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

Abstract

This invention discloses a multi-split air conditioner, its control method, storage medium, and electronic equipment. The multi-split air conditioner includes an outdoor unit and an indoor unit. The method includes: obtaining the theoretical refrigerant quantity of the outdoor unit based on the saturation temperature corresponding to pressure parameters, the outdoor ambient temperature, and the outdoor unit volume; obtaining the refrigerant quantity of the indoor unit based on the saturation temperature, the indoor ambient temperature, and the total volume of the indoor unit heat exchanger; obtaining the actual refrigerant quantity of the outdoor unit based on the refrigerant charge of the multi-split air conditioner and the refrigerant quantity of the indoor unit; and performing start-up control on the multi-split system based on the actual and theoretical refrigerant quantities of the outdoor unit. This control method obtains the actual and theoretical refrigerant quantities of the outdoor unit through system parameters and uses them as the basis for selecting the start-up strategy. This can protect the system and compressor during start-up control, improving the reliability of the multi-split 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 conditioners 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 an indoor unit on top and an outdoor unit 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 the compressor to draw in a large amount of liquid. This will lead to abnormal compressor start-up, 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 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 comprising an outdoor unit and an indoor unit, the method comprising: obtaining the theoretical refrigerant quantity of the outdoor unit based on the saturation temperature corresponding to the pressure parameters, the outdoor ambient temperature, and the outdoor unit volume; obtaining the refrigerant quantity of the indoor unit based on the saturation temperature, the indoor ambient temperature, and the total volume of the indoor unit heat exchanger; obtaining the actual refrigerant quantity of the outdoor unit based on the refrigerant charge quantity and the indoor unit refrigerant quantity; and performing start-up control on the multi-split system based on the actual refrigerant quantity and the theoretical refrigerant quantity of the outdoor unit.

[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 obtain the actual refrigerant quantity and theoretical refrigerant quantity of the outdoor unit based on the system parameters before the multi-split system starts in low-temperature heating mode. This is used to evaluate the severity of the start-up, and the evaluation results are then used as the basis for selecting the system start-up strategy. This changes the situation where multi-split air conditioners start 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.

[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 of a control method for a multi-split air conditioner according to an embodiment of the present invention;

[0011] Figure 2 This is a detailed flowchart of step S103 of an example of the present invention;

[0012] Figure 3 This is a detailed flowchart of step S103 of another example of the present invention;

[0013] Figure 4 This is a detailed flowchart of step S104 of an example of the present invention;

[0014] Figure 5 This is a structural block diagram of a multi-split air conditioner according to an embodiment of the present invention. Detailed Implementation

[0015] Currently, many multi-split air conditioner manufacturers have conducted extensive control optimizations during the low-temperature heating start-up process to avoid problems such as compressor liquid slugging and vibration. However, none of these optimizations address the identification of system parameters before startup. Furthermore, if the system has excessive refrigerant or severe refrigerant migration on the outdoor unit side, direct startup is not advisable in this state, as the compressor will inevitably experience liquid return, causing internal wear. Additional measures are needed to mitigate the refrigerant migration effect before attempting startup. Therefore, this invention proposes a multi-split air conditioner, its control method, storage medium, and electronic equipment.

[0016] 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.

[0017] The following description, with reference to the accompanying drawings, describes a multi-split air conditioner, its control method, storage medium, and electronic equipment according to embodiments of the present invention.

[0018] Figure 1 This is a flowchart of a control method for a multi-split air conditioner according to an embodiment of the present invention.

[0019] 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.

[0020] 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.

[0021] like Figure 1 As shown, the control methods for multi-split air conditioners include:

[0022] S101: Based on the saturation temperature corresponding to the pressure parameters, the outdoor ambient temperature, and the outdoor unit volume, the theoretical refrigerant quantity of the outdoor unit is obtained, and based on the saturation temperature, the indoor ambient temperature, and the total volume of the indoor unit heat exchanger, the refrigerant quantity of the indoor unit is obtained.

[0023] Specifically, the refrigerant charge, pressure parameters, outdoor unit volume, and total indoor unit heat exchanger volume of the multi-split air conditioner can be obtained first, along with the outdoor and indoor ambient temperatures. Then, the corresponding saturation temperature is obtained based on the pressure parameters. Finally, the theoretical refrigerant charge for the outdoor unit is calculated based on the saturation temperature corresponding to the pressure parameters, the outdoor ambient temperature, and the outdoor unit volume. Finally, the refrigerant charge for the indoor unit is calculated based on the saturation temperature, the indoor ambient temperature, and the total indoor unit heat exchanger volume.

[0024] The pressure parameters can be the high-pressure Pd and low-pressure Ps of the outdoor unit. The high-pressure Pd can be detected by a pressure sensor installed at the exhaust port of the outdoor unit compressor, and the low-pressure Ps can be detected by a pressure sensor installed at the intake port of the outdoor unit compressor. The correspondence between pressure parameters (such as high-pressure Pd) and saturation temperature Tc can be saved in advance. After obtaining the pressure parameters, the corresponding saturation temperature can be obtained by looking up the correspondence (such as by looking up a table).

[0025] The outdoor unit volume V1 and the total indoor unit heat exchanger volume V3 are inherent parameters of multi-split air conditioners and can be pre-stored for direct retrieval when needed.

[0026] The outdoor ambient temperature T4 can be detected by the temperature sensor installed on the outdoor unit. When there are multiple outdoor units, the average outdoor temperature detected by the temperature sensors on multiple outdoor units can be used as the outdoor ambient temperature. The calculation formula is as follows: Where N is the number of outdoor units, T4 i The outdoor temperature is the temperature detected by the temperature sensor on the i-th outdoor unit; alternatively, the outdoor temperature detected by the temperature sensor on any outdoor unit can be used as the outdoor ambient temperature.

[0027] Similarly, the indoor ambient temperature T1 can be obtained by the temperature sensor installed on the indoor unit. When there are multiple indoor units, the average indoor temperature detected by the temperature sensors on multiple indoor units can be used as the indoor ambient temperature. The calculation formula is as follows: Where M is the number of indoor units, T1 i The indoor temperature is detected by the temperature sensor on the i-th indoor unit.

[0028] Optionally, the outdoor and indoor ambient temperatures can also be obtained by linking with other home appliances that include outdoor and indoor temperature sensors.

[0029] As an example, the system piping of a multi-split air conditioning system can also be considered, and the piping volume can be obtained. The piping volume V2 can be calculated using the piping length L and the piping diameter D, with the formula: V2 = L × 2π(D / 2) 2 The piping length L and piping diameter D are engineering parameters that can be input via the debugging board (or other methods) and stored in the E-chip on the outdoor unit board for later retrieval.

[0030] S102: Based on the refrigerant charge and indoor unit refrigerant charge of the multi-split air conditioner, the actual refrigerant charge of the outdoor unit is obtained.

[0031] The actual refrigerant quantity of the outdoor unit is the difference between the refrigerant charge and the refrigerant quantity of the indoor unit, i.e., m4 = m1 - m3, where m4 is the actual refrigerant quantity of the outdoor unit, m3 is the refrigerant quantity of the indoor unit, and m1 is the refrigerant charge.

[0032] S103 controls the start-up of the multi-split air conditioning system based on the actual and theoretical refrigerant quantities of the outdoor unit.

[0033] 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 assessed based on the actual and theoretical refrigerant capacity of the outdoor unit. For example, if the actual refrigerant capacity is significantly less than the theoretical capacity, the startup conditions are considered moderately severe. In this case, only the outdoor unit compressor needs preheating. Once certain preheating conditions are met (e.g., a certain preheating time), the normal startup logic (the conventional logic suitable for direct startup) is executed. Conversely, if the actual refrigerant capacity is greater than the theoretical capacity, the startup conditions are considered relatively severe. In this case, while preheating the outdoor unit compressor, electric auxiliary heating can be applied to the indoor unit, the compressor can be started at a specific frequency, and the electronic expansion valves of both units can be adjusted. Once certain conditions are met, the normal startup logic is executed. Therefore, determining the startup logic based on the severity of the startup conditions can change the situation where multi-split air conditioners start first and then protect themselves in low-temperature heating conditions, improving the reliability of multi-split air conditioners and reducing maintenance costs.

[0034] In one embodiment of the present invention, such as Figure 2 As shown, the step S101, which involves obtaining the theoretical refrigerant quantity for the outdoor unit based on the saturation temperature, outdoor ambient temperature, and outdoor unit volume, may include:

[0035] S201, based on the saturation temperature and the outdoor ambient temperature, obtains the first refrigerant state.

[0036] As an example, step S201 may include: when the saturation temperature is detected to be greater than the outdoor ambient temperature, the first refrigerant state is determined to be subcooled liquid; when the saturation temperature is detected to be equal to the outdoor ambient temperature, the first refrigerant state is determined to be saturated liquid.

[0037] As another example, step S201 may include: pre-storing the correspondence between saturation temperature and outdoor ambient temperature and the first refrigerant state, such as a table or curve, and then looking up the correspondence based on the saturation temperature and outdoor ambient temperature to obtain the first refrigerant state.

[0038] S202, the density of liquid refrigerant on the outdoor unit side is obtained based on the first refrigerant state.

[0039] S203, based on the liquid refrigerant density on the outdoor unit side and the outdoor unit volume, yields the theoretical refrigerant quantity for the outdoor unit.

[0040] Specifically, different refrigerant states correspond to different refrigerant densities in the outdoor unit, and this correspondence can be stored in advance. After obtaining the first refrigerant state, the corresponding liquid refrigerant density p1 on the outdoor unit side can be obtained according to this correspondence, and then the theoretical refrigerant quantity m2 of the outdoor unit can be calculated. The calculation formula is: m2=V1×p1, where V1 is the volume of the outdoor unit.

[0041] In one embodiment of the present invention, such as Figure 3 As shown, the step S101, which involves obtaining the refrigerant quantity for the indoor unit based on the saturation temperature, indoor ambient temperature, and the total volume of the indoor unit heat exchanger, may include:

[0042] S301, based on the saturation temperature and the indoor ambient temperature, obtains the second refrigerant state.

[0043] Step S301 may include: when the saturation temperature is detected to be lower than the indoor ambient temperature, the second refrigerant state is obtained as a superheated state; when the saturation temperature is detected to be equal to the indoor ambient temperature, the second refrigerant state is obtained as a saturated gaseous state.

[0044] S302, the density of gaseous refrigerant on the indoor unit side is obtained based on the second refrigerant state.

[0045] S303, based on the density of the gaseous refrigerant on the indoor unit side and the total volume of the indoor unit heat exchanger, the amount of refrigerant in the indoor unit is obtained.

[0046] Specifically, different refrigerant states correspond to different indoor refrigerant densities, and this correspondence can be stored in advance. After obtaining the refrigerant state, the corresponding indoor unit gaseous refrigerant density p2 can be obtained according to this correspondence, and then the indoor unit refrigerant quantity m3 can be obtained. The calculation formula is: m3 = V3 × p2, where V3 is the total volume of the indoor unit heat exchanger.

[0047] As an example, during low-temperature standby, the refrigerant releases heat and condenses, causing a large amount of liquid refrigerant to flow into the outdoor unit. To ensure the startup logic can cover the worst-case scenario, system piping can be considered, with the piping located on the indoor unit side. In this case, the piping temperature is the indoor ambient temperature T1. In this example, the formula for calculating the indoor unit refrigerant volume m3 is: m3 = (V2 + V3) × p2. It should be noted that the situation on the outdoor unit side is more severe when piping is not considered compared to the case where piping is considered.

[0048] Since the compressor typically draws in a large amount of liquid, leading to abnormal compressor startup, abnormal vibration in the system piping, and serious compressor damage, it's advisable to first determine the startup conditions of the multi-split air conditioner. This is because such problems usually occur after a prolonged period of low-temperature standby in a multi-split air conditioner.

[0049] As one embodiment of the present invention, the standby time and outdoor ambient temperature of the multi-split air conditioner can be obtained first; when the standby time is detected to be greater than or equal to a first preset time and the outdoor ambient temperature is less than or equal to a first preset temperature, the steps of obtaining the theoretical refrigerant quantity of the outdoor unit and obtaining the refrigerant quantity of the indoor unit are executed.

[0050] Specifically, this invention mainly targets the low-temperature start-up of multi-split air conditioners. Therefore, the low-temperature start-up conditions can be determined first. The determination method is as follows: if the low-temperature start-up conditions are met, the start-up conditions of the multi-split air conditioner can be considered severe, and the severity of the condition can be further determined; if the conditions are not met, the start-up conditions of the multi-split air conditioner can be considered not severe, and the severity of the condition is not determined. Among them, the low-temperature heating start-up conditions include: condition a, the standby time t0 is not less than the minimum standby time TimeOff_Max (i.e., the first preset time); condition b, the outdoor ambient temperature T4 is lower than the minimum set temperature for normal start-up T4_max (i.e., the first preset temperature). The outdoor ambient temperature T4 can be obtained by a temperature sensor installed on any outdoor unit, or it can be obtained by linkage with other home appliances that contain outdoor temperature sensors.

[0051] Optionally, condition a can also be that the difference between the compressor discharge port temperature and the outdoor ambient temperature is less than or equal to a first difference threshold, wherein the first difference threshold can be a very small value, such as a value between 0.01 and 0.5, in which case the compressor discharge port temperature and the outdoor ambient temperature are basically equal.

[0052] In one embodiment of the present invention, such as Figure 4 As shown, step S103, which involves controlling the start-up of the multi-split system based on the actual and theoretical refrigerant quantities of the outdoor unit, may include:

[0053] S401, calculate the reference refrigerant quantity based on the theoretical refrigerant quantity of the outdoor unit, where the reference refrigerant quantity is the product of the theoretical refrigerant quantity of the outdoor unit and a preset constant.

[0054] S402: When it is detected that the actual refrigerant quantity of the outdoor unit is less than the reference refrigerant quantity, the multi-split air conditioner is preheated for a second preset time, and then the multi-split air conditioner is controlled to perform the normal start-up process.

[0055] S403: When the actual refrigerant quantity of the outdoor unit is detected to be greater than or equal to the reference refrigerant quantity, the multi-split air conditioner is preheated for a second preset time. Then, the compressor of the multi-split air conditioner is started and the four-way valve connected to the compressor is delayed in reversing. When the compressor's running time reaches a third preset time or the compressor's exhaust superheat is greater than or equal to a preset superheat threshold, the compressor's frequency is reduced and the four-way valve is reversed. Then, the multi-split air conditioner is controlled to perform the normal start-up process.

[0056] The preheating methods in steps S402 and S403 may include one or more of the following: compressor crankshaft heating, compressor electric heating belt, low-pressure tank electric heating belt, and chassis heating.

[0057] Specifically, upon receiving a start command (e.g., heating start) from a multi-split air conditioner, the system first checks whether the air conditioner meets the low-temperature start conditions. If the air conditioner does not simultaneously meet the aforementioned low-temperature start conditions a and b, including meeting either condition a or b, or if neither condition a nor b is met, the air conditioner can be started directly according to the normal start procedure. If the air conditioner simultaneously meets the aforementioned low-temperature start conditions a and b, the low-temperature start logic is executed, including: determining the relationship between the actual refrigerant quantity m4 and the theoretical refrigerant quantity m2 of the outdoor unit; if m4 < m2 × c, execute the freezer start logic 1; if m4 ≥ m2 × c, meaning the outdoor unit has accumulated a large amount of liquid refrigerant, posing a risk of liquid slugging, execute start logic 2. Here, c is a preset constant, with a value greater than 0.5 and less than 0.9, such as 0.6.

[0058] The startup logic is as follows: Logic 1: After the multi-split air conditioner is powered on, it performs pre-heating start-up actions, such as compressor self-preheating and electric heating element activation. After a duration of t1 (the second preset duration), it executes the normal cooling start-up logic. Logic 2: After the multi-split air conditioner is powered on, it performs pre-heating start-up actions, such as compressor self-preheating and electric heating element activation. After a duration of t1 (the second preset duration), the compressor starts, and the four-way valve delays switching. When it detects that the compressor has been running on the preheating platform for t3 (the third preset duration) or the exhaust superheat Tdsh ≥ a preset superheat threshold (e.g., 10℃), it reduces the frequency and switches to the normal cooling start-up logic. The exhaust superheat can be the difference between the compressor exhaust temperature and the heat exchanger pipe temperature, or the difference between the compressor exhaust temperature and the saturation temperature corresponding to the compressor exhaust pressure.

[0059] In one embodiment of the present invention, the method may further include: obtaining the outdoor unit model and the indoor unit model; and determining a preset constant c based on the outdoor unit model and the indoor unit model.

[0060] Specifically, the correspondence between the outdoor unit model, the indoor unit model, and the preset constant c can be stored in advance. Then, when needed, the corresponding relationship can be found based on the outdoor unit model and the indoor unit model to obtain the preset constant c.

[0061] In one embodiment of the present invention, during the preheating process of a multi-split air conditioner, the method may further include: controlling the electronic expansion valve of the outdoor unit to maintain its maximum opening, adjusting the fan speed of the outdoor unit according to pressure parameters, controlling the electronic expansion valve of the indoor unit to maintain its minimum opening, activating the electric auxiliary heating of the indoor unit, and turning off the fan of the indoor unit. This ensures reliable startup at low temperatures.

[0062] In summary, the control method for multi-split air conditioners in this embodiment of the invention, based on the system parameters before the multi-split system starts up in low-temperature heating mode, first obtains the actual refrigerant quantity and theoretical refrigerant storage quantity of the outdoor unit through the system parameters, and then evaluates the severity of the start-up based on the actual refrigerant quantity and theoretical refrigerant storage quantity of the outdoor unit. The evaluation result is then used as the basis for selecting the system start-up strategy to change the situation where multi-split air conditioners 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.

[0063] Based on the control method for multi-split air conditioners described in the above embodiments, this invention proposes a computer-readable storage medium.

[0064] 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.

[0065] When the computer-readable storage medium of this invention stores a computer program corresponding to the control method described above, and the program is executed, it can further protect the system and compressor, thereby improving the reliability of the multi-split air conditioner and reducing its maintenance costs.

[0066] Based on the control method for multi-split air conditioners described in the above embodiments, the present invention also proposes an electronic device.

[0067] 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.

[0068] The electronic device of this invention, by executing the above-described control method through a processor, can further protect the system and compressor, thereby improving the reliability of the multi-split air conditioner and reducing its maintenance costs.

[0069] Furthermore, the present invention also proposes a multi-split air conditioner.

[0070] Figure 5 This is a structural block diagram of a multi-split air conditioner according to an embodiment of the present invention.

[0071] like Figure 5 As shown, the multi-split air conditioner 100 includes the electronic device 10 of the above embodiment.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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 embodied 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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: Based on the saturation temperature corresponding to the pressure parameters, the outdoor ambient temperature, and the outdoor unit volume, the theoretical refrigerant quantity of the outdoor unit is obtained, and based on the saturation temperature, the indoor ambient temperature, and the total volume of the indoor unit heat exchanger, the refrigerant quantity of the indoor unit is obtained. The actual refrigerant charge of the outdoor unit is obtained based on the refrigerant charge of the multi-split air conditioner and the refrigerant charge of the indoor unit. Based on the actual refrigerant quantity and the theoretical refrigerant quantity of the outdoor unit, the multi-split air conditioning system is started and controlled, including: The reference refrigerant quantity is calculated based on the theoretical refrigerant quantity of the outdoor unit, wherein the reference refrigerant quantity is the product of the theoretical refrigerant quantity of the outdoor unit and a preset constant. When the actual refrigerant quantity of the outdoor unit is detected to be less than the reference refrigerant quantity, the multi-split air conditioner is preheated for a second preset time, and then the multi-split air conditioner is controlled to execute the normal start-up process. When the actual refrigerant quantity of the outdoor unit is detected to be greater than or equal to the reference refrigerant quantity, the multi-split air conditioner is preheated for a second preset time, and then the compressor of the multi-split air conditioner is controlled to start, and the four-way valve connected to the compressor is controlled to delay switching. When the compressor's running time reaches a third preset time or the compressor's exhaust superheat is greater than or equal to a preset superheat threshold, the compressor's frequency is controlled to decrease and the four-way valve is controlled to switch, and then the multi-split air conditioner is controlled to execute the normal start-up process.

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 steps of obtaining the theoretical refrigerant quantity of the outdoor unit and obtaining the refrigerant quantity of the indoor unit are executed.

3. The method according to claim 1, characterized in that, The theoretical refrigerant load for the outdoor unit is obtained based on the saturation temperature corresponding to the pressure parameters, the outdoor ambient temperature, and the outdoor unit volume, including: The first refrigerant state is obtained based on the saturation temperature and the outdoor ambient temperature; The density of the liquid refrigerant on the outdoor unit side is obtained based on the first refrigerant state. The theoretical refrigerant quantity of the outdoor unit is obtained based on the liquid refrigerant density on the outdoor unit side and the outdoor unit volume.

4. The method according to claim 1, characterized in that, The process of determining the refrigerant quantity for the indoor unit based on the saturation temperature, indoor ambient temperature, and the total volume of the indoor unit heat exchanger includes: The second refrigerant state is obtained based on the saturation temperature and the indoor ambient temperature; The density of the gaseous refrigerant on the indoor unit side is obtained based on the second refrigerant state. The amount of refrigerant in the indoor unit is obtained based on the density of the gaseous refrigerant on the indoor unit side and the total volume of the indoor unit heat exchanger.

5. The method according to claim 1, characterized in that, During the preheating process of the multi-split air conditioner, the method further includes: The electronic expansion valve of the outdoor unit is controlled to maintain its maximum opening. The fan speed of the outdoor unit is adjusted according to the pressure parameters. The electronic expansion valve of the indoor unit is controlled to maintain its minimum opening. The electric auxiliary heating of the indoor unit is turned on, and the fan of the indoor unit is turned off.

6. The method according to claim 1, characterized in that, The method further includes: The preset constants are determined based on the outdoor unit model and the indoor unit model.

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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