Control method of compressor and compressor unit

Abstract

The present application discloses a control method for a compressor and a compressor unit, relating to the technical field of gas boosting. The control method includes: receiving a target operation; when the target operation is to switch to the power frequency mode, adjusting the motor speed of the compressor to be equal to the rated power frequency speed, closing the variable frequency high-voltage cabinet, and opening the power frequency high-voltage cabinet; when the target operation is to switch to the variable frequency mode, closing the power frequency high-voltage cabinet, opening the variable frequency high-voltage cabinet, and adjusting the motor speed of the compressor to be equal to the rated variable frequency speed. This solution can solve the problem that the compressor stops when there are faults or maintenance in the variable frequency control system or the power frequency control system of the current compressor.

Description

Technical Field

[0001] The present application belongs to the technical field of gas pressurization, and in particular relates to a compressor control method and a compressor unit. Background Art

[0002] A compressor is a gas boosting equipment. The working modes of the compressor mainly include variable frequency working mode and industrial frequency working mode. Among them, the variable frequency working mode is mainly based on process requirements or energy-saving needs, by changing the motor frequency for speed regulation, or saving energy according to the use of on-site equipment; and the industrial frequency working mode is to operate at the rated power of the motor itself, with a frequency of 50HZ.

[0003] Since the compressor under variable frequency working condition has the effect of energy saving, therefore, in the actual use process, the compressor is usually operated under variable frequency working condition. However, due to the complexity of variable frequency regulation, the variable frequency control system has the situation of sudden failure or overhaul and maintenance, in which case the compressor needs to be shut down, which will cause production to stop; in addition, when the power frequency control system has sudden failure or overhaul and maintenance, the compressor also needs to be shut down, which will cause production to stop. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a compressor control method and a compressor unit, which can solve the problem that the compressor currently shuts down when a variable frequency control system or an industrial frequency control system fails or is undergoing maintenance.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a method for controlling a compressor, the method comprising:

[0007] Receive target operation;

[0008] When the target operation is to switch to the industrial frequency mode, the motor speed of the compressor is adjusted to be equal to the rated speed of the industrial frequency, the variable frequency high voltage cabinet is turned off, and the industrial frequency high voltage cabinet is turned on;

[0009] When the target operation is to switch to the variable frequency mode, the industrial frequency high voltage cabinet is turned off, and the variable frequency high voltage cabinet is turned on, and the motor speed of the compressor is adjusted to be equal to the variable frequency rated speed.

[0010] In a second aspect, an embodiment of the present application further provides a compressor unit, comprising:

[0011] A variable frequency and industrial frequency switching device, used to receive a target operation, and when the target operation is switching to the industrial frequency mode, close the variable frequency high voltage cabinet and open the industrial frequency high voltage cabinet, and when the target operation is switching to the variable frequency mode, close the industrial frequency high voltage cabinet and open the variable frequency high voltage cabinet;

[0012] A variable frequency control system is used to adjust the motor speed of the compressor to be equal to the power frequency rated speed when the target operation is to switch to the power frequency mode.

[0013] A power frequency control system is used to adjust the motor speed of the compressor to be equal to the variable frequency rated speed when the target operation is to switch to the variable frequency mode.

[0014] In the embodiment of the present application, when a fault occurs in the variable frequency control system for controlling the compressor or maintenance is required, first, the motor speed of the compressor is adjusted by the variable frequency control system to be equal to the power frequency rated speed, then the variable frequency high-voltage cabinet is closed, and at the same time, the power frequency high-voltage cabinet is opened. At this time, the variable frequency control system stops working, and the power frequency control system starts to work, so as to switch the compressor from the variable frequency mode to the power frequency mode to avoid the compressor from stopping; when the variable frequency control system can resume normal operation or a fault occurs in the power frequency control system and maintenance is required, first, the power frequency high-voltage cabinet is closed, and at the same time, the variable frequency high-voltage cabinet is opened, then the motor speed of the compressor is adjusted by the power frequency control system to be equal to the variable frequency rated speed. At this time, the power frequency control system stops working, and the variable frequency control system starts to work, so as to switch the compressor from the power frequency mode to the variable frequency mode, which can also avoid the compressor from stopping. It can be seen from this that the embodiment of the present application can realize the flexible switching of the compressor between the variable frequency mode and the power frequency mode, thereby solving the problem that the compressor stops when there is a fault in the variable frequency control system or the power frequency control system or maintenance is carried out. Description of the Drawings

[0015] Figure 1 It is a schematic structural diagram of a compressor unit disclosed in the embodiment of the present application, where solid lines represent medium pipelines, dotted lines represent high-voltage cables, and dashed lines represent signal cables.

[0016] Figure 2 It is a flowchart of a control method for a compressor disclosed in the embodiment of the present application.

[0017] Description of the Reference Numerals:

[0018] 100 - Compressor, 110 - Motor, 120 - Return Valve, 130 - First Flow Detection Component, 140 - Control Valve, 150 - First Pressure Detection Component, 160 - Second Pressure Detection Component, 170 - First Temperature Detection Component, 180 - Second Temperature Detection Component, 190 - Second Flow Detection Component;

[0019] 200 - Variable Frequency High-Voltage Cabinet;

[0020] 300 - Power Frequency High-Voltage Cabinet;

[0021] 400 - Variable Frequency Control System;

[0022] 500 - Power Frequency Control System;

[0023] 600 - Frequency - conversion power - frequency switching device;

[0024] 700 - Power - supply switching device. Detailed implementation manners

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0026] The terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same category, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / " generally means an "or" relationship between the associated objects before and after.

[0027] The control method of the compressor and the compressor unit provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings and through specific embodiments and their application scenarios.

[0028] As Figures 1 to 2 shown, the embodiments of the present application provide a control method of a compressor, including:

[0029] S110. Receive a target operation.

[0030] The target operation here specifically refers to an operation performed by the user on the compressor, such as switching from the frequency - conversion mode to the power - frequency mode, or switching from the power - frequency mode to the frequency - conversion mode as described below.

[0031] S210. When the target operation is to switch to the power - frequency mode, adjust the motor speed of the compressor 100 to be equal to the rated power - frequency speed, turn off the frequency - conversion high - voltage cabinet 200, and turn on the power - frequency high - voltage cabinet 300.

[0032] The variable-frequency high-voltage cabinet 200 here specifically refers to a power supply device whose output frequency and voltage are adjustable within a certain range. When the compressor 100 is in the variable-frequency mode and the variable-frequency control system 400 fails or needs to be repaired, and thus it is necessary to switch from the variable-frequency mode to the power-frequency mode, the motor speed of the compressor 100 is adjusted by the variable-frequency high-voltage cabinet 200 to be equal to the power-frequency rated speed. The power-frequency rated speed here specifically refers to the speed of the motor 110 when the compressor 100 is operating under the power-frequency mode conditions at a frequency of 50 Hz; of course, it can also be the speed at a frequency of 60 Hz; optionally, the power-frequency rated speed here can be a specific value or a value range, and no specific limitation is made here.

[0033] S310. When the target operation is to switch to the variable-frequency mode, turn off the power-frequency high-voltage cabinet 300, turn on the variable-frequency high-voltage cabinet 200, and adjust the motor speed of the compressor 100 to be equal to the variable-frequency rated speed.

[0034] The power-frequency high-voltage cabinet 300 here specifically refers to a power supply device whose output frequency and voltage are both fixed and unchanged. When the compressor 100 is in the power-frequency mode and the power-frequency control system 500 fails or needs to be repaired, and thus it is necessary to switch from the power-frequency mode to the variable-frequency mode, the motor speed of the compressor 100 is adjusted by the power-frequency high-voltage cabinet 300 to be equal to the variable-frequency rated speed. The variable-frequency rated speed here specifically refers to the speed of the motor 110 when the compressor 100 is operating under the variable-frequency mode conditions; optionally, the variable-frequency rated speed here can be a specific value or a value range, and no specific limitation is made here.

[0035] In the embodiment of the present application, when a failure occurs in the variable-frequency control system 400 for controlling the compressor 100 or maintenance is required, first, the motor speed of the compressor 100 is adjusted by the variable-frequency control system 400 to be equal to the power-frequency rated speed, then the variable-frequency high-voltage cabinet 200 is closed, and at the same time, the power-frequency high-voltage cabinet 300 is turned on. At this time, the variable-frequency control system 400 stops working, and the power-frequency control system 500 starts to work, so as to switch the compressor 100 from the variable-frequency mode to the power-frequency mode to avoid the shutdown of the compressor 100; when the variable-frequency control system 400 can resume normal operation or the power-frequency control system 500 fails and maintenance is required, first, the power-frequency high-voltage cabinet 300 is closed, and at the same time, the variable-frequency high-voltage cabinet 200 is turned on, then the motor speed of the compressor 100 is adjusted by the power-frequency control system 500 to be equal to the variable-frequency rated speed. At this time, the power-frequency control system 500 stops working, and the variable-frequency control system 400 starts to work, so as to switch the compressor 100 from the power-frequency mode to the variable-frequency mode, which can also avoid the shutdown of the compressor 100. It can be seen from this that the embodiment of the present application can realize the flexible switching of the compressor 100 between the variable-frequency mode and the power-frequency mode, thereby solving the problem that the compressor 100 stops when there is a failure in the variable-frequency control system 400 or the power-frequency control system 500 or maintenance is carried out on them currently.

[0036] It should be noted that the variable-frequency rated speed in the above embodiment is less than the power-frequency rated speed.

[0037] In an alternative embodiment, adjusting the motor speed of the compressor 100 in step S210 to be equal to the power-frequency rated speed specifically includes:

[0038] S211. Determine whether the compressor 100 meets the first switching condition.

[0039] The first switching condition here specifically refers to whether the operating parameters of the compressor 100 meet the requirements, such as the pressure and temperature of the medium, which are not specifically limited here. Optionally, various working parameters of the compressor 100 can be monitored by the variable-frequency and power-frequency switching device 600. Of course, they can also be monitored by other devices, which are not specifically limited here.

[0040] S212. When the compressor 100 meets the first switching condition, adjust the motor speed of the compressor 100 to be equal to the power-frequency rated speed.

[0041] In this embodiment, first, according to the parameters monitored by the frequency conversion power frequency switching device 600, it is accurately determined whether the compressor 100 meets the first switching condition. When the compressor 100 meets the first switching condition, the frequency conversion power frequency switching device 600 sends a signal to the frequency conversion control system 400. At this time, the frequency conversion control system 400 controls the frequency conversion high-voltage cabinet 200 to adjust the motor speed of the compressor 100 to be equal to the power frequency rated speed; otherwise, the operating parameters of the compressor 100 need to be manually adjusted to make it meet the first switching condition, and then the motor speed of the compressor 100 is adjusted to be equal to the power frequency rated speed, so as to protect the compressor 100 and improve the switching efficiency of the compressor 100 between the frequency conversion mode and the power frequency mode at the same time.

[0042] In a further optional embodiment, after adjusting the motor speed of the compressor 100 in step S210 to be equal to the power frequency rated speed, the control method further includes:

[0043] S220. Obtain the first flow rate of the medium at the exhaust port of the compressor 100.

[0044] Here, the first flow rate specifically refers to the flow rate of the medium flowing out of the exhaust port of the compressor 100 per unit time when the motor speed of the compressor 100 is equal to the power frequency rated speed.

[0045] Optionally, a first flow rate detection component 130 is provided at the exhaust port of the compressor 100 for detecting the first flow rate of the medium at the exhaust port. Optionally, the first flow rate detection component 130 is electrically connected to the frequency conversion power frequency switching device 600, and the detection signal of the first flow rate detection component 130 is transmitted to the frequency conversion power frequency switching device 600.

[0046] S230. When the first flow rate is greater than the first preset flow rate, open the reflux valve 120 at the exhaust port of the compressor 100 to make part of the medium discharged from the exhaust port of the compressor 100 flow back to the intake port of the compressor 100.

[0047] It should be noted that the intake port of the reflux valve 120 is connected to the exhaust port of the compressor 100, and the exhaust port of the reflux valve 120 is connected to the intake port of the compressor 100. In addition, the first preset flow rate specifically refers to the flow rate of the medium allowed to pass through the compressor 100 when the intake and exhaust volumes of the compressor 100 are in dynamic balance under the operating conditions of the compressor 100 in the power frequency mode; optionally, the first preset flow rate can be a specific value or a numerical range, and no specific limitation is made here.

[0048] In this solution, when the first flow rate is greater than the first preset flow rate, that is, after the rotational speed of the compressor 100 increases, correspondingly, the medium discharged from the exhaust port of the compressor 100 increases. When it exceeds the flow rate of the operating condition of the compressor 100, part of the medium re-enters the compressor 100 through the reflux valve 120, so that the operating condition of the compressor 100 is in a dynamic balance state to protect the compressor 100 and extend the service life of the compressor 100.

[0049] In a further optional embodiment, after closing the variable-frequency high-voltage cabinet 200 and opening the power-frequency high-voltage cabinet 300 in step S210, the control method further includes:

[0050] S240. Adjust the opening degree of the regulating valve 140 at the air inlet of the compressor 100 to the first preset opening degree.

[0051] The first preset opening degree here specifically refers to the opening degree of the regulating valve 140 when the air intake and exhaust of the compressor 100 are in dynamic balance under the operating condition of the compressor 100 in the power-frequency mode.

[0052] S250. Close the reflux valve 120.

[0053] Optionally, the regulating valve 140 can be electrically connected to the variable-frequency control system 400, and the opening degree of the regulating valve 140 is controlled through the variable-frequency control system 400.

[0054] In this solution, when the variable-frequency mode is switched to the power-frequency mode, the compressor 100 operates at its rated power. At this time, the opening degree of the regulating valve 140 is adjusted to the first preset opening degree to reduce the air intake at the air inlet of the compressor 100, and further reduce the flow rate of the medium discharged from the exhaust port of the compressor 100, meeting the operating condition requirements of the compressor 100. Correspondingly, there is no need to reflux part of the medium to the air inlet of the compressor 100. Therefore, the reflux valve 120 is closed at this time to make the operation of the entire compressor in a dynamic balance state.

[0055] In another optional embodiment, closing the variable-frequency high-voltage cabinet 200 and opening the power-frequency high-voltage cabinet 300 in step S210 specifically includes:

[0056] S213. Close the variable-frequency control system 400 and open the power-frequency control system 500 through the variable-frequency power-frequency switching device 600.

[0057] S214. Output a first control signal to the power supply switching device 700 through the variable-frequency power-frequency switching device 600. The power supply switching device 700 closes the variable-frequency high-voltage cabinet 200 and opens the power-frequency high-voltage cabinet 300 according to the first control signal.

[0058] When the motor speed of the compressor 100 is adjusted from the variable-frequency rated speed to the power-frequency rated speed, the variable-frequency power-frequency switching device 600 will issue two control signals, specifically, the first control signal and the third control signal. Among them, the third control signal is sent to the variable-frequency control system 400 and the power-frequency control system 500, so as to control the variable-frequency control system 400 to close and simultaneously turn on the power-frequency control system 500; while the first control signal is sent to the power supply switching device 700. At this time, the power supply switching device 700 controls the variable-frequency high-voltage cabinet 200 to close and simultaneously turn on the power-frequency high-voltage cabinet 300 according to the first control signal, that is, the output circuit breaker of the variable-frequency high-voltage cabinet 200 is disconnected from the motor 110, and the output circuit breaker of the power-frequency high-voltage cabinet 300 is closed with the motor 110, so that the power-frequency high-voltage cabinet 300 supplies power to the motor 110. This solution adopts this control method, which is convenient for centralized control and improves the switching efficiency from the variable-frequency mode to the power-frequency mode.

[0059] The above-mentioned first control signal specifically refers to the signal for the power supply switching device 700 to control the variable-frequency high-voltage cabinet 200 to close and the power-frequency high-voltage cabinet 300 to turn on. The third control signal specifically refers to the signal for closing the variable-frequency control system 400 and turning on the power-frequency control system 500.

[0060] In another alternative embodiment, before closing the power-frequency high-voltage cabinet 300 and turning on the variable-frequency high-voltage cabinet 200 in step S310, the control method further includes:

[0061] S320. Determine whether the compressor 100 meets the second switching condition.

[0062] The second switching condition here specifically refers to whether the operating parameters of the compressor 100 meet the requirements, such as the pressure and temperature of the medium, which are not specifically limited here. Optionally, the variable-frequency power-frequency switching device 600 can be used to monitor the various working parameters of the compressor 100. Of course, other devices can also be used for monitoring, which are not specifically limited here.

[0063] S330. When the compressor 100 meets the second switching condition, adjust the opening of the regulating valve 140 at the air inlet of the compressor 100 to the second preset opening.

[0064] The second preset opening here specifically refers to the opening of the regulating valve 140 when the intake air volume and exhaust air volume of the compressor 100 are in dynamic balance under the operating conditions of the compressor 100 in the variable-frequency mode; optionally, the second preset opening can be in the fully open state, and of course, it can also be in a state close to fully open, which is not specifically limited here. Optionally, the regulating valve 140 can be electrically connected to the power-frequency control system 500, and the opening of the regulating valve 140 is controlled through the power-frequency control system 500.

[0065] In this solution, before adjusting the speed of the motor 110 to the variable-frequency rated speed, it is first determined whether the operating condition of the compressor 100 meets the second switching condition. When the operating condition of the compressor 100 meets the second switching condition, the opening degree of the regulating valve 140 at the air inlet of the compressor 100 is adjusted to the fully open state, so as to increase the medium flow rate in the compressor 100, ensure the pressure stability at the exhaust port of the compressor 100, make the operating condition of the compressor 100 in a dynamic balance state, and thus protect the compressor 100.

[0066] In a further optional embodiment, after adjusting the opening degree of the regulating valve 140 at the air inlet of the compressor 100 in step S310 to the second preset opening degree, the control method further includes:

[0067] S340. Obtain the second flow rate of the medium at the exhaust port of the compressor 100.

[0068] The second flow rate here specifically refers to the medium flow rate flowing out of the exhaust port of the compressor 100 per unit time when the opening degree of the regulating valve 140 at the air inlet of the compressor 100 is opened to the second preset opening degree.

[0069] Optionally, a first flow rate detection component 130 is provided at the exhaust port of the compressor 100 for detecting the second flow rate of the medium at the exhaust port. Optionally, the first flow rate detection component 130 is electrically connected to the variable-frequency power-frequency switching device 600, and the detection signal of the first flow rate detection component 130 is transmitted to the variable-frequency power-frequency switching device 600.

[0070] S350. When the second flow rate is greater than the second preset flow rate, open the return valve 120 at the exhaust port of the compressor 100, so that part of the medium discharged from the exhaust port of the compressor 100 flows back to the air inlet of the compressor 100.

[0071] It should be noted that the air inlet of the return valve 120 is connected to the exhaust port of the compressor 100, and the exhaust port of the return valve 120 is connected to the air inlet of the compressor 100. In addition, the second preset flow rate here specifically refers to the medium flow rate allowed to enter the compressor 100 when the intake air volume and exhaust air volume of the compressor 100 are in dynamic balance under the operating condition of the compressor 100 in the variable-frequency mode; optionally, the second preset flow rate can be a specific value or a value range, and no specific limitation is made here.

[0072] In this solution, when the second flow rate is greater than the second preset flow rate, that is, after the medium flowing into the intake port of the compressor 100 increases, and the medium discharged from the exhaust port of the compressor 100 exceeds the operating condition flow rate of the compressor 100, at this time, part of the medium re-enters the compressor 100 through the reflux valve 120, so that the operating condition of the compressor 100 is in a dynamic balance state, thereby protecting the compressor 100 and being beneficial to extending the service life of the compressor 100.

[0073] In a further optional embodiment, after closing the industrial frequency high-voltage cabinet 300 and opening the variable frequency high-voltage cabinet 200 in step S310, the control method further includes:

[0074] S360. Close the reflux valve 120.

[0075] In this solution, when the intake air volume at the intake port of the compressor 100 increases and the variable frequency high-voltage cabinet 200 supplies power to the motor 110 of the compressor 100, that is, after the industrial frequency mode is switched to the variable frequency mode, the flow rate discharged from the exhaust port of the compressor 100 also increases accordingly. At this time, the medium flow rate introduced into the compressor 100 and the medium flow rate discharged can meet the operating condition requirements. Correspondingly, there is no need to reflux part of the medium to the intake port of the compressor 100. Therefore, the reflux valve 120 is closed at this time, and the operating condition of the compressor 100 is in a dynamic balance state.

[0076] Optionally, a first pressure detection component 150 is provided at the exhaust port of the compressor 100 for detecting the first pressure of the medium at the exhaust port of the compressor 100. Here, the first pressure specifically refers to the pressure of the medium flowing out of the exhaust port of the compressor 100; a second pressure detection component 160 is provided at the intake port of the compressor 100 for detecting the second pressure of the medium at the intake port of the compressor 100. Here, the second pressure specifically refers to the pressure of the medium flowing into the compressor 100 at the intake port of the compressor 100. At least one of the first switching condition and the second switching condition in the above embodiment includes that the difference between the first pressure of the medium at the exhaust port of the compressor 100 and the second pressure of the medium at the intake port of the compressor 100 is equal to a first preset value. Here, the first preset value specifically refers to the difference between the pressure of the medium allowed to flow into the compressor 100 and the pressure of the medium flowing out. The first preset value can be a specific value or a value range, and no specific limitation is made here. When the difference between the first pressure of the medium at the exhaust port of the compressor 100 and the second pressure of the medium at the intake port of the compressor 100 is greater than or less than the first preset value, the operating parameters of the compressor 100 can be manually adjusted to meet the first preset condition or the second preset condition.

[0077] Optionally, a first temperature detector 170 is provided at the exhaust port of the compressor 100 for detecting the first temperature of the medium at the exhaust port of the compressor 100. Here, the first temperature specifically refers to the temperature of the medium flowing out of the exhaust port of the compressor 100; a second temperature detector 180 is provided at the intake port of the compressor 100 for detecting the second temperature of the medium at the intake port of the compressor 100. Here, the second temperature specifically refers to the temperature of the medium flowing out of the exhaust port of the compressor 100. At least one of the first switching condition and the second switching condition in the above embodiments may include that the difference between the first temperature of the medium at the exhaust port of the compressor 100 and the second temperature of the medium at the intake port of the compressor 100 is equal to a second preset value. Here, the second preset value specifically refers to the difference between the temperature of the medium allowed to flow into the compressor 100 and the temperature of the medium flowing out. The second preset value may be a specific value or a value range, and no specific limitation is made here. When the difference between the first temperature of the medium at the exhaust port of the compressor 100 and the second temperature of the medium at the intake port of the compressor 100 is greater than or less than the second preset value, the operating parameters of the compressor 100 can be manually adjusted to meet the first preset condition or the second preset condition.

[0078] Optionally, a first flow detector 130 is provided at the exhaust port of the compressor 100 for detecting the third flow rate of the medium at the exhaust port of the compressor 100. Here, the third flow rate specifically refers to the flow rate of the medium flowing out of the exhaust port of the compressor 100 per unit time; a second flow detector 190 is provided at the intake port of the compressor 100 for detecting the fourth flow rate of the medium at the intake port of the compressor 100. Here, the fourth flow rate specifically refers to the flow rate of the medium flowing into the compressor 100 at the intake port per unit time. At least one of the first switching condition and the second switching condition in the above embodiments includes that the difference between the third flow rate of the medium at the exhaust port of the compressor 100 and the fourth flow rate of the medium at the intake port of the compressor 100 is equal to a third preset value. Here, the third preset value specifically refers to the difference between the flow rate of the medium allowed to flow into the compressor 100 and the flow rate of the medium flowing out. The third preset value may be a specific value or a value range, and no specific limitation is made here. When the difference between the third flow rate of the medium at the exhaust port of the compressor 100 and the fourth flow rate of the medium at the intake port of the compressor 100 is greater than or less than the third preset value, the operating parameters of the compressor 100 can be manually adjusted to meet the first preset condition or the second preset condition.

[0079] Optionally, at least one of the first switching condition and the second switching condition in the above embodiments may also include that at least two of the difference between the first pressure of the medium at the exhaust port of the compressor 100 and the second pressure of the medium at the intake port of the compressor 100 being equal to a first preset value, the difference between the first temperature of the medium at the exhaust port of the compressor 100 and the second temperature of the medium at the intake port of the compressor 100 being equal to a second preset value, and the difference between the third flow rate of the medium at the exhaust port of the compressor 100 and the fourth flow rate of the medium at the intake port of the compressor 100 being equal to a third preset value, so as to improve the detection accuracy. Of course, it is also possible to simultaneously detect the pressure, temperature, and flow rate at the exhaust port and the intake port of the compressor 100. When all three simultaneously meet at least one of the first switching condition and the second switching condition, the compressor 100 is then controlled to switch between the variable-frequency mode and the power-frequency mode, so as to further improve the detection accuracy.

[0080] In yet another alternative embodiment, the closing of the power-frequency high-voltage cabinet 300 and the opening of the variable-frequency high-voltage cabinet 200 in step S310 specifically include:

[0081] S311. Close the power-frequency control system 500 and open the variable-frequency control system 400 through the variable-frequency and power-frequency switching device 600.

[0082] S312. Output a second control signal to the power supply switching device 700 through the variable-frequency and power-frequency switching device 600. The power supply switching device 700 closes the power-frequency high-voltage cabinet 300 and opens the variable-frequency high-voltage cabinet 200 according to the second control signal.

[0083] When the motor speed of the compressor 100 is adjusted from the power-frequency rated speed to the variable-frequency rated speed, the variable-frequency and power-frequency switching device 600 will send out two control signals, specifically the second control signal and the fourth control signal. Among them, the fourth control signal is sent to the variable-frequency control system 400 and the power-frequency control system 500, so as to control the power-frequency control system 500 to close and simultaneously open the variable-frequency control system 400; while the second control signal is sent to the power supply switching device 700. At this time, the power supply switching device 700 controls the power-frequency high-voltage cabinet 300 to close and simultaneously open the variable-frequency high-voltage cabinet 200 according to the second control signal, that is, the output circuit breaker of the power-frequency high-voltage cabinet 300 is disconnected from the motor 110, and the output circuit breaker of the variable-frequency high-voltage cabinet 200 is closed with the motor 110, so that the variable-frequency high-voltage cabinet 200 supplies power to the motor 110 of the compressor 100. This solution adopts this control method, which is convenient for centralized control and improves the switching efficiency from the variable-frequency mode to the power-frequency mode at the same time.

[0084] The above-mentioned second control signal specifically refers to the signal for the power supply switching device 700 to control the closing of the power-frequency high-voltage cabinet 300 and the opening of the variable-frequency high-voltage cabinet 200. The fourth control signal specifically refers to the signal for closing the power-frequency control system 500 and opening the variable-frequency control system 400.

[0085] As Figure 1 shown, based on the compressor control method disclosed in the embodiments of the present application, the embodiments of the present application further provide a compressor unit. Applying the control method described in any of the above embodiments, the compressor unit includes a frequency conversion power frequency switching device 600, a frequency conversion control system 400, and a power frequency control system 500. The frequency conversion power frequency switching device 600 is configured to receive a target operation. When the target operation is to switch to the power frequency mode, the frequency conversion high-voltage cabinet 200 is closed, and the power frequency high-voltage cabinet 300 is opened. When the target operation is to switch to the frequency conversion mode, the power frequency high-voltage cabinet 300 is closed, and the frequency conversion high-voltage cabinet 200 is opened. The frequency conversion control system 400 is configured to adjust the motor speed of the compressor 100 to be equal to the power frequency rated speed when the target operation is to switch to the power frequency mode. The power frequency control system 500 is configured to adjust the motor speed of the compressor 100 to be equal to the frequency conversion rated speed when the target operation is to switch to the frequency conversion mode.

[0086] Optionally, the compressor unit further includes a power supply switching device 700. The power supply switching device 700 is configured to close the frequency conversion high-voltage cabinet 200 according to a first control signal and open the power frequency high-voltage cabinet 300. In addition, the frequency conversion power frequency switching device 600 is further configured to close the frequency conversion control system 400 and open the power frequency control system 500.

[0087] Optionally, a first pressure detection component 150, a first temperature detection component 170, and a first flow detection component 130 are disposed at the exhaust port of the compressor 100. The first pressure detection component 150 is configured to detect the first pressure of the medium at the exhaust port of the compressor 100. The first temperature detection component 170 is configured to detect the first temperature of the medium at the exhaust port of the compressor 100. The first flow detection component 130 is configured to detect the third flow of the medium at the intake port of the compressor 100. The first pressure detection component 150, the first temperature detection component 170, and the first flow detection component 130 are all electrically connected to the frequency conversion power frequency switching device 600. In addition, during the process of switching from the frequency conversion mode to the power frequency mode, the first flow detection component 130 is further configured to detect the first flow; during the process of switching from the power frequency mode to the frequency conversion mode, the first flow detection component 130 is further configured to detect the second flow.

[0088] A second pressure detection component 160, a second temperature detection component 180, and a second flow detection component 190 are disposed at the intake port of the compressor 100. The second pressure detection component 160 is configured to detect the second pressure of the medium at the intake port of the compressor 100. The second temperature detection component 180 is configured to detect the second temperature of the medium at the intake port of the compressor 100. The second flow detection component 190 is configured to detect the fourth flow of the medium at the intake port of the compressor 100. The second pressure detection component 160, the second temperature detection component 180, and the second flow detection component 190 are all electrically connected to the frequency conversion power frequency switching device 600.

[0089] Optionally, a reflux valve 120 is further provided at the exhaust port of the compressor 100, and the reflux valve 120 is used to reflux part of the medium back into the intake port of the compressor 100. A regulating valve 140 is further provided at the intake port of the compressor 100, and the regulating valve 140 is used to regulate the medium flow rate at the intake port of the compressor 100.

[0090] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them belong to the protection scope of the present application.

Claims

1. A control method for a compressor, characterized in that, Including: Receiving a target operation; When the target operation is to switch to the power frequency mode, determining whether the compressor meets the first switching condition. If so, adjusting the motor speed of the compressor to be equal to the rated power frequency speed, closing the variable frequency high-voltage cabinet, and opening the power frequency high-voltage cabinet; When the target operation is to switch to the variable frequency mode, determining whether the compressor meets the second switching condition. If so, adjusting the opening degree of the regulating valve at the intake port of the compressor to a second preset opening degree, closing the power frequency high-voltage cabinet, and opening the variable frequency high-voltage cabinet, and adjusting the motor speed of the compressor to be equal to the rated variable frequency speed, The first switching condition and the second switching condition include: The difference between the first pressure of the medium at the exhaust port of the compressor and the second pressure of the medium at the intake port of the compressor is equal to a first preset value; and / or, The difference between the first temperature of the medium at the exhaust port of the compressor and the second temperature of the medium at the intake port of the compressor is equal to a second preset value; and / or, The difference between the third flow rate of the medium at the exhaust port of the compressor and the fourth flow rate of the medium at the intake port of the compressor is equal to a third preset value.

2. The control method of the compressor according to claim 1, characterized in that, After adjusting the motor speed of the compressor to be equal to the rated power frequency speed, the control method further includes: Obtaining the first flow rate of the medium at the exhaust port of the compressor; When the first flow rate is greater than a first preset flow rate, opening the reflux valve at the exhaust port of the compressor so that part of the medium discharged from the exhaust port of the compressor flows back to the intake port of the compressor.

3. The control method of the compressor according to claim 2, characterized in that, After closing the variable frequency high-voltage cabinet and opening the power frequency high-voltage cabinet, the control method further includes: Adjusting the opening degree of the regulating valve at the intake port of the compressor to a first preset opening degree; Closing the reflux valve.

4. The control method of the compressor according to claim 1, wherein Closing the variable frequency high-voltage cabinet and opening the power frequency high-voltage cabinet specifically includes: Closing the variable frequency control system and opening the power frequency control system through a variable frequency-power frequency switching device; Outputting a first control signal to the power supply switching device through the variable frequency-power frequency switching device, and the power supply switching device closes the variable frequency high-voltage cabinet and opens the power frequency high-voltage cabinet according to the first control signal.

5. The control method of the compressor according to claim 1, characterized in that, After adjusting the opening degree of the regulating valve at the intake port of the compressor to the second preset opening degree, the control method further includes: Obtaining the second flow rate of the medium at the exhaust port of the compressor; When the second flow rate is greater than a second preset flow rate, opening the reflux valve at the exhaust port of the compressor so that part of the medium discharged from the exhaust port of the compressor flows back to the intake port of the compressor.

6. The control method of the compressor according to claim 5, characterized in that, After closing the power frequency high-voltage cabinet and opening the variable frequency high-voltage cabinet, the control method further includes: Closing the reflux valve.

7. The control method of the compressor according to claim 1, characterized in that, Closing the power frequency high-voltage cabinet and opening the variable frequency high-voltage cabinet specifically includes: Closing the power frequency control system and opening the variable frequency control system through a variable frequency-power frequency switching device; Outputting a second control signal to the power supply switching device through the variable frequency-power frequency switching device, and the power supply switching device closes the power frequency high-voltage cabinet and opens the variable frequency high-voltage cabinet according to the second control signal.

8. A compressor unit applying the control method according to any one of claims 1 to 7, characterized in that, Including: A frequency conversion power frequency switching device is used to receive a target operation. When the target operation is to switch to the power frequency mode, it closes the variable frequency high-voltage cabinet and opens the power frequency high-voltage cabinet. When the target operation is to switch to the frequency conversion mode, it closes the power frequency high-voltage cabinet and opens the variable frequency high-voltage cabinet; A variable frequency control system is used to adjust the motor speed of the compressor to be equal to the power frequency rated speed when the target operation is to switch to the power frequency mode; A power frequency control system is used to adjust the motor speed of the compressor to be equal to the variable frequency rated speed when the target operation is to switch to the frequency conversion mode.

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