Control method and control device of multi-split air conditioning system and multi-split air conditioning system

Abstract

The invention relates to the technical field of multi-split air conditioners, and provides a control method and device of a multi-split air conditioning system and the multi-split air conditioning system.The control method of the multi-split air conditioning system comprises the steps that when an operation mode is a refrigeration mode, the fluctuation frequency is larger than or equal to the preset frequency, and the fluctuation correlation state is a correlation state, the multi-split air conditioning system is started; if yes, sending a signal for controlling the operation frequency of the compressor to be the target frequency; wherein the target frequency is lower than the current frequency, and the frequency difference value is a preset frequency difference value. When the multi-split air conditioning system operates in the refrigeration mode, if the exhaust temperature of the compressor fluctuates for multiple times within the first preset duration, and the temperature fluctuation is caused by opening and closing of the liquid spraying valve, the operation frequency of the compressor is controlled to be reduced to the target frequency from the current frequency, and the target frequency is reduced to the target frequency. And at the moment, the exhaust temperature is maintained between the first preset temperature and the second preset temperature, fluctuation of the air outlet temperature of the indoor unit caused by frequent opening and closing of the liquid spraying valve is avoided, and the comfort level of a user is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-split air conditioners, and in particular to a control method and a control device of a multi-split air conditioner system and a multi-split air conditioner system. Background Art

[0002] When the multi-split air conditioning system is in operation, the parameters of the compressor during operation must meet the requirements of the operating specifications for the protection of the air conditioning system. Operating points beyond the boundaries may cause damage to the compressor, and then cause failure of the air conditioning system. The multi-split air conditioning system will perform a series of controls around compressor protection and constant system pressure to ensure that all operating pressure points are within a reasonable range. In related technologies, in order to maintain the stability of system operation, when the air conditioning system is adjusted, the air outlet temperature will fluctuate, reducing the user's comfort. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention proposes a control method for a multi-split air conditioning system, which reduces the operating frequency of the compressor to a target frequency when the exhaust temperature of the compressor fluctuates frequently, thereby reducing the exhaust temperature and suction temperature of the compressor, thereby avoiding the fluctuation of the indoor unit outlet temperature caused by the frequent switching state of the liquid injection valve, and thereby improving the stability of the outlet temperature.

[0004] The invention also provides a control device for the multi-connected air conditioning system.

[0005] The invention also provides a multi-connected air conditioning system.

[0006] According to a control method of a multi-split air conditioning system provided by an embodiment of a first aspect of the present invention, the refrigerant circulation circuit of the multi-split air conditioning system includes a liquid injection valve, and the control method includes:

[0007] Obtaining the operation mode of the multi-split air conditioning system, the number of fluctuations of the exhaust temperature of the compressor within a first preset time, the current frequency of the compressor, and the number of openings and closings of the injection valve within the first preset time, and determining the fluctuation association state according to the fluctuation number, the opening and closing number, and the pre-acquired association relationship; wherein the fluctuation association state includes an unrelated state and a related state;

[0008] When the operating mode is the cooling mode, and the number of fluctuations is greater than or equal to the preset number, and the fluctuation association state is the related state, a signal is sent to control the operating frequency of the compressor to be the target frequency; wherein the target frequency is lower than the current frequency, and the frequency difference is the preset frequency difference.

[0009] According to one embodiment of the present invention, the number of fluctuations of the exhaust gas temperature of the compressor within a first preset time period is obtained by the following steps:

[0010] Acquire the exhaust temperature of the compressor, and record the over-temperature moment when the exhaust temperature is greater than the pre-acquired first preset temperature and the under-temperature moment when the exhaust temperature is less than the pre-acquired second preset temperature;

[0011] When there is an over-temperature moment and a low-temperature moment between two adjacent recorded moments, it is determined that a fluctuation occurs;

[0012] The number of fluctuations is determined according to all recorded moments within the first preset time period.

[0013] According to an embodiment of the present invention, the step of determining the fluctuation association state according to the fluctuation number, the opening and closing number, and the pre-acquired association relationship specifically includes:

[0014] When the number of fluctuations is equal to the number of opening and closing, the fluctuation association state is a related state;

[0015] When the fluctuation number is not equal to the opening and closing number, the fluctuation association state is an irrelevant state.

[0016] According to an embodiment of the present invention, the step of determining the fluctuation association state according to the fluctuation number, the opening and closing number, and the pre-acquired association relationship further includes:

[0017] Recording the end time of a fluctuation of the exhaust temperature of the compressor, and recording the end time of a closing and opening of the liquid injection valve;

[0018] When the number of fluctuations is equal to the number of opening and closing, and the fluctuation termination time and the opening and closing termination time appear alternately, the fluctuation association state is a related state;

[0019] When the number of fluctuations is not equal to the number of opening and closing, or the fluctuation termination time and the opening and closing termination time do not appear alternately, the fluctuation association state is an irrelevant state.

[0020] According to one embodiment of the present invention, the multi-split air conditioning system includes a plurality of indoor units, and an indoor valve is provided at an air inlet of an evaporator of each indoor unit, then the step of sending a signal for controlling the operating frequency of the compressor to be a target frequency further includes:

[0021] After the second preset time, obtaining the number of fluctuations of the exhaust temperature of the compressor within a third preset time;

[0022] When the number of fluctuations is greater than zero, the openings of the multiple indoor valves are obtained, and a signal is sent to adjust the minimum opening among the multiple openings to a first target opening; wherein, at the first target opening, the superheat of the corresponding indoor unit evaporator is reduced by a preset temperature.

[0023] According to one embodiment of the present invention, the step of issuing a signal to adjust the minimum opening among the plurality of openings to the first target opening further includes:

[0024] After the fourth preset time period, obtaining the number of fluctuations of the exhaust temperature of the compressor within the first preset time period;

[0025] When the number of fluctuations is greater than zero, the operation of the compressor is controlled again according to the fluctuation association state within the first preset time period.

[0026] According to one embodiment of the present invention, the step of obtaining the number of fluctuations of the exhaust temperature of the compressor within the third preset time period further includes:

[0027] When the number of fluctuations is zero, the current outdoor ambient temperature is obtained, and the temperature difference between the current outdoor temperature and the initial outdoor ambient temperature obtained in advance at startup is calculated;

[0028] When the temperature difference is less than or equal to a preset temperature threshold, a signal is sent to control the operating frequency of the compressor to return to a preset frequency; wherein the preset frequency is determined according to a pre-stored compressor operating logic.

[0029] According to one embodiment of the present invention, when the number of fluctuations is greater than zero, the control method further includes:

[0030] The current wind speed of the indoor fan is obtained, and the current wind speed of the indoor fan is adjusted to a target wind speed; wherein a wind speed difference between the current wind speed and the target wind speed is positively correlated with the preset temperature.

[0031] A control device for a multi-split air conditioning system according to a second aspect of the present invention includes:

[0032] an acquisition module, for acquiring an operation mode of the multi-split air conditioning system, a number of fluctuations of the exhaust temperature of the compressor within a first preset time, a current frequency of the compressor, and an opening and closing number of the liquid injection valve within the first preset time, and determining a fluctuation association state according to the fluctuation number, the opening and closing number, and a pre-acquired association relationship; wherein the fluctuation association state includes an unrelated state and a related state;

[0033] A signal sending module is used to send a signal to control the operating frequency of the compressor to a target frequency when the operating mode is a cooling mode, the number of fluctuations is greater than or equal to a preset number, and the fluctuation associated state is the related state; wherein the target frequency is lower than the current frequency, and the frequency difference is a preset frequency difference.

[0034] According to an embodiment of the third aspect of the present invention, a multi-split air-conditioning system is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the control method of the multi-split air-conditioning system provided by the embodiment of the first aspect of the present invention are implemented.

[0035] The above one or more technical solutions in the present invention have at least one of the following technical effects:

[0036] According to the first aspect of the present invention, a control method for a multi-split air-conditioning system provided by an embodiment includes: obtaining an operating mode of the multi-split air-conditioning system, the number of fluctuations of the exhaust temperature of the compressor within a first preset time period, the current frequency of the compressor, and the number of opening and closing times of the injection valve within the first preset time period, and determining a fluctuation association state based on the number of fluctuations, the number of opening and closing times, and a pre-acquired association relationship; wherein the fluctuation association state includes an unrelated state and a related state; when the operating mode is a cooling mode, and the number of fluctuations is greater than or equal to a preset number, and the fluctuation association state is the related state, a signal is sent to control the operating frequency of the compressor to a target frequency; wherein the target frequency is lower than the current frequency, and the frequency difference is a preset frequency difference. When the multi-split air-conditioning system is operating in the cooling mode, if the exhaust temperature of the compressor fluctuates multiple times within a first preset time period, and the temperature fluctuation is caused by the opening and closing of the spray valve, the operating frequency of the compressor is controlled to be reduced from the current frequency to the target frequency. At this time, the exhaust temperature and the suction temperature of the compressor are reduced, and the exhaust temperature can be maintained between the first preset temperature and the second preset temperature, avoiding fluctuations in the outlet air temperature of the indoor unit due to frequent opening and closing of the spray valve, maintaining the stability of the outlet air temperature, and improving the user's comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 One of the flow charts of the control method of the multi-split air conditioning system provided by the embodiment of the present invention;

[0039] Figure 2 A second flowchart of a control method for a multi-split air conditioning system provided by an embodiment of the present invention;

[0040] Figure 3 A schematic structural diagram of a control device for a multi-split air conditioning system provided by an embodiment of the present invention;

[0041] Figure 4 A schematic structural diagram of a multi-split air conditioning system provided in an embodiment of the present invention.

[0042] Reference numerals:

[0043] 301, acquisition module; 302, signal sending module. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the invention clearer, the technical solution in the invention will be clearly described below in conjunction with the drawings in the invention. Obviously, the described embodiments are part of the embodiments of the invention, not all of the embodiments. Based on the embodiments in the invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the invention.

[0045] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0046] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0047] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0049] The multi-split air conditioning system will perform a series of controls around compressor protection and system pressure stability to ensure that all operating pressure points are within a reasonable range. In related technologies, in order to maintain the stability of system operation, when the air conditioning system is regulated, the outlet temperature will fluctuate, reducing the user's comfort.

[0050] The multi-split air conditioning system provided by the embodiment of the present invention includes multiple indoor units or multiple outdoor units, multiple indoor units are connected in parallel, multiple outdoor units are connected in parallel, and then connected through a total refrigerant pipe. The indoor unit includes an evaporator and an indoor fan, etc., the outdoor unit includes a condenser and an outdoor fan, etc., and the remaining components are the same as or adapted to the components of other air conditioning systems. In order to make the refrigerant amount and refrigerant state in the multi-split air conditioning system meet the requirements of normal operation, the evaporator inlet of each indoor unit is also provided with an indoor valve, and the condenser inlet of each outdoor unit is also provided with an outdoor valve. The indoor valve and the outdoor valve can adjust the refrigerant flow rate of the refrigerant flowing downstream, and can control the superheat before and after the refrigerant heat exchange. Taking the evaporator as an example, when the indoor fan speed remains unchanged and the indoor ambient temperature is stable, the heat that the indoor air can exchange with the evaporator per unit time is determined; if the opening of the indoor valve is increased, the refrigerant flow rate flowing into the evaporator per unit time increases, and under the same heat exchange efficiency, the refrigerant temperature at the outlet of the evaporator changes less, and the suction temperature of the compressor is reduced.

[0051] At the same time, a liquid spray valve is also provided on the refrigerant circulation loop of the multi-split air-conditioning system, and the liquid spray valve can be opened and closed when the exhaust temperature changes. When the exhaust temperature of the compressor is greater than the first preset temperature, for example, greater than 90 degrees Celsius, it is in an open state. At this time, the suction temperature of the compressor is reduced, and the exhaust temperature is reduced at the same time. After the liquid spray valve is opened for a certain period of time, the exhaust temperature decreases until it is less than the second preset temperature, for example, less than 80 degrees Celsius, at which time the liquid spray valve is closed. As the liquid spray valve closes, the exhaust temperature begins to gradually rise again, and the liquid spray valve will open again. The periodic fluctuation causes the opening of the indoor valve to change periodically, the indoor coil temperature of the evaporator to change periodically, and the outlet temperature of the indoor fan to fluctuate.

[0052] According to a first aspect of the present invention, a control method for a multi-split air conditioning system is provided, comprising:

[0053] Obtaining the operation mode of the multi-split air conditioning system, the number of fluctuations of the exhaust temperature of the compressor within a first preset time, the current frequency of the compressor, and the number of openings and closings of the injection valve within the first preset time, and determining the fluctuation association state according to the fluctuation number, the opening and closing number, and the pre-acquired association relationship; wherein the fluctuation association state includes an unrelated state and a related state;

[0054] When the operating mode is cooling mode, and the number of fluctuations is greater than or equal to the preset number, and the fluctuation association state is a related state, a signal is sent to control the operating frequency of the compressor to be the target frequency; wherein the target frequency is lower than the current frequency, and the frequency difference is the preset frequency difference.

[0055] It is understandable that when the multi-split air conditioning system is running in cooling mode and the outdoor ambient temperature is higher than the high temperature threshold, in order to improve the heat exchange efficiency of the air conditioning system, the exhaust temperature of the compressor will be higher. At this time, the number of fluctuations of the exhaust temperature of the compressor within the first preset time is detected. For example, the exhaust temperature fluctuates 4 times within 30 minutes, and the preset number is 3 times. At this time, the exhaust temperature of the compressor fluctuates more frequently, which will cause the outlet air temperature of the indoor unit to fluctuate frequently. It is necessary to further determine whether the exhaust temperature fluctuation is related to the opening and closing of the spray valve.

[0056] The fluctuation association state is determined based on the number of fluctuations in the compressor exhaust temperature within a first preset time period, the number of opening and closing times of the injection valve, and a pre-acquired association relationship. The pre-acquired association relationship is a program set in the storage module. The fluctuation association state can be determined based on the number of fluctuations in the compressor exhaust temperature and the number of opening and closing times of the injection valve, wherein the fluctuation association state includes an unrelated state and a related state.

[0057] If the fluctuation correlation state is a related state, it means that the fluctuation of exhaust temperature is caused by the opening and closing action of the injection valve. At this time, measures need to be taken to avoid frequent opening and closing of the injection valve. If the fluctuation correlation state is an unrelated state, it is necessary to find other reasons and solve the phenomenon of exhaust temperature fluctuation through other means.

[0058] When the operating mode is cooling mode, and the number of fluctuations is greater than or equal to the preset number, and the fluctuation association state is a related state, a signal is sent to control the operating frequency of the compressor to be the target frequency; wherein the target frequency is lower than the current frequency, and the frequency difference is the preset frequency difference.

[0059] It is understandable that reducing the operating frequency of the compressor by a preset frequency difference from the current frequency to the target frequency can reduce the exhaust temperature of the compressor. When the heat exchange efficiency does not change, the suction temperature of the compressor will also decrease, thereby limiting the exhaust temperature of the compressor between the first preset temperature and the second preset temperature, for example, between 90 degrees Celsius and 80 degrees Celsius, corresponding to the opening temperature and closing temperature of the injection valve.

[0060] When the exhaust temperature of the compressor is between the first preset temperature and the second preset temperature, the injection valve will not open and close frequently, thereby not causing the exhaust temperature of the compressor to fluctuate. At this time, the air outlet temperature of the indoor unit can remain stable.

[0061] See also Figure 1 The control method of the multi-split air conditioning system provided by the embodiment of the present invention includes the following process:

[0062] S100, obtaining the operating mode of the multi-split air conditioning system, obtaining the number of fluctuations of the exhaust temperature of the compressor within a first preset time period, obtaining the current frequency of the compressor and the number of opening and closing times of the injection valve within the first preset time period.

[0063] S110, judging whether: the operation mode is the cooling mode, and the number of fluctuations is greater than or equal to a preset number.

[0064] If not, execute step S120; if yes, execute step S130.

[0065] S120: Sending a signal to control the compressor to operate according to the current frequency.

[0066] S130, determining a fluctuation association state according to the fluctuation times, the opening and closing times, and the pre-acquired association relationship.

[0067] S140: Determine whether the fluctuation association state is a related state.

[0068] If not, execute step S150; if yes, execute step S160.

[0069] S150: Send a signal to control the operating frequency of the compressor to be the current frequency.

[0070] S160: Send a signal to control the operating frequency of the compressor to be the target frequency.

[0071] It should be noted that the above process is only one implementation method of the control method of the multi-split air-conditioning system. Other similar processes can execute step S160 when the operating mode is the cooling mode, the number of fluctuations is greater than or equal to the preset number, and the fluctuation association state is a related state, which also belongs to the technical concept of the embodiment of the present invention.

[0072] In the embodiment of the present invention, the frequent opening and closing of the liquid injection valve is avoided by reducing the suction temperature and exhaust temperature of the compressor. The number of fluctuations of the exhaust temperature of the compressor within the first preset time is obtained by the following steps:

[0073] The exhaust temperature of the compressor is obtained, and the over-temperature moment when the exhaust temperature is greater than the pre-acquired first preset temperature and the low-temperature moment when the exhaust temperature is less than the pre-acquired second preset temperature are recorded.

[0074] When there is an over-temperature moment and a low-temperature moment between two adjacent recorded moments, it is determined that a fluctuation occurs.

[0075] The number of fluctuations is determined according to all recorded moments within the first preset time period.

[0076] It is understandable that the first preset temperature and the second preset temperature are pre-stored in the system, for example, 90 degrees Celsius and 80 degrees Celsius, corresponding to the opening temperature and the closing temperature of the injection valve. When the exhaust temperature fluctuates, it needs to continuously experience a situation where the temperature is greater than the first preset temperature once, and a situation where the temperature is less than the second preset temperature once.

[0077] When the exhaust temperature is determined to be greater than the first preset temperature, the corresponding over-temperature moment is recorded immediately; when the exhaust temperature is determined to be less than the second preset temperature, the corresponding low-temperature moment is recorded immediately. In the above manner, multiple over-temperature moments and multiple low-temperature moments can be recorded. Only when two adjacent recorded moments are respectively the over-temperature moment and the low-temperature moment, is it confirmed that a fluctuation has been completed. At this time, the indoor unit's air outlet temperature fluctuates greatly, which has a greater impact on the user.

[0078] Afterwards, all recorded moments within the first preset time period are counted, and the number of fluctuations within the first preset time period can be obtained based on whether the moments of two adjacent records meet the confirmation condition.

[0079] Through the above method, the total number of fluctuations of the exhaust temperature of the compressor within the first preset time period can be obtained, and the fluctuation of the outlet air temperature can be determined accordingly.

[0080] It should be noted that the first preset duration can be 10 minutes, 20 minutes or 30 minutes, etc., determined according to actual conditions. At the same time, the preset number of times will also change with the adjustment of the first preset duration. For example, if the fluctuation is more than twice within 10 minutes, or more than four times within 30 minutes, it will be confirmed as frequent fluctuation.

[0081] In some embodiments, the step of determining the fluctuation association state according to the fluctuation times, the opening and closing times, and the pre-acquired association relationship specifically includes:

[0082] When the number of fluctuations is equal to the number of opening and closing, the fluctuation association state is the related state.

[0083] When the number of fluctuations is not equal to the number of opening and closing, the fluctuation association state is an irrelevant state.

[0084] It can be understood that within the first preset time, if the number of fluctuations is equal to the number of opening and closing times, it means that there is a direct correlation between the opening and closing of the liquid injection valve and the fluctuation of the exhaust temperature, and the fluctuation association state is a related state. If the number of fluctuations is not equal to the number of opening and closing times, it means that there is no direct correlation between the opening and closing of the liquid injection valve and the fluctuation of the exhaust temperature, and the fluctuation association state is an unrelated state.

[0085] In some other embodiments, the step of determining the fluctuation association state according to the fluctuation times, the opening and closing times, and the pre-acquired association relationship further includes:

[0086] The exhaust gas temperature of the compressor completes a fluctuation and ends the fluctuation, and the injection valve completes a closing and opening and closing and ends the fluctuation.

[0087] When the number of fluctuations is equal to the number of opening and closing, and the fluctuation termination moment and the opening and closing termination moment appear alternately, the fluctuation association state is a related state.

[0088] When the number of fluctuations is not equal to the number of opening and closing, or the fluctuation end time and the opening and closing end time do not appear alternately, the fluctuation association state is an irrelevant state.

[0089] It is understandable that if it is determined that there is an over-temperature moment and a low-temperature moment between two adjacent recorded moments, the latter of the two adjacent recorded moments is used as the fluctuation termination moment. The opening and closing of the liquid injection valve is controlled by the controller, and one opening and closing can be determined to be completed according to two adjacent control signals including a low level and a high level, and the moment of each opening and closing is recorded, and the latter of the two adjacent recorded opening and closing moments is used as the opening and closing termination moment.

[0090] After the spray valve is opened or closed, the refrigerant temperature changes directly, but there is a certain lag in reaching the highest or lowest point. If the temperature fluctuation is caused by the opening and closing of the spray valve, the fluctuation end time and the opening and closing end time will appear alternately. If the above conditions are not met, it means that the fluctuation association state is an irrelevant state.

[0091] See also Figure 2 The control method of the multi-split air conditioning system provided by the embodiment of the present invention includes the following process:

[0092] S200, obtaining the operating mode of the multi-split air-conditioning system, obtaining the number of fluctuations of the exhaust temperature of the compressor within a first preset time period, obtaining the current frequency of the compressor and the number of opening and closing times of the injection valve within the first preset time period, recording the end time of the fluctuation of the exhaust temperature of the compressor after completing one fluctuation, and recording the end time of the opening and closing of the injection valve after completing one opening and closing.

[0093] S210, determining whether the operation mode is the cooling mode and whether the number of fluctuations is greater than or equal to a preset number.

[0094] If not, execute step S220; if yes, execute step S231.

[0095] S220: Send a signal to control the operating frequency of the compressor to be the current frequency.

[0096] S231, determine whether the following conditions are met: the number of fluctuations is equal to the number of opening and closing times, and the fluctuation end time and the opening and closing end time appear alternately.

[0097] If not, execute step S232; if yes, execute step S233.

[0098] S232: Send a signal to control the operating frequency of the compressor to be the current frequency.

[0099] S233. Determine that the fluctuation association state is a related state.

[0100] S240: Determine whether the fluctuation association state is a related state.

[0101] If not, execute step S250; if yes, execute step S260.

[0102] S250: Send a signal to control the operating frequency of the compressor to be the current frequency.

[0103] S260: Send a signal to control the operating frequency of the compressor to be the target frequency.

[0104] It should be noted that the above process is only one implementation method of the control method of the multi-split air-conditioning system. Other similar processes can execute step S260 when the operating mode is the cooling mode, the number of fluctuations is greater than or equal to the preset number, and the fluctuation association state is a related state.

[0105] In some embodiments, the step of issuing a signal for controlling the operating frequency of the compressor to be the target frequency further includes:

[0106] After the second preset time period, the number of fluctuations of the exhaust temperature of the compressor within a third preset time period is obtained.

[0107] When the number of fluctuations is greater than zero, the openings of multiple indoor valves are obtained, and a signal is sent to adjust the minimum opening among the multiple openings to a first target opening; wherein, at the first target opening, the superheat of the evaporator of the corresponding indoor unit is reduced by a preset temperature.

[0108] It is understandable that after the compressor operating frequency is reduced to the target frequency, the compressor suction temperature and exhaust temperature will be reduced, and the opening and closing action of the injection valve will be limited. However, there are many interference factors during the operation of the multi-split air conditioning system, and the control effect still needs to be detected and corrected.

[0109] After running for a second preset time, for example, after running for 30 minutes, it is possible to detect again whether the exhaust temperature of the compressor still fluctuates within the next third preset time. When the number of fluctuations is greater than zero, that is, the fluctuation of the air outlet temperature has not been completely resolved, the suction temperature of the compressor can be adjusted by adjusting the opening of the indoor valve.

[0110] A multi-split air-conditioning system has multiple indoor units and multiple indoor valves. There is a minimum opening among the multiple openings. The minimum opening is increased to the first target opening, for example, opening +1. At this time, the refrigerant flow in the corresponding indoor unit evaporator increases. When the heat exchange efficiency does not change, the refrigerant temperature at the evaporator outlet decreases, and the suction temperature of the compressor decreases, which can further lead to a decrease in the exhaust temperature.

[0111] By adopting the above method, it is possible to avoid further reducing the frequency of the compressor, and the compressor can be operated efficiently to meet the cooling demand. Moreover, the adjustment is made to the indoor valve with the minimum opening, which has little impact on the heat exchange efficiency of other indoor units, and also has little impact on the indoor unit corresponding to the adjusted indoor valve.

[0112] In some embodiments, the step of issuing a signal to adjust the minimum opening of the plurality of openings to the first target opening further includes:

[0113] After the fourth preset time period, the number of fluctuations of the exhaust temperature of the compressor within the first preset time period is obtained.

[0114] When the number of fluctuations is greater than zero, the compressor operation is controlled again according to the fluctuation correlation state within the first preset time period.

[0115] It can be understood that the above steps are further adjustment strategies after the indoor unit valve is adjusted. In the first stage, the frequency of the compressor is reduced to avoid fluctuations in the outlet air temperature; in the second stage, the opening of the indoor unit valve is adjusted in a way that has the least impact; in the third stage, the operating frequency of the compressor is adjusted again to control the fluctuations in the indoor unit outlet air temperature. The above method can make the exhaust temperature of the compressor gradually approach the first preset temperature and the second preset temperature, which can make the indoor unit outlet air temperature fluctuate less and the system relatively stable and reliable.

[0116] In some embodiments, the step of obtaining the number of fluctuations of the exhaust gas temperature of the compressor within the third preset time period further includes:

[0117] When the number of fluctuations is zero, the current outdoor ambient temperature is obtained, and the temperature difference between the current outdoor temperature and the initial outdoor ambient temperature obtained in advance at startup is calculated.

[0118] When the temperature difference is less than or equal to a preset temperature threshold, a signal is sent to control the operating frequency of the compressor to return to a preset frequency; wherein the preset frequency is determined according to a pre-stored compressor operating logic.

[0119] It is understandable that as the operating frequency of the compressor decreases to the target frequency, the number of fluctuations decreases to zero, indicating that the above control strategy is effective. When the multi-split air conditioning system continues to operate, the outdoor ambient temperature will change. For example, the outdoor ambient temperature is high at noon, and steps S100 to S160 can be executed; in the afternoon, the outdoor ambient temperature decreases, and the exhaust temperature of the compressor rarely exceeds the temperature. At this time, the operating frequency of the compressor can be controlled to return to the preset frequency; wherein the preset frequency is determined according to the pre-stored compressor operation logic and is related to the outdoor ambient temperature.

[0120] In some embodiments, when the number of fluctuations is greater than zero, the control method of the multi-split air conditioning system further includes:

[0121] The current wind speed of the indoor fan is obtained, and the current wind speed of the indoor fan is adjusted to a target wind speed; wherein the wind speed difference between the current wind speed and the target wind speed is positively correlated with a preset temperature.

[0122] It is understandable that lowering the suction temperature of the compressor can effectively control the opening and closing action of the spray valve and the fluctuation of the indoor unit's air outlet temperature. After the operating frequency of the compressor is reduced, if there is still temperature fluctuation, then in order to maintain the efficient operation of the compressor, the operating frequency of the compressor can be reduced instead of continuing to be adjusted down. Instead, the wind speed of the indoor fan can be reduced to reduce the heat exchange efficiency between the indoor air and the refrigerant in the evaporator. At this time, the refrigerant temperature at the evaporator outlet is reduced, and the suction temperature of the compressor is reduced, which can also achieve a similar effect. Among them, the greater the wind speed difference between the current wind speed and the target wind speed, the more the evaporator heat exchange efficiency is reduced, and the preset temperature will also be greater. The wind speed difference is positively correlated with the preset temperature.

[0123] According to the second aspect of the present invention, the control device of the multi-split air conditioning system is provided. Figure 3 ,include:

[0124] The acquisition module 301 is used to acquire the operation mode of the multi-split air conditioning system, the number of fluctuations of the exhaust temperature of the compressor within a first preset time, the current frequency of the compressor, and the number of openings and closings of the injection valve within the first preset time, and determine the fluctuation association state according to the fluctuation number, the opening and closing number, and the pre-acquired association relationship; wherein the fluctuation association state includes an unrelated state and a related state;

[0125] The signal sending module 401 is used to send a signal to control the operating frequency of the compressor to a target frequency when the operating mode is a cooling mode, the number of fluctuations is greater than or equal to a preset number, and the fluctuation associated state is the related state; wherein the target frequency is lower than the current frequency, and the frequency difference is a preset frequency difference.

[0126] It should be noted that the above steps S100 to S160, as well as other steps, are only for the convenience of expression and do not constitute a time sequence limitation for each step in the control method of the multi-split air-conditioning system. In addition, some contents are described in detail in the control method of the multi-split air-conditioning system provided in the first aspect embodiment, and the contents in all the control methods of the multi-split air-conditioning system are also applicable to the control device of the multi-split air-conditioning system provided in the second aspect embodiment, and in order to avoid repetition, the control device of the multi-split air-conditioning system provided in the third aspect embodiment is not described in detail. Similarly, the contents in the above two aspects of the embodiments can be used to explain the contents of all the subsequent aspects of the embodiments, so the repeated contents will not be repeated in the subsequent embodiments. The technical effect of the control device of the multi-split air-conditioning system provided in the embodiment of the present invention corresponds to the technical effect of the above-mentioned control method of the multi-split air-conditioning system, which will not be repeated here.

[0127] According to an embodiment of the third aspect of the present invention, a multi-split air-conditioning system is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the control method of the multi-split air-conditioning system provided by the embodiment of the first aspect of the present invention are implemented.

[0128] Figure 4 An example of a physical structure diagram of an electronic device is provided, and the electronic device may include: a processor 810, a communication interface 820, a memory 830, and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute a control method for a multi-split air conditioning system, and the method includes: obtaining the operation mode of the multi-split air conditioning system, the number of fluctuations of the exhaust temperature of the compressor within a first preset time length, the current frequency of the compressor, and the number of openings and closings of the injection valve within the first preset time length, and determining the fluctuation association state according to the number of fluctuations, the number of openings and closings, and the pre-acquired association relationship; wherein the fluctuation association state includes an irrelevant state and a relevant state; when the operation mode is a cooling mode, and the number of fluctuations is greater than or equal to the preset number, and the fluctuation association state is the relevant state, a signal is sent to control the operation frequency of the compressor to be a target frequency; wherein the target frequency is lower than the current frequency, and the frequency difference is a preset frequency difference.

[0129] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0130] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0131] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution 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 can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0132] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method for a multi-split air conditioning system, characterized in that: The refrigerant circulation loop of the multi-split air conditioning system includes a liquid injection valve, and the control method includes: Obtaining the operation mode of the multi-split air conditioning system, the number of fluctuations of the exhaust temperature of the compressor within a first preset time, the current frequency of the compressor, and the number of openings and closings of the injection valve within the first preset time, and determining the fluctuation association state according to the fluctuation number, the opening and closing number, and the pre-acquired association relationship; wherein the fluctuation association state includes an unrelated state and a related state; When the operating mode is the cooling mode, and the number of fluctuations is greater than or equal to the preset number, and the fluctuation association state is the related state, a signal is sent to control the operating frequency of the compressor to be the target frequency; wherein the target frequency is lower than the current frequency, and the frequency difference is the preset frequency difference.

2. The control method of the multi-split air conditioning system according to claim 1, characterized in that: The number of fluctuations of the exhaust gas temperature of the compressor within the first preset time period is obtained by the following steps: Acquire the exhaust temperature of the compressor, and record the over-temperature moment when the exhaust temperature is greater than the pre-acquired first preset temperature and the under-temperature moment when the exhaust temperature is less than the pre-acquired second preset temperature; When there is an over-temperature moment and a low-temperature moment between two adjacent recorded moments, it is determined that a fluctuation occurs; The number of fluctuations is determined according to all recorded moments within the first preset time period.

3. The control method of the multi-split air conditioning system according to claim 2, characterized in that: The step of determining the fluctuation association state according to the fluctuation number, the opening and closing number, and the pre-acquired association relationship specifically includes: When the number of fluctuations is equal to the number of opening and closing, the fluctuation association state is a related state; When the fluctuation number is not equal to the opening and closing number, the fluctuation association state is an irrelevant state.

4. The control method of a multi-split air conditioning system according to claim 2, characterized in that: The step of determining the fluctuation association state according to the fluctuation number, the opening and closing number, and the pre-acquired association relationship further includes: Recording the end time of a fluctuation of the exhaust temperature of the compressor, and recording the end time of a closing and opening of the liquid injection valve; When the number of fluctuations is equal to the number of opening and closing, and the fluctuation termination time and the opening and closing termination time appear alternately, the fluctuation association state is a related state; When the number of fluctuations is not equal to the number of opening and closing, or the fluctuation termination time and the opening and closing termination time do not appear alternately, the fluctuation association state is an irrelevant state.

5. The control method of a multi-split air conditioning system according to any one of claims 1 to 4, characterized in that: The multi-split air conditioning system includes a plurality of indoor units, and an indoor valve is provided at the air inlet of the evaporator of each indoor unit. Then, the step of sending a signal for controlling the operating frequency of the compressor to be the target frequency further includes: After the second preset time, obtaining the number of fluctuations of the exhaust temperature of the compressor within a third preset time; When the number of fluctuations is greater than zero, the openings of the multiple indoor valves are obtained, and a signal is sent to adjust the minimum opening among the multiple openings to a first target opening; wherein, at the first target opening, the superheat of the corresponding indoor unit evaporator is reduced by a preset temperature.

6. The control method of the multi-split air conditioning system according to claim 5, characterized in that: The step of sending a signal to adjust the minimum opening among the plurality of openings to the first target opening further includes: After the fourth preset time period, obtaining the number of fluctuations of the exhaust temperature of the compressor within the first preset time period; When the number of fluctuations is greater than zero, the operation of the compressor is controlled again according to the fluctuation association state within the first preset time period.

7. The control method of a multi-split air conditioning system according to claim 5, characterized in that: The step of obtaining the number of fluctuations of the exhaust temperature of the compressor within the third preset time period further includes: When the number of fluctuations is zero, the current outdoor ambient temperature is obtained, and the temperature difference between the current outdoor temperature and the initial outdoor ambient temperature obtained in advance at startup is calculated; When the temperature difference is less than or equal to a preset temperature threshold, a signal is sent to control the operating frequency of the compressor to return to a preset frequency; wherein the preset frequency is determined according to a pre-stored compressor operating logic.

8. The control method of a multi-split air conditioning system according to claim 5, characterized in that: When the number of fluctuations is greater than zero, the control method further includes: The current wind speed of the indoor fan is obtained, and the current wind speed of the indoor fan is adjusted to a target wind speed; wherein the wind speed difference between the current wind speed and the target wind speed is positively correlated with the preset temperature.

9. A control device for a multi-split air conditioning system, characterized in that: include: an acquisition module, for acquiring an operation mode of the multi-split air conditioning system, a number of fluctuations of the exhaust temperature of the compressor within a first preset time, a current frequency of the compressor, and an opening and closing number of the liquid injection valve within the first preset time, and determining a fluctuation association state according to the fluctuation number, the opening and closing number, and a pre-acquired association relationship; wherein the fluctuation association state includes an unrelated state and a related state; A signal sending module is used to send a signal to control the operating frequency of the compressor to a target frequency when the operating mode is a cooling mode, the number of fluctuations is greater than or equal to a preset number, and the fluctuation associated state is the related state; wherein the target frequency is lower than the current frequency, and the frequency difference is a preset frequency difference.

10. A multi-split air conditioning system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the control method of the multi-split air conditioning system as described in any one of claims 1 to 8 are implemented.

Images