Magnetic levitation air compressor unit and control method thereof

Abstract

This invention provides a magnetic levitation air compressor unit and its control method. The device includes: a magnetic levitation air compressor comprising a primary turbine and a secondary turbine; a primary intake pipe connected to the intake end of the primary turbine, an outlet end of the primary turbine connected to a primary outlet pipe, a secondary intake pipe connected to the intake end of the secondary turbine, and a secondary outlet pipe connected to the outlet end of the secondary turbine; a primary exhaust return pipe connecting the primary intake pipe and the primary outlet pipe, and a first vent valve provided on the primary exhaust return pipe; a secondary exhaust return pipe connecting the secondary intake pipe and the secondary outlet pipe, and a second vent valve provided on the secondary exhaust return pipe; pressure sensors are respectively installed on the primary intake pipe and the primary outlet pipe, and on the secondary intake pipe and the secondary outlet pipe. By setting an exhaust return pipe between the outlet and the inlet of each stage, high-pressure gas is returned to the inlet for recovery, improving device efficiency and reducing energy consumption.

Description

Technical Field

[0001] This invention relates to the field of magnetic levitation air compressor technology, and more particularly to a magnetic levitation air compressor unit and its control method. Background Technology

[0002] Surge is a common system phenomenon in magnetic levitation centrifugal air compressors. When the flow rate of the air compressor is less than its limit flow rate, the operating point appears in the unstable region, and the strong periodic back-and-forth flow of air leads to increased noise and blade stress, generating significant impact forces on the impeller and its connecting components. When these forces increase to a certain extent, they can cause the rotating and stationary parts of the air compressor to break, or even destroy the entire air compressor and piping system. Therefore, preventing surge in magnetic levitation air compressors and ensuring their safe and reliable operation is of great importance.

[0003] Anti-surge venting valves are widely used devices in magnetic levitation centrifugal air compressors to prevent surge. By installing a venting valve on the machine's outlet pipeline, when the compressor's flow rate decreases to near the surge flow rate, the valve opens, causing an immediate drop in the compressor's outlet pressure and a subsequent increase in flow rate. However, while this existing solution can prevent surge, it also wastes compressed gas that has gained energy from the impeller, reducing the overall efficiency of the device and increasing energy consumption. Summary of the Invention

[0004] This invention provides a magnetic levitation air compressor unit and its control method to solve the problems of reduced efficiency and increased energy consumption in existing magnetic levitation air compressors.

[0005] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0006] In a first aspect, embodiments of the present invention provide a magnetic levitation air compressor unit, comprising:

[0007] Magnetic levitation air compressor, primary intake pipeline, primary outlet pipeline, secondary intake pipeline, secondary outlet pipeline, primary exhaust return pipeline, secondary exhaust return pipeline, first vent valve, second vent valve and pressure sensor;

[0008] The magnetic levitation air compressor includes a primary turbine and a secondary turbine. The primary intake pipe is connected to the intake end of the primary turbine, the exhaust end of the primary turbine is connected to the primary exhaust pipe, the secondary intake pipe is connected to the intake end of the secondary turbine, and the secondary exhaust pipe is connected to the exhaust end of the secondary turbine.

[0009] The first-stage exhaust return pipeline is used to connect the first-stage intake pipeline and the first-stage exhaust pipeline. The first-stage exhaust return pipeline is provided with a first vent valve, which is used to return at least a portion of the compressed gas output by the first-stage turbine to the intake end of the first-stage turbine after being opened.

[0010] The secondary exhaust return pipeline is used to connect the secondary intake pipeline and the secondary exhaust pipeline. The secondary exhaust return pipeline is provided with a second vent valve. The second vent valve is used to return at least a portion of the compressed gas output by the secondary turbine to the intake end of the secondary turbine after being opened.

[0011] Pressure sensors are respectively installed in the first-stage intake pipe and the first-stage exhaust pipe near the first-stage turbine, and in the second-stage intake pipe and the second-stage exhaust pipe near the second-stage turbine. The pressure sensors are used to detect the first-stage intake pressure and the second-stage exhaust pressure.

[0012] Optional, also includes:

[0013] Temperature sensors are provided at the locations near the first-stage turbine in the first-stage intake pipe and the first-stage outlet pipe, and at the locations of the second-stage intake pipe and the second-stage outlet pipe, respectively, for detecting the first-stage intake temperature, the first-stage outlet temperature, the second-stage intake temperature, and the second-stage outlet temperature.

[0014] Optional, also includes:

[0015] A first butterfly valve and a second butterfly valve, wherein the first butterfly valve is connected in parallel with the first vent valve, and the second butterfly valve is connected in parallel with the second vent valve.

[0016] Optional, also includes:

[0017] At least one third vent valve and at least one fourth vent valve, wherein the diameter of the third vent valve is smaller than the diameter of the first vent valve, and the diameter of the fourth vent valve is smaller than the diameter of the second vent valve.

[0018] The third vent valve is connected in parallel with the first butterfly valve, and the fourth vent valve is connected in parallel with the second butterfly valve.

[0019] Optional, also includes:

[0020] An intercooler is connected in series on the pipeline between the primary intake pipeline and the secondary exhaust pipeline.

[0021] In a second aspect, embodiments of the present invention provide a control method for a magnetic levitation air compressor unit, applied to a magnetic levitation air compressor unit as described in any one of the first aspects, the control method for the magnetic levitation air compressor unit comprising:

[0022] Obtain the primary intake pressure and the secondary exhaust pressure;

[0023] Based on the first-stage inlet pressure and the second-stage outlet pressure, the current operating point of the magnetic levitation air compressor is determined. The operating point of the magnetic levitation air compressor is used to characterize the volumetric flow rate and pressure of the gas.

[0024] Based on the operating condition point of the magnetic levitation air compressor, the opening and closing of the first vent valve and the second vent valve are controlled based on the pressure surge shutdown line and the pressure surge warning line, wherein the pressure surge warning line is a surge warning line with a safety margin established based on the pressure surge shutdown line; and / or, based on the operating condition point of the magnetic levitation air compressor, the opening and closing of the first vent valve and the second vent valve are controlled based on the pressure ratio surge shutdown line and the pressure ratio surge warning line, wherein the pressure ratio surge warning line is a surge warning line with a safety margin established based on the pressure ratio surge shutdown line.

[0025] Optionally, before the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure surge shutdown line and pressure surge warning line, the method further includes:

[0026] The magnetic levitation air compressor is controlled to run at its highest speed and at its highest speed respectively, so as to obtain at least two surge pressure operating points for testing;

[0027] According to the preset first margin, the corresponding surge pressure warning point is determined based on the surge pressure operating point.

[0028] The pressure surge shutdown line is obtained by fitting at least two of the surge pressure operating points;

[0029] A pressure surge warning line is obtained by fitting at least two of the aforementioned surge pressure warning points.

[0030] Optionally, before the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure ratio surge shutdown line and pressure ratio surge warning line, the method further includes:

[0031] The magnetic levitation air compressor is controlled to run at its highest speed and at its highest speed respectively, and at least two surge pressure ratio operating points are obtained for testing.

[0032] According to the preset first margin, the corresponding surge pressure ratio warning point is determined based on the surge pressure ratio operating point;

[0033] The pressure ratio surge shutdown line is obtained by fitting at least two of the aforementioned surge pressure ratio operating points;

[0034] A pressure ratio surge warning line is obtained by fitting at least two of the aforementioned surge pressure ratio warning points.

[0035] Optionally, based on the primary intake pressure and the secondary outlet pressure, the current operating point of the magnetic levitation air compressor is determined, including:

[0036] Calculate the volumetric flow rate of the first-stage intake based on the first-stage intake pressure;

[0037] The current operating point of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first-stage intake air and the second-stage outlet air pressure.

[0038] Optionally, the volumetric flow rate of the first-stage intake air can be calculated based on the first-stage intake pressure using the following formula:

[0039] ;

[0040] ;

[0041] in, For mass flow rate; This is the boundary layer correction factor; This refers to the first-level import cross-sectional area; The static pressure of the gas in the first-stage intake pipe; The differential pressure measured by the differential pressure transmitter in the air inlet section; The adiabatic coefficient; This refers to the volumetric flow rate of the first-stage intake. The constant of the medium gas; This refers to the total gas pressure of the first-stage intake pipeline under standard operating conditions. This refers to the temperature of the first-stage intake manifold under standard operating conditions. This represents the density of the imported gas.

[0042] Optional, also includes:

[0043] Obtain the primary exhaust pressure and the secondary intake pressure;

[0044] The ratio of the first-stage outlet pressure to the first-stage inlet pressure is taken as the first-stage pressure ratio;

[0045] The ratio of the secondary outlet pressure to the secondary inlet pressure is taken as the secondary pressure ratio;

[0046] The current operating point of the first stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first stage air intake and the first stage pressure ratio.

[0047] The current operating point of the secondary stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the primary intake and the pressure ratio of the secondary stage.

[0048] Optionally, when the magnetic levitation air compressor unit further includes a temperature sensor, before the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure ratio surge shutdown line and the pressure ratio surge warning line, the following method is further included:

[0049] Obtain the temperature of the primary exhaust pipe and the temperature of the secondary intake pipe;

[0050] Calculate the total gas pressure of the first-stage intake based on the first-stage intake pressure and the first-stage intake pipeline temperature;

[0051] Calculate the total gas pressure of the first-stage outlet based on the first-stage outlet pressure and the first-stage outlet pipeline temperature;

[0052] Calculate the total gas pressure of the second-stage intake based on the second-stage intake pressure and the second-stage intake pipeline temperature;

[0053] The ratio of the total pressure of the first-stage gas to the total pressure of the first-stage gas is taken as the first-stage pressure ratio;

[0054] The ratio of the total pressure of the gas exiting the second stage to the total pressure of the gas exiting the second stage is taken as the second stage pressure ratio;

[0055] The current operating point of the first stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first stage air intake and the first stage pressure ratio.

[0056] The current operating point of the secondary stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the primary intake and the pressure ratio of the secondary stage.

[0057] Optionally, based on the operating condition point of the magnetic levitation air compressor, the opening and closing of the first vent valve and the second vent valve are controlled according to the pressure ratio surge shutdown line and the pressure ratio surge warning line, including:

[0058] When the first-level operating condition point and the second-level operating condition point are operating to the right of the pressure ratio surge warning line, the first vent valve and the second vent valve shall be kept closed.

[0059] When the first-level operating condition point and the second-level operating condition point are operating to the left of the pressure ratio surge warning line and to the right of the pressure ratio surge shutdown line, the first vent valve and the second vent valve are controlled to open.

[0060] When the first vent valve and the second vent valve are opened, and the primary operating point and the secondary operating point are still operating to the left of the pressure ratio surge shutdown line, the magnetic levitation air compressor is controlled to stop.

[0061] Optionally, when the magnetic levitation air compressor unit further includes a temperature sensor, the current operating point of the magnetic levitation air compressor is determined based on the primary intake pressure and the secondary outlet pressure, including:

[0062] Obtain the temperature of the primary intake pipe and the temperature of the secondary exhaust pipe;

[0063] Calculate the volumetric flow rate of the first-stage intake based on the first-stage intake pressure and the first-stage intake pipeline temperature.

[0064] Calculate the total gas pressure of the secondary outlet based on the secondary outlet pressure and the secondary outlet pipeline temperature;

[0065] The current operating point of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first-stage intake air and the total gas pressure of the second-stage outlet air.

[0066] Optionally, the volumetric flow rate of the first-stage intake air can be calculated based on the first-stage intake pressure and the first-stage intake pipeline temperature according to the following formula:

[0067] ;

[0068] ;

[0069] ;

[0070] in, For mass flow rate; This is the boundary layer correction factor; This refers to the first-level import cross-sectional area; The static pressure of the gas in the first-stage intake pipe; The differential pressure measured by the differential pressure transmitter in the air inlet section; The adiabatic coefficient; This is the mass flow rate converted to standard operating conditions. This refers to the total gas pressure of the first-stage intake pipeline under standard operating conditions. This refers to the temperature of the first-stage intake manifold under standard operating conditions. This refers to the temperature of the primary intake manifold. This refers to the volumetric flow rate of the first-stage intake. The constant of the medium gas;

[0071] Calculate the total gas pressure of the secondary outlet gas based on the secondary outlet pressure and the secondary outlet pipeline temperature using the following formula:

[0072]

[0073] in,

[0074] in, The density of the gas; It is the static pressure of the gas; For temperature; This refers to the total gas pressure. For mass flow rate; The cross-sectional area; Flow rate.

[0075] Optionally, based on the operating condition point of the magnetic levitation air compressor, the opening and closing of the first vent valve and the second vent valve are controlled according to the pressure surge shutdown line and the pressure surge warning line, including:

[0076] When the operating point of the magnetic levitation air compressor is located to the right of the pressure surge warning line, the first vent valve and the second vent valve shall be kept closed.

[0077] When the operating point of the magnetic levitation air compressor is located to the left of the pressure surge warning line and to the right of the pressure surge shutdown line, the first vent valve and the second vent valve are controlled to open.

[0078] When the first vent valve and the second vent valve are opened, and the operating point of the magnetic levitation air compressor is still running to the left of the pressure surge stop line, the magnetic levitation air compressor stops.

[0079] Optionally, based on the operating condition point of the magnetic levitation air compressor, the opening and closing of the first vent valve and the second vent valve are controlled according to the pressure ratio surge shutdown line and the pressure ratio surge warning line, including:

[0080] When the operating point of the magnetic levitation air compressor is located to the right of the pressure ratio surge warning line, the first vent valve and the second vent valve shall be kept closed.

[0081] When the operating condition point of the magnetic levitation air compressor is located to the left of the pressure ratio surge warning line and to the right of the pressure ratio surge shutdown line, the first vent valve and the second vent valve are controlled to open.

[0082] When the first vent valve and the second vent valve are opened, and the operating point of the magnetic levitation air compressor is still running to the left of the pressure ratio surge stop line, the magnetic levitation air compressor is controlled to stop.

[0083] Optionally, when the magnetic levitation air compressor unit includes: a first butterfly valve, a second butterfly valve, at least one third vent valve, and at least one fourth vent valve, the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure surge shutdown line and pressure surge early warning line includes:

[0084] When the operating point of the magnetic levitation air compressor is located to the right of the pressure surge warning line, the first vent valve, the second vent valve, the third vent valve and the fourth vent valve shall be kept closed;

[0085] When the operating condition point of the magnetic levitation air compressor is located to the left of the second pressure surge warning line and to the right of the first pressure surge warning line, the third vent valve and the fourth vent valve are controlled to open, and the opening degree of the first butterfly valve and the second butterfly valve is controlled to keep the operating pressure constant. The warning range of the second pressure surge warning line is smaller than that of the first pressure surge warning line.

[0086] When the operating condition point of the magnetic levitation air compressor is on the left side of the first pressure surge warning line and on the right side of the pressure surge shutdown line, the first vent valve and the second vent valve are controlled to open, and the opening degree of the first butterfly valve and the second butterfly valve is controlled to be at its maximum.

[0087] When the first vent valve and the second vent valve are opened, and the operating point of the magnetic levitation air compressor is still running to the left of the pressure surge stop line, the magnetic levitation air compressor stops.

[0088] Optionally, when the magnetic levitation air compressor unit includes: a first butterfly valve, a second butterfly valve, at least one third vent valve, and at least one fourth vent valve, the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure ratio surge shutdown line and the pressure ratio surge warning line includes:

[0089] When the operating point of the magnetic levitation air compressor is located to the right of the pressure ratio surge warning line, the first vent valve, the second vent valve, the third vent valve and the fourth vent valve shall be kept closed;

[0090] When the operating condition point of the magnetic levitation air compressor is located to the left of the second pressure ratio surge warning line and to the right of the first pressure ratio surge warning line, the third vent valve and the fourth vent valve are controlled to open, and the opening degree of the first butterfly valve and the second butterfly valve is controlled to maintain the operating pressure ratio unchanged. The warning range of the second pressure surge warning line is smaller than that of the first pressure surge warning line.

[0091] When the operating condition point of the magnetic levitation air compressor is to the left of the first pressure ratio surge warning line and to the right of the pressure ratio surge shutdown line, the first vent valve and the second vent valve are controlled to open, and the opening degree of the first butterfly valve and the second butterfly valve is controlled to be at its maximum.

[0092] When the first vent valve and the second vent valve are opened, and the operating point of the magnetic levitation air compressor is still running to the left of the pressure ratio surge stop line, the magnetic levitation air compressor stops.

[0093] Thirdly, embodiments of the present invention provide a magnetic levitation air compressor system, comprising: a magnetic levitation air compressor unit and a controller as described in any one of the first aspects, wherein the magnetic levitation air compressor unit is electrically connected to the controller, and the controller is used to execute the steps in the magnetic levitation air compressor unit as described in any one of the second aspects to achieve control of the magnetic levitation air compressor unit.

[0094] Fourthly, embodiments of the present invention provide an electronic device, including: a memory and a processor; the memory stores computer execution instructions; the processor executes the computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of the second aspects.

[0095] Fifthly, embodiments of the present invention provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of the second aspects. (Magnetic levitation air compressor unit)

[0096] In this invention, a magnetic levitation air compressor, a primary intake pipe, a primary outlet pipe, a secondary intake pipe, a secondary outlet pipe, a primary exhaust return pipe, a secondary exhaust return pipe, a first vent valve, a second vent valve, and a pressure sensor are provided. The magnetic levitation air compressor includes a primary turbine and a secondary turbine. The primary intake pipe is connected to the intake end of the primary turbine, the outlet end of the primary turbine is connected to the primary outlet pipe, the secondary intake pipe is connected to the intake end of the secondary turbine, and the secondary outlet pipe is connected to the outlet end of the secondary turbine. The series design of the primary and secondary turbines allows the gas to be pressurized twice in succession. Compared with traditional single-stage compression, this can expand the effective output pressure range while maintaining high speed stability, significantly improving the system's compression capacity and airflow. The primary exhaust return pipe connects the primary intake pipe and the primary outlet pipe. The primary exhaust return pipe is equipped with the first vent valve, which is used to open... Then, at least a portion of the compressed gas output from the first-stage turbine is returned to the intake end of the first-stage turbine; the second-stage exhaust return pipeline is used to connect the second-stage intake pipeline and the second-stage outlet pipeline. The second-stage exhaust return pipeline is equipped with a second vent valve. The second vent valve is used to return at least a portion of the compressed gas output from the second-stage turbine to the intake end of the second-stage turbine after being opened. An independent exhaust return pipeline is set between the inlet and outlet of each stage turbine and equipped with a corresponding vent valve. When any stage turbine approaches the surge condition due to a sudden decrease in flow, the vent valve corresponding to that stage can be opened independently to return a portion of the high-pressure gas at the outlet to the inlet of that stage. By increasing the instantaneous volumetric flow rate at the turbine inlet, the impeller angle of attack recovery force is improved, avoiding mechanical vibration damage caused by airflow separation and periodic return. Moreover, the two independent anti-surge circuits do not interfere with each other, enabling the system to achieve precise local control rather than global linkage when facing complex load changes, effectively reducing unnecessary energy leakage and equipment disturbance.Pressure sensors are installed near the first-stage inlet and outlet pipes and near the first-stage turbine, respectively, and near the second-stage inlet and outlet pipes and near the second-stage turbine, respectively. By real-time acquisition of instantaneous inlet and outlet pressure values ​​during the operation of each turbine stage and combining this data with flow meter data to calculate the inlet volumetric flow rate and outlet total pressure, the control system is provided with pressure difference and pressure ratio parameters that accurately identify the current equipment load status. This allows surge detection to not only rely on static thresholds but also establish differentiated surge warning and shutdown lines based on independent state monitoring of each turbine stage. Real-time determination of the first-stage operating point or the second-stage single-stage operating point triggers the rapid opening and closing response of the corresponding vent valve, ensuring accurate identification of surge risks and timely intervention and adjustment at each stage of the multi-stage compressor system. This avoids monitoring blind spots caused by insufficient sensor quantity or improper sensor placement. It also provides crucial pressure fluctuation data for equipment health assessment and fault diagnosis, ultimately achieving safety assurance and energy efficiency optimization for the high-speed, high-precision characteristics of the magnetic levitation air compressor throughout the entire operation process. Attached Figure Description

[0097] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0098] Figure 1 This is a schematic diagram of the structure of a magnetic levitation air compressor unit provided in an embodiment of the present invention;

[0099] Figure 2 This is a schematic diagram of another magnetic levitation air compressor unit provided in an embodiment of the present invention;

[0100] Figure 3 This is a schematic diagram of another magnetic levitation air compressor unit provided in an embodiment of the present invention;

[0101] Figure 4 This is a flowchart of a control method for a magnetic levitation air compressor unit provided in an embodiment of the present invention;

[0102] Figure 5 This is a schematic diagram of the pressure operating range of a control method for a magnetic levitation air compressor unit provided in an embodiment of the present invention;

[0103] Figure 6 This is a schematic diagram of the pressure ratio operating range of a control method for a magnetic levitation air compressor unit provided in an embodiment of the present invention;

[0104] Figure 7 This is a schematic diagram of the pressure operating range of another control method for a magnetic levitation air compressor unit provided in an embodiment of the present invention;

[0105] Figure 8 This is a schematic diagram of the pressure ratio operating range of another control method for a magnetic levitation air compressor unit provided in an embodiment of the present invention.

[0106] Figure label:

[0107] Magnetic levitation air compressor unit 01;

[0108] Magnetic levitation air compressor 1; primary intake pipe 2; primary exhaust pipe 3; secondary intake pipe 4; secondary exhaust pipe 5; intercooler 6; primary exhaust return pipe 7; secondary exhaust return pipe 8; first vent valve 9; second vent valve 10; pressure sensor 11; temperature sensor 12; first butterfly valve 13; second butterfly valve 14; third vent valve 15; fourth vent valve 16; primary turbine 101; secondary turbine 102. Detailed Implementation

[0109] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0110] Please refer to Figure 1 This invention provides a magnetic levitation air compressor unit 01, which may include:

[0111] The magnetic levitation air compressor includes: 1. primary intake pipe; 2. primary outlet pipe; 3. secondary intake pipe; 4. secondary outlet pipe; 5. intercooler; 6. primary exhaust return pipe; 7. secondary exhaust return pipe; 8. first vent valve; 9. second vent valve; 10. pressure sensor; and 11.

[0112] The magnetic levitation air compressor 1 includes a primary turbine 101 and a secondary turbine 102. The primary intake pipe 4 is connected to the intake end of the primary turbine 101, the outlet end of the primary turbine 101 is connected to the primary outlet pipe 3, the secondary intake pipe 4 is connected to the intake end of the secondary turbine 102, and the secondary outlet pipe 5 is connected to the outlet end of the secondary turbine 102. The primary exhaust return pipe 7 is used to connect the primary intake pipe 2 and the primary outlet pipe 3. The primary exhaust return pipe 7 is provided with a first vent valve 9, which is used to return at least a portion of the compressed gas output by the primary turbine 101 to the intake end of the primary turbine 101 after being opened.

[0113] The secondary exhaust return line 8 is used to connect the secondary intake line 4 and the secondary exhaust line 5. The secondary exhaust return line 8 is provided with a second vent valve 10. The second vent valve 10 is used to return at least part of the compressed gas output by the secondary turbine 102 to the intake end of the secondary turbine 102 after being opened.

[0114] Pressure sensors 11 can be installed at the first-stage intake pipe 2 and the first-stage exhaust pipe 3 near the first-stage turbine 101, and at the second-stage intake pipe 4 and the second-stage exhaust pipe 5 near the second-stage turbine 102.

[0115] In this embodiment of the invention, surge is the periodic oscillation of gas in the magnetic levitation air compressor and its outlet pipe. The gas medium undergoes mechanical vibration due to the excitation effect of periodic intake and discharge. Once surge causes resonance in the pipe, the magnetic levitation air compressor and its supporting structure, it will have serious consequences. To prevent surge, the magnetic levitation air compressor must be operated outside the surge zone. Since surge is extremely harmful, when surge is about to occur, it is necessary to immediately increase the flow rate of the magnetic levitation air compressor to make the unit operate outside the surge zone.

[0116] In this embodiment, the magnetic levitation air compressor 1 may include a rotating shaft, and a first-stage turbine 101 and a second-stage turbine 102 may be respectively disposed at both ends of the rotating shaft.

[0117] In this embodiment, the flow rates of the first vent valve 9 and the second vent valve 10 can be the same or different, and the specific flow rate can be determined according to the actual situation. This embodiment does not limit this.

[0118] In this embodiment, the pressure sensor 11 can be located near the turbine. Preferably, the pressure sensor used to measure the inlet pressure can be located on the side of the primary exhaust return pipe 7 near the primary intake pipe 2, i.e., downstream of the primary exhaust return pipe 7, and on the side of the secondary exhaust return pipe 8 near the secondary intake pipe 4, i.e., downstream of the secondary exhaust return pipe 8. The pressure sensor used to measure the outlet pressure can be located on the side of the primary exhaust return pipe 7 near the primary outlet pipe 3, i.e., upstream of the primary exhaust return pipe 7, and on the side of the secondary exhaust return pipe 8 near the secondary outlet pipe 2, i.e., upstream of the secondary exhaust return pipe 8. The pressure sensor 11 is used to detect the key pressure parameters at the inlet and outlet of each stage of the turbine, monitor the operating condition of the magnetic levitation air compressor 01 in real time, and determine whether it is approaching the surge region. In this embodiment, by reasonably setting pressure sensors 11 at specific locations in the primary and secondary exhaust return pipelines, accurate monitoring of the inlet and outlet pressures is achieved. This enables the control system to acquire the actual operating status parameters of the air compressor in real time, accurately calculate the inlet volume flow rate and pressure ratios at each stage, and effectively identify the surge critical point. This improves the accuracy and response speed of data acquisition, ensuring that the anti-surge control strategy executes the opening and closing operation of the vent valve in a timely manner under the precise triggering of the warning line and the shutdown line, thereby enhancing the safety protection capability and operational stability of the magnetic levitation air compressor under complex working conditions.

[0119] In this embodiment of the invention, a magnetic levitation air compressor 1, a primary intake pipe 2, a primary outlet pipe 3, a secondary intake pipe 4, a secondary outlet pipe 5, an intercooler 6, a primary exhaust return pipe 7, a secondary exhaust return pipe 8, a first vent valve 9, a second vent valve 10, and a pressure sensor 11 are provided. The magnetic levitation air compressor 1 includes a primary turbine 101 and a secondary turbine 102. The primary intake pipe 4 is connected to the intake end of the primary turbine 101, the outlet end of the primary turbine 101 is connected to the primary outlet pipe 3, the secondary intake pipe 4 is connected to the intake end of the secondary turbine 102, and the secondary outlet pipe 5 is connected to the secondary turbine 102. The exhaust end of turbine 102 is connected to the exhaust pipe 7; the first-stage exhaust return pipe 7 is used to connect the first-stage intake pipe 2 and the first-stage exhaust pipe 3. The first-stage exhaust return pipe 7 is provided with a first vent valve 9. The first vent valve 9 is used to return at least part of the compressed gas output by the first-stage turbine 101 to the intake end of the first-stage turbine 101 after being opened; the second-stage exhaust return pipe 8 is used to connect the second-stage intake pipe 4 and the second-stage exhaust pipe 5. The second-stage exhaust return pipe 8 is provided with a second vent valve 10. The second vent valve 10 is used to return at least part of the compressed gas output by the second-stage turbine 102 to the intake end of the second-stage turbine 102 after being opened;

[0120] Pressure sensors 11 can be installed at the first-stage intake pipe 2 and the first-stage exhaust pipe 3 near the first-stage turbine 101, and at the second-stage intake pipe 4 and the second-stage exhaust pipe 5 near the second-stage turbine 102, respectively. By setting an exhaust return pipe between the exhaust port and the intake port of each stage turbine of the magnetic levitation air compressor, the vented high-pressure gas is returned to the intake port of the magnetic levitation air compressor for recovery, thereby increasing the flow rate of the magnetic levitation air compressor. This achieves the goal of improving the efficiency of the device and reducing energy consumption while preventing surge of the magnetic levitation air compressor.

[0121] In this embodiment of the invention, the materials of the primary intake pipe 2, primary exhaust pipe 3, secondary intake pipe 4, secondary exhaust pipe 5, intercooler 6, primary exhaust return pipe 7, and secondary exhaust return pipe 8 can be selected from stainless steel, carbon steel, or composite materials according to the customer's compressed gas (temperature, corrosiveness).

[0122] In this embodiment, the first vent valve 9 and the second vent valve 10 can be configured as large-diameter vent valves. The specific diameter selection can be determined according to the actual situation, and this embodiment does not limit this. By installing exhaust return pipelines between the outlet and inlet of each stage turbine of the magnetic levitation air compressor, the vented high-pressure gas is returned to the inlet of the magnetic levitation air compressor for recovery, increasing the flow rate of the magnetic levitation air compressor. This achieves the goal of improving system efficiency and reducing energy consumption while preventing surge in the magnetic levitation air compressor. Pressure sensors are installed in the primary inlet pipeline, primary outlet pipeline, secondary inlet pipeline, and secondary outlet pipeline to detect pressure. The control system calculates the actual pressure ratio of any stage of the magnetic levitation air compressor, thereby rationally controlling the operating status of the compressor to maintain the main flow rate above the surge threshold and prevent surge caused by excessively low flow. Furthermore, it avoids direct discharge of vented gas into the atmosphere and can be used to treat toxic, flammable, explosive, or economically valuable gases. Direct venting of high-pressure gas generates high-decibel noise; the graded anti-surge return pipeline significantly reduces the noise impact on the working environment by recovering high-pressure gas.

[0123] Please refer to Figure 2 In this embodiment of the invention, optionally, it may also include:

[0124] Temperature sensors 12 are installed at the first-stage intake pipe 2 and the first-stage exhaust pipe 4 near the first-stage turbine 101, and at the second-stage intake pipe 5 and the second-stage exhaust pipe 4, respectively, to detect the first-stage intake temperature, the first-stage exhaust temperature, the second-stage intake temperature and the second-stage exhaust temperature.

[0125] In this embodiment of the invention, temperature sensors are installed in the primary and secondary intake and exhaust pipes to achieve real-time monitoring of gas temperature, thereby ensuring that the system operates under optimal conditions. The compressor's operating parameters are dynamically adjusted based on real-time temperature data to ensure that the equipment operates at high efficiency, thereby optimizing compression efficiency. Furthermore, the temperature sensors can promptly detect temperature anomalies, trigger alarms, and take corresponding measures to avoid potential equipment damage and maintain the stable operation of the magnetic levitation air compressor.

[0126] Please refer to Figure 3 In this embodiment of the invention, optionally, it also includes:

[0127] The first butterfly valve 13 and the second butterfly valve 14 are connected in parallel with the first vent valve 9, and the second butterfly valve 14 is connected in parallel with the second vent valve 10.

[0128] In this embodiment of the invention, the air inlet end of the first butterfly valve 13 is connected to the air inlet end of the first vent valve 9, and the air outlet end of the first butterfly valve 13 is connected to the air outlet end of the first vent valve 9; the air inlet end of the second butterfly valve 14 is connected to the air inlet end of the second vent valve 10, and the air outlet end of the second butterfly valve 14 is connected to the air outlet end of the second vent valve 10.

[0129] In this embodiment of the invention, the arrangement of the first butterfly valve 13 and the second butterfly valve 14 makes the control of gas flow more flexible. By adjusting the opening of the butterfly valve, the gas flow rate can be precisely controlled to meet the needs under different working conditions, thereby improving the overall efficiency of the system. By simultaneously setting the vent valve and the butterfly valve, the pressure can be smoothly adjusted to maintain the vent stability of the ultra-high speed magnetic levitation control system.

[0130] In this embodiment of the invention, optionally, it may also include:

[0131] At least one third vent valve 15 and at least one fourth vent valve 16, wherein the diameter of the third vent valve 15 is smaller than the diameter of the first vent valve 9, and the diameter of the fourth vent valve 16 is smaller than the diameter of the second vent valve 10.

[0132] Among them, the third vent valve 15 is connected in parallel with the first butterfly valve 13, and the fourth vent valve 16 is connected in parallel with the second butterfly valve 14.

[0133] In this embodiment of the invention, the third and fourth vent valves are used as small-diameter auxiliary actuators to perform fine control tasks in the first-level warning stage. When they are opened, only a small amount of gas backflow is needed to eliminate slight surge tendency, avoiding the sudden and violent fluctuations in system pressure and energy waste caused by fully opening the large-diameter main vent valve. A stepped response mechanism for flow control is realized through parallel connection. When the operating point is close to the left of the surge warning line, the small valve acts first to maintain system stability. Only when the small valve cannot pull the operating point back to the safe zone after opening, the large-diameter main valve is activated to provide greater backflow capacity. The graded linkage strategy not only ensures the reliability of anti-surge protection but also significantly reduces the frequency of valve action. Furthermore, the cooperation between the large and small valves allows the system to have an adjustable flow range covering the entire range from minor disturbances to extreme operating conditions when facing different levels of surge risk. This realizes a controllable transition from coarse to fine anti-surge intervention, effectively reducing the abnormal mechanical stress on the magnetic levitation bearing and impeller due to pressure changes, and extending the service life of the equipment.

[0134] In this embodiment of the invention, the air inlet of the third vent valve 15 is connected to the air inlet of the first butterfly valve 13, and the air outlet of the third vent valve 15 is connected to the air outlet of the first butterfly valve 13; the air inlet of the fourth vent valve 16 is connected to the air inlet of the second butterfly valve 14, and the air outlet of the fourth vent valve 16 is connected to the air outlet of the second butterfly valve 14.

[0135] In this embodiment of the invention, the third vent valve 15 and the fourth vent valve 16 are small-diameter vent valves, and multiple valves can be connected in parallel. The connection design between the butterfly valve and the vent valve achieves internal pressure balance. With appropriate vent control, the pressure can be quickly adjusted to prevent system instability and surge. By precisely controlling the gas flow, it is ensured that the gas at each stage can be compressed under optimal conditions, thereby improving the overall operating efficiency of the equipment.

[0136] In this embodiment of the invention, optionally, the magnetic levitation air compressor unit 01 may further include: an intercooler 7, which is connected in series on the pipeline between the primary intake pipeline 2 and the secondary outlet pipeline 3.

[0137] In this embodiment, the intercooler 7 is connected in series in the pipeline between the first-stage intake pipeline and the second-stage outlet pipeline. It performs forced cooling on the high-temperature gas after compression by the first-stage turbine, so that the high-pressure, high-temperature gas leaving the first-stage impeller has a significantly lower temperature before entering the second-stage turbine. This significantly reduces the mechanical power required for second-stage compression, improves the overall operating efficiency of the unit, and reduces energy waste. At the same time, the interstage location of the intercooler allows it to recover and utilize heat energy without affecting the independent operation of the first-stage compressor and the anti-surge regulation function. By converting the energy of the high-temperature gas into a low-temperature medium state, it avoids failures such as the degradation of the magnetic bearing lubricating oil performance and the thermal expansion and deformation of the impeller material caused by excessive temperature, thus extending the service life of key components.

[0138] Please refer to Figure 4 This invention provides a control method for a magnetic levitation air compressor unit, applied to the magnetic levitation air compressor unit described in the above embodiments. The control method for the magnetic levitation air compressor unit may include:

[0139] Step S41: Obtain the primary intake pressure and the secondary exhaust pressure;

[0140] In this embodiment of the invention, core monitoring parameters are provided for anti-surge control to ensure accurate positioning of the operating point of the magnetic levitation air compressor. This can be achieved by real-time acquisition of the primary intake pressure to understand the initial state of the gas entering the system, and by acquiring the secondary outlet pressure to reflect the final output capacity of the entire machine. This allows for precise mapping of the current operating point, effectively preventing the magnetic levitation air compressor from operating within unsafe pressure ranges, thus avoiding equipment damage caused by excessive pressure or vibration. Setting a pressure surge warning line allows for early identification of potential surge problems during equipment operation, enabling timely measures to reduce the probability of failure. Accurate pressure control improves overall efficiency.

[0141] In this embodiment, the primary intake pressure and the secondary exhaust pressure can be obtained simultaneously, or the primary intake pressure and the secondary exhaust pressure can be obtained separately. It is understood that the method and timing of obtaining the primary intake pressure and the secondary exhaust pressure can be determined according to the actual situation, and this embodiment does not limit this.

[0142] Step S42: Based on the first-stage inlet pressure and the second-stage outlet pressure, determine the current operating point of the magnetic levitation air compressor. The operating point of the magnetic levitation air compressor is used to characterize the volumetric flow rate and pressure of the gas.

[0143] In this embodiment of the invention, the operating condition point of the magnetic levitation air compressor is determined based on the primary intake pressure and the secondary outlet pressure, realizing a precise mapping between the current working state of the equipment and the gas flow and pressure parameters. This provides an accurate data basis for surge prevention and control. By comparing and judging with the preset surge warning line and shutdown line, the surge risk tendency is identified in a timely manner and the corresponding vent valve adjustment action is triggered, which improves the response speed and accuracy of surge control. It effectively avoids the problem of excessive blade stress and equipment damage caused by insufficient flow, and ensures the stable and efficient operation of the magnetic levitation air compressor under various load changes.

[0144] In this embodiment, the operating point of the magnetic levitation air compressor can be a two-dimensional coordinate point, determined by the gas volumetric flow rate and pressure, or the pressure ratio between the first and second stages. It is understood that the operating point can also be a one-dimensional or three-dimensional coordinate point. The operating point can be composed of the first-stage inlet pressure and the second-stage outlet pressure, or the gas volumetric flow rate, the first-stage inlet pressure, and the second-stage outlet pressure, or the gas volumetric flow rate and the first-stage pressure ratio. Alternatively, it can be composed of the gas volumetric flow rate and the second-stage pressure ratio. Of course, the operating point can also be composed of other possible data, which can be determined according to the actual situation. This embodiment does not limit this.

[0145] In this embodiment of the invention, optionally, determining the current operating point of the magnetic levitation air compressor based on the primary intake pressure and the secondary outlet pressure includes:

[0146] Calculate the volumetric flow rate of the first-stage intake based on the first-stage intake pressure;

[0147] The current operating point of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first-stage intake air and the second-stage outlet air pressure.

[0148] In this embodiment, the operating point of the magnetic levitation air compressor can be determined using a pressure-volume conversion model with fixed parameters. Specifically: the first pressure sensor installed near the turbine intake end of the first-stage intake pipe collects the current absolute pressure value of the first-stage intake in real time; the second-stage outlet pressure is monitored by a second pressure sensor installed near the turbine outlet end of the second-stage outlet pipe, which collects the current absolute pressure value of the second-stage outlet in real time; a simplified ideal gas state equation is used for conversion, and the calculated absolute pressure value of the first-stage intake, the volumetric flow rate of the first-stage intake, and the absolute pressure value of the second-stage outlet are combined to form a coordinate vector. This vector is the real-time operating point of the magnetic levitation air compressor. The control system can quickly obtain the compression ratio and flow characteristics of the current unit using a fixed-parameter calculation method, which serves as the basis for anti-surge judgment.

[0149] To enhance the system's accuracy in detecting changes in ambient temperature, an additional temperature sensor module is added. Specifically, a temperature sensor is installed upstream of the turbine inlet in the first intake pipe, and a similar temperature sensor is installed downstream of the turbine outlet in the second-stage outlet pipe. The temperature and pressure values ​​detected in the first intake pipe are substituted into the ideal gas law to calculate the corrected first-stage intake volumetric flow rate. This volumetric flow rate is then compared with the second-stage outlet absolute pressure value P. t2 The coordinate vector is formed by combining the temperature value T2 and T2. The first pressure sensor can be set at the upstream of the first-stage exhaust return pipe, at a distance from the turbine inlet, and the second pressure sensor can be set at the downstream of the second-stage exhaust return pipe, at a distance of 0.2~0.4m from the turbine outlet. Through the above temperature compensation scheme, the accuracy of surge judgment is improved in high-temperature summer or low-temperature winter environments.

[0150] In this embodiment of the invention, the volumetric flow rate of the first-stage intake air is calculated by combining the first-stage intake pressure with the medium temperature and pressure parameters; then, the calculated volumetric flow rate of the first-stage intake air is combined with the second-stage outlet pressure to form a two-dimensional operating point coordinate system, which characterizes the compression load and output capacity of the air compressor. This ensures that the anti-surge judgment can accurately fall between the preset warning line and the shutdown line for comparison, and promptly triggers the vent valve adjustment or protection action. Moreover, it effectively avoids the risk of misjudgment that may be caused by relying solely on a single pressure parameter.

[0151] In this embodiment of the invention, specifically, the volumetric flow rate of the first-stage intake air is calculated based on the first-stage intake pressure according to the following formula:

[0152] ;

[0153] ;

[0154] in, For mass flow rate; This is the boundary layer correction factor; This refers to the first-level import cross-sectional area; The static pressure of the gas in the first-stage intake pipe; The differential pressure measured by the differential pressure transmitter in the air inlet section; The adiabatic coefficient; This refers to the volumetric flow rate of the first-stage intake. The constant of the medium gas; This refers to the total gas pressure of the first-stage intake pipeline under standard operating conditions. This refers to the temperature of the first-stage intake manifold under standard operating conditions. This represents the density of the imported gas.

[0155] In this embodiment of the invention, a theoretical benchmark value is established. and Real-time deviation calculations are performed using fixed theoretical values ​​as reference points. Surge boundary conditions are quantified through standard parameters to avoid surge line drift under different test conditions.

[0156] Step S43: Based on the operating condition point of the magnetic levitation air compressor, control the opening and closing of the first vent valve and the second vent valve based on the pressure surge shutdown line and the pressure surge warning line, wherein the pressure surge warning line is a surge warning line with a safety margin established based on the pressure surge shutdown line; and / or, based on the operating condition point of the magnetic levitation air compressor, control the opening and closing of the first vent valve and the second vent valve based on the pressure ratio surge shutdown line and the pressure ratio surge warning line, wherein the pressure ratio surge warning line is a surge warning line with a safety margin established based on the pressure ratio surge shutdown line.

[0157] In this embodiment of the invention, the operating condition point of the magnetic levitation air compressor is the coordinate point formed by the key operating parameters of the magnetic levitation air compressor at a certain instantaneous operating state. It is used to characterize the actual load state and outlet pressure level of the air compressor at the current time. It is the core basis for the anti-surge control system to determine whether the equipment is in a safe operating range and whether intervention measures need to be triggered.

[0158] In this embodiment of the invention, intelligent opening and closing control of the first and second vent valves is achieved based on the pressure surge shutdown line and the pressure surge warning line. This realizes a precise matching and graded response mechanism between the equipment operating state and the safety threshold. By setting the pressure surge warning line as the upstream reference boundary of the pressure surge shutdown line, combined with the safety margin, a buffer handling range is provided for the control system. When the operating point enters the area between the warning line and the shutdown line, the system prioritizes triggering the vent valve opening action instead of directly shutting down, which effectively avoids the occurrence of surge phenomenon and ensures the stability of continuous equipment operation. By simultaneously using pressure... The dual judgment mechanism combining the surge warning line and the pressure ratio surge shutdown line expands the anti-surge control from a single pressure parameter to a multi-dimensional monitoring scope of pressure ratio, significantly improving the accuracy of identification and anti-interference ability, and reducing the risk of misjudgment. Furthermore, the coordinated opening and closing control strategy of the first and second vent valves enables the system to make differentiated adjustments according to the specific surge risk level of the first and second stages of the air compressor, realizing the refined execution of graded anti-surge control, ensuring the safe and stable operation of the magnetic levitation air compressor under various complex working conditions, extending the service life of the equipment and reducing unplanned downtime losses.

[0159] In this embodiment of the invention, intelligent opening and closing control of the first and second vent valves is performed based on the operating condition point of the magnetic levitation air compressor, using the pressure surge shutdown line and pressure surge warning line, and / or the pressure ratio surge shutdown line and pressure ratio surge warning line. Specifically, by setting the pressure surge warning line as the upstream reference boundary of the pressure surge shutdown line, a graded handling buffer zone is provided for the control system. When the operating condition point enters the area between the warning line and the shutdown line, the system prioritizes triggering the vent valve opening action instead of directly shutting down, which effectively avoids the occurrence of surge phenomenon and ensures the stability of continuous equipment operation. The dual judgment mechanism combining the pressure ratio surge warning line and the pressure ratio surge shutdown line also expands the anti-surge control from a single pressure parameter to multi-dimensional monitoring, improving the accuracy of identification and anti-interference ability, and reducing the risk of misjudgment. Furthermore, the linkage opening and closing control strategy of the two-stage vent valves enables the system to make fine adjustments according to the specific surge risk level of each level of the air compressor, realizing graded anti-surge control.

[0160] In this embodiment of the invention, optionally, before the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure surge shutdown line and pressure surge early warning line, the following may be included:

[0161] The magnetic levitation air compressor is controlled to run at its highest speed and at its highest speed respectively, so as to obtain at least two surge pressure operating points for testing;

[0162] According to the preset first margin, the corresponding surge pressure warning point is determined based on the surge pressure operating point.

[0163] The pressure surge shutdown line is obtained by fitting at least two of the surge pressure operating points;

[0164] A pressure surge warning line is obtained by fitting at least two of the aforementioned surge pressure warning points.

[0165] In this embodiment, the pressure surge stop line and the pressure surge warning line can be stored in a preset location after being pre-tested before leaving the factory, or they can be calculated after the first power-on. The specifics can be determined according to the actual situation, and this embodiment does not limit them.

[0166] In this embodiment, the first margin B% is the percentage difference between the warning line and the shutdown line set based on the pressure surge shutdown line. It is used to define the early intervention time window when judging the surge risk by monitoring the absolute pressure at the outlet. When the operating condition point enters this margin range, the vent valve is triggered to open to prevent direct overshoot.

[0167] In this embodiment of the invention, a pressure surge shutdown line is obtained by fitting at least two surge pressure operating points, specifically:

[0168] Pressure sensors are installed in the primary intake pipe, primary exhaust pipe, secondary intake pipe, and secondary exhaust pipe to detect pressure. (i represents the turbine stage number, j represents 1 intake manifold / 2 exhaust manifolds), including the first-stage intake pressure. First-stage exhaust pressure Secondary intake pressure Secondary exhaust pressure Temperature sensors should be installed in the primary intake pipe, primary exhaust pipe, secondary intake pipe, and secondary exhaust pipe to detect temperature. Including primary intake temperature Primary outlet air temperature Secondary intake temperature Secondary outlet temperature A large-diameter vent valve is installed on the exhaust return pipeline, which is normally closed when not venting.

[0169] Test the pressure of the secondary exhaust pipeline Simultaneously calculate the first-stage inlet volumetric flow rate. :

[0170] ;

[0171] ;

[0172] in, For mass flow rate; This is the boundary layer correction factor; This refers to the import cross-sectional area; The static pressure of the gas in the first-stage intake pipe; This refers to the temperature of the first-stage intake manifold; if no temperature sensor is installed, the default temperature under standard operating conditions is used. K; The differential pressure measured by the differential pressure transmitter in the air inlet section; The adiabatic coefficient; This refers to the volumetric flow rate of the first-stage intake. The constant of the medium gas; This refers to the total gas pressure of the first-stage intake pipeline under standard operating conditions. This refers to the temperature of the first-stage intake manifold under standard operating conditions.

[0173] In this embodiment of the invention, a theoretical benchmark value is established. and Real-time deviation calculations are performed using fixed theoretical values ​​as reference points. Surge boundary conditions are quantified through standard parameters to avoid surge line drift under different test conditions.

[0174] A pressure surge warning line can be obtained by fitting at least two of the surge pressure warning points, and may include:

[0175] The surge pressure operating point was determined based on the surge test of the magnetic levitation air compressor. , and , Set a certain first margin B% to determine the surge pressure warning point. , and , :

[0176] ;

[0177] ;

[0178] according to , and , Confirm the pressure surge shutdown line (e.g.) Figure 5 (as shown)

[0179] ;

[0180] according to , and , Confirm the pressure surge warning line (such as...) Figure 5 (as shown)

[0181] .

[0182] The above embodiments illustrate the determination of the pressure surge shutdown line using two surge pressure operating points as examples. Similarly, determining the pressure surge warning line using two surge pressure warning points is also merely an example. In some embodiments, the pressure surge shutdown line and the pressure surge warning line can be determined by fitting more surge pressure operating points. The pressure surge shutdown line and the pressure surge warning line can be straight lines, curves, or other possible irregular lines, depending on the actual situation. This specification does not limit this aspect in the embodiments.

[0183] In this embodiment of the invention, a surge test is conducted by controlling a magnetic levitation air compressor to run at different speeds, obtaining at least two pressure operating points and fitting a pressure surge shutdown line accordingly. Combined with a preset safety margin, a corresponding surge pressure warning line is determined. The surge pressure operating points are adjusted with a safety margin through a preset first margin, which reasonably balances the sensitivity of the anti-surge response and the stability of system operation. This avoids frequent false triggers while ensuring that early warnings and intervention measures can be taken when the system is truly close to the critical state. This fitting method makes the pressure line and pressure ratio line have continuous functional expressions rather than discrete point values, improving the accuracy and response speed of dynamic monitoring.

[0184] In this embodiment of the invention, optionally, before the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure ratio surge shutdown line and the pressure ratio surge warning line, the following may be included:

[0185] The magnetic levitation air compressor is controlled to run at its highest speed and at its highest speed respectively, and at least two surge pressure ratio operating points are obtained for testing.

[0186] According to the preset first margin, the corresponding surge pressure ratio warning point is determined based on the surge pressure ratio operating point;

[0187] The pressure ratio surge shutdown line is obtained by fitting at least two of the aforementioned surge pressure ratio operating points;

[0188] A pressure ratio surge warning line is obtained by fitting at least two of the aforementioned surge pressure ratio warning points.

[0189] In this embodiment, the magnetic levitation air compressor can be controlled to operate stably at the highest permissible speed and the lowest critical safe speed until it enters the surge state. The pressure ratio operating condition coordinate points corresponding to the critical moment when the first gas loss instability is triggered at each speed are recorded. Based on the surge pressure ratio operating condition point coordinates obtained from at least two tests, a continuous pressure ratio surge shutdown line function expression is generated using a polynomial fitting or curve approximation algorithm. Then, according to the preset first margin percentage, the corresponding time advance and flow lag are calculated forward on the shutdown line and converted into a spatial distance threshold. The surge critical value of each speed point is shifted upward to calculate the corresponding multiple pressure ratio warning points. Then, the same fitting method is used to form a pressure ratio surge warning line that completely covers the entire speed range, providing a graded protection benchmark for different operating condition intervals.

[0190] In the initial stage of equipment operation, a fixed parameter operation strategy can be adopted and all instantaneous pressure and flow sensor data collected during normal operation can be recorded. The system continuously monitors the dynamic response curve of the air compressor under various load levels, autonomously identifies potential surge critical data segments close to the boundary of the stable operating range, and refits at least two typical surge pressure ratio operating points automatically selected from these historical operating big data to generate the initial pressure ratio surge shutdown line. At the same time, according to the preset first margin, the pressure ratio corresponding to each set of candidate critical points is converted into multiple warning critical position coordinates by safety margin conversion. The pressure ratio surge warning line covering the actual operating speed range is connected by the interpolation algorithm. The system can continuously fine-tune the deformation of the fitting curve of the two boundary lines according to the subsequent long-term operating data to adapt to the performance drift caused by equipment aging or environmental changes.

[0191] In this embodiment of the invention, the method for determining the pressure ratio surge shutdown line and the pressure ratio surge warning line for each stage is as follows:

[0192] The control system calculates the inlet volumetric flow rate. Compared to each pressure level : ;

[0193] in, For the first Level pressure ratio; For the first Export pressure at the level; For the first Import pressure at the level;

[0194] Specifically, the calculation of the pressure ratio for each stage involves obtaining the first-stage outlet pressure and the second-stage intake pressure.

[0195] The ratio of the first-stage outlet pressure to the first-stage inlet pressure is taken as the first-stage pressure ratio;

[0196] The ratio of the secondary outlet pressure to the secondary inlet pressure is taken as the secondary pressure ratio;

[0197] The current operating point of the first stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first stage air intake and the first stage pressure ratio.

[0198] The current operating point of the second stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first-stage intake and the pressure ratio of the second stage.

[0199] The surge pressure ratio operating point was determined based on surge testing of a magnetic levitation air compressor. , and , Set a certain first margin B%, and determine the surge pressure ratio warning point. , and , :

[0200] %

[0201] ;

[0202] according to , and , Determine the pressure ratio surge stop line (e.g.) Figure 6 (as shown)

[0203] ;

[0204] according to , and , Confirm the pressure ratio to the surge warning line (e.g.) Figure 6 (as shown)

[0205] .

[0206] In this embodiment of the invention, by controlling the magnetic levitation air compressor to operate at different speeds and obtaining at least two pressure ratio surge condition points, a pressure ratio surge shutdown line is fitted. A corresponding pressure ratio surge warning point is determined by combining this with a preset first margin, and then a warning line is fitted. Using the pressure ratio as the judgment criterion effectively eliminates the influence of different operating environments on surge judgment, making the critical boundary more stable and reliable. The preset first margin achieves a balance between safety redundancy and response sensitivity. The advance of the warning line relative to the shutdown line ensures that the system has sufficient time to intervene when it truly approaches the critical state, preventing false triggering from affecting production continuity and ensuring timely protection response at critical moments. This scheme, together with the aforementioned pressure line judgment mechanism, forms a dual safety guarantee system, making anti-surge control more comprehensive and multi-dimensional. It is particularly suitable for ensuring the safe and stable operation of high-precision, high-speed equipment such as magnetic levitation air compressors under various complex operating conditions, effectively extending the service life of core components and reducing unnecessary downtime.

[0207] In this embodiment of the invention, optionally, controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure ratio surge shutdown line and pressure ratio surge warning line includes:

[0208] Based on the primary operating condition point and / or the secondary operating condition point, the opening and closing of the first vent valve and the second vent valve are controlled according to the pressure ratio surge shutdown line and the pressure ratio surge early warning line.

[0209] In this embodiment of the invention, by precisely matching the operating point (primary and / or secondary) of the magnetic levitation air compressor with the pressure ratio surge shutdown line and the pressure ratio surge warning line, intelligent hierarchical control of the first and second vent valves is achieved. By independently monitoring the primary and secondary operating points and separately judging the pressure ratio, the surge risk occurring in either the primary or secondary level is avoided from being missed in the control blind zone, improving the stability and reliability of the system's judgment under complex operating conditions. Furthermore, it supports both individual-level anti-surge intervention and multi-level coordinated response, enhancing the applicability of the technical solution. In one embodiment, optionally, when the magnetic levitation air compressor unit further includes a temperature sensor, determining the current operating point of the magnetic levitation air compressor based on the primary inlet pressure and the secondary outlet pressure includes:

[0210] Obtain the temperature of the primary intake pipe and the temperature of the secondary exhaust pipe;

[0211] Calculate the volumetric flow rate of the first-stage intake based on the first-stage intake pressure and the first-stage intake pipeline temperature.

[0212] Calculate the total gas pressure of the secondary outlet based on the secondary outlet pressure and the secondary outlet pipeline temperature;

[0213] The current operating point of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first-stage intake air and the total gas pressure of the second-stage outlet air.

[0214] In this embodiment, by adding real-time monitoring of the temperature of the primary intake pipeline and the secondary outlet pipeline and combining it with the corresponding pressure data, the operating condition point of the magnetic levitation air compressor is determined. Introducing temperature sensors allows for accurate acquisition of the actual thermodynamic state parameters of the gas at the inlet. Using the ideal gas law or compressibility coefficient correction formula, the primary intake pressure is converted into volumetric flow rate under standard conditions, effectively eliminating the impact of gas density changes caused by ambient temperature variations, seasonal temperature differences, or load fluctuations on flow rate calculation. Synchronous acquisition of secondary outlet pressure and temperature data further refines the calculation of the absolute total pressure of the gas, improving the physical accuracy of surge boundary determination. Furthermore, by incorporating temperature compensation into the operating condition point calculation process, the control system can still ensure the reliability and consistency of flow and pressure parameters in complex operating conditions such as high-temperature environments, start-up preheating stages, or variable load transition periods, avoiding the risk of misjudgment due to temperature deviations. This embodiment, through a more refined surge monitoring mechanism, enables the anti-surge control strategy to construct operating trajectory points based on more accurate inlet volumetric flow rate and outlet total pressure, enhancing the system's adaptability to surge boundary movement.

[0215] Specifically, the volumetric flow rate of the first-stage intake air can be calculated based on the first-stage intake pressure and the first-stage intake pipeline temperature using the following formula:

[0216] ;

[0217] ;

[0218] ;

[0219] in, For mass flow rate; This is the boundary layer correction factor; This refers to the first-level import cross-sectional area; The static pressure of the gas in the first-stage intake pipe; The differential pressure measured by the differential pressure transmitter in the air inlet section; The adiabatic coefficient; This is the mass flow rate converted to standard operating conditions. This refers to the first-stage intake pressure under standard operating conditions. Temperature under standard operating conditions; This refers to the temperature of the primary intake manifold. This refers to the volumetric flow rate of the first-stage intake. The constant of the medium gas;

[0220] Specifically, the total gas pressure of the secondary outlet is calculated based on the secondary outlet pressure and the secondary outlet pipeline temperature using the following formula:

[0221]

[0222] in,

[0223] in, The density of the gas; It is the static pressure of the gas; For temperature; This refers to the total gas pressure. For mass flow rate; The cross-sectional area; Flow rate.

[0224] In one embodiment, optionally, it may also include:

[0225] Obtain the temperature of the primary exhaust pipe and the temperature of the secondary intake pipe;

[0226] Calculate the total gas pressure of the first-stage intake based on the first-stage intake pressure and the first-stage intake pipeline temperature;

[0227] Calculate the total gas pressure of the first-stage outlet based on the first-stage outlet pressure and the first-stage outlet pipeline temperature;

[0228] Calculate the total gas pressure of the second-stage intake based on the second-stage intake pressure and the second-stage intake pipeline temperature;

[0229] The ratio of the total pressure of the first-stage gas to the total pressure of the first-stage gas is taken as the first-stage pressure ratio;

[0230] The ratio of the total pressure of the gas exiting the second stage to the total pressure of the gas exiting the second stage is taken as the second stage pressure ratio;

[0231] The current operating point of the first stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first stage air intake and the first stage pressure ratio.

[0232] The current operating point of the secondary stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the primary intake and the pressure ratio of the secondary stage.

[0233] In this embodiment, temperature sensors 12 can be respectively installed in the primary intake pipe 2, the primary outlet pipe 3, the secondary intake pipe 4, and the secondary outlet pipe 5. By installing temperature sensors in the primary and secondary intake and outlet pipes, the target temperature obtained by the temperature sensors can be monitored in real time, thereby ensuring that the system operates under optimal conditions. The addition of temperature data makes the calculation of the total gas pressure more accurate and complete, and the inlet and outlet pressures are corrected by temperature compensation, thereby eliminating the errors in flow and pressure calculation caused by changes in gas density due to changes in ambient temperature, seasonal temperature differences, or load fluctuations. The total gas pressure parameters at each pipeline location in the first and second stages are calculated separately, ensuring that the state of the compression process at each stage can be judged independently rather than being evaluated in a mixed manner. This avoids the situation where a problem in one stage is misjudged as a problem in another stage, improving the positioning accuracy and targeting of anti-surge control. By combining temperature and pressure calculations, a more complete data support system is provided for the full-state monitoring of the magnetic levitation air compressor. This not only enhances the accuracy and reliability of surge identification, but also supports multi-dimensional application needs such as equipment health diagnosis, performance degradation assessment, and energy efficiency optimization through temperature data trajectory analysis. This effectively extends the service life of key components and improves the safety redundancy of the overall system.

[0234] In this embodiment of the invention, optionally, controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor, and according to the pressure surge shutdown line and the pressure surge early warning line, may include:

[0235] When the operating point of the magnetic levitation air compressor is located to the right of the pressure surge warning line, it indicates that the magnetic levitation air compressor is in operation and the first vent valve and the second vent valve can be kept closed.

[0236] When the operating point of the magnetic levitation air compressor is located to the left of the pressure surge warning line and to the right of the pressure surge shutdown line, it indicates that the magnetic levitation air compressor may have airflow oscillation. If it is not controlled in time, surge will occur. At this time, the first vent valve and the second vent valve can be opened at the same time to increase the return gas flow rate, so that the operating point moves to the right to a safe area and eliminates the oscillation phenomenon caused by insufficient air intake.

[0237] When the first vent valve and the second vent valve are opened, if the operating point of the magnetic levitation air compressor is still running to the left of the pressure surge shutdown line, it indicates that the anti-surge adjustment measures are insufficient to offset the airflow backflow effect caused by the current load change or that there is a potential fault in the system that cannot be restored to a safe operating state in time, and the magnetic levitation air compressor will be shut down.

[0238] In this embodiment of the invention, when the magnetic levitation air compressor unit includes a temperature sensor, the volumetric flow rate of the first-stage intake air can be calculated according to the following formula. and the total pressure of the secondary exhaust pipeline :

[0239] ;

[0240] ;

[0241] ;

[0242] in, Mass flow rate (kg / s); This is the boundary layer correction factor; The inlet cross-sectional area is m2; The static pressure of the gas in the first-stage intake pipe is Pa; The differential pressure (Pa) measured by the differential pressure transmitter in the air inlet section; The adiabatic coefficient; This is the mass flow rate converted to standard operating conditions. This refers to the total gas pressure of the first-stage intake pipeline under standard operating conditions. This refers to the temperature of the first-stage intake manifold under standard operating conditions. This refers to the temperature of the primary intake manifold. This refers to the volumetric flow rate of the first-stage intake. The constant of the medium gas;

[0243] ;

[0244] ;

[0245] Where i represents the number of turbine stages, and j represents a 1-intake / 2-outtake pipeline; The gas density in the secondary outlet pipeline; The static pressure of the gas in the secondary outlet pipeline; This refers to the temperature of the secondary exhaust pipe. The total gas pressure of the secondary outlet pipeline; For mass flow rate; This refers to the cross-sectional area of ​​the secondary exit. Flow rate.

[0246] The surge pressure operating point was determined based on the air compressor surge test: the volumetric flow rate of the first-stage intake air under standard operating conditions. The absolute total pressure of the second-stage exhaust gas under standard operating conditions Volumetric flow rate of secondary intake under standard operating conditions The absolute total pressure of the second-stage exhaust gas under standard operating conditions Set a certain first margin B%, and determine the surge pressure warning point: first-stage intake volumetric flow rate. The total pressure of the gas at the second stage outlet and the volumetric flow rate of the second-stage intake The total pressure of the gas at the secondary outlet The subscript 1 corresponds to the lowest speed test point ( Figure 5 ), subscript 2 corresponds to the highest speed test point ( Figure 5 Specifically:

[0247] ;

[0248] ;

[0249] according to , and , Confirm the pressure surge shutdown line (e.g.) Figure 5 (as shown)

[0250] ;

[0251] according to , and , Confirm the pressure surge warning line (such as...) Figure 5 (as shown)

[0252] ;

[0253] like Figure 5 As shown, when the air compressor is operating at its operating point , When operating to the right of the pressure surge warning line, normal operation is maintained.

[0254] When the magnetic levitation air compressor is in operation , When operating on the left side of the pressure surge warning line and the right side of the pressure surge shutdown line, the pressure sensor sends a signal to the control system, and at the same time opens the first vent valve and the second vent valve on the primary exhaust return pipeline and the secondary exhaust return pipeline, thereby increasing the flow rate and keeping the magnetic levitation air compressor away from the surge condition.

[0255] When the first and second vent valves are open, the pressure in the secondary outlet pipeline still increases, which is the operating point of the magnetic levitation air compressor. , When the unit reaches the left side of the pressure surge shutdown line, it will shut down.

[0256] In this embodiment of the invention, the first and second vent valves are controlled in stages according to the relative positions of the operating point of the magnetic levitation air compressor with the pressure surge warning line and the shutdown line. When the operating point is in the safe zone to the right of the warning line, the vent valve remains closed, ensuring the full flow output and maximum energy efficiency of the air compressor under normal load, and avoiding system efficiency reduction and energy consumption increase caused by erroneous opening of the vent valve. When the operating point crosses the warning line and enters the buffer zone between the warning line and the shutdown line, the vent valve is immediately triggered to open instead of waiting for the critical state to trigger shutdown, thereby increasing the gas flow in the return pipeline through early intervention. The system quickly shifts the operating point to the right to a safe zone, effectively preventing surge and ensuring the stability of continuous equipment operation. When the operating point fails to return to the right side of the warning line after the vent valve is opened and continues to enter the critical danger zone to the left of the shutdown line, an emergency shutdown protection command is automatically executed. This prevents mechanical damage to the impeller, magnetic bearing, and other connecting components caused by severe backflow of airflow due to insufficient anti-surge adjustment or system failure. It achieves a precise control strategy with graded indexing, avoiding equipment disturbance and signal jitter caused by frequent start-stop of the vent valve, and ensuring sufficient redundant operating space when truly approaching the surge boundary.

[0257] In this embodiment of the invention, optionally, controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure ratio surge shutdown line and pressure ratio surge warning line may include:

[0258] When the operating point of the magnetic levitation air compressor is located to the right of the pressure ratio surge warning line, it indicates that the magnetic levitation air compressor is in operation and the first vent valve and the second vent valve can be kept closed.

[0259] When the operating point of the magnetic levitation air compressor is located to the left of the pressure ratio surge warning line and to the right of the pressure ratio surge shutdown line, it indicates that the magnetic levitation air compressor may have airflow oscillation. If it is not controlled in time, surge will occur. At this time, the first vent valve and the second vent valve can be opened at the same time to increase the return gas flow rate, so that the operating point moves to the right to a safe area and eliminates the oscillation phenomenon caused by insufficient air intake.

[0260] When the first vent valve and the second vent valve are opened, if the operating point of the magnetic levitation air compressor is still running to the left of the pressure surge shutdown line, it indicates that the anti-surge adjustment measures are insufficient to offset the airflow backflow effect caused by the current load change or that there is a potential fault in the system that cannot be restored to a safe operating state in time, and the magnetic levitation air compressor will be shut down.

[0261] In this embodiment of the invention, when using pressure ratio control at each stage, the control system calculates the volumetric flow rate of the first-stage intake air. Compared to each pressure level : ;in, For the first Level pressure ratio; For the first Overall export pressure; For the first Total import pressure at the level;

[0262] The surge pressure operating point was determined based on the air compressor surge test: the volumetric flow rate of the first-stage intake air under standard operating conditions. The absolute total pressure of the second-stage exhaust gas under standard operating conditions Volumetric flow rate of secondary intake under standard operating conditions The absolute total pressure of the second-stage exhaust gas under standard operating conditions Set a certain first margin B%, and determine the surge pressure warning point: first-stage intake volumetric flow rate. The total pressure of the gas at the second stage outlet and the volumetric flow rate of the second-stage intake The total pressure of the gas at the secondary outlet The subscript 1 corresponds to the lowest speed test point ( Figure 6 ), subscript 2 corresponds to the highest speed test point ( Figure 6 Specifically:

[0263] %

[0264] ;

[0265] according to , and , Confirm the pressure ratio to the surge shutdown line (e.g.) Figure 6 (as shown)

[0266] ;

[0267] according to , and , Confirm the pressure ratio to the surge warning line (e.g.) Figure 6 (as shown)

[0268] ;

[0269] like Figure 6 As shown, when the air compressor is operating at its operating point , When operating to the right of the pressure ratio surge warning line, normal operation is maintained.

[0270] When the magnetic levitation air compressor is in operation , When operating to the left of the pressure ratio surge warning line and to the right of the pressure ratio surge shutdown line, the sensor sends a signal to the control system, and at the same time opens the first vent valve and the second vent valve on the primary exhaust return pipeline and the secondary exhaust return pipeline, thereby increasing the flow rate and keeping the magnetic levitation air compressor away from the surge condition.

[0271] When the first and second vent valves are open, the pressure in the secondary outlet pipeline continues to increase, which is the operating point of the magnetic levitation air compressor. , When the unit reaches the left side of the pressure ratio surge shutdown line, it will shut down.

[0272] In this embodiment of the invention, the first and second vent valves are controlled in stages based on their relative positions to the operating point of the magnetic levitation air compressor and the pressure ratio surge warning line and shutdown line. When the operating point is in the safe zone to the right of the pressure ratio surge warning line, both vent valves remain closed to ensure full flow output and maximize energy efficiency of the air compressor, avoiding energy leakage and equipment efficiency reduction caused by premature opening of the vent valves. When the operating point crosses the warning line and enters the buffer zone between the two lines, the vent valves are immediately triggered to open, rapidly shifting the operating point to the right to the safe zone by increasing the return gas flow. This provides sufficient time margin for control response to proactively avoid surge risks rather than passively executing shutdown protection only at the critical point. This pressure ratio determination mechanism, compared to simple pressure... The parameters effectively eliminate the influence of external factors such as atmospheric pressure changes and temperature fluctuations on surge judgment, ensuring the stability and accuracy of the warning line and shutdown line in different seasons and altitudes. This effectively reduces the risk of misjudgment and missed judgment caused by environmental changes, and realizes a precise indexing intelligent control strategy. It avoids system disturbances and equipment wear caused by frequent opening and closing of the vent valve, and ensures sufficient redundant operating space to protect equipment safety when truly approaching the surge boundary. Designed for the high-speed and high-precision operation characteristics of magnetic levitation air compressors, the surge boundary curve is established by pressure ratio rather than absolute pressure value, making the anti-surge logic more consistent with the physical nature of impeller aerodynamic performance changes, providing reliable protection for the stable and efficient operation of the equipment under various complex working conditions.

[0273] In some embodiments, optionally, when the magnetic levitation air compressor unit further includes: a first butterfly valve, a second butterfly valve, at least one third vent valve, and at least one fourth vent valve, the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure surge shutdown line and pressure surge warning line may include:

[0274] When the operating condition point of the magnetic levitation air compressor is located to the right of the pressure surge warning line, it indicates that the magnetic levitation air compressor is in operation and the first vent valve, the second vent valve, the third vent valve and the fourth vent valve can be kept closed.

[0275] When the operating point of the magnetic levitation air compressor is located to the left of the second pressure surge warning line and to the right of the first pressure surge warning line, it indicates that the magnetic levitation air compressor may have airflow oscillation. If it is not controlled in time, surge will occur. At this time, the third vent valve and the fourth vent valve can be opened simultaneously, and the opening of the first butterfly valve and the second butterfly valve can be controlled to keep the operating pressure constant. In order to increase the return gas flow, the operating point can be moved to the right to a safe area, eliminating the oscillation phenomenon caused by insufficient air intake. The warning range of the second pressure surge warning line is smaller than that of the first pressure surge warning line.

[0276] When the operating point of the magnetic levitation air compressor is to the left of the first pressure surge warning line and to the right of the pressure surge shutdown line, it indicates that the magnetic levitation air compressor may have airflow oscillation. If it is not controlled in time, surge will occur. At this time, the first vent valve and the second vent valve can be opened at the same time, and the first butterfly valve and the second butterfly valve can be fully opened to increase the return gas flow rate, so that the operating point can be moved to the right to a safe area, and the oscillation phenomenon caused by insufficient air intake can be eliminated.

[0277] When the first vent valve and the second vent valve are opened, if the operating point of the magnetic levitation air compressor is still running to the left of the pressure surge shutdown line, it indicates that the anti-surge adjustment measures are insufficient to offset the airflow backflow effect caused by the current load change or that there is a potential fault in the system that cannot be restored to a safe operating state in time, and the magnetic levitation air compressor will be shut down.

[0278] In this embodiment, the opening and closing of the first vent valve and the second vent valve are controlled based on the operating condition point of the magnetic levitation air compressor, according to the pressure surge shutdown line and the pressure surge early warning line. Specifically:

[0279] The control system detects the pressure of the secondary exhaust pipeline. Simultaneously calculate the volumetric flow rate of the first-stage intake. :

[0280] ;

[0281] ;

[0282] in, For mass flow rate; This is the boundary layer correction factor; This refers to the first-level import cross-sectional area; The static pressure of the gas in the first-stage intake pipe; The differential pressure measured by the differential pressure transmitter in the air inlet section; The adiabatic coefficient; This is the mass flow rate converted to standard operating conditions. This refers to the total gas pressure of the first-stage intake pipeline under standard operating conditions. This refers to the temperature of the first-stage intake manifold under standard operating conditions. This refers to the temperature of the primary intake manifold. This refers to the volumetric flow rate of the first-stage intake. The constant of the medium gas;

[0283] The surge pressure operating point was determined based on the surge test of the magnetic levitation air compressor. , and , Based on a certain initial margin B% (the margin can be adjusted according to actual conditions), determine the surge pressure warning point. , and , The system controls the opening of the large-diameter first and second vent valves; based on a certain second margin C%, (the second margin C% is a safety boundary difference set between the warning line and the shutdown line of the pressure ratio surge shutdown line, serving as a buffer index in the graded response mechanism; the second margin is smaller than the first margin, and the two are used to achieve graded judgment of surge risk through differentiated threshold settings, ensuring timely anti-surge intervention while avoiding system efficiency loss due to premature triggering, reflecting the optimal balance design between equipment safety and operating economy, and the design of the second margin includes a first pressure surge warning line and a second pressure surge warning line) the surge pressure warning point is determined. , and , Controls the opening of the small-diameter third and fourth vent valves, and multiple pressure warning points can be set according to the number of small vent valves connected in parallel:

[0284] ;

[0285] ;

[0286] ;

[0287] ;

[0288] according to , and , Confirm the pressure surge shutdown line (e.g.) Figure 7 (as shown)

[0289] ;

[0290] according to , and , Confirm the first pressure surge warning line B (e.g.) Figure 7 (as shown)

[0291] ;

[0292] according to , and , Confirm the second pressure surge warning line C (e.g.) Figure 7 (as shown)

[0293] .

[0294] In this embodiment, based on the relative positions of the operating point of the magnetic levitation air compressor with the two-stage pressure surge warning line and the shutdown line, multi-valve coordinated hierarchical control is implemented for the first and second vent valves, as well as the third and fourth vent valves and the first and second butterfly valves. A multi-stage surge warning line is introduced in conjunction with different levels of actuators to construct a two-stage anti-surge buffer mechanism. When the operating point enters the first-stage warning zone, small fluctuations can be eliminated simply by opening the auxiliary vent valve and adjusting its opening to maintain the output pressure. This avoids triggering the high-energy state protection of full-flow backflow under slight disturbances, effectively reducing the frequency and intensity of equipment control actions. Furthermore, by maintaining a constant pipeline operating pressure when the first / second butterfly valve is in conjunction with the third / fourth vent valve, the system effectively prevents such fluctuations. This ensures that the continuous gas flow demand of downstream users is not affected by the air compressor surge regulation, and decouples the anti-surge operation from the system's gas supply stability. When the operating point further deteriorates to the secondary warning area, the system automatically upgrades the intervention strategy, opening the main vent valve to provide maximum backflow capacity and fully opening the butterfly valve to eliminate pipeline resistance to achieve rapid flow recovery. This response logic, from light to heavy, improves the anti-surge safety factor while avoiding over-protection. Through multi-level linkage, it further compresses the physical space where surge occurs, giving the system a higher response margin. It also reduces the mechanical stress fluctuations borne by the magnetic bearing through the differentiated actions of the valve combination, extends the life of key components, and ensures the stable operation of the entire gas supply system.

[0295] In some embodiments, optionally, when the magnetic levitation air compressor unit includes: a first butterfly valve, a second butterfly valve, at least one third vent valve, and at least one fourth vent valve, the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure ratio surge shutdown line and the pressure ratio surge warning line includes:

[0296] When the operating point of the magnetic levitation air compressor is located to the right of the pressure ratio surge warning line, the first vent valve, the second vent valve, the third vent valve and the fourth vent valve shall be kept closed;

[0297] When the operating condition point of the magnetic levitation air compressor is to the left of the second pressure ratio surge warning line and to the right of the first pressure ratio surge warning line, the third vent valve and the fourth vent valve are controlled to open, and the opening degree of the first butterfly valve and the second butterfly valve is controlled to maintain the operating pressure ratio unchanged.

[0298] When the operating condition point of the magnetic levitation air compressor is to the left of the first pressure ratio surge warning line and to the right of the pressure ratio surge shutdown line, the first vent valve and the second vent valve are controlled to open, and the opening degree of the first butterfly valve and the second butterfly valve is controlled to be at its maximum.

[0299] When the first vent valve and the second vent valve are opened, and the operating point of the magnetic levitation air compressor is still running to the left of the pressure ratio surge stop line, the magnetic levitation air compressor stops.

[0300] In this embodiment, the opening and closing of the first vent valve and the second vent valve are controlled based on the operating condition point of the magnetic levitation air compressor, according to the pressure ratio surge shutdown line and the pressure ratio surge warning line. Specifically:

[0301] When using each stage of pressure ratio control, the control system calculates the inlet volumetric flow rate. Compared to each pressure level : ;

[0302] in: For the first Level pressure ratio; For the first Export pressure at the level; For the first Import pressure at the level;

[0303] The surge pressure ratio operating point was determined based on surge testing of a magnetic levitation air compressor. , and , Based on a certain first margin B%, the surge pressure warning point is determined. , and , Control the opening of the large-diameter vent valve; determine the surge pressure warning point based on a certain second margin C%. , and , Controls the opening of small-diameter vent valves, and multiple pressure warning points can be set according to the number of small vent valves connected in parallel:

[0304] ;

[0305] ;

[0306] ;

[0307] ;

[0308] according to , and , Confirm the pressure ratio to the surge shutdown line (e.g.) Figure 8 (as shown)

[0309] ;

[0310] according to , and , Confirm the first pressure ratio to the surge warning line (e.g.) Figure 8 (as shown)

[0311] ;

[0312] according to , and , Confirm the second pressure ratio to the surge warning line (e.g.) Figure 8 (as shown)

[0313] .

[0314] In this embodiment, the setting of the first butterfly valve and the second butterfly valve makes the control of gas flow more flexible. By adjusting the opening of the butterfly valve, the gas flow rate can be precisely controlled to meet the needs under different working conditions, thereby improving the overall efficiency of the system. By setting the vent valve and the butterfly valve at the same time, the pressure can be smoothly adjusted to maintain the vent stability of the ultra-high speed magnetic levitation control system.

[0315] In some embodiments, the third and fourth vent valves are small-diameter vent valves, and multiple valves can be connected in parallel. The connection design between the butterfly valve and the vent valve achieves internal pressure balance. With appropriate vent control, the pressure can be quickly adjusted to prevent system instability and surge. By precisely controlling the gas flow, it is ensured that the gas at each stage can be compressed under optimal conditions, thereby improving the overall operating efficiency of the equipment.

[0316] In this embodiment, by increasing the opening degree of the first and second butterfly valves, the flow rate increases, thus keeping the magnetic levitation air compressor away from surge conditions. Specifically, the opening strategy of the first and second butterfly valves is as follows: when the inlet volumetric flow rate of the magnetic levitation air compressor at its operating point... , When operating to the right of the C-force surge warning line, the butterfly valve does not open; when the inlet volumetric flow rate of the magnetic levitation air compressor is at the operating point... , When operating to the left of the C-force surge warning line and to the right of the B-pressure surge warning line, set the operating pressure to f, and adjust the butterfly valve from D to B to increase the opening to maintain the operating pressure f constant; when the inlet volumetric flow rate of the magnetic levitation air compressor is at the operating point... , When operating to the left of the B pressure surge warning line, the butterfly valve is 100% open.

[0317] Opening the vent valve increases the flow rate, keeping the magnetic levitation air compressor away from surge conditions. The vent valve opening strategy is as follows: when the magnetic levitation air compressor is operating at its operating point... , When operating to the right of the C-pressure surge warning line, normal operation is maintained; when the magnetic levitation air compressor is in operation... , When operating at the left side of the C pressure surge warning line and the right side of the B pressure surge warning line, open the small-diameter vent valves on the primary exhaust return line and the secondary exhaust return line, namely the third vent valve and the fourth vent valve; when the magnetic levitation air compressor is operating at its operating point... , When operating at the left side of the pressure surge warning line and the right side of the pressure surge shutdown line, open the large-diameter vent valves on the primary exhaust return pipeline and the secondary exhaust return pipeline, namely the first vent valve and the second vent valve; when the first vent valve and the second vent valve are open, the pressure in the secondary exhaust pipeline still increases, and the operating point of the magnetic levitation air compressor is... , When the unit reaches the left side of the pressure surge shutdown line, it will shut down.

[0318] At the same time, the operating point of the magnetic levitation air compressor was determined. , When operating to the right of the C-pressure ratio surge warning line, it is in normal operation; when the magnetic levitation air compressor is in its operating condition... , When operating at the left side of the C pressure ratio surge warning line and the right side of the B pressure ratio surge warning line, the pressure sensor sends a signal to the control system, simultaneously opening the small-diameter vent valves on the primary and secondary exhaust return lines, namely the third and fourth vent valves, increasing the flow rate and keeping the magnetic levitation air compressor away from the surge condition; when the magnetic levitation air compressor is operating at its operating point... , When operating at the left side of the pressure ratio surge warning line and the right side of the pressure ratio surge shutdown line, the sensor sends a signal to the control system, simultaneously opening the large-diameter vent valves on the primary and secondary exhaust return lines (i.e., the first and second vent valves), increasing the flow rate and moving the magnetic levitation air compressor away from the surge condition. Even with the first and second vent valves open, the pressure in the secondary exhaust line still increases, and the magnetic levitation air compressor's operating point... , When the unit reaches the left side of the pressure ratio surge shutdown line, it will shut down.

[0319] This invention provides a magnetic levitation air compressor system, which may include: a magnetic levitation air compressor unit and a controller, wherein the magnetic levitation air compressor unit is electrically connected to the controller, and the controller is used to perform actions such as... Figure 4The steps in the magnetic levitation air compressor unit described herein are used to achieve control of the magnetic levitation air compressor unit.

[0320] This invention provides a readable storage medium on which a program or instruction is stored. When the program or instruction is executed by a processor, it implements the various processes of the compressor gap matching control method embodiment as described above, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0321] This application also provides a computer program product, including computer instructions, which, when executed by a processor, implement the above-described... Figure 4 The various processes of the method embodiments shown can achieve the same technical effect, and will not be described again here to avoid repetition.

[0322] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0323] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0324] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A magnetic levitation air compressor unit, characterized in that, include: Magnetic levitation air compressor, primary intake pipeline, primary outlet pipeline, secondary intake pipeline, secondary outlet pipeline, primary exhaust return pipeline, secondary exhaust return pipeline, first vent valve, second vent valve and pressure sensor; The magnetic levitation air compressor includes a primary turbine and a secondary turbine. The primary intake pipe is connected to the intake end of the primary turbine, the exhaust end of the primary turbine is connected to the primary exhaust pipe, the secondary intake pipe is connected to the intake end of the secondary turbine, and the secondary exhaust pipe is connected to the exhaust end of the secondary turbine. The first-stage exhaust return pipeline is used to connect the first-stage intake pipeline and the first-stage exhaust pipeline. The first-stage exhaust return pipeline is provided with a first vent valve, which is used to return at least a portion of the compressed gas output by the first-stage turbine to the intake end of the first-stage turbine after being opened. The secondary exhaust return pipeline is used to connect the secondary intake pipeline and the secondary exhaust pipeline. The secondary exhaust return pipeline is provided with a second vent valve. The second vent valve is used to return at least a portion of the compressed gas output by the secondary turbine to the intake end of the secondary turbine after being opened. Pressure sensors are respectively installed in the first-stage intake pipe and the first-stage exhaust pipe near the first-stage turbine, and in the second-stage intake pipe and the second-stage exhaust pipe near the second-stage turbine. The pressure sensors are used to detect the first-stage intake pressure and the second-stage exhaust pressure.

2. The magnetic levitation air compressor unit according to claim 1, characterized in that, Also includes: Temperature sensors are provided at the locations near the first-stage turbine in the first-stage intake pipe and the first-stage outlet pipe, and at the locations of the second-stage intake pipe and the second-stage outlet pipe, respectively, for detecting the first-stage intake temperature, the first-stage outlet temperature, the second-stage intake temperature, and the second-stage outlet temperature.

3. The magnetic levitation air compressor unit according to claim 1, characterized in that, Also includes: A first butterfly valve and a second butterfly valve, wherein the first butterfly valve is connected in parallel with the first vent valve, and the second butterfly valve is connected in parallel with the second vent valve.

4. The magnetic levitation air compressor unit according to claim 3, characterized in that, Also includes: At least one third vent valve and at least one fourth vent valve, wherein the diameter of the third vent valve is smaller than the diameter of the first vent valve, and the diameter of the fourth vent valve is smaller than the diameter of the second vent valve. The third vent valve is connected in parallel with the first butterfly valve, and the fourth vent valve is connected in parallel with the second butterfly valve.

5. The magnetic levitation air compressor unit according to claim 1, characterized in that, Also includes: An intercooler is connected in series on the pipeline between the primary intake pipeline and the secondary exhaust pipeline.

6. A control method for a magnetic levitation air compressor unit, characterized in that, The control method for the magnetic levitation air compressor unit, applicable to any one of claims 1-5, includes: Obtain the primary intake pressure and the secondary exhaust pressure; Based on the first-stage inlet pressure and the second-stage outlet pressure, the current operating point of the magnetic levitation air compressor is determined. The operating point of the magnetic levitation air compressor is used to characterize the volumetric flow rate and pressure of the gas. Based on the operating condition point of the magnetic levitation air compressor, the opening and closing of the first vent valve and the second vent valve are controlled based on the pressure surge shutdown line and the pressure surge warning line, wherein the pressure surge warning line is a surge warning line with a safety margin established based on the pressure surge shutdown line; and / or, based on the operating condition point of the magnetic levitation air compressor, the opening and closing of the first vent valve and the second vent valve are controlled based on the pressure ratio surge shutdown line and the pressure ratio surge warning line, wherein the pressure ratio surge warning line is a surge warning line with a safety margin established based on the pressure ratio surge shutdown line.

7. The control method for the magnetic levitation air compressor unit according to claim 6, characterized in that, Before the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure surge shutdown line and pressure surge early warning line, the method further includes: The magnetic levitation air compressor is controlled to run at its highest speed and at its highest speed respectively, so as to obtain at least two surge pressure operating points for testing; According to the preset first margin, the corresponding surge pressure warning point is determined based on the surge pressure operating point. The pressure surge shutdown line is obtained by fitting at least two of the surge pressure operating points; A pressure surge warning line is obtained by fitting at least two of the aforementioned surge pressure warning points.

8. The control method for the magnetic levitation air compressor unit according to claim 6, characterized in that, Before the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure ratio surge shutdown line and the pressure ratio surge warning line, the method further includes: The magnetic levitation air compressor is controlled to run at its highest speed and at its highest speed respectively, and at least two surge pressure ratio operating points are obtained for testing. According to the preset first margin, the corresponding surge pressure ratio warning point is determined based on the surge pressure ratio operating point; The pressure ratio surge shutdown line is obtained by fitting at least two of the aforementioned surge pressure ratio operating points; A pressure ratio surge warning line is obtained by fitting at least two of the aforementioned surge pressure ratio warning points.

9. The control method for the magnetic levitation air compressor unit according to claim 6, characterized in that, Based on the primary intake pressure and the secondary outlet pressure, the current operating condition point of the magnetic levitation air compressor is determined, including: Calculate the volumetric flow rate of the first-stage intake based on the first-stage intake pressure; The current operating point of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first-stage intake air and the second-stage outlet air pressure.

10. The control method for the magnetic levitation air compressor unit according to claim 9, characterized in that, The volumetric flow rate of the first-stage intake air is calculated based on the first-stage intake pressure using the following formula: ； ； in, For mass flow rate; This is the boundary layer correction factor; This refers to the first-level import cross-sectional area; The static pressure of the gas in the first-stage intake pipe; The differential pressure measured by the differential pressure transmitter in the air inlet section; The adiabatic coefficient; This refers to the volumetric flow rate of the first-stage intake. The constant of the medium gas; This refers to the total gas pressure of the first-stage intake pipeline under standard operating conditions. This refers to the temperature of the first-stage intake manifold under standard operating conditions. This represents the density of the imported gas.

11. The control method for the magnetic levitation air compressor unit according to claim 6, characterized in that, Also includes: Obtain the primary exhaust pressure and the secondary intake pressure; The ratio of the first-stage outlet pressure to the first-stage inlet pressure is taken as the first-stage pressure ratio; The ratio of the secondary outlet pressure to the secondary inlet pressure is taken as the secondary pressure ratio; The current operating point of the first stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first stage air intake and the first stage pressure ratio. The current operating point of the secondary stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the primary intake and the pressure ratio of the secondary stage.

12. The control method for the magnetic levitation air compressor unit according to claim 6, characterized in that, When the magnetic levitation air compressor unit further includes a temperature sensor, before the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure ratio surge shutdown line and the pressure ratio surge warning line, the following method is further included: Obtain the temperature of the primary exhaust pipe and the temperature of the secondary intake pipe; Calculate the total gas pressure of the first-stage intake based on the first-stage intake pressure and the first-stage intake pipeline temperature; Calculate the total gas pressure of the first-stage outlet based on the first-stage outlet pressure and the first-stage outlet pipeline temperature; Calculate the total gas pressure of the second-stage intake based on the second-stage intake pressure and the second-stage intake pipeline temperature; The ratio of the total pressure of the first-stage gas to the total pressure of the first-stage gas is taken as the first-stage pressure ratio; The ratio of the total pressure of the gas exiting the second stage to the total pressure of the gas exiting the second stage is taken as the second stage pressure ratio; The current operating point of the first stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first stage air intake and the first stage pressure ratio. The current operating point of the secondary stage of the magnetic levitation air compressor is determined by using the volumetric flow rate of the primary intake and the pressure ratio of the secondary stage.

13. The control method for a magnetic levitation air compressor unit according to claim 11 or 12, characterized in that, Based on the operating conditions of the magnetic levitation air compressor, the opening and closing of the first vent valve and the second vent valve are controlled according to the pressure ratio surge shutdown line and the pressure ratio surge warning line, including: When the first-level operating condition point and the second-level operating condition point are operating to the right of the pressure ratio surge warning line, the first vent valve and the second vent valve shall be kept closed. When the first-level operating condition point and the second-level operating condition point are operating to the left of the pressure ratio surge warning line and to the right of the pressure ratio surge shutdown line, the first vent valve and the second vent valve are controlled to open. When the first vent valve and the second vent valve are opened, and the primary operating point and the secondary operating point are still operating to the left of the pressure ratio surge shutdown line, the magnetic levitation air compressor is controlled to stop.

14. The control method for the magnetic levitation air compressor unit according to claim 6, characterized in that, When the magnetic levitation air compressor unit also includes a temperature sensor, the current operating condition point of the magnetic levitation air compressor is determined based on the primary intake pressure and the secondary outlet pressure, including: Obtain the temperature of the primary intake pipe and the temperature of the secondary exhaust pipe; Calculate the volumetric flow rate of the first-stage intake based on the first-stage intake pressure and the first-stage intake pipeline temperature. Calculate the total gas pressure of the secondary outlet based on the secondary outlet pressure and the secondary outlet pipeline temperature; The current operating point of the magnetic levitation air compressor is determined by using the volumetric flow rate of the first-stage intake air and the total gas pressure of the second-stage outlet air.

15. The control method for the magnetic levitation air compressor unit according to claim 11, characterized in that, The volumetric flow rate of the first-stage intake air is calculated based on the first-stage intake pressure and the first-stage intake pipeline temperature using the following formula: ； ； ； in, For mass flow rate; This is the boundary layer correction factor; This refers to the first-level import cross-sectional area; The static pressure of the gas in the first-stage intake pipe; The differential pressure measured by the differential pressure transmitter in the air inlet section; The adiabatic coefficient; This is the mass flow rate converted to standard operating conditions. This refers to the total gas pressure of the first-stage intake pipeline under standard operating conditions. This refers to the temperature of the first-stage intake manifold under standard operating conditions. This refers to the temperature of the primary intake manifold. This refers to the volumetric flow rate of the first-stage intake. The constant of the medium gas; Calculate the total gas pressure of the secondary outlet gas based on the secondary outlet pressure and the secondary outlet pipeline temperature using the following formula: in, in, The gas density in the secondary outlet pipeline; The static pressure of the gas in the secondary outlet pipeline; This refers to the temperature of the secondary exhaust pipe. The total gas pressure of the secondary outlet pipeline; For mass flow rate; This refers to the cross-sectional area of ​​the secondary exit. Flow rate.

16. The control method for the magnetic levitation air compressor unit according to any one of claims 6-15, characterized in that, Based on the operating conditions of the magnetic levitation air compressor, the opening and closing of the first vent valve and the second vent valve are controlled according to the pressure surge shutdown line and the pressure surge warning line, including: When the operating point of the magnetic levitation air compressor is located to the right of the pressure surge warning line, the first vent valve and the second vent valve shall be kept closed. When the operating point of the magnetic levitation air compressor is located to the left of the pressure surge warning line and to the right of the pressure surge shutdown line, the first vent valve and the second vent valve are controlled to open. When the first vent valve and the second vent valve are opened, and the operating point of the magnetic levitation air compressor is still running to the left of the pressure surge stop line, the magnetic levitation air compressor stops.

17. The control method for the magnetic levitation air compressor unit according to claims 6-15, characterized in that, Based on the operating conditions of the magnetic levitation air compressor, the opening and closing of the first vent valve and the second vent valve are controlled according to the pressure ratio surge shutdown line and the pressure ratio surge warning line, including: When the operating point of the magnetic levitation air compressor is located to the right of the pressure ratio surge warning line, the first vent valve and the second vent valve shall be kept closed. When the operating condition point of the magnetic levitation air compressor is located to the left of the pressure ratio surge warning line and to the right of the pressure ratio surge shutdown line, the first vent valve and the second vent valve are controlled to open. When the first vent valve and the second vent valve are opened, and the operating point of the magnetic levitation air compressor is still running to the left of the pressure ratio surge stop line, the magnetic levitation air compressor is controlled to stop.

18. The control method for the magnetic levitation air compressor unit according to any one of claims 6-15, characterized in that, When the magnetic levitation air compressor unit includes: a first butterfly valve, a second butterfly valve, at least one third vent valve, and at least one fourth vent valve, the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure surge shutdown line and pressure surge early warning line includes: When the operating point of the magnetic levitation air compressor is located to the right of the pressure surge warning line, the first vent valve, the second vent valve, the third vent valve and the fourth vent valve shall be kept closed; When the operating condition point of the magnetic levitation air compressor is located to the left of the second pressure surge warning line and to the right of the first pressure surge warning line, the third vent valve and the fourth vent valve are controlled to open, and the opening degree of the first butterfly valve and the second butterfly valve is controlled to keep the operating pressure constant. The warning range of the second pressure surge warning line is smaller than that of the first pressure surge warning line. When the operating condition point of the magnetic levitation air compressor is on the left side of the first pressure surge warning line and on the right side of the pressure surge shutdown line, the first vent valve and the second vent valve are controlled to open, and the opening degree of the first butterfly valve and the second butterfly valve is controlled to be at its maximum. When the first vent valve and the second vent valve are opened, and the operating point of the magnetic levitation air compressor is still running to the left of the pressure surge stop line, the magnetic levitation air compressor stops.

19. The control method for the magnetic levitation air compressor unit according to any one of claims 6-15, characterized in that, When the magnetic levitation air compressor unit includes: a first butterfly valve, a second butterfly valve, at least one third vent valve, and at least one fourth vent valve, the step of controlling the opening and closing of the first vent valve and the second vent valve based on the operating condition point of the magnetic levitation air compressor and the pressure ratio surge shutdown line and the pressure ratio surge warning line includes: When the operating point of the magnetic levitation air compressor is located to the right of the pressure ratio surge warning line, the first vent valve, the second vent valve, the third vent valve and the fourth vent valve shall be kept closed; When the operating condition point of the magnetic levitation air compressor is located to the left of the second pressure ratio surge warning line and to the right of the first pressure ratio surge warning line, the third vent valve and the fourth vent valve are controlled to open, and the opening degree of the first butterfly valve and the second butterfly valve is controlled to maintain the operating pressure ratio unchanged. The warning range of the second pressure surge warning line is smaller than that of the first pressure surge warning line. When the operating condition point of the magnetic levitation air compressor is to the left of the first pressure ratio surge warning line and to the right of the pressure ratio surge shutdown line, the first vent valve and the second vent valve are controlled to open, and the opening degree of the first butterfly valve and the second butterfly valve is controlled to be at its maximum. When the first vent valve and the second vent valve are opened, and the operating point of the magnetic levitation air compressor is still running to the left of the pressure ratio surge stop line, the magnetic levitation air compressor stops.

20. A magnetic levitation air compressor system, characterized in that, include: The magnetic levitation air compressor unit and controller according to any one of claims 1 to 5, wherein the magnetic levitation air compressor unit is electrically connected to the controller, and the controller is used to perform the steps of the magnetic levitation air compressor unit according to any one of claims 6 to 19 to realize the control of the magnetic levitation air compressor unit.

21. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 6 to 19.

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