Multi-connected air conditioner, control method and storage medium thereof, and electronic device

Abstract

The application discloses a multi-connected air conditioner and a control method and a storage medium and an electronic device thereof, and the method comprises the following steps: obtaining a theoretical exhaust pressure according to the geometric parameters of an outdoor unit, the air supply port parameters of an indoor unit, the outdoor environment temperature and the indoor environment temperature; obtaining a pressure deviation degree according to the high-pressure pressure of the outdoor unit and the theoretical exhaust pressure; and performing start control on the multi-connected system according to the pressure deviation degree. Therefore, the method can change the condition that the multi-connected air conditioner starts at low temperature first and then is protected, improve the reliability of the multi-connected air conditioner, and reduce the maintenance cost of the multi-connected air conditioner.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to a multi-split air conditioner, its control method, storage medium, and electronic equipment. Background Technology

[0002] Currently, the lower limit of the low-temperature heating operation range for multi-split air conditioning systems has reached -30°C. Compared to conventional heating conditions, the start-up and operation conditions for ultra-low temperature heating are much more severe, especially during prolonged ultra-low temperature standby. For multi-refrigerant systems with indoor units on top and outdoor units below, when starting ultra-low temperature heating after a long period of ultra-low temperature standby, due to gravity and temperature difference, a large amount of low-temperature liquid refrigerant migrates to the outdoor unit side of the multi-split system. This results in a large amount of liquid refrigerant remaining in the outdoor unit's heat exchanger, low-pressure tank, and compressor. A full low-pressure tank means that when the compressor starts, the liquid refrigerant directly returns to the compressor's return port, inevitably causing a large amount of liquid to be carried into the compressor's intake. This will lead to abnormal compressor startup, causing abnormal vibration in the system piping and serious damage to the compressor. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the purpose of this invention is to propose a multi-split air conditioner and its control method, which can store media and electronic devices, to change the situation where multi-split air conditioners start up first and then protect themselves at low temperatures, thereby improving the reliability of multi-split air conditioners and reducing their maintenance costs.

[0004] In a first aspect, the present invention proposes a control method for a multi-split air conditioner, the multi-split air conditioner including an outdoor unit and an indoor unit, the method comprising: obtaining a theoretical exhaust pressure based on the geometric parameters of the outdoor unit, the air outlet parameters of the indoor unit, the outdoor ambient temperature and the indoor ambient temperature; obtaining a pressure deviation based on the high pressure of the outdoor unit and the theoretical exhaust pressure; and performing start-up control on the multi-split system based on the pressure deviation.

[0005] Secondly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the method of the above embodiments.

[0006] Thirdly, the present invention provides an electronic device including a memory, a processor, and a computer program stored in the memory, wherein the computer program, when executed by the processor, implements the method of the above embodiments.

[0007] Fourthly, the present invention proposes a multi-split air conditioner, including the electronic equipment described in the above embodiments.

[0008] The multi-split air conditioner and its control method, storage medium, and electronic equipment of this invention first evaluate the severity of the start-up based on the system parameters before the multi-split system starts up in low-temperature heating mode. Then, the evaluation results are used as the basis for selecting the system start-up strategy to change the situation where the multi-split system starts up first and then protects itself in low-temperature heating mode. Through start-up diagnosis, the system and compressor are further protected, thereby improving the reliability of the multi-split air conditioner and reducing the maintenance cost of the multi-split air conditioner.

[0009] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0010] Figure 1 This is a flowchart illustrating a control method for a multi-split air conditioner according to an embodiment of the present invention;

[0011] Figure 2 This is a schematic diagram of the structure of a multi-split air conditioner according to an embodiment of the present invention. Detailed Implementation

[0012] With the continuous upgrading of the HVAC market demand and the need to meet various customer requirements, multi-split air conditioners, as a part of the air conditioning market, also face higher challenges. One of these demands is the requirement for multi-split air conditioners to operate reliably over a wider range of cooling and heating conditions. Therefore, the long standby low-temperature heating start-up of multi-split air conditioners is a crucial issue that needs to be carefully considered during the design process. Currently, many multi-split air conditioner manufacturers have conducted extensive control optimizations on the low-temperature heating start-up process to avoid problems such as compressor liquid slugging and vibration. However, none of these technologies address the identification of system parameters before startup. Furthermore, in reality, if the system is in a state of refrigerant overload or severe refrigerant migration on the outdoor unit side, it is not advisable to start directly, as the compressor will inevitably experience liquid return, causing internal wear. Additional measures are needed to mitigate the refrigerant migration effect before attempting startup. To solve these problems, this invention proposes a multi-split air conditioner, its control method, storage medium, and electronic equipment.

[0013] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0014] The following is a reference appendix. Figure 1-2 This invention describes a multi-split air conditioner, its control method, storage medium, and electronic equipment according to embodiments of the present invention.

[0015] Figure 1This is a flowchart illustrating the control method for a multi-split air conditioner according to an embodiment of the present invention.

[0016] In an embodiment of the present invention, a multi-split air conditioner includes an outdoor unit and an indoor unit, wherein the outdoor unit is placed outdoors and the indoor unit is placed indoors. The number of indoor units may be one or more. The outdoor unit is connected to each indoor unit through piping, and the outdoor unit includes a compressor.

[0017] Furthermore, the outdoor unit also includes an oil separator, a four-way valve, and a gas-liquid separator. The outlet of the gas-liquid separator is connected to the return port of the compressor via a return pipe. The discharge port of the compressor is connected to the inlet of the oil separator. The discharge port of the oil separator is connected to the first end of the four-way valve. The second end of the four-way valve is connected to one end of the indoor heat exchanger of the indoor unit via a gas pipe. The other end of the indoor heat exchanger is connected to one end of the outdoor heat exchanger via a liquid pipe. The other end of the outdoor heat exchanger is connected to the third end of the four-way valve. The fourth end of the four-way valve is connected to the inlet of the gas-liquid separator. Each indoor unit includes an indoor heat exchanger, and the outdoor unit also includes an outdoor heat exchanger and a throttling device connecting the outdoor heat exchanger and the indoor heat exchanger. The throttling device can be an electronic expansion valve.

[0018] like Figure 1 As shown, the control methods for multi-split air conditioners include:

[0019] S101. Based on the geometric parameters of the outdoor unit, the air outlet parameters of the indoor unit, the outdoor ambient temperature, and the indoor ambient temperature, the theoretical exhaust pressure is obtained.

[0020] Specifically, first obtain the geometric parameters (including length OduL) of all outdoor units in a separate refrigerant circulation system. i , width OduW i , high OduH i ), parameters of the air outlets of all indoor units (including: length of the air outlet). i , width IduW i ), outdoor ambient temperature sensor values ​​T4 for each outdoor unit i Temperature T1 of each indoor unit's ambient temperature sensor i In this multi-split air conditioner, the number of outdoor units is M, and the number of indoor units is N. The geometric parameters of the outdoor units and the air outlet parameters of the indoor units are inherent parameters of the refrigerant circulation system and can be pre-stored for direct retrieval. The outdoor ambient temperature can be measured in real time by temperature sensors installed on the outdoor units, and the indoor ambient temperature can be measured in real time by temperature sensors installed on the indoor units. Then, the theoretical exhaust pressure can be obtained based on the geometric parameters of the outdoor units, the air outlet parameters of the indoor units, the outdoor ambient temperature, and the indoor ambient temperature.

[0021] S102. Based on the high pressure of the outdoor unit and the theoretical exhaust pressure, the pressure deviation is obtained.

[0022] Specifically, the high pressure of the outdoor unit can be obtained by installing a high pressure sensor at the exhaust port of the multi-split air conditioner compressor, and recorded as the high pressure sensor value. Furthermore, the obtained theoretical exhaust pressure value... Comparison with high pressure sensor values By comparison, the pressure deviation DP can be calculated. The calculation process includes: calculating the difference between the theoretical exhaust pressure and the high-pressure pressure; calculating the ratio between the difference and the high-pressure pressure to obtain the pressure deviation DP. The formula for calculating the pressure deviation DP is: .

[0023] S103. Control the start-up of the multi-split system based on the pressure deviation.

[0024] Specifically, when the outdoor ambient temperature is low and normal startup of a multi-split air conditioner might cause damage, the severity of the startup conditions can be judged based on the pressure deviation. For example, if the pressure deviation is large, the startup conditions can be considered generally severe. In this case, only the outdoor unit compressor can be preheated. Once certain conditions are met (such as a certain preheating time), the normal startup logic of the multi-split air conditioner (i.e., the conventional logic suitable for direct startup) can be executed. If the pressure deviation is small, the startup conditions can be considered relatively severe. In this case, while preheating the outdoor unit compressor, electric auxiliary heating of the indoor unit can be applied, the compressor can be started at a specific frequency, and the electronic expansion valves of the indoor and outdoor units can be adjusted. Once certain conditions are met, the normal startup logic of the multi-split air conditioner can be executed. Therefore, determining the startup logic based on the severity of the startup conditions of the multi-split air conditioner can change the situation where multi-split air conditioners start first and then protect themselves when heating at low temperatures, thereby improving the reliability of multi-split air conditioners and reducing maintenance costs.

[0025] In one embodiment of the present invention, M and N can both be integers greater than 1.

[0026] In this embodiment, step S101 may include: obtaining the outdoor unit's radiative heat transfer area based on M geometric parameters, obtaining the indoor unit's radiative heat transfer area based on N air outlet parameters, obtaining the outdoor unit's average ambient temperature based on M outdoor ambient temperatures, and obtaining the indoor unit's average ambient temperature based on N indoor ambient temperatures; obtaining the theoretical exhaust saturation temperature and the theoretical intake saturation temperature based on the outdoor unit's radiative heat transfer area, the indoor unit's radiative heat transfer area, the outdoor unit's average ambient temperature, and the indoor unit's average ambient temperature; and obtaining the theoretical exhaust pressure based on the theoretical exhaust saturation temperature and the theoretical intake saturation temperature.

[0027] In another embodiment of the present invention, the values ​​of M and N are both 1.

[0028] In this embodiment, the calculation of the average ambient temperature of the outdoor unit and the average ambient temperature of the indoor unit is not required. The theoretical exhaust saturation temperature and the theoretical intake saturation temperature can be obtained directly based on the radiative heat transfer area of ​​the outdoor unit, the radiative heat transfer area of ​​the indoor unit, the outdoor ambient temperature, and the indoor ambient temperature.

[0029] Specifically, the outdoor unit's radiative heat transfer area can be obtained using the following formula:

[0030] ,

[0031] in, This refers to the radiant heat exchange area of ​​the outdoor unit. , , These are the length, width, and height of the i-th outdoor unit, respectively.

[0032] The radiant heat transfer area of ​​the indoor unit can be obtained using the following formula:

[0033] ,

[0034] in, This refers to the radiant heat exchange area of ​​the indoor unit. , These are the length and width of the air outlet of the i-th indoor unit, respectively.

[0035] The average ambient temperature of the outdoor unit can be obtained using the following formula:

[0036] ,

[0037] in, The outdoor unit's average ambient temperature. The outdoor ambient temperature is collected by the temperature sensor installed on the i-th outdoor unit.

[0038] The average ambient temperature of the indoor unit can be obtained using the following formula:

[0039] ,

[0040] in, This represents the average ambient temperature of the indoor unit. The indoor ambient temperature is collected by the temperature sensor installed on the i-th indoor unit.

[0041] Furthermore, based on the aforementioned outdoor unit radiative heat exchange area... Indoor unit radiant heat exchange area Average ambient temperature of outdoor unit Average ambient temperature of indoor unit Furthermore, calculations can yield the theoretical exhaust saturation temperature Tc and theoretical intake saturation temperature Te of the system under ideal conditions, i.e., when the exhaust pipe is not filled with liquid refrigerant. The corresponding theoretical exhaust pressure Pc can then be obtained by querying the physical property parameters. Alternatively, the correspondence between the theoretical exhaust saturation temperature Tc, theoretical intake saturation temperature Te, and theoretical exhaust pressure Pc can be pre-saved. After obtaining the theoretical exhaust saturation temperature Tc and theoretical intake saturation temperature Te, this correspondence can be directly looked up to obtain the corresponding theoretical exhaust pressure Pc.

[0042] In this embodiment, the theoretical exhaust saturation temperature Tc and the theoretical intake saturation temperature Te can be obtained by the following formula:

[0043] ,and ,

[0044] in, For theoretical heat transfer intensity, This refers to the radiant heat exchange area of ​​the outdoor unit. This refers to the radiant heat exchange area of ​​the indoor unit. As the first coefficient, As the second coefficient, This is the theoretical exhaust saturation temperature. This is the theoretical intake saturation temperature. The outdoor unit's average ambient temperature. This represents the average ambient temperature of the indoor unit.

[0045] In one embodiment of the present invention, step S103 includes: when the pressure deviation is detected to be greater than or equal to a first deviation, controlling the multi-split air conditioner to execute a normal start-up process; when the pressure deviation is detected to be less than the first deviation and greater than or equal to a second deviation, preheating the multi-split air conditioner for a second preset time, then controlling the compressor to run at the minimum allowable operating frequency for a third preset time, then controlling the multi-split air conditioner to execute a normal start-up process; when the pressure deviation is detected to be less than the second deviation, preheating the multi-split air conditioner until the difference between the compressor exhaust port temperature and the condensing temperature of the multi-split air conditioner is greater than a second difference threshold, then controlling the multi-split air conditioner to execute a normal start-up process; wherein, the preheating power is greater than or equal to the theoretical heat exchange intensity, and the theoretical heat exchange intensity is obtained based on the outdoor unit radiative heat exchange area, the indoor unit radiative heat exchange area, the outdoor unit average ambient temperature, and the indoor unit average ambient temperature.

[0046] Specifically, if pressure deviation DP is detected If the first deviation is detected, the multi-split air conditioner's startup conditions can be considered suitable, and the multi-split air conditioner can be directly controlled to execute the normal startup procedure. If the pressure deviation DP is detected... (i.e., the first deviation), and the pressure deviation DP If the deviation is less than the second deviation, the multi-split air conditioner's starting conditions are considered poor. In this case, starting strategy one can be adopted to execute the starting process. Specifically, starting strategy one can be as follows: after the multi-split air conditioner is powered on, it performs the starting preparation action, that is, it starts the preheating measures (including one or more of the following: compressor crankshaft heating, compressor electric heating belt, low-pressure tank electric heating belt, and chassis heating), and maintains... After a set time (i.e., the second preset time), the compressor is controlled to operate at the minimum permissible operating frequency. After a certain period of time (i.e., the third preset period of time), the multi-split air conditioner will execute the normal start-up process.

[0047] If pressure deviation DP is detected If the deviation is too high (i.e., the second deviation), the multi-split air conditioner can be considered to have poor start-up conditions. In this case, start-up strategy two can be adopted to execute the start-up process. Specifically, start-up strategy two can be as follows: After the multi-split air conditioner is powered on, start-up preparation actions are performed, i.e., preheating measures are initiated (including one or more of the following: compressor crankshaft heating, compressor electric heating belt, low-pressure tank electric heating belt, and chassis heating). During this period, the compressor exhaust temperature TP and the multi-split air conditioner's condensing temperature TC can be collected in real time. When the difference between the compressor exhaust temperature and the multi-split air conditioner's condensing temperature, i.e., TP-TC, is greater than the second difference threshold (such as the minimum start-up exhaust superheat), the start-up strategy is considered to be successful. When the preheating is completed, the multi-split air conditioner is then controlled to perform the normal start-up process.

[0048] Wherein, the heating power of the preheating is greater than or equal to the theoretical heat transfer intensity calculated above. .

[0049] As an example, the first deviation Second deviation It is not a fixed value, but rather derived from the heat exchanger area and internal volume of the outdoor and indoor units of the current system, i.e., under different system configurations. The values ​​are all different.

[0050] As an example, during the normal startup process after preheating, the method may also include: calculating the current fluctuation amplitude based on the startup current; when the current fluctuation amplitude is detected to be greater than a preset amplitude threshold, stopping the normal startup process and returning to the preheating step.

[0051] Specifically, after the pre-start procedure is completed, during the normal chiller start-up strategy, additional monitoring of the starting current is required. This can be achieved by monitoring the instantaneous current fluctuations during compressor operation. After excluding the initial start-up period, the current values ​​at any two adjacent data collection points are recorded in real time. and Current value and Calculate the current fluctuation amplitude The calculation method is similar to that of the pressure deviation mentioned above, and the calculation formula is as follows: If detected Exceeding the maximum current fluctuation limit If the preset amplitude threshold is reached, it can be considered that the compressor has started abnormally. In this case, the normal start-up process should be stopped immediately and the process should return to the preheating step.

[0052] It should be understood that once the normal startup process has been executed, the entire startup control process will exit.

[0053] It should be noted that, generally, the compressor may only start abnormally after a multi-split air conditioner has been idle at low temperatures for an extended period, leading to abnormal vibration of the system piping and serious damage to the compressor. Therefore, the starting conditions of the multi-split air conditioner should be determined before performing step S101.

[0054] As one embodiment of the present invention, before obtaining the theoretical exhaust pressure, it is necessary to obtain the low-temperature start-up condition parameters of the multi-split air conditioner, determine whether the low-temperature start-up condition parameters meet the preset low-temperature start-up conditions, and if they do, then execute the step of obtaining the theoretical exhaust pressure based on the geometric parameters, the air outlet parameters, the outdoor ambient temperature and the indoor ambient temperature.

[0055] The low-temperature start-up condition parameters include the standby time of the multi-split air conditioner, the compressor exhaust port temperature, and the outdoor ambient temperature. The preset low-temperature start-up condition is any one of the following: the standby time is greater than or equal to the first preset time, and the outdoor ambient temperature is less than or equal to the first preset temperature; or, the difference between the compressor exhaust port temperature and the outdoor ambient temperature is less than or equal to the first difference threshold, and the outdoor ambient temperature is less than or equal to the first preset temperature.

[0056] Specifically, when the standby time T0 is greater than or equal to the minimum standby time TimeOff_Max (i.e., the first preset time), that is, T0≥TimeOff_Max, and the outdoor ambient temperature T4 is less than or equal to the highest temperature T4 for entering the low-temperature start-up mode. max (i.e., the first preset temperature), i.e., T4≤T4 max Alternatively, the difference between the compressor discharge port temperature TP and the outdoor ambient temperature T4 is less than or equal to the first difference threshold dT4. max That is, |TP-T4|≤dT4 max And the outdoor ambient temperature T4 is less than or equal to the first preset temperature T4 max At that time, the theoretical exhaust pressure is obtained based on geometric parameters, air outlet parameters, outdoor ambient temperature, and indoor ambient temperature.

[0057] Wherein, the outdoor ambient temperature T4 can be any outdoor ambient temperature corresponding to the outdoor unit, or it can be the average of multiple outdoor ambient temperatures. The first difference threshold can be a very small value, such as a value between 0.01 and 0.5, at which point the compressor discharge port temperature is basically equal to the outdoor ambient temperature.

[0058] In summary, the control method for this multi-split air conditioner, based on the system parameters before the multi-split system starts in low-temperature heating mode, first obtains the pressure deviation from the system parameters, evaluates the severity of the start-up based on the pressure deviation, and then uses the evaluation result as the basis for selecting the system start-up strategy. This changes the situation where multi-split systems start up first and then protect themselves in low-temperature heating mode. Through start-up diagnosis, the system and compressor are further protected, thereby improving the reliability of the multi-split air conditioner and reducing its maintenance costs.

[0059] Based on the control method for multi-split air conditioners described in the above embodiments, this invention proposes a computer-readable storage medium.

[0060] In an embodiment of the present invention, a computer program is stored on a computer-readable storage medium, and when the computer program is executed by a processor, the control method of the multi-split air conditioner described in the above embodiment is implemented.

[0061] When the computer program corresponding to the control method described above, stored on the computer-readable storage medium of this invention is executed, it diagnoses the severity of the startup conditions and performs startup control based on the diagnosis results. This changes the situation where multi-split air conditioners start up first and then protect themselves when heating at low temperatures, further protecting the system and compressor, thereby improving the reliability of multi-split air conditioners and reducing their maintenance costs.

[0062] Based on the control method for multi-split air conditioners described in the above embodiments, the present invention also proposes an electronic device.

[0063] In an embodiment of the present invention, the electronic device includes a memory, a processor, and a computer program stored in the memory. When the computer program is executed by the processor, it implements the control method of the multi-split air conditioner described in the above embodiment.

[0064] The electronic device of this invention executes a computer program stored in the memory corresponding to the control method described above by a processor. By diagnosing the severity of the start-up conditions and performing start-up control based on the diagnosis results, it can change the situation where multi-split air conditioners start up first and then protect themselves when heating at low temperatures, thereby further protecting the system and compressor, improving the reliability of multi-split air conditioners and reducing their maintenance costs.

[0065] Furthermore, the present invention also proposes a multi-split air conditioner.

[0066] Figure 2 This is a structural block diagram of a multi-split air conditioner according to an embodiment of the present invention.

[0067] like Figure 2 As shown, the multi-split air conditioner 100 includes the electronic device 10 of the above embodiment.

[0068] In an embodiment of the present invention, a multi-split air conditioner includes an outdoor unit and an indoor unit, wherein the outdoor unit is placed outdoors and the indoor unit is placed indoors. The number of indoor units may be one or more. The outdoor unit is connected to each indoor unit through piping, and the outdoor unit includes a compressor.

[0069] Furthermore, the outdoor unit also includes an oil separator, a four-way valve, and a gas-liquid separator. The outlet of the gas-liquid separator is connected to the return port of the compressor via a return pipe. The discharge port of the compressor is connected to the inlet of the oil separator. The discharge port of the oil separator is connected to the first end of the four-way valve. The second end of the four-way valve is connected to one end of the indoor heat exchanger of the indoor unit via a gas pipe. The other end of the indoor heat exchanger is connected to one end of the outdoor heat exchanger via a liquid pipe. The other end of the outdoor heat exchanger is connected to the third end of the four-way valve. The fourth end of the four-way valve is connected to the inlet of the gas-liquid separator. Each indoor unit includes an indoor heat exchanger, and the outdoor unit also includes an outdoor heat exchanger and a throttling device connecting the outdoor heat exchanger and the indoor heat exchanger. The throttling device can be an electronic expansion valve.

[0070] The multi-split air conditioner of this invention, through the aforementioned electronic equipment, can further protect the system and compressor, thereby improving the reliability of the multi-split air conditioner and reducing its maintenance costs.

[0071] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0072] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0073] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0074] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0075] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0076] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0077] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0078] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A control method for a multi-split air conditioner, characterized in that, The multi-split air conditioner includes an outdoor unit and an indoor unit, and the method includes: The theoretical exhaust pressure is obtained based on the geometric parameters of the outdoor unit, the air outlet parameters of the indoor unit, the outdoor ambient temperature, and the indoor ambient temperature. The pressure deviation is obtained based on the high pressure of the outdoor unit and the theoretical exhaust pressure. The start-up control of the multi-split air conditioner is based on the pressure deviation. The step of controlling the start-up of the multi-split air conditioner based on the pressure deviation includes: When the pressure deviation is detected to be greater than or equal to the first deviation, the multi-split air conditioner is controlled to perform a normal start-up procedure. When the pressure deviation is detected to be less than the first deviation and greater than or equal to the second deviation, the multi-split air conditioner is preheated for a second preset time, then the compressor is controlled to run at the lowest allowable operating frequency for a third preset time, and then the multi-split air conditioner is controlled to perform the normal start-up process. When the pressure deviation is detected to be less than the second deviation, the multi-split air conditioner is preheated until the difference between the compressor exhaust temperature and the condensing temperature of the multi-split air conditioner is greater than the second difference threshold, and then the multi-split air conditioner is controlled to perform the normal start-up process. The preheating power is greater than or equal to the theoretical heat exchange intensity, which is obtained based on the radiative heat exchange area of ​​the outdoor unit, the radiative heat exchange area of ​​the indoor unit, the average ambient temperature of the outdoor unit, and the average ambient temperature of the indoor unit.

2. The method according to claim 1, characterized in that, The method further includes: When it is detected that the standby time of the multi-split air conditioner is greater than or equal to the first preset time, and the outdoor ambient temperature is less than or equal to the first preset temperature, the step of obtaining the theoretical exhaust pressure is executed.

3. The method according to claim 1, characterized in that, The number of outdoor units is M, the number of indoor units is N, and obtaining the theoretical exhaust pressure includes: The radiant heat transfer area of ​​the outdoor unit is obtained based on M geometric parameters, the radiant heat transfer area of ​​the indoor unit is obtained based on N air outlet parameters, the average ambient temperature of the outdoor unit is obtained based on M outdoor ambient temperatures, and the average ambient temperature of the indoor unit is obtained based on N indoor ambient temperatures. Based on the radiative heat exchange area of ​​the outdoor unit, the radiative heat exchange area of ​​the indoor unit, the average ambient temperature of the outdoor unit, and the average ambient temperature of the indoor unit, the theoretical exhaust saturation temperature and the theoretical intake saturation temperature are obtained. The theoretical exhaust pressure is obtained based on the theoretical exhaust saturation temperature and the theoretical intake saturation temperature.

4. The method according to claim 1, characterized in that, After preheating, during the normal startup process, the method further includes: Calculate the current fluctuation amplitude based on the starting current; When the current fluctuation amplitude is detected to be greater than the preset amplitude threshold, the normal startup process is stopped and the process returns to the preheating step.

5. The method according to claim 1, characterized in that, The theoretical exhaust saturation temperature is obtained by the following formula. Theoretical intake saturation temperature and theoretical heat transfer intensity : ,and , in, The outdoor unit's radiative heat exchange area is [area missing]. The radiative heat exchange area of ​​the indoor unit. As the first coefficient, As the second coefficient, The average ambient temperature of the outdoor unit. The average ambient temperature of the indoor unit.

6. The method according to claim 1, characterized in that, The process of obtaining the pressure deviation based on the high pressure and the theoretical exhaust pressure includes: Calculate the difference between the theoretical exhaust pressure and the high pressure; The pressure deviation is obtained by calculating the ratio of the difference to the high pressure.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-6.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory, characterized in that, When the computer program is executed by the processor, it implements the method as described in any one of claims 1-6.

9. A multi-split air conditioner, characterized in that, Including the electronic device as described in claim 8.

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