Control method and device for heat exchange system and heat exchange system

Abstract

The invention relates to the technical field of heat exchange systems, and discloses a control method and device for a heat exchange system and the heat exchange system. The heat exchange system comprises a heat exchange loop and a refrigerant adjusting branch, the heat exchange loop comprises a compressor, a condenser, a throttling device and an evaporator which are sequentially connected, and the first end of the refrigerant adjusting branch is connected with the part, between the condenser and the throttling device, of the heat exchange loop. The second end of the refrigerant adjusting branch is connected with the heat exchange loop between the throttling device and the evaporator; the control method comprises the steps that operation parameters of the heat exchange system are obtained; and the refrigerant storage amount of the refrigerant adjusting branch is adjusted according to the operation parameters of the heat exchange system. According to the embodiment of the invention, the operation parameters of the heat exchange system can be obtained, and the refrigerant storage amount of the refrigerant adjusting branch is adjusted according to the operation parameters of heat exchange, so that the rationality of the refrigerant amount, participating in heat exchange circulation, of the heat exchange system under different working conditions is improved, and the performance of the heat exchange system is improved.

Description

Technical Field

[0001] The present application relates to the technical field of heat exchange systems, for example, to a control method and device for a heat exchange system, and a heat exchange system. Background Art

[0002] The refrigerant in the air conditioning system circulates in the system to achieve cooling or heating operation mode. When the air conditioner is running in cooling mode with different loads or heating mode with different loads, the optimal refrigerant circulation volume required by the heat exchange system is different, but for the heat exchange system, the refrigerant filling volume is fixed. When the outside temperature of the cooling system is high or the outside temperature of the heating system is low, the rated refrigerant volume may cause the air conditioning system to overload, resulting in poor cooling or heating effects; and when the outside temperature of the cooling system is low or the outside temperature of the heating system is high, the air conditioning system is running at low load, and the amount of refrigerant may be in a surplus situation. This part of the refrigerant does not play a role in heat exchange during system operation, resulting in low energy efficiency of the temperature control equipment unit and failure to bring into play the optimal performance of the heat exchange system.

[0003] In the related art, the refrigerant in the heat exchange system is generally regulated by adjusting the opening of the throttle to reduce the pressure, cool down or increase the pressure and heat the refrigerant, so that the refrigerant state meets the needs of the indoor heat exchanger and puts the heat exchange system in a relatively good state.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art:

[0005] Since the throttle opening adjustment capability is limited and the adjustment range is small, when the refrigerant required by the heat exchange system varies greatly, the throttle cannot meet the refrigerant adjustment requirements and the performance of the heat exchange system is poor.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0007] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0008] The embodiments of the present disclosure provide a control method and device for a heat exchange system, and a heat exchange system, so as to adjust the amount of refrigerant participating in the heat exchange cycle in the heat exchange system and improve the performance of the heat exchange system.

[0009] According to an embodiment of the first aspect of the present application, a control method for a heat exchange system is provided, wherein the heat exchange system includes a heat exchange circuit and a refrigerant regulating branch, the heat exchange circuit includes a compressor, a condenser, a throttling device and an evaporator connected in sequence, the first end of the refrigerant regulating branch is connected to the heat exchange circuit between the condenser and the throttling device, and the second end of the refrigerant regulating branch is connected to the heat exchange circuit between the throttling device and the evaporator; the control method includes: obtaining operating parameters of the heat exchange system; and adjusting the refrigerant storage capacity of the refrigerant regulating branch according to the operating parameters of the heat exchange system.

[0010] In some optional embodiments, the operating parameters of the heat exchange system include the operating load of the heat exchange system; according to the operating parameters of the heat exchange system, the refrigerant reserves of the refrigerant regulating branch are adjusted, including: when the operating load of the heat exchange system is high load operation, reducing the refrigerant reserves of the refrigerant regulating branch; when the operating load of the heat exchange system is low load operation, increasing the refrigerant reserves of the refrigerant regulating branch.

[0011] In some optional embodiments, the refrigerant regulating branch includes a solenoid valve, a liquid storage device and a self-excited expansion valve connected in sequence, the solenoid valve is arranged at the first end of the refrigerant regulating branch, the solenoid valve is connected to the first port of the liquid storage device, the self-excited expansion valve is arranged at the second end of the refrigerant regulating branch, the self-excited expansion valve is connected to the second port of the liquid storage device, and the opening of the self-excited expansion valve is related to the pressure difference at both ends of the self-excited expansion valve; the operating parameters of the heat exchange system include the first refrigerant pressure of the refrigerant between the evaporator and the throttling device and the second refrigerant pressure in the liquid storage device; according to the operating parameters of the heat exchange system, the refrigerant reserve of the refrigerant regulating branch is adjusted, including: obtaining the target opening of the self-excited expansion valve; determining the target pressure difference at both ends of the self-excited expansion valve corresponding to the target opening of the self-excited expansion valve; wherein the target pressure difference is the difference between the target refrigerant pressure of the liquid storage device and the first refrigerant pressure; determining the target refrigerant pressure according to the first refrigerant pressure and the target pressure difference; and controlling the opening of the solenoid valve according to the target refrigerant pressure and the second refrigerant pressure.

[0012] In some optional embodiments, determining the target refrigerant pressure according to the first refrigerant pressure and the target pressure difference includes: when the first refrigerant pressure is greater than or equal to the preset pressure, determining the target opening of the self-excited expansion valve to be the first opening; determining the target pressure difference corresponding to the first opening to be the first pressure difference; determining the target refrigerant pressure to be the first target refrigerant pressure according to the first refrigerant pressure and the first pressure difference; and / or,

[0013] When the first refrigerant pressure is less than the preset pressure, determining the target opening of the self-excited expansion valve to be a second opening; determining the target pressure difference corresponding to the second opening to be a second pressure difference; determining the target refrigerant pressure to be a second target refrigerant pressure according to the first refrigerant pressure and the second pressure difference;

[0014] The first opening degree is smaller than the second opening degree, and the first target refrigerant pressure is smaller than the second target refrigerant pressure.

[0015] In some optional embodiments, controlling the opening of the solenoid valve according to the target refrigerant pressure and the second refrigerant pressure includes: when the target refrigerant pressure is the first target refrigerant pressure and the second refrigerant pressure is greater than the first target refrigerant pressure, controlling the solenoid valve to open to a third opening;

[0016] When the target refrigerant pressure is the first target refrigerant pressure and the second refrigerant pressure is equal to the first target refrigerant pressure, controlling the solenoid valve to open to a fourth opening degree;

[0017] When the target refrigerant pressure is the first target refrigerant pressure and the second refrigerant pressure is less than the first target refrigerant pressure, the solenoid valve is controlled to open to a fifth opening degree;

[0018] The third opening is greater than the fourth opening, and the fourth opening is greater than the fifth opening.

[0019] In some optional embodiments, controlling the opening of the solenoid valve according to the target refrigerant pressure and the second refrigerant pressure further includes: when the target refrigerant pressure is the second target refrigerant pressure, controlling the solenoid valve to open;

[0020] When the second refrigerant pressure is greater than the second target refrigerant pressure, and the pressure difference between the second refrigerant pressure and the second target refrigerant pressure is greater than the preset pressure difference, the solenoid valve is controlled to be closed.

[0021] In some optional embodiments, when the operation mode of the heat exchange system is a cooling operation mode, the opening pressure difference of the self-actuated expansion valve is determined to be a third pressure difference;

[0022] When the operation mode of the heat exchange system is the heating operation mode, the opening pressure difference of the self-excited expansion valve is determined to be a fourth pressure difference; wherein the third pressure difference is greater than the fourth pressure difference.

[0023] According to an embodiment of the second aspect of the present application, a control device for a heat exchange system is provided, comprising a processor and a memory storing program instructions, wherein the processor is configured to execute a control method for a heat exchange system as described in any of the foregoing items when running the program instructions.

[0024] According to an embodiment of the third aspect of the present application, a heat exchange system is provided, comprising: a heat exchange circuit, comprising a compressor, a condenser, a throttling device and an evaporator connected in sequence; a refrigerant regulating branch, a first end of the refrigerant regulating branch being connected to the heat exchange circuit between the condenser and the throttling device, and a second end of the refrigerant regulating branch being connected to the heat exchange circuit between the throttling device and the evaporator; and a control device for the heat exchange system as described above.

[0025] In some optional embodiments, the refrigerant regulating branch includes: a liquid storage device; a solenoid valve, disposed at a first end of the refrigerant regulating branch, the solenoid valve being connected to a first port of the liquid storage device; a self-excited expansion valve, disposed at a second end of the refrigerant regulating branch, the self-excited expansion valve being connected to a second port of the liquid storage device, and the opening of the self-excited expansion valve is related to the pressure difference across the two ends of the self-excited expansion valve.

[0026] The control method and device for a heat exchange system and the heat exchange system provided in the embodiments of the present disclosure can achieve the following technical effects:

[0027] The heat exchange system includes a heat exchange circuit and a refrigerant regulating branch, wherein the first end of the refrigerant regulating branch is connected to the refrigerant circuit between the condenser and the throttling device, and the second end of the refrigerant regulating branch is connected to the heat exchange circuit between the throttling device and the evaporator. In this way, the refrigerant in the heat exchange system can enter the refrigerant regulating branch through the first end of the refrigerant regulating branch or the second end of the refrigerant regulating branch, so as to store the refrigerant in the refrigerant regulating branch and reduce the amount of refrigerant participating in the heat exchange cycle. Similarly, the refrigerant in the refrigerant regulating branch can flow into the heat exchange system through the second end of the refrigerant regulating branch or the first end of the refrigerant regulating branch to increase the amount of refrigerant participating in the heat exchange cycle. The disclosed embodiment can obtain the operating parameters of the heat exchange system, and adjust the refrigerant storage of the refrigerant regulating branch according to the operating parameters of the heat exchange, so as to improve the rationality of the amount of refrigerant participating in the heat exchange cycle of the heat exchange system under different working conditions, and improve the performance of the heat exchange system.

[0028] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0030] Figure 1 is a flow chart of a control method for a heat exchange system provided by an embodiment of the present disclosure;

[0031] Figure 2 is a flow chart of another control method for a heat exchange system provided by an embodiment of the present disclosure;

[0032] Figure 3 is a flow chart of another control method for a heat exchange system provided by an embodiment of the present disclosure;

[0033] Figure 4 is a flow chart of another control method for a heat exchange system provided by an embodiment of the present disclosure;

[0034] Figure 5 is a structural schematic diagram of a heat exchange system provided by an embodiment of the present disclosure;

[0035] Figure 6 is a structural schematic diagram of another heat exchange system provided by an embodiment of the present disclosure;

[0036] Figure 7 It is a structural schematic diagram of a control device for a heat exchange system provided in an embodiment of the present disclosure.

[0037] Reference numerals:

[0038] 100. Processor; 101. Memory; 102. Communication interface; 103. Bus; 200. Compressor; 300. Condenser; 400. Throttling device; 500. Evaporator; 600. Refrigerant regulating branch; 610. Solenoid valve; 620. Liquid storage device; 630. Self-excited expansion valve. DETAILED DESCRIPTION

[0039] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0040] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0041] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0042] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0043] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0044] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0045] The present disclosure provides a heat exchange system, such as Figure 5 and Figure 6 As shown, the heat exchange system includes a heat exchange circuit and a refrigerant regulating branch 600. The heat exchange circuit includes a compressor 200, a condenser 300, a throttling device 400 and an evaporator 500 connected in sequence. The first end of the refrigerant regulating branch 600 is connected to the heat exchange circuit between the condenser 300 and the throttling device 400, and the second end of the refrigerant regulating branch 600 is connected to the heat exchange circuit between the throttling device 400 and the evaporator 500.

[0046] In this embodiment, the heat exchange system includes a heat exchange circuit and a refrigerant regulating branch 600, wherein the first end of the refrigerant regulating branch 600 is connected to the refrigerant circuit between the condenser 300 and the throttling device 400, and the second end of the refrigerant regulating branch 600 is connected to the heat exchange circuit between the throttling device 400 and the evaporator 500. In this way, the refrigerant in the heat exchange system can enter the refrigerant regulating branch 600 through the first end of the refrigerant regulating branch 600 or the second end of the refrigerant regulating branch 600, so as to store the refrigerant in the refrigerant regulating branch 600 and reduce the amount of refrigerant participating in the heat exchange cycle. Similarly, the refrigerant in the refrigerant regulating branch 600 can flow into the heat exchange system through the second end of the refrigerant regulating branch 600 or the first end of the refrigerant regulating branch 600 to increase the amount of refrigerant participating in the heat exchange cycle. The disclosed embodiment can adjust the refrigerant storage capacity of the refrigerant regulating branch 600 to improve the rationality of the refrigerant amount participating in the heat exchange cycle of the heat exchange system under different working conditions and improve the performance of the heat exchange system.

[0047] Optionally, the condenser 300 is an outdoor heat exchanger, and the evaporator 500 is an indoor heat exchanger. Figure 6As shown, when the heat exchange system operates in the cooling mode, the refrigerant flows out of the compressor 200, flows through the condenser 300, the throttling device 400 and the evaporator 500 in sequence, and then flows back into the compressor 200 to complete a refrigeration cycle. At this time, the refrigerant condenses and releases heat in the condenser 300. The refrigerant evaporates and absorbs heat in the evaporator 500 to absorb the heat in the room, provide cooling to the room, and reduce the indoor temperature.

[0048] like Figure 5 As shown in the figure, when the heat exchange system operates in the heating mode, the refrigerant flows out of the compressor 200, passes through the evaporator 500, the throttling device 400 and the condenser 300 in sequence, and then flows back into the compressor 200 to complete a heating cycle. At this time, the refrigerant condenses and releases heat in the evaporator 500 to increase the heat in the room and increase the indoor temperature. The refrigerant evaporates and absorbs heat in the condenser 300, and becomes a gaseous refrigerant to be supplied to the compressor 200.

[0049] In some optional embodiments, such as Figure 5 and Figure 6 As shown, the refrigerant regulating branch 600 includes a solenoid valve 610, a liquid storage device 620 and a self-excited expansion valve 630 which are connected in sequence. The solenoid valve 610 is arranged at the first end of the refrigerant regulating branch 600, and the solenoid valve 610 is connected to the first port of the liquid storage device 620. The self-excited expansion valve 630 is arranged at the second end of the refrigerant regulating branch 600, and the self-excited expansion valve 630 is connected to the second port of the liquid storage device 620. The opening degree of the self-excited expansion valve 630 is related to the pressure difference at both ends of the self-excited expansion valve 630.

[0050] In this optional embodiment, the solenoid valve 610 is disposed at the first end of the refrigerant regulating branch 600, the solenoid valve 610 is connected to the first port of the liquid storage device 620, and the first end of the refrigerant regulating branch 600 is connected to the heat exchange circuit between the condenser 300 and the throttling device 400. In this way, the opening and closing of the solenoid valve 610 can control the connection and disconnection of the heat exchange circuit between the condenser 300 and the throttling device 400 and the liquid storage device 620. The refrigerant can flow into the liquid storage device 620 through the heat exchange circuit, or flow into the heat exchange circuit from the liquid storage device 620, or the refrigerant does not flow between the heat exchange circuit and the liquid storage device 620, so as to adjust the refrigerant storage in the liquid storage device 620 and the amount of refrigerant participating in the heat exchange cycle.

[0051] The self-excited expansion valve 630 is disposed at the second end of the refrigerant regulating branch 600, and the self-excited expansion valve 630 is connected to the second port of the liquid storage device 620, and the second end of the refrigerant regulating branch 600 is connected to the heat exchange circuit between the throttling device 400 and the evaporator 500. In this way, the refrigerant between the throttling device 400 and the evaporator 500 can flow into the liquid storage device 620 through the self-excited expansion valve 630 and the second end of the refrigerant regulating branch 600 to adjust the refrigerant storage in the liquid storage device 620. The opening of the self-excited expansion valve 630 is related to the pressure difference at both ends of the self-excited expansion valve 630. In this way, the opening and closing and the opening of the self-excited expansion valve 630 can be adjusted by adjusting the difference between the pressure of the refrigerant in the heat exchange circuit between the evaporator 500 and the throttling device 400 and the pressure of the refrigerant in the liquid storage device 620.

[0052] Further, when the pressure difference across the self-excited expansion valve 630 is greater than or equal to the opening pressure difference, the self-excited expansion valve 630 is opened. When the pressure difference across the self-excited expansion valve 630 is less than the opening pressure difference, the self-excited expansion valve 630 is closed.

[0053] When the self-excited expansion valve 630 is opened, the opening degree of the self-excited expansion valve 630 is proportional to the pressure difference across the self-excited expansion valve 630. Specifically, when the pressure difference across the self-excited expansion valve 630 is larger, the opening degree of the self-excited expansion valve 630 is larger. When the pressure difference across the self-excited expansion valve 630 is smaller, the opening degree of the self-excited expansion valve 630 is smaller.

[0054] Exemplarily, the self-excited expansion valve 630 includes a valve body, a valve seat, a valve core and a control component. The valve body is arranged at the second end of the refrigerant regulating branch 600. The first end of the valve body is connected to the heat exchange circuit between the throttling device 400 and the evaporator 500. The other end of the valve body is connected to the liquid storage device 620. The valve body is provided with a valve seat, a valve core and a control component. The valve seat is used to install the valve core and the control component. The valve core is used to control the opening of the valve seat. The control component is used to drive the valve core to move and cooperate with the valve core to control the opening of the valve seat. The valve body is sleeved with a valve seat. The valve core is arranged in the valve seat and cooperates with the control component to control the opening and closing of the self-excited expansion valve 630. The control component is installed between the valve seat and the valve core, and one end of the control component abuts the valve seat and the other end abuts the valve core.

[0055] When the pressure difference between the two ends of the self-excited expansion valve 630 is greater than or equal to the opening pressure difference, the valve core can control the flow rate of the self-excited expansion valve 630 under the action of the control component and the refrigerant pressure difference. In this way, the self-excited expansion valve 630 can be opened and closed by pressure difference control, and the self-excited expansion valve 630 can be unidirectionally conductive.

[0056] Optionally, the control member comprises an elastic component. For example, the control member comprises a spring.

[0057] Figure 1 1 is a flow chart of a control method for a heat exchange system provided by an embodiment of the present disclosure. The control method for a heat exchange system can be executed in a controller of the heat exchange system.

[0058] S011, the controller obtains operating parameters of the heat exchange system.

[0059] S012: According to the operating parameters of the heat exchange system, the controller adjusts the refrigerant storage capacity of the refrigerant regulating branch.

[0060] In this embodiment, the operating parameters of the heat exchange system can be obtained, and the refrigerant storage capacity of the refrigerant regulating branch can be adjusted according to the operating parameters of the heat exchange system to adjust the amount of refrigerant participating in the heat exchange cycle in the heat exchange circuit, so that the amount of refrigerant participating in the heat exchange cycle is different under different operating parameters of the heat exchange system, so as to improve the rationality of the amount of refrigerant participating in the heat exchange cycle of the heat exchange system under different working conditions and improve the performance of the heat exchange system.

[0061] In some optional embodiments, the operating parameters of the heat exchange system include the operating load of the heat exchange system. According to the operating parameters of the heat exchange system, adjusting the refrigerant storage capacity of the refrigerant regulating branch includes: when the operating load of the heat exchange system is high load operation, reducing the refrigerant storage capacity of the refrigerant regulating branch; when the operating load of the heat exchange system is low load operation, increasing the refrigerant storage capacity of the refrigerant regulating branch.

[0062] With this optional embodiment, when the heat exchange system is running at high load, the heat exchange amount of the heat exchange system increases, and the amount of refrigerant required by the heat exchange system to participate in the heat exchange cycle increases. At this time, the controller can reduce the refrigerant storage of the refrigerant regulating branch, so that the refrigerant returns to the heat exchange loop to increase the amount of refrigerant participating in the heat exchange cycle, thereby improving the performance of the heat exchange system.

[0063] When the heat exchange system is running at low load, the heat exchange capacity of the heat exchange system is reduced. The amount of refrigerant involved in the heat exchange cycle can be reduced, and a smaller amount of refrigerant can meet the heat exchange capacity required by the heat exchange system when the heat exchange system is running at low load. At this time, the refrigerant storage capacity of the refrigerant regulating branch can be increased, the amount of refrigerant involved in the heat exchange cycle in the heat exchange loop can be reduced, and the increase in energy consumption when more refrigerant participates in the heat exchange cycle can be reduced, so as to improve the heat exchange performance of the heat exchange system.

[0064] Further, the operating load of the heat exchange system may be determined as follows: the controller acquires the operating frequency of the compressor. When the operating frequency of the compressor is greater than or equal to the preset frequency, the controller determines that the operating load of the heat exchange system is high load operation. When the operating frequency of the compressor is less than the preset frequency, the controller determines that the operating load of the heat exchange system is low load operation.

[0065] When the compressor operates at a high frequency, that is, when the compressor operates at a high frequency, the heat exchange amount of the heat exchange system increases, and it can be determined that the operating load of the heat exchange system is high-load operation. When the compressor operates at a low frequency, that is, when the compressor operates at a low frequency, the heat exchange amount of the heat exchange system decreases, and it can be determined that the operating load of the heat exchange system is low-load operation.

[0066] Figure 2 1 is a flow chart of another control method for a heat exchange system provided by an embodiment of the present disclosure. The control method for a heat exchange system can be executed in a controller of the heat exchange system.

[0067] S021, the controller obtains operating parameters of the heat exchange system.

[0068] Exemplarily, the operating parameters of the heat exchange system also include a first refrigerant pressure of the refrigerant between the evaporator and the throttling device and a second refrigerant pressure in the liquid storage device.

[0069] In this embodiment, the operating parameters of the heat exchange system also include a first refrigerant pressure and a second refrigerant pressure, that is, the controller obtains the front and rear refrigerant pressures of the self-excited expansion valve. When the refrigerant flows along the compressor, evaporator, throttling device and condenser, the first refrigerant pressure is the front refrigerant pressure of the self-excited expansion valve, and the second refrigerant pressure is the rear refrigerant pressure of the self-excited expansion valve. When the refrigerant flows along the compressor, condenser, throttling device and evaporator, the first refrigerant pressure is the rear refrigerant pressure of the self-excited expansion valve, and the second refrigerant pressure is the front refrigerant pressure of the self-excited expansion valve.

[0070] S022, the controller obtains the target opening of the self-excited expansion valve.

[0071] Furthermore, the target opening of the self-excited expansion valve can be determined by:

[0072] When the operation mode of the heat exchange system is the heating operation mode, the controller obtains the first refrigerant pressure of the refrigerant between the evaporator and the throttling device. When the first refrigerant pressure is greater than or equal to the preset pressure, the controller determines the target opening of the self-excited expansion valve to be the first opening; when the first refrigerant pressure is less than the preset pressure, the controller determines the target opening of the self-excited expansion valve to be the second opening; wherein the first opening is less than the second opening.

[0073] In this embodiment, when the operation mode of the heat exchange system is the heating operation mode, the refrigerant flows in sequence between the compressor, the evaporator, the throttling device and the condenser. When the first refrigerant pressure is greater than or equal to the preset pressure, it means that the operating frequency of the compressor is greater than or equal to the preset frequency, the operating load of the heat exchange system is a high load, and the refrigerant storage in the liquid storage device needs to be reduced. When the first refrigerant pressure is less than the preset refrigerant pressure, it means that the operating frequency of the compressor is less than the preset frequency, the operating load of the heat exchange system is a low load, and the refrigerant storage in the liquid storage device needs to be increased.

[0074] Optionally, the operating parameters of the heat exchange system also include a third refrigerant pressure of the refrigerant between the condenser and the throttling device. When the operating mode of the heat exchange system is the cooling operating mode, the controller obtains the third refrigerant pressure, and when the third refrigerant pressure is greater than or equal to the first preset pressure, the controller determines the target opening of the self-excited expansion valve to be the third opening; when the third refrigerant pressure is less than the first preset pressure, the controller determines the target opening of the self-excited expansion valve to be the fourth opening; wherein the third opening is greater than the fourth opening.

[0075] S023, the controller determines a target pressure difference across the self-excited expansion valve corresponding to a target opening of the self-excited expansion valve.

[0076] The target pressure difference is the difference between the target refrigerant pressure of the liquid storage device and the first refrigerant pressure.

[0077] Exemplarily, when the target opening degree of the self-excited expansion valve is a first opening degree, the controller determines that the target pressure difference corresponding to the first opening degree is the first pressure difference.

[0078] When the target opening degree of the self-excited expansion valve is the second opening degree, the controller determines that the target pressure difference corresponding to the second opening degree is the second pressure difference.

[0079] Furthermore, the target opening of the self-excited expansion valve is proportional to the target pressure difference at both ends of the self-excited expansion valve corresponding to the target opening. When the target pressure difference at both ends of the self-excited expansion valve increases, the target opening of the self-excited expansion valve increases, and when the target pressure difference at both ends of the self-excited expansion valve decreases, the target opening of the self-excited expansion valve decreases.

[0080] S024: The controller determines a target refrigerant pressure according to the first refrigerant pressure and the target pressure difference.

[0081] Further, when the operation mode of the heat exchange system is the heating operation mode, the controller determines the target refrigerant pressure according to the first refrigerant pressure and the target pressure difference.

[0082] When the target pressure difference is the first pressure difference, the controller determines the target refrigerant pressure as the first target refrigerant pressure according to the first refrigerant pressure and the first pressure difference.

[0083] When the target pressure difference is the second pressure difference, the controller determines the target refrigerant pressure as the second target refrigerant pressure according to the first refrigerant pressure and the second pressure difference, wherein the first target refrigerant pressure is less than the second target refrigerant pressure.

[0084] S025, the controller controls the opening of the solenoid valve according to the target refrigerant pressure and the second refrigerant pressure.

[0085] In this embodiment, the target refrigerant pressure of the liquid storage device is the refrigerant pressure in the liquid storage device that causes the self-excited expansion valve to open to the target opening. The second refrigerant pressure is the current refrigerant pressure of the liquid storage device. The controller can adjust the pressure of the refrigerant in the liquid storage device by adjusting the opening of the solenoid valve, so that the second refrigerant pressure is the target refrigerant pressure, and the self-excited expansion valve is opened to the target opening.

[0086] Figure 3 1 is a flow chart of another control method for a heat exchange system provided by an embodiment of the present disclosure. The control method for a heat exchange system can be executed in a controller of the heat exchange system.

[0087] S031, the controller obtains operating parameters of the heat exchange system.

[0088] Exemplarily, the operating parameters of the heat exchange system also include a first refrigerant pressure of the refrigerant between the evaporator and the throttling device and a second refrigerant pressure in the liquid storage device.

[0089] S032, the controller obtains the target opening of the self-excited expansion valve.

[0090] When the first refrigerant pressure is greater than or equal to the preset pressure, the controller determines the target opening of the self-excited expansion valve to be the first opening; when the first refrigerant pressure is less than the preset pressure, the controller determines the target opening of the self-excited expansion valve to be the second opening; wherein the first opening is less than the second opening.

[0091] S033, the controller determines a target pressure difference across the self-excited expansion valve corresponding to a target opening of the self-excited expansion valve.

[0092] The target pressure difference is the difference between the target refrigerant pressure of the liquid storage device and the first refrigerant pressure.

[0093] Exemplarily, when the target opening degree of the self-excited expansion valve is a first opening degree, the controller determines that the target pressure difference corresponding to the first opening degree is the first pressure difference.

[0094] When the target opening degree of the self-excited expansion valve is the second opening degree, the controller determines that the target pressure difference corresponding to the second opening degree is the second pressure difference.

[0095] S034: The controller determines a target refrigerant pressure according to the first refrigerant pressure and the target pressure difference.

[0096] When the target pressure difference is the first pressure difference, the controller determines the target refrigerant pressure as the first target refrigerant pressure according to the first refrigerant pressure and the first pressure difference.

[0097] When the target pressure difference is the second pressure difference, the controller determines the target refrigerant pressure as the second target refrigerant pressure according to the first refrigerant pressure and the second pressure difference, wherein the first target refrigerant pressure is less than the second target refrigerant pressure.

[0098] S035 , when the target refrigerant pressure is the first target refrigerant pressure and the second refrigerant pressure is greater than the first target refrigerant pressure, the controller controls the solenoid valve to open to a third opening degree.

[0099] In this embodiment, when the target refrigerant pressure is the first target refrigerant pressure, it means that the target pressure difference is the first pressure difference, the opening of the self-excited expansion valve is the first opening, and the first refrigerant pressure is greater than or equal to the preset pressure. At this time, the heat exchange system is running at high load, and it is necessary to reduce the refrigerant storage in the liquid storage device to increase the amount of refrigerant participating in the heat exchange cycle. When the second refrigerant pressure is greater than the first target refrigerant pressure, it means that the refrigerant pressure in the liquid storage device is greater than the target refrigerant pressure. At this time, the controller controls the solenoid valve to open to the third opening, so that the refrigerant in the liquid storage device flows into the heat exchange circuit between the throttling device and the condenser through the first end of the refrigerant regulating branch, so as to increase the refrigerant participating in the heat exchange circuit and reduce the second refrigerant pressure in the liquid storage device.

[0100] S036: When the target refrigerant pressure is the first target refrigerant pressure and the second refrigerant pressure is equal to the first target refrigerant pressure, the controller controls the solenoid valve to open to a fourth opening degree.

[0101] In this embodiment, the second refrigerant pressure in the liquid storage device is continuously reduced to reduce the second refrigerant pressure to be equal to the first target refrigerant pressure. At this time, the self-excited expansion valve is at the first opening. The first opening is smaller than the second opening, the self-excited expansion valve is slightly opened, the self-excited expansion valve is equivalent to a throttling device, and the self-excited expansion valve can throttle the refrigerant flowing through. In addition, the controller controls the solenoid valve opening to a fourth opening, the fourth opening is smaller than the third opening, and the fourth opening corresponds to the first opening of the self-excited expansion valve. So that the pressure of the refrigerant flowing into the liquid storage device is equal to or corresponds to the pressure of the refrigerant flowing out of the liquid storage device, so that the opening of the self-excited expansion valve is maintained at the first opening. In this way, the refrigerant flowing into the liquid storage device from the second end of the refrigerant regulating branch can be converted into a gas-liquid two-phase refrigerant through the self-excited expansion valve and flow into the liquid storage device, and the liquid refrigerant in the liquid storage device can flow out of the liquid storage device through the solenoid valve and the first end of the refrigerant regulating branch to flow into the heat exchange circuit. This reduces the amount of liquid refrigerant stored in the liquid storage device and increases the amount of refrigerant participating in the heat exchange cycle.

[0102] S037: When the target refrigerant pressure is the first target refrigerant pressure and the second refrigerant pressure is less than the first target refrigerant pressure, the controller controls the solenoid valve to open to a fifth opening degree.

[0103] In this embodiment, when the second refrigerant pressure is less than the first target refrigerant pressure, the controller controls the solenoid valve to open to the fifth opening, and the fifth opening is less than the fourth opening, so as to reduce the refrigerant of the liquid storage device flowing out from the solenoid valve and the first end of the refrigerant regulating branch, thereby increasing the refrigerant pressure in the liquid storage device, making the second refrigerant equal to the first target refrigerant pressure, so as to maintain the self-excited expansion valve at the first opening.

[0104] Figure 4 1 is a flow chart of another control method for a heat exchange system provided by an embodiment of the present disclosure. The control method for a heat exchange system can be executed in a controller of the heat exchange system.

[0105] S041, the controller obtains operating parameters of the heat exchange system.

[0106] S042, the controller obtains the target opening of the self-excited expansion valve.

[0107] S043, the controller determines a target pressure difference across the self-excited expansion valve corresponding to a target opening of the self-excited expansion valve.

[0108] The target pressure difference is the difference between the target refrigerant pressure of the liquid storage device and the first refrigerant pressure.

[0109] S044: The controller determines a target refrigerant pressure according to the first refrigerant pressure and the target pressure difference.

[0110] S045, when the target refrigerant pressure is the second target refrigerant pressure, the controller controls the solenoid valve to open.

[0111] In this embodiment, when the target refrigerant pressure is the second target refrigerant pressure, it means that the target pressure difference is the second pressure difference, the opening of the self-excited expansion valve is the second opening, and the first refrigerant pressure is less than the preset pressure. At this time, the operating load of the heat exchange system is a low load, and it is necessary to increase the refrigerant storage capacity of the liquid storage device and reduce the amount of refrigerant participating in the heat exchange cycle. The opening of the self-excited expansion valve is the second opening, and the second opening is greater than the first opening. In this way, the high-pressure liquid refrigerant flowing out of the evaporator can flow into the liquid storage device through the second end of the refrigerant regulating branch and the self-excited expansion valve to increase the refrigerant in the liquid storage device.

[0112] Furthermore, the controller controls the electromagnetic valve to open, and the opening of the electromagnetic valve can be the maximum opening, so that the refrigerant pressure in the liquid storage device can be the same as the refrigerant pressure of the refrigerant in the heat exchange circuit between the throttling device and the condenser, so as to increase the pressure difference between the second refrigerant pressure and the second refrigerant pressure, so that the pressure difference is the second pressure difference, so that the opening of the self-excited expansion valve is the second opening. The second pressure difference is greater than the first pressure difference, and the second opening is greater than the first opening.

[0113] S046: When the second refrigerant pressure is greater than the second target refrigerant pressure and the pressure difference between the second refrigerant pressure and the second target refrigerant pressure is greater than a preset pressure difference, the controller controls the solenoid valve to close.

[0114] In this embodiment, the solenoid valve is opened, and the high-pressure liquid refrigerant flowing out of the evaporator continues to replenish the liquid refrigerant in the liquid storage device through the self-excited expansion valve and the second end of the refrigerant regulating branch. The gaseous refrigerant in the liquid storage device flows out of the liquid storage device through the first end of the refrigerant regulating branch. With the inflow of the high-pressure liquid refrigerant, the refrigerant pressure in the liquid storage device gradually increases. When the second refrigerant pressure is greater than the second target refrigerant pressure, and the pressure difference between the second refrigerant pressure and the second target refrigerant pressure is greater than the preset pressure difference, the controller controls the solenoid valve to close. After the solenoid valve is closed, when the difference between the pressure of the second refrigerant and the pressure of the first refrigerant is greater than the opening pressure difference of the self-excited expansion valve, the liquid refrigerant can continue to flow into the liquid storage device through the self-excited expansion valve and the second end of the refrigerant regulating branch. As the second refrigerant pressure in the liquid storage device increases, when the second refrigerant pressure increases to a difference with the first refrigerant pressure that is less than or equal to the opening pressure difference of the self-excited expansion valve, the self-excited expansion valve closes, and the liquid storage device can store liquid refrigerant.

[0115] Furthermore, when the pressure difference between the second refrigerant pressure and the second target refrigerant pressure is greater than the preset pressure difference, the controller controls the solenoid valve to close. This can also reduce the occurrence of liquid refrigerant flowing out of the evaporator directly flowing into the condenser through the refrigerant regulating branch, thereby improving the heat exchange efficiency of the heat exchange system.

[0116] In some optional embodiments, when the operation mode of the heat exchange system is a cooling operation mode, the controller determines that the opening pressure difference of the self-excited expansion valve is a third pressure difference. When the operation mode of the heat exchange system is a heating operation mode, the controller determines that the opening pressure difference of the self-excited expansion valve is a fourth pressure difference. The third pressure difference is greater than the fourth pressure difference.

[0117] When the heat exchange system is in cooling operation or heating operation, the flow direction of the refrigerant is different, and the direction in which the refrigerant flows into or flows out of the liquid storage device is also different. In this embodiment, the controller determines that the opening pressure difference of the self-actuated expansion valve is different to adapt to the refrigerant regulation requirements of the heat exchange system in different operating modes.

[0118] Optionally, when the operation mode of the heat exchange system is a cooling operation mode, the controller determines the opening degree of the solenoid valve according to the third refrigerant pressure.

[0119] When the operation mode of the heat exchange system is the cooling operation mode, when the third refrigerant pressure is less than the cooling preset pressure, the controller controls the solenoid valve to open to the seventh opening degree.

[0120] In this embodiment, when the operation mode of the heat exchange system is the refrigeration operation mode, the refrigerant flows through the compressor, condenser, throttling device and evaporator in sequence. When the third refrigerant pressure is less than the refrigeration preset pressure, the heat exchange system is operating at a low load, and the refrigerant storage in the liquid storage device needs to be increased. At this time, the controller controls the solenoid valve to open to the seventh opening, and the high-pressure refrigerant flowing out of the condenser can flow into the liquid storage device through the first end of the refrigerant regulating branch to increase the refrigerant storage of the liquid storage device. Optionally, the seventh opening is greater than 90% of the maximum opening of the solenoid valve. In addition, the opening pressure difference of the self-excited expansion valve during refrigeration operation is greater than the opening pressure difference of the heat exchange system during heating operation, so that the opening pressure difference of the self-excited expansion valve is greater than the difference between the first refrigerant pressure and the third refrigerant pressure when the heat exchange system is operating in heating (when the solenoid valve is the seventh opening, the refrigerant pressure in the liquid storage device is equal to the third refrigerant pressure). At this time, the self-excited expansion valve is closed.

[0121] When the operation mode of the heat exchange system is the cooling operation mode, when the third refrigerant pressure is greater than or equal to the preset cooling pressure, the controller controls the solenoid valve to open to the sixth opening degree.

[0122] In this embodiment, when the third refrigerant pressure is greater than or equal to the preset refrigeration pressure, the heat exchange system is operating at high load. At this time, it is necessary to reduce the refrigerant storage capacity in the liquid storage device. The controller controls the solenoid valve to open to the sixth opening. At this time, the solenoid valve is equivalent to a throttling device. The solenoid valve can throttle the refrigerant flowing through the first end of the refrigerant regulating branch, so that the refrigerant flowing into the liquid storage device is a gas-liquid two-phase refrigerant to increase the second refrigerant pressure in the liquid storage device. When the second refrigerant pressure increases to a value greater than the pressure difference of the first refrigerant pressure than the pressure difference of the self-excited expansion valve, the self-excited expansion valve opens, and the liquid refrigerant in the liquid storage device can flow out of the liquid storage device through the self-excited expansion valve to reduce the refrigerant storage capacity of the liquid storage device.

[0123] Combination Figure 7 As shown, an embodiment of the present disclosure provides a control device for a heat exchange system, including a processor 100 and a memory 101. Optionally, the control device may also include a communication interface 102 and a bus 103. The processor 100, the communication interface 102, and the memory 101 may communicate with each other through the bus 103. The communication interface 102 may be used for information transmission. The processor 100 may call the logic instructions in the memory 101 to execute the control method for a heat exchange system of the above embodiment.

[0124] In addition, the logic instructions in the memory 101 described above may be implemented in the form of software functional units and when sold or used as independent products, may be stored in a computer-readable storage medium.

[0125] The memory 101 is a computer-readable storage medium that can be used to store software programs and computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 100 executes functional applications and data processing by running the program instructions / modules stored in the memory 101, that is, implements the control method for the heat exchange system in the above embodiment.

[0126] The memory 101 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory 101 may include a high-speed random access memory and may also include a non-volatile memory.

[0127] A heat exchange system provided in an embodiment of the present disclosure also includes a heat exchange system body and the above-mentioned control device for the heat exchange system. The control device for the heat exchange system is installed in the heat exchange system body. The installation relationship described here is not limited to placement inside the product, but also includes installation connections with other components of the product, including but not limited to physical connections, electrical connections, or signal transmission connections. It can be understood by those skilled in the art that the control device for the heat exchange system can be adapted to a feasible heat exchange system body, thereby realizing other feasible embodiments.

[0128] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to execute the above-mentioned control method for a heat exchange system.

[0129] The computer-readable storage medium mentioned above may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0130] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in the embodiment of the present disclosure. The aforementioned storage medium may be a non-transient storage medium, including: a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk, and other media that can store program codes, or a transient storage medium.

[0131] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible changes. Unless explicitly required, separate components and functions are optional, and the order of operation may vary. The parts and features of some embodiments may be included in or replace the parts and features of other embodiments. Moreover, the words used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and the claims, unless the context clearly indicates, the singular forms of "a", "an" and "the" are intended to include plural forms as well. Similarly, the term "and / or" as used in this application refers to any and all possible combinations of listings containing one or more associated ones. In addition, when used in the present application, the term "comprise" and its variants "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the presence of other identical elements in the process, method or device comprising the elements. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the various embodiments may refer to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can refer to the description of the method part.

[0132] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods for each specific application to implement the described functions, but such implementations should not be considered to exceed the scope of the embodiments of the present disclosure. The technicians may clearly understand that, for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above may refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0133] In the embodiments disclosed herein, the disclosed methods and products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units can be only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to implement this embodiment. In addition, each functional unit in the embodiment of the present disclosure may be integrated in a processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit.

[0134] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A control method for a heat exchange system, characterized in that: The heat exchange system includes a heat exchange circuit and a refrigerant regulating branch, the heat exchange circuit includes a compressor, a condenser, a throttling device and an evaporator connected in sequence, the first end of the refrigerant regulating branch is connected to the heat exchange circuit between the condenser and the throttling device, and the second end of the refrigerant regulating branch is connected to the heat exchange circuit between the throttling device and the evaporator; the control method includes: Obtaining operating parameters of the heat exchange system; According to the operating parameters of the heat exchange system, the refrigerant storage capacity of the refrigerant regulating branch is adjusted.

2. The control method according to claim 1, characterized in that: The operating parameters of the heat exchange system include the operating load of the heat exchange system; according to the operating parameters of the heat exchange system, the refrigerant storage of the refrigerant regulating branch is adjusted, including: When the heat exchange system is running at high load, reduce the refrigerant storage capacity of the refrigerant regulating branch; When the heat exchange system is operated at a low load, the refrigerant storage capacity of the refrigerant regulating branch is increased.

3. The control method according to claim 1, characterized in that: The refrigerant regulating branch includes a solenoid valve, a liquid storage device and a self-excited expansion valve connected in sequence, the solenoid valve is arranged at a first end of the refrigerant regulating branch, the solenoid valve is connected to a first port of the liquid storage device, the self-excited expansion valve is arranged at a second end of the refrigerant regulating branch, the self-excited expansion valve is connected to a second port of the liquid storage device, and the opening degree of the self-excited expansion valve is related to the pressure difference at both ends of the self-excited expansion valve; The operating parameters of the heat exchange system include the first refrigerant pressure of the refrigerant between the evaporator and the throttling device and the second refrigerant pressure in the liquid storage device; according to the operating parameters of the heat exchange system, adjusting the refrigerant storage of the refrigerant regulating branch includes: Obtaining a target opening of a self-actuated expansion valve; Determine a target pressure difference between two ends of the self-excited expansion valve corresponding to a target opening of the self-excited expansion valve; wherein the target pressure difference is a difference between a target refrigerant pressure of the liquid storage device and a first refrigerant pressure; determining a target refrigerant pressure according to the first refrigerant pressure and the target pressure difference; The opening of the solenoid valve is controlled according to the target refrigerant pressure and the second refrigerant pressure.

4. The control method according to claim 3, characterized in that: Determining a target refrigerant pressure according to the first refrigerant pressure and the target pressure difference includes: When the first refrigerant pressure is greater than or equal to the preset pressure, determining the target opening of the self-excited expansion valve as the first opening; determining the target pressure difference corresponding to the first opening as the first pressure difference; determining the target refrigerant pressure as the first target refrigerant pressure according to the first refrigerant pressure and the first pressure difference; and / or, When the first refrigerant pressure is less than the preset pressure, determining the target opening of the self-excited expansion valve to be a second opening; determining the target pressure difference corresponding to the second opening to be a second pressure difference; determining the target refrigerant pressure to be a second target refrigerant pressure according to the first refrigerant pressure and the second pressure difference; The first opening degree is smaller than the second opening degree, and the first target refrigerant pressure is smaller than the second target refrigerant pressure.

5. The heat exchange system according to claim 4, characterized in that: According to the target refrigerant pressure and the second refrigerant pressure, the opening of the solenoid valve is controlled, including: When the target refrigerant pressure is the first target refrigerant pressure and the second refrigerant pressure is greater than the first target refrigerant pressure, controlling the solenoid valve to open to a third opening degree; When the target refrigerant pressure is the first target refrigerant pressure and the second refrigerant pressure is equal to the first target refrigerant pressure, controlling the solenoid valve to open to a fourth opening degree; When the target refrigerant pressure is the first target refrigerant pressure and the second refrigerant pressure is less than the first target refrigerant pressure, the solenoid valve is controlled to open to a fifth opening degree; The third opening is greater than the fourth opening, and the fourth opening is greater than the fifth opening.

6. The control method according to claim 4, characterized in that: Controlling the opening of the solenoid valve according to the target refrigerant pressure and the second refrigerant pressure also includes: When the target refrigerant pressure is the second target refrigerant pressure, the solenoid valve is controlled to open; When the second refrigerant pressure is greater than the second target refrigerant pressure, and the pressure difference between the second refrigerant pressure and the second target refrigerant pressure is greater than the preset pressure difference, the solenoid valve is controlled to be closed.

7. The control method according to any one of claims 3 to 6, characterized in that: When the operation mode of the heat exchange system is a cooling operation mode, determining the opening pressure difference of the self-excited expansion valve to be a third pressure difference; When the operation mode of the heat exchange system is the heating operation mode, determining the opening pressure difference of the self-excited expansion valve to be a fourth pressure difference; The third pressure difference is greater than the fourth pressure difference.

8. A control device for a heat exchange system, comprising a processor and a memory storing program instructions, characterized in that: The processor is configured to execute the control method for a heat exchange system according to any one of claims 1 to 7 when running the program instructions.

9. A heat exchange system, characterized in that: include: A heat exchange circuit, comprising a compressor, a condenser, a throttling device and an evaporator connected in sequence; A refrigerant regulating branch, wherein a first end of the refrigerant regulating branch is connected to a heat exchange circuit between the condenser and the throttling device, and a second end of the refrigerant regulating branch is connected to a heat exchange circuit between the throttling device and the evaporator; The control device for a heat exchange system as claimed in claim 8.

10. The heat exchange system according to claim 9, characterized in that: The refrigerant conditioning branch includes: liquid storage device; A solenoid valve is disposed at a first end of the refrigerant regulating branch, and the solenoid valve is connected to a first port of the liquid storage device; The self-excited expansion valve is arranged at the second end of the refrigerant regulating branch. The self-excited expansion valve is connected to the second port of the liquid storage device. The opening of the self-excited expansion valve is related to the pressure difference at both ends of the self-excited expansion valve.

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