Refrigerant circulation control system, method and device and air conditioning equipment

Abstract

The invention provides a refrigerant circulation control system, method and device and air conditioning equipment, and relates to the technical field of air conditioners, a first circulation branch, a compressor and an oil separator form a first circulation loop, and a second circulation branch and a refrigerant circulation main path form a second circulation loop; when the first control valve is opened, and the electronic expansion valve and the second control valve are closed, a refrigerant in the refrigerant circulation control system circulates through the first circulation loop, and preheating of the compressor is achieved; when the first control valve, the electronic expansion valve and the second control valve are opened, refrigerants circulate through the first circulation loop and the second circulation loop so as to gradually drive the whole system refrigerants to circulate after preheating of the compressor is completed, the situation that a large amount of liquid refrigerants enter a compression cavity of the compressor in a short time is reduced, and the low-temperature starting liquid return risk of the compressor is reduced; when the first control valve is closed, and the electronic expansion valve and the second control valve are both opened, the refrigerant in the refrigerant circulation control system circulates through the second circulation loop, and energy conservation and emission reduction are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioners, and particularly to a refrigerant circulation control system, method, device and air conditioning equipment. Background Art

[0002] Currently, multi-connected systems are widely used in many fields because of their various advantages and the ability to meet the needs of different scenarios. However, since multi-connected systems are usually large and require a relatively large amount of refrigerant filling, that is, the refrigerant charge of multi-connected systems is large, this significantly increases the risk of refrigerant liquid return to the air-conditioning compressor, especially when used in cold regions, the liquid return situation is more serious.

[0003] To alleviate the problem of refrigerant liquid return to the air-conditioning compressor, the commonly used existing method is mainly to add an oil heating belt to the compressor. Before starting at low temperature, the refrigerant and oil at the bottom of the compressor are heated by the oil heating belt to alleviate the liquid return during compressor startup and reduce the risk of liquid return during the low-temperature startup process of the compressor.

[0004] However, the existing oil heating belt preheating scheme has too long a preheating time, and the normal operation of the oil heating belt must be ensured under low-temperature conditions, resulting in a large amount of energy waste and being unfavorable for energy conservation and emission reduction. Summary of the Invention

[0005] In view of this, the present application provides a refrigerant circulation control system, method, device and air conditioning equipment to solve the problem of resource waste caused by using an oil heating belt for preheating to alleviate the liquid return during the startup of an air-conditioning compressor in the prior art.

[0006] According to the first aspect of the embodiments of the present application, a refrigerant circulation control system is provided, including: a main refrigerant circulation path, a first circulation branch and a second circulation branch;

[0007] A first control valve is arranged on the first circulation branch; an electronic expansion valve is arranged on the second circulation branch; a compressor, an oil separator, a second control valve and a gas-liquid separator are arranged on the main refrigerant circulation path;

[0008] The inlet of the first circulation branch is connected between the outlet of the oil separator and the second control valve; the inlet of the second circulation branch is communicated with the outlet of the gas-liquid separator, and the outlets of the first circulation branch, the second circulation branch and the inlet of the compressor are communicated; the first circulation branch and the compressor and the oil separator form a first circulation loop, and the second circulation branch and the main refrigerant circulation path form a second circulation loop;

[0009] When the first control valve is opened and the electronic expansion valve and the second control valve are closed, the refrigerant in the refrigerant circulation control system circulates through the first circulation loop;

[0010] When the first control valve, the electronic expansion valve, and the second control valve are all open, the refrigerant in the refrigerant circulation control system circulates through the first circulation loop and the second circulation loop;

[0011] When the first control valve is closed, and the electronic expansion valve and the second control valve are both open, the refrigerant in the refrigerant circulation control system circulates through the second circulation loop.

[0012] In an alternative embodiment, a first check valve is further provided in the second circulation branch. The inlet of the first check valve is communicated with the outlet of the electronic expansion valve, and the outlet of the first check valve is communicated with the outlet of the first circulation branch and the inlet of the compressor.

[0013] In an alternative embodiment, the refrigerant circulation control system further includes a control device; the control device is electrically connected to the first control valve, the second control valve, and the electronic expansion valve respectively;

[0014] The control device is configured to control the refrigerant circulation control system to enter a target start mode according to the ambient temperature detection information, and determine the current exhaust superheat degree based on the discharge pressure and discharge temperature of the compressor, so as to control the start and operation state of the refrigerant circulation control system according to the current exhaust superheat degree and the opening degree of the electronic expansion valve.

[0015] In an alternative embodiment, a pressure sensor and an exhaust temperature thermosensitive package are further provided in the main refrigerant circulation path. The pressure sensor is used to detect the discharge pressure of the compressor, and the exhaust temperature thermosensitive package is used to detect the discharge temperature of the compressor. The control device is further configured to adjust the opening degree of the electronic expansion valve according to the current exhaust superheat degree.

[0016] In an alternative embodiment, the ambient temperature detection information includes the ambient temperature and the shutdown time corresponding to the ambient temperature;

[0017] An ambient temperature thermosensitive package is provided between the second control valve and the inlet of the gas-liquid separator in the main refrigerant circulation path; the ambient temperature thermosensitive package is used to detect the ambient temperature;

[0018] The control of the refrigerant circulation control system to enter the target start mode according to the ambient temperature detection information includes: when the ambient temperature is less than the preset temperature threshold corresponding to the target start mode, and the shutdown time reaches the preset shutdown duration threshold corresponding to the temperature threshold, determining that the ambient temperature detection information meets the preset mode trigger condition; when the ambient temperature detection information meets the preset mode trigger condition, controlling the refrigerant circulation control system to enter the first operation stage of the target start mode.

[0019] According to the second aspect of the embodiments of the present application, there is provided a refrigerant cycle control method, which is applied to the refrigerant cycle control system according to any one of the first aspects. The refrigerant cycle control method includes:

[0020] When the compressor starts, obtain the ambient temperature detection information;

[0021] When the ambient temperature detection information meets the preset mode trigger condition, control the refrigerant cycle control system to enter the first operation stage of the target start mode, and determine the current exhaust superheat degree according to the exhaust pressure and exhaust temperature of the compressor. The first operation stage is used to control the refrigerant in the refrigerant cycle control system to circulate through the first circulation loop;

[0022] When the current exhaust superheat degree meets the second stage trigger condition, control the refrigerant cycle control system to enter the second operation stage of the target start mode, and adjust the opening degree of the electronic expansion valve according to the current exhaust superheat degree. The second operation stage is used to control the refrigerant to circulate through the first circulation loop and the second circulation loop;

[0023] When the electronic expansion valve is fully open and the current exhaust superheat degree is greater than the preset first heat threshold, exit the target start mode to control the refrigerant cycle control system to enter the third operation stage of startup operation. The third operation stage of startup operation is used to control the refrigerant to circulate through the second circulation loop.

[0024] In an optional implementation manner, the ambient temperature detection information includes the ambient temperature and the shutdown time corresponding to the ambient temperature. When the ambient temperature detection information meets the preset mode trigger condition, controlling the refrigerant cycle control system to enter the first operation stage of the target start mode includes:

[0025] When the ambient temperature is less than the preset temperature threshold corresponding to the target start mode and the shutdown time reaches the preset shutdown duration threshold corresponding to the temperature threshold, it is determined that the ambient temperature detection information meets the preset mode trigger condition, and control the first control valve to open and the second control valve to close to control the refrigerant cycle control system to enter the first operation stage;

[0026] In the case of the first operation stage, the refrigerant cycle control method further includes: controlling the compressor to operate at a preset initial startup frequency.

[0027] In an optional implementation manner, after the refrigerant cycle control method determines the current exhaust superheat degree according to the exhaust pressure and exhaust temperature of the compressor, it further includes:

[0028] Compare the current exhaust superheat degree with a preset second heat threshold;

[0029] When the current exhaust superheat degree is not less than the second heat threshold, it is determined that the current exhaust superheat degree meets the second stage trigger condition.

[0030] In an optional embodiment, after the refrigerant cycle control method controls the refrigerant cycle control system to enter the second operation stage of the target start-up mode, it further includes:

[0031] When the electronic expansion valve is fully open and the current exhaust superheat degree is not greater than a preset first heat threshold, adjust the operating frequency of the compressor to a preset first operating frequency, and the first operating frequency is higher than the initial start-up frequency;

[0032] Control the compressor to operate at the first operating frequency until the refrigerant cycle control system exits the target start-up mode.

[0033] In an optional embodiment, after the refrigerant cycle control method controls the refrigerant cycle control system to enter the first operation stage of the target start-up mode, it further includes:

[0034] When the current exhaust superheat degree is less than a preset second heat threshold, detect the current operating frequency of the compressor;

[0035] If the current operating frequency reaches a preset second operating frequency, control the second control valve and the electronic expansion valve to open to control the refrigerant cycle control system to enter the second operation stage of the target start-up mode, and control the compressor to operate at the current operating frequency. The second operating frequency is higher than the first operating frequency.

[0036] In an optional embodiment, determining the current exhaust superheat degree based on the exhaust pressure and exhaust temperature of the compressor includes:

[0037] Detect the exhaust pressure of the compressor through a pressure sensor in the refrigerant cycle control system, and determine the saturation temperature corresponding to the exhaust pressure;

[0038] Detect the exhaust temperature of the compressor through a temperature sensing element for the exhaust temperature in the refrigerant cycle control system;

[0039] Perform calculations based on the exhaust temperature and the saturation temperature to obtain the current exhaust superheat degree.

[0040] According to the third aspect of the embodiments of the present application, a refrigerant cycle control device is provided. The control device is configured to implement the refrigerant cycle control method according to any one of the first aspect.

[0041] According to the fourth aspect of the embodiments of the present application, an air-conditioning device is provided. The air-conditioning device includes a refrigerant cycle control system according to any one of the first aspect.

[0042] The technical solutions provided by the embodiments of the present application may include the following beneficial effects: In the present application, the refrigerant circulation control system includes a main refrigerant circulation path, a first circulation branch, and a second circulation branch. A first circulation loop is formed by the first circulation branch, the compressor, and the oil separator, and a second circulation loop is formed by the second circulation branch and the main refrigerant circulation path. When the compressor starts, by obtaining the ambient temperature detection information, when the ambient temperature detection information meets the preset mode trigger condition, the refrigerant circulation control system is controlled to enter the first operation stage of the target start mode, so that the refrigerant in the refrigerant circulation control system circulates through the first circulation loop, and the current exhaust superheat is determined based on the exhaust pressure and exhaust temperature of the compressor. When the current exhaust superheat meets the trigger condition of the second stage, the refrigerant circulation control system is controlled to enter the second operation stage of the target start mode, so that the refrigerant in the refrigerant circulation control system circulates through the first circulation loop and the second circulation loop, and the opening of the electronic expansion valve is adjusted according to the current exhaust superheat. When the electronic expansion valve is fully open and the current exhaust superheat is greater than the preset first heat threshold, the target start mode is exited, and the refrigerant is controlled to circulate through the second circulation loop. Therefore, the refrigerant can circulate through the first circulation loop when the compressor starts to preheat the compressor. After the compressor is preheated, the refrigerant of the entire system is gradually driven to circulate, which can effectively reduce the large amount of liquid refrigerant entering the compressor compression cavity in a short time, reduce the risk of liquid return during low-temperature start-up of the compressor, and can replace the electric heating preheating scheme used in the existing related technologies to achieve energy conservation and emission reduction.

[0043] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present invention and, together with the specification, are used to explain the principles of the present invention.

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0046] One or more embodiments are illustrated by way of example in the accompanying drawings, and these illustrative descriptions do not limit the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the drawings in the drawings do not constitute a proportional limitation.

[0047] Figure 1It is a schematic structural diagram of a refrigerant cycle control system shown according to an exemplary embodiment;

[0048] Figure 2 It is a schematic diagram of refrigerant circulation through the first circulation loop shown according to an exemplary embodiment;

[0049] Figure 3 It is a schematic diagram of refrigerant circulation through the first circulation loop and the second circulation loop shown according to an exemplary embodiment;

[0050] Figure 4 It is a schematic diagram of refrigerant circulation through the second circulation loop shown according to an exemplary embodiment;

[0051] Figure 5 It is a schematic block diagram of a refrigerant cycle control system shown according to an exemplary embodiment;

[0052] Figure 6 It is a schematic flow diagram of a refrigerant cycle control method shown according to an exemplary embodiment;

[0053] Figure 7 It is a schematic block diagram of an air conditioning device shown according to an exemplary embodiment.

[0054] Reference numerals:

[0055] 100, refrigerant cycle control system; 110, main refrigerant circulation path; 111, compressor; 112, oil separator; 113, second control valve; 114, vapor-liquid separator; 115, first valve; 116, second valve; 117, first electronic expansion valve; 118, ambient temperature thermosensor; 120, first circulation branch; 121, first control valve; 122, second check valve; 130, second circulation branch; 140, control device; 131, electronic expansion valve; 132, first check valve; 41, pressure sensor; 42, exhaust temperature thermosensor; 43, suction temperature sensor; 44, first heat exchanger; 45, fan; 46, second heat exchanger; 47, centrifugal fan; 700, air conditioning device. Detailed embodiments

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0057] The following disclosure provides many different embodiments or examples for implementing different aspects of the present invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0058] For ease of description, spatially relative terms may be used in the text to describe the relative positional relationship or movement of one element or feature shown in the figures relative to another element or feature. These relative relationship terms such as "inside", "outside", "inner side", "outer side", "below", "beneath", "above", "over", "front", "rear", etc. This spatially relative relationship term is intended to include different orientations of the device in use or operation other than the orientation depicted in the figures. For example, if the device in the figure undergoes a position flip or attitude change or motion state change, then these directional indications will change accordingly. For example, an element described as "below other elements or features" or "beneath other elements or features" will subsequently be oriented as "above other elements or features" or "over other elements or features". Thus, the exemplary term "below" can include both above and below orientations. The device may be oriented otherwise (rotated 90 degrees or in other directions) and the spatially relative descriptors used in the text are interpreted accordingly.

[0059] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application schematically. Therefore, only the components related to the present application are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation may be arbitrarily changed, and the component layout type may also be more complex.

[0060] The embodiments of the present application will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application and not for limiting the protection scope of the present application.

[0061] At present, the refrigerant charge of the multi-connected air-conditioning system is relatively large, and the problem of liquid return during low-temperature startup is relatively serious. Specifically, when the air-conditioning unit starts up in a low-temperature environment, due to the low temperature, a large amount of refrigerant enters the compressor. That is, liquid refrigerant will enter the compression chamber of the compressor instantaneously during startup, increasing the load, and the compression chamber may be damaged due to the incompressibility of the liquid. Therefore, it is crucial to control the entry of liquid refrigerant into the compression chamber.

[0062] To solve the technical problem of resource waste caused by using an oil heating belt for preheating to relieve the liquid return during the startup of the air-conditioning compressor in the prior art, the present application provides a refrigerant circulation control system, method, device and air-conditioning equipment. By adding some components to construct a new refrigerant circulation control system, and by adding a branch pipeline (denoted as the first circulation branch) participated by some components, a new circulation loop with a smaller refrigerant volume (denoted as the first circulation loop) is constructed, so that the refrigerant circulates through the first circulation loop during low-temperature startup. After the compressor is preheated, it gradually drives the refrigerant circulation of the whole system, thereby effectively reducing the large amount of liquid refrigerant entering the compression chamber of the compressor in a short time, reducing the risk of liquid return during the low-temperature startup of the compressor, and can replace the electric heating preheating scheme adopted in the existing related technologies, reducing energy consumption and achieving energy conservation and emission reduction.

[0063] Among them, the refrigerant circulation control system 100 in the present application includes: a main refrigerant circulation path 110, a first circulation branch 120 and a second circulation branch 130, as Figure 1As shown, a first control valve 121 is provided on the first circulation branch 120, an electronic expansion valve 131 is provided on the second circulation branch 130, a compressor 111, an oil separator 112, a second control valve 113 and a vapor-liquid separator 114 are provided on the main refrigerant circulation path 110. The inlet of the first circulation branch 120 is connected between the outlet of the oil separator 112 and the inlet of the second control valve 113. The inlet of the second circulation branch 130 is communicated with the outlet of the vapor-liquid separator 114, and the outlet of the first circulation branch 120, the outlet of the second circulation branch 130 and the inlet of the compressor 111 are communicated. The first circulation branch 120, the compressor 111 and the oil separator 112 form a first circulation loop, and the second circulation branch 130 and the main refrigerant circulation path 110 form a second circulation loop. During low-temperature startup, such as when the compressor 111 starts up, by obtaining the ambient temperature detection information, when the ambient temperature detection information meets the low-temperature startup mode condition (denoted as the preset mode trigger condition), it directly enters the low-temperature startup mode (denoted as the target startup mode). At this time, the first control valve 121 is controlled to open, and the electronic expansion valve 131 and the second control valve 113 are closed, so as to perform refrigerant circulation through the first circulation loop. After the compressor 111 is fully preheated, the entire system refrigerant circulation is gradually driven through the first circulation loop and the second circulation loop, thereby effectively reducing the large amount of liquid refrigerant entering the compression cavity of the compressor 111 in a short time and reducing the risk of liquid return during the low-temperature startup of the compressor 111.

[0064] In an exemplary embodiment of the present application, a refrigerant circulation control system 100 is provided, as well as a refrigerant circulation control method, a refrigerant circulation control device applied to the above refrigerant circulation control system 100, and an air-conditioning device including the above refrigerant circulation control system 100. Refer to Figure 1 As shown, the refrigerant circulation control system 100 may include: a main refrigerant circulation path 110, a first circulation branch 120 and a second circulation branch 130; a first control valve 121 is provided on the first circulation branch 120, an electronic expansion valve 131 is provided on the second circulation branch 130, a compressor 111, an oil separator 112, a second control valve 113 and a vapor-liquid separator 114 are provided on the main refrigerant circulation path 110. The inlet of the first circulation branch 120 is connected between the outlet of the oil separator 112 and the inlet of the second control valve 113. The inlet of the second circulation branch 130 is communicated with the outlet of the vapor-liquid separator 114, and the outlet of the first circulation branch 120, the outlet of the second circulation branch 130 and the inlet of the compressor 111 are communicated. The first circulation branch 120, the compressor 111 and the oil separator 112 form a first circulation loop, and the second circulation branch 130 and the main refrigerant circulation path 110 form a second circulation loop.

[0065] Among them, the first control valve 121 and the second control valve 113 may be solenoid valves. For example, the first control valve 121 is the first solenoid valve, and the first solenoid valve is configured to conduct the first circulation branch 120 when the refrigerant circulation control system 100 enters the target startup mode; for another example, the second control valve 113 is the second solenoid valve, and the second solenoid valve is configured to shut off the second circulation loop in the case of the first stage when the refrigerant circulation control system 100 enters the target startup mode. The embodiments of the present application do not specifically limit the types of the first control valve 121 and the second control valve 113.

[0066] In the present application, when the first control valve 121 is opened, and the electronic expansion valve 131 and the second control valve 113 are closed, the refrigerant in the refrigerant circulation control system 100 circulates through the first circulation loop, as Figure 2 shown; when the first control valve 121, the electronic expansion valve 131, and the second control valve 113 are all opened, the refrigerant in the refrigerant circulation control system 100 circulates through the first circulation loop and the second circulation loop, as Figure 3 shown; when the first control valve 121 is closed, and the electronic expansion valve 131 and the second control valve 113 are both opened, the refrigerant in the refrigerant circulation control system 100 circulates through the second circulation loop, as Figure 4 shown.

[0067] It can be seen that the electronic expansion valve 131 in the embodiments of the present application can be used to shut off the second circulation branch 130 to disconnect the second circulation loop, that is, the refrigerant in the refrigerant circulation control system 100 does not circulate through the second circulation loop. Furthermore, a new circulation system with a small refrigerant amount can be constructed by using the first circulation loop. After the compressor 111 is preheated, the refrigerant circulation of the entire system can be gradually driven through the first circulation loop and the second circulation loop, thereby effectively reducing the short-term large amount of liquid refrigerant entering the compression cavity of the compressor 111 and reducing the risk of liquid return during the low-temperature startup of the compressor 111.

[0068] In some alternative embodiments of the present application, a first check valve 132 is further provided in the second circulation branch 130, so that the refrigerant flowing out of the first circulation branch 120 cannot be delivered to the gas-liquid separator 114 through the second circulation branch 130. The outlet of the first circulation branch 120 is communicated with the inlet of the compressor 111, and all the refrigerant flowing out of the first circulation branch 120 flows into the cavity of the compressor 111. For example, the first check valve 132 may be provided between the gas-liquid separator 114 and the electronic expansion valve 131, or may be provided between the outlet of the second circulation branch 130 and the electronic expansion valve 131. The embodiments of the present application do not limit this.

[0069] As an example of the present application, as Figure 1 shown, the inlet of the first one-way valve 132 is communicated with the outlet of the electronic expansion valve 131, and the outlet of the first one-way valve 132 is communicated with the outlet of the first circulation branch 120 and the inlet of the compressor 111, so that the refrigerant flowing out of the first circulation branch 120 cannot be delivered to the electronic expansion valve 131 and the gas-liquid separator 114 through the second circulation branch 130. For another example, the inlet of the first one-way valve 132 is communicated with the outlet of the electronic expansion valve 131, and the outlet of the first one-way valve 132 is communicated with the inlet of the compressor 111. Optionally, the outlet of the first one-way valve 132 is communicated with the outlet of the first circulation branch 120 and the inlet of the compressor 111, so that the refrigerant flowing out of the first circulation branch 120 cannot be delivered to the electronic expansion valve 131 and the gas-liquid separator 114 through the second circulation branch 130.

[0070] Certainly, a one-way valve (denoted as the second one-way valve 122) may also be provided in the first circulation branch 120 in the example of the present application, so that the refrigerant flowing out of the second circulation branch 130 cannot be delivered to the second control valve 113 and the oil separator 112 through the first circulation branch 120. By communicating the outlet of the second circulation branch 130 with the inlet of the compressor 111, all the refrigerant flowing out of the second circulation branch 130 flows to the cavity of the compressor 111. For example, as Figure 4 shown, the second one-way valve 122 on the first circulation branch 120 may be provided between the first control valve 121 and the outlet of the first circulation branch 120; specifically, the inlet of the second one-way valve 122 is communicated with the outlet of the first control valve 121, and the outlet of the second one-way valve 122 is communicated with the inlet of the compressor 111. Optionally, the outlet of the second one-way valve 122 is communicated with the outlet of the first circulation branch 120 and the inlet of the compressor 111, so that the refrigerant flowing out of the second circulation branch 130 cannot be delivered to the first control valve 121 through the first circulation branch 120.

[0071] Optionally, as Figure 5As shown, the refrigerant circulation control system 100 in the implementation of the present application may further include a control device 140. The first control valve 121, the second control valve 113, and the electronic expansion valve 131 are respectively electrically connected to the control device 140. The control device 140 may use a programmable logic controller (PLC) as the core control unit. It can integrate multiple sensor interfaces, including the suction pressure sensor interface, the discharge pressure sensor interface, the temperature sensor interface, and the current sensor interface of the compressor 111, etc., and can collect various operating parameters of the refrigerant circulation control system 100 in real time, so that the control device 140 can control the refrigerant circulation control system 100 to enter the target startup mode according to the ambient temperature detection information, and determine the current discharge superheat degree based on the discharge pressure and discharge temperature of the compressor 111, so as to control the startup and operation state of the refrigerant circulation control system 100 according to the current discharge superheat degree and the opening degree of the electronic expansion valve 131. Among them, the temperature sensor interface may include the discharge temperature sensor interface of the compressor 111, the ambient temperature sensor interface, the suction temperature sensor interface of the gas-liquid separator 114, etc., and the embodiments of the present application do not limit this.

[0072] In this embodiment, the control device is configured to, when the compressor 111 starts, control the refrigerant circulation control system 100 to enter the target startup mode according to the ambient temperature detection information, and determine the current discharge superheat degree based on the discharge pressure and discharge temperature of the compressor 111, so as to control the startup and operation state of the refrigerant circulation control system 100 according to the current discharge superheat degree and the opening degree of the electronic expansion valve 131. When it is detected that the compressor 111 starts and the ambient temperature detection information meets the preset mode trigger condition, by controlling the first control valve 121 to open, and controlling the electronic expansion valve 131 and the second control valve 113 to close, to control the refrigerant circulation control system 100 to enter the first operation stage of the target startup mode, so that the refrigerant circulates through the first circulation loop. Among them, the target startup mode is a low-temperature startup mode, and the first operation stage of the target startup model is used to control the refrigerant in the refrigerant circulation control system 100 to circulate through the first circulation loop; the electronic expansion valve 131 is configured to cut off the second circulation branch 130 in the case of the first stage of the refrigerant circulation system entering the target startup mode, so as to disconnect the second circulation loop, so that the refrigerant circulates through the first circulation loop, enabling the refrigerant circulation system to circulate with a smaller refrigerant volume and realizing preheating of the compressor 111.

[0073] Among them, a dedicated control algorithm program can be stored inside the control device. During the startup process of the compressor 111, based on the data fed back by the sensors, it can accurately judge the startup and operation status of the refrigerant circulation control system 100, and timely issue control instructions to control the closing and opening of the first control valve 121, the second control valve 113, and the electronic expansion valve 131. For example, it determines the current exhaust superheat degree based on the exhaust pressure and exhaust temperature of the compressor 111, and adjusts the opening degree of the electronic expansion valve 131 according to the current exhaust superheat degree when the electronic expansion valve 131 is opened, so as to gradually drive the refrigerant circulation of the entire system after the preheating of the compressor 111 is completed. And when the electronic expansion valve 131 is fully opened and the current exhaust superheat degree is greater than the preset first heat threshold value, it exits the target startup mode, that is, controls the first control valve 121 to close, so as to control the refrigerant circulation control system 100 to enter the third stage of startup and operation, enabling the refrigerant to circulate through the second circulation loop, and then the refrigerant circulation volume can be reasonably distributed. First, the refrigerant circulates in the first circulation loop, and part of the refrigerant is circulated to preheat the compressor 111. After the compression preheating is complete, the refrigerant circulation of the entire system is gradually driven, thereby reducing the risk of liquid return during the low-temperature startup of the compressor 111. Among them, the third stage of startup and operation is used to control the refrigerant to circulate through the second circulation loop so that the system can be normally controlled according to requirements.

[0074] Optionally, the ambient temperature detection information in the implementation of this application includes the ambient temperature and the shutdown time corresponding to the ambient temperature. An ambient temperature thermosensitive package 118 is provided between the second control valve 113 and the inlet of the gas-liquid separator 114 in the main refrigerant circulation path 110, and the ambient temperature thermosensitive package 118 is used to detect the ambient temperature. The control device controls the refrigerant circulation control system to enter the target startup mode based on the ambient temperature detection information. Specifically, it may include: when the ambient temperature is less than the preset temperature threshold corresponding to the target startup mode and the shutdown time reaches the preset shutdown duration threshold corresponding to the temperature threshold, it is determined that the ambient temperature detection information meets the preset mode trigger condition. In the case where the ambient temperature detection information meets the preset mode trigger condition, the refrigerant circulation control system 100 is controlled to enter the first operation stage of the target startup mode, so that the refrigerant can circulate through the first circulation loop to realize the preheating of the compressor.

[0075] Of course, in addition to the compressor 111, the oil separator 112, the second control valve 113, the gas-liquid separator 114, and the ambient temperature thermosensitive package 118, other devices may also be provided in the main refrigerant circulation path 110. For example, a first valve 115, a second valve 116, a first electronic expansion valve 117, a pressure sensor 41, an exhaust temperature thermosensitive package 42, an intake temperature thermosensitive package 43, a heat exchanger, etc. may also be provided. The embodiments of this application do not make specific limitations on this.

[0076] Optionally, a first heat exchanger 44 is provided between the second control valve 113 and the inlet of the vapor-liquid separator 114 in the main refrigerant circulation path 110, and the inlet of the first heat exchanger 44 is communicated with the outlet of the second control valve.

[0077] Optionally, the main refrigerant circulation path 110 may further be provided with a first valve 115, and the first valve 115 is provided between the outlet of the first heat exchanger 44 and the inlet of the vapor-liquid separator 114.

[0078] Optionally, the main refrigerant circulation path 110 is further provided with a second valve 116 and a second heat exchanger 46; the second heat exchanger 46 is provided between the outlet of the first valve 115 and the inlet of the second valve 116, and the outlet of the second valve 116 is communicated with the inlet of the vapor-liquid separator 114.

[0079] Optionally, the main refrigerant circulation path 110 in the embodiment of the present application is further provided with a pressure sensor 41 and an exhaust temperature thermosensitive package 42; the pressure sensor 41 is used to detect the exhaust pressure of the compressor 111, and the exhaust temperature thermosensitive package 42 is used to detect the exhaust temperature of the compressor 111, so that the control device can determine the current exhaust superheat degree according to the exhaust pressure and exhaust temperature of the compressor 111, and control the start-up operation state of the refrigerant circulation control system 100 according to the current exhaust superheat degree and the opening degree of the electronic expansion valve 131. Optionally, the control device in the embodiment of the present application is further used to adjust the opening degree of the electronic expansion valve 131 according to the current exhaust superheat degree.

[0080] In some alternative embodiments of the present application, the pressure sensor 41 may be a high-pressure sensor. For example, as Figure 3 shown, the pressure sensor 41 may be disposed between the exhaust port of the compressor 111 and the exhaust temperature thermosensitive package 42. The pressure sensor 41 is configured to detect the exhaust pressure of the compressor 111, so that the refrigerant circulation control system 100 can determine the current exhaust superheat degree according to the exhaust pressure of the compressor 111 and the exhaust temperature detected by the exhaust temperature thermosensitive package 42. Thus, when the current exhaust superheat degree meets the triggering condition of the second stage, the electronic expansion valve 131 can be controlled to open, so as to control the refrigerant circulation control system 100 to enter the second operation stage of the target start-up mode, and the refrigerant can circulate through the second circulation loop and the first circulation loop, as Figure 3As shown in the figure, the opening degree of the electronic expansion valve 131 is adjusted according to the current exhaust superheat degree, so as to control the starting and running state of the refrigerant circulation control system 100 according to the current exhaust superheat degree and the opening degree of the electronic expansion valve 131. For example, when the electronic expansion valve 131 is fully open and the current exhaust superheat degree is greater than the preset first heat threshold, the first control valve 121 is controlled to close, that is, the first circulation loop is disconnected, and the target starting mode is exited, so as to control the refrigerant circulation control system 100 to enter the third stage of starting and running, so that the refrigerant circulates through the second circulation loop, and then the refrigerant circulation can be controlled according to requirements.

[0081] Among them, the preset first heat threshold has a negative correlation with the ambient temperature. For example, the lower the ambient temperature, the larger the preset first heat threshold. The main function is to prevent a large amount of lubricating oil from being discharged, resulting in problems such as wear of the compressor 111. For example, the preset first heat threshold can be set to 5°C. When the electronic expansion valve 131 is fully open and the current exhaust superheat degree △ is greater than 5°C, that is, when △>5°C, the refrigerant circulation control system 100 is triggered to exit the low-temperature starting mode and enter the third stage of starting and running; this third stage of starting and running is used to control the refrigerant to circulate through the second circulation loop, that is, the electronic expansion valve 131 is fully open, the second control valve 113 is open, and the first control valve 121 is closed, so that the system can be normally controlled according to requirements.

[0082] It can be seen that the refrigerant circulation main path 110 in the embodiment of the present application is also provided with a heat exchanger, a first valve 115, a second valve 116, and a first electronic expansion valve 117; among them, the heat exchanger can be divided into a first heat exchanger 44 arranged between the second control valve 113 and the first valve 115 and a second heat exchanger 46 arranged between the first electronic expansion valve 117 and the second valve 116, and a blower 45 can be arranged on one side of the first heat exchanger 44 to form an evaporator in the refrigerant circulation main path 110; a first electronic expansion valve 117 is arranged between the door 115 and the second heat exchanger 46 to control the refrigerant flowing to the second heat exchanger 46 through the first electronic expansion valve 117, and a centrifugal blower 47 can be arranged on one side of the second heat exchanger 46 to form a condenser in the refrigerant circulation main path 110 through the second heat exchanger and the centrifugal blower 47, and the second valve 116 can be arranged between the second heat exchanger 47 and the inlet of the gas-liquid separator 114 to control the refrigerant flowing to the gas-liquid separator 114 through the second valve 116, so that the refrigerant circulation control system 100 can control the amount of refrigerant circulating in the second circulation loop through the refrigerant circulation main path 110 to meet the refrigerant circulation requirements.

[0083] In an exemplary embodiment, a refrigerant circulation control method is provided, which is applied to the above-mentioned refrigerant circulation control system 100. As the control method of the above-mentioned refrigerant circulation control system 100, refer to Figures 1 to 4As shown, in the refrigerant circulation control system 100, during the low-temperature startup process of the compressor 111, due to low temperature, a large amount of liquid refrigerant may enter the compression cavity of the compressor 111 in a short time, increasing the loss of the compressor 111 and even damaging the compressor 111, affecting the service life of the compressor 111.

[0084] In this embodiment, as Figure 6 shown, in the case of starting the compressor, the refrigerant circulation control method obtains the ambient temperature detection information, and determines whether the ambient temperature detection information meets the low-temperature startup mode condition (denoted as the preset mode trigger condition), so as to control the refrigerant circulation control system 100 to enter the first operation stage of the target startup mode when the ambient temperature detection information meets the preset mode trigger condition, and determine the current exhaust superheat degree according to the exhaust pressure and exhaust temperature of the compressor. Among them, the current exhaust superheat degree refers to the exhaust superheat degree of the compressor 111 at present; the ambient temperature detection information may refer to the information detected for the ambient temperature, and specifically may include the detected ambient temperature and the shutdown time of the compressor 111 in the system. This embodiment does not limit this; the first operation stage is used to control the refrigerant in the refrigerant circulation control system 100 to circulate through the first circulation loop.

[0085] In some alternative embodiments of the present application, a temperature preset value A (denoted as the preset temperature threshold) can be set in advance for the low-temperature startup mode (denoted as the target startup mode), and a corresponding shutdown time threshold B (denoted as the preset shutdown duration threshold) can be set for the preset temperature threshold A, so as to determine whether the current ambient temperature detection information meets the preset mode trigger condition by judging whether the ambient temperature is lower than the preset temperature threshold A and whether the shutdown time corresponding to the ambient temperature is greater than the shutdown time threshold B when the unit in the refrigerant circulation control system 100 starts, such as when the compressor 111 starts. Therefore, when the detected ambient temperature is less than the preset temperature threshold A and the shutdown time corresponding to the ambient temperature is greater than the preset shutdown duration threshold B corresponding to the temperature threshold A, it is considered that the ambient temperature detection information meets the preset mode trigger condition.

[0086] Optionally, in the case where the ambient temperature detection information meets the preset mode trigger condition, the embodiment of the present application controls the refrigerant circulation control system 100 to enter the first operation stage of the target startup mode, which may specifically include: when the ambient temperature is less than the preset temperature threshold corresponding to the target startup mode and the shutdown time reaches the preset shutdown duration threshold corresponding to the temperature threshold, determining that the ambient temperature detection information meets the preset mode trigger condition, and controlling the first control valve to open and the second control valve to close, so as to control the refrigerant circulation control system 100 to enter the first operation stage.

[0087] For example, if the refrigerant cycle control system 100 detects that the ambient temperature is lower than the preset temperature threshold A and the shutdown time is greater than the preset shutdown duration threshold B corresponding to the temperature threshold A, when the unit starts up, it directly enters the low-temperature start-up mode (denoted as the target start-up mode). Among them, there is a corresponding relationship between the preset temperature threshold A and the shutdown duration threshold B. Exemplarily, the value ranges of the temperature threshold A and its corresponding shutdown duration threshold B are shown in Table 1. The specific value data of the temperature threshold A and the shutdown duration threshold B in the embodiments of the present application are not specifically limited.

[0088] A B 1 hour 2 hours 3 hours -10℃ Do not enter Do not enter Enter -20℃ Do not enter Enter Enter -30℃ Enter Enter Enter

[0089] Table 1

[0090] When the refrigerant cycle control system 100 enters the low-temperature start-up mode, at this time, in the first stage of the low-temperature start-up mode (denoted as the first operating stage of the target start-up mode), the electronic expansion valve 131 is closed, the second control valve 113 is closed, and the first control valve 121 is opened, so that the refrigerant in the refrigerant cycle control system 100 circulates through the first circulation loop, that is, the refrigerant cycle control system 100 performs refrigerant circulation through the first circulation loop. As Figure 2 shown, the first circulation loop is composed of a compressor 111, a pressure sensor 41, an exhaust temperature thermosensitive package 42, an oil separator 112, and a first control valve 121 to form a new small refrigerant volume circulation system to realize the preheating of the compressor 111.

[0091] In addition, when the refrigerant cycle control system 100 is in the first stage of the low-temperature start-up mode, it controls the compressor 111 to operate at a low frequency (denoted as the preset initial start-up frequency). Exemplarily, the preset initial start-up frequency can be 10 Hz. That is, in the first operating stage of the target start-up mode, the compressor 111 can operate at a low frequency of 10 Hz; and the current exhaust superheat can be determined based on the exhaust pressure and exhaust temperature of the compressor, so as to control the refrigerant cycle control system 100 to enter the second stage of the low-temperature start-up mode (denoted as the second operating stage of the target start-up mode) when the current exhaust superheat meets the trigger condition of the second stage. This second operating stage is used to control the refrigerant to circulate through the first circulation loop and the second circulation loop to gradually drive the refrigerant circulation of the entire system, thereby effectively reducing the large amount of liquid refrigerant entering the compressor compression cavity in a short time and reducing the risk of liquid return during the low-temperature start-up of the compressor.

[0092] Optionally, in the case of the first operating stage of the target start-up mode, the refrigerant cycle control method provided by the embodiments of the present application further includes: controlling the compressor to operate at the preset initial start-up frequency to realize the low-frequency preheating of the compressor.

[0093] In some alternative embodiments of the present application, after determining the current exhaust superheat degree according to the exhaust pressure and exhaust temperature of the compressor, the refrigerant cycle control method further includes the following steps:

[0094] Step S11, comparing the current exhaust superheat degree with a preset second superheat degree threshold;

[0095] Step S12, when the current exhaust superheat degree is not less than the second superheat degree threshold, determining that the current exhaust superheat degree meets the trigger condition of the second stage.

[0096] Specifically, after determining the current exhaust superheat degree according to the exhaust pressure and exhaust temperature of the compressor, the control device in the refrigerant cycle control system 100 can compare the previous exhaust superheat degree with a preset second superheat degree threshold; if the current exhaust superheat degree is not less than the second superheat degree threshold, for example, when the current exhaust superheat degree is denoted as △ and the preset second superheat degree threshold is denoted as △1, when △≥△1, it is determined that the current exhaust superheat degree meets the trigger condition of the second stage. At this time, the electronic expansion valve and the second control valve are opened to control the refrigerant cycle control system 100 to enter the second operation stage of the target start mode, so that the refrigerant circulates through the first circulation loop and the second circulation loop, as Figure 3 shown. At this time, the opening degree of the electronic expansion valve 131 is related to the current exhaust superheat degree. Among them, the second operation stage is used to control the refrigerant to circulate through the first circulation loop and the second circulation loop; the preset second superheat degree threshold △1 can be set according to the ambient temperature to prevent a large amount of lubricating oil from being discharged, thereby solving the problem of compressor wear caused by a large amount of lubricating oil discharge and extending the service life of the compressor.

[0097] For example, when the initial opening degree of the electronic expansion valve 131 is 50 steps and the full load is 480 steps, the opening degree of the electronic expansion valve 131 can be adjusted according to the electronic expansion valve opening degree calculation formula K = 50 * △ / △1 until the electronic expansion valve 131 is fully opened and the exhaust superheat degree △ is greater than the preset first superheat degree threshold, and then the target start mode is exited, that is, the first control valve 121 is controlled to close to control the refrigerant cycle control system 100 to enter the third stage of start-up operation, so that the refrigerant circulates through the second circulation loop. Among them, all the calculation parameters in the electronic expansion valve opening degree calculation formula are examples, and the maximum value of the K value is 480. The specific values of the calculation parameters in the embodiments of the present application are not limited.

[0098] It can be seen that when the current exhaust superheat degree in the embodiment of the present application meets the triggering condition of the second stage, the refrigerant circulation control system 100 is controlled to enter the second operation stage of the target start mode, and the opening degree of the electronic expansion valve is adjusted according to the current exhaust superheat degree. When the electronic expansion valve is fully open and the current exhaust superheat degree is greater than the preset first heat threshold, the target start mode is exited to control the refrigerant circulation control system 100 to enter the third stage of start operation, so that the system is normally controlled according to requirements.

[0099] Optionally, the embodiment of the present application determines the current exhaust superheat degree based on the exhaust pressure and exhaust temperature of the compressor, which may specifically include: detecting the exhaust pressure of the compressor through the pressure sensor in the refrigerant circulation control system 100 and determining the saturation temperature corresponding to the exhaust pressure; detecting the exhaust temperature of the compressor through the exhaust temperature thermosensitive package in the refrigerant circulation control system 100; calculating based on the exhaust temperature and the saturation temperature to obtain the current exhaust superheat degree.

[0100] For example, when the pressure sensor 41 in the refrigerant circulation control system 100 is a high-pressure sensor, after detecting the exhaust pressure through the high-pressure sensor, the saturation temperature corresponding to the exhaust high pressure (denoted as the saturation temperature corresponding to the exhaust pressure) can be determined using the exhaust pressure, and calculations are performed based on this saturation temperature and the exhaust temperature. For example, according to the exhaust superheat degree calculation formula △ = exhaust temperature - saturation temperature corresponding to the exhaust high pressure, calculations are performed using the saturation temperature and the exhaust temperature to obtain the current exhaust superheat degree △. When the current exhaust superheat degree △ meets the triggering condition of the second stage, the refrigerant circulation control system 100 is controlled to enter the second operation stage of the target start mode, and the opening degree of the electronic expansion valve 131 is adjusted according to the current exhaust superheat degree. Furthermore, when the electronic expansion valve 131 is fully open and the current exhaust superheat degree is greater than the preset first heat threshold, the target start mode is exited, that is, the first control valve 121 is controlled to close to control the refrigerant circulation control system 100 to enter the third stage of start operation.

[0101] Of course, when the electronic expansion valve 131 is fully open, in addition to determining whether to exit the target start mode by judging whether the current exhaust superheat degree is greater than the preset first heat threshold, other methods can also be used to determine whether to exit the target start mode to enter the third stage of start operation. The embodiment of the present application does not make specific limitations on this.

[0102] In some alternative embodiments of the present application, after the refrigerant cycle control method controls the refrigerant cycle control system 100 to enter the second operation stage of the target start-up mode, it may further include: when the electronic expansion valve is fully open and the current exhaust superheat is not greater than a preset first heat threshold, adjusting the operating frequency of the compressor to a preset first operating frequency, and the first operating frequency is higher than the initial start-up frequency; controlling the compressor to operate at the first operating frequency until the refrigerant cycle control system 100 exits the target start-up mode.

[0103] For example, when the preset first heat threshold is 5°C, if the electronic expansion valve is fully open and the current exhaust superheat Δ≤5°C, the operating frequency of the compressor 111 is adjusted to the preset first operating frequency, so that the compressor 111 increases the frequency to the preset first operating frequency, then the exhaust superheat of the compressor can be increased. Until the refrigerant cycle control system 100 exits the target start-up mode and enters the third operation stage of start-up operation, the operating frequency of the compressor 111 is controlled according to the system requirements to achieve energy conservation and emission reduction. Among them, the preset first operating frequency is related to the system, and its main function is to increase the exhaust superheat. Specifically, it can be set according to the system parameters. However, the preset first operating parameter cannot be set too high to prevent too large a pressure difference during mode switching, which is not conducive to control. It should be noted that the system parameters may refer to the parameters in the refrigerant cycle control system 100, and specifically may include hardware parameters and / or software control parameters. The embodiments of the present application do not limit this.

[0104] Of course, after the embodiment of the present application enters the first operation stage of the target start-up mode, in addition to determining whether to control the refrigerant cycle control system 100 to enter the second operation stage of the target start-up mode by judging whether the current exhaust superheat meets the trigger condition of the second stage, other methods may also be used to determine whether to enter the second operation stage of the target start-up mode. For example, it can be determined to enter the second operation stage of the target start-up mode by judging whether the current operating frequency of the compressor (denoted as the current operating frequency) reaches a preset second operating frequency. The embodiments of the present application do not make specific limitations on this.

[0105] Among them, the preset second operating frequency is related to the system, and its main function is to increase the exhaust superheat. Specifically, it can be set according to the system parameters to increase the exhaust superheat of the compressor by increasing the operating frequency of the compressor. However, the preset second operating parameter cannot be set too high to prevent too large a pressure difference during mode switching, which is not conducive to control.

[0106] Optionally, after the above refrigerant cycle control method controls the refrigerant cycle control system 100 to enter the first operation stage of the target start mode, it may further include: detecting the current operating frequency of the compressor; when the current operating frequency reaches a preset second operating frequency and the current exhaust superheat degree is less than a preset second superheat threshold, controlling the second control valve and the electronic expansion valve to open, so as to control the refrigerant cycle control system 100 to enter the second operation stage of the target start mode, and controlling the compressor to operate according to the current operating frequency, and the second operating frequency is higher than the first operating frequency.

[0107] For example, when the preset second superheat threshold is denoted as △1 and the current exhaust superheat degree is denoted as △, if △<△1 is continuously detected in the first stage of the target start mode, it can be determined by judging whether the current operating frequency of the compressor 111 is increased to the preset second operating frequency; if the compressor 111 is increased to the preset second operating frequency at this time, the second control valve 113 and the electronic expansion valve 131 can be controlled to open until entering the second operation stage, and the operating frequency of the compressor 111 in the first operation stage can be extended to the second operation stage, so that the compressor 111 operates according to the preset second operating frequency, ensuring that the exhaust superheat degree of the compressor 111 is high enough to meet the system control requirements.

[0108] In an exemplary embodiment, a refrigerant cycle control device is provided, which is applied to the above refrigerant cycle control system 100 and can be used as the control device of the above refrigerant cycle control system 100, such as Figure 6As shown, the refrigerant cycle control system 100100 may include a control device 610, the refrigerant cycle main path 110, the first circulation branch 120, and the second circulation branch 130 described in any of the above embodiments. Among them, the connection relationship between the control device 160 and other devices in the refrigerant cycle control system 100100 can refer to the above embodiments and will not be elaborated here. The control device 610 is configured to implement the refrigerant cycle control method described in any of the above embodiments. When the compressor starts, by obtaining the ambient temperature detection information and determining whether the ambient temperature detection information meets the low-temperature start mode condition (denoted as the preset mode trigger condition), in the case where the ambient temperature detection information meets the preset mode trigger condition, control the refrigerant cycle control system 100 to enter the first operation stage of the target start mode, so that the refrigerant circulates through the first circulation loop to realize compressor preheating, and determine the current exhaust superheat degree according to the exhaust pressure and exhaust temperature of the compressor. In the case where the current exhaust superheat degree meets the second-stage trigger condition, control the refrigerant cycle control system 100 to enter the second operation stage of the target start mode, so that the refrigerant circulates through the first circulation loop and the second circulation loop after the compressor preheating is completed, and adjust the opening degree of the electronic expansion valve according to the current exhaust superheat degree to gradually drive the refrigerant circulation of the entire system, effectively reducing the short-time large amount of liquid refrigerant entering the compressor compression cavity, reducing the risk of liquid return during low-temperature start of the compressor, and in the case where the electronic expansion valve is fully open and the current exhaust superheat degree is greater than the preset first heat threshold, exit the target start mode to control the refrigerant cycle control system 100 to enter the third operation stage of startup operation, so that the refrigerant circulates through the second circulation loop to perform control according to requirements, realizing energy conservation and emission reduction.

[0109] In a specific implementation, the refrigerant circulation control system 100 described in any of the above embodiments can be integrated into an air conditioning device. When the compressor starts, the air conditioning device obtains ambient temperature detection information, and when the ambient temperature detection information meets the preset mode trigger condition, controls the refrigerant circulation control system 100 to enter the first operation stage of the target start mode, enabling the refrigerant to circulate through the first circulation loop to achieve compressor preheating. Subsequently, based on the discharge pressure and discharge temperature of the compressor, the current superheat degree of discharge is determined. When the current superheat degree of discharge meets the trigger condition for the second stage, controls the refrigerant circulation control system 100 to enter the second operation stage of the target start mode, enabling the refrigerant to circulate through the first circulation loop and the second circulation loop after the compressor preheating is completed, and adjusting the opening degree of the electronic expansion valve according to the current superheat degree of discharge to gradually drive the refrigerant circulation of the entire system, thereby effectively reducing the short-time large amount of liquid refrigerant entering the compressor compression cavity, reducing the risk of liquid return during low-temperature startup of the compressor, and when the electronic expansion valve is fully open and the current superheat degree of discharge is greater than the preset first heat threshold, exiting the target start mode to control the refrigerant circulation control system 100 to enter the third operation stage of startup operation, enabling the refrigerant to circulate through the second circulation loop, and then being able to be controlled according to requirements to achieve energy conservation and emission reduction.

[0110] As Figure 7 shown, an embodiment of the present application further provides an air conditioning device 700, which includes the refrigerant circulation control system 100 described in any of the above embodiments. When the air conditioning device starts at a low temperature, it can circulate the refrigerant through the first circulation loop in the refrigerant circulation control system 100 to achieve compressor preheating. After the compressor preheating is completed, it gradually drives the refrigerant circulation of the entire system, thereby effectively reducing the short-time large amount of liquid refrigerant entering the compressor compression cavity, reducing the risk of liquid return during low-temperature startup of the compressor, extending the service life of the compressor, and at the same time reducing energy consumption to achieve energy conservation and emission reduction.

[0111] Those skilled in the art should further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Skilled professionals can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0112] It should be noted that phrases such as "one embodiment", "embodiment", "exemplary embodiment", "some embodiments", etc. mentioned in the specification indicate that the described embodiments may include specific features, structures or characteristics, but not necessarily every embodiment includes such specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. Moreover, when combining specific features, structures or characteristics with an embodiment, it is within the knowledge scope of those skilled in the art to implement such features, structures or characteristics in combination with other embodiments, whether explicitly or implicitly described.

[0113] It should be noted that in this text, relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without more limitations, an element defined by the statement "including an..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0114] The above embodiments are only preferred embodiments given to fully illustrate the present application, and the protection scope of the present application is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present application are within the protection scope of the present application.

Claims

1. A refrigerant cycle control system, characterized in that, Comprising: A main refrigerant circulation path, a first circulation branch, and a second circulation branch; A first control valve is provided on the first circulation branch; an electronic expansion valve is provided on the second circulation branch; A compressor, an oil separator, a second control valve, and a vapor-liquid separator are provided on the main refrigerant circulation path; The inlet of the first circulation branch is connected between the outlet of the oil separator and the second control valve; the inlet of the second circulation branch communicates with the outlet of the vapor-liquid separator, and the outlet of the first circulation branch, the outlet of the second circulation branch, and the inlet of the compressor communicate; the first circulation branch, the compressor, and the oil separator form a first circulation loop, and the second circulation branch and the main refrigerant circulation path form a second circulation loop; When the first control valve is open and the electronic expansion valve and the second control valve are closed, the refrigerant in the refrigerant circulation control system circulates through the first circulation loop; When the first control valve, the electronic expansion valve, and the second control valve are all open, the refrigerant in the refrigerant circulation control system circulates through the first circulation loop and the second circulation loop; When the first control valve is closed and the electronic expansion valve and the second control valve are both open, the refrigerant in the refrigerant circulation control system circulates through the second circulation loop.

2. The refrigerant circulation control system according to claim 1, wherein A first check valve is further provided on the second circulation branch. The inlet of the first check valve communicates with the outlet of the electronic expansion valve, and the outlet of the first check valve communicates with the outlet of the first circulation branch and the inlet of the compressor.

3. The refrigerant cycle control system according to claim 1, characterized in that Further comprising: A control device, which is electrically connected to the first control valve, the second control valve, and the electronic expansion valve respectively; The control device is configured to, when the compressor is started, control the refrigerant circulation control system to enter a target start mode according to the ambient temperature detection information, and determine the current exhaust superheat degree based on the discharge pressure and discharge temperature of the compressor, so as to control the start and operation state of the refrigerant circulation control system according to the current exhaust superheat degree and the opening degree of the electronic expansion valve.

4. The refrigerant cycle control system according to claim 3, wherein, A pressure sensor and an exhaust temperature thermosensitive package are further provided on the main refrigerant circulation path; The pressure sensor is configured to detect the discharge pressure of the compressor; The exhaust temperature thermosensitive package is configured to detect the discharge temperature of the compressor; The control device is further configured to adjust the opening degree of the electronic expansion valve according to the current exhaust superheat degree.

5. The refrigerant cycle control system according to claim 3, wherein The ambient temperature detection information includes the ambient temperature and the shutdown time corresponding to the ambient temperature; An ambient temperature thermosensitive package is provided between the second control valve and the inlet of the vapor-liquid separator on the main refrigerant circulation path; The ambient temperature thermosensitive package is configured to detect the ambient temperature; The control of the refrigerant circulation control system to enter the target start mode according to the ambient temperature detection information includes: when the ambient temperature is less than the preset temperature threshold corresponding to the target start mode and the shutdown time reaches the preset shutdown duration threshold corresponding to the temperature threshold, determining that the ambient temperature detection information meets the preset mode trigger condition; When the detected environmental temperature information meets the preset mode triggering condition, control the refrigerant circulation control system to enter the first operation stage of the target start mode.

6. A refrigerant cycle control method, characterized in that, Applied to the refrigerant circulation control system according to any one of claims 1-5, the refrigerant circulation control method includes: When the compressor starts, obtain the detected environmental temperature information; When the detected environmental temperature information meets the preset mode triggering condition, control the refrigerant circulation control system to enter the first operation stage of the target start mode, and determine the current superheat degree of exhaust according to the exhaust pressure and exhaust temperature of the compressor. The first operation stage is used to control the refrigerant in the refrigerant circulation control system to circulate through the first circulation loop; When the current superheat degree of exhaust meets the second stage triggering condition, control the refrigerant circulation control system to enter the second operation stage of the target start mode, and adjust the opening degree of the electronic expansion valve according to the current superheat degree of exhaust. The second operation stage is used to control the refrigerant to circulate through the first circulation loop and the second circulation loop; When the electronic expansion valve is fully open and the current superheat degree of exhaust is greater than the preset first heat threshold, exit the target start mode to control the refrigerant circulation control system to enter the third operation stage of startup operation. The third operation stage of startup operation is used to control the refrigerant to circulate through the second circulation loop.

7. The refrigerant cycle control method according to claim 6, characterized in that, The detected environmental temperature information includes the environmental temperature and the shutdown time corresponding to the environmental temperature. When the detected environmental temperature information meets the preset mode triggering condition, controlling the refrigerant circulation control system to enter the first operation stage of the target start mode includes: When the environmental temperature is lower than the preset temperature threshold corresponding to the target start mode and the shutdown time reaches the preset shutdown duration threshold corresponding to the temperature threshold, determine that the detected environmental temperature information meets the preset mode triggering condition, and control the first control valve to open and the second control valve to close to control the refrigerant circulation control system to enter the first operation stage; In the case of the first operation stage, the refrigerant circulation control method further includes: controlling the compressor to operate at a preset initial startup frequency.

8. The refrigerant cycle control method according to claim 7, wherein, After the refrigerant circulation control method determines the current superheat degree of exhaust according to the exhaust pressure and exhaust temperature of the compressor, it further includes: Comparing the current superheat degree of exhaust with a preset second heat threshold; When the current superheat degree of exhaust is not less than the second heat threshold, determine that the current superheat degree of exhaust meets the second stage triggering condition.

9. The refrigerant cycle control method according to claim 7, wherein After the refrigerant circulation control method controls the refrigerant circulation control system to enter the second operation stage of the target start mode, it further includes: When the electronic expansion valve is fully open and the current superheat degree of exhaust is not greater than the preset first heat threshold, adjust the operating frequency of the compressor to a preset first operating frequency, and the first operating frequency is higher than the initial startup frequency; Control the operation of the compressor according to the first operating frequency until the refrigerant circulation control system exits the target startup mode.

10. The refrigerant cycle control method according to claim 9, characterized in that, After the first operating stage of the refrigerant circulation control method for controlling the refrigerant circulation control system to enter the target startup mode, it further includes: Detect the current operating frequency of the compressor; When the current operating frequency reaches a preset second operating frequency and the current exhaust superheat degree is less than a preset second superheat threshold, control the second control valve and the electronic expansion valve to open, so as to control the refrigerant circulation control system to enter the second operating stage of the target startup mode, and control the operation of the compressor according to the current operating frequency, and the second operating frequency is higher than the first operating frequency.

11. The refrigerant cycle control method according to any one of claims 6 to 10, characterized in that, The determination of the current exhaust superheat degree based on the exhaust pressure and exhaust temperature of the compressor includes: Detect the exhaust pressure of the compressor through the pressure sensor in the refrigerant circulation control system, and determine the saturation temperature corresponding to the exhaust pressure; Detect the exhaust temperature of the compressor through the exhaust temperature thermosensitive element in the refrigerant circulation control system; Perform calculations based on the exhaust temperature and the saturation temperature to obtain the current exhaust superheat degree.

12. A refrigerant cycle control device, characterized in that, The control device is configured to implement the refrigerant circulation control method according to any one of claims 6-11.

13. An air conditioning device, characterized in that, The air-conditioning equipment includes the refrigerant circulation control system according to any one of claims 1 to 5.

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