Refrigerant migration prevention control method and heat pump system

Abstract

The invention relates to the technical field of heat pump systems, in particular to a refrigerant migration prevention control method and a heat pump system. The refrigerant migration prevention control method comprises the following steps that the current outdoor environment temperature and the shutdown duration of a compressor are detected; the following control modes are selected according to the outdoor environment temperature and the shutdown duration of the compressor: when the outdoor environment temperature is in a first temperature interval, the compressor is directly started, and the frequency is increased to the platform frequency; when the outdoor environment temperature is in a second temperature interval and the shutdown duration of the compressor is longer than a first preset shutdown duration, a first anti-migration control mode is executed; and in the first anti-migration control mode, the bypass electromagnetic valve is opened, the compressor is started after a first preset delay time is delayed, the compressor operates at a first low frequency, and the bypass electromagnetic valve is closed and the frequency of the compressor is increased to the platform frequency until a first exit condition is met. According to the refrigerant migration prevention control method, the liquid impact phenomenon of the compressor can be reduced, the reliability and stability of the compressor are improved, and the service life is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pump systems, and particularly to a refrigerant migration prevention control method and a heat pump system. Background Art

[0002] Currently, in a conventional heat pump system, when the ambient temperature is low and the compressor is shut down for a long time, the refrigerant will gradually migrate into the compressor due to the pressure difference, resulting in a large amount of liquid refrigerant accumulating in the compressor cylinder. If the compressor is directly started and quickly increased to the operating frequency at this time, the liquid refrigerant will cause a liquid hammer phenomenon due to its incompressibility, and in severe cases, mechanical components inside the compressor will be damaged, significantly reducing the reliability and service life of the heat pump system.

[0003] Therefore, it is urgent to design a refrigerant migration prevention control method and a heat pump system to solve the above technical problems. Summary of the Invention

[0004] The first object of the present invention is to propose a refrigerant migration prevention control method, which can reduce the occurrence of liquid hammer in the compressor, improve the reliability and stability of the compressor, and extend the service life.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] The present invention provides a refrigerant migration prevention control method, including the following steps:

[0007] Detect the current outdoor ambient temperature and the compressor shutdown duration;

[0008] Select the following control modes according to the outdoor ambient temperature and the compressor shutdown duration:

[0009] When the outdoor ambient temperature is within the first temperature range, directly start the compressor and increase the frequency to the platform frequency;

[0010] When the outdoor ambient temperature is within the second temperature range and the compressor shutdown duration is greater than the first preset shutdown duration, execute the first anti-migration control mode;

[0011] In the first anti-migration control mode, open the bypass solenoid valve and start the compressor after delaying for the first preset delay time, and operate at the first low frequency until the first exit condition is met, then close the bypass solenoid valve and increase the compressor frequency to the platform frequency.

[0012] As an optional technical solution of the refrigerant migration prevention control method, the first exit condition includes that the compressor running time reaches the first preset running time or the pressure difference between the high-pressure side and the low-pressure side of the compressor is less than the first preset pressure difference.

[0013] As an alternative technical solution of an anti-refrigerant migration control method, the first temperature range is outdoor ambient temperature > 15°C;

[0014] The second temperature range is 0°C < outdoor ambient temperature ≤ 15°C, the first preset shutdown duration is 4 hours, the first preset delay time is 10 seconds, and the first low frequency is 30 Hz.

[0015] As an alternative technical solution of an anti-refrigerant migration control method, the first preset operation time is 5 minutes, and the first preset pressure difference is 0.5 MPa.

[0016] As an alternative technical solution of an anti-refrigerant migration control method, when the outdoor ambient temperature is in the third temperature range and the compressor shutdown duration is greater than the second preset shutdown duration, the second anti-migration control mode is executed;

[0017] In the second anti-migration control mode, the bypass solenoid valve is opened and the compressor is started after delaying the second preset delay time, and it operates at the second low frequency until the second exit condition is met, then the bypass solenoid valve is closed and the compressor is up-regulated to the platform frequency.

[0018] As an alternative technical solution of an anti-refrigerant migration control method, the second exit condition includes that the compressor operation time reaches the second preset operation time or the pressure difference between the high-pressure side and the low-pressure side of the compressor is less than the second preset pressure difference.

[0019] As an alternative technical solution of an anti-refrigerant migration control method, the third temperature range is outdoor ambient temperature ≤ 0°C, the second preset shutdown duration is 2 hours, the second preset delay time is 10 seconds, and the second low frequency is 30 Hz.

[0020] As an alternative technical solution of an anti-refrigerant migration control method, the second preset operation time is 10 minutes, and the second preset pressure difference is 0.3 MPa.

[0021] The second object of the present invention is to propose a heat pump system, which can reduce the phenomenon of liquid slugging in the compressor and extend the service life of the heat pump system.

[0022] To achieve this purpose, the present invention adopts the following technical solutions:

[0023] The present invention provides a heat pump system, which includes:

[0024] A bypass solenoid valve;

[0025] A compressor, the high-pressure side and the low-pressure side of the compressor are respectively connected to the bypass solenoid valve;

[0026] A first gas-liquid separator, which is connected in series in the exhaust pipeline of the compressor;

[0027] A temperature sensor for detecting the outdoor ambient temperature;

[0028] A pressure sensor disposed on the high-pressure side and the low-pressure side of the compressor to detect the pressures of the compressor exhaust pipe and the suction pipe;

[0029] A controller electrically connected to the bypass solenoid valve, the compressor, and the first gas-liquid separator; the controller is configured to execute the anti-refrigerant migration control method described above according to the data of the temperature sensor and the pressure sensor.

[0030] As an alternative technical solution of a heat pump system, a heating component is provided inside the first gas-liquid separator, and the heating component is connected to the compressor exhaust port through a heat conduction pipeline, so that the exhaust waste heat at the compressor exhaust port assists in gasifying the liquid refrigerant.

[0031] The beneficial effects of the present invention at least include:

[0032] The present invention provides an anti-refrigerant migration control method, which includes the following steps: detecting the current outdoor ambient temperature and the compressor shutdown duration; selecting the following control modes according to the outdoor ambient temperature and the compressor shutdown duration: when the outdoor ambient temperature is in the first temperature range, directly start the compressor and increase the frequency to the platform frequency; when the outdoor ambient temperature is in the second temperature range and the compressor shutdown duration is greater than the first preset shutdown duration, execute the first anti-migration control mode; in the first anti-migration control mode, open the bypass solenoid valve and start the compressor after delaying for the first preset delay time, and operate at the first low frequency until the first exit condition is met, then close the bypass solenoid valve and increase the frequency of the compressor to the platform frequency.

[0033] Above, when the outdoor ambient temperature is in the first temperature range, directly start the compressor and increase the frequency to the platform frequency. This mode is applicable to scenarios where the ambient temperature is relatively high and the risk of refrigerant migration is low, without additional anti-refrigerant migration control steps, simplifying the control process and improving the operating efficiency of the heat pump system in a suitable environment. For the case where the outdoor ambient temperature is in the second temperature range and the compressor shutdown duration is greater than the first preset shutdown duration, execute the first anti-migration control mode, open the bypass solenoid valve and start the compressor after delaying for the first preset delay time, and the compressor operates at the first low frequency until the first exit condition is met. This mode effectively uses the bypass solenoid valve and low-frequency start method to make the compressor operate at a low load for a period of time when the outdoor ambient temperature is low and the compressor shutdown time is long, providing buffer conditions for refrigerant circulation and gasification, reducing the risk of liquid refrigerant entering the compressor and causing liquid hammer to damage the mechanical components of the compressor, improving the reliability and stability of the compressor, and extending its service life.

[0034] The present invention provides a heat pump system, which can reduce the phenomenon of liquid slugging in the compressor, improve the reliability and stability of the compressor, and extend the service life of the heat pump system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the content of the embodiments of the present invention and these drawings.

[0036] Figure 1 It is a flowchart of the anti-refrigerant migration control method provided in the first embodiment of the present invention;

[0037] Figure 2 It is a flowchart of the anti-refrigerant migration control method provided in the second embodiment of the present invention;

[0038] Figure 3 It is a schematic diagram of the heat pump system provided in the third embodiment of the present invention.

[0039] Reference Numerals

[0040] 10. Compressor; 20. Bypass solenoid valve; 30. First gas-liquid separator; 40. Four-way valve; 50. Plate heat exchanger; 60. Electronic expansion valve; 70. Finned heat exchanger; 80. Second gas-liquid separator; 90. Pressure sensor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0043] It should be noted that similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0044] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0045] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "set" and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature is at a higher horizontal level than the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature is at a lower horizontal level than the second feature.

[0047] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0048] Embodiment 1

[0049] This embodiment provides a refrigerant migration prevention control method, which can reduce the phenomenon of liquid slugging in the compressor, improve the reliability and stability of the compressor, and extend its service life.

[0050] As Figure 1 shown, the refrigerant migration prevention control method mainly includes the following steps:

[0051] Detect the current outdoor ambient temperature and the shutdown duration of the compressor 10;

[0052] Select the following control modes according to the outdoor ambient temperature and the shutdown duration of the compressor 10:

[0053] When the outdoor ambient temperature is within the first temperature range, directly start the compressor 10 and increase the frequency to the platform frequency;

[0054] When the outdoor ambient temperature is within the second temperature range and the shutdown duration of the compressor 10 is greater than the first preset shutdown duration, execute the first anti-migration control mode;

[0055] In the first anti-migration control mode, open the bypass solenoid valve 20 and start the compressor 10 after delaying for the first preset delay time, and operate at the first low frequency until the first exit condition is met, then close the bypass solenoid valve 20 and increase the frequency of the compressor 10 to the platform frequency.

[0056] Based on the above design, first detect the current outdoor ambient temperature and the shutdown duration of the compressor 10, and select the targeted control mode according to different ambient temperature ranges and shutdown durations.

[0057] Specifically, when the outdoor ambient temperature is within the first temperature range (>15°C), directly start the compressor 10 and increase the frequency to the platform frequency. This mode is applicable to scenarios with relatively high ambient temperature and low refrigerant migration risk, without additional steps for preventing refrigerant migration, simplifying the control process and improving the operating efficiency of the heat pump system in a suitable environment. For the case where the outdoor ambient temperature is within the second temperature range (0°C < outdoor ambient temperature ≤ 15°C) and the shutdown duration of the compressor 10 is greater than the first preset shutdown duration (4h), execute the first anti-migration control mode, open the bypass solenoid valve 20 and start the compressor 10 after delaying for the first preset delay time, and the compressor 10 operates at the first low frequency until the first exit condition is met. This mode effectively uses the bypass solenoid valve 20 and low-frequency startup to make the compressor 10 operate at a low load for a period of time when the outdoor ambient temperature is low and the compressor 10 has been shutdown for a long time, providing buffer conditions for refrigerant circulation and vaporization, reducing the risk of liquid refrigerant entering the compressor 10 and causing liquid hammer to damage the mechanical components of the compressor 10, improving the reliability and stability of the compressor 10, and extending its service life.

[0058] Further, the first exit condition includes that the operating time of the compressor 10 reaches the first preset operating time or the pressure difference between the high-pressure side and the low-pressure side of the compressor 10 is less than the first preset pressure difference. In other words, the first exit condition monitors the operating state of the compressor 10 from two dimensions of time and pressure difference, providing double guarantees. Specifically, on the one hand, when the operating time of the compressor 10 reaches the preset value, it means that the refrigerant circulation and vaporization have been carried out to a certain extent. At this time, it is considered that the liquid refrigerant has been effectively separated, and the heat pump system can safely exit the first anti-migration control mode. On the other hand, the pressure difference between the high-pressure side and the low-pressure side of the compressor 10 is used as an index of the pressure balance of the heat pump system. When the pressure difference is less than the preset value, it indicates that the internal pressure of the system tends to be stable, and the distribution of the liquid refrigerant in the system is also relatively reasonable. At this time, the bypass solenoid valve 20 is closed and the compressor 10 is frequency-upgraded to the platform frequency, which can not only avoid the long-term inefficient operation of the compressor 10, but also ensure the smooth transition of the heat pump system to the normal operation mode in a safe state.

[0059] Exemplarily, in this embodiment, the first temperature range is the outdoor ambient temperature > 15°C, the second temperature range is 0°C < outdoor ambient temperature ≤ 15°C, the first preset shutdown duration is 4 hours, the first preset delay time is 10 seconds, and the first low frequency is 30 Hz. The first preset operating time is 5 minutes, and the first preset pressure difference is 0.5 MPa. By comprehensively considering factors such as the migration speed of the refrigerant and the startup stability of the heat pump system, the heat pump system can respond quickly and accurately at different outdoor ambient temperatures, effectively prevent the damage caused by refrigerant migration to the compressor 10, and ensure the stable operation of the heat pump system under various actual working conditions.

[0060] Embodiment 2

[0061] As Figure 2 shown, in this embodiment, when the outdoor ambient temperature is in the third temperature range and the shutdown duration of the compressor 10 is greater than the second preset shutdown duration, the second anti-migration control mode is executed. In the second anti-migration control mode, the bypass solenoid valve 20 is opened and the compressor 10 is started after delaying the second preset delay time, and operates at the second low frequency until the second exit condition is met, then the bypass solenoid valve 20 is closed and the compressor 10 is frequency-upgraded to the platform frequency.

[0062] In the more severe low-temperature environment, the second anti-migration control mode further adapts to the refrigerant migration characteristics by extending the low-frequency operation time or adjusting the pressure difference threshold, enhancing the protection of the compressor 10, ensuring the reliable operation of the heat pump system in cold regions, and increasing the applicable range of the heat pump system. This enables the anti-refrigerant migration control method to cover a wider range of ambient temperature ranges and shutdown duration ranges, further improving the protection of the heat pump system.

[0063] Exemplarily, the third temperature range is that the outdoor ambient temperature ≤ 0°C, the second preset shutdown duration is 2 hours, the second preset delay time is 10 seconds, and the second low frequency is 30 Hz.

[0064] The second exit condition includes that the operating time of the compressor 10 reaches the second preset operating time or the pressure difference between the high-pressure side and the low-pressure side of the compressor 10 is less than the second preset pressure difference. Exemplarily, the second preset operating time is 10 minutes and the second preset pressure difference is 0.3 MPa. By setting the second preset operating time of 10 minutes and the second preset pressure difference of 0.3 MPa, for the operating characteristics in the third temperature range, the time and pressure difference control standards of the compressor 10 in the low-frequency operation stage are further refined. This enables the system to more fully ensure the circulation and vaporization of the refrigerant in a low-temperature environment, ensuring that the internal pressure of the compressor 10 reaches a more balanced state before exiting the second anti-migration control mode, improving the safety and stability of the heat pump system under extremely low-temperature conditions and enhancing the protection effect on the compressor 10.

[0065] Embodiment 3

[0066] As Figure 3 shown, this embodiment provides a heat pump system, which includes a bypass solenoid valve 20, a compressor 10, a first gas-liquid separator 30, a temperature sensor, a pressure sensor 90, and a controller. Among them, the high-pressure side and the low-pressure side of the compressor 10 are respectively connected to the bypass solenoid valve 20, the first gas-liquid separator 30 is connected in series in the exhaust pipe of the compressor 10, the temperature sensor is used to detect the outdoor ambient temperature, the pressure sensor 90 is arranged on the high-pressure side and the low-pressure side of the compressor 10 to detect the pressures of the exhaust pipe and the suction pipe of the compressor 10, and the controller is electrically connected to the bypass solenoid valve 20, the compressor 10, and the first gas-liquid separator 30; the controller is configured to execute the anti-refrigerant migration control method in Embodiment 1 or Embodiment 2 according to the data of the temperature sensor and the pressure sensor 90.

[0067] The bypass solenoid valve 20 is installed between the high and low pressure sides of the compressor 10, which can quickly switch the refrigerant circulation path, cooperate with the low-frequency startup of the compressor 10, and provide a buffer for the refrigerant circulation and vaporization. The first gas-liquid separator 30 is connected in series in the exhaust pipe of the compressor 10, which can effectively separate the liquid refrigerant and prevent it from entering the compressor 10 and causing damage to the compressor 10. The temperature sensor and the pressure sensor 90 respectively detect the outdoor ambient temperature and the pressures of the high and low pressure sides of the compressor 10, providing accurate data support for the controller. This heat pump system effectively solves the problem of compressor 10 damage caused by refrigerant migration under different outdoor ambient temperatures and shutdown durations, improves the stability and reliability of the heat pump system, and reduces the maintenance cost and equipment failure rate.

[0068] Exemplarily, the pressure sensor 90 includes a high-pressure sensor and a low-pressure sensor. The high-pressure sensor is disposed on the exhaust pipe of the compressor 10 , and the low-pressure sensor is disposed on the intake pipe of the compressor 10 .

[0069] In some optional embodiments, a heating component (not shown in the figure) is provided inside the first gas-liquid separator 30, and the heating component is connected to the exhaust port of the compressor 10 through a heat-conducting pipeline, so that the exhaust waste heat of the exhaust port of the compressor 10 assists in gasification of the liquid refrigerant. Through the above design, on the one hand, the waste heat of the exhaust of the compressor 10 is fully utilized, the secondary utilization of energy is achieved, and the energy utilization efficiency of the heat pump system is improved; on the other hand, the auxiliary gasification effect of the heating component on the liquid refrigerant further accelerates the gasification speed of the refrigerant, improves the gas-liquid separation efficiency, and reduces the possibility of liquid refrigerant entering the compressor 10, thereby more effectively protecting the compressor 10, enhancing the reliability and safety of the heat pump system, and extending the service life of the compressor 10 and the heat pump system.

[0070] like Figure 3 As shown, the heat pump system further includes a four-way valve 40, a plate heat exchanger 50, an electronic expansion valve 60, a fin heat exchanger 70, a second gas-liquid separator 80 and a number of pipelines. The normal working modes of the heat pump system include a heating mode and a cooling mode.

[0071] After being compressed into high-temperature and high-pressure gas in the compressor 10, the refrigerant first enters the four-way valve 40. The four-way valve 40 can change the flow direction of the refrigerant according to the operating mode of the heat pump system (cooling mode or heating mode). In the heating mode, the refrigerant flows from the four-way valve 40 to the plate heat exchanger 50; in the cooling mode, the refrigerant flows to the fin heat exchanger 70. In this way, the four-way valve 40 ensures that the refrigerant can switch between different circuits according to the needs of the heat pump system, thereby realizing the conversion of the heating function and the cooling function of the heat pump system.

[0072] In the heating mode, the refrigerant flows out of the four-way valve 40 and enters the plate heat exchanger 50. The working principle of the plate heat exchanger 50 is to use the refrigerant to exchange heat with the water flowing through the plate heat exchanger 50. The refrigerant releases heat in it, so that the water temperature rises to meet the indoor heating demand. The refrigerant itself decreases in temperature during this process, but still maintains a high pressure state.

[0073] Then, the refrigerant flows through the electronic expansion valve 60. The electronic expansion valve 60 precisely controls the flow and pressure reduction of the refrigerant by adjusting the opening. The electronic expansion valve 60 throttles and reduces the pressure of the high-temperature and high-pressure refrigerant into a low-temperature and low-pressure gas-liquid mixture, preparing for the subsequent evaporation process.

[0074] Then, the refrigerant enters the fin heat exchanger 70. In the fin heat exchanger 70, the refrigerant exchanges heat with the outside air. If the heat pump system is in the heating mode, the refrigerant absorbs heat from the air, causing its temperature to rise and gradually vaporize; if the heat pump system is in the cooling mode, the refrigerant releases heat into the air to cool the air.

[0075] Finally, the refrigerant flows through the second gas-liquid separator 80. The function of the second gas-liquid separator 80 is to further separate the liquid components in the refrigerant, enabling as much gaseous refrigerant as possible to return to the compressor 10, thereby reducing the entry of liquid refrigerant into the compressor 10 and reducing the occurrence of liquid slugging in the compressor 10.

[0076] Throughout the process, it is ensured that the refrigerant can circulate efficiently and achieve the refrigeration or heating function of the heat pump system, while protecting the compressor 10 from liquid slugging damage and extending its service life.

[0077] Obviously, the above are only the preferred embodiments of the present invention and the applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments here, and various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the inventive concept, it can also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

[0078] Note that in the description of this specification, the descriptions referring to the terms "some embodiments", "other embodiments", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

Claims

1. A refrigerant migration prevention control method, characterized in that, It includes the following steps: Detect the current outdoor ambient temperature and the compressor shutdown duration; Select the following control modes according to the outdoor ambient temperature and the compressor shutdown duration: When the outdoor ambient temperature is within the first temperature range, directly start the compressor and increase the frequency to the platform frequency; When the outdoor ambient temperature is within the second temperature range and the compressor shutdown duration is greater than the first preset shutdown duration, execute the first anti-migration control mode; In the first anti-migration control mode, open the bypass solenoid valve and start the compressor after delaying for the first preset delay time, and operate at the first low frequency until the first exit condition is met, then close the bypass solenoid valve and increase the frequency of the compressor to the platform frequency.

2. The anti-refrigerant migration control method according to claim 1, characterized in that The first exit condition includes that the compressor operation time reaches the first preset operation time or the pressure difference between the high-pressure side and the low-pressure side of the compressor is less than the first preset pressure difference.

3. The anti-refrigerant migration control method according to claim 1, wherein The first temperature range is outdoor ambient temperature > 15°C; The second temperature range is 0°C < outdoor ambient temperature ≤ 15°C, the first preset shutdown duration is 4 hours, the first preset delay time is 10 seconds, and the first low frequency is 30 Hz.

4. The anti-refrigerant migration control method according to claim 2, wherein The first preset operation time is 5 minutes, and the first preset pressure difference is 0.5 MPa.

5. The anti-refrigerant migration control method according to claim 1, characterized in that, When the outdoor ambient temperature is within the third temperature range and the compressor shutdown duration is greater than the second preset shutdown duration, execute the second anti-migration control mode; In the second anti-migration control mode, open the bypass solenoid valve and start the compressor after delaying for the second preset delay time, and operate at the second low frequency until the second exit condition is met, then close the bypass solenoid valve and increase the frequency of the compressor to the platform frequency.

6. The anti-refrigerant migration control method according to claim 5, characterized in that, The second exit condition includes that the compressor operation time reaches the second preset operation time or the pressure difference between the high-pressure side and the low-pressure side of the compressor is less than the second preset pressure difference.

7. The anti-refrigerant migration control method according to claim 5, characterized in that The third temperature range is outdoor ambient temperature ≤ 0°C, the second preset shutdown duration is 2 hours, the second preset delay time is 10 seconds, and the second low frequency is 30 Hz.

8. The anti-refrigerant migration control method according to claim 6, wherein The second preset operation time is 10 minutes, and the second preset pressure difference is 0.3 MPa.

9. A heat pump system, characterized in that, The heat pump system includes: A bypass solenoid valve; A compressor, the high-pressure side and the low-pressure side of the compressor are respectively connected to the bypass solenoid valve; A first gas-liquid separator, the first gas-liquid separator is connected in series in the exhaust pipeline of the compressor; A temperature sensor, the temperature sensor is used to detect the outdoor ambient temperature; A pressure sensor, the pressure sensor is arranged on the high-pressure side and the low-pressure side of the compressor to detect the pressures of the exhaust pipeline and the suction pipeline of the compressor; A controller, the controller is electrically connected to the bypass solenoid valve, the compressor and the first gas-liquid separator; the controller is configured to execute the anti-refrigerant migration control method according to any one of claims 1-8 based on the data of the temperature sensor and the pressure sensor.

10. The heat pump system according to claim 9, characterized in that, The first gas-liquid separator is internally provided with a heating component, and the heating component is connected to the exhaust port of the compressor through a heat conduction pipeline, so that the exhaust waste heat of the exhaust port of the compressor assists in gasifying the liquid refrigerant.

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