Control method of multi-connected air conditioning unit, electronic equipment and multi-connected air conditioning unit

Abstract

The embodiment of the invention discloses a control method of a multi-connected air conditioning unit, electronic equipment and the multi-connected air conditioning unit, and belongs to the technical field of multi-connected air conditioners. The control method comprises the steps that when the multi-connected air conditioning unit operates in a heating mode, whether a first indoor unit in a standby state exists in the multi-connected air conditioning unit or not is determined; under the condition that the first indoor unit exists, first parameters related to the target first indoor unit are determined, and second parameters related to all the second indoor units in the running state are determined; the first parameter at least comprises a first inner pipe temperature and a first inner ring temperature, and the second parameter at least comprises a second inner pipe temperature and a second inner ring temperature; and according to the first parameter and the second parameter, the opening degree of a target electronic expansion valve connected with the target first indoor unit is controlled. According to the embodiment of the invention, when part of the indoor units in the multi-connected air conditioner operate in the heating mode, the refrigerant can be effectively prevented from being gathered in the indoor units in the standby state, and meanwhile, the heating effect of the indoor units in the heating mode state is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of multi-connected air conditioners, in particular to a control method of a multi-connected air conditioner unit, an electronic device and the multi-connected air conditioner unit. BACKGROUND

[0002] The existing multi-connected air conditioner unit connects multiple indoor units with one outdoor unit, and each indoor unit can be simultaneously turned on or individually turned on. When multiple indoor units are simultaneously turned on, in order to reasonably distribute refrigerant among different indoor units and ensure that each indoor unit has appropriate refrigerant flow, multiple electronic expansion valves are usually arranged between the outdoor unit condenser and the indoor heat exchanger of each indoor unit, that is, each indoor heat exchanger has a corresponding electronic expansion valve for individually controlling the refrigerant flow thereof.

[0003] When the multi-connected air conditioner unit operates in a heating mode, if some of the connected indoor units are in an on state and some are in a standby state, if the electronic expansion valve corresponding to the indoor unit in the standby state is completely closed, because the refrigerant passes through the indoor heat exchanger first and then the electronic expansion valve during heating operation, the refrigerant will accumulate in the indoor heat exchanger. Since the fan blade of the indoor unit in the standby state does not operate, the refrigerant in the indoor heat exchanger will become more and more blocked, the system pressure will become higher and higher, and the refrigerant flowing through the normally operating indoor unit will become less and less, which may cause high-pressure protection shutdown or poor heating effect of the normally operating indoor unit, thereby seriously affecting the normal operation of the multi-connected air conditioner. Therefore, the electronic expansion valve corresponding to the indoor unit in the heating mode is usually not set to a completely closed state, but to an appropriate open state to ensure that the refrigerant can pass through at a low flow rate. The opening degree cannot be set too large, and a too large opening degree may cause abnormal noise in the standby indoor unit. Due to the machining precision of the electronic expansion valve, different electronic expansion valves have different opening degrees at the same standby opening degree, and some valves may be opened to a large flow rate, and some valves may not be opened to the extent. Therefore, it is necessary to study a new control logic for determining whether the electronic expansion valve has been opened to a state in which the refrigerant is at a low flow rate but does not accumulate in the indoor unit in the standby state. SUMMARY

[0004] The embodiments of the present application provide a multi-connected air conditioner unit, an electronic device and a control method to at least solve the technical problem that the opening degrees of the electronic expansion valves corresponding to the indoor units in the standby state are inconsistent when some indoor units of the multi-connected air conditioner unit operate in a heating mode, which causes the refrigerant to accumulate in the indoor unit in the standby state and causes system false high-pressure protection or affects the heating effect of the operating indoor unit.

[0005] According to a first aspect of the embodiments of this application, a control method for a multi-split air conditioning unit is provided, the control method comprising: When the multi-split air conditioning unit is running in heating mode, determine whether there is a first indoor unit in standby mode in the multi-split air conditioning unit; In the presence of the first indoor unit, a first parameter related to the target first indoor unit is determined, and a second parameter related to the second indoor unit in operation is determined; the first parameter includes at least the first inner pipe temperature and the first inner ambient temperature, and the second parameter includes at least the second inner pipe temperature and the second inner ambient temperature; Based on the first parameter and the second parameter, control the opening degree of the target electronic expansion valve connected to the target first indoor unit; Wherein: the first inner pipe temperature is the pipe temperature of the heat exchanger of the first target indoor unit, and the second inner pipe temperature is the pipe temperature of the heat exchanger of the second indoor unit; the first inner ring temperature is the temperature of the environment where the first target indoor unit is located, and the second inner ring temperature is the temperature of the environment where the second indoor unit is located.

[0006] In this embodiment, when some indoor units of a multi-split air conditioning unit are operating in heating mode, the refrigerant can pass through the indoor units in standby mode at a low flow rate. This prevents refrigerant buildup in the standby indoor units from reducing the refrigerant flow rate in the normally operating indoor units, thus affecting the heating effect of the normally operating indoor units. Furthermore, it ensures that the refrigerant pump passes through the heat exchanger of the indoor units in standby mode at a stable low flow rate, preventing refrigerant buildup in the standby indoor units from causing system pressure increases, abnormal noise, and abnormal shutdowns such as high-pressure protection.

[0007] In conjunction with the first aspect, in an optional implementation of this application embodiment, controlling the opening degree of the target electronic expansion valve connected to the target first indoor unit according to the first parameter and the second parameter includes: Determine a first difference value for the target first indoor unit and a second difference value for each of the second indoor units. The first difference value includes at least a first target difference value, which is the difference between the first inner pipe temperature and the first inner ring temperature of the target first indoor unit. The second difference value is the difference between the second inner pipe temperature and the second inner ring temperature of the second indoor unit. Determine the minimum difference among all the second differences of the second internal units; The opening degree of the target electronic expansion valve is controlled at least based on the first target difference and the minimum difference.

[0008] In conjunction with the first aspect, in an optional implementation of this application embodiment, controlling the opening degree of the target electronic expansion valve based at least on the first target difference and the minimum difference includes: When the first target difference is greater than the first set value and the first target difference is greater than the minimum difference, the opening of the target electronic expansion valve is increased.

[0009] In conjunction with the first aspect, in an optional implementation of this application embodiment, the first parameter further includes a first external pipe temperature, the second parameter further includes a second external pipe temperature, and the first difference further includes a second target difference; the first external pipe temperature is the temperature of the pipe connecting the outdoor unit heat exchanger and the target first indoor unit heat exchanger; the second external pipe temperature is the temperature of the pipe connecting the outdoor unit heat exchanger and the second indoor unit heat exchanger; the second target difference is the difference between the first external pipe temperature of the target first indoor unit and the maximum external pipe temperature, wherein the maximum external pipe temperature is the maximum value among the second external pipe temperatures of all second indoor units; Controlling the opening degree of the target electronic expansion valve based at least on the first target difference and the minimum difference includes: The opening degree of the target electronic expansion valve is controlled based on the first target difference, the second target difference, and the minimum difference.

[0010] In conjunction with the first aspect, in an optional implementation of this application embodiment, controlling the opening degree of the target electronic expansion valve based on the first target difference, the second target difference, and the minimum difference includes: If one of the first and second control conditions is met, and the third control condition is also met, increase the opening of the target electronic expansion valve. The first control condition is: the first target difference > the first set value; The second control condition is: the second target difference < the second set value; The third adjustment is: the first target difference is greater than the minimum difference.

[0011] In conjunction with the first aspect, in one optional implementation of the embodiments of this application, increasing the opening degree of the target electronic expansion valve includes: increasing the opening degree of the target electronic expansion valve by a preset number of steps every preset time interval.

[0012] In conjunction with the first aspect, in an optional implementation of this application embodiment, when the first target difference is less than the first set value - the preset buffer value, and the first target difference is less than the minimum difference - the preset buffer value, the opening of the target electronic expansion valve is reduced: and / or, The current opening of the target electronic expansion valve is maintained when the first set value - preset buffer value ≤ first target difference ≤ first set value, or the minimum difference - preset buffer value ≤ first target difference ≤ minimum difference.

[0013] In conjunction with the first aspect, in an optional implementation of this application embodiment, the control method further includes: exiting the control of the target electronic expansion valve opening degree when the following exit conditions are met: The exit conditions include: the opening degree of the target electronic expansion valve reaches the maximum or minimum allowable opening degree in the standby state of the target first indoor unit.

[0014] According to a second aspect of the present application, an electronic device is provided, which includes one or more processors and a non-transitory computer-readable storage medium storing program instructions. When the one or more processors execute the program instructions, the one or more processors are used to implement the control method provided in the first aspect of the present application.

[0015] According to a third aspect of the embodiments of this application, a multi-split air conditioning unit is provided, wherein the multi-split air conditioning unit is controlled by the control method provided in the first aspect of the embodiments of this application, or includes the electronic equipment provided in the second aspect of the embodiments of this application. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the multi-split air conditioning unit provided in the embodiments of this application.

[0017] Figure 2 This is one of the control flowcharts for the multi-split air conditioning unit provided in the embodiments of this application.

[0018] Figure 3 This is the second control flowchart of the multi-split air conditioning unit provided in the embodiments of this application.

[0019] Figure 4 This is a control flow diagram of a multi-split air conditioning unit provided based on a specific example.

[0020] Figure 5 This is a structural block diagram of the electronic device provided in the embodiments of this application. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0022] It should be understood that "multiple" as mentioned herein refers to two or more. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, to facilitate a clear description of the technical solutions of the embodiments of this application, the terms "first," "second," etc., are used in the embodiments of this application to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or execution order, and the terms "first," "second," etc., do not necessarily imply differentness. Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0023] The control method in this embodiment is applied to a multi-split air conditioning unit. First, a brief introduction to the structure of the multi-split air conditioning unit is given, referring to... Figure 1 The structural diagram shows a multi-split air conditioning unit, which includes a compressor, an outdoor unit, and multiple indoor units. The outdoor unit includes an outdoor heat exchanger, and each indoor unit includes an indoor heat exchanger. Multiple indoor heat exchangers (1, 2, 3, ...) corresponding to the indoor units are connected to the outdoor heat exchanger via liquid pipes (1, 2, 3, ...). Each liquid pipe is equipped with a liquid pipe temperature sensor to detect the liquid pipe temperature, and each liquid pipe also has an electronic expansion valve. The compressor's suction port is connected to the outdoor unit, and the compressor's discharge port is connected to each of the indoor heat exchangers via gas pipes (1, 2, 3, ...). Each indoor unit is equipped with an inner loop temperature sensor to detect the inner loop temperature, and each indoor heat exchanger is equipped with an inner pipe temperature sensor to detect the inner pipe temperature.

[0024] In practical applications, all indoor units can be controlled to start running simultaneously or some indoor units can be controlled to start running while others remain in standby mode, as needed.

[0025] When a multi-split air conditioning unit is in heating mode, the electronic expansion valve controlling the refrigerant flow in the indoor unit during standby is usually not set to a fully closed state, but rather to a slightly open state to ensure that the refrigerant can pass through at a very low flow rate. The specific degree of this opening is controlled by the standby opening degree set in the control program. However, due to the influence of the machining precision of the electronic expansion valve, different electronic expansion valves may open to different degrees at the same standby opening degree. Some valves may open to a large flow rate, while others may not open to the required degree. Therefore, the control method in this embodiment is used to determine whether the electronic expansion valve of the indoor unit in standby mode has opened to the appropriate state required by the system, and to adjust the opening degree of the electronic expansion valve if the appropriate opening degree has not been reached, so as to ensure that the refrigerant passes through the indoor unit at a stable low flow rate in standby mode, prevent refrigerant accumulation, and improve the reliability and stability of system operation.

[0026] The following is a detailed introduction to the control methods of multi-split air conditioning units.

[0027] Reference Figure 2 The control flowchart for multi-split air conditioning units shows the following steps: S21. When the multi-split air conditioning unit is running in heating mode, determine whether there is a first indoor unit in the multi-split air conditioning unit that is in standby mode. S22. In the presence of a first indoor unit, determine a first parameter related to the target first indoor unit, and determine a second parameter related to the second indoor unit that is in operation.

[0028] S23. Based on the first parameter and the second parameter, control the opening degree of the target electronic expansion valve connected to the target first internal unit.

[0029] Specifically, when a multi-split air conditioning unit is operating in heating mode, it is necessary to first determine whether there is a first indoor unit in standby mode. If so, it is necessary to determine whether the opening degree of the electronic expansion valve of the first indoor unit is appropriate. If it is not appropriate, it indicates that there is a risk of refrigerant accumulating in the first indoor unit, and the opening degree of the first indoor unit needs to be adjusted.

[0030] For the electronic expansion valve of the first indoor unit in standby mode, the unit will preset an initial standby opening range. In standby mode, the corresponding electronic expansion valve can only be adjusted within this range. Different indoor units are designated as Indoor Unit A, B, C, etc., and the minimum and maximum opening P of the corresponding electronic expansion valve can be set according to the size of the indoor unit's heat exchanger. Amin P Bmin、 P Cmin and maximum opening P Amax P Bmax、 P CmaxGenerally, the larger the heat exchange area of ​​the indoor heat exchanger, the larger this opening degree should be. All of the above opening degrees need to be verified experimentally to ensure that the maximum standby opening degree P is maintained. max Under normal circumstances, the electronic expansion valve has a certain flow rate. Because the indoor unit fan does not run in standby mode, the maximum standby opening P... max It must also be set to a smaller opening than the electronic expansion valve of the indoor unit in all operating states to avoid abnormal noise caused by a large flow of refrigerant through the indoor unit in standby mode. max The preferred range is 80~120B. P min The minimum number of valve opening steps in the flow curve of the electronic expansion valve can be directly used, which is the minimum opening degree that guarantees flow as determined by the electronic expansion valve manufacturer. min The preferred range is 40~60B.

[0031] Combination Figure 4 The flowchart illustrates how, when the first indoor unit first enters standby mode, the initial standby opening degree is calculated for different indoor units based on the maximum and minimum standby opening degrees mentioned above. For example, P 初始待机A =(P Amin +P Amax ) / 2; P 初始待机B =(P Bmin +P Bmax ) / 2; P 初始待机C =(P Cmin +P Cmax The initial standby opening is preferably within the range of 60~90B. Setting it within this range ensures that the electronic expansion valve will not shut off completely.

[0032] Afterwards, the first indoor unit enters standby mode and the standby time reaches the program-set value T. 待机 Afterwards, it was determined that a basically stable state had been reached, T 待机 The preferred time is 5 to 15 minutes, at which point the electronic expansion valve control stage of the first indoor unit begins.

[0033] Then, the first parameter of the target first indoor unit is determined, as well as the second parameter related to the second indoor unit in operation. The target first indoor unit can be all indoor units in standby mode, or some indoor units in standby mode; no specific limitation is made here, but preferably, all indoor units in standby mode are the target first indoor unit. In actual control, the first electronic expansion valves corresponding to each first indoor unit can be controlled sequentially or simultaneously.

[0034] The first parameter includes at least the first inner pipe temperature and the first inner ring temperature, and the second parameter includes at least the second inner pipe temperature and the second inner ring temperature. The first inner pipe temperature is the pipe temperature of the heat exchanger of the target first indoor unit, and the second inner pipe temperature is the pipe temperature of the heat exchanger of the second indoor unit; the first inner ring temperature is the temperature of the environment where the target first indoor unit is located, and the second inner ring temperature is the temperature of the environment where the second indoor unit is located.

[0035] Finally, the opening degree of the target electronic expansion valve corresponding to the target first indoor unit is controlled based on the first parameter and the second parameter.

[0036] Using the control method of this embodiment, when some indoor units in a multi-split air conditioning unit are operating in heating mode, the refrigerant can pass through the indoor units in standby mode at a low flow rate. This avoids refrigerant accumulation in the standby indoor units, which would reduce the refrigerant flow rate in the normally operating indoor units and thus affect the heating effect of the normally operating indoor units. Furthermore, it ensures that the refrigerant pump passes through the heat exchanger of the indoor units in standby mode at a stable low flow rate, preventing refrigerant accumulation in the standby indoor units from causing system pressure increases, abnormal noise, and abnormal shutdowns such as high-pressure protection.

[0037] In one alternative implementation, refer to Figure 3 The control flowchart, based on the first parameter and the second parameter, controls the opening degree of the target electronic expansion valve connected to the target first indoor unit, including the following steps: S31. Determine the first difference value of the target first indoor unit and the second difference value of each second indoor unit. The first difference value includes at least the first target difference value. The first target difference value is the difference between the first inner pipe temperature and the first inner ring temperature of the target first indoor unit. The second difference value is the difference between the second inner pipe temperature and the second inner ring temperature of the second indoor unit. S32. Determine the minimum difference among all the second differences of the second internal units; S33. Control the opening degree of the target electronic expansion valve based at least on the difference between the first target value and the minimum difference.

[0038] Specifically, the heat exchanger tube temperature T of the first indoor unit being tested is... 内管待机1 T 内管待机2 And the inner ring temperature T of the target first indoor unit. 内环待机1 T 内环待机2 Then, calculate the first target difference ΔT1 between the internal pipe temperature and the internal ambient temperature of the first indoor unit, where ΔT1 = T 内管待机 -T 内环待机 Under normal circumstances, because refrigerant flows inside the target's first indoor unit, the heat exchanger of the target's first indoor unit still has a certain heating effect. ΔT1 needs to be set to a positive value, and a target value ΔT2 can be set according to the experimental conditions. 目标 The preferred range for this target value is 10~15℃; The heat exchanger tube temperature T of all the second indoor units in operation was monitored. 内管运行1 T 内管运行2 And the corresponding inner ring temperature T 内环运行1 T 内环运行2 Calculate the temperature difference ΔT2 between the inner pipe temperature and the inner ring temperature of all second indoor units, where ΔT2 = T 内管运行 -T 内环运行 And record its minimum difference ΔT2 min .

[0039] Finally, the opening degree of the target electronic expansion valve is controlled based at least on the difference between the first target value and the minimum difference.

[0040] In one example, controlling the opening of the target electronic expansion valve based at least on a first target difference and a minimum difference includes: increasing the opening of the target electronic expansion valve when the first target difference is greater than a first set value and the first target difference is greater than the minimum difference.

[0041] Specifically, in combination Figure 4 The flowchart shows that when the first target difference > the first set value, it indicates that the first inner pipe temperature of the target first indoor unit is higher than the first inner ambient temperature by the first set value, meaning there is too much refrigerant in the heat exchanger of this target first indoor unit. To avoid misjudgment due to setting deviation, it is necessary to further determine the magnitude of the first target difference and the minimum difference. When the first target difference > the minimum difference, it indicates that the heat exchanger temperature rise of the target first indoor unit is higher than that of all second indoor units, meaning there is too much refrigerant in the heat exchanger of this target first indoor unit. However, if both of the above conditions are met simultaneously, it is determined that there is too much refrigerant in the target first indoor unit, and the opening of the target electronic expansion valve needs to be increased.

[0042] In one optional implementation, the first parameter further includes a first external pipe temperature, the second parameter further includes a second external pipe temperature, and the first difference further includes a second target difference; the first external pipe temperature is the temperature of the pipe connecting the outdoor unit heat exchanger and the target first indoor unit heat exchanger, i.e. Figure 1 The temperature of the liquid pipe corresponding to the indoor unit in standby mode. The second external pipe temperature is the temperature of the pipe connecting the outdoor unit heat exchanger and the second indoor unit heat exchanger, which is... Figure 1 The liquid pipe temperature corresponds to the indoor unit in operation. The second target difference is the difference between the first external pipe temperature of the target first indoor unit and the maximum external pipe temperature, where the maximum external pipe temperature is the highest value among the second external pipe temperatures of all second indoor units.

[0043] Controlling the opening degree of the target electronic expansion valve based at least on the first target difference and the minimum difference includes: controlling the opening degree of the target electronic expansion valve based on the first target difference, the second target difference, and the minimum difference.

[0044] This embodiment employs a triple judgment mechanism that compares the first target difference, the second target difference, and the minimum difference. Combined with the program control strategy of the electronic expansion valve, it achieves dynamic adjustment of the refrigerant flow state in the indoor unit during heating standby mode. This ensures that the refrigerant flows stably through the indoor unit at a low flow rate during standby mode, preventing refrigerant accumulation and improving the reliability and stability of system operation.

[0045] In one optional implementation, controlling the opening of the target electronic expansion valve based on a first target difference, a second target difference, and a minimum difference includes: increasing the opening of the target electronic expansion valve when one of a first control condition and a second control condition is met, and a third control condition is also met; the first control condition is: the first target difference > a first set value; the second control condition is: the second target difference < a second set value; and the third control condition is: the first target difference > a minimum difference.

[0046] Specifically, the heat exchanger tube temperature T of the first indoor unit being tested is... 内管待机1 T 内管待机2 And the inner ring temperature T of the target first indoor unit. 内环待机1 T 内环待机2 Then, calculate the first target difference ΔT1 between the internal pipe temperature and the internal ambient temperature of the first indoor unit, where ΔT1 = T 内管待机 -T 内环待机 Under normal circumstances, because refrigerant flows inside the target's first indoor unit, the heat exchanger of the target's first indoor unit still has a certain heating effect. ΔT1 needs to be set to a positive value, and a target value ΔT2 can be set according to the experimental conditions. 目标 The preferred range for this target value is 10~15℃; The heat exchanger tube temperature T of all the second indoor units in operation was monitored. 内管运行1 T 内管运行2 And the corresponding inner ring temperature T 内环运行1 T 内环运行2 Calculate the temperature difference ΔT2 between the inner pipe temperature and the inner ring temperature of all second indoor units, where ΔT2 = T 内管运行 -T 内环运行 And record its minimum difference ΔT2 min .

[0047] The first external pipe temperature T of the first indoor unit of the detection target is... 液管待机1 T 液管待机2 etc., and the second external pipe temperature T of all second indoor units. 液管运行1 T 液管运行2 Then, record the maximum value T of the second external pipe temperature of all second indoor units. 液管运行max Then determine the first target internal unit and the second target value ΔT3, where ΔT3 = T 液管待机 -T 液管运行max .

[0048] Under normal circumstances, the electronic expansion valve opening of the indoor unit in standby mode is smaller than that of all indoor units in operating mode, resulting in a much smaller refrigerant flow. Combined with the poor heat exchange effect due to the indoor fan not running, the refrigerant subcooling is smaller than that of all indoor units in operating mode. Consequently, the liquid line temperature is also higher than that of indoor units in operating mode. ΔT3 needs to be set to a positive value; a target value ΔT3 can be set according to experimental conditions. 目标 The preferred range for this target value is 4~8℃.

[0049] Then determine whether the following first, second, and third control conditions are met respectively: The first control condition is: the first target difference ΔT1 > the first set value (ΔT1) 目标 This indicates that the temperature of the first inner pipe of the target first indoor unit is higher than the first inner ambient temperature by a first set value, and there is too much refrigerant in the heat exchanger of this target first indoor unit.

[0050] The second control condition is: the second target difference ΔT3 < the second set value (ΔT3). 目标 This indicates that the subcooling of the first indoor unit of the target is too large, and it is judged that there is too much refrigerant in the heat exchanger of the first indoor unit of the target.

[0051] The third control condition is: the first target difference ΔT1 > the minimum difference (ΔT2) min This indicates that the heat exchanger temperature rise of the first indoor unit is higher than that of all the second indoor units, and that there is too much refrigerant in the heat exchanger of the first indoor unit.

[0052] The first and second control conditions mentioned above are based on the situation of the target first internal unit. To avoid parameter ΔT1 目标、 ΔT3 目标 If a setting deviation leads to a misjudgment, a third control condition needs to be added to compare the temperature rise of the indoor unit under normal operating conditions, thus avoiding misjudgments.

[0053] When either the first or second control condition is met, and the third control condition is also met, it indicates that there is too much refrigerant in the heat exchanger of the target first indoor unit, resulting in a high temperature of the heat exchanger. This indicates that the opening of the corresponding electronic expansion valve is too small, and the refrigerant flow is too small, causing the refrigerant to accumulate inside the indoor heat exchanger. Consequently, the temperature of the corresponding liquid pipe is too low, and the refrigerant subcooling is too large. At this time, the program needs to perform refrigerant anti-accumulation control, that is, increase the opening of the target electronic expansion valve.

[0054] In one optional implementation, increasing the opening degree of the target electronic expansion valve includes: increasing the opening degree of the target electronic expansion valve by a preset number of steps every preset time interval.

[0055] Specifically, when it is determined that there is refrigerant accumulation in the heat exchanger of the target first indoor unit, the opening of the target electronic expansion valve is increased by a preset number of steps every preset time interval, for example, by increasing the opening by P steps (preferred range 2 to 5B) every M minutes (preferred range 1 to 3 minutes).

[0056] Through the above control, the opening of the electronic expansion valve of the target first indoor unit, which is in a state of refrigerant accumulation, can be gradually increased, thereby increasing the flow of refrigerant in the heat exchanger of this indoor unit, alleviating and gradually eliminating the refrigerant accumulation, and preventing the reduced refrigerant flow of the indoor unit during operation from affecting its heating effect.

[0057] In one optional implementation, if the first target difference is less than the first set value minus the preset buffer value and the first target difference is less than the minimum difference minus the preset buffer value, it indicates that the refrigerant flow rate in the heat exchanger of the target first indoor unit is too large, which will affect the heat exchange effect of the second indoor unit in operation. Also, the excessive opening will cause the target first indoor unit to generate abnormal noise. Therefore, it is necessary to reduce the opening of the target electronic expansion valve. The operation of reducing the opening of the target electronic expansion valve is similar to the operation of increasing the opening. For example, the opening of the target electronic expansion valve is reduced by a preset number of steps every preset time.

[0058] And / or, if the first set value - preset buffer value ≤ first target difference ≤ first set value, or the minimum difference - preset buffer value ≤ first target difference ≤ minimum difference, it indicates that the target electronic expansion valve opening is appropriate, and the current opening of the target electronic expansion valve can be maintained.

[0059] In one optional implementation, combined Figure 4 The flowchart and control method also include: when the following exit conditions are met, the control of the target electronic expansion valve opening is exited: the exit conditions include: the opening of the target electronic expansion valve reaches the maximum or minimum allowable opening in the standby state of the target first indoor unit, indicating that the subcooling of the target first indoor unit is no higher than the target value set by the program, and there is no longer a risk of refrigerant accumulation, so the control of the target electronic expansion valve is exited.

[0060] In summary, this embodiment ensures that when a multi-split air conditioner connects multiple indoor units for heating operation, the refrigerant can flow through the heat exchanger of the indoor unit at a low flow rate in the standby state. This prevents refrigerant buildup in the indoor unit during standby, which would reduce the refrigerant flow rate in the indoor unit during normal operation and affect its heating performance. Simultaneously, it also prevents refrigerant buildup in the indoor unit during standby from causing system pressure increases, abnormal noise, or abnormal shutdowns due to high-pressure protection.

[0061] This embodiment also proposes an electronic device, which includes one or more processors and a non-transitory computer-readable storage medium storing program instructions. When the one or more processors execute the program instructions, the one or more processors are used to implement the control method proposed above.

[0062] Specifically, such as Figure 5 As shown, the electronic device includes a processor 100, at least one communication bus 200, a user interface 300, at least one external communication interface 400, and a memory 500. The communication bus 200 is configured to enable communication between these components. The user interface 300 may include a display screen, and the external communication interface 400 may include standard wired and wireless interfaces. The memory 500 stores control methods for multi-split air conditioning units. The processor 100 is used to employ the aforementioned methods when executing the control methods for multi-split air conditioning units stored in the memory 500.

[0063] This embodiment also proposes a multi-split air conditioning unit, which is controlled by the control method proposed above, or includes the electronic equipment proposed above.

[0064] The descriptions of the above electronic devices and multi-split air conditioning units are similar to those of the above method embodiments, and have similar beneficial effects. For any technical details not disclosed in the electronic devices and multi-split air conditioning units of this application, please refer to the descriptions of the method embodiments of this application for understanding.

[0065] The sequence numbers or order of description of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0066] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A control method of a multi-connected air conditioning unit, characterized by, The control method comprises: When the multi-connected air conditioning unit is running in a heating mode, it is determined whether there is a first indoor unit in a standby state in the multi-connected air conditioning unit; In the case where the first indoor unit exists, a first parameter related to a target first indoor unit is determined, and a second parameter related to a second indoor unit in a running state is determined; the first parameter at least comprises a first indoor tube temperature and a first indoor ring temperature, and the second parameter at least comprises a second indoor tube temperature and a second indoor ring temperature; According to the first parameter and the second parameter, the opening degree of a target electronic expansion valve connected with the target first indoor unit is controlled; Wherein, the first indoor tube temperature is the tube temperature of the heat exchanger of the target first indoor unit, and the second indoor tube temperature is the tube temperature of the heat exchanger of the second indoor unit; the first indoor ring temperature is the temperature of the environment where the target first indoor unit is located, and the second indoor ring temperature is the temperature of the environment where the second indoor unit is located.

2. The control method of the multi-connected air conditioning unit according to claim 1, characterized by, According to the first parameter and the second parameter, the opening degree of a target electronic expansion valve connected with the target first indoor unit is controlled, comprising: Determine the first difference value of the target first indoor unit and the second difference value of each second indoor unit, the first target difference value of the target first indoor unit and the first indoor ring temperature, the second difference value of the second indoor unit and the second indoor ring temperature; Determine the minimum difference value of the second difference value of all second indoor units; At least according to the first target difference value and the minimum difference value, the opening degree of the target electronic expansion valve is controlled.

3. The control method of the multi-connected air conditioning unit according to claim 2, characterized by, At least according to the first target difference value and the minimum difference value, the opening degree of the target electronic expansion valve is controlled, comprising: In the case where the first target difference value > first set value, and the first target difference value > the minimum difference value, the opening degree of the target electronic expansion valve is increased.

4. The control method of the multi-connected air conditioning unit according to claim 2, wherein The first parameter further comprises a first outer tube temperature, the second parameter further comprises a second outer tube temperature, and the first difference value further comprises a second target difference value; the first outer tube temperature is the temperature of the pipeline connecting the outdoor unit heat exchanger and the target first indoor unit heat exchanger; the second outer tube temperature is the temperature of the pipeline connecting the outdoor unit heat exchanger and the second indoor unit heat exchanger; the second target difference value is the difference between the first outer tube temperature of the target first indoor unit and the maximum outer tube temperature, and the maximum outer tube temperature is the maximum value of the second outer tube temperature of all second indoor units; At least according to the first target difference value and the minimum difference value, the opening degree of the target electronic expansion valve is controlled, comprising: According to the first target difference value, the second target difference value and the minimum difference value, the opening degree of the target electronic expansion valve is controlled.

5. The control method of the multi-connected air conditioning unit according to claim 4, wherein According to the first target difference value, the second target difference value and the minimum difference value, the opening degree of the target electronic expansion valve is controlled, comprising: In the case where one of the first regulation condition and the second regulation condition is met, and the third regulation condition is met, the opening degree of the target electronic expansion valve is increased; The first regulation condition is: the first target difference value > first set value; The second regulation condition is: the second target difference value < second set value; The third regulation is: the first target difference value > the minimum difference value.

6. The control method of the multi-connected air conditioning unit according to claim 3 or 5, wherein The opening of the target electronic expansion valve is increased, including: increasing the opening of the target electronic expansion valve by a preset step number every preset time.

7. The control method of the multi-connected air conditioning unit according to any one of claims 3 to 5, characterized by, The opening of the target electronic expansion valve is controlled according to at least the first target difference and the minimum difference, and the control method further includes: In a case where the first target difference < first set value - preset buffer value, and the first target difference < the minimum difference - preset buffer value, the opening of the target electronic expansion valve is decreased; and / or, In a case where first set value - preset buffer value ≤ the first target difference ≤ first set value, or the minimum difference - preset buffer value ≤ the first target difference ≤ the minimum difference, the current opening of the target electronic expansion valve is maintained.

8. The control method of the multi-connected air conditioning unit according to claim 7, wherein The control method further includes: when the following exit condition is met, exiting the regulation of the opening of the target electronic expansion valve: The exit condition includes: the opening of the target electronic expansion valve reaches the maximum allowable opening or the minimum allowable opening in the target first indoor unit standby state.

9. An electronic device, comprising: The electronic device includes one or more processors and a non-transitory computer-readable storage medium having stored program instructions, and when the one or more processors execute the program instructions, the one or more processors are configured to implement the control method of any one of claims 1-8.

10. A multi-connected air conditioning unit, characterized by, The multi-connected air conditioning unit is controlled by the control method of any one of claims 1-8, or includes the electronic device of claim 9.

Images