Control method of heat pump system, heat pump system, and storage medium

Abstract

The application provides a control method of a heat pump system, the heat pump system and a storage medium. The method comprises the following steps: starting a compressor to make the compressor pump refrigerant into a target section; adjusting a current opening degree of an expansion valve to increase the pressure of the target section, and form a negative pressure difference of a first storage assembly relative to the target section; opening a solenoid valve to make the first storage assembly absorb the refrigerant from the target section based on the negative pressure difference; and closing the solenoid valve when the negative pressure difference meets a preset first condition. In this way, the first storage assembly can store a part of the refrigerant, the solenoid valve plays a role of isolating the first storage assembly from a circulating loop, the refrigerant storage amount in the circulating loop is reduced, and the risk of explosion of the heat pump system can be effectively reduced.

Description

Technical Field

[0001] This application relates to the field of heat pump system technology, and in particular to a control method for a heat pump system, a heat pump system, and a storage medium. Background Technology

[0002] Heat pump systems utilize electrical energy to transfer heat from low to high temperatures, and are widely used due to their high efficiency and energy saving. However, traditional heat pump systems may face a rapid increase in internal pressure under certain environments, posing a risk of bursting. Currently, the industry mainly attempts to reduce this risk by limiting the refrigerant charge, but this method may still fail under extreme ambient temperature conditions. In short, there is an urgent need for a method to reduce the risk of heat pump system bursting. Summary of the Invention

[0003] This application provides a control method for a heat pump system, a heat pump system, and a storage medium. The method allows a first storage component to store a portion of the refrigerant, while the solenoid valve isolates the first storage component from the circulation loop, reducing the amount of refrigerant stored in the circulation loop and effectively reducing the risk of heat pump system explosion.

[0004] In a first aspect, a control method for a heat pump system is provided. The heat pump system includes a circulation loop consisting of a first heat exchanger, a compressor, a one-way valve, a second heat exchanger, and an expansion valve connected end-to-end; a solenoid valve connected to a target section in the circulation loop; and a first storage component connected to the solenoid valve. The two ends of the target section are the one-way valve and the expansion valve, respectively. The circulation loop is filled with refrigerant. The method includes:

[0005] Start the compressor to pump refrigerant into the target section;

[0006] The current opening of the expansion valve is adjusted to increase the pressure in the target section, creating a negative pressure difference between the first storage component and the target section.

[0007] Open the solenoid valve to allow the first storage component to draw refrigerant from the target section based on the negative pressure difference;

[0008] When the negative pressure difference meets the preset first condition, the solenoid valve is closed.

[0009] In a second aspect, a heat pump system is provided, the heat pump system including a memory, a processor, a circulation loop consisting of a first heat exchanger, a compressor, a one-way valve, a second heat exchanger, and an expansion valve connected end to end, a solenoid valve connected to a target segment in the circulation loop, and a first storage component connected to the solenoid valve, wherein the two ends of the target segment are a one-way valve and an expansion valve, respectively, and the circulation loop is filled with refrigerant.

[0010] Memory, used to store executable program code;

[0011] The processor is used to call and run executable program code from memory, so that the heat pump system performs any of the above-mentioned heat pump system control methods.

[0012] Thirdly, a computer-readable storage medium is provided, which stores computer program code that, when executed, implements the control method of the heat pump system described above.

[0013] The beneficial effects of the technical solutions provided by some embodiments of this application include at least the following: Adding a solenoid valve and a first storage component to the heat pump system, wherein the solenoid valve is connected to the target section in the circulation loop of the heat pump system, and the first storage component is connected to the solenoid valve. When the compressor is started, the current opening degree of the expansion valve is adjusted to increase the pressure of the target section, forming a negative pressure difference between the first storage component and the target section. Then, the solenoid valve is opened to allow the first storage component to draw refrigerant from the target section. Finally, the solenoid valve is closed, allowing the first storage component to store a portion of the refrigerant. The solenoid valve isolates the first storage component from the circulation loop, reducing the amount of refrigerant stored in the circulation loop and effectively reducing the risk of heat pump system explosion. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of a heat pump system provided in an embodiment of this application;

[0016] Figure 2 This is a schematic diagram of the structure of a heat pump system provided in an embodiment of this application;

[0017] Figure 3 This is a schematic diagram of the structure of a heat pump system provided in an embodiment of this application;

[0018] Figure 4 This is a schematic flowchart of a control method for a heat pump system provided in an embodiment of this application;

[0019] Figure 5 This is a schematic diagram illustrating the effect of refrigerant storage according to an embodiment of this application;

[0020] Figure 6 This is a schematic diagram illustrating the effect of refrigerant storage according to an embodiment of this application;

[0021] Figure 7 This is a schematic diagram of a process for controlling the discharge of refrigerant from a first storage component, provided in an embodiment of this application.

[0022] Figure 8 This is a schematic diagram of a process for controlling the discharge of lubricating oil from a first storage component, provided in an embodiment of this application.

[0023] Figure 9 This is a schematic diagram illustrating the effect of conventional storage of lubricating oil according to an embodiment of this application;

[0024] Figure 10 This is a schematic diagram illustrating the effect of density reversal between lubricating oil and refrigerant provided in an embodiment of this application;

[0025] Figure 11 This is a schematic diagram illustrating the effect of a first storage component storing lubricating oil and refrigerant at a high level, as provided in an embodiment of this application.

[0026] Figure 12 This is a schematic diagram illustrating the effect of a first storage component discharging lubricating oil according to an embodiment of this application;

[0027] Figure 13 This is a schematic diagram of the structure of a heat pump system provided in an embodiment of this application.

[0028] Explanation of icon numbers:

[0029] label name label name 601 First heat exchanger 607 First storage component 602 compressor 608 refrigerant 603 one-way valve 609 Second storage component 604 Second heat exchanger 610 lubricating oil 605 Expansion valve 611 capillary 606 Solenoid valve 612 oil return hole Detailed Implementation

[0030] To make the features and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0032] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0033] The following will provide a detailed description of each example. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments.

[0034] A heat pump system is a device that uses electricity to drive a compressor, transferring heat from a low-temperature heat source to a high-temperature heat source to achieve heating or cooling. Heat pump systems offer significant advantages in energy utilization and energy saving, and are widely used in various temperature control applications.

[0035] In various configurations of a heat pump system, one common design includes a compressor, a check valve, an expansion valve, and two heat exchangers. These components together form a closed-loop circulation system. This circulation system is filled with a specific refrigerant, which plays a crucial role in heat transfer during system operation. Please refer to [link / reference]. Figure 1 This is a schematic diagram of a heat pump system provided in an embodiment of this application. Figure 1 In the structure of the heat pump system shown, the first heat exchanger 601, compressor 602, one-way valve 603, second heat exchanger 604, and expansion valve 605 are connected end-to-end to form a circulation loop filled with refrigerant. Driven by compressor 602, the refrigerant circulates in the following direction: first heat exchanger 601, compressor 602, one-way valve 603, second heat exchanger 604, and expansion valve 605. That is, after flowing out of expansion valve 605, the refrigerant flows back into first heat exchanger 601. It can be understood that the first heat exchanger 601 can be an evaporator, while the second heat exchanger 604 can be a condenser or an air cooler.

[0036] Heat pump systems can use a wide variety of refrigerants, and different types can be selected depending on different application requirements and environmental conditions. Among them, carbon dioxide (CO2), as a natural, environmentally friendly, and efficient refrigerant, has been used in some heat pump systems.

[0037] However, CO2 possesses unique thermophysical properties, characterized by a low critical temperature and a high critical pressure. This means that even when stationary, the internal pressure of a CO2 heat pump system increases dramatically with rising ambient temperature. Particularly under extreme environmental conditions, sudden pressure changes can lead to the risk of the CO2 heat pump system bursting, seriously threatening its safe and stable operation. Currently, the industry standard is to precisely calculate the system volume and design a maximum refrigerant charge to mitigate this risk. However, this approach has limitations in practical applications. Firstly, due to the complexity of the internal structure and operating conditions of CO2 heat pump systems, precise control of the refrigerant charge is often difficult. Secondly, this approach has poor environmental adaptability, especially in the face of sudden extreme environments (such as high temperatures), where the designed maximum refrigerant charge may fail, potentially leading to a safety accident.

[0038] To address the aforementioned issues, this application proposes adding a solenoid valve 6 and a first storage component to the heat pump system. The solenoid valve is connected to the target section in the heat pump system's circulation loop, and the first storage component is connected to the solenoid valve. When the compressor is started, the current opening of the expansion valve is adjusted to increase the pressure in the target section, creating a negative pressure difference between the first storage component and the target section. Then, the solenoid valve is opened, allowing the first storage component to draw refrigerant from the target section. Finally, the solenoid valve is closed, allowing the first storage component to store a portion of the refrigerant. The solenoid valve effectively isolates the first storage component from the circulation loop, reducing the amount of refrigerant stored in the circulation loop and effectively lowering the risk of heat pump system explosion.

[0039] based on Figure 1 The structural diagram is shown below, in conjunction with... Figure 2 - Figure 12 The control method of the heat pump system provided in the embodiments of this application will be described in detail.

[0040] Please see Figure 2 and Figure 3 , Figure 2 and Figure 3 These are schematic diagrams of a heat pump system provided in an embodiment of this application. Figure 2 / Figure 3 As shown, the heat pump system involved in this embodiment includes a circulation loop consisting of a first heat exchanger 601, a compressor 602, a one-way valve 603, a second heat exchanger 604, and an expansion valve 603 connected end to end, a solenoid valve 606 connected to a target section in the circulation loop, and a first storage component 607 connected to the solenoid valve 606. The two ends of the target section are the one-way valve 603 and the expansion valve 603, respectively. The circulation loop is filled with refrigerant.

[0041] Specifically, the circulation loop in a heat pump system is a closed loop consisting of multiple components connected by pipes, used to realize the working principle of the heat pump, namely, transferring heat. The following will describe in detail the structure of this circulation loop, the function of each component, and the flow mode of the refrigerant within it.

[0042] The components of a loop:

[0043] First heat exchanger 601: First heat exchanger 601 usually refers to the evaporator of a heat pump system, which absorbs heat from the environment.

[0044] Compressor 602: Compressor 602 is the core component of the heat pump system. Its function is to compress the low-temperature, low-pressure refrigerant into a high-temperature, high-pressure refrigerant, that is, to increase the temperature and pressure of the refrigerant.

[0045] One-way valve 603: One-way valve 603 ensures that the refrigerant can only flow in one direction and prevents backflow.

[0046] Second heat exchanger 604: Second heat exchanger 604 usually refers to an air cooler (for CO2 heat pump systems) or a condenser, whose function is to release heat into the environment.

[0047] Expansion valve 603: The function of expansion valve 603 is to reduce the pressure and temperature of the refrigerant.

[0048] The aforementioned components are connected end-to-end via pipelines to form a closed loop. Specifically, the outlet of the first heat exchanger 601 is connected to the inlet of the compressor 602 via a pipeline; the outlet of the compressor 602 is connected to the inlet of the one-way valve 603 via a pipeline; the outlet of the one-way valve 603 is connected to the inlet of the second heat exchanger 604 via a pipeline; the outlet of the second heat exchanger 604 is then connected to the inlet of the expansion valve 603 via a pipeline; and finally, the outlet of the expansion valve 603 is connected to the inlet of the first heat exchanger 601 via a pipeline, thus forming a closed loop.

[0049] The following describes the roles of each component in the refrigerant circulation loop: The refrigerant passes through the first heat exchanger 601, absorbing heat from the environment. It then flows from the first heat exchanger 601 into the compressor 602, which performs work on the refrigerant, increasing its temperature and pressure to provide power for heat transfer. From the compressor 602, the refrigerant flows into and out of the one-way valve 603, ensuring unidirectional flow. From the one-way valve 603, the refrigerant flows into the second heat exchanger 604, releasing heat into the environment. From the second heat exchanger 604, the refrigerant flows into the expansion valve 603, which reduces the refrigerant's pressure and temperature, preparing for the next heat absorption process. Finally, the refrigerant flows from the expansion valve 603 back into the first heat exchanger 601, completing one cycle. Understandably, during operation, the heat pump system controls components such as compressor 602 and expansion valve 603 to drive the refrigerant to complete multiple cycles in the circulation loop.

[0050] To address the issue of a rapid increase in internal pressure that a heat pump system may face under certain conditions, this application embodiment adds a solenoid valve 606 and a first storage component 607 to the heat pump system. The solenoid valve 606 is connected to the target section in the circulation loop, and the first storage component 607 is connected to the solenoid valve 606. The target section consists of a check valve 603, an expansion valve 603, piping between the check valve 603 and the expansion valve 603, and other components (including a second heat exchanger 604 and any additional components that may be added). Specifically, the two ends of the target section are the check valve 603 and the expansion valve 603, respectively.

[0051] To better illustrate the connection relationship between the solenoid valve 606, the first storage component 607, and the circulation loop, Figure 2 and Figure 3 Two different connection methods are provided for connecting the solenoid valve 606 to the target section.

[0052] like Figure 2 As shown, one end of the solenoid valve 606 is connected to the connection section between the second heat exchanger 604 and the expansion valve 603, and the other end is connected to the refrigerant inlet / outlet of the first storage component 607. With this connection, the temperature of the refrigerant entering the first storage component 607 decreases because it has already been cooled by the second heat exchanger 604.

[0053] like Figure 3 As shown, one end of the solenoid valve 606 is connected to the connection section between the one-way valve 603 and the second heat exchanger 604, and the other end is connected to the refrigerant inlet and outlet of the first storage component 607. In this connection configuration, the refrigerant entering the first storage component 607 does not undergo heat dissipation through the second heat exchanger 604, resulting in a higher temperature.

[0054] Based on the above Figure 2 , Figure 3 The following section will introduce the heat pump system in conjunction with... Figure 4 This application proposes a control method for a heat pump system according to an embodiment. For example... Figure 4 As shown, the method may include the following steps S101-S104.

[0055] S101, start the compressor so that it pumps refrigerant into the target section.

[0056] Specifically, the compressor is started first, initiating its operation. When the compressor starts, it draws in refrigerant from the first heat exchanger and compresses it into a high-pressure, high-temperature state through an internal compression process. This process consumes energy, typically electrical energy. The compressor converts this electrical energy into mechanical energy through its internal motor and compression mechanism, thereby compressing the refrigerant.

[0057] As the compressor operates, the compressed, high-temperature, high-pressure refrigerant is pumped into the target section. The start-up of the compressor not only provides the power for the flow of refrigerant in the circulation loop, but also marks the beginning of the entire heat pump system's operation.

[0058] S102, adjust the current opening of the expansion valve to increase the pressure of the target section and form a negative pressure difference between the first storage component and the target section.

[0059] Specifically, the pressure in the target section can be increased by reducing or maintaining the current opening degree of the expansion valve. The current opening degree of the expansion valve refers to the degree to which the valve is open. In a heat pump system, the expansion valve is used to control the flow rate of refrigerant from the high-pressure side to the low-pressure side, thereby regulating the inlet flow rate of the first heat exchanger and the pressure within the system.

[0060] If the current opening of the expansion valve is small enough, maintaining the current opening of the expansion valve can limit the flow of refrigerant through the expansion valve, thereby increasing the pressure in the target section.

[0061] If the current opening of the expansion valve is not small enough, reducing the current opening of the expansion valve can limit the flow of refrigerant through the expansion valve, thereby increasing the pressure in the target section.

[0062] When the pressure in the target section increases, if the pressure inside the first storage component is relatively low, a negative pressure difference will be created between the target section and the first storage component. This negative pressure difference is the driving force that propels the refrigerant from the high-pressure target section to the low-pressure first storage component.

[0063] S103, open the solenoid valve to allow the first storage component to draw refrigerant from the target section based on the negative pressure difference.

[0064] Specifically, once a negative pressure difference is established, the solenoid valve opens, allowing the first storage component to draw refrigerant from the target section based on the negative pressure difference. The solenoid valve acts as a control valve here; its opening and closing directly determines whether refrigerant can flow from the target section into the first storage component.

[0065] When the solenoid valve opens, because the pressure in the target section is higher than the pressure in the first storage component, the refrigerant will automatically flow from the target section to the first storage component under the influence of the negative pressure difference. This process is automatic and requires no additional external force, relying entirely on the negative pressure difference established in the previous steps.

[0066] S104, when the negative pressure difference meets the preset first condition, the solenoid valve is closed.

[0067] Specifically, the heat pump system will shut off the solenoid valve when the negative pressure difference meets a preset first condition. This preset first condition can be set based on the actual operating conditions and needs of the heat pump system. For example, when the negative pressure difference reaches or exceeds a certain preset threshold, it can be determined that the negative pressure difference meets the preset first condition.

[0068] The purpose of closing the solenoid valve is to isolate the first storage component from the circulation loop, preventing refrigerant in the target section from flowing into the first storage component, and also preventing refrigerant in the first storage component from flowing into the circulation loop. In this way, the first storage component can stably store a portion of the refrigerant, reducing the amount of refrigerant in the circulation loop and maintaining stable pressure within the heat pump system.

[0069] To more intuitively understand the judgment logic of the preset first condition, an example is provided below. Assume the negative pressure difference is ΔP. ​​The preset first condition can be judged based on a preset negative pressure difference threshold, which is denoted as ΔP_threshold.

[0070] When ΔP ≥ ΔP_threshold (meaning the negative pressure difference is greater than or equal to the preset negative pressure difference threshold), it is determined that ΔP meets the preset first condition, which can further trigger the action of closing the solenoid valve.

[0071] Alternatively, if we consider the absolute value of the negative pressure difference:

[0072] When |ΔP|≥|ΔP_threshold| (meaning the absolute value of the negative pressure difference is greater than or equal to the absolute value of the preset negative pressure difference threshold), it is determined that ΔP meets the preset first condition, which can further trigger the action of closing the solenoid valve.

[0073] To further demonstrate the refrigerant storage performance of the first storage component, please refer to [link / reference]. Figure 5 and Figure 6 , Figure 5 and Figure 6 These are schematic diagrams illustrating the effect of refrigerant storage according to embodiments of this application. Figure 2 / Figure 3 Based on the structure of the heat pump system shown, Figure 5 / Figure 6 The heat pump system shown has a second storage component 609 added to its circulation loop. This second storage component 609 is primarily used to store the refrigerant in the circulation loop. Preferably, the second storage component 609 is located between the first heat exchanger 601 and the compressor 602; that is, the outlet of the first heat exchanger 601 is connected to the inlet of the second storage component 609 via a pipe, and the outlet of the second storage component 609 is connected to the inlet of the compressor 602 via a pipe. The refrigerant passes through the second storage component 609 before flowing from the first heat exchanger 601 to the compressor 602.

[0074] The second storage component 609 is used to regulate the flow and pressure of the refrigerant to ensure the stable operation of the heat pump system. Simultaneously, it can also act as a buffer, allowing for adjustment when a temporary imbalance occurs in the supply and demand of the refrigerant in the heat pump system.

[0075] In some possible implementations, the second storage component 609 can be a low-pressure tank, the main functions of which are as follows:

[0076] Buffering and storage: The low-pressure tank can store a certain amount of refrigerant, thus providing sufficient refrigerant to maintain stable system operation when the demand of the heat pump system fluctuates. In some cases, the low-pressure tank can even store the lubricating oil 610 required by the compressor 602.

[0077] Pressure regulation: The low-pressure tank can act as a pressure regulator. When the operating state of the compressor 602 changes, it can help stabilize the pressure of the heat pump system and prevent damage to the heat pump system due to pressure fluctuations.

[0078] It can be seen that, in Figure 5 / Figure 6 In the heat pump system shown, the second storage component 609 is part of the circulation loop. The refrigerant will inevitably pass through the second storage component 609 when circulating in the circulation loop, and a considerable part of the refrigerant storage work is completed by the second storage component 609.

[0079] exist Figure 5 In the heat pump system shown, the second storage component 609 stores a larger amount of refrigerant, while the first storage component 607 stores a smaller amount. At this time, the heat pump system may be in operation, and the large amount of refrigerant in the second storage component 609 can directly participate in the refrigerant circulation of the loop.

[0080] exist Figure 6 In the heat pump system shown, the second storage component 609 stores less refrigerant, while the first storage component 607 stores more refrigerant. At this time, the heat pump system may be in a static state, with the large amount of refrigerant in the first storage component 607 isolated from the circulation loop, ensuring that the heat pump system will not burst due to increased refrigerant pressure in the circulation loop.

[0081] exist Figure 5 Based on the heat pump system shown, executing steps S101-S104 of this embodiment allows the first storage component 607 to absorb a large amount of refrigerant from the circulation loop (including the second storage component 609), thereby reducing the amount of refrigerant in the circulation loop and achieving... Figure 6 The refrigerant storage effect of the heat pump system is shown.

[0082] In this embodiment, a solenoid valve and a first storage component are added to the heat pump system. The solenoid valve is connected to the target section in the heat pump system's circulation loop, and the first storage component is connected to the solenoid valve. When the compressor is started, the current opening of the expansion valve is adjusted to increase the pressure in the target section, creating a negative pressure difference between the first storage component and the target section. Then, the solenoid valve is opened, allowing the first storage component to draw refrigerant from the target section. Finally, the solenoid valve is closed, allowing the first storage component to store a portion of the refrigerant. The solenoid valve isolates the first storage component from the circulation loop, reducing the amount of refrigerant stored in the circulation loop and effectively reducing the risk of heat pump system explosion.

[0083] In one possible implementation, for Figure 4 Step S102 of the illustrated embodiment can be further refined to include the following steps:

[0084] If the current opening of the expansion valve is zero, then the current opening of the expansion valve is maintained to increase the pressure of the target section and form a negative pressure difference between the first storage component and the target section.

[0085] If the current opening of the expansion valve is not zero, then the current opening of the expansion valve is reduced to increase the pressure of the target section, thereby creating a negative pressure difference between the first storage component and the target section.

[0086] Specifically, in a heat pump system, the expansion valve is a crucial component, and its opening degree directly affects the flow rate of refrigerant through the expansion valve and the pressure distribution within the circulation loop. To create a negative pressure difference between the first storage component and the target section, one can choose to maintain the current opening degree of the expansion valve or reduce its current opening degree.

[0087] If the expansion valve is currently open to zero, it means the valve is completely closed, and no refrigerant can pass through. In this case, if it is necessary to increase the pressure in the target section, it is only necessary to maintain the current opening of the expansion valve at zero. At this time, if the compressor is running, the refrigerant pressure in the target section will gradually accumulate and rise; if the compressor 602 is shut down, the refrigerant in the target section will be restricted by the check valve, expansion valve, and solenoid valve and will not be able to flow out of the target section. It can be seen that although the refrigerant pressure in the target section will not gradually accumulate and rise, it will still be maintained at a relatively high pressure.

[0088] If the current opening of the expansion valve is not zero, it means that the valve is not completely closed; it may be partially or fully open, allowing refrigerant to pass through. In this case, if it is necessary to increase the pressure in the target section, the current opening of the expansion valve can be reduced. If the compressor is running, the reduced opening of the expansion valve will decrease the amount of refrigerant flowing out of the target section, causing the refrigerant pressure to gradually increase. If the compressor is off, the refrigerant in the target section cannot flow out through the check valve and expansion valve. Again, the reduced opening of the expansion valve will decrease the amount of refrigerant flowing out of the target section. Therefore, although the refrigerant pressure in the target section will gradually decrease, it can still maintain a relatively high pressure for a short period.

[0089] As the pressure in the target section rises or remains at a high pressure, a negative pressure difference is formed between the first storage component and the target section. This negative pressure difference drives the refrigerant to flow from the high-pressure area to the low-pressure area, thereby achieving heat transfer and balance in the system.

[0090] In this embodiment, reducing the current opening degree of the expansion valve or maintaining the current opening degree of the expansion valve at zero opening degree can create a negative pressure difference between the first storage component and the target section, providing a negative pressure difference as a driving force for the first storage component to draw refrigerant from the target section.

[0091] In one possible implementation, for Figure 4 Step S102 of the illustrated embodiment can be further refined to include the following steps:

[0092] When the compressor is shut down, the current opening of the expansion valve is adjusted to increase the pressure in the target section, creating a negative pressure difference between the first storage component and the target section.

[0093] Specifically, in this embodiment, shutting down the compressor is used as the condition to trigger the adjustment of the current opening of the expansion valve. The compressor shutdown action occurs during... Figure 4 Between steps S101 and S102 of the illustrated embodiment, after the compressor is started, the compressor pumps refrigerant into the target section, gradually increasing the pressure of the target section. Then the compressor is turned off. The target section is in a high-pressure state when the compressor is turned off. At this time, the current opening of the expansion valve is maintained at zero or the current opening of the expansion valve is reduced, thereby forming a negative pressure difference between the first storage component and the target section.

[0094] In this embodiment, adjusting the current opening of the expansion valve when the compressor is shut down has at least the following two advantages.

[0095] To avoid excessive pressure in the target section: When the compressor is running, it continuously compresses and pushes refrigerant into the target section, causing the pressure there to rise continuously. If the expansion valve's opening is adjusted during this time, especially by reducing the opening or maintaining it at zero, the pressure in the target section will increase rapidly. However, after the compressor is shut off, no new compressed refrigerant enters the target section. This allows for safer and more precise adjustment of the expansion valve's opening to achieve the desired pressure in the target section, thus avoiding the problem of excessive pressure in the target section caused by continuous compressor operation during expansion valve adjustment.

[0096] Eliminating the risk of heat pump system explosion during quiescent operation: When the heat pump system enters a quiescent state, the compressor is also shut down. Triggering the reduction of the expansion valve's current opening or maintaining it at zero opening, based on the condition of compressor shutdown, allows the first storage component to draw refrigerant from the circulation loop when the heat pump system enters a quiescent state, reducing the amount of refrigerant in the circulation loop and thus eliminating the risk of the heat pump system exploding during quiescent operation.

[0097] Based on the above Figure 4 The illustrated embodiment proposes a method for controlling the discharge of refrigerant from the first storage component. Please refer to [link to relevant documentation]. Figure 7, Figure 7 This is a schematic diagram of a process for controlling the discharge of refrigerant from a first storage component, provided in an embodiment of this application, including the following steps S201-S204.

[0098] S201, start the compressor so that it pumps refrigerant into the target section.

[0099] For a detailed implementation of step S201, please refer to [link to relevant documentation]. Figure 4 The explanation of step S101 in the illustrated embodiment will not be repeated here.

[0100] S202, adjust the current opening of the expansion valve to reduce the pressure in the target section and create a positive pressure difference between the first storage component and the target section.

[0101] Specifically, the pressure in the target section can be reduced by increasing or maintaining the current opening degree of the expansion valve. The current opening degree of the expansion valve refers to the degree to which the valve is open. In a heat pump system, the expansion valve is a key component controlling the flow of refrigerant from the high-pressure side to the low-pressure side, and its opening degree directly affects the refrigerant flow rate and the pressure distribution within the system.

[0102] If the pressure in the target segment is too high, the current opening of the expansion valve needs to be increased to allow more refrigerant to flow through, thereby reducing refrigerant buildup in the target segment and lowering its pressure. Alternatively, in some cases, if the current opening of the expansion valve is large enough, maintaining that opening can also reduce the pressure in the target segment.

[0103] When the pressure in the target section decreases, if the pressure in the first storage component is relatively high, a positive pressure difference will be formed between the target section and the first storage component. This positive pressure difference is the driving force that propels the refrigerant from the high-pressure first storage component to the low-pressure target section.

[0104] S203, open the solenoid valve to allow the first storage component to discharge refrigerant to the target section based on the positive pressure difference.

[0105] Specifically, once a positive pressure differential is established, the solenoid valve opens, allowing the first storage component to discharge refrigerant into the target section based on the positive pressure differential. The solenoid valve acts as a control valve here; its opening and closing directly determines whether refrigerant can flow from the first storage component into the target section.

[0106] When the solenoid valve opens, because the pressure in the first storage component is higher than the pressure in the target section, the refrigerant will automatically flow from the first storage component to the target section under the influence of the positive pressure difference. This process is automatic and requires no additional external force, relying entirely on the positive pressure difference established in the previous steps.

[0107] S204, when the positive pressure difference meets the preset second condition, close the solenoid valve.

[0108] Specifically, the heat pump system will shut off the solenoid valve when the positive pressure difference meets a preset second condition. This preset second condition is also set based on the actual operating needs and performance requirements of the heat pump system. For example, when the positive pressure difference reaches or exceeds a certain preset threshold, it can be considered that the positive pressure difference meets the preset second condition.

[0109] After the solenoid valve is closed, the first storage component and the circulation loop will be relatively isolated. This means that the refrigerant in the first storage component can no longer flow into the target section, and the refrigerant in the target section cannot flow back to the first storage component. The purpose of this is to allow the refrigerant that was originally stored in the first storage component to return to the circulation loop, and to prevent the refrigerant in the circulation loop from flowing back to the first storage component by the solenoid valve.

[0110] To more intuitively understand the judgment logic of the preset second condition, an example is provided below. Assuming the positive pressure difference is ΔP', the preset second condition can be judged based on a preset positive pressure difference threshold, which is denoted as ΔP'_threshold.

[0111] When ΔP'≥ΔP'_threshold (i.e., the positive pressure difference is greater than or equal to the preset positive pressure difference threshold), it is determined that ΔP' meets the preset second condition, which can further trigger the action of closing the solenoid valve.

[0112] Alternatively, if we consider the absolute value of the positive pressure difference:

[0113] When |ΔP'|≥|ΔP'_threshold| (i.e., the absolute value of the positive pressure difference is greater than or equal to the absolute value of the preset positive pressure difference threshold), it is determined that ΔP' meets the preset second condition, which can further trigger the action of closing the solenoid valve.

[0114] To further demonstrate the refrigerant storage performance of the first storage component, please refer to [link / reference]. Figure 5 and Figure 6 .exist Figure 5 In the heat pump system shown, the second storage component 609 stores a larger amount of refrigerant 608, while the first storage component 607 stores a smaller amount of refrigerant 608. Figure 6 In the heat pump system shown, the second storage component 609 stores less refrigerant 608, while the first storage component 607 stores more refrigerant 608.

[0115] exist Figure 6Based on the heat pump system shown, executing steps S201-S204 of this embodiment can cause the first storage component 607 to discharge a large amount of refrigerant 608 into the circulation loop (including the second storage component 609), thereby ensuring sufficient refrigerant 608 in the circulation loop to achieve [the desired effect]. Figure 5 The heat pump system shown demonstrates the storage effect of refrigerant 608.

[0116] In this embodiment, when the compressor is started, the current opening of the expansion valve is adjusted to reduce the pressure in the target section, creating a positive pressure difference between the first storage component and the target section. Then, the solenoid valve is opened to allow the first storage component to discharge refrigerant into the target section. Finally, the solenoid valve is closed, which isolates the first storage component from the circulation loop, allowing the refrigerant previously stored in the first storage component to return to the circulation loop, ensuring sufficient refrigerant in the circulation loop to support the normal operation of the heat pump system.

[0117] Based on the above Figure 4 The illustrated embodiment proposes a method for controlling the discharge of lubricating oil from the first storage component. Please refer to [link to relevant documentation]. Figure 8 , Figure 8 This is a schematic diagram of a process for controlling the discharge of lubricating oil from a first storage component, provided in an embodiment of this application, including steps S301-S305.

[0118] S301, start the compressor so that it pumps refrigerant into the target section.

[0119] S302, when lubricating oil is present in the first storage component, the solenoid valve is opened to equalize the pressure between the first storage component and the target section.

[0120] S303, adjust the current opening of the expansion valve to increase the pressure of the first storage component and the target section.

[0121] S304 After a preset time has elapsed, the current opening of the expansion valve is increased to reduce the pressure of the target section, forming a positive pressure difference between the first storage component and the target section. The first storage component discharges lubricating oil to the target section based on the positive pressure difference.

[0122] S305, the solenoid valve is closed when the first storage component has completely discharged the lubricating oil.

[0123] Specifically, in a heat pump system, the compressor is the core component. It requires lubricating oil to ensure the smooth operation of its internal moving parts, reduce wear, and aid in sealing and cooling. This lubricating oil is typically injected into the compressor, and during compressor operation, some of it may enter the circulation loop along with the refrigerant. Understandably, the first storage unit not only draws in the refrigerant from the target section but may also draw in the lubricating oil flowing through it. To maintain the normal operation of the heat pump system, it is sometimes necessary to drain this lubricating oil from the first storage unit to prevent excessive lubricating oil buildup, which could potentially affect the performance and efficiency of the heat pump system.

[0124] As the refrigerant cycle begins, the compressor is started first, pumping the refrigerant into the target section. As the compressor continues to operate, the pressure within the target section gradually increases, laying the foundation for subsequent operations.

[0125] Next, after confirming the presence of lubricating oil in the first storage component, the solenoid valve is opened. The purpose of this step is to achieve pressure equalization between the first storage component and the target section. Specifically, opening the solenoid valve balances the pressure in the first storage component and the target section.

[0126] Subsequently, the flow of refrigerant needs to be restricted by either reducing the current opening of the expansion valve or maintaining it at zero, thereby increasing the pressure in the first storage component and the target section. Specifically, if the current opening of the expansion valve is small enough, maintaining it will restrict the flow of refrigerant through the valve, thus increasing the pressure in the first storage component and the target section. If the current opening is not small enough, reducing it will restrict the flow of refrigerant through the valve, also increasing the pressure in the first storage component and the target section.

[0127] While reducing the current opening of the expansion valve or maintaining it at zero, a timer can be started. When the timer reaches a preset time (equivalent to the preset time elapsed), the pressure in the first storage component and the target section reaches a stable state. Immediately afterwards, the current opening of the expansion valve is increased to allow more refrigerant to flow through, increasing the refrigerant flow rate in the target section and thus reducing its pressure. This pressure change creates a positive pressure difference between the first storage component and the target section, which is the driving force for lubricant discharge. Under the action of this positive pressure difference, the lubricant in the first storage component is pushed towards the lower-pressure target section, achieving lubricant discharge.

[0128] Typically, the first storage unit stores both refrigerant and lubricating oil. The refrigerant has a lower density, while the lubricating oil has a higher density. The inlet and outlet of the first storage unit are located at the bottom. Once it is confirmed that the lubricating oil in the first storage unit has been completely drained, promptly closing the solenoid valve can prevent further refrigerant outflow. Simultaneously, closing the solenoid valve also marks the end of the entire lubricating oil draining process, allowing the heat pump system to return to normal operation.

[0129] To more intuitively understand the above-mentioned adjustment process of lubricating oil in the circulation loop, please refer to [link to relevant documentation]. Figure 9 - Figure 12 .

[0130] like Figure 9 As shown, Figure 9 This is a schematic diagram illustrating the effect of conventional lubricant storage according to an embodiment of this application. The second storage component 609 has an oil return hole 612 near its bottom. At normal temperatures, the density of the refrigerant 608 in the second storage component 609 is less than the density of the lubricant 610, and the refrigerant 608 and lubricant 610 are immiscible or poorly miscible (for example, the refrigerant 608 can be CO2, which is generally immiscible with the lubricant 610 commonly used in CO2 heat pump systems). Therefore, the refrigerant 608 and lubricant 610 in the second storage component 609 are clearly separated, with the refrigerant 608 on top and the lubricant 610 on the bottom. The lubricant 610 in the bottom layer has sufficient quantity and can be transported to the compressor 602 through the oil return hole 612. Additionally, the first storage component 607 also stores refrigerant 608 and a small amount of lubricant 610.

[0131] like Figure 10 As shown, Figure 10 This is a schematic diagram illustrating the effect of density reversal between lubricating oil and refrigerant provided in an embodiment of this application. Figure 9 The second storage component 609 shown is different. Figure 10The density reversal between the lubricating oil 610 and refrigerant 608 in the second storage component 609 is typically caused by extreme environmental conditions. For example, when the refrigerant 608 in the second storage component 609 is CO2, the intermolecular distance of CO2 decreases with increasing pressure, thus increasing the CO2 density. Similarly, when the refrigerant 608 in the second storage component 609 is CO2, the thermal motion of CO2 molecules slows down with decreasing temperature, reducing the average distance between molecules and leading to an increase in CO2 density. In this density reversal scenario, the refrigerant 608 is located in the lower layer, while the lubricating oil 610 is located in the upper layer. The lower layer of refrigerant 608 prevents the upper layer of lubricating oil 610 from being delivered to the compressor 602 through the oil return hole 612, potentially causing oil shortage in the compressor 602, affecting the normal operation of the heat pump system, and even posing a risk of failure.

[0132] like Figure 11 As shown, Figure 11 This is a schematic diagram illustrating the effect of a first storage component storing lubricating oil and refrigerant at a high level, as provided in an embodiment of this application. Figure 10 Based on the heat pump system shown, execute Figure 4 In the illustrated embodiment, steps S101-S104 allow the first storage component 607 to draw refrigerant 608 and lubricating oil 610 from the circulation loop, achieving... Figure 11 The effect of the first storage component 607 storing lubricating oil 610 and refrigerant 608 at a high level is shown. Figure 11 In this configuration, the first storage component 607 stores most of the refrigerant 608 and lubricating oil 610, while the second storage component 609 stores only a small portion of the refrigerant 608 and lubricating oil 610. At this time, the small amount of refrigerant 608 in the lower layer of the second storage component 609 does not prevent the small amount of lubricating oil 610 in the upper layer from being transported to the compressor 602 through the oil return hole 612; however, the lubricating oil 610 in the second storage component 609 still faces the problem of insufficient oil quantity.

[0133] like Figure 12 As shown, Figure 12 This is a schematic diagram illustrating the effect of a first storage component discharging lubricating oil according to an embodiment of this application. Figure 11 Based on the heat pump system shown, execute Figure 8 In the illustrated embodiment, steps S301-S305 allow the first storage component 607 to discharge lubricating oil 610 into the circulation loop, achieving... Figure 12 The storage effect of the second storage component 609 is shown. Figure 12In the first storage component 607, most of the refrigerant 608 is stored, while the second storage component 609 stores a small amount of refrigerant 608 and most of the lubricating oil 610. The small amount of refrigerant 608 in the lower layer does not prevent most of the lubricating oil 610 in the upper layer from being delivered to the compressor 602 through the oil return hole 612. At this time, the amount of lubricating oil 610 in the second storage component 609 is sufficient to ensure that the compressor 602 receives a continuous supply of lubricating oil 610, thus ensuring the normal operation of the heat pump system.

[0134] In this embodiment, by controlling the opening degree of the expansion valve and the opening and closing of the solenoid valve, the pressure difference between the first storage component and the target section is adjusted, thereby effectively discharging lubricating oil from the first storage component into the circulation loop, ultimately ensuring a sufficient supply of lubricating oil to the compressor. This adjustment not only prevents wear and failure of the compressor due to insufficient oil, but also optimizes the overall operation of the heat pump system. Especially under extreme environmental conditions, when the density of the refrigerant and lubricating oil reverses, this solution can quickly adjust to maintain the normal operation of the heat pump system. In addition, this solution improves the adaptability of the heat pump system to various environmental conditions, extends the service life of the system, and reduces maintenance costs.

[0135] Based on the above Figure 1 The structural diagram is shown below, in conjunction with... Figure 13 This application provides a detailed description of the heat pump system provided in its embodiments. Please refer to [link / reference]. Figure 13 , Figure 13 This is a schematic diagram of a heat pump system provided in an embodiment of this application. It should be noted that... Figure 13 The heat pump system in the present application is used to perform the functions described herein. Figure 2 - Figure 12 The methods shown in the embodiments are illustrated for ease of explanation, showing only the parts relevant to the embodiments of this application. For specific technical details not disclosed, please refer to this application. Figure 2 - Figure 12 The embodiment shown. Specifically, the heat pump system may include a memory, a processor, a circulation loop consisting of a first heat exchanger, a compressor, a one-way valve, a second heat exchanger, and an expansion valve connected end to end, a solenoid valve connected to a target segment in the circulation loop, and a first storage component connected to the solenoid valve. The two ends of the target segment are a one-way valve and an expansion valve, respectively, and the circulation loop is filled with refrigerant.

[0136] The processor is the control center of the heat pump system. It connects various parts of the heat pump system through various interfaces and lines. By running or calling computer program code stored in memory, and calling data stored in memory, it executes various functions of the heat pump system and processes data, thereby monitoring the heat pump system as a whole.

[0137] The memory is used to store software programs and modules. The processor executes various functional applications and controls the heat pump system by running the computer program code and modules stored in the memory. The memory can mainly include a program storage area and a data storage area. The program storage area can store the operating system, computer program code required for at least one function, etc.; the data storage area can store data created based on the use of the heat pump system, etc.

[0138] Furthermore, the memory may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state memory device. Accordingly, the memory may also include a memory controller to provide the processor with access to the memory.

[0139] In this embodiment, the processor in the heat pump system loads the instructions corresponding to one or more computer program codes into the memory according to the following steps, and then the processor runs the computer program code stored in the memory to realize various functions, as follows:

[0140] Start the compressor to pump refrigerant into the target section;

[0141] The current opening of the expansion valve is adjusted to increase the pressure in the target section, creating a negative pressure difference between the first storage component and the target section.

[0142] Open the solenoid valve to allow the first storage component to draw refrigerant from the target section based on the negative pressure difference;

[0143] When the negative pressure difference meets the preset first condition, the solenoid valve is closed.

[0144] Optionally, when the processor adjusts the current opening of the expansion valve to increase the pressure of the target segment and form a negative pressure difference between the first storage component and the target segment, it specifically performs the following: if the current opening of the expansion valve is zero, then maintain the current opening of the expansion valve to increase the pressure of the target segment and form a negative pressure difference between the first storage component and the target segment; if the current opening of the expansion valve is not adjusted to zero, then decrease the current opening of the expansion valve to increase the pressure of the target segment and form a negative pressure difference between the first storage component and the target segment.

[0145] Optionally, when the processor adjusts the current opening of the expansion valve to increase the pressure of the target segment and form a negative pressure difference between the first storage component and the target segment, it specifically performs the following: when the compressor is shut down, adjust the current opening of the expansion valve to increase the pressure of the target segment and form a negative pressure difference between the first storage component and the target segment.

[0146] Optionally, after the processor starts the compressor to pump refrigerant into the target section, it may also perform the following: adjust the current opening of the expansion valve to reduce the pressure in the target section and create a positive pressure difference between the first storage component and the target section; open the solenoid valve to allow the first storage component to discharge refrigerant into the target section based on the positive pressure difference; and close the solenoid valve when the positive pressure difference meets a preset second condition.

[0147] Optionally, after the processor starts the compressor to pump refrigerant into the target section, it may also perform the following: when lubricating oil is present in the first storage component, open the solenoid valve to equalize the pressure between the first storage component and the target section; adjust the current opening of the expansion valve to increase the pressure between the first storage component and the target section; after a preset time has elapsed, increase the current opening of the expansion valve to reduce the pressure in the target section, creating a positive pressure difference between the first storage component and the target section, and the first storage component discharges lubricating oil into the target section based on the positive pressure difference; and close the solenoid valve when the first storage component has completely discharged the lubricating oil.

[0148] Among some possible implementations, Figure 13 The heat pump system shown also includes a second storage component in the circulation loop. The first heat exchanger and the compressor are connected through the second storage component, which is provided with an oil return hole for delivering lubricating oil from the second storage component to the compressor.

[0149] Specifically, the oil return hole is located in the connecting pipeline between the compressor and the second storage component, and is located near the bottom of the second storage component. Figure 9 - Figure 12 The connection method of the second storage component 609 in the circulation loop and the setting position of the oil return hole 612 in the second storage component 609 are provided by way of example. It should be noted that the second storage component 609 is usually a low-pressure tank. Using the second storage component 609, the refrigerant and lubricating oil 610 in the circulation loop can be stored and regulated; using the oil return hole 612, the compressor 602 can be returned oil, ensuring the normal operation of the compressor 602.

[0150] Among some possible implementations, Figure 13 The solenoid valve in the heat pump system shown is connected to the connection section between the second heat exchanger and the expansion valve.

[0151] Specifically, Figure 2 , Figure 5 - Figure 6 , Figure 9 - Figure 12An exemplary connection between the solenoid valve 606 and the circulation loop is provided, wherein one end of the solenoid valve 606 is connected to the connection section between the second heat exchanger 604 and the expansion valve 603, and the other end is connected to the refrigerant inlet / outlet of the first storage component 607. With this connection, the temperature of the refrigerant entering the first storage component 607 is reduced because it has already been cooled by the second heat exchanger 604. This reduces the requirements for the structural rigidity and high-temperature resistance of the first storage component 607, thereby lowering its cost.

[0152] Among some possible implementations, Figure 13 The heat pump system shown also includes a capillary tube, one end of which is connected to the connection section between the compressor and the one-way valve, and the other end is connected to the connection section between the expansion valve and the first heat exchanger.

[0153] Specifically, Figure 5 - Figure 6 , Figure 9 - Figure 12 The connection between the capillary tube 611 and the circulation loop is provided as an example. The refrigerant flowing out of the compressor 602 enters the capillary tube 611, then flows out through the capillary tube 611 to the connection section between the expansion valve 603 and the first heat exchanger 601, and finally enters the first heat exchanger 601, which can play a certain role in regulating the flow and temperature of the first heat exchanger 601.

[0154] In this embodiment, a solenoid valve and a first storage component are added to the heat pump system. The solenoid valve is connected to the target section in the heat pump system's circulation loop, and the first storage component is connected to the solenoid valve. When the compressor is started, the current opening of the expansion valve is adjusted to increase the pressure in the target section, creating a negative pressure difference between the first storage component and the target section. Then, the solenoid valve is opened, allowing the first storage component to draw refrigerant from the target section. Finally, the solenoid valve is closed, allowing the first storage component to store a portion of the refrigerant. The solenoid valve isolates the first storage component from the circulation loop, reducing the amount of refrigerant stored in the circulation loop and effectively reducing the risk of heat pump system explosion.

[0155] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the above-described related method steps to implement a control method for a heat pump system provided in the above embodiment.

[0156] The storage medium may include: read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0157] Since the instructions stored in the storage medium can execute the steps in any of the heat pump system control methods provided in the embodiments of this application, the beneficial effects that any of the heat pump system control methods provided in the embodiments of this application can achieve can be realized, as detailed in the preceding embodiments, and will not be repeated here.

[0158] The control method, heat pump system, and storage medium of the heat pump system provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The above embodiments are only for the purpose of helping to understand the methods and core ideas of this application; at the same time, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A control method for a heat pump system, characterized in that, The heat pump system includes a circulation loop consisting of a first heat exchanger, a compressor, a one-way valve, a second heat exchanger, and an expansion valve connected end-to-end; a solenoid valve connected to a target section in the circulation loop; and a first storage component connected to the solenoid valve. The two ends of the target section are the one-way valve and the expansion valve, respectively. The circulation loop is filled with refrigerant. The method includes: Start the compressor to pump the refrigerant into the target section; The current opening of the expansion valve is adjusted to increase the pressure of the target segment, thereby creating a negative pressure difference between the first storage component and the target segment. Open the solenoid valve to allow the first storage component to draw refrigerant from the target section based on the negative pressure difference; When the negative pressure difference meets the preset first condition, the solenoid valve is closed.

2. The control method for a heat pump system according to claim 1, characterized in that, Adjusting the current opening of the expansion valve to increase the pressure in the target segment and create a negative pressure difference between the first storage component and the target segment includes: If the current opening of the expansion valve is zero, the current opening of the expansion valve is maintained to increase the pressure of the target segment, thereby creating a negative pressure difference between the first storage component and the target segment. If the current opening of the expansion valve is not zero, the current opening of the expansion valve is reduced to increase the pressure of the target segment, thereby creating a negative pressure difference between the first storage component and the target segment.

3. The control method for a heat pump system according to claim 1, characterized in that, Adjusting the current opening of the expansion valve to increase the pressure in the target segment and create a negative pressure difference between the first storage component and the target segment includes: When the compressor is shut down, the current opening of the expansion valve is adjusted to increase the pressure of the target segment, thereby creating a negative pressure difference between the first storage component and the target segment.

4. The control method for a heat pump system according to claim 1, characterized in that, After starting the compressor to pump the refrigerant into the target section, the process further includes: The current opening of the expansion valve is adjusted to reduce the pressure in the target segment, thereby creating a positive pressure difference between the first storage component and the target segment. Open the solenoid valve to allow the first storage component to discharge the refrigerant into the target section based on the positive pressure difference; When the positive pressure difference meets the preset second condition, the solenoid valve is closed.

5. The control method for a heat pump system according to claim 1, characterized in that, After starting the compressor to pump the refrigerant into the target section, the process further includes: When lubricating oil is present in the first storage component, the solenoid valve is opened to equalize the pressure between the first storage component and the target segment. The current opening of the expansion valve is adjusted to increase the pressure of the first storage component and the target segment; After a preset time has elapsed, the current opening of the expansion valve is increased to reduce the pressure of the target segment, thereby creating a positive pressure difference between the first storage component and the target segment. The first storage component then discharges the lubricating oil into the target segment based on this positive pressure difference. The solenoid valve is closed when the first storage component has completely discharged the lubricating oil.

6. A heat pump system, characterized in that, The heat pump system includes a memory, a processor, a circulation loop consisting of a first heat exchanger, a compressor, a one-way valve, a second heat exchanger, and an expansion valve connected end to end, a solenoid valve connected to a target section in the circulation loop, and a first storage component connected to the solenoid valve. The two ends of the target section are the one-way valve and the expansion valve, respectively. The circulation loop is filled with refrigerant. The memory is used to store executable program code; The processor is configured to call and run the executable program code from the memory, causing the heat pump system to perform the method as described in any one of claims 1 to 5.

7. The heat pump system according to claim 6, characterized in that, The heat pump system further includes a second storage component in the circulation loop. The first heat exchanger and the compressor are connected through the second storage component. The second storage component is provided with an oil return hole, which is used to deliver the lubricating oil in the second storage component to the compressor.

8. The heat pump system according to claim 6, characterized in that, The solenoid valve is connected to the connection section between the second heat exchanger and the expansion valve.

9. The heat pump system according to claim 6, characterized in that, The heat pump system also includes a capillary tube, one end of which is connected to the connection section between the compressor and the one-way valve, and the other end is connected to the connection section between the expansion valve and the first heat exchanger.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program code that, when executed, implements the method as described in any one of claims 1 to 5.

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