Multi-split air conditioner

Abstract

The invention discloses a multi-split air conditioner which comprises at least two indoor heat exchangers, an outdoor heat exchanger, a compressor, an exhaust pressure detection device arranged at an exhaust port of the compressor, an indoor inlet air temperature detection device arranged at an air inlet and an indoor outlet air temperature detection device arranged at an air outlet. After the unit normally operates for a period of time, when the unit operates in a refrigeration mode, if the difference value between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within a first judgment value range and the number of abnormal indoor units exceeds a second judgment value, the unit operates in the refrigeration mode; wherein the abnormal indoor unit is defined as an indoor unit of which the difference value between the indoor air inlet temperature and the indoor air outlet temperature is not within the first judgment value range; and when the difference value between the indoor air inlet temperature and the indoor air outlet temperature of all the abnormal indoor units reaches the upper limit value of the first judgment value range, and the exhaust pressure reaches the upper limit value of the third judgment value range, an electric signal representing that the refrigerant charging amount is excessive is output. Intelligent calculation is carried out according to feedback values detected by all the detection devices in the operation process, the refrigerant charging amount judgment result is output, and misjudgment of the refrigerant charging amount is avoided.

Description

Technical Field

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

[0002] For air-conditioning products, refrigerant is the only medium for heat transfer. Whether the filling amount is appropriate is crucial to the stable operation of the entire refrigeration system, the reliability of components, the unit effect and energy efficiency.

[0003] Refrigerant charging for air conditioners involves two steps. One step is the refrigerant that comes with the outdoor unit when it leaves the factory. This charging process isn't standardized, and the exact amount of refrigerant can be accurate. However, if piping is damaged during transportation or installation, or if there are operational errors, unnoticeable leaks can result, leading to refrigerant shortages.

[0004] The other part is charged according to the indoor unit and pipe length matched on site, which needs to be calculated and approved by on-site personnel. In this process, the refrigerant may be over-charged or under-charged.

[0005] In related technologies, the system can be monitored in real time based on parameters such as exhaust pressure, internal valve opening, and subcooling, thereby realizing automatic determination of the refrigerant quantity during the charging process. However, determination based on a single parameter will be affected by various factors such as indoor and outdoor ambient temperature and machine model, which may lead to certain deviations in the determined refrigerant quantity.

[0006] In view of this, this application is filed. Summary of the Invention

[0007] To address the issue of determining the amount of refrigerant charged, this application proposes a technical solution that utilizes air conditioner operating parameters. The refrigerant charge status is comprehensively determined based on the difference between the indoor inlet and outlet air temperatures and the exhaust pressure, avoiding biased determinations due to a single factor.

[0008] The present application provides a multi-split air conditioner, which includes:

[0009] At least two indoor heat exchangers, the indoor heat exchangers being connected in parallel, the indoor heat exchangers being provided in the indoor unit and being used for exchanging heat with indoor air;

[0010] An outdoor heat exchanger is provided in the outdoor unit and is used to exchange heat with outdoor air;

[0011] A compressor comprising an air intake port and an air discharge port for compressing a high-temperature and high-pressure refrigerant and discharging the compressed refrigerant, wherein the outdoor heat exchanger, the indoor heat exchanger, and the compressor are connected to form a refrigerant circuit;

[0012] Indoor air outlet temperature detection device, which is installed at the air outlet of the indoor unit and is used to detect the indoor air outlet temperature;

[0013] Indoor air inlet temperature detection device, which is installed at the air inlet of the indoor unit and is used to detect the indoor air inlet temperature;

[0014] an exhaust pressure detection device, which is provided at the exhaust port of the compressor and is used to detect the exhaust pressure of the compressor;

[0015] The controller is configured to, after the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in cooling mode, determine if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within a first judgment value range, and the number of abnormal indoor units exceeds a second judgment value; wherein the abnormal indoor unit is defined as an indoor unit whose difference between the indoor air inlet temperature and the indoor air outlet temperature is not within the first judgment value range;

[0016] When the difference between the indoor air inlet temperature and the indoor air outlet temperature of all abnormal indoor units reaches the upper limit of the first judgment value range, and the exhaust pressure reaches the upper limit of the third judgment value range, an electrical signal representing excessive refrigerant charge is output.

[0017] In some embodiments, the controller is configured to: after the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in cooling mode, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within a first judgment value range, and the number of abnormal indoor units exceeds a second judgment value;

[0018] When the difference between the indoor inlet air temperature and the indoor outlet air temperature of all the abnormal indoor units does not exceed the lower limit of the first judgment value range, if the exhaust pressure does not exceed the lower limit of the sixth judgment value range, an electrical signal representing insufficient refrigerant charging is output.

[0019] In some embodiments, the controller is configured to:

[0020] The multi-split air conditioner is turned on, and after the unit operates normally for a period of time, when operating in cooling mode, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within the first judgment value range, if the number of abnormal indoor units does not reach the second judgment value, or / and the difference between the indoor air inlet temperature and the indoor air outlet temperature of some of the abnormal indoor units does not reach the upper limit value of the first judgment value range, and / or the difference between the indoor air inlet temperature and the indoor air outlet temperature of some of the abnormal indoor units exceeds the lower limit value of the first judgment value range, it is determined that the refrigerant quantities of at least two indoor units are different at this time.

[0021] In some embodiments, the multi-split air conditioner further comprises:

[0022] an outdoor exhaust temperature detection device, which is provided at the exhaust port of the compressor and is used to detect the exhaust temperature of the compressor;

[0023] The controller is configured to, after the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in a heating mode, if the indoor air outlet temperature of all indoor units does not reach the lower limit of the fourth judgment value range, determine the relationship between the second difference between the exhaust temperature and the saturation temperature corresponding to the condensing pressure and the fifth judgment value range;

[0024] When the second difference exceeds the upper limit of the fifth determination value range, an electrical signal indicating that the refrigerant charge amount is insufficient is output.

[0025] In some embodiments, the controller is configured to, when the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in heating mode, if the indoor air outlet temperature of all indoor units does not reach the lower limit of the fourth judgment value range, and the second difference between the exhaust temperature and the condensing temperature corresponding to the exhaust pressure does not reach the lower limit of the fifth judgment value range, output an electrical signal representing an excessive amount of refrigerant.

[0026] In some embodiments, the controller is configured such that, after the multi-split air conditioner is turned on and the unit operates normally for a period of time, when the heating mode is operated, if the indoor air outlet temperature of all indoor units does not reach the lower limit of the fourth judgment value range, and the second difference exceeds the lower limit of the fifth judgment value range and the second difference does not reach the upper limit of the fifth judgment value range, it is determined that the length of the connecting pipe between the indoor unit and the outdoor unit exceeds the preset length or the diameter of the connecting pipe is smaller than the preset diameter.

[0027] In some embodiments, the controller is configured such that, after the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in heating mode, if the indoor air outlet temperature of some indoor units does not reach the lower limit of the fourth judgment value range, it is determined that the refrigerant quantities of at least two indoor units are different at this time.

[0028] In some embodiments, the controller is configured to, after the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in cooling mode, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within a first judgment value range, and the number of abnormal indoor units exceeds a second judgment value;

[0029] When it is determined that the difference between the indoor air inlet temperature and the indoor air outlet temperature of the abnormal indoor unit at this time reaches the upper limit value of the first judgment value range, if the exhaust pressure exceeds the lower limit value of the third judgment value range and does not reach the upper limit value of the third judgment value range, it is determined that the air inlet area of ​​the air inlet of the abnormal indoor unit at this time is not equal to the area of ​​the air inlet.

[0030] In some embodiments, the controller is configured to, when the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in cooling mode, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within a first judgment value range, and the number of abnormal indoor units exceeds a second judgment value;

[0031] When the difference between the indoor inlet air temperature and the indoor outlet air temperature of all the abnormal indoor units does not exceed the lower limit of the first judgment value range, if the exhaust pressure exceeds the lower limit of the sixth judgment value range and does not reach the upper limit of the sixth judgment value range, it is determined that the air inlet area of ​​the air inlet of the abnormal indoor unit is not equal to the area of ​​the air inlet.

[0032] The present application discloses a multi-split air conditioner, comprising at least two indoor heat exchangers, an outdoor heat exchanger, a compressor, an exhaust pressure detection device provided at the compressor outlet, an indoor inlet air temperature detection device provided at the air inlet, and an indoor outlet air temperature detection device provided at the air outlet. The controller is configured to, when the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in cooling mode, if the difference between the indoor inlet air temperature and the indoor outlet air temperature of each indoor unit is not within a first judgment value range, and the number of abnormal indoor units exceeds a second judgment value; wherein an abnormal indoor unit is defined as an indoor unit whose difference between the indoor inlet air temperature and the indoor outlet air temperature is not within the first judgment value range; when the difference between the indoor inlet air temperature and the indoor outlet air temperature of all abnormal indoor units reaches the upper limit of the first judgment value range, and the exhaust pressure reaches the upper limit of a third judgment value range, output an electrical signal representing an excessive refrigerant charge. Intelligent calculation is performed based on the feedback values ​​detected by each detection device during operation, and a refrigerant charge determination result is output to avoid misjudgment of the refrigerant charge.

[0033] The present application also proposes another multi-split air conditioner, which comprises:

[0034] At least two indoor heat exchangers, the indoor heat exchangers being connected in parallel, the indoor heat exchangers being provided in the indoor unit and being used for exchanging heat with indoor air;

[0035] An outdoor heat exchanger is provided in the outdoor unit and is used to exchange heat with outdoor air;

[0036] A compressor comprising an air intake port and an air discharge port for compressing a high-temperature and high-pressure refrigerant and discharging the compressed refrigerant, wherein the outdoor heat exchanger, the indoor heat exchanger, and the compressor are connected to form a refrigerant circuit;

[0037] an outdoor exhaust temperature detection device, which is provided at the exhaust port of the compressor and is used to detect the exhaust temperature of the compressor;

[0038] Indoor air outlet temperature detection device, which is installed at the air outlet of the indoor unit and is used to detect the indoor air outlet temperature;

[0039] an exhaust pressure detection device, which is provided at the exhaust port of the compressor and is used to detect the exhaust pressure of the compressor;

[0040] The controller is configured to, after the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in a heating mode, if the indoor air outlet temperature of all indoor units does not reach the lower limit of the fourth judgment value range, determine the relationship between the second difference between the condensing temperature corresponding to the exhaust temperature and the exhaust pressure and the fifth judgment value range;

[0041] When the second difference exceeds the upper limit of the fifth determination value range, an electrical signal indicating that the refrigerant charge amount is insufficient is output. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0043] Figure 1 is a structural block diagram of a multi-split air conditioner in one embodiment of the present invention;

[0044] Figure 2 is a connection diagram of an outdoor unit and an indoor unit in one embodiment of the present invention;

[0045] Figure 3 is a system block diagram of an air conditioning system in one embodiment of the present invention;

[0046] Figure 4 is a hardware block diagram of a controller in one embodiment of the present invention;

[0047] Figure 5 is a hardware connection block diagram of a controller and a detection device in one embodiment of the present invention;

[0048] Figure 6 is the control logic for refrigerant charge verification in one embodiment of the present invention;

[0049] Figure 7 It is the judgment logic of the refrigerant charge amount under the refrigeration condition in one embodiment of the present invention;

[0050] Figure 8 It is another judgment logic of the refrigerant charge amount under the refrigeration condition in one embodiment of the present invention;

[0051] Figure 9 In one embodiment of the present invention, the refrigerant charge amount verification logic is as follows:

[0052] Figure 10 This is the judgment logic of the refrigerant charge amount under heating conditions in one embodiment of the present invention.

[0053] Figure 11 This is another judgment logic for the refrigerant charge amount under heating conditions in one embodiment of the present invention;

[0054] Figure 12 It is the refrigerant charge amount verification logic in the heating mode in one embodiment of the present invention;

[0055] In the above picture:

[0056] Multi-split air conditioner 100; controller 21; bus 211; memory 212; processor 213; communication interface 214;

[0057] Compressor 1; four-way valve 4; gas-liquid separator 6; electronic expansion valve 7; outdoor heat exchanger 8;

[0058] Gas side stop valve 9; liquid side stop valve 10; outdoor unit 14; indoor unit 16; connecting pipe 17;

[0059] Indoor air inlet temperature detection device 23; exhaust pressure detection device 24; outdoor exhaust temperature detection device 25;

[0060] Indoor air outlet temperature detection device 26; indoor heat exchanger 27; outdoor environment temperature detection device 28. DETAILED DESCRIPTION

[0061] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0062] In the description of the present invention, it should be understood that the terms "center", "transverse", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0063] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0064] This application proposes a multi-split air conditioner 100, referring to Figure 1 The multi-split air conditioner 100 includes an indoor unit.

[0065] The indoor unit group includes two indoor units 16. The plurality of indoor units 16 are connected in parallel.

[0066] The multi-split air conditioner 100 includes an outdoor unit.

[0067] The outdoor unit includes at least two outdoor units 14 and indoor units 16 connected in parallel.

[0068] The outdoor unit 14 is installed outdoors.

[0069] Reference Figure 2 , the indoor unit 16 and the outdoor unit 14 are connected by a connecting pipe 17 for the flow of refrigerant.

[0070] The length of the connecting pipe 17 is set according to the model of the multi-split air conditioner 100.

[0071] The diameter of the connecting pipe 17 will be set according to the model of the multi-split air conditioner 100.

[0072] The indoor unit 16 includes an indoor casing that forms an outer contour of the indoor unit 16 and houses internal components of the indoor unit 16 .

[0073] Reference Figure 5 The multi-split air conditioner 100 further includes an indoor ambient temperature detection device. The indoor ambient temperature detection device is mounted on the outdoor housing and is used to detect the indoor ambient temperature.

[0074] The indoor housing is provided with an air inlet (not shown) of the indoor unit 16. The indoor air inlet is used for supplying indoor wind into the indoor housing.

[0075] Reference Figure 5 The multi-split air conditioner 100 further includes an indoor air inlet temperature detection device 23. The indoor air inlet detection device is installed at the air inlet of the indoor unit 16. It is used to detect the indoor air inlet temperature.

[0076] In some embodiments, the indoor air inlet temperature is used as the indoor ambient temperature in logic judgment.

[0077] The indoor housing has an air outlet (not shown) for the indoor unit 16. The indoor air outlet is used to discharge the air from the indoor housing. Indoor air enters the indoor housing through the indoor air inlet and is then blown out from the indoor air outlet.

[0078] Reference Figure 5 The multi-split air conditioner 100 further includes an indoor air outlet temperature detection device 26. The indoor air outlet temperature detection device 26 is installed at the air outlet of the indoor unit 16. It is used to detect the indoor air outlet temperature.

[0079] The indoor unit 16 includes an indoor heat exchanger 27. The indoor heat exchanger 27 is installed in an indoor housing. The indoor heat exchanger 27 is used to exchange heat with indoor air entering the indoor housing.

[0080] The indoor unit 16 includes an indoor fan. The indoor fan is installed in an indoor housing. The indoor fan rotates to allow indoor air to enter the indoor housing. The indoor air exchanges heat with the indoor heat exchanger 27 and flows out of the indoor housing.

[0081] In this application, the indoor unit 16 includes but is not limited to a wall-mounted air conditioner, a cabinet air conditioner, and a ducted air conditioner.

[0082] The outdoor unit 14 includes an outdoor housing that defines the exterior of the outdoor unit 14 and houses internal components of the outdoor unit 14 .

[0083] Reference Figure 5 The multi-split air conditioner 100 includes an outdoor ambient temperature detection device 28. The outdoor ambient temperature detection device 28 is installed on the outdoor housing and is used to detect the outdoor ambient temperature.

[0084] The multi-split air conditioner 100 further includes an exhaust temperature detection device 25. The exhaust temperature detection device 25 is provided at the exhaust port of the compressor and is used to detect the exhaust temperature of the compressor.

[0085] The multi-split air conditioner 100 further includes an exhaust pressure detection device 24 , which is disposed at the exhaust port of the compressor and is used to detect the exhaust pressure of the compressor.

[0086] The exhaust superheat should be the temperature difference between the temperature of the compressor exhaust pipe or condenser inlet and the saturation temperature corresponding to the actual condensing pressure.

[0087] The condensing pressure is the pressure at which the refrigerant condenses from gas into liquid in the condenser. Since the pressure inside the condenser in the refrigeration system cannot be measured, and in fact, the pressure drop of the refrigerant in the exhaust pipe and the condenser is actually very small, it is generally believed that the exhaust pressure is approximately equal to the condensing pressure regardless of design, commissioning or maintenance.

[0088] The outdoor shell is provided with an outdoor air inlet, which is used for allowing outdoor wind to enter the outdoor shell.

[0089] The outdoor shell is provided with an outdoor air outlet, which is used to discharge the wind from the outdoor shell. The outdoor wind enters the outdoor shell through the outdoor air inlet and is then blown out from the outdoor air outlet.

[0090] The outdoor unit 14 includes an outdoor heat exchanger 8 , which is installed in an outdoor housing. The outdoor heat exchanger 8 is used to exchange heat with outdoor air entering the outdoor housing.

[0091] The outdoor unit 14 includes an outdoor fan, which is installed in an outdoor housing. The outdoor fan rotates to allow outdoor air to enter the outdoor housing. The outdoor air exchanges heat with the outdoor heat exchanger 8 and flows out of the outdoor housing.

[0092] Reference Figure 3 , describing the system configuration of the air-conditioning system in this application.

[0093] The outdoor unit 14 includes a compressor 1. The compressor 1 can compress a high-temperature and high-pressure gas refrigerant and discharge the compressed gas refrigerant.

[0094] The compressor 1 includes a suction port. Refrigerant flows into the compressor 1 from the suction port to be compressed.

[0095] The compressor 1 includes an exhaust port. Refrigerant enters the compressor 1 from the intake port and is compressed by the compressor 1 before being discharged from the exhaust port.

[0096] The outdoor unit 14 further includes a gas-liquid separator 6. The gas-liquid separator 6 is installed at the air intake of the compressor 1. The gas-liquid separator 6 is used for gas-liquid separation.

[0097] The outdoor unit 14 also includes a four-way valve 4. A first port of the four-way valve 4 is connected to the exhaust port of the compressor 1. A second port of the four-way valve 4 is connected to the intake port of the compressor 1. A third port of the four-way valve 4 is connected to the indoor unit 16. A fourth port of the four-way valve 4 is connected to the outdoor heat exchanger 8.

[0098] The outdoor unit 14 further includes an electronic expansion valve 7. The electronic expansion valve 7 is disposed between the outdoor heat exchanger 8 and the indoor heat exchanger 27. The electronic expansion valve 7 is used for throttling. The electronic expansion valve 7 expands the high-temperature, high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant.

[0099] In some embodiments, the electronic expansion valve is provided in the outdoor unit 14. Figure 3 shown.

[0100] In some embodiments, an electronic expansion valve is provided in the indoor unit 16. This is not shown in the drawings.

[0101] The outdoor unit 14 also includes a one-way valve. The one-way valve can be installed at the exhaust port of the compressor 1. The one-way valve is installed between the exhaust port of the compressor 1 and the first port of the four-way valve 4. It is used to prevent the refrigerant in the pipeline from flowing back into the compressor 1.

[0102] The outdoor unit 14 further includes a gas-side stop valve 9 . The gas-side stop valve 9 is provided at the third port of the four-way valve 4 .

[0103] The outdoor unit 14 further includes a liquid-side stop valve 10 , which is provided between the indoor unit 16 and the subcooler 11 .

[0104] The outdoor unit 14 further includes filters, which are arranged on both sides of the electronic expansion valve.

[0105] The outdoor unit 14 further includes a flow divider, which is arranged on a side of the outdoor heat exchanger close to the indoor heat exchanger 27 and is used to control the flow direction of the refrigerant.

[0106] The indoor heat exchanger 27 and the outdoor heat exchanger 8 function as a condenser or an evaporator. When the indoor heat exchanger 27 functions as a condenser, the air conditioner functions as a heater in heating mode. When the indoor heat exchanger 27 functions as an evaporator, the air conditioner functions as a cooler in cooling mode.

[0107] The multi-split air conditioner 100 uses the flow of refrigerant to blow out air conditioned air that is higher than the indoor temperature, lower than the indoor temperature, or the same as the indoor temperature to adjust the temperature and humidity of the indoor environment; or uses the speed of the indoor fan to adjust the air flow rate of the indoor environment.

[0108] The cooling mode and the heating mode of the multi-split air conditioner 100 are described by taking one of the outdoor units 14 as an example.

[0109] During cooling operation of the multi-split air conditioner 100, the refrigerant from compressor 1 is condensed through the outdoor heat exchanger 8. The condensed refrigerant then flows through the electronic expansion valve 7 and expands. The expanded condensate evaporates through the indoor heat exchanger 27. The evaporated refrigerant then circulates back into compressor 1.

[0110] When the multi-split air conditioner 100 is in heating mode, the refrigerant from compressor 1 flows through indoor heat exchanger 27 to condense, and the condensed refrigerant expands by flowing through electronic expansion valve 7. The expanded condensed refrigerant evaporates through outdoor heat exchanger 8. The evaporated refrigerant then circulates back to compressor 1.

[0111] As an important medium for heat transfer in air-conditioning systems, the appropriate amount of refrigerant is very important to the stable operation of the entire air-conditioning system, the reliability of each component, the unit effect and energy efficiency.

[0112] In some embodiments, the refrigerant charge consists of two parts. The first part is the factory-installed refrigerant. The second part is charged based on the indoor unit 16 and piping length used on-site. However, since this part is manually controlled, there is a risk of overcharging or undercharging due to calculation errors or manual charging mistakes, thus affecting the operation of the entire unit.

[0113] This application proposes a multi-split air conditioner 100 that can determine whether the refrigerant charge is appropriate.

[0114] In some embodiments of the present application, the multi-split air conditioner 100 includes a remote controller, through which a user inputs commands to the controller 21 to select an operating mode of the indoor unit 16 or the outdoor unit 14 .

[0115] In some embodiments, the working modes of the multi-split air conditioner 100 vary according to different models and user needs. In this application, the cooling mode and the heating mode are selected for introduction.

[0116] In the cooling mode, the air flowing into the room by the indoor unit 16 is cold air. The cold air can be defined as airflow with a temperature lower than that of the indoor air.

[0117] In the heating mode, the air flowing into the room from the indoor unit 16 is hot air. The hot air can be defined as airflow with a temperature higher than that of the indoor air. The heating mode and the cooling mode are common knowledge among those skilled in the art.

[0118] In the present application, whether the multi-split air conditioner 100 executes the heating mode or the cooling mode can be set by the user, or it can be determined based on the range of the indoor ambient temperature detected by the indoor ambient temperature detection device and the outdoor ambient temperature detected by the outdoor ambient temperature detection device 28.

[0119] In some embodiments of the present application, the multi-split air conditioner 100 includes a controller 21. The controller 21 is used to send instructions to the multi-split air conditioner 100 to control the working process of the multi-split air conditioner 100.

[0120] The controller 21 includes an indoor controller 21. The indoor controller 21 is installed in the indoor unit 16. The indoor controller 21 can be used to control the working state of each component inside the indoor unit 16.

[0121] The controller 21 includes an outdoor controller 21. The outdoor controller 21 is installed in the outdoor unit 14. The outdoor controller 21 can be used to control the working state of each component inside the outdoor unit 14.

[0122] Wired communication is used between the indoor controller 21 and the outdoor controller 21 .

[0123] In other embodiments, the above communication method may also be wireless communication.

[0124] In this application, the outdoor controller 21 is used to read the detection values ​​of the pressure detection device 5, the coil temperature detection device 13 and the ambient temperature detection device 15 at a set time after receiving the shutdown command, and compare them with the set conditions to determine whether to shut down the outdoor unit 14 and whether liquid backflow occurs, so as to solve the liquid backflow problem of the compressor 1 to a certain extent.

[0125] At the same time, the outdoor controller 21 and the indoor controller 21 can also rotate the units according to the hardware conditions, operating hours, actual working conditions, etc. of each indoor unit 16 and each outdoor unit 14 to achieve efficient coordination between each indoor unit 16 and each outdoor unit 14.

[0126] In some embodiments of the present application, no specific distinction is made between the indoor controller 21 and the outdoor controller 21 , and the indoor controller 21 and the outdoor controller 21 are collectively referred to as the controller 21 .

[0127] The controller 21 is used to coordinate the operation of the entire multi-split air conditioner 100. This includes receiving user instructions, operating in cooling mode, heating mode, blowing mode, shutdown mode, and uploading the operating status of the multi-split air conditioner 100 to the cloud.

[0128] The structures of the indoor controller 21 and the outdoor controller 21 are substantially the same, and the structure of the indoor controller 21 is described below by taking the indoor controller 21 as an example.

[0129] The indoor controller 21 includes a memory 212. The memory 212 may include a high-speed random access memory 212 (RAM) or a non-volatile memory 212 (NVM).

[0130] For example, there is at least one disk storage 212. The storage 212 is used to store programs.

[0131] Reference Figure 4 The indoor controller 21 includes a communication interface 214. The communication interface 214 is used to implement communication with related components.

[0132] The communication interface 214 of the indoor controller 21 is used to communicate with each detection device and the outdoor controller 21. The communication interface 214 of the controller 21 is used to communicate with the indoor air outlet temperature detection device 26, the indoor air inlet temperature detection device 23, the exhaust pressure detection device 24, the outdoor ambient temperature detection device 28, the indoor ambient temperature detection device, and the exhaust temperature detection device 25.

[0133] The indoor controller 21 includes a processor 213. The processor 213 is used to execute executable modules stored in the memory 212, such as computer programs. The code of the computer program can be in source code form, object code form, executable file or some other form.

[0134] The indoor controller 21 includes a bus 211. The bus 211 is used to connect the communication interface 214 and the processor 213. The bus 211 can be an ISA bus 211, a PCI bus 211, or an EISA bus 211.

[0135] The outdoor controller 21 of the outdoor unit 14 and the indoor controller 21 of each indoor unit 16 each include at least one software function module that can be stored in the memory 212 in the form of software or firmware.

[0136] In this application, after receiving the execution instruction, the processor 213 executes the program to implement Figure 6-12 The logical control method for detecting the refrigerant charge amount is shown in .

[0137] In some embodiments of the present application, the controller 21 is at least used to receive data detected by the indoor outlet air temperature detection device 26, the indoor inlet air temperature detection device 23, the exhaust pressure detection device 24, the outdoor ambient temperature detection device 28, the indoor ambient temperature detection device, and the exhaust temperature detection device 25.

[0138] In some embodiments, after the air conditioning unit is installed, the installer first performs a startup test.

[0139] If the unit cannot operate normally, a fault code will be output.

[0140] If the unit is operating normally, the operating environment coefficients are collected after a period of operation T1. The operating environment coefficients include outdoor ambient temperature, indoor ambient temperature, indoor unit model, and online ratio.

[0141] After collecting the operating environment coefficients, confirm the operating conditions.

[0142] In some embodiments, the operating mode (cooling mode or heating mode) and operating parameters (outdoor unit 14 compressor frequency, outdoor fan gear, outdoor unit 14 electronic expansion valve opening, indoor fan gear, etc.) are confirmed according to the operating environment.

[0143] In some embodiments, after confirming the operation mode and operation parameters, the system is operated according to the established mode and after a period of time T2, the operation parameters are collected and the calculation of whether the refrigerant charge amount is appropriate is performed.

[0144] In some embodiments, when the unit determines that the refrigerant charge is appropriate, it sends an electrical signal to inform the commissioning personnel.

[0145] In some embodiments, the debugger is informed by displaying the corresponding code and scrolling to display the recording parameters, so that the debugger can record them easily.

[0146] In some embodiments, if the unit determines that the refrigerant charge is too little or too much, the operation ends, the corresponding code is output, and the recorded parameters are scrolled and displayed. After the recording is completed, the code is manually dialed to exit the refrigerant verification mode.

[0147] In some embodiments, when the detected indoor ambient temperature reaches a first preset value and the outdoor ambient temperature reaches a second preset value, the multi-split air conditioner 100 executes the cooling mode.

[0148] In some embodiments, when the detected indoor ambient temperature does not reach the first preset value and the outdoor ambient temperature reaches the third preset value, the multi-split air conditioner 100 executes the heating mode.

[0149] In some embodiments, if the above two judgment conditions are not met, it is determined that the operating condition of the unit is abnormal or the monitoring data is wrong, the unit stops running, and the corresponding code is output.

[0150] Through the above embodiments, the unit can intelligently select the operating mode according to the operating environment of the multi-split air conditioner 100, set the target operating parameters, realize the automation of the operation of the multi-split air conditioner 100, and change the operating mode in time according to changes in the external environment, reducing manpower input.

[0151] In some embodiments, the operating parameter settings specifically include preset execution parameters in the program inside the controller 21 based on actual experimental tests and theoretical data for different indoor ambient temperatures, outdoor ambient temperatures, and indoor and outdoor unit connection ratios.

[0152] The execution parameters include the operating frequency of the compressor, the opening of the electronic expansion valve (set at the indoor unit 16 and / or the outdoor unit 14), the gear position of the indoor fan and the gear position of the outdoor fan.

[0153] In some embodiments, when the multi-split air conditioner 100 is in heating mode, the opening of the electronic expansion valve is calculated based on a preset basic opening, the indoor and outdoor unit connection ratio, the outdoor ambient temperature, and the compressor frequency.

[0154] In some embodiments, when the multi-split air conditioner 100 is in cooling mode, the opening of the electronic expansion valve is calculated based on a preset basic opening, the number of indoor units, and the operating frequency of the compressor.

[0155] In some embodiments, reference Figure 6 , explaining the control logic of refrigerant charge quantity verification in this application.

[0156] In some embodiments, the refrigerant charge verification mode is entered by dialing a code.

[0157] The multi-split air conditioner 100 is started up for trial operation (S601);

[0158] Determine whether the multi-split air conditioner 100 is operating (S602);

[0159] In step S602, if the multi-split air conditioner 100 unit is not operating normally, step S604 is executed to perform troubleshooting according to the alarm content of the unit and restart the unit after troubleshooting.

[0160] In some embodiments, after executing step S604, step S602 may be continued.

[0161] In step S602, if the multi-split air conditioner 100 is operating normally, step S603 is executed, and the unit is continuously operated for a period of time;

[0162] Collect operating environment parameters (S605); according to the operating environment, the multi-split air conditioner 100 unit operates according to preset parameters (S606); after the unit continuously operates for a period of time with the preset parameters (S607), it is determined whether the refrigerant charge amount is appropriate (S608);

[0163] In step S608, if the refrigerant charge amount is appropriate, step S609 is executed, and the outdoor seven-segment code displays a code carrying information that the refrigerant charge amount is appropriate;

[0164] In step S608, if the refrigerant charge is inappropriate, step S610 is executed to display the corresponding fault code; and the operating parameters are displayed cyclically (S611).

[0165] It should be noted that the execution logic of S610 and S611 is not sequential and does not necessarily exist at the same time. That is, in some embodiments, S610 can be executed alone, or S611 can be executed alone.

[0166] After executing S610 and S611 , the operating parameters are recorded and the refrigerant verification mode is manually exited ( S612 ).

[0167] Reference Figure 7 , which explains the judgment logic of the refrigerant charge amount under refrigeration conditions.

[0168] In some embodiments, the controller 21 is configured to operate the multi-split air conditioner 100 in a cooling mode ( S701 ).

[0169] In some embodiments, the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit 16 is not within the first determination value range ( S702 ).

[0170] In some embodiments, when the number of abnormal indoor units 16 exceeds the second judgment value (S703), the abnormal indoor units 16 are defined as indoor units 16 whose difference between the indoor air inlet temperature and the indoor air outlet temperature is not within the first judgment value range.

[0171] In some embodiments, when the difference between the indoor air inlet temperature and the indoor air outlet temperature of all abnormal indoor units 16 reaches the upper limit of the first determination value range ( S704 ).

[0172] In some embodiments, the exhaust pressure reaches an upper limit value of a third determination value range ( S705 ).

[0173] In some embodiments, it is defined that the refrigerant charge amount is excessive at this time, and an electrical signal representing the excessive refrigerant charge amount is output ( S706 ).

[0174] In the above judgment logic, the unit performs intelligent calculations based on the feedback values ​​of each detection device during operation and outputs the refrigerant charge amount judgment result.

[0175] In the above control logic, the logic in S702, S703, S704, and S705 is a progressive relationship, and the judgment order is not changed under normal circumstances.

[0176] In some embodiments, when an electrical signal indicating an excessive refrigerant charge is received, the amount of refrigerant in the air conditioning system may be reduced by discharging the refrigerant.

[0177] Reference Figure 8 , which explains another judgment logic for the refrigerant charge amount under refrigeration conditions.

[0178] In some embodiments, the controller 21 is configured to operate the multi-split air conditioner 100 in a cooling mode ( S801 ).

[0179] In some embodiments, the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit 16 is not within the first determination value range ( S802 ).

[0180] In some embodiments, the number of abnormal indoor units 16 exceeds a second determination value ( S803 );

[0181] In some embodiments, the difference between the indoor air inlet temperature and the indoor air outlet temperature of all abnormal indoor units 16 does not exceed the lower limit of the first determination value range (S804).

[0182] In some embodiments, the exhaust pressure does not exceed a lower limit of a sixth determination value range ( S805 ).

[0183] In some embodiments, it is defined that the refrigerant charging amount is insufficient at this time, and an electrical signal representing the insufficient refrigerant charging amount is output (S806).

[0184] In the above judgment logic, the unit performs intelligent calculations based on the feedback values ​​of each detection device during operation and outputs the refrigerant charge amount judgment result.

[0185] In the above control logic, the logic in S802, S803, S804, and S805 is a progressive relationship, and the judgment order is not changed under normal circumstances.

[0186] In some embodiments, when an electrical signal indicating insufficient refrigerant charge is received, the amount of refrigerant in the air conditioning system is increased.

[0187] In some embodiments, the controller 21 is configured to, after the multi-split air conditioner 100 is turned on and the unit operates normally for a period of time, operate in cooling mode, and if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit 16 is not within the first determination value range, proceed to the next logical determination.

[0188] In some embodiments, when the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit 16 is not within the first judgment value range and the number of abnormal indoor units 16 does not reach the second judgment value, it is determined that the refrigerant quantities of at least two indoor units 16 are different at this time.

[0189] In some embodiments, when the number of abnormal indoor units 16 exceeds the second judgment value and the difference between the indoor inlet air temperature and the indoor outlet air temperature of some abnormal indoor units 16 does not reach the upper limit of the first judgment value range, it is determined that the refrigerant quantities of at least two indoor units 16 are different.

[0190] In some embodiments, when the number of abnormal indoor units 16 exceeds the second judgment value and the difference between the indoor inlet air temperature and the indoor outlet air temperature of some abnormal indoor units 16 exceeds the lower limit of the first judgment value range, it is determined that the refrigerant quantities of at least two indoor units 16 are different at this time.

[0191] By determining the relationship between the operating data of the abnormal indoor unit 16 and the set range, it is preliminarily determined whether the abnormality of the indoor unit 16 is due to insufficient refrigerant charge or uneven distribution of the refrigerant.

[0192] When the refrigerant is unevenly distributed, it is necessary to adjust the flow distribution of the refrigerant in each indoor unit 16 by switching the opening of the electronic expansion valve.

[0193] The unit analyzes system failures caused by other reasons based on the feedback values ​​of various detection devices during operation and outputs the results. This avoids attributing all abnormalities to insufficient refrigerant charge, which can lead to misjudgment and affect the operation of the air conditioning system.

[0194] In some embodiments, after the multi-split air conditioner 100 is powered on and the unit operates normally for a period of time, when operating in cooling mode, the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit 16 is not within a first determination value range, and the number of abnormal indoor units 16 exceeds a second determination value.

[0195] In some embodiments, it is determined that the difference between the indoor air inlet temperature and the indoor air outlet temperature of the abnormal indoor unit 16 reaches an upper limit of the first determination value range.

[0196] In some embodiments, if the exhaust pressure exceeds the lower limit of the third judgment value range and does not reach the upper limit of the third judgment value range, it is determined that the air inlet area of ​​the air inlet of the abnormal indoor unit 16 is not equal to the area of ​​the air inlet.

[0197] At this time, the air inlet area of ​​the indoor unit 16 is not equal to the area of ​​the air inlet, which means that the air inlet is blocked, resulting in reduced air intake inside the indoor unit 16, resulting in poor heat exchange effect of the indoor heat exchanger 27, and the exhaust pressure will increase.

[0198] In some embodiments, the multi-split air conditioner 100 is turned on, and after the unit operates normally for a period of time, when operating in cooling mode, the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit 16 is not within the first judgment value range, and the number of abnormal indoor units 16 exceeds the second judgment value.

[0199] In some embodiments, it is determined that the difference between the indoor air inlet temperature and the indoor air outlet temperature of all abnormal indoor units 16 does not exceed the lower limit of the first determination value range.

[0200] In some embodiments, if the exhaust pressure exceeds the lower limit of the sixth judgment value range and does not reach the upper limit of the sixth judgment value range, it is determined that the air inlet area of ​​the air inlet of the abnormal indoor unit 16 is not equal to the area of ​​the air inlet.

[0201] Reference Figure 9 , which explains the verification logic of the refrigerant charge amount in cooling mode.

[0202] First, it is determined whether the difference between the indoor air inlet temperature and the indoor air outlet temperature of all indoor units 16 is within a first judgment value range (step S901);

[0203] In step S901, if it is met, step S902 is executed to determine whether the refrigerant charging amount is normal.

[0204] In step S901, if it does not meet the requirements, step S903 is executed to determine whether the ratio of the number of abnormal indoor units to the total number of indoor units is less than or equal to a second judgment value.

[0205] In step S903, if yes, step S904 is executed to check that the refrigerant in the indoor unit 16 is unevenly distributed. After the troubleshooting is completed, the refrigerant test operation is performed again.

[0206] If not in step S903, a consistency determination is performed, and step S905 is executed to determine whether the difference between the indoor air inlet temperature and the indoor air outlet temperature of all abnormal indoor units is greater than or equal to the upper limit of the first judgment value range, or whether the difference is less than or equal to the lower limit of the first judgment value range;

[0207] In step S905, if both are negative, step S904 is executed.

[0208] In step S905, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of all abnormal indoor units is greater than or equal to the upper limit of the first judgment value range, step S906 is executed to determine whether the exhaust pressure is greater than or equal to the upper limit of the third judgment value range.

[0209] In step S906, if yes, step S912 is executed to determine whether the refrigerant is overcharged.

[0210] In step S906, if not, step S908 is executed to determine whether the exhaust pressure is greater than the lower limit of the third determination value range;

[0211] In step S908, step S909 is executed to determine whether the air intake of the indoor unit 16 is abnormal.

[0212] In step S905, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of all abnormal indoor units is ≤ the lower limit of the first judgment value range, step S907 is executed to check whether the exhaust pressure is ≤ the lower limit of the third judgment value range.

[0213] In step S907, if yes, step S910 is executed to determine whether the refrigerant is insufficiently charged.

[0214] In step S907, if not, step S911 is executed to determine whether the exhaust pressure is less than the upper limit of the third determination value range;

[0215] In step S911, if yes, execute step S909.

[0216] Reference Figure 10 , which explains the judgment logic of the refrigerant charge amount under heating conditions.

[0217] In some embodiments, the controller 21 is configured to operate the multi-split air conditioner 100 in a heating mode ( S1001 ).

[0218] In some embodiments, the indoor air outlet temperature of all indoor units 16 does not reach the lower limit of the fourth determination value range ( S1002 ).

[0219] In some embodiments, determining a relationship between a second difference between the exhaust temperature and the saturation temperature corresponding to the condensing pressure and a fifth determination value range ( S1003 );

[0220] In some embodiments, when the second difference exceeds the upper limit of the fifth determination value range, it is defined that the refrigerant charging amount is insufficient, and an electrical signal representing the insufficient refrigerant charging amount is output (S1004).

[0221] In some embodiments, when an electrical signal indicating insufficient refrigerant charge is received, the amount of refrigerant in the air conditioning system is increased.

[0222] Reference Figure 11 , which explains the judgment logic of the refrigerant charge amount under heating conditions.

[0223] In some embodiments, the multi-split air conditioner 100 operates in a heating mode ( S1101 ).

[0224] In some embodiments, the indoor air outlet temperatures of all indoor units 16 do not reach the lower limit of the fourth determination value range ( S1102 ).

[0225] In some embodiments, the second difference between the exhaust temperature and the condensation temperature corresponding to the exhaust pressure does not reach the lower limit of the fifth determination value range ( S1103 ).

[0226] In some embodiments, it is defined that the refrigerant charge amount is excessive at this time, and an electrical signal representing the excessive refrigerant charge amount is output (S1104).

[0227] In the above judgment logic, the multi-split air conditioner 100 unit performs intelligent calculations based on the feedback values ​​of each detection device during operation in the heating mode, and outputs a refrigerant charge amount judgment result.

[0228] In some embodiments, when an electrical signal indicating an excessive refrigerant charge is received, the amount of refrigerant in the air conditioning system may be reduced by discharging the refrigerant.

[0229] It should be noted that the second difference between the exhaust temperature and the condensing temperature corresponding to the exhaust pressure refers to the exhaust superheat of the multi-split air conditioner 100.

[0230] In some embodiments, the controller 21 is configured to, when the multi-split air conditioner 100 is turned on and the unit operates normally for a period of time, when running in heating mode, if the indoor air outlet temperature of all indoor units 16 does not reach the lower limit of the fourth determination value range, then perform the next logical judgment.

[0231] In some embodiments, if the indoor air outlet temperature of all indoor units 16 does not reach the lower limit of the fourth determination value range and the second difference exceeds the lower limit of the fifth determination value range and the second difference does not reach the upper limit of the fifth determination value range, it is determined that the length of the connecting pipe 17 between the indoor unit 16 and the outdoor unit 14 exceeds the preset length or the diameter of the connecting pipe 17 is smaller than the preset diameter.

[0232] When the exhaust gas superheat is normal, the air conditioning system's cooling capacity is considered to be normal. However, if an abnormality occurs, it may be due to excessive refrigerant loss during transmission. Therefore, in the above embodiment, when the exhaust gas superheat is within the set range, it is determined to be due to refrigerant transmission loss in connecting pipe 17. Parameters related to loss in connecting pipe 17 include its length and diameter. Excessive length of connecting pipe 17 can lead to unnecessary heat loss; excessively small diameter of connecting pipe 17 can also lead to unnecessary refrigerant loss.

[0233] In some embodiments, the controller 21 is configured to, when the multi-split air conditioner 100 is turned on and the unit operates normally for a period of time, when running in heating mode, if the indoor air outlet temperature of some indoor units 16 does not reach the lower limit of the fourth judgment value range, it is determined that the refrigerant quantities of at least two indoor units 16 are different at this time.

[0234] Reference Figure 12 , which explains the verification logic of the refrigerant charge amount in heating mode.

[0235] First, the air outlet temperature of all indoor units 16 is judged to determine whether the air outlet temperature of all indoor units 16 is greater than or equal to the lower limit of the fourth judgment value range (S1201);

[0236] In step S1201, if yes, step S1202 is executed to determine whether the refrigerant charge amount is appropriate.

[0237] If the answer is no in step S1202, step S1203 is executed to determine whether the air outlet temperatures of all abnormal indoor units 16 are lower than the seventh determination value.

[0238] If not in step S1203, step S1204 is executed to determine whether the refrigerant distribution in the indoor unit 16 is uneven.

[0239] In step S1203, if yes, step S1205 is executed to determine whether the upper limit of the fifth determination value range is greater than the difference between the exhaust temperature and the exhaust pressure corresponding to the condensing temperature and the lower limit of the fifth determination value range is satisfied;

[0240] In step S1205, if yes, step S1206 is executed to determine whether the internal and external unit connecting pipe 17 is too long or the pipe diameter is too small.

[0241] In step S1205 , if the upper limit of the fifth determination value range is ≤ the difference between the exhaust temperature and the exhaust pressure corresponding to the condensing temperature, step S1207 is executed to determine that the refrigerant charge amount is too small.

[0242] In step S1205 , if the difference between the exhaust gas temperature and the condensing temperature corresponding to the exhaust gas pressure is ≤ the lower limit of the fifth determination value range, step S1208 is executed to determine that the refrigerant is overcharged.

[0243] This application proposes a multi-split air conditioner 100 that automatically determines the refrigerant charge level based on operating parameter feedback, replacing manual determination. This reduces reliance on human intervention, resulting in more scientific determination results, more accurate refrigerant charge levels, and more energy-efficient, safer, and more reliable air conditioning system operation.

[0244] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0245] For ease of explanation, the above description has been presented in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations are possible. The above embodiments have been selected and described to better explain the principles and practical applications, thereby enabling those skilled in the art to better utilize the embodiments and various variations of the embodiments suitable for specific use considerations.

Claims

1. A multi-split air conditioner, characterized in that: include: At least two indoor heat exchangers, the indoor heat exchangers being connected in parallel, the indoor heat exchangers being provided in the indoor unit and being used for exchanging heat with indoor air; An outdoor heat exchanger is provided in the outdoor unit and is used to exchange heat with outdoor air; A compressor comprising an air intake port and an air discharge port for compressing a high-temperature and high-pressure refrigerant and discharging the compressed refrigerant, wherein the outdoor heat exchanger, the indoor heat exchanger, and the compressor are connected to form a refrigerant circuit; Indoor air outlet temperature detection device, which is installed at the air outlet of the indoor unit and is used to detect the indoor air outlet temperature; Indoor air inlet temperature detection device, which is installed at the air inlet of the indoor unit and is used to detect the indoor air inlet temperature; an exhaust pressure detection device, which is provided at the exhaust port of the compressor and is used to detect the exhaust pressure of the compressor; The controller is configured to, after the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in cooling mode, determine if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within a first judgment value range, and the number of abnormal indoor units exceeds a second judgment value; wherein the abnormal indoor unit is defined as an indoor unit whose difference between the indoor air inlet temperature and the indoor air outlet temperature is not within the first judgment value range; When the difference between the indoor air inlet temperature and the indoor air outlet temperature of all abnormal indoor units reaches the upper limit of the first judgment value range, and the exhaust pressure reaches the upper limit of the third judgment value range, an electrical signal representing excessive refrigerant charge is output.

2. The multi-split air conditioner according to claim 1, characterized in that: The controller is configured to, when the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in cooling mode, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within a first judgment value range, and the number of abnormal indoor units exceeds a second judgment value; When the difference between the indoor inlet air temperature and the indoor outlet air temperature of all the abnormal indoor units does not exceed the lower limit of the first judgment value range, if the exhaust pressure does not exceed the lower limit of the sixth judgment value range, an electrical signal representing insufficient refrigerant charging is output.

3. The multi-split air conditioner according to any one of claims 1-2, characterized in that: The controller is configured to, The multi-split air conditioner is turned on, and after the unit operates normally for a period of time, when operating in cooling mode, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within the first judgment value range, if the number of abnormal indoor units does not reach the second judgment value, or / and the difference between the indoor air inlet temperature and the indoor air outlet temperature of some of the abnormal indoor units does not reach the upper limit value of the first judgment value range, and / or the difference between the indoor air inlet temperature and the indoor air outlet temperature of some of the abnormal indoor units exceeds the lower limit value of the first judgment value range, it is determined that the refrigerant quantities of at least two indoor units are different at this time.

4. The multi-split air conditioner according to claims 1-3, characterized in that: Also includes: an outdoor exhaust temperature detection device, which is provided at the exhaust port of the compressor and is used to detect the exhaust temperature of the compressor; The controller is configured to, after the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in a heating mode, if the indoor air outlet temperature of all indoor units does not reach the lower limit of the fourth judgment value range, determine the relationship between the second difference between the exhaust temperature and the saturation temperature corresponding to the condensing pressure and the fifth judgment value range; When the second difference exceeds the upper limit of the fifth determination value range, an electrical signal indicating that the refrigerant charge amount is insufficient is output.

5. The multi-split air conditioner according to claim 4, characterized in that: The controller is configured to output an electrical signal representing excessive refrigerant charge when the multi-split air conditioner is turned on and the unit operates normally for a period of time, and when operating in heating mode, if the indoor air outlet temperature of all indoor units does not reach the lower limit of the fourth judgment value range, and the second difference between the exhaust temperature and the condensing temperature corresponding to the exhaust pressure does not reach the lower limit of the fifth judgment value range.

6. The multi-split air conditioner according to claim 5, characterized in that: The controller is configured to, after the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in heating mode, if the indoor air outlet temperature of all indoor units does not reach the lower limit of the fourth judgment value range, and the second difference exceeds the lower limit of the fifth judgment value range and the second difference does not reach the upper limit of the fifth judgment value range, determine that the length of the connecting pipe between the indoor unit and the outdoor unit exceeds the preset length or the diameter of the connecting pipe is smaller than the preset diameter.

7. The multi-split air conditioner according to claim 5, characterized in that: The controller is configured to, when the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in heating mode, if the indoor air outlet temperature of some indoor units does not reach the lower limit of the fourth judgment value range, determine that the refrigerant quantities of at least two indoor units are different at this time.

8. The multi-split air conditioner according to claim 1, characterized in that: The controller is configured to, when the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in cooling mode, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within a first judgment value range, and the number of abnormal indoor units exceeds a second judgment value; When it is determined that the difference between the indoor air inlet temperature and the indoor air outlet temperature of the abnormal indoor unit at this time reaches the upper limit value of the first judgment value range, if the exhaust pressure exceeds the lower limit value of the third judgment value range and does not reach the upper limit value of the third judgment value range, it is determined that the air inlet area of ​​the air inlet of the abnormal indoor unit at this time is not equal to the area of ​​the air inlet.

9. The multi-split air conditioner according to claim 3, characterized in that: The controller is configured to, when the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in cooling mode, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within a first judgment value range, and the number of abnormal indoor units exceeds a second judgment value; When the difference between the indoor inlet air temperature and the indoor outlet air temperature of all the abnormal indoor units does not exceed the lower limit of the first judgment value range, if the exhaust pressure exceeds the lower limit of the sixth judgment value range and does not reach the upper limit of the sixth judgment value range, it is determined that the air inlet area of ​​the air inlet of the abnormal indoor unit is not equal to the area of ​​the air inlet.

10. A multi-split air conditioner, characterized in that: include: At least two indoor heat exchangers, the indoor heat exchangers being connected in parallel, the indoor heat exchangers being provided in the indoor unit and being used for exchanging heat with indoor air; An outdoor heat exchanger is provided in the outdoor unit and is used to exchange heat with outdoor air; A compressor comprising an air intake port and an air discharge port for compressing a high-temperature and high-pressure refrigerant and discharging the compressed refrigerant, wherein the outdoor heat exchanger, the indoor heat exchanger, and the compressor are connected to form a refrigerant circuit; an outdoor exhaust temperature detection device, which is provided at the exhaust port of the compressor and is used to detect the exhaust temperature of the compressor; Indoor air outlet temperature detection device, which is installed at the air outlet of the indoor unit and is used to detect the indoor air outlet temperature; an exhaust pressure detection device, which is provided at the exhaust port of the compressor and is used to detect the exhaust pressure of the compressor; The controller is configured to, after the multi-split air conditioner is turned on and the unit operates normally for a period of time, when operating in a heating mode, if the indoor air outlet temperature of all indoor units does not reach the lower limit of the fourth judgment value range, determine the relationship between the second difference between the condensing temperature corresponding to the exhaust temperature and the exhaust pressure and the fifth judgment value range; When the second difference exceeds the upper limit of the fifth determination value range, an electrical signal indicating that the refrigerant charge amount is insufficient is output.

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