Multi-connected air conditioner, control method, controller and storage medium thereof

Abstract

Embodiments of the present application provide a multi-split air conditioner, a control method, a controller and a storage medium. The method comprises: obtaining indoor temperature and set temperature for each indoor unit in an open state to determine a temperature difference; selecting a first target indoor unit and a second target indoor unit corresponding to a temperature difference of the first target indoor unit from all indoor units; and controlling the opening degree of a throttling device of the first target indoor unit and / or the second target indoor unit, so that the total load demand of all indoor units is greater than a preset load demand. Embodiments of the present application can adjust the state of the throttling device of different indoor units, stagger the peak and valley of the load demand of different indoor units, realize the peak and valley suppression and coordination of the load demand of multiple indoor units, maintain the stability of system capacity and demand, and solve the problems of frequent start-stop of the compressor or large frequency fluctuation range of the compressor in the low load state of the system capacity and demand under the existing control method, resulting in non-energy-saving operation, high compressor failure rate and other problems.

Description

Technical Field

[0001] This application relates to the field of air conditioner technology, and in particular to a multi-split air conditioner and its control method, controller and storage medium. Background Technology

[0002] In related technologies, multi-split air conditioning systems have multiple indoor units. Each indoor unit receives an independent temperature setting and determines its load requirements based on the set temperature and the actual temperature. The outdoor unit controls the frequency increase, decrease, start, and stop of the outdoor compressor according to the load requirements of the indoor units.

[0003] Under the current control method, if the room load is low and all indoor units in the multi-split system meet the load requirements, the system energy demand will turn to zero. When the compressor of the multi-split system can no longer reduce the frequency, it will stop running. After a period of time, when the room temperature rises, i.e. when the load demand increases, the compressor will start running again, resulting in frequent start-stop of the compressor. Moreover, each restart requires starting from a high frequency, consuming too much energy and damaging the compressor's lifespan. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a multi-split air conditioner and its control method, controller, and storage medium, aiming to avoid frequent compressor start-stop or excessive frequency fluctuations when the system is under low load conditions.

[0005] In a first aspect, embodiments of this application provide a control method for a multi-split air conditioner, including:

[0006] For each indoor unit that is turned on, the indoor temperature and the set temperature are obtained, and the temperature difference is determined based on the indoor temperature and the set temperature.

[0007] Select a first target indoor unit and a second target indoor unit from all the indoor units, wherein the temperature difference corresponding to the first target indoor unit is smaller than the temperature difference corresponding to the second target indoor unit;

[0008] Control the opening degree of the throttling device of the first target indoor unit and / or the second target indoor unit so that the total load demand of all indoor units is greater than the preset load demand.

[0009] According to some embodiments of this application, when the control method includes controlling the opening degree of the throttling device of the first target indoor unit, controlling the opening degree of the throttling device of the first target indoor unit includes:

[0010] Obtain the on / off state of the first throttling device corresponding to the first target indoor unit;

[0011] The first throttling device is turned on or off depending on its on / off state.

[0012] According to some embodiments of this application, turning the first throttling device on or off according to its switching state includes at least one of the following:

[0013] When the first throttling device is in the closed state, the first throttling device remains in the closed state;

[0014] When only the first throttling device corresponding to the first target indoor unit is in the open state, the first throttling device remains in the open state;

[0015] When the first throttling device corresponding to the first target indoor unit is in the open state, and the first target indoor unit is not the only indoor unit with the throttling device open, the first throttling device is controlled to close.

[0016] According to some embodiments of this application, when the control method includes controlling the opening degree of the throttling device of the second target indoor unit, controlling the opening degree of the throttling device of the second target indoor unit includes:

[0017] Obtain the on / off state of the second throttling device corresponding to the second target indoor unit;

[0018] The second throttling device is turned on or off depending on its on / off state.

[0019] According to some embodiments of this application, turning the second throttling device on or off according to its switching state includes at least one of the following:

[0020] When the second throttling device is in the open state, the second throttling device remains in the open state;

[0021] When the second throttling device is in the closed state, control the second throttling device to open.

[0022] According to some embodiments of this application, after the second throttling device is turned on or off according to its switching state, the control method further includes:

[0023] Obtain the current superheat of the refrigerant in the heat exchanger coil of the second target indoor unit;

[0024] The opening degree of the second throttling device is adjusted according to the current superheat and the preset lower limit of superheat.

[0025] According to some embodiments of this application, the step of selecting the first target indoor unit and the second target indoor unit from all the indoor units includes:

[0026] At preset intervals, a first target indoor unit and a second target indoor unit are selected from all the indoor units.

[0027] According to some embodiments of this application, the step of selecting the first target indoor unit and the second target indoor unit from all the indoor units includes:

[0028] Select the target temperature difference value with the largest value from the multiple temperature difference values;

[0029] Obtain the compressor's current operating frequency and lower limit operating frequency, and determine the frequency difference between the current operating frequency and the lower limit operating frequency;

[0030] When there are multiple indoor units in the on state, the target temperature difference is less than or equal to a preset upper temperature limit difference, and the frequency difference is less than a preset frequency, the first target indoor unit and the second target indoor unit are selected from all the indoor units.

[0031] According to some embodiments of this application, after controlling the opening degree of the throttling device of the first target indoor unit and / or the second target indoor unit, the control method further includes:

[0032] Obtain the first indoor temperature and the first set temperature corresponding to the first target indoor unit;

[0033] The first temperature difference is determined based on the first indoor temperature and the first set temperature;

[0034] When the first temperature difference is less than the preset lower limit difference, stop selecting the first target indoor unit and the second target indoor unit from all the indoor units.

[0035] According to some embodiments of this application, after controlling the opening degree of the throttling device of the first target indoor unit and / or the second target indoor unit, the control method further includes:

[0036] Obtain the second indoor temperature and the second set temperature corresponding to the second target indoor unit;

[0037] The second temperature difference is determined based on the second indoor temperature and the second set temperature;

[0038] When the second temperature difference is greater than the preset upper temperature limit difference, stop filtering the first target indoor unit and the second target indoor unit from all the indoor units again.

[0039] According to some embodiments of this application, the first target indoor unit is the indoor unit with the smallest temperature difference among all the indoor units, and the second target indoor unit is the indoor unit with the largest temperature difference among all the indoor units.

[0040] Secondly, embodiments of this application provide a controller, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the control method for a multi-split air conditioner as described in the first aspect above when running the computer program.

[0041] Thirdly, embodiments of this application provide an air conditioner, including the controller described in the second aspect above.

[0042] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions for performing the control method for a multi-split air conditioner as described in the first aspect above.

[0043] According to the technical solution of this application embodiment, at least the following beneficial effects are achieved: First, for each indoor unit in the on state, this application embodiment acquires the indoor temperature and the set temperature, and determines the temperature difference based on the indoor temperature and the set temperature; then, this application embodiment selects a first target indoor unit and a second target indoor unit from all indoor units, wherein the temperature difference corresponding to the first target indoor unit is less than the temperature difference corresponding to the second target indoor unit; next, this application embodiment controls the opening degree of the throttling device of the first target indoor unit and / or the second target indoor unit, so that the total load demand of all indoor units is greater than the preset load demand. Since this application embodiment can adjust the state of the throttling device of different indoor units to stagger the peak and valley of the load demand of different indoor units, it can achieve the peak and valley smoothing and coordination of the load demand of multiple indoor units, so that the system energy demand can be maintained in a stable range. This solves the problems of frequent compressor start-stop or large compressor frequency fluctuation range caused by the existing control method when the system energy demand is low, resulting in energy-inefficient operation and high compressor failure rate.

[0044] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0045] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0046] Figure 1 This is a flowchart of a control method for a multi-split air conditioner provided in one embodiment of this application;

[0047] Figure 2 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0048] Figure 3 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0049] Figure 4 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0050] Figure 5 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0051] Figure 6 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0052] Figure 7 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0053] Figure 8 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0054] Figure 9 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0055] Figure 10 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0056] Figure 11 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0057] Figure 12 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0058] Figure 13 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application;

[0059] Figure 14 This is a schematic flowchart of the control method for a multi-split air conditioner provided in one embodiment of this application;

[0060] Figure 15 This is a schematic diagram illustrating the change in total load demand in one embodiment of this application;

[0061] Figure 16This is a schematic diagram of a controller for performing a control method for a multi-split air conditioner according to an embodiment of this application. Detailed Implementation

[0062] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0063] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0064] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0065] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0066] In related technologies, multi-split air conditioning systems have multiple indoor units. Each indoor unit receives an independent temperature setting and determines its load requirements based on the set temperature and the actual temperature. The outdoor unit controls the frequency increase, decrease, start, and stop of the outdoor compressor according to the load requirements of the indoor units.

[0067] Under the current control method, if the room load is low and all indoor units in the multi-split system meet the load requirements, the system energy demand will turn to zero. When the compressor of the multi-split system can no longer reduce the frequency, it will stop running. After a period of time, when the room temperature rises, i.e. when the load demand increases, the compressor will start running again, resulting in frequent start-stop of the compressor. Moreover, each restart requires starting from a high frequency, consuming too much energy and damaging the compressor's lifespan.

[0068] Based on the above, this application proposes a control method, controller, air conditioner, and computer-readable storage medium for a multi-split air conditioner, aiming to achieve controllable air outlet temperature, thereby realizing gentle direct airflow and improving user comfort.

[0069] The various embodiments of the control method for multi-split air conditioners of this application will be further described below with reference to the accompanying drawings.

[0070] like Figure 1 As shown, Figure 1 This is a flowchart of a control method for a multi-split air conditioner according to an embodiment of this application. The control method for the multi-split air conditioner may include, but is not limited to, steps S110 to S130.

[0071] Step S110: For each indoor unit that is in the on state, obtain the indoor temperature and the set temperature, and determine the temperature difference based on the indoor temperature and the set temperature.

[0072] Step S120: Select the first target indoor unit and the second target indoor unit from all indoor units.

[0073] Step S130: Control the opening degree of the throttling device of the first target indoor unit and / or the second target indoor unit so that the total load demand of all indoor units is greater than the preset load demand.

[0074] It should be understood that the indoor temperature here refers to the indoor temperature of the space where each indoor unit is located.

[0075] It should be understood that the temperature difference corresponding to the first target indoor unit is less than the temperature difference corresponding to the second target indoor unit.

[0076] It should be understood that "all indoor units" here refers to all indoor units that are currently turned on.

[0077] It should be understood that adjusting the opening degree of the throttling device here includes, but is not limited to, opening a closed throttling device, closing an open throttling device, and adjusting the opening degree of an open throttling device to control the refrigerant flow.

[0078] In one embodiment, a multi-split air conditioner includes one outdoor unit and multiple indoor units. The outdoor unit is connected to each of the indoor units, and the outdoor unit delivers the refrigerant, after heat exchange, to each indoor unit for further heat exchange. When multiple indoor units are running, the heat exchange requirements of the indoor spaces where each indoor unit is located differ, resulting in different load requirements for each indoor unit. As the multi-split air conditioner stabilizes, the heat exchange rate of each indoor unit tends to stabilize, causing the indoor temperature of each indoor unit to approach its set temperature. This gradually reduces the load requirement of each indoor unit, and consequently, the total load requirement of all indoor units gradually decreases. When the total load requirement of all indoor units is less than or equal to the preset load requirement, the outdoor unit will reduce its frequency or even shut down until the total load requirement exceeds the preset load requirement, at which point it will increase its frequency again. To ensure that the outdoor unit remains within a certain frequency range, the total load requirement needs to be adjusted.

[0079] Specifically, firstly, for each activated indoor unit, the indoor temperature of the space where the indoor unit is located and the set temperature of the indoor unit are obtained, and the temperature difference is determined based on the indoor temperature and the set temperature. Target indoor units are then selected based on the temperature difference, resulting in a first target indoor unit and a second target indoor unit with a temperature difference less than that of the first target indoor unit. The opening of the throttling device of at least one of the first and second target indoor units is controlled to adjust the load demand of at least one of the first and second target indoor units, so that the total load demand of all indoor units exceeds the preset load demand.

[0080] Temperature difference reflects the heat exchange demand of an indoor space, which in turn reflects the load demand of the indoor unit. A smaller temperature difference indicates that the indoor temperature is closer to the indoor unit's set temperature. The closer the indoor temperature is to the set temperature, the lower the heat exchange demand and the lower the load demand on the indoor unit. When the temperature difference is less than or equal to 0, the heat exchange demand is at its minimum. At this point, the indoor unit meets its load requirements, minimizing its load demand. The indoor unit only needs to maintain a minimum heat exchange capacity by controlling the throttling device to maintain the current state until the indoor temperature exceeds the set temperature. Then, the indoor unit resumes cooling to bring the indoor temperature back down to or below the set temperature.

[0081] By selecting first and second target indoor units from all activated indoor units, the load requirements of both are adjusted to change the total load requirement. By controlling the opening of the throttling device of at least one of the first and second target indoor units, the heat exchange efficiency of at least one of the first and second target indoor units is changed, thereby maintaining a certain load requirement and achieving a total load requirement of all indoor units that is greater than the preset load requirement.

[0082] It should be understood that the first target indoor unit and the second target indoor unit here both refer to a type of indoor unit that meets the conditions. There may be one or more units, and they may be the following embodiments or other embodiments. This application does not limit the embodiments in this regard.

[0083] In one embodiment, a first target indoor unit and a second target indoor unit are determined by setting a temperature difference threshold. Among all indoor units, those below the temperature difference threshold are designated as the first target indoor unit, and those above the temperature difference threshold are designated as the second target indoor unit.

[0084] In one embodiment, one of the multiple indoor units that meet a first specific temperature difference value is designated as the first target indoor unit, and one of the multiple indoor units that meet a second specific temperature difference value is designated as the second target indoor unit.

[0085] In one embodiment, the temperature difference values ​​are ranked, and two indoor units that meet a specific ranking are identified as the first target indoor unit and the second target indoor unit, respectively.

[0086] The following are specific implementation examples in real-world application scenarios.

[0087] In one embodiment, the first target indoor unit is the indoor unit with the smallest temperature difference among all indoor units, and the second target indoor unit is the indoor unit with the largest temperature difference among all indoor units.

[0088] By obtaining the indoor temperature and set temperature of each indoor unit, the temperature difference of each indoor unit is obtained. All temperature differences are sorted to obtain the maximum temperature difference and the minimum temperature difference. The indoor unit corresponding to the minimum temperature difference is determined as the first target indoor unit, and the indoor unit with the maximum temperature difference is determined as the second target indoor unit.

[0089] For the first target indoor unit, since its temperature difference is the smallest, its heat exchange demand is also the smallest. If the first target indoor unit continues to exchange heat at its current efficiency, the heat exchange demand will continue to decrease, leading to a further reduction in its load demand and consequently, a decrease in the total load demand of all indoor units. Therefore, by reducing the opening of the throttling device on the first target indoor unit to lower its heat exchange efficiency, the temperature difference can be kept within a small range or even maintained at a specific value. In this case, due to the temperature difference, the first target indoor unit needs to continuously cool and exchange heat to bring the temperature difference closer to zero. Alternatively, under specific circumstances, the throttling device corresponding to the first target indoor unit can be closed to increase the temperature difference, thereby increasing the load demand of the first target indoor unit. By implementing either of these methods, a certain load demand is maintained for the first target indoor unit.

[0090] For the second target indoor unit, since its temperature difference is the largest and its heat exchange demand is the greatest, the second target indoor unit has a certain load demand at this time. When only the second target indoor unit is adjusted, the heat exchange efficiency of the second target indoor unit is improved by increasing the opening of the throttling device of the second target indoor unit, so that the indoor temperature where the second target indoor unit is located drops faster.

[0091] Increasing the throttling device opening of the second target indoor unit means increasing the load demand of the second target indoor unit. Without adjusting the throttling device opening of other indoor units, increasing the load demand of the second target indoor unit can increase the total load demand of the multi-split air conditioner.

[0092] In this specific embodiment, the throttling device opening degree adjustment of the first target indoor unit and the second target indoor unit is performed selectively or both are performed according to the total load demand. That is, for the first target indoor unit and the second target indoor unit, one of them is selected to perform in order to keep the total load demand greater than the preset load demand. When the total load demand cannot exceed the preset load demand after one of them is performed, the opening degree of the throttling device of the first target indoor unit and the second target indoor unit is adjusted.

[0093] In another specific embodiment, the throttling device opening of the first target indoor unit and the second target indoor unit is adjusted in all cases to keep the total load demand of all indoor units greater than the preset load demand.

[0094] In another specific embodiment, regardless of the circumstances, the throttling device opening adjustment of the first target indoor unit and the second target indoor unit is selectively executed based on the total load demand.

[0095] In all the above specific embodiments, since the first target indoor unit and / or the second target indoor unit adjust the opening of the throttling device, while the throttling devices of other indoor units are not adjusted, the temperature difference value corresponding to the first target indoor unit is not the minimum temperature difference value and / or the corresponding temperature difference value is not the maximum temperature difference value after a period of time. At this time, the first target indoor unit and / or the second target indoor unit will be re-determined and the above method will be executed again.

[0096] This application embodiment can adjust the state of the throttling device of different indoor units to stagger the peak and valley load demand of different indoor units, realize the peak and valley smoothing and coordination of the load demand of multiple indoor units, and enable the system energy demand to be maintained in a stable range. It solves the problems of frequent compressor start-stop or large compressor frequency fluctuation range caused by the existing control method when the system energy demand is low load, resulting in energy-inefficient operation and high compressor failure rate.

[0097] like Figure 2 As shown, Figure 2This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, when the control method includes controlling the opening degree of the throttling device of the first target indoor unit, step S103 includes, but is not limited to, the following sub-steps.

[0098] Step S210: Obtain the on / off status of the first throttling device corresponding to the first target indoor unit.

[0099] Step S220: Open or close the first throttling device according to its on / off state.

[0100] Because the temperature difference between the first target indoor unit and the second target indoor unit is smaller, the first target indoor unit is more likely to reach the edge state of minimum load demand. The load demand of the first target indoor unit will gradually decrease until it reaches the minimum load demand. During the process of the load demand decreasing to the minimum load demand and while the first target indoor unit is maintaining the minimum load demand, the first target indoor unit obtains the minimum superheat by frequently opening and closing the first throttling device, so that the first target indoor unit can maintain the minimum temperature difference.

[0101] It should be understood that the essence of step S220 is to break the state of the first target indoor unit being under load requirements, increase the load demand of the first target indoor unit, so that the outdoor unit can continue to operate. Step S220 can be specifically implemented in the following embodiments or in other embodiments, and this application does not limit it.

[0102] like Figure 3 As shown, Figure 3 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, step S220 includes, but is not limited to, the following sub-steps.

[0103] Step S310: When the first throttling device is in the closed state, keep the first throttling device in the closed state.

[0104] Specifically, when the first throttling device is closed, the first target indoor unit has a certain superheat to maintain heat exchange and reduce the temperature difference. However, in reality, objects or people in the indoor space also emit heat. When the first throttling device remains closed, the superheat of the first target indoor unit gradually increases as objects or people in the indoor space also emit more heat, causing the indoor temperature to gradually rise, i.e., the temperature difference to increase, requiring the first target indoor unit to restart heat exchange. After the first target indoor unit restarts heat exchange, its load demand will increase, thus increasing the total load demand of the multi-split air conditioner.

[0105] like Figure 4 As shown, Figure 4This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, step S220 includes, but is not limited to, the following sub-steps.

[0106] Step S410: When only the first throttling device corresponding to the first target indoor unit is in the open state, keep the first throttling device in the open state.

[0107] Specifically, when only the first throttling device corresponding to the first target indoor unit is in the open state, it means that the heat exchange of the other indoor units has reached their respective requirements, that is, the other indoor units are maintaining the minimum load requirement. For the first target indoor unit, in order to obtain the superheat to maintain the minimum temperature difference when the first throttling device is in the open state, the first throttling device will close after obtaining the superheat to maintain the minimum temperature difference. At this time, the total load requirement of the multi-split air conditioner will drop to the minimum, which will cause the outdoor unit to reduce the frequency significantly or even stop. Therefore, it is necessary to keep the first throttling device in the open state to maintain a certain total load requirement.

[0108] In one embodiment, since keeping the first throttling device in the open state will cause the temperature difference to approach 0 more quickly, the opening degree of the throttling device can be adjusted to ensure a certain load requirement.

[0109] like Figure 5 As shown, Figure 5 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, step S220 includes, but is not limited to, the following sub-steps.

[0110] Step S510: When the first throttling device corresponding to the first target indoor unit is in the open state, and the first target indoor unit is not the only indoor unit with the throttling device open, control the first throttling device to close.

[0111] Specifically, the first target indoor unit is not the only indoor unit with the throttling device activated. At this time, the total load demand is kept within a certain range. The first throttling device is then closed, causing the indoor temperature of the room where the first target indoor unit is located to rise, thereby increasing the load demand of the first target indoor unit and thus increasing the total load demand.

[0112] like Figure 6 As shown, Figure 6 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, when the control method includes controlling the opening degree of the throttling device of the second target indoor unit, step S130 includes, but is not limited to, the following sub-steps.

[0113] Step S610: Obtain the on / off status of the second throttling device corresponding to the second target indoor unit.

[0114] Step S620: Open or close the second throttling device according to its on / off state.

[0115] Since the temperature difference between the second target indoor unit and the first target indoor unit is greater, the second target indoor unit has a considerable heat exchange requirement. It continuously exchanges heat to quickly meet the heat exchange requirement.

[0116] It should be understood that the essence of step S620 is to increase the heat exchange rate obtained by the second target indoor unit and accelerate the decrease of the indoor temperature in the indoor space where the second target indoor unit is located, thereby increasing the load demand of the second target indoor unit and thus keeping the outdoor unit running at a certain frequency. Step S602 can be specifically implemented in the following embodiments or other embodiments, and the embodiments of this application do not limit it.

[0117] like Figure 7 As shown, Figure 7 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, step S620 includes, but is not limited to, the following sub-steps.

[0118] Step S710: When the second throttling device is in the open state, keep the second throttling device in the open state.

[0119] When the second throttling device is open, it indicates that the second target indoor unit needs to obtain superheat. After the second target indoor unit obtains a certain amount of superheat, the second throttling device will close until its own superheat is insufficient, and then open again. By keeping the second throttling device open, the second target indoor unit can obtain superheat exceeding its own needs, causing the indoor temperature of the room where the second target indoor unit is located to drop faster. After a certain period of operation, the superheat provided by the outdoor unit to each indoor unit stabilizes. By increasing the superheat obtained by the second target indoor unit, the load demand of the second target indoor unit is increased. At this time, the total load demand will increase, requiring the outdoor unit to enhance its refrigerant liquefaction capacity to provide more liquid refrigerant to the second target indoor unit, thereby making the total load demand greater than the preset load demand.

[0120] like Figure 8 As shown, Figure 8 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, step S620 includes, but is not limited to, the following sub-steps.

[0121] Step S810: When the second throttling device is in the closed state, control the second throttling device to open.

[0122] When the second throttling device is closed, it indicates that the superheat currently acquired by the second target indoor unit is sufficient. After the superheat of the second target indoor unit is reduced to a certain level by the indoor space where the second target indoor unit is located, the second throttling device is opened again to acquire superheat. Since other outdoor units will also frequently open and close their throttling devices in order to acquire sufficient superheat, the total load demand will continue to decrease. By opening the second throttling device, the superheat acquired by the second target indoor unit is increased to more than the previous superheat, thereby increasing the load demand of the second target indoor unit and thus increasing the total load demand, so that the total load demand is greater than the preset load demand.

[0123] like Figure 9 As shown, Figure 9 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, step S620 includes, but is not limited to, the following sub-steps.

[0124] Step S910: Obtain the current superheat of the refrigerant in the heat exchanger coil of the second target indoor unit.

[0125] Step S920: Adjust the opening of the second throttling device according to the current superheat and the preset superheat threshold.

[0126] It should be understood that the preset overheating thresholds here are varied, including upper and lower overheating thresholds.

[0127] Due to limitations in its internal structure and materials, the indoor unit's heat exchanger coil has an upper limit for superheat. Exceeding this limit will cause the indoor unit to shut down as a protective measure. For the second target indoor unit, the adjustment method involves controlling the second throttling device and keeping it open. The superheat acquired by the second target indoor unit gradually increases. To ensure the second target indoor unit remains operational and provides a certain load, it is necessary to control the superheat acquired by it to prevent overheating.

[0128] Ideally, the refrigerant in the indoor unit should be in a gaseous state before entering the outdoor unit. This allows the outdoor unit to maintain optimal operating conditions. If liquid refrigerant enters the outdoor unit, it needs to evaporate the liquid refrigerant, affecting the outdoor unit's heat exchange efficiency. Therefore, the indoor unit needs to maintain a certain superheat. If the current superheat is below the lower limit, it will affect the outdoor unit's heat exchange efficiency.

[0129] It should be understood that the specific implementation of step S920 is diverse and may be one of the following embodiments or other embodiments. This application does not limit this embodiment.

[0130] In one embodiment, if the current superheat is greater than or equal to the lower limit superheat threshold, the opening of the second throttling device is maintained; if the current superheat is less than the lower limit superheat threshold, the opening of the second throttling device is increased.

[0131] In one embodiment, if the current superheat is less than the lower limit superheat threshold, the opening of the second throttling device is increased; if the current superheat is greater than or equal to the preset lower limit superheat, the opening of the second throttling device is decreased.

[0132] In one embodiment, if the current superheat is less than the lower limit superheat threshold, the opening of the second throttling device is increased; if the current superheat is greater than the lower limit superheat threshold, the opening of the second throttling device is maintained; if the current superheat is equal to the lower limit superheat threshold, the opening of the second throttling device is decreased.

[0133] In one embodiment, if the current superheat is greater than or equal to the upper superheat threshold, the opening of the second throttling device is reduced; if the current superheat is less than the upper superheat threshold, the opening of the second throttling device is maintained.

[0134] In one embodiment, if the current superheat is greater than or equal to the upper limit superheat threshold, the opening of the second throttling device is reduced; if the current superheat is less than the upper limit superheat threshold, the opening of the second throttling device is increased.

[0135] In one embodiment, if the current superheat is greater than the upper superheat threshold, the opening of the second throttling device is reduced; if the current superheat is equal to the upper superheat threshold, the opening of the second throttling device is maintained; if the current superheat is less than the upper superheat threshold, the opening of the second throttling device is increased.

[0136] It should be understood that the current superheat of the refrigerant can be obtained in various ways, including the following embodiments and other embodiments. This application does not limit this method.

[0137] In one embodiment, since the indoor unit vaporizes the refrigerant through heat exchange, and the temperature can reflect the superheat to a certain extent, a pressure sensor is installed in the heat exchanger coil to measure the pressure value in the heat exchanger coil, and the refrigerant temperature is obtained based on the pressure value, and the superheat is obtained based on the refrigerant temperature.

[0138] In one embodiment, a temperature sensor is installed outside the heat exchanger coil to measure the coil temperature, and the superheat is obtained based on the coil temperature.

[0139] like Figure 10 As shown, Figure 10 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, step S120 includes, but is not limited to, the following sub-steps.

[0140] Step S1010: Select the first target indoor unit and the second target indoor unit from all indoor units at preset intervals.

[0141] Because the throttling device opening of at least one of the first and second target indoor units is adjusted, while the throttling devices of the other indoor units are not adjusted, after each indoor unit operates at its corresponding throttling device opening for a certain period of time, the temperature difference between the indoor units will change. At least one of the first and second target indoor units may not meet the corresponding screening criteria. If the state and opening of the throttling device are adjusted according to the preset throttling device adjustment method, it will actually reduce the load demand of at least one of them, having a reverse adjustment effect on the total load demand, thus reducing the total load demand and failing to guarantee that the total load demand is greater than the preset load demand. This embodiment of the application redetermines the adjustment target at preset intervals to ensure the adjustment effect of the total load demand.

[0142] In one embodiment, after a preset time interval, the temperature difference value corresponding to all indoor units is judged. If the current first target indoor unit meets the screening conditions of the first target indoor unit, the current first target indoor unit continues to be the first target indoor unit in the next preset time interval. If the current first target indoor unit does not meet the screening conditions of the first target indoor unit, the first target indoor unit is re-screened from all indoor units until the end of the next preset time interval. Similarly, the second target indoor unit is screened to obtain the second target indoor unit until the end of the next preset time interval.

[0143] like Figure 11 As shown, Figure 11 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, step S130 includes, but is not limited to, the following sub-steps.

[0144] Step S1110: Select the target temperature difference with the largest value from multiple temperature difference values;

[0145] Step S1120: Obtain the current operating frequency and lower limit operating frequency of the compressor, and determine the frequency difference between the current operating frequency and the lower limit operating frequency;

[0146] Step S1130: When there are multiple indoor units in the on state, the target temperature difference is less than or equal to the first upper limit temperature difference, and the frequency difference is less than the preset frequency, select the first target indoor unit and the second target indoor unit from all indoor units.

[0147] In one embodiment, the maximum temperature difference is selected from the temperature differences corresponding to all indoor units as the target temperature difference. The compressor operating frequency and lower limit operating frequency in the outdoor unit are obtained, and the frequency difference is obtained based on the two. When the conditions of "multiple indoor units are in the on state", "target temperature difference is less than or equal to the first upper limit temperature difference" and "frequency difference is less than the preset frequency" are met simultaneously, the first target indoor unit and the second target indoor unit are selected from all indoor units.

[0148] When there are multiple indoor units that are turned on, as the multi-split air conditioner operates, the indoor temperature of the room where each of the turned-on indoor units is located will gradually approach the corresponding set temperature. During this process, the total load demand will gradually decrease.

[0149] To save energy, the compressor matches the total load demand and reduces its operating frequency. When the target temperature difference is less than or equal to the preset upper temperature limit difference, the total load demand is at its lowest, and the compressor continues to reduce its operating frequency. If the current operating frequency drops to the lower limit, the compressor will stop because it cannot reduce the frequency further. If the compressor is restarted after stopping, it will first increase its frequency and then gradually decrease it. However, after a multi-split air conditioner has been running for a certain period of time, the indoor temperature of each indoor unit will approach the corresponding set temperature, and the indoor temperature will fluctuate around the corresponding set temperature. This will cause the operating frequency to fluctuate around the lower limit, resulting in frequent compressor starts and stops and significant changes in the compressor frequency.

[0150] When only one indoor unit is active, the total load requirement is smaller than when multiple indoor units are active. The limited variation in total load requirement results in a smaller frequency fluctuation in the compressor compared to when multiple indoor units are active. This embodiment of the application controls the opening of the throttling device of the first and / or second target indoor units to maintain the total load requirement within a small fluctuation range. This ensures that the fluctuation range of the total load requirement when multiple indoor units are active is similar to or equal to that when only one indoor unit is active, thereby guaranteeing that the compressor does not stop.

[0151] like Figure 12 As shown, Figure 12 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, step S130 includes, but is not limited to, the following sub-steps.

[0152] Step S1210: Obtain the first indoor temperature and the first set temperature corresponding to the first target indoor unit.

[0153] Step S1220: Determine the first temperature difference based on the first indoor temperature and the first set temperature.

[0154] Step S1230: When the first temperature difference is less than the preset lower limit difference, stop filtering the first target indoor unit and the second target indoor unit from all indoor units again.

[0155] It should be understood that the first indoor temperature here refers to the indoor temperature of the room where the first target indoor unit is located at the current moment, the first set temperature here refers to the set temperature of the first target indoor unit at the current moment, and the preset lower limit difference here represents the lower limit of the user's comfortable temperature.

[0156] Since this method can be repeated multiple times, for users in the indoor space where the first target indoor unit is located, during the execution of the above method, the user may adjust the set temperature of the first target indoor unit to obtain better comfort. Due to the change in the set temperature, the corresponding temperature difference of the first target indoor unit changes. If the user lowers the temperature, the first temperature difference will increase, and the load demand of the first target indoor unit will be artificially increased by the user. At this time, the theoretical total load demand will increase. If the opening of the throttling device of the first target indoor unit is adjusted in the current throttling device adjustment method, the superheat obtained by the first target indoor unit will not be able to meet the current heat exchange demand in the room, and the actual total load demand will be lower than the theoretical total load demand, affecting the normal operation of the outdoor unit and the user's comfort.

[0157] It should be understood that the specific implementation of step S1230 is diverse and may be one of the following embodiments or other embodiments. This application does not limit this embodiment.

[0158] In one embodiment, when the first temperature difference is less than a preset lower limit difference, the process of selecting the first target indoor unit and the second target indoor unit from all indoor units is stopped. All indoor units are adjusted according to the preset throttling device adjustment method of the multi-split air conditioner. When the first throttling device corresponding to the first target indoor unit is in the closed state, the first throttling device is controlled to open and the opening degree of the first throttling device is increased. When the first throttling device corresponding to the first target indoor unit is in the open state, the first throttling device is kept in the open state and the opening degree of the first throttling device is increased, so as to improve the superheat of the first target indoor unit and make the heat exchange effect of the first target indoor unit better.

[0159] like Figure 13 As shown, Figure 13 This is a flowchart of a control method for a multi-split air conditioner provided in another embodiment of this application. In one embodiment, step S130 includes, but is not limited to, the following sub-steps.

[0160] Step S1310: Obtain the second indoor temperature and the second set temperature corresponding to the second target indoor unit.

[0161] Step S1320: Determine the second temperature difference based on the second indoor temperature and the second set temperature.

[0162] Step S1330: When the second temperature difference is greater than the second temperature upper limit difference, stop filtering the first target indoor unit and the second target indoor unit from all indoor units again.

[0163] It should be understood that the second indoor temperature here refers to the indoor temperature of the space where the second target indoor unit is located at the current moment, the second set temperature here refers to the set temperature of the second target indoor unit at the current moment, and the difference between the upper limit of the second preset temperature here represents the upper limit of the user's comfortable temperature.

[0164] It should be noted that the first preset temperature upper limit difference that appears in step S1130 can be the same value as the second preset temperature upper limit difference that appears in step S1330, or they can be different values.

[0165] Since this method can be repeated multiple times, for users in the indoor space where the second target indoor unit is located, during the execution of the above method, the user may adjust the set temperature of the second target indoor unit to obtain better comfort. Due to the change in the set temperature, the corresponding temperature difference of the second target indoor unit changes. If the user lowers the temperature, the temperature difference increases, and the theoretical total load demand will increase. At this time, whether all indoor units operate according to the control method provided in this application embodiment, the total load demand will be greater than the preset load demand. Therefore, there is no need to select the first target indoor unit and the second target indoor unit to increase their respective load demand by controlling the opening of the throttling device. The user's comfort requirements mean that even if all indoor units do not operate according to the control method provided in this application embodiment, the total load demand can still be greater than the preset load demand.

[0166] In one embodiment, when the second temperature difference is greater than the second preset upper limit temperature difference, the process of selecting the first target indoor unit and the second target indoor unit from all indoor units is stopped. All indoor units are adjusted according to the preset throttling device adjustment method of the multi-split air conditioner. When the second throttling device corresponding to the second target indoor unit is in the closed state, the first throttling device is controlled to open and the opening degree of the second throttling device is increased. When the second throttling device is in the open state, the second throttling device is kept in the open state and the opening degree of the second throttling device is increased, so that the heat exchange effect of the second target indoor unit is better.

[0167] Based on the control methods for multi-split air conditioners described in the above embodiments, the following are overall embodiments of the control methods for multi-split air conditioners of this application.

[0168] like Figure 14 and Figure 15 As shown, Figure 14 This is a schematic flowchart of the control method for a multi-split air conditioner provided in one embodiment of this application. Figure 15 This is a schematic diagram illustrating the change in total load demand in one embodiment of this application. Figure 14 The overall process includes, but is not limited to, the following steps.

[0169] Step S1401: Obtain the number of indoor units turned on X, the indoor temperature Tin and set temperature Tset of each indoor unit, the system operating power F and the minimum operating power Fmin. Obtain the temperature difference ΔT of each indoor unit based on Tin and Tset, obtain the frequency difference ΔF based on F and Fmin, and obtain the maximum temperature difference max(ΔT) based on ΔT of all indoor units.

[0170] Step S1402: Determine whether the conditions X≥2 and max(ΔT)≤ first preset temperature upper limit difference A1 and ΔF≤ preset frequency B1 are met. If yes, proceed to step S1403; otherwise, return to step S1401.

[0171] Step S1403: Based on the ΔT of all indoor units, obtain the minimum temperature difference min(ΔT), determine the indoor unit corresponding to the minimum temperature difference min(ΔT) as the first target indoor unit, and determine the indoor unit corresponding to the maximum temperature difference max(ΔT) as the second target indoor unit.

[0172] Step S1404: Determine whether the condition that the first throttling device of the first target indoor unit is in the open state is met. If not, proceed to step S1406; if yes, proceed to step S1405.

[0173] Step S1405: Determine whether the condition is met that the first throttling device of the first target indoor unit is the only throttling device that is turned on among all indoor units. If yes, proceed to step S1406; otherwise, proceed to step S1407.

[0174] Step S1406: Keep the first throttling device in its current state.

[0175] Step S1407: Close the first throttling device of the first target indoor unit.

[0176] Step S1408: Determine whether the condition that the second throttling device of the second target indoor unit is in the open state is met. If yes, proceed to step S1409; otherwise, proceed to step S1410.

[0177] Step S1409: Keep the second throttling device in the open state, obtain the first superheat SH1 of the second target indoor unit every first interval time t1, adjust the opening degree of the second throttling device according to SH1, and proceed to step S1411.

[0178] Step S1410: Open the second throttling device, obtain the second superheat SH2 of the second target indoor unit every t1, adjust the opening of the second throttling device according to SH2, and proceed to step S1411.

[0179] Step S1411: Maintain the current system state for the second interval t2.

[0180] Step S1412: Update the first temperature difference ΔT1 of the first target indoor unit and the second temperature difference ΔT2 of the second target indoor unit.

[0181] Step S1413: Determine whether the condition ΔT1 < preset lower limit difference A2 is met. If not, proceed to step S1414; if yes, return to step S1403.

[0182] Step S1414: Determine whether the condition ΔT2 > the difference of the second upper temperature limit A3 is met. If not, return to step S1403; if yes, return to step S1401.

[0183] Specifically, based on the above Figure 14 The control method includes the following implementation steps:

[0184] 1. Determine if total load demand needs adjustment: Obtain the number of indoor units turned on X, the system frequency difference ΔF, and the maximum temperature difference max(ΔT) among all the indoor units turned on ΔT. If the conditions X≥2, max(ΔT)≤the first preset upper limit temperature difference A1 and ΔF≤the preset frequency B1 are met, then there is a need to adjust the total load demand, and proceed to step 2.

[0185] 2. Adjusting the load demand of the first and second target indoor units: Determine the first and second target indoor units based on the ΔT of all the indoor units that are turned on. Adjust the load according to the opening status of the corresponding throttling devices. At each first interval, adjust the opening of the second throttling device corresponding to the second target indoor unit based on the overheat of the second target indoor unit. After the first interval has elapsed in step two, determine whether the following conditions are met: the first temperature difference ΔT1 of the first target indoor unit is less than the preset lower limit difference A2, and the second temperature difference ΔT2 of the second target indoor unit is greater than the second upper limit difference A3. If neither of the two conditions is met, the total load demand adjustment is completed, and the process returns to step one. Otherwise, step two is executed again.

[0186] It should be understood that steps S1404 to S1407 are adjustment steps for the first target indoor unit, and steps S1408 to S1410 are adjustment steps for the second target indoor unit.

[0187] This application embodiment can adjust the state of the throttling device of different indoor units to stagger the peak and valley load demand of different indoor units, realize the peak and valley smoothing and coordination of the load demand of multiple indoor units, and enable the system energy demand to be maintained in a stable range. It solves the problems of frequent compressor start-stop or large compressor frequency fluctuation range caused by the existing control method when the system energy demand is low load, resulting in energy-inefficient operation and high compressor failure rate.

[0188] Based on the control methods for multi-split air conditioners described in the above embodiments, the following presents various embodiments of the controller, air conditioner, and computer-readable storage medium of this application.

[0189] like Figure 16 As shown, Figure 16 This is a schematic diagram of the structure of a controller for executing a control method for a multi-split air conditioner according to an embodiment of this application. The controller 100 implemented in this application includes: a processor 110, a memory 120, and a computer program stored in the memory 120 and executable on the processor 110, wherein... Figure 15 The example uses a processor 110 and a memory 120.

[0190] Processor 110 and memory 120 can be connected via a bus or other means. Figure 15 Taking the example of a connection between China and Israel via a bus.

[0191] Memory 120, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory 120 may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory 120 may optionally include remotely located memories 120 relative to processor 110, which can be connected to controller 100 via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0192] Those skilled in the art will understand that Figure 16 The device structure shown does not constitute a limitation on the controller 100 and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0193] exist Figure 16In the controller 100 shown, the processor 110 can be used to call the control program of the multi-split air conditioner stored in the memory 120, thereby implementing the control method of the multi-split air conditioner described above. Specifically, the non-transitory software program and instructions required to implement the control method of the multi-split air conditioner in the above embodiment are stored in the memory 120. When executed by the processor 110, the control method of the multi-split air conditioner in the above embodiment is executed.

[0194] It is worth noting that, since the controller 100 of this application embodiment can execute the control method of the multi-split air conditioner of any of the above embodiments, the specific implementation method and technical effects of the controller 100 of this application embodiment can be referred to the specific implementation method and technical effects of the control method of the multi-split air conditioner of any of the above embodiments.

[0195] In addition, one embodiment of this application also provides an air conditioner, including the controller described in the above embodiment.

[0196] It is worth noting that, since the air conditioner of this application embodiment includes the controller of the above embodiments, and the controller of the above embodiments can execute the control method of the multi-split air conditioner of any of the above embodiments, the specific implementation method and technical effect of the air conditioner of this application embodiment can refer to the specific implementation method and technical effect of the control method of the multi-split air conditioner of any of the above embodiments.

[0197] Furthermore, one embodiment of this application provides a computer-readable storage medium storing computer-executable instructions for performing the control method for a multi-split air conditioner described above. Exemplarily, the above-described method is executed... Figures 1 to 14 The methods and steps in the text.

[0198] It is worth noting that, since the computer-readable storage medium of this application embodiment can execute the control method of the multi-split air conditioner of any of the above embodiments, the specific implementation and technical effects of the computer-readable storage medium of this application embodiment can be referred to the specific implementation and technical effects of the control method of the multi-split air conditioner of any of the above embodiments.

[0199] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically include computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0200] The above provides a detailed description of the preferred embodiments of this application. However, this application is not limited to the above-described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A control method for a multi-split air conditioner, characterized in that, include: For each indoor unit that is turned on, the indoor temperature and the set temperature are obtained, and the temperature difference is determined based on the indoor temperature and the set temperature. Select a first target indoor unit and a second target indoor unit from all the indoor units, wherein the temperature difference corresponding to the first target indoor unit is smaller than the temperature difference corresponding to the second target indoor unit; Control the opening degree of the throttling device of the first target indoor unit and / or the second target indoor unit so that the total load demand of all indoor units is greater than the preset load demand; Wherein, when the control method includes controlling the opening degree of the throttling device of the first target indoor unit, controlling the opening degree of the throttling device of the first target indoor unit includes: obtaining the on / off state of the first throttling device corresponding to the first target indoor unit; when the first throttling device is in the off state, keeping the first throttling device in the off state; when only the first throttling device corresponding to the first target indoor unit is in the on state, keeping the first throttling device in the on state; when the first throttling device corresponding to the first target indoor unit is in the on state, and the first target indoor unit is not the only indoor unit with the throttling device on, controlling the first throttling device to close. In addition, when the control method includes controlling the opening degree of the throttling device of the second target indoor unit, controlling the opening degree of the throttling device of the second target indoor unit includes: obtaining the on / off state of the second throttling device corresponding to the second target indoor unit; when the second throttling device is in the on state, keeping the second throttling device in the on state; when the second throttling device is in the off state, controlling the second throttling device to open. In addition, the step of selecting the first target indoor unit and the second target indoor unit from all the indoor units includes: selecting the target temperature difference with the largest value from a plurality of temperature difference values; obtaining the current operating frequency and the lower limit operating frequency of the compressor, and determining the frequency difference between the current operating frequency and the lower limit operating frequency; and selecting the first target indoor unit and the second target indoor unit from all the indoor units when there are multiple indoor units in the on state, the target temperature difference is less than or equal to the first preset upper limit temperature difference, and the frequency difference is less than the preset frequency.

2. The control method according to claim 1, characterized in that, After the second throttling device is turned on or off according to its on / off state, the control method further includes: Obtain the current superheat of the refrigerant in the heat exchanger coil of the second target indoor unit; The opening degree of the second throttling device is adjusted according to the current superheat and the preset superheat threshold.

3. The control method according to claim 1, characterized in that, The step of selecting the first target indoor unit and the second target indoor unit from all the indoor units includes: At preset intervals, a first target indoor unit and a second target indoor unit are selected from all the indoor units.

4. The control method according to claim 1, characterized in that, After controlling the opening degree of the throttling device of the first target indoor unit and / or the second target indoor unit, the control method further includes: Obtain the first indoor temperature and the first set temperature corresponding to the first target indoor unit; The first temperature difference is determined based on the first indoor temperature and the first set temperature; When the first temperature difference is less than the preset lower limit difference, stop selecting the first target indoor unit and the second target indoor unit from all the indoor units.

5. The control method according to claim 1, characterized in that, After controlling the opening degree of the throttling device of the first target indoor unit and / or the second target indoor unit, the control method further includes: Obtain the second indoor temperature and the second set temperature corresponding to the second target indoor unit; The second temperature difference is determined based on the second indoor temperature and the second set temperature; When the second temperature difference is greater than the second upper temperature limit difference, stop filtering the first target indoor unit and the second target indoor unit from all the indoor units again.

6. The control method according to claim 1, characterized in that, The first target indoor unit is the indoor unit with the smallest temperature difference among all the indoor units, and the second target indoor unit is the indoor unit with the largest temperature difference among all the indoor units.

7. A controller, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, performs the control method as described in any one of claims 1 to 6.

8. An air conditioner, characterized in that, Includes the controller as described in claim 7.

9. A computer-readable storage medium, characterized in that: The device stores computer-executable instructions for performing the control method as described in any one of claims 1 to 6.

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