Multi-connected air conditioner

Abstract

The application discloses a multi-connected 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 outlet 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. A controller is configured to start the multi-connected air conditioner, and after the air conditioner normally operates for a period of time, when a cooling mode is operated, if the difference between the indoor inlet air temperature and the indoor outlet air temperature of each indoor unit is not within a first determination value range, and the number of abnormal indoor units exceeds a second determination value; wherein the abnormal indoor unit is defined as the indoor unit whose difference between the indoor inlet air temperature and the indoor outlet air temperature is not within the first determination value range; when the difference between the indoor inlet air temperature and the indoor outlet air temperature of all abnormal indoor units reaches an upper limit value of the first determination value range, and the exhaust pressure reaches an upper limit value of a third determination value range, an electric signal representing an excessive refrigerant charge amount is output. According to the feedback values detected by the detection devices during operation, intelligent calculation is performed, and a refrigerant charge determination result is output, so that the misjudgment of the refrigerant charge amount is avoided.

Description

Technical Field

[0001] This invention belongs to the field of air conditioner technology, and particularly relates to a multi-split air conditioner. Background Technology

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

[0003] Air conditioning unit refrigerant charging consists of two parts. One part is the refrigerant that comes with the outdoor unit at the factory. This part of the charging process is not standardized, and the charging amount is not accurate. However, if pipeline damage or operational errors occur during transportation or installation, resulting in micro-leakage that is not thought to be noticeable, it will cause insufficient refrigerant.

[0004] Another part involves charging the refrigerant based on the indoor unit and pipe length on site. This requires on-site personnel to calculate and verify the refrigerant, and during this process, there may be instances of overcharging or undercharging.

[0005] In related technologies, the system can be monitored in real time based on parameters such as exhaust pressure, indoor unit valve opening, and subcooling, thereby enabling automatic determination of the refrigerant charge during the charging process. However, the determination of a single parameter is affected by various factors such as indoor and outdoor ambient temperature and model, which leads to a certain deviation in the determined refrigerant charge.

[0006] In view of the above, this application is hereby submitted. Summary of the Invention

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

[0008] This application embodiment proposes a multi-split air conditioner, which includes:

[0009] At least two indoor heat exchangers are connected in parallel and are located in the indoor unit for exchanging heat with indoor air.

[0010] The outdoor heat exchanger is located in the outdoor unit and is used to exchange heat with the outdoor air.

[0011] The compressor includes an intake port and an exhaust port, and is used to compress refrigerant under high temperature and high pressure and discharge the compressed refrigerant. The outdoor heat exchanger, the indoor heat exchanger and the compressor are connected to form a refrigerant circuit.

[0012] An indoor air outlet temperature detection device is installed at the air outlet of the indoor unit to detect the indoor air outlet temperature.

[0013] An indoor air intake temperature detection device is installed at the air intake of the indoor unit to detect the indoor air intake temperature.

[0014] An exhaust pressure detection device is installed at the exhaust port of the compressor to detect the exhaust pressure of the compressor.

[0015] The controller is configured such that, after the multi-split air conditioner is turned on and the unit has been running normally for a period of time, when the cooling mode is in operation, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within the range of a first determination value, and the number of abnormal indoor units exceeds a second determination value; wherein, an 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 range of the first determination value.

[0016] When the difference between the indoor intake air temperature and the indoor exhaust 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 the third judgment value range, an electrical signal representing excessive refrigerant charge is output.

[0017] In some embodiments, the controller is configured such that, after the multi-split air conditioner is turned on and the unit has been running normally for a period of time, when the cooling mode is in operation, if the difference between the indoor air intake temperature and the indoor air outlet temperature of each indoor unit is not within the range of the first determination value, and the number of abnormal indoor units exceeds the second determination value;

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

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

[0020] When the multi-split air conditioner is turned on and the unit has been running normally for a period of time, if the difference between the indoor air intake temperature and the indoor air outlet temperature of each indoor unit is not within the first judgment value range when the cooling mode is activated, if the number of abnormal indoor units does not reach the second judgment value, or / and the difference between the indoor air intake temperature and the indoor air outlet temperature of some of the abnormal indoor units does not reach the upper limit of the first judgment value range, and / or the difference between the indoor air intake temperature and the indoor air outlet temperature of some of the abnormal indoor units exceeds the lower limit of the first judgment value range, it is determined that at least two indoor units have different refrigerant charges at this time.

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

[0022] An outdoor exhaust temperature detection device is installed at the exhaust port of the compressor to detect the exhaust temperature of the compressor.

[0023] The controller is configured such that, when the multi-split air conditioner is turned on and the unit has been running normally for a period of time, when the heating mode is in operation, if the indoor air outlet temperature of all indoor units has not reached the lower limit of the fourth judgment value range, the controller determines 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 judgment value range, an electrical signal representing insufficient refrigerant charge is output.

[0025] In some embodiments, the controller is configured to, when the multi-split air conditioner is turned on and the unit has been running normally for a period of time, output an electrical signal representing excessive refrigerant charge when the heating mode is in operation, 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.

[0026] In some embodiments, the controller is configured such that, when the multi-split air conditioner is turned on and the unit has been running normally for a period of time, when the heating mode is in operation, 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 but 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 has been running normally for a period of time, when the heating mode is in operation, if the indoor air outlet temperature of some indoor units does not reach the lower limit of the fourth determination value range, then it is determined that at least two indoor units have different refrigerant charges.

[0028] In some embodiments, the controller is configured such that, after the multi-split air conditioner is turned on and the unit has been running normally for a period of time, when the cooling mode is running, if the difference between the indoor air intake temperature and the indoor air outlet temperature of each indoor unit is not within the range of the first determination value, and the number of abnormal indoor units exceeds the second determination value;

[0029] If the difference between the indoor air inlet temperature and the indoor air outlet temperature of the abnormal indoor unit reaches the upper limit of the first judgment value range, and if the exhaust pressure exceeds the lower limit of the third judgment value range but does not reach the upper limit of the third judgment value range, then the air inlet area of ​​the abnormal indoor unit is determined to be equal to the air inlet area.

[0030] In some embodiments, the controller is configured such that, after the multi-split air conditioner is turned on and the unit has been running normally for a period of time, when the cooling mode is running, if the difference between the indoor air intake temperature and the indoor air outlet temperature of each indoor unit is not within the range of the first determination value, and the number of abnormal indoor units exceeds the second determination value;

[0031] When the difference between the indoor air inlet temperature and the indoor air outlet 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 but does not reach the upper limit of the sixth judgment value range, it is determined that the air inlet area of ​​the abnormal indoor unit is not equal to the air inlet area.

[0032] This application discloses a multi-split air conditioner, including at least two indoor heat exchangers, an outdoor heat exchanger, a compressor, an exhaust pressure detection device located at the compressor's exhaust port, an indoor inlet air temperature detection device located at the air inlet, and an indoor outlet air temperature detection device located at the air outlet. The controller is configured such that, after the multi-split air conditioner is turned on and the unit has been running 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 the third judgment value range, an electrical signal representing excessive refrigerant charge is output. Intelligent calculation is performed based on the feedback values ​​detected by each detection device during operation to output a refrigerant charge determination result, avoiding misjudgment of refrigerant charge.

[0033] This application also proposes another multi-split air conditioner, which includes:

[0034] At least two indoor heat exchangers are connected in parallel and are located in the indoor unit for exchanging heat with indoor air.

[0035] The outdoor heat exchanger is located in the outdoor unit and is used to exchange heat with the outdoor air.

[0036] The compressor includes an intake port and an exhaust port, and is used to compress refrigerant under high temperature and high pressure and discharge the compressed refrigerant. 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 is installed at the exhaust port of the compressor to detect the exhaust temperature of the compressor.

[0038] An indoor air outlet temperature detection device is installed at the air outlet of the indoor unit to detect the indoor air outlet temperature.

[0039] An exhaust pressure detection device is installed at the exhaust port of the compressor to detect the exhaust pressure of the compressor.

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

[0041] When the second difference exceeds the upper limit of the fifth judgment value range, an electrical signal representing insufficient refrigerant charge is output. Attached Figure Description

[0042] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

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

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

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

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

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

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

[0049] Figure 7 This is the logic for determining the refrigerant charge amount under refrigeration conditions in one embodiment of the present invention;

[0050] Figure 8 This is another logic for determining the refrigerant charge amount under refrigeration conditions in one embodiment of the present invention;

[0051] Figure 9 This is a verification logic for refrigerant charge quantity in refrigeration mode in one embodiment of the present invention.

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

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

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

[0055] In the above image:

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

[0057] 1. Compressor; 4. Four-way valve; 6. Gas-liquid separator; 7. Electronic expansion valve; 8. Outdoor heat exchanger;

[0058] Gas-side shut-off valve 9; Liquid-side shut-off valve 10; Outdoor unit 14; Indoor unit 16; Connecting pipe 17;

[0059] Indoor air intake 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 ambient temperature detection device 28. Detailed Implementation

[0061] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0062] In the description of this invention, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not 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.

[0063] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

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

[0065] The indoor unit consists of two indoor units 16. Multiple indoor units 16 are connected in parallel.

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

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

[0068] 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 to allow refrigerant to flow.

[0070] The length of the connecting pipe 17 will be 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 housing. The indoor housing forms the outer contour of the indoor unit 16 and houses the internal components of the indoor unit 16.

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

[0074] The indoor casing has an air inlet (not shown in the figure) for the indoor unit 16. The indoor air inlet is used to allow indoor air to enter the indoor casing.

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

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

[0077] The indoor casing has an air outlet (not shown in the figure) for the indoor unit 16. The indoor air outlet is used to exhaust air from the indoor casing. Indoor air enters the indoor casing 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 also 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 and 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 inside the indoor casing. The indoor heat exchanger 27 is used to exchange heat with indoor air entering the indoor casing.

[0080] The indoor unit 16 includes an indoor fan. The indoor fan is installed inside the indoor casing. The indoor fan rotates to allow indoor air to enter the indoor casing. After exchanging heat with the indoor heat exchanger 27, the indoor air flows out of the indoor casing.

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

[0082] The outdoor unit 14 includes an outdoor housing. The outdoor housing forms the outer outline of the outdoor unit 14 and houses the 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 mounted on the outdoor casing and is used to detect the outdoor ambient temperature.

[0084] The multi-split air conditioner 100 also includes an exhaust temperature detection device 25. The exhaust temperature detection device 25 is located at the compressor's exhaust port and is used to detect the compressor's exhaust temperature.

[0085] The multi-split air conditioner 100 also includes an exhaust pressure detection device 24, which is installed 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] Condensing pressure is the pressure at which refrigerant condenses from gas into liquid inside the condenser. Since the pressure inside the condenser in a refrigeration system cannot be measured, and in reality, the pressure drop of refrigerant in the exhaust pipe and inside the condenser is very small, the exhaust pressure is generally considered to be approximately equal to the condensing pressure, whether in design, commissioning, or maintenance.

[0088] The outdoor casing has an outdoor air inlet, which is used to allow outdoor air to enter the outdoor casing.

[0089] The outdoor casing has an outdoor air outlet, which is used to exhaust air from the outdoor casing. Outdoor air enters the outdoor casing 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 inside the outdoor casing and is used to exchange heat with the outdoor air entering the outdoor casing.

[0091] The outdoor unit 14 includes an outdoor fan, which is installed inside the outdoor casing. The outdoor fan rotates to allow outdoor air to enter the outdoor casing. After exchanging heat with the outdoor heat exchanger 8, the outdoor air flows out of the outdoor casing.

[0092] Reference Figure 3 This describes 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 the gaseous refrigerant at high temperature and high pressure and discharge the compressed gaseous refrigerant.

[0094] Compressor 1 includes an intake port. Refrigerant flows into compressor 1 from the intake port to be compressed.

[0095] Compressor 1 includes a discharge port. Refrigerant enters compressor 1 through the suction port, is compressed by compressor 1, and is discharged through the discharge port.

[0096] The outdoor unit 14 also includes a gas-liquid separator 6. The gas-liquid separator 6 is installed at the suction port 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. The first port of the four-way valve 4 is connected to the discharge port of the compressor 1. The second port of the four-way valve 4 is connected to the suction port of the compressor 1. The third port of the four-way valve 4 is connected to the indoor unit 16. The fourth port of the four-way valve 4 is connected to the outdoor heat exchanger 8.

[0098] The outdoor unit 14 also includes an electronic expansion valve 7. The electronic expansion valve 7 is located 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 causes the high-temperature, high-pressure liquid refrigerant condensed in the condenser to expand into a low-pressure liquid refrigerant.

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

[0100] In some embodiments, an electronic expansion valve is disposed in the indoor unit 16. No illustrations are shown in this application.

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

[0102] The outdoor unit 14 also includes a gas-side shut-off valve 9. The gas-side shut-off valve 9 is located at the third port of the four-way valve 4.

[0103] The outdoor unit 14 also includes a liquid-side shut-off valve 10, which is located between the indoor unit 16 and the subcooler 11.

[0104] The outdoor unit 14 also includes a filter, which is located on both sides of the electronic expansion valve.

[0105] The outdoor unit 14 also includes a distributor. The distributor is located on the side of the outdoor heat exchanger near the indoor heat exchanger 27. It is used to control the flow of refrigerant.

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

[0107] Multi-split air conditioners 100 use refrigerant flow to blow out air that is higher or lower than the indoor temperature, or the same as the indoor temperature, in order to adjust the temperature and humidity of the indoor environment; or they use the speed of the indoor fan to adjust the airflow speed of the indoor environment.

[0108] Taking one of the outdoor units 14 as an example, we will explain the cooling and heating modes of the multi-split air conditioner 100.

[0109] When the multi-split air conditioner 100 is in cooling mode, the refrigerant from compressor 1 is condensed by the outdoor heat exchanger 8. The condensed refrigerant then expands through the electronic expansion valve 7. The expanded condensate evaporates through the indoor heat exchanger 27. The evaporated refrigerant then circulates back to 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 and condenses. The condensed refrigerant then expands by flowing through electronic expansion valve 7. The expanded condensate 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 appropriateness of the refrigerant charge is crucial to the stable operation of the entire air conditioning system, the reliability of various components, the unit's performance, and energy efficiency.

[0112] In some embodiments, the refrigerant charge consists of two parts. The first part is the amount supplied at the factory. The second part is charged according to the indoor unit 16 and piping length installed on-site. However, since this part is done manually, there is a possibility of overcharging or undercharging due to calculation errors or mistakes in manual charging, which can affect 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 this application, the multi-split air conditioner 100 includes a remote control. The user inputs commands to the controller 21 via the remote control to select the operating modes of the indoor unit 16 and the outdoor unit 14.

[0115] In some implementations, the operating modes of the multi-split air conditioner 100 vary depending on the model and user needs. In this application, the cooling mode and the heating mode are selected for description.

[0116] In the cooling mode, the air flowing from the indoor unit 16 into the room is cold air. This cold air can be defined as airflow that is lower than the indoor air temperature.

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

[0118] In this application, the decision of whether the multi-split air conditioner 100 operates in heating or cooling mode can be made by the user setting or by determining the range of indoor ambient temperature detected by the indoor ambient temperature detection device and outdoor ambient temperature detected by the outdoor ambient temperature detection device 28.

[0119] In some embodiments of this 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 operating status of various components 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 operating status of various components inside the outdoor unit 14.

[0122] The indoor controller 21 and the outdoor controller 21 communicate via wired communication.

[0123] In other embodiments, the above-described 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 a shutdown command, and compare them with the set conditions to determine whether to shut down the outdoor unit 14 or whether liquid return has occurred, so as to solve the liquid return problem of the compressor 1 to a certain extent.

[0125] Meanwhile, the outdoor controller 21 and the indoor controller 21 can also rotate the units according to the hardware conditions, running time, and actual working conditions of each indoor unit 16 and each outdoor unit 14, so as to achieve efficient cooperation between each indoor unit 16 and each outdoor unit 14.

[0126] In some embodiments of this application, the indoor controller 21 and the outdoor controller 21 are not specifically distinguished, and are collectively referred to as controller 21.

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

[0128] The indoor controller 21 and the outdoor controller 21 have roughly the same structure. The structure of the indoor controller 21 will be explained using the indoor controller 21 as an example.

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

[0130] For example, at least one disk storage device 212. Storage device 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 communicate with related components.

[0132] The communication interface 214 of the indoor controller 21 is used to communicate with various detection devices 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 the form of source code, object code, executable file, or some of these forms.

[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, etc.

[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 an execution instruction, the processor 213 executes the program to implement... Figure 6-12 The logic control method for detecting refrigerant charge amount is shown.

[0137] In some embodiments of this application, the controller 21 is at least used to receive data detected by 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.

[0138] In some embodiments, after the air conditioning unit is installed, the installers first conduct a start-up test.

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

[0140] If the unit is running normally, the operating environment coefficient will be collected after running for a period of time T1. The operating environment coefficient includes outdoor ambient temperature, indoor ambient temperature, indoor unit model 16, and connection ratio, etc.

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

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

[0143] In some embodiments, after confirming the operating mode and operating parameters, the system operates according to the predetermined mode. After operating for a period of time T2, the operating parameters are collected and the appropriateness of the refrigerant charge is calculated.

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

[0145] In some embodiments, the corresponding code is displayed and the recorded parameters are scrolled to inform the debugger, so that the debugger can record them.

[0146] In some embodiments, if the unit determines that the refrigerant charge is too low or too high, the operation ends, the corresponding code is output, and the recorded parameters are displayed in a scrolling manner. After the recording is completed, the unit manually dials the switch to exit the refrigerant calibration 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 unit's operating condition is abnormal or the monitoring data is incorrect, the unit stops operating, and the corresponding code is output.

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

[0151] In some embodiments, the setting of operating parameters specifically includes, based on actual test data and theoretical data, preset execution parameters in the program inside the controller 21 for different indoor ambient temperatures, outdoor ambient temperatures and indoor-outdoor unit connection ratios.

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

[0153] In some embodiments, when the multi-split air conditioner 100 is in heating mode, the opening degree of the electronic expansion valve is calculated based on the preset basic opening degree, 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 degree of the electronic expansion valve is calculated based on the preset basic opening degree, the indoor unit horsepower, and the compressor operating frequency.

[0155] In some embodiments, refer to Figure 6 This describes the control logic for refrigerant charge verification in this application.

[0156] In some embodiments, the refrigerant charge verification mode is entered via a DIP switch.

[0157] Multi-split air conditioner 100 trial operation start-up (S601);

[0158] Determine if the multi-split air conditioning unit 100 is operating (S602);

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

[0160] In some embodiments, after performing step S604, step S602 may be performed.

[0161] In step S602, if the multi-split air conditioning unit 100 is operating normally, then step S603 is executed, and the unit runs continuously for a period of time.

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

[0163] In step S608, if the refrigerant charge is appropriate, then step S609 is executed, and the outdoor seven-segment display shows a code carrying information that the refrigerant charge is appropriate.

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

[0165] It is important to understand that the execution logic of S610 and S611 is not sequential and does not necessarily exist simultaneously. That is, in some embodiments, S610 can be executed alone, or S611 can be executed alone.

[0166] After executing S610 and S611, record the operating parameters and manually exit the refrigerant calibration mode (S612).

[0167] Reference Figure 7 This explains the logic for determining the refrigerant charge amount under refrigeration conditions.

[0168] In some embodiments, the controller 21 is configured to allow the multi-split air conditioner 100 to operate in 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 range of the first determination value (S702).

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

[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 the upper limit of the third determination value range (S705).

[0173] In some embodiments, it is defined that the refrigerant charge is excessive at this time, and an electrical signal representing the excessive refrigerant charge 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 determination result.

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

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

[0177] Reference Figure 8 This explains another logic for determining the refrigerant charge amount under refrigeration conditions.

[0178] In some embodiments, the controller 21 is configured to allow the multi-split air conditioner 100 to operate in 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 range of the first determination value (S802).

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

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

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

[0183] In some embodiments, it is defined that the refrigerant charge is insufficient at this time, and an electrical signal representing insufficient refrigerant charge 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 determination result.

[0185] In the above control logic, the logic in S802, S803, S804, and S805 is in a progressive relationship, and the order of judgment 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 such that when the multi-split air conditioner 100 is turned on and the unit operates normally for a period of time, it runs in cooling mode. If the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit 16 is not within the range of the first determination value, then the next logical judgment is performed.

[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 range of the first determination value and the number of abnormal indoor units 16 does not reach the second determination value, it is determined that at least two indoor units 16 have different refrigerant charges.

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

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

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

[0192] When the refrigerant is unevenly distributed, the refrigerant flow distribution of each indoor unit 16 needs to be adjusted by switching the opening of the electronic expansion valve.

[0193] The unit analyzes feedback values ​​from various detection devices during operation to identify other causes of system malfunctions and outputs the results. This avoids attributing all abnormalities to insufficient refrigerant charge, which could lead to misjudgments and affect the operation of the air conditioning system.

[0194] In some embodiments, after the multi-split air conditioner 100 is turned on and the unit has been running normally for a period of time, when the cooling mode is activated, the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit 16 is not within the range of the first determination value. Furthermore, the number of abnormal indoor units 16 exceeds the 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 the upper limit of the first determination value range.

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

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

[0198] In some embodiments, after the multi-split air conditioner 100 is turned on and the unit has been running normally for a period of time, when the cooling mode is running, the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit 16 is not within the range of the first judgment value, 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 determination value range but does not reach the upper limit of the sixth determination value range, it is determined that the air inlet area of ​​the abnormal indoor unit 16 is not equal to the air inlet area.

[0201] Reference Figure 9 This explains the refrigerant charge verification logic in refrigeration mode.

[0202] First, determine whether the difference between the indoor air intake temperature and the indoor air outlet temperature of all indoor units 16 is within the range of the first judgment value (step S901).

[0203] If the conditions are met in step S901, then step S902 is executed to determine that the refrigerant charge is normal.

[0204] If the condition is not met in step S901, then step S903 is executed to determine whether the ratio of the abnormal indoor unit to the total number of units is less than or equal to the second judgment value.

[0205] If so in step S903, then step S904 is executed. The refrigerant distribution in the indoor unit 16 is uneven. After the troubleshooting is completed, the refrigerant calibration operation is performed again.

[0206] In step S903, if not, 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 ≥ the upper limit of the first judgment value range, or whether the difference is ≤ the lower limit of the first judgment value range.

[0207] If none of the above applies in step S905, then 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, then step S906 is executed to check whether the exhaust pressure is greater than or equal to the upper limit of the third judgment value range.

[0209] If so in step S906, then step S912 is executed to determine that the refrigerant is overcharged.

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

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

[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 less than or equal to the lower limit of the first judgment value range, then step S907 is executed to check whether the exhaust pressure is less than or equal to the lower limit of the third judgment value range.

[0213] If so in step S907, then step S910 is executed to determine that the refrigerant charge is too low.

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

[0215] If so in step S911, then step S909 is executed.

[0216] Reference Figure 10 This explains the logic for determining the refrigerant charge amount under heating conditions.

[0217] In some embodiments, the controller 21 is configured to allow the multi-split air conditioner 100 to operate in 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, the relationship between the second difference between the exhaust temperature and the saturation temperature corresponding to the condensation pressure and the range of the fifth determination value is determined (S1003).

[0220] In some embodiments, when the second difference exceeds the upper limit of the range of the fifth determination value, it is defined that the refrigerant charge is insufficient, and an electrical signal representing the insufficient refrigerant charge 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 This explains the logic for determining the refrigerant charge amount under heating conditions.

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

[0224] 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 (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 is excessive at this time, and an electrical signal representing the excessive refrigerant charge is output (S1104).

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

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

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

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

[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 but 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 a preset length or the pipe diameter of the connecting pipe 17 is smaller than a preset pipe diameter.

[0232] When the exhaust superheat is normal, the cooling capacity of the air conditioning system can be considered to be normal. If an abnormality occurs, it may be due to excessive refrigerant loss during transmission. Therefore, in the above embodiment, when the exhaust superheat is within the set range, it is determined that the problem is due to refrigerant transmission loss in the connecting pipe 17. The parameters related to loss in the connecting pipe 17 include its length and diameter. When the length of the connecting pipe 17 is too long, it will lead to unnecessary heat loss; when the diameter of the connecting pipe 17 is too small, it will also lead to unnecessary refrigerant loss.

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

[0234] Reference Figure 12 This explains the verification logic for refrigerant charge in heating mode.

[0235] First, determine the air outlet temperature of all indoor units 16 and 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] If so in step S1201, then step S1202 is executed to determine that the refrigerant charge is appropriate.

[0237] In step S1202, if not, then step S1203 is executed to determine whether the air outlet temperature of all abnormal indoor units 16 is less than the seventh determination value.

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

[0239] In step S1203, if yes, then proceed to step S1205 to determine whether the upper limit of the fifth judgment value range is greater than the difference between the exhaust temperature and the condensation temperature corresponding to the exhaust pressure, which is greater than the lower limit of the fifth judgment value range.

[0240] If so in step S1205, then step S1206 is executed to determine whether the connecting pipe 17 between the indoor and outdoor units is too long or too small in diameter.

[0241] In step S1205, if the upper limit of the fifth determination value range is less than or equal to the difference between the exhaust temperature and the condensation temperature corresponding to the exhaust pressure, then step S1207 is executed to determine that the refrigerant charge is too low.

[0242] In step S1205, if the difference between the exhaust temperature and the condensing temperature corresponding to the exhaust pressure is less than or equal to the lower limit of the fifth judgment value range, then 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 amount based on feedback from operating parameters, replacing manual determination. This reduces reliance on human intervention, provides more scientific determination results, ensures more accurate refrigerant charge levels, and makes the air conditioning system more energy-efficient, safe, and reliable.

[0244] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0245] For ease of explanation, the above description has been provided 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. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the embodiments and various different variations of the embodiments suitable for specific application considerations.

Claims

1. A multi-split air conditioner, characterized in that, include: At least two indoor heat exchangers are connected in parallel and are located in the indoor unit for exchanging heat with indoor air. The outdoor heat exchanger is located in the outdoor unit and is used to exchange heat with the outdoor air. The compressor includes an intake port and an exhaust port, and is used to compress refrigerant under high temperature and high pressure and discharge the compressed refrigerant. The outdoor heat exchanger, the indoor heat exchanger and the compressor are connected to form a refrigerant circuit. An indoor air outlet temperature detection device is installed at the air outlet of the indoor unit to detect the indoor air outlet temperature. An indoor air intake temperature detection device is installed at the air intake of the indoor unit to detect the indoor air intake temperature. An exhaust pressure detection device is installed at the exhaust port of the compressor to detect the exhaust pressure of the compressor. The controller is configured such that, after the multi-split air conditioner is turned on and the unit has been running normally for a period of time, when the cooling mode is in operation, if the difference between the indoor air inlet temperature and the indoor air outlet temperature of each indoor unit is not within the range of a first determination value, and the number of abnormal indoor units exceeds a second determination value; wherein, an 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 range of the first determination value. 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. If the difference between the indoor air inlet temperature and the indoor air outlet temperature of the abnormal indoor unit reaches the upper limit of the first judgment value range, and if the exhaust pressure exceeds the lower limit of the third judgment value range but does not reach the upper limit of the third judgment value range, then the air inlet area of ​​the abnormal indoor unit is determined to be equal to the air inlet area.

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

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

4. The multi-split air conditioner according to claim 3, characterized in that, Also includes: An outdoor exhaust temperature detection device is installed at the exhaust port of the compressor to detect the exhaust temperature of the compressor. The controller is configured such that, when the multi-split air conditioner is turned on and the unit has been running normally for a period of time, when the heating mode is in operation, if the indoor air outlet temperature of all indoor units has not reached the lower limit of the fourth judgment value range, the controller determines 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 judgment value range, an electrical signal representing insufficient refrigerant charge is output.

5. The multi-split air conditioner according to claim 4, characterized in that, The controller is configured such that, when the multi-split air conditioner is turned on and the unit has been running normally for a period of time, 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, an electrical signal representing excessive refrigerant charge is output.

6. The multi-split air conditioner according to claim 5, characterized in that, The controller is configured such that, when the multi-split air conditioner is turned on and the unit has been running normally for a period of time, when the heating mode is in operation, 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 but 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.

7. The multi-split air conditioner according to claim 5, characterized in that, The controller is configured such that, when the multi-split air conditioner is turned on and the unit has been running normally for a period of time, if the indoor air outlet temperature of some indoor units does not reach the lower limit of the fourth judgment value range when the heating mode is running, it is determined that at least two indoor units have different refrigerant charges.

8. The multi-split air conditioner according to claim 3, characterized in that, The controller is configured such that, after the multi-split air conditioner is turned on and the unit has been running normally for a period of time, when the cooling mode is in operation, if the difference between the indoor air intake temperature and the indoor air outlet temperature of each indoor unit is not within the range of the first judgment value, and the number of abnormal indoor units exceeds the second judgment value; When the difference between the indoor air inlet temperature and the indoor air outlet 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 but does not reach the upper limit of the sixth judgment value range, it is determined that the air inlet area of ​​the abnormal indoor unit is not equal to the air inlet area.

Images