Multi-connected air conditioner self-cleaning method and multi-connected air conditioner system

Abstract

The application discloses a multi-connected air conditioner self-cleaning method and system, and relates to the technical field of air conditioners. The multi-connected air conditioner comprises an air conditioner outdoor unit and a plurality of air conditioner indoor units. The method comprises the following steps: an air conditioner indoor unit acquires a refrigeration instruction of an air conditioner outdoor unit, and the air conditioner indoor unit performs refrigeration according to the refrigeration instruction, so that the air conditioner indoor unit is frosted; when the air conditioner indoor unit performs refrigeration, the heat exchanger outlet pipe temperature of each air conditioner indoor unit is acquired, the highest temperature value in the plurality of heat exchanger outlet pipe temperatures is taken as a first target temperature, the operating frequency of the compressor of the air conditioner outdoor unit is adjusted, and the operating rotating speed of the fan of each air conditioner indoor unit is adjusted, so that the air conditioner indoor unit continuously frosts and the frost amount is increased; the air conditioner indoor unit performs heating according to a heating instruction, so that the air conditioner indoor unit is defrosted; when the air conditioner indoor unit is defrosted, the air conditioner indoor unit continuously performs heating according to the heating instruction, so that the temperature of the air conditioner indoor unit reaches a target sterilization temperature, and the air conditioner indoor unit is high-temperature sterilized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioners, in particular to a multi-split air conditioner self-cleaning method and a multi-split air conditioner system. BACKGROUND

[0002] In recent years, with the improvement of people's living standards, consumer concepts are also changing. People not only pay attention to the aesthetics of home decoration, but also pay more and more attention to indoor air quality, resulting in an increasing share of multi-split air conditioners in the home decoration market year by year, and the multi-split air conditioner self-cleaning function is gradually becoming a standard configuration.

[0003] However, the multi-split air conditioner is a combination of one outdoor unit and multiple indoor units. If each indoor unit is cleaned in turn when entering the self-cleaning mode, the cleaning time is too long. If the self-cleaning mode is entered at the same time, some indoor units may have short frosting time and poor cleaning effect. SUMMARY

[0004] The present application aims to at least solve one of the problems in the prior art. To this end, the present application proposes a multi-split air conditioner self-cleaning method, which can simultaneously clean multiple indoor units while ensuring good cleaning effect.

[0005] The present application also proposes a multi-split air conditioner system applying the above multi-split air conditioner self-cleaning method.

[0006] The multi-split air conditioner self-cleaning method according to the first aspect of the present application, the multi-split air conditioner comprises an air conditioner outdoor unit and multiple air conditioner indoor units, and the multi-split air conditioner self-cleaning method comprises the following steps:

[0007] The air conditioner indoor unit obtains a refrigeration instruction of the air conditioner outdoor unit, and performs refrigeration according to the refrigeration instruction to frost the air conditioner indoor unit;

[0008] When the air conditioner indoor unit performs refrigeration, the heat exchanger outlet pipe temperature of each air conditioner indoor unit is obtained, the highest temperature value among the multiple heat exchanger outlet pipe temperatures corresponding to the multiple air conditioner indoor units is taken as a first target temperature, the operating frequency of the compressor of the air conditioner outdoor unit is adjusted, and the operating speed of the fan of each air conditioner indoor unit is adjusted to continuously frost the air conditioner indoor unit;

[0009] The air conditioner indoor unit obtains a heating instruction of the air conditioner outdoor unit, and performs heating according to the heating instruction to defrost the air conditioner indoor unit;

[0010] When the air conditioner indoor unit completes defrosting, the air conditioner indoor unit continuously performs heating according to the heating instruction to make the temperature of the air conditioner indoor unit reach a target sterilization temperature.

[0011] The multi-connected air conditioner self-cleaning method according to the embodiment of the present application has at least the following beneficial effects: in the step of the multi-connected air conditioner self-cleaning method, when the air conditioner indoor unit is refrigerating and frosting, the highest temperature value in the multiple heat exchanger outlet pipe temperatures corresponding to the multiple air conditioner indoor units is taken as the first target temperature, and the operation frequency of the compressor and the operation speed of the air conditioner indoor unit fan are controlled with the first target temperature as the reference, so that the evaporator temperature of the multiple air conditioner indoor units can meet the frosting temperature condition, thereby ensuring continuous frosting of the air conditioner indoor unit and achieving the frosting amount meeting the cleaning effect; when the air conditioner indoor unit is heating and defrosting, more defrosting water can be generated to clean the outer surface of the evaporator, thereby improving the cleaning effect.

[0012] According to some embodiments of the present application, the step of adjusting the operation frequency of the compressor of the air conditioner outdoor unit comprises:

[0013] determining the first target frequency of the compressor according to the first target temperature;

[0014] adjusting the initial frequency of the compressor according to the first target frequency, so that the upper limit of the first target temperature is less than a preset temperature, and the preset temperature is less than 0℃.

[0015] According to some embodiments of the present application, the step of adjusting the operation speed of the fan of each air conditioner indoor unit comprises:

[0016] presetting the first operation speed of the fan of the air conditioner indoor unit;

[0017] when the air conditioner indoor unit is refrigerating, obtaining the operation speed of each fan;

[0018] adjusting the operation speed of the fan according to the first operation speed, so that the operation speed of the fan is adjusted to the first operation speed.

[0019] According to some embodiments of the present application, the multi-connected air conditioner self-cleaning method further comprises the following steps:

[0020] when the air conditioner indoor unit is refrigerating, obtaining the heat exchanger inlet pipe temperature of each air conditioner indoor unit;

[0021] adjusting the opening degree of the electronic expansion valve of the multi-connected air conditioner, so that the heat exchanger outlet pipe temperature is equal to the heat exchanger inlet pipe temperature.

[0022] According to some embodiments of the present application, the step of adjusting the opening degree of the electronic expansion valve of the multi-connected air conditioner comprises:

[0023] preset a second running time for the indoor unit of the air conditioner to continuously cool;

[0024] when the outlet pipe temperature of the heat exchanger continuously remains less than or equal to the preset temperature for the second running time, the electronic expansion valve of the indoor unit is controlled to be closed, and the indoor unit is switched to a blowing mode.

[0025] According to some embodiments of the present application, the step of adjusting the opening degree of the electronic expansion valve of the multi-split air conditioner further comprises:

[0026] a third running time for the last indoor unit of the air conditioner to continuously cool and frost is preset, and the third running time is less than the second running time;

[0027] The outlet pipe temperature of the heat exchanger of the indoor unit is obtained, and when the outlet pipe temperature of the heat exchanger of the indoor unit continuously remains less than or equal to the preset temperature for the third running time, the opening degree of the electronic expansion valve is increased and the running frequency of the compressor is reduced.

[0028] According to some embodiments of the present application, the step of heating the indoor unit according to the heating instruction comprises:

[0029] The step of heating the indoor unit according to the heating instruction comprises:

[0030] a fourth running time for the compressor of the outdoor unit is preset;

[0031] In response to the heating instruction, the fan of the indoor unit is controlled to stop running, the reversing valve of the multi-split air conditioner is controlled to reverse, and the running frequency of the compressor is controlled to be increased and the compressor is controlled to run for the fourth running time, so that the indoor unit is defrosted.

[0032] According to some embodiments of the present application, the step of defrosting the indoor unit comprises:

[0033] a first saturation temperature and a second saturation temperature of a refrigerant of the multi-split air conditioner are preset, the first saturation temperature and the second saturation temperature are condensation temperatures of the refrigerant to be liquefied, and the first saturation temperature is less than the second saturation temperature;

[0034] determining a sterilization running frequency of the compressor according to the target sterilization temperature;

[0035] adjusting the sterilization running frequency of the compressor according to the target sterilization temperature, so that the inlet pipe temperature of the heat exchanger is equal to or greater than the target sterilization temperature, and the target sterilization temperature is greater than the first saturation temperature and less than the second saturation temperature.

[0036] According to some embodiments of the present application, the step after the defrosting of the indoor unit of the air conditioner is further comprising:

[0037] A fifth running time of the indoor unit of the air conditioner for continuous heating is preset, a sixth running time of the fan of the indoor unit of the air conditioner for running is preset, and a second running speed of the fan of the indoor unit of the air conditioner for running is preset;

[0038] The inlet pipe temperature of the heat exchanger is obtained, and when the inlet pipe temperature of the heat exchanger is greater than or equal to the target sterilization temperature for the fifth running time, the fan of the indoor unit of the air conditioner is controlled to run at the second running speed;

[0039] After the fan of the indoor unit of the air conditioner runs at the second running speed for the sixth running time, the multi-split air conditioner exits the self-cleaning program.

[0040] According to the multi-split air conditioner system of the second aspect of the embodiments of the present application, the multi-split air conditioner system comprises an indoor unit and an outdoor unit, and further comprises a running control device, the running control device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the multi-split air conditioner self-cleaning method of any one of the first aspect when executing the computer program.

[0041] According to the multi-split air conditioner system of the embodiments of the present application, at least the following beneficial effects are achieved: when the running control device of the multi-split air conditioner system executes the computer program on the memory thereof, the multi-split air conditioner self-cleaning method of any one of the first aspect can be implemented, thereby increasing the frost amount of the evaporator of the indoor unit of the multi-split air conditioner, and further increasing the defrosting water to improve the cleaning effect of the indoor unit of the air conditioner.

[0042] Additional aspects and advantages of the present application will be made apparent from the following description of the embodiments of the present application, which will become apparent to those skilled in the art from the following description of the embodiments of the present application, which will become apparent to those skilled in the art from the following description of the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0043] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the description of the embodiments, given below, when taken in conjunction with the drawings, in which:

[0044] Figure 1 The flowchart for entering the self-cleaning mode of the multi-split air conditioner self-cleaning method of the embodiments of the present application;

[0045] Figure 2 The flowchart of the multi-split air conditioner self-cleaning method of the embodiments of the present application;

[0046] Figure 3 For Figure 2A refrigeration defrosting flowchart of the illustrated multi-split air conditioner self-cleaning method;

[0047] Figure 4 For Figure 2 A heating defrosting and high-temperature sterilization flowchart of the illustrated multi-split air conditioner self-cleaning method. DETAILED DESCRIPTION

[0048] The embodiments of the present application are described in detail below with reference to the accompanying drawings, wherein the same or similar components are denoted by the same or similar reference numerals throughout the drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0049] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0050] In the description of the present application, the meaning of several is one or more, and the meaning of multiple is more than two, greater than, less than, more than, etc. are understood as not including the number, and above, below, etc. are understood as including the number. If it is described as first, second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of indicated technical features.

[0051] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0052] Referring to Figures 1 to 2 According to the multi-split air conditioner self-cleaning method of the first aspect embodiment of the present application, the multi-split air conditioner comprises an air conditioner outdoor unit and a plurality of air conditioner indoor units, and the multi-split air conditioner self-cleaning method comprises the following steps:

[0053] The air conditioner indoor unit obtains a refrigeration instruction of the air conditioner outdoor unit, and the air conditioner indoor unit performs refrigeration according to the refrigeration instruction, so that the air conditioner indoor unit performs defrosting;

[0054] In the process of refrigeration of the air conditioner indoor unit, the heat exchanger outlet pipe temperature of each air conditioner indoor unit is obtained, the highest temperature value in the multiple heat exchanger outlet pipe temperatures corresponding to the multiple air conditioner indoor units is taken as the first target temperature, the operating frequency of the compressor of the air conditioner outdoor unit is adjusted, and the operating rotating speed of the fan of each air conditioner indoor unit is adjusted, so that the air conditioner indoor unit continuously defrosts;

[0055] The air conditioner indoor unit obtains the heating instruction of the air conditioner outdoor unit, and performs heating according to the heating instruction, so that the air conditioner indoor unit defrosts;

[0056] When the air conditioner indoor unit completes defrosting, the air conditioner indoor unit continuously heats according to the heating instruction, so that the temperature of the air conditioner indoor unit reaches the target sterilization temperature.

[0057] In the embodiment, the multi-split air conditioner self-cleaning method can effectively automatically clean the multi-split air conditioner system, and improve the use efficiency and hygiene level of the air conditioner. Specifically, the multi-split air conditioner system includes an air conditioner outdoor unit and multiple (at least two) air conditioner indoor units. The air conditioner outdoor unit is mainly responsible for sending refrigeration and heating instructions and operating control of the compressor. The air conditioner indoor unit performs refrigeration, heating and self-cleaning operation according to the instruction of the outdoor unit, and each air conditioner indoor unit is equipped with a fan for adjusting the flow of indoor air.

[0058] According to the above steps, first, the air conditioner indoor unit obtains the refrigeration instruction sent by the air conditioner outdoor unit. This instruction is the first step to start the self-cleaning process, and is used to tell the air conditioner indoor unit to start performing refrigeration according to the refrigeration instruction. After receiving the refrigeration instruction, the air conditioner indoor unit will perform refrigeration according to the preset program, so that the surface of the evaporator of the air conditioner indoor unit starts to condense and frost. The purpose of frosting is to use the melting of frost to remove the dirt and bacteria on the evaporator in the subsequent defrosting process. It should be emphasized that when the air conditioner indoor unit performs refrigeration, the highest temperature value in the multiple heat exchanger outlet pipe temperatures corresponding to the multiple air conditioner indoor units can be taken as the first target temperature, and the operating frequency of the compressor of the air conditioner outdoor unit is adjusted according to the first target temperature, so as to maintain stable refrigeration effect. At the same time, the rotating speed of the fan of each air conditioner indoor unit is also adjusted to ensure that the flow of indoor air in the air conditioner indoor unit can drive the flow of indoor air to maintain the continuous frosting of the surface of the evaporator, and to prepare for the subsequent defrosting and sterilization stage.

[0059] Then, when the air conditioner indoor unit frosts to a certain extent (the frost amount reaches the preset requirement or the frosting time reaches the preset time), the air conditioner outdoor unit sends a heating instruction to the air conditioner indoor unit. After receiving the heating instruction, the air conditioner indoor unit will immediately switch from the refrigeration mode to the heating mode and start the defrosting operation. In the heating process, the frost on the evaporator will melt rapidly, and the defrosted frost water can remove the dirt and bacteria on the surface of the evaporator. The melted water will be discharged outside through the drainage system of the air conditioner indoor unit, thereby completing the first step of self-cleaning.

[0060] Then, after the defrosting is completed, the air conditioner indoor unit continues to heat according to the heating instruction of the air conditioner outdoor unit, so that the temperature of the air conditioner indoor unit gradually rises to reach the target sterilization temperature. This temperature is usually set within a range that can effectively kill bacteria without causing damage to the air conditioner indoor unit. Through continuous heating, the bacteria inside the air conditioner indoor unit are killed by high temperature, thereby achieving the purpose of sterilization.

[0061] It should also be noted that during the self-cleaning process, the communication between the air conditioner outdoor unit and the air conditioner indoor unit must be kept smooth to ensure accurate transmission and execution of the instructions. During the refrigeration frosting stage, the compressor operating frequency and the fan operating speed are adjusted according to the actual situation, such as taking the highest temperature value among the multiple heat exchanger outlet pipe temperatures corresponding to the multiple air conditioner indoor units as the first target temperature, adjusting the compressor operating frequency through the first target temperature, and at the same time ensuring that each air conditioner indoor unit of the multi-split air conditioner can be refrigeration frosted, and the fan operating speed should ensure the air flow inside the air conditioner indoor unit to drive the indoor air flow to ensure that the evaporator can be normally frosted, and finally to ensure the smooth progress of the self-cleaning process. During the high-temperature sterilization stage, the temperature of the air conditioner indoor unit should be strictly controlled to avoid damage to the reliability of the air conditioner or incomplete sterilization caused by excessively high or low temperature. Through the self-cleaning method of the multi-split air conditioner of the present application, the air conditioner indoor unit can be effectively automatically cleaned and sterilized, and the use efficiency and hygiene level of the air conditioner can be improved. At the same time, the method can also prolong the service life of the air conditioner and reduce the cost of maintenance and repair.

[0062] Therefore, it can be understood that the self-cleaning method of the multi-split air conditioner according to the embodiment of the present application has at least the following beneficial effects: in the step of the self-cleaning method of the multi-split air conditioner, when the air conditioner indoor unit is refrigeration frosted, the heat exchanger outlet pipe temperature of each air conditioner indoor unit is obtained, the highest temperature value among the multiple heat exchanger outlet pipe temperatures corresponding to the multiple air conditioner indoor units is taken as the first target temperature, and the first target temperature is taken as the reference to control the operating frequency of the compressor and the operating speed of the air conditioner indoor unit fan, and by taking the highest temperature value among the multiple heat exchanger outlet pipe temperatures as the first target temperature, it can be ensured that the evaporator temperature of the multiple air conditioner indoor units meets the frosting temperature condition, thereby ensuring that the air conditioner indoor unit continuously frosts to reach the frosting amount that meets the cleaning effect; when the air conditioner indoor unit is defrosted, more defrosting water is generated to clean the outer surface of the evaporator, thereby improving the cleaning effect.

[0063] It should also be noted that with reference to Figure 1Before the multi-split air conditioner enters the self-cleaning mode, the multi-split air conditioner is in a shutdown state, that is, the indoor unit and the outdoor unit of the air conditioner are in a shutdown state, and a certain indoor unit or multiple indoor units enter the self-cleaning mode according to the self-cleaning instruction received in advance, at this time, the fan of the indoor unit does not work, and the self-cleaning instruction is sent to the outdoor unit, and the outdoor unit can send the self-cleaning instruction to all online indoor units, so that the multi-split air conditioner enters the self-cleaning mode.

[0064] And a certain indoor unit or multiple indoor units enter the self-cleaning mode according to the self-cleaning instruction received in advance, the fan of the indoor unit does not work and the self-cleaning instruction is sent to the outdoor unit, if the outdoor unit is in a non-shutdown state at this time, the outdoor unit maintains the current working state and continues to work, and a certain indoor unit or multiple indoor units with self-cleaning demand remain in a shutdown state and wait for the outdoor unit to enter the shutdown state. After the outdoor unit receives the shutdown instruction, the outdoor unit is immediately shut down, and then triggers the outdoor unit to send the self-cleaning instruction to all online indoor units, so that the multi-split air conditioner enters the self-cleaning mode. When the outdoor unit enters the self-cleaning mode, the self-cleaning command is sent to all other online indoor units, all online indoor units enter the self-cleaning mode, and thus the self-cleaning program of the multi-split air conditioner starts.

[0065] Further, with reference to Figures 2 to 3 In some embodiments of the present application, the step of adjusting the operating frequency of the compressor of the outdoor unit includes:

[0066] After the compressor operates at the initial frequency for the first operating time, the heat exchanger outlet pipe temperature of the evaporator of each indoor unit is obtained, the heat exchanger outlet pipe temperature is the temperature of the refrigerant flowing out of the evaporator, and the highest temperature value of the heat exchanger outlet pipe temperature of the evaporator is taken as the first target temperature;

[0067] The first target frequency of the compressor is determined according to the first target temperature;

[0068] The initial frequency of the compressor is adjusted according to the first target frequency, so that the upper limit of the first target temperature is less than the preset temperature, and the preset temperature is less than 0℃.

[0069] From the self-cleaning method of the multi-split air conditioner in the above embodiments, it can be seen that adjusting the operating frequency of the compressor of the outdoor unit is one of the key steps to ensure efficient self-cleaning process. Specifically:

[0070] At the beginning stage of the self-cleaning process, the compressor first runs at a preset initial frequency for a first running time. This initial frequency is preset to ensure that the air conditioning system can start smoothly and gradually enter the working state. The length of the first running time can be adjusted according to the specific design and actual situation of the air conditioning system, i.e., it can be a fixed value or a variable value determined according to the environmental temperature and the capacity of the outdoor unit. Therefore, in some embodiments, the initial frequency of the compressor can be any value between 10 Hz and 70 Hz, such as 10 Hz, 70 Hz, or 45 Hz, which is not limited in this embodiment as long as the air conditioning system can start smoothly and gradually enter the working state.

[0071] Similarly, the first running time mentioned above can also be preset to ensure that the air conditioning system can start smoothly and gradually enter the working state; at the same time, it also needs to ensure that the evaporator of the air conditioning indoor unit can enter the working state stably and obtain the temperature of the refrigerant at the inlet of the coil in the evaporator. Therefore, the first running time in this embodiment can also not be specifically limited, i.e., the first running time can be a running time lower than 10 min, such as 3 min or 10 min, etc.

[0072] Then, after the compressor runs for the first running time, the multi-split air conditioning system obtains the heat exchanger outlet temperature of the evaporator of each air conditioning indoor unit. This temperature is the temperature of the refrigerant just flowing out of the evaporator, which reflects the current working state and refrigeration effect of the evaporator. In order to obtain the accurate evaporator temperature, a temperature sensor can be installed at the outlet of the evaporator to monitor the temperature change of the refrigerant in real time.

[0073] Next, after obtaining the heat exchanger outlet temperature of the evaporator of each air conditioning indoor unit, the system compares these temperature values to find the highest outlet temperature, which is taken as the first target temperature. According to the determined first target temperature, the system calculates the first target frequency of the compressor. This frequency is the best running frequency that can keep the first target temperature within a preset temperature range. The preset temperature is a set value less than 0℃, which ensures that the evaporator can continuously frost at low temperature and avoids system damage or energy efficiency decline due to too low temperature. Therefore, it can be understood that the purpose of this step is to ensure that in the subsequent frequency adjustment process, the highest heat exchanger outlet temperature can be used as a basis to ensure that the highest heat exchanger outlet temperature is less than 0℃, so that the heat exchanger outlet temperature of all air conditioning indoor units can be less than 0℃, and thus the evaporators of all air conditioning indoor units can achieve ideal frosting effect. The preset temperature can also be a set value less than 0℃, which can make the heat exchanger outlet temperature of the evaporator of all air conditioning indoor units lower, thereby improving the frosting effect and increasing the amount of frost.

[0074] After calculating the first target frequency, the system adjusts the initial frequency of the compressor according to this frequency. By adjusting the operating frequency of the compressor, the temperature of the evaporator can be precisely controlled, so that the upper limit of the first target temperature is always less than the preset temperature. This step relies on advanced control systems and precise algorithms to ensure the accuracy and stability of frequency adjustment. After the compressor operates at the first target frequency, the system continuously monitors the temperature changes of the evaporator of each air conditioner indoor unit. If any abnormalities or deviations from the preset temperature range are found, the system will immediately make corresponding adjustments to ensure the smooth progress of the self-cleaning process.

[0075] In summary, by precisely adjusting the operating frequency of the compressor, the multi-split air conditioner self-cleaning method of the present application can ensure that the evaporator continuously frosts in the ideal temperature range, increasing the amount of frost to lay a solid foundation for the subsequent defrosting and sterilization stages.

[0076] Further, with reference to Figures 2 to 3 In some embodiments of the present application, the step of adjusting the operating air speed of the fan of each air conditioner indoor unit comprises:

[0077] presetting a first operating rotational speed of the fan of the air conditioner indoor unit;

[0078] when the air conditioner indoor unit is in cooling mode, obtaining the operating rotational speed of each fan;

[0079] adjusting the operating rotational speed of the fan according to the first operating rotational speed, so that the operating rotational speed of the fan is adjusted to the first operating rotational speed.

[0080] From the multi-split air conditioner self-cleaning method of the above-mentioned embodiments, it can be seen that adjusting the operating air speed of the fan of each air conditioner indoor unit is also one of the key steps to ensure the efficient progress of the self-cleaning process. Specifically:

[0081] Before the multi-split air conditioner enters the self-cleaning mode, the first running speed of the fan of each air conditioner indoor unit needs to be preset. This step can be completed through the control panel of the air conditioning system or the remote controller. The setting of the first running speed should be based on the model, rated power of the air conditioner indoor unit, and the expected self-cleaning effect, to ensure that the internal dust can be effectively removed without causing excessive wear to the air conditioner components. Usually, the first running speed is set to a low speed value that can ensure cleaning efficiency without generating excessive noise. It should be noted that the first running speed can be 0 to 1500 r / min, and the specific value can be based on the model, rated power of the air conditioner indoor unit, and the expected self-cleaning effect. It should also be noted that in the self-cleaning mode of the multi-split air conditioner in this embodiment, the first running speed of the fan of the air conditioner indoor unit can be 250 r / min, which can make the fan of the air conditioner indoor unit produce a small wind speed. When using the self-cleaning mode in a cold weather environment where it is not desirable to blow cold air indoors, a smaller wind speed can reduce the cold feeling and improve the user experience. According to the above embodiment, the self-cleaning mode of the multi-split air conditioner is forcibly started in the off state, and it can be understood that when the self-cleaning mode forces the multi-split air conditioner to start, the fan of the air conditioner indoor unit produces a small wind speed, thereby meeting the user's demand that indoor air is not blown out as cold air.

[0082] However, it should be emphasized that based on the differences in the model and rated power of the air conditioner indoor unit, the first running speed of the fan that produces a small wind speed by the fan of the air conditioner indoor unit will also be different, so in this embodiment, the first running speed can not be specifically limited, and the effect of the fan producing a small wind speed without obvious blowing feeling can be met.

[0083] When the air conditioner indoor unit starts and enters the refrigeration mode, the system will automatically or through user instructions enter the preparation phase of the self-cleaning program. At this time, the control system will obtain the actual running speed of the fan of each air conditioner indoor unit in real time. This step is usually realized by a built-in sensor, which can accurately monitor the rotational speed of the fan and transmit the data to the control system for analysis. After obtaining the current running speed of the fan of each air conditioner indoor unit, the control system will adjust the fan speed of each air conditioner indoor unit according to the preset first running speed. The adjustment process is realized by controlling the working voltage or current of the motor to ensure that the speed of the fan smoothly transitions to the preset first running speed. During this process, the control system needs to continuously monitor the speed change of the fan until the running speed of all fans reaches the preset value and remains stable. After the fan speed adjustment is completed, the fan of the air conditioner indoor unit generates airflow at the first running speed, which ensures that the indoor air flows and does not have a significant blowing feeling, meeting the user's experience. The flow of air can drive the water molecules in the indoor air to flow through the evaporator, thereby increasing the amount of frost on the evaporator. It should be noted that the length of time of the self-cleaning frosting process can be set according to actual needs, and it is generally recommended not to exceed 30 minutes.

[0084] Reference Figures 2 to 3 In some embodiments of the present application, the multi-split air conditioner self-cleaning method further comprises the following steps:

[0085] When the air conditioner indoor unit is in refrigeration, the heat exchanger inlet temperature and the heat exchanger outlet temperature of each air conditioner indoor unit are obtained. The heat exchanger inlet temperature is the temperature of the refrigerant flowing into the evaporator, and the heat exchanger outlet temperature is the temperature of the refrigerant flowing out of the evaporator.

[0086] Adjust the opening of the electronic expansion valve of the multi-split air conditioner so that the heat exchanger inlet temperature is equal to the heat exchanger outlet temperature.

[0087] In this embodiment, specifically, when the air conditioner indoor unit is in refrigeration operation, the system obtains the heat exchanger inlet temperature and the heat exchanger outlet temperature of each air conditioner indoor unit in real time. The heat exchanger inlet temperature refers to the temperature of the refrigerant flowing into the evaporator, which reflects the state of the refrigerant at the inlet of the evaporator; and the heat exchanger outlet temperature refers to the temperature of the refrigerant flowing out of the evaporator, which represents the state of the refrigerant at the outlet of the evaporator. In order to accurately obtain these two temperature values, temperature sensors can be installed at the inlet and outlet of the evaporator to monitor the temperature change of the refrigerant in real time.

[0088] After obtaining the heat exchanger inlet pipe temperature and the heat exchanger outlet pipe temperature, the system compares the two temperature values and calculates the temperature difference between them. The size of the temperature difference directly reflects the flow state and refrigerant flow rate of the evaporator. If the temperature difference is too large, it means that the refrigerant flow rate in the evaporator is not appropriate, which not only affects the frosting effect of the evaporator itself, but also affects the frosting effect of other air conditioner indoor units.

[0089] To reduce the temperature difference and improve the frosting effect of the evaporator, the system adjusts the opening degree of the electronic expansion valve of the multi-split air conditioner according to the calculated temperature difference. The electronic expansion valve is a key component for controlling the flow rate of refrigerant. By adjusting its opening degree, the flow rate and flow speed of refrigerant through the air conditioner indoor unit can be changed, thereby improving the refrigerant distribution in the entire multi-split air conditioning system and optimizing the frosting effect of the air conditioner indoor unit. The system automatically adjusts the opening degree of the electronic expansion valve according to the preset algorithm and temperature difference threshold, so that the heat exchanger inlet pipe temperature gradually approaches the heat exchanger outlet pipe temperature. It can be understood that during the refrigeration process, the heat exchanger outlet pipe temperature is higher than the heat exchanger inlet pipe temperature due to heat exchange in the evaporator. By adjusting the opening degree of the electronic expansion valve, the flow rate and flow speed of refrigerant can be changed, so that the difference between the heat exchanger outlet pipe temperature and the heat exchanger inlet pipe temperature gradually approaches 0℃, i.e. the heat exchanger outlet pipe temperature gradually approaches the heat exchanger inlet pipe temperature, thereby ensuring that the temperature at any point in the entire evaporator does not exceed the preset temperature in the above embodiment, i.e. the maximum temperature does not exceed 0℃, and further ensuring the frosting and frosting amount.

[0090] After adjusting the opening degree of the electronic expansion valve, the system continuously monitors the temperature change of the evaporator of each air conditioner indoor unit and makes fine adjustments according to the actual situation. If the temperature difference is still large or the evaporator temperature does not reach the expected value, the system will adjust the opening degree of the electronic expansion valve again until the optimal refrigeration effect and self-cleaning state are achieved. In the optimized refrigeration state, the frosting and defrosting process on the surface of the evaporator is more uniform and efficient, thereby effectively improving the self-cleaning effect. After the self-cleaning process is completed, the system automatically returns to the normal operating mode or standby state, waiting for the next self-cleaning instruction to be triggered.

[0091] Further, in some embodiments of the present application, the step of adjusting the opening degree of the electronic expansion valve of the multi-split air conditioner comprises: Figures 2 to 3

[0092] presetting a second running time for the air conditioner indoor unit to continuously refrigerate;

[0093] obtaining the heat exchanger outlet pipe temperature, and when the heat exchanger outlet pipe temperature is less than or equal to the preset temperature for the second running time, controlling the electronic expansion valve of the air conditioner indoor unit to be closed, so that the air conditioner indoor unit enters the air supply mode.

[0094] ​In the present embodiment, specifically, during the execution of the multi-split air conditioner self-cleaning method, in order to accurately control the refrigeration effect of the evaporator and the progress of the self-cleaning, the system will preset a second running time for the air conditioner indoor unit to continuously refrigerate. This time is set according to the model, refrigeration capacity of the air conditioner indoor unit, and the needs of self-cleaning, aiming to ensure that the evaporator has enough refrigeration time to form a stable frosting state (i.e. the refrigeration frosting time for each air conditioner indoor unit), laying the foundation for the subsequent self-cleaning process. It should be noted that in some embodiments, the second running time can be 10-60 minutes, specifically 25 minutes, which is set based on the model, refrigeration capacity of the air conditioner indoor unit, and the needs of self-cleaning, and its specific value can not be specifically limited, as long as it can ensure the frosting time and amount of the evaporator of the air conditioner indoor unit.

[0095] After the second running time starts, the system will continuously obtain the heat exchanger outlet pipe temperature of each air conditioner indoor unit. The heat exchanger outlet pipe temperature is the temperature of the refrigerant flowing out of the evaporator, which reflects the refrigeration effect and heat exchange state at the outlet of the evaporator. By monitoring the heat exchanger outlet pipe temperature in real time, the system can accurately judge the refrigeration condition of the evaporator, providing a basis for the subsequent electronic expansion valve adjustment. Then, the system will compare the obtained heat exchanger outlet pipe temperature with the preset temperature threshold. The preset temperature is a temperature value set according to the design parameters of the air conditioner indoor unit and the needs of self-cleaning, which represents the ideal temperature state that the evaporator should reach during the self-cleaning process, such as the preset temperature mentioned in the foregoing embodiments. If the heat exchanger outlet pipe temperature is less than or equal to the preset temperature for the second running time, it means that the refrigeration effect of the evaporator has reached or exceeded the level required for self-cleaning.

[0096] When the system determines that the heat exchanger outlet pipe temperature meets the condition, it will control the electronic expansion valve of the air conditioner indoor unit to close. The electronic expansion valve is a key component for controlling the flow of refrigerant, and closing the electronic expansion valve can stop the flow of refrigerant, so that the evaporator stops further refrigeration. The purpose of this step is to reduce the refrigeration load and transfer the cold energy to other indoor units that are still frosting, while preparing for the next self-cleaning phase. After the electronic expansion valve is closed, the air conditioner indoor unit will automatically enter the air supply mode. In the air supply mode, the fan of the air conditioner indoor unit still operates, but no longer performs refrigeration or heating operation, but simply circulates and blows the indoor air, using the low-grade heat in the air for pre-defrosting.

[0097] It should be noted that when the system determines that the heat exchanger outlet pipe temperature of the evaporator of a certain air conditioner indoor unit meets the condition, it will control the electronic expansion valve of that air conditioner indoor unit to close, so that the evaporator stops further refrigeration, and the remaining refrigerant flows to other online air conditioner indoor units, facilitating the frosting of the remaining air conditioner indoor units that have not reached the frosting amount.

[0098] Through the above specific embodiments, the self-cleaning method of the multi-connected air conditioner can ensure that the evaporator reaches an ideal refrigeration state in the self-cleaning process, and ensure the amount of frosting, thereby improving the self-cleaning ability and performance stability of the air conditioning system

[0099] Further, in some embodiments of the present application, with reference to Figures 2 to 3 , the step of adjusting the opening degree of the electronic expansion valve of the multi-connected air conditioner further comprises:

[0100] presetting a third running time for the last air conditioner indoor unit to continuously refrigerate and frost, the third running time being less than the second running time;

[0101] obtaining the heat exchanger outlet pipe temperature of the evaporator of the air conditioner indoor unit, and when the heat exchanger outlet pipe temperature of the air conditioner indoor unit is less than or equal to the preset temperature for the third running time, increasing the opening degree of the electronic expansion valve of the multi-connected air conditioner and reducing the running frequency of the compressor.

[0102] In the present embodiment, the control logic for adjusting the opening degree of the electronic expansion valve is further refined in the above embodiments to achieve a more precise and efficient self-cleaning process.

[0103] First of all, it should be clear that the multi-connected air conditioner system in the present embodiment includes multiple air conditioner indoor units, each equipped with an evaporator, and the system is provided with an air conditioner indoor unit electronic expansion valve and an air conditioner outdoor unit electronic expansion valve and a compressor as key control components. In the above embodiments, the first running time for the air conditioner indoor unit (the compressor runs at an initial frequency) to initially refrigerate and frost and the second running time for deep refrigeration and frosting have been set, and the opening degree of the electronic expansion valve and the running frequency of the compressor have been adjusted according to the temperature feedback of the evaporator.

[0104] A specific third running time is preset in the system control program, which is used to define the duration of the last air conditioner indoor unit (or a specific air conditioner indoor unit that needs special attention) in the continuous refrigeration and frosting stage. Importantly, this third running time is set to be less than the second running time, which, on the premise of ensuring the self-cleaning effect, aims to prevent the compressor from stopping running after all air conditioner indoor units are switched to the air supply mode, so the third running time is set to be less than the second running time, so that the last indoor unit exits the frosting stage before switching to air supply, the compressor reduces the frequency, all online indoor units increase the opening degree of the electronic expansion valve, and directly enters the stage of recovering liquid refrigerant, preparing for the next step of the compressor not stopping and directly switching from refrigeration to heating mode.

[0105] It should be noted that in the embodiment, the third running time is less than the second running time, and in some embodiments, the second running time can be 10-60 minutes, and specifically can be 25 minutes, which is set based on the model of the air conditioner indoor unit, the refrigeration capacity, and the demand for self-cleaning, and the specific value can not be specifically limited, as long as it can ensure the frosting time and the frosting amount of the evaporator of the air conditioner indoor unit. Therefore, the third running time can be any value less than 60 minutes, as long as it is lower than the second running time. For example, if the second running time is 25 minutes, the third running time can be 24 minutes, or 23 minutes and 30 seconds, etc. The third running time is closer to the second running time, which can ensure a longer frosting time, and thus ensure that the frosting of each air conditioner indoor unit does not differ much, and the cleaning effect does not differ much.

[0106] In the refrigeration frosting process of the air conditioner indoor unit, the temperature of the evaporator thereof is monitored in real time by the temperature sensor, which is recorded as the heat exchanger outlet pipe temperature. This step is to obtain real-time temperature data as a basis for subsequent adjustment of the operating parameters of the electronic expansion valve and the compressor. The system continuously monitors and records the heat exchanger outlet pipe temperature to determine whether it remains less than or equal to the preset temperature within the given third running time. The preset temperature here is set in advance according to the design characteristics of the air conditioner indoor unit and the demand for self-cleaning, as mentioned in the foregoing embodiments.

[0107] If the heat exchanger outlet pipe temperature remains less than or equal to the preset temperature within the third running time, it indicates that the current refrigeration frosting effect meets the preset frosting amount requirement. At this time, the system will automatically perform the following adjustment operations: reduce the operating frequency of the compressor; increase the opening degree of the electronic expansion valve of all online air conditioner indoor units to recover excess liquid refrigerant in the air conditioner indoor unit, the connecting pipe, etc., to prevent liquid hammer during the subsequent switching to the heating mode and the four-way valve reversing. Further, after the multi-split air conditioning system reduces the operating frequency of the compressor and increases the opening degree of the electronic expansion valve of all online air conditioner indoor units to recover excess liquid refrigerant in the air conditioner indoor unit, the connecting pipe, etc., it can further perform the heating defrosting program.

[0108] It should also be noted that in the above step of reducing the operating frequency of the compressor, the reduced operating frequency of the compressor can be reduced to a fixed operating frequency, which can be any value between 10 Hz and 30 Hz, and at the same time, it is operated for 0-10 minutes (not including 0 minutes). In this embodiment, the fixed operating frequency of the compressor at this stage is not specifically limited, as long as it meets the reduced operating frequency and the effect of slowing down the refrigerant liquefaction and recovering the liquid refrigerant. It can also be understood that, in order to prevent the four-way valve from being hit by the refrigerant, the opening degree of the electronic expansion valve can also be maximized to quickly recover the liquid refrigerant in the air conditioner indoor unit and the connecting pipe, so the opening degree of the electronic expansion valve can also not be specifically limited.

[0109] After adjustment, the system continues to monitor the temperature of the evaporator and the overall operating state of the system, and fine-tune as necessary to ensure that the self-cleaning process proceeds smoothly and does not cause damage to the equipment. Through the above implementation, the multi-split air conditioning system can more finely control the frosting process of each air conditioner indoor unit during self-cleaning, ensuring the effectiveness of self-cleaning and preventing liquid refrigerant from affecting the four-way valve during the subsequent reversing, thereby improving the stability and service life of the system.

[0110] Referring to Figure 2 and Figure 4 In some embodiments of the present application, the step of the air conditioner indoor unit performing heating according to the heating instruction comprises:

[0111] presetting a fourth running time of the compressor of the air conditioner outdoor unit;

[0112] in response to the heating instruction, controlling the fan of the air conditioner indoor unit to stop running, controlling the reversing valve of the multi-split air conditioner to reverse, and controlling the compressor to increase the running frequency and continue running for the fourth running time, so that the air conditioner indoor unit performs defrosting.

[0113] In the step in the present embodiment, specifically, before implementing the method, first, the fourth running time of the compressor in the air conditioner outdoor unit needs to be preset. The fourth running time is the defrosting time of the present embodiment, which is determined based on the specific configuration of the air conditioning system, the environmental temperature, humidity, and historical operation data, etc. factors, aiming to ensure that the defrosting process is both efficient and safe. For example, the fourth running time can be set to a value between 0 min and 10 min according to experimental data or empirical values, which can be adjusted according to actual conditions, aiming to completely melt the frost on the surface of the evaporator in the air conditioner indoor unit.

[0114] controlling the air conditioner indoor unit fan to stop running: when the system receives a heating instruction and determines that defrosting is needed, the fan of the air conditioner indoor unit is first controlled to stop running. Then, the control system will instruct the reversing valve to perform reversing operation, so that the original circulating path for refrigeration is changed to heating mode. This conversion is the key to defrosting, as it allows the system to use the heat of the outdoor unit to melt the ice and frost on the indoor unit. After the reversing is completed, the control system will control the compressor to increase the running frequency to a defrosting running frequency to achieve the defrosting effect. The compressor will continue to run at the defrosting frequency for the preset fourth running time, ensuring that the ice and frost on the indoor unit can be fully melted. During this period, the system may monitor the defrosting progress in real time through the temperature sensor to adjust the running parameters if necessary.

[0115] It should be noted that in the defrosting phase, the compressor is frequency-raised to a defrosting operation frequency, which can be in the range of 10-70 Hz, can be a fixed value, or can be a variable value determined by the ambient temperature and the outdoor unit capacity. Specifically, the defrosting operation frequency can be set to 30 Hz, which is not limited in the present embodiment.

[0116] Further, with reference to Figure 2 and Figure 4 In some embodiments of the present application, the step of continuously heating the indoor unit according to the heating instruction includes:

[0117] The first saturation temperature and the second saturation temperature of the refrigerant of the multi-split air conditioner are preset, and the first saturation temperature and the second saturation temperature are the condensation temperature of the refrigerant liquefaction, and the first saturation temperature is less than the second saturation temperature;

[0118] The sterilization operation frequency of the compressor is determined according to the target sterilization temperature;

[0119] The sterilization operation frequency of the compressor is adjusted according to the target sterilization temperature, so that the heat exchanger inlet temperature is equal to or greater than the target sterilization temperature, and the target sterilization temperature is greater than the first saturation temperature and less than the second saturation temperature.

[0120] In the present embodiment, the specific implementation steps of the indoor unit of the air conditioner during continuous heating are described in detail, aiming to achieve efficient sterilization and self-cleaning function through precise control. The specific implementation steps are as follows:

[0121] Determine the saturation temperature: first, according to the type of refrigerant used in the multi-split air conditioner system, the first saturation temperature and the second saturation temperature are preset. These two temperatures are the condensation temperature of the refrigerant liquefaction, and the first saturation temperature is lower than the second saturation temperature. At the same time, in order to ensure a higher sterilization temperature, the first saturation temperature and the second saturation temperature are both between 45℃ and 80℃, for example, for commonly used R410A refrigerant, the first saturation temperature can be set to 58℃ (or adjusted according to the specific refrigerant characteristics), and the second saturation temperature is 60℃. Under the premise of ensuring system reliability, the first saturation temperature and the second saturation temperature can be as large as possible to ensure the effect of high-temperature sterilization. The setting of the first saturation temperature and the second saturation temperature is to ensure that the refrigerant can work in the appropriate temperature range during sterilization, neither too low to affect the sterilization effect, nor too high to damage the air conditioner system or affect the service life.

[0122] Setting the target sterilization temperature: According to the design of the air conditioning system and the sterilization requirement, a target sterilization temperature is preset. This temperature should be higher than the first saturation temperature and lower than the second saturation temperature, to ensure that the system can run stably and not cause excessive liquefaction or vaporization of the refrigerant while sterilizing. For example, the target sterilization temperature can be set to 58℃.

[0123] Calculating the sterilization operation frequency: Based on the target sterilization temperature, the sterilization operation frequency of the compressor is determined through the control algorithm of the air conditioning system or experimental data. This frequency should be able to make the evaporator temperature of the air conditioning system reach or exceed the target sterilization temperature, so as to effectively kill bacteria. During the process of the air conditioner indoor unit continuously heating according to the heating instruction, the system should monitor the temperature of the evaporator and the running state of the compressor in real time.

[0124] Adjusting the compressor operation frequency: According to the real-time monitoring data, the running frequency of the compressor is dynamically adjusted to ensure that the temperature of the first evaporator is always equal to or greater than the target sterilization temperature. This step is the key to the sterilization process, and through precise control of the compressor frequency, fine adjustment of the evaporator temperature can be achieved, thereby achieving the best sterilization effect.

[0125] In summary, through the specific embodiments described above, the high-efficiency and safe multi-split air conditioner self-cleaning method provided by the embodiments of the present application can achieve effective sterilization effect while continuously heating, thereby improving the overall performance of the air conditioning system and user experience.

[0126] Reference Figure 2 , and Figure 4 , further, in some embodiments of the present application, the step of continuously heating the air conditioner indoor unit according to the heating instruction further comprises:

[0127] presetting a fifth running time of the air conditioner indoor unit continuously heating, presetting a sixth running time of the fan of the air conditioner indoor unit running, and presetting a second running speed of the fan of the air conditioner indoor unit running;

[0128] obtaining the heat exchanger inlet temperature, when the heat exchanger inlet temperature is greater than or equal to the target sterilization temperature for the fifth running time, controlling the fan of the air conditioner indoor unit to run at the second running speed;

[0129] after the fan of the air conditioner indoor unit runs at the second running speed for the sixth running time, the multi-split air conditioner exits the self-cleaning program.

[0130] This embodiment further refines the specific control steps of the air conditioner indoor unit during continuous heating, especially the setting of the fan running time and speed. The specific implementation steps are as follows:

[0131] First, preset the fifth running time and the sixth running time: before the air conditioner indoor unit starts continuous heating according to the heating instruction, first preset a fifth running time. This time refers to the minimum time for which the heat exchanger inlet pipe temperature needs to continuously reach or exceed the target sterilization temperature to ensure the sterilization effect. For example, the fifth running time can be set to 25 to 60 min, but the minimum time can be as large as possible, such as the fifth running time being 30 min. At the same time, the sixth running time of the air conditioner indoor unit fan is preset. This time refers to the time for which the fan needs to continuously run at the second running speed after the high-temperature sterilization reaches the fifth running time, in order to ensure that the sterilization effect is consolidated and the air inside the air conditioner is fully exchanged. For example, the sixth running time can be set to 0 to 10 min, and specifically the sixth running time is 3 min.

[0132] Then, preset the second running speed: preset the second running speed of the air conditioner indoor unit fan. This speed should be higher than the speed in the normal heating or cooling mode, and should also be at a lower speed, for example, the second running speed can be set to 0 to 2000 r / min, a lower speed to promote air circulation and exchange inside the air conditioner while reducing the impact on the user.

[0133] Obtain the heat exchanger inlet pipe temperature: during the continuous heating of the air conditioner indoor unit, the system should obtain the temperature data of the first evaporator in real time. The system determines whether the heat exchanger inlet pipe temperature continuously reaches or exceeds the target sterilization temperature and whether the duration reaches the preset fifth running time. If these conditions are met, it means that the sterilization effect has reached the expected value. When the heat exchanger inlet pipe temperature continuously reaches or exceeds the target sterilization temperature and the duration reaches the fifth running time, the system controls the fan of the air conditioner indoor unit to start running at the second running speed, promoting air circulation and exchange inside the air conditioner. At the same time, the system should monitor the running time of the fan at the second running speed in real time to ensure that it reaches the preset sixth running time. When the fan runs at the second running speed for the sixth running time, the system determines that the self-cleaning program has been completed.

[0134] Exit the self-cleaning program: the system controls the multi-split air conditioner to exit the self-cleaning program and restore the normal heating operation mode, cooling operation mode or shut down. At the same time, the system may also need to perform a series of subsequent operations, such as self-checking, cleaning, etc., to ensure the normal operation of the air conditioning system and preparation for the next use.

[0135] In summary, the more refined multi-split air conditioner self-cleaning method provided by the present application can ensure the sterilization effect while ensuring the stable operation of the air conditioning system and the user experience by presetting and controlling the time, fan running time and speed of the air conditioner indoor unit continuous heating, etc.

[0136] The multi-split air conditioning system (not shown in the figure) according to the second aspect embodiment of the present application comprises the indoor unit of any one of the above first aspect embodiments and the outdoor unit, and further comprises a running control device.

[0137] The second aspect embodiment of the present application further provides a multi-split air conditioning system, which comprises the indoor unit and the outdoor unit of any one of the above first aspect embodiments, and further comprises a running control device.

[0138] Specifically, the indoor unit is responsible for the regulation of indoor air, and has the functions of heating, cooling, dehumidifying, etc., and integrates the self-cleaning functional components and sensors in the above first aspect embodiments. The outdoor unit is usually installed outdoors, and is responsible for providing cold and heat sources for the indoor unit, and is connected to the indoor unit through refrigerant circulation. The running control device mainly comprises a memory, a processor, and a computer program stored in the memory and executable on the processor. The running control device serves as the command center of the entire multi-split air conditioning system, and is responsible for receiving user instructions, monitoring system status, and executing control logic. In the running control device, the memory is used to store the computer program, system configuration information, historical data, etc. It should be noted that the storage space provided by the memory should be large enough to accommodate all necessary programs and data. The processor, as the core of the running control device, is responsible for executing the computer program stored in the memory. The processor should have sufficient computing power and response speed to ensure efficient operation of the system. Furthermore, the computer program is a collection of instructions for guiding the processor to execute the multi-split air conditioning self-cleaning method. Therefore, the program should include all steps and logic of the self-cleaning method in any one of the above first aspect embodiments.

[0139] When the processor executes the computer program stored in the memory, the self-cleaning method in any one of the above first aspect embodiments will be implemented. The specific steps include:

[0140] Receiving user instructions: the running control device receives the self-cleaning instructions issued by the user through a user interface or other input devices.

[0141] System detection: the processor controls the indoor unit and the outdoor unit to perform necessary system detection to ensure the safe operation of the self-cleaning process.

[0142] Self-cleaning process execution: According to the preset logic and parameters, the processor controls the air conditioner indoor unit to perform heating, cooling, dehumidification and other operations to achieve the self-cleaning effect. At the same time, the processor is also responsible for monitoring the running state of the air conditioner indoor unit and the air conditioner outdoor unit to ensure the smooth progress of the self-cleaning process.

[0143] Process end and feedback: When the self-cleaning process is completed, the processor controls the air conditioning system to return to the normal running state, and provides feedback to the user through the user interface or other output devices. The feedback content may include the success or failure of the self-cleaning process, the current state of the system, etc.

[0144] Therefore, it can also be understood that the multi-split air conditioning system according to the embodiments of the present application at least has the following beneficial effects: the running control device of the multi-split air conditioning system can implement the self-cleaning method of the multi-split air conditioner of any one of the first aspect when executing the computer program on its memory, thereby increasing the frost amount of the evaporator of the air conditioner indoor unit of the multi-split air conditioner, and further increasing the defrosting water to improve the cleaning effect of the air conditioner indoor unit.

[0145] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge range of ordinary skilled in the art without departing from the purpose of the present application.

Claims

1. A method of self-cleaning of a multi VRF air conditioner, the multi VRF air conditioner comprising an air conditioner outdoor unit and a plurality of air conditioner indoor units, the method comprising: determining whether a self-cleaning operation is required; and performing the self-cleaning operation when the self-cleaning operation is required. The multi-split air conditioner self-cleaning method comprises the following steps: The air conditioner indoor unit obtains the refrigeration instruction of the air conditioner outdoor unit, and performs refrigeration according to the refrigeration instruction, so that the air conditioner indoor unit is frosted; When the air conditioner indoor unit performs refrigeration, the heat exchanger outlet pipe temperature of each air conditioner indoor unit is obtained, the highest temperature value in the multiple heat exchanger outlet pipe temperatures corresponding to the multiple air conditioner indoor units is taken as a first target temperature, the operating frequency of the compressor of the air conditioner outdoor unit is adjusted, and the operating rotating speed of the fan of each air conditioner indoor unit is adjusted, so that the air conditioner indoor unit is continuously frosted; The air conditioner indoor unit obtains the heating instruction of the air conditioner outdoor unit, and performs heating according to the heating instruction, so that the air conditioner indoor unit is defrosted; When the air conditioner indoor unit is defrosted, the air conditioner indoor unit continuously performs heating according to the heating instruction, so that the temperature of the air conditioner indoor unit reaches a target sterilization temperature; The step of adjusting the operating frequency of the compressor of the air conditioner outdoor unit further comprises: the compressor operates at an initial frequency for a first operating time; a first target frequency of the compressor is determined according to the first target temperature; the initial frequency of the compressor is adjusted to the first target frequency, so that the upper limit of the first target temperature is less than a preset temperature, and the preset temperature is less than 0℃; The multi-split air conditioner self-cleaning method further comprises the following steps: when the air conditioner indoor unit performs refrigeration, the heat exchanger inlet pipe temperature of each air conditioner indoor unit is obtained; and the opening degree of the electronic expansion valve of the multi-split air conditioner is adjusted, so that the heat exchanger outlet pipe temperature is equal to the heat exchanger inlet pipe temperature; The step of adjusting the opening degree of the electronic expansion valve of the multi-split air conditioner comprises: a second operating time for which the air conditioner indoor unit continuously performs refrigeration is preset; when the heat exchanger outlet pipe temperature is less than or equal to the preset temperature for the second operating time, the electronic expansion valve of the air conditioner indoor unit is controlled to be closed, so that the air conditioner indoor unit enters an air supply mode.

2. The multi-split air conditioner self-cleaning method of claim 1, wherein, The step of adjusting the operating rotating speed of the fan of each air conditioner indoor unit comprises: A first operating rotating speed of the fan of the air conditioner indoor unit is preset; When the air conditioner indoor unit performs refrigeration, the operating rotating speed of each fan is obtained; The operating rotating speed of the fan is adjusted to the first operating rotating speed, so that the operating rotating speed of the fan is adjusted to the first operating rotating speed. 3.The multi-split air conditioner self-cleaning method of claim 1, wherein, The step of adjusting the opening degree of the electronic expansion valve of the multi-split air conditioner further comprises: A third operating time for which the last air conditioner indoor unit continuously performs refrigeration is preset, and the third operating time is less than the second operating time; The heat exchanger outlet pipe temperature of the air conditioner indoor unit is obtained, and when the heat exchanger outlet pipe temperature of the air conditioner indoor unit is less than or equal to the preset temperature for the third operating time, the opening degree of the electronic expansion valve is increased and the operating frequency of the compressor is reduced.

4. The self-cleaning method of a multi-split air conditioner according to any one of claims 1 to 3, characterized in that, The step of performing heating according to the heating instruction by the air conditioner indoor unit comprises: A fourth operating time of the compressor of the air conditioner outdoor unit is preset; In response to the heating instruction, the fan of the air conditioner indoor unit is controlled to stop running, the reversing valve of the multi-split air conditioner is controlled to reverse, and the compressor is controlled to increase the running frequency and continuously run for the fourth running time, so that the air conditioner indoor unit defrosts.

5. The multi-split air conditioner self-cleaning method according to any one of claims 1 to 3, characterized in that, The step after the defrosting of the air conditioner indoor unit is completed comprises: The first saturation temperature and the second saturation temperature of the refrigerant of the multi-split air conditioner are preset, the first saturation temperature and the second saturation temperature are the condensation temperature of the refrigerant liquefaction, and the first saturation temperature is less than the second saturation temperature; The sterilization running frequency of the compressor is determined according to the target sterilization temperature; The sterilization running frequency of the compressor is adjusted according to the target sterilization temperature, so that the heat exchanger inlet temperature is equal to or greater than the target sterilization temperature, and the target sterilization temperature is greater than the first saturation temperature and less than the second saturation temperature. 6.The multi-split air conditioner self-cleaning method of claim 5, wherein, The step after the defrosting of the air conditioner indoor unit is completed further comprises: The fifth running time of the air conditioner indoor unit continuously heating is preset, the sixth running time of the fan of the air conditioner indoor unit running is preset, and the second running speed of the fan of the air conditioner indoor unit running is preset; The heat exchanger inlet temperature is obtained, and when the heat exchanger inlet temperature is greater than or equal to the target sterilization temperature for the fifth running time, the fan of the air conditioner indoor unit is controlled to run at the second running speed; After the fan of the air conditioner indoor unit runs at the second running speed for the sixth running time, the multi-split air conditioner exits the self-cleaning program.

7. A multi-split air conditioning system, characterized in that, The multi-split air conditioner system comprises an air conditioner indoor unit and an air conditioner outdoor unit, and further comprises a running control device, the running control device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the multi-split air conditioner self-cleaning method according to any one of claims 1 to 6 when executing the computer program.

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