Bearing gas supply system and method of controlling the same

Abstract

The application provides a bearing gas supply system and a control method thereof. The bearing gas supply system comprises a bypass pipeline, one end of the bypass pipeline being communicated with an exhaust port of the evaporator, the other end of the bypass pipeline being communicated with a liquid discharge port of the evaporator; and an ejector device. The bearing gas supply system and the control method thereof provided by the application send gaseous refrigerant and / or liquid refrigerant at the evaporator to the bearing of the compressor by the ejector device, realize real-time control of the temperature and / or pressure at the bearing, ensure stable and safe operation of the bearing, reduce the motor cooling load, ensure the service life of the compressor, select gaseous refrigerant or liquid refrigerant of the evaporator according to the temperature control at the bearing, thereby realizing reliable adjustment of the temperature, control the refrigerant flow in the evaporator by the ejector device according to the gas supply pressure at the bearing, avoid excessively high pressure at the bearing to affect the operation stability of the bearing, and further improve the reliability of the bearing and the compressor.

Description

Technical Field

[0001] This invention relates to the field of compression equipment technology, and in particular to a bearing air supply system and its control method. Background Technology

[0002] In a static pressure air-suspended bearing air supply system, the stability of the supply air temperature and pressure is crucial to the stable operation and service life of the bearing. When the supply air temperature is too high, it reduces the viscosity of the refrigerant, decreasing the lubrication effect of the refrigerant gas film, thus increasing bearing wear and reducing bearing life. It also causes the already high-temperature bearing, due to high-speed operation, to continue heating up, increasing the cooling load on the motor. Furthermore, excessively high supply air pressure can also lead to unstable bearing operation, causing bearing damage and reducing bearing life. However, in existing air supply systems, liquid refrigerant is pumped from the bottom of the condenser and sent to a storage tank. In the storage tank, the liquid refrigerant is heated and evaporated by an electric heater into a high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant flows directly from the storage tank through radial and axial intake pipes to the compressor bearing for support and lubrication. This system cannot regulate the refrigerant temperature and pressure at the compressor bearing, resulting in decreased bearing stability and reduced bearing life. Summary of the Invention

[0003] To address the technical problems of decreased bearing operational stability and reduced bearing service life in existing technologies, a bearing gas supply system and its control method are provided, in which refrigerant is introduced into the evaporator to regulate the refrigerant temperature and / or refrigerant pressure.

[0004] A bearing gas supply system is used in a refrigerant heat exchange cycle, the refrigerant heat exchange cycle including a compressor, an evaporator, and a gas receiver, and the bearing gas supply system further includes:

[0005] A bypass pipe, one end of which is connected to the exhaust port of the evaporator, and the other end of which is connected to the liquid drain port of the evaporator;

[0006] An ejector device is provided, wherein the main ejector port of the ejector device is connected to the gas supply port of the gas storage tank, the ejected port of the ejector device is connected to the bypass pipeline, and the outlet of the ejector device is connected to the compressor.

[0007] The bearing gas supply system further includes a first on / off mechanism and a second on / off mechanism. The first on / off mechanism is located between the bypass pipeline and the exhaust port of the evaporator, and the second on / off mechanism is located between the bypass pipeline and the liquid drain port of the evaporator.

[0008] The bearing air supply system also includes a temperature detection device, which is mounted on the compressor and is electrically connected to the first on / off mechanism and / or the second on / off mechanism.

[0009] The compressor includes a radial bearing and an axial thrust bearing. The temperature detection device includes a first temperature detection mechanism and a second temperature detection mechanism. The first temperature detection mechanism is used to detect the air supply temperature at the axial thrust bearing, and the second temperature detection mechanism is used to detect the air supply temperature at the radial bearing. The first on / off mechanism can be controlled based on the detection results of the first temperature detection mechanism and / or the detection results of the second temperature detection mechanism; and / or, the second on / off mechanism can be controlled based on the detection results of the first temperature detection mechanism and / or the detection results of the second temperature detection mechanism.

[0010] The bearing air supply system also includes a flow regulating mechanism, which is disposed between the ejector device and the bypass pipeline.

[0011] The bearing air supply system also includes a pressure detection device, which is mounted on the compressor and electrically connected to the flow regulating mechanism.

[0012] The ejector device includes a first ejector mechanism and a second ejector mechanism, and the compressor includes a radial bearing and an axial thrust bearing;

[0013] The first ejector mechanism has a main ejector port connected to the gas supply port of the gas storage tank, an ejected port connected to the bypass pipeline, and an outlet connected to the position of the axial thrust bearing.

[0014] The second ejector mechanism has a main ejector port connected to the liquid supply port of the gas storage tank, an ejected port connected to the bypass pipeline, and an outlet connected to the radial bearing position.

[0015] The bearing air supply system further includes a first throttling mechanism and a second throttling mechanism. The first throttling mechanism is disposed between the ejector port of the first ejector mechanism and the bypass pipeline, and the second throttling mechanism is disposed between the ejector port of the second ejector mechanism and the bypass pipeline.

[0016] The pressure detection device includes a first pressure detection mechanism and a second pressure detection mechanism. The first pressure detection mechanism is used to detect the air supply pressure at the axial thrust bearing, and the second pressure detection mechanism is used to detect the air supply pressure at the radial bearing. The first throttling mechanism is electrically connected to the first pressure detection mechanism, and the second throttling mechanism is electrically connected to the second pressure detection mechanism.

[0017] A control method for the aforementioned bearing gas supply system, wherein the bearing gas supply system further includes a first on / off mechanism and a second on / off mechanism, the first on / off mechanism being disposed between the bypass pipeline and the exhaust port of the evaporator, and the second on / off mechanism being disposed between the bypass pipeline and the liquid drain port of the evaporator, the control method comprising:

[0018] Step S101: Obtain the real-time temperature T0 at the bearing of the compressor and determine whether T0 is within the preset temperature range X;

[0019] Step S102: If T0 is within the preset temperature range X and T0 is greater than the first preset value T1, then the first on / off mechanism is turned on and the second on / off mechanism is turned off.

[0020] The bearing air supply system further includes a pressure detection device, which is mounted on the compressor and electrically connected to the flow regulating mechanism. Step S102 further includes:

[0021] Step S201: Obtain the real-time air supply pressure A0 at the bearing of the compressor, and compare the real-time air supply pressure A0 with the preset pressure value A1;

[0022] Step S202: If A0 is greater than A1, then increase the opening degree of the flow regulation mechanism.

[0023] Following step S101, the method further includes:

[0024] If T0 is greater than Xmax, the second on / off mechanism is activated and the first on / off mechanism is deactivated, where Xmax is the maximum value in the preset temperature range X.

[0025] After the statement that if T0 is greater than Xmax, the second on / off mechanism is activated and the first on / off mechanism is deactivated, the following further includes:

[0026] Obtain the real-time pressure A0 at the compressor bearing and compare the real-time pressure A0 with the preset pressure value A1;

[0027] If A0 is greater than A1, then the opening degree of the flow regulation mechanism is increased.

[0028] The ejector device includes a first ejector mechanism, and the compressor includes an axial thrust bearing. The main ejector port of the first ejector mechanism is connected to the gas supply port of the gas storage tank, the ejected port of the first ejector mechanism is connected to the bypass pipeline, and the outlet of the first ejector mechanism is connected to the position of the axial thrust bearing. The bearing gas supply system further includes a first throttling mechanism, which is disposed between the ejected port of the first ejector mechanism and the bypass pipeline. The pressure detection device includes a first pressure detection mechanism, which is used to detect the gas supply pressure at the axial thrust bearing. The first throttling mechanism is electrically connected to the first pressure detection mechanism. The control method further includes:

[0029] Obtain the air supply pressure a0 at the axial thrust bearing of the compressor, and compare a0 with the preset axial pressure a1;

[0030] If a0 > a1, then adjust the opening degree of the first throttling mechanism.

[0031] The ejector device includes a second ejector mechanism, and the compressor includes a radial bearing. The main ejector port of the second ejector mechanism is connected to the liquid supply port of the gas storage tank, the ejected port of the second ejector mechanism is connected to the bypass pipeline, and the outlet of the second ejector mechanism is connected to the radial bearing. The bearing gas supply system further includes a second throttling mechanism, which is disposed between the ejected port of the second ejector mechanism and the bypass pipeline. The pressure detection device includes a second pressure detection mechanism, which is used to detect the gas supply pressure at the radial bearing. The second throttling mechanism is electrically connected to the second pressure detection mechanism. The control method further includes:

[0032] Obtain the air supply pressure b0 at the axial thrust bearing of the compressor, and compare b0 with the preset axial pressure b1;

[0033] If b0 > b1, then adjust the opening of the second throttling mechanism.

[0034] The bearing gas supply system and control method provided by this invention utilize an ejector device to deliver gaseous and / or liquid refrigerant from the evaporator to the compressor bearing, achieving real-time control of the temperature and / or pressure at the bearing. This ensures stable and safe bearing operation, reduces motor cooling load, and extends compressor lifespan. The system selects between gaseous and liquid refrigerant from the evaporator based on the bearing temperature, thus achieving reliable temperature regulation. Furthermore, the system controls the refrigerant flow rate within the evaporator obtained by the ejector device based on the bearing supply pressure, preventing excessive pressure at the bearing and ensuring bearing operational stability, thereby further improving the reliability of both the bearing and the compressor. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the bearing air supply system provided in an embodiment of the present invention;

[0036] In the picture:

[0037] 1. Compressor; 2. Evaporator; 3. Gas receiver; 4. Bypass pipeline; 5. First on / off mechanism; 6. Second on / off mechanism; 7. First ejector mechanism; 8. Second ejector mechanism; 9. First throttling mechanism; 10. Second throttling mechanism. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0039] like Figure 1 The bearing gas supply system shown is used in a refrigerant heat exchange cycle. The refrigerant heat exchange cycle includes a compressor 1, an evaporator 2, and a gas storage tank 3. The refrigerant heat exchange cycle also includes a condenser. High-temperature and high-pressure liquid refrigerant in the condenser is pumped to the gas storage tank 3. An electric heater in the gas storage tank 3 heats and evaporates the high-temperature and high-pressure liquid refrigerant into high-temperature and high-pressure gaseous refrigerant. Under the pressure difference between the gas storage tank 3 and the compressor 1, the heated high-temperature and high-pressure gaseous refrigerant flows from the gas storage tank 3 through the radial and axial inlet pipes to the compressor 1. The high-temperature and high-pressure gaseous refrigerant forms a gas film around the bearing in the compressor 1, which supports and lubricates the bearing, allowing it to operate stably. The bearing gas supply system further includes: a bypass pipe 4, one end of which is connected to the exhaust port of the evaporator 2, and the other end of which is connected to the liquid drain port of the evaporator 2; and an ejector device, the main ejector port of which is connected to the gas supply port of the gas storage tank 3, the ejected port of which is connected to the bypass pipe 4, and the outlet of which is connected to the compressor 1. The ejector device delivers gaseous and / or liquid refrigerant from the evaporator 2 to the bearing of the compressor 1, enabling real-time control of the temperature and / or pressure at the bearing, ensuring stable and safe bearing operation, reducing the motor cooling load, and extending the service life of the compressor 1.

[0040] When the bearing gas supply system is working, the ejector device can obtain gaseous and / or liquid refrigerant from the evaporator 2 through the bypass pipe 4, and under the gas supply of the gas tank 3, it is ejected to the bearing of the compressor 1. Thus, the gaseous and / or liquid refrigerant in the evaporator 2 can be mixed with the refrigerant in the gas tank 3 to achieve the purpose of regulating the refrigerant temperature and / or refrigerant pressure, thereby regulating the temperature and pressure at the bearing, ensuring the stable and safe operation of the bearing, reducing the motor cooling load, and ensuring the service life of the compressor 1.

[0041] Specifically, the bearing gas supply system further includes a first on / off mechanism 5 and a second on / off mechanism 6. The first on / off mechanism 5 is located between the bypass pipe 4 and the exhaust port of the evaporator 2, and the second on / off mechanism 6 is located between the bypass pipe 4 and the liquid drain port of the evaporator 2. The first on / off mechanism 5 controls whether the gaseous refrigerant in the evaporator 2 enters the bypass pipe 4, and the second on / off mechanism 6 controls whether the liquid refrigerant in the evaporator 2 enters the bypass pipe 4. The first on / off mechanism 5 and the second on / off mechanism 6 are not opened simultaneously to prevent the gaseous and liquid refrigerants in the evaporator 2 from being connected through the bypass pipe 4, thereby reducing the heat exchange effect of the evaporator 2.

[0042] The bearing air supply system also includes a temperature detection device, which is installed on the compressor 1 and electrically connected to the first on / off mechanism 5 and / or the second on / off mechanism 6. The temperature detection device detects and judges the temperature at the bearing of the compressor 1, and determines whether gaseous refrigerant or liquid refrigerant from the evaporator 2 is needed based on the judgment result. When gaseous refrigerant from the evaporator 2 is selected, since it is in a low-temperature, low-pressure state, when it mixes with the refrigerant in the gas storage tank 3, the sensible heat of the gaseous refrigerant in the evaporator 2 can cool the refrigerant in the gas storage tank 3, thereby achieving the purpose of regulating the temperature of the refrigerant entering the compressor 1. When liquid refrigerant is selected in evaporator 2, the liquid refrigerant will be heated by the refrigerant in gas tank 3 and turn into gaseous refrigerant when it mixes with the refrigerant in gas tank 3. During this process, the latent heat of liquid refrigerant can cool down the refrigerant in gas tank 3 (this cooling range is greater than that of gaseous refrigerant), thereby achieving the purpose of regulating the temperature of refrigerant entering compressor 1.

[0043] The compressor 1 includes a radial bearing and an axial thrust bearing. The temperature detection device includes a first temperature detection mechanism and a second temperature detection mechanism. The first temperature detection mechanism is used to detect the air supply temperature at the axial thrust bearing, and the second temperature detection mechanism is used to detect the air supply temperature at the radial bearing. The first on / off mechanism 5 can be controlled based on the detection results of the first temperature detection mechanism and / or the detection results of the second temperature detection mechanism; and / or, the second on / off mechanism 6 can be controlled based on the detection results of the first temperature detection mechanism and / or the detection results of the second temperature detection mechanism. The actual temperatures at the radial bearing and the axial thrust bearing are detected separately. If the actual temperature of either the radial bearing or the axial thrust bearing exceeds the preset temperature value, the working states of the first on / off mechanism 5 and the second on / off mechanism 6 are adjusted to mix the liquid refrigerant with the refrigerant in the gas tank 3, thereby significantly reducing the temperature of the refrigerant entering the radial bearing or the axial thrust bearing, thus achieving a significant cooling effect for both the radial bearing and the axial thrust bearing. Only when the actual temperatures of both the radial bearing and the axial thrust bearing are within their respective safe operating temperature ranges is the temperature controlled by mixing the gaseous refrigerant with the refrigerant in the gas tank 3, ensuring that both the radial bearing and the axial thrust bearing operate at their respective set temperature values.

[0044] The bearing gas supply system also includes a flow regulating mechanism, which is located between the ejector device and the bypass pipe 4. The flow regulating mechanism adjusts the refrigerant flow rate entering the ejector device to control the gas supply pressure reaching the bearing. When the gas supply pressure is too high, the refrigerant flow rate is increased, increasing the flow rate of low-pressure refrigerant in the evaporator 2. With the same amount of refrigerant, the amount of high-pressure refrigerant used in the gas storage tank 3 is reduced, effectively lowering the pressure. When the gas supply pressure is too low, the refrigerant flow rate is decreased, reducing the amount of low-pressure refrigerant used in the evaporator 2, thereby increasing the amount of high-pressure refrigerant used in the gas storage tank 3, effectively increasing the pressure. Specifically, the bearing gas supply system also includes a pressure detection device, which is located on the compressor 1 and electrically connected to the flow regulating mechanism. The pressure detection device is used to obtain the gas supply pressure at the bearing.

[0045] The ejector device includes a first ejector mechanism 7 and a second ejector mechanism 8. The compressor 1 includes a radial bearing and an axial thrust bearing. The first ejector mechanism 7 has its main ejector port connected to the gas supply port of the gas storage tank 3, its ejected port connected to the bypass pipeline 4, and its outlet connected to the axial thrust bearing. The second ejector mechanism 8 has its main ejector port connected to the liquid supply port of the gas storage tank 3, its ejected port connected to the bypass pipeline 4, and its outlet connected to the radial bearing. The first ejector mechanism 7 guides the refrigerant in the evaporator 2 to the axial thrust bearing, and the second ejector mechanism 8 guides the refrigerant in the evaporator 2 to the radial bearing, thereby achieving separate control of the gas supply to the radial bearing and the axial thrust bearing.

[0046] Specifically, the bearing air supply system further includes a first throttling mechanism 9 and a second throttling mechanism 10. The first throttling mechanism 9 is disposed between the ejector port of the first ejector mechanism 7 and the bypass pipe 4, and the second throttling mechanism 10 is disposed between the ejector port of the second ejector mechanism 8 and the bypass pipe 4. The first throttling mechanism 9 is used to adjust the amount of refrigerant supplied to the axial thrust bearing, thereby adjusting the air supply pressure at the axial thrust bearing. The second throttling mechanism 10 is used to adjust the amount of refrigerant supplied to the radial bearing, thereby adjusting the air supply pressure at the radial bearing.

[0047] The pressure detection device includes a first pressure detection mechanism and a second pressure detection mechanism. The first pressure detection mechanism is used to detect the air supply pressure at the axial thrust bearing, and the second pressure detection mechanism is used to detect the air supply pressure at the radial bearing. The first throttling mechanism 9 is electrically connected to the first pressure detection mechanism, and the second throttling mechanism 10 is electrically connected to the second pressure detection mechanism. The first throttling mechanism 9 is controlled and adjusted according to the air supply pressure of the axial thrust bearing, and the second throttling mechanism 10 is controlled and adjusted according to the air supply pressure of the radial bearing.

[0048] Another aspect of the present invention provides a control method for the above-described bearing air supply system, wherein the bearing air supply system further includes a first on / off mechanism 5 and a second on / off mechanism 6, the first on / off mechanism 5 being disposed between the bypass pipe 4 and the exhaust port of the evaporator 2, and the second on / off mechanism 6 being disposed between the bypass pipe 4 and the liquid drain port of the evaporator 2, the control method comprising:

[0049] Step S101: Obtain the real-time temperature T0 at the bearing of compressor 1, and determine whether T0 is within the preset temperature range X;

[0050] Step S102: If T0 is within the preset temperature range X and T0 is greater than the first preset value T1, then the first on / off mechanism 5 is turned on and the second on / off mechanism 6 is turned off.

[0051] When the real-time temperature T0 at the bearing is within the preset temperature range X, it indicates that the bearing is operating within a safe temperature range, and it can function normally without adjustment. However, to further improve bearing reliability, when T0 > T1, it indicates that the bearing temperature will still have a negative impact, meaning it has not reached the bearing's optimal operating temperature. In this case, a small temperature adjustment of the refrigerant in the gas tank 3 can be performed using the gaseous refrigerant in the evaporator 2. When T0 ≤ T1, the current operating state can be maintained.

[0052] The bearing air supply system further includes a pressure detection device, which is mounted on the compressor 1 and electrically connected to the flow regulating mechanism. Step S102 further includes:

[0053] Step S201: Obtain the real-time air supply pressure A0 at the bearing of compressor 1, and compare the real-time air supply pressure A0 with the preset pressure value A1;

[0054] Step S202: If A0 is greater than A1, then increase the opening degree of the flow regulation mechanism. By increasing the opening degree of the flow regulation mechanism, the amount of low-pressure refrigerant used in the evaporator 2 is increased. After mixing with the high-pressure refrigerant in the gas storage tank 3, the gas supply pressure can be reduced under the same refrigerant quantity.

[0055] Following step S101, the method further includes:

[0056] If T0 is greater than Xmax, the actual temperature at the bearing is already higher than the safe operating temperature range. In this case, the second on / off mechanism 6 is activated, and the first on / off mechanism 5 is closed. Xmax is the maximum value within the preset temperature range X. The low-temperature liquid refrigerant is mixed with the refrigerant in the gas tank 3. Utilizing the temperature and phase change of the liquid refrigerant, the temperature is significantly reduced, thereby lowering the actual temperature at the bearing to within the safe operating temperature range.

[0057] After the statement that if T0 is greater than Xmax, the second on / off mechanism 6 is activated and the first on / off mechanism 5 is deactivated, the following further includes:

[0058] Obtain the real-time pressure A0 at the bearing of compressor 1, and compare the real-time pressure A0 with the preset pressure value A1;

[0059] If A0 is greater than A1, the opening degree of the flow regulating mechanism is increased. By increasing the opening degree of the flow regulating mechanism, the amount of low-pressure refrigerant used in the evaporator 2 is increased. After mixing with the high-pressure refrigerant in the gas storage tank 3, the gas supply pressure can be reduced under the same refrigerant quantity.

[0060] The ejector device includes a first ejector mechanism 7, and the compressor 1 includes an axial thrust bearing. The main ejector port of the first ejector mechanism 7 is connected to the gas supply port of the gas storage tank 3, the ejected port of the first ejector mechanism 7 is connected to the bypass pipeline 4, and the outlet of the first ejector mechanism 7 is connected to the position of the axial thrust bearing. The bearing gas supply system also includes a first throttling mechanism 9, which is disposed between the ejected port of the first ejector mechanism 7 and the bypass pipeline 4. The pressure detection device includes a first pressure detection mechanism, which is used to detect the gas supply pressure at the axial thrust bearing. The first throttling mechanism 9 is electrically connected to the first pressure detection mechanism. The control method further includes:

[0061] Obtain the air supply pressure a0 at the axial thrust bearing of compressor 1, and compare a0 with the preset axial pressure a1;

[0062] If a0 > a1, then adjust the opening degree of the first throttling mechanism 9.

[0063] The ejector device includes a second ejector mechanism 8, and the compressor 1 includes a radial bearing; the main ejector port of the second ejector mechanism 8 is connected to the liquid supply port of the gas storage tank 3, the ejected port of the second ejector mechanism 8 is connected to the bypass pipeline 4, and the outlet of the second ejector mechanism 8 is connected to the radial bearing position. The bearing gas supply system also includes a second throttling mechanism 10, which is disposed between the ejected port of the second ejector mechanism 8 and the bypass pipeline 4. The pressure detection device includes a second pressure detection mechanism for detecting the gas supply pressure at the radial bearing. The second throttling mechanism 10 is electrically connected to the second pressure detection mechanism. The control method further includes:

[0064] Obtain the air supply pressure b0 at the axial thrust bearing of compressor 1, and compare b0 with the preset axial pressure b1;

[0065] If b0 > b1, then adjust the opening of the second throttling mechanism 10.

[0066] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A bearing gas supply system, applied in a refrigerant heat exchange cycle, the refrigerant heat exchange cycle comprising a compressor (1), an evaporator (2), and a gas storage tank (3), characterized in that: The bearing air supply system also includes: Bypass pipe (4), one end of which is connected to the exhaust port of the evaporator (2), and the other end of which is connected to the liquid drain port of the evaporator (2); The ejector device has a main ejector port connected to the gas supply port of the gas storage tank (3), an ejected port connected to the bypass pipeline (4), and an outlet connected to the compressor (1). The ejector device includes a first ejector mechanism (7) and a second ejector mechanism (8), and the compressor (1) includes a radial bearing and an axial thrust bearing; The first ejector mechanism (7) has its main ejector port connected to the gas supply port of the gas storage tank (3), its ejected port connected to the bypass pipeline (4), and its outlet connected to the position of the axial thrust bearing. The second ejector mechanism (8) has its main ejector port connected to the liquid supply port of the gas storage tank (3), its ejected port connected to the bypass pipeline (4), and its outlet connected to the radial bearing position.

2. The bearing air supply system according to claim 1, characterized in that: The bearing gas supply system further includes a first switching mechanism (5) and a second switching mechanism (6). The first switching mechanism (5) is located between the bypass pipe (4) and the exhaust port of the evaporator (2), and the second switching mechanism (6) is located between the bypass pipe (4) and the drain port of the evaporator (2).

3. The bearing air supply system according to claim 2, characterized in that: The bearing air supply system also includes a temperature detection device, which is installed on the compressor (1) and is electrically connected to the first on / off mechanism (5) and / or the second on / off mechanism (6).

4. The bearing air supply system according to claim 3, characterized in that: The compressor (1) includes a radial bearing and an axial thrust bearing. The temperature detection device includes a first temperature detection mechanism and a second temperature detection mechanism. The first temperature detection mechanism is used to detect the gas supply temperature at the axial thrust bearing, and the second temperature detection mechanism is used to detect the gas supply temperature at the radial bearing. The first on / off mechanism (5) can be controlled according to the detection results of the first temperature detection mechanism and / or the detection results of the second temperature detection mechanism; and / or, the second on / off mechanism (6) can be controlled according to the detection results of the first temperature detection mechanism and / or the detection results of the second temperature detection mechanism.

5. The bearing air supply system according to claim 1, characterized in that: The bearing air supply system also includes a flow regulation mechanism, which is located between the ejector device and the bypass pipeline (4).

6. The bearing air supply system according to claim 5, characterized in that: The bearing air supply system also includes a pressure detection device, which is installed on the compressor (1) and is electrically connected to the flow regulating mechanism.

7. The bearing air supply system according to claim 1, characterized in that: The bearing air supply system further includes a first throttling mechanism (9) and a second throttling mechanism (10). The first throttling mechanism (9) is disposed between the ejector port of the first ejector mechanism (7) and the bypass pipe (4), and the second throttling mechanism (10) is disposed between the ejector port of the second ejector mechanism (8) and the bypass pipe (4).

8. The bearing air supply system according to claim 7, characterized in that: The bearing air supply system also includes a pressure detection device, which includes a first pressure detection mechanism and a second pressure detection mechanism. The first pressure detection mechanism is used to detect the air supply pressure at the axial thrust bearing, and the second pressure detection mechanism is used to detect the air supply pressure at the radial bearing. The first throttling mechanism (9) is electrically connected to the first pressure detection mechanism, and the second throttling mechanism (10) is electrically connected to the second pressure detection mechanism.

9. A control method for a bearing air supply system according to any one of claims 1 to 8, characterized in that: The bearing gas supply system further includes a first switching mechanism (5) and a second switching mechanism (6). The first switching mechanism (5) is located between the bypass pipe (4) and the exhaust port of the evaporator (2), and the second switching mechanism (6) is located between the bypass pipe (4) and the liquid drain port of the evaporator (2). The control method includes: Step S101: Obtain the real-time temperature T0 at the bearing of the compressor (1) and determine whether T0 is within the preset temperature range X; Step S102: If T0 is within the preset temperature range X and T0 is greater than the first preset value T1, then the first on / off mechanism (5) is turned on and the second on / off mechanism (6) is turned off.

10. The control method according to claim 9, characterized in that: The bearing air supply system also includes a pressure detection device, which is mounted on the compressor (1) and electrically connected to the flow regulating mechanism. In step S102, the system further includes: Step S201: Obtain the real-time air supply pressure A0 at the bearing of the compressor (1) and compare the real-time air supply pressure A0 with the preset pressure value A1; Step S202: If A0 is greater than A1, then increase the opening degree of the flow regulation mechanism.

11. The control method according to claim 10, characterized in that: Following step S101, the method further includes: If T0 is greater than Xmax, then the second on / off mechanism (6) is activated and the first on / off mechanism (5) is deactivated, where Xmax is the maximum value in the preset temperature range X.

12. The control method according to claim 11, characterized in that: After the statement that if T0 is greater than Xmax, the second on / off mechanism (6) is activated and the first on / off mechanism (5) is deactivated, the following further applies: Obtain the real-time air supply pressure A0 at the bearing of the compressor (1), and compare the real-time air supply pressure A0 with the preset pressure value A1; If A0 is greater than A1, then the opening degree of the flow regulation mechanism is increased.

13. The control method according to claim 10 or 12, characterized in that: The ejector device includes a first ejector mechanism (7), and the compressor (1) includes an axial thrust bearing; the main ejector port of the first ejector mechanism (7) is connected to the gas supply port of the gas storage tank (3), the ejected port of the first ejector mechanism (7) is connected to the bypass pipeline (4), and the outlet of the first ejector mechanism (7) is connected to the position of the axial thrust bearing. The bearing gas supply system also includes a first throttling mechanism (9), which is located between the ejected port of the first ejector mechanism (7) and the bypass pipeline (4). The pressure detection device includes a first pressure detection mechanism, which is used to detect the gas supply pressure at the axial thrust bearing. The first throttling mechanism (9) is electrically connected to the first pressure detection mechanism. The control method also includes: Obtain the air supply pressure a0 at the axial thrust bearing of the compressor (1), and compare a0 with the preset axial pressure a1; If a0 > a1, then adjust the opening degree of the first throttling mechanism (9).

14. The control method according to claim 10 or 12, characterized in that: The ejector device includes a second ejector mechanism (8), and the compressor (1) includes a radial bearing; the main ejector port of the second ejector mechanism (8) is connected to the liquid supply port of the gas storage tank (3), the ejected port of the second ejector mechanism (8) is connected to the bypass pipeline (4), and the outlet of the second ejector mechanism (8) is connected to the radial bearing position. The bearing gas supply system also includes a second throttling mechanism (10), which is located between the ejected port of the second ejector mechanism (8) and the bypass pipeline (4). The pressure detection device includes a second pressure detection mechanism, which is used to detect the gas supply pressure at the radial bearing. The second throttling mechanism (10) is electrically connected to the second pressure detection mechanism. The control method also includes: Obtain the air supply pressure b0 at the axial thrust bearing of the compressor (1), and compare b0 with the preset axial pressure b1; If b0 > b1, then adjust the opening of the second throttling mechanism (10).

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