain port 17, the high pressure lubricating oil enters the heat exchanger assembly 3 through the pipeline under the action of pressure; while the high temperature and high pressure oil-gas mixture floats above the drive motor and enters the exhaust pipe 16 from the air outlet on the side wall of the oil-gas chamber of the scroll pressure pack 1 under the action of high pressure. The heat generated by the compression of the scroll plate 10 is absorbed by the lubricating oil, causing its temperature to rise. This creates a pressure difference with the oil-gas mixture entering the scroll plate 10, driving the lubricating oil to circulate without the need for an additional oil pump. The high and low pressure difference also drives the oil-gas mixture sequentially into the heat exchanger assembly 3 and the oil-gas separator 4, again without the need for an additional gas pump. Furthermore, the high and low pressure difference allows the lubricating oil to directly enter the bearing 11, enabling self-priming without the need for an internal drive pump. The structure of the scroll compressor 1 saves space in the helium compressor's component layout, reducing component costs. The cost of retrofitting a commercially available, mass-produced air conditioning scroll compressor is approximately 10,000 yuan lower than that of an imported dedicated helium scroll compressor. The scroll compressor is a core component of the helium compressor and is generally not maintained; the entire unit is replaced when problems occur.

[0042] The oil-gas separator 4 is connected to the air inlet pipe 20 via the second oil inlet pipe 40, and is also connected to the buffer tank 2 and the adsorber 5 via related pipelines. The oil-gas separator 4 separates the mixed oil and gas. The separated lubricating oil enters the air inlet pipe 20 through the second oil inlet pipe 40 and mixes with the helium in the air inlet pipe 20 before entering the oil-gas pipe 14. A small amount of lubricating oil remains in the helium separated by the oil-gas separator 4, which enters the adsorber 5 through pipelines for further purification to ensure that the helium is at room temperature, high pressure, and high purity. The adsorber 5 is connected to a helium compressor, and the outlet of the helium compressor is connected to cryogenic refrigeration equipment such as the GM refrigerator cold head. The purified helium enters the cryogenic refrigeration equipment such as the GM refrigerator cold head through the outlet of the helium compressor. After expansion and work in the cryogenic refrigeration equipment such as the GM refrigerator cold head, the low-pressure helium enters the buffer tank 2 through pipelines for pressure stabilization, and the stabilized helium enters the air inlet pipe 20.

[0043] Preferably, the buffer tank 2 and the oil-gas separator 4 are connected by a helium bypass pipeline. A one-way valve and a solenoid valve are installed in parallel on the helium bypass pipeline. The one-way valve and the solenoid valve play a role in pressure control and pressure balancing of the helium compressor system.

[0044] Further, please refer to the appendix to the instruction manual. Figure 3 In this embodiment, the height from the bottom of the motor coil 12 to the bottom of the casing of the scroll pressure 1 is H1, the height from the lubricating oil level A to the bottom of the casing of the scroll pressure 1 is H2, the height from the oil drain port 17 to the bottom of the casing of the scroll pressure 1 is H3, and the height from the bottom of the shaft oil suction port 18 to the bottom of the casing of the scroll pressure 1 is H4. The lubricating oil at the bottom of the scroll pressure 1 is led out through the oil drain port 17 into an external heat exchanger for heat exchange. Height H3 determines the minimum value of the lubricating oil level A at the bottom of the scroll pressure 1. The minimum value of the lubricating oil level A must be greater than height H4. To ensure sufficient oil suction at the shaft oil suction port 18, the minimum value of the lubricating oil level A is...

[0045] When the height H2 of the lubricating oil level A at the bottom of the vortex press 1 is lower than the height H4 from the bottom of the oil suction port 18 of the rotating shaft to the bottom of the shell of the vortex press 1, the lubricating oil cannot be drawn out for heat exchange. At this time, the temperature of the exhaust pipe 16 rises rapidly. When the temperature sensor 15 detects that the temperature of the exhaust pipe 16 has risen to a preset value, the vortex press 1 stops working. At this time, the height H2 of the lubricating oil level A at the bottom of the vortex press 1 is always higher than the height H4 from the bottom of the oil suction port 18 of the rotating shaft to the bottom of the shell of the vortex press 1. With this structure in this embodiment, it can be ensured that the operating parts of the vortex press 1 always operate under oil lubrication, without dry friction due to lack of oil, thus ensuring the operational reliability and service life of the vortex press 1.

[0046] When the height H2 of the lubricating oil level A at the bottom of the vortex pressure tank 1 is too high, resulting in excessive lubricating oil at the bottom of the vortex pressure tank 1, the rotation of the drive motor causes the liquid surface to break, increasing the oil content in the helium gas at the outlet of the vortex pressure tank 1. This increases the filter load in the oil-gas separator 4, causing a decrease in filtration efficiency and shortening the service life of the adsorber 5. Therefore, the height H2 of the lubricating oil level A at the bottom of the vortex pressure tank 1 is limited to be lower than the height H1 from the bottom of the motor coil 12 to the bottom of the housing of the vortex pressure tank 1. That is, the height H4 from the bottom of the oil suction port 18 of the rotating shaft to the bottom of the housing of the vortex pressure tank 1 is less than H1. The height H4 of the oil discharge port 17 is set at a certain height. The following steps are taken to ensure smooth oil drainage.

[0047] In summary, the oil chamber of the vortex pressure pack 1 contains lubricating oil, and the optimal level of the lubricating oil is determined by the height of H3: The reliability of bearing 11 is determined by the height H3 from the oil drain port 17 to the bottom of the scroll pressure tank 1:

[0048] Preferably, multiple oil drain ports 17 are provided on the side wall of the oil cavity of the vortex pressure pack 1 within the preferred height range of H3, and the multiple oil drain ports 17 are arranged in parallel.

[0049] By employing this structure in this embodiment, by defining the height H2 of the lubricating oil level A at the bottom of the scroll compressor 1 as higher than the height H4 from the bottom of the oil inlet 18 to the bottom of the casing of the scroll compressor 1, a stable oil intake at the oil inlet 18 can be ensured. The initial level of the lubricating oil level A is determined by the amount of oil replenished. When the height H2 of the lubricating oil level A is greater than the height H3 from the oil outlet 17 to the bottom of the casing of the scroll compressor 1, the helium compressor system operates normally. When the oil separator fails, the lubricating oil decreases, or the initial oil replenishment is insufficient, the height of the lubricating oil level A falls below H2. At this time, the lubricating oil circulation of the helium compressor is poor, the temperature of the exhaust pipe 16 rises, and the system shuts down for protection. This ensures that the helium compressor can smoothly draw oil from the oil inlet 18 during both normal and abnormal processes, allowing the scroll compressor 1 to operate normally. Furthermore, when the liquid level in the scroll compressor 1 drops to an abnormal state, it can shut down in time to protect the service life of the scroll compressor 1.

[0050] The oil-lubricated helium compressor structure with self-protection function of the present invention has an internal pressure in the casing of the scroll compressor 1 that is greater than the internal pressure of the bearing 11, with a pressure difference between 15-17 barg, and possibly between 10-20 barg. The mixed oil and gas entering the scroll plate 10 generate a pressure difference, which drives the lubricating oil to circulate, eliminating the need for an additional oil pump. The high and low pressure difference of the lubricating oil drives the oil-gas mixture to sequentially enter the heat exchanger assembly 3 and the oil-gas separator 4, again eliminating the need for an additional gas pump. The high and low pressure difference of the lubricating oil allows it to directly enter the bearing 11, enabling the bearing 11 to achieve self-lubrication, eliminating the need for an internal drive pump. The structure of the scroll compressor 1 saves space for the helium compressor components, reducing component costs. The unit cost of the scroll compressor 1 of the present invention is 0.5 million yuan, while the unit cost of the existing helium scroll compressor structure is 30,000 yuan. Compared with the existing structure, the scroll compressor 1 of the present invention saves 2.5 million yuan in costs.

[0051] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics of the solutions is not described in detail here. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the present invention is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An oil-lubricated helium compressor with self-protection function, comprising a scroll compressor (1), the scroll compressor (1) comprising a drive motor, a bearing (11), an oil drain port (17), and a scroll plate; characterized in that, The drive motor is located inside the vortex press (1), and the interior of the vortex press (1) is divided into an oil-gas chamber and an oil chamber. The oil-gas chamber is located in the space between the drive motor and the top of the vortex press (1), and the oil chamber is located in the bottom space of the vortex press (1). There is a gap between the drive motor and the inner wall of the vortex press (1). The bearing (11) passes through the drive motor, with one end closed and connected to the scroll plate, and the other end facing the bottom of the scroll pressure pack (1); the bottom of the bearing (11) is provided with a rotating shaft oil suction port (18), and the oil chamber side wall of the scroll pressure pack (1) is provided with at least one oil discharge port (17); the oil and gas chamber side wall of the scroll pressure pack (1) is provided with an air outlet. The scroll disk includes a fixed scroll disk and a moving scroll disk. The fixed scroll disk is fixed to the inner wall of the scroll press (1), and the moving scroll disk is connected to the bearing (11). The fixed scroll disk and the moving scroll disk are eccentrically arranged and installed facing each other. The scroll profiles of the fixed scroll disk and the moving scroll disk have a phase angle difference. The meshing line and side wall surface of the fixed scroll disk and the moving scroll disk form multiple compressed oil-gas mixture volume chambers. The top of the scroll press (1) is provided with a channel communicating with the volume chambers. The oil-gas mixture enters the volume chamber of the scroll disk through the channel at the top of the scroll press (1). The bearing (11) drives the moving scroll disk to rotate relative to the fixed scroll disk and compress the oil-gas mixture in the volume chamber of the scroll disk. The scroll plate has an exhaust passage and an oil discharge passage. The exhaust passage and the oil discharge passage are two collinear openings on the side walls of the fixed scroll plate and the moving scroll plate, which are arranged from the middle to the outer edge. After the fixed scroll plate and the moving scroll plate are rotated and compressed to a certain extent, the two openings on the side walls of the fixed scroll plate and the moving scroll plate are aligned. The high-temperature and high-pressure oil-gas mixture after compression enters the scroll pressure tank (1) through the exhaust passage and the oil discharge passage. The high-temperature and high-pressure oil-gas mixture is located in the oil-gas chamber of the scroll pressure tank (1) and is discharged through the outlet under high pressure. High-temperature and high-pressure lubricating oil is deposited at the bottom of the vortex pressure tank (1) along the gap between the drive motor and the inner wall of the vortex pressure tank (1). The internal pressure of the bearing (11) is less than the external pressure. Under the action of pressure, the high-temperature and high-pressure lubricating oil enters the bearing (11) through the oil suction port (18) of the rotating shaft for lubrication. When the lubricating oil level at the bottom of the vortex pressure tank (1) is higher than the height of the oil discharge port (17), the lubricating oil is discharged from the oil discharge port (17) under high pressure. There is a preset distance between the oil suction port (18) of the rotating shaft and the bottom of the housing of the vortex pressure pack (1), and the oil discharge port (17) is located between the drive motor and the oil discharge port (17), so that the oil suction port (18) of the rotating shaft is always lubricated.

2. The oil-lubricated helium compressor with self-protection function according to claim 1, characterized in that, The height from the bottom of the drive motor to the bottom of the vortex press (1) is H1, the height from the oil outlet (17) to the bottom of the vortex press (1) is H3, and the height from the bottom of the shaft oil inlet (18) to the bottom of the vortex press (1) is H4, where H4 < H3 < H1.

3. The oil-lubricated helium compressor with self-protection function according to claim 2, characterized in that, The oil chamber of the vortex pressure chamber (1) contains lubricating oil, and the optimal level of the lubricating oil is determined by the height of H3:

4. The oil-lubricated helium compressor with self-protection function according to claim 2 or 3, characterized in that, The reliability of bearing (11) is determined by the height H3 from the oil drain port (17) to the bottom of the scroll pressure tank (1):

5. The oil-lubricated helium compressor with self-protection function according to claim 2, characterized in that, Multiple oil drain ports (17) are provided on the side wall of the oil cavity of the vortex pressure pack (1) within the preferred height range of H3, and the multiple oil drain ports (17) are arranged in parallel.

6. The oil-lubricated helium compressor with self-protection function according to claim 1, characterized in that, The vortex press (1) also includes an oil and gas pipe (14), one end of which is inserted into the vortex press (1) and communicates with the compression chamber of the vortex disk, and the other end extends out of the vortex press (1).

7. The oil-lubricated helium compressor with self-protection function according to claim 6, characterized in that, The oil-lubricated helium compressor with self-protection function also includes a buffer tank (2), a heat exchanger assembly (3), an oil-gas separator (4), and an adsorber (5); The oil and gas pipe (14) is connected to the buffer tank (2) and the heat exchanger assembly (3) through pipelines, and the connecting pipeline between the oil and gas pipe (14) and the buffer tank (2) and the connecting pipeline between the oil and gas pipe (14) and the heat exchanger assembly (3) are interconnected; the side wall of the oil and gas chamber of the vortex pressure pack (1) is provided with an outlet, and the outlet is connected to the heat exchanger assembly (3) through a pipeline. The heat exchanger assembly (3) is connected to the oil and gas separator (4) through a pipeline. The oil and gas separator (4) is connected to the adsorber (5). One end of the external low-temperature refrigeration equipment is connected to the adsorber (5), and the other end is connected to the buffer tank (2).

8. The oil-lubricated helium compressor with self-protection function according to claim 7, characterized in that, The oil-gas separator (4) is connected to the buffer tank (2) and the oil-gas pipe (14) of the buffer tank (2) via two pipelines respectively; a check valve and a solenoid valve are installed in parallel on the connecting pipeline between the oil-gas separator (4) and the buffer tank (2).

9. The oil-lubricated helium compressor with self-protection function according to claim 7, characterized in that, The oil-lubricated helium compressor with self-protection function also includes a temperature sensor, which is installed on the connecting pipe between the outlet and the heat exchanger assembly (3).

10. The oil-lubricated helium compressor with self-protection function according to claim 7, characterized in that, The high-temperature and high-pressure lubricating oil in the oil chamber of the vortex pressure pack (1) enters the heat exchanger assembly (3) through the oil outlet (17) and is cooled. After being cooled, it mixes with the helium in the pipeline from the buffer tank (2) to the oil-gas pipe (14) and then enters the oil-gas pipe (14). The mixed oil and gas in the oil-gas chamber of the vortex pressure pack (1) enters the heat exchanger assembly (3) through the gas outlet and is cooled. After being cooled, it enters the oil-gas separator (4). The lubricating oil separated by the oil-gas separator (4) enters the pipeline from the buffer tank (2) to the oil-gas pipe (14) and mixes. The helium in the residual lubricating oil separated by the oil-gas separator (4) enters the adsorber (5) for purification and is then transported to the external cryogenic refrigeration equipment. After being expanded by the external cryogenic refrigeration equipment, it returns to the buffer tank (2).

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