Air conditioner

Abstract

The air conditioner comprises a storage and a controller, the storage is used for storing welding blockage fault information, and the welding blockage fault information is used for representing that a target coil pipe branch where an outdoor coil pipe temperature sensor is located has a welding blockage fault; the controller is configured to judge whether welding blockage fault information is stored in the storage or not when the air conditioner starts refrigeration operation; if yes, welding blockage fault information is read, and if not, whether a welding blockage fault exists in the target coil pipe branch or not is judged; if yes, welding blockage fault information is obtained, and the welding blockage fault information is stored in a storage; after the welding blockage fault information is read or obtained, the preset anti-overload control strategy is executed based on the virtual outdoor coil pipe temperature, the accuracy of welding blockage fault detection is improved, anti-overload protection is conducted based on the virtual outdoor coil pipe temperature, system overload or damage caused by the welding blockage fault is effectively prevented, and the service life of the system is prolonged. And the reliability of the air conditioner is guaranteed, so that the user experience is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and in particular to an air conditioner. Background Art

[0002] During cooling operation, due to the large refrigerant flow resistance, the outdoor heat exchanger is usually divided into multiple branches, and a temperature sensor located on one of the branches is used to detect the tube temperature of the outdoor heat exchanger to control the refrigeration system pressure and the outdoor motor speed.

[0003] However, due to the thin pipe diameter, welding blockage is prone to occur during the manufacturing welding process, resulting in no refrigerant passing through the welded branch, which in turn reduces the effective volume of the outdoor heat exchanger and increases the condensation temperature. At the same time, since the temperature detected by the outdoor coil temperature sensor of the welded branch is close to the outdoor ambient temperature, the outdoor motor speed remains low and the refrigeration system cannot operate normally. Moreover, after a welding blockage failure occurs, the existing overload protection measures may fail, affecting the performance of the entire refrigeration system and thus affecting the user experience. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the prior art. To this end, the object of the present invention is to provide an air conditioner.

[0005] The present invention provides an air conditioner, comprising: A refrigerant circulation loop, wherein the refrigerant undergoes a refrigeration cycle in a loop consisting of a compressor, a condenser, a throttling element, and an evaporator, wherein one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; Indoor temperature sensor, used to detect indoor ambient temperature; Indoor coil temperature sensor, used to detect indoor coil temperature; an exhaust temperature sensor, used to detect the exhaust temperature of the compressor; Outdoor ambient temperature sensor, used to detect outdoor ambient temperature; Outdoor coil temperature sensor, used to detect outdoor coil temperature; A memory, configured to store welding blockage fault information, wherein the welding blockage fault information is used to indicate that a welding blockage fault exists in the target coil branch where the outdoor coil temperature sensor is located; A controller configured to: When the air conditioner is turned on for cooling operation, determining whether the welding blockage fault information is stored in the memory; if so, reading the welding blockage fault information; if not, determining whether the target coil branch has a welding blockage fault; if so, obtaining the welding blockage fault information and storing the welding blockage fault information in the memory; after reading or obtaining the welding blockage fault information, executing a preset anti-overload control strategy based on the virtual outdoor coil temperature; The process of obtaining the welding blockage fault information includes: Detecting a first operating parameter of the air conditioner and determining a second operating parameter based on the first operating parameter, wherein the first operating parameter includes: the indoor ambient temperature, the indoor coil temperature, the exhaust temperature, the outdoor ambient temperature, the outdoor coil temperature, and the entire machine current; gradually determining whether the target coil branch has a welding blockage fault based on the first operating parameter and the second operating parameter; if it is determined that the target coil branch has a welding blockage fault, gradually adjusting the speed gear of the outdoor motor according to a first preset control strategy, wherein the second operating parameter includes: the indoor heat exchange temperature difference, the exhaust superheat, the outdoor heat exchange temperature difference, and the exhaust outer ring temperature difference; until the speed gear of the outdoor motor is adjusted from the initial gear to the preset target gear, if it is still determined that the target coil branch has a welding blockage fault, determining that the target coil branch has a welding blockage fault, generating welding blockage fault information, and switching to a second preset control strategy to control the speed gear of the outdoor motor, and / or executing the preset overload prevention control strategy.

[0006] In addition, the air conditioner according to the embodiment of the present invention may also have the following additional technical features: Furthermore, the first preset control strategy is to perform multi-speed control according to the outdoor coil temperature; the second preset control strategy is to divide the temperature interval according to the outdoor ambient temperature, and set different speed gears of the outdoor motor according to different temperature intervals of the outdoor ambient temperature.

[0007] The above technical solution has the following advantages or beneficial effects: when a welding blockage fault has been confirmed, the operating state of the air conditioner can be adjusted more finely according to the outdoor ambient temperature, ensuring that the air conditioner can maintain efficient and stable operation as much as possible while dealing with the welding blockage fault, while reducing the impact of the welding blockage fault on the air conditioner.

[0008] Furthermore, when gradually judging whether the target coil branch has a welding blockage fault based on the first operating parameter and the second operating parameter, if it is judged that the target coil branch has a welding blockage fault, the speed gear of the outdoor motor is gradually adjusted according to the first preset control strategy, the controller is configured to: control the operation of the compressor and control the outdoor motor to run at the initial gear for the first preset time, and detect the first operating parameter and the second operating parameter; if the indoor heat exchange temperature difference is less than or equal to the first preset indoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the first preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the first preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the first preset indoor heat exchange temperature difference, then it is preliminarily judged that the target coil branch has a welding blockage fault, and the speed gear of the outdoor motor is adjusted to the first preset gear and runs for the second preset time according to the first preset control strategy.

[0009] The above technical solution has the following advantages or beneficial effects: it can avoid the misjudgment caused by directly determining that the target coil branch has a welding blockage fault after the target coil branch has been initially judged to have a welding blockage fault. By adjusting the speed gear of the outdoor motor to further judge the welding blockage fault, the accuracy of the target coil branch welding blockage fault detection can be improved.

[0010] Furthermore, after adjusting the speed gear of the outdoor motor to the first preset gear and running for the second preset time according to the first control strategy, the controller is configured to: control the compressor to run for a third preset time, detect the first operating parameter and the second operating parameter, wherein the third preset time is the sum of the first preset time and the second preset time; if the indoor heat exchange temperature difference is less than or equal to the first preset indoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the second preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the second preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the second preset indoor heat exchange temperature difference, then it is further determined that there is a welding blockage fault in the target coil branch, and the speed gear of the outdoor motor is adjusted to the second preset gear and running for the second preset time according to the first preset control strategy.

[0011] The above technical solution has the following advantages or beneficial effects: it can avoid the misjudgment caused by directly determining that the target coil branch has a welding blockage fault after the target coil branch has been judged to have a welding blockage fault in the first preset gear. By adjusting the speed gear of the outdoor motor to further judge the welding blockage fault, the accuracy of the target coil branch welding blockage fault detection can be improved.

[0012] Furthermore, after adjusting the speed gear of the outdoor motor to the second preset gear and running for the second preset time according to the first preset control strategy, the controller is configured to: control the compressor to run for a fourth preset time, detect the first operating parameter and the second operating parameter, wherein the fourth preset time is the sum of the third preset time and the second preset time; if the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the third preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the third preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the third preset indoor heat exchange temperature difference, then it is determined that there is a welding blockage fault in the target coil branch, and the speed gear of the outdoor motor is adjusted to the preset target gear and runs for the second preset time according to the first preset control strategy.

[0013] The above technical solution has the following advantages or beneficial effects: it can avoid the misjudgment caused by directly determining that the target coil branch has a welding blockage fault after the target coil branch has been judged to have a welding blockage fault at the second preset gear. By adjusting the speed gear of the outdoor motor to further judge the welding blockage fault, the accuracy of the target coil branch welding blockage fault detection can be improved.

[0014] Furthermore, after adjusting the speed gear of the outdoor motor to the preset target gear and running for the second preset time according to the first preset control strategy, the controller is configured to: control the compressor to run for the fifth preset time, detect the first operating parameter and the second operating parameter, wherein the fifth preset time is the sum of the fourth preset time and the second preset time; if the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the third preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the third preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the third preset indoor heat exchange temperature difference, then it is determined that there is a welding blockage fault in the target coil branch.

[0015] The above technical solution has the following advantages or beneficial effects: by repeatedly determining whether the target coil branch has a welding blockage fault and continuously adjusting the speed of the outdoor motor to repeatedly verify whether the target coil branch does have a welding blockage fault, misjudgment of the welding blockage fault detection can be avoided, and the accuracy of the welding blockage fault detection can be improved.

[0016] Furthermore, when executing a preset anti-overload control strategy based on the virtual outdoor coil temperature, the controller is configured to: obtain the outdoor ambient temperature, subcooling and condenser outlet temperature, wherein the subcooling is calculated based on the outdoor ambient temperature and the operating frequency of the compressor through a preset operation function; determine the virtual outdoor coil temperature based on the outdoor ambient temperature, the subcooling and the condenser outlet temperature; and when it is determined that the virtual outdoor coil temperature exceeds a preset temperature threshold, reduce the current frequency of the compressor.

[0017] The above technical solution has the following advantages or beneficial effects: by reducing the operating frequency of the compressor, the heat and load generated by it are reduced, thereby effectively performing overload protection, avoiding damage or failure of the compressor due to overheating, and thus ensuring the reliability and stability of the refrigeration system.

[0018] Furthermore, after determining that the target coil branch has a welding blockage fault, the controller is configured to control the air conditioner to no longer perform refrigerant leakage fault judgment in the cooling mode.

[0019] The above technical solution has the following advantages or beneficial effects: it avoids misjudging a welding blockage fault as a refrigerant leakage fault, thereby improving the accuracy of welding blockage fault detection.

[0020] Furthermore, before the air conditioner starts cooling operation, the controller is configured to: determine whether the outdoor coil temperature sensor is faulty; if so, report the fault, and switch to the second preset control strategy to control the speed gear of the outdoor motor, and / or execute the preset anti-overload control strategy; if not, execute the steps of reading the welding blockage fault information or obtaining the welding blockage fault information.

[0021] The above technical solution has the following advantages or beneficial effects: it is possible to monitor and respond to welding blockage failures that may occur during the refrigeration operation process, so as to ensure the smooth and safe operation of the refrigeration process.

[0022] Furthermore, the outdoor coil temperature sensor includes one or more outdoor coil temperature sensors. When there are multiple outdoor coil temperature sensors, the multiple outdoor coil temperature sensors are arranged in a one-to-one correspondence on multiple coil branches of the outdoor heat exchanger.

[0023] The above technical solution has the following advantages or beneficial effects: it not only improves the accuracy of temperature measurement, but also helps to promptly detect and respond to potential welding blockage faults, thereby ensuring efficient and stable operation of the air conditioner.

[0024] According to the air conditioner of an embodiment of the present invention, after the controller controls the air conditioner to start cooling operation, it continuously detects the first operating parameter of the air conditioner, determines the second operating parameter based on the first operating parameter, and then gradually detects whether the target coil branch has a welding blockage fault based on the first operating parameter and the second operating parameter. When it is determined based on the operating parameters that the target coil branch has a welding blockage fault, the controller will gradually adjust the speed gear of the outdoor motor according to the first preset control strategy. Until the speed gear of the outdoor motor is adjusted from the initial gear to the preset target gear, if it is still determined that the target coil branch has a welding blockage fault, it can be determined that the target coil branch has a welding blockage fault. In this way, by repeatedly determining that the target coil branch has a welding blockage fault and continuously adjusting the speed gear of the outdoor motor, it is verified multiple times that the target coil branch does have a welding blockage fault, which can avoid misjudgment of welding blockage fault detection and improve the accuracy of welding blockage fault detection.

[0025] The welding blockage fault information is then stored in a memory. The characteristics of the memory can determine whether the welding blockage fault information can be directly read the next time the cooling system is started. If the current memory has an overwrite function, the welding blockage fault information can be directly read the next time the cooling system is turned on, saving fault detection time. If the memory does not have an overwrite function, the welding blockage fault information is re-acquired based on the above steps after the cooling system is turned on. After determining that a welding blockage fault exists in the target coil branch, the second preset control strategy is switched to control the speed gear of the outdoor motor. Overload protection is implemented based on the virtual outdoor coil temperature, effectively preventing system overload or damage caused by the welding blockage fault, ensuring the reliability of the air conditioner, while also improving the safety of the air conditioner and enhancing the user experience.

[0026] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which: Figure 1 is a structural diagram of an air conditioner according to an embodiment of the present invention; Figure 2 is a schematic structural diagram of a controller according to an embodiment of the present invention; Figure 3 is a structural diagram of an air conditioner according to another embodiment of the present invention; Figure 4 is a schematic diagram of the relationship between subcooling and the operating frequency of the compressor according to one embodiment of the present invention; Figure 5 2. It is a schematic diagram of temperature relationship when welding plugging failure occurs according to an embodiment of the present invention; Figure 6 is a schematic diagram of temperature relationships in the event of a refrigerant leakage fault according to another embodiment of the present invention; Figure 7 is a schematic diagram of temperature relationships under normal conditions according to an embodiment of the present invention; Figure 8 A schematic diagram of temperature relationships under a welding plugging fault according to an embodiment of the present invention; Figure 9 A schematic diagram of a second preset control strategy according to an embodiment of the present invention; Figure 10 is a flowchart of a method for controlling an air conditioner according to another embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "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 operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0030] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0031] 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 in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and 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.

[0032] The embodiment of the present invention provides an air conditioner 10, referring to Figure 1 The air conditioner 10 includes a refrigeration system for exchanging heat with indoor air to meet cooling or heating needs.

[0033] The refrigeration system includes a compressor, a condenser, an electronic expansion valve, and an evaporator. In the present invention, the air conditioner 10 performs a refrigeration cycle of the air conditioner 10 by using the compressor, the condenser, the electronic expansion valve, and the evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation, and supplies refrigerant to the conditioned and heat-exchanged air.

[0034] The compressor compresses high-temperature, high-pressure refrigerant gas and discharges the compressed gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, releasing heat into the surrounding environment through the condensation process.

[0035] The electronic expansion valve expands the high-temperature, high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant expanded in the electronic expansion valve and returns the low-temperature, low-pressure refrigerant gas to the compressor.

[0036] The evaporator can achieve a cooling effect by utilizing the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled. In the entire cycle, the air conditioner 10 can adjust the temperature of the indoor space.

[0037] The outdoor unit 2 of the air conditioner 10 refers to a portion of a refrigeration cycle including a compressor and an outdoor heat exchanger, the indoor unit 1 of the air conditioner 10 includes an indoor heat exchanger, and an electronic expansion valve may be provided in the indoor unit 1 or the outdoor unit 2 .

[0038] The indoor heat exchanger and the outdoor heat exchanger function as a condenser or an evaporator. When the indoor heat exchanger functions as a condenser, the air conditioner 10 functions as a heater in a heating mode, and when the indoor heat exchanger functions as an evaporator, the air conditioner 10 functions as a cooler in a cooling mode.

[0039] The air conditioner 10 of the present invention includes an indoor unit 1 and an outdoor unit 2. The indoor unit 1 and the outdoor unit 2 can be configured as an integrated unit or a split unit. The indoor unit 1 can be configured as a wall-mounted unit, a ceiling unit, a duct unit, etc., and the indoor unit 1 is installed at the top or ceiling of the indoor room.

[0040] Reference Figure 1 Taking an indoor hanging machine as an example, the indoor hanging machine is usually installed at a location such as an indoor wall. For another example, an indoor cabinet machine (not shown in the figure) is also a form of the indoor machine 1 .

[0041] Taking a split unit as an example, the air conditioner 10 includes an indoor unit 1 and an outdoor unit 2, wherein the outdoor unit 2 is usually set outdoors for heat exchange with the indoor environment.

[0042] Furthermore, as shown in the figure, the air conditioner 10 includes a controller 71 for controlling the operation of various components within the air conditioner 10, thereby enabling the various components of the air conditioner 10 to operate and realize various predetermined functions of the air conditioner 10. Furthermore, the air conditioner 10 is also provided with a control device 200. For example, the control device 200 is specifically configured as a remote control that is capable of communicating with the controller 71 using, for example, infrared or other communication methods. The remote control is used by the user to control the air conditioner 10 in various ways, thereby enabling interaction between the user and the air conditioner 10.

[0043] The indoor unit 1 of the air conditioner 10 in the embodiment of the present invention is arranged at the top or upper part of the room. Generally speaking, the installation height of the indoor unit 1 is higher than the user activity area. The indoor unit 1 includes a return air inlet and an air outlet connected to the room. The indoor air passes through the indoor unit 1 in the return air inlet and flows back to the room through the air outlet.

[0044] The refrigerant circulation circuit of the present invention circulates refrigerant through a loop consisting of a compressor, condenser, electronic expansion valve, and evaporator. One of the condenser and evaporator functions as an outdoor heat exchanger, while the other functions as an indoor heat exchanger. The indoor heat exchanger exchanges heat with the air in indoor unit 1, while the outdoor unit 2 heat exchanger exchanges heat with the air in outdoor unit 2, thereby achieving the cooling or heating requirements of air conditioner 10.

[0045] The indoor unit 1 also includes an indoor fan, which is arranged near the return air port or the air outlet of the indoor heat exchanger and is used to deliver the heat-exchanged air into the room. The indoor fan includes multiple gears for changing the outlet air flow speed of the outlet.

[0046] An air guide plate is provided at the position of the air outlet. The air guide plate adjusts the outflow direction of the air flowing through the air outlet by changing the relative rotation angle between the air guide plate and the air outlet, thereby affecting the indoor air temperature stratification.

[0047] In the illustrated embodiment of the present invention, the air conditioner 10 further includes a controller 71. Controller 71 is a device that generates an operation control signal based on an instruction opcode and a timing signal, thereby instructing the air conditioner 10 to execute the control instruction. For example, in response to a power-on or power-off instruction received from a user, controller 71 may execute an operation associated with the object selected by the power-on or power-off instruction.

[0048] The embodiment of the present invention also provides a hardware structure diagram of a controller 71, as shown in FIG. Figure 2 As shown, the controller 71 includes a processor 83 and, optionally, a memory 82 and a communication interface 84 connected to the processor 83. The processor 83, the memory 82 and the communication interface 84 are connected via a bus 81.

[0049] The processor 83 may be a central processing unit (CPU), a general-purpose processor (GP3), a network processor (NP), a digital signal processor (DSP), a microprocessor (MCU), a microcontroller (MCU), a programmable logic device (PLD), or any combination thereof. The processor 83 may also be any other device having processing functionality, such as a circuit, a device, or a software module. The processor 83 may also include multiple CPUs, and the processor 83 may be a single-CPU processor or a multi-CPU processor. The processor 83 herein may refer to one or more devices, circuits, or processing cores for processing data (e.g., computer program instructions).

[0050] The memory 82 can be a read-only memory 82 (ROM) or other type of static storage device that can store static information and instructions, a random access memory 82 (RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory 82 (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer. The embodiment of the present invention does not impose any restrictions on this. The memory 82 can exist independently or be integrated with the processor 83. The memory 82 can contain computer program code. The processor 83 is used to execute the computer program code stored in the memory 82, thereby implementing the air conditioner control method provided in the embodiment of the present invention.

[0051] The communication interface 84 can be used to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area network (WLAN), etc.). The communication interface 84 can be a module, a circuit, a transceiver or any device that can achieve communication.

[0052] The bus 81 may be a peripheral component interconnect (PCI) bus 81 or an extended industry standard architecture (EISA) bus 81. The bus 81 may be divided into an address bus 81, a data bus 81, a control bus 81, etc. For ease of representation, Figure 2 Only one thick line is used in the figure, but it does not mean that there is only one bus 81 or one type of bus 81.

[0053] Reference below Figure 3-10 An air conditioner according to an embodiment of the present invention is described.

[0054] Figure 3 FIG. 1 is a schematic diagram of the structure of an air conditioner according to an embodiment of the present invention. Figure 3 As shown, an air conditioner 10 includes: a refrigerant circulation loop 11, an indoor temperature sensor 12, an indoor coil temperature sensor 13, an exhaust temperature sensor 14, an outdoor ambient temperature sensor 15, an outdoor coil temperature sensor 16, a memory 17 and a controller 71.

[0055] Among them, the refrigerant circulation loop 11 allows the refrigerant to perform a refrigeration cycle in the loop composed of a compressor, a condenser, a throttling element, and an evaporator. One of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger; the indoor temperature sensor 12 is used to detect the indoor ambient temperature; the indoor coil temperature sensor 13 is used to detect the indoor coil temperature; the exhaust temperature sensor 14 is used to detect the exhaust temperature of the compressor; the outdoor ambient temperature sensor 15 is used to detect the outdoor ambient temperature; the outdoor coil temperature sensor 16 is used to detect the outdoor coil temperature; the memory 17 is used to store welding blockage fault information, and the welding blockage fault information is used to indicate that there is welding blockage in the target coil branch where the indoor coil temperature sensor is located.

[0056] The controller 71 is configured to: when the air conditioner is turned on for cooling operation, determine whether welding blockage fault information is stored in the memory; if so, read the welding blockage fault information; if not, determine whether there is a welding blockage fault in the target coil branch; if so, obtain the welding blockage fault information and store the welding blockage fault information in the memory; after reading the welding blockage fault information or obtaining the welding blockage fault information, execute a preset anti-overload control strategy based on the virtual outdoor coil temperature.

[0057] Among them, the process of obtaining welding blockage fault information includes: detecting a first operating parameter of the air conditioner 10, and determining a second operating parameter based on the first operating parameter, wherein the first operating parameter includes: indoor ambient temperature, indoor coil temperature, exhaust temperature, outdoor ambient temperature, outdoor coil temperature and whole machine current; based on the first operating parameter and the second operating parameter, gradually judging whether the target coil branch has a welding blockage fault, if it is determined that the target coil branch has a welding blockage fault, then gradually adjusting the speed gear of the outdoor motor according to the first preset control strategy, wherein the second operating parameter includes: indoor heat exchange temperature difference, exhaust superheat, outdoor heat exchange temperature difference and exhaust outer ring temperature difference; until the speed gear of the outdoor motor is adjusted from the initial gear to the preset target gear, if it is still determined that the target coil branch has a welding blockage fault, then determining that the target coil branch has a welding blockage fault, generating welding blockage fault information, and switching to the second preset control strategy to control the speed gear of the outdoor motor, and / or executing the preset anti-overload control strategy.

[0058] Among them, the throttling element includes, for example, an expansion valve, a capillary tube, or a throttle valve; the memory 17 includes, for example, a memory with a rewrite function and a memory without a rewrite function, and the memory with a rewrite function is, for example, an EEPROM memory (Electrically Erasable Programmable Read Only Memory).

[0059] For example, the indoor ambient temperature is recorded as Tin, the indoor coil temperature is recorded as Tc, the exhaust temperature is recorded as Td, the outdoor ambient temperature is recorded as Tout, the outdoor coil temperature is recorded as Te, the whole machine current is recorded as Ih, the indoor heat exchange temperature difference is recorded as △Tin, the exhaust superheat is recorded as DSH, the outdoor heat exchange temperature difference is recorded as △Tout and the exhaust outer ring temperature difference is recorded as D_Tout.

[0060] In an embodiment, when the air conditioner 10 starts cooling operation, it will first determine whether welding blockage fault information is stored in the memory 17. If welding blockage fault information is stored in the memory 17, the welding blockage fault information will be directly read. If welding blockage fault information is not stored in the memory 17, it will be determined whether there is a welding blockage fault in the target coil branch. If it is determined based on the judgment result that there is a welding blockage fault in the target coil branch, the controller 71 will obtain the welding blockage fault information and store the welding blockage fault information in the memory.

[0061] Specifically, the first operating parameters of the air conditioner 10 are continuously detected, that is, the indoor ambient temperature Tin, indoor coil temperature Tc, exhaust temperature Td, outdoor ambient temperature Tout, outdoor coil temperature Te and whole machine current Ih of the air conditioner 10 are continuously obtained. Based on the obtained first operating parameters, the second operating parameters can be calculated.

[0062] In a specific embodiment, the indoor heat exchange temperature difference ΔTin is the difference between the indoor ambient temperature Tin and the indoor coil temperature Tc, that is, ΔTin=Tin-Tc; the exhaust superheat DSH is the difference between the exhaust temperature Td and the outdoor coil temperature Te, that is, DSH=Td-Te; the outdoor heat exchange temperature difference ΔTout is the difference between the outdoor coil temperature Te and the outdoor ambient temperature Tout, that is, ΔTout=Te-Tout; and the exhaust outer ring temperature difference D_Tout is the difference between the exhaust temperature Td and the outdoor ambient temperature Tout, that is, D_Tout=Td-Tout.

[0063] After calculating the second operating parameter, combined with the first operating parameter, the controller 71 will gradually determine whether the target coil branch has a welding blockage fault based on the operating parameters. If it is suspected that the target coil branch has a welding blockage fault, the controller 71 will adjust the speed gear of the outdoor motor according to the first preset control strategy, so as to verify multiple times whether the target coil branch actually has a fault by adjusting the speed gear of the outdoor motor, thereby improving the accuracy of welding blockage fault detection.

[0064] If, during multiple verifications, i.e., even after adjusting the speed gear of the outdoor motor from the initial gear to the preset target gear, it is still determined that the target coil branch has a welding blockage fault, then it can be determined that the target coil branch has a welding blockage fault. In this case, the second preset control strategy will be switched to adjust the speed gear of the outdoor motor. At the same time, to ensure the safe and stable operation of the air conditioner 10, if the overload protection condition is triggered, the controller 71 will obtain the virtual outdoor coil temperature and perform overload protection based on the virtual outdoor coil temperature, thereby effectively preventing system overload or damage caused by the welding blockage fault, ensuring the reliability of the air conditioner 10, while also improving the safety of the air conditioner 10 and enhancing the user experience.

[0065] In one embodiment of the present invention, the first preset control strategy is to perform multi-speed control according to the outdoor coil temperature; the second preset control strategy is to divide the temperature range according to the outdoor ambient temperature, and set different speed gears of the outdoor motor according to different temperature ranges of the outdoor ambient temperature.

[0066] In an embodiment, the first preset control strategy is to perform multi-speed control based on the outdoor coil temperature Te. When a suspected welding blockage fault occurs, the controller 71 will dynamically adjust the speed gear of the outdoor motor based on the real-time monitored outdoor coil temperature Te, repeatedly verifying whether the target coil branch actually has a welding blockage problem through multiple different gears. If, after multiple verifications, it is still determined that the target coil branch has a welding blockage fault, the controller 71 will switch to the second preset control strategy. This strategy divides the temperature into several intervals based on the outdoor ambient temperature Tout and sets a specific outdoor motor speed gear for each temperature interval. In this way, when a welding blockage fault has been confirmed, the operating state of the air conditioner 10 can be adjusted more precisely according to the outdoor ambient conditions, ensuring that the air conditioner 10 can maintain efficient and stable operation as much as possible while responding to the welding blockage fault, while reducing the impact of the welding blockage fault on the air conditioner 10.

[0067] In one embodiment of the present invention, when gradually judging whether the target coil branch has a welding blockage fault based on the first operating parameter and the second operating parameter, if it is judged that the target coil branch has a welding blockage fault, the speed gear of the outdoor motor is gradually adjusted according to the first preset control strategy, the controller 71 is configured to: control the operation of the compressor and control the outdoor motor to run at the initial gear for the first preset time, and detect the first operating parameter and the second operating parameter; if the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the first preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the first preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the first preset indoor heat exchange temperature difference, then it is preliminarily judged that the target coil branch has a welding blockage fault, and the speed gear of the outdoor motor is adjusted to the first preset gear and runs for the second preset time according to the first preset control strategy.

[0068] For example, the first preset outdoor heat exchange temperature difference is recorded as △Tout1, the first preset exhaust outer ring temperature difference is recorded as D_Tout1, the first preset whole machine current is recorded as Ih1 and the first preset indoor heat exchange temperature difference is recorded as △Tin1, the first preset time is recorded as t1, the second preset time is recorded as t2, the initial gear is recorded as R0, and the first preset gear is recorded as R1.

[0069] The outdoor heat exchange temperature difference detected at the first preset time is recorded as ΔTout(1), the exhaust outer ring temperature difference is recorded as D_Tout(1), the whole machine current is recorded as Ih(1) and the indoor heat exchange temperature difference is recorded as ΔTin(1).

[0070] In this embodiment, when determining whether a target coil branch has a weld blockage fault, the controller 71 starts the compressor and operates the outdoor motor at an initial gear for a first preset time, such as three minutes. During this first preset time, the controller 71 continuously monitors the first and second operating parameters to determine whether they meet the determination criteria.

[0071] Specifically, within the first preset time, it is detected that the outdoor heat exchange temperature difference ΔTout(1) is less than or equal to the first preset outdoor heat exchange temperature difference ΔTout1, that is, ΔTout(1) △Tout1, and the exhaust outer ring temperature difference D_Tout(1) is greater than or equal to the first preset exhaust outer ring temperature difference D_Tout1, that is, D_Tout(1) D_Tout1, and the whole machine current Ih(1) is greater than or equal to the first preset whole machine current Ih1, that is, Ih(1) Ih1, and the indoor heat exchange temperature difference △Tin(1) is greater than or equal to the first preset indoor heat exchange temperature difference △Tin1, that is, △Tin(1) △Tin1. When these judgment conditions are met simultaneously, the controller 71 will preliminarily determine that a welding blockage fault exists in the target coil branch, i.e., it is suspected that the target coil branch has a welding blockage fault. At this time, the controller 71 will immediately increase the speed gear of the outdoor motor from the initial gear R0 to the first preset gear R1 according to the first preset control strategy, and control the outdoor motor to operate at the first preset gear R1 for the second preset time t2, for example, the second preset time t2 is 2 minutes, to further verify and adjust the system status and ensure an accurate and timely response to the welding blockage fault. This can avoid the misjudgment caused by directly determining that the target coil branch has a welding blockage fault after the initial gear R0 determines that the target coil branch has a welding blockage fault. By adjusting the speed gear of the outdoor motor to further determine the welding blockage fault, the accuracy of the target coil branch welding blockage fault detection can be improved.

[0072] In one embodiment of the present invention, after the speed gear of the outdoor motor is adjusted to the first preset gear and runs for the second preset time according to the first control strategy, the controller 71 is configured to: control the compressor to run for the third preset time, detect the first operating parameter and the second operating parameter, wherein the third preset time is the sum of the first preset time and the second preset time; if the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the second preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the second preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the second preset indoor heat exchange temperature difference, then it is further determined that there is a welding blockage fault in the target coil branch, and the speed gear of the outdoor motor is adjusted to the second preset gear and runs for the second preset time according to the first preset control strategy.

[0073] For example, the second preset exhaust outer ring temperature difference is recorded as D_Tout2, the second preset whole machine current is recorded as Ih2, and the second preset indoor heat exchange temperature difference is recorded as ΔTin2.

[0074] The outdoor heat exchange temperature difference detected at the third preset time is recorded as ΔTout(2), the exhaust outer ring temperature difference is recorded as D_Tout(2), the whole machine current is recorded as Ih(2), and the indoor heat exchange temperature difference is recorded as ΔTin(2).

[0075] Specifically, after the speed gear of the outdoor motor is adjusted to the first preset gear and runs continuously for the second preset time according to the first control strategy, the controller 71 will further control the compressor to continue running for a longer time, that is, the third preset time. This time length is the sum of the previous first preset time and the second preset time. In other words, the compressor runs continuously after starting. When the outdoor motor runs at the initial gear for 3 minutes, the compressor is also running at the same time and runs for 3 minutes. After the outdoor motor runs at the first preset gear for 2 minutes, the compressor also runs for 2 minutes. Therefore, during the operation from the initial gear to the first preset gear, the compressor runs continuously. The third preset time is the sum of the first preset time and the second preset time, that is, t3=t1+t2=5 minutes.

[0076] During the third preset time, the controller 71 will continue to detect the first operating parameter and the second operating parameter. If the outdoor heat exchange temperature difference ΔTout(2) is detected to be less than or equal to the first preset outdoor heat exchange temperature difference ΔTout1 after the compressor is started for 5 minutes, that is, ΔTout(2) △Tout1, and the exhaust outer ring temperature difference D_Tout(2) is greater than or equal to the second preset exhaust outer ring temperature difference D_Tout2, that is, D_Tout(2) D_Tout2, and the whole machine current Ih(2) is greater than or equal to the second preset whole machine current Ih2, that is, Ih(2) Ih2, and the indoor heat exchange temperature difference △Tin(2) is greater than or equal to the second preset indoor heat exchange temperature difference △Tin2, that is, △Tin(2) △Tin2. When these determination conditions are simultaneously met, the controller 71 will further determine that a welding blockage fault exists in the target coil branch, i.e., it is suspected that the target coil branch has a welding blockage fault. At this time, the controller 71 will immediately increase the speed gear of the outdoor motor from the first preset gear R1 to the second preset gear R2 according to the first preset control strategy, and control the outdoor motor to operate at the second preset gear R2 for the second preset time t2. This further verifies and adjusts the system state to ensure an accurate and timely response to the welding blockage fault. This can avoid the misjudgment caused by directly determining that the target coil branch has a welding blockage fault after determining that the target coil branch has a welding blockage fault at the first preset gear R1. By adjusting the speed gear of the outdoor motor to further determine the welding blockage fault, the accuracy of the target coil branch welding blockage fault detection can be improved.

[0077] In one embodiment of the present invention, after the speed gear of the outdoor motor is adjusted to the second preset gear and runs for the second preset time according to the first preset control strategy, the controller 71 is configured to: control the compressor to run for a fourth preset time, detect the first operating parameter and the second operating parameter, wherein the fourth preset time is the sum of the third preset time and the second preset time; if the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the third preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the third preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the third preset indoor heat exchange temperature difference, then it is determined that there is a welding blockage fault in the target coil branch, and the speed gear of the outdoor motor is adjusted to the preset target gear and runs for the second preset time according to the first preset control strategy.

[0078] For example, the third preset exhaust outer ring temperature difference is recorded as D_Tout3, the third preset whole machine current is recorded as Ih3, the third preset indoor heat exchange temperature difference is recorded as ΔTin3, and the preset target gear is recorded as R3.

[0079] The outdoor heat exchange temperature difference detected at the fourth preset time is recorded as ΔTout(3), the exhaust outer ring temperature difference is recorded as D_Tout(3), the whole machine current is recorded as Ih(3), and the indoor heat exchange temperature difference is recorded as ΔTin(3).

[0080] Specifically, after the speed gear of the outdoor motor is adjusted to the second preset gear R2 according to the first control strategy and runs continuously for the second preset time t2, the controller 71 will further control the compressor to continue running for a longer time, that is, the fourth preset time. This time length is the sum of the previous third preset time and the second preset time. In other words, the compressor continues to run after starting. When the outdoor motor runs at the initial gear for 3 minutes, the compressor is also running at the same time and runs for 3 minutes. After the outdoor motor runs at the first preset gear for 2 minutes, the compressor also runs for 2 minutes. When the outdoor motor runs at the second preset gear for 2 minutes, the compressor also starts for 2 minutes. Therefore, during the operation from the initial gear to the second preset gear, the compressor runs continuously. The fourth preset time is the sum of the third preset time and the second preset time, that is, t4=t3+t2=7 minutes, that is, t4=t1+2×t2.

[0081] During the fourth preset time, the controller 71 will continue to detect the first operating parameter and the second operating parameter. If the outdoor heat exchange temperature difference ΔTout(3) is detected to be less than or equal to the first preset outdoor heat exchange temperature difference ΔTout1 after the compressor is started for 7 minutes, that is, ΔTout(3) △Tout1, and the exhaust outer ring temperature difference D_Tout(3) is greater than or equal to the third preset exhaust outer ring temperature difference D_Tout3, that is, D_Tout(3) D_Tout3, and the whole machine current Ih(3) is greater than or equal to the third preset whole machine current Ih3, that is, Ih(3) Ih3, and the indoor heat exchange temperature difference △Tin(3) is greater than or equal to the third preset indoor heat exchange temperature difference △Tin3, that is, △Tin(3) △Tin3. When these determination conditions are simultaneously met, the controller 71 will further determine that a welding blockage fault exists in the target coil branch, i.e., it is suspected that the target coil branch has a welding blockage fault. At this point, the controller 71 will immediately increase the speed gear of the outdoor motor from the second preset gear R2 to the preset target gear R3 according to the first preset control strategy, and control the outdoor motor to operate at the preset target gear R3 for the second preset time t2. This further verifies and adjusts the system state to ensure an accurate and timely response to the welding blockage fault. This avoids the misjudgment caused by directly determining that the target coil branch has a welding blockage fault after determining that the target coil branch has a welding blockage fault at the second preset gear R2. By adjusting the speed gear of the outdoor motor to further determine the welding blockage fault, the accuracy of the target coil branch welding blockage fault detection can be improved.

[0082] In one embodiment of the present invention, after the speed gear of the outdoor motor is adjusted to a preset target gear and runs for a second preset time according to a first preset control strategy, the controller 71 is configured to: control the compressor to run for a fifth preset time, detect the first operating parameter and the second operating parameter, wherein the fifth preset time is the sum of the fourth preset time and the second preset time; if the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the third preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the third preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the third preset indoor heat exchange temperature difference, then it is determined that there is a welding blockage fault in the target coil branch.

[0083] The outdoor heat exchange temperature difference detected at the fifth preset time is recorded as ΔTout(4), the exhaust outer ring temperature difference is recorded as D_Tout(4), the whole machine current is recorded as Ih(4), and the indoor heat exchange temperature difference is recorded as ΔTin(4).

[0084] In the embodiment, after the speed gear of the outdoor motor is adjusted to the preset target gear R3 according to the first control strategy and continuously runs for the second preset time t2, the controller 71 will further control the compressor to continue running for a longer time, namely the fifth preset time. This time length is the sum of the previous fourth preset time and the second preset time. In other words, the compressor continues to run after starting. When the outdoor motor runs at the initial gear for 3 minutes, the compressor is also running at the same time and runs for 3 minutes. After the outdoor motor runs at the first preset gear for 2 minutes, the compressor also runs for 2 minutes. When the outdoor motor runs at the second preset gear for 2 minutes, the compressor also starts for 2 minutes. When the compressor runs at the preset target gear R3 for 2 minutes, the compressor also runs for 2 minutes. Therefore, during the operation from the initial gear to the preset target gear, the compressor runs continuously. The fifth preset time is the sum of the fourth preset time and the second preset time, that is, t4=t4+t2=9 minutes, that is, t4=t1+3×t2.

[0085] During the fourth preset time, the controller 71 will continue to detect the first operating parameter and the second operating parameter. If the outdoor heat exchange temperature difference ΔTout(4) is detected to be less than or equal to the first preset outdoor heat exchange temperature difference ΔTout1 after the compressor is started for 9 minutes, that is, ΔTout(4) △Tout1, and the exhaust outer ring temperature difference D_Tout(4) is greater than or equal to the third preset exhaust outer ring temperature difference D_Tout3, that is, D_Tout(4) D_Tout3, and the whole machine current Ih(4) is greater than or equal to the third preset whole machine current Ih3, that is, Ih(4) Ih3, and the indoor heat exchange temperature difference △Tin(4) is greater than or equal to the third preset indoor heat exchange temperature difference △Tin3, that is, △Tin(4) △Tin3, when these determination conditions are simultaneously met, the controller 71 will determine that there is a welding blockage fault in the target coil branch and switch to the second preset control strategy to control the speed of the outdoor motor. In this way, by repeatedly determining that there is a welding blockage fault in the target coil branch and continuously adjusting the speed of the outdoor motor to repeatedly verify that there is indeed a welding blockage fault in the target coil branch, it is possible to avoid misjudgment in the detection of welding blockage faults and improve the accuracy of welding blockage fault detection.

[0086] In a specific embodiment, the first preset outdoor heat exchange temperature difference △Tout1 is less than or equal to 4°C, △Tout1 4°C; the first preset exhaust outer ring temperature difference D_Tout1 is greater than 5°C, the first preset exhaust outer ring temperature difference D_Tout1 is less than the second preset exhaust outer ring temperature difference D_Tout2, and the second preset exhaust outer ring temperature difference D_Tout2 is less than the third preset exhaust outer ring temperature difference D_Tout3, that is, 5°C < D_Tout1 < D_Tout2 < D_Tout3; the first preset total machine current Ih1 is greater than 2A (the specific value varies according to the platform), the first preset total machine current Ih1 is less than the second preset total machine current Ih2, and the second preset total machine current Ih2 is less than the third preset total machine current Ih3, that is, 2A < Ih1 < Ih2 < Ih3; the first preset indoor heat exchange temperature difference △Tin1 is greater than or equal to 10°C, and the first preset indoor heat exchange temperature difference △Tin1 is less than or equal to the second preset indoor heat exchange temperature difference △Tin2, and the second preset indoor heat exchange temperature difference △Tin2 is less than or equal to the third preset indoor heat exchange temperature difference △Tin3, 10°C △Tin3.

[0087] In an embodiment of the present invention, when executing the preset overload prevention control strategy based on the virtual outdoor coil temperature, the controller 71 is configured to: obtain the outdoor ambient temperature, the degree of supercooling, and the condenser outlet temperature, where the degree of supercooling is calculated based on the outdoor ambient temperature and the operating frequency of the compressor through a preset operation function; determine the virtual outdoor coil temperature according to the outdoor ambient temperature, the degree of supercooling, and the condenser outlet temperature; when it is determined that the virtual outdoor coil temperature exceeds the preset temperature threshold, reduce the current frequency of the compressor.

[0088] In the embodiment, the refrigeration overload protection in the refrigeration system is a key mechanism to ensure the stable operation of the entire system, to prevent system damage or performance degradation caused by overload. During actual operation, if there is a welding blockage fault in the target coil branch, the original overload protection measures may fail, which will not only lead to a significant decrease in refrigeration capacity and a sharp increase in the total machine power, but also greatly reduce the reliability of the compressor, thus affecting the performance and lifespan of the entire refrigeration system. In order to effectively avoid these problems, including possible short - circuit and open - circuit faults of the outdoor coil temperature sensor, overload protection will be carried out through the virtual outer disc temperature.

[0089] Specifically, the virtual outdoor coil temperature is recorded as Te', for example. The virtual outdoor coil temperature Te' is a theoretical value obtained through a series of calculations and is used to replace the actual outdoor coil temperature for cooling overload protection.

[0090] During the operation of the refrigeration system, the outdoor coil temperature not only participates in the closed-loop control of the outdoor motor speed, but also plays a key role in the refrigeration overload protection. The outdoor coil temperature ensures that the condensing temperature of the refrigeration system does not exceed the upper limit specified in the compressor specification, thereby maintaining the reliability of the compressor operation. In a normally operating refrigeration system, when the outdoor ambient temperature remains at a stable value, the outdoor coil temperature will increase accordingly as the operating frequency of the compressor increases. At this time, the difference between the condensing temperature and the condenser outlet temperature, that is, the subcooling degree, is Figure 4 As shown, there is a positive correlation between the degree of supercooling and the operating frequency of the compressor, that is, the higher the operating frequency of the compressor, the greater the degree of supercooling, which helps to understand the working status inside the refrigeration system and ensure that the air conditioner 10 can operate within a safe and efficient parameter range.

[0091] Therefore, when calculating the virtual outdoor coil temperature Te', it is necessary to obtain the compressor operating frequency (e.g., F), the outdoor ambient temperature Tout, the degree of subcooling (e.g., SC), and the condenser outlet temperature (e.g., A). The condenser outlet temperature A can also be understood as the subcooled refrigerant temperature. Based on the outdoor ambient temperature Tout and the compressor operating frequency F, the degree of subcooling SC can be calculated using a preset calculation function: SC = k1 × F + k2 × Tout. Here, k1 and k2 are dimensionless coefficients and real numbers, 0.001 ≤ k1 ≤ 0.500, and -0.300 ≤ k2 ≤ 0.300. The specific values are determined by the configuration of the refrigeration system of air conditioner 10. The condenser outlet temperature A can be set between 1°C and 8°C.

[0092] According to the outdoor coil temperature Te being equal to the sum of the outdoor ambient temperature Tout, the subcooling degree SC and the condenser outlet temperature A, that is, Te=Tout+SC+A, combined with the above calculation formula for the subcooling degree SC, the virtual outdoor coil temperature Te' can be obtained, that is, Te'≈Tout+k1×F+k2×Tout+A.

[0093] If the calculated virtual outdoor coil temperature Te’ is less than the preset temperature threshold, which is denoted as T for example, that is, when Te’ < T, it means that the current outdoor coil temperature is within the safe range and there is no risk of overloading the compressor. Therefore, the controller 71 does not need to activate the preset anti-overload control strategy, that is, to keep the current operating frequency of the compressor unchanged to ensure the normal operation and efficiency of the system; if the calculated virtual outdoor coil temperature Te’ exceeds the preset temperature threshold T, that is, Te’ > T, it indicates that the current outdoor coil temperature has risen to a level that may threaten the safe operation of the compressor. At this time, the controller 71 will immediately activate the preset anti-overload control strategy, reducing the operating frequency of the compressor to reduce the heat and load generated by it, thereby effectively performing anti-overload protection and avoiding damage or failure of the compressor due to overheating.

[0094] In this way, even when the actual outdoor coil temperature cannot be accurately measured or the outdoor coil temperature sensor fails, the refrigeration anti-overload protection can be effectively carried out, thereby ensuring the reliability and stability of the refrigeration system.

[0095] In an embodiment of the present invention, after determining that there is a welding blockage fault in the target coil branch, the controller 71 is configured to: control the air conditioner 10 not to perform the refrigerant leakage fault judgment in the refrigeration mode.

[0096] In the embodiment, in order to ensure the normal operation of the refrigeration system of the air conditioner 10, usually multiple conditions are comprehensively considered to judge whether there is a refrigerant leakage fault. One important judgment condition is that the real-time operating frequency of the compressor exceeds 60 Hz, and at the same time, the real-time outdoor heat exchange temperature difference is less than 3°C, and the real-time exhaust superheat degree is greater than 60°C.

[0097] In a specific embodiment, when there is a welding blockage fault in the target coil branch, it will cause a significant decrease in the heat exchange efficiency of this part. At this time, the outdoor coil temperature is only slightly higher than the outdoor ambient temperature because the welding blockage hinders the effective transfer of heat. At the same time, since the exhaust temperature of the air conditioner 10 of the system remains normal, as Figure 5 shown, the calculated outdoor heat exchange temperature difference will be very small, which means that the temperature difference between the outdoor heat exchanger and the surrounding environment is not large and the outdoor heat exchanger is inefficient. On the other hand, the exhaust superheat degree will become very large because the exhaust temperature is normal while the outer disk temperature is abnormally low.

[0098] However, as Figure 6As shown, in the event of a serious refrigerant leakage, the performance of the air conditioner 10 will be greatly affected. Refrigerant leakage will cause a significant reduction in the refrigerant circulation volume, causing the temperature of the gas discharged from the compressor to rise sharply, which is likely to trigger the exhaust temperature protection mechanism, causing the compressor to frequently increase or decrease the frequency to protect itself from damage. At the same time, due to insufficient refrigerant, the outdoor coil temperature will also decrease and will fluctuate with the fluctuation of the refrigerant. In this state, although the outdoor heat exchange temperature difference is also very small, the reason is different from that of welding plugging. This is because the overall heat exchange capacity is reduced due to insufficient refrigerant. At the same time, the exhaust superheat will also be very large because the exhaust temperature is abnormally high and the outdoor coil temperature is low.

[0099] Therefore, whether the target coil branch has a welding blockage fault or a refrigerant leakage fault, it will lead to a decrease in the outdoor heat exchange temperature difference and an increase in the exhaust superheat.

[0100] Therefore, when a target coil branch experiences a welding blockage, refrigerant flow in that target coil branch is severely impeded, causing the outdoor coil temperature Te in that target coil branch to become very close to the outdoor ambient temperature Tout. This prevents the refrigerant from effectively circulating and dissipating heat within that target coil branch. Furthermore, since welding blockage typically occurs near the condenser outlet, the discharge air temperature Td remains comparable to that in a normal refrigeration system and does not significantly decrease due to the blockage. Consequently, the calculated real-time outdoor heat exchange temperature difference ΔTout is very small, typically less than 3°C, because the outdoor coil temperature Te and the outdoor ambient temperature Tout are nearly equal. On the other hand, the discharge air superheat DSH increases abnormally, typically exceeding 60°C, because the outdoor coil temperature Te approaches the outdoor ambient temperature Tout due to the welding blockage, while the discharge air temperature Td remains normally high.

[0101] Under these conditions, if the compressor's operating frequency exceeds 60Hz, the data monitored by controller 71 will meet the pre-set criteria for a severe refrigerant leak, mistakenly misdiagnosing a weld blockage as a refrigerant leak. However, once a weld blockage is confirmed, it's clear that the refrigeration system itself is not lacking refrigerant. Therefore, once a weld blockage is determined for the target coil branch, controller 71 will control air conditioner 10 to no longer participate in refrigerant leak detection in cooling mode, avoiding false alarms and unnecessary maintenance operations, thereby improving the accuracy of weld blockage detection.

[0102] In one embodiment of the present invention, before the air conditioner 10 starts cooling operation, the controller 71 is configured to: determine whether the outdoor coil temperature sensor is faulty; if so, report the fault, and switch to the second preset control strategy to control the speed gear of the outdoor motor, and / or execute the preset anti-overload control strategy; if not, execute the steps of reading the welding fault information or obtaining the welding fault information.

[0103] In this embodiment, before the air conditioner 10 starts cooling operation, the controller 71 first checks the operating status of the outdoor coil temperature sensor. If a fault is detected in the outdoor coil temperature sensor, such as an open or short circuit, the air conditioner 10 will be unable to accurately obtain the outdoor coil temperature. Once the fault is determined, the controller 71 sends fault information to the cloud to report the fault. Simultaneously, the controller 71 switches to a second preset control strategy to adjust the speed of the outdoor motor. This ensures that the air conditioner 10 maintains basic operation and a certain level of regulation capability even in the event of a fault in the outdoor coil temperature sensor. The controller 71 may also execute a preset anti-overload control strategy to prevent system overloads that may result from a faulty outdoor coil temperature sensor.

[0104] If the indoor coil temperature sensor is working properly and no fault occurs, the controller 71 will continue to execute its preset process, that is, read the welding fault information or obtain the welding fault information, so as to monitor and respond to possible welding faults during the refrigeration operation to ensure the smooth and safe operation of the refrigeration process.

[0105] In one embodiment of the present invention, the outdoor coil temperature sensor includes one or more outdoor coil temperature sensors. When there are multiple outdoor coil temperature sensors, the multiple outdoor coil temperature sensors are disposed on multiple coil branches of the outdoor heat exchanger in a one-to-one correspondence.

[0106] In the embodiment, the design of the outdoor coil temperature sensor takes into account the complexity of the outdoor heat exchanger and the uneven temperature distribution, and therefore adopts a configuration including one or more outdoor coil temperature sensors. When there are multiple outdoor coil temperature sensors, these outdoor coil temperature sensors are each correspondingly arranged on different coil branches of the outdoor heat exchanger. This layout enables the controller 71 to more accurately and comprehensively monitor the temperature changes of each coil branch in the outdoor heat exchanger, thereby providing more accurate temperature data, providing a solid foundation for the intelligent control and optimized operation of the air conditioner 10. In this way, not only is the accuracy of temperature measurement improved, but it also helps to promptly detect and respond to potential welding blockage faults, ensuring the efficient and stable operation of the air conditioner 10.

[0107] In summary, for example, the first preset time t1 is 3 minutes, the second preset time t2 is 2 minutes, the first preset outdoor heat exchange temperature difference ΔTout1 is 3°C, the first preset exhaust outer ring temperature difference D_Tout1 is 7°C, the second preset exhaust outer ring temperature difference D_Tout2 is 20°C, and the third preset exhaust outer ring temperature difference D_Tout3 is 30°C.

[0108] The first preset indoor heat exchange temperature difference △Tin1 is 6°C, the second preset indoor heat exchange temperature difference △Tin2 is 12°C, the third preset indoor heat exchange temperature difference △Tin3=15°C, the first preset whole machine current Ih1 is 2.0A, the second preset whole machine current Ih2=3.0A, the third preset whole machine current Ih3=4.0A, k1=0.15°C / Hz, k2=0.1, the condenser outlet temperature A is 3°C, the initial gear R0 is D10, the first preset gear R1 is D11, the second preset gear R2 is D13, the target preset gear R3 is D15, the first preset outdoor ambient temperature Tout1 is 24°C, the second preset outdoor ambient temperature Tout2 is 30°C, the third preset outdoor ambient temperature Tout3 is 42°C, and the preset temperature threshold T is 61°C.

[0109] When the memory does not have the rewrite function, when the air conditioner 10 starts the cooling operation mode, the user sets the temperature to 26°C, controls the indoor wind speed automatically and controls the compressor to start, controls the outdoor motor to run at the initial gear R0=D10, and runs for the first preset time t1 (i.e., 3 minutes). It is detected that the outdoor heat exchange temperature difference △Tout(1)=0°C, the exhaust outer ring temperature difference D_Tout(1)=10°C, the indoor heat exchange temperature difference △Tin(1)=8°C, and the whole machine current Ih(1)=2 .4A, at this time, since △Tout(1)=0℃<△Tout1=3℃, D_Tout(1)=10℃>D_Tout1=7℃, Ih(1)=2.4A>Ih1=2.0A, △Tin(1)=8℃>△Tin1=6℃, it is suspected that there is a welding blockage fault in the target coil branch, and the controller 71 controls the outdoor motor to increase from the initial gear R0 to the first preset gear R1 and run for the second preset time t2, that is, increase to D11 gear and run for 2 minutes.

[0110] At this time, the compressor starts for the third preset time t3 (i.e., 5 minutes). At 5 minutes, it is detected that the outdoor heat exchange temperature difference △Tout(2)=1.0℃, the exhaust outer ring temperature difference D_Tout(2)=25℃, the indoor heat exchange temperature difference △Tin(2)=12℃, and the whole machine current Ih(2)=3.6A. At this time, △Tout(2)=1.0℃<△Tout1=3℃, D_Tout(2)=25℃>D_Tout2=20℃, Ih(2)=3.6A>Ih2=3.0A, △Tin(2)=12℃=△Tin2=12℃, so it is suspected that there is a welding blockage fault in the target coil branch. The controller 71 controls the outdoor motor to increase from the first preset gear R1 to the second preset gear R2 and run for the second preset time, that is, increase to D13 gear and run for 2 minutes.

[0111] At this time, when the compressor starts for the fourth preset time t4 (i.e., 7 minutes), at 7 minutes, it is detected that the outdoor heat exchange temperature difference △Tout(3)=1.0℃, the exhaust outer ring temperature difference D_Tout(3)=35℃, the indoor heat exchange temperature difference △Tin(3)=15℃, and the whole machine current Ih(3)=4.4A. At this time, △Tout(3)=1.0℃<△Tout1=3℃, D_Tout(3)=35℃>D_Tout3=30℃, Ih(3)=4.4A>Ih3=4.0A, △Tin(3)=15℃>△Tin3=13℃, so it is suspected that there is a welding blockage fault in the target coil branch. The controller 71 controls the outdoor motor to increase from the second preset gear R2 to the preset target gear R3 and run for the second preset time, that is, increase to D15 gear and run for 2 minutes.

[0112] At this time, when the compressor starts for the fifth preset time t5 (i.e., 9 minutes), at 9 minutes, it is detected that the outdoor heat exchange temperature difference △Tout(4) = 1.5℃, the exhaust outer ring temperature difference D_Tout(4) = 40℃, the indoor heat exchange temperature difference △Tin(4) = 16℃, and the whole machine current Ih(4) = 4.6A. At this time, △Tout(4) = 1.5℃ < △Tout1 = 3℃, D_Tout(4) = 40℃ > D_Tout3 = 30℃, Ih(4) = 4.6A > Ih3 = 4.0A, △Tin(4) = 16℃ > △Tin3 = 13℃, and it is determined that the target coil branch has a welding blockage fault.

[0113] In addition, during the operation of the refrigeration system, the current outdoor ambient temperature is first detected. This outdoor ambient temperature is used as a reference for determining the initial speed (initial gear) of the outdoor motor. The air conditioner 10 then enters an open-loop control phase, which lasts for t1 minutes, during which the outdoor motor operates at this initial gear. Figure 7 As shown, the air conditioner 10 switches to the closed-loop control stage. In this stage, the air conditioner 10 dynamically adjusts the speed gear of the outdoor motor based on the continuously detected outdoor coil temperature. This adjustment process is gradual and may be gradually increased, gradually decreased, or kept unchanged. Each adjustment is based on the outdoor coil temperature detected every second preset time. This closed-loop control method is intended to optimize cooling efficiency. However, if Figure 8As shown, if a welding blockage occurs in the target coil branch where the outdoor coil temperature sensor is located, the detected outdoor coil temperature will be abnormal, only slightly higher than the outdoor ambient temperature. In this case, the speed control of the outdoor motor will fail because the air conditioner 10 cannot accurately obtain the actual condensing temperature change. Even if the actual condensing temperature is rising, the actual speed of the outdoor motor may decrease because the air conditioner 10 mistakenly believes that the condensing temperature has not changed significantly. This mismatch between the speed and the condensing temperature can greatly reduce the efficiency of the refrigeration cycle and may even cause the condensing temperature of the refrigeration system to rise abnormally, exceeding the upper limit of the system design, thereby posing a threat to the stability and safety of the system.

[0114] Among them, the open-loop control stage refers to the stage in which the outdoor motor runs at the initial gear for the first preset time; the closed-loop control stage refers to the stage in which the outdoor motor runs at the first preset gear, the second preset gear and the target preset gear respectively for the second preset time.

[0115] Therefore, the controller 71 switches the outdoor motor from the first preset control strategy to the second preset control strategy, wherein the first preset control strategy can be understood as a multi-speed control of the outdoor coil temperature, such as Figure 9 As shown, the second preset control strategy can be understood as a four-speed control strategy for the outdoor ambient temperature, namely, R1-R4, with R1 = D6, R2 = D10, R3 = D15, and R4 = D18. At this time, the outdoor ambient temperature Tout = 45°C, the compressor operating frequency F is 54Hz, and the current outdoor ambient temperature Tout is greater than the sum of the third preset outdoor ambient temperature and 1°C, that is, Tout > Tout3 + 1°C. Therefore, the controller 71 switches the speed gear to R4, or D18.

[0116] When the memory has an overwrite function, if the air conditioner 10 is turned on for the first time for cooling operation after installation, the above steps are used to determine whether the target coil branch has a welding blockage fault. If it is determined that the target coil branch has a welding blockage fault, the welding blockage fault information is stored in the memory, and the welding blockage fault information can be directly read during the next cooling operation.

[0117] If the air conditioner 10 is not in cooling operation for the first time after installation, the welding blockage fault information can be directly read. For example, if the user sets the temperature to 26°C, the controller 71 controls the indoor fan speed automatically. When the welding blockage fault information in the memory is read or a fault in the outdoor coil temperature sensor is detected, the outdoor ambient temperature Tout is detected to be 28°C, and the outdoor motor is controlled to operate in the R2 gear, i.e., the D10 gear.

[0118] After determining that there is a welding blockage fault in the target coil branch or detecting a fault in the outdoor coil temperature sensor, the virtual outdoor coil temperature is started for overload protection control. The virtual outdoor coil temperature Te’ is calculated based on the outdoor ambient temperature Tout, the operating frequency F of the compressor, and the condenser outlet temperature A, i.e.: Te’≈Tout + k1×F + k2×Tout + A = 45 + 0.15×60 + 0.1×45 + 3 ≈ 60.5℃. At this time, the calculated virtual outdoor coil temperature is less than the preset temperature threshold T, i.e., Te’ < T, then the controller 71 does not need to start the preset overload protection control strategy, that is, to keep the current operating frequency of the compressor unchanged to ensure the normal operation and efficiency of the system. After several minutes, it is detected that the current outdoor ambient temperature Tout is 46℃ and the operating frequency F of the compressor is 54Hz. The virtual outdoor coil temperature Te’≈46 + 0.15×60 + 0.1×46 + 3 ≈ 61.5℃. When the calculated virtual outdoor coil temperature Te’ exceeds the preset temperature threshold T, i.e., Te’ > T, it means that the current outdoor coil temperature has risen to a level that may threaten the safe operation of the compressor. At this time, the controller 71 will immediately start the preset overload protection control strategy, reduce the operating frequency of the compressor to reduce the heat and load generated by it, so as to effectively carry out overload protection.

[0119] At this time, it has been determined that there is a welding blockage fault in the target coil branch, so the refrigerant leakage fault protection in the refrigeration mode is invalid, and the refrigerant leakage fault judgment in the refrigeration mode will no longer be carried out.

[0120] According to the air conditioner 10 of the embodiment of the present invention, after the controller 71 controls the air conditioner to start refrigeration operation, it continuously detects the first operating parameter of the air conditioner 10, determines the second operating parameter based on the first operating parameter, and then gradually detects whether there is a welding blockage fault in the target coil branch according to the first operating parameter and the second operating parameter. When it is determined based on the operating parameter that there is a welding blockage fault in the target coil branch, the controller 71 will gradually adjust the speed gear of the outdoor motor according to the first preset control strategy until the speed gear of the outdoor motor is adjusted from the initial gear to the preset target gear, and it is still determined that there is a welding blockage fault in the target coil branch, then it can be determined that there is a welding blockage fault in the target coil branch. In this way, by repeatedly determining that there is a welding blockage fault in the target coil branch and continuously adjusting the speed gear of the outdoor motor to verify multiple times that there is indeed a welding blockage fault in the target coil branch, the misjudgment of the welding blockage fault detection can be avoided and the accuracy of the welding blockage fault detection can be improved.

[0121] The welding blockage fault information is then stored in a memory. The characteristics of the memory can determine whether the welding blockage fault information can be directly read the next time the cooling is started. If the current memory has an overwrite function, the welding blockage fault information can be directly read the next time the cooling operation is started, saving fault detection time. If the memory does not have an overwrite function, the welding blockage fault information is re-acquired based on the above steps after the cooling operation is started. After determining that the target coil branch has a welding blockage fault, the second preset control strategy is switched to control the speed gear of the outdoor motor, and overload protection is performed based on the virtual outdoor coil temperature, thereby effectively preventing system overload or damage caused by the welding blockage fault, ensuring the reliability of the air conditioner 10, and also improving the safety of the air conditioner 10, thereby enhancing the user experience.

[0122] Reference below Figure 10 A method for controlling an air conditioner according to an embodiment of the present invention is described.

[0123] like Figure 10 As shown, the air conditioner control method according to the embodiment of the present invention at least includes steps S1 to S4.

[0124] Step S1 : when the air conditioner is in cooling operation, determining whether welding blockage fault information is stored in the memory.

[0125] Step S2: If yes, read the welding blockage fault information; if no, determine whether the target coil branch has a welding blockage fault.

[0126] Step S3: If it exists, obtain the welding blockage fault information and store the welding blockage fault information in the memory.

[0127] Step S4: After reading or obtaining the welding blockage fault information, executing a preset anti-overload control strategy based on the virtual outdoor coil temperature.

[0128] Among them, the process of obtaining welding blockage fault information includes: detecting a first operating parameter of the air conditioner, and determining a second operating parameter based on the first operating parameter, wherein the first operating parameter includes: indoor ambient temperature, indoor coil temperature, exhaust temperature, outdoor ambient temperature, outdoor coil temperature and whole machine current; based on the first operating parameter and the second operating parameter, gradually judging whether the target coil branch has a welding blockage fault, if it is determined that the target coil branch has a welding blockage fault, then gradually adjusting the speed gear of the outdoor motor according to the first preset control strategy, wherein the second operating parameter includes: indoor heat exchange temperature difference, exhaust superheat, outdoor heat exchange temperature difference and exhaust outer ring temperature difference; until the speed gear of the outdoor motor is adjusted from the initial gear to the preset target gear, if it is still determined that the target coil branch has a welding blockage fault, then determining that the target coil branch has a welding blockage fault, generating welding blockage fault information, and switching to the second preset control strategy to control the speed gear of the outdoor motor, and / or executing the preset anti-overload control strategy.

[0129] In one embodiment of the present invention, the first preset control strategy is to perform multi-speed control according to the outdoor coil temperature; the second preset control strategy is to divide the temperature range according to the outdoor ambient temperature, and set different speed gears of the outdoor motor according to different temperature ranges of the outdoor ambient temperature.

[0130] In one embodiment of the present invention, when judging whether a target coil branch has a welding blockage fault step by step based on a first operating parameter and a second operating parameter, if it is judged that a welding blockage fault exists in the target coil branch, the speed gear of the outdoor motor is gradually adjusted according to a first preset control strategy, including: controlling the operation of the compressor and controlling the outdoor motor to operate at an initial gear for a first preset time, detecting the first operating parameter and the second operating parameter; if the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the first preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the first preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the first preset indoor heat exchange temperature difference, then it is preliminarily judged that a welding blockage fault exists in the target coil branch, and the speed gear of the outdoor motor is adjusted to the first preset gear and operated for a second preset time according to the first preset control strategy.

[0131] In one embodiment of the present invention, after the speed gear of the outdoor motor is adjusted to the first preset gear and runs for the second preset time according to the first control strategy, it includes: controlling the compressor to run for a third preset time, detecting the first operating parameter and the second operating parameter, wherein the third preset time is the sum of the first preset time and the second preset time; if the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor and indoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the second preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the second preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the second preset indoor heat exchange temperature difference, then it is further determined that there is a welding blockage fault in the target coil branch, and the speed gear of the outdoor motor is adjusted to the second preset gear and runs for the second preset time according to the first preset control strategy.

[0132] In one embodiment of the present invention, after the speed gear of the outdoor motor is adjusted to the second preset gear and runs for the second preset time according to the first preset control strategy, it includes: controlling the compressor to run for a fourth preset time, detecting the first operating parameter and the second operating parameter, wherein the fourth preset time is the sum of the third preset time and the second preset time; if the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the third preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the third preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the third preset indoor heat exchange temperature difference, then it is determined that there is a welding blockage fault in the target coil branch, and the speed gear of the outdoor motor is quickly adjusted to the preset target gear and runs for the second preset time according to the first preset control strategy.

[0133] In one embodiment of the present invention, after the speed gear of the outdoor motor is adjusted to the preset target gear and runs for the second preset time according to the first preset control strategy, it includes: controlling the compressor to run for the fifth preset time, detecting the first operating parameter and the second operating parameter, wherein the fifth preset time is the sum of the fourth preset time and the second preset time; if the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor and indoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the third preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the third preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the third preset indoor heat exchange temperature difference, then it is determined that there is a welding blockage fault in the target coil branch.

[0134] In one embodiment of the present invention, when executing a preset anti-overload control strategy based on a virtual outdoor coil temperature, the strategy includes: obtaining the outdoor ambient temperature, subcooling, and condenser outlet temperature, wherein the subcooling is calculated based on the outdoor ambient temperature and the operating frequency of the compressor through a preset operation function; determining the virtual outdoor coil temperature based on the outdoor ambient temperature, the subcooling, and the condenser outlet temperature; and reducing the current frequency of the compressor when it is determined that the virtual outdoor coil temperature exceeds a preset temperature threshold.

[0135] In one embodiment of the present invention, after determining that a welding blockage fault exists in the target coil branch, the method includes: controlling the air conditioner to no longer perform refrigerant leakage fault determination in the cooling mode.

[0136] In one embodiment of the present invention, before the air conditioner starts cooling operation, it includes: determining whether the outdoor coil temperature sensor is faulty; if so, reporting the fault, switching to a second preset control strategy to control the speed gear of the outdoor motor, and / or executing a preset anti-overload control strategy; if not, executing the step of reading welding blockage fault information or obtaining welding blockage fault information.

[0137] In one embodiment of the present invention, the outdoor coil temperature sensor includes one or more outdoor coil temperature sensors. When there are multiple outdoor coil temperature sensors, the multiple outdoor coil temperature sensors are disposed on multiple coil branches of the outdoor heat exchanger in a one-to-one correspondence.

[0138] According to the control method of the air conditioner of the embodiment of the present invention, after the air conditioner is controlled to start cooling operation, the first operating parameter of the air conditioner is continuously detected, the second operating parameter is determined based on the first operating parameter, and then the target coil branch is gradually detected based on the first operating parameter and the second operating parameter. When it is judged based on the operating parameters that the target coil branch has a welding blockage fault, the speed gear of the outdoor motor is gradually adjusted according to the first preset control strategy. Until the speed gear of the outdoor motor is adjusted from the initial gear to the preset target gear, if it is still determined that the target coil branch has a welding blockage fault, it can be determined that the target coil branch has a welding blockage fault. In this way, by repeatedly judging that the target coil branch has a welding blockage fault and continuously adjusting the speed gear of the outdoor motor, it is verified multiple times that the target coil branch does have a welding blockage fault, which can avoid misjudgment of welding blockage fault detection and improve the accuracy of welding blockage fault detection.

[0139] The welding blockage fault information is then stored in a memory. The characteristics of the memory can determine whether the welding blockage fault information can be directly read the next time the cooling system is started. If the current memory has an overwrite function, the welding blockage fault information can be directly read the next time the cooling system is turned on, saving fault detection time. If the memory does not have an overwrite function, the welding blockage fault information is re-acquired based on the above steps after the cooling system is turned on. After determining that a welding blockage fault exists in the target coil branch, the second preset control strategy is switched to control the speed gear of the outdoor motor. Overload protection is implemented based on the virtual outdoor coil temperature, effectively preventing system overload or damage caused by the welding blockage fault, ensuring the reliability of the air conditioner, while also improving the safety of the air conditioner and enhancing the user experience.

[0140] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0141] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. An air conditioner, characterized in that: include: A refrigerant circulation loop, wherein the refrigerant undergoes a refrigeration cycle in a loop consisting of a compressor, a condenser, a throttling element, and an evaporator, wherein one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; Indoor temperature sensor, used to detect indoor ambient temperature; Indoor coil temperature sensor, used to detect indoor coil temperature; an exhaust temperature sensor, used to detect the exhaust temperature of the compressor; Outdoor ambient temperature sensor, used to detect outdoor ambient temperature; Outdoor coil temperature sensor, used to detect outdoor coil temperature; A memory, configured to store welding blockage fault information, wherein the welding blockage fault information is used to indicate that a welding blockage fault exists in the target coil branch where the outdoor coil temperature sensor is located; A controller configured to: When the air conditioner is turned on for cooling operation, determining whether the welding blockage fault information is stored in the memory; If yes, read the welding blockage fault information; if no, determine whether the target coil branch has a welding blockage fault; If so, obtaining the welding blockage fault information and storing the welding blockage fault information in the memory; After reading the welding blockage fault information or obtaining the welding blockage fault information, executing a preset anti-overload control strategy based on the virtual outdoor coil temperature; The process of obtaining the welding blockage fault information includes: detecting a first operating parameter of the air conditioner and determining a second operating parameter based on the first operating parameter, wherein the first operating parameter includes: the indoor ambient temperature, the indoor coil temperature, the exhaust temperature, the outdoor ambient temperature, the outdoor coil temperature, and the entire machine current; Based on the first operating parameter and the second operating parameter, gradually determining whether the target coil branch has a welding blockage fault; if it is determined that the target coil branch has a welding blockage fault, gradually adjusting the speed gear of the outdoor motor according to a first preset control strategy, wherein the second operating parameter includes: indoor heat exchange temperature difference, exhaust superheat, outdoor heat exchange temperature difference, and exhaust outer ring temperature difference; After the speed gear of the outdoor motor is adjusted from the initial gear to the preset target gear, if it is still determined that the target coil branch has a welding blockage fault, it is determined that the target coil branch has a welding blockage fault, the welding blockage fault information is generated, and the second preset control strategy is switched to control the speed gear of the outdoor motor, and / or the preset anti-overload control strategy is executed.

2. The air conditioner according to claim 1, characterized in that The first preset control strategy is to perform multi-speed control according to the outdoor coil temperature; The second preset control strategy is to divide the temperature range according to the outdoor ambient temperature, and set different speed gears of the outdoor motor according to different temperature ranges of the outdoor ambient temperature.

3. The air conditioner according to claim 1, characterized in that When determining step by step whether the target coil branch has a welding blockage fault based on the first operating parameter and the second operating parameter, and if it is determined that the target coil branch has a welding blockage fault, then adjusting the speed gear of the outdoor motor step by step according to a first preset control strategy, the controller is configured to: Controlling the compressor to operate and controlling the outdoor motor to operate at an initial gear for a first preset time, and detecting the first operating parameter and the second operating parameter; If the indoor heat exchange temperature difference is less than or equal to the first preset indoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the first preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the first preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the first preset indoor heat exchange temperature difference, then it is preliminarily determined that there is a welding blockage fault in the target coil branch, and the speed gear of the outdoor motor is adjusted to the first preset gear and runs for the second preset time according to the first preset control strategy.

4. The air conditioner according to claim 3, characterized in that After the speed gear of the outdoor motor is adjusted to the first preset gear according to the first control strategy and runs for the second preset time, the controller is configured to: controlling the compressor to operate for a third preset time, detecting the first operating parameter and the second operating parameter, wherein the third preset time is the sum of the first preset time and the second preset time; If the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the second preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the second preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the second preset indoor heat exchange temperature difference, it is further determined that there is a welding blockage fault in the target coil branch, and the speed gear of the outdoor motor is adjusted to the second preset gear and runs for the second preset time according to the first preset control strategy.

5. The air conditioner according to claim 4, characterized in that After the speed gear of the outdoor motor is adjusted to the second preset gear according to the first preset control strategy and runs for the second preset time, the controller is configured to: controlling the compressor to operate for a fourth preset time, detecting the first operating parameter and the second operating parameter, wherein the fourth preset time is the sum of the third preset time and the second preset time; If the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor heat exchange temperature difference, and the exhaust outer ring temperature difference is greater than or equal to the third preset exhaust outer ring temperature difference, and the whole machine current is greater than or equal to the third preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the third preset indoor heat exchange temperature difference, it is determined that there is a welding blockage fault in the target coil branch, and the speed gear of the outdoor motor is adjusted to the preset target gear according to the first preset control strategy and runs for the second preset time.

6. The air conditioner according to claim 5, characterized in that After the speed gear of the outdoor motor is adjusted to a preset target gear according to the first preset control strategy and runs for the second preset time, the controller is configured to: controlling the compressor to operate for a fifth preset time, detecting the first operating parameter and the second operating parameter, wherein the fifth preset time is the sum of the fourth preset time and the second preset time; If the outdoor heat exchange temperature difference is less than or equal to the first preset outdoor heat exchange temperature difference, the exhaust outer ring temperature difference is greater than or equal to the third preset exhaust outer ring temperature difference, the whole machine current is greater than or equal to the third preset whole machine current, and the indoor heat exchange temperature difference is greater than or equal to the third preset indoor heat exchange temperature difference, it is determined that there is a welding blockage fault in the target coil branch.

7. The air conditioner according to claim 1, wherein: When executing a preset anti-overload control strategy based on the virtual outdoor coil temperature, the controller is configured to: Obtaining the outdoor ambient temperature, subcooling degree, and condenser outlet temperature, wherein the subcooling degree is calculated based on the outdoor ambient temperature and the operating frequency of the compressor through a preset operation function; determining the virtual outdoor coil temperature according to the outdoor ambient temperature, the subcooling degree, and the condenser outlet temperature; When it is determined that the virtual outdoor coil temperature exceeds a preset temperature threshold, the current frequency of the compressor is reduced.

8. The air conditioner according to claim 1, wherein: After determining that a welding blockage fault exists in the target coil branch, the controller is configured to: The air conditioner is controlled to no longer perform refrigerant leakage fault judgment in the cooling mode.

9. The air conditioner according to claim 1, wherein: Before the air conditioner starts cooling operation, the controller is configured to: Determine whether the outdoor coil temperature sensor is faulty, and if so, report the fault, switch to the second preset control strategy to control the speed gear of the outdoor motor, and / or execute the preset anti-overload control strategy; If not, the step of reading the welding blockage fault information or obtaining the welding blockage fault information is performed.

10. The air conditioner according to claim 1, wherein The outdoor coil temperature sensor includes one or more outdoor coil temperature sensors. When there are multiple outdoor coil temperature sensors, the multiple outdoor coil temperature sensors are arranged in a one-to-one correspondence on the multiple coil branches of the outdoor heat exchanger.

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