Heating control method and device of multi-split air conditioning system and electronic equipment

Abstract

The embodiment of the invention provides a heating control method and device of a multi-split air conditioning system, electronic equipment and a computer readable storage medium, and relates to the field of air conditioners. The method comprises the steps that under the heating working condition, the environment temperature and the outlet pipe temperature of each air conditioner indoor unit in the current period are collected; and for each air conditioner indoor unit, under the conditions that the environment temperature of the air conditioner indoor unit in the current period is larger than or equal to the average value of the environment temperatures of all the air conditioner indoor units, and the outlet pipe temperature of the air conditioner indoor unit in the current period is smaller than or equal to the average value of the outlet pipe temperatures of all the air conditioner indoor units, it is determined that accumulated liquid exists in the air conditioner indoor units in the current period. According to the embodiment of the invention, the accumulated liquid inner machine with the abnormally low pipe temperature in the high-temperature environment can be accurately identified, and the interference of environment temperature fluctuation and load non-uniformity on accumulated liquid judgment is effectively eliminated.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and more specifically, to a heating control method, apparatus, electronic device, computer-readable storage medium, and computer program product for a multi-split air conditioning system. Background Technology

[0002] Currently, in multi-split air conditioning systems, due to varying pressure losses among the multiple indoor units (e.g., some indoor units have long connecting pipes, and some have long internal heat exchanger flow paths), refrigerant tends to accumulate in large quantities inside these indoor units during heating, resulting in low pipe temperatures and poor performance.

[0003] The relevant technologies rely on subcooling or judge liquid accumulation solely based on the difference between the outlet pipe temperature and the average value, which has the drawback of being easily affected by fluctuations in ambient temperature. Summary of the Invention

[0004] This application provides a heating control method, device, electronic equipment, computer-readable storage medium, and computer program product for a multi-split air conditioning system, which can solve the above-mentioned problems of the prior art. The technical solution is as follows: According to one aspect of the embodiments of this application, a heating control method for a multi-split air conditioning system is provided, the method comprising: Under heating conditions, obtain the ambient temperature and outlet pipe temperature of each indoor air conditioning unit in the current cycle; For each indoor air conditioner unit, if the ambient temperature of the indoor air conditioner unit in the current cycle is greater than or equal to the average ambient temperature of all indoor air conditioner units, and the outlet pipe temperature of the indoor air conditioner unit in the current cycle is less than or equal to the average outlet pipe temperature of all indoor air conditioner units, it is determined that there is liquid accumulation in the indoor air conditioner unit in the current cycle.

[0005] According to another aspect of the embodiments of this application, a heating control device for a multi-split air conditioning system is provided, the multi-split air conditioning system including multiple indoor air conditioning units, the device comprising: The parameter acquisition module is used to collect the ambient temperature and outlet pipe temperature of each indoor air conditioner unit in the current cycle under heating conditions. The liquid accumulation detection module is used to determine that liquid accumulation exists in the current cycle of each indoor air conditioner unit when the ambient temperature of the indoor air conditioner unit in the current cycle is greater than or equal to the average ambient temperature of all indoor air conditioner units, and the outlet pipe temperature of the indoor air conditioner unit in the current cycle is less than or equal to the average outlet pipe temperature of all indoor air conditioner units.

[0006] According to another aspect of the embodiments of this application, an electronic device is provided, which includes a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the heating control method of the multi-split air conditioning system described above.

[0007] According to another aspect of the embodiments of this application, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the heating control method of the multi-split air conditioning system described above.

[0008] According to one aspect of the embodiments of this application, a computer program product is provided, including a computer program that, when executed by a processor, implements the above-described method.

[0009] The beneficial effects of the technical solution provided in this application are as follows: Unlike related technologies that rely on subcooling or judge liquid accumulation solely based on the difference between the outlet pipe temperature and the average value, which is easily affected by ambient temperature fluctuations, this application comprehensively compares the ambient temperature of the indoor unit in the current cycle with the average ambient temperature of all indoor units, and the outlet pipe temperature with the average outlet pipe temperature of all indoor units. It accurately identifies indoor units with abnormally low pipe temperatures in high-temperature environments, effectively eliminating the interference of ambient temperature fluctuations and uneven load on liquid accumulation judgment, achieving proactive prevention and accurate positioning of liquid accumulation status, and laying the foundation for improving system operation stability, reducing compressor load, and reducing ineffective cooling. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below.

[0011] Figure 1 This is a schematic diagram of the structure of a multi-split air conditioning system provided in an embodiment of this application; Figure 2 A schematic diagram illustrating the refrigerant flow in an indoor unit under heating conditions, provided as an embodiment of this application; Figure 3 A schematic flowchart illustrating a heating control method for an online air conditioning system provided in an embodiment of this application; Figure 4 A schematic diagram of a heating control method for an online air conditioning system provided in an embodiment of this application; Figure 5 A schematic diagram of a heating control method for an online air conditioning system provided in an embodiment of this application; Figure 6 A schematic diagram of the structure of a heating control device for a multi-split air conditioning system provided in this application embodiment; Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0012] The embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the embodiments described below with reference to the accompanying drawings are exemplary descriptions for explaining the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions of the embodiments of this application.

[0013] Those skilled in the art will understand that, unless otherwise stated, the singular forms “a,” “an,” and “the” used herein may also include the plural forms. It should be further understood that the terms “comprising” and “including” as used in embodiments of this application mean that the corresponding feature can be implemented as the presented feature, information, data, step, operation, element, and / or component, but do not exclude implementation as other features, information, data, step, operation, element, component, and / or combinations thereof supported by the art. It should be understood that when we say that an element is “connected” or “coupled” to another element, the one element can be directly connected or coupled to the other element, or it can mean that the one element and the other element establish a connection relationship through an intermediate element. Furthermore, “connected” or “coupled” as used herein can include wireless connection or wireless coupling. The term “and / or” as used herein indicates at least one of the items defined by the term; for example, “A and / or B” can be implemented as “A,” or as “B,” or as “A and B.”

[0014] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0015] First, let's introduce and explain several terms used in this application: Subcooling refers to the temperature of a liquid refrigerant being lower than its saturation temperature (the temperature at which the refrigerant begins to change from a liquid to a gaseous state under that pressure, also known as the condensation temperature). For example, at the condenser outlet, the refrigerant is in a liquid state. If its actual temperature is 35°C, and the corresponding saturation temperature at that pressure is 40°C, then the subcooling is 40 - 35 = 5°C.

[0016] Superheat refers to the temperature of a gaseous refrigerant that is higher than its saturation temperature (the temperature at which the refrigerant begins to change from a gaseous to a liquid state under that pressure, also known as the evaporation temperature). For example, at the evaporator outlet, the refrigerant is in a gaseous state. If its actual temperature is 10°C, and the corresponding saturation temperature at that pressure is 5°C, then the superheat is 10 - 5 = 5°C.

[0017] Please see Figure 1 The figure exemplifies the structure of a multi-split air conditioning system. As shown, the multi-split air conditioning system includes an outdoor unit and n indoor units (referred to as indoor units), where n is an integer greater than 1. Specifically, The outdoor unit contains core components such as a compressor, condenser, and main control board. The compressor is responsible for compressing the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The condenser allows the high-temperature, high-pressure gaseous refrigerant to exchange heat with the outside air, and after heat dissipation, it becomes a high-temperature, high-pressure liquid refrigerant. The main control board controls and regulates the entire system.

[0018] Each indoor unit is equipped with components such as an evaporator and a fan, which are mainly responsible for exchanging heat with indoor air to achieve cooling or heating functions to meet the temperature requirements of different rooms.

[0019] like Figure 1 As shown, the outdoor unit is also connected to each indoor unit via an electronic expansion valve (EVA). An EVA is a throttling element that can adjust the refrigerant flow rate into the refrigeration unit according to a preset program. It can precisely control the refrigerant flow rate based on system operating parameters (such as superheat) to meet the operating requirements of different indoor units. The electronic expansion valve in this embodiment is also referred to as the outdoor unit expansion valve.

[0020] Figure 2 The diagram illustrates the refrigerant flow in the indoor unit during heating operation, as provided in this embodiment. In heating mode, the high-temperature, high-pressure gaseous refrigerant discharged from the outdoor unit compressor is transported through pipelines into the indoor unit's heat exchanger. The heat exchanger acts as a condenser, transferring heat to the indoor air flowing through it, thus lowering its own temperature and condensing into a high-temperature, high-pressure liquid refrigerant. The liquid refrigerant then flows out of the heat exchanger and reaches the energy-level electronic expansion valve (EVN). Based on the system's control logic and relevant parameter feedback, the EVN precisely adjusts its opening to throttle and depressurize the refrigerant, transforming it into a low-temperature, low-pressure mixture of liquid and gaseous refrigerant. The depressurized refrigerant then flows back to the outdoor unit through pipelines, completing one heating cycle, and continues to participate in the next heating cycle in the outdoor unit. The energy-level electronic expansion valve in this embodiment is also referred to as the indoor unit expansion valve.

[0021] Ambient temperature Ta refers to the indoor ambient temperature where the indoor unit is located. The system can adjust the operating status of the indoor unit, such as the fan speed, based on the difference between the ambient temperature Ta and the user-set temperature. It also provides a reference for EVN control to achieve precise heating control and meet indoor temperature requirements.

[0022] Currently, in multi-split air conditioning systems, due to varying pressure losses among the multiple indoor units (e.g., some indoor units have long connecting pipes, and some have long internal heat exchanger circuits), refrigerant tends to accumulate in large quantities inside these indoor units during heating, resulting in low pipe temperatures and poor performance.

[0023] The relevant technology optimizes the overall system performance by adjusting the opening degree of the EVN of each indoor unit in real time, balancing the pressure loss differences between different indoor units.

[0024] In the pressure loss monitoring and difference identification stage, the relevant technology uses pipe temperature sensors to monitor the evaporator outlet temperature of each indoor unit in real time, i.e., the outlet pipe temperature. The pipe temperature differences arise because variations in the indoor unit's installation location, pipe length, or local load lead to differences in refrigerant flow resistance (pressure loss), thus causing uneven pipe temperature. Based on this, the valve opening adjustment strategy of the relevant technology is as follows: For indoor units with high pipe temperatures: Reduce EVN opening → limit refrigerant flow → reduce evaporation pressure → reduce evaporator superheat → decrease pipe temperature.

[0025] For indoor units with low pipe temperatures: Increase EVN opening → increase refrigerant flow → increase evaporation pressure → enhance evaporator heat exchange → increase pipe temperature.

[0026] The relevant technology reduces the temperature difference between indoor units by adjusting the temperature in a "peak shaving and valley filling" manner, making the overall system operation closer to the design conditions. The essence of this technology is capacity redistribution, that is, appropriately reducing the cooling capacity of indoor units with higher pipe temperatures and transferring refrigerant resources to indoor units with lower pipe temperatures.

[0027] In multi-split air conditioning systems, the connecting pipes between the indoor units vary in length, and the refrigerant circulation path also varies. During heating operation, due to pressure loss in the pipes, the refrigerant encounters greater difficulties flowing through indoor units with longer paths or connecting pipes. This easily leads to refrigerant buildup in these units, a severe liquid accumulation phenomenon, which significantly reduces heating efficiency. Essentially, this is due to increased pipe resistance, hindering the smooth flow of refrigerant.

[0028] The heating control method, device, electronic equipment, computer-readable storage medium, and computer program product for multi-split air conditioning systems provided in this application aim to solve the above-mentioned technical problems of the prior art. For multi-split systems, when identifying indoor units with large pressure loss and low pipe temperature, the control method increases the opening of the outdoor unit valve to reduce the refrigerant resistance of the indoor unit with accumulated liquid, thereby improving the capacity of the indoor unit.

[0029] In heating mode, the indoor unit valves automatically adjust based on the subcooling level to optimize control; while the outdoor unit valves automatically adjust based on the suction superheat to prevent refrigerant backflow. Since the resistance encountered by the refrigerant flow in the indoor unit mainly stems from the regulating action of the indoor and outdoor unit valves, when liquid accumulation is detected in the indoor unit, this application's embodiment adopts the following optimization strategy: Provided that refrigerant backflow is prevented, the opening of the outdoor unit's EVA valve should be increased appropriately to regulate the refrigerant flow. At the same time, the speed of the outdoor fan should be increased to enhance airflow and thus improve evaporation efficiency.

[0030] The combined effect of these two measures can effectively reduce the resistance to refrigerant flow in the liquid-filled indoor unit, significantly improving the heating or cooling performance of the unit.

[0031] The technical solutions of this application and their effects are described below through several exemplary embodiments. It should be noted that the following embodiments can be referenced, borrowed from, or combined with each other. Identical terms, similar features, and similar implementation steps in different embodiments will not be repeated.

[0032] This application provides a heating control method for a multi-split air conditioning system, such as... Figure 3 As shown, the method includes: S101. Under heating conditions, obtain the ambient temperature and outlet pipe temperature of each indoor air conditioner unit in the current cycle.

[0033] Considering that during heating startup, components such as the compressor, condenser, and evaporator need to gradually heat up from a low temperature, parameters such as refrigerant flow, pressure, and temperature will experience drastic fluctuations. Immediately assessing liquid accumulation may lead to misjudgment due to parameter instability. In some embodiments, the air conditioning system can be run in heating mode for a preset period, such as 20 minutes, until the temperatures of various system components stabilize and the refrigerant circulation reaches dynamic equilibrium. At this time, the measured parameters such as ambient temperature and outlet pipe temperature can more accurately reflect the system status and improve the accuracy of the assessment.

[0034] The ambient temperature of the indoor unit of an air conditioner, also known as the indoor return air temperature, is the temperature of the surrounding air collected by the air conditioner through the air inlet, representing the current indoor heat load demand.

[0035] The outlet pipe temperature Tm refers to the pipe temperature at which the refrigerant flows out of the heat exchanger of the indoor unit of the air conditioner. By monitoring the outlet pipe temperature Tm, the system can understand the condensation status of the refrigerant in the indoor unit's heat exchanger. For example, if the outlet pipe temperature Tm is too high, it may mean that the refrigerant is not condensing sufficiently, and parameters such as the EVN opening degree can be adjusted accordingly to ensure that the refrigerant condition meets the requirements.

[0036] It should be understood that the indoor air conditioner referred to in the various embodiments of this application refers to the indoor air conditioner in the powered-on state.

[0037] The embodiments of this application do not limit the duration of the cycle, for example, it can be within 1 minute to 10 minutes.

[0038] S102. For each indoor air conditioner unit, if the ambient temperature of the indoor air conditioner unit in the current cycle is greater than or equal to the average ambient temperature of each indoor air conditioner unit, and the outlet pipe temperature of the indoor air conditioner unit in the current cycle is less than or equal to the average outlet pipe temperature of each indoor air conditioner unit, it is determined that there is liquid accumulation in the indoor air conditioner unit in the current cycle.

[0039] This application obtains the average ambient temperature of each indoor air conditioner unit after acquiring the ambient temperature of each unit in the current cycle. For example, if there are three indoor air conditioners in operation, and their ambient temperatures are 26.5℃, 26.7℃, and 26.9℃ respectively, then the average ambient temperature is determined to be 26.7℃. Similarly, by calculating the average outlet pipe temperature of each indoor air conditioner unit, the average outlet pipe temperature of each unit can be obtained.

[0040] It should be noted that in this embodiment, liquid accumulation in the air conditioner is determined only when both conditions of the air conditioner indoor unit are met. If only one condition is met, such as the outlet pipe temperature of the air conditioner indoor unit being less than or equal to the average outlet pipe temperature of all air conditioner indoor units in the current cycle, liquid accumulation in the air conditioner indoor unit cannot be determined.

[0041] This application's embodiment differs from related technologies that rely on subcooling or judge liquid accumulation solely based on the difference between the outlet pipe temperature and the average value, which are susceptible to interference from ambient temperature fluctuations. By comprehensively comparing the ambient temperature of the indoor unit in the current cycle with the average ambient temperature of all indoor units, and the outlet pipe temperature with the average outlet pipe temperature of all indoor units, it accurately identifies indoor units with abnormally low pipe temperatures in high-temperature environments, effectively eliminating interference from ambient temperature fluctuations and uneven load on liquid accumulation judgment. This achieves proactive prevention and precise location of liquid accumulation status, laying the foundation for subsequently improving system operational stability, reducing compressor load, and reducing ineffective cooling.

[0042] Based on the above embodiments, as an optional embodiment, if the ambient temperature of the indoor unit of the air conditioner in the current cycle is greater than or equal to the average ambient temperature of each indoor unit of the air conditioner, and the outlet pipe temperature of the indoor unit of the air conditioner in the current cycle is less than or equal to the average outlet pipe temperature of each indoor unit of the air conditioner for a preset duration, it is determined that there is liquid accumulation in the indoor unit of the air conditioner in the current cycle.

[0043] During air conditioner operation, ambient temperature or pipe temperature may experience momentary anomalies due to transient factors (such as direct sunlight, wind speed fluctuations, and sensor errors). Relying solely on a single data point to determine liquid accumulation can easily lead to false triggering. Therefore, this application improves the accuracy of judgment by continuously determining whether liquid accumulation exists in the indoor unit of the air conditioner for a preset duration. This application does not specify a particular preset duration; for example, it can be 1-3 minutes, or even 2 minutes.

[0044] Based on the above embodiments, as an optional embodiment, for each indoor air conditioner unit, if it is determined that there is liquid accumulation in the indoor air conditioner unit in the current cycle, the method further includes executing a first strategy; The first strategy includes at least one of the following: Increase the opening degree of the indoor unit expansion valve of the air conditioner in the next cycle; Increase the opening degree of the outdoor unit expansion valve of the air conditioner in the next cycle; Increase the fan speed of the outdoor unit of the air conditioner in the next cycle.

[0045] It should be noted that this application can directly increase the refrigerant flow into the indoor unit by increasing the opening degree of the expansion valve of the indoor unit with accumulated liquid in the next cycle.

[0046] Simply increasing the opening of the indoor unit's expansion valve directly increases the refrigerant flow into the indoor unit. However, if the evaporator's heat exchange capacity is insufficient, the liquid refrigerant may not evaporate completely, exacerbating the liquid accumulation problem and even causing liquid slugging that could damage the compressor. This application's embodiment increases the opening of the outdoor unit's expansion valve, prioritizing the adjustment of the system's total refrigerant flow, thus reducing the risk of excessive refrigerant entering the indoor unit's circulation at the source.

[0047] In some embodiments, the expansion valve of the outdoor unit and the expansion valve of the indoor unit are adjusted in tandem to more accurately match the actual heat load demand of the room and avoid insufficient heat exchange caused by excessive flow in the indoor unit.

[0048] Considering that simply adjusting the indoor unit's expansion valve cannot solve the problem of insufficient heat exchange on the outdoor unit side, such as high ambient temperature and low airflow leading to increased condensing pressure, this ingenious embodiment can also increase the fan speed. Increasing the fan speed can accelerate airflow, enhance the heat dissipation capacity of the outdoor unit's condenser, and reduce condensing temperature and pressure, thereby reducing refrigerant retention on the high-pressure side and promoting the conversion of liquid refrigerant to gaseous state.

[0049] It should be noted that adjusting the opening of the indoor unit's expansion valve requires gradually affecting the system state through refrigerant circulation, resulting in a relatively slow response time. This is especially true in multi-split systems, where load differences between indoor units may cause adjustment lag. By synchronously adjusting the outdoor unit's expansion valve and fan, the system's pressure-temperature relationship can be quickly changed, accelerating the refrigerant phase change process and shortening the liquid accumulation removal time.

[0050] In some embodiments, increasing the opening degree of the indoor unit expansion valve of the air conditioner in the next cycle includes: determining the opening degree of the indoor unit expansion valve of the air conditioner in the next cycle based on the opening degree of the indoor unit expansion valve in the current cycle and a first opening degree increment. The first opening degree increment is 4-20 PLS, for example, 10 PLS.

[0051] In some embodiments, increasing the opening degree of the outdoor unit expansion valve of the air conditioner in the next cycle includes: determining the opening degree of the outdoor unit expansion valve in the next cycle based on the opening degree of the outdoor unit expansion valve in the current cycle and a second opening degree increment. The second opening degree increment is 4-20 PLS, for example, 5 PLS.

[0052] In some embodiments, increasing the rotational speed of the outdoor unit's fan in the next cycle includes: determining the fan's rotational speed in the next cycle based on the fan's rotational speed in the current cycle and the rotational speed increment. The rotational speed increment is between 5 and 100 revolutions per minute (RPM).

[0053] It should be noted that the adjustment of the indoor unit expansion valve, outdoor unit expansion valve and fan in this application adopts a scheme to obtain the value of the next cycle based on the value of the current cycle and the increment. This scheme can achieve precise and smooth control of the indoor unit expansion valve, outdoor unit expansion valve and fan, effectively solve the liquid accumulation problem and improve system stability.

[0054] Based on the above embodiments, as an optional embodiment, for each indoor air conditioner unit, if the opening degree of the outdoor unit expansion valve in the current cycle does not reach its maximum value and at least one of the following conditions is met, the opening degree of the outdoor unit expansion valve in the next cycle is increased: The indoor unit expansion valve of the air conditioner reaches its maximum opening degree in the current cycle; The first temperature difference of the outdoor unit of the air conditioner in the current cycle is greater than or equal to the first threshold.

[0055] In this embodiment, the opening of the indoor unit's expansion valve is adjusted first. Only when the opening of the indoor unit's expansion valve reaches its maximum value is the opening of the outdoor unit's expansion valve increased. When the opening of the expansion valve of a certain indoor unit reaches its maximum value, it indicates that the indoor unit is already operating at full load, but the refrigerant flow is still insufficient. At this time, by increasing the opening of the outdoor unit's expansion valve, the high-pressure side pressure of the system is reduced, and the refrigerant circulation is increased, thereby removing the flow restriction of the indoor unit's expansion valve and enabling the indoor unit to output greater heating capacity to meet high load demands.

[0056] It should be noted that, in the embodiments of this application, the first temperature difference is the difference between the exhaust temperature and the saturation temperature corresponding to the exhaust pressure. In some embodiments, the first temperature difference is also referred to as exhaust superheat.

[0057] When the first temperature difference exceeds the first threshold, it indicates that the refrigerant flow in the system is insufficient or the evaporator heat exchange efficiency has decreased. By increasing the opening of the outdoor unit's expansion valve, the refrigerant flow can be increased, reducing the first temperature difference to a reasonable range, preventing the compressor from overheating and protecting itself, and simultaneously improving the system's heat exchange efficiency.

[0058] In some embodiments, the first threshold is 18-23°C, for example, it can be 20°C.

[0059] Based on the above embodiments, as an optional embodiment, for each indoor air conditioning unit, if the fan speed in the current cycle does not reach its maximum value and at least one of the following conditions is met, the fan speed in the next cycle is increased: The indoor unit expansion valve of the air conditioner reaches its maximum opening degree in the current cycle; The first temperature difference of the outdoor unit of the air conditioner in the current cycle is greater than or equal to the first threshold.

[0060] It should be noted that when the indoor unit's expansion valve reaches its maximum opening, it indicates that the current refrigerant flow is insufficient to meet the indoor unit's heat exchange requirements. Increasing the fan speed at this point can enhance air-side heat exchange, compensate for insufficient refrigerant flow, and prevent the indoor unit's capacity from decreasing. Furthermore, the embodiments of this application achieve dynamic matching between the air cooler's speed and load demand, avoiding energy waste caused by prolonged high-speed fan operation. For example, maintaining a low speed when the indoor unit's expansion valve is not at its maximum and the first temperature difference is normal can reduce fan power consumption; increasing the speed only when the indoor unit's expansion valve is under high load achieves "on-demand energy supply," improving the overall energy efficiency ratio (EER) by 5%-10%.

[0061] When the first temperature difference is greater than or equal to the first threshold, it indicates that the refrigerant circulation efficiency of the system has decreased. Increasing the fan speed can accelerate the heat dissipation of the outdoor unit, reduce the exhaust temperature, restore the first temperature difference to a reasonable range, and ensure stable compressor operation. Limiting the fan speed by the first threshold prevents the outdoor unit from causing the compressor to overheat or liquid slugging due to insufficient heat dissipation; at the same time, it avoids frequent fan start-stop, reduces mechanical wear, extends the service life of the fan and compressor, and reduces maintenance costs.

[0062] Please see Figure 4 The figure illustrates a flowchart of a heating control method for a multi-split air conditioning system according to an embodiment of this application, as shown in the figure, including: S201. Under heating conditions, initialize the opening degree of each indoor unit expansion valve, the opening degree of the outdoor unit expansion valve, and the speed of the outdoor unit fan. S202. Obtain the ambient temperature and outlet pipe temperature of each indoor air conditioning unit in the current cycle; S203. For each indoor air conditioner unit, determine whether the indoor air conditioner unit simultaneously meets conditions 1 and 2. If it meets both conditions, execute S204; otherwise, execute S207. Condition 1 is that the ambient temperature of the indoor unit of the air conditioner in the current cycle is greater than or equal to the average ambient temperature of each indoor unit of the air conditioner. Condition 2 is that the outlet pipe temperature of the indoor air conditioner in the current cycle is less than or equal to the average outlet pipe temperature of all indoor air conditioners. S204. Determine whether at least one of conditions 3 and 4 is satisfied. If not, execute S205; if yes, execute S206. Among them, condition 3 is that the opening degree of the indoor unit expansion valve of the air conditioner reaches the maximum value in the current cycle; Condition 4 is that the superheat of the outdoor unit of the air conditioner is greater than or equal to the first threshold in the current cycle; S205. Increase the opening degree of the indoor unit expansion valve of the air conditioner in the next cycle, and return to execute S202 when entering the next cycle; S206. Increase at least one of the opening degree of the outdoor unit expansion valve in the next cycle and the speed of the fan in the next cycle, and return to execute S202 when entering the next cycle; S207. Keep the opening degree of each indoor unit expansion valve, the opening degree of the outdoor unit expansion valve, and the speed of the outdoor unit fan unchanged, and return to execute S202 when entering the next cycle.

[0063] Based on the above embodiments, as an optional embodiment, this application embodiment further includes: Obtain the first temperature difference of the outdoor unit of the air conditioner in the current cycle; For each indoor air conditioner unit, the second strategy is executed when the first temperature difference is less than or equal to the second threshold, or when the ambient temperature of the indoor air conditioner unit in the current cycle is less than the average ambient temperature of each indoor air conditioner unit.

[0064] The second threshold in this embodiment is lower than the first threshold.

[0065] In some embodiments, the second threshold is 13-17°C, for example, it can be 15°C.

[0066] The second strategy in this application embodiment includes at least one of the following: The opening degree of the indoor unit expansion valve of the air conditioner indoor unit in the next cycle is the same as the opening degree in the current cycle; The opening degree of the outdoor unit expansion valve in the next cycle is the same as the opening degree in the current cycle; The fan speed of the outdoor unit of the air conditioner is kept the same in the next cycle as in the current cycle.

[0067] It should be noted that when one indoor unit needs to execute the first strategy and another indoor unit needs to execute the second strategy, if both strategies involve the operation of the same outdoor unit components (outdoor unit expansion valve and fan), the first strategy has a higher priority than the second strategy. For example, if indoor unit 1 needs to execute the first strategy, which includes increasing the opening of the outdoor unit expansion valve in the next cycle, and indoor unit 2 needs to execute the second strategy, which includes keeping the opening of the outdoor unit expansion valve unchanged in the next cycle, then the opening of the outdoor unit expansion valve will be increased in the next cycle, rather than keeping it unchanged.

[0068] Please see Figure 5 The figure illustrates a flowchart of a heating control method for a multi-split air conditioning system according to an embodiment of this application, as shown in the figure, including: S301. Under heating conditions, initialize the opening degree of each indoor unit expansion valve, the opening degree of the outdoor unit expansion valve, and the speed of the outdoor unit fan. S302. Obtain the superheat of the outdoor unit of the air conditioner and the ambient temperature and outlet pipe temperature of each indoor unit of the air conditioner in the current cycle. S303a. For each indoor air conditioner unit, if the ambient temperature of the indoor air conditioner unit in the current cycle is greater than or equal to the average ambient temperature of each indoor air conditioner unit, and the outlet pipe temperature of the indoor air conditioner unit in the current cycle is less than or equal to the average outlet pipe temperature of each indoor air conditioner unit, the first strategy shall be executed. S303b. For each indoor air conditioner unit, if the ambient temperature of the indoor air conditioner unit in the current cycle is less than the average ambient temperature of all indoor air conditioner units, the outlet pipe temperature of the indoor air conditioner unit in the current cycle is greater than the average outlet pipe temperature of all indoor air conditioner units, or the exhaust superheat is less than or equal to the second threshold, the second strategy shall be executed.

[0069] It should be noted that, in the operational optimization study of multi-split air conditioning systems in heating mode, this application proposes a liquid accumulation identification and global compensation control method based on dynamic parameter adjustment to address the problem of abnormally increased subcooling in remote or high-resistance indoor units caused by uneven refrigerant distribution. This method locates the refrigerant stagnation area by constructing a joint criterion of indoor unit ambient temperature and outlet pipe temperature, and adjusts and improves the refrigerant distribution balance, thereby effectively suppressing the subcooling deviation of remote indoor units. Specifically, when the ambient temperature of a certain indoor unit in the current cycle is not lower than the average ambient temperature of all indoor units (indicating high heating demand) and the outlet pipe temperature is not higher than the average (reflecting incomplete refrigerant evaporation), it is determined that the indoor unit has refrigerant liquid accumulation; at this time, by increasing at least one of the following measures—increasing the opening of the outdoor unit expansion valve or the outdoor unit fan speed—the total refrigerant circulation volume of the system is increased in the next cycle, and the refrigerant flow resistance distribution is optimized. Its working mechanism is as follows: through dynamic compensation of outdoor unit parameters, on the one hand, it increases the total refrigerant flow of the system, which alleviates the insufficient refrigerant supply to the remote indoor unit caused by the difference in pipeline resistance; on the other hand, it reduces the condensing pressure, increases the pressure difference between the inlet and outlet of the evaporator, promotes the flow of refrigerant in the branch with greater resistance, thereby reducing local subcooling.

[0070] This application provides a heating control method for a multi-split air conditioning system. After the unit has been running normally in heating mode for 20 minutes, if the i-th indoor unit detects that the following four conditions are met for 2 consecutive minutes: 1) The ambient temperature T of the i-th indoor unit ai ≥The average ambient temperature of all indoor units (T) a_ave +A; This condition indicates that the ambient temperature of the indoor unit is too high. 2) The outlet pipe temperature T of the i-th indoor unit mi +B ≤ the average outlet pipe temperature T of all indoor units m_ave This condition refers to a situation where the ambient temperature of the indoor unit is too high, resulting in excessive subcooling during heating, insufficient refrigerant flowing into the indoor unit, high refrigerant resistance, and liquid accumulation in the indoor unit. 3) Valve opening degree EVN of the i-th indoor unit i =Maximum opening; This condition means that the electronic expansion valve of the indoor unit has reached its maximum opening and cannot allow more refrigerant to flow through. Therefore, the electronic expansion valve of the outdoor unit can only be opened to allow more refrigerant to flow in. 4) Exhaust superheat T dsh ≥20℃; This condition is to ensure that opening the electronic expansion valve of the outdoor unit at this temperature will not cause liquid backflow for the compressor, making it safe and reliable for the compressor. Therefore, the following procedure should be followed: 1) Valve opening degree EVA of the outdoor unit in the current cycle n （n） =EVA （n-1） +X; can reduce resistance; 2) The fan speed F during the current period n （n）=F （n-1） +Y; can increase inhaled superheat.

[0071] Maintain the current valve opening and fan parameters when the following conditions are detected.

[0072] Exhaust superheat T dsh <15℃; The outlet pipe temperature T of the i-th indoor unit mi >The average outlet pipe temperature T of all indoor units m_ave .

[0073] Where A is a fixed constant with a value range of 0-3℃; B is a fixed constant with a value range of 3-8℃; X is a fixed constant with a value range of 4-20 PLS; and Y is a fixed constant with a value range of 5-100 RPM.

[0074] This application provides a heating control device for a multi-split air conditioning system, such as... Figure 6 As shown, the heating control device of the multi-split air conditioning system may include: a parameter acquisition module 601 and a liquid accumulation judgment module 602, wherein, The parameter acquisition module 601 is used to acquire the ambient temperature and outlet pipe temperature of each indoor air conditioner unit in the current cycle under heating conditions. The liquid accumulation judgment module 602 is used to determine that liquid accumulation exists in the air conditioner indoor unit in the current cycle if the ambient temperature of the air conditioner indoor unit in the current cycle is greater than or equal to the average ambient temperature of all air conditioner indoor units, and the outlet pipe temperature of the air conditioner indoor unit in the current cycle is less than or equal to the average outlet pipe temperature of all air conditioner indoor units.

[0075] The multi-split air conditioning system in this application embodiment also includes an outdoor unit connected to each indoor unit. The device also includes a strategy module for executing a first strategy for each indoor air conditioner unit when it is determined that there is liquid accumulation in the indoor air conditioner unit in the current cycle; The first strategy includes at least one of the following: Increase the opening degree of the indoor unit expansion valve of the air conditioner in the next cycle; Increase the opening degree of the outdoor unit expansion valve of the air conditioner in the next cycle; Increase the fan speed of the outdoor unit of the air conditioner in the next cycle.

[0076] Based on the above embodiments, as an optional embodiment, for each indoor air conditioner unit, if the opening degree of the outdoor unit expansion valve in the current cycle does not reach its maximum value and at least one of the following conditions is met, the opening degree of the outdoor unit expansion valve in the next cycle is increased: The indoor unit expansion valve of the air conditioner reaches its maximum opening degree in the current cycle; The first temperature difference of the outdoor unit of the air conditioner in the current cycle is greater than or equal to a first threshold, wherein the first temperature difference is the difference between the exhaust temperature and the saturation temperature corresponding to the exhaust pressure.

[0077] Based on the above embodiments, as an optional embodiment, for each indoor air conditioning unit, if the fan speed in the current cycle does not reach its maximum value and at least one of the following conditions is met, the fan speed in the next cycle is increased: The indoor unit expansion valve of the air conditioner reaches its maximum opening degree in the current cycle; The first temperature difference of the outdoor unit of the air conditioner in the current cycle is greater than or equal to the first threshold.

[0078] Based on the above embodiments, as an optional embodiment, the parameter acquisition module is also used to obtain the first temperature difference of the outdoor unit of the air conditioner in the current cycle; The strategy module is also used to execute the second strategy for each indoor air conditioner unit when the first temperature difference is less than or equal to the second threshold, or when the ambient temperature of the indoor air conditioner unit in the current cycle is less than the average ambient temperature of each indoor air conditioner unit. Wherein, the second threshold is lower than the first threshold; the second strategy includes at least one of the following: The opening degree of the indoor unit expansion valve of the air conditioner indoor unit in the next cycle is the same as the opening degree in the current cycle; The opening degree of the outdoor unit expansion valve in the next cycle is the same as the opening degree in the current cycle; The fan speed of the outdoor unit of the air conditioner is kept the same in the next cycle as in the current cycle.

[0079] Based on the above embodiments, as an optional embodiment, the first threshold is 18-23℃ and the second threshold is 13-17℃.

[0080] Based on the above embodiments, as an optional embodiment, The step of increasing the opening degree of the indoor unit expansion valve of the air conditioner in the next cycle includes: determining the opening degree of the indoor unit expansion valve of the air conditioner in the next cycle based on the opening degree of the indoor unit expansion valve in the current cycle and the first opening degree increment. The step of increasing the opening degree of the outdoor unit expansion valve of the air conditioner in the next cycle includes: determining the opening degree of the outdoor unit expansion valve in the next cycle based on the opening degree of the outdoor unit expansion valve in the current cycle and the second opening degree increment; Increasing the speed of the fan of the outdoor unit of the air conditioner in the next cycle includes: determining the speed of the fan in the next cycle based on the speed of the fan of the outdoor unit of the air conditioner in the current cycle and the speed increment.

[0081] Based on the above embodiments, as an optional embodiment, the first opening increment is between 4 and 20 pulses (PLS); The second opening increment is between 4 and 20 PLS; The speed increment is between 5 and 100 revolutions per minute.

[0082] The apparatus of this application embodiment can execute the method provided in this application embodiment. The implementation principle is similar. The actions performed by each module in the apparatus of each embodiment of this application correspond to the steps in the method of each embodiment of this application. For detailed functional descriptions of each module of the apparatus, please refer to the descriptions in the corresponding methods shown above, which will not be repeated here.

[0083] This application provides an electronic device, including a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps of a heating control method for a multi-split air conditioning system. Compared with related technologies, this method achieves the following: Unlike related technologies that rely on subcooling or judge liquid accumulation solely based on the difference between the outlet pipe temperature and the average value, and are easily affected by ambient temperature fluctuations, this method comprehensively compares the ambient temperature of the indoor unit in the current cycle with the average ambient temperature of all indoor units, and the outlet pipe temperature with the average outlet pipe temperature of all indoor units. It accurately identifies indoor units with abnormally low pipe temperatures in high-temperature environments, effectively eliminating the interference of ambient temperature fluctuations and uneven load on liquid accumulation judgment, achieving proactive prevention and precise positioning of liquid accumulation status, and laying the foundation for improving system operation stability, reducing compressor load, and reducing ineffective cooling.

[0084] In one alternative embodiment, an electronic device is provided, such as Figure 7 As shown, Figure 7 The illustrated electronic device 4000 includes a processor 4001 and a memory 4003. The processor 4001 and the memory 4003 are connected, for example, via a bus 4002. Optionally, the electronic device 4000 may further include a transceiver 4004, which can be used for data interaction between the electronic device and other electronic devices, such as sending and / or receiving data. It should be noted that in practical applications, the transceiver 4004 is not limited to one type, and the structure of the electronic device 4000 does not constitute a limitation on the embodiments of this application.

[0085] Processor 4001 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. Processor 4001 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0086] Bus 4002 may include a pathway for transmitting information between the aforementioned components. Bus 4002 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. Bus 4002 can be divided into address bus, data bus, control bus, etc. For ease of representation, bus 4002 is represented by only one thick line in the figure, but this does not indicate that there is only one bus or one type of bus.

[0087] The memory 4003 may be ROM (Read Only Memory) or other types of static storage devices capable of storing static information and instructions, RAM (Random Access Memory) or other types of dynamic storage devices capable of storing information and instructions, or EEPROM (Electrically Erasable Programmable Read Only Memory), CD-ROM (Compact Disc Read Only Memory) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media, other magnetic storage devices, or any other medium capable of carrying or storing computer programs and capable of being read by a computer, without limitation herein.

[0088] The memory 4003 stores computer programs that execute embodiments of this application, and its execution is controlled by the processor 4001. The processor 4001 executes the computer programs stored in the memory 4003 to implement the steps shown in the foregoing method embodiments.

[0089] This application provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it can implement the steps and corresponding content of the aforementioned method embodiments.

[0090] This application also provides a computer program product, including a computer program that, when executed by a processor, can implement the steps and corresponding content of the aforementioned method embodiments.

[0091] The terms "first," "second," "third," "fourth," "1," "2," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in a sequence other than that shown in the illustrations or text descriptions.

[0092] It should be understood that although arrows indicate various operation steps in the flowcharts of this application's embodiments, the order in which these steps are implemented is not limited to the order indicated by the arrows. Unless explicitly stated herein, in some implementation scenarios of this application's embodiments, the implementation steps in each flowchart can be executed in other orders as required. Furthermore, some or all steps in each flowchart, based on the actual implementation scenario, may include multiple sub-steps or multiple stages. Some or all of these sub-steps or stages can be executed at the same time, and each sub-step or stage can also be executed at different times. In scenarios where execution times differ, the execution order of these sub-steps or stages can be flexibly configured according to requirements, and this application's embodiments do not limit this.

[0093] The above description is only an optional implementation method for some implementation scenarios of this application. It should be noted that for those skilled in the art, other similar implementation methods based on the technical concept of this application without departing from the technical concept of this application also fall within the protection scope of the embodiments of this application.

Claims

1. A heating control method of a multi-split air conditioning system, characterized by, The multi-split air conditioning system includes multiple indoor air conditioning units, and the method includes: Under heating conditions, obtain the ambient temperature and outlet pipe temperature of each indoor air conditioning unit in the current cycle; For each indoor air conditioner unit, if the ambient temperature of the indoor air conditioner unit in the current cycle is greater than or equal to the average ambient temperature of all indoor air conditioner units, and the outlet pipe temperature of the indoor air conditioner unit in the current cycle is less than or equal to the average outlet pipe temperature of all indoor air conditioner units, it is determined that there is liquid accumulation in the indoor air conditioner unit in the current cycle.

2. The method of claim 1, wherein, The multi-split air conditioning system also includes an outdoor unit connected to each indoor unit. For each indoor air conditioner unit, if liquid accumulation exists in the indoor air conditioner unit during the current cycle, the method further includes executing a first strategy; The first strategy includes at least one of the following: Increase the opening degree of the indoor unit expansion valve of the air conditioner in the next cycle; Increase the opening degree of the outdoor unit expansion valve of the air conditioner in the next cycle; Increase the fan speed of the outdoor unit of the air conditioner in the next cycle.

3. The method of claim 2, wherein, For each indoor air conditioning unit, if the opening of the outdoor unit's expansion valve does not reach its maximum value in the current cycle and at least one of the following conditions is met, the opening of the outdoor unit's expansion valve in the next cycle shall be increased: The indoor unit expansion valve of the air conditioner reaches its maximum opening degree in the current cycle; The first temperature difference of the outdoor unit of the air conditioner in the current cycle is greater than or equal to a first threshold; wherein, the first temperature difference is the difference between the exhaust temperature and the saturation temperature corresponding to the exhaust pressure.

4. The method according to claim 2 or 3, characterized in that, For each indoor air conditioning unit, if the fan speed in the current cycle does not reach its maximum value and at least one of the following conditions is met, the fan speed in the next cycle shall be increased: The indoor unit expansion valve of the air conditioner reaches its maximum opening degree in the current cycle; The first temperature difference of the outdoor unit of the air conditioner in the current cycle is greater than or equal to the first threshold.

5. The method of claim 2, wherein, Also includes: Obtain the first temperature difference of the outdoor unit of the air conditioner in the current cycle; For each indoor air conditioner unit, if the first temperature difference is less than or equal to the second threshold, or if the ambient temperature of the indoor air conditioner unit in the current cycle is less than the average ambient temperature of each indoor air conditioner unit, the second strategy is executed. Wherein, the second threshold is lower than the first threshold; the second strategy includes at least one of the following: The opening degree of the indoor unit expansion valve of the air conditioner indoor unit in the next cycle is the same as the opening degree in the current cycle; The opening degree of the outdoor unit expansion valve in the next cycle is the same as the opening degree in the current cycle; The fan speed of the outdoor unit of the air conditioner is kept the same in the next cycle as in the current cycle.

6. The method of claim 5, wherein, The first threshold is 18-23℃, and the second threshold is 13-17℃.

7. The method according to claim 2, characterized in that, The step of increasing the opening degree of the indoor unit expansion valve of the air conditioner in the next cycle includes: determining the opening degree of the indoor unit expansion valve of the air conditioner in the next cycle based on the opening degree of the indoor unit expansion valve in the current cycle and the first opening degree increment. The step of increasing the opening degree of the outdoor unit expansion valve of the air conditioner in the next cycle includes: determining the opening degree of the outdoor unit expansion valve in the next cycle based on the opening degree of the outdoor unit expansion valve in the current cycle and the second opening degree increment; Increasing the speed of the fan of the outdoor unit of the air conditioner in the next cycle includes: determining the speed of the fan in the next cycle based on the speed of the fan of the outdoor unit of the air conditioner in the current cycle and the speed increment.

8. The method of claim 7, wherein, The first opening increment is between 4 and 20 pulses (PLS). The second opening increment is between 4 and 20 PLS; The speed increment is between 5 and 100 revolutions per minute.

9. The method of claim 1, wherein, The determination that liquid accumulation exists in the indoor unit of the air conditioner in the current cycle, when the ambient temperature of the indoor unit is greater than or equal to the average ambient temperature of all indoor units, and the outlet pipe temperature of the indoor unit is less than or equal to the average outlet pipe temperature of all indoor units, includes: If the ambient temperature of the indoor unit of the air conditioner in the current cycle is greater than or equal to the average ambient temperature of all indoor units of the air conditioner, and the outlet pipe temperature of the indoor unit of the air conditioner in the current cycle is less than or equal to the average outlet pipe temperature of all indoor units of the air conditioner for a preset duration, it is determined that there is liquid accumulation in the indoor unit of the air conditioner in the current cycle.

10. A heating control device of a multi-split air conditioning system, characterized in that, The multi-split air conditioning system includes multiple indoor air conditioning units, and the device includes: The parameter acquisition module is used to collect the ambient temperature and outlet pipe temperature of each indoor air conditioner unit in the current cycle under heating conditions. The liquid accumulation detection module is used to determine that liquid accumulation exists in the current cycle of each indoor air conditioner unit when the ambient temperature of the indoor air conditioner unit in the current cycle is greater than or equal to the average ambient temperature of all indoor air conditioner units, and the outlet pipe temperature of the indoor air conditioner unit in the current cycle is less than or equal to the average outlet pipe temperature of all indoor air conditioner units.

11. An electronic device comprising a memory, a processor, and a computer program stored on the memory, wherein the computer program comprises instructions that, when executed by the processor, cause the electronic device to perform the method of any one of claims 1-10. The processor executes the computer program to implement the heating control method for the multi-split air conditioning system according to any one of claims 1-9.

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 heating control method of the multi-split air conditioning system according to any one of claims 1-9.

13. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the heating control method of the multi-split air conditioning system according to any one of claims 1-9.

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