Compact air-cooled helium compressor

Abstract

The invention discloses a compact air-cooled helium compressor which comprises a vortex pressing bag, a liquid spraying cooling pipe arranged in a high-pressure cavity in the vortex pressing bag and an air-cooled heat exchanger connected with an exhaust port of the vortex pressing bag. Under the control of the variable flow adjusting device, the gas and the liquid are fully mixed into an oil-gas mixture through the gas-liquid mixing atomizer, the oil-gas mixture enters the vortex pressing bag from the liquid spraying cooling pipe, high-temperature gas in the vortex disc is cooled, the power consumption and the compression ratio of the vortex pressing bag are reduced, the requirement for the maximum heat exchange amount of the air-cooled heat exchanger is lowered, and therefore the design size of the heat exchanger is reduced. When the compressor continuously works, the pressure difference between the air inlet pressure and the exhaust pressure of the compressor is lower than the set minimum value, the variable flow adjusting device is closed, helium and lubricating oil enter the vortex pressing bag from the air return opening, and then the helium and the lubricating oil are exhausted after being cooled through the air cooling heat exchanger. And a new thought is provided for compact design of the helium compressor.

Description

Technical Field

[0001] The present invention relates to the technical field of scroll helium compressors, and in particular to a compact air-cooled helium compressor. Background Art

[0002] Currently, in ultra-low temperature industrial and commercial applications, lightweight and portable equipment are urgently needed due to limited installation space. Traditional compressors are typically large and require water cooling, which takes up a lot of space. The design concept of compact compressors is to achieve efficient operation in limited spaces through optimized structure and reduced size.

[0003] In recent years, the common approach to achieving compact compressor design has been to reduce the size of the compressor's internal tank. This approach, by reducing the size of the adsorber, oil separator, or buffer tank, allows for a more compact component layout within the compressor. However, reducing compressor size requires comprehensive optimization across multiple dimensions, including design, materials, and technological innovation. It also requires balancing key performance indicators such as compression efficiency, heat dissipation, and reliability. Simply reducing the compressor's internal tank size is not enough. A small-sized helium compressor that meets both heat dissipation requirements and a balanced compression ratio is urgently needed. Summary of the Invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a compact air-cooled helium compressor that uses a liquid spray cooling pipe to introduce high-pressure, low-temperature helium into a vortex pressure pack, thereby reducing the heat exchange demand of the compressor and thus reducing the size of the air-cooled heat exchanger.

[0005] Technical solution: The present invention provides a compact air-cooled helium compressor, comprising a scroll pack and an air-cooled heat exchanger connected to the exhaust port of the scroll pack. A liquid spray cooling pipe is provided on the scroll disk of the scroll pack. The high-pressure helium discharged from the exhaust port is heat exchanged in the air-cooled heat exchanger, and then enters the scroll pack from the liquid spray cooling pipe through a second variable flow regulating device. The opening of the second variable flow regulating device is controlled according to the pressure difference between the compressor intake pressure and the exhaust pressure.

[0006] Furthermore, the scroll pack features a return port that feeds the oil-air mixture into the scroll disc. This port connects to the helium compressor's intake pipe and oil separator. Gas-liquid mixing atomizers are installed at both the return port and the liquid spray cooling pipe to promote thorough atomization of the oil-air mixture, enhancing the cooling and protective properties of the lubricating oil.

[0007] Preferably, the jet nozzle of the liquid cooling pipe is located in the mid- and high-pressure chambers of the scroll disk. This allows the high-pressure, low-temperature oil-air mixture to enter the scroll disk of the vortex compressor under the action of a pressure differential. It is then mixed with the oil-air mixture entering from the return air port before being compressed, separated, and discharged. This prevents backflow of the oil-air mixture, while minimizing power consumption in the compressor and improving efficiency.

[0008] Furthermore, the compact air-cooled helium compressor also includes an oil drain port arranged below the exhaust port of the scroll pressure package. The oil drain port is arranged below the oil level in the scroll pressure package. It is an improvement on the conventional horizontal air-conditioning Freon pressure package. An oil drain port is added to the bottom of the scroll pressure package. The oil drain port is located below the oil level, which can meet the needs of an independent circulating oil circuit and realize the transformation of the Freon pressure package into a helium pressure package.

[0009] Furthermore, the lubricating oil discharged from the oil drain port is heat exchanged in the air-cooled heat exchanger, and then enters the vortex pressure package from the spray cooling pipe through the first variable flow regulating device. The opening of the first variable flow regulating device is controlled according to the pressure difference between the compressor intake pressure and exhaust pressure.

[0010] Furthermore, the lubricating oil discharged from the oil discharge port is heated by the air-cooled heat exchanger and then enters the vortex pressure pack from the return air port through the first fixed flow regulating device.

[0011] Furthermore, the compact air-cooled helium compressor includes a temperature monitoring system that adjusts the fan speed of the air-cooled heat exchanger based on temperature differentials. The temperature monitoring system includes a first temperature sensor for monitoring the surface temperature of the air-cooled heat exchanger, a second temperature sensor for monitoring the helium temperature before heat exchange, and a second temperature sensor for monitoring the helium temperature after heat exchange. Upper and lower temperature limits are programmable. When these limits are exceeded, the system adjusts the fan speed based on the differential to correct the error. In extreme cases, an alarm signal may be issued or the compressor may even shut down.

[0012] Furthermore, a scroll disk driving component is provided in the scroll pressure package, and the driving component includes a left rotating shaft, a motor rotor, a motor stator coil, a silicon steel sheet, a right rotating shaft and an oil suction port provided at one end of the right rotating shaft. The oil suction port sucks in the lubricating oil deposited at the bottom of the scroll pressure package to lubricate the driving component.

[0013] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) A liquid spray cooling pipe is used to introduce helium and part of the lubricating oil into the high-pressure cavity of the vortex disk, thereby cooling the high-temperature gas in the vortex disk, reducing the power consumption of the vortex compressor, reducing the bypass loss of the compressor, and improving the efficiency of the compressor in the cooling stage; (2) The exhaust temperature of the vortex compressor is reduced, the required maximum heat exchange amount is reduced, and the workload of the air-cooled heat exchanger can be reduced, thereby reducing the fin area of ​​the air-cooled heat exchanger from the selection point of view, reducing the overall size of the air-cooled heat exchanger, and realizing a compact design of the air-cooled compressor; (3) The cooling capacity provided at the lowest temperature is guaranteed to remain unchanged. When the compressor continues to work, the pressure difference between the compressor inlet pressure and the exhaust pressure is lower than the set minimum value, the variable flow control device is closed, and the helium and lubricating oil enter the vortex compressor from the return air port, and then are discharged after being cooled by the air-cooled heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1It is a structural schematic diagram of the present invention;

[0015] Figure 2 2 is a schematic structural diagram of a second embodiment of the present invention;

[0016] Figure 3 Schematic diagram of the structure of the scroll in the present invention;

[0017] Figure 4 The graphs show how the total power consumption of a device using the present invention changes with the startup time and how the total power consumption of a device using a conventional bypass loop changes with the startup time. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0019] First embodiment

[0020] like Figure 1 As shown, a compact air-cooled helium compressor 1 of the present invention includes a vortex pressure pack 2. The vortex pressure pack 2 adopts a horizontal high-pressure chamber vortex pressure pack. Compared with the traditional vertical vortex pressure pack, the size of the scroll disk is smaller, the overall size of the pressure pack is reduced, the space utilization rate of the compressor is increased, and the design requirements of the compact compressor are met. The vortex pressure pack 2 is provided with a return air port 3, a liquid spray cooling pipe 5, an exhaust port 13, and an oil discharge port 14. The vortex pressure pack 2 is provided with a scroll disk 5, an oil suction port 12 and a driving component. The driving component includes a left rotating shaft 7, a motor rotor 8, a motor stator coil 9, a silicon steel sheet 10, a right rotating shaft 11 and an oil suction port 12 provided at one end of the right rotating shaft. The oil suction port 12 sucks in the lubricating oil deposited at the bottom of the vortex pressure pack 2 to lubricate the driving component.

[0021] The scroll disk of the vortex compressor is as follows Figure 3 As shown, the scroll consists of a fixed scroll and a moving scroll, which mesh with each other. Both scrolls have a spiral profile and are mounted eccentrically and 180° apart. Reference 6a denotes the medium- and high-pressure chambers within the scroll. High-pressure helium introduced by the liquid cooling pipe enters the scroll through reference 6a, where it mixes with the existing medium- and high-pressure helium and continues to be compressed before being discharged into the high-pressure chamber at reference 6b.

[0022] The air circuit system of the compact air-cooled helium compressor 1 is as follows: low-pressure helium enters through the air supply pipe 35 and the air inlet pipe 34. The air supply pipe 35 and the air inlet pipe 34 are connected to one end of the second pressure sensor 31. The second pressure sensor 31 is used to monitor the intake pressure of the compressor. The pressure gauge 33 is connected to the intake pipe 34. The other end of the second pressure sensor 31 is connected to one end of the buffer tank 29, and the other end of the buffer tank 29 is connected to one end of the first gas-liquid mixing atomizer 21. The helium is mixed with the lubricating oil in this section, and then enters the first gas-liquid mixing atomizer 21 for full mixing and atomization. It then enters the vortex pressure pack 2 from the return air port 3. The helium is compressed in the vortex disk 6 of the vortex pressure pack 2. When compressed to an intermediate pressure, it is mixed with the high-pressure, low-temperature oil and gas mixture introduced from one end of the liquid spray cooling pipe 5. The mixed oil and gas mixture continues to be compressed to a high pressure in the vortex disk 6. After the helium is separated by gravity, it is discharged from one end of the exhaust port 13.

[0023] The other end of the exhaust port 13 is connected to one end of a second temperature sensor 23, which is used to monitor the temperature of the helium before heat exchange. After the helium enters the air-cooled heat exchanger 19 from the exhaust port 13 for heat exchange and cooling, a portion of the helium passes through the second variable flow control device 26 and enters the medium- and high-pressure chamber of the vortex compressor 2 from the liquid spray cooling pipe 5. A second gas-liquid mixing atomizer 22 is provided at the liquid spray cooling pipe 5 to fully mix the oil and gas. Another portion of the helium passes through the oil separator 30 and adsorber 37 and is discharged through the exhaust pipe 36. The oil separator is used to separate oil mist from the helium, and the adsorber is used to absorb the oil carried by the helium at the oil separator outlet. A safety valve 32 is also provided between the oil separator 30 and the adsorber 37 to release pressure to the atmosphere when the gas pressure is excessive.

[0024] The air-cooled heat exchanger 19 is connected to a fan 24, which rotates to cool the high-temperature helium and lubricating oil at the ladle outlet. A first temperature sensor 20 is also installed on the air-cooled heat exchanger 19 to monitor its surface temperature. A third temperature sensor 15 is located at the outlet of the air-cooled heat exchanger 19 to monitor the temperature of the helium after heat exchange. Upper and lower temperature limits are programmable. If the range is exceeded, the system adjusts the fan speed based on the difference to correct the difference. In extreme cases, an alarm signal may be issued or the system may even shut down.

[0025] A first pressure sensor 27 is installed before the oil separator 30 to monitor the compressor's exhaust pressure. A second pressure sensor 31 is located in the intake line to monitor the compressor's intake pressure. The pressure differential between the first and second pressure sensors serves as a signal to control the opening of the second variable flow control device, reintroducing the low-temperature, high-pressure helium lost in the bypass back into the medium- and high-pressure chambers of the pressure pack.

[0026] To further reduce the compressor's heat exchange, the present invention also improves the oil circuit system. After separation by the oil separator 30, the lubricating oil enters the second filter 28 to remove impurities from the returned oil. It then flows through the second fixed flow regulator 38 and rejoins the gas system, along with the low-pressure helium gas, into the return air port 3. After being pressurized by the scroll 6, the oil and gas mixture separates under gravity. The lubricating oil flows rightward through the gap between the motor rotor 8 and the motor stator coil 9, and between the motor stator silicon steel sheet 10 and the housing 4 of the scroll pack 2. Finally, it settles at the right bottom of the scroll pack 2, forming a relatively stable oil level. This process absorbs some of the heat from the motor, cooling it. A portion of the lubricating oil deposited at the bottom of the scroll pack 2 is drawn in through the oil intake 12 on the right rotating shaft 11. The oil intake duct 12 extends downward to below the oil level and flows leftward along the left rotating shaft 7 to lubricate the drive components of the scroll 6. A further portion of the lubricating oil exits the scroll pack 2 through the oil discharge port 14. The oil discharge port 14 should be set below the exhaust port 13 and above the pipe opening of the oil suction port 12. There is no ready-made interface between the oil discharge port 14 and the vortex pressure package 2, and it is necessary to open a hole by yourself.

[0027] The lubricating oil discharged from the oil discharge port is cooled by heat exchange in the air-cooled heat exchanger 19. A portion of the low-temperature lubricating oil is filtered for impurities by the first filter 17, the flow rate is adjusted by the first variable flow control device 15, and it is fully mixed by the second gas-liquid mixing atomizer 22 before entering the vortex compression package through the liquid spray cooling pipe 5. The remaining portion of the lubricating oil enters the vortex compression package from the return air port 3 through the first fixed flow control device 16 and the first gas-liquid mixing atomizer 21.

[0028] When the compressor is first started, the refrigerant material in the cold head is cooling down. At this point, the high-low pressure differential between the compressor and the compressor exceeds the system's maximum differential pressure, and the first and second variable flow control devices activate under the control of the pressure differential signal. High-pressure helium lost during operation is mixed with some high-pressure lubricating oil through a bypass and introduced into the medium- and high-pressure chambers of the vortex pack. Throughout the cycle, helium discharged from the cold head passes through a buffer tank, enters the vortex pack, mixes with high-pressure helium in the liquid spray cooling pipe, and is discharged through the exhaust port. After cooling in the air-cooled heat exchanger, some helium bypasses the liquid spray cooling pipe and returns to the vortex pack. The remaining helium passes through an oil separator and adsorber before entering the cold head. The lubricating oil is discharged through the oil drain port, passes through a filter, and is then directed to the liquid spray cooling pipe under the control of the first variable flow control device. The remaining lubricating oil passes through the first gas-liquid mixing atomizer and enters the pack. The lubricating oil separated by the oil separator passes through a second filter and enters the intake manifold. Compared with the press package without liquid spray cooling pipe, the total power consumption will be reduced by about 5%-10%. In addition, the exhaust temperature of the mixed helium will be lower than the temperature without liquid spray cooling, so the maximum heat exchange will be reduced.

[0029] When the compressor continues to operate and the refrigerant material in the cold head cools to its lowest temperature, the density of some helium in the cold head increases, causing it to concentrate there. This reduces the circulating helium pressure and the power consumption of the compression package. At this point, the maximum pressure differential falls below the programmed minimum value of the variable flow control device, and both the first and second variable flow control devices are closed. Due to the reduced compressor power consumption, the heat exchange rate of the air-cooled heat exchanger decreases. Helium, after exiting the cold head, passes through the buffer tank and enters the vortex compression package, where it mixes with the high-pressure helium in the liquid spray cooling pipe. It is then discharged from the exhaust port. After cooling in the air-cooled heat exchanger, it passes through the oil separator and adsorber before entering the cold head. Lubricating oil is discharged from the oil drain port and mixed with helium at the return air port. The lubricating oil separated by the oil separator passes through the second filter and the first gas-liquid mixing atomizer before entering the intake manifold.

[0030] During the cold head cooling stage, bypass loss will occur because the high and low pressure difference of the compressor is greater than the maximum pressure difference designed for the system. Figure 4 The figure shows how the total power consumption of the compressor changes over time for both a conventional bypass circuit and one using a liquid spray cooling pipe. As can be seen, the use of a liquid spray cooling pipe to direct lost helium into the high-pressure chamber of the scroll reduces the power consumption of the compressor, minimizes compressor bypass losses, and improves compressor efficiency during the cooling phase. Furthermore, when the cold head reaches its lowest temperature and the first and second flow control devices are closed, the overall power consumption of the compressor remains unchanged, ensuring that the cold head's cooling capacity remains unchanged while improving efficiency.

[0031] Second embodiment

[0032] like Figure 4 As shown, the layout of the compressor's gas circuit has been modified. Lubricating oil adsorbed by the oil separator is introduced into the liquid spray cooling pipe loop. The first variable flow control device is removed. Instead, all lubricating oil cooled by the air-cooled heat exchanger is throttled through the first fixed flow control device, mixed with helium, and then introduced into the return air pipe. This embodiment optimizes the flow control device and some piping in the oil system, simplifying the equipment while reducing the weight and size of the compressor.

Claims

1. A compact air-cooled helium compressor, comprising a scroll compressor (2), an air-cooled heat exchanger (19) connected to an exhaust port (13) of the scroll compressor (2), characterized in that: A liquid spray cooling pipe (5) is provided on the vortex disk (6) of the vortex compression package (2). The high-pressure helium gas discharged from the exhaust port (13) is heat-exchanged in the air-cooled heat exchanger (19) and then enters the vortex compression package (2) from the liquid spray cooling pipe (5) through a second variable flow regulating device (26). The opening of the second variable flow regulating device (26) is controlled according to the pressure difference between the compressor intake pressure and the exhaust pressure.

2. The compact air-cooled helium compressor according to claim 1, characterized in that: The jet port of the liquid spray cooling pipe (5) is arranged at the middle and high pressure cavity of the vortex disk (6).

3. The compact air-cooled helium compressor according to claim 1, characterized in that: The vortex compressor (2) is also provided with a return air port (3) for sending the oil-gas mixture into the vortex disk (6); the return air port (3) is connected to the air inlet pipe (34) of the helium compressor and the oil separator (30).

4. The compact air-cooled helium compressor according to claim 3, characterized in that: The air return port (3) and the liquid spray cooling pipe (5) are both provided with gas-liquid mixing atomizers.

5. The compact air-cooled helium compressor according to claim 1, characterized in that: It also includes an oil discharge port (14) arranged below the exhaust port (13) of the vortex compression package (2). The lubricating oil discharged from the oil discharge port (14) is mixed with helium after heat exchange in the air-cooled heat exchanger (19) and re-enters the vortex compression package (2).

6. The compact air-cooled helium compressor according to claim 5, characterized in that: The oil discharge port (14) is arranged below the oil level in the vortex pressure pack (2).

7. The compact air-cooled helium compressor according to claim 5, characterized in that: The lubricating oil discharged from the oil discharge port (14) is heat-exchanged in the air-cooled heat exchanger (19) and then enters the vortex pressure package (2) from the liquid spray cooling pipe (5) through the first variable flow regulating device (15). The opening of the first variable flow regulating device (15) is controlled according to the pressure difference between the intake pressure and the exhaust pressure of the compressor.

8. The compact air-cooled helium compressor according to claim 5, characterized in that: The lubricating oil discharged from the oil discharge port (14) is heat-exchanged in the air-cooled heat exchanger (19) and then enters the vortex pressure pack (2) from the return air port (3) through the first fixed flow regulating device (16).

9. The compact air-cooled helium compressor according to claim 1, characterized in that: The scroll pack (2) is provided with a scroll disk driving component, the driving component comprising a left rotating shaft (7), a motor rotor (8), a motor stator coil (9), a silicon steel sheet (10), a right rotating shaft (11), and an oil suction port (12) provided at one end of the right rotating shaft, the oil suction port (12) sucking in lubricating oil deposited at the bottom of the scroll pack (2) to lubricate the driving component.

10. The compact air-cooled helium compressor according to claim 1, characterized in that: The invention also includes a temperature monitoring system for adjusting the rotation speed of a fan (24) of an air-cooled heat exchanger (19) by a temperature difference, wherein the temperature monitoring system includes a first temperature sensor (20) for monitoring the surface temperature of the air-cooled heat exchanger (19), a second temperature sensor (23) for monitoring the temperature of helium before heat exchange, and a second temperature sensor (25) for monitoring the temperature of helium after heat exchange.

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