Multi-split air conditioner and cleaning method, control device and readable storage medium thereof

Abstract

The present invention discloses a cleaning method for a multi-split air conditioner, the method comprising: controlling the multi-split air conditioner to operate in a cooling manner so as to frost a target indoor unit; the target indoor unit is an indoor unit that receives a cleaning instruction among at least two of the indoor units; controlling the multi-split air conditioner to operate in a heating manner so as to defrost the target indoor unit; when defrosting of the target indoor unit is completed, controlling the multi-split air conditioner to maintain a heating operation and adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches a target sterilization temperature. The present invention also discloses an air conditioning control device, a multi-split air conditioner, and a computer-readable storage medium. The present invention aims to achieve high-temperature sterilization of the indoor unit after cleaning, improve the cleaning effect, and ensure that the air after heat exchange in the indoor unit can ensure the health of indoor users.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and in particular to a cleaning method for a multi-split air conditioner, an air conditioner control device, a multi-split air conditioner and a computer-readable storage medium. Background Art

[0002] A multi-split air conditioner refers to an air conditioner with multiple indoor units. Most multi-split air conditioners have a self-cleaning function, which generally includes two stages: refrigeration frosting and heating defrosting. The dirt in the indoor unit is condensed through refrigeration frosting, and then the frost with condensed dirt is melted through heating defrosting, so that the dirt flows away with the defrost water, thereby cleaning the indoor unit.

[0003] However, currently multi-split air conditioners are not sterilized after cleaning, and bacteria are easily left in the indoor unit. The air that has undergone heat exchange in the indoor unit carries the bacteria, resulting in poor cleaning effects and affecting the health of indoor users. Summary of the invention

[0004] The main purpose of the present invention is to provide a cleaning method for a multi-split air conditioner, aiming to achieve high-temperature sterilization of the indoor unit after cleaning, improve the cleaning effect, and ensure that the air after heat exchange in the indoor unit can ensure the health of indoor users.

[0005] To achieve the above object, the present invention provides a method for cleaning a multi-split air conditioner, wherein the multi-split air conditioner includes at least two indoor units, and the method for cleaning the multi-split air conditioner includes the following steps:

[0006] Controlling the multi-split air conditioner to operate in a cooling mode so as to cause frost to form on a target indoor unit; the target indoor unit is an indoor unit that receives a cleaning instruction among at least two of the indoor units;

[0007] Controlling the heating operation of the multi-split air conditioner to defrost the target indoor unit;

[0008] When defrosting of the target indoor unit is completed, the multi-split air conditioner is controlled to maintain heating operation, and the operating frequency of the compressor is adjusted so that the temperature of the target indoor unit reaches the target sterilization temperature.

[0009] Optionally, the step of adjusting the operating frequency of the compressor includes:

[0010] Obtaining the temperature of the first heat exchanger corresponding to the turned-on indoor unit;

[0011] determining a first frequency adjustment parameter of the compressor according to the first heat exchanger temperature and the target sterilization temperature;

[0012] The compressor is controlled to adjust the operating frequency according to the first frequency adjustment parameter.

[0013] Optionally, the first frequency adjustment parameter includes a first adjustment direction, and the step of determining the first frequency adjustment parameter of the compressor according to the first heat exchanger temperature and the target sterilization temperature includes:

[0014] Determining a first magnitude relationship between the first heat exchanger temperature and the target sterilization temperature;

[0015] When the first magnitude relationship is that the first heat exchanger temperature is greater than the target sterilization temperature, determining that the first adjustment direction is to reduce the frequency;

[0016] When the first magnitude relationship is that the first heat exchanger temperature is lower than the target sterilization temperature, the first adjustment direction is determined to be increasing the frequency.

[0017] Optionally, before the step of determining a first magnitude relationship between the first heat exchanger temperature and the target sterilization temperature, the step further includes:

[0018] determining a first temperature deviation between the first heat exchanger temperature and the target sterilization temperature;

[0019] When the first temperature deviation is greater than or equal to a first preset threshold, the step of determining a first magnitude relationship between the first heat exchanger temperature and the target sterilization temperature is performed.

[0020] Optionally, the first frequency adjustment parameter further includes a first adjustment rate, and in the process of determining the first adjustment direction according to the first heat exchanger temperature and the target sterilization temperature, the process further includes:

[0021] determining the first adjustment rate according to a first temperature deviation between the first heat exchanger temperature and the target sterilization temperature;

[0022] The first adjustment rate tends to increase as the first temperature deviation increases.

[0023] Optionally, the step of determining the first adjustment rate according to a first temperature deviation between the first heat exchanger temperature and the target sterilization temperature includes:

[0024] When the first adjustment direction is to increase the frequency, determining the first adjustment rate according to the first temperature deviation within a first rate range;

[0025] When the first adjustment direction is to reduce the frequency, determining the first adjustment rate according to the first temperature deviation within a second rate range;

[0026] The rate in the first rate range is greater than the rate in the second rate range.

[0027] Optionally, the number of turned-on indoor units is more than one, and the step of obtaining the first heat exchanger temperature corresponding to the turned-on indoor units includes:

[0028] detecting the temperature of the first coil of each turned-on indoor unit;

[0029] The first heat exchanger temperature is determined based on more than one of the first coil temperatures.

[0030] Optionally, the step of determining the first heat exchanger temperature based on more than one first coil temperature comprises:

[0031] Obtain the first rated cooling capacity of each turned-on indoor unit;

[0032] Determine a first weight value corresponding to each turned-on indoor unit according to the acquired first rated cooling capacity;

[0033] A weighted average calculation operation is performed on more than one first coil temperature according to the first weight value to obtain the first heat exchanger temperature.

[0034] Optionally, before the step of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature, the step further includes:

[0035] Get the outdoor ambient temperature;

[0036] The target sterilization temperature is obtained according to the outdoor ambient temperature.

[0037] Optionally, the target sterilization temperature tends to decrease as the outdoor ambient temperature decreases.

[0038] Optionally, before the step of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature, the step further includes:

[0039] When defrosting of the target indoor unit is completed, the fans of the turned-on indoor units among the at least two indoor units are controlled to operate at a rotation speed lower than the first set rotation speed.

[0040] Optionally, when defrosting of the target indoor unit is completed, the process of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature further includes:

[0041] When the multi-split air conditioner meets the first sterilization end condition or the second sterilization end condition, the compressor is controlled to stop, and the fan corresponding to the indoor unit is controlled to run at a speed greater than the second set speed;

[0042] When the multi-split air conditioner does not meet the first sterilization end condition and the second sterilization end condition, maintaining the step of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature;

[0043] Among them, the first sterilization termination condition is that the duration of the heating operation of the multi-split air conditioner is greater than or equal to the target sterilization duration, and the second sterilization termination condition is that the temperature of the indoor unit is greater than or equal to the preset temperature and maintained for a preset time, the preset time is less than the target sterilization duration, and the preset temperature is greater than the target sterilization temperature.

[0044] Optionally, when defrosting of the target indoor unit is completed, the process of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature further includes:

[0045] Obtaining operating status parameters of the multi-split air conditioner;

[0046] If the operating state parameter is that the multi-split air conditioner does not have an outdoor unit defrosting operation and a compressor oil return operation after the target indoor unit defrosting is completed, then the first duration is obtained as the target sterilization duration;

[0047] If the operating state parameter is that the multi-split air conditioner has an outdoor unit defrosting operation or a compressor oil return operation after the target indoor unit defrosting is completed, then the second duration is obtained as the target sterilization duration;

[0048] The second duration is greater than the first duration.

[0049] Optionally, the refrigeration and frosting process of the multi-split air conditioner includes a first refrigeration stage and a second refrigeration stage in sequence, and the step of controlling the refrigeration operation of the multi-split air conditioner to frost the target indoor unit includes:

[0050] In the first cooling stage, controlling the cooling operation of the multi-split air conditioner according to the first parameter to cause condensation in the target indoor unit;

[0051] In the second cooling stage, the cooling operation of the multi-split air conditioner is controlled according to the second parameter so that the condensation on the target indoor unit condenses into frost.

[0052] Optionally, the first parameter includes a target frequency of the compressor, and the step of controlling the cooling operation of the multi-split air conditioner according to the first parameter in the first cooling stage so as to cause condensation in the target indoor unit includes:

[0053] In the first cooling stage, obtaining a second rated cooling capacity of the target indoor unit and obtaining a third rated cooling capacity of the compressor;

[0054] determining a frequency correction parameter according to a numerical relationship between the second rated cooling capacity and the third rated cooling capacity;

[0055] Determining the target frequency according to the set maximum frequency of the multi-split air conditioner cooling operation and the frequency correction parameter;

[0056] The compressor is controlled to perform cooling operation at the target frequency.

[0057] Optionally, before the step of controlling the compressor to operate at the target frequency, the method further comprises:

[0058] Comparing the target frequency with a set minimum frequency for cooling operation of the multi-split air conditioner;

[0059] If the target frequency is less than or equal to the set minimum frequency, controlling the compressor to operate at the set minimum frequency to cause condensation in the target indoor unit;

[0060] If the target frequency is greater than the set minimum frequency, the step of controlling the compressor to perform cooling operation at the target frequency is performed.

[0061] Optionally, the second parameter includes a second frequency adjustment parameter of the compressor, and the step of controlling the cooling operation of the multi-split air conditioner according to the second parameter in the second cooling stage so that the condensation on the target indoor unit condenses into frost includes:

[0062] In the second cooling stage, obtaining the second heat exchanger temperature corresponding to the turned-on indoor unit;

[0063] determining a second frequency adjustment parameter of the compressor according to the second heat exchanger temperature and a target evaporation temperature;

[0064] The compressor is controlled to adjust the refrigeration frequency according to the second frequency adjustment parameter.

[0065] Optionally, the step of determining the second frequency adjustment parameter of the compressor according to the second heat exchanger temperature and the target evaporation temperature includes:

[0066] determining a second magnitude relationship between the second heat exchanger temperature and the target evaporation temperature, and determining a second temperature deviation between the second heat exchanger temperature and the target evaporation temperature;

[0067] Determine a second adjustment direction of the compressor frequency according to the second magnitude relationship, and determine a second adjustment rate of the compressor frequency according to the second temperature deviation;

[0068] The second adjustment direction and the second adjustment rate are determined as the second frequency adjustment parameters.

[0069] Optionally, the second adjustment rate tends to increase as the second temperature deviation increases.

[0070] Optionally, the step of determining a second adjustment direction of the compressor frequency according to the second magnitude relationship includes:

[0071] When the second magnitude relationship is that the second heat exchanger temperature is greater than the target evaporation temperature, determining that the second adjustment direction is to increase the frequency;

[0072] When the second magnitude relationship is that the second heat exchanger temperature is lower than the target evaporation temperature, the second adjustment direction is determined to be reducing the frequency.

[0073] Optionally, before the step of determining the second adjustment direction of the compressor frequency according to the second magnitude relationship and determining the second adjustment rate of the compressor frequency according to the second temperature deviation, the step further includes:

[0074] Comparing the second temperature deviation with a second preset threshold;

[0075] If the comparison result is that the second temperature deviation is greater than or equal to the second preset threshold, the steps of determining the second adjustment direction of the compressor frequency according to the second size relationship and determining the second adjustment rate of the compressor frequency according to the second temperature deviation are executed.

[0076] Optionally, the number of turned-on indoor units is more than one, and the step of obtaining the temperature of the second heat exchanger corresponding to the turned-on indoor units includes:

[0077] Detecting the second coil temperature of each turned-on indoor unit to obtain the fourth rated cooling capacity of each turned-on indoor unit;

[0078] Determining a second weight value corresponding to each turned-on indoor unit according to the acquired fourth rated cooling capacity;

[0079] A weighted average calculation operation is performed on more than one second coil temperature according to the second weight value to obtain the second heat exchanger temperature.

[0080] Optionally, the cleaning method of the multi-split air conditioner further comprises:

[0081] In the first cooling stage, if the multi-split air conditioner reaches the condensation completion condition, the multi-split air conditioner is controlled to enter the second cooling stage;

[0082] Among them, the condensation completion condition includes that the multi-split air conditioner operates with the first parameter for a time period greater than or equal to a first set time period or the coil temperature of the target indoor unit is less than or equal to a first set temperature.

[0083] Optionally, in the first cooling stage, the fan corresponding to the turned-on indoor unit is controlled to run at a speed less than a third set speed; and / or,

[0084] Before the step of controlling the cooling operation of the multi-split air conditioner according to the second parameter, the method further includes:

[0085] When entering the second cooling stage, controlling the fan corresponding to the turned-on indoor unit to stop running for a second set time;

[0086] Controlling the fan corresponding to the turned-on indoor unit to run at a speed lower than a fourth set speed for a third set time period;

[0087] Execute the step of controlling the cooling operation of the multi-split air conditioner according to the second parameter.

[0088] Optionally, the step of controlling the heating operation of the multi-split air conditioner to defrost the target indoor unit includes:

[0089] In the heating state of the multi-split air conditioner, obtaining the temperature of the third heat exchanger corresponding to the turned-on indoor unit;

[0090] determining a third frequency adjustment parameter of the compressor according to the third heat exchanger temperature and a target defrosting temperature; the target defrosting temperature is less than or equal to the target sterilization temperature;

[0091] The compressor is controlled to adjust the heating frequency according to the third frequency adjustment parameter.

[0092] Optionally, the step of determining the third frequency adjustment parameter of the compressor according to the third heat exchanger temperature and the target defrost temperature includes:

[0093] determining a third magnitude relationship between the third heat exchanger temperature and the target defrost temperature, and determining a third temperature deviation between the third heat exchanger temperature and the target defrost temperature;

[0094] determining a third adjustment direction of the compressor frequency according to the third magnitude relationship, and determining a third adjustment rate of the compressor frequency according to the third temperature deviation;

[0095] The third adjustment direction and the third adjustment rate are determined as the third frequency adjustment parameter.

[0096] Optionally, the third adjustment rate increases with the increase of the third temperature deviation; and / or,

[0097] The step of determining the third adjustment direction of the compressor frequency according to the third magnitude relationship comprises:

[0098] When the third magnitude relationship is that the third heat exchanger temperature is greater than the target defrosting temperature, determining that the third adjustment direction is to reduce the frequency;

[0099] When the third magnitude relationship is that the third heat exchanger temperature is less than the target defrosting temperature, the third adjustment direction is determined to be increasing the frequency.

[0100] Optionally, before the step of controlling the compressor to adjust the heating frequency according to the third frequency adjustment parameter, the method further includes:

[0101] When the multi-split air conditioner starts heating operation, the compressor and the fans corresponding to the indoor units are controlled to stop;

[0102] When the compressor and the fans corresponding to the indoor unit are stopped for a fourth set time, the step of controlling the compressor to adjust the heating frequency according to the third frequency adjustment parameter is performed.

[0103] In addition, in order to achieve the above-mentioned purpose, the present application also proposes an air-conditioning control device, which includes: a memory, a processor, and a cleaning program for a multi-split air conditioner stored on the memory and executable on the processor. When the cleaning program for the multi-split air conditioner is executed by the processor, the steps of the cleaning method for the multi-split air conditioner as described in any one of the above items are implemented.

[0104] In addition, in order to achieve the above-mentioned purpose, the present application also proposes a multi-split air conditioner, which comprises:

[0105] At least two indoor units; and

[0106] The air conditioning control device as described above is connected to the indoor unit.

[0107] In addition, in order to achieve the above-mentioned purpose, the present application also proposes a computer-readable storage medium, on which a cleaning program for a multi-split air conditioner is stored. When the cleaning program for the multi-split air conditioner is executed by a processor, the steps of the cleaning method for the multi-split air conditioner as described in any of the above items are implemented.

[0108] The present invention proposes a cleaning method for a multi-split air conditioner. After cleaning a target indoor unit that receives a cleaning instruction in a multi-split air conditioner with refrigeration frosting and heating defrosting, the method maintains heating operation through the air conditioner and adjusts the frequency of the compressor to make the coil temperature of the target indoor unit reach a target sterilization temperature. After the indoor unit is cleaned, a sufficiently high temperature is used to sterilize the indoor unit, which can ensure that the air after heat exchange through the target indoor unit after cleaning will not carry bacteria, thereby improving the cleaning effect of the indoor unit and ensuring the health of indoor users. BRIEF DESCRIPTION OF THE DRAWINGS

[0109] Figure 1 A schematic diagram of the hardware structure involved in the operation of an embodiment of an air conditioning control device of the present invention;

[0110] Figure 2 A schematic diagram of a flow chart of an embodiment of a method for cleaning a multi-split air conditioner according to the present invention;

[0111] Figure 3 A schematic diagram of another embodiment of a cleaning method for a multi-split air conditioner according to the present invention;

[0112] Figure 4 A schematic flow chart of another embodiment of a method for cleaning a multi-split air conditioner according to the present invention;

[0113] Figure 5 A schematic flow chart of another embodiment of a cleaning method for a multi-split air conditioner of the present invention;

[0114] Figure 6 The figure is a flow chart of another embodiment of the cleaning method of a multi-split air conditioner of the present invention.

[0115] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0116] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0117] The main solution of the embodiment of the present invention is: controlling the multi-split air conditioner to operate in cooling mode so as to frost the target indoor unit; the target indoor unit is the indoor unit that receives the cleaning instruction among at least two of the indoor units; controlling the multi-split air conditioner to operate in heating mode so as to defrost the target indoor unit; when the defrosting of the target indoor unit is completed, controlling the multi-split air conditioner to maintain heating mode and adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature.

[0118] In the prior art, multi-split air conditioners are not sterilized after cleaning, and bacteria are easily left in the indoor unit. The air that has undergone heat exchange in the indoor unit carries the bacteria, resulting in poor cleaning effects and affecting the health of indoor users.

[0119] The present invention provides the above-mentioned solution, aiming to achieve high-temperature sterilization of the indoor unit after cleaning, thereby improving the cleaning effect and ensuring that the air after heat exchange in the indoor unit can ensure the health of indoor users.

[0120] The embodiment of the present invention provides a multi-split air conditioner.

[0121] In this embodiment, the multi-split air conditioner includes at least two indoor units 2 and one outdoor unit, and the outdoor unit is connected to the at least two indoor units 2. The outdoor unit is provided with a compressor 1 and an outdoor heat exchanger connected to each indoor unit 2. At least two indoor units 2 are distributed in different indoor spaces. Specifically, each indoor unit 2 includes an indoor heat exchanger and an indoor fan arranged corresponding to the indoor heat exchanger. Each indoor unit 2 also has an electronic expansion valve arranged one-to-one with it, and each electronic expansion valve is arranged between its corresponding indoor heat exchanger and the compressor 1 to adjust the flow rate of the refrigerant flowing into the indoor heat exchanger for heat exchange. It should be noted that the operation of each indoor unit 2 in the multi-split air conditioner can be independently regulated according to the user needs in the indoor space where it is located. For example, the indoor unit 2 of at least two indoor units 2 can be partially turned on and partially turned off; for example, at least two indoor units 2 can partially turn on the self-cleaning function, partially turn off the self-cleaning function, and so on.

[0122] The multi-split air conditioner may further include a reversing valve 3, which may be arranged in a connecting pipe between the indoor unit 2 and the outdoor unit to enable the multi-split air conditioner to switch between different operating states in cooling operation and heating operation.

[0123] Furthermore, the multi-split air conditioner may also include a temperature sensor 4 for detecting relevant temperature data during the operation of the multi-split air conditioner. The number of temperature sensors 4 may be set to one or more according to actual needs. The temperature sensor 4 may be set in each indoor unit 2 (such as the coil of the indoor heat exchanger) to detect the coil temperature corresponding to the indoor unit 2. The temperature sensor 4 may also be set at the return air outlet of each indoor unit 2 to detect the indoor ambient temperature of the indoor space where the indoor unit 2 is located. The temperature sensor 4 may also be set in the housing of the outdoor unit to detect the outdoor ambient temperature, and so on.

[0124] Furthermore, an embodiment of the present invention also provides an air conditioning control device for controlling the above-mentioned multi-split air conditioner.

[0125] In the embodiment of the present invention, refer to Figure 1 The air conditioning control device includes: a processor 1001 (such as a CPU), a memory 1002, a timer 1003, etc. The processor 1001, the memory 1002 and the timer 1003 can be connected via a communication bus. The memory 1002 can be a high-speed RAM memory or a stable memory (non-volatile memory), such as a disk memory. The memory 1002 can also be a storage device independent of the aforementioned processor 1001.

[0126] The compressor 1, the indoor unit 2, the reversing valve 3 and the temperature sensor 4 in the multi-split air conditioner can be connected to an air conditioning control device.

[0127] Those skilled in the art will understand that Figure 1 The device structure shown in the figure does not constitute a limitation of the device, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0128] like Figure 1 As shown, the memory 1002 as a computer-readable storage medium may include a cleaning program for the multi-split air conditioner. Figure 1 In the device shown, the processor 1001 can be used to call the cleaning program of the multi-split air conditioner stored in the memory 1002, and execute the relevant steps of the cleaning method of the multi-split air conditioner in the following embodiment.

[0129] An embodiment of the present invention further provides a method for cleaning a multi-split air conditioner, which is applied to clean the multi-split air conditioner.

[0130] Reference Figure 2 , an embodiment of a cleaning method for a multi-split air conditioner of the present application is proposed. In this embodiment, the cleaning method for the multi-split air conditioner includes:

[0131] Step S10, controlling the multi-split air conditioner to operate in a cooling mode so as to cause frost to form on a target indoor unit; the target indoor unit is an indoor unit that has received a cleaning instruction among at least two of the indoor units;

[0132] When the multi-split air conditioner receives a cleaning instruction, the multi-split air conditioner can be controlled to enter a self-cleaning mode. In the self-cleaning mode, the multi-split air conditioner can be controlled to start executing step S10. When any one of the multiple indoor units in the multi-split air conditioner receives a cleaning instruction, the multi-split air conditioner can be controlled to enter a self-cleaning mode.

[0133] The number of target indoor units can be set according to the actual needs of the user, and there can be one or more. Specifically, all indoor units that receive cleaning instructions within a set time period can be identified as target indoor units. In the self-cleaning mode, other indoor units except the target indoor unit do not need to be cleaned in the self-cleaning mode of the multi-split air conditioner.

[0134] In the self-cleaning mode, the cooling operation of the multi-split air conditioner can be controlled according to the preset parameters or the parameters determined based on the actual energy demand of the multi-split air conditioner, so that the target indoor unit is frosted. When the multi-split air conditioner is in cooling operation, the indoor heat exchanger in the target indoor unit is in an evaporating state, and the indoor heat exchangers in other indoor units except the target indoor unit can be in an evaporating state, or in a stop heat exchange state (the corresponding electronic expansion valve is closed), or even in a condensing state. The specific setting can be made according to the heat exchange demand of the indoor space corresponding to the other indoor units. Among them, the operating parameters of the multi-split air conditioner during the cooling operation process can be not specifically limited, and it is only necessary to ensure that the target indoor unit is frosted. For example, the fan corresponding to the target indoor unit and / or the fans corresponding to all indoor units can be operated at a low speed less than the set speed or even turned off, the compressor can be operated at a high frequency greater than the set frequency, the electronic expansion valve corresponding to the target indoor unit can be operated at a small opening less than the first set opening, and / or the electronic expansion valves corresponding to indoor units other than the target indoor unit can be operated at a large opening greater than the second set opening (the second set opening is greater than or equal to the first set opening), etc., so as to achieve a sufficiently low temperature of the indoor heat exchanger in the target indoor unit, and the moisture in the air in the target indoor unit can condense and frost on the surface of the indoor unit, and the formed frost layer can absorb dirt in the indoor unit.

[0135] Step S20, controlling the multi-split air conditioner to operate in heating mode so as to defrost the target indoor unit;

[0136] In the self-cleaning mode, when the cooling operation time of the multi-split air conditioner reaches the preset time or the coil temperature of the indoor unit is low enough, it can be considered that the frost on the surface of the target indoor unit has been completed. At this time, the reversing valve in the multi-split air conditioner can be controlled to switch from cooling operation to heating operation.

[0137] When the multi-split air conditioner is in heating operation, the indoor heat exchanger of the target indoor unit can be switched from the evaporating state to the condensing state, while the indoor heat exchangers in other indoor units except the target indoor unit can be in the condensing state, in the heat exchange stop state (the corresponding electronic expansion valve is closed), or even in the evaporating state. The specific settings can be made according to the heat exchange requirements of the indoor space corresponding to other indoor units.

[0138] After the multi-split air conditioner is switched to the heating state, the heating operation of the multi-split air conditioner can be controlled according to the preset parameters or the parameters determined based on the actual energy demand of the multi-split air conditioner, so as to defrost the target indoor unit. The operating parameters of the multi-split air conditioner during the heating operation process may not be specifically limited, and it is only necessary to ensure that the frost layer of the target indoor unit melts. For example, the fan corresponding to the target indoor unit and / or the fans corresponding to all indoor units can be operated at a low speed less than the set speed or even turned off, the compressor can be operated at a high frequency greater than the set frequency, the electronic expansion valve corresponding to the target indoor unit can be operated at a large opening greater than the third set opening, and / or the electronic expansion valve corresponding to the indoor unit other than the target indoor unit can be operated at a small opening less than the fourth set opening (the third set opening is greater than or equal to the fourth set opening), etc., so as to realize that the indoor heat exchanger in the target indoor unit releases heat into the frost layer to melt the frost layer, and the dirt in the target indoor unit can be melted after the frost layer melts.

[0139] Step S30, when the defrosting of the target indoor unit is completed, controlling the multi-split air conditioner to maintain heating operation, and adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature.

[0140] The target sterilization temperature specifically refers to the target value of the indoor unit coil temperature that allows bacteria to survive in this temperature environment for no longer than a preset time. The preset time here can be set according to actual needs, such as 3s, 5s, etc. The target sterilization temperature can be a fixed parameter preset by the system, a parameter set by the user, or a parameter selected from multiple parameters preset by the system based on the actual operating conditions of the multi-split air conditioner.

[0141] During the heating operation of the multi-split air conditioner, the operating parameters of the multi-split air conditioner (such as heating time, coil temperature of the indoor unit, etc.) can be monitored. When it is monitored that the operating parameters reach the defrosting end conditions, it can be considered that the defrosting of the target indoor unit is completed. At this time, the multi-split air conditioner can be controlled to maintain heating operation.

[0142] In the process of maintaining heating in the multi-split air conditioner, the operating frequency of the compressor can be adjusted with the target sterilization temperature as the target. The adjustment method of the compressor operating frequency may specifically include increasing the frequency, decreasing the frequency, or maintaining the current frequency. Specifically, the adjustment parameters of the compressor operating frequency (such as adjustment direction, adjustment amplitude and / or adjustment rate, etc.) can be determined based on the temperature parameters characterizing the current temperature of the target indoor unit and the target sterilization temperature, and the operating frequency of the compressor is adjusted according to the determined adjustment parameters, so that the temperature of the target indoor unit after the compressor frequency is adjusted is closer to the temperature range that reaches the target sterilization temperature than the temperature of the target indoor unit before the adjustment.

[0143] After the defrosting of the target indoor unit is completed, during the process of realizing sterilization by adjusting the compressor frequency in the heating state, the operating parameters of the multi-connected air conditioner related to the sterilization process of the target indoor unit can be monitored. When the monitored operating parameters reach the sterilization end condition, it can be considered that the sterilization of the target indoor unit is completed. When the sterilization of the target indoor unit is completed, the multi-connected air conditioner can be controlled to enter the air supply mode. In the air supply mode, the fan of the target indoor unit operates at a speed greater than or equal to the set speed. When the air supply mode runs for the set duration, the multi-connected air conditioner can be controlled to exit the self-cleaning mode and resume normal operation. Among them, the fans of other indoor units except the target indoor unit in the air supply mode can be turned on or off according to actual needs.

[0144] A cleaning method for a multi-connected air conditioner proposed in an embodiment of the present invention. After cleaning the target indoor unit to be cleaned in the multi-connected air conditioner through refrigeration frosting and heating defrosting, the air conditioner maintains heating operation and adjusts the frequency of the compressor to make the coil temperature of the target indoor unit reach the target sterilization temperature. Thus, after the indoor unit is cleaned, the indoor unit is sterilized at a sufficiently high temperature, which can ensure that the air passing through the heat exchange of the target indoor unit after cleaning does not carry bacteria, improve the cleaning effect of the indoor unit, and ensure the health of indoor users.

[0145] Specifically, in this embodiment, before step S30, the process of obtaining the target sterilization temperature is as follows: obtain the outdoor ambient temperature; obtain the target sterilization temperature according to the outdoor ambient temperature. Different outdoor ambient temperatures correspond to different target sterilization temperatures. The correspondence between the outdoor ambient temperature and the target sterilization temperature can be preset in the form of calculation formulas, mapping relationships, etc. Among them, the target sterilization temperature shows a decreasing trend as the outdoor ambient temperature decreases.

[0146] For example, in this embodiment, the correspondence between the outdoor ambient temperature and the target sterilization temperature is shown in the following table:

[0147]

[0148] In the above table, T4a and T4b are the critical values of the preset temperature intervals, and T4a < T4b. When the outdoor ambient temperature is in different temperature intervals, the target sterilization temperature has different values. T2_targetheat2_1 < T2_targetheat2_2 < T2_targetheat2_3.

[0149] Here, different outdoor ambient temperatures correspond to different target sterilization temperatures for sterilization, so as to ensure that the sterilization process of the multi-connected air conditioner can be accurately matched with its operating conditions, ensure the sterilization effect, and ensure the reliable operation of the multi-connected air conditioner under the current conditions.

[0150] Furthermore, in the present embodiment, when the defrosting of the target indoor unit is completed, the fans of the turned-on indoor units among at least two indoor units are controlled to run at a speed less than the first set speed. The first set speed can be determined according to actual conditions, for example, 30% of the maximum operating speed allowed for the fan can be used as the first set speed. Among them, when the number of turned-on indoor units other than the target indoor unit is not 0, the target indoor unit can run at a speed less than the first set speed, and the other indoor units can run at a speed greater than or equal to the first set speed or at a speed less than the first set speed according to actual needs. In the present embodiment, the fans of all turned-on indoor units run at a speed less than the first set speed.

[0151] Within the speed range less than the first set speed, the fan speeds of different indoor units can be set to be the same or different according to actual needs. In this embodiment, the fan speeds of different indoor units can be different, wherein the fan speed of the target indoor unit is the smallest among all the turned-on fans, and the fan speeds of other indoor units can be specifically determined in combination with the heat exchange requirements in their respective indoor spaces (e.g., the set temperature of the air conditioner operation). It should be noted that in the process of adjusting the compressor frequency to sterilize the indoor unit after defrosting, the turned-on fans all maintain a low speed operation less than the first set speed.

[0152] In this embodiment, by running the indoor fan at a low speed, the heat exchange of the indoor unit can be reduced, which is beneficial to increasing the temperature of the circulating refrigerant in the multi-split air-conditioning refrigerant system, thereby helping the target indoor unit to quickly reach the target sterilization temperature under the regulation of the operating frequency of the compressor to sterilize the target indoor unit, which is beneficial to increasing the sterilization time and improving the sterilization effect, especially when all the fans that have been turned on are running at a low speed.

[0153] Further, based on the above embodiment, another embodiment of the cleaning method of the multi-split air conditioner of the present application is proposed. Figure 3 The step of adjusting the operating frequency of the compressor in the above step S30 includes:

[0154] Step S31, obtaining the temperature of the first heat exchanger corresponding to the turned-on indoor unit;

[0155] The first heat exchanger temperature is specifically a temperature that characterizes the temperature condition of the turned-on indoor unit, and may be based on a detected coil temperature value, or may be a temperature value calculated or screened based on multiple detected coil temperatures.

[0156] In the process of cleaning the target indoor unit, the indoor units other than the target indoor unit in the multi-split air conditioner can be turned on or off according to the actual needs of the user. Based on this, the coil temperature of each turned-on indoor unit in the multi-split air conditioner can be obtained, and the first heat exchanger temperature here is determined based on the obtained coil temperature. The number of the obtained coil temperatures is less than or equal to the number of the turned-on indoor units.

[0157] In this embodiment, in order to ensure that the determined compressor operating frequency can achieve the cleaning of the target indoor unit while meeting the heat exchange requirements in the space where other turned-on indoor units are located, the number of coil temperatures obtained is the same as the number of turned-on indoor units. Specifically, when the number of turned-on indoor units including the target indoor unit is one, the first heat exchanger temperature specifically refers to the coil temperature of the target indoor unit. When the number of turned-on indoor units including the target indoor unit is more than one, the first coil temperature of each turned-on indoor unit is detected; and the first heat exchanger temperature is determined according to more than one first coil temperature. Here, the first heat exchanger temperature can be specifically determined by screening, calculating, etc. of the multiple coil temperatures obtained. For example, the lowest temperature among the multiple coil temperatures can be determined as the first heat exchanger temperature, the median of the multiple coil temperatures can be determined as the first heat exchanger temperature, and the first heat exchanger temperature can also be calculated by multiple coil temperatures according to a set rule (such as taking the average, etc.).

[0158] Specifically, in order to further improve the accuracy of compressor frequency control and to further improve the balance between cleaning and meeting the heat exchange requirements of different indoor spaces, in this embodiment, the first rated cooling capacity of each turned-on indoor unit is obtained; the first weight value corresponding to each turned-on indoor unit is determined based on the obtained first rated cooling capacity; and the weighted average calculation operation is performed on more than one first coil temperature based on the first weight value to obtain the first heat exchanger temperature. The first rated cooling capacity specifically refers to the cooling capacity of the indoor unit measured under rated working conditions. The first weight value of each turned-on indoor unit is the ratio of its own first rated cooling capacity to the sum of the first rated capacities of all turned-on indoor units. For example, there are x indoor units currently in need of energy, and the nominal capacity of each indoor unit is n1, n2, n3...nx, and the coil temperature of the indoor heat exchanger of each indoor unit is T1, T2, T3...Tx. Then the temperature of the first heat exchanger T=(n1*T1+n2*T2+n3*T3+...nx*Tx) / (n1+n2+n3+...+nx).

[0159] Step S32, determining a first frequency adjustment parameter of the compressor according to the first heat exchanger temperature and the target sterilization temperature;

[0160] The first frequency adjustment parameter specifically includes an adjustment direction, an adjustment amplitude and / or an adjustment rate, etc.

[0161] The first frequency adjustment parameters of the compressor for different first heat exchanger temperatures and different target sterilization temperatures. The correspondence between the first heat exchanger temperature, the target sterilization temperature and the frequency adjustment parameters can be preset, and can be in the form of a calculation formula, a mapping relationship, etc. Specifically, different quantitative relationships between the first heat exchanger temperature and the target sterilization temperature (such as size relationship, temperature deviation, ratio, etc.) can correspond to different frequency adjustment parameters. Based on the preset correspondence, the frequency adjustment parameters of the compressor corresponding to the current first heat exchanger temperature and the target sterilization temperature can be determined.

[0162] In this embodiment, the first frequency adjustment parameter includes a first adjustment direction, and the determination process of the first adjustment direction is as follows: determining the first magnitude relationship between the first heat exchanger temperature and the target sterilization temperature; when the first magnitude relationship is that the first heat exchanger temperature is greater than the target sterilization temperature, determining the first adjustment direction to reduce the frequency; when the first magnitude relationship is that the first heat exchanger temperature is less than the target sterilization temperature, determining the first adjustment direction to increase the frequency. In the process of increasing or decreasing the frequency, the frequency adjustment rate and / or adjustment amplitude can be a preset fixed parameter, or can be determined according to the actual operating condition information of the air conditioner (for example, determining the adjustment rate in the manner mentioned later). Here, when the first heat exchanger temperature is greater than the target sterilization temperature, it indicates that the overall temperature of the indoor unit of the multi-split air conditioner that has been turned on is too high, and reliability problems are prone to occur under the current working conditions. Therefore, by reducing the frequency, sterilization can be achieved while ensuring reliable operation of the air conditioner. When the first coil characteristic parameter temperature is less than the target sterilization temperature, it indicates that the overall temperature of the indoor unit of the multi-split air conditioner that has been turned on is too low, and the temperature of the target indoor unit is not enough to kill the bacteria inside it. Therefore, the temperature of the target indoor unit is increased by increasing the frequency, thereby effectively improving the sterilization effect.

[0163] Further, in order to ensure the accuracy of the compressor frequency regulation and control, so as to ensure the stable operation of the multi-split air conditioning system, before increasing or decreasing the frequency of the compressor based on the first magnitude relationship, the first temperature deviation between the first heat exchanger temperature and the target sterilization temperature can be determined first; when the first temperature deviation is greater than or equal to the first preset threshold, the step of determining the first magnitude relationship between the first heat exchanger temperature and the target sterilization temperature is performed; when the first temperature deviation is less than the first preset threshold, the compressor can be controlled to maintain the current frequency operation. Specifically, the range of the first preset threshold can be set according to actual needs. In this embodiment, the range of the first preset threshold is 1 degree Celsius. In other embodiments, the first preset threshold can also be set to 1.5 degrees Celsius, 2 degrees Celsius, 3 degrees Celsius, etc. In this embodiment, by setting the first preset threshold, the compressor frequency of the outdoor unit is adjusted only when the deviation between the first heat exchanger temperature and the target sterilization temperature is large, which can effectively avoid frequent adjustment of the compressor frequency and ensure the stability of the overall operation of the multi-split air conditioner.

[0164] Furthermore, in order to further improve the accuracy of compressor frequency regulation, the first frequency adjustment parameter also includes a first adjustment rate. Based on this, in the process of determining the first adjustment direction, it also includes: determining the first adjustment rate according to the first temperature deviation between the first heat exchanger temperature and the target sterilization temperature; wherein the first adjustment rate tends to increase as the first temperature deviation increases. The correspondence between the first temperature deviation and the first adjustment rate can be preset, and can be in the form of a calculation formula, a mapping relationship, etc. For example, when the first temperature deviation is in different temperature difference ranges, there are different first adjustment rates. In this embodiment, the adjustment rate of the compressor is determined in combination with the first temperature deviation, so as to ensure that the frequency adjustment rate can match the temperature deviation between the first heat exchanger temperature and the target sterilization temperature when reducing or increasing the frequency, and ensure that the temperature of the target indoor unit can quickly reach the temperature range where the target sterilization temperature is located through the adjustment of the frequency.

[0165] Further, in order to ensure that the frequency regulation can ensure the sterilization effect of the target indoor unit, in this embodiment, the numerical range of the first adjustment rate corresponding to different first adjustment directions is different. Specifically, the numerical range of the first adjustment rate corresponding to the first adjustment direction when the first adjustment direction is to increase the frequency is defined as the first rate range, and the numerical range of the first adjustment rate corresponding to the first adjustment direction when the first adjustment direction is to decrease the frequency is defined as the second rate range, and the rate in the first rate range is greater than the rate in the second rate range. Based on this, after determining the first adjustment direction, the first adjustment rate is determined to obtain the numerical range corresponding to the first adjustment rate based on the first adjustment direction. When the first adjustment direction is to increase the frequency, the first adjustment rate of the compressor is determined within the first rate range according to the first temperature deviation or other methods (such as the fan speed of the target indoor unit, etc.), and the first adjustment rate of the compressor is determined within the second range according to the first temperature deviation or other methods (such as the fan speed of the target indoor unit, etc.). Specifically, in this embodiment, when the first adjustment direction is to increase the frequency, the first adjustment rate is determined according to the first temperature deviation within the first rate range; when the first adjustment direction is to decrease the frequency, the first adjustment rate is determined according to the first temperature deviation within the second rate range. Here, when it is necessary to increase the frequency, adjusting the frequency at a higher rate is beneficial to ensure that the temperature of the target indoor unit can be quickly raised to above the target sterilization temperature, so as to ensure that there is a sufficiently high temperature to sterilize the target indoor unit; when it is necessary to reduce the frequency, adjusting the frequency at a lower rate is beneficial to maintain the target indoor unit at a sufficiently high temperature for a longer time, so as to improve the sterilization effect of the target indoor unit.

[0166] The first temperature deviation in this embodiment refers to the absolute value of the difference between the first heat exchanger temperature and the target sterilization temperature. The target sterilization temperature in this embodiment can be obtained in the manner mentioned in the above embodiment, which will not be described in detail.

[0167] Step S33: controlling the compressor to adjust the operating frequency according to the first frequency adjustment parameter.

[0168] Specifically, when the first frequency adjustment parameter includes an adjustment direction, the current operating frequency of the compressor is increased or decreased according to the adjustment direction; when the first frequency adjustment parameter also includes an adjustment rate, the current operating frequency of the compressor is increased or decreased according to the adjustment rate.

[0169] It should be noted that when determining the adjustment direction of the compressor frequency according to the first size relationship in this embodiment, the adjustment frequency of the compressor can be determined in other ways besides according to the first temperature deviation; in addition to determining the adjustment frequency of the compressor according to the first temperature deviation in this embodiment, the adjustment direction of the compressor frequency can also be determined in other ways.

[0170] Specifically, in this embodiment, the first heat exchanger temperature is defined as T2_avg, and the target sterilization temperature is defined as T2_targetheat2. The compressor frequency adjustment parameter is determined based on the first heat exchanger temperature and the target sterilization temperature. The determination can be performed in the following manner:

[0171] 1) T2_avg-T2_targetheat2>2, the compressor frequency decreases at a rate of 2Hz every 30 seconds;

[0172] 2) 1<T2_avg-T2_targetheat2≤2, the compressor frequency decreases at a rate of 1Hz every 60 seconds;

[0173] 3) -1<T2_avg-T2_targetheat2≤1, the compressor frequency remains unchanged;

[0174] 4) -3<T2_avg-T2_targetheat2≤-1, the compressor frequency increases at a rate of 1Hz every 120 seconds;

[0175] 5) T2_avg-T2_targetheat2≤-3, the compressor frequency increases at a rate of 2Hz every 90 seconds.

[0176] In this embodiment, the temperature of the first heat exchanger of the turned-on indoor unit can characterize the actual load conditions of all turned-on indoor units of the multi-split air conditioner, including the target indoor unit. Based on this, the frequency adjustment parameters of the compressor are determined in combination with the heat exchanger temperature and the target sterilization temperature, thereby ensuring the accuracy of the determined frequency adjustment parameters when regulating the compressor, thereby ensuring the sterilization effect of the target indoor unit while ensuring the reliable operation of the multi-split air conditioner.

[0177] Further, based on any of the above embodiments, another embodiment of the cleaning method of the multi-split air conditioner of the present application is proposed. Figure 4 , when the defrosting of the target indoor unit is completed, the process of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature also includes:

[0178] Step S301, determining whether the multi-split air conditioner meets the first sterilization end condition or the second sterilization end condition;

[0179] When the multi-split air conditioner satisfies the first sterilization end condition or the second sterilization end condition, or when the multi-split air conditioner does not satisfy the first sterilization end condition and the second sterilization end condition, step S303 is performed.

[0180] Step S302, controlling the compressor to stop, and controlling the fan corresponding to the indoor unit to operate at a speed greater than a second set speed;

[0181] Step S303, maintaining the step of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature;

[0182] Among them, the first sterilization termination condition is that the duration of the heating operation of the multi-split air conditioner is less than or equal to the target sterilization duration, and the second sterilization termination condition is that the temperature of the indoor unit is greater than or equal to the preset temperature and maintained for a preset time, the preset time is less than the target sterilization duration, and the preset temperature is greater than the target sterilization temperature.

[0183] It should be noted that, in this embodiment, steps S301 to S303 are executed synchronously with step S30, and in the process of adjusting the compressor frequency, step S301 can be executed at intervals of a set time.

[0184] The duration of the heating operation specifically refers to the sum of the duration of the defrosting process and the duration of the sterilization process after the defrosting is completed, which starts when the air conditioner starts heating after frosting is completed.

[0185] The second set speed is a pre-set parameter, and its specific size can be set according to the actual situation. The second set speed in this embodiment is greater than the first set speed in the above embodiment. Specifically, in this embodiment, the second set speed is 60% of the maximum operating speed of the fan. When the air conditioner reaches the first sterilization end condition or the second sterilization end condition, the compressor stops and the fan corresponding to the indoor unit runs at 60% of the maximum speed of the fan. Among them, the fans of the turned-on indoor units can all run at a speed greater than or equal to the second set speed, or the fans of the target indoor units among the turned-on indoor units can be limited to run at a speed greater than or equal to the second set speed, and the fans of other indoor units can be operated according to the actual air outlet demand.

[0186] The specific value of the target sterilization time can be set according to actual conditions. It can be a pre-set fixed parameter or it can be set based on the actual operation of the air conditioner during the cleaning process.

[0187] Specifically, in this embodiment, the target sterilization duration is obtained as follows: when the target indoor unit defrosts, the operating frequency of the compressor is adjusted so that the temperature of the target indoor unit reaches the target sterilization temperature. Before step S301, the operating state parameter of the multi-split air conditioner can also be obtained; if the operating state parameter is that the multi-split air conditioner does not have an outdoor unit defrost operation and a compressor oil return operation after the target indoor unit defrosts, then the first duration is obtained as the target sterilization duration; if the operating state parameter is that the multi-split air conditioner has an outdoor unit defrost operation or a compressor oil return operation after the target indoor unit defrosts, then the second duration is obtained as the target sterilization duration; wherein the second duration is greater than the first duration. The specific values ​​of the first duration and the second duration can be set according to actual conditions. In this embodiment, the first duration and the second duration are pre-set fixed parameters, for example, the first duration is 70 minutes and the second duration is 100 minutes. In other embodiments, the first duration and the second duration can also be determined according to the actual operation process of the air conditioner after the air conditioner defrosts.

[0188] In this embodiment, when the air conditioner heating time is long enough or the indoor unit maintains a higher temperature for a long time, it indicates that the air conditioner can achieve a better sterilization effect, and if the heating operation continues, it will affect the cleaning efficiency and even cause reliability problems in the air conditioner. Therefore, when the air conditioner meets the first sterilization end condition or the second sterilization end condition, the air conditioner compressor stops and the fan delivers air at a higher wind speed, which is beneficial to the drying and rapid cooling of the target indoor unit, so as to improve the cleaning effect of the target indoor unit while improving the reliability of the multi-split air conditioner operation; when the air conditioner does not meet the first sterilization end condition and the second sterilization end condition, the air conditioner maintains adjusting the compressor frequency to ensure the sterilization effect.

[0189] Further, based on any of the above embodiments, another embodiment of the cleaning method of the multi-split air conditioner of the present application is proposed. In this embodiment, the refrigeration and frosting process of the multi-split air conditioner includes a first refrigeration stage and a second refrigeration stage in sequence. The first refrigeration stage and the second refrigeration stage can be divided based on a preset time length, or can be determined according to the actual operation of the air conditioning refrigeration process. Specifically, in this embodiment, in the first refrigeration stage, if the multi-split air conditioner reaches the condensation completion condition, the multi-split air conditioner is controlled to enter the second refrigeration stage; wherein the condensation completion condition includes that the multi-split air conditioner runs for a time greater than or equal to the first set time or the coil temperature of the target indoor unit is less than or equal to the first set temperature. The specific values ​​of the first set time and the first set temperature here can be set according to actual conditions. When the air conditioner runs for a long enough time with the first parameter or the coil temperature of the target indoor unit is low enough, it indicates that the air conditioner has formed enough sleep on the surface of the target indoor unit in the first refrigeration stage to cover the dirt, and then enters the second refrigeration stage to frost in time to improve the cleaning efficiency.

[0190] On this basis, based on the division of the cleaning process into the condensation stage and the frosting stage during the refrigeration operation, step S10 includes:

[0191] Step S11, in the first cooling stage, controlling the cooling operation of the multi-split air conditioner according to a first parameter to cause condensation in the target indoor unit;

[0192] The first parameter specifically refers to the operating parameter of any refrigeration component in the air conditioner that can cause condensation in the target indoor unit. Specifically, the first parameter may include parameters such as compressor frequency, fan speed, electronic expansion valve opening, etc. The specific value and type of the first parameter can be set according to actual conditions, and it is only necessary to ensure condensation in the target indoor unit.

[0193] Specifically, in this embodiment, the first parameter includes the target frequency of the compressor. Figure 5 , step S11 comprises:

[0194] Step S111, in the first cooling stage, obtaining a second rated cooling capacity of the target indoor unit and obtaining a third rated cooling capacity of the compressor;

[0195] The second rated cooling capacity here specifically refers to the cooling capacity of the indoor unit measured under rated working conditions. The third rated cooling capacity specifically refers to the output capacity of the compressor measured under rated cooling working conditions. When the number of target indoor units is more than one, the second rated cooling capacity is the sum of the rated cooling capacities of all target indoor units.

[0196] Step S112, determining a frequency correction parameter according to a numerical relationship between the second rated cooling capacity and the third rated cooling capacity;

[0197] The numerical relationship between the second rated cooling capacity and the third rated cooling capacity specifically includes a difference, ratio or sum of the second rated cooling capacity and the third rated cooling capacity. Different numerical relationships correspond to different frequency correction parameters, and the frequency correction parameters specifically include correction amplitude, correction rate and / or correction direction.

[0198] Step S113, determining the target frequency according to the set maximum frequency of the multi-split air conditioner cooling operation and the frequency correction parameter;

[0199] Specifically, the difference between the set maximum frequency and the frequency correction parameter may be used as the target frequency; and the result of reducing the set maximum frequency in proportion to the frequency correction parameter may be used as the target frequency.

[0200] In this embodiment, the ratio of the second rated cooling capacity to the third rated cooling capacity is used as the frequency correction parameter, and the product of the set maximum frequency and the frequency correction parameter is used as the target frequency. For example, the target frequency of the outdoor compressor operation is calculated as follows: target frequency = maximum cooling frequency * total nominal cooling capacity of the indoor units that need self-cleaning / nominal cooling capacity of the outdoor units. For example, in a one-to-two system, one 56 and one 22 receive the self-cleaning model, then the target frequency of the outdoor compressor = maximum cooling frequency * (56 + 22) / 160.

[0201] Step S114, controlling the compressor to perform cooling operation at the target frequency.

[0202] Here, the refrigeration capacity of the indoor unit that needs to be cleaned and the output capacity of the compressor are comprehensively considered to determine the corresponding correction parameters. The frequency obtained after correcting the maximum frequency of the compressor is used as the operating frequency of the air conditioner in the condensation stage, thereby ensuring that the indoor unit that needs to be cleaned can condense quickly, which is beneficial to improving the cleaning efficiency of the target indoor unit.

[0203] Furthermore, before step S114, the method further includes: comparing the target frequency with the set minimum frequency of the multi-split air conditioner cooling operation; if the target frequency is less than or equal to the set minimum frequency, controlling the compressor to operate at the set minimum frequency to cause condensation in the target indoor unit; if the target frequency is greater than the set minimum frequency, executing the step of controlling the compressor to operate at the target frequency for cooling. Based on this, it can be ensured that the compressor has sufficient output capacity to ensure condensation in the target indoor unit.

[0204] Step S12, in the second cooling stage, controlling the cooling operation of the multi-split air conditioner according to the second parameter so that the condensation on the target indoor unit condenses into frost.

[0205] The second parameter specifically refers to the operating parameter of any refrigeration component in the air conditioner that can cause frost on the target indoor unit. Specifically, the second parameter may include a frequency parameter of the compressor, a speed parameter of the fan, an opening parameter of the electronic expansion valve, etc. The specific value and type of the second parameter can be set according to actual conditions, and it is only necessary to ensure that the condensation on the target indoor unit turns into frost.

[0206] Specifically, in this embodiment, the second parameter includes a second frequency adjustment parameter of the compressor, referring to Figure 5 , the step S12 comprises:

[0207] Step S121, in the second cooling stage, obtaining a second heat exchanger temperature corresponding to the turned-on indoor unit;

[0208] If there are more than one indoor units turned on, the step of obtaining the second heat exchanger temperature corresponding to the turned-on indoor units includes: detecting the second coil temperature of each turned-on indoor unit to obtain the fourth rated cooling capacity of each turned-on indoor unit; determining the second weight value corresponding to each turned-on indoor unit according to the obtained fourth rated cooling capacity; and performing a weighted average calculation operation on more than one second coil temperature according to the second weight value to obtain the second heat exchanger temperature.

[0209] It should be noted that the method for obtaining the second heat exchanger temperature and the technical effect it brings here can be analogously referred to the implementation method related to the first heat exchanger temperature in the above embodiment, and will not be elaborated here.

[0210] Step S122, determining a second frequency adjustment parameter of the compressor according to the second heat exchanger temperature and the target evaporation temperature;

[0211] The target evaporating temperature specifically refers to the heat exchanger temperature of the turned-on indoor unit in the evaporating state that can cause frost on the target indoor unit. The target evaporating temperature can be a pre-set fixed parameter or a parameter determined based on the actual operating conditions of the air conditioner (such as indoor and outdoor ambient temperatures, etc.).

[0212] In this embodiment, the second frequency adjustment parameter specifically includes an adjustment direction, an adjustment amplitude and / or an adjustment rate, etc.

[0213] Second frequency adjustment parameters of compressors for different second heat exchanger temperatures and different target evaporation temperatures. The correspondence between the second heat exchanger temperature, the target evaporation temperature and the frequency adjustment parameters can be preset, and can be in the form of calculation formulas, mapping relationships, etc. Specifically, different quantitative relationships between the second coil temperature characteristic temperature and the target evaporation temperature (such as size relationship, temperature deviation, ratio, etc.) can correspond to different frequency adjustment parameters. Based on the preset correspondence, the frequency adjustment parameters of the compressor corresponding to the current second heat exchanger temperature and the target evaporation temperature can be determined.

[0214] Specifically, in the embodiment, step S122 includes:

[0215] Step S122a, determining a second magnitude relationship between the second heat exchanger temperature and the target evaporation temperature, and determining a second temperature deviation between the second heat exchanger temperature and the target evaporation temperature;

[0216] The second temperature deviation refers to the absolute value of the difference between the second heat exchanger temperature and the target evaporation temperature.

[0217] Step S122b, determining a second adjustment direction of the compressor frequency according to the second magnitude relationship, and determining a second adjustment rate of the compressor frequency according to the second temperature deviation;

[0218] Specifically, if the second magnitude relationship is different, the second adjustment direction of the compressor frequency is different. When the second magnitude relationship is that the second heat exchanger temperature is greater than the target evaporation temperature, the second adjustment direction is determined to be increasing the frequency; when the second magnitude relationship is that the second heat exchanger temperature is less than the target evaporation temperature, the second adjustment direction is determined to be decreasing the frequency. Here, when the second heat exchanger temperature is greater than the target evaporation temperature, it indicates that the overall temperature of the indoor unit of the multi-split air conditioner that has been turned on is too high, and the condensation on the target indoor unit is difficult to frost. Therefore, by increasing the frequency, effective frost can be achieved on the target indoor unit to ensure the cleaning effect of the target indoor unit. When the second coil characteristic parameter temperature is less than the target evaporation temperature, it indicates that the overall temperature of the indoor unit of the multi-split air conditioner that has been turned on is too low, and the temperature of the target indoor unit is sufficient to condense the condensation into frost. Therefore, reducing the frequency is beneficial to improving the energy efficiency of the multi-split air conditioning system to ensure that the air conditioner can achieve the cleaning of the target indoor unit with better energy efficiency.

[0219] The corresponding relationship between the second temperature deviation and the second adjustment rate can be preset, and can be in the form of a calculation formula, a mapping relationship, etc. The second adjustment rate tends to increase with the increase of the second temperature deviation. For example, when the second temperature deviation is in different temperature difference intervals, different second adjustment rates correspond to it. In this embodiment, the adjustment rate of the compressor is determined in combination with the second temperature deviation, so as to ensure that the frequency adjustment rate can match the temperature deviation between the second heat exchanger temperature and the target evaporation temperature when the frequency is reduced or increased, and ensure that the temperature of the target indoor unit can quickly reach the temperature interval where the target evaporation temperature is located through the adjustment of the frequency.

[0220] Further, before the step of determining the second adjustment direction of the compressor frequency according to the second magnitude relationship and determining the second adjustment rate of the compressor frequency according to the second temperature deviation, it also includes: comparing the magnitude of the second temperature deviation with the second preset threshold; if the comparison result is that the second temperature deviation is greater than or equal to the second preset threshold, then executing the step of determining the second adjustment direction of the compressor frequency according to the second magnitude relationship and determining the second adjustment rate of the compressor frequency according to the second temperature deviation; when the second temperature deviation is less than the second preset threshold, the compressor can be controlled to maintain the current frequency operation. Specifically, the range of the second preset threshold can be set according to actual needs. In this embodiment, the range of the second preset threshold is 1 degree Celsius. In other embodiments, the second preset threshold can also be set to 1.5 degrees Celsius, 2 degrees Celsius, 3 degrees Celsius, etc. In this embodiment, by setting the second preset threshold, the compressor frequency of the outdoor unit is adjusted only when the deviation between the second heat exchanger temperature and the target evaporation temperature is large, which can effectively avoid frequent adjustment of the compressor frequency and ensure the stability of the overall operation of the multi-split air conditioner.

[0221] For example, the second heat exchanger temperature is defined as T2_avg, and the target evaporation temperature is defined as T2_targetcool. Then, the process of determining the frequency adjustment parameter of the compressor by combining the second heat exchanger temperature and the target evaporation temperature can be specifically determined based on the following relationship:

[0222] 1) T2_avg-T2_targetcool>5, the compressor frequency increases at a rate of 3Hz every 30 seconds;

[0223] 2) 3<T2_avg-T2_targetcool≤5, the compressor frequency increases at a rate of 2Hz every 60 seconds;

[0224] 3) 1<T2_avg-T2_targetcool≤3, the compressor frequency increases at a rate of 1Hz every 120 seconds;

[0225] 4) -1<T2_avg-T2_targetcool≤1, the compressor frequency remains unchanged;

[0226] 5) -3<T2_avg-T2_targetcool≤-1, the compressor frequency decreases at a rate of 1Hz every 90 seconds;

[0227] 6) -5<T2_avg-T2_targetcool≤-3, the compressor frequency decreases at a rate of 2Hz every 60 seconds;

[0228] 7) T2_avg-T2_targetcool≤-5, the compressor frequency decreases at a rate of 3Hz every 30 seconds.

[0229] Step S122c: determine the second adjustment direction and the second adjustment rate as the second frequency adjustment parameters.

[0230] Step S123: controlling the compressor to adjust the refrigeration frequency according to the second frequency adjustment parameter.

[0231] In this embodiment, when the air conditioner is in cooling operation, different parameters are used in stages to regulate the operation of the air conditioner, thereby ensuring rapid frosting of the target indoor unit and achieving rapid and effective cleaning of the target indoor unit.

[0232] Furthermore, in the first cooling stage, in order to achieve rapid condensation of the target indoor unit, the fan corresponding to the turned-on indoor unit can also be controlled to run at a speed less than the third set speed. The specific value of the third set speed here can be determined according to actual conditions, and the third set speed is greater than or equal to the first set speed in the above embodiment. Specifically, the fans of all turned-on indoor units or the fans of the target indoor unit can be controlled to run at a low speed to reduce the heat exchange of the evaporator, which is beneficial to reduce the temperature of the heat exchanger in the target indoor unit, thereby accelerating the condensation of moisture in the target indoor unit. Among them, the control of the fan here can be executed synchronously with the operation of the above-mentioned compressor at the target frequency, thereby further improving the condensation efficiency of the target indoor unit, which is beneficial to further improve the cleaning efficiency of the target indoor unit.

[0233] Furthermore, before the step of controlling the cooling operation of the multi-split air conditioner according to the second parameter, it also includes: when entering the second cooling stage, controlling the fan corresponding to the turned-on indoor unit to stop running for a second set time; controlling the fan corresponding to the turned-on indoor unit to run at a speed less than the fourth set speed for a third set time; executing the step of controlling the cooling operation of the multi-split air conditioner according to the second parameter. The specific values ​​of the second set time and the third set time here can be set according to the situation. In this embodiment, the second set time is 7 minutes and the third set time is 4 minutes.

[0234] Furthermore, in this embodiment, in the first cooling stage, the second cooling stage is entered after 10 minutes of operation or when the temperature of any indoor evaporator T2 is ≤-10°C; in the second cooling stage, frosting is considered to be completed after 10 minutes of operation or when the temperature of any indoor evaporator T2 is ≤-10°C, and the air conditioner can be controlled to switch to heating operation to defrost the target indoor unit.

[0235] Further, based on any of the above embodiments, another embodiment of the cleaning method of the multi-split air conditioner of the present application is proposed. In this embodiment, refer to Figure 6 , step S20 comprises:

[0236] Step S21, in the heating state of the multi-split air conditioner, obtaining the temperature of the third heat exchanger corresponding to the turned-on indoor unit;

[0237] In this embodiment, the method of obtaining the temperature of the third heat exchanger and the technical effects brought about by it can be referred to in analogy with the above embodiments, and will not be elaborated here.

[0238] Step S22, determining a third frequency adjustment parameter of the compressor according to the third heat exchanger temperature and a target defrosting temperature; the target defrosting temperature is less than or equal to the target sterilization temperature;

[0239] The target defrost temperature specifically refers to the target value that the heat exchanger temperature of the turned-on indoor unit needs to reach in order to melt the frost of the target indoor unit. Specifically, the target defrost temperature can be a preset fixed parameter, or a parameter determined based on the operation conditions in the previous refrigeration and frosting process.

[0240] In this embodiment, the third frequency adjustment parameter specifically includes an adjustment direction, an adjustment amplitude and / or an adjustment rate, etc.

[0241] The third frequency adjustment parameters of the compressor for different third heat exchanger temperatures and different target defrost temperatures. The correspondence between the third heat exchanger temperature, the target defrost temperature and the frequency adjustment parameters can be preset, and can be in the form of calculation formulas, mapping relationships, etc. Specifically, the quantitative relationship between the third coil temperature characteristic temperature and the target defrost temperature is different (such as size relationship, temperature deviation, ratio, etc.), and different frequency adjustment parameters can be corresponding. Based on the preset correspondence, the frequency adjustment parameters of the compressor corresponding to the current third heat exchanger temperature and the target defrost temperature can be determined.

[0242] Specifically, in this embodiment, step S22 includes:

[0243] Step S221, determining a third magnitude relationship between the third heat exchanger temperature and the target defrost temperature, and determining a third temperature deviation between the third heat exchanger temperature and the target defrost temperature;

[0244] The third temperature deviation refers to the absolute value of the difference between the third heat exchanger temperature and the target defrosting temperature.

[0245] Step S222, determining a third adjustment direction of the compressor frequency according to the third magnitude relationship, and determining a third adjustment rate of the compressor frequency according to the third temperature deviation;

[0246] Among them, if the third magnitude relationship is different, the third adjustment direction is different. When the third magnitude relationship is that the third heat exchanger temperature is greater than the target defrost temperature, the third adjustment direction is determined to be to reduce the frequency; when the third magnitude relationship is that the third heat exchanger temperature is less than the target defrost temperature, the third adjustment direction is determined to be to increase the frequency. Here, when the third heat exchanger temperature is less than the target defrost temperature, it indicates that the overall temperature of the indoor unit of the multi-split air conditioner that has been turned on is low, and the frost on the target indoor unit is difficult to melt. Therefore, by increasing the frequency, the target indoor unit can be quickly defrosted to ensure the cleaning effect of the target indoor unit. When the third coil characteristic parameter temperature is greater than the target defrost temperature, it indicates that the overall temperature of the indoor unit of the multi-split air conditioner that has been turned on is high enough, and the temperature of the target indoor unit is sufficient to melt the frost quickly. Therefore, by reducing the frequency, it is beneficial to ensure that the air conditioning system cleans the target indoor unit while operating reliably.

[0247] The corresponding relationship between the third temperature deviation and the third adjustment rate can be preset, and can be in the form of a calculation formula, a mapping relationship, etc. The third adjustment rate tends to increase with the increase of the third temperature deviation. For example, when the third temperature deviation is in different temperature difference intervals, different third adjustment rates correspond to it. In this embodiment, the adjustment rate of the compressor is determined in combination with the third temperature deviation, so as to ensure that the frequency adjustment rate can match the temperature deviation between the third heat exchanger temperature and the target defrost temperature when the frequency is reduced or increased, and ensure that the temperature of the target indoor unit can quickly reach the temperature interval where the target defrost temperature is located through the adjustment of the frequency.

[0248] Further, before the step of determining the third adjustment direction of the compressor frequency according to the third magnitude relationship and determining the third adjustment rate of the compressor frequency according to the third temperature deviation, it also includes: comparing the magnitude of the third temperature deviation with the third preset threshold; if the comparison result is that the third temperature deviation is greater than or equal to the third preset threshold, then executing the step of determining the third adjustment direction of the compressor frequency according to the third magnitude relationship and determining the third adjustment rate of the compressor frequency according to the third temperature deviation; when the third temperature deviation is less than the third preset threshold, the compressor can be controlled to maintain the current frequency operation. Specifically, the range of the third preset threshold can be set according to actual needs. In this embodiment, the range of the third preset threshold is 1 degree Celsius. In other embodiments, the third preset threshold can also be set to 1.5 degrees Celsius, 2 degrees Celsius, 3 degrees Celsius, etc. In this embodiment, by setting the third preset threshold, the compressor frequency of the outdoor unit is adjusted only when the deviation between the third heat exchanger temperature and the target defrosting temperature is large, which can effectively avoid frequent adjustment of the compressor frequency and ensure the stability of the overall operation of the multi-split air conditioner.

[0249] Step S223: Determine the third adjustment direction and the third adjustment rate as the third frequency adjustment parameter.

[0250] For example, in this embodiment, the third heat exchanger temperature is defined as T2_avg, and the target defrost temperature is defined as T2_targetheat1. Then, the process of determining the compressor frequency adjustment parameter based on the third heat exchanger temperature and the target defrost temperature can be specifically performed according to the following corresponding relationship:

[0251] 1) T2_avg-T2_targetheat1>3, the compressor frequency decreases at a rate of 2Hz every 30 seconds;

[0252] 2) 1<T2_avg-T2_targetheat1≤3, the compressor frequency decreases at a rate of 1Hz every 60 seconds;

[0253] 3) -1<T2_avg-T2_targetheat1≤1, the compressor frequency remains unchanged;

[0254] 4) -3<T2_avg-T2_targetheat1≤-1, the compressor frequency increases at a rate of 1Hz every 120 seconds;

[0255] 5) T2_avg-T2_targetheat1≤-3, the compressor frequency increases at a rate of 2Hz every 60 seconds.

[0256] Step S23: controlling the compressor to adjust the heating frequency according to the third frequency adjustment parameter.

[0257] In this embodiment, the temperature of the third heat exchanger of the turned-on indoor unit can characterize the actual load conditions of all turned-on indoor units of the multi-split air conditioner, including the target indoor unit. Based on this, the frequency adjustment parameters of the compressor are determined in combination with the heat exchanger temperature and the target defrost temperature, thereby ensuring the accuracy of the determined frequency adjustment parameters when regulating the compressor, thereby ensuring the cleaning effect of the target indoor unit while ensuring the reliable operation of the multi-split air conditioner.

[0258] Furthermore, in this embodiment, before the step of controlling the compressor to adjust the heating frequency according to the third frequency adjustment parameter, it also includes: when the multi-split air conditioner starts heating operation, controlling the compressor and the fans corresponding to the indoor unit to stop; when the shutdown of the compressor and the fans corresponding to the indoor unit reaches the fourth set time, executing the step of controlling the compressor to adjust the heating frequency according to the third frequency adjustment parameter. Here, in the initial stage of switching from refrigeration and frosting to heating and defrosting operation, the system pressure can be effectively avoided from being too high by stopping the compressor and the fan, ensuring the reliable operation of the system. It should be noted that in the process of adjusting the frequency, the fan of the target indoor unit remains in a closed state, and the fans of other indoor units can be turned on or off according to actual needs.

[0259] In addition, an embodiment of the present invention also proposes a computer-readable storage medium, on which a cleaning program for a multi-split air conditioner is stored. When the cleaning program for the multi-split air conditioner is executed by a processor, the relevant steps of any embodiment of the above-mentioned cleaning method for the multi-split air conditioner are implemented.

[0260] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0261] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0262] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, including a number of instructions for enabling a terminal device (which can be a mobile phone, a computer, a server, a multi-split air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0263] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for cleaning a multi-split air conditioner, wherein the multi-split air conditioner comprises at least two indoor units, characterized in that: The cleaning method of the multi-split air conditioner comprises the following steps: Controlling the multi-split air conditioner to operate in a cooling mode so as to cause frost to form on a target indoor unit; the target indoor unit is an indoor unit that receives a cleaning instruction among at least two of the indoor units; Controlling the heating operation of the multi-split air conditioner to defrost the target indoor unit; When the target indoor unit is defrosted, the multi-split air conditioner is controlled to maintain heating operation, and the operating frequency of the compressor is adjusted so that the temperature of the target indoor unit reaches the target sterilization temperature; The step of adjusting the operating frequency of the compressor comprises: Acquire the first heat exchanger temperature corresponding to the turned-on indoor unit; if the number of turned-on indoor units is more than one, the step of acquiring the first heat exchanger temperature corresponding to the turned-on indoor unit comprises: detecting the first coil temperature of each turned-on indoor unit; determining the lowest temperature among the multiple coil temperatures as the first heat exchanger temperature; determining a first frequency adjustment parameter of the compressor according to the first heat exchanger temperature and the target sterilization temperature; Controlling the compressor to adjust the operating frequency according to the first frequency adjustment parameter; Before the step of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature, the method further includes: When the defrosting of the target indoor unit is completed, controlling the fans of all turned-on indoor units to run at a speed less than a first set speed, wherein the fan speed of the target indoor unit is the smallest among all turned-on fans; The refrigeration and frosting process of the multi-split air conditioner includes a first refrigeration stage and a second refrigeration stage in sequence, and the step of controlling the refrigeration operation of the multi-split air conditioner to frost the target indoor unit includes: In the first cooling stage, the multi-split air conditioner is controlled to operate in cooling mode according to a first parameter so that condensation occurs in the target indoor unit; the first parameter includes a target frequency of the compressor, and the step of controlling the multi-split air conditioner to operate in cooling mode according to the first parameter so that condensation occurs in the target indoor unit in the first cooling stage comprises: obtaining a second rated cooling capacity of the target indoor unit and a third rated cooling capacity of the compressor in the first cooling stage; determining a frequency correction parameter according to a numerical relationship between the second rated cooling capacity and the third rated cooling capacity; determining the target frequency according to a set maximum frequency of the multi-split air conditioner in cooling mode and the frequency correction parameter; and controlling the compressor to operate in cooling mode at the target frequency; In the second cooling stage, the cooling operation of the multi-split air conditioner is controlled according to the second parameter so that the condensation on the target indoor unit condenses into frost.

2. The method for cleaning a multi-split air conditioner according to claim 1, characterized in that: The first frequency adjustment parameter includes a first adjustment direction, and the step of determining the first frequency adjustment parameter of the compressor according to the first heat exchanger temperature and the target sterilization temperature includes: Determining a first magnitude relationship between the first heat exchanger temperature and the target sterilization temperature; When the first magnitude relationship is that the first heat exchanger temperature is greater than the target sterilization temperature, determining that the first adjustment direction is to reduce the frequency; When the first magnitude relationship is that the first heat exchanger temperature is lower than the target sterilization temperature, the first adjustment direction is determined to be increasing the frequency.

3. The cleaning method of a multi-split air conditioner according to claim 2, characterized in that: Before the step of determining the first magnitude relationship between the first heat exchanger temperature and the target sterilization temperature, the method further includes: determining a first temperature deviation between the first heat exchanger temperature and the target sterilization temperature; When the first temperature deviation is greater than or equal to a first preset threshold, the step of determining a first magnitude relationship between the first heat exchanger temperature and the target sterilization temperature is performed.

4. The method for cleaning a multi-split air conditioner according to claim 2, characterized in that: The first frequency adjustment parameter also includes a first adjustment rate. In the process of determining the first adjustment direction according to the first heat exchanger temperature and the target sterilization temperature, the first frequency adjustment parameter also includes: determining the first adjustment rate according to a first temperature deviation between the first heat exchanger temperature and the target sterilization temperature; The first adjustment rate tends to increase as the first temperature deviation increases.

5. The method for cleaning a multi-split air conditioner according to claim 4, characterized in that: The step of determining the first adjustment rate according to a first temperature deviation between the first heat exchanger temperature and the target sterilization temperature comprises: When the first adjustment direction is to increase the frequency, determining the first adjustment rate according to the first temperature deviation within a first rate range; When the first adjustment direction is to reduce the frequency, determining the first adjustment rate according to the first temperature deviation within a second rate range; The rate in the first rate range is greater than the rate in the second rate range.

6. The method for cleaning a multi-split air conditioner according to claim 1, characterized in that: Before the step of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature, the method further includes: Get the outdoor ambient temperature; The target sterilization temperature is obtained according to the outdoor ambient temperature.

7. The method for cleaning a multi-split air conditioner according to claim 6, characterized in that: The target sterilization temperature tends to decrease as the outdoor ambient temperature decreases.

8. The method for cleaning a multi-split air conditioner according to any one of claims 1 to 7, characterized in that: When the defrosting of the target indoor unit is completed, the process of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature also includes: When the multi-split air conditioner meets the first sterilization end condition or the second sterilization end condition, the compressor is controlled to stop, and the fan corresponding to the indoor unit is controlled to run at a speed greater than the second set speed; When the multi-split air conditioner does not meet the first sterilization end condition and the second sterilization end condition, maintaining the step of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature; Among them, the first sterilization termination condition is that the duration of the heating operation of the multi-split air conditioner is greater than or equal to the target sterilization duration, and the second sterilization termination condition is that the temperature of the indoor unit is greater than or equal to the preset temperature and maintained for a preset time, the preset time is less than the target sterilization duration, and the preset temperature is greater than the target sterilization temperature.

9. The method for cleaning a multi-split air conditioner according to claim 8, characterized in that: When the defrosting of the target indoor unit is completed, the process of adjusting the operating frequency of the compressor so that the temperature of the target indoor unit reaches the target sterilization temperature also includes: Obtaining operating status parameters of the multi-split air conditioner; If the operating state parameter is that the multi-split air conditioner does not have an outdoor unit defrosting operation and a compressor oil return operation after the target indoor unit defrosting is completed, then the first duration is obtained as the target sterilization duration; If the operating state parameter is that the multi-split air conditioner has an outdoor unit defrosting operation or a compressor oil return operation after the target indoor unit defrosting is completed, then the second duration is obtained as the target sterilization duration; The second duration is greater than the first duration.

10. The method for cleaning a multi-split air conditioner according to any one of claims 1 to 7, characterized in that: Before the step of controlling the compressor to operate at the target frequency, the method further includes: Comparing the target frequency with a set minimum frequency for cooling operation of the multi-split air conditioner; If the target frequency is less than or equal to the set minimum frequency, controlling the compressor to operate at the set minimum frequency to cause condensation in the target indoor unit; If the target frequency is greater than the set minimum frequency, the step of controlling the compressor to perform cooling operation at the target frequency is performed.

11. The method for cleaning a multi-split air conditioner according to any one of claims 1 to 7, characterized in that: The second parameter includes a second frequency adjustment parameter of the compressor, and the step of controlling the cooling operation of the multi-split air conditioner according to the second parameter in the second cooling stage so that the condensation on the target indoor unit condenses into frost includes: In the second cooling stage, obtaining the second heat exchanger temperature corresponding to the turned-on indoor unit; determining a second frequency adjustment parameter of the compressor according to the second heat exchanger temperature and a target evaporation temperature; The compressor is controlled to adjust the refrigeration frequency according to the second frequency adjustment parameter.

12. The method for cleaning a multi-split air conditioner according to claim 11, characterized in that: The step of determining the second frequency adjustment parameter of the compressor according to the second heat exchanger temperature and the target evaporation temperature comprises: determining a second magnitude relationship between the second heat exchanger temperature and the target evaporation temperature, and determining a second temperature deviation between the second heat exchanger temperature and the target evaporation temperature; Determine a second adjustment direction of the compressor frequency according to the second magnitude relationship, and determine a second adjustment rate of the compressor frequency according to the second temperature deviation; The second adjustment direction and the second adjustment rate are determined as the second frequency adjustment parameters.

13. The method for cleaning a multi-split air conditioner according to claim 12, characterized in that: The second adjustment rate tends to increase as the second temperature deviation increases.

14. The method for cleaning a multi-split air conditioner according to claim 12, characterized in that: The step of determining the second adjustment direction of the compressor frequency according to the second magnitude relationship comprises: When the second magnitude relationship is that the second heat exchanger temperature is greater than the target evaporation temperature, determining that the second adjustment direction is to increase the frequency; When the second magnitude relationship is that the second heat exchanger temperature is lower than the target evaporation temperature, the second adjustment direction is determined to be reducing the frequency.

15. The method for cleaning a multi-split air conditioner according to claim 14, characterized in that: Before the step of determining the second adjustment direction of the compressor frequency according to the second magnitude relationship and determining the second adjustment rate of the compressor frequency according to the second temperature deviation, the method further includes: Comparing the second temperature deviation with a second preset threshold; If the comparison result is that the second temperature deviation is greater than or equal to the second preset threshold, the steps of determining the second adjustment direction of the compressor frequency according to the second size relationship and determining the second adjustment rate of the compressor frequency according to the second temperature deviation are executed.

16. The method for cleaning a multi-split air conditioner according to claim 12, characterized in that: If the number of turned-on indoor units is more than one, the step of obtaining the temperature of the second heat exchanger corresponding to the turned-on indoor units includes: Detecting the second coil temperature of each turned-on indoor unit to obtain the fourth rated cooling capacity of each turned-on indoor unit; Determining a second weight value corresponding to each turned-on indoor unit according to the acquired fourth rated cooling capacity; A weighted average calculation operation is performed on more than one second coil temperature according to the second weight value to obtain the second heat exchanger temperature.

17. The method for cleaning a multi-split air conditioner according to any one of claims 1 to 7, characterized in that: The cleaning method of the multi-split air conditioner also includes: In the first cooling stage, if the multi-split air conditioner reaches the condensation completion condition, the multi-split air conditioner is controlled to enter the second cooling stage; Among them, the condensation completion condition includes that the multi-split air conditioner operates with the first parameter for a time period greater than or equal to a first set time period or the coil temperature of the target indoor unit is less than or equal to a first set temperature.

18. The method for cleaning a multi-split air conditioner according to any one of claims 1 to 7, characterized in that: In the first cooling stage, the fan corresponding to the turned-on indoor unit is controlled to run at a speed lower than the third set speed; and / or, Before the step of controlling the cooling operation of the multi-split air conditioner according to the second parameter, the method further includes: When entering the second cooling stage, controlling the fan corresponding to the turned-on indoor unit to stop running for a second set time; Controlling the fan corresponding to the turned-on indoor unit to run at a speed lower than a fourth set speed for a third set time period; Execute the step of controlling the cooling operation of the multi-split air conditioner according to the second parameter.

19. The method for cleaning a multi-split air conditioner according to any one of claims 1 to 7, characterized in that: The step of controlling the heating operation of the multi-split air conditioner to defrost the target indoor unit comprises: In the heating state of the multi-split air conditioner, obtaining the temperature of the third heat exchanger corresponding to the turned-on indoor unit; determining a third frequency adjustment parameter of the compressor according to the third heat exchanger temperature and a target defrosting temperature; the target defrosting temperature is less than or equal to the target sterilization temperature; The compressor is controlled to adjust the heating frequency according to the third frequency adjustment parameter.

20. The method for cleaning a multi-split air conditioner according to claim 19, characterized in that: The step of determining the third frequency adjustment parameter of the compressor according to the third heat exchanger temperature and the target defrost temperature comprises: determining a third magnitude relationship between the third heat exchanger temperature and the target defrost temperature, and determining a third temperature deviation between the third heat exchanger temperature and the target defrost temperature; determining a third adjustment direction of the compressor frequency according to the third magnitude relationship, and determining a third adjustment rate of the compressor frequency according to the third temperature deviation; The third adjustment direction and the third adjustment rate are determined as the third frequency adjustment parameter.

21. The method for cleaning a multi-split air conditioner according to claim 20, characterized in that: The third adjustment rate increases with the increase of the third temperature deviation; and / or, The step of determining the third adjustment direction of the compressor frequency according to the third magnitude relationship comprises: When the third magnitude relationship is that the third heat exchanger temperature is greater than the target defrosting temperature, determining that the third adjustment direction is to reduce the frequency; When the third magnitude relationship is that the third heat exchanger temperature is less than the target defrosting temperature, the third adjustment direction is determined to be increasing the frequency.

22. The method for cleaning a multi-split air conditioner according to claim 19, characterized in that: Before the step of controlling the compressor to adjust the heating frequency according to the third frequency adjustment parameter, the method further includes: When the multi-split air conditioner starts heating operation, the compressor and the fans corresponding to the indoor units are controlled to stop; When the compressor and the fans corresponding to the indoor unit are stopped for a fourth set time, the step of controlling the compressor to adjust the heating frequency according to the third frequency adjustment parameter is performed.

23. An air conditioning control device, characterized in that: The air conditioning control device includes: a memory, a processor, and a cleaning program for a multi-split air conditioner stored in the memory and executable on the processor. When the cleaning program for the multi-split air conditioner is executed by the processor, the steps of the cleaning method for the multi-split air conditioner as described in any one of claims 1 to 22 are implemented.

24. A multi-split air conditioner, characterized in that: The multi-split air conditioner comprises: At least two indoor units; and The air conditioning control device as described in claim 23, wherein the air conditioning control device is connected to the indoor unit.

25. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a cleaning program for a multi-split air conditioner, and when the cleaning program for the multi-split air conditioner is executed by a processor, the steps of the cleaning method for the multi-split air conditioner as described in any one of claims 1 to 22 are implemented.

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