Anti-surge control method of compressor and air conditioner

Abstract

This invention relates to the field of refrigeration equipment technology, specifically to a compressor anti-surge control method and an air conditioner. The compressor anti-surge control method provided by this invention is applied to a refrigeration system, which includes a compressor and a bypass valve connected in parallel with the compressor. The compressor anti-surge control method includes a compressor start-up control method; specifically, the bypass valve is first opened to a first preset opening degree, and then the compressor is started. Under the action of the bypass valve, the high-pressure gaseous refrigerant discharged from the compressor exhaust port is bypassed back to the inlet port. This reduces the rate of pressure increase at the exhaust port while increasing the pressure at the inlet port, thereby reducing the compressor's pressure ratio and ensuring that the compressor's actual output frequency is always greater than the surge frequency at which compressor surge occurs, thus preventing compressor surge. When the compressor speed is greater than or equal to the minimum starting speed, the compressor is considered to have completed starting, and at this time, the bypass valve is closed at a preset closing speed.

Description

Technical Field

[0001] This invention relates to the field of refrigeration equipment technology, specifically to a method for preventing surge control of a compressor and an air conditioner. Background Technology

[0002] Data centers typically use centrifugal compressor air conditioning systems for cooling to prevent equipment malfunctions. However, due to unstable data center loads or improperly designed air conditioning systems, compressors are prone to surge shutdowns, significantly impacting the stability of data center temperature control.

[0003] In the process of realizing this invention, the inventors discovered at least the following problems in the prior art: How to avoid the risk of surge shutdown in advance and increase the operational stability of air conditioning and refrigeration systems is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] (a) The problem to be solved by the present invention is to avoid the risk of surge shutdown in advance and increase the operational stability of the air conditioning refrigeration system.

[0005] (II) Technical Solution To address the aforementioned technical problems, this invention provides a method for preventing surge in a compressor, applied to a refrigeration system. The refrigeration system includes a compressor and a bypass valve, wherein the bypass valve is connected in parallel with the compressor. The compressor anti-surge control method includes: a compressor start-up control method; The compressor start-up control method includes: Open the bypass valve to the first preset opening degree; Start the compressor; When the compressor speed is greater than or equal to the minimum starting speed, the bypass valve is closed at a preset valve closing speed.

[0006] Furthermore, the compressor start-up control method also includes: Calculate the surge frequency of the compressor when it surges, and the actual output frequency of the compressor, and adjust the preset valve closing speed in real time according to the surge frequency so that the actual output frequency of the compressor is greater than the surge frequency of the compressor.

[0007] Furthermore, the compressor start-up control method also includes: The surge frequency of the compressor when surge occurs is calculated based on the surge pressure ratio of the compressor; and the actual output frequency of the compressor is calculated in real time based on the actual pressure ratio of the compressor.

[0008] Furthermore, the compressor start-up control method also includes: When the actual output frequency of the compressor is equal to the surge frequency of the compressor, the bypass valve is stopped from closing.

[0009] Furthermore, the compressor start-up control method also includes: Based on the surge frequency and the cooling capacity requirement of the refrigeration system, the actual output frequency of the compressor and the opening degree of the bypass valve are adaptively adjusted.

[0010] Furthermore, the preset valve closing speed is 1% / s-1% / 20s; the opening range of the first preset opening degree is 30%-100%.

[0011] Furthermore, it also includes: compressor shutdown control methods; The compressor shutdown control method includes: The bypass valve is opened to a second preset opening degree, wherein the opening degree of the second preset opening degree is within the range of 30%-100%; Turn off the compressor. After the compressor stops rotating, the bypass valve is closed.

[0012] Furthermore, it also includes: compressor operation control methods; The compressor operation control method includes: The compressor pressure ratio is monitored in real time. When the compressor pressure ratio is greater than the preset pressure ratio of the compressor and continues for a preset time, a first surge warning signal is issued. And / or, monitor the compressor current fluctuation range in real time, and when the compressor current fluctuation range exceeds the preset current fluctuation range value and continues to exceed the preset number of times, issue a second surge warning signal.

[0013] Furthermore, the compressor operation control method also includes: The bypass valve is opened to a third preset opening degree, and the surge frequency when the compressor surges and the actual output frequency of the compressor are calculated. The opening degree of the bypass valve is adjusted according to the surge frequency so that the actual output frequency is always greater than the surge frequency.

[0014] Another embodiment of the present invention provides an air conditioner including a centrifugal compressor, wherein the centrifugal compressor operates using the anti-surge control method for compressors described in any of the above embodiments.

[0015] The beneficial effects of this invention are: This invention provides a compressor anti-surge control method applied to a refrigeration system, the refrigeration system including a compressor and a bypass valve, the bypass valve being connected in parallel with the compressor; the compressor anti-surge control method includes: a compressor start-up control method; the compressor start-up control method includes: opening the bypass valve to a first preset opening degree; starting the compressor; when the compressor speed is greater than or equal to the minimum start-up speed, closing the bypass valve according to a preset valve closing speed.

[0016] A bypass valve is connected in parallel to the compressor's suction and discharge ports. Before the compressor starts, the bypass valve is opened to a first preset opening degree, allowing the high-pressure gaseous refrigerant discharged from the compressor's discharge port to bypass back to the suction port. This reduces the rate of pressure increase at the discharge port while increasing the pressure at the suction port, thereby reducing the compressor's pressure ratio. This ensures that the compressor's actual output frequency is always higher than the surge frequency that causes compressor surging. Compared to existing technologies, this method avoids compressor surging, thus mitigating the risk of surge-induced shutdown and increasing the operational stability of the air conditioning refrigeration system. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 A flowchart of a compressor start-up control method provided in an embodiment of the present invention; Figure 2 A flowchart of a compressor start-up control method provided in an embodiment of the present invention; Figure 3 A flowchart of a compressor shutdown control method provided in an embodiment of the present invention; Figure 4 A flowchart of a compressor operation control method provided in an embodiment of the present invention; Figure 5 A flowchart of a compressor operation control method in another embodiment of the present invention is provided; Figure 6 This is a schematic diagram of the compressor provided in an embodiment of the present invention.

[0019] Icons: 11-Compressor; 12-Bypass valve. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] One embodiment of the present invention provides a surge control method for a compressor 11, wherein the compressor 11 is optionally a centrifugal compressor.

[0022] In this embodiment, the compressor 11 anti-surge control method is applied to a refrigeration system, wherein, as Figure 6 As shown, the refrigeration system includes a compressor 11 and a bypass valve 12, and the bypass valve 12 is connected in parallel with the compressor 11; wherein, the refrigeration system also includes at least an evaporator, a condenser and a throttling device, etc., and the refrigeration system achieves mechanical refrigeration through the compressor 11.

[0023] In this embodiment, the bypass valve 12 is connected in parallel with the compressor 11, that is, one end of the bypass valve 12 is connected to the air inlet of the compressor 11, and the other end is connected to the air outlet of the compressor 11.

[0024] During operation, the compressor 11 opens the bypass valve 12, allowing the high-pressure gaseous refrigerant at the exhaust port of the compressor 11 to bypass back to the intake port through the bypass valve 12. This controls the pressure ratio between the exhaust port and the intake port, ensuring that the pressure ratio of the compressor 11 is less than its set surge pressure ratio, thereby avoiding surge in advance.

[0025] The pressure ratio refers to the ratio between the absolute pressure of the exhaust at the discharge port of the compressor 11 and the absolute pressure of the intake at the intake port of the compressor 11. Generally, the surge pressure ratio of the compressor 11 is related to the structural design of the compressor 11, that is, the surge pressure ratio is a fixed value of the compressor 11, which is set at the factory.

[0026] The anti-surge control method for the compressor 11 provided in this embodiment includes a compressor 11 start-up control method, a compressor 11 shutdown control method, and a compressor 11 operation control method. The three methods are explained in turn below.

[0027] like Figure 1 As shown, the compressor 11 anti-surge control method includes: compressor 11 start-up control method; The compressor 11 start-up control method includes the following steps: Open the bypass valve 12 to the first preset opening degree; Start the compressor 11; When the speed of the compressor 11 is greater than or equal to the minimum starting speed, the bypass valve 12 is closed at a preset valve closing speed.

[0028] First, it should be noted that the opening degree of the bypass valve 12 refers to the degree to which the bypass valve 12 is open or closed, which is a percentage; the minimum starting speed refers to the minimum speed of the compressor 11 during normal operation. When the compressor 11 starts up and starts to normal operation, the speed of the compressor 11 gradually increases until the speed of the compressor 11 reaches the minimum starting speed, which means that the compressor 11 has started successfully. The minimum starting speed of the compressor 11 is also related to the structure of the compressor 11 and is set at the factory.

[0029] According to an embodiment of the present invention, a compressor 11 start-up control method is provided. Before starting the compressor 11, the bypass valve 12 of the compressor 11 needs to be opened to a first preset opening degree. Through the bypass valve 12, a portion of the high-pressure gaseous refrigerant at the compressor 11 discharge port can be bypassed back to the compressor 11 inlet port, thereby ensuring that the pressure ratio of the compressor 11 is less than the surge pressure ratio, thus ensuring that the compressor 11 will not surge during the start-up process. After the bypass valve 12 is opened to the first preset opening degree, the compressor 11 is started, and the motor of the compressor 11 begins to drive the impeller inside the compressor 11 to rotate. When the speed of the compressor 11 is greater than or equal to the minimum starting speed of the compressor 11, the compressor 11 is considered to have started successfully. At this time, the opening degree of the bypass valve 12 can be gradually reduced according to a preset valve closing speed to ensure the discharge volume at the compressor 11 discharge port, thereby ensuring the cooling capacity of the refrigeration system.

[0030] When compressor 11 is started, it compresses the refrigerant and discharges high-temperature and high-pressure gaseous refrigerant. As a result, the pressure at the discharge port of compressor 11 will gradually increase, which will cause the pressure ratio of compressor 11 to gradually increase. When the pressure ratio is higher than the surge pressure ratio of compressor 11, compressor 11 will surge.

[0031] Therefore, in this embodiment, before the compressor 11 is started, the bypass valve 12 is first opened to the first preset opening degree. After the bypass valve 12 is opened, the high-pressure gaseous refrigerant discharged from the exhaust port will bypass back to the intake port. In this way, the rate of pressure increase at the exhaust port can be reduced while the pressure at the intake port can be increased, thereby reducing the pressure ratio of the compressor 11 and making the compressor 11 less prone to surge.

[0032] In this embodiment, the opening range of the first preset opening degree is 30%-100%. Furthermore, since the compressor speed will further increase if the cooling capacity of the refrigeration system still does not reach the target cooling capacity after the compressor 11 is successfully started, the specific value of the first preset opening degree needs to ensure that the pressure ratio of the compressor 11 is less than the surge pressure ratio when the compressor 11 starts at its minimum starting speed, and also needs to match the target compressor 11 frequency after the compressor 11 starts normally. Specifically, it can be calculated based on the target compressor 11 frequency after the compressor 11 starts normally, so that the pressure ratio of the compressor 11 is always less than its surge pressure ratio during the start-up process and after the start-up is successful through the first preset opening degree.

[0033] Furthermore, the preset valve closing speed is 1% / s-1% / 20s. After the compressor 11 starts normally, it needs to gradually close the bypass valve 12 to ensure the amount of refrigerant discharged by the compressor 11, thereby ensuring the cooling capacity of the compressor 11. However, if the valve closing speed is too fast, the pressure ratio of the compressor 11 will increase rapidly. When the pressure ratio is higher than the surge pressure ratio, it will trigger a shunt. Therefore, the preset valve closing speed needs to be controlled at 1% / s-1% / 20s to ensure that the pressure ratio of the compressor 11 is always less than its surge pressure ratio. Moreover, by controlling the speed, the valve closing can be stopped when the pressure ratio of the compressor 11 is close to its surge pressure ratio. In practical applications, the preset valve closing speed can be a variable value. The valve closing speed can be faster at the beginning and gradually slow down over time.

[0034] This invention provides a method for preventing surge in a compressor 11, such as... Figure 2 As shown, the compressor 11 start-up control method further includes: Calculate the surge frequency when the compressor 11 experiences surge, and the actual output frequency of the compressor 11, and adjust the preset valve closing speed in real time according to the surge frequency so that the actual output frequency is greater than the surge frequency.

[0035] Specifically, during the process of closing the bypass valve 12, it is necessary to calculate the surge frequency of the compressor 11 when it surges, as well as the actual output frequency of the compressor 11 during operation. The actual output frequency of the compressor 11 is then compared with the surge frequency of the compressor 11 when it surges, to ensure that the actual output frequency of the compressor 11 is always greater than the surge frequency of the compressor 11 when it surges during the valve closing process, thus preventing the compressor 11 from surging.

[0036] The present invention provides a compressor 11 anti-surge control method, the compressor 11 start-up control method further includes: calculating the surge frequency of the compressor 11 when surge occurs based on the surge pressure ratio of the compressor 11; and calculating the actual output frequency of the compressor 11 in real time based on the actual pressure ratio of the compressor 11.

[0037] Specifically, when the cooling capacity of the refrigeration system is fixed, the discharge volume of the compressor 11 is fixed, and the compression of the compressor 11 is the sum of the discharge volume and the bypass volume. Therefore, when the bypass valve 12 gradually closes, the bypass volume decreases. In order to ensure that the discharge volume of the compressor 11 is fixed, the actual output frequency of the compressor 11 needs to be reduced accordingly, thereby reducing the compression of the compressor 11. At this time, since the bypass volume of the compressor 11 intake port is reduced, the intake pressure of the compressor 11 decreases, and the pressure ratio of the compressor 11 increases. Thus, when the actual output frequency of the compressor 11 decreases to the point where the actual output frequency is equal to the surge frequency, surge will occur.

[0038] Thus, the surge frequency of the compressor 11 can be calculated based on the surge pressure ratio of the compressor 11 itself, through the system cooling capacity, the opening degree of the bypass valve 12, etc., and the actual output frequency of the compressor 11 can be calculated based on the actual pressure ratio of the compressor 11, through the system cooling capacity, the opening degree of the bypass valve 12, etc.; the specific calculation formula can be based on existing technology and is not limited here.

[0039] During use, the pressure ratio of compressor 11 is monitored in real time to obtain the real-time pressure ratio of compressor 11, and the cooling capacity of the refrigeration system is monitored in real time, as well as the opening degree of bypass valve 12 is monitored to obtain the surge frequency and actual output frequency of compressor 11.

[0040] It should be noted that, in order to ensure the accuracy of the results, the monitoring of the pressure ratio of compressor 11, the monitoring of the cooling capacity of the refrigeration system, and the monitoring of the opening degree of bypass valve 12 are all carried out simultaneously.

[0041] Furthermore, the compressor 11 anti-surge control method provided in this embodiment of the invention further includes: When the actual output frequency of the compressor 11 is equal to the surge frequency of the compressor 11, the bypass valve 12 is stopped from closing.

[0042] In this embodiment, as mentioned above, during the closing process of the bypass valve 12, it is necessary to compare the actual output frequency of the compressor 11 with the surge frequency of the compressor 11 when it surges. When the actual output frequency of the compressor 11 is equal to the surge frequency of the compressor 11 when it surges, the bypass valve 12 is stopped from closing. In this way, the pressure ratio of the compressor 11 can always be less than its surge pressure ratio, so that the compressor 11 will not surge.

[0043] Optionally, in this embodiment, if the actual output frequency is always greater than the surge frequency during the process of closing the bypass valve 12, the opening of the bypass valve 12 can be closed to 0%.

[0044] An embodiment of the present invention provides a compressor 11 anti-surge control method, wherein the compressor 11 start-up control method further includes: Based on the surge frequency and the cooling capacity requirement of the refrigeration system, the actual output frequency of the compressor 11 and the opening degree of the bypass valve 12 are adaptively adjusted.

[0045] In this embodiment, after the compressor 11 is started, the actual output frequency of the compressor 11 and the opening of the bypass valve 12 are adaptively adjusted according to the calculated surge frequency and the cooling capacity requirements of the refrigeration system during application, so that the refrigeration system can meet the actual usage requirements and prevent the compressor 11 from surging.

[0046] This invention provides a compressor 11 anti-surge control method, wherein the opening range of the first preset opening degree is 30%-100%. The preset valve closing speed is 1% / s-1% / 20s.

[0047] In this embodiment, the opening range of the first preset opening is 30%-100%.

[0048] For example, compressor 11 has a pressure ratio of 1.2 to 1.5 and a first preset opening degree of 30%; compressor 11 has a pressure ratio of 1.6 to 1.8 and a first preset opening degree of 60%; compressor 11 has a pressure ratio of 1.9 or higher and a first preset opening degree of 100%.

[0049] In this embodiment, the preset valve closing speed is 1% / s-1% / 20s. Closing the bypass valve 12 at this speed ensures that the compressor 11 will not encounter problems during normal operation.

[0050] For example, compressor 11 corresponds to a pressure ratio of 1.1~1.3 and a valve closing speed of 1% / 1s; compressor 11 corresponds to a pressure ratio of 1.4~1.8 and a valve closing speed of 1% / 5s; compressor 11 corresponds to a pressure ratio of 2.5 or higher and a valve closing speed of 1% / 20s.

[0051] This invention provides a method for preventing surge in a compressor 11, such as... Figure 3 As shown, it also includes a compressor 11 shutdown control method. The compressor 11 shutdown control method includes the following steps: The bypass valve 12 is opened to a second preset opening degree, the opening degree of which is 30%-100%; Turn off the compressor 11; After the compressor 11 stops rotating, the bypass valve 12 is closed.

[0052] In this embodiment, after the compressor 11 is shut down, its rotational speed gradually decreases until it reaches zero. As the compressor 11's rotational speed decreases from its initial operating speed to zero, the airflow rate at the inlet also gradually decreases. To prevent the compressor 11's pressure ratio from rising to the surge pressure ratio and causing surge, the bypass valve 12 is opened to a second preset opening degree before shutting down the compressor 11. Then, the compressor 11 is shut down, and the bypass valve 12 is completely closed after the compressor 11's impeller has completely stopped rotating. This prevents surge during the shutdown process, avoids damage to the compressor 11, and extends its service life.

[0053] In this embodiment, optionally, the second preset opening degree corresponds to the pressure ratio of the compressor 11 during normal operation, ensuring that the pressure ratio of the compressor 11 is always less than the surge pressure ratio during the impeller deceleration process.

[0054] In this embodiment, optionally, the opening range of the second preset opening is 30%-100%.

[0055] In this embodiment, the opening range of the second preset opening degree is 30%-100%, which can be specifically combined with... Figure 1 The specific timeframe is determined based on the actual operating conditions of the compressor 11, namely, ensuring that the compressor 11 does not experience surge before the impeller speed reaches the minimum starting speed.

[0056] For example, compressor 11 corresponds to a pressure ratio of 1.2~1.5 and a second preset opening degree of 30%; compressor 11 corresponds to a pressure ratio of 1.6~1.8 and a second preset opening degree of 60%; compressor 11 corresponds to a pressure ratio of 1.9 or above and a second preset opening degree of 100%.

[0057] The present invention provides a compressor 11 anti-surge control method, which also includes a compressor 11 operation control method for controlling the compressor 11 to avoid surge during operation, to prevent damage to the compressor 11 during operation, and to prevent the refrigeration system from failing to meet normal operating requirements.

[0058] like Figure 4 and Figure 5As shown, the compressor 11 operation control method includes the following steps: The pressure ratio of the compressor 11 is monitored in real time. When the pressure ratio of the compressor 11 is greater than the preset pressure ratio of the compressor 11 and continues for a preset time, a first surge warning signal is issued. And / or, monitor the current fluctuation range of the compressor 11 in real time, and when the current fluctuation range of the compressor 11 exceeds the preset current fluctuation range value of the compressor 11 and continues to exceed the preset number of times, issue a second surge warning signal.

[0059] In this embodiment, during the operation of the compressor 11, a pre-surge alarm signal can be issued when the compressor 11 is about to surge by monitoring the pressure ratio of the compressor 11, or a pre-surge alarm signal can be issued when the compressor 11 is about to surge by monitoring the current fluctuation range of the compressor 11, or a combination of the above two methods can be used.

[0060] Specifically, in this embodiment, compressor 11 will experience surge during operation. The specific reasons have been described above and will not be repeated here. When compressor 11 is running at a certain speed, the pressure ratio of compressor 11 needs to be monitored in real time, and the monitored pressure ratio information of compressor 11 is compared with the preset pressure ratio of compressor 11. When the monitored pressure ratio of compressor 11 is greater than the preset pressure ratio of compressor 11 and continues for a preset time, a first surge warning signal is issued to warn compressor 11 that surge is about to occur.

[0061] The preset pressure ratio can be set according to the kicking vibration pressure ratio, and can be set to be smaller than the panting vibration pressure ratio. The preset time can also be set according to experience value, and there is no limit here.

[0062] When the pressure ratio reaches the preset pressure ratio and remains at the preset pressure ratio for a preset time, the working pressure ratio of the compressor 11 can be restored to less than or equal to the preset pressure ratio of the compressor 11 by increasing the opening of the bypass valve 12 and thereby increasing the gas flow rate at the inlet, so as to avoid the compressor 11 from surging.

[0063] In this embodiment, when the compressor 11 is running, its current information needs to be monitored in real time. When the compressor 11 is running, its current is in a fluctuating state. When surge occurs, its current fluctuation range increases and the fluctuation frequency also increases. Therefore, the monitored current information of the compressor 11 is compared with the preset current fluctuation range value of the compressor 11. When the current fluctuation range of the compressor 11 exceeds the preset current fluctuation range value of the compressor 11 and continues to exceed the preset number of times, a second surge warning signal is issued to warn that the compressor 11 is about to surge and the opening of the bypass valve 12 needs to be adjusted in time to avoid damage to the compressor 11 due to surge.

[0064] The preset current fluctuation range value and the preset number of times can be set according to the current fluctuation range value when the compressor 11 reaches the surge frequency and the frequency of exceeding the number of times. That is, they can be set to be less than or equal to the current fluctuation range value corresponding to the surge frequency, and the preset number of times can be set to be less than or equal to the number of times exceeding the surge frequency. There is no limitation here.

[0065] At this time, the compressor 11 can be prevented from surging by increasing the opening of the bypass valve 12 and thus increasing the gas flow rate at the inlet.

[0066] In this embodiment, the compressor 11 can be monitored for surge during operation using any of the methods described above, or a combination of the two methods described above can be used.

[0067] This invention provides a compressor 11 anti-surge control method, the compressor 11 operation control method further includes: The bypass valve 12 is opened to a third preset opening degree, and the surge frequency when the compressor 11 surges and the actual output frequency of the compressor 11 are calculated. The opening degree of the bypass valve 12 is adjusted according to the surge frequency so that the actual output frequency is always greater than the surge frequency.

[0068] In this embodiment, after the compressor 11 is turned on and can maintain normal operation, the bypass valve 12 is opened to the third preset opening degree so that the actual output frequency of the compressor 11 can be greater than the surge frequency, thereby preventing the compressor 11 from surging, ensuring that the refrigeration system can operate normally, and improving the service life of the compressor 11.

[0069] Furthermore, in this embodiment, during normal operation of the compressor 11, it is also necessary to calculate the surge frequency when the compressor 11 experiences surge, and to calculate the output frequency of the compressor 11 in real time. The specific calculation method is the same as that in the compressor 11 start-up control method. The calculated surge frequency and the output frequency are compared, and the opening of the bypass valve 12 is adjusted according to their magnitudes to ensure that the actual output frequency of the compressor 11 is always greater than the surge frequency when the compressor 11 experiences surge. This ensures that the refrigeration system can meet actual usage requirements, while preventing damage to the compressor 11 due to surge and improving the service life of the compressor 11.

[0070] For example, in this embodiment, when the actual output frequency of the compressor 11 is less than the surge frequency when the compressor 11 surges, the opening of the bypass valve 12 can be increased to avoid the compressor 11 from surging.

[0071] The present invention provides a method for anti-surge control of a compressor 11, wherein the compressor 11 further includes a controller.

[0072] Both the compressor 11 and the bypass valve 12 are electrically connected to the controller, and the controller is used to control and monitor the working status of the compressor 11 and the bypass valve 12.

[0073] In this embodiment, the compressor 11 also includes a controller. The operation of the compressor 11 and the bypass valve 12 are both realized through the controller, so as to realize the automation of the regulation of the compressor 11 and the bypass valve 12.

[0074] Specifically, both the compressor 11 and the bypass valve 12 are electrically connected to the controller, which can monitor the pressure ratio and / or current of the compressor 11. Simultaneously, the controller can also control the opening degree of the bypass valve 12 and monitor its opening degree. Furthermore, the controller can also control the opening degree of the bypass valve 12 by monitoring the pressure ratio and / or current of the compressor 11.

[0075] Another embodiment of the present invention provides an air conditioner, the air conditioner including a centrifugal compressor, the centrifugal compressor being controlled by the anti-surge control method of compressor 11 described in any of the above embodiments.

[0076] In the description of this invention, it should be noted that the terms "upper" and "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0077] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preventing surge control of a compressor, applied to a refrigeration system, the refrigeration system including a compressor and a bypass valve, the bypass valve being connected in parallel with the compressor; Its features are, The compressor anti-surge control method includes: a compressor start-up control method; The compressor start-up control method includes: Open the bypass valve to the first preset opening degree; Start the compressor; When the compressor speed is greater than or equal to the minimum starting speed, the bypass valve is closed at a preset valve closing speed; During the process of closing the bypass valve, the surge frequency of the compressor when it surges is calculated based on the surge pressure ratio of the compressor, and the actual output frequency of the compressor is calculated in real time based on the actual pressure ratio of the compressor. The preset valve closing speed is adjusted in real time according to the surge frequency so that the actual output frequency of the compressor is greater than the surge frequency of the compressor. When the actual output frequency of the compressor is equal to the surge frequency of the compressor, the closing of the bypass valve is stopped.

2. The anti-surge control method for compressors according to claim 1, characterized in that, The compressor start-up control method also includes: Based on the surge frequency and the cooling capacity requirement of the refrigeration system, the actual output frequency of the compressor and the opening degree of the bypass valve are adaptively adjusted.

3. The anti-surge control method for compressors according to claim 1, characterized in that, The preset valve closing speed is 1% / s-1% / 20s; the opening range of the first preset opening degree is 30%-100%.

4. The compressor anti-surge control method according to claim 1, characterized in that, Also includes: Compression shutdown control method; The compressor shutdown control method includes: The bypass valve is opened to a second preset opening degree, wherein the opening degree of the second preset opening degree is within the range of 30%-100%; Turn off the compressor. After the compressor stops rotating, the bypass valve is closed.

5. The anti-surge control method for a compressor according to claim 1, characterized in that, Also includes: Compressor operation control methods; The compressor operation control method includes: The compressor pressure ratio is monitored in real time. When the compressor pressure ratio is greater than the preset pressure ratio of the compressor and continues for a preset time, a first surge warning signal is issued. And / or, monitor the compressor current fluctuation range in real time, and when the compressor current fluctuation range exceeds the preset current fluctuation range value and continues to exceed the preset number of times, issue a second surge warning signal.

6. The anti-surge control method for a compressor according to claim 5, characterized in that, The compressor operation control method further includes: The bypass valve is opened to a third preset opening degree, and the surge frequency when the compressor surges and the actual output frequency of the compressor are calculated. The opening degree of the bypass valve is adjusted according to the surge frequency so that the actual output frequency is always greater than the surge frequency.

7. An air conditioner, characterized in that, The invention includes a centrifugal compressor, which operates using the anti-surge control method for a compressor as described in any one of claims 1 to 6.

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