US-12624694-B2 - Control method for compressor and compressor system

Abstract

A control method includes: a detection step of: detecting a vibration amplitude of the compressor; a determination step of: determining whether the detected vibration amplitude of the compressor is greater than or equal to a predetermined threshold; and a speed adjustment step of changing a switching frequency of a frequency converter or/and modulate a frequency of the compressor if the detected vibration amplitude of the compressor is greater than or equal to the predetermined threshold. A compressor system is also provided by an embodiment. The control method and the compressor system make it convenient to know whether abnormal vibration of the compressor occurs, and can avoid the resonance frequency range.

Inventors

• Yingke Sun
• Wanzhen Liu
• Qingyue Meng
• Li Yao
• Shizhong Ji

Assignees

• DANFOSS (TIANJIN) LTD.

Dates

Publication Date

20260512

Application Date

20231229

Priority Date

20221230

Claims (19)

1. 1 . A control method for a compressor, the control method comprising: a detection step of detecting a vibration amplitude of the compressor; a determination step of determining whether the detected vibration amplitude of the compressor is greater than or equal to a predetermined threshold; and a speed adjustment step of changing a switching frequency of a frequency converter or/and modulating a frequency of the compressor if the detected vibration amplitude of the compressor is greater than or equal to the predetermined threshold; wherein the compressor comprises: a shell having a lower part, a refrigerant discharge pipe connected to the shell; wherein the detection step comprises: detecting at least one of a first vibration amplitude in a first direction, a second vibration amplitude in a second direction, and a third vibration amplitude in a third direction of the lower part of the shell of the compressor; wherein the first direction is an axial direction of the refrigerant discharge pipe, the second direction is tangential to the first direction, and the third direction is perpendicular to the first and second directions.
2. 2 . The control method for the compressor according to claim 1 , wherein the compressor comprises: a shell having a lower part, and a refrigerant discharge pipe connected to the shell; wherein the detection step comprises: detecting the vibration amplitude at the lower part of the shell of the compressor in a horizontal direction and tangential to an axial direction of the refrigerant discharge pipe.
3. 3 . The control method for the compressor according to claim 1 , wherein the refrigerant discharge pipe extends in a horizontal direction, and the first and second directions defines a horizontal plane.
4. 4 . The control method for a compressor according to claim 1 , wherein the lower part of the shell of the compressor is provided with a vibration sensor, wherein the vibration sensor is in a normal direction of the shell.
5. 5 . The control method for the compressor according to claim 3 , wherein the determination step comprises: determining whether each of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold; and the speed adjustment step comprises: if the second vibration amplitude is greater than or equal to the predetermined threshold, and the first and third vibration amplitudes are less than a first threshold, modulating the frequency of the compressor by the frequency converter.
6. 6 . The control method for the compressor according to claim 3 , wherein the determination step comprises: determining whether at least one of the first vibration amplitude, the second vibration amplitude and the third vibration amplitude is greater than or equal to the predetermined threshold; and the speed adjustment step comprises: if the at least one of the first vibration amplitude, the second vibration amplitude and the third vibration amplitude is greater than or equal to the predetermined threshold and if the compressor is in an acceleration or deceleration stage, modulating the frequency of the compressor by the frequency converter.
7. 7 . The control method for the compressor according to claim 3 , wherein the determination step comprises: determining whether each of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold; and the speed adjustment step comprises: if each of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold, changing the switching frequency of the frequency converter.
8. 8 . The control method for a compressor according to claim 3 , wherein the determination step comprises: determining whether at least one of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold; and the speed adjustment step comprises: if the at least one of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold, and if the compressor is in a constant speed operation stage, changing the switching frequency of the frequency converter.
9. 9 . The control method for the compressor according to claim 1 , further comprising: determining whether the vibration amplitude of the compressor has decreased below the predetermined amplitude after changing the switching frequency of the frequency converter or/and modulating the frequency of the compressor; and giving an alarm and stopping the operation of the compressor if the vibration amplitude of the compressor does not decrease below the predetermined amplitude.
10. 10 . A compressor system, comprising: a compressor; a vibration sensor configured to detect a vibration amplitude of the compressor; a frequency converter configured to provide power to the compressor; and a controller configured to determine whether the vibration amplitude of the compressor is greater than or equal to a predetermined threshold, and to modulate a frequency of the compressor or/and change a switching frequency of a frequency converter if the detected vibration amplitude of the compressor is greater than or equal to the predetermined threshold; wherein the compressor comprises a shell having a lower part, and a refrigerant discharge pipe connected to the shell; and the vibration sensor is configured to detect at least one of a first vibration amplitude in a first direction, a second vibration amplitude in a second direction and a third vibration amplitude in a third direction of the lower part of the shell of the compressor; wherein the first direction is an axial direction of the refrigerant discharge pipe, the second direction is tangential to the first direction, and the third direction is perpendicular to the first and second directions.
11. 11 . The compressor system according to claim 10 , wherein the compressor comprises a shell having a lower part, and a refrigerant discharge pipe connected to the shell, and the vibration sensor is located at a normal direction of the shell and is configured to detect the vibration amplitude at the lower part of the shell of the compressor in a horizontal direction tangential to an axial direction of the refrigerant discharge pipe.
12. 12 . The compressor system according to claim 10 , wherein the refrigerant discharge pipe extends in the horizontal direction, and the first and second directions define a horizontal plane.
13. 13 . The compressor system according to claim 10 , wherein the vibration sensor is provided at the lower part of the shell of the compressor.
14. 14 . The compressor system according to claim 12 , wherein the controller is further configured to determine whether each of the first vibration amplitude, the second vibration amplitude and the third vibration amplitude is greater than or equal to the predetermined threshold, and to modulate the frequency of the compressor by the frequency converter, if the second vibration amplitude is greater than or equal to the predetermined threshold and if the first and third vibration amplitudes are less than a first threshold.
15. 15 . The compressor system according to claim 12 , wherein the controller is further configured to determine whether at least one of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold, and to, if the at least one of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold and if the compressor is in an acceleration or deceleration stage, modulate the frequency of the compressor by the frequency converter.
16. 16 . The compressor system according to claim 12 , wherein the controller is further configured to determine whether each of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold; and to change the switching frequency of the frequency converter if each of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold.
17. 17 . The compressor system according to claim 12 , wherein the controller is further configured to determine whether at least one of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold; and to change the switching frequency of the frequency converter, if the at least one of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold and if the compressor operates at a constant speed.
18. 18 . The compressor system according to claim 10 , wherein the controller is further configured to determine whether the vibration amplitude of the compressor has decreased below the predetermined amplitude after changing the switching frequency of the frequency converter or/and modulating the frequency of the compressor; and to give an alarm and stop the compressor if the vibration amplitude of the compressor has not decreased below the predetermined amplitude.
19. 19 . A control method for a compressor, the control method comprising: a detection step of detecting a vibration amplitude of the compressor; a determination step of determining whether the detected vibration amplitude of the compressor is greater than or equal to a predetermined threshold; and a speed adjustment step of modulating frequency of the compressor and/or changing a control parameter of a frequency converter if the detected vibration amplitude of the compressor is greater than or equal to the predetermined threshold, wherein the compressor comprises: a shell having a lower part, a refrigerant discharge pipe connected to the shell; wherein the detection step comprises: detecting at least one of a first vibration amplitude in a first direction, a second vibration amplitude in a second direction, and a third vibration amplitude in a third direction of the lower part of the shell of the compressor; wherein the first direction is an axial direction of the refrigerant discharge pipe, the second direction is tangential to the first direction, and the third direction is perpendicular to the first and second directions.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims foreign priority benefits under 35 U.S.C. § 119 from Chinese Patent Application No. 202211743093.8, filed Dec. 30, 2022, the content of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD Embodiments of the present disclosure relate to a control method for a compressor and a compressor system. BACKGROUND Compressors will have abnormal vibration phenomena (caused by resonance) at different mechanical rotation speeds due to different quality, different installation ways, and different fixing manners of the compressors. When mechanical components such as compressor bearings, scrolls, and suction and discharge ports are worn out, the abnormal vibration of the compressor also occurs. These abnormal vibrations will aggravate the damage of the mechanical components of the compressor and generate noise. Currently, before the compressor and frequency converter leave the factory, several sets of resonance frequency points are preset in the frequency converter. No matter what environment in the field the compressor is installed, frequency hopping is performed according to the preset frequency hopping points to avoid these preset resonance points. When the mechanical components of the compressor are worn out, there is currently no subsequent processing for hopping points. After leaving the factory, the compressor will be installed and fixed on any different occasions and foundations by a customer, and pipelines rigidly connected to the compressor are also different. These factors will cause change in the natural frequency of the compressor, which will cause change in the resonance point. If the frequency hopping is performed according to the preset frequency hopping points, some smooth frequency points will be directly skipped, and the compressor will still operate for a long time at some frequency points with large vibrations, thereby aggravating the damage of the mechanical components of the compressor. SUMMARY An embodiment of the present disclosure is to provide a control method for a compressor, whereby, for example, it is convenient to know whether abnormal vibration of the compressor occurs, and the resonance frequency range of the compressor may be avoided and the service life of the compressor may be extended by changing switching frequency of a frequency converter or modulating the frequency of the compressor. According to an embodiment of the present disclosure, there is provided a control method for a compressor, including: a detection step of: detecting a vibration amplitude of the compressor; a determination step of: determining whether the detected vibration amplitude of the compressor is greater than or equal to a predetermined threshold; and a speed adjustment step of: changing a switching frequency of a frequency converter or/and modulating a frequency of the compressor if the detected vibration amplitude of the compressor is greater than or equal to the predetermined threshold. According to an embodiment of the present disclosure, the compressor includes: a shell having a lower part; and a refrigerant discharge pipe connected to the shell, wherein the detection step includes: detecting the vibration amplitude of the lower part of the shell of the compressor in a horizontal direction and perpendicular to an axial direction of the refrigerant discharge pipe. According to an embodiment of the present disclosure, the compressor includes: a shell having a lower part; and a refrigerant discharge pipe connected to the shell; wherein the detection step includes: detecting at least one of a first vibration amplitude in a first direction, a second vibration amplitude in a second direction, and a third vibration amplitude in a third direction of the lower part of the shell of the compressor; wherein the first direction is an axial direction of the refrigerant discharge pipe, the second direction is perpendicular to the first direction, and the third direction is perpendicular to the first and second directions. According to an embodiment of the present disclosure, the refrigerant discharge pipe extends in a horizontal direction, and the first and second directions defines a horizontal plane. According to an embodiment of the present disclosure, the lower part of the shell of the compressor is provided with a vibration sensor. According to an embodiment of the present disclosure, the determination step includes: determining whether each of the first vibration amplitude, the second vibration amplitude, and the third vibration amplitude is greater than or equal to the predetermined threshold; and the speed adjustment step includes: if the second vibration amplitude is greater than or equal to the predetermined threshold, and the first and third vibration amplitudes are less than a first threshold, modulating the frequency of the compressor by the frequency converter. According to an embodiment of the present disclosure, the deter