WO2023083040A1

WO2023083040A1 - Air conditioner

Info

Publication number: WO2023083040A1
Application number: PCT/CN2022/128698
Authority: WO
Inventors: 路海滨; 夏兴祥; 张恒; 孟建军; 石磊; 董辰
Original assignee: 青岛海信日立空调系统有限公司
Priority date: 2021-11-11
Filing date: 2022-10-31
Publication date: 2023-05-19

Abstract

Some embodiments of the present disclosure provide an air conditioner, and relate to the technical field of air conditioning apparatuses. The air conditioner comprises an outdoor unit, at least one indoor unit, a refrigerant filling device, and a controller. The outdoor unit comprises a compressor and a first heat exchanger. Each indoor unit comprises a second heat exchanger. The refrigerant filling device is configured to provide a refrigerant. The controller is coupled to the compressor and the refrigerant filling device, and is configured to: control the air conditioner to enter a refrigeration working state in response to having received a refrigerant filling instruction; obtain a supercooling degree threshold value of a liquid discharge port of the first heat exchanger, the supercooling degree threshold value being determined according to a first internal volume of the outdoor unit and a second internal volume of the at least one indoor unit; obtain a supercooling degree at the liquid discharge port of the first heat exchanger every first time period; control the refrigerant filling device to fill the compressor with the refrigerant if the supercooling degree is smaller than the supercooling degree threshold value; and control the refrigerant filling device to stop filling the compressor with the refrigerant if the supercooling degree is greater than or equal to the supercooling degree threshold value.

Description

air conditioner

This application claims the priority of the Chinese patent application with application number 202111334540.X filed on November 11, 2021, and the priority of the Chinese patent application with application number 202111421239.2 filed on November 26, 2021; The entire contents of which are incorporated by reference in this application.

technical field

The present disclosure relates to the technical field of air conditioning equipment, in particular to an air conditioner.

Background technique

Proper refrigerant charge is the basis for reliable and efficient operation of the air conditioner. If the amount of refrigerant in the air conditioner is more than the amount of refrigerant required for the operation of the air conditioner, there may be liquid refrigerant in the suction port of the compressor in the air conditioner, which may cause damage to the compressor, or cause the pressure in the air conditioner to be too high. Thus triggering the high voltage shutdown protection. If the amount of refrigerant in the air conditioner is less than the amount of refrigerant required for the operation of the air conditioner, it may lead to insufficient refrigerant in the indoor unit, which cannot meet the cooling or heating needs of the user, and may cause excessive overheating in the air conditioner , thus triggering the exhaust high temperature shutdown protection or low pressure shutdown protection.

Contents of the invention

In one aspect, some embodiments of the present disclosure provide an air conditioner. The air conditioner includes an outdoor unit, at least one indoor unit, a refrigerant charging device and a controller. The outdoor unit includes a compressor and a first heat exchanger. The compressor is configured to compress refrigerant to drive the refrigerant to circulate in the air conditioner. The first heat exchanger is configured to one of liquefy or vaporize the refrigerant. The at least one indoor unit communicates with the outdoor unit, and each indoor unit includes a second heat exchanger. The second heat exchanger is configured to either liquefy or vaporize the refrigerant. The refrigerant charging device communicates with the compressor and is configured to supply the refrigerant.

The controller is coupled to the compressor and the refrigerant charging device, and is configured to:

In response to receiving a refrigerant charging instruction, control the air conditioner to enter the cooling working state; obtain the subcooling degree threshold at the liquid discharge port of the first heat exchanger; the subcooling degree threshold is based on the outdoor unit Determine the first internal volume and the second internal volume of the at least one indoor unit; obtain the subcooling degree at the liquid discharge port of the first heat exchanger every first time period; if the subcooling degree is less than the specified When the subcooling degree threshold value is exceeded, the refrigerant charging device is controlled to charge the refrigerant into the compressor; when the subcooling degree is greater than or equal to the subcooling degree threshold value, the refrigerant charging device is controlled to Stop charging the refrigerant into the compressor.

On the other hand, other embodiments of the present disclosure provide an air conditioner. The air conditioner includes an outdoor unit, at least one indoor unit, a refrigerant charging device and a controller. The outdoor unit includes a compressor and a first heat exchanger. The compressor is configured to compress refrigerant to drive the refrigerant to circulate in the air conditioner. The first heat exchanger is configured to one of liquefy or vaporize the refrigerant. The at least one indoor unit communicates with the outdoor unit, and each indoor unit includes a second heat exchanger. The second heat exchanger is configured to either liquefy or vaporize the refrigerant. The refrigerant charging device communicates with the compressor and is configured to supply the refrigerant.

The controller is coupled to the compressor and the refrigerant charging device, and is configured to: control the air conditioner to enter a cooling working state in response to receiving a refrigerant charging instruction; The subcooling degree at the liquid discharge port of the first heat exchanger; if the subcooling degree is less than the subcooling degree threshold, control the refrigerant charging device to charge the refrigerant into the compressor; control The second degree of superheat at the exhaust port of the second heat exchanger is within a preset second degree of superheat range, controlling the discharge pressure at the discharge port of the compressor to be within a preset discharge pressure range, and controlling the first working temperature of the second heat exchanger to be within a preset working temperature range; when the degree of subcooling is greater than or equal to the threshold of the degree of subcooling, controlling the refrigerant charging device to stop charging the refrigerant to the The compressor is filled with the refrigerant.

Description of drawings

In order to illustrate the technical solutions in the present disclosure more clearly, the following will briefly introduce the accompanying drawings required in some embodiments of the present disclosure, however, the accompanying drawings in the following description are only drawings of some embodiments of the present disclosure , for those skilled in the art, other drawings can also be obtained according to these drawings. In addition, the drawings in the following description can be regarded as schematic diagrams, and are not limitations on the actual size of the product involved in the embodiments of the present disclosure, the actual process of the method, the actual timing of signals, and the like.

Fig. 1 is a structural diagram of an air conditioner in the related art;

Fig. 2 is another structural diagram of the air conditioner in the related art;

Fig. 3 is a graph showing the relationship between the amount of refrigerant and the degree of subcooling according to some embodiments;

FIG. 4 is a block diagram of an air conditioner according to some embodiments;

Fig. 5 is another structural diagram of an air conditioner according to some embodiments;

Fig. 6 is a graph showing the relationship between the volume ratio of indoor and outdoor units and the subcooling degree threshold according to some embodiments;

Fig. 7 is a flowchart of a control method of a first expansion valve according to some embodiments;

Fig. 8 is another structural diagram of an air conditioner according to some embodiments;

Fig. 9 is another structural diagram of an air conditioner according to some embodiments;

Fig. 10 is a flowchart of a control method of a second expansion valve according to some embodiments;

Fig. 11 is a flowchart of a control method of a first fan according to some embodiments;

Fig. 12 is a flowchart of a control method of a second fan according to some embodiments.

Detailed ways

The technical solutions in some embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are only some of the embodiments of the present disclosure, not all of them. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments provided in the present disclosure belong to the protection scope of the present disclosure.

Throughout the specification and claims, unless the context requires otherwise, the term "comprise" and other forms such as the third person singular "comprises" and the present participle "comprising" are used Interpreted as the meaning of openness and inclusion, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific examples" example)" or "some examples (some examples)" etc. are intended to indicate that specific features, structures, materials or characteristics related to the embodiment or examples are included in at least one embodiment or example of the present disclosure. Schematic representations of the above terms are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be included in any suitable manner in any one or more embodiments or examples.

Hereinafter, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

In describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. The term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral body; it can be a direct connection or an indirect connection through an intermediary. The term "coupled", for example, indicates that two or more elements are in direct physical or electrical contact. The terms "coupled" or "communicatively coupled" may also mean that two or more components are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments disclosed herein are not necessarily limited by the context herein.

"A and/or B" includes the following three combinations: A only, B only, and a combination of A and B.

The use of "suitable for" or "configured to" herein means open and inclusive language that does not exclude devices that are suitable for or configured to perform additional tasks or steps.

Additionally, the use of "based on" is meant to be open and inclusive, as a process, step, calculation, or other action that is "based on" one or more stated conditions or values may in practice be based on additional conditions or beyond stated values.

In the related art, an air conditioner 1000' includes an outdoor unit 10' and at least one indoor unit 20' as shown in FIG. 1 . The outdoor unit 10' is the equipment installed in the outside of the wall or the roof of the house in the air conditioner 1000'. The outdoor unit 10' is mainly used to compress refrigerant and drive the refrigerant to circulate in the air conditioner 1000'. The refrigerant is a substance that easily absorbs heat and becomes a gas, and also easily releases heat and becomes a liquid. The indoor unit 20' is a device installed indoors in the air conditioner 1000'. The indoor unit 20' is mainly used to transmit cold air or hot air to the indoor space where it is located, so as to adjust the temperature of the indoor space.

Continuing to refer to FIG. 1 , the outdoor unit 10' communicates with each indoor unit 20' through at least two pipes. On the first pipeline 61' connecting the first end d11' of the outdoor unit 10' and the first end d21' of the indoor unit 20', a first cut-off valve 51' is provided to control the on-off of the first pipeline 61' ; On the second pipe 62' connecting the second end d12' of the outdoor unit 10' and the second end d22' of the indoor unit 20', a second shut-off valve 52' is provided to control the flow of the second pipe 62'; broken.

The outdoor unit 10' includes a compressor 101', a gas-liquid separator 102', a four-way valve 103', a first heat exchanger 104', a first fan 105' and a third expansion valve 106'. The discharge port of the compressor 101' communicates with the D' end of the four-way valve 103', and the suction port of the compressor 101' communicates with the discharge port of the gas-liquid separator 102'. The suction port of the gas-liquid separator 102' communicates with the S' end of the four-way valve 103'. The C' end of the four-way valve 103' communicates with the first end of the first heat exchanger 104', and the E' end of the four-way valve 103' communicates with the first end of the first stop valve 51'. The second end of the first heat exchanger 104' communicates with the first end of the third expansion valve 106', and the second end of the third expansion valve 106' communicates with the first end of the second stop valve 52'.

Each indoor unit 20' of the at least one indoor unit 20' includes a second heat exchanger 201', a second fan 202' and a second expansion valve 203'. The first end of the second heat exchanger 201' communicates with the second end of the first stop valve 51', and the second end of the second heat exchanger 201' communicates with the first end of the second expansion valve 203'. The second end of the second expansion valve 203' communicates with the second end of the second stop valve 52'.

As shown in FIG. 2, the air conditioner 1000' further includes a controller 30'. The controller 30' is coupled to the compressor 101', the four-way valve 103', the first fan 105' and the third expansion valve 106' in the outdoor unit 10', and is connected to the second fan 202' in the indoor unit 20'. It is coupled with the second expansion valve 203'. The controller 30' is configured to control the working status of each component coupled to the controller 30'.

In some embodiments, the above-mentioned air conditioner 1000' works in a cooling working state to reduce the temperature of the indoor space. In the cooling working state, the controller 30' controls the compressor 101' to start working, and controls the D' end of the four-way valve 103' to communicate with the C' end, and the S' end to communicate with the E' end. In addition, the controller 30' also controls the third expansion valve 106', the second expansion valve 203', the first cut-off valve 51' and the second cut-off valve 52' to be in an open state.

In this way, the compressor 101' compresses the gaseous refrigerant to obtain a high-temperature, high-pressure gaseous refrigerant, and drives the compressed refrigerant to pass through the D' end and C' end of the four-way valve 103' to reach the first heat exchanger. 104' to enter the first heat exchanger 104'. After the high-temperature, high-pressure gaseous refrigerant is liquefied into a low-temperature, low-pressure liquid refrigerant in the first heat exchanger 104', it passes through the second end of the first heat exchanger 104', the third expansion valve 106', and the second shut-off valve. 52' and the second expansion valve 203' reach the second end of the second heat exchanger 201' to enter the second heat exchanger 201'. The low-temperature, low-pressure liquid refrigerant is vaporized into a gaseous refrigerant in the second heat exchanger 201 ′, thereby absorbing heat around the second heat exchanger 201 ′ to reduce the temperature of the indoor space. Then, the vaporized gaseous refrigerant passes through the first end of the second heat exchanger 201' and the first cut-off valve 51' to reach the four-way valve 103', and then passes through the E' end and S' end of the four-way valve 103' to reach the gas refrigerant. The suction port of the liquid separator 102'. The gaseous refrigerant may condense to produce liquid during the process of being transferred from the second heat exchanger 201' to the gas-liquid separator 102'. After the gas-liquid separator 102' separates the liquid, the gaseous refrigerant is input into the compressor 101' In order to realize the recycling of refrigerant.

It should be noted that, in the cooling working state, the first end of the first heat exchanger 104' is the suction port of the first heat exchanger 104', and the second end of the first heat exchanger 104' is the air inlet of the first heat exchanger 104'. The liquid outlet of the first heat exchanger 104'; the second end of the second heat exchanger 201' is the liquid suction port of the second heat exchanger 201', and the first end of the second heat exchanger 201' is The exhaust port of the second heat exchanger 201'.

In some other embodiments, the above-mentioned air conditioner 1000' works in a heating working state to increase the temperature of the indoor space. Different from the above cooling working state, in the heating working state, the controller 30' controls the D' end of the four-way valve 103' to communicate with the E' end, and the S' end to communicate with the C' end.

In this way, the high-temperature, high-pressure gaseous refrigerant obtained after the compression process of the compressor 101' passes through the D' end and the E' end of the four-way valve 103', and enters the second heat exchanger 201' from the first end of the second heat exchanger 201'. Heater 201'. The high-temperature, high-pressure gaseous refrigerant is liquefied into a low-temperature, low-pressure liquid refrigerant in the second heat exchanger 201 ′, thereby releasing heat to the surroundings of the second heat exchanger 201 ′ to increase the temperature of the indoor space. Then, the low-temperature, low-pressure liquid refrigerant flows out of the second heat exchanger 201' from the second end of the second heat exchanger 201', and enters the first heat exchanger from the second end of the first heat exchanger 104' 104' in. The low-temperature, low-pressure liquid refrigerant is vaporized into a gaseous refrigerant in the first heat exchanger 104', and then transferred to the gas-liquid separator 102' through the C' end and S' end of the four-way valve 103', and then returns to the compression machine 101'.

In the above-mentioned cooling working state or heating working state, the first fan 105' is configured to start working under the control of the controller 30' to transfer the heat generated by the first heat exchanger 104' to liquefy the refrigerant or the heat generated by the vaporized refrigerant. The cold generated is discharged from the outdoor unit 10'; the second fan 202' is configured to start working under the control of the controller 30', so as to transfer the cold generated by the second heat exchanger 201' to the vaporized refrigerant or the liquefied refrigerant. The heat of the indoor unit 20' is exhausted to adjust the temperature of the indoor space where the indoor unit 20' is located.

When the air conditioner 1000' leaves the factory, the compressor 101' of the air conditioner 1000' usually contains a small amount of refrigerant, and the amount of cooling or heat generated by the vaporization or liquefaction of the small amount of refrigerant is not enough to meet the daily needs of users. cooling or heating demand. Therefore, when the air conditioner 1000' is installed, it is necessary to supplement the refrigerant into the compressor 101'. In the related art, installers usually need to calculate the amount of refrigerant required in the air conditioner 1000' according to the length and diameter of the connecting pipe between the outdoor unit 10' and the indoor unit 20', and then manually supply the refrigerant to the compressor. Refrigerant is supplemented in 101'.

However, when the air conditioner 1000' is replaced with a new one, the installer usually only replaces the outdoor unit 10' and the indoor unit 20', and keeps the original connecting pipe between the outdoor unit 10' and the indoor unit 20'. To simplify the installation process and save installation costs. At this time, the installer cannot obtain the parameters of the previously connected pipes, and thus cannot calculate the amount of refrigerant required by the replaced air conditioner 1000 ′.

Aiming at the above-mentioned technical problems, a possible solution is: the installer first uses the small amount of refrigerant contained in the compressor 101' to start the air conditioner 1000' to work, then detects the system pressure of the air conditioner 1000', and then according to the system The size of the pressure determines the amount of refrigerant that needs to be added. However, since the system pressure of the air conditioner 1000' is greatly affected by factors such as the ambient temperature of the outdoor unit 10' and the ambient temperature of the indoor unit 20', the accuracy of the refrigerant quantity estimated through the system pressure is relatively low. .

Aiming at the technical problems in related technologies and possible solutions, the inventors of the present application have found through research that: when the air conditioner 1000' is in the cooling working state, the amount of refrigerant required by the air conditioner 1000' is the same as that of the first heat exchanger There is a positive correlation between the degrees of subcooling at the liquid outlet of 104' as shown in FIG. 3 . If the air conditioner 1000' is kept in the cooling working state during the refrigerant charging process, the amount of refrigerant required by the air conditioner 1000' can be determined according to the degree of supercooling at the liquid discharge port of the first heat exchanger 104', Furthermore, the refrigerant charging amount of the air conditioner 1000' can be accurately controlled to improve the operation effect of the air conditioner 1000' after the refrigerant charging is completed.

Based on the above technical concept, some embodiments of the present disclosure provide an air conditioner 1000 . The air conditioner 1000 is provided with a refrigerant charging device 40, so that the controller 30 can control the refrigerant charging device 40 to charge the air conditioner 1000 according to the amount of refrigerant required by the air conditioner 1000 determined by the degree of subcooling. Inject proper amount of refrigerant.

As shown in FIG. 4 and FIG. 5 , the air conditioner 1000 includes an outdoor unit 10 , at least one indoor unit 20 , a controller 30 and a refrigerant charging device 40 .

The outdoor unit 10 includes a compressor 101 and a first heat exchanger 104 . The compressor 101 is configured to compress refrigerant to drive the refrigerant to circulate in the air conditioner 1000 . The first heat exchanger 104 is configured to either liquefy or vaporize the refrigerant.

Each of the at least one indoor unit 20 communicates with the outdoor unit 10 , and each indoor unit 20 includes a second heat exchanger 201 . The second heat exchanger 201 is configured to liquefy or vaporize the refrigerant.

The refrigerant charging device 40 communicates with the compressor 101 and is configured to supply refrigerant.

The controller 30 is coupled to the compressor 101 and the refrigerant charging device 40, and is configured to: control the air conditioner 1000 to enter the cooling working state in response to receiving the refrigerant charging instruction; obtain the discharge port of the first heat exchanger 104 The subcooling degree threshold SCO at , the subcooling degree threshold SCO is determined according to the first internal volume VO of the outdoor unit 10 and the second internal volume VI of the at least one indoor unit 20; the first heat exchange value is obtained every first time period The subcooling degree SC at the liquid outlet of the device 104; if the subcooling degree SC is less than the subcooling degree threshold value SCO, then control the refrigerant charging device 40 to charge refrigerant into the compressor 101; when the subcooling degree SC is greater than or equal to the supercooling degree When the coldness threshold SCO is reached, the refrigerant charging device 40 is controlled to stop charging the refrigerant into the compressor 101 .

In some embodiments, after the installer presses the button on the electric control panel or the remote control of the air conditioner 1000 for instructing the air conditioner 1000 to charge the refrigerant, the electric control panel or the remote control can give the controller 30 sends the above-mentioned refrigerant charging command, so that the controller 30 makes the above-mentioned response.

In the air conditioner 1000 provided by the embodiment of the present disclosure, after the controller 30 receives the refrigerant charging instruction, it can compare the subcooling degree SC at the liquid discharge port of the first heat exchanger 104 with the subcooling degree threshold SCO It is judged whether it is necessary to add refrigerant to the air conditioner 1000 according to the size relationship. When the subcooling degree SC is less than the subcooling degree threshold SCO, the air conditioner 1000 may determine that the current amount of refrigerant is insufficient, and that refrigerant needs to be supplemented. At this time, the air conditioner 1000 can control the refrigerant charging device 40 to start charging the refrigerant into the compressor 101 until the subcooling degree SC is greater than or equal to the subcooling degree threshold SCO, and the air conditioner 1000 can control the refrigerant charging device 40 to stop charging the refrigerant to the compressor 101. The compressor 101 is filled with refrigerant. In this way, according to the positive correlation between the subcooling degree SC at the liquid discharge port of the first heat exchanger 104 and the amount of refrigerant in the air conditioner 1000, as well as the first internal volume VO of the outdoor unit 10 and each indoor unit The subcooling degree threshold SCO determined by the second inner volume VI of 20 accurately determines the amount of refrigerant required by the air conditioner 1000, thereby preventing the amount of refrigerant in the air conditioner 1000 from being greater than the amount of refrigerant required by the air conditioner 1000 and failing to Normal operation also avoids that the amount of refrigerant in the air conditioner 1000 is less than the amount of refrigerant required by the air conditioner 1000 and cannot meet the user's cooling or heating needs, thereby improving the operating effect of the air conditioner 1000 after refrigerant charging . In addition, by setting the refrigerant charging device 40 , the air conditioner 1000 can automatically charge the refrigerant without requiring the installer to manually add refrigerant, thereby improving the refrigerant charging efficiency of the air conditioner 1000 and simplifying the installation procedure of the air conditioner 1000 .

It should be noted that, as shown in Figure 4, the outdoor unit 10 of the air conditioner 1000 also includes a gas-liquid separator 102, a four-way valve 103, a first fan 105 and a third expansion valve 106, and the indoor unit 20 also includes a second The fan 202 , the second expansion valve 203 , and the connecting pipe between the outdoor unit 10 and the indoor unit 20 further include a first stop valve 51 and a second stop valve 52 . For the connection relationship of the foregoing components and the working mode of the components in the cooling working state of the air conditioner 1000 , reference may be made to the previous descriptions of related technologies, which will not be repeated here.

In some embodiments, the first inner volume VO of the outdoor unit 10 refers to the inner volume of the first heat exchanger 104, and the second inner volume VI of the indoor unit 20 refers to the second heat exchanger 201 of the indoor unit 20. internal volume. Since the above-mentioned subcooling degree threshold SCO is determined according to the first inner volume VO of the outdoor unit 10 and the second inner volume VI of each indoor unit 20, for different first inner volumes VO and second inner volumes VI, For the air conditioner 1000, the value of the subcooling degree threshold SCO is different. In this way, the amount of refrigerant determined by the subcooling degree threshold SCO can be applied to air conditioners 1000 of different specifications, thereby further improving the accuracy of the determined amount of refrigerant.

It should be noted that the above subcooling degree SC is the difference between the saturation temperature Tdc of the refrigerant under the discharge pressure Pd and the temperature Te at the liquid discharge port of the first heat exchanger 104 , ie, SC=Tdc−Te. Exemplarily, the controller 30 can detect the discharge pressure Pd through the pressure sensor provided at the discharge port of the compressor 101, and calculate (or query) according to the calculation formula (or lookup table) pre-input into the air conditioner 1000 The saturation temperature Tdc of the refrigerant at the discharge pressure Pd is obtained. Exemplarily, the controller 30 may detect the temperature Te through a temperature sensor disposed at the liquid outlet of the first heat exchanger 104 , so as to obtain the subcooling degree SC according to the saturation temperature Tdc and the temperature Te.

In addition, the supercooling degree threshold SCO may be determined by the installer according to the first inner volume VO and the second inner volume VI, and then input into the air conditioner 1000 . At this time, the controller 30 can directly invoke the supercooling degree threshold SCO, thereby reducing operation steps and improving the data processing efficiency of the controller 30 . Alternatively, the controller 30 may determine the supercooling degree threshold SCO according to the first inner volume VO and the second inner volume VI. In this way, the operating steps of the installer can be reduced and the degree of automation can be improved.

In some embodiments, the supercooling degree threshold SCO is determined according to the ratio between the sum of the second internal volumes VI of the at least one indoor unit 20 and the first internal volume VO. In some examples, the air conditioner 1000 includes one indoor unit 20 . At this time, there is a positive correlation between the ratio VI/VO between the second inner volume VI and the first inner volume VO and the subcooling degree threshold SCO as shown in FIG. 6 . In this way, the controller 30 can obtain the subcooling degree threshold SCO corresponding to the ratio VI/VO according to the ratio VI/VO and the positive correlation.

It should be noted that the different subcooling degree thresholds SCO corresponding to different ratios between the sum of the second inner volume VI and the first inner volume VO can be determined through methods such as pre-conducted experimental tests or simulations.

The structure of the above-mentioned refrigerant charging device 40 will be exemplarily described below mainly in conjunction with the accompanying drawings.

In some embodiments, referring to FIG. 4 , the refrigerant charging device 40 includes a refrigerant tank 41 and a refrigerant charging pipeline 42 . The refrigerant tank 41 is configured to store refrigerant. One end of the refrigerant charging pipeline 42 communicates with the refrigerant tank 41 , and the other end of the refrigerant charging pipeline 42 communicates with the suction port of the compressor 101 to charge the refrigerant from the refrigerant tank 41 into the compressor 101 .

In this way, the controller 30 can control the refrigerant charging device 40 to start or stop charging the refrigerant into the compressor 101 by controlling the opening or closing of the refrigerant charging pipeline 42 .

In some embodiments, the refrigerant charging device 40 further includes a throttle 43 . The throttling member 43 is disposed on the refrigerant charging pipeline 42 and is configured to adjust the charging speed of the refrigerant and/or control the opening and closing of the refrigerant charging pipeline 42 .

In some examples, with continued reference to FIG. 4 , the throttle member 43 includes a first expansion valve 431 . The controller 30 is coupled to the first expansion valve 431 to control the opening or closing of the first expansion valve 431 , so as to control the refrigerant charging device 40 to start or stop charging the refrigerant into the compressor 101 . In addition, the controller 30 can also adjust the charging speed of the refrigerant by controlling the opening degree of the first expansion valve 431 . Wherein, the opening degree refers to the opening degree of the expansion valve. The larger the opening degree of the first expansion valve 431 is, the greater the amount of refrigerant that can pass through the first expansion valve 431 per unit time is, thus the faster the charging speed of the refrigerant is. For the convenience of description, the opening degree of the expansion valve in the embodiment of the present disclosure is represented by EV, and the unit of the opening degree is, for example, "step (PLS)".

In this example, the controller 30 is further configured to obtain the first degree of superheat at the suction port of the compressor 101 every second time period after controlling the refrigerant charging device 40 to charge the refrigerant into the compressor 101 Tssh: according to the first degree of superheat Tssh, the opening degree of the first expansion valve 431 is controlled to adjust the charging speed of the refrigerant.

In this way, the controller 30 can reduce the opening of the first expansion valve 431 when the refrigerant charging speed is fast, so as to prevent the refrigerant charged into the air conditioner 1000 by the refrigerant charging device 40 from accumulating on the compressor 101 or other components. place, so as to prevent the pressure of the refrigerant accumulation part from being too high, triggering the high-pressure shutdown protection of the air conditioner 1000. The controller 30 may increase the opening degree of the first expansion valve 431 when the refrigerant charging speed is relatively slow, so as to improve the refrigerant charging efficiency and save the charging time.

It should be noted that the first degree of superheat Tssh is the difference between the temperature Ts at the suction port of the compressor 101 and the saturation temperature Tsc of the refrigerant under the suction pressure Ps, ie, Tssh=Ts−Tsc. Regarding the manner in which the controller 30 obtains the temperature Ts and the saturation temperature Tsc, reference may be made to the relevant descriptions of obtaining the temperature Te and the saturation temperature Tdc in the foregoing embodiments, and details are not repeated here.

Exemplarily, the controller 30 is configured to: control the opening degree of the first expansion valve 431 to increase when the first degree of superheat Tssh is greater than the upper limit of the preset first degree of superheat range; At the lower limit of the superheat range, the opening degree of the first expansion valve 431 is controlled to decrease.

For example, as shown in FIG. 7, when the controller 30 controls the refrigerant charging device 40 to charge refrigerant into the compressor 101, it can control the first expansion valve 431 to open, and make the opening degree EVC of the first expansion valve 431 to be Initial opening EVC0. During the filling process, if the first superheat degree Tssh is outside the first superheat degree range, the controller 30 can use ΔEVC as a fixed adjustment value to adjust the temperature of the first expansion valve 431 at the end of the last second time period. On the basis of the opening degree EVC(N), add or subtract ΔEVC to control the opening degree of the first expansion valve 431 to increase or decrease. If the first superheat degree Tssh is within the first superheat degree range, the controller 30 maintains the opening degree of the first expansion valve 431 at EVC(N). When the subcooling degree SC is greater than or equal to the subcooling degree threshold SCO, the refrigerant charging is completed, and the controller 30 may control the first expansion valve 431 to close (that is, control the opening degree EVC of the first expansion valve 431 to be zero).

The upper limit of the first degree of superheat range may be, for example, the sum of the first degree of superheat threshold Tssh0 and the first value g, and the lower limit of the first degree of superheat range may be, for example, the difference between the first degree of superheat threshold Tssh0 and the second value h value. Wherein, the first superheat threshold TsshO can be obtained according to pre-experiment or simulation; the first value g is a constant greater than zero; the second value h is a constant greater than zero. The first value g and the second value h may be equal or not. When the first degree of superheat Tssh is within the range of the first degree of superheat, it can be considered that the amount of refrigerant at each component in the air conditioner 1000 is relatively balanced.

In some other examples, as shown in FIG. 8 , the throttle member 43 includes a solenoid valve 432 and a capillary 433 . Wherein, the solenoid valve 432 is coupled to the controller 30 , and one end of the solenoid valve 432 communicates with one end of the capillary 433 . At this time, the controller 30 can control the refrigerant charging device 40 to start or stop charging the refrigerant into the compressor 101 by controlling the solenoid valve 432 to open or close. In this example, the capillary 433 can control the charging speed of the refrigerant, so as to prevent the high pressure shutdown protection from being charged too fast.

In some other examples, as shown in FIG. 9 , the throttle member 43 includes a capillary 433 . At this time, the throttling member 43 is only used to adjust the charging speed of the refrigerant.

In some embodiments, referring to FIG. 4 , FIG. 8 and FIG. 9 , the refrigerant charging device 40 further includes a regulating valve 44 . The regulating valve 44 is disposed on the refrigerant charging pipeline 42 and coupled with the controller 30 . One end of the regulating valve 44 communicates with the refrigerant tank 41 , and the other end communicates with the throttle 43 . In this way, when the throttling member 43 includes the capillary 433 , the controller 30 can control the refrigerant charging device 40 to start or stop charging the refrigerant into the compressor 101 by controlling the opening or closing of the regulating valve 44 .

When the number of indoor units 20 in the air conditioner 1000 is large, the amount of refrigerant required by the air conditioner 1000 is generally large. Since the capacity of the refrigerant tank 41 is limited, in this case, the refrigerant in one refrigerant tank 41 may not be sufficient to raise the subcooling degree SC to the subcooling degree threshold SCO. Therefore, in some embodiments, the controller 30 is further configured to: after controlling the refrigerant charging device 40 to charge the refrigerant into the compressor 101, acquire the supercooling degree SC at the last third time every third time period increase within the segment; when the increase is less than the preset first threshold, a first prompt message is sent; the first prompt message is used to indicate that the amount of refrigerant in the refrigerant tank 41 is insufficient.

In this embodiment, when the increase of the subcooling degree SC in the last third time period is less than the preset first threshold, the controller 30 may determine that the air conditioner is charged into the air conditioner in the last third time period. If the amount of refrigerant in the air conditioner 1000 is less than the amount of refrigerant required by the air conditioner 1000, it may be that the refrigerant in the refrigerant tank 41 has been exhausted. At this time, the controller 30 sends a first prompt message to the installer, which may remind the installer to replace the new refrigerant tank 41 or replenish the refrigerant in the current refrigerant tank 41 . In this way, it can be ensured that the amount of refrigerant supplied to the air conditioner 1000 is sufficient.

In some examples, the air conditioner 1000 further includes at least one speaker. At this time, the above-mentioned first prompt information may be, for example, a prompt sound issued by the speaker. In some other examples, the air conditioner 1000 further includes a display screen. At this time, the above-mentioned first prompt information may be, for example, text information displayed on the display screen.

It should be noted that, in the embodiment of the present disclosure, there is no limitation on the order in which the controller 30 obtains the first superheat degree Tssh and obtains the increase amount of the subcooling degree SC. In the case where the length relationship between the second time period and the third time period is different, the sequence is different. Exemplarily, if the second time period is shorter than the third time period, the controller 30 acquires the first superheat degree Tssh first, and then acquires the increase amount of the subcooling degree SC if the acquisition times are the same. Alternatively, if the second time period is equal to the third time period, the controller 30 acquires the increments of the first superheating degree Tssh and the supercooling degree SC at the same time.

In some embodiments, the controller 30 is further configured to: obtain the first ambient temperature of the outdoor unit 10 and the second ambient temperature of the indoor unit 20 in response to receiving the refrigerant charging instruction; when the first environment When the temperature is within the preset first temperature range and the second ambient temperature is within the preset second temperature range, the air conditioner 1000 is controlled to enter the cooling working state.

When the first ambient temperature is outside the preset first temperature range, or the second ambient temperature is outside the preset second temperature range, the degree of subcooling SC shown in FIG. 3 and the amount of refrigerant required by the air conditioner 1000 The relationship between , and the relationship between the subcooling threshold SCO and the ratio VI/VO as shown in FIG. 6 may be changed. Therefore, the air conditioner 1000 in the above embodiment can further improve the accuracy of the amount of refrigerant determined according to the subcooling degree threshold SCO and the subcooling degree SC, thereby improving the operation effect of the air conditioner 1000 after refrigerant charging is completed.

In some embodiments, the controller 30 is further configured to: after controlling the air conditioner 1000 to enter the cooling working state, acquire the discharge temperature Td at the discharge port of the compressor 101 at the last fourth time period every fourth time period. The amount of change within a time period; when the amount of change is less than the preset second threshold, the subcooling degree threshold SCO at the liquid discharge port of the first heat exchanger 104 is acquired.

Since the discharge temperature Td at the discharge port of the compressor 101 changes rapidly within a certain period of time after the air conditioner 1000 enters the cooling working state, the operation of the air conditioner 1000 is not stable at this time. If the refrigerant is charged according to the subcooling degree SC at the liquid discharge port of the first heat exchanger 104 at this time, the amount of refrigerant actually charged into the air conditioner 1000 may not match the amount of refrigerant required for the smooth operation of the air conditioner 1000 . Therefore, the air conditioner 1000 in the above embodiment can judge whether the air conditioner 1000 is running smoothly through the change amount of the discharge temperature Td at the discharge port of the compressor 101 in the last fourth time period, and determine whether the air conditioner 1000 is running smoothly according to the change amount If it is less than the preset second threshold, it is determined that the air conditioner 1000 has been running stably in the cooling working state, and then the subcooling degree threshold SCO is obtained for subsequent steps. In this way, the air conditioner 1000 can further improve the accuracy of the amount of refrigerant charged into the air conditioner 1000 .

In some other embodiments, in the case that the air conditioner 1000 includes multiple indoor units 20 , the controller 30 may acquire the second degree of superheat at the exhaust outlets of the multiple indoor units 20 every fourth time period. If the minimum value among the second superheat degrees of the plurality of indoor units 20 is greater than the first preset value for a preset time period, and the maximum value among the second superheat degrees of the plurality of indoor units 20 is less than the second preset value value and lasts for a preset period of time, the controller 30 can determine that the air conditioner 1000 has been running stably in the cooling working state.

Some embodiments of the present disclosure also provide an air conditioner 1000 . For the components included in the air conditioner 1000 and the working methods of the components, etc., reference may be made to the description of the air conditioner 1000 in the foregoing embodiments, and details are not repeated here.

Different from the previous embodiments, the controller 30 in the air conditioner 1000 in this embodiment is further configured to control the discharge of the second heat exchanger 201 after controlling the refrigerant charging device 40 to charge the refrigerant into the compressor 101 . The second degree of superheat SH at the gas port is within the preset second degree of superheat range, the discharge pressure Pd at the discharge port of the compressor 101 is controlled to be within the preset discharge pressure range, and the second heat exchange is controlled The first working temperature TG of the device 201 is within a preset working temperature range.

The magnitude of the second degree of superheat SH at the discharge port of the second heat exchanger 201, the discharge pressure Pd at the discharge port of the compressor 101, and the first operating temperature TG of the second heat exchanger 201 Changes may cause changes in the degree of subcooling SC at the liquid outlet of the first heat exchanger 104. In this way, when the degree of subcooling SC is greater than or equal to the threshold value SCO of the degree of subcooling, the amount of refrigerant in the air conditioner 1000 may be less The amount of refrigerant that is greater than or equal to the actual requirement of the air conditioner 1000. Therefore, the air conditioner 1000 in this embodiment controls the second superheat degree SH to be within the preset second superheat degree range, the discharge pressure Pd to be within the preset discharge pressure range, and the first working temperature TG to be within the preset range. Within the working temperature range, it is possible to avoid the influence of the second degree of superheat SH, the discharge pressure Pd and the first working temperature TG on the degree of subcooling SC, so that the degree of supercooling SC can be used in the process from the start of refrigerant charging to the stop of charging. Mainly according to the change of the amount of refrigerant in the air conditioner 1000, so as to improve the accuracy of the refrigerant amount determined according to the subcooling degree SC and the subcooling degree threshold SCO, and then improve the operation effect of the air conditioner 1000 after the refrigerant charging is completed .

It should be noted that the second degree of superheat SH is the difference between the temperature Ti at the exhaust port of the second heat exchanger 201 and the saturation temperature Tsc, that is, SH=Ti−Tsc. Regarding the manner in which the controller 30 acquires the temperature Ti, reference may be made to relevant descriptions on acquiring the temperature Te in the foregoing embodiments, and details are not repeated here.

In addition, since the air conditioner 1000 is in the cooling working state, the first heat exchanger 104 in the refrigerant charging process is used to condense the refrigerant, which can be called a condenser; the second heat exchanger 201 is used to evaporate the refrigerant, and can be called a condenser. Evaporator. Therefore, the second working temperature TL of the first heat exchanger 104 can also be called the condensation temperature of the air conditioner 1000 , and the first working temperature TG of the second heat exchanger 201 can also be called the evaporation temperature of the air conditioner 1000 .

In some examples, the controller 30 may obtain the first working temperature TG through a temperature sensor disposed outside the second heat exchanger 201 . Exemplarily, a plurality of temperature sensors may be provided outside the second heat exchanger 201 , and the controller 30 may average the temperatures detected by the plurality of temperature sensors, and determine the average value as the first working temperature TG. In this way, the accuracy of the first working temperature TG acquired by the controller 30 can be improved.

In the following, the method of adjusting the second degree of superheat SH, the discharge pressure Pd and the first working temperature TG by the controller 30 will be exemplarily described mainly in conjunction with the accompanying drawings.

In some embodiments, referring to FIG. 4 and FIG. 5 , the indoor unit 20 further includes a second expansion valve 203 . The second expansion valve 203 is coupled with the controller 30 . One end of the second expansion valve 203 communicates with the liquid suction port of the second heat exchanger 201 and is configured to adjust the speed of refrigerant flowing into the second heat exchanger 201 .

The controller 30 is configured to: obtain the second degree of superheat SH every fifth time period; when the second degree of superheat SH is greater than the upper limit of the second degree of superheat range, control the opening degree of the second expansion valve 203 to increase; When the second degree of superheat SH is less than the lower limit of the second degree of superheat range, the opening degree of the second expansion valve 203 is controlled to decrease.

In this embodiment, after the opening degree of the second expansion valve 203 is increased, the amount of liquid refrigerant flowing into the second heat exchanger 201 through the second expansion valve 203 per unit time will increase. After the amount of refrigerant used for evaporative heat exchange in the second heat exchanger 201 increases, under the condition that the total amount of heat in the indoor space absorbed by the evaporation of the refrigerant is the same, the unit volume of refrigerant in the second heat exchanger 201 The heat absorbed is reduced. Therefore, by controlling the opening degree of the second expansion valve 203 to increase, the second degree of superheat SH can be reduced. Similarly, by controlling the opening degree of the second expansion valve 203 to decrease, the second degree of superheat SH can be increased.

For example, as shown in FIG. 10, when the controller 30 controls the refrigerant charging device 40 to charge refrigerant into the compressor 101, it can control the second expansion valve 203 to open, and make the opening EV7 of the second expansion valve 203 to be Initial opening EV70. During the filling process, if the second degree of superheat SH is outside the range of the second degree of superheat, the controller 30 can use ΔEV7 as a fixed adjustment value to adjust the temperature of the second expansion valve 203 at the end of the last fifth time period. On the basis of the opening degree EV7(N), add or subtract ΔEV7 to control the opening degree of the second expansion valve 203 to increase or decrease. If the second degree of superheat SH is within the second degree of superheat range, the controller 30 maintains the opening degree of the second expansion valve 203 at EV7(N).

The upper limit of the second superheat range, for example, may be the sum of the second superheat threshold SHO and the third value a, and the lower limit of the second superheat range may be, for example, the sum of the second superheat threshold SHO and the fourth value b difference. Wherein, the values of the second superheat threshold SHO, the third numerical value a and the fourth numerical value b can refer to the values of the first superheat threshold Tssh0, the first numerical value g and the second numerical value h in the foregoing embodiment respectively, in This will not be repeated here. When the second degree of superheat SH is within the range of the second degree of superheat, it can be considered that the second degree of superheat SH does not affect the accuracy of the amount of refrigerant determined according to the degree of subcooling SC.

In some embodiments, referring to FIG. 4 and FIG. 5 , the outdoor unit 10 further includes a first fan 105 . The first fan 105 is coupled to the controller 30 and configured to adjust the second working temperature TL of the first heat exchanger 104 .

The controller 30 is also configured to: obtain the exhaust pressure Pd every sixth time period; when the exhaust pressure Pd is greater than the upper limit of the exhaust pressure range, control the operating frequency of the first fan 105 to increase; when the exhaust pressure Pd When it is less than the lower limit of the exhaust pressure range, the operating frequency of the first fan 105 is controlled to decrease.

In the cooling working state, the first heat exchanger 104 is used to condense the high-temperature, high-pressure gaseous refrigerant into a low-temperature, low-pressure liquid refrigerant.

In this embodiment, after the operating frequency of the first fan 105 is increased, the dissipating speed of the heat generated by the first heat exchanger 104 can be accelerated, thereby increasing the heat exchange efficiency of the first heat exchanger 104 to reduce the second Working temperature TL. Since the first heat exchanger 104 is used to condense the high-temperature, high-pressure gaseous refrigerant into a low-temperature, low-pressure liquid refrigerant in the cooling working state, therefore, increasing the heat exchange efficiency of the first heat exchanger 104 can speed up the first heat exchange. The device 104 reduces the efficiency of the refrigerant pressure, thereby reducing the discharge pressure Pd. Similarly, by controlling the operating frequency of the first fan 105 to decrease, the discharge pressure Pd can be increased.

For example, as shown in FIG. 11 , when the controller 30 controls the refrigerant charging device 40 to charge refrigerant into the compressor 101 , it can control the operating frequency Fe of the first fan 105 to be the initial frequency Fe0. During the charging process, if the discharge pressure Pd is outside the range of the discharge pressure, the controller 30 can use ΔFe as a fixed adjustment amount, and the operating frequency Fe of the first blower 105 at the end of the last sixth time period is On the basis of (N), add or subtract ΔFe to control the operating frequency of the first fan 105 to increase or decrease. If the discharge pressure Pd is within the discharge pressure range, the controller 30 maintains the operating frequency of the first blower 105 as Fe(N).

The upper limit of the exhaust pressure range may be, for example, the sum of the exhaust pressure threshold PdO and the fifth value c, and the lower limit of the exhaust pressure range may be, for example, the difference between the exhaust pressure threshold PdO and the sixth value d. Wherein, the exhaust pressure threshold PdO, the fifth numerical value c and the sixth numerical value d can refer to the values of the first superheat degree threshold TsshO, the first numerical value g and the second numerical value h in the foregoing embodiment respectively, here No longer. When the exhaust pressure Pd is within the exhaust pressure range, it can be considered that the exhaust pressure Pd does not affect the accuracy of the refrigerant amount determined according to the subcooling degree SC.

In some embodiments, referring to FIG. 4 and FIG. 5 , the indoor unit 20 further includes a second fan 202 . The second fan 202 is coupled to the controller 30 and configured to adjust the first working temperature TG of the second heat exchanger 201 .

The controller 30 is also configured to: obtain the first working temperature TG every seventh time period; when the first working temperature TG is greater than the upper limit of the working temperature range, control the operating frequency of the second fan 202 to decrease; when the first working When the temperature TG is lower than the lower limit of the working temperature range, the operating frequency of the second fan 202 is controlled to increase.

In this embodiment, after the operating frequency of the second fan 202 is reduced, the dissipating speed of the cold generated by the second heat exchanger 201 can be slowed down, thereby reducing the first working temperature TG of the second heat exchanger 201 . Similarly, by controlling the operating frequency of the second fan 202 to increase, the first working temperature TG of the second heat exchanger 201 can be increased.

For example, as shown in FIG. 12 , when the controller 30 controls the refrigerant charging device 40 to charge refrigerant into the compressor 101 , it can control the operating frequency Fi of the second fan 202 to be the initial frequency Fi0. During the filling process, if the first working temperature TG is outside the working temperature range, the controller 30 can use ΔFi as a fixed adjustment value, and the operating frequency Fi of the second fan 202 at the end of the last seventh time period On the basis of (N), add or subtract ΔFi to control the operating frequency of the second fan 202 to increase or decrease. If the first working temperature TG is within the working temperature range, the controller 30 maintains the operating frequency of the second blower 202 as Fi(N).

The upper limit of the above-mentioned operating temperature range may be, for example, the sum of the operating temperature threshold TGO and the seventh value e, and the lower limit of the above-mentioned operating temperature range may be, for example, the difference between the operating temperature threshold TGO and the eighth value f. Wherein, the values of the working temperature threshold TIO, the seventh value e and the eighth value f can refer to the values of the first superheat threshold Tssh0, the first value g and the second value h in the foregoing embodiment respectively, and are not described here. Let me repeat. When the first working temperature TG is within the working temperature range, it can be considered that the first working temperature TG does not affect the accuracy of the amount of refrigerant determined according to the degree of subcooling SC.

It should be noted that, in the embodiment of the present disclosure, there is no limitation on the order in which the controller 30 controls the second degree of superheat SH, controls the discharge pressure Pd, and controls the first working temperature TG. In the case where the length relationship among the fifth time period, the sixth time period and the seventh time period is different, the sequence is different. Exemplarily, if the fifth time period is shorter than the sixth time period, and the sixth time period is shorter than the seventh time period, in the case of the same control times, the controller 30 first controls the second superheat degree SH to be at the second Within the superheat range, control the discharge pressure Pd to be within the discharge pressure range, and then control the first working temperature TG to be within the working temperature range. Alternatively, if the fifth time period is equal to the sixth time period and equal to the seventh time period, the controller 30 controls the second superheat degree SH, controls the discharge pressure Pd and controls the first working temperature TG simultaneously.

In summary, the air conditioner 1000 provided by some embodiments of the present disclosure can accurately determine the refrigerant required by the air conditioner 1000 according to the subcooling degree SC at the liquid discharge port of the first heat exchanger 104 and the subcooling degree threshold SCO amount, so as to improve the operation effect of the air conditioner 1000 after charging the refrigerant. In addition, the air conditioner 1000 can also automatically charge the refrigerant without requiring the installer to manually add refrigerant, thereby improving the refrigerant charging efficiency of the air conditioner 1000 and simplifying the installation procedure of the air conditioner 1000 . In addition, the air conditioner 1000 provided by some embodiments of the present disclosure can also prevent the second degree of superheat SH, the exhaust pressure Pd and the first operating temperature TG from affecting the degree of subcooling SC, so that the degree of supercooling SC is mainly based on the The amount of refrigerant varies, thereby improving the accuracy of the amount of refrigerant determined according to the degree of subcooling SC and the threshold value SCO of the degree of subcooling.

Those skilled in the art will understand that the disclosed scope of the present invention is not limited to the specific embodiments described above, and some elements of the embodiments can be modified and replaced without departing from the spirit of the application. The scope of the application is limited by the appended claims.

Claims

An air conditioner, comprising:

Outdoor units, including:

a compressor configured to compress a refrigerant to drive the refrigerant to circulate in the air conditioner;

The first heat exchanger is configured to one of liquefy or vaporize the refrigerant;

At least one indoor unit communicates with the outdoor unit, and each indoor unit includes:

a second heat exchanger configured to either liquefy or vaporize the refrigerant;

a refrigerant charging device communicated with the compressor and configured to provide the refrigerant;

A controller, coupled to the compressor and the refrigerant charging device, and configured to:

In response to receiving a refrigerant charging instruction, controlling the air conditioner to enter a cooling working state;

Obtaining the subcooling degree threshold at the liquid outlet of the first heat exchanger; the subcooling degree threshold is determined according to the first internal volume of the outdoor unit and the second internal volume of the at least one indoor unit;

Obtaining the degree of subcooling at the liquid outlet of the first heat exchanger every first time period;

If the subcooling degree is less than the subcooling degree threshold, control the refrigerant charging device to charge the refrigerant into the compressor;

When the subcooling degree is greater than or equal to the subcooling degree threshold, the refrigerant charging device is controlled to stop charging the refrigerant into the compressor.
The air conditioner according to claim 1, wherein the subcooling degree threshold is determined according to a ratio between the sum of the second internal volumes of the at least one indoor unit and the first internal volume.
The air conditioner according to claim 1 or 2, wherein the refrigerant charging device comprises:

a refrigerant tank configured to store the refrigerant;

Refrigerant charging pipeline; one end of the refrigerant charging pipeline communicates with the refrigerant tank, and the other end of the refrigerant charging pipeline communicates with the suction port of the compressor, so as to transfer the refrigerant from the The refrigerant tank is filled into the compressor.
The air conditioner according to claim 3, wherein the refrigerant charging device further comprises:

A throttling member is arranged on the refrigerant charging pipeline and is configured to adjust the charging speed of the refrigerant and/or control the opening and closing of the refrigerant charging pipeline.
The air conditioner according to claim 4, wherein the throttling member includes a first expansion valve, and the first expansion valve is coupled to the controller;

The controller is also configured to:

After controlling the refrigerant charging device to charge the refrigerant into the compressor, acquiring the first degree of superheat at the suction port of the compressor every second time period;

According to the first degree of superheat, the opening degree of the first expansion valve is controlled to adjust the charging speed of the refrigerant.
The air conditioner according to claim 5, wherein the controller is configured to:

When the first degree of superheat is greater than the upper limit of a preset first degree of superheat range, controlling the opening degree of the first expansion valve to increase;

When the first degree of superheat is less than the lower limit of the range of the first degree of superheat, the opening degree of the first expansion valve is controlled to decrease.
The air conditioner according to any one of claims 3 to 6, wherein the controller is further configured to:

After controlling the refrigerant charging device to charge the refrigerant into the compressor, acquiring the increase of the subcooling degree in the last third time period every third time period;

When the increase amount is less than the preset first threshold, a first prompt message is issued; the first prompt message is used to indicate that the amount of refrigerant in the refrigerant tank is insufficient.
The air conditioner according to any one of claims 1 to 7, wherein the controller is further configured to:

Responding to receiving the refrigerant charging instruction, acquiring a first ambient temperature of the outdoor unit and a second ambient temperature of the indoor unit;

When the first ambient temperature is within a preset first temperature range and the second ambient temperature is within a preset second temperature range, the air conditioner is controlled to enter the cooling working state.
The air conditioner according to any one of claims 1 to 8, wherein the controller is further configured to:

After the air conditioner is controlled to enter the cooling working state, the change amount of the discharge temperature at the discharge port of the compressor in the previous fourth time period is obtained every fourth time period;

When the change amount is smaller than the preset second threshold, the subcooling degree threshold at the liquid discharge port of the first heat exchanger is obtained.
An air conditioner, comprising:

Outdoor units, including:

a compressor configured to compress a refrigerant to drive the refrigerant to circulate in the air conditioner;

The first heat exchanger is configured to one of liquefy or vaporize the refrigerant;

At least one indoor unit communicates with the outdoor unit, and each indoor unit includes:

a second heat exchanger configured to either liquefy or vaporize the refrigerant;

a refrigerant charging device communicated with the compressor and configured to provide the refrigerant;

A controller, coupled to the compressor and the refrigerant charging device, and configured to:

In response to receiving a refrigerant charging instruction, controlling the air conditioner to enter a cooling working state;

Obtaining the degree of subcooling at the liquid outlet of the first heat exchanger every first time period;

If the subcooling degree is less than the subcooling degree threshold, control the refrigerant charging device to charge the refrigerant into the compressor;

controlling the second degree of superheat at the discharge port of the second heat exchanger to be within a preset range of the second degree of superheat, and controlling the discharge pressure at the discharge port of the compressor to be within a preset discharge pressure within the range, and controlling the first working temperature of the second heat exchanger to be within the preset working temperature range;

When the subcooling degree is greater than or equal to the subcooling degree threshold, the refrigerant charging device is controlled to stop charging the refrigerant into the compressor.
The air conditioner according to claim 10, wherein the indoor unit further comprises:

The second expansion valve is coupled to the controller, one end of the second expansion valve communicates with the liquid suction port of the second heat exchanger, and is configured to adjust the flow of the refrigerant into the second heat exchanger the speed of the device;

The controller is configured as:

acquiring the second degree of superheat every fifth time period;

When the second degree of superheat is greater than the upper limit of the second degree of superheat range, controlling the opening degree of the second expansion valve to increase;

When the second degree of superheat is less than the lower limit of the range of the second degree of superheat, the opening degree of the second expansion valve is controlled to decrease.
The air conditioner according to claim 10 or 11, wherein the outdoor unit further comprises:

a first blower coupled to the controller and configured to adjust a second operating temperature of the first heat exchanger;

The controller is also configured to:

acquiring the exhaust pressure every sixth time period;

When the exhaust pressure is greater than the upper limit of the exhaust pressure range, controlling the operating frequency of the first fan to increase;

When the exhaust pressure is lower than the lower limit of the exhaust pressure range, the operating frequency of the first fan is controlled to decrease.
The air conditioner according to any one of claims 10 to 12, wherein the indoor unit further comprises:

a second blower coupled to the controller and configured to adjust the first operating temperature of the second heat exchanger;

The controller is also configured to:

acquiring the first working temperature every seventh time period;

When the first working temperature is greater than the upper limit of the working temperature range, controlling the operating frequency of the second fan to decrease;

When the first working temperature is lower than the lower limit of the working temperature range, the operating frequency of the second fan is controlled to increase.
The air conditioner according to any one of claims 10 to 13, wherein the refrigerant charging device comprises:

a refrigerant tank configured to store the refrigerant;

Refrigerant charging pipeline; one end of the refrigerant charging pipeline communicates with the refrigerant tank, and the other end of the refrigerant charging pipeline communicates with the suction port of the compressor, so as to transfer the refrigerant from the The refrigerant tank is filled into the compressor.
The air conditioner according to claim 14, wherein the refrigerant charging device further comprises:

A throttling member is arranged on the refrigerant charging pipeline and is configured to adjust the charging speed of the refrigerant and/or control the opening and closing of the refrigerant charging pipeline.
The air conditioner according to claim 15, wherein the throttling member includes a first expansion valve, and the first expansion valve is coupled to the controller;

The controller is also configured to:

After controlling the refrigerant charging device to charge the refrigerant into the compressor, acquiring the first degree of superheat at the suction port of the compressor every second time period;

According to the first degree of superheat, the opening degree of the first expansion valve is controlled to adjust the charging speed of the refrigerant.
The air conditioner according to claim 16, wherein the controller is configured to:

When the first degree of superheat is greater than the upper limit of a preset first degree of superheat range, controlling the opening degree of the first expansion valve to increase;

When the first degree of superheat is less than the lower limit of the range of the first degree of superheat, the opening degree of the first expansion valve is controlled to decrease.
The air conditioner according to any one of claims 14 to 17, wherein the controller is further configured to:

After controlling the refrigerant charging device to charge the refrigerant into the compressor, acquire the increment of the subcooling degree in the last third time period every third time period;

When the increase amount is less than a preset first threshold, a first prompt message is issued; the first prompt message is used to indicate that the amount of refrigerant in the refrigerant tank is insufficient;

When the increase is greater than the first threshold, continue to control the refrigerant charging device to charge the refrigerant into the compressor until the degree of subcooling is greater than or equal to the threshold of degree of supercooling.
The air conditioner according to any one of claims 10 to 18, wherein the controller is further configured to:

Responding to receiving the refrigerant charging instruction, acquiring a first ambient temperature of the outdoor unit and a second ambient temperature of the indoor unit;

When the first ambient temperature is within a preset first temperature range and the second ambient temperature is within a preset second temperature range, the air conditioner is controlled to enter the cooling working state.
The air conditioner according to any one of claims 10 to 19, wherein the controller is further configured to:

After the air conditioner is controlled to enter the cooling working state, the change amount of the discharge temperature at the discharge port of the compressor in the previous fourth time period is obtained every fourth time period;

When the change amount is smaller than the preset second threshold, the subcooling degree threshold at the liquid discharge port of the first heat exchanger is obtained.