Multi-connected air conditioning unit control method and device, multi-connected air conditioning unit and storage medium

Abstract

The application relates to a multi-connected air conditioner unit control method and device, a multi-connected air conditioner unit, a storage medium and a computer program product. A bypass electronic expansion valve is arranged, a first end of the bypass electronic expansion valve is connected to a refrigerant pipeline between a compressor exhaust port of an outdoor unit of the multi-connected air conditioner unit and an indoor unit, and a second end of the bypass electronic expansion valve is connected to a refrigerant pipeline between a compressor air inlet of the outdoor unit and the indoor unit. If the multi-connected air conditioner unit is separately started to heat operation of one indoor unit, when it is detected that a preset noise optimization condition is met, the bypass electronic expansion valve is controlled to operate according to operation parameters, so that the refrigerant pressure in the multi-connected air conditioner unit can be balanced, a large amount of high-temperature and high-pressure gaseous refrigerant can be prevented from impacting an electronic expansion valve core part and a pipeline assembly, and the phenomenon that refrigerant noise is generated when the multi-connected air conditioner unit is operated in a heating mode and one indoor unit with a small rated cooling capacity is separately started can be relieved.

Description

Technical Field

[0001] This application relates to the field of air conditioner technology, and in particular to a control method, device, multi-split air conditioning unit, storage medium, and computer program product for a multi-split air conditioning unit. Background Technology

[0002] With the development of science and technology and the continuous improvement of people's living standards, air conditioners are being used more and more widely in daily life and production. Multi-split air conditioning units adopt a one-to-many configuration, meaning one outdoor unit can simultaneously drive multiple indoor units, regulating the temperature of different areas at the same time. Therefore, in the same multi-split air conditioning unit, it is inevitable that the outdoor unit will have a larger displacement compressor, while the indoor units will have a smaller rated cooling capacity.

[0003] When a multi-split air conditioning unit operates in heating mode with only one indoor unit running at a lower rated cooling capacity, if the compressor's minimum operating frequency exceeds the indoor unit's target operating frequency (i.e., over-output occurs), excessive circulating refrigerant and excessively high system pressure will result. Ultimately, a large amount of high-temperature, high-pressure gaseous refrigerant in the indoor unit will impact the electronic expansion valve core and piping components, generating noticeable refrigerant noise. Summary of the Invention

[0004] Therefore, it is necessary to provide a control method, device, multi-split air conditioning unit, storage medium, and computer program product for multi-split air conditioning units to alleviate the problem of refrigerant noise generated when a single indoor unit with a smaller rated cooling capacity is running in heating mode.

[0005] A method for controlling a multi-split air conditioning unit includes: if the multi-split air conditioning unit turns on only one indoor unit for heating operation, detecting whether the operation of the multi-split air conditioning unit meets preset noise optimization conditions; if the preset noise optimization conditions are met, acquiring the operating parameters of the multi-split air conditioning unit; and controlling the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters; wherein, a first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor exhaust port of the outdoor unit of the multi-split air conditioning unit and the indoor unit, and a second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit and the indoor unit.

[0006] The aforementioned multi-split air conditioning unit control method includes a bypass electronic expansion valve. The first end of the bypass electronic expansion valve connects to the refrigerant line between the compressor discharge port of the outdoor unit and the indoor unit, i.e., the first end of the bypass electronic expansion valve is connected to the higher-pressure refrigerant line of the multi-split air conditioning unit. The second end of the bypass electronic expansion valve connects to the refrigerant line between the compressor inlet of the outdoor unit and the indoor unit, i.e., the second end of the bypass electronic expansion valve is connected to the lower-pressure refrigerant line of the multi-split air conditioning unit. If a single indoor unit of the multi-split air conditioning unit is operating in heating mode, and the preset noise optimization conditions are met, the bypass electronic expansion valve is controlled to operate according to the operating parameters. This balances the refrigerant pressure in the multi-split air conditioning unit, preventing a large amount of high-temperature, high-pressure gaseous refrigerant from impacting the valve core and piping components of the electronic expansion valve. This alleviates the refrigerant noise generated when a single indoor unit with a smaller rated cooling capacity is operating in heating mode.

[0007] In one embodiment, detecting whether the multi-split air conditioning unit operates in accordance with preset noise optimization conditions includes: obtaining the ratio of the actual to the theoretical output capacity of the multi-split air conditioning unit; detecting whether the ratio of the actual to the theoretical output capacity is greater than a preset ratio threshold; if the ratio of the actual to the theoretical output capacity is greater than the preset ratio threshold, determining that the multi-split air conditioning unit operates in accordance with preset noise optimization conditions.

[0008] In one embodiment, obtaining the ratio of the actual to the theoretical output capacity of the multi-split air conditioning unit includes: obtaining the actual operating frequency of the compressor, the compressor displacement, and the rated capacity of the indoor unit of the multi-split air conditioning unit; and calculating the ratio based on the actual operating frequency of the compressor, the compressor displacement, and the rated capacity to obtain the ratio of the actual to the theoretical output capacity of the multi-split air conditioning unit.

[0009] In one embodiment, controlling the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters includes: obtaining a first target high-pressure value when the indoor unit meets the actual heating demand and a second target high-pressure value when the indoor unit meets the noise-free operation demand according to the operating parameters; and controlling the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters, the first target high-pressure value and the second target high-pressure value.

[0010] In one embodiment, the operating parameters include the rated capacity of the indoor unit and the ambient temperature of the environment in which the indoor unit is located; obtaining the first target high-pressure value when the indoor unit meets the actual heating demand and the second target high-pressure value when the indoor unit meets the noise-free operation demand based on the operating parameters includes: obtaining the first target high-pressure value when the indoor unit meets the actual heating demand based on the rated capacity, the ambient temperature, and a preset correspondence between the rated capacity, the ambient temperature, and the target high-pressure value; and obtaining the second target high-pressure value when the indoor unit meets the noise-free operation demand based on the rated capacity and the preset correspondence between the rated capacity and the target high-pressure value.

[0011] In one embodiment, the operating parameters include the actual system high pressure; controlling the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters, the first target high pressure value, and the second target high pressure value includes: controlling the bypass electronic expansion valve of the multi-split air conditioning unit to open and operate at a preset initial opening degree; and adjusting the opening degree of the bypass electronic expansion valve according to the actual system high pressure, the first target high pressure value, and the second target high pressure value.

[0012] In one embodiment, adjusting the opening of the bypass electronic expansion valve based on the actual system high pressure, the first target high pressure value, and the second target high pressure value includes: if the first target high pressure value is less than or equal to the second target high pressure value, acquiring the actual system high pressure of the multi-split air conditioning unit in real time; if the actual system high pressure is less than the first target high pressure value, adjusting the opening of the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit so that the actual system high pressure is greater than or equal to the first target high pressure value; if the actual system high pressure is greater than or equal to the first target high pressure value and less than or equal to the second target high pressure value, maintaining the opening of the bypass electronic expansion valve unchanged; if the actual system high pressure is greater than the second target high pressure value, increasing the opening of the bypass electronic expansion valve by a first preset opening threshold.

[0013] In one embodiment, adjusting the opening of the bypass electronic expansion valve based on the actual system high pressure, the first target high pressure value, and the second target high pressure value includes: if the first target high pressure value is greater than the second target high pressure value, acquiring the actual system high pressure of the multi-split air conditioning unit in real time; if the actual system high pressure is less than the first target high pressure value, adjusting the opening of the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit so that the actual system high pressure is greater than or equal to the first target high pressure value; if the actual system high pressure is greater than or equal to the first target high pressure value, and the difference between the actual system high pressure and the first target high pressure value is less than or equal to a preset difference threshold, maintaining the opening of the bypass electronic expansion valve unchanged; if the actual system high pressure is greater than or equal to the first target high pressure value, and the difference between the actual system high pressure and the first target high pressure value is greater than a preset difference threshold, increasing the opening of the bypass electronic expansion valve by a second preset opening threshold.

[0014] In one embodiment, adjusting the opening of the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit to make the actual system high pressure greater than or equal to the first target high pressure value includes: opening the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit with a third preset opening threshold; if the opening duration of the indoor electronic expansion valve of the shut-off indoor unit reaches a first preset duration, closing the indoor electronic expansion valve of the shut-off indoor unit; if the closing duration of the indoor electronic expansion valve of the shut-off indoor unit reaches a second preset duration, detecting whether the actual system high pressure is greater than or equal to the first target high pressure value; if the actual system high pressure is greater than or equal to the first target high pressure value, closing the bypass electronic expansion valve, and returning to the step of real-time acquisition of the actual system high pressure of the multi-split air conditioning unit.

[0015] In one embodiment, after detecting whether the actual high pressure of the system is greater than or equal to the first target high pressure value if the duration of closing the indoor electronic expansion valve of the shut-off indoor unit reaches a second preset duration, the method further includes: if the actual high pressure of the system is less than the first target high pressure value, reducing the opening degree of the bypass electronic expansion valve to a fourth preset opening degree threshold, and returning to the step of real-time acquisition of the actual high pressure of the multi-split air conditioning unit.

[0016] A multi-split air conditioning unit control device includes: an optimization verification module, used to detect whether the multi-split air conditioning unit meets preset noise optimization conditions if only one indoor unit of the multi-split air conditioning unit is turned on for heating operation; a parameter acquisition module, used to acquire the operating parameters of the multi-split air conditioning unit if the preset noise optimization conditions are met; and an optimization control module, used to control the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters; wherein, a first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor exhaust port of the outdoor unit of the multi-split air conditioning unit and the indoor unit, and a second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit and the indoor unit.

[0017] A multi-split air conditioning unit includes an outdoor unit, a bypass electronic expansion valve, a controller, and at least one indoor unit. The outdoor unit, the indoor unit, and the bypass electronic expansion valve are respectively connected to the controller, which is used to implement the steps of the above-described multi-split air conditioning unit control method.

[0018] In one embodiment, the outdoor unit includes an outdoor electronic expansion valve, an outdoor heat exchanger, a four-way valve, a compressor, and a gas-liquid separator. The compressor's discharge port is connected to the four-way valve via a refrigerant line. The four-way valve is connected to the indoor unit via a refrigerant line. The indoor unit is connected to the outdoor electronic expansion valve via a refrigerant line. The outdoor electronic expansion valve is connected to the outdoor heat exchanger via a refrigerant line. The outdoor heat exchanger is connected to the four-way valve via a refrigerant line. The four-way valve is connected to the gas-liquid separator via a refrigerant line. The gas-liquid separator is connected to the compressor's inlet via a refrigerant line.

[0019] In one embodiment, the first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor exhaust port of the outdoor unit of the multi-split air conditioning unit and the indoor unit, including: the first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the four-way valve and the indoor unit.

[0020] In one embodiment, the first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor exhaust port of the outdoor unit of the multi-split air conditioning unit and the indoor unit, including: the first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the four-way valve and the compressor exhaust port.

[0021] In one embodiment, the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit and the indoor unit, including: the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the four-way valve and the gas-liquid separator.

[0022] In one embodiment, the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit and the indoor unit, including: the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the outdoor electronic expansion valve and the indoor unit.

[0023] In one embodiment, the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit and the indoor unit, including: the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the outdoor electronic expansion valve and the outdoor heat exchanger.

[0024] In one embodiment, the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit and the indoor unit, including: the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the outdoor heat exchanger and the four-way valve.

[0025] In one embodiment, the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit and the indoor unit, including: the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the gas-liquid separator and the compressor inlet.

[0026] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described multi-split air conditioning unit control method.

[0027] A computer program product includes a computer program that, when executed by a processor, implements the steps of the above-described multi-split air conditioning unit control method. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram illustrating an application scenario of the multi-split air conditioning unit control method in one embodiment of this application;

[0030] Figure 2 This is a schematic flowchart of a multi-split air conditioning unit control method in one embodiment of this application;

[0031] Figure 3 This is a schematic diagram of the optimization analysis process in one embodiment of this application;

[0032] Figure 4This is a schematic diagram of the optimized analysis process in another embodiment of this application;

[0033] Figure 5 This is a schematic diagram of the control method for a multi-split air conditioning unit in another embodiment of this application;

[0034] Figure 6 This is a schematic diagram of the control method for a multi-split air conditioning unit in another embodiment of this application;

[0035] Figure 7 This is a schematic flowchart of a multi-split air conditioning unit control method in another embodiment of this application;

[0036] Figure 8 This is a schematic diagram of the bypass electronic expansion valve opening adjustment in one embodiment of this application;

[0037] Figure 9 This is a schematic diagram of the bypass electronic expansion valve opening adjustment in another embodiment of this application;

[0038] Figure 10 This is a schematic diagram of the indoor unit shutdown control in one embodiment of this application;

[0039] Figure 11 This is a schematic diagram of the indoor unit shutdown control in another embodiment of this application;

[0040] Figure 12 This is a schematic diagram of a multi-split air conditioning unit control method in one embodiment of this application;

[0041] Figure 13 This is a schematic diagram of the control device structure of a multi-split air conditioning unit in one embodiment of this application;

[0042] Figure 14 This is a schematic diagram of a multi-split air conditioning unit structure in one embodiment of this application;

[0043] Figure 15 This is a schematic diagram of a multi-split air conditioning unit structure in another embodiment of this application;

[0044] Figure 16 This is a schematic diagram of a multi-split air conditioning unit structure in another embodiment of this application. Detailed Implementation

[0045] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0046] The air conditioning operation control method provided in this application is applied to a multi-split air conditioning unit, which includes at least one outdoor unit, and each outdoor unit can drive at least one indoor unit. Please refer to the relevant documentation for details. Figure 1 In this embodiment, the solution is illustrated by taking one outdoor unit 10 driving multiple indoor units 20 as an example. The indoor units 20 are connected in parallel (specifically shown in Figure 100). The outdoor unit 10 includes a gas-liquid separator 14, a compressor 15, a four-way valve 13, an outdoor electronic expansion valve 11, and an outdoor heat exchanger 12. These components are connected via refrigerant piping. Specifically, the gas-liquid separator 14, the outdoor heat exchanger 12, and the compressor 15 are each connected to the four-way valve 13. The outdoor heat exchanger 12 is connected to the indoor unit 20 via the outdoor electronic expansion valve 11. The compressor 15 is connected to the gas-liquid separator 14. Simultaneously, the four-way valve 13 is also connected to the indoor unit 20. The indoor unit 20 includes an indoor heat exchanger 22 and an indoor electronic expansion valve 21. The indoor electronic expansion valve 21 is connected to the outdoor electronic expansion valve 11 of the outdoor unit 10, and the indoor heat exchanger 22 is connected to both the indoor electronic expansion valve 21 and the four-way valve 13 of the outdoor unit 10.

[0047] Furthermore, the multi-split air conditioning unit also includes a bypass electronic expansion valve ( Figure 1 (Not shown), the first end of the bypass electronic expansion valve is connected to the refrigerant line between the compressor exhaust port (i.e., the compressor exhaust port 15) of the outdoor unit 10 of the multi-split air conditioning unit and the indoor unit 20, and the second end of the bypass electronic expansion valve is connected to the refrigerant line between the compressor inlet (i.e., the compressor inlet 15) of the outdoor unit 10 and the indoor unit 20.

[0048] Please see Figure 2 A method for controlling a multi-split air conditioning unit includes steps 202, 204 and 206.

[0049] Step 202: If a multi-split air conditioning unit starts heating operation on a single indoor unit, check whether the multi-split air conditioning unit meets the preset noise optimization conditions.

[0050] Specifically, heating operation means that the indoor unit operates in heating mode, while the outdoor unit provides the indoor unit with high-temperature, high-pressure refrigerant, thereby raising the temperature of the environment where the indoor unit is located. Preset noise optimization conditions are preset conditions that the multi-split air conditioning unit must meet to optimize noise control during operation, eliminating refrigerant noise generated by the multi-split air conditioning unit. Single indoor unit heating operation of a multi-split air conditioning unit refers to simultaneously operating one outdoor unit and one indoor unit in heating mode within the same multi-split air conditioning system (one outdoor unit and multiple indoor units). It can be understood that the same multi-split air conditioning unit can include at least one multi-split system, and the multi-split air conditioning unit control method of this application can be used to control any single indoor unit in a multi-split system operating in heating mode.

[0051] During operation, the controller of the multi-split air conditioning unit can monitor the location and number of currently active indoor units in real time, and also detect the operating mode of the active indoor units. When it detects that the multi-split air conditioning unit is operating with only one indoor unit in heating mode, the multi-split air conditioning unit control method of this application embodiment is executed. When the multi-split air conditioning unit is operating with only one indoor unit in heating mode, the controller first analyzes the operation of that indoor unit and detects whether the multi-split air conditioning unit meets the preset noise optimization conditions when operating with only one indoor unit in heating mode.

[0052] It is understood that the specific location of the controller is not unique. In one embodiment, the controller may be an additional device, independent of both the outdoor and indoor units. In another embodiment, the controller may be the controller of the indoor unit of a multi-split air conditioning unit, or the controller of the outdoor unit of a multi-split air conditioning unit; the specific location is not limited. For ease of understanding of the technical solution of this application, the following embodiments will use the controller of the outdoor unit of a multi-split air conditioning unit for explanation and description.

[0053] Step 204: If the preset noise optimization conditions are met, obtain the operating parameters of the multi-split air conditioning unit.

[0054] Specifically, operating parameters are the parameters generated during the operation of the multi-split air conditioning unit and related to its operating status. When the controller detects that the multi-split air conditioning unit meets the noise optimization conditions, that is, it assumes that if the multi-split air conditioning unit operates in the current state, it will generate relatively obvious refrigerant noise due to the impact of high-pressure and high-temperature refrigerant, and at this time, it will acquire the operating parameters of the multi-split air conditioning unit.

[0055] It should be noted that the method of acquiring operating parameters is not unique. In one embodiment, the multi-split air conditioning unit is equipped with a parameter acquisition device to collect the operating parameters generated during the operation of the multi-split air conditioning unit and send them to the controller. The specific type of parameter acquisition device is not unique; it will vary depending on the specific operating parameters. For example, the parameter acquisition device may include an ambient temperature acquisition device. In another embodiment, operating parameters can also be generated based on the start-up signal of the multi-split air conditioning unit or the user's operation commands to the multi-split air conditioning unit, such as the rated capacity of the indoor unit, the compressor operating frequency, or the compressor displacement, etc., depending on the actual needs.

[0056] Step 206: Control the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters.

[0057] The first end of the bypass electronic expansion valve is connected to the refrigerant line between the compressor discharge port of the outdoor unit and the indoor unit of the multi-split air conditioning unit, and the second end of the bypass electronic expansion valve is connected to the refrigerant line between the compressor inlet of the outdoor unit and the indoor unit.

[0058] Specifically, the refrigerant piping between the compressor discharge port of the outdoor unit and the indoor unit of a multi-split air conditioning unit—that is, the refrigerant piping through which the high-temperature, high-pressure refrigerant is output from the compressor discharge port and transferred to the outdoor unit—is considered a higher-pressure refrigerant piping because the refrigerant is at high temperature and high pressure at this time. Similarly, the refrigerant piping between the compressor inlet of the outdoor unit and the indoor unit—that is, the refrigerant piping through which the high-temperature, high-pressure refrigerant exchanges heat with the indoor unit's environment to obtain lower-pressure refrigerant, and then is transferred back to the compressor—is considered a lower-pressure refrigerant piping (or medium-low pressure refrigerant piping) because the refrigerant pressure is lower at this time.

[0059] In this embodiment, when the multi-split air conditioning unit meets the preset noise optimization conditions, the controller, based on the acquired operating parameters, controls the operation of the bypass electronic expansion valve. Through the bypass function of the electronic expansion valve, a portion of the higher-pressure refrigerant in the high-pressure refrigerant line is transferred to the medium- and low-pressure refrigerant lines, balancing the refrigerant pressure of the multi-split air conditioning unit. This avoids refrigerant noise from indoor units operating only in heating mode, while ensuring that the actual capacity requirements of the indoor units are met. Furthermore, it eliminates the need to activate the indoor electronic expansion valve corresponding to indoor units that are frequently switched on and off, thus preventing refrigerant noise from the shut-off indoor unit.

[0060] It is understood that, in one embodiment, if the controller detects that the multi-split air conditioning unit does not meet the noise optimization conditions, it means that the multi-split air conditioning unit will not produce significant refrigerant noise when operating in its current state, and no additional adjustments are required. Therefore, in this embodiment, the bypass electronic expansion valve does not need to be activated. The controller only needs to control the outdoor unit's compressor to start at the corresponding frequency and control the corresponding indoor electronic expansion valve of the indoor unit to open at the required degree, according to user needs. This achieves the normal control of the multi-split unit.

[0061] It should be noted that the location of the bypass electronic expansion valve is not unique; it is acceptable as long as the first end of the bypass electronic expansion valve is connected to a higher-pressure refrigerant line and the second end is connected to a lower-pressure refrigerant line. For example, in one embodiment, using... Figure 1Taking the multi-split air conditioning unit as an example, the first end of the bypass electronic expansion valve can be connected to the refrigerant line between the four-way valve and the indoor unit, or to the refrigerant line between the four-way valve and the compressor's discharge port. The second end of the bypass electronic expansion valve can be connected to the refrigerant line between the four-way valve and the gas-liquid separator, the refrigerant line between the outdoor electronic expansion valve and the indoor unit, the refrigerant line between the outdoor electronic expansion valve and the outdoor heat exchanger, the refrigerant line between the outdoor heat exchanger and the four-way valve, or the refrigerant line between the gas-liquid separator and the compressor's inlet. The specific connection should be selected based on actual needs.

[0062] The aforementioned multi-split air conditioning unit control method includes a bypass electronic expansion valve. The first end of the bypass electronic expansion valve connects to the refrigerant line between the compressor discharge port of the outdoor unit and the indoor unit, i.e., the first end of the bypass electronic expansion valve is connected to the higher-pressure refrigerant line of the multi-split air conditioning unit. The second end of the bypass electronic expansion valve connects to the refrigerant line between the compressor inlet of the outdoor unit and the indoor unit, i.e., the second end of the bypass electronic expansion valve is connected to the lower-pressure refrigerant line of the multi-split air conditioning unit. If a single indoor unit of the multi-split air conditioning unit is operating in heating mode, and the preset noise optimization conditions are met, the bypass electronic expansion valve is controlled to operate according to the operating parameters. This balances the refrigerant pressure in the multi-split air conditioning unit, preventing a large amount of high-temperature, high-pressure gaseous refrigerant from impacting the valve core and piping components of the electronic expansion valve. This alleviates the refrigerant noise generated when a single indoor unit with a smaller rated cooling capacity is operating in heating mode.

[0063] Please see Figure 3 In one embodiment, detecting whether the multi-split air conditioning unit is operating in accordance with preset noise optimization conditions includes steps 302, 304 and 306.

[0064] Step 302: Obtain the ratio of the actual to the theoretical output capacity of the multi-split air conditioning unit.

[0065] Step 304: Detect whether the ratio of actual to theoretical output capability is greater than a preset ratio threshold.

[0066] Step 306: If the ratio of actual to theoretical output capacity is greater than the preset ratio threshold, it is determined that the operation of the multi-split air conditioning unit meets the preset noise optimization conditions.

[0067] Specifically, the ratio of actual to theoretical output capacity is the ratio of the actual output capacity of the multi-split air conditioning unit to the theoretically required output capacity of the current indoor unit. The preset ratio threshold is a preset threshold for the ratio of the actual output capacity of the multi-split air conditioning unit to the theoretically required output capacity.

[0068] In this embodiment, the controller detects whether the multi-split air conditioning unit meets the preset noise optimization conditions by detecting whether the ratio of the actual to the theoretical output capacity of the multi-split air conditioning unit exceeds a preset ratio threshold. If the ratio of the actual to the theoretical output capacity is greater than the preset ratio threshold, the multi-split air conditioning unit is considered to meet the preset noise optimization conditions. If the ratio of the actual to the theoretical output capacity is less than or equal to the preset ratio threshold, the multi-split air conditioning unit is considered not to meet the preset noise optimization conditions.

[0069] It is understood that the preset ratio threshold is not unique. In one embodiment, the preset ratio threshold can be set to a constant greater than 1, such as 1.2, 1.4, 1.6, etc., without specific limitation. That is, the solution of this embodiment determines whether the multi-split air conditioning unit meets the preset noise optimization conditions by detecting whether the multi-split air conditioning unit has output. If output has occurred, it is considered to meet the preset noise optimization conditions.

[0070] This method is used to detect whether a multi-split air conditioning unit is operating in accordance with preset noise optimization conditions. It combines noise optimization with the actual operation of the multi-split air conditioning unit and has high detection accuracy.

[0071] Please see Figure 4 In one embodiment, step 302 includes steps 402 and 404.

[0072] Step 402: Obtain the actual operating frequency of the compressor, the compressor displacement, and the rated capacity of the indoor unit of the multi-split air conditioning unit.

[0073] Step 404: Calculate the ratio of the actual operating frequency, displacement, and rated capacity of the compressor to obtain the ratio of the actual to the theoretical output capacity of the multi-split air conditioning unit.

[0074] Specifically, the compressor's actual operating frequency is the frequency at which the compressor actually operates for heating under the current operating conditions. The compressor displacement is the actual displacement of the compressor during heating operation under the current operating conditions. The indoor unit's rated capacity is the heating capacity corresponding to the currently running indoor unit operating at its rated power.

[0075] The method by which the controller obtains the ratio of the actual to the theoretical output capacity of a multi-split air conditioning unit is not unique. In this embodiment, the actual output capacity of the multi-split air conditioning unit is calculated by combining the actual operating frequency and displacement of the compressor when the single-unit heating indoor unit is running. Then, the theoretical output capacity required by the multi-split air conditioning unit is calculated by combining this with the rated capacity of the currently active indoor unit. Finally, the ratio of the actual output capacity to the theoretical output capacity is used as the actual-to-theoretical output capacity ratio.

[0076] It is understandable that the controller may not have a single way of obtaining the compressor’s actual operating frequency, compressor displacement, and rated capacity. In a more detailed embodiment, the compressor’s actual operating frequency and compressor displacement are generated based on parameters or instructions related to user needs, while the rated frequency is sent to the controller by the corresponding indoor unit when it is turned on.

[0077] It should be noted that the specific method of calculating the ratio is not unique. In a more detailed embodiment, the method of calculating the ratio includes: ε = (actual operating frequency of the compressor × compressor displacement) / (A × rated capacity of the indoor unit when it is turned on), where ε represents the ratio of actual to theoretical output capacity, and A represents an empirical constant, the specific value of which is not unique. In a more detailed embodiment, it can be 220.

[0078] Please see Figure 5 In one embodiment, step 206 includes steps 502 and 504.

[0079] Step 502: Based on the operating parameters, obtain the first target high pressure value when the indoor unit meets the actual heating demand, and the second target high pressure value when the indoor unit meets the noise-free operation demand.

[0080] Step 504: Control the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters, the first target high pressure value, and the second target high pressure value.

[0081] Specifically, the first target high-pressure value is the actual system high pressure that the multi-split air conditioning unit can achieve when the indoor unit meets the actual heating demand, which is also the compressor's discharge pressure. The second target high-pressure value is the actual system high pressure that the multi-split air conditioning unit can achieve when the indoor unit is running in a noise-free state. Depending on the current operating parameters of the multi-split air conditioning unit, the corresponding first and second target high-pressure values ​​will differ. Therefore, when noise optimization of the multi-split air conditioning unit is required, the corresponding first and second target high-pressure values ​​will be matched based on the operating parameters. Then, based on the real-time acquired operating parameters, as well as the first and second target high-pressure values, the opening of the outdoor bypass electronic expansion valve is adjusted to balance the refrigerant pressure of the multi-split air conditioning unit and avoid high-pressure refrigerant surges that could cause refrigerant noise.

[0082] It should be noted that the method for determining the first and second target high-voltage values ​​based on operating parameters is not unique. In one embodiment, please refer to [link to relevant documentation]. Figure 6 The operating parameters include the rated capacity of the indoor unit and the ambient temperature of the environment where the indoor unit is located; step 502 includes steps 602 and 604.

[0083] Step 602: Based on the rated capacity, ambient temperature, and the preset correspondence between rated capacity, ambient temperature, and target high pressure value, obtain the first target high pressure value when the indoor unit meets the actual heating demand.

[0084] Step 604: Based on the rated capacity and the preset correspondence between the rated capacity and the target high voltage value, obtain the second target high voltage value when the indoor unit meets the requirement of noiseless operation.

[0085] Specifically, the method of obtaining ambient temperature is not unique. In a more detailed embodiment, each indoor unit's environment (or the temperature control zone corresponding to the indoor unit) is equipped with an ambient temperature detector. The ambient temperature detector is communicatively connected to the controller, collecting ambient temperature data and sending it to the controller. The preset correspondence between rated capacity, ambient temperature, and target high pressure value, as well as the preset correspondence between rated capacity and target high pressure value, are obtained through experimental analysis of multi-split air conditioning units of the same model as the multi-split air conditioning unit. This data is stored in the controller in the form of a database, graphs, or tables, and can be directly accessed later.

[0086] When a single-operation heating indoor unit meets the actual heating demand, there exists a first target high-pressure value T. 目标1 This value is related to the rated capacity of the indoor unit and the ambient temperature. The larger the rated capacity and the lower the ambient temperature, the higher the first target high pressure value; conversely, the smaller the rated capacity and the higher the ambient temperature, the lower the first target high pressure value. To meet heating demands, the actual system high pressure T of the multi-split air conditioning unit needs to be adjusted during actual operation. 实际 Adjust to T 实际 >T 目标1 .

[0087] When the refrigerant quantity of a multi-split air conditioning unit is matched with the configuration of the indoor units, and no refrigerant noise is generated, there exists a second target high-pressure value T. 目标2 This value is related to the rated capacity of the indoor unit. The larger the rated capacity, the higher the second target high pressure value; the smaller the rated capacity, the lower the second target high pressure value. To avoid refrigerant noise, it is generally necessary to adjust the actual system high pressure T. 实际 Adjust to T 实际 <T 目标2 .

[0088] The above scheme, combining rated capacity, ambient temperature, and preset correspondence, can quickly match the first target high voltage value and the second target high voltage value corresponding to the current indoor unit, ensuring the operating efficiency of the multi-split air conditioning unit control method.

[0089] Please see Figure 7 In one embodiment, the operating parameters include the actual high voltage of the system; step 504 includes steps 702 and 704.

[0090] Step 702: Control the bypass electronic expansion valve of the multi-split air conditioning unit to start operation at a preset initial opening.

[0091] Step 704: Adjust the opening of the bypass electronic expansion valve according to the actual high pressure of the system, the first target high pressure value, and the second target high pressure value.

[0092] Specifically, the actual high pressure of the system is the actual high pressure value obtained by collecting pressure data from the compressor's exhaust port during the actual operation of the multi-split air conditioning unit. In this embodiment, when the multi-split air conditioning unit meets the preset noise optimization conditions, the bypass electronic expansion valve is first controlled to open at a preset initial opening. Then, based on the collected actual high pressure of the system, the first target high pressure value, and the second target high pressure value obtained from the analysis of operating parameters, the opening of the bypass electronic expansion valve is adjusted to ensure that the multi-split air conditioning unit operates without refrigerant noise.

[0093] It should be noted that the preset initial opening is not unique; it only needs to be greater than 1. For example, in a more detailed embodiment, the preset initial opening can be set to 30 pls (pulse units).

[0094] Further, in one embodiment, please refer to Figure 8 Step 704 includes steps 801, 803, 805 and 807.

[0095] Step 801: If the first target high pressure value is less than or equal to the second target high pressure value, obtain the actual system high pressure of the multi-split air conditioning unit in real time.

[0096] Step 803: If the actual high pressure of the system is less than the first target high pressure value, adjust the opening of the indoor electronic expansion valve of the indoor unit of the multi-split air conditioning unit so that the actual high pressure of the system is greater than or equal to the first target high pressure value.

[0097] Step 805: If the actual high pressure of the system is greater than or equal to the first target high pressure value and less than or equal to the second target high pressure value, maintain the opening of the bypass electronic expansion valve unchanged.

[0098] Step 807: If the actual high pressure of the system is greater than the second target high pressure value, the opening degree of the bypass electronic expansion valve is increased by the first preset opening degree threshold.

[0099] Specifically, under normal temperature conditions, the first target high-pressure value is less than the second target high-pressure value. Therefore, in this embodiment, when matching the first and second target high-pressure values, the solution first determines the magnitude of the first and second target high-pressure values. If the first target high-pressure value is less than or equal to the second target high-pressure value, the solution further considers the actual range of the system's actual high pressure relative to the first and second target high-pressure values, and performs corresponding adjustment operations on the bypass electronic expansion valve. Ultimately, this ensures that the acquired actual system high pressure is between the first and second target high-pressure values, i.e., T. 目标1 ≤T 实际 ≤T 目标2 .

[0100] If the actual system high pressure is detected to be lower than the first target high pressure value, the system high pressure is first adjusted to be above or equal to the first target high pressure value by adjusting the indoor electronic expansion valve of the shut-off indoor unit. Then, based on the system high pressure being greater than or equal to the first target high pressure value, it is analyzed whether the actual system high pressure is now greater than the second target high pressure value. If it is not greater than the second target high pressure value, the bypass electronic expansion valve is maintained at its current opening. If the analysis shows that the actual system high pressure is greater than the second target high pressure value, the opening of the bypass electronic expansion valve needs to be adjusted. Based on the current opening, the opening of the bypass electronic expansion valve is increased by a first preset opening threshold, and the system high pressure of the multi-split air conditioning unit is retrieved in real time for the next round of analysis. This cycle of adjustment continues until the actual system high pressure is greater than or equal to the first target high pressure value and less than or equal to the second target high pressure value.

[0101] Please see Figure 9 In one embodiment, step 704 includes steps 901, 903, 905 and 907.

[0102] Step 901: If the first target high pressure value is greater than the second target high pressure value, obtain the actual system high pressure of the multi-split air conditioning unit in real time.

[0103] Step 903: If the actual high pressure of the system is less than the first target high pressure value, adjust the opening of the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit so that the actual high pressure of the system is greater than or equal to the first target high pressure value.

[0104] Step 905: If the actual high pressure of the system is greater than or equal to the first target high pressure value, and the difference between the actual high pressure of the system and the first target high pressure value is less than or equal to the preset difference threshold, the opening of the bypass electronic expansion valve remains unchanged.

[0105] Step 907: If the actual high pressure of the system is greater than or equal to the first target high pressure value, and the difference between the actual high pressure of the system and the first target high pressure value is greater than the preset difference threshold, the opening degree of the bypass electronic expansion valve is increased to the second preset opening degree threshold.

[0106] Specifically, in this embodiment, the solution may conflict with the first target high voltage value and the second target high voltage value due to operation at lower ambient temperatures, meaning the first target high voltage value may be greater than the second target high voltage value. In this case, it is necessary to prioritize adjusting the system's actual high voltage to be greater than or equal to the first target high voltage value. Therefore, in this embodiment, when the first target high voltage value is greater than the second target high voltage value, the solution further considers the actual range of the system's actual high voltage relative to the first and second target high voltage values ​​and performs corresponding adjustment operations on the bypass electronic expansion valve, ultimately ensuring that the acquired system's actual high voltage is greater than or equal to the first target high voltage value, i.e., T. 实际 ≥T 目标1 .

[0107] If the actual system high pressure is detected to be lower than the first target high pressure value, the system high pressure is first adjusted to be above or equal to the first target high pressure value by adjusting the indoor electronic expansion valve of the shut-off indoor unit. Then, based on the actual system high pressure being greater than or equal to the first target high pressure value, the difference between the actual system high pressure and the first target high pressure value is analyzed to see if it exceeds a preset difference threshold. If the difference is less than or equal to the preset difference threshold, the bypass electronic expansion valve is maintained at its current opening. If the difference exceeds the preset difference threshold, the opening of the bypass electronic expansion valve is increased by a second preset opening threshold, and the system high pressure of the multi-split air conditioning unit is retrieved in real time. The next round of analysis and control is then performed until the final actual system high pressure is greater than or equal to the first target high pressure value, and the difference between the actual system high pressure and the first target high pressure value is less than or equal to the preset difference threshold.

[0108] It is understood that there is no single way to adjust the opening of the indoor electronic expansion valve of the shut-off indoor unit in a multi-split air conditioning unit. For a more detailed embodiment, please refer to [link / reference needed]. Figure 10 When the first target high pressure value is greater than the second target high pressure value, and when the first target high pressure value is less than or equal to the second target high pressure value, the adjustment method of the indoor electronic expansion valve of the shut-off indoor unit is the same. Adjusting the opening of the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit to make the actual system high pressure greater than or equal to the first target high pressure value includes steps 902, 904, 906, and 908.

[0109] Step 902: Open the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit with the third preset opening threshold.

[0110] Step 904: If the opening time of the indoor electronic expansion valve of the shut-off indoor unit reaches the first preset time, close the indoor electronic expansion valve of the shut-off indoor unit.

[0111] Step 906: If the duration of closing the indoor electronic expansion valve of the indoor unit reaches the second preset duration, check whether the actual high pressure of the detection system is greater than or equal to the first target high pressure value.

[0112] Step 908: If the actual system high pressure is greater than or equal to the first target high pressure value, close the bypass electronic expansion valve. Then return to the step of obtaining the actual system high pressure of the multi-split air conditioning unit in real time.

[0113] Specifically, in this embodiment, the solution involves briefly opening the indoor electronic expansion valve of the shut-off indoor unit to attempt to adjust the actual system pressure to be greater than or equal to the first target pressure value. First, the controller opens the electronic expansion valve of the shut-off indoor unit to a third preset opening threshold and maintains the open state for a first preset duration, then returns it to the closed state. After the indoor electronic expansion valve has been closed for a second preset duration, it is determined whether the actual system pressure is greater than or equal to the first target pressure value. If the actual system pressure is greater than or equal to the first target pressure value, it indicates that refrigerant has accumulated in the heat exchanger of the shut-off indoor unit after prolonged operation, resulting in a refrigerant shortage in the system. Therefore, by briefly opening the electronic expansion valve of the shut-off indoor unit, the system pressure can be restored without adjusting the bypass electronic expansion valve; simply closing the bypass electronic expansion valve is sufficient. The system then returns to re-acquiring and detecting the actual system pressure until the final acquired actual system pressure is between the first and second target pressure values, or between the first target pressure value and the first target pressure value plus a preset difference threshold.

[0114] It should be noted that in the solution of this embodiment, when the indoor electronic expansion valve of the shut-off indoor unit is opened for a short time, it can be to control the opening of the indoor electronic expansion valve corresponding to any one indoor unit in the multi-split air conditioning unit, or to control the opening of the indoor electronic expansion valves corresponding to two or more indoor units. There is no specific limitation, and the choice can be made according to actual needs.

[0115] Further, in one embodiment, please refer to Figure 11 After step 906, the method further includes step 112.

[0116] Step 112: If the actual system high pressure is less than the first target high pressure value, reduce the opening of the bypass electronic expansion valve to the fourth preset opening threshold. Then return to the step of obtaining the actual system high pressure of the multi-split air conditioning unit in real time.

[0117] Specifically, in this embodiment, if opening the indoor electronic expansion valve corresponding to the shut-off indoor unit fails to make the actual system high pressure greater than or equal to the first target high pressure value, it indicates that this state is not caused by refrigerant accumulating in the heat exchanger of the shut-off indoor unit, but rather by the bypass electronic expansion valve being opened too large. Therefore, it is necessary to reduce the opening degree of the bypass electronic expansion valve to the fourth preset opening threshold, that is, to lower the opening degree of the bypass electronic expansion valve from the current opening degree to the fourth opening threshold.

[0118] It is understandable that after reducing the opening of the bypass electronic expansion valve to the fourth preset opening threshold, the system will return to reacquire the actual high pressure. If the actual high pressure of the system is less than the first target high pressure value, the opening of the bypass electronic expansion valve will continue to be reduced to the fourth preset opening threshold until the final acquired actual high pressure of the system is greater than or equal to the first target high pressure value.

[0119] To facilitate understanding of the technical solution of this application, the following detailed embodiments will be used to explain and illustrate this application.

[0120] Please refer to the following: Figure 12 When a multi-split air conditioning unit is in operation, the first step is to identify and analyze its operating mode, detecting whether the unit is currently operating with only one indoor unit in heating mode. If it is operating with only one indoor unit in heating mode, the actual operating frequency and displacement of the compressor, as well as the rated capacity of the operating indoor unit, are obtained. These values ​​are then substituted into ε = (actual operating frequency of compressor × compressor displacement) / (A × rated capacity of the operating indoor unit) for analysis and calculation to obtain the ratio of actual to theoretical output capacity.

[0121] Next, the ratio of actual to theoretical output capacity ε is compared and analyzed with a preset ratio threshold B to determine whether the ratio is greater than the preset ratio threshold. If the ratio is less than or equal to the preset ratio threshold, the bypass electronic expansion valve does not need to be opened. If the ratio is greater than the preset ratio threshold, the bypass electronic expansion valve is controlled to open at a preset initial opening. The rated capacity and ambient temperature of the currently operating indoor unit are obtained and matched against a preset correspondence between rated capacity, ambient temperature, and target high pressure value to obtain the first target high pressure value T. 目标1 The second target high voltage value T is obtained by matching the preset rated capacity with the target high voltage value. 目标2 .

[0122] Then, combined with the first target high pressure value T 目标1 Second target high pressure value T 目标2 The magnitude of the pressure varies, allowing for different adjustments to the bypass electronic expansion valve. At the first target high pressure value T... 目标1 Less than or equal to the second target high pressure value T目标2 In the case of analyzing the actual high voltage T of the system 实际 Is it less than the first target high pressure value T? 目标1 If the actual high voltage T of the system 实际 Less than the first target high pressure value T 目标1 First, try briefly opening and closing the indoor electronic expansion valve corresponding to the indoor unit that is turned off to see if the actual high pressure T in the system can be reduced. 实际 Adjust to a value greater than or equal to the first target high pressure value T 目标1 Specifically, the indoor electronic expansion valve of the off indoor unit in the multi-split air conditioning unit is opened at a third preset opening threshold. After the opening time reaches a first preset time, the indoor electronic expansion valve of the off indoor unit is closed. After the time the indoor electronic expansion valve of the off indoor unit is closed reaches a second preset time, the actual high pressure T of the system is detected. 实际 Is it greater than or equal to the first target high pressure value T? 目标1 If the actual high voltage T of the system 实际 Greater than or equal to the first target high pressure value T 目标1 If so, close the bypass electronic expansion valve and reacquire the actual system high pressure for further regulation. If the actual system high pressure T 实际 Still less than the first target high pressure value T 目标1 If this happens, the opening of the bypass electronic expansion valve needs to be adjusted. The opening of the bypass electronic expansion valve should be periodically reduced to the fourth preset opening threshold, and the system's actual high pressure should be reacquired until the actual system high pressure T is reached. 实际 Greater than or equal to the first target high pressure value T 目标1 .

[0123] In the actual high voltage T of the system 实际 Greater than or equal to the first target high pressure value T 目标1 In the case of analyzing the actual high voltage T of the system 实际 Is it greater than the second target high pressure value T? 目标2 If the actual high voltage T of the system 实际 Greater than the second target high pressure value T 目标2 Then, based on the current opening degree of the bypass electronic expansion valve, the opening degree of the bypass electronic expansion valve needs to be increased by the first preset opening degree threshold, and then the actual high pressure T of the system needs to be re-detected. 实际 Until finally the actual high voltage T of the system is achieved. 实际 Greater than or equal to the first target high pressure value T 目标1 And less than or equal to the second target high pressure value T 目标2 In the actual high voltage T of the system 实际 Greater than or equal to the first target high pressure value T 目标1 And less than or equal to the second target high pressure value T 目标2 In this case, simply maintain the opening of the bypass electronic expansion valve unchanged.

[0124] And the first target high pressure value T 目标1 Greater than the second target high pressure value T 目标2 In this case, first analyze the actual high voltage T of the system at this time. 实际 Is it less than the first target high pressure value T? 目标1 If the actual high voltage T of the system 实际 Less than the first target high pressure value T 目标1 By briefly opening and closing the indoor electronic expansion valve corresponding to the indoor unit that is turned off, we can try to see if the actual high pressure T in the system can be reduced. 实际 Adjust to a value greater than or equal to the first target high pressure value T 目标1 Specifically, the indoor electronic expansion valve of the off indoor unit in the multi-split air conditioning unit is opened at a third preset opening threshold. After the opening time reaches a first preset time, the indoor electronic expansion valve of the off indoor unit is closed. After the time the indoor electronic expansion valve of the off indoor unit is closed reaches a second preset time, the actual high pressure T of the system is detected. 实际 Is it greater than or equal to the first target high pressure value T? 目标1 If the actual high voltage T of the system 实际 Greater than or equal to the first target high pressure value T 目标1 If so, close the bypass electronic expansion valve and reacquire the actual system high pressure for further regulation. If the actual system high pressure T 实际 Still less than the first target high pressure value T 目标1 If this happens, the opening of the bypass electronic expansion valve needs to be adjusted. The opening of the bypass electronic expansion valve should be periodically reduced to the fourth preset opening threshold, and the system's actual high pressure should be reacquired until the actual system high pressure T is reached. 实际 Greater than or equal to the first target high pressure value T 目标1 .

[0125] In the actual high voltage T of the system 实际 Greater than or equal to the first target high pressure value T 目标1 In the case of analyzing the actual high voltage T of the system 实际 With the first target high pressure value T 目标1 The difference is checked against a preset threshold. If the difference exceeds the preset threshold, the opening of the bypass electronic expansion valve needs to be increased by a second preset threshold based on the current opening. Afterward, the actual system high pressure T is rechecked. 实际 This continues until the difference is ultimately less than or equal to a preset difference threshold. In the actual high-voltage T system... 实际 Greater than or equal to the first target high pressure value T 目标1 And the actual high voltage T of the system 实际 With the first target high pressure value T 目标1 If the difference is less than or equal to the preset difference threshold, the opening of the bypass electronic expansion valve can be kept constant.

[0126] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0127] Based on the same inventive concept, this application also provides a multi-split air conditioning unit control device for implementing the multi-split air conditioning unit control method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in the one or more multi-split air conditioning unit control device embodiments provided below can be found in the limitations of the multi-split air conditioning unit control method described above, and will not be repeated here.

[0128] Please see Figure 13 A control device for a multi-split air conditioning unit includes: an optimization verification module 132, a parameter acquisition module 134, and an optimization control module 136.

[0129] The optimization verification module 132 is used to detect whether the multi-split air conditioning unit meets the preset noise optimization conditions when only one indoor unit of the multi-split air conditioning unit is turned on for heating operation. The parameter acquisition module 134 is used to acquire the operating parameters of the multi-split air conditioning unit if the preset noise optimization conditions are met. The optimization control module 136 is used to control the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters.

[0130] In one embodiment, the optimization verification module 132 is further used to obtain the ratio of the actual to the theoretical output capacity of the multi-split air conditioning unit; detect whether the ratio of the actual to the theoretical output capacity is greater than a preset ratio threshold; if the ratio of the actual to the theoretical output capacity is greater than the preset ratio threshold, determine that the operation of the multi-split air conditioning unit meets the preset noise optimization conditions.

[0131] In one embodiment, the optimization verification module 132 is further used to obtain the actual operating frequency of the compressor, the compressor displacement, and the rated capacity of the indoor unit of the multi-split air conditioning unit; and to calculate the ratio of the actual and theoretical output capacity of the multi-split air conditioning unit based on the ratio of the actual operating frequency, compressor displacement, and rated capacity.

[0132] In one embodiment, the optimization control module 136 is further configured to obtain, based on the operating parameters, a first target high pressure value when the indoor unit meets the actual heating demand, and a second target high pressure value when the indoor unit meets the noise-free operation demand; and to control the operation of the bypass electronic expansion valve of the multi-split air conditioning unit based on the operating parameters, the first target high pressure value, and the second target high pressure value.

[0133] In one embodiment, the optimization control module 136 is further configured to obtain a first target high pressure value when the indoor unit meets the actual heating demand, based on the rated capacity, ambient temperature, and a preset correspondence between the rated capacity, ambient temperature, and target high pressure value; and to obtain a second target high pressure value when the indoor unit meets the noise-free operation requirement, based on the rated capacity and the preset correspondence between the rated capacity and target high pressure value.

[0134] In one embodiment, the optimization control module 136 is also used to control the bypass electronic expansion valve of the multi-split air conditioning unit to start operation at a preset initial opening; and to adjust the opening of the bypass electronic expansion valve according to the actual high pressure of the system, the first target high pressure value, and the second target high pressure value.

[0135] In one embodiment, the optimization control module 136 is further configured to: acquire the actual system high pressure of the multi-split air conditioning unit in real time if the first target high pressure value is less than or equal to the second target high pressure value; adjust the opening of the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit if the actual system high pressure is less than the first target high pressure value, so that the actual system high pressure is greater than or equal to the first target high pressure value; increase the opening of the bypass electronic expansion valve to a first preset opening threshold if the actual system high pressure is greater than or equal to the first target high pressure value and less than or equal to the second target high pressure value; and maintain the opening of the bypass electronic expansion valve unchanged if the actual system high pressure is greater than or equal to the first target high pressure value and less than or equal to the second target high pressure value.

[0136] In one embodiment, the optimization control module 136 is further configured to: if the first target high pressure value is greater than the second target high pressure value, acquire the actual system high pressure of the multi-split air conditioning unit in real time; if the actual system high pressure is less than the first target high pressure value, adjust the opening of the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit so that the actual system high pressure is greater than or equal to the first target high pressure value; if the actual system high pressure is greater than or equal to the first target high pressure value, and the difference between the actual system high pressure and the first target high pressure value is less than or equal to a preset difference threshold, maintain the opening of the bypass electronic expansion valve unchanged; if the actual system high pressure is greater than or equal to the first target high pressure value, and the difference between the actual system high pressure and the first target high pressure value is greater than a preset difference threshold, increase the opening of the bypass electronic expansion valve by a second preset opening threshold.

[0137] In one embodiment, the optimization control module 136 is further configured to open the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit at a third preset opening threshold; if the opening duration of the indoor electronic expansion valve of the shut-off indoor unit reaches a first preset duration, close the indoor electronic expansion valve of the shut-off indoor unit; if the duration of closing the indoor electronic expansion valve of the shut-off indoor unit reaches a second preset duration, detect whether the actual high pressure of the system is greater than or equal to the first target high pressure value; if the actual high pressure of the system is greater than or equal to the first target high pressure value, end the adjustment of the indoor electronic expansion valve of the shut-off indoor unit.

[0138] In one embodiment, the optimization control module 136 is further configured to periodically reduce the opening of the bypass electronic expansion valve by a fourth preset opening threshold if the actual high pressure of the system is less than the first target high pressure value, until the actual high pressure of the system is greater than or equal to the first target high pressure value.

[0139] Each module in the aforementioned multi-split air conditioning unit control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0140] The aforementioned multi-split air conditioning unit control device is equipped with a bypass electronic expansion valve. The first end of the bypass electronic expansion valve connects to the refrigerant line between the compressor discharge port of the outdoor unit and the indoor unit, i.e., the first end of the bypass electronic expansion valve is connected to the higher-pressure refrigerant line of the multi-split air conditioning unit. The second end of the bypass electronic expansion valve connects to the refrigerant line between the compressor inlet of the outdoor unit and the indoor unit, i.e., the second end of the bypass electronic expansion valve is connected to the lower-pressure refrigerant line of the multi-split air conditioning unit. If the multi-split air conditioning unit operates a single indoor unit in heating mode, and the preset noise optimization conditions are met, the bypass electronic expansion valve is controlled to operate according to the operating parameters. This balances the refrigerant pressure in the multi-split air conditioning unit, preventing a large amount of high-temperature, high-pressure gaseous refrigerant from impacting the valve core and piping components of the electronic expansion valve. This alleviates the refrigerant noise generated when the multi-split air conditioning unit operates a single indoor unit with a smaller rated cooling capacity in heating mode.

[0141] A multi-split air conditioning unit includes an outdoor unit, a bypass electronic expansion valve, a controller, and at least one indoor unit. The outdoor unit, the indoor unit, and the bypass electronic expansion valve are respectively connected to the controller, which is used to implement the steps of the above-described multi-split air conditioning unit control method.

[0142] Specifically, the control method for the multi-split air conditioning unit is as shown in the above embodiments and accompanying drawings, and will not be repeated here. The aforementioned multi-split air conditioning unit is equipped with a bypass electronic expansion valve. The first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor discharge port of the outdoor unit and the indoor unit, that is, the first end of the bypass electronic expansion valve is connected to the higher-pressure refrigerant pipeline of the multi-split air conditioning unit. The second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit and the indoor unit, that is, the second end of the bypass electronic expansion valve is connected to the lower-pressure refrigerant pipeline of the multi-split air conditioning unit. If the multi-split air conditioning unit operates a single indoor unit in heating mode, when the preset noise optimization conditions are detected, the bypass electronic expansion valve is controlled to operate according to the operating parameters. This balances the refrigerant pressure in the multi-split air conditioning unit, preventing a large amount of high-temperature, high-pressure gaseous refrigerant from impacting the valve core and pipeline components of the electronic expansion valve, thus mitigating the refrigerant noise generated when the multi-split air conditioning unit operates a single indoor unit with a smaller rated cooling capacity in heating mode.

[0143] Please refer to the following: Figure 14 In one embodiment, the outdoor unit 10 includes an outdoor electronic expansion valve 11, an outdoor heat exchanger 12, a four-way valve 13, a compressor 15, and a gas-liquid separator 14. The exhaust port of the compressor 15 is connected to the four-way valve 13 via a refrigerant line. The four-way valve 13 is connected to the indoor unit 20 via a refrigerant line. The indoor unit 20 is connected to the outdoor electronic expansion valve 11 via a refrigerant line. The outdoor electronic expansion valve 11 is connected to the outdoor heat exchanger 12 via a refrigerant line. The outdoor heat exchanger 12 is connected to the four-way valve 13 via a refrigerant line. The four-way valve 13 is connected to the gas-liquid separator 14 via a refrigerant line. The gas-liquid separator 14 is connected to the air inlet of the compressor 15 via a refrigerant line.

[0144] Specifically, when the multi-split air conditioning unit is in heating mode, the high-pressure, high-temperature refrigerant output by the compressor 15 is transmitted to the indoor heat exchanger 22 of the indoor unit 20 through the four-way valve 13. Heat exchange occurs at the indoor heat exchanger 22, resulting in a lower-pressure refrigerant. This refrigerant then passes through the indoor electronic expansion valve 21 and is transmitted back to the outdoor unit 10. From there, it passes through the outdoor electronic expansion valve 11, the outdoor heat exchanger 12, the four-way valve 13, and the gas-liquid separator 14 of the outdoor unit 10, and finally returns to the compressor 15. The compressor 15 then compresses the refrigerant again into a high-pressure refrigerant for the next cycle.

[0145] The specific connection method for bypass electronic expansion valves in multi-split air conditioning units is not unique; please refer to relevant documentation. Figure 14 In one embodiment, the first end of the bypass electronic expansion valve 142 is connected to the refrigerant pipeline between the compressor exhaust port of the outdoor unit 10 of the multi-split air conditioning unit and the indoor unit 20, including: the first end of the bypass electronic expansion valve 142 is connected to the refrigerant pipeline between the four-way valve 13 and the indoor unit 20.

[0146] Please refer to the following: Figure 15 In one embodiment, the first end of the bypass electronic expansion valve 142 is connected to the refrigerant pipeline between the compressor exhaust port of the outdoor unit 10 of the multi-split air conditioning unit and the indoor unit 20, including: the first end of the bypass electronic expansion valve 142 is connected to the refrigerant pipeline between the four-way valve 13 and the exhaust port of the compressor 15.

[0147] Specifically, a four-way valve 13 is installed between the compressor discharge port and the indoor unit 20. The refrigerant flowing in the refrigerant line between the compressor discharge port and the four-way valve 13 is a high-temperature and high-pressure refrigerant. The refrigerant flowing in the refrigerant line between the four-way valve 13 and the indoor unit 20 is also a high-pressure and high-temperature refrigerant. Therefore, the first end of the bypass electronic expansion valve 142 can be connected to the refrigerant line between the four-way valve 13 and the indoor unit 20, or the second end of the bypass electronic expansion valve 142 can be connected to a lower-pressure refrigerant line between the compressor discharge port and the four-way valve 13.

[0148] Please refer to the following: Figure 14 or Figure 15 In one embodiment, the second end of the bypass electronic expansion valve 142 is connected to the refrigerant line between the compressor inlet of the outdoor unit 10 and the indoor unit 20, including: the second end of the bypass electronic expansion valve 142 is connected to the refrigerant line between the four-way valve 13 and the gas-liquid separator 14.

[0149] Please refer to the following: Figure 16 In one embodiment, the second end of the bypass electronic expansion valve 142 is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit 10 and the indoor unit 20, including: the second end of the bypass electronic expansion valve 142 is connected to the refrigerant pipeline between the outdoor electronic expansion valve 11 and the indoor unit 20.

[0150] In one embodiment, the second end of the bypass electronic expansion valve 142 is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit 10 and the indoor unit 20, including: the second end of the bypass electronic expansion valve 142 is connected to the refrigerant pipeline between the outdoor electronic expansion valve 11 and the outdoor heat exchanger 12.

[0151] In one embodiment, the second end of the bypass electronic expansion valve 142 is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit 10 and the indoor unit 20, including: the second end of the bypass electronic expansion valve 142 is connected to the refrigerant pipeline between the outdoor heat exchanger 12 and the four-way valve 13.

[0152] In one embodiment, the second end of the bypass electronic expansion valve 142 is connected to the refrigerant line between the compressor inlet of the outdoor unit 10 and the indoor unit 20, including: the second end of the bypass electronic expansion valve 142 is connected to the refrigerant line between the gas-liquid separator 14 and the compressor inlet 15.

[0153] Specifically, in a multi-split air conditioning unit, after the high-pressure refrigerant undergoes heat exchange in the indoor unit 20, it is converted into a lower-pressure, lower-temperature refrigerant, which is then returned to the outdoor unit 10 for further processing, where it is converted back into a high-temperature, high-pressure refrigerant. During this process, the refrigerant is compressed by the compressor 15 of the outdoor unit 10. Therefore, before the refrigerant flows back to the compressor 15, its pressure is always lower than the refrigerant pressure between the compressor exhaust port and the indoor unit 20; that is, it is always a lower-pressure refrigerant.

[0154] Therefore, the second end of the bypass electronic expansion valve 142 can be connected to the refrigerant line between the four-way valve 13 and the gas-liquid separator 14. When the bypass electronic expansion valve 142 is open, some high-pressure refrigerant is transferred to the refrigerant line between the four-way valve 13 and the gas-liquid separator 14 to balance the refrigerant pressure.

[0155] In another embodiment, the second end of the bypass electronic expansion valve 142 can be connected to the refrigerant pipeline between the outdoor electronic expansion valve 11 and the indoor unit 20. When the bypass electronic expansion valve 142 is open, a portion of the high-pressure refrigerant is transferred to the refrigerant pipeline between the outdoor electronic expansion valve 11 and the indoor unit 20 to balance the refrigerant pressure.

[0156] In another embodiment, the second end of the bypass electronic expansion valve 142 can be connected to the refrigerant pipeline between the outdoor electronic expansion valve 11 and the outdoor heat exchanger 12. When the bypass electronic expansion valve 142 is open, a portion of the high-pressure refrigerant is transferred to the refrigerant pipeline between the outdoor electronic expansion valve 11 and the outdoor heat exchanger 12 to balance the refrigerant pressure.

[0157] In another embodiment, the second end of the bypass electronic expansion valve 142 can be connected to the refrigerant pipeline between the outdoor heat exchanger 12 and the four-way valve 13. When the bypass electronic expansion valve 142 is open, a portion of the high-pressure refrigerant is transferred to the refrigerant pipeline between the outdoor heat exchanger 12 and the four-way valve 13 to balance the refrigerant pressure.

[0158] In another embodiment, the second end of the bypass electronic expansion valve 142 can be connected to the refrigerant pipeline between the gas-liquid separator 14 and the air inlet of the compressor 15. When the bypass electronic expansion valve 142 is open, a portion of the high-pressure refrigerant is transferred to the refrigerant pipeline between the gas-liquid separator 14 and the air inlet of the compressor 15 to balance the refrigerant pressure.

[0159] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0160] If a multi-split air conditioning unit starts heating operation on a single indoor unit, check whether the multi-split air conditioning unit meets the preset noise optimization conditions; if it meets the preset noise optimization conditions, obtain the operating parameters of the multi-split air conditioning unit; based on the operating parameters, control the operation of the bypass electronic expansion valve of the multi-split air conditioning unit.

[0161] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps:

[0162] If a multi-split air conditioning unit starts heating operation on a single indoor unit, check whether the multi-split air conditioning unit meets the preset noise optimization conditions; if it meets the preset noise optimization conditions, obtain the operating parameters of the multi-split air conditioning unit; based on the operating parameters, control the operation of the bypass electronic expansion valve of the multi-split air conditioning unit.

[0163] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0164] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A control method for a multi-split air conditioning unit, characterized in that, include: If a multi-split air conditioning unit starts heating operation on one of its indoor units, check whether the multi-split air conditioning unit meets the preset noise optimization conditions. If the preset noise optimization conditions are met, the operating parameters of the multi-split air conditioning unit are obtained; the operating parameters include the actual high pressure of the system. According to the operating parameters, the bypass electronic expansion valve of the multi-split air conditioning unit is controlled to operate; wherein, the first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor exhaust port of the outdoor unit and the indoor unit, and the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit and the indoor unit. The step of detecting whether the multi-split air conditioning unit meets the preset noise optimization conditions includes: obtaining the ratio of the actual to the theoretical output capacity of the multi-split air conditioning unit; detecting whether the ratio of the actual to the theoretical output capacity is greater than a preset ratio threshold; if the ratio of the actual to the theoretical output capacity is greater than the preset ratio threshold, determining that the multi-split air conditioning unit meets the preset noise optimization conditions. The step of controlling the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters includes: obtaining a first target high pressure value when the indoor unit meets the actual heating demand and a second target high pressure value when the indoor unit meets the noise-free operation demand according to the operating parameters; and controlling the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters, the first target high pressure value and the second target high pressure value. The step of controlling the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters, the first target high pressure value, and the second target high pressure value includes: controlling the bypass electronic expansion valve of the multi-split air conditioning unit to open and operate at a preset initial opening degree; and adjusting the opening degree of the bypass electronic expansion valve according to the actual system high pressure, the first target high pressure value, and the second target high pressure value. The step of adjusting the opening of the bypass electronic expansion valve based on the actual system high pressure, the first target high pressure value, and the second target high pressure value includes: if the first target high pressure value is less than or equal to the second target high pressure value, acquiring the actual system high pressure of the multi-split air conditioning unit in real time; if the actual system high pressure is less than the first target high pressure value, adjusting the opening of the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit so that the actual system high pressure is greater than or equal to the first target high pressure value; if the actual system high pressure is greater than or equal to the first target high pressure value and less than or equal to the second target high pressure value, maintaining the opening of the bypass electronic expansion valve unchanged; if the actual system high pressure is greater than the second target high pressure value, increasing the opening of the bypass electronic expansion valve by a first preset opening threshold.

2. The multi-split air conditioning unit control method according to claim 1, characterized in that, The process of obtaining the ratio of the actual to the theoretical output capacity of the multi-split air conditioning unit includes: Obtain the actual operating frequency of the compressor, the compressor displacement, and the rated capacity of the indoor unit of the multi-split air conditioning unit; The ratio of the actual to the theoretical output capacity of the multi-split air conditioning unit is calculated by comparing the actual operating frequency of the compressor, the compressor displacement, and the rated capacity.

3. The multi-split air conditioning unit control method according to claim 1, characterized in that, The operating parameters also include the rated capacity of the indoor unit and the ambient temperature of the environment in which the indoor unit is located; The step of obtaining the first target high-pressure value when the indoor unit meets the actual heating demand and the second target high-pressure value when the indoor unit meets the noise-free operation demand based on the operating parameters includes: Based on the rated capacity, the ambient temperature, and the preset correspondence between the rated capacity, ambient temperature, and target high pressure value, the first target high pressure value when the indoor unit meets the actual heating demand is obtained; Based on the rated capacity and the preset correspondence between the rated capacity and the target high voltage value, the second target high voltage value is obtained when the indoor unit meets the requirement of noiseless operation.

4. The multi-split air conditioning unit control method according to claim 1, characterized in that, The step of adjusting the opening of the bypass electronic expansion valve according to the actual high pressure of the system, the first target high pressure value, and the second target high pressure value includes: If the first target high pressure value is greater than the second target high pressure value, the actual system high pressure of the multi-split air conditioning unit is obtained in real time. If the actual high pressure of the system is less than the first target high pressure value, adjust the opening of the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit so that the actual high pressure of the system is greater than or equal to the first target high pressure value. If the actual high pressure of the system is greater than or equal to the first target high pressure value, and the difference between the actual high pressure of the system and the first target high pressure value is less than or equal to a preset difference threshold, the opening of the bypass electronic expansion valve remains unchanged. If the actual high pressure of the system is greater than or equal to the first target high pressure value, and the difference between the actual high pressure of the system and the first target high pressure value is greater than a preset difference threshold, the opening degree of the bypass electronic expansion valve is increased by a second preset opening degree threshold.

5. The multi-split air conditioning unit control method according to claim 1 or 4, characterized in that, Adjusting the opening of the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit to make the actual high pressure of the system greater than or equal to the first target high pressure value includes: The indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit is opened at the third preset opening threshold. If the opening time of the indoor electronic expansion valve of the shut-off indoor unit reaches the first preset time, the indoor electronic expansion valve of the shut-off indoor unit is closed. If the duration of closing the indoor electronic expansion valve of the shut-off indoor unit reaches the second preset duration, detect whether the actual high pressure of the system is greater than or equal to the first target high pressure value; If the actual high pressure of the system is greater than or equal to the first target high pressure value, the bypass electronic expansion valve is closed, and the process returns to the step of obtaining the actual high pressure of the multi-split air conditioning unit in real time.

6. The multi-split air conditioning unit control method according to claim 5, characterized in that, If the duration for which the indoor electronic expansion valve of the shut-off indoor unit is closed reaches a second preset duration, after detecting whether the actual high pressure of the system is greater than or equal to the first target high pressure value, the method further includes: If the actual high pressure of the system is less than the first target high pressure value, the opening degree of the bypass electronic expansion valve is reduced to a fourth preset opening degree threshold, and the process returns to the step of real-time acquisition of the actual high pressure of the multi-split air conditioning unit.

7. A control device for a multi-split air conditioning unit, characterized in that, include: The optimization verification module is used to detect whether the multi-split air conditioning unit meets the preset noise optimization conditions when one of the indoor units of the multi-split air conditioning unit is turned on for heating operation. The parameter acquisition module is used to acquire the operating parameters of the multi-split air conditioning unit if the preset noise optimization conditions are met; the operating parameters include the actual high pressure of the system. An optimized control module is used to control the operation of the bypass electronic expansion valve of the multi-split air conditioning unit according to the operating parameters; wherein, the first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor exhaust port of the outdoor unit and the indoor unit of the multi-split air conditioning unit, and the second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit and the indoor unit. The optimization verification module is further configured to: obtain the ratio of the actual to the theoretical output capacity of the multi-split air conditioning unit; detect whether the ratio of the actual to the theoretical output capacity is greater than a preset ratio threshold; if the ratio of the actual to the theoretical output capacity is greater than the preset ratio threshold, determine that the operation of the multi-split air conditioning unit meets the preset noise optimization conditions; The optimization control module is further configured to: obtain, based on the operating parameters, a first target high-pressure value when the indoor unit meets the actual heating demand, and a second target high-pressure value when the indoor unit meets the noise-free operation demand; and control the operation of the bypass electronic expansion valve of the multi-split air conditioning unit based on the operating parameters, the first target high-pressure value, and the second target high-pressure value. The optimization control module is also used to: control the bypass electronic expansion valve of the multi-split air conditioning unit to open and operate at a preset initial opening; and adjust the opening of the bypass electronic expansion valve according to the actual high pressure of the system, the first target high pressure value, and the second target high pressure value. The optimization control module is further configured to: if the first target high pressure value is less than or equal to the second target high pressure value, acquire the actual system high pressure of the multi-split air conditioning unit in real time; if the actual system high pressure is less than the first target high pressure value, adjust the opening of the indoor electronic expansion valve of the shut-off indoor unit in the multi-split air conditioning unit so that the actual system high pressure is greater than or equal to the first target high pressure value; if the actual system high pressure is greater than or equal to the first target high pressure value and less than or equal to the second target high pressure value, maintain the opening of the bypass electronic expansion valve unchanged; if the actual system high pressure is greater than the second target high pressure value, increase the opening of the bypass electronic expansion valve by a first preset opening threshold.

8. A multi-split air conditioning unit, characterized in that, The system includes an outdoor unit, a bypass electronic expansion valve, a controller, and at least one indoor unit. The outdoor unit, the indoor unit, and the bypass electronic expansion valve are respectively connected to the controller. The controller is used to implement the steps of the multi-split air conditioning unit control method according to any one of claims 1 to 6.

9. The multi-split air conditioning unit according to claim 8, characterized in that, The outdoor unit includes an outdoor electronic expansion valve, an outdoor heat exchanger, a four-way valve, a compressor, and a gas-liquid separator. The compressor's discharge port is connected to the four-way valve via a refrigerant line. The four-way valve is connected to the indoor unit via a refrigerant line. The indoor unit is connected to the outdoor electronic expansion valve via a refrigerant line. The outdoor electronic expansion valve is connected to the outdoor heat exchanger via a refrigerant line. The outdoor heat exchanger is connected to the four-way valve via a refrigerant line. The four-way valve is connected to the gas-liquid separator via a refrigerant line. The gas-liquid separator is connected to the compressor's inlet via a refrigerant line.

10. The multi-split air conditioning unit according to claim 9, characterized in that, The first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor discharge port of the outdoor unit of the multi-split air conditioning unit and the indoor unit, including any one of the following: First item: The first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the four-way valve and the indoor unit; Second item: The first end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the four-way valve and the exhaust port of the compressor.

11. The multi-split air conditioning unit according to claim 9, characterized in that, The second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the compressor inlet of the outdoor unit and the indoor unit, including any one of the following: First item: The second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the four-way valve and the gas-liquid separator; Second item: The second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the outdoor electronic expansion valve and the indoor unit; Third item: The second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the outdoor electronic expansion valve and the outdoor heat exchanger; Fourth item: The second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the outdoor heat exchanger and the four-way valve; Fifth item: The second end of the bypass electronic expansion valve is connected to the refrigerant pipeline between the gas-liquid separator and the air inlet of the compressor.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the multi-split air conditioning unit control method according to any one of claims 1 to 6.

13. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the multi-split air conditioning unit control method according to any one of claims 1 to 6.

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