A reliability test method for magnetic levitation centrifugal air compressor

Abstract

The present invention discloses a reliability test method for a magnetic levitation centrifugal air compressor, which comprises the following steps: S1: constructing a reliability test system for a magnetic levitation centrifugal air compressor; building a magnetic levitation rotor test strategy, an air compressor temperature rise test strategy, an air compressor surge test strategy and an air compressor power-off protection test strategy; S2: constructing a magnetic levitation centrifugal air compressor test system based on a system platform, and implementing a rotor reliability test of the magnetic levitation centrifugal air compressor according to the magnetic levitation rotor test strategy; and for a magnetic levitation centrifugal air compressor that meets the rotor reliability test, executing any one of steps S3 to implement reliability verification of the magnetic levitation centrifugal air compressor; S3: executing a temperature rise reliability test on the magnetic levitation centrifugal air compressor according to the air compressor temperature rise test strategy; or executing a surge reliability test on the magnetic levitation centrifugal air compressor according to the air compressor surge test strategy; or executing a surge reliability test on the magnetic levitation centrifugal air compressor according to the air compressor power-off protection test strategy. The present invention solves the problem that the test items of traditional centrifugal air compressors can no longer meet the reliability verification requirements of magnetic levitation centrifugal air compressors, causing the magnetic levitation control system to be unstable, surge and motor temperature to be high in actual use, thereby causing a high product failure rate.

Description

Technical Field

[0001] The present invention relates to the technical field of reliability testing of magnetic levitation centrifugal air compressors, and in particular to a reliability testing method of magnetic levitation centrifugal air compressors. Background Art

[0002] The magnetic levitation centrifugal air compressor is a new type of air compressor that combines magnetic levitation bearing technology and intelligent control technology with high-speed centrifugal air compressors, resulting in high efficiency, low noise, and environmentally friendly air compressors. Currently, there are no standards specifying the test items for magnetic levitation centrifugal air compressors. Products on the market are generally verified according to the factory tests of traditional centrifugal air compressors. Test items generally include exhaust pressure, inlet flow, noise, exhaust temperature, motor temperature rise, etc. Traditional centrifugal air compressor test items no longer meet the reliability verification requirements of magnetic levitation centrifugal air compressors. For example, during the use of magnetic levitation centrifugal air compressors in the textile, food, fermentation and other industries, it was found that some magnetic levitation control systems lacked stability, and experienced problems such as surge and excessive motor temperature. This resulted in high product failure rates and poor reliability. Product reliability has become a major factor influencing user selection. Therefore, a reliability test method for magnetic levitation centrifugal air compressors is urgently needed to address the problem that the traditional factory test verification method for centrifugal air compressors cannot guarantee the reliability of magnetic levitation centrifugal air compressors, which in turn leads to high product failure rates on the market. Summary of the Invention

[0003] The present invention provides a reliability test method for a magnetic levitation centrifugal air compressor to overcome the above technical problems.

[0004] In order to achieve the above object, the technical solution of the present invention is:

[0005] A reliability test method for a magnetic levitation centrifugal air compressor comprises the following steps:

[0006] S1: Reliability test system for magnetic levitation centrifugal air compressor;

[0007] The reliability test system includes a system platform for building a magnetic levitation centrifugal air compressor test system, and a magnetic levitation rotor test module, a magnetic levitation centrifugal air compressor temperature rise test module, a magnetic levitation centrifugal air compressor surge test module, and a magnetic levitation centrifugal air compressor power-off protection test module respectively connected to the system platform;

[0008] The magnetic levitation rotor test module is used to construct a magnetic levitation rotor test strategy;

[0009] The magnetic levitation centrifugal air compressor temperature rise test module is used to construct an air compressor temperature rise test strategy;

[0010] The magnetic levitation centrifugal air compressor surge test module is used to construct an air compressor surge test strategy;

[0011] The magnetic levitation centrifugal air compressor power-off protection test module is used to construct an air compressor power-off protection test strategy;

[0012] S2: Building a magnetic levitation centrifugal air compressor test system based on the system platform, and implementing a rotor reliability test of the magnetic levitation centrifugal air compressor according to the magnetic levitation rotor test strategy;

[0013] And for the magnetic levitation centrifugal air compressor that meets the rotor reliability test, perform any one of step S3 to achieve reliability verification of the magnetic levitation centrifugal air compressor;

[0014] S3: Perform a temperature rise reliability test on the magnetic levitation centrifugal air compressor according to the air compressor temperature rise test strategy; or perform a surge reliability test on the magnetic levitation centrifugal air compressor according to the air compressor surge test strategy;

[0015] Or perform surge reliability test on magnetic levitation centrifugal air compressor according to the air compressor power-off protection test strategy.

[0016] Furthermore, the magnetic levitation centrifugal air compressor test system includes a magnetic levitation air compressor, an air outlet pipeline and an electric proportional control valve;

[0017] The magnetic levitation air compressor is connected to the air outlet pipeline, and the electric proportional control valve is arranged on the air outlet pipeline. The electric proportional control valve is used to adjust the air compressor flow and outlet pressure to ensure that the air compressor operates at the set flow and outlet pressure;

[0018] The magnetic levitation air compressor includes a load switch, a high-speed frequency converter, a transformer, an uninterruptible power supply UPS, a magnetic levitation motor, a magnetic levitation bearing, a magnetic levitation controller, a PLC main control unit, a touch screen unit, a cooling system and a compressor;

[0019] The load switch is connected to an external power supply and is used to transmit the external power supply to the high-speed frequency converter, transformer and cooling system;

[0020] The transformer is connected to an uninterruptible power supply UPS, and is used to convert the received external power supply and transmit the converted external power supply to the uninterruptible power supply UPS; and the uninterruptible power supply UPS is connected to a magnetic levitation controller;

[0021] The PLC main control unit is connected to the touch screen unit, the magnetic suspension controller, the high-frequency transmission and the cooling system respectively;

[0022] The touch screen unit is used to send control instructions of the magnetic suspension controller or the high-speed frequency converter or the cooling system through the PLC main control unit;

[0023] The magnetic levitation controller is used to receive control instructions of the magnetic levitation controller sent by the PLC main control unit to control the magnetic levitation bearing to achieve suspension, and the magnetic levitation bearing is equipped with a displacement sensor and a temperature sensor; the displacement sensor is used to monitor the position of the magnetic levitation rotor of the magnetic levitation bearing; the temperature sensor is used to monitor the temperature of the magnetic levitation bearing; and the output data of the displacement sensor and the temperature sensor are transmitted to the touch screen unit through the magnetic levitation controller and the PLC main control unit in sequence;

[0024] The high-speed frequency converter is used to receive the high-speed frequency converter control instructions sent by the PLC main control unit to control the operation of the magnetic suspension motor and thus realize the rotation of the magnetic suspension bearing;

[0025] The cooling system is connected to the magnetic levitation motor, and is used to receive control instructions of the cooling system sent by the PLC main control unit to achieve cooling of the magnetic levitation motor and the compressor;

[0026] The outlet of the compressor is connected to the air outlet pipeline through a metal bellows.

[0027] Furthermore, the magnetic levitation rotor test strategy described in S1 is specifically as follows:

[0028] S11: Starting the magnetic levitation centrifugal air compressor test system built on the system platform;

[0029] The magnetic suspension controller receives control instructions of the magnetic suspension controller sent by the PLC main control unit, controls the suspension of the magnetic suspension bearing, and obtains data information of the magnetic suspension bearing;

[0030] The data information includes at least displacement data, front and rear end impeller running track percentage ORB F / ORB R and load capacity percentage;

[0031] The displacement data includes the radial displacement X1 / Y1 of the front end of the radial bearing, the radial displacement X2 / Y2 of the rear end of the radial bearing, and the axial displacement Z of the axial bearing;

[0032] The bearing capacity includes the radial bearing front end bearing capacity LDX1 / LDY1, the radial bearing rear end bearing capacity LDX2 / LDY2 and the axial bearing bearing capacity LDZ;

[0033] S12: Adjust the electric proportional control valve on the outlet pipe to a preset opening threshold, and control the magnetic suspension motor and the air compressor to reach the set first operating speed through the high-speed inverter; and monitor the data information of the magnetic suspension bearing during startup and operation through the touch screen unit;

[0034] When the first preset operation time value is reached, respectively determining the magnitude of the displacement data, the front and rear end impeller operation track percentages ORB F / ORB R, and the load capacity percentage relative to the first, second, and third preset thresholds;

[0035] S13: If it is determined that the displacement data X1 / Y1 / X2 / Y2 / Z is less than the first preset threshold;

[0036] And the front and rear end impeller running track percentage ORB F / ORB R is less than the second preset threshold;

[0037] and the bearing capacity percentage LDX1 / LDY1 / LDX2 / LDY2 / LDZ is less than the third preset threshold;

[0038] It is then confirmed that there is no abnormality in the magnetic levitation rotor test result, the magnetic levitation rotor is reliable, and step S14 is executed;

[0039] Otherwise, it is determined that the magnetic levitation rotor test result is abnormal, the magnetic levitation rotor is unreliable, and step S15 is executed;

[0040] S14: Controlling the magnetic levitation motor and the air compressor to decrease to a set second operating speed through the high-speed inverter, and when the second preset operating time value is reached, controlling the magnetic levitation motor and the air compressor through the high-speed inverter to increase the second operating speed to the first operating speed, and again monitoring the data information of the magnetic levitation bearing during the startup and operation process through the touch screen unit, and repeating step S13 until it is confirmed again that the magnetic levitation rotor test results are normal and the magnetic levitation rotor is reliable;

[0041] S15: Adjust the control current of the magnetic suspension bearing through the magnetic suspension controller, and repeat step S12 until the magnetic suspension rotor test results are normal and the reliability of the magnetic suspension bearing control current is confirmed.

[0042] Furthermore, the air compressor temperature rise test strategy described in S1 is specifically as follows:

[0043] S101: monitoring the magnetic bearing through the touch screen unit to obtain operating data when the magnetic bearing continuously operates for a third preset operating time under rated conditions;

[0044] The operating data includes the temperature rise of the magnetic levitation motor winding, the temperature rise of the magnetic levitation bearing, and the current data information of the magnetic levitation bearing;

[0045] The current data information includes the current displacement data, the current front and rear end impeller running track percentage ORBF / ORB R and the current load capacity percentage;

[0046] S102: Determine the difference between the temperature rise of the magnetic levitation motor winding and a fourth preset threshold, and the difference between the temperature rise of the magnetic levitation bearing and a fifth preset threshold;

[0047] and determining whether the test result of the current data information is abnormal based on step S13;

[0048] S103: If it is determined that the temperature rise of the magnetic levitation motor winding is less than a fourth preset threshold;

[0049] and the temperature rise of the magnetic bearing is less than the fifth preset threshold;

[0050] And based on the judgment in step S13 that the test result of the current data information is normal, it is confirmed that the air compressor temperature rise test is reliable;

[0051] Otherwise, it is determined that the air compressor temperature rise test is unreliable and step S104 is executed;

[0052] S104: Based on the touch screen unit, the PLC main control unit is controlled to send control instructions for the cooling system to achieve cooling of the magnetic levitation motor and the compressor through the air cooling system, and continue to execute steps S102 to S103 until it is confirmed that the air compressor temperature rise test is reliable, and the reliability of the air compressor temperature rise test and the cooling performance of the air cooling system are obtained.

[0053] Furthermore, the air compressor surge test strategy described in S1 is specifically as follows:

[0054] S010: When the magnetic levitation air compressor is operating under rated conditions, based on the preset surge protection line, the opening of the electric proportional valve is adjusted to simulate the situation of increased external resistance, so that the operating point of the magnetic levitation air compressor moves toward the surge line;

[0055] S011: When the opening of the electric proportional valve is adjusted so that the operating point of the magnetic levitation air compressor reaches the surge protection line operating point, the magnetic levitation air compressor is monitored through the touch screen unit to determine whether a surge alarm is issued and the compressor is shut down;

[0056] S012: If the touch screen unit monitors and determines that the surge protection line operating point has been reached, the magnetic levitation air compressor will issue a surge alarm and shut down, and confirm that the air compressor surge test is reliable;

[0057] Otherwise, the surge protection line is reset, and step S011 is repeatedly performed until the air compressor surge test is confirmed to be reliable, and a reliability surge protection line of the air compressor surge test is obtained.

[0058] Furthermore, the air compressor power-off protection test strategy described in S1 is specifically as follows:

[0059] S100: Controlling the magnetic levitation motor and the air compressor to operate at the second operating speed through the high-speed inverter, and cutting off the power supply to the high-speed inverter based on the load switch;

[0060] S110: confirming, through a touch screen unit, whether the magnetic bearing falls during the process of stopping the magnetic levitation motor and the air compressor, and monitoring, through a PLC unit, speed data within a preset time period of the shutdown process to obtain a time-speed curve, and confirming the smoothness of the shutdown process based on the slope of the time-speed curve;

[0061] S111: If, during the process of stopping the magnetic levitation motor and the air compressor, the touch screen unit determines that the magnetic levitation bearing has not fallen and the shutdown process is confirmed to be smooth, then the power-off protection test is confirmed to be reliable, and step S112 is executed;

[0062] If the touch screen unit determines that the magnetic bearing has fallen or the shutdown process is not smooth during the process of stopping the magnetic levitation motor and the air compressor, the power-off protection test is determined to be unreliable, and step S113 is executed:

[0063] S112: Resupply power to the high-speed inverter based on the load switch, and control the magnetic levitation motor and the air compressor to operate under rated conditions through the high-speed inverter based on the PLC unit. Cut off the power supply to the high-speed inverter based on the load switch again, and repeat steps S110 to S111 until the magnetic levitation bearing does not fall during the two shutdown operations and the shutdown process is confirmed to be smooth. In this way, the power-off protection test is confirmed to be reliable, and the reliability of the air compressor power-off protection test uninterruptible power supply UPS is obtained;

[0064] S113: Replace the uninterruptible power supply UPS, and the capacity of the uninterruptible power supply UPS after replacement is greater than the capacity of the uninterruptible power supply UPS before replacement, and repeat S100 to S112.

[0065] Beneficial effects: The present invention provides a reliability test method for a magnetic levitation centrifugal air compressor. A magnetic levitation centrifugal air compressor test system is constructed through a system platform, and a rotor reliability test of the magnetic levitation centrifugal air compressor is implemented according to the constructed magnetic levitation rotor test strategy; a temperature rise reliability test is performed on the magnetic levitation centrifugal air compressor according to the air compressor temperature rise test strategy; a surge reliability test is performed on the magnetic levitation centrifugal air compressor according to the air compressor surge test strategy; and a surge reliability test is performed on the magnetic levitation centrifugal air compressor according to the air compressor power-off protection test strategy. This allows the stability of the magnetic levitation system of the magnetic levitation centrifugal air compressor, the effectiveness of surge protection and power-off protection, and the rationality of temperature control to be verified during the product factory test phase, fully verifying the reliability of the magnetic levitation air compressor. This solves the problems of unstable magnetic levitation control system, surge, and high motor temperature in actual use of magnetic levitation centrifugal air compressors, which in turn cause a high product failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0067] Figure 1 This is a flow chart of a reliability test method for a magnetic levitation centrifugal air compressor according to the present invention;

[0068] Figure 2 This is a schematic diagram of a magnetic levitation centrifugal air compressor test system built in this embodiment;

[0069] Figure 3 This is the logic diagram of the reliability test of the magnetic levitation centrifugal air compressor in this embodiment. DETAILED DESCRIPTION

[0070] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0071] This embodiment provides a reliability test method for a magnetic levitation centrifugal air compressor. Figure 1 As shown, the following steps are included:

[0072] S1: Reliability test system for magnetic levitation centrifugal air compressor;

[0073] The reliability test system includes a system platform for building a magnetic levitation centrifugal air compressor test system, and a magnetic levitation rotor test module, a magnetic levitation centrifugal air compressor temperature rise test module, a magnetic levitation centrifugal air compressor surge test module, and a magnetic levitation centrifugal air compressor power-off protection test module respectively connected to the system platform;

[0074] Specifically, if Figure 2 As shown, the magnetic levitation centrifugal air compressor test system includes a magnetic levitation air compressor, an air outlet pipeline and an electric proportional control valve;

[0075] The magnetic levitation air compressor is connected to the air outlet pipeline, and the electric proportional control valve is arranged on the air outlet pipeline. The electric proportional control valve is used to adjust the air compressor flow and outlet pressure to ensure that the air compressor operates at the set flow and outlet pressure;

[0076] The magnetic levitation air compressor includes a load switch, a high-speed frequency converter, a transformer, an uninterruptible power supply UPS, a magnetic levitation motor, a magnetic levitation bearing, a magnetic levitation controller, a PLC main control unit, a touch screen unit, a cooling system and a compressor;

[0077] The load switch is connected to an external power supply and is used to transmit the external power supply to the high-speed frequency converter, transformer and cooling system;

[0078] The transformer is connected to an uninterruptible power supply UPS, and is used to convert the received external power supply and transmit the converted external power supply to the uninterruptible power supply UPS; and the uninterruptible power supply UPS is connected to a magnetic levitation controller;

[0079] The PLC main control unit is connected to the touch screen unit, the magnetic suspension controller, the high-frequency transmission and the cooling system respectively;

[0080] The touch screen unit is used to send control instructions of the magnetic suspension controller or the high-speed frequency converter or the cooling system through the PLC main control unit;

[0081] The magnetic levitation controller is used to receive control instructions of the magnetic levitation controller sent by the PLC main control unit to control the magnetic levitation bearing to achieve suspension, wherein the method of controlling the magnetic levitation bearing to achieve suspension through the control instructions of the magnetic levitation controller is an existing well-known technical means, that is, the excitation current given value of the suspension winding set by the magnetic levitation bearing is obtained through the magnetic levitation controller, and this excitation current given value is input to the suspension converter, and the suspension converter outputs the excitation current to the suspension winding, so that the rotating body rises smoothly to and remains at the suspension equilibrium point, which will not be described in detail here; and the magnetic levitation bearing is equipped with a displacement sensor and a temperature sensor; the displacement sensor is used to monitor the magnetic levitation rotor position of the magnetic levitation bearing; the temperature sensor is used to monitor the temperature of the magnetic levitation bearing; and the output data of the displacement sensor and the temperature sensor are transmitted to the touch screen unit through the magnetic levitation controller and the PLC main control unit in sequence;

[0082] The high-speed frequency converter is used to receive the high-speed frequency converter control instructions sent by the PLC main control unit to control the operation of the magnetic suspension motor and thus realize the rotation of the magnetic suspension bearing;

[0083] The cooling system is connected to the magnetic levitation motor, and is used to receive control instructions of the cooling system sent by the PLC main control unit to achieve cooling of the magnetic levitation motor and the compressor; the cooling system is specifically an air cooling and water cooling system, which is a well-known technical means and will not be described in detail here;

[0084] The outlet of the compressor is connected to the air outlet pipeline through a metal bellows.

[0085] The magnetic levitation rotor test module is used to construct a magnetic levitation rotor test strategy;

[0086] Specifically, if Figure 3 As shown, the magnetic levitation rotor test strategy is specifically as follows:

[0087] In this example, a two-stage magnetic levitation air compressor is selected as the description object: the air compressor pressure is 1.5 Bar, the flow rate is 70m3 / min, the operating speed is 24000rpm, and the vent valve closing speed is 18000rpm;

[0088] S11: Starting the magnetic levitation centrifugal air compressor test system built on the system platform;

[0089] The magnetic suspension controller receives control instructions of the magnetic suspension controller sent by the PLC main control unit, controls the suspension of the magnetic suspension bearing, and obtains data information of the magnetic suspension bearing;

[0090] The data information includes at least displacement data, front and rear end impeller running track percentage ORB F / ORB R and load capacity percentage;

[0091] The displacement data includes the front bearing radial displacement X1 / Y1, the rear bearing radial displacement X2 / Y2, and the axial bearing axial displacement Z;

[0092] The load-bearing capacity percentage includes the radial bearing front end load-bearing capacity LDX1 / LDY1, the radial bearing rear end load-bearing capacity LDX2 / LDY2 and the axial bearing load-bearing capacity LDZ;

[0093] S12: Adjusting the electric proportional control valve on the outlet pipe to a preset opening threshold, and controlling the magnetic levitation motor and the air compressor to reach a set first operating speed through a high-speed inverter; and monitoring data information of the magnetic levitation bearing during startup and operation through a touch screen unit; the first operating speed is specifically 24,000 rpm;

[0094] When a first preset operating time value is reached, specifically 5 minutes, the displacement data, the front and rear impeller running track percentages ORB F / ORB R, and the load capacity percentage are respectively determined relative to a first preset threshold, a second preset threshold, and a third preset threshold; wherein the first preset threshold is 10 μm, the second preset threshold is 15%, and the third preset threshold is 35%.

[0095] S13: If it is determined that the displacement data X1 / Y1 / X2 / Y2 / Z is less than the first preset threshold;

[0096] And the front and rear end impeller running track percentage ORB F / ORB R is less than the second preset threshold;

[0097] and the bearing capacity percentage LDX1 / LDY1 / LDX2 / LDY2 / LDZ is less than the third preset threshold;

[0098] It is then confirmed that there is no abnormality in the magnetic levitation rotor test result, the magnetic levitation rotor is reliable, and step S14 is executed;

[0099] Otherwise, that is, if it is determined that the displacement data X1 / Y1 / X2 / Y2 / Z ≥ the first preset threshold;

[0100] Or the front and rear end impeller running track percentage ORB F / ORB R ≥ the second preset threshold;

[0101] or the bearing capacity percentage LDX1 / LDY1 / LDX2 / LDY2 / LDZ ≥ the third preset threshold;

[0102] It is confirmed that the magnetic levitation rotor test result is abnormal, the magnetic levitation rotor is unreliable, and step S15 is executed;

[0103] S14: Controlling the magnetic levitation motor and the air compressor to a set second operating speed through a high-speed frequency converter, specifically 18500 rpm, and when a second preset operating time value, specifically 1 minute, is reached, controlling the magnetic levitation motor and the air compressor through the high-speed frequency converter to increase the second operating speed to the first operating speed, and again monitoring the data information of the magnetic levitation bearing during startup and operation through the touch screen unit, and repeating step S13 until it is confirmed again that the magnetic levitation rotor test results are normal and the magnetic levitation rotor is reliable;

[0104] S15: Adjust the control current of the magnetic suspension bearing through the magnetic suspension controller, and repeat step S12 until the magnetic suspension rotor test results are normal and the reliability of the magnetic suspension bearing control current is confirmed.

[0105] In this embodiment, the opening of the electric proportional valve on the outlet pipe is adjusted to near the specified performance point of the air compressor. The air compressor is started until it reaches the operating speed. The data during the startup and operation of the magnetic levitation rotor is monitored using a computer or display screen (touch screen unit) to monitor whether the operating data is abnormal. Then, a speed change and start-stop test is performed. If there are no abnormalities after two cycles, it indicates that the magnetic levitation rotor is reliable.

[0106] The magnetic levitation centrifugal air compressor temperature rise test module is used to construct an air compressor temperature rise test strategy;

[0107] Specifically, the air compressor temperature rise test strategy is as follows:

[0108] S101: Monitoring the magnetic bearing through the touch screen unit to obtain operating data when the magnetic bearing is continuously operated for a third preset operating time under rated conditions; that is, operating the magnetic bearing at a specified performance point for 2 hours to observe the temperature rise of the magnetic bearing winding;

[0109] The operating data includes the temperature rise of the magnetic levitation motor winding, the temperature rise of the magnetic levitation bearing, and the current data information of the magnetic levitation bearing; the current data information includes the current displacement data, the current front and rear end impeller operation trajectory percentage ORBF / ORB R, and the current load capacity percentage;

[0110] S102: Determine the difference between the temperature rise of the magnetic levitation motor winding and a fourth preset threshold, and the temperature rise of the magnetic levitation bearing and a fifth preset threshold, respectively; the fourth preset threshold is 100K, and the fifth preset threshold is 80K;

[0111] and determining whether the test result of the current data information is abnormal based on step S13;

[0112] S103: If it is determined that the temperature rise of the magnetic levitation motor winding is less than a fourth preset threshold;

[0113] and the temperature rise of the magnetic bearing is less than the fifth preset threshold;

[0114] And based on the judgment in step S13 that the test result of the current data information is normal, it is confirmed that the air compressor temperature rise test is reliable;

[0115] Otherwise, that is, if it is determined that the temperature rise of the magnetic levitation motor winding is greater than or equal to the fourth preset threshold;

[0116] Or the temperature rise of the magnetic bearing is ≥ the fifth preset threshold;

[0117] Or if the test result of the current data information is determined to be abnormal based on step S13, the air compressor temperature rise test is determined to be unreliable and step S104 is executed;

[0118] S104: Based on the touch screen unit, the PLC main control unit is controlled to send control instructions for the cooling system to achieve cooling of the magnetic levitation motor and the compressor through the air cooling system, and continue to execute steps S102 to S103 until it is confirmed that the air compressor temperature rise test is reliable, and the reliability of the air compressor temperature rise test and the cooling performance of the air cooling system are obtained.

[0119] The magnetic levitation centrifugal air compressor surge test module is used to construct an air compressor surge test strategy;

[0120] Specifically, the air compressor surge test strategy is as follows:

[0121] S010: When the magnetic levitation air compressor is operating under rated conditions, based on the preset surge protection line, the opening of the electric proportional valve is adjusted to simulate the situation of increased external resistance, so that the operating point of the magnetic levitation air compressor moves toward the surge line;

[0122] Specifically, the air compressor surge protection line consists of a surge warning line and a surge shutdown line. The surge shutdown line is a protection line set to indicate the compressor is about to surge. It consists of a series of operating points at different speeds where the compressor operates at minimum flow without surging. These operating points are called surge points. Surge points are measured during the air compressor aerodynamic performance test. The surge shutdown line is formed by connecting these surge points into a line. Generally, the surge shutdown line is a surge line with a 3%-5% margin based on the surge flow rate, not the actual surge. The surge warning line reserves a 5%-10% surge margin on top of the surge shutdown line to alert the user. The measured aerodynamic performance curve and surge protection line of the air compressor were set in the magnetic levitation air compressor PLC unit. When the magnetic levitation air compressor was running at the specified performance point, the electric valve opening was gradually adjusted. When the operating point reached the surge line, the magnetic levitation air compressor human-computer interactive touch screen was checked for surge alarms and the compressor was shut down. The shutdown process was smooth and no downtime occurred.

[0123] S011: When the opening of the electric proportional valve is adjusted so that the operating point of the magnetic levitation air compressor reaches the surge protection line operating point, the magnetic levitation air compressor is monitored through the touch screen unit to determine whether a surge alarm is issued and the compressor is shut down;

[0124] Specifically, when the compressor reaches the surge warning line, the compressor will issue a surge warning and display it on the touch screen unit. If the electric proportional valve opening is further reduced until the operating point of the magnetic levitation compressor reaches the surge shutdown line, the compressor will issue a surge alarm and shut down. A smooth shutdown process indicates that the surge protection is reliable. If surge and rotor drop occur during the shutdown process, the surge protection line will be corrected, that is, the surge protection line will be shifted to the high flow area.

[0125] S012: If the touch screen unit monitors and determines that the surge protection line operating point has been reached, the magnetic levitation air compressor will issue a surge alarm and shut down, and confirm that the air compressor surge test is reliable;

[0126] Otherwise, the surge protection line is reset, and step S011 is repeatedly performed until the air compressor surge test is confirmed to be reliable, and a reliability surge protection line of the air compressor surge test is obtained.

[0127] The magnetic levitation centrifugal air compressor power-off protection test module is used to construct an air compressor power-off protection test strategy;

[0128] Specifically, the air compressor power-off protection test strategy is as follows:

[0129] S100: Controlling the magnetic levitation motor and the air compressor to operate at the second operating speed through the high-speed inverter, and cutting off the power supply to the high-speed inverter based on the load switch;

[0130] S110: confirming, through a touch screen unit, whether the magnetic bearing falls during the process of stopping the magnetic levitation motor and the air compressor, and monitoring, through a PLC unit, speed data within a preset time period of the shutdown process to obtain a time-speed curve, and confirming the smoothness of the shutdown process based on the slope of the time-speed curve;

[0131] S111: If, during the process of stopping the magnetic levitation motor and the air compressor, the touch screen unit determines that the magnetic levitation bearing has not fallen and the shutdown process is confirmed to be smooth, then the power-off protection test is confirmed to be reliable, and step S112 is executed;

[0132] If the touch screen unit determines that the magnetic bearing has fallen or the shutdown process is not smooth during the process of stopping the magnetic levitation motor and the air compressor, the power-off protection test is determined to be unreliable, and step S113 is executed:

[0133] S112: Resupply power to the high-speed inverter based on the load switch, and control the magnetic levitation motor and the air compressor to operate under rated conditions through the high-speed inverter based on the PLC unit. Cut off the power supply to the high-speed inverter based on the load switch again, and repeat steps S110 to S111 until the magnetic levitation bearing does not fall during the two shutdown operations and the shutdown process is confirmed to be smooth. In this way, the power-off protection test is confirmed to be reliable, and the reliability of the air compressor power-off protection test uninterruptible power supply UPS is obtained;

[0134] S113: Replace the uninterruptible power supply UPS, and the capacity of the uninterruptible power supply UPS after replacement is greater than the capacity of the uninterruptible power supply UPS before replacement, and repeat S100 to S112.

[0135] Specifically, the purpose of the air compressor power-off protection test is to confirm that the magnetic bearing does not drop in the event of a sudden power outage and that the compressor shuts down smoothly. For the first test, it is recommended that the speed be no higher than 80% of the maximum operating speed. After the compressor stabilizes, disconnect the load switch or circuit breaker on the magnetic levitation compressor. Observe whether the compressor begins to shut down by monitoring the bearing suspension status display on the magnetic levitation compressor's human-machine interface touchscreen unit to see if the magnetic bearing drops. Displacement and temperature sensors are embedded within the magnetic bearing. Control cables from the magnetic bearing are connected to the magnetic levitation controller via connectors. Signals are transmitted via the control cables. Rotor operation data from the magnetic levitation controller is transmitted to the touchscreen via a programmable logic controller (PLC) and displayed on the touchscreen, where it indicates whether the magnetic bearing is floating or dropping. If there is no drop, close the load switch or circuit breaker and restart the magnetic levitation compressor, operating it at the rated performance point. After stable operation, disconnect the load switch or circuit breaker again to observe whether the compressor shuts down smoothly and whether the magnetic bearing has dropped. If a fall occurs, check whether the uninterruptible power supply of the magnetic suspension controller and the vent valve are working properly.

[0136] S2: Building a magnetic levitation centrifugal air compressor test system based on the system platform, and implementing a rotor reliability test of the magnetic levitation centrifugal air compressor according to the magnetic levitation rotor test strategy;

[0137] And for the magnetic levitation centrifugal air compressor that meets the rotor reliability test, perform any one of step S3 to achieve reliability verification of the magnetic levitation centrifugal air compressor;

[0138] S3: Perform a temperature rise reliability test on the magnetic levitation centrifugal air compressor according to the air compressor temperature rise test strategy; or perform a surge reliability test on the magnetic levitation centrifugal air compressor according to the air compressor surge test strategy;

[0139] Or perform surge reliability test on magnetic levitation centrifugal air compressor according to the air compressor power-off protection test strategy.

[0140] In this embodiment, a magnetic levitation centrifugal compressor test system is constructed using a system platform. Based on the constructed magnetic levitation rotor test strategy, rotor reliability testing of the magnetic levitation centrifugal compressor is performed. Temperature rise reliability testing is performed on the magnetic levitation centrifugal compressor according to the compressor temperature rise test strategy; surge reliability testing is performed on the magnetic levitation centrifugal compressor according to the compressor surge test strategy; and surge reliability testing is performed on the magnetic levitation centrifugal compressor according to the compressor power-off protection test strategy. This allows the stability of the magnetic levitation system, the effectiveness of surge and power-off protections, and the rationality of temperature control to be verified during the product delivery test phase, fully verifying the reliability of the magnetic levitation centrifugal compressor. This solves the problem of magnetic levitation control system instability, surge, and high motor temperatures that can occur in actual field applications of magnetic levitation centrifugal compressors, leading to high product failure rates. Direct testing verifies the reliability of the magnetic levitation rotor, temperature protection, surge protection, and power-off protection, ensuring product quality and improving user experience and product adaptability to field environments.

[0141] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reliability test method for a magnetic levitation centrifugal air compressor, characterized in that: The following steps are involved: S1: Build a magnetic levitation centrifugal air compressor test system; The test system includes a system platform, and a magnetic levitation rotor test module, a magnetic levitation centrifugal air compressor temperature rise test module, a magnetic levitation centrifugal air compressor surge test module, and a magnetic levitation centrifugal air compressor power-off protection test module respectively connected to the system platform; The magnetic levitation rotor test module is used to construct a magnetic levitation rotor test strategy; The magnetic levitation centrifugal air compressor temperature rise test module is used to construct an air compressor temperature rise test strategy; The magnetic levitation centrifugal air compressor surge test module is used to construct an air compressor surge test strategy; The magnetic levitation centrifugal air compressor power-off protection test module is used to construct an air compressor power-off protection test strategy; The magnetic levitation centrifugal air compressor test system specifically includes a magnetic levitation air compressor, an air outlet pipeline and an electric proportional control valve; The magnetic levitation air compressor is connected to the air outlet pipeline, and the electric proportional control valve is arranged on the air outlet pipeline. The electric proportional control valve is used to adjust the air compressor flow and outlet pressure to ensure that the air compressor operates at the set flow and outlet pressure; The magnetic levitation air compressor includes a load switch, a high-speed frequency converter, a transformer, an uninterruptible power supply, a magnetic levitation motor, a magnetic levitation bearing, a magnetic levitation controller, a PLC main control unit, a touch screen unit, a cooling system and a compressor; The load switch is connected to an external power supply and is used to transmit the external power supply to the high-speed frequency converter, transformer and cooling system; The transformer is connected to the uninterruptible power supply and is used to convert the received external power and transmit the converted external power to the uninterruptible power supply; and the uninterruptible power supply is connected to the magnetic levitation controller; The PLC main control unit is connected to the touch screen unit, magnetic suspension controller, high-speed frequency converter and cooling system respectively; The touch screen unit is used to send control instructions of the magnetic suspension controller, high-speed frequency converter or cooling system through the PLC main control unit; The magnetic levitation controller is used to receive control instructions of the magnetic levitation controller sent by the PLC main control unit to control the magnetic levitation bearing to achieve suspension, and the magnetic levitation bearing is equipped with a displacement sensor and a temperature sensor; the displacement sensor is used to monitor the position of the magnetic levitation rotor of the magnetic levitation bearing; the temperature sensor is used to monitor the temperature of the magnetic levitation bearing; the output data of the displacement sensor and the temperature sensor are transmitted to the touch screen unit in sequence through the magnetic levitation controller and the PLC main control unit; The high-speed frequency converter is used to receive the control instructions of the high-speed frequency converter sent by the PLC main control unit to control the operation of the magnetic suspension motor and thus realize the rotation of the magnetic suspension bearing; The cooling system is connected to the magnetic levitation motor, and is used to receive control instructions of the cooling system sent by the PLC main control unit to achieve cooling of the magnetic levitation motor and the compressor; The outlet of the compressor is connected to the outlet pipe via a metal bellows; S2: A magnetic levitation centrifugal air compressor test system built based on the system platform, and according to the magnetic levitation rotor test strategy, to realize the rotor reliability test of the magnetic levitation centrifugal air compressor; And for the magnetic levitation centrifugal air compressor that meets the rotor reliability test, perform any one of step S3 to achieve reliability verification of the magnetic levitation centrifugal air compressor; S3: Perform a temperature rise reliability test on the magnetic levitation centrifugal air compressor according to the air compressor temperature rise test strategy; or perform a surge reliability test on the magnetic levitation centrifugal air compressor according to the air compressor surge test strategy; Or according to the air compressor power-off protection test strategy, perform a power-off protection reliability test on the magnetic levitation centrifugal air compressor.

2. A magnetic levitation centrifugal air compressor reliability test method according to claim 1, characterized in that: The specific test strategy of the magnetic levitation rotor described in S1 is: S11: Starting the magnetic levitation centrifugal air compressor test system built on the system platform; The magnetic suspension controller receives control instructions of the magnetic suspension controller sent by the PLC main control unit, controls the suspension of the magnetic suspension bearing, and obtains data information of the magnetic suspension bearing; The data information includes at least displacement data, percentage of front and rear end impeller running tracks and percentage of bearing capacity; The displacement data includes radial displacement of the front end of the radial bearing, radial displacement of the rear end of the radial bearing, and axial displacement of the axial bearing; The bearing capacity includes the bearing capacity of the front end of the radial bearing, the bearing capacity of the rear end of the radial bearing and the bearing capacity of the axial bearing; S12: Adjust the electric proportional control valve on the outlet pipe to a preset opening threshold, and control the magnetic suspension motor and compressor to reach a set first operating speed through a high-speed inverter; and monitor the data information of the magnetic suspension bearing during startup and operation through a touch screen unit; When the first preset operation time value is reached, respectively determining the magnitude of the displacement data, the percentage of the front and rear impeller running tracks, and the load capacity percentage relative to the first, second, and third preset thresholds; S13: If it is determined that the displacement data is less than the first preset threshold; And the percentage of the front and rear end impeller running tracks is less than the second preset threshold; and the bearing capacity percentage is less than a third preset threshold; It is then confirmed that there is no abnormality in the magnetic levitation rotor test result, the magnetic levitation rotor is reliable, and step S14 is executed; Otherwise, it is determined that the magnetic levitation rotor test result is abnormal, the magnetic levitation rotor is unreliable, and step S15 is executed; S14: controlling the magnetic levitation motor and the compressor to decrease to a set second operating speed through the high-speed inverter, and when a second preset operating time value is reached, controlling the magnetic levitation motor and the compressor through the high-speed inverter to increase the second operating speed to the first operating speed, again monitoring the data information of the magnetic levitation bearing during the startup and operation process through the touch screen unit, and repeating step S13 until it is confirmed again that the magnetic levitation rotor test results are normal and the magnetic levitation rotor is reliable; S15: Adjust the control current of the magnetic suspension bearing through the magnetic suspension controller, and repeat step S12 until the magnetic suspension rotor test results are normal and the reliability of the magnetic suspension bearing control current is confirmed.

3. A magnetic levitation centrifugal air compressor reliability test method according to claim 2, characterized in that: The specific test strategy for the air compressor temperature rise described in S1 is: S101: Monitoring, through a touch screen unit, operating data of a magnetic bearing and a magnetic motor when they continuously run for a third preset operating time under rated conditions; The operating data includes the temperature rise of the magnetic levitation motor winding, the temperature rise of the magnetic levitation bearing, and the current data information of the magnetic levitation bearing; The current data information includes the current displacement data, the current percentage of the front and rear end impeller running tracks and the current load-bearing capacity percentage; S102: Determine the difference between the temperature rise of the magnetic levitation motor winding and a fourth preset threshold, and the difference between the temperature rise of the magnetic levitation bearing and a fifth preset threshold; and determining whether the test result of the current data information is abnormal based on step S13; S103: If it is determined that the temperature rise of the magnetic levitation motor winding is less than a fourth preset threshold; and the temperature rise of the magnetic bearing is less than the fifth preset threshold; And based on the judgment in step S13 that the test result of the current data information is normal, it is confirmed that the air compressor temperature rise test is reliable; Otherwise, it is determined that the air compressor temperature rise test is unreliable and step S104 is executed; S104: Based on the touch screen unit, the PLC main control unit is controlled to send control instructions for the cooling system to achieve cooling of the magnetic levitation motor and the compressor through the air cooling system, and continue to execute steps S102 to S103 until it is confirmed that the air compressor temperature rise test is reliable, and the reliability of the air compressor temperature rise test and the cooling performance of the air cooling system are obtained.

4. A magnetic levitation centrifugal air compressor reliability test method according to claim 2, characterized in that: The air compressor surge test strategy described in S1 is as follows: S010: When the magnetic levitation air compressor is operating under rated conditions, based on the preset surge protection line, the opening of the electric proportional valve is adjusted to simulate the situation of increased external resistance, so that the operating point of the magnetic levitation air compressor moves toward the surge line; S011: When the opening of the electric proportional valve is adjusted so that the working point of the magnetic levitation air compressor reaches the surge protection line working point, the touch screen unit is used to monitor whether the magnetic levitation air compressor issues a surge alarm and shuts down; S012: If the magnetic levitation air compressor issues a surge alarm and shuts down, it is confirmed that the air compressor surge test is reliable; Otherwise, the surge protection line is reset, and step S011 is repeatedly performed until the air compressor surge test is confirmed to be reliable, and a reliability surge protection line of the air compressor surge test is obtained.

5. A magnetic levitation centrifugal air compressor reliability test method according to claim 2, characterized in that: The air compressor power-off protection test strategy described in S1 is specifically as follows: S100: controlling the magnetic levitation motor and the compressor to operate at the second operating speed through the high-speed inverter, and cutting off the power supply to the high-speed inverter based on the load switch; S110: confirming, through a touch screen unit, whether the magnetic bearing falls during the process of stopping the magnetic levitation motor and the compressor, and monitoring the speed data of the shutdown process within a preset time period through a PLC main control unit to obtain a time-speed curve, and confirming the smoothness of the shutdown process based on the slope of the time-speed curve; S111: If, during the process of stopping the magnetic levitation motor and the compressor, it is determined through the touch screen unit that the magnetic levitation bearing has not fallen and the shutdown process is confirmed to be smooth, then the power-off protection test is confirmed to be reliable, and step S112 is executed; If the touch screen unit determines that the magnetic bearing has fallen or the shutdown process is not smooth during the process of stopping the magnetic levitation motor and the compressor, the power-off protection test is determined to be unreliable, and step S113 is executed: S112: Resupply power to the high-speed inverter based on the load switch, and control the magnetic levitation motor and the compressor to operate under rated conditions through the high-speed inverter based on the PLC main control unit. Cut off the power supply to the high-speed inverter based on the load switch again, and repeat steps S110 to S111 until the magnetic levitation bearing does not fall during the two shutdown operations and the shutdown process is confirmed to be smooth. In this way, the power-off protection test is confirmed to be reliable, and the reliability of the uninterruptible power supply for the air compressor power-off protection test is obtained; S113: Replace the uninterruptible power supply, and the capacity of the uninterruptible power supply after replacement is greater than the capacity of the uninterruptible power supply before replacement, and repeat S100 to S112.

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