Heating and ventilation device, storage medium, compressor and control method and control device thereof

Abstract

The application discloses a heating and ventilation device, a storage medium, a compressor and a control method and a control device thereof. The control method of the compressor comprises the following steps: acquiring an electric current amplitude of the compressor; judging whether the fluctuation of the electric current amplitude is abnormal; and controlling the compressor to change the rotating speed if the fluctuation of the electric current amplitude is abnormal. According to the control method of the compressor, the abnormality of the compressor can be found in time, so that the rotating speed of the compressor or the shutdown processing can be performed, and thus the problems, such as the component wear caused by the instability of the compressor, can be avoided or reduced.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and in particular to a compressor control method, a compressor control device including the control method, a compressor including the control method, a storage medium including the control method, and a heating, ventilation, and air conditioning (HVAC) device including the control method. Background Technology

[0002] my country is the world's largest producer, consumer, and exporter of refrigeration products, with refrigeration energy consumption accounting for 15% of total social energy consumption. During peak summer seasons, the increased refrigeration load, including air conditioning, not only places a heavy burden on the power grid but also generates significant greenhouse gas emissions. Therefore, promoting green and efficient refrigeration has become an important and urgent need for countries to promote energy conservation and emission reduction and address climate change. Dynamic pressure gas bearings (gas bearings) have advantages such as high speed, high efficiency, low friction loss, simple structure, and low cost, making them ideal for small and medium-sized centrifugal compressors.

[0003] Centrifugal compressors experience surge under abnormal operating conditions when the flow rate decreases to a certain level. Surge poses a serious threat to both the compressor and bearings. Traditional centrifugal compressors control the relationship between the compressor rotor speed, flow rate, and the compressor itself to operate within the non-surge region, thus avoiding the damage caused by compressor surge. However, in the refrigeration compressor field, when the ambient temperature changes abruptly, the unit cannot promptly identify the potential for a brief surge phenomenon in its current operating range. Magnetic levitation compressors, on the other hand, can detect rotor instability during surge using displacement sensors. If instability occurs, the sensor signal triggers the unit's shutdown procedure, protecting the compressor and bearings and preventing shortened compressor and bearing life or even failure due to surge.

[0004] Compared to magnetic levitation compressors, gas bearing compressors do not require displacement sensors to detect rotor position. While this reduces costs and simplifies the structure, it also makes it impossible to shut down the compressor in real time based on the rotor's position and stability. Especially when sudden environmental changes cause the compressor unit to surge, the inability to immediately identify rotor instability and shut down the compressor in time leads to more severe wear on the gas bearings, thus affecting the compressor's lifespan. Summary of the Invention

[0005] One objective of this invention is to provide a compressor control method that can promptly detect abnormal fluctuations in the compressor's current amplitude, thereby enabling speed adjustment of the compressor and avoiding or reducing problems such as component wear caused by compressor instability.

[0006] Another object of the present invention is to provide a compressor control device, including the aforementioned compressor control method.

[0007] Another object of the present invention is to provide a compressor, including the aforementioned method for controlling the compressor.

[0008] Another object of the present invention is to provide a storage medium including the aforementioned method for controlling the compressor.

[0009] Another object of the present invention is to provide a heating, ventilation and air conditioning (HVAC) device including the aforementioned method for controlling the compressor.

[0010] A compressor control method according to an embodiment of the present invention includes: acquiring the current amplitude of the compressor; determining whether the fluctuation of the current amplitude is abnormal; and controlling the compressor to change its speed if the fluctuation of the current amplitude is abnormal.

[0011] According to the compressor control method of the present invention, abnormal fluctuations in the compressor current amplitude can be detected in a timely manner, so as to adjust the compressor speed and avoid or reduce problems such as component wear caused by compressor instability.

[0012] Optionally, the step of controlling the compressor to change its speed if the current amplitude fluctuation is abnormal includes: if the current amplitude fluctuation is abnormal and the compressor speed is less than a predetermined threshold, then controlling the compressor speed to increase by a predetermined value.

[0013] Optionally, the predetermined value is in the range of 2% to 5% of the compressor's rated speed.

[0014] Optionally, the step of controlling the compressor to change its speed if the fluctuation of the current amplitude is abnormal further includes: controlling the compressor to stop if the fluctuation of the current amplitude is abnormal and the speed of the compressor is not less than a predetermined threshold.

[0015] Optionally, before obtaining the current amplitude of the compressor, the method further includes: obtaining the current frequency of the compressor; determining whether the fluctuation of the current frequency is abnormal; and if the fluctuation of the current frequency is abnormal, controlling the compressor to stop.

[0016] A compressor control device according to an embodiment of the present invention includes the aforementioned compressor control method, comprising a speed monitoring element for detecting the compressor speed value; an amplitude monitoring element for detecting the compressor current amplitude; and a controller connected to the speed monitoring element and the amplitude monitoring element respectively. The controller is used to acquire the compressor current amplitude, determine whether the fluctuation of the current amplitude is abnormal, and compare the compressor speed value with a predetermined threshold. If the fluctuation of the current amplitude is abnormal and the compressor speed value is less than the predetermined threshold, the controller controls the compressor to increase its speed.

[0017] The compressor according to an embodiment of the present invention includes the control method of the compressor as described above; or the control device of the compressor as described above.

[0018] Optionally, the compressor includes a gas bearing.

[0019] According to an embodiment of the present invention, a storage medium storing a compressor control program is provided thereon. When the compressor control program is executed by a processor, it implements the compressor control method as described above.

[0020] The heating, ventilation, and air conditioning equipment according to an embodiment of the present invention includes the compressor as described above.

[0021] The HVAC equipment, storage medium, compressor, and control method and device according to embodiments of the present invention can promptly detect abnormal fluctuations in the compressor's current amplitude, etc., facilitating speed adjustment or shutdown of the compressor, thereby avoiding or reducing problems such as component wear caused by compressor instability. Furthermore, it can prevent small problems from escalating due to increased fluctuations in the compressor and HVAC equipment during operation, thus reducing maintenance costs and improving the stability of the HVAC equipment. Attached Figure Description

[0022] Figure 1 This is a schematic flowchart of a compressor control method according to an embodiment of the present invention.

[0023] Figure 2 This is a flowchart illustrating a compressor control method according to another embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of an air conditioning system according to an embodiment of the present invention.

[0025] Figure 4 This is a flowchart illustrating a compressor control method according to another embodiment of the present invention.

[0026] Figure 5 This is a flowchart illustrating a compressor control method according to another embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of a compressor control device according to an embodiment of the present invention.

[0028] Figure 7 This is a schematic diagram of a heating, ventilation, and air conditioning (HVAC) device according to an embodiment of the present invention.

[0029] Figure 8 This is a schematic diagram of the rotor of a compressor and its gas bearing in accordance with an embodiment of the present invention.

[0030] Reference numerals: HVAC equipment 100, check valve 5, condenser 8, evaporator 10, liquid receiver 3, pressure three-way valve 1, primary bypass valve 2, secondary bypass valve 4, throttle valve 9, compressor 6, control device 11, speed monitoring device 111, frequency monitoring device 112, amplitude monitoring device 113, controller 114, rotor 12, radial gas bearing 13, axial gas bearing 14. Detailed Implementation

[0031] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0032] like Figure 1 According to an embodiment of the present invention, a compressor control method includes:

[0033] Obtain the current amplitude of the compressor.

[0034] When a compressor becomes unstable during operation, the amplitude of the current flowing to the compressor will change. Therefore, by observing the changes in the current amplitude during compressor operation, it is possible to determine whether the compressor is unstable and to understand its operating status in a timely manner.

[0035] Determine whether the fluctuation of the current amplitude is abnormal.

[0036] When the compressor current amplitude changes, the compressor's operating status can be determined by judging the fluctuation of the current amplitude. This can avoid misjudgment caused by normal fluctuations in the current amplitude (such as fluctuations caused by an increase in compressor power), improve the accuracy of judging the compressor's operating status, and facilitate better control of the compressor's stable operation.

[0037] If the fluctuation of the current amplitude is abnormal, the compressor speed is controlled to change.

[0038] When a compressor becomes unstable, you can try to eliminate the instability by controlling the compressor speed. For example, you can control the compressor speed to increase or decrease the speed to quickly resolve the instability problem and maintain the compressor's continuous and stable operation as much as possible, avoiding energy loss caused by direct shutdown.

[0039] According to the control method of the present invention, the instability of the compressor is determined by judging the current amplitude of the compressor, and the instability of the compressor is alleviated by adjusting the speed of the compressor. This can improve the stability of the compressor, avoid damage to the compressor or other structures caused by the continuous instability of the compressor, reduce losses, and at the same time, solve the instability problem as much as possible without stopping the machine, improve the stability of compressor operation, and save energy and protect the environment.

[0040] Optionally, the fluctuation of the current amplitude can be monitored by the Hall element of the frequency converter. In this invention, when the frequency converter fluctuates n times (n≥10) within 1 minute, the compressor speed is increased / decreased by controlling the frequency converter. If n times (n≥10) fluctuations occur within 1 minute after adjusting the speed, the intelligent shutdown program is activated and an abnormal current fluctuation shutdown alarm is triggered, prompting the machine room to restart.

[0041] Optionally, determining whether the fluctuation of the current amplitude is abnormal may include the following steps:

[0042] The difference between two consecutive detected current amplitudes is calculated to obtain an amplitude difference value, and the absolute value of the amplitude difference is compared with a predetermined amplitude threshold. Specifically, within a predetermined time range, multiple current amplitudes are acquired sequentially, and the difference between two adjacent current amplitudes is calculated to obtain multiple amplitude differences. If the current amplitude fluctuates within the predetermined time range, and the number of amplitude differences whose absolute values ​​exceed the predetermined amplitude threshold is greater than a predetermined number, then the fluctuation of the current amplitude is determined to be abnormal. Fluctuation of the current amplitude refers to ups and downs in the current amplitude, for example, multiple detected current amplitudes first increase and then decrease, or first decrease and then increase.

[0043] Specifically, multiple current amplitudes can be continuously detected to obtain a sequence of current amplitudes, such as continuously detecting current amplitudes I1, I2, I3, I4, I5… n I n+1 …; Calculate the difference between two adjacent detected current amplitudes to obtain the amplitude difference, for example, obtain the amplitude difference I. 12 =I2-I1、I 23 =I3-I2、I 34 =I4-I3、I 45 =I5-I4…I n(n+1) =I n+1 -I n …; among them, when multiple amplitude differences are obtained, both positive and negative values ​​are present, it is determined that the current amplitude fluctuates, for example, I 12 >0, I 23 <0, I 34 >0, I 45A value less than 0 indicates a fluctuation in current amplitude; among the multiple amplitude differences obtained, the absolute value exceeding the threshold I... s When the number of amplitude differences exceeds a predetermined number, the fluctuation of the current amplitude is determined to be abnormal.

[0044] Alternatively, the fluctuation of current amplitude can be continuously monitored by continuously updating the current amplitude sequence. For example, the current amplitude can be re-detected, and the new detection result can completely replace the previous detection result to form a new current amplitude sequence. Or, the current amplitude can be continuously monitored, and the current amplitude sequence can be updated using the new detection results. For instance, if the current amplitudes used in the previous determination of whether the current amplitude was abnormal included I1, I2, I3, I4, and I5, after replacing them with newly detected current amplitudes, the new current amplitude sequence can be changed to I2, I3, I4, I5, and I6. Of course, other current amplitude updating methods can also be used in this invention, and these are all within the scope of protection of this invention.

[0045] By detecting the compressor current amplitude, it is possible to quickly determine whether there is an abnormality in the compressor's operation, thereby improving the efficiency and effectiveness of compressor anomaly detection, enhancing compressor stability, and reducing compressor maintenance costs.

[0046] Optionally, the predetermined amplitude threshold is not less than 2% of the compressor's rated current. For example, the predetermined amplitude threshold can be set to 2%, 3%, 4.5%, 5%, etc., of the compressor's rated current, or it can be set to less than 2% (e.g., 1%) of the compressor's rated current. This can improve the efficiency and effectiveness of compressor detection, avoid false alarms due to abnormal current amplitude caused by setting the predetermined amplitude threshold too low, and also avoid the inability to detect compressor failures in a timely manner due to setting the predetermined amplitude threshold too high.

[0047] The above-described methods for judging abnormal fluctuations in current amplitude are merely some specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Other methods can also be used in the present invention to judge whether abnormal fluctuations in current amplitude have occurred.

[0048] As mentioned earlier, when the current amplitude fluctuates abnormally and the compressor speed is less than a predetermined threshold, the compressor operation can be stabilized by controlling the compressor speed to change. Specifically, the compressor speed can be increased to achieve stable operation, or the compressor speed can be decreased to stabilize the compressor.

[0049] like Figure 2As shown, in some embodiments of the present invention, compressor instability is eliminated by increasing the compressor speed. Specifically, if the current amplitude fluctuates abnormally and the compressor speed is less than a predetermined threshold, the compressor speed is increased by a predetermined value. In other words, when the current amplitude fluctuates abnormally and the compressor speed is less than a predetermined threshold, the compressor's operating state can be changed by increasing the compressor speed, thus maintaining stable compressor operation.

[0050] Optionally, the predetermined value can be 2% to 5% of the rated speed of the compressor. For example, the predetermined value can be set to 2%, 3%, 3.5%, 4%, etc. of the rated speed of the compressor.

[0051] When the compressor speed is not less than a predetermined threshold, it becomes difficult to improve the instability problem by increasing the compressor speed. In this case, the compressor can be shut down. The predetermined threshold can be the compressor's rated speed or other safe speed value. When the compressor speed has reached the predetermined threshold, it is difficult to improve the instability problem by increasing the speed. By shutting down the compressor in time, damage to the compressor and its surrounding components can be avoided, the compressor's stability can be maintained, and maintenance costs can be reduced.

[0052] In addition, other methods can be used to maintain the stability of the compressor or air conditioning system in the air conditioning system.

[0053] Specifically, such as Figure 3 As shown, the present invention also provides an air conditioning system, which includes a compressor 6, a condenser 8, an evaporator 10, a liquid storage passage, and a receiver 3. The first end of the condenser 8 is connected to the exhaust port of the compressor 6. The first end of the evaporator 10 is connected to the second end of the condenser 8. The second end of the evaporator 10 is connected to the suction port of the compressor 6. The first end of the liquid storage passage can be selectively connected to the second end of the condenser 8 or the first end of the evaporator 10, and the second end of the liquid storage passage is connected to the suction port of the compressor 6. A receiver 3 is provided on the liquid storage passage, which is used to store or release refrigerant in the air conditioning system piping to increase or decrease the total amount of refrigerant flowing in the air conditioning system piping. By providing a liquid storage passage and a receiver 3 on the liquid storage passage in the air conditioning system, and by using the receiver 3 to store refrigerant in the air conditioning system, the total amount of refrigerant flowing in the air conditioning system can be controlled by changing the amount of heat exchanged according to actual needs under different operating conditions, thereby effectively improving the energy efficiency of the air conditioning system.

[0054] The air conditioning system includes a pressure three-way valve 1. The pressure three-way valve 1 is located on the liquid storage passage, and the first end of the liquid discharge passage can be selectively connected to the second end of the condenser 8 or the first end of the evaporator 10 via the pressure three-way valve 1. This arrangement allows refrigerant located in the piping system to flow into the liquid receiver 3.

[0055] The air conditioning system also includes a primary bypass valve 2 and a secondary bypass valve 4. The primary bypass valve 2 is located on the pipeline between the pressure three-way valve 1 and the receiver 3. The secondary bypass valve 4 is located on the pipeline between the receiver 3 and the suction port of the compressor 6. This arrangement effectively controls the amount of refrigerant entering the receiver 3 and allows for the smooth release of refrigerant from the receiver 3 into the air conditioning system. In this invention, when there is abnormal fluctuation in the current amplitude and the compressor 6's rotational speed is not less than a predetermined threshold, the secondary bypass valve 4 can also be opened.

[0056] To prevent refrigerant backflow during refrigerant release, the air conditioning system is also equipped with a one-way valve 5. The one-way valve 5 is located on the pipeline between the secondary bypass valve 4 and the suction port of the compressor 6.

[0057] A throttling valve 9 is installed on the pipeline between the second end of the condenser 8 and the first end of the evaporator 10. One inlet branch of the pressure three-way valve 1 is located on the pipeline between the second end of the condenser 8 and the throttling valve 9, and the other inlet branch of the pressure three-way valve 1 is located on the pipeline between the throttling valve 9 and the first end of the evaporator 10. The air conditioning system also includes a four-way valve. The discharge port of the compressor 6 can be selectively connected to either the first end of the condenser 8 or the second end of the evaporator 10 via the four-way valve. This configuration allows the air conditioning system to switch between cooling and heating modes.

[0058] Specifically, such as Figure 2 As shown, the compressor control method of the present invention includes the following steps:

[0059] Step s1: Determine if there are any abnormal fluctuations in the current amplitude;

[0060] Step s2: If the fluctuation of the current amplitude is not abnormal, the compressor continues to operate normally;

[0061] Step s3: If the fluctuation of the current amplitude is abnormal, determine whether the compressor speed has reached the maximum speed;

[0062] Step s4: If the compressor speed reaches the maximum speed, control the compressor to stop or open the secondary bypass;

[0063] Step s5: If the compressor speed does not reach the maximum speed, increase the compressor speed by 2% to 5% of the rated speed value, and return to step s1.

[0064] In addition, the present invention can also determine the operating status of the compressor through other methods.

[0065] like Figure 4 As shown, in some embodiments of the present invention, the control method further includes: before acquiring the compressor current amplitude, acquiring the compressor speed value, and determining whether the compressor is operating stably based on the compressor's configuration. Specifically, after acquiring the compressor speed value, it is determined whether the speed value fluctuation is abnormal; if the compressor speed value fluctuation is abnormal, the compressor is controlled to stop. This can further improve the stability of compressor operation.

[0066] The determination of whether the rotational speed fluctuation is abnormal includes: calculating the difference between two adjacent detected rotational speed values ​​to obtain a rotational speed difference value, and comparing the absolute value of the rotational speed difference value with a predetermined rotational speed threshold. Specifically, within a predetermined time range, multiple rotational speed values ​​are acquired sequentially, and the difference between two adjacent rotational speed values ​​is calculated to obtain multiple rotational speed differences. If the rotational speed value fluctuates within the predetermined time range, and the number of rotational speed differences whose absolute value exceeds the predetermined rotational speed threshold is greater than a predetermined number, then the fluctuation of the rotational speed value is determined to be abnormal. Fluctuation of the rotational speed value refers to ups and downs in the rotational speed value, for example, multiple detected rotational speed values ​​first increasing and then decreasing, or first decreasing and then increasing, etc.

[0067] For example, multiple rotational speed values ​​can be continuously detected to obtain a sequence of rotational speed values, such as continuously detecting and obtaining rotational speed values ​​V1, V2, V3, V4, V5…V n V n+1 …; Calculate the difference between two adjacent detected rotational speed values ​​to obtain the rotational speed difference value, for example, obtain the rotational speed difference value V. 12 =V2-V1, V 23 =V3-V2, V 34 =V4-V3, V 45 =V5-V4…V n(n+1) =V n+1 -V n …; where multiple obtained speed difference values ​​contain both positive and negative values, it is determined that the speed value fluctuates, for example, V 12 >0, V 23 <0, V 34 >0, V 45 When the value is less than 0…, the rotational speed is considered to be fluctuating; among the multiple rotational speed differences obtained, the absolute value exceeds the threshold V. s When the number of speed difference values ​​exceeds a predetermined number, the speed value fluctuation is determined to be abnormal.

[0068] Alternatively, the fluctuation of rotational speed values ​​can be continuously monitored by continuously updating the sequence of rotational speed values. For example, the rotational speed values ​​can be re-detected, and the new detection results can completely replace the previous detection results to form a new sequence of rotational speed values. Alternatively, the rotational speed values ​​can be continuously detected, and the sequence can be updated using the new detection results. For instance, if the rotational speed values ​​used in the previous determination of whether the rotational speed values ​​were abnormal included V1, V2, V3, V4, and V5, the new sequence of rotational speed values ​​can be changed to V2, V3, V4, V5, and V6 after replacing them with newly detected rotational speed values. Of course, other methods for updating rotational speed values ​​can also be used in this invention, and these are all within the scope of protection of this invention.

[0069] This invention enables rapid determination of whether the compressor is malfunctioning by detecting its rotational speed, thereby improving the efficiency and effectiveness of compressor malfunction detection, enhancing compressor stability, and reducing compressor maintenance costs.

[0070] Optionally, the predetermined speed threshold is within the range of 400 rpm to 600 rpm. For example, the predetermined speed threshold can be set to 450 rpm, 510 rpm, 560 rpm, 580 rpm, etc., or it can be set to less than 400 rpm (e.g., 200 rpm) or greater than 600 rpm (e.g., 800 rpm). This can improve the detection efficiency and effectiveness of the compressor, avoid false alarms due to abnormal speed values ​​caused by setting the predetermined speed threshold too low, and also avoid the inability to detect compressor failures in a timely manner due to setting the predetermined speed threshold too high.

[0071] like Figure 5 As shown, in some embodiments of the present invention, before obtaining the compressor current amplitude, the method further includes obtaining the compressor current frequency and determining the compressor's operating status based on the compressor current frequency. After obtaining the compressor current frequency, it can be determined whether the fluctuation of the compressor current frequency is abnormal. If the fluctuation of the current frequency is abnormal, the compressor is controlled to stop.

[0072] A method for determining whether fluctuations in current frequency are abnormal may include: calculating the difference between two adjacent detected current frequencies to obtain frequency differences, and comparing the absolute value of the frequency differences with a predetermined frequency threshold. Specifically, within a predetermined time range, multiple current frequencies are acquired sequentially, and the difference between two adjacent current frequencies is calculated to obtain multiple frequency differences. If the current frequency fluctuates within the predetermined time range, and the number of frequency differences whose absolute values ​​exceed the predetermined frequency threshold is greater than a predetermined number, then the fluctuation of the current frequency is determined to be abnormal. Fluctuations in current frequency refer to ups and downs in the current frequency, for example, multiple detected current frequencies first increasing and then decreasing, or first decreasing and then increasing, etc.

[0073] Specifically, multiple current frequencies can be continuously detected to obtain a sequence of current frequencies, such as f1, f2, f3, f4, f5…f… n f n+1 …; Calculate the difference between the frequencies of two adjacent detected currents to obtain the frequency difference, for example, obtain the frequency difference f. 12 =f2-f1, f 23 =f3-f2, f 34 =f4-f3, f 45 =f5-f4…f n(n+1) =f n+1 -f n …; among them, when multiple frequency differences are obtained, both positive and negative values ​​are present, it is determined that the current frequency fluctuates, for example, f 12 >0, f 23 <0, f 34 >0, f 45 A value less than 0 indicates a fluctuation in the current frequency; among the multiple frequency differences obtained, the absolute value exceeds the threshold f. s When the number of frequency differences exceeds a predetermined number, the fluctuation of the current frequency is determined to be abnormal.

[0074] Alternatively, fluctuations in the current frequency can be continuously monitored by continuously updating the current frequency sequence. For example, the current frequency can be re-detected, and the new detection result can completely replace the previous one, forming a new current frequency sequence. Or, the current frequency can be continuously monitored, and the current frequency sequence can be updated using the new detection results. For instance, if the current frequencies used in the previous determination of whether the current frequency was abnormal included f1, f2, f3, f4, and f5, after replacing them with newly detected current frequencies, the new current frequency sequence can be changed to f2, f3, f4, f5, and f6. Of course, other current frequency update methods can also be used in this invention, and these are all within the scope of protection of this invention.

[0075] By detecting the compressor current frequency, it is possible to quickly determine whether there is an abnormality in the compressor's operation, thereby improving the efficiency and effectiveness of compressor anomaly detection, enhancing compressor stability, and reducing compressor maintenance costs.

[0076] Optionally, the predetermined frequency threshold is within the range of 5Hz to 20Hz. For example, the predetermined frequency threshold can be set to 6Hz, 10Hz, 13Hz, 16Hz, etc., or it can be set to less than 5Hz (e.g., 3Hz), or it can be set to greater than 20Hz (e.g., 50Hz). This can improve the detection efficiency and effectiveness of the compressor, avoid false alarms of abnormal current frequency due to setting the predetermined frequency threshold too low, and also avoid the inability to detect compressor failures in a timely manner due to setting the predetermined frequency threshold too high.

[0077] Furthermore, to improve the accuracy and efficiency of the detection results and facilitate timely judgment of compressor malfunctions, in some embodiments of the present invention, the predetermined quantity is set to be no less than 5. For example, the predetermined quantity can be set to 5, 7, 10, 14, 20, etc. Of course, the predetermined quantity can also be set to be less than 5 (e.g., 3, etc.). Additionally, the predetermined time is no less than 30 seconds. For example, the predetermined time can be set to 30 seconds, 50 seconds, 60 seconds, 200 seconds, 300 seconds, etc. Of course, the predetermined quantity can also be set to be less than 30 seconds (e.g., 15 seconds, etc.).

[0078] Furthermore, the above-described solution of the present invention is particularly applicable to centrifugal air-suspension compressors, and of course, it is also applicable to other types of compressors, such as magnetic levitation compressors. Combined with the foregoing embodiments, the detection and control of the compressor operation process are increased to maintain the stability of compressor operation and avoid damage to the components in the compressor. Specifically, taking an air-suspension compressor as an example:

[0079] When the compressor experiences abnormal speed fluctuations, it can affect the performance and lifespan of the gas bearing. This abnormality needs to be avoided during operation. This invention proposes a method to monitor current frequency fluctuations through a frequency converter, thereby achieving abnormal speed shutdown.

[0080] Normal acceleration and deceleration do not affect the operation of the bearing. When the frequency only increases or decreases, it is considered normal. When the speed fluctuation exceeds 600 rpm and the frequency fluctuation exceeds 10 Hz (taking a two-pole motor as an example, and 20 Hz for a four-pole motor), the inverter's automatic shutdown program will be started, and the abnormal speed fluctuation shutdown will be displayed. An abnormal speed fluctuation alarm will be issued, prompting the machine room to restart.

[0081] When the compressor is operating, if surge occurs and the inverter current amplitude fluctuates abnormally, the Hall element of the inverter continuously monitors the current amplitude fluctuation. If the inverter experiences 10 fluctuations (n ​​times, n≥10) within one minute, the inverter controls the compressor speed to increase / decrease (or the system controls the guide vane opening), continuously monitoring the current fluctuation. If, after adjusting the speed or guide vane opening, 10 fluctuations (n ​​times, n≥10) occur within one minute, the intelligent shutdown procedure is initiated, and an abnormal current fluctuation shutdown alarm is triggered, prompting the machine room to restart. The control method is as follows: Figure 2 As shown; other methods can also be used, when the frequency converter fluctuates 10 times (n times, n≥10) within 1 minute, the shutdown procedure can be started directly and an alarm for abnormal current fluctuation shutdown can be triggered, prompting the machine room to restart.

[0082] In comparison, in related technologies, abnormal speed fluctuations in compressors can affect the performance and lifespan of gas bearings. This abnormality needs to be avoided during operation. This invention proposes a method to monitor current frequency fluctuations using a frequency converter, thereby achieving abnormal speed shutdown. Normal acceleration and deceleration do not affect bearing operation; increases or decreases in frequency are considered normal. When speed fluctuations exceed 600 rpm and frequency fluctuations exceed 10 Hz, the frequency converter's automatic shutdown program is activated, displaying an abnormal speed fluctuation shutdown message.

[0083] In addition, compressor surge is accompanied by fluctuations in motor and inverter current. This invention identifies surge and other anomalies by monitoring current fluctuations through the inverter, and then avoids or shuts down the compressor. After the compressor is started, the inverter of the permanent magnet synchronous motor monitors the current amplitude inside the compressor. When the current amplitude fluctuates, the inverter automatically increases or decreases the motor speed. If the inverter current no longer fluctuates abnormally at this time, it means that the surge area has been quickly avoided and the compressor can continue to operate stably. If the current continues to fluctuate after speed adjustment, the automatic shutdown program is initiated, and the compressor enters the shutdown protection state.

[0084] In addition, such as Figure 6 The present invention also provides a control device 11 for a compressor 6, which can implement the aforementioned compressor 6 control method.

[0085] like Figure 6As shown, a control device 11 for a compressor 6 according to an embodiment of the present invention includes the aforementioned control method for the compressor 6. The control device 11 includes a speed monitoring element 111, an amplitude monitoring element 113, and a controller 114. The speed monitoring element 111 is used to detect the speed value of the compressor 6; the amplitude monitoring element 113 is used to detect the current amplitude of the compressor 6; the controller 114 is connected to the speed monitoring element 111 and the amplitude monitoring element 113 respectively, and the controller 114 is used to acquire the current amplitude of the compressor, determine whether the fluctuation of the current amplitude is abnormal, and compare the speed value of the compressor with a predetermined threshold. If the fluctuation of the current amplitude is abnormal and the speed value of the compressor is less than the predetermined threshold, the controller controls the compressor to increase its speed.

[0086] The speed monitoring component 111 may include a Hall element, and the frequency detection component and amplitude detection component may be a frequency converter.

[0087] In addition, the control device 11 of the present invention may also include a frequency monitoring element for detecting the current frequency of the compressor or inverter, and the controller 114 is connected to the frequency monitoring element to determine the operating status of the compressor based on the current frequency.

[0088] The compressor 6 according to an embodiment of the present invention includes a control device 11 according to the aforementioned compressor 6; or includes a control method according to the aforementioned compressor 6.

[0089] According to the embodiments of the present invention, the compressor 6 and the control device 11 of the compressor 6 can use the aforementioned control method to detect abnormalities in the compressor 6 in a timely manner, so as to adjust the speed or stop the compressor 6, thereby avoiding or reducing problems such as component wear caused by compressor 6 instability, and also preventing the compressor 6 from continuing to run and causing greater failures or wear, thereby reducing the maintenance cost of the compressor 6.

[0090] like Figure 8 In some embodiments of the present invention, the compressor 6 includes a gas bearing. The compressor 6 may include a radial gas bearing 13 and an axial gas bearing 14. The gas bearing can be used to improve the stability of the compressor 6 rotor 12 during operation, and combined with the aforementioned control method, wear of the gas bearing can be avoided.

[0091] Specifically, the compressor 6 includes a rotor 12 and a gas bearing. By setting the gas bearing, the stability of the rotor 12 assembly during operation can be improved and the damping during the rotation of the rotor 12 can be reduced.

[0092] The gas bearing may include a radial gas bearing 13, which is sleeved on the outer periphery of the rotor 12. The radial gas bearing 13 is a gas bearing according to the aforementioned embodiment. The mounting base, corrugated foil, and top foil of the radial gas bearing 13 are stacked sequentially from the outside to the inside along the radial direction BB of the rotor 12. During use, as the rotor 12 assembly rotates, it pushes the top foil toward the mounting base, forming an air film on the surface of the top foil. Simultaneously, it causes the top foil to expand outward and press against the corrugated foil. Furthermore, the corrugated foil provides support for the top foil, ensuring an appropriate distance between the corrugated foil and the rotating shaft to maintain the stability of the air film between the top foil and the rotating shaft. This also maintains stable rotation of the rotor 12 and reduces radial runout of the rotor 12.

[0093] Additionally, the rotor 12 assembly may also include an axial gas bearing 14, which cooperates with the rotor 12. The axial gas bearing 14 is a gas bearing according to the aforementioned embodiment. The mounting base, corrugated foil, and top foil of the axial gas bearing 14 are sequentially stacked along the axial direction AA of the rotor 12. During use, as the rotor 12 assembly rotates, it will push the top foil toward the mounting base and form an air film on the surface of the top foil. The top foil presses against the corrugated foil. Furthermore, the corrugated foil provides support for the top foil to ensure an appropriate distance between the corrugated foil and the rotating shaft, thereby maintaining the stability of the air film between the top foil and the rotating shaft.

[0094] The present invention also provides a storage medium, which can be a computer-readable storage medium, storing a control program for a compressor 6 thereon. When executed by a processor, the control program for the compressor 6 implements the control method for the compressor 6 as described above. This storage medium can be placed on the control device 11 of the compressor 6 to provide control over the compressor 6, improve the stability of the compressor 6's operation, and reduce maintenance costs and failure rates. Furthermore, this storage medium can also be used to upgrade and update the control strategy of the compressor 6.

[0095] like Figure 7 The heating, ventilation and air conditioning equipment 100 according to an embodiment of the present invention includes the compressor 6 as described above.

[0096] According to the embodiments of the present invention, the HVAC equipment 100, storage medium, compressor 6, and their control method and control device 11 can promptly detect abnormalities in the compressor 6, facilitating speed adjustment or shutdown of the compressor 6, thereby avoiding or reducing problems such as component wear caused by compressor 6 instability. Furthermore, it can prevent increased fluctuations in the operation of the compressor 6 and HVAC equipment 100 during operation, thus preventing small problems from escalating, thereby reducing the maintenance costs of the HVAC equipment 100 and improving its stability.

[0097] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0098] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0099] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0100] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0101] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for controlling a compressor, characterized in that, include: Obtain the current amplitude of the compressor; Determine whether the fluctuation of the current amplitude is abnormal; Calculate the difference between two consecutive detected current amplitudes to obtain an amplitude difference value, and compare the absolute value of the amplitude difference value with a predetermined amplitude threshold. If the fluctuation of the current amplitude is abnormal, the compressor speed will be controlled to change. The step of controlling the compressor to change its speed if the fluctuation of the current amplitude is abnormal includes: If the fluctuation of the current amplitude is abnormal and the speed of the compressor is less than a predetermined threshold, the speed of the compressor is controlled to increase by a predetermined value.

2. The compressor control method according to claim 1, characterized in that, The predetermined value is in the range of 2% to 5% of the compressor's rated speed.

3. The compressor control method according to claim 1, characterized in that, The method of controlling the compressor to change its speed if the fluctuation of the current amplitude is abnormal also includes: If the fluctuation of the current amplitude is abnormal and the speed of the compressor is not less than a predetermined threshold, the compressor is controlled to stop.

4. The compressor control method according to any one of claims 1-3, characterized in that, Before obtaining the current amplitude of the compressor, the process also includes: Obtain the compressor's rotational speed value; Determine whether the fluctuation of the speed value is abnormal; If the speed value fluctuates abnormally, the compressor will be shut down.

5. The compressor control method according to any one of claims 1-3, characterized in that, Before obtaining the current amplitude of the compressor, the process also includes: Obtain the current frequency of the compressor; Determine whether the fluctuation of the current frequency is abnormal; If the fluctuation of the current frequency is abnormal, the compressor is controlled to stop.

6. A control device for a compressor, the control device comprising a control method for a compressor according to any one of claims 1-5, characterized in that, include: Speed ​​monitoring components are used to detect the compressor's speed. Amplitude monitoring device, used to detect the current amplitude of the compressor; Calculate the difference between two consecutive detected current amplitudes to obtain an amplitude difference value, and compare the absolute value of the amplitude difference value with a predetermined amplitude threshold. The controller is connected to the speed monitoring device and the amplitude monitoring device respectively. The controller is used to obtain the current amplitude of the compressor, determine whether the fluctuation of the current amplitude is abnormal, and compare the speed value of the compressor with a predetermined threshold. If the fluctuation of the current amplitude is abnormal and the speed value of the compressor is less than the predetermined threshold, the controller controls the compressor to increase the speed. The step of controlling the compressor to change its speed if the fluctuation of the current amplitude is abnormal includes: If the fluctuation of the current amplitude is abnormal and the speed of the compressor is less than a predetermined threshold, the speed of the compressor is controlled to increase by a predetermined value.

7. A compressor, characterized in that, The compressor control method according to any one of claims 1-5; or the compressor control device according to claim 6.

8. The compressor according to claim 7, characterized in that, The compressor includes a gas bearing.

9. A storage medium, characterized in that, It stores a compressor control program, which, when executed by a processor, implements the compressor control method as described in any one of claims 1-5.

10. A heating, ventilation, and air conditioning (HVAC) device, characterized in that, Includes the compressor as described in claim 7 or 8.

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