Multi-connected air conditioner control method and device, air conditioner, equipment and product

Abstract

The embodiment of the application belongs to air conditioner control technology, and provides a multi-split air conditioner control method, device, air conditioner, equipment and product. The method comprises the following steps: acquiring real-time dew point temperatures of multiple indoor units in a multi-split air conditioner, and determining a target dew point temperature according to the multiple real-time dew point temperatures; taking a sum of the target dew point temperature and a correction amount as a target evaporation temperature; wherein the correction amount is a positive value, and is negatively correlated with a difference between return air temperatures of the multiple indoor units and a set temperature; and controlling an outdoor unit of the multi-split air conditioner to operate at the target evaporation temperature. Through real-time adjustment of the evaporation temperature of the multi-split air conditioner, the application can reduce the situation that the surface temperature of the coil is lower than the dew point temperature and condensation occurs, and improves the reliability of air conditioner control.

Description

Technical Field

[0001] This application relates to air conditioning control technology. More specifically, it relates to a multi-split air conditioning control method, apparatus, air conditioner, equipment, and product. Background Technology

[0002] Multi-split air conditioning systems are widely used in high sensible heat environments such as data centers, laboratories, and offices. They can efficiently handle large sensible heat loads while precisely controlling the temperature. By independently adjusting multiple indoor units, the system can focus on cooling localized high-temperature areas, avoiding excessive dehumidification, maintaining stable ambient humidity, and improving comfort and equipment safety.

[0003] In related technologies, to improve the cooling capacity of the system under high sensible heat conditions, the capacity ratio of the indoor and outdoor units is increased. However, this design relies solely on a static ratio and cannot dynamically adjust according to actual operating conditions such as partial load and changes in ambient temperature. This leads to the indoor unit's outlet air temperature easily falling below the dew point temperature during partial load operation, causing a risk of condensation. Therefore, the current problem to be solved is how to improve the reliability of multi-split air conditioning systems. Summary of the Invention

[0004] This application provides a method, apparatus, air conditioner, equipment, and product for controlling multi-split air conditioners, in order to improve the reliability of air conditioner control.

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

[0006] The system acquires the real-time dew point temperatures of multiple indoor units in a multi-split air conditioner and determines the target dew point temperature based on these temperatures. The sum of the target dew point temperature and the correction value is used as the target evaporation temperature. The correction value is positive and negatively correlated with the difference between the return air temperature and the set temperature of the multiple indoor units. The system controls the evaporation temperature of the outdoor unit in the multi-split air conditioner to operate at the target evaporation temperature.

[0007] In some embodiments of this application, the method further includes: when the indoor unit is operating in low fan mode, acquiring the condensing pressure, target condenser subcooling, and condenser liquid pipe temperature of the outdoor unit at the current moment; calculating a first difference between the target condenser subcooling and condenser liquid pipe temperature at the current moment, and a second difference between the target condenser subcooling and condenser liquid pipe temperature at the previous moment; determining a first opening adjustment amount at the current moment based on the first difference and the second difference; determining a second opening adjustment amount at the current moment based on the condensing pressure; wherein the second opening adjustment amount is positively correlated with the condensing pressure; and using the sum of the first opening adjustment amount and the second opening adjustment amount at the current moment and the expansion valve opening at the previous moment as the expansion valve opening at the current moment for expansion valve control.

[0008] In some embodiments of this application, the method further includes: when the indoor unit is operating in low fan mode, obtaining the refrigerant saturation temperature corresponding to the condensing pressure of the outdoor unit at the current moment, and the capacity ratio of the indoor unit and the outdoor unit at the current moment; when the capacity ratio is greater than or equal to a preset capacity threshold, using the difference between the refrigerant saturation temperature and a first preset temperature as the target condenser subcooling at the current moment; when the capacity ratio is less than the preset capacity threshold, using the difference between the refrigerant saturation temperature and a second preset temperature as the target condenser subcooling at the current moment; wherein, the second preset temperature is less than the first preset temperature.

[0009] In some embodiments of this application, determining the second opening adjustment amount at the current moment based on the condensing pressure includes: when the condensing pressure is greater than or equal to a first pressure threshold, determining a second opening adjustment amount with a value of a first preset value; when the condensing pressure is less than the first pressure threshold but greater than or equal to a second pressure threshold, taking the minimum of the percentage value of the expansion valve opening at the previous moment and the second preset value as the second opening adjustment amount; wherein the second pressure threshold is less than the first pressure threshold, and the second preset value is less than the first preset value; when the condensing pressure is less than the second pressure threshold, determining a second opening adjustment amount with a value of 0.

[0010] In some embodiments of this application, determining the first opening adjustment amount at the current moment based on the first difference and the second difference includes: calculating the first product of the first difference and the first weight, and calculating the second product of the difference between the first difference and the second difference and the second weight; using the sum of the first product and the second product as the first opening adjustment amount; wherein, when the indoor unit is operating in the first working condition, both the first weight and the second weight are 1, and when the indoor unit is operating in the second working condition, the first weight is greater than 1 and the second weight is less than 1.

[0011] In some embodiments of this application, the correction amount includes a first correction value and a fixed second correction value, wherein the second correction value is negatively correlated with the maximum value among multiple differences between the return air temperature and the set temperature of multiple indoor units; determining the target dew point temperature based on multiple real-time dew point temperatures includes: taking the largest real-time dew point temperature as the target dew point temperature among the multiple real-time dew point temperatures.

[0012] Secondly, embodiments of this application provide a multi-split air conditioning control device, comprising:

[0013] The acquisition module is used to acquire the real-time dew point temperature of multiple indoor units in the multi-split air conditioner and determine the target dew point temperature based on the multiple real-time dew point temperatures; the calculation module is used to use the sum of the target dew point temperature and the correction amount as the target evaporation temperature; wherein, the correction amount is a positive value and is negatively correlated with the difference between the return air temperature and the set temperature of multiple indoor units; the control module is used to control the evaporation temperature of the outdoor unit in the multi-split air conditioner to operate at the target evaporation temperature.

[0014] Thirdly, embodiments of this application provide a multi-split air conditioner, including the multi-split air conditioner control device as described above.

[0015] Fourthly, embodiments of this application provide an electronic device, including:

[0016] The processor, and the memory that is in communication with the processor;

[0017] The memory stores the instructions that the computer executes;

[0018] The processor executes computer-executable instructions stored in memory to achieve the method described above.

[0019] Fifthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the aforementioned method.

[0020] This application provides embodiments of a multi-split air conditioner control method, apparatus, air conditioner, equipment, and product. It acquires the real-time dew point temperatures of multiple indoor units in a multi-split air conditioner and determines a target dew point temperature based on these temperatures. A target evaporation temperature is then determined based on the target dew point temperature and a correction amount. The correction amount is positive and negatively correlated with the difference between the return air temperature and the set temperature of the multiple indoor units. The evaporation temperature of the outdoor unit in the multi-split air conditioner is controlled to operate at the target evaporation temperature. This application achieves real-time adjustment of the evaporation temperature of the multi-split air conditioner by dynamically acquiring the real-time dew point temperatures of multiple indoor units and correcting the target evaporation temperature based on the negative correlation between the return air temperature and the set temperature. This enables adaptive adaptation to temperature and humidity fluctuations and reduces the possibility of the coil surface temperature falling below the dew point temperature, thereby enhancing operational reliability and user comfort. Attached Figure Description

[0021] To more clearly illustrate the implementation methods in the embodiments of this application or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0022] Figure 1 This is a schematic diagram of a multi-split air conditioner operation scenario provided in an embodiment of this application.

[0023] Figure 2 An exemplary block diagram of the configuration of the control device according to an exemplary embodiment is shown.

[0024] Figure 3 This is a schematic diagram of the structure of a multi-split air conditioner provided in an embodiment of this application.

[0025] Figure 4This is a flowchart illustrating a multi-split air conditioning control method provided in this application.

[0026] Figure 5 This is a flowchart illustrating a multi-split air conditioning control method provided in this application.

[0027] Figure 6 This is a flowchart illustrating a multi-split air conditioning control method provided in this application.

[0028] Figure 7 This is a flowchart illustrating a multi-split air conditioning control method provided in this application.

[0029] Figure 8 This is a flowchart illustrating a multi-split air conditioning control method provided in this application.

[0030] Figure 9 This is a structural schematic diagram of a multi-split air conditioning control device provided in this application.

[0031] Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0032] To make the objectives, implementation methods and advantages of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the described exemplary embodiments are only some embodiments of this application, and not all embodiments.

[0033] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0034] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclusively include, for example, a product or device that includes a series of components is not necessarily limited to those that are explicitly listed, but may include other components that are not explicitly listed or that are inherent to such product or device.

[0035] A multi-split air conditioner is a centralized air conditioning system consisting of one outdoor unit connected to multiple indoor units. It typically includes a compressor, inverter controller, refrigerant piping, and various indoor units (such as ducted and wall-mounted units). It is mainly used in small to medium-sized commercial spaces, office buildings, villas, and multi-room residences. Compared to traditional split air conditioners, multi-split systems offer significant energy-saving advantages (by adjusting refrigerant flow through inverter technology), each indoor unit can be independently temperature-controlled, and the outdoor unit occupies less space, allowing for more flexible installation. Compared to traditional central air conditioning, it eliminates the need for large ducts, reducing ceiling height requirements, making maintenance easier, and operating with lower noise.

[0036] In existing technologies, high sensible heat multi-split air conditioning systems typically achieve high sensible heat requirements by increasing the capacity ratio of indoor and outdoor units, such as making the total capacity of indoor units 200% of the capacity of outdoor units. By increasing the cooling capacity of the indoor units, the system can maintain a high sensible heat ratio even when operating under partial load.

[0037] However, existing systems control cooling capacity through fixed evaporation temperatures or simple ratio designs, failing to dynamically respond to changes in indoor unit return air temperature and humidity. When the indoor environment approaches the dew point temperature, the system cannot adjust the evaporation temperature in time, causing the coil surface temperature to drop below the dew point temperature, resulting in condensation. For example, in low-temperature, high-humidity environments (such as nighttime operation in winter), existing systems may produce condensate due to excessively low evaporation temperatures, leading to equipment corrosion or product contamination.

[0038] Furthermore, to achieve high sensible heat, existing systems typically employ a high compression ratio design, resulting in an increase in the amount of refrigerant stored in the indoor unit. This reduces the amount of refrigerant and subcooling in the outdoor unit's condenser, especially during low fan speed operation (such as in energy-saving mode), significantly increasing refrigerant flow noise and impacting user comfort.

[0039] This application achieves real-time adjustment of the evaporation temperature of multi-split air conditioners by dynamically acquiring the real-time dew point temperature of multiple indoor units and correcting the target evaporation temperature based on the negative correlation between the return air temperature and the set temperature. This enables the system to adapt to temperature and humidity fluctuations and reduces the possibility of the coil surface temperature falling below the dew point temperature, enhancing operational reliability and user comfort. Furthermore, by acquiring condensing pressure, target condenser subcooling, and condenser liquid line temperature in real time, and calculating the dual-opening adjustment amount based on the dynamic change of the subcooling difference and the positive correlation with the condensing pressure, the expansion valve opening is adjusted in real time. This improves the problem of unstable subcooling caused by uneven refrigerant distribution in traditional high compression ratio designs, thus helping to alleviate the phenomenon of increased refrigerant flow noise in low fan mode, improving the system's quiet operation and user comfort.

[0040] The technical solutions of this application will be described in detail below with reference to specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0041] Below, in conjunction with Figures 1 to 3 The multi-split air conditioning system provided in the embodiments of this application will be described.

[0042] Figure 1 This is a schematic diagram illustrating a multi-split air conditioner operation scenario provided in an embodiment of this application. Figure 1 As shown, users can operate the multi-split air conditioner 200 through the smart device 300 or the control device 100.

[0043] In some embodiments, the control device 100 may be a remote control. Communication between the remote control and the display device includes infrared protocol communication, Bluetooth protocol communication, and other short-range communication methods, controlling the multi-split air conditioner 200 wirelessly or via wired means. Users can control the multi-split air conditioner 200 by inputting user commands through buttons on the remote control, voice input, control panel input, etc.

[0044] In some embodiments, a smart device 300 (such as a mobile terminal, tablet computer, computer, laptop computer, etc.) can also be used to control the multi-split air conditioner 200. For example, an application running on the smart device can be used to control the multi-split air conditioner 200.

[0045] In some embodiments, multi-split air conditioners may receive commands not through the aforementioned smart devices or control devices, but through touch or gestures.

[0046] In some embodiments, the multi-split air conditioner 200 can also be controlled in ways other than the control device 100 and the smart device 300. For example, it can be controlled by directly receiving the user's voice commands through a module configured inside the multi-split air conditioner 200, or it can be controlled by receiving the user's voice commands through a voice control device set outside the multi-split air conditioner 200.

[0047] In some embodiments, the multi-split air conditioner 200 also communicates with the server 400. The multi-split air conditioner 200 may communicate via a local area network (LAN), wireless local area network (WLAN), and other networks. The server 400 may provide various content and interactive features to the multi-split air conditioner 200. The server 400 may be a cluster or multiple clusters, and may include one or more types of servers.

[0048] Figure 2 An exemplary block diagram of the configuration of the control device according to an exemplary embodiment is shown. Figure 2As shown, the control device 100 includes a controller 110, a communication interface 130, a user input / output interface 140, a memory, and a power supply. The control device 100 can receive user input operation commands and convert the operation commands into commands that the multi-split air conditioner 200 can recognize and respond to, thus acting as an intermediary for interaction between the user and the multi-split air conditioner 200.

[0049] Figure 3 This is a structural schematic diagram of a multi-split air conditioner provided as an embodiment of this application. Figure 3 As shown, the multi-split air conditioner 200 may include an indoor unit 220 and an outdoor unit 210.

[0050] The indoor unit 220 is installed indoors and is used for heat exchange with the indoor environment.

[0051] The outdoor unit 210 is installed outdoors to carry indoor heat to the outside.

[0052] like Figure 3 As shown, the indoor unit 220 includes multiple indoor units 221 connected in parallel, and the multiple indoor units 221 are connected to the outdoor unit 210. The multiple indoor units 221 are respectively installed in different rooms.

[0053] Indoor unit 221 can include, but is not limited to, wall-mounted, ducted, and curtain units.

[0054] Furthermore, the multi-split air conditioning system may include a controller. The controller is electrically connected to the indoor and outdoor units to control the operation of their internal components, so that the various components of the multi-split air conditioning system can perform their predetermined functions, including receiving user commands, operating in cooling mode, heating mode, fan mode, etc., and uploading the operating status of the multi-split air conditioning system to the cloud.

[0055] The controller includes an indoor controller and an outdoor controller. The indoor controller is installed in the indoor unit. The indoor controller is used to control the operating status of various components inside the indoor unit. The outdoor controller is used to control the operating status of various components inside the outdoor unit.

[0056] The indoor controller and the outdoor controller communicate via wired or wireless communication.

[0057] In some embodiments of this application, no specific distinction is made between indoor controllers and outdoor controllers; both indoor controllers and outdoor controllers are collectively referred to as controllers.

[0058] The following explanation uses the processor of a multi-split air conditioner as an example to illustrate the automatic control strategy of a multi-split air conditioner.

[0059] The technical solutions of this application will be described in detail below with reference to specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0060] Figure 4 This is a flowchart illustrating a multi-split air conditioning control method provided in this application. Figure 4 As shown, the method includes the following steps:

[0061] S401. Obtain the real-time dew point temperature of multiple indoor units in a multi-split air conditioner, and determine the target dew point temperature based on the multiple real-time dew point temperatures.

[0062] S402. The sum of the target dew point temperature and the correction amount is taken as the target evaporation temperature; wherein, the correction amount is a positive value and is negatively correlated with the difference between the return air temperature and the set temperature of multiple indoor units;

[0063] S403. Control the evaporation temperature of the outdoor unit in the multi-split air conditioner to operate at the target evaporation temperature.

[0064] It should be noted that this solution is mainly applied to multi-split air conditioning systems with high sensible heat demand. In order to improve the cooling capacity, these systems usually adopt a high ratio of indoor unit to outdoor unit capacity. For example, in actual configurations, the total capacity of indoor units may reach 200% of the capacity of outdoor units, that is, the capacity ratio is two to one. This hardware design enhances the sensible heat cooling effect of the system under partial load, but it also brings the problem of insufficient dynamic response.

[0065] For example, when the indoor unit operates under partial load or the outdoor ambient temperature is slightly lower, the outlet air temperature of the indoor unit can easily be lowered to the dew point temperature of the indoor air, easily causing condensation. Therefore, when the system requires precise temperature and humidity control, this solution can be implemented to achieve an anti-condensation effect by dynamically adjusting the evaporation temperature to adapt to environmental changes and avoid the limitations of fixed evaporation temperature control. However, the solution in this application is not limited to high sensible heat multi-split air conditioning systems, but can also be applied to conventional multi-split air conditioning systems or other multi-split air conditioning systems to achieve the corresponding technical effects.

[0066] In some embodiments, obtaining the real-time dew point temperature of multiple indoor units in a multi-split air conditioner is typically based on real-time calculation. For example, one method is to use the return air dry-bulb temperature and relative humidity measured by the indoor unit sensors, and then calculate the dew point temperature using an empirical formula such as the Magnus formula, which expresses the dew point temperature as a function of temperature and humidity. In the specific calculation, the water vapor pressure is first obtained from the relative humidity, and then the dew point temperature is deduced from it.

[0067] For example, the formula for calculating the real-time dew point temperature (Tdew) is:

[0068] Tdew = 237.70 × a / (17.27 - a)

[0069] Where a = 17.27 × Ti / (237.70 + Ti) + ln(Hi / 100), Ti is the air inlet temperature of each indoor unit, and Hi is the air inlet relative humidity of each indoor unit. In practical applications, the air inlet relative humidity can be rounded for easier calculation.

[0070] Alternatively, another method for calculating dew point temperature is to use the difference between wet-bulb and dry-bulb temperatures, combined with air pressure parameters, to calculate an approximate formula or lookup table for the dew point temperature based on the wet-bulb temperature. This method is more effective because wet-bulb temperature is easier to measure in air ducts. Both methods rely on accurate sensor data and are updated in real-time by the controller's algorithm to ensure the dew point temperature reflects the current environmental conditions.

[0071] In some embodiments, when determining the target dew point temperature based on multiple real-time dew point temperatures, the status of all indoor units needs to be considered comprehensively. One approach is to select the maximum real-time dew point temperature among all indoor units as the target dew point temperature. This ensures that the indoor unit most prone to condensation is protected and prevents any coil surface temperature from falling below the dew point.

[0072] In some optional embodiments, the target dew point temperature is obtained by calculating the average or weighted average of multiple real-time dew point temperatures. The weights can be allocated according to the operating status or load of the indoor unit. For example, the dew point temperature of the indoor unit with a larger load has a higher weight to achieve overall optimization. The determination of the target dew point temperature needs to balance the anti-condensation requirements and system energy efficiency, ensuring that the evaporation temperature is adjusted reasonably and avoiding excessive conservatism that leads to a decrease in cooling capacity.

[0073] It is understandable that the correction amount is a positive parameter used to adjust the target evaporation temperature. Its value is negatively correlated with the difference between the return air temperature of multiple indoor units and the set temperature. That is, the larger the difference, the smaller the correction amount, and the smaller the difference, the larger the correction amount. This reflects that when the room temperature is close to the set temperature, the system needs to be more careful to reduce the evaporation temperature to prevent condensation.

[0074] For example, the correction amount can be equal to a base constant minus a term proportional to the average difference, such as correction amount = AB × ΔT, where ΔT is the average difference between the return air temperature and the set temperature, and A and B are positive coefficients. By adjusting the coefficients, different system characteristics can be adapted.

[0075] For example, the correction amount can be = C × exp(-D × ΔT), where C and D are adjustment parameters. This calculation makes the correction amount decrease rapidly as the difference increases, adapting to nonlinear changes and responding more precisely to environmental fluctuations.

[0076] In some embodiments, when determining the target evaporation temperature based on the target dew point temperature and the correction amount, an additive operation is used, meaning the target evaporation temperature equals the target dew point temperature plus the correction amount. Since the correction amount is a positive value, the target evaporation temperature will always be higher than the target dew point temperature, which sets a safe baseline for the evaporator coil surface temperature.

[0077] The key aspect is the negative correlation between the correction amount and the difference between the return air temperature and the set temperature: when the actual indoor temperature is far from the set temperature (large difference), the correction amount is small, and the target evaporation temperature is slightly higher than the dew point temperature. This allows the system to operate with strong cooling capacity while preventing condensation, quickly lowering the room temperature. As the indoor temperature gradually approaches the set temperature (smaller difference), the correction amount automatically increases, further raising the target evaporation temperature. This effectively suppresses excessive cooling and dehumidification of the coils, and once comfort is satisfied, the system switches to an energy-saving operating mode. This calculation process dynamically coordinates the relationship between anti-condensation, cooling capacity, and energy efficiency.

[0078] This example uses the target dew point temperature, calculated in real-time, as the safety baseline for preventing condensation, and adds a correction factor determined by temperature deviation to ultimately set the evaporation temperature. When cooling demand is strong (large temperature difference), a smaller correction factor keeps the evaporation temperature close to the dew point temperature. The system operates at a lower evaporation temperature with higher energy efficiency, prioritizing cooling capacity while minimizing the risk of condensation. When the room temperature is close to the set value (small temperature difference), an increased correction factor raises the evaporation temperature. This further moves the coil surface temperature away from the dew point, fundamentally eliminating condensation conditions. Simultaneously, the increased evaporation pressure reduces compressor power consumption, achieving energy savings.

[0079] The multi-split air conditioner control method provided in this application includes: acquiring the real-time dew point temperatures of multiple indoor units in the multi-split air conditioner, and determining a target dew point temperature based on the multiple real-time dew point temperatures; determining a target evaporation temperature based on the target dew point temperature and a correction amount; wherein the correction amount is a positive value and is negatively correlated with the difference between the return air temperature and the set temperature of the multiple indoor units; and controlling the evaporation temperature of the outdoor unit in the multi-split air conditioner to operate at the target evaporation temperature. This application achieves real-time adjustment of the evaporation temperature of the multi-split air conditioner by dynamically acquiring the real-time dew point temperatures of multiple indoor units and correcting the target evaporation temperature based on the negative correlation between the return air temperature and the set temperature. This enables adaptive adaptation to temperature and humidity fluctuations and reduces the possibility of the coil surface temperature falling below the dew point temperature, thereby enhancing operational reliability and user comfort.

[0080] Figure 5 This is a flowchart illustrating a multi-split air conditioning control method provided in this application. Figure 5 As shown, the method also includes the following steps:

[0081] S501. When the indoor unit is running in low fan mode, obtain the condensing pressure of the outdoor unit, the target condenser subcooling degree, and the condenser liquid pipe temperature at the current moment.

[0082] S502. Calculate the first difference between the target condenser subcooling and the condenser liquid tube temperature at the current moment, and the second difference between the target condenser subcooling and the condenser liquid tube temperature at the previous moment. Determine the first opening adjustment amount at the current moment based on the first difference and the second difference.

[0083] S503. Determine the second opening adjustment amount at the current moment based on the condensing pressure; wherein, the second opening adjustment amount is positively correlated with the condensing pressure;

[0084] S504. The sum of the first and second opening adjustment amounts at the current moment and the expansion valve opening at the previous moment is used as the expansion valve opening at the current moment for expansion valve control.

[0085] In practical applications, multi-split air conditioning systems typically employ high-compression-ratio compressor designs. This results in more refrigerant being stored in the heat exchanger of the indoor unit during the refrigeration cycle. Consequently, the amount of refrigerant stored in the outdoor unit's condenser and the resulting subcooling are relatively reduced. Especially when the indoor unit operates in low fan speed mode, the reduced airflow leads to changes in heat exchange efficiency, and the refrigerant flow rate and state in the pipes become unstable, easily generating refrigerant flow noise and affecting the user experience.

[0086] For example, low fan speed mode usually refers to the state in which the indoor unit fan runs continuously at a relatively low fixed speed or speed percentage. Specifically, it can be determined by the control system based on the fan drive signal or feedback speed. For example, when the fan speed is lower than 30% of its maximum design speed and runs continuously for more than a certain period of time, such as five minutes, it can be identified as a stable low fan speed mode.

[0087] For example, the condensing pressure of the outdoor unit at the current moment is usually obtained by directly measuring it through a pressure sensor installed at the condenser outlet or compressor exhaust end; the target condenser subcooling is an ideal value preset by the system or dynamically calculated according to the current operating conditions, used to guide the control; the condenser liquid line temperature is obtained by measuring it through a temperature sensor installed on the liquid line after the condenser outlet.

[0088] In some embodiments, the current moment and the previous moment are two consecutive sampling control cycle points in the operation of the control system. The adjustment cycle, i.e., the time interval between two consecutive executions of this control logic, can be set according to the system response speed, for example, one second or five seconds. The first difference refers to the difference between the "target condenser subcooling" and the "condenser liquid tube temperature" calculated at the current moment, which reflects the actual state of the current subcooling. The second difference refers to the difference between the same two parameters calculated in the immediately preceding control cycle. Comparing the first difference and the second difference is essentially observing the trend of the "subcooling deviation" over time, whether it increases, decreases, or remains stable.

[0089] In some embodiments, the first opening adjustment amount at the current moment is determined based on the first difference and the second difference. One approach is to employ the derivative concept in proportional-integral-derivative (PID) control, i.e., calculating the difference between the first and second differences, which is the rate of change of the subcooling deviation. This rate of change is multiplied by a negative proportional coefficient to obtain the first opening adjustment amount. If the positive subcooling gap is widening, the opening is adjusted in the negative direction to suppress it. Another approach is to combine incremental calculations of integral and derivative, comparing the current subcooling deviation with the deviation at the previous moment, and mapping and outputting an adjustment amount based on the magnitude and direction of the deviation using a preset fuzzy rule table or nonlinear function. This approach can handle the nonlinearity of the system more smoothly.

[0090] In some embodiments, the second opening adjustment amount at the current moment is determined based on the condensing pressure. One method is linear positive correlation calculation, where a reference pressure value is set. When the measured condensing pressure is higher than this reference, the second opening adjustment amount is equal to a proportional coefficient multiplied by the amount by which the pressure exceeds the reference. The higher the pressure, the greater the increase in opening amount, thus promoting refrigerant flow. A second method uses a piecewise function or lookup table, dividing the actual measured value of the condensing pressure into several intervals. Each interval corresponds to a fixed opening adjustment amount or a different proportional coefficient. For example, the adjustment amount is small in the normal pressure range, increases linearly in the higher pressure range, and increases significantly in the extremely high pressure range. This method is more convenient for engineering calibration and adapts to different system characteristics.

[0091] In this example, the expansion valve opening at the end of the previous control cycle is used as the base position for the current control. Based on this, a first opening adjustment calculated from the subcooling deviation is added, along with a second opening adjustment calculated from the condensing pressure state, to obtain the new opening to be set for the current control cycle. The first adjustment primarily responds to the dynamic trend of subcooling changes, aiming to stabilize it at the target value; the second adjustment responds to the system pressure level, used to macroscopically regulate the refrigerant flow. The two adjustments are combined and work together to influence the final control output.

[0092] The solution presented in this example utilizes a first opening adjustment based on changes in subcooling difference. This adjustment quickly compensates for dynamic subcooling deviations caused by refrigerant flow fluctuations or load changes, suppressing oscillations. The second opening adjustment, based on condensing pressure, addresses the overall system pressure level. When condensing pressure may be high in low-fan mode, it actively increases the expansion valve opening to increase refrigerant flow in the main path, helping to introduce more refrigerant to the outdoor condenser side and improve its subcooling. When subcooling becomes stable and sufficient, the dryness of the refrigerant liquid phase in the condenser increases, reducing turbulence and flash gas generated during the two-phase flow before the expansion valve and during throttling, thereby reducing refrigerant flow noise. Therefore, this solution, while maintaining necessary cooling capacity, significantly improves the abnormal noise problem caused by uneven refrigerant distribution and insufficient subcooling in high-compression ratio multi-split systems operating in low-fan mode, enhancing quietness and user comfort.

[0093] Figure 6 This is a flowchart illustrating a multi-split air conditioning control method provided in this application. Figure 6 As shown, the method also includes the following steps:

[0094] S601. When the indoor unit is running in low fan mode, obtain the refrigerant saturation temperature corresponding to the condensing pressure of the outdoor unit at the current moment, as well as the capacity ratio of the indoor unit and the outdoor unit at the current moment.

[0095] S602. When the capacity ratio is greater than or equal to the preset capacity threshold, the difference between the refrigerant saturation temperature and the first preset temperature is taken as the target condenser subcooling at the current moment.

[0096] S603. When the capacity ratio is less than the preset capacity threshold, the difference between the refrigerant saturation temperature and the second preset temperature is taken as the target condenser subcooling at the current moment; wherein, the second preset temperature is less than the first preset temperature.

[0097] In practical applications, determining the refrigerant saturation temperature corresponding to the condensing pressure of the outdoor unit usually relies on a pressure sensor installed at the condenser outlet or compressor discharge end. This sensor measures the condensing pressure of the system in real time. After receiving the pressure signal, the controller converts and calculates the saturation temperature of the refrigerant at the current pressure based on the physical properties of the specific type of refrigerant used in the system, using a built-in pressure-temperature correspondence table or empirical formula. For example, for common refrigerants such as R410A, there is a clear correspondence between its saturation temperature and pressure, which can be obtained by looking up a table or by interpolation.

[0098] For example, obtaining the capacity ratio of indoor and outdoor units requires based on the system configuration and real-time operating status. The capacity ratio is defined as the ratio of the total rated cooling capacity of all currently running indoor units to the rated cooling capacity of the outdoor unit. During system initialization, the controller stores the rated capacity data of each indoor and outdoor unit. During actual operation, the controller dynamically calculates the total capacity of these indoor units based on the indoor units turned on by the user, and then divides it by the rated capacity of the outdoor unit to obtain the real-time capacity ratio.

[0099] In some embodiments, the specific values ​​of the preset capacity threshold, the first preset temperature, and the second preset temperature need to be calibrated according to the actual design and performance requirements of the multi-split air conditioning system.

[0100] For example, the preset capacity threshold is a key value used to distinguish between high load and low load operating states. In systems designed for high sensible heat, which operate in low-wind mode, the preset capacity threshold is often set between 0.4 and 0.6.

[0101] For example, the first preset temperature and the second preset temperature are reference offsets used to calculate the target condenser subcooling. The first preset temperature is usually set higher, such as five degrees Celsius, while the second preset temperature is lower, such as three degrees Celsius. In this way, when the capacity ratio is higher than the threshold, the target subcooling calculated using the higher first preset temperature is smaller, while when the capacity ratio is lower than the threshold, the target subcooling calculated using the lower second preset temperature is larger. These specific values ​​can be determined through system debugging and optimization experiments.

[0102] When the capacity ratio of the current indoor unit to the outdoor unit is detected to be greater than or equal to a preset capacity threshold, the system is considered to be operating in a high capacity ratio state. In this case, the target condenser subcooling is calculated by subtracting a first preset temperature from the refrigerant saturation temperature obtained from the condensing pressure. Since the first preset temperature is relatively high, the resulting difference, i.e., the target subcooling, will be relatively small. This setting is because a high capacity ratio usually means a large indoor load demand and a large refrigerant circulation volume. The system tends to maintain a low subcooling to prevent excessive increases in condensing pressure, thereby ensuring that the cooling capacity is fully utilized. Simultaneously, it avoids excessive refrigerant accumulation in the condenser due to excessive subcooling, which would affect flow efficiency and stability. This helps the system maintain efficient operation under high loads and adapt to temperature control under high sensible heat demand.

[0103] When the current capacity ratio of the indoor unit to the outdoor unit is detected to be less than a preset capacity threshold, the system is considered to be operating in a low capacity ratio state. In this case, the target condenser subcooling is calculated by subtracting a second preset temperature from the refrigerant saturation temperature. Since the second preset temperature is lower than the first preset temperature, the resulting difference, i.e., the target subcooling, will be relatively large. This setting is because the system load is smaller at low capacity ratios, resulting in a relatively smaller refrigerant circulation volume. Increasing the target subcooling promotes sufficient cooling of the refrigerant in the condenser, increases the storage of liquid refrigerant, improves system efficiency, and reduces the risk of flash gas generation before the expansion valve. This helps stabilize refrigerant distribution, reduces flow noise, and especially improves operational smoothness in low-fan mode. This optimizes system performance under partial load.

[0104] The solution presented in this example prioritizes cooling capacity and response speed by setting a smaller target subcooling degree at high capacity ratios, preventing excessively high condensing pressure. At low capacity ratios, a larger target subcooling degree is set to enhance the refrigerant subcooling effect and improve refrigerant flow characteristics. This solution improves the adaptability and stability of multi-split air conditioning systems under variable load operation. Particularly in low-fan mode, by avoiding insufficient or excessive subcooling, it reduces refrigerant flow noise and vibration, enhancing user comfort. Furthermore, by optimizing the subcooling degree setting, it improves system energy efficiency and reliability.

[0105] Figure 7 This is a flowchart illustrating a multi-split air conditioning control method provided in this application. Figure 7 As shown, step S503, which determines the second opening adjustment amount at the current moment based on the condensing pressure, includes:

[0106] S701. When the condensing pressure is greater than or equal to the first pressure threshold, the second opening adjustment amount, which is determined to be a first preset value, is determined.

[0107] S702. When the condensing pressure is less than the first pressure threshold and greater than or equal to the second pressure threshold, the minimum value between the percentage value of the expansion valve opening at the previous moment and the second preset value is used as the second opening adjustment amount; wherein, the second pressure threshold is less than the first pressure threshold and the second preset value is less than the first preset value.

[0108] S703. When the condensing pressure is less than the second pressure threshold, the second opening adjustment amount is determined to be 0.

[0109] For example, the first and second pressure thresholds need to be determined based on the type of refrigerant used in the multi-split air conditioning system, its design operating pressure range, and safety operating standards. Typically, the first pressure threshold is set near the upper limit of the system's permissible condensing pressure. For instance, for systems using common environmentally friendly refrigerants, this value might be between 3.35 MPa and 3.45 MPa, indicating that the system is under high pressure and requires active intervention to reduce the pressure. The second pressure threshold is set slightly below the first threshold, for example, between 3.2 MPa and 3.3 MPa, serving as the lower limit of the medium pressure zone to distinguish between high pressure and normal pressure conditions.

[0110] For example, the first preset value is a fixed opening adjustment amount applied when the condensing pressure reaches the high-pressure threshold. This could be five to ten percent of the expansion valve's maximum opening, such as 100 pulse steps, designed to quickly increase refrigerant flow to alleviate high pressure. The second preset value is used for medium pressure zones and is smaller, such as 25 pulse steps, serving as the upper limit of the adjustment amount to ensure a smooth adjustment. These specific values ​​need to be optimized through system commissioning and performance testing to adapt to different models and operating conditions, while also considering the impact of ambient temperature changes and system load.

[0111] In this example, in step S701, when the condensing pressure is detected to reach or exceed the first pressure threshold, it is determined that the pressure is too high, posing a safety risk or reducing efficiency. Therefore, a large fixed opening adjustment amount, i.e., the first preset value, is directly assigned. This can quickly increase the expansion valve opening, promote refrigerant flow, and effectively reduce the condensing pressure, preventing the system from triggering protection or generating noise due to high-pressure operation. In step S702, when the condensing pressure is between the first and second pressure thresholds, although the pressure is not too high, preventative adjustment is required. A certain percentage value of the expansion valve opening at the previous moment is calculated as the basic adjustment amount, but it does not exceed the second preset value. The minimum of the two is taken as the final adjustment amount. This method achieves gradual control, combining the proportional adjustment of historical openings and the limitation of the preset upper limit, avoiding system oscillations caused by sudden changes in opening and ensuring a smooth transition. In step S703, when the condensing pressure is below the second pressure threshold, it indicates that the system pressure is within the ideal range and no additional adjustment is required. Therefore, the second opening adjustment amount is set to zero. The system mainly relies on other parameters such as subcooling for fine-tuning, which helps maintain stable operation, reduces unnecessary intervention, and optimizes energy efficiency.

[0112] This example demonstrates a system that dynamically adjusts the expansion valve opening using a segmented strategy based on the real-time level of the condensing pressure. By setting three pressure zones—high pressure, medium pressure, and low pressure—corresponding to aggressive, conservative, and maintenance adjustment modes respectively, the system can accurately respond to pressure changes. At high pressure, the opening is rapidly increased to alleviate pressure; at medium pressure, a proportional limit is applied based on historical opening values ​​to ensure a smooth transition; and at low pressure, no adjustment is made to avoid excessive intervention.

[0113] In terms of technical effectiveness, this solution improves the operational stability of multi-split air conditioning systems in low-fan mode. By preventing abnormal increases in condensing pressure, it reduces compressor load and refrigerant flow noise. Simultaneously, it optimizes refrigerant distribution and subcooling, reducing vibration and noise caused by pressure fluctuations and enhancing user comfort. Furthermore, zoned control improves energy efficiency and extends the lifespan of system components, particularly in high-compression ratio designs, effectively mitigating problems caused by uneven refrigerant distribution.

[0114] Figure 8 This is a flowchart illustrating a multi-split air conditioning control method provided in this application. Figure 8 As shown, step S502, which determines the first opening adjustment amount at the current moment based on the first difference and the second difference, includes:

[0115] S801, Calculate the first product of the first difference and the first weight, and calculate the second product of the difference between the first difference and the second difference and the second weight;

[0116] S802. The sum of the first product and the second product is used as the first opening adjustment amount; wherein, when the indoor unit is operating in the first working condition, both the first weight and the second weight are 1, and when the indoor unit is operating in the second working condition, the first weight is greater than 1 and the second weight is less than 1.

[0117] The first product represents the first difference between the target condenser subcooling and the condenser liquid line temperature at the current moment (i.e., the current subcooling deviation) multiplied by the first weight. This part directly reflects the difference between the instantaneous state of the system and the target value. The second product is the difference between the current first difference and the second difference at the previous moment (i.e., the rate of change of the subcooling deviation) multiplied by the second weight. This part captures the dynamic direction of the deviation. Adding these two products together as the first opening adjustment amount allows the control output to take into account both the magnitude and rate of change of the deviation, thus enabling smoother and more precise actuation of the expansion valve.

[0118] In some embodiments, the first operating condition is defined as a stable operating condition for normal system operation. This can be specifically defined by operating parameters. For example, when the difference between the indoor unit's return air temperature and the set temperature remains within ±1 degree Celsius, and the system operates continuously for more than ten minutes, with condensing pressure fluctuations less than 0.1 MPa, it can be considered to have entered a normal operating condition. Under this condition, the system state is relatively stable, and the subcooling deviation and its rate of change are both small. Therefore, setting both the first and second weights to 1 means that the control algorithm assigns equal importance to the deviation value and the trend of change, achieving a balanced adjustment strategy to maintain stable system operation.

[0119] In some embodiments, the second operating condition refers to the transitional operating condition after the multi-split air conditioning system is turned on or after the indoor unit is switched on or off, such as the first three minutes after the system starts from a stopped state, or a short period of time when the system load changes significantly due to the sudden on or off of an indoor unit. Under this condition, system parameters such as temperature, pressure, and subcooling are in a rapid change phase with large fluctuations. At this time, the weighting is adjusted so that the first weight is greater than 1 (e.g., set to 1.5), and the second weight is less than 1 (e.g., set to 0.5). Under this condition, the system needs to respond quickly to offset the large initial deviation. Therefore, amplifying the impact of the current deviation (first weight greater than 1) can make the expansion valve opening adjustment more rapid, accelerating the system towards stability. Simultaneously, since the rate of change may be large and unstable in the initial stage, reducing its impact on the adjustment amount (second weight less than 1) can avoid overly aggressive control actions due to drastic fluctuations in the rate of change.

[0120] The scheme in this example employs balanced weighting for fine-tuning under stable operating conditions to maintain system stability. Under transitional operating conditions, it strengthens the ability to correct deviations in the current state by increasing the weighting of deviations and decreasing the weighting of the rate of change, while mitigating interference from dynamic fluctuations. This allows the control strategy to flexibly adapt to different operating stages, ensuring that the condenser subcooling quickly and accurately approaches the target value, thereby optimizing the refrigerant circulation state.

[0121] As yet another example, based on any example, the correction amount includes a first correction value and a fixed second correction value, wherein the second correction value is negatively correlated with the maximum of a plurality of differences between the return air temperature and the set temperature of a plurality of indoor units;

[0122] Determining the target dew point temperature based on multiple real-time dew point temperatures includes: selecting the highest real-time dew point temperature among the multiple real-time dew point temperatures as the target dew point temperature.

[0123] For example, the first correction value is typically set to a relatively small positive value to provide a basic temperature offset. This value may be set around 2 degrees Celsius depending on the system model and environmental baseline, aiming to ensure a basic anti-condensation safety margin. The second correction value can decrease as the maximum of multiple differences between the return air temperature and the set temperature of the multiple indoor units increases. For instance, the second correction value is 5 when the maximum value is ≤0, 3 when the maximum value is 1, 2 when the maximum value is 2, 1 when the maximum value is 3, and 0 when the maximum value is ≥4.

[0124] In practical applications, because multi-split air conditioning systems consist of multiple indoor units operating in parallel, the local environments (such as temperature, humidity, and load) of each indoor unit may differ, resulting in varying real-time dew point temperatures. Selecting the highest real-time dew point temperature among all indoor units as the global target dew point temperature means setting the safety baseline for the evaporation temperature based on the indoor unit most prone to condensation. Therefore, regardless of the environment of other indoor units, the system ensures that the evaporator coil surface temperature of no indoor unit will fall below this highest dew point temperature, thus globally avoiding the risk of condensation occurring in any single indoor unit.

[0125] This example uses the maximum dew point temperature as the absolute safe lower limit for preventing condensation, while flexibly adjusting the actual set value of the evaporation temperature through correction. When the return air temperature of all indoor units is close to the set temperature, the second correction value is larger, resulting in a larger total correction and thus raising the target evaporation temperature higher. This not only completely eliminates the possibility of condensation but also reduces excessive dehumidification and compressor power consumption, achieving energy savings. When some indoor units still require strong cooling, the second correction value becomes smaller, the total correction is smaller, and the target evaporation temperature is only slightly higher than the target dew point temperature. The system can operate with high energy efficiency while minimizing the risk of condensation, prioritizing cooling needs.

[0126] The multi-split air conditioner control method provided in this application includes: acquiring the real-time dew point temperatures of multiple indoor units in the multi-split air conditioner, and determining a target dew point temperature based on the multiple real-time dew point temperatures; determining a target evaporation temperature based on the target dew point temperature and a correction amount; wherein the correction amount is a positive value and is negatively correlated with the difference between the return air temperature and the set temperature of the multiple indoor units; and controlling the evaporation temperature of the outdoor unit in the multi-split air conditioner to operate at the target evaporation temperature. This application achieves real-time adjustment of the evaporation temperature of the multi-split air conditioner by dynamically acquiring the real-time dew point temperatures of multiple indoor units and correcting the target evaporation temperature based on the negative correlation between the return air temperature and the set temperature. This enables adaptive adaptation to temperature and humidity fluctuations and reduces the possibility of the coil surface temperature falling below the dew point temperature, thereby enhancing operational reliability and user comfort.

[0127] Figure 9 This is a structural schematic diagram of a multi-split air conditioning control device provided in this application. Figure 9 As shown, the device includes:

[0128] The acquisition module 91 is used to acquire the real-time dew point temperature of multiple indoor units in a multi-split air conditioner, and determine the target dew point temperature based on the multiple real-time dew point temperatures.

[0129] The calculation module 92 is used to use the sum of the target dew point temperature and the correction amount as the target evaporation temperature; wherein, the correction amount is a positive value and is negatively correlated with the difference between the return air temperature and the set temperature of multiple indoor units;

[0130] Control module 93 is used to control the evaporation temperature of the outdoor unit in a multi-split air conditioner to operate at the target evaporation temperature.

[0131] In one example, control module 93 is also used for:

[0132] When the indoor unit is running in low fan mode, obtain the outdoor unit's condensing pressure, target condenser subcooling degree, and condenser liquid line temperature at the current moment;

[0133] Calculate the first difference between the target condenser subcooling and the condenser liquid line temperature at the current moment, and the second difference between the target condenser subcooling and the condenser liquid line temperature at the previous moment. Determine the first opening adjustment amount at the current moment based on the first difference and the second difference.

[0134] The second opening adjustment amount at the current moment is determined based on the condensing pressure; wherein, the second opening adjustment amount is positively correlated with the condensing pressure;

[0135] The sum of the first and second opening adjustment amounts at the current moment and the expansion valve opening at the previous moment is used as the expansion valve opening at the current moment for expansion valve control.

[0136] In one example, control module 93 is also used for:

[0137] When the indoor unit is running in low fan mode, obtain the refrigerant saturation temperature corresponding to the condensing pressure of the outdoor unit at the current moment, as well as the capacity ratio of the indoor unit and the outdoor unit at the current moment.

[0138] When the capacity ratio is greater than or equal to the preset capacity threshold, the difference between the refrigerant saturation temperature and the first preset temperature is used as the target condenser subcooling at the current moment.

[0139] When the capacity ratio is less than the preset capacity threshold, the difference between the refrigerant saturation temperature and the second preset temperature is used as the target condenser subcooling at the current moment; wherein, the second preset temperature is less than the first preset temperature.

[0140] In one example, control module 93 is specifically used for:

[0141] When the condensing pressure is greater than or equal to the first pressure threshold, the second opening adjustment amount is determined to be the first preset value.

[0142] When the condensing pressure is less than the first pressure threshold and greater than or equal to the second pressure threshold, the minimum of the percentage value of the expansion valve opening at the previous moment and the second preset value is used as the second opening adjustment amount; wherein, the second pressure threshold is less than the first pressure threshold and the second preset value is less than the first preset value;

[0143] When the condensing pressure is less than the second pressure threshold, the second opening adjustment amount is set to 0.

[0144] In one example, control module 93 is specifically used for:

[0145] Calculate the first product of the first difference and the first weight, and calculate the second product of the difference between the first difference and the second difference and the second weight;

[0146] The sum of the first product and the second product is used as the first opening adjustment amount; wherein, when the indoor unit is operating in the first working condition, both the first weight and the second weight are 1, and when the indoor unit is operating in the second working condition, the first weight is greater than 1 and the second weight is less than 1.

[0147] In one example, the correction includes a first correction value and a fixed second correction value, wherein the second correction value is negatively correlated with the maximum of a plurality of differences between the return air temperature and the set temperature of a plurality of indoor units;

[0148] The acquisition module 91 is specifically used to: select the highest real-time dew point temperature from multiple real-time dew point temperatures as the target dew point temperature.

[0149] The multi-split air conditioning control device provided in this application embodiment can execute the multi-split air conditioning control method in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described again here.

[0150] It should be noted that the above Figure 9 The division of modules shown is merely illustrative. This application does not limit the division of modules or the naming of modules.

[0151] This application also provides a multi-split air conditioner, which includes the multi-split air conditioner control device as described in any of the above embodiments.

[0152] This application also provides an electronic device. This electronic device can be the controller for the aforementioned multi-split air conditioner. Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 10 As shown, the electronic device includes:

[0153] The electronic device includes a processor 291 and a memory 292; it may also include a communication interface 293 and a bus 294. The processor 291, memory 292, and communication interface 293 can communicate with each other via the bus 294. The communication interface 293 can be used for information transmission. The processor 291 can invoke logical instructions stored in the memory 292 to execute the methods of the above embodiments.

[0154] Furthermore, the logic instructions in the aforementioned memory 292 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0155] The memory 292, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this application. The processor 291 executes functional applications and data processing by running the software programs, instructions, and modules stored in the memory 292, thereby implementing the methods in the above-described method embodiments.

[0156] The memory 292 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 292 may include high-speed random access memory and may also include non-volatile memory.

[0157] This application also provides a computer-readable storage medium, which may include various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk. Specifically, the computer-readable storage medium stores program instructions, which are used in the methods described in the above embodiments.

[0158] This application also provides a program product including executable instructions stored in a readable storage medium. At least one control module of a display device can read the executable instructions from the readable storage medium, and the at least one control module executes the executable instructions to cause the display device to implement the handwriting erasure methods provided in the various embodiments described above.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0160] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the embodiments and various different variations of embodiments suitable for specific application considerations.

Claims

1. A method for controlling a multi-split air conditioning system, characterized in that, include: The real-time dew point temperature of multiple indoor units in the multi-split air conditioner is obtained, and the target dew point temperature is determined based on the multiple real-time dew point temperatures. The target evaporation temperature is the sum of the target dew point temperature and the correction amount; wherein the correction amount is a positive value and is negatively correlated with the difference between the return air temperature and the set temperature of the plurality of indoor units. The evaporation temperature of the outdoor unit in the multi-split air conditioner is controlled to operate at the target evaporation temperature.

2. The method according to claim 1, characterized in that, The method further includes: When the indoor unit is running in low fan mode, the condensing pressure, target condenser subcooling degree, and condenser liquid pipe temperature of the outdoor unit at the current moment are obtained. Calculate the first difference between the target condenser subcooling and the condenser liquid line temperature at the current moment, and the second difference between the target condenser subcooling and the condenser liquid line temperature at the previous moment. Determine the first opening adjustment amount at the current moment based on the first difference and the second difference. The second opening adjustment amount at the current moment is determined based on the condensing pressure; wherein, the second opening adjustment amount is positively correlated with the condensing pressure; The sum of the first and second opening adjustment amounts at the current moment and the expansion valve opening at the previous moment is used as the expansion valve opening at the current moment for expansion valve control.

3. The method according to claim 2, characterized in that, The method further includes: When the indoor unit is running in low fan mode, obtain the refrigerant saturation temperature corresponding to the condensing pressure of the outdoor unit at the current moment, as well as the capacity ratio of the indoor unit and the outdoor unit at the current moment; When the capacity ratio is greater than or equal to the preset capacity threshold, the difference between the refrigerant saturation temperature and the first preset temperature is taken as the target condenser subcooling at the current moment. When the capacity ratio is less than the preset capacity threshold, the difference between the refrigerant saturation temperature and the second preset temperature is taken as the target condenser subcooling at the current moment; wherein the second preset temperature is less than the first preset temperature.

4. The method according to claim 2, characterized in that, The step of determining the second opening adjustment amount at the current moment based on the condensation pressure includes: When the condensation pressure is greater than or equal to the first pressure threshold, a second opening adjustment amount is determined to be a first preset value. When the condensing pressure is less than the first pressure threshold and greater than or equal to the second pressure threshold, the minimum value between the percentage value of the expansion valve opening at the previous moment and the second preset value is used as the second opening adjustment amount; wherein, the second pressure threshold is less than the first pressure threshold and the second preset value is less than the first preset value; When the condensation pressure is less than the second pressure threshold, the second opening adjustment amount with a value of 0 is determined.

5. The method according to claim 2, characterized in that, The step of determining the first opening adjustment amount at the current moment based on the first difference and the second difference includes: Calculate the first product of the first difference and the first weight, and calculate the second product of the difference between the first difference and the second difference and the second weight; The sum of the first product and the second product is used as the first opening adjustment amount; wherein, when the indoor unit is operating in the first working condition, both the first weight and the second weight are 1, and when the indoor unit is operating in the second working condition, the first weight is greater than 1 and the second weight is less than 1.

6. The method according to any one of claims 1-5, characterized in that, The correction amount includes a first correction value and a fixed second correction value, wherein the second correction value is negatively correlated with the maximum value among multiple differences between the return air temperature and the set temperature of the plurality of indoor units; Determining a target dew point temperature based on the plurality of real-time dew point temperatures includes: selecting the highest real-time dew point temperature among the plurality of real-time dew point temperatures as the target dew point temperature.

7. A multi-split air conditioning control device, characterized in that, include: The acquisition module is used to acquire the real-time dew point temperature of multiple indoor units in the multi-split air conditioner, and determine the target dew point temperature based on the multiple real-time dew point temperatures. The calculation module is used to take the sum of the target dew point temperature and the correction amount as the target evaporation temperature; wherein the correction amount is a positive value and is negatively correlated with the difference between the return air temperature and the set temperature of the plurality of indoor units; The control module is used to control the evaporation temperature of the outdoor unit in the multi-split air conditioner to operate at the target evaporation temperature.

8. A multi-split air conditioner, characterized in that, Includes the multi-split air conditioning control device as described in claim 7.

9. An electronic device, characterized in that, include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory to implement the method as described in any one of claims 1-6.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions that, when executed by a processor, implement the method as described in any one of claims 1-6.

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