Air conditioner

Abstract

The invention discloses an air conditioner which comprises a controller, and the controller is configured to judge whether welding blockage fault information is stored in a storage or not when the air conditioner starts heating 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, whether the air conditioner meets the defrosting control entering condition or not is judged according to the exhaust temperature, when the defrosting control entering condition is met, the air conditioner is controlled to execute the defrosting action, and when the defrosting action is executed, the air conditioner is controlled to execute the defrosting action. According to the method, whether the air conditioner meets the defrosting quitting control condition or not is judged according to the temperature of the indoor coil pipe, when the defrosting quitting control condition is met, the air conditioner is controlled to stop executing the defrosting action, the accuracy of welding blockage fault detection can be improved, the comfort experience of a user is improved, and efficient utilization of energy is achieved.

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] When the outdoor heat exchanger is in heating operation, due to the large refrigerant flow resistance, it is usually designed into multiple branches, and the tube temperature of the outdoor heat exchanger is monitored by an outdoor coil temperature sensor located on one of the branches.

[0003] However, due to the small diameter of the copper tube, welding problems are prone to welding blockage during the manufacturing process. Once a branch is welded and blocked, no refrigerant will flow through that branch, causing the outdoor heat exchange temperature difference to decrease sharply. Under low-temperature heating conditions, even if the frost layer on the surface of the outdoor heat exchanger is already thick, the defrost program may not be started because the preset defrost conditions are not met. As a result, the frost layer continues to accumulate, seriously affecting the heating effect. The reduced outdoor air volume exacerbates the reduction in evaporation rate, preventing the refrigerant from fully evaporating and easily flowing back into the compressor, thereby increasing the risk of liquid hammer damage to the compressor and 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 heating operation, determining whether the memory stores the welding blockage fault information; 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 the welding blockage fault information or obtaining the welding blockage fault information, determining whether the air conditioner meets a defrost control entry condition based on the exhaust gas temperature; if the defrost control entry condition is met, controlling the air conditioner to perform a defrost action; and, when performing a defrost action, determining whether the air conditioner meets a defrost control exit condition based on the indoor coil temperature; if the defrost control exit condition is met, controlling the air conditioner to stop performing the defrost action; The process of obtaining the welding blockage fault information includes: Stepwise detection of first operating parameters of the air conditioner at different operating times of the compressor, and determination of second operating parameters based on the first operating parameters, wherein the first operating parameters include the indoor ambient temperature, the indoor coil temperature, the exhaust temperature, the outdoor ambient temperature, the outdoor coil temperature, the whole machine current, and the compressor operating frequency, and the second operating parameters include the indoor heat exchange temperature difference, the exhaust superheat, and the outdoor heat exchange temperature difference; stepwise determination of whether the target coil branch has a welding blockage fault based on the first operating parameters and the second operating parameters, until the operating time of the compressor reaches a preset target time, if it is still determined that the target coil branch has a welding blockage fault, determination of whether the target coil branch has a welding blockage fault is made, and generation of welding blockage fault information.

[0006] In addition, the air conditioner according to the embodiment of the present invention may also have the following additional technical features: Furthermore, when gradually judging whether the target coil branch has a welding blockage fault according to the first operating parameter and the second operating parameter, until the operating time of the compressor reaches the preset target time, if it is still determined that the target coil branch has a welding blockage fault, then when determining that the target coil branch has a welding blockage fault, the controller is configured to: detect the first operating parameter and the second operating parameter when the compressor runs to the first 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 superheat is greater than or equal to the first preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then preliminarily judge that the target coil branch has a welding blockage fault.

[0007] 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 determining that the target coil branch has a welding blockage fault at the first preset moment, and further performing the welding blockage fault judgment by changing the operating time of the compressor, thereby improving the accuracy of the target coil branch welding blockage fault detection.

[0008] Furthermore, after preliminarily determining that a welding blockage fault exists in the target coil branch, the controller is configured to: detect the first operating parameter and the second operating parameter of the compressor when it runs from the first preset moment to the second preset moment according to the first 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 superheat is greater than or equal to the second preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then it is further determined that a welding blockage fault exists in the target coil branch.

[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 determining that the target coil branch has a welding blockage fault at the second preset moment, and further performing the welding blockage fault judgment by changing the operating time of the compressor, thereby improving the accuracy of the target coil branch welding blockage fault detection.

[0010] Furthermore, after further determining that a welding blockage fault exists in the target coil branch, the controller is configured to: detect the first operating parameter and the second operating parameter of the compressor when it operates from the second preset moment to the third preset moment according to the first 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 superheat is greater than or equal to the third preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then it is determined that a welding blockage fault exists in the target coil branch.

[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 determining that the target coil branch has a welding blockage fault at the third preset time. By changing the operating time of the compressor to further perform welding blockage fault judgment, the accuracy of target coil branch welding blockage fault detection can be improved.

[0012] Furthermore, after determining that a welding blockage fault exists in the target coil branch, the controller is configured to: detect the first operating parameter and the second operating parameter of the compressor when it runs from the third preset moment to the preset target moment according to the first 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 superheat is greater than or equal to the third preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then it is determined that a welding blockage fault exists in the target coil branch.

[0013] The above technical solution has the following advantages or beneficial effects: by repeatedly verifying that the target coil branch does have a welding blockage fault, misjudgment of welding blockage fault detection can be avoided, and the accuracy of welding blockage fault detection is improved.

[0014] Furthermore, when judging whether the air conditioner meets the conditions for entering defrost control based on the exhaust temperature, and controlling the air conditioner to perform a defrost action when the conditions for entering defrost control are met, the controller is configured to: continuously detect the exhaust temperature, determine the maximum exhaust temperature based on the exhaust temperature, take the time when the maximum exhaust temperature occurs as the starting time, periodically obtain the exhaust temperature once every second preset time, and determine the exhaust temperature change value within each cycle, wherein the exhaust temperature change value is the difference between the exhaust temperature at the start time and the exhaust temperature at the end of the current cycle; if the exhaust temperature change values of multiple consecutive cycles are greater than the first preset temperature, and the exhaust temperature change values of multiple consecutive cycles show an increasing trend, and the outdoor ambient temperature is lower than the second preset temperature, and the running time of the compressor exceeds the third preset time and the running frequency of the compressor is higher than the second preset running frequency, then it is determined that the air conditioner meets the conditions for entering defrost control, and the air conditioner is controlled to perform a defrost action.

[0015] The above technical solution has the following advantages or beneficial effects: it can remove frost that may hinder the heat exchange efficiency, restore the heating efficiency and performance of the air conditioner, and ensure the normal operation efficiency and performance of the air conditioner.

[0016] Furthermore, when determining the maximum exhaust temperature based on the exhaust temperature, the controller is configured to: continuously detect the exhaust temperature; if the newly detected exhaust temperature is higher than the currently recorded maximum exhaust temperature, update the maximum exhaust temperature; if the newly detected exhaust temperature is lower than the currently recorded maximum exhaust temperature, maintain the maximum exhaust temperature unchanged until an exhaust temperature higher than the current maximum exhaust temperature no longer occurs during the heating operation.

[0017] The above technical solution has the following advantages or beneficial effects: it ensures that the defrosting operation can be completed, thereby ensuring the normal operating efficiency and performance of the air conditioner.

[0018] Furthermore, when judging whether the air conditioner meets the conditions for exiting defrost control based on the indoor coil temperature, when the conditions for exiting defrost control are met, before controlling the air conditioner to stop performing the defrost action, the controller is configured to: control the indoor fan and the outdoor fan to be in a stopped state, the four-way valve to be in a preset position, and control the operating frequency of the compressor to be at a third preset operating frequency, and when the opening of the throttling element is adjustable, also control the throttling element to be at a preset opening.

[0019] The above technical solution has the following advantages or beneficial effects: the air conditioner can efficiently complete defrosting and then quickly restore the heating function.

[0020] Furthermore, when the indoor fan and the outdoor fan are controlled to be in a stopped state, the four-way valve is in a preset position, and the operating frequency of the compressor is controlled to be at a third preset operating frequency, and when the opening of the throttling element is adjustable, the throttling element is also controlled to be at a preset opening, the controller is configured to: detect the indoor coil temperature once every fourth preset time; if the newly detected indoor coil temperature is lower than the currently recorded lowest indoor coil temperature, update the lowest indoor coil temperature; if the newly detected indoor coil temperature is higher than the currently recorded lowest indoor coil temperature, maintain the lowest indoor coil temperature unchanged until the indoor coil temperature lower than the currently recorded lowest indoor coil temperature no longer appears during the execution of the defrost action, and the currently recorded lowest indoor coil temperature is used as the lowest evaporating temperature; if the difference between the indoor coil temperature detected thereafter and the lowest evaporating temperature is greater than or equal to the preset temperature threshold, determine that the air conditioner meets the exit defrost control condition, and control the air conditioner to stop executing the defrost action.

[0021] The above technical solution has the following advantages or beneficial effects: it ensures that the air conditioner can switch between defrosting and heating smoothly and efficiently.

[0022] Furthermore, before the air conditioner starts heating operation, the controller is configured to: determine whether the outdoor coil temperature sensor has a fault; if so, report the fault; and determine whether the air conditioner meets the conditions for entering defrost control based on the exhaust temperature; when the conditions for entering defrost control are met, control the air conditioner to perform the defrost action; and, when performing the defrost action, determine whether the air conditioner meets the conditions for exiting defrost control based on the indoor coil temperature; when the conditions for exiting defrost control are met, control the air conditioner to stop performing the defrost action; if not, execute the steps of reading the welding blockage fault information or obtaining the welding blockage fault information.

[0023] 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 heating operation process, so as to ensure the smooth and safe operation of the heating process.

[0024] 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.

[0025] The above technical solution has the following advantages or beneficial effects: it improves the accuracy of temperature measurement, helps to promptly detect and respond to potential welding blockage faults, and ensures efficient and stable operation of the air conditioner.

[0026] According to the air conditioner of an embodiment of the present invention, after the controller controls the air conditioner to start heating operation, it will first determine whether welding blockage fault information is stored in the memory. If not, it will gradually detect the first operating parameters of the air conditioner at different operating times of the compressor, and calculate the second operating parameters based on the first operating parameters. Thereafter, it will gradually determine whether the target coil branch has a welding blockage fault in combination with the first operating parameters. If it is still determined that the target coil branch has a welding blockage fault after the preset target time of the compressor is detected, it is determined that the target coil branch has a welding blockage fault, and welding blockage fault information is generated.

[0027] The weld blockage fault information is then stored in memory. The memory's characteristics can determine whether the weld blockage fault information can be directly read the next time heating is started. If the current memory has an overwrite function, the weld blockage fault information can be directly read the next time heating is turned on, saving fault detection time. If the memory does not have an overwrite function, the weld blockage fault information is re-acquired based on the above steps after heating is turned on. After determining that the target coil branch has a weld blockage fault, defrost control is performed based on the exhaust temperature and the indoor coil temperature, effectively avoiding large indoor temperature fluctuations caused by prolonged defrosting. This not only improves the user's comfort experience, but also reduces unnecessary energy loss, achieves efficient energy utilization, and further enhances the air conditioner's heating efficiency.

[0028] 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

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying 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 temperature relationships under normal conditions according to an embodiment of the present invention; Figure 5 is a schematic diagram of temperature relationships in the case of a welding plugging failure according to an embodiment of the present invention; Figure 6 is a schematic diagram of temperature changes under normal conditions and during defrosting according to another embodiment of the present invention; Figure 7 is a flowchart of a method for controlling an air conditioner according to another embodiment of the present invention. DETAILED DESCRIPTION

[0030] 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. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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 .

[0040] 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.

[0041] 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.

[0042] 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 .

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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).

[0052] 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.

[0053] 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.

[0054] 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.

[0055] Reference below Figure 3-Figure 7 An air conditioner according to an embodiment of the present invention is described.

[0056] Figure 3 FIG. 1 is a schematic diagram of the structure of an air conditioner according to an embodiment of the present invention. Figure 3As 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.

[0057] 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 a welding blockage fault in the target coil branch where the indoor coil temperature sensor is located.

[0058] The controller 71 is configured to: when the air conditioner 10 starts heating operation, determine whether welding blockage fault information is stored in the memory 17; 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 17; after reading the welding blockage fault information or obtaining the welding blockage fault information, determine whether the air conditioner 10 meets the conditions for entering the defrost control according to the exhaust temperature, and when the conditions for entering the defrost control are met, control the air conditioner 10 to perform the defrost action, and, when performing the defrost action, determine whether the air conditioner 10 meets the conditions for exiting the defrost control according to the indoor coil temperature, and when the conditions for exiting the defrost control are met, control the air conditioner 10 to stop performing the defrost action.

[0059] Among them, the process of obtaining welding blockage fault information includes: gradually detecting the first operating parameters of the air conditioner at different operating times of the compressor, and determining the second operating parameters based on the first operating parameters, wherein the first operating parameters include indoor ambient temperature, indoor coil temperature, exhaust temperature, outdoor ambient temperature, outdoor coil temperature, whole machine current and compressor operating frequency, and the second operating parameters include indoor heat exchange temperature difference, exhaust superheat and outdoor heat exchange temperature difference; according to the first operating parameters and the second operating parameters, gradually judging whether there is a welding blockage fault in the target coil branch, until the operating time of the compressor reaches the preset target time, if it is still determined that there is a welding blockage fault in the target coil branch, then it is determined that there is a welding blockage fault in the target coil branch, and welding blockage fault information is generated.

[0060] 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).

[0061] 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, and the outdoor heat exchange temperature difference is recorded as △Tout.

[0062] In an embodiment, when the air conditioner 10 starts heating 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, based on the judgment result, it is determined 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 17.

[0063] Specifically, the first operating parameters of the air conditioner 10 at different operating times of the compressor are continuously detected, that is, the operating time of the compressor is determined, and 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.

[0064] In a specific embodiment, the indoor heat exchange temperature difference ΔTin is the difference between the indoor coil temperature Tc and the indoor ambient temperature Tin, that is, ΔTin=Tc-Tin; the exhaust superheat DSH is the difference between the exhaust temperature Td and the indoor coil temperature Tc, that is, DSH=Td-Tc; and the outdoor heat exchange temperature difference ΔTout is the difference between the outdoor ambient temperature Tout and the outdoor coil temperature Te, that is, ΔTout=Tout-Te.

[0065] After calculating the second operating parameter, controller 71 will combine it with the first operating parameter and gradually determine whether the target coil branch has a welding blockage fault based on the operating parameter. If the target coil branch is suspected of having a welding blockage fault, controller 71 will again obtain the compressor operating time. After the compressor operating time reaches the preset target time, if it is still determined that the target coil branch has a welding blockage fault, the target coil branch is determined to have a welding blockage fault and welding blockage fault information is generated. If memory 17 has an overwrite function, the welding blockage fault information is stored in memory 17. The welding blockage fault information can be directly read the next time the heating operation is turned on, saving welding blockage fault detection time. By repeatedly verifying whether the target coil branch is indeed faulty, the accuracy of welding blockage fault detection is improved.

[0066] After determining that a welding blockage fault exists in the target coil branch, controller 71 further determines, based on exhaust temperature Td, whether air conditioner 10 has met the conditions for defrost control. Once the conditions for entering defrost control are met, controller 71 controls air conditioner 10 to initiate defrost operation and execute the defrost action. Simultaneously, during the defrost process, controller 71 also monitors whether the conditions for exiting defrost control have been met based on indoor coil temperature Tc. Once the conditions for exiting defrost control are met, defrost operation is immediately stopped, effectively avoiding large fluctuations in indoor temperature caused by prolonged defrosting. This not only improves user comfort, but also reduces unnecessary energy loss, achieves efficient energy utilization, and further enhances the heating efficiency of air conditioner 10.

[0067] In one embodiment of the present invention, when determining whether a welding blockage fault exists in the target coil branch based on the first operating parameter and the second operating parameter step by step until the operating time of the compressor reaches the preset target time, if it is still determined that the target coil branch has a welding blockage fault, then when determining that the target coil branch has a welding blockage fault, the controller 71 is configured to: detect the first operating parameter and the second operating parameter of the compressor when it runs to the first 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 superheat is greater than or equal to the first preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then it is preliminarily determined that a welding blockage fault exists in the target coil branch.

[0068] For example, the first preset outdoor heat exchange temperature difference is recorded as ΔTout1, the first preset exhaust superheat is recorded as DSH1, the first preset whole machine current is recorded as Ih1, the first preset indoor heat exchange temperature difference is recorded as ΔTin1, the first preset operating frequency is recorded as F1, and the first preset time is recorded as t1.

[0069] The outdoor heat exchange temperature difference detected at the first preset time is recorded as ΔTout(1), the exhaust superheat is recorded as DSH(1), the whole machine current is recorded as Ih(1), the indoor heat exchange temperature difference is recorded as ΔTin(1) and the operating frequency of the compressor is recorded as F(1).

[0070] In the embodiment, when it is necessary to determine whether the target coil branch has a welding blockage fault, the controller 71 detects the first operating parameter and the second operating parameter of the compressor when it runs to the first preset time t1. For example, if the compressor runs for 8 minutes and the operating parameters of the air conditioner 10 at 8 minutes are detected, if the outdoor heat exchange temperature difference ΔTout(1) detected at 8 minutes is less than or equal to the first preset outdoor heat exchange temperature difference ΔTout1, that is, ΔTout(1) △Tout1, and the exhaust superheat DSH(1) is greater than or equal to the first preset exhaust superheat DSH1, that is, DSH(1) DSH1, 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, △Tin(1) △Tin1, and the operating frequency F(1) of the compressor is greater than or equal to the first preset operating frequency F1, F(1) F1, it is preliminarily determined that there is a welding blockage fault in the target coil branch, that is, it is suspected that there is a welding blockage fault in the target coil branch. This can avoid the misjudgment caused by directly determining that there is a welding blockage fault in the target coil branch after judging that there is a welding blockage fault in the target coil branch at the first preset time t1. By changing the operating time of the compressor to further judge the welding blockage fault, the accuracy of the target coil branch welding blockage fault detection can be improved.

[0071] In one embodiment of the present invention, after preliminarily determining that a welding blockage fault exists in the target coil branch, the controller 71 is configured to: detect the first operating parameter and the second operating parameter of the compressor running from the first preset moment to the second preset moment according to the first 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 superheat is greater than or equal to the second preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then it is further determined that a welding blockage fault exists in the target coil branch.

[0072] Among them, the second preset exhaust superheat is recorded as DSH2, the second preset whole machine current is recorded as Ih2, the second preset indoor heat exchange temperature difference is recorded as △Tin2, the second preset time is recorded as t2, and the first preset time is recorded as m1, for example, 2 minutes.

[0073] The outdoor heat exchange temperature difference detected at the second preset time is recorded as ΔTout(2), the exhaust superheat is recorded as DSH(2), the whole machine current is recorded as Ih(2), the indoor heat exchange temperature difference is recorded as ΔTin(2) and the operating frequency of the compressor is recorded as F(2).

[0074] In the embodiment, when the compressor is controlled to operate from the first preset time t1 to the second preset time t2 at a time interval of 2 minutes, that is, 10 minutes, the controller 71 detects the first operating parameter and the second operating parameter of the compressor when the compressor operates to the second preset time t2. For example, if the compressor operates for 10 minutes and the operating parameters of the air conditioner 10 at 10 minutes are detected, if the outdoor heat exchange temperature difference ΔTout(2) detected at 10 minutes is less than or equal to the first preset outdoor heat exchange temperature difference ΔTout1, that is, ΔTout(2) △Tout1, and the exhaust superheat DSH(2) is greater than or equal to the second preset exhaust superheat DSH2, that is, DSH(2) DSH2, 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, and the operating frequency F(2) of the compressor is greater than or equal to the first preset operating frequency F1, that is, F(2) F1, it is further determined that the target coil branch has a welding blockage fault, that is, it is suspected that the target coil branch has a welding blockage fault. This can avoid the misjudgment caused by directly determining that the target coil branch has a welding blockage fault after the target coil branch is determined to have a welding blockage fault at the second preset time t2. By further determining the welding blockage fault by changing the operating time of the compressor, the accuracy of the target coil branch welding blockage fault detection can be improved.

[0075] In one embodiment of the present invention, after further determining that a welding blockage fault exists in the target coil branch, the controller 71 is configured to: detect the first operating parameter and the second operating parameter of the compressor running from the second preset moment to the third preset moment according to the first 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 superheat is greater than or equal to the third preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then it is determined that a welding blockage fault exists in the target coil branch.

[0076] The third preset exhaust superheat is recorded as DSH3, the third preset whole machine current is recorded as Ih3, the third preset indoor heat exchange temperature difference is recorded as ΔTin3, and the third preset time is recorded as t3.

[0077] The outdoor heat exchange temperature difference detected at the third preset time is recorded as ΔTout(3), the exhaust superheat is recorded as DSH(3), the whole machine current is recorded as Ih(3), the indoor heat exchange temperature difference is recorded as ΔTin(3) and the operating frequency of the compressor is recorded as F(3).

[0078] In the embodiment, when the compressor is controlled to operate from the second preset time t2 to the third preset time t3 at a time interval of 2 minutes, that is, 12 minutes, the controller 71 detects the first operating parameter and the second operating parameter of the compressor when the compressor operates to the third preset time t3. For example, if the compressor operates for 12 minutes and the operating parameters of the air conditioner 10 at 12 minutes are detected, if the outdoor heat exchange temperature difference ΔTout(3) detected at 12 minutes is less than or equal to the first preset outdoor heat exchange temperature difference ΔTout1, that is, ΔTout(3) △Tout1, and the exhaust superheat DSH(3) is greater than or equal to the third preset exhaust superheat DSH3, that is, DSH(3) DSH3, 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, and the operating frequency F(3) of the compressor is greater than or equal to the first preset operating frequency F1, F(3) F1, it is determined that the target coil branch has a welding blockage fault, and it is also suspected that the target coil branch has a 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 third preset time t3. By changing the operating time of the compressor to further perform welding blockage fault judgment, the accuracy of target coil branch welding blockage fault detection can be improved.

[0079] In one embodiment of the present invention, after determining that a welding blockage fault exists in the target coil branch, the controller 71 is configured to: detect the first operating parameter and the second operating parameter of the compressor running from the third preset moment to the preset target moment according to the first 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 superheat is greater than or equal to the third preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then it is determined that a welding blockage fault exists in the target coil branch.

[0080] Here, for example, the preset target time is recorded as t4, the outdoor heat exchange temperature difference detected at the fourth preset time is recorded as ΔTout(4), the exhaust superheat is recorded as DSH(4), the whole machine current is recorded as Ih(4), the indoor heat exchange temperature difference is recorded as ΔTin(4), and the operating frequency of the compressor is recorded as F(4).

[0081] In the embodiment, when the compressor is controlled to operate from the third preset time t3 to the preset target time t4 at a time interval of 2 minutes, that is, 14 minutes, the controller 71 detects the first operating parameter and the second operating parameter of the compressor when the compressor operates to the preset target time t4. For example, if the compressor operates for 14 minutes and the operating parameters of the air conditioner 10 at 14 minutes are detected, if the outdoor heat exchange temperature difference ΔTout(4) detected at 14 minutes is less than or equal to the first preset outdoor heat exchange temperature difference ΔTout1, that is, ΔTout(4) △Tout1, and the exhaust gas superheat DSH(4) is greater than or equal to the third preset exhaust gas superheat DSH3, that is, DSH(4) DSH3, 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, and the operating frequency F(4) of the compressor is greater than or equal to the first preset operating frequency F1, F(4) F1, it is determined that there is a welding blockage fault in the target coil branch. In this way, multiple interruptions and verifications can be performed to verify that there is indeed a welding blockage fault in the target coil branch, which can avoid misjudgment of welding blockage fault detection and improve the accuracy of welding blockage fault detection.

[0082] In one embodiment of the present invention, when judging whether the air conditioner 10 meets the conditions for entering defrost control based on the exhaust temperature, and when the conditions for entering defrost control are met, controlling the air conditioner 10 to perform the defrost action, the controller 71 is configured to: continuously detect the exhaust temperature, determine the maximum exhaust temperature based on the exhaust temperature, take the time when the maximum exhaust temperature occurs as the starting time, periodically obtain the exhaust temperature once every second preset time, and determine the exhaust temperature change value within each cycle, wherein the exhaust temperature change value is the difference between the exhaust temperature at the start time and the exhaust temperature at the end of the current cycle; if the exhaust temperature change values of multiple consecutive cycles are greater than the first preset temperature, and the exhaust temperature change values of multiple consecutive cycles show an increasing trend, and the outdoor ambient temperature is lower than the second preset temperature, and the compressor operation time exceeds the third preset time and the compressor operation frequency is higher than the second preset operation frequency, then it is determined that the air conditioner 10 meets the conditions for entering defrost control, and the air conditioner 10 is controlled to perform the defrost action.

[0083] Among them, the second preset time is recorded as m2, and m2 is 2 minutes, the exhaust temperature change value is recorded as △Td, the maximum exhaust temperature is recorded as Tdmax, the first preset temperature is recorded as T1 and T1 is 0°C, the second preset temperature is recorded as T2 and T2 is 6°C, the third preset time is recorded as m3, and the second preset operating frequency is recorded as F2.

[0084] In a specific embodiment, during heating operation of the air conditioner 10, when the evaporating temperature drops below 0°C, the outdoor heat exchanger is at risk of frost formation. The rate of frost formation is influenced by both the evaporating temperature and the outdoor relative humidity. The lower the evaporating temperature and the higher the outdoor relative humidity, the more likely frost will form. When the refrigeration system is operating stably, the difference between the outdoor ambient temperature and the evaporating temperature when there is no frost or only a thin layer of frost on the outdoor heat exchanger is defined as the standard heat exchange temperature difference. As the frost layer on the outdoor heat exchanger gradually thickens, the evaporating temperature further decreases, causing the outdoor heat exchange temperature difference to increase. Under normal circumstances, when the outdoor heat exchange temperature difference exceeds the preset defrost threshold, the outdoor coil temperature is below 0°C, and the compressor has been running continuously for a specified period of time, the controller 71 determines that the outdoor heat exchanger is thick with frost and triggers the defrost sequence. However, if the target coil branch of the outdoor heat exchanger is welded, although the evaporating temperature will be slightly lower than the outdoor ambient temperature, parameters such as the indoor heat exchange temperature difference, exhaust temperature, and total system current may remain within normal ranges. However, in high-temperature, frost-free areas (i.e., evaporating temperatures above 0°C), the outdoor heat exchanger will not frost, and the air conditioner 10 can continue to heat normally. However, once the evaporating temperature drops below 0°C, frost will begin to form on the outdoor heat exchanger. As the frost layer thickens, heat exchange efficiency decreases significantly. The evaporating temperature continues to drop, but because the outdoor heat exchange capacity remains at a low level, the defrost triggering conditions may not be met, resulting in the air conditioner 10 being unable to defrost, thus affecting normal heating function.

[0085] Air conditioner 10 is in heating mode, and during the defrost cycle, the outdoor coil temperature can be used to determine whether the frost on the outdoor heat exchanger has been completely removed. If the frost is not completely removed, the next heating cycle will resume, and the remaining frost or ice water on the outdoor heat exchanger will quickly freeze, rapidly reducing heating capacity. Generally, the defrost exit condition is that the outdoor coil temperature exceeds a preset threshold or the defrost time has reached a maximum time threshold. Meeting either of these conditions terminates the defrost process. The maximum defrost time threshold is typically set to a long time, such as 12 minutes, to prevent the worst-case scenario. However, due to a weld blockage in the target coil branch, the correct outdoor coil temperature cannot be detected. Therefore, defrost cannot be terminated in a timely manner even when the frost has been completely removed. The defrost process can only be terminated when the maximum defrost time threshold is met. Under normal circumstances, most defrost times are within 6 minutes. Meeting the maximum defrost time threshold of 12 minutes is significantly excessive, causing a significant drop in indoor temperature due to the prolonged defrost process. This results in significant temperature fluctuations during the defrost period, causing user discomfort and wasting energy.

[0086] When the target coil branch has a welding blockage fault, such as the outdoor ambient temperature is less than 6°C (when the outdoor ambient temperature is lower than 6°C, under normal circumstances, the standard heat exchange temperature difference is around 5~6°C, so the evaporation temperature should be lower than 0°C at this time), and the operating frequency of the compressor is greater than 70Hz, for example. If the outdoor heat exchanger has begun to frost at this time, then as the frost layer thickens, the exhaust temperature will inevitably gradually decrease after reaching the maximum value. When the frost layer is very thick, the outdoor wind resistance is very large, and the outdoor circulating air volume drops sharply, causing the evaporation temperature to drop faster, which also drives the exhaust temperature to drop faster. Therefore, the above parameter characteristics can be used to determine the entry conditions for defrosting when the target coil branch has a welding blockage fault, combined with Figure 4 and Figure 5 shown.

[0087] Therefore, during the heating operation, the controller 71 will monitor and record the compressor's exhaust temperature Td in real time, identify the highest exhaust temperature Tdmax, and mark this moment as the starting moment. Subsequently, the controller 71 enters a periodic detection mode, re-acquiring the exhaust temperature every second preset time m2, that is, acquiring the exhaust temperature every 2 minutes. In each such time period, the controller 71 will calculate the exhaust temperature change value, which is the difference between the exhaust temperature at the beginning of the period and the exhaust temperature at the end of the period. In other words, the first detection cycle starts at 2 minutes, and the exhaust temperature detected at this moment is recorded as Td(n-1). After the compressor has run for 2 minutes, the exhaust temperature detected at the end of the detection cycle (i.e., 4 minutes) is Td(n), then △Td=Td(n-1)-Td(n).

[0088] Furthermore, the controller 71 analyzes the exhaust temperature change values within a plurality of such consecutive cycles. If these exhaust temperature change values continue to be higher than the first preset temperature T1, for example, the exhaust temperature change values detected within a plurality of cycles are recorded as △Td(1), △Td(2), ..., △Td(n), that is, △Td(1), △Td(2), ..., △Td(n) are all greater than 0°C, this means that the exhaust temperature is gradually decreasing since reaching the maximum exhaust temperature, which may be because frost has accumulated on the outdoor heat exchanger, affecting the heat exchange efficiency.

[0089] At the same time, the exhaust temperature change values in multiple consecutive detection cycles show an increasing trend. For example, if there are j detection cycles, the exhaust temperature change values of j detection cycles are recorded as △Td(nj), △Td(n-j+1),..., △Td(n), that is, when △Td(nj)<△Td(n-j+1)<...<△Td(n), the exhaust temperature at this time is decreasing at an accelerated rate.

[0090] And the outdoor ambient temperature is lower than the second preset temperature, that is, Tout<6°C, and the running time of the compressor exceeds the third preset time, and the operating frequency of the compressor is higher than the second preset operating frequency, that is, F>F2, then it is determined that the air conditioner 10 meets the conditions for entering defrost control, and the air conditioner 10 is controlled to perform defrost action to remove frost that may hinder the heat exchange efficiency, restore the heating efficiency and performance of the air conditioner 10, and ensure the normal operation efficiency and performance of the air conditioner 10.

[0091] In one embodiment of the present invention, when determining the maximum exhaust temperature based on the exhaust temperature, the controller 71 is configured to: continuously detect the exhaust temperature; if the newly detected exhaust temperature is higher than the currently recorded maximum exhaust temperature, update the maximum exhaust temperature; if the newly detected exhaust temperature is lower than the currently recorded maximum exhaust temperature, maintain the maximum exhaust temperature unchanged until an exhaust temperature higher than the current maximum exhaust temperature no longer occurs during the heating operation.

[0092] In an embodiment, the controller 71 will detect the exhaust temperature Td of the compressor in real time and continuously, and perform an immediate analysis of each newly detected exhaust temperature Td. Whenever the controller 71 detects a new exhaust temperature Td, it will immediately compare the new exhaust temperature with the currently recorded maximum exhaust temperature Tdmax. If the newly detected temperature Td is higher than the maximum exhaust temperature Tdmax, the controller 71 will immediately update the record of the maximum exhaust temperature Tdmax and replace the old record with the new exhaust temperature, that is, the currently acquired exhaust temperature will be used as the maximum exhaust temperature. However, if the newly detected temperature does not exceed the currently recorded maximum exhaust temperature Tdmax, the new exhaust temperature will be discarded by the controller 71 and will not be used to update the record of the maximum exhaust temperature.

[0093] This process continues until the entire heating cycle is complete and no exhaust temperature higher than the currently recorded maximum exhaust temperature Tdmax is detected during this process. At this point, the maximum exhaust temperature Tdmax recorded by the controller 71 is considered the highest exhaust temperature during this heating process, representing the maximum heat load state of the compressor when operating in the heating state.

[0094] Once the maximum exhaust temperature Tdmax is determined, the controller 71 will perform analysis based on the maximum exhaust temperature to ensure that the defrost operation can be completed, thereby ensuring the normal operating efficiency and performance of the air conditioner 10.

[0095] In one embodiment of the present invention, when determining whether the air conditioner 10 meets the conditions for exiting the defrost control based on the indoor coil temperature, when the conditions for exiting the defrost control are met, before controlling the air conditioner 10 to stop performing the defrost action, the controller 71 is configured to: control the indoor fan and the outdoor fan to be in a stopped state, the four-way valve to be in a preset position, and the operating frequency of the compressor to be at a third preset operating frequency, and, when the opening of the throttling element is adjustable, also control the throttling element to be at a preset opening.

[0096] In this embodiment, during the defrost phase of the air conditioner 10, the controller 71 stops the indoor and outdoor fans. This prevents unnecessary airflow disturbances during the defrost process and reduces energy loss. Simultaneously, the four-way valve switches to a preset position (i.e., the cooling position). This redirects the refrigerant flow, redirecting the refrigerant condensing in the indoor heat exchanger to the outdoor heat exchanger, where its heat melts the frost.

[0097] Furthermore, when the throttling element has an adjustable opening, such as an expansion valve, the controller 71 further controls the throttling element to a predetermined opening, for example, to a predetermined defrost opening. In this case, the defrost opening is greater than the opening during normal heating mode to increase the flow of refrigerant and thereby accelerate the defrosting of the outdoor heat exchanger. Simultaneously, the compressor's operating frequency is increased to a third predetermined operating frequency (i.e., the defrost frequency). This relatively high defrost frequency provides greater cooling capacity and further accelerates the defrosting process, allowing the air conditioner 10 to efficiently complete defrosting and subsequently quickly resume heating.

[0098] On the other hand, when the throttling element is a component that does not have an opening adjustment function, such as a capillary tube or a throttle valve, the size of the internal flow cross-section is fixed, so there is no need to adjust its opening.

[0099] In one embodiment of the present invention, when the indoor fan and the outdoor fan are controlled to be in a stopped state, the four-way valve is in a preset position, and the operating frequency of the compressor is controlled to be at a third preset operating frequency, and when the opening of the throttling element is adjustable, the throttling element is also controlled to be at the preset opening, the controller 71 is configured to: detect the indoor coil temperature once every fourth preset time; if the newly detected indoor coil temperature is lower than the currently recorded lowest indoor coil temperature, update the lowest indoor coil temperature; if the newly detected indoor coil temperature is higher than the currently recorded lowest indoor coil temperature, maintain the lowest indoor coil temperature unchanged until the indoor coil temperature no longer drops below the currently recorded lowest indoor coil temperature during the defrosting operation, and use the currently recorded lowest indoor coil temperature as the lowest evaporating temperature; if the difference between the indoor coil temperature detected thereafter and the lowest evaporating temperature is greater than or equal to the preset temperature threshold, determine that the air conditioner 10 meets the conditions for exiting the defrosting control, and control the air conditioner 10 to stop performing the defrosting operation.

[0100] In a specific embodiment, the defrosting process is actually a refrigeration process. In order to prevent cold air from blowing out from the room and to quickly remove the frost from the outdoor heat exchanger, the indoor fan and the outdoor fan are stopped during defrosting. During the defrosting period, the indoor coil temperature (i.e., the evaporation temperature) first drops rapidly. As the frost layer on the outdoor heat exchanger decreases, when the frost has been completely removed, the outdoor condensation temperature and the exhaust temperature will also increase rapidly, causing the indoor coil temperature to drop to the minimum value and then gradually rise. The process of the indoor coil temperature dropping to the minimum and then rising again indicates that the frost on the outdoor heat exchanger has been removed. Therefore, the parameter characteristics of the indoor coil temperature can be used to determine the exit conditions for defrosting when there is a welding blockage fault in the target coil branch. For example Figure 6 shown.

[0101] Therefore, when the indoor and outdoor fans are stopped, the four-way valve is adjusted to a preset position, the throttling element is set to a preset opening, and the compressor operating frequency is controlled at a third preset frequency, the controller 10 will monitor the indoor coil temperature Tc at a fixed fourth preset interval. During this process, whenever a new indoor coil temperature Tc is detected, the controller 71 compares it with the currently recorded minimum indoor coil temperature. If the newly detected indoor coil temperature Tc is lower than the currently recorded minimum indoor coil temperature, the controller 71 updates the minimum indoor coil temperature record. Conversely, if the newly detected indoor coil temperature Tc is not lower than the currently recorded minimum indoor coil temperature, the indoor coil temperature is ignored and not used to update the minimum indoor coil temperature, and the minimum indoor coil temperature record remains unchanged. This monitoring process continues until the defrost operation is completed. If no temperature lower than the currently recorded minimum indoor coil temperature is detected during this period, the lowest temperature is determined as the minimum evaporating temperature, for example, the minimum evaporating temperature is recorded as Tcmin. At this time, the controller 71 will mark this time point as the reference time at time 0, which means that the defrosting operation has reached a critical stage, that is, the lowest evaporation temperature has been determined.

[0102] Next, the controller 71 will continue to detect the change of the indoor coil temperature Tc. When it is detected that the difference between the indoor coil temperature Tc and the minimum evaporation temperature Temin is greater than or equal to the preset temperature threshold (for example, Tc1), that is, Tc-Tcmin At Tc1, the air conditioner 10's heating capacity has recovered sufficiently to exit defrost control mode. At this point, the controller 71 issues a command to the air conditioner 10 to stop defrosting and re-enter normal heating control. This process ensures that the air conditioner 10 can switch smoothly and efficiently between defrosting and heating.

[0103] In one embodiment of the present invention, before the air conditioner 10 starts heating operation, the controller 71 is configured to: determine whether the outdoor coil temperature sensor is faulty; if so, report the fault; and determine whether the air conditioner 10 meets the conditions for entering defrost control based on the exhaust temperature; when the conditions for entering defrost control are met, control the air conditioner 10 to perform the defrost action; and, when performing the defrost action, determine whether the air conditioner 10 meets the conditions for exiting defrost control based on the indoor coil temperature; when the conditions for exiting defrost control are met, control the air conditioner 10 to stop performing the defrost action; if not, execute the steps of reading the welding blockage fault information or obtaining the welding blockage fault information.

[0104] In this embodiment, before the air conditioner 10 starts heating, 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 circuit 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. At the same time, the controller 71 determines whether the air conditioner 10 has met the conditions for entering defrost control based on the exhaust temperature. Once these conditions are met, the air conditioner 10 will perform a defrost operation to remove frost generated by heating and ensure efficient operation of the air conditioner 10. During the defrost period, the controller 71 also monitors whether the conditions for exiting defrost control have been met based on the indoor coil temperature. If these conditions are met, the controller 71 will control the air conditioner 10 to end the defrost operation.

[0105] 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 heating operation to ensure the smooth and safe operation of the heating process.

[0106] 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.

[0107] 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.

[0108] In summary, for example, the first preset time t1=8min, the first preset time m1=2min, the second preset time m2=2min, the third preset time m3=50min, the fourth preset time m4=2s, the first preset outdoor heat exchange temperature difference △Tout1 is 3°C, the first preset exhaust superheat DSH1 is 15°C, the second preset exhaust superheat DSH2 is 17°C, the third preset exhaust superheat DSH3 is 19°C, the first preset indoor heat exchange temperature difference △Tin1 is 10°C, the second preset indoor heat exchange temperature difference △Tin2 is 12°C, the third preset indoor heat exchange temperature difference △Tin3 is 14°C, the first preset whole machine current Ih1 is 2.0A, the second preset whole machine current Ih2 is 2.4A, The third preset whole machine current Ih3 is 2.8A, the preset temperature threshold Tc1 = 1.5°C, the first preset operating frequency F1 = 65Hz, the second preset operating frequency F2 = 70Hz, the detection cycle j = 3 times, the third preset operating frequency = 90Hz, and when the throttling element is an expansion valve, the preset opening is set to 300 steps.

[0109] When the memory does not have the rewrite function, when the air conditioner 10 is turned on for heating operation, the user sets the temperature to 23°C, controls the indoor wind speed automatically, and controls the compressor to start. When the compressor runs for 8 minutes, it is detected that the outdoor heat exchange temperature difference △Tout(1) at 8 minutes is 0°C, the exhaust superheat DSH(1) is 20°C, the indoor heat exchange temperature difference △Tin(1) is 15°C, the whole machine current Ih(1) is 2.8A, and the compressor operating frequency F(1) is 90Hz. At this time, △Tout(1)<△Tout1, DSH(1)>DSH1, Ih(1)>Ih1, △Tin(1)>△Tin1, and F(1)>F1, so it is suspected that the target coil branch has a welding blockage fault.

[0110] When the compressor is started for 10 minutes, the outdoor heat exchange temperature difference △Tout(2) at 10 minutes is 0.5℃, the exhaust superheat DSH(2) is 25℃, the indoor heat exchange temperature difference △Tin(2) is 18℃, the whole machine current Ih(2) is 3.4A, and the compressor operating frequency F(2) is 90Hz. At this time, △Tout(2)<△Tout1, DSH(2)>DSH2, Ih(2)>Ih2, △Tin(2)>△Tin2 and F(2)>F1, so it is suspected that the target coil branch has a welding blockage fault.

[0111] When the compressor is started for 12 minutes, the outdoor heat exchange temperature difference △Tout(3) at 12 minutes is 1.0℃, the exhaust superheat DSH(3) is 35℃, the indoor heat exchange temperature difference △Tin(3) is 20℃, the whole machine current Ih(3) is 4.4A, and the compressor operating frequency F(3) is 90Hz. At this time, △Tout(3)<△Tout1, DSH(3)>DSH3, Ih(3)>Ih3, △Tin(3)>△Tin3 and F(3)>F1, so it is suspected that the target coil branch has a welding blockage fault.

[0112] When the compressor is started for 14 minutes, the outdoor heat exchange temperature difference △Tout(4) is detected at 14 minutes, which is 1.0℃, the exhaust superheat DSH(4) is 40℃, the indoor heat exchange temperature difference △Tin(4) is 25℃, and the whole machine current Ih(4) is 5.2A. At this time, △Tout(4)<△Tout1, DSH(4)>DSH4, Ih(4)>Ih4, △Tin(4)>△Tin4, so it is determined that the target coil branch has a welding blockage fault.

[0113] When the memory has an overwrite function, if the air conditioner 10 is turned on for the first time to start heating 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 heating operation.

[0114] If the air conditioner 10 is not started for cooling operation for the first time after installation, the welding blockage fault information can be directly read.

[0115] After reading or obtaining weld blockage fault information, the defrost entry condition is changed to a defrost control in which the exhaust temperature reaches its highest value and then accelerates to a lower value. That is, the maximum exhaust temperature is found based on the exhaust temperature, and defrost control is performed based on the maximum exhaust temperature. The current outdoor ambient temperature is detected to be 2°C, and the exhaust temperature Td is detected in real time, and the maximum exhaust temperature Tdmax is recorded. After the maximum exhaust temperature Tdmax=86℃ is detected, the exhaust temperature is obtained every 2 minutes. For example, the exhaust temperatures obtained at 2min, 4min, 6min, 8min, 10min, 12min, and 14min are recorded as Td(1)=85℃, Td(2)=84℃, Td(3)=82℃, Td(4)=80℃, Td(5)=77℃, Td(6)=73℃, and Td(7)=67℃, respectively. The exhaust temperature change value in each detection cycle is calculated, that is, △Td(1)=85-85=0℃, △Td(2)=85-84=1℃, △Td(3)=84-82=2℃, △Td(4)=82-80=1℃. =2℃、△Td(5)=80-77=3℃、△Td(6)=77-73=4℃、△Td(7)=73-67=5℃、△Td(1),△Td(2),...,△Td(7) are all greater than 0℃. At this time, the exhaust temperature change value △Td is continuously decreasing, and △Td(5)<△Td(6)<△Td(7). At this time, the compressor has been running for 52 minutes, and the operating frequency of the compressor = 90Hz, and the outdoor ambient temperature = 2℃, that is, the operating time of the compressor exceeds the third preset time, the operating frequency of the compressor exceeds the second preset operating frequency, and the outdoor ambient temperature is less than 6℃, which meets the conditions for entering defrost control, then enters defrost control and performs defrost operation.

[0116] The indoor and outdoor fans are stopped, the four-way valve is switched to the cooling position, the expansion valve is opened to 300 steps, and the compressor frequency is increased to the third preset operating frequency, i.e., 90 Hz. The indoor coil temperature Tc is detected every 2 seconds and the lowest indoor coil temperature is recorded as -31°C. When the recorded lowest indoor coil temperature no longer reaches a new low, the recorded lowest indoor coil temperature is used as the minimum evaporating temperature Temin, i.e., Temin = -31°C, and the new indoor coil temperature Tc = -29°C, and Tc - Tcmin = -29 - (-31)°C = 2°C > Tc1 = 1.5°C, then the air conditioner 10 is determined to have met the conditions for exiting defrost control, and the air conditioner 10 is controlled to stop performing the defrost operation and switch to heating and restart operation.

[0117] According to the air conditioner 10 of the embodiment of the present invention, after the controller 71 controls the air conditioner to start heating operation, it will first determine whether there is welding blockage fault information stored in the memory. If not, it will gradually detect the first operating parameters of the air conditioner 10 at different operating times of the compressor, and calculate the second operating parameters based on the first operating parameters. Thereafter, it will gradually determine whether there is a welding blockage fault in the target coil branch in combination with the first operating parameters. If it is still determined that there is a welding blockage fault in the target coil branch after the preset target time of the compressor is detected, it is determined that there is a welding blockage fault in the target coil branch, and welding blockage fault information is generated.

[0118] 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 heating is started. If the current memory has an overwrite function, the welding blockage fault information can be directly read the next time heating 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 heating is started. After determining that a welding blockage fault exists in the target coil branch, defrost control is performed based on the exhaust temperature and the indoor coil temperature, effectively avoiding large fluctuations in indoor temperature caused by prolonged defrosting. This not only improves the user's comfort experience, but also reduces unnecessary energy loss, achieves efficient energy utilization, and further enhances the heating efficiency of the air conditioner 10.

[0119] Reference below Figure 7 A method for controlling an air conditioner according to an embodiment of the present invention is described.

[0120] like Figure 7 As shown, the air conditioner control method according to the embodiment of the present invention at least includes steps S1 to S4.

[0121] Step S1 : when the air conditioner is turned on for heating operation, it is determined whether welding blockage fault information is stored in the memory.

[0122] Step S2: If yes, read the welding blockage fault information; if no, determine whether the target coil branch has a welding blockage fault.

[0123] Step S3: If it exists, obtain the welding blockage fault information and store the welding blockage fault information in the memory.

[0124] Step S4, after reading the welding blockage fault information or obtaining the welding blockage fault information, determine whether the air conditioner meets the conditions for entering the defrost control according to the exhaust temperature, and when the conditions for entering the defrost control are met, control the air conditioner to perform the defrost action, and, when performing the defrost action, determine whether the air conditioner meets the conditions for exiting the defrost control according to the indoor coil temperature, and when the conditions for exiting the defrost control are met, control the air conditioner to stop performing the defrost action.

[0125] Among them, the process of obtaining welding blockage fault information includes: gradually detecting the first operating parameters of the air conditioner at different operating times of the compressor, and determining the second operating parameters based on the first operating parameters, wherein the first operating parameters include indoor ambient temperature, indoor coil temperature, exhaust temperature, outdoor ambient temperature, outdoor coil temperature, whole machine current and compressor operating frequency, and the second operating parameters include indoor heat exchange temperature difference, exhaust superheat and outdoor heat exchange temperature difference; according to the first operating parameters and the second operating parameters, gradually judging whether there is a welding blockage fault in the target coil branch, until the operating time of the compressor reaches the preset target time, if it is still determined that there is a welding blockage fault in the target coil branch, then it is determined that there is a welding blockage fault in the target coil branch, and welding blockage fault information is generated.

[0126] In one embodiment of the present invention, whether a target coil branch has a welding blockage fault is gradually determined according to the first operating parameter and the second operating parameter until the operating time of the compressor reaches a preset target time. 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 includes: detecting the first operating parameter and the second operating parameter when the compressor operates to a first 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 superheat is greater than or equal to the first preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then preliminarily determining that the target coil branch has a welding blockage fault.

[0127] In one embodiment of the present invention, after preliminarily determining that a target coil branch has a welding blockage fault, the method includes: detecting a first operating parameter and a second operating parameter of the compressor when the compressor operates from a first preset moment to a second preset moment according to a first 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 superheat is greater than or equal to the second preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then it is further determined that the target coil branch has a welding blockage fault.

[0128] In one embodiment of the present invention, after further determining that a welding blockage fault exists in the target coil branch, the method includes: detecting a first operating parameter and a second operating parameter of the compressor when the compressor operates from a second preset moment to a third preset moment according to a first 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 superheat is greater than or equal to the third preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then it is determined that a welding blockage fault exists in the target coil branch.

[0129] In one embodiment of the present invention, after determining that a target coil branch has a welding blockage fault, the method includes: detecting a first operating parameter and a second operating parameter of the compressor when the compressor operates from a third preset moment to a preset target moment according to a first 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 superheat is greater than or equal to the third preset exhaust superheat, 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, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, then it is determined that a welding blockage fault exists in the target coil branch.

[0130] In one embodiment of the present invention, when judging whether the air conditioner meets the conditions for entering defrost control based on the exhaust temperature, and when the conditions for entering defrost control are met, controlling the air conditioner to perform a defrost action, it includes: continuously detecting the exhaust temperature, determining the maximum exhaust temperature based on the exhaust temperature, taking the time when the maximum exhaust temperature occurs as the starting time, periodically obtaining the exhaust temperature once every second preset time, and determining the exhaust temperature change value within each cycle, wherein the exhaust temperature change value is the difference between the exhaust temperature at the start time and the exhaust temperature at the end time of the current cycle; if the exhaust temperature change values of multiple consecutive cycles are greater than the first preset temperature, and the exhaust temperature change values of multiple consecutive cycles show an increasing trend, and the outdoor ambient temperature is lower than the second preset temperature, and the running time of the compressor exceeds the third preset time and the running frequency of the compressor is higher than the second preset running frequency, it is determined that the air conditioner meets the conditions for entering defrost control, and the air conditioner is controlled to perform a defrost action.

[0131] In one embodiment of the present invention, when determining the maximum exhaust temperature based on the exhaust temperature, it includes: continuously detecting the exhaust temperature, if the newly detected exhaust temperature is higher than the currently recorded maximum exhaust temperature, updating the maximum exhaust temperature, if the newly detected exhaust temperature is lower than the currently recorded maximum exhaust temperature, maintaining the maximum exhaust temperature unchanged until an exhaust temperature higher than the current maximum exhaust temperature no longer occurs during the heating operation.

[0132] In one embodiment of the present invention, whether the air conditioner meets the conditions for exiting the defrost control is determined based on the indoor coil temperature. When the conditions for exiting the defrost control are met, the air conditioner is controlled to stop performing the defrost action, including: controlling the indoor fan and the outdoor fan to be in a stopped state, the four-way valve to be in a preset position, and controlling the operating frequency of the compressor to be at a third preset operating frequency, and when the opening of the throttling element is adjustable, the throttling element is also controlled to be at a preset opening.

[0133] In one embodiment of the present invention, when the indoor fan and the outdoor fan are controlled to be in a stopped state, the four-way valve is in a preset position, and the operating frequency of the compressor is controlled to be at a third preset operating frequency, and when the opening of the throttling element is adjustable, the throttling element is also controlled to be at a preset opening, the method includes: detecting the indoor coil temperature once every fourth preset time, if the newly detected indoor coil temperature is lower than the currently recorded lowest indoor coil temperature, updating the lowest indoor coil temperature, if the newly detected indoor coil temperature is higher than the currently recorded lowest indoor coil temperature, maintaining the lowest indoor coil temperature unchanged, until the indoor coil temperature no longer drops below the currently recorded lowest indoor coil temperature during the defrosting operation, and the currently recorded lowest indoor coil temperature is used as the lowest evaporating temperature; if the difference between the indoor coil temperature detected thereafter and the lowest evaporating temperature is greater than or equal to the preset temperature threshold, determining that the air conditioner meets the conditions for exiting the defrosting control, and controlling the air conditioner to stop performing the defrosting operation.

[0134] In one embodiment of the present invention, before the air conditioner starts heating operation, it includes: judging whether the outdoor coil temperature sensor has a fault, and if so, reporting the fault, and judging whether the air conditioner meets the conditions for entering the defrost control based on the exhaust temperature, and when the conditions for entering the defrost control are met, controlling the air conditioner to perform the defrost action, and, when performing the defrost action, judging whether the air conditioner meets the conditions for exiting the defrost control based on the indoor coil temperature, and when the conditions for exiting the defrost control are met, controlling the air conditioner to stop performing the defrost action; if not, executing the steps of reading the welding blockage fault information or obtaining the welding blockage fault information.

[0135] 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.

[0136] According to the control method of the air conditioner according to an embodiment of the present invention, after the air conditioner is controlled to start heating operation, it will first be determined whether welding blockage fault information is stored in the memory. If not, the first operating parameters of the air conditioner at different operating times of the compressor will be gradually detected, and the second operating parameters will be calculated based on the first operating parameters. Thereafter, it will be gradually determined whether the target coil branch has a welding blockage fault in combination with the first operating parameters. If it is still determined that the target coil branch has a welding blockage fault after the preset target time of the compressor is detected, it will be determined that the target coil branch has a welding blockage fault, and welding blockage fault information will be generated.

[0137] The weld blockage fault information is then stored in memory. The memory's characteristics can determine whether the weld blockage fault information can be directly read the next time heating is started. If the current memory has an overwrite function, the weld blockage fault information can be directly read the next time heating is turned on, saving fault detection time. If the memory does not have an overwrite function, the weld blockage fault information is re-acquired based on the above steps after heating is turned on. After determining that the target coil branch has a weld blockage fault, defrost control is performed based on the exhaust temperature and the indoor coil temperature, effectively avoiding large indoor temperature fluctuations caused by prolonged defrosting. This not only improves the user's comfort experience, but also reduces unnecessary energy loss, achieves efficient energy utilization, and further enhances the air conditioner's heating efficiency.

[0138] 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.

[0139] 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 heating 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 or acquiring the welding blockage fault information, determining whether the air conditioner meets a defrost control entry condition based on the exhaust temperature, and controlling the air conditioner to perform a defrost action when the defrost control entry condition is met; and, while performing the defrost action, determining whether the air conditioner meets a defrost control exit condition based on the indoor coil temperature, and controlling the air conditioner to stop performing the defrost action when the defrost control exit condition is met; The process of obtaining the welding blockage fault information includes: gradually detecting first operating parameters of the air conditioner at different operating moments of the compressor, and determining second operating parameters based on the first operating parameters, wherein the first operating parameters include the indoor ambient temperature, the indoor coil temperature, the exhaust temperature, the outdoor ambient temperature, the outdoor coil temperature, the entire machine current, and the compressor operating frequency, and the second operating parameters include the indoor heat exchange temperature difference, the exhaust superheat, and the outdoor heat exchange temperature difference; Whether the target coil branch has a welding blockage fault is determined step by step based on the first operating parameter and the second operating parameter until the compressor operation time reaches a preset target time. If it is still determined that the target coil branch has a welding blockage fault, the target coil branch is determined to have a welding blockage fault and welding blockage fault information is generated.

2. The air conditioner according to claim 1, characterized in that Whether the target coil branch has a welding blockage fault is gradually determined based on the first operating parameter and the second operating parameter until the compressor operation time reaches a preset target time. If it is still determined that the target coil branch has a welding blockage fault, then when determining that the target coil branch has a welding blockage fault, the controller is configured to: detecting the first operating parameter and the second operating parameter when the compressor operates to a first 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 superheat is greater than or equal to the first preset exhaust superheat, the whole machine current is greater than or equal to the first preset whole machine current, the indoor heat exchange temperature difference is greater than or equal to the first preset indoor heat exchange temperature difference, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, it is preliminarily determined that there is a welding blockage fault in the target coil branch.

3. The air conditioner according to claim 2, characterized in that After preliminarily determining that a welding blockage fault exists in the target coil branch, the controller is configured to: detecting the first operating parameter and the second operating parameter of the compressor when the compressor operates from the first preset moment to a second preset moment according to a first 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 superheat is greater than or equal to the second preset exhaust superheat, the whole machine current is greater than or equal to the second preset whole machine current, the indoor heat exchange temperature difference is greater than or equal to the second preset indoor heat exchange temperature difference, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, it is further determined that there is a welding blockage fault in the target coil branch.

4. The air conditioner according to claim 3, characterized in that After further determining that a welding blockage fault exists in the target coil branch, the controller is configured to: detecting the first operating parameter and the second operating parameter of the compressor when the compressor operates from the second preset moment to the third preset moment according to the first 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 superheat is greater than or equal to the third preset exhaust superheat, the whole machine current is greater than or equal to the third preset whole machine current, the indoor heat exchange temperature difference is greater than or equal to the third preset indoor heat exchange temperature difference, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, it is determined that the target coil branch has a welding blockage fault.

5. The air conditioner according to claim 4, characterized in that After determining that a welding blockage fault exists in the target coil branch, the controller is configured to: detecting the first operating parameter and the second operating parameter of the compressor when the compressor operates from the third preset time to the preset target time according to the first 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 superheat is greater than or equal to the third preset exhaust superheat, the whole machine current is greater than or equal to the third preset whole machine current, the indoor heat exchange temperature difference is greater than or equal to the third preset indoor heat exchange temperature difference, and the operating frequency of the compressor is greater than or equal to the first preset operating frequency, it is determined that there is a welding blockage fault in the target coil branch.

6. The air conditioner according to claim 1, characterized in that When determining whether the air conditioner meets a defrost control condition according to the exhaust temperature, and controlling the air conditioner to perform a defrost action when the defrost control condition is met, the controller is configured to: continuously detecting the exhaust temperature, determining a maximum exhaust temperature based on the exhaust temperature, taking the time when the maximum exhaust temperature occurs as a starting time, periodically acquiring the exhaust temperature every second preset time, and determining an exhaust temperature change value within each period, wherein the exhaust temperature change value is the difference between the exhaust temperature at the starting time and the exhaust temperature at the end time of the current period; If the exhaust temperature change values for multiple consecutive cycles are greater than the first preset temperature, and the exhaust temperature change values for multiple consecutive cycles show an increasing trend, and the outdoor ambient temperature is lower than the second preset temperature, and the operating time of the compressor exceeds the third preset time and the operating frequency of the compressor is higher than the second preset operating frequency, it is determined that the air conditioner meets the conditions for entering defrost control, and the air conditioner is controlled to perform defrost action.

7. The air conditioner according to claim 6, characterized in that When determining the maximum exhaust temperature based on the exhaust temperature, the controller is configured to: The exhaust temperature is continuously detected. If the newly detected exhaust temperature is higher than the currently recorded maximum exhaust temperature, the maximum exhaust temperature is updated. If the newly detected exhaust temperature is lower than the currently recorded maximum exhaust temperature, the maximum exhaust temperature is maintained unchanged until an exhaust temperature higher than the currently recorded maximum exhaust temperature no longer occurs during the heating operation.

8. The air conditioner according to claim 7, characterized in that Before determining whether the air conditioner meets a defrost control exit condition based on the indoor coil temperature and controlling the air conditioner to stop performing the defrost action when the defrost control exit condition is met, the controller is configured to: The indoor fan and the outdoor fan are controlled to be in a stopped state, the four-way valve is in a preset position, and the operating frequency of the compressor is controlled to be at a third preset operating frequency. Moreover, when the opening of the throttling element is adjustable, the throttling element is also controlled to be at a preset opening.

9. The air conditioner according to claim 8, characterized in that When the indoor fan and the outdoor fan are controlled to be in a stopped state, the four-way valve is in a preset position, the operating frequency of the compressor is controlled to be at a third preset operating frequency, and when the opening of the throttling element is adjustable, the throttling element is further controlled to be at a preset opening, the controller is configured to: detecting the indoor coil temperature once every fourth preset time interval, and if the newly detected indoor coil temperature is lower than the currently recorded lowest indoor coil temperature, updating the lowest indoor coil temperature; and if the newly detected indoor coil temperature is higher than the currently recorded lowest indoor coil temperature, maintaining the lowest indoor coil temperature unchanged until an indoor coil temperature lower than the currently recorded lowest indoor coil temperature no longer occurs during the execution of the defrosting action, and then using the currently recorded lowest indoor coil temperature as the lowest evaporating temperature; If the difference between the indoor coil temperature detected thereafter and the minimum evaporating temperature is greater than or equal to a preset temperature threshold, it is determined that the air conditioner meets the defrost control exit condition, and the air conditioner is controlled to stop performing the defrost action.

10. The air conditioner according to claim 1, wherein Before the air conditioner starts heating operation, the controller is configured to: determining whether the outdoor coil temperature sensor is faulty, and if so, reporting the fault, and determining whether the air conditioner meets a defrost control entry condition based on the exhaust temperature, and controlling the air conditioner to perform a defrost action when the defrost control entry condition is met; and, while performing the defrost action, determining whether the air conditioner meets a defrost control exit condition based on the indoor coil temperature, and controlling the air conditioner to stop performing the defrost action when the defrost control exit condition is met; If not, the step of reading the welding blockage fault information or obtaining the welding blockage fault information is performed.

11. 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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