Fault detection method and device of air conditioning system, storage medium and air conditioning system

Abstract

The application discloses a kind of fault detection method, device, storage medium and air conditioning system of air conditioning system.The method comprises: when monitoring triggered compressor abnormal early warning signal, it is judged whether the first cumulative trigger number of compressor abnormal early warning signal is less than first preset number;If less than first preset number, oil return control is carried out to air conditioning system, and based on the operation data of compressor after oil return control end control trigger operation for compressor abnormal early warning signal, and return to execute when monitoring triggered compressor abnormal early warning signal, it is judged whether the first cumulative trigger number of compressor abnormal early warning signal is less than first preset number operation;If greater than or equal to first preset number, generate the fault detection result indicating compressor abnormality.The method can realize accurate detection of compressor fault without replacing compressor or external detection tool, reduce fault detection cost, simplify detection process and improve detection efficiency.

Description

Technical Field

[0001] This application relates to the field of air conditioning system technology, and in particular to a fault detection method, device, storage medium and air conditioning system for an air conditioning system. Background Technology

[0002] As the core component of an air conditioner, the compressor's operating status directly determines the air conditioner's operational stability, energy efficiency, and lifespan. With increased usage time, the compressor inevitably experiences some natural wear and tear. Coupled with factors such as refrigerant deterioration, refrigeration oil loss, and impurities entering the piping, this leads to performance degradation and abnormal operation of the compressor itself and the entire air conditioner unit.

[0003] In the past, compressor fault detection was mainly carried out by replacing the compressor or using external testing fixtures. However, this detection technology requires the purchase of special equipment and professional personnel to disassemble / stop the machine for external connection, resulting in high fault detection costs and cumbersome testing procedures. Summary of the Invention

[0004] This application provides a method, apparatus, storage medium, and air conditioning system for fault detection in an air conditioning system. It enables reliable detection of compressor faults without replacing the compressor or using external testing fixtures, effectively reducing testing costs and simplifying the testing process. The above technical solution is as follows: In a first aspect, embodiments of this application provide a fault detection method for an air conditioning system, the air conditioning system including a compressor, the method comprising: When a compressor abnormality warning signal is detected, it is determined whether the first cumulative number of triggers of the compressor abnormality warning signal is less than a first preset number; If the first cumulative trigger count is less than the first preset count, then the air conditioning system is controlled to return oil, and the compressor's operating data after the return oil control is completed is used to control the triggering operation for the compressor abnormal warning signal, and the operation of determining whether the first cumulative trigger count of the compressor abnormal warning signal is less than the first preset count is returned to be executed when the triggered compressor abnormal warning signal is detected. If the first cumulative trigger count is greater than or equal to the first preset count, a fault detection result indicating abnormal compressor operation is generated.

[0005] In conjunction with the first aspect, in some possible implementations, the air conditioning system includes a refrigerant circulation loop, in which the compressor, a four-way valve, and a throttling device are provided; the oil return control of the air conditioning system includes: Determine the current operating mode of the air conditioning system and the target oil return frequency of the compressor; The compressor's operating frequency is adjusted according to the target oil return frequency, and the four-way valve and the throttling device are adjusted according to the working mode to allow the lubricating oil in the refrigerant circulation loop to flow back into the compressor.

[0006] In conjunction with the first aspect, in some possible implementations, the throttling device includes an indoor throttling device and an outdoor throttling device, and adjusting the four-way valve and the throttling device according to the operating mode includes: When the operating mode is indicated as cooling mode, increase the opening of the indoor throttling device; When the operating mode is indicated as heating mode, the four-way valve is switched to cooling connection mode, and the opening of the outdoor throttling device is increased.

[0007] In conjunction with the first aspect, in some possible implementations, determining the target oil return frequency of the compressor includes: Obtain the pressure and temperature values ​​detected for the refrigerant in the refrigerant circulation loop; Based on a preset thermodynamic model, the Froude constant is determined according to the detected pressure and temperature values; The target oil return frequency of the compressor is determined based on the Froude constant.

[0008] In conjunction with the first aspect, in some possible implementations, the triggering operation of the compressor abnormality warning signal controlled based on the compressor's operating data after the oil return control ends includes: When the oil return control ends and a first preset time has elapsed, the operating data of the compressor is acquired, including the actual input electrical parameters; The theoretical input electrical parameters of the compressor under the corresponding operating state are determined based on the operating data. The actual input electrical parameters and the theoretical input electrical parameters include current parameters or power parameters. Based on the theoretical input electrical parameters and the actual input electrical parameters, control the triggering operation for the compressor abnormality warning signal.

[0009] In conjunction with the first aspect, in some possible implementations, controlling the triggering operation for the compressor abnormality warning signal based on the theoretical input electrical parameters and the actual input electrical parameters includes: Calculate the deviation between the actual input electrical parameters and the theoretical input electrical parameters; Determine whether the ratio between the deviation value and the theoretical input electrical parameter is greater than a first preset value, or whether it is greater than a second preset value for a second preset period of time, wherein the first preset value is greater than the second preset value; If so, the compressor abnormality warning signal is triggered, and the first cumulative trigger count is updated.

[0010] In conjunction with the first aspect, in some possible implementations, after determining whether the ratio between the deviation value and the theoretical input electrical parameter is greater than a first preset value, or continuously greater than a second preset value for a second preset duration, the method further includes: If not, then the compressor normal operation signal is triggered, and the second cumulative trigger count of the compressor normal operation signal is updated; Determine whether the updated second cumulative trigger count is greater than the second preset count; When the second cumulative trigger count is greater than the second preset count, the first cumulative trigger count is reset to zero.

[0011] In conjunction with the first aspect, in some possible implementations, the method further includes, before triggering the compressor malfunction warning signal: Determine whether the air conditioning system is currently in a preset operating state; If the air conditioning system is not currently in the preset working state, then the operation of triggering the compressor abnormality warning signal is executed.

[0012] Secondly, embodiments of this application provide a fault detection device for an air conditioning system, the air conditioning system including a compressor, the device comprising: The judgment unit is used to determine whether the first cumulative number of times the compressor abnormality warning signal is triggered is less than a first preset number when a triggered compressor abnormality warning signal is detected. The control unit is configured to perform oil return control on the air conditioning system if the first cumulative trigger count is less than the first preset count, and control the triggering operation for the compressor abnormal warning signal based on the compressor's operating data after the oil return control ends, and return to execute the operation of determining whether the first cumulative trigger count of the compressor abnormal warning signal is less than the first preset count when the triggered compressor abnormal warning signal is detected. The generation unit is used to generate a fault detection result indicating that the compressor is operating abnormally if the first cumulative trigger count is greater than or equal to the first preset count.

[0013] Thirdly, embodiments of this application provide an air conditioning system, including: Memory, used to store executable program code; A processor is configured to call and run the executable program code from the memory, causing the air conditioning system to perform the method provided by the first aspect of the embodiments of this application or any possible implementation thereof.

[0014] Fourthly, embodiments of this application provide a computer storage medium storing a plurality of instructions, which are adapted to be loaded by a processor and executed by the method steps provided in the first aspect of the embodiments of this application or any possible implementation thereof.

[0015] Fifthly, embodiments of this application provide a computer program product, which includes computer program code. When the computer program code is run on a computer, the computer performs the method steps provided by the first aspect of the embodiments of this application or any possible implementation thereof.

[0016] The beneficial effects of the technical solutions provided in some embodiments of this application include at least the following: In one or more embodiments of this application, when a triggered compressor abnormality warning signal is detected, it is determined whether the first cumulative trigger count of the compressor abnormality warning signal is less than a first preset count. If the first cumulative trigger count is less than the first preset count, oil return control is performed on the air conditioning system, and the triggering operation for the compressor abnormality warning signal is controlled based on the compressor's operating data after the oil return control ends. The operation of determining whether the first cumulative trigger count of the compressor abnormality warning signal is less than the first preset count is then executed again. If the first cumulative trigger count is greater than or equal to the first preset count, a fault detection result indicating a compressor abnormality is generated. That is, by determining whether the first cumulative trigger count is less than the first preset count each time a compressor abnormality warning signal is triggered, a fault detection result indicating a compressor abnormality is generated. When a warning signal is received, on the one hand, the cumulative number of abnormalities is combined to filter out occasional and non-continuous abnormal interference; on the other hand, the oil return control is actively executed, and after the oil return control ends, a secondary verification of the actual input electrical parameters (such as input current or input power) is introduced to evaluate the effectiveness of the oil return control, indirectly verifying whether the previous abnormality was a recoverable abnormality caused by temporary lubricating oil retention or other substantial faults. Thus, the compressor fault can be accurately detected without replacing the compressor or external testing fixtures, which not only reduces the fault detection cost, simplifies the detection process, and improves the detection efficiency, but also minimizes unnecessary shutdowns caused by occasional fluctuations in operating conditions, significantly improving the operational continuity of the air conditioning system and the user experience.

[0017] The above description is merely an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the piping connection structure of an air conditioning system in cooling mode, provided as an exemplary embodiment of this application; Figure 2 A schematic diagram of the piping connection structure of an air conditioning system in heating mode, provided as an exemplary embodiment of this application; Figure 3 A flowchart illustrating a fault detection method for an air conditioning system provided as an exemplary embodiment of this application; Figure 4 A flowchart illustrating another fault detection method for an air conditioning system provided as an exemplary embodiment of this application; Figure 5 A schematic diagram of the structure of a fault detection device for an air conditioning system provided as an exemplary embodiment of this application; Figure 6 This is a schematic diagram of the structure of an air conditioning system provided for an exemplary embodiment of this application. Detailed Implementation

[0020] To make the features and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The terms "first," "second," "third," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0022] This application provides a fault detection method, device, air conditioning system, storage medium, and computer program product for an air conditioning system.

[0023] Please refer to Figure 1 and Figure 2 , Figure 1 A schematic diagram of the piping connection structure of an air conditioning system in cooling mode, provided as an exemplary embodiment of this application. Figure 2 This is a schematic diagram of the piping connection structure of an air conditioning system in heating mode, provided as an exemplary embodiment of this application. The air conditioning system 100 includes a refrigerant circulation loop and a water circulation loop. The refrigerant circulation loop uses refrigerant as the medium and achieves heat absorption and release through a phase change cycle of compression → condensation → throttling → evaporation. The water circulation loop uses water as the medium and serves as an intermediate carrier for heat transfer, connecting the refrigerant circulation loop to the terminal heat dissipation / heat absorption equipment. Through forced convection circulation of water, it delivers cooling / heat to the end user side, achieving indoor environmental regulation.

[0024] Specifically, the refrigerant circulation loop includes a compressor 101, a four-way valve 102 (including four ports: S, C, E, and D), a throttling device, a heat exchanger, and an exhaust system. The throttling device can be an electronic expansion valve, including an indoor throttling device 103 and an outdoor throttling device 104. The heat exchanger includes an indoor heat exchanger 105 (refrigerant side) and an outdoor heat exchanger 106. The indoor heat exchanger 105 can be a plate heat exchanger, with refrigerant flowing on one side and water flowing on the other. The outdoor heat exchanger 106 can be a finned heat exchanger. The exhaust system includes an indoor exhaust system 107 and an outdoor exhaust system 108. The components in the refrigerant circulation loop can form an indoor unit assembly AA and an outdoor unit assembly BB. The indoor heat exchanger 105, indoor throttling device 103, and indoor exhaust device 107 are located in the indoor unit assembly AA, while the outdoor heat exchanger 106, outdoor throttling device 104, outdoor exhaust device 108, four-way valve 102, gas-liquid separator 109, and compressor 101 are located in the outdoor unit assembly BB. The water circulation loop includes a user-side terminal device (not shown in the figure), the indoor heat exchanger 105 (water side), and a circulating water pump (not shown in the figure), all connected sequentially via piping.

[0025] Air conditioning system 100 includes two operating modes: cooling mode and heating mode. Please continue reading. Figure 1In cooling mode, the refrigerant circulation path in the refrigerant circulation loop is as follows: Compressor 101 → Four-way valve 102 (D port and C port connected) → Outdoor heat exchanger 106 (condenser) → Outdoor throttling device 104 → Liquid pipe → Indoor throttling device 103 → Indoor heat exchanger 105 (evaporator) → Gas pipe → Four-way valve 102 (E port connected to S port) → Gas-liquid separator 109 → Compressor 101. Specifically, the compressor 101 compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant, which is then introduced into the outdoor heat exchanger 106 via the D→C passage of the four-way valve 102. At this time, the outdoor heat exchanger 106 acts as a condenser. Under the forced heat exchange effect of the outdoor exhaust device 108, the high-temperature, high-pressure refrigerant releases heat to the outdoor air and condenses into a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows through the outdoor throttling device 104, where the valve opening is adjusted to achieve a first-stage throttling and pressure reduction, transforming it into a gas-liquid mixture. Refrigerant; the mixed refrigerant is transported to the indoor throttling device 103 via a liquid pipe, where it undergoes secondary throttling and pressure reduction to form a low-temperature, low-pressure gas-liquid mixed refrigerant. This mixture then enters the refrigerant side of the indoor heat exchanger 105. In the indoor heat exchanger 105, the low-temperature, low-pressure refrigerant absorbs heat from the water in the water circulation loop and evaporates into a low-temperature, low-pressure gaseous refrigerant. The gaseous refrigerant flows back to the gas-liquid separator 109 via a gas pipe and the E→S passage of the four-way valve 102. After separating the liquid refrigerant, it returns to the compressor 101, completing the refrigerant cycle. Simultaneously, in the water circulation loop, the cooled low-temperature water is transported to the user-side terminal device via a circulating water pump. After absorbing heat from the indoor air, it flows back to the indoor heat exchanger 105, achieving continuous cooling.

[0026] Please continue reading Figure 2In heating mode, the refrigerant circulation path in the refrigerant circulation loop is as follows: compressor 101 → four-way valve 102 (D port and E port connected) → gas pipe → indoor heat exchanger 105 (condenser, refrigerant side) → indoor throttling device 103 → liquid pipe → outdoor throttling device 104 → outdoor heat exchanger 106 (evaporator) → four-way valve 102 (C port and S port connected) → gas-liquid separator 109 → compressor 101. Specifically, the compressor 101 compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. After the four-way valve 102 switches the path, the refrigerant is directly introduced into the refrigerant side of the indoor heat exchanger 105 via the D→E path and gas pipe. The indoor heat exchanger 105 acts as a condenser, where the high-temperature, high-pressure refrigerant releases heat to the water in the water circulation loop, condensing into a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows through the indoor throttling device 103, where the valve opening is adjusted to achieve a first-stage throttling and pressure reduction, converting it into a gas-liquid mixed refrigerant. The refrigerant is transported via a liquid pipe to the outdoor throttling device 104, where it undergoes secondary throttling and pressure reduction to form a low-temperature, low-pressure gas-liquid mixture. This mixture then enters the outdoor heat exchanger 106, which acts as an evaporator. Under the forced convection heat exchange of the outdoor exhaust device 108, the low-temperature, low-pressure refrigerant absorbs heat from the outdoor environment and evaporates into a low-temperature, low-pressure gaseous refrigerant. The gaseous refrigerant flows back to the gas-liquid separator 109 via the C→S passage of the four-way valve 102, where it separates from the liquid refrigerant and returns to the compressor 101, completing the heating cycle. Simultaneously, in the water circulation loop, heated high-temperature water is pumped to the user-side terminal device, releasing heat into the indoor air before returning to the indoor heat exchanger 105, achieving continuous heating.

[0027] Based on the air conditioning system described in the above embodiments, this application provides a fault detection method for an air conditioning system. Please refer to... Figure 3 , Figure 3 This is a flowchart illustrating a fault detection method for an air conditioning system provided as an exemplary embodiment of this application. Specifically, the fault detection method for the air conditioning system includes the following steps S201-S203, wherein: S201. When a compressor abnormality warning signal is detected, determine whether the first cumulative number of triggers of the compressor abnormality warning signal is less than the first preset number. If yes, then execute the following step S202; if no, then execute the following step S203.

[0028] The compressor abnormality warning signal is a signal indicating that the compressor's operating status deviates from the normal threshold. It is typically determined by real-time compressor operating data to see if the compressor's operating status deviates from the normal threshold. When it does, the compressor abnormality warning signal is triggered. The first preset number of times can be set according to requirements, such as 2-3 times. This setting is to prevent false alarms and avoid misjudging a substantial compressor malfunction due to occasional, discontinuous abnormal interference (such as insufficient oil, low refrigerant, liquid return, etc.) causing temporary compressor malfunctions.

[0029] Optionally, within a single compressor start-up cycle, if a compressor abnormality warning signal is triggered for the first time, the first cumulative trigger count can be set to 1. When the compressor abnormality warning signal is triggered again in subsequent cycles, the cumulative count can be updated according to the set rules. For example, if it is a continuous trigger, the cumulative count increases by 1 for each trigger.

[0030] S202. Perform oil return control on the air conditioning system, and control the triggering operation for the compressor abnormal warning signal based on the compressor's operating data after the oil return control ends, and return to execute the above step S201.

[0031] It's important to explain that during compressor operation, lubricating oil is required to lubricate moving parts such as bearings and seals. However, this lubricating oil circulates with the refrigerant into the system piping (especially the evaporator, gas-liquid separator, and gas pipes). If it's not effectively returned to the compressor, a series of problems will occur, such as insufficient oil in the compressor: poor lubrication, increased wear, and in severe cases, compressor burnout; decreased system efficiency: oil adheres to the inner wall of heat exchangers (especially the evaporator), forming an oil film that severely affects heat exchange efficiency. Simultaneously, oil also adheres to the inner wall of the gas pipes, forming an oil film, reducing the inner pipe diameter, increasing pressure loss, and decreasing flow rate, thereby reducing heat exchange efficiency. Therefore, the fundamental goal of oil return control is to ensure that, under any operating condition, the oil discharged from the compressor returns to the compressor along with the refrigerant, maintaining the oil level in the crankcase (or oil reservoir) within a safe range.

[0032] The operating data includes key compressor operating parameters such as compressor speed, suction pressure, discharge pressure, input current, and input power. Under different operating modes (such as cooling mode and heating mode), the air conditioning system can employ different strategies for oil return control. These strategies include one or more combinations of operations, such as adjusting the compressor's operating frequency, adjusting the opening of throttling devices (indoor electronic expansion valve and outdoor electronic expansion valve), adjusting the reversing direction of the four-way valve, and adjusting the speed of the exhaust fan.

[0033] It should be noted that abnormal refrigerant circulation flow and operating conditions deviating from the design range can cause compressor lubricating oil to migrate (remain) with the refrigerant into the system pipeline, leading to compressor malfunctions due to temporary oil shortage or poor oil return. However, such malfunctions are often reversible, and the compressor can be restored to normal operation by actively implementing oil return control, rather than causing irreversible damage like mechanical wear. To address this, this embodiment filters out sporadic, non-continuous anomalies by combining the cumulative number of anomalies each time a compressor anomaly warning signal is triggered. This avoids directly diagnosing a compressor fault based on a single anomaly, improving the accuracy and reliability of fault detection results. Furthermore, it actively executes oil return control to attempt to resolve reversible anomalies caused by insufficient or poor oil return. After the oil return control ends, a secondary verification of the actual input electrical parameters (such as input current or input power) is introduced to evaluate the effectiveness of the oil return control. This indirectly verifies whether the previous anomaly was a recoverable anomaly caused by temporary lubricant retention or another substantial fault (such as internal mechanical wear of the compressor). This achieves reliable compressor fault detection, accurately distinguishes between reversible anomalies and irreversible substantial faults, and avoids misjudging temporary lubricant retention as a serious fault requiring shutdown for maintenance.

[0034] S203. Generate fault detection results indicating abnormal compressor operation.

[0035] When the first cumulative trigger count of the compressor abnormality warning signal is greater than or equal to the first preset count, it indicates that the abnormality persists after multiple oil return control operations. It can be determined that the oil return control strategy can no longer eliminate the abnormality. At this time, it can be considered that the compressor has an irreversible substantial fault, such as internal mechanical wear (e.g., bearing wear, piston jamming), impurity blockage (e.g., welding slag, copper shavings blocking the oil passage in the system). Such faults cannot be repaired by conventional restorative control strategies. Manual inspection or replacement of parts must be intervened to prevent the fault from further expanding and causing the compressor to be completely destroyed.

[0036] As described above, the fault detection method for the air conditioning system provided in this embodiment, when a triggered compressor abnormality warning signal is detected, determines whether the first cumulative trigger count of the compressor abnormality warning signal is less than a first preset count. If the first cumulative trigger count is less than the first preset count, oil return control is performed on the air conditioning system, and the triggering operation for the compressor abnormality warning signal is controlled based on the compressor's operating data after the oil return control ends. The method then returns to the operation of determining whether the first cumulative trigger count of the compressor abnormality warning signal is less than the first preset count when the triggered compressor abnormality warning signal is detected. If the first cumulative trigger count is greater than or equal to the first preset count, a fault detection result indicating compressor abnormality is generated. That is, by each... When a compressor malfunction warning signal is triggered, on the one hand, the cumulative number of malfunctions is used to filter out occasional, non-continuous abnormal interference; on the other hand, the oil return control is actively executed, and after the oil return control ends, a secondary verification of the actual input electrical parameters (such as input current or input power) is introduced to evaluate the effectiveness of the oil return control. This indirectly verifies whether the previous malfunction was a recoverable malfunction caused by temporary lubricating oil retention or other substantial faults. Therefore, accurate detection of compressor faults can be achieved without replacing the compressor or external testing equipment. This not only reduces fault detection costs, simplifies the detection process, and improves detection efficiency, but also minimizes unnecessary downtime caused by occasional fluctuations in operating conditions, significantly improving the operational continuity of the air conditioning system and the user experience.

[0037] Based on the fault detection method for the air conditioning system described in the above embodiments, please refer to Figure 4 , Figure 4 This is a flowchart illustrating another fault detection method for an air conditioning system provided as an exemplary embodiment of this application. Specifically, the air conditioning system includes a refrigerant circulation loop, in which a compressor, a four-way valve, and a throttling device are provided. The throttling device includes an indoor throttling device and an outdoor throttling device. The fault detection method for this air conditioning system includes the following steps S301-S307, wherein: S301. When a compressor abnormality warning signal is detected, determine whether the first cumulative number of triggers of the compressor abnormality warning signal is less than the first preset number; if yes, then execute the following steps S302-S306; if no, then execute the following step S307.

[0038] The steps S301 and S201 are the same as those described above, and will not be repeated here.

[0039] S302. Determine the current operating mode of the air conditioning system and determine the target oil return frequency of the compressor.

[0040] The operating modes of an air conditioning system include cooling and heating modes, and may also include dehumidification modes and other modes. Under different operating modes, the refrigerant circulation path, heat exchanger function (evaporator / condenser switching), and lubricating oil flow characteristics differ. Therefore, targeted oil return control is necessary, and the oil return frequency is one of the core parameters of oil return control. The target oil return frequency (usually a relatively high frequency) refers to the minimum operating frequency at which the compressor can effectively achieve lubricating oil return. Its core function is to ensure that the refrigerant circulation flow is large enough to carry the lubricating oil retained in the system pipeline back to the compressor crankcase. If the compressor operating frequency is lower than this value, the refrigerant flow is insufficient, and the lubricating oil easily remains in the pipeline, failing to achieve effective oil return.

[0041] In some embodiments, the step of "determining the target oil return frequency of the compressor" specifically includes: Obtain the pressure and temperature values ​​of the refrigerant in the refrigerant circulation loop; Based on a pre-defined thermodynamic model, the Froude constant is determined according to the detected pressure and temperature values. The target oil return frequency of the compressor is determined based on the Froude constant.

[0042] Pressure and temperature sensors can be installed at key locations in the refrigerant circulation loop (such as the compressor suction and discharge ports, and the outdoor heat exchanger inlet and outlet ports) to monitor the refrigerant pressure (P) and temperature (T) in real time. The density of the gaseous refrigerant can then be calculated by combining the monitoring data with a thermodynamic model. 0; The oil temperature in the compressor crankcase or oil circuit is detected by an installed oil temperature sensor, and the oil density is calculated by combining the temperature-density fitting formula of the lubricating oil. The refrigerant flow rate Q is calculated by taking the compressor speed and displacement, and then the gaseous refrigerant velocity is calculated by combining this with the pipe inner diameter D. 0 and oil flow rate 0; then, the Froude constant is calculated using the formula. r : r =( × 0+ × 0) / ( × × D ); Density of gaseous refrigerant, kg / m3; Oil density, kg / m3; 0, 0: Flow velocity (m / s) when gaseous refrigerant or oil flows freely in a pipe. D: Pipe inner diameter, in meters; : Gravitational acceleration, m / s².

[0043] Finally, the calculated r The value and the preset critical Froude constant r0 If a comparison is made, r < r0 Based on r = r0 The critical condition is determined by using the above formula to deduce the minimum gaseous refrigerant flow rate that satisfies the oil return requirement. 0, minimum oil flow rate 0; then calculate the minimum refrigerant flow rate Q based on the pipe cross-sectional area, and combine it with the compressor displacement and volumetric efficiency characteristics to calculate the corresponding minimum operating frequency of the compressor, which is used as the target oil return frequency of the compressor. Control the compressor to operate at this frequency to ensure that the lubricating oil returns smoothly.

[0044] S303. Adjust the compressor's operating frequency according to the target oil return frequency, and adjust the four-way valve and throttling device according to the working mode to allow the lubricating oil in the refrigerant circulation loop to flow back into the compressor.

[0045] In some embodiments, the above step "adjusting the four-way valve and throttling device according to the operating mode" specifically includes: When the operating mode is indicated as cooling mode, increase the opening of the indoor throttling device; When the operating mode is indicated as heating mode, the control four-way valve switches to cooling connection mode and the opening of the outdoor throttling device is increased.

[0046] In the air conditioning system, when in cooling mode, the indoor heat exchanger is the evaporator (prone to oil buildup), and the outdoor heat exchanger is the condenser. The refrigerant circulation path is roughly as follows: compressor → four-way valve (D-to-C) → outdoor heat exchanger (condenser) → outdoor throttling device (electronic expansion valve) → liquid line → indoor throttling device → indoor heat exchanger (evaporator) → gas line → four-way valve (E-to-S) → gas-liquid separator → compressor. When oil return control is implemented, the oil return circulation path is kept consistent with the refrigerant circulation path. Simultaneously, the opening of the indoor throttling device is significantly increased to allow more liquid refrigerant to flow into the indoor heat exchanger (evaporator), resulting in a significant increase in evaporation pressure. This causes unevaporated refrigerant and accumulated oil in the evaporator, as well as oil retained in the gas line and gas-liquid separator, to be flushed away by a high-speed, large-volume flow of refrigerant. At this point, the oil and liquid refrigerant have good miscibility, and the oil can return to the compressor along with the refrigerant.

[0047] Specifically, during oil return control in normal cooling mode, the operating states of various components in the air conditioning system (mainly the refrigerant circulation loop) are as follows: the compressor typically operates at high frequency (target oil return frequency) or full speed to generate a larger refrigerant flow and provide stronger oil return purging power; the outdoor exhaust fan operates at high frequency to ensure refrigerant effectiveness, ensuring sufficient refrigerant in the refrigerant circulation loop to flush the pipes; the indoor exhaust fan maintains a medium-low speed to maintain a certain airflow, helping the refrigerant in the evaporator absorb heat and vaporize; the four-way valve maintains the refrigeration connection mode to maintain the original refrigerant circulation path, ensuring that oil returns from the indoor heat exchanger (evaporator) to the compressor; the indoor throttling device is significantly opened (e.g., the opening is adjusted to 80%-100%) to reduce throttling, increase evaporation pressure, increase the refrigerant flow entering the evaporator, and achieve the "oil flushing" effect.

[0048] When the air conditioning system is in heating mode, the indoor heat exchanger is the condenser and the outdoor heat exchanger is the evaporator. The refrigerant circulation path is roughly as follows: compressor → four-way valve (D to E) → gas pipe → indoor heat exchanger (condenser) → indoor throttling device → liquid pipe → outdoor throttling device → outdoor heat exchanger (evaporator) → four-way valve (C to S) → compressor. Oil tends to accumulate in the gas pipe and in the outdoor evaporator, which has a lower temperature and a longer pipe. When oil return control is performed, the oil return circulation path and the refrigerant circulation path are completely opposite. This can be achieved by switching the conduction path of the four-way valve and adjusting the opening of the outdoor throttling device. Specifically, the four-way valve is switched from the heating connection mode (D to E, C to S) in the original heating mode to the cooling connection mode (D to C, E to S), and the opening of the outdoor throttling device is increased, so that the system briefly enters the "cooling mode". The outdoor heat exchanger becomes a condenser, and the high-temperature and high-pressure refrigerant gas enters the cold outdoor heat exchanger. The high-speed and large amount of liquid refrigerant flushes the oil accumulated in the heat exchanger. At the same time, the indoor heat exchanger becomes an evaporator. However, the indoor exhaust device can be stopped and then turned on at this time to prevent cold air from blowing out and causing discomfort to the user. The unevaporated liquid refrigerant enters the gas pipe and gas-liquid separator, and finally carries the oil accumulated in the pipeline back to the compressor.

[0049] Specifically, during oil return control in normal heating mode, the operating states of various components in the air conditioning system (mainly the refrigerant circulation loop) are as follows: the compressor typically runs at high frequency (target oil return frequency) or full speed to generate greater refrigerant flow and heat to flush out the oil accumulation in the outdoor unit; the outdoor exhaust fan is turned on or off as needed (e.g., based on evaporation temperature or defrosting requirements); the indoor exhaust fan is turned off briefly before being turned on again to prevent cold air from blowing into the room when the system switches to "cooling," affecting comfort; the four-way valve switches to cooling connection mode to change the refrigerant flow direction, allowing high-temperature exhaust to directly reach the oil-accumulated outdoor heat exchanger; the indoor throttling device is opened significantly (e.g., adjusted to 80%-100%) to increase the pressure and temperature of the original outdoor evaporator (now condenser), accelerating the flushing of the oil film and oil return in the heat exchange tubes; the indoor throttling device uses a fixed opening or is adjusted according to the target subcooling degree.

[0050] S304. When the oil return control ends and the first preset time has elapsed, acquire the compressor's operating data, which includes the actual input electrical parameters.

[0051] The duration of the oil return control can be set according to requirements, such as 8 minutes. After the set duration is reached, the oil return control ends, and all components return to their original operating states (e.g., the compressor operates at a variable frequency according to load demand, rather than maintaining a high target oil return frequency). Considering that the pressure, temperature, and oil level in the system are fluctuating drastically immediately after the high-frequency oil return ends, to prevent the collected data from being inaccurate in reflecting the compressor's true operating state due to slow temperature response, which could lead to misjudgments during re-execution, a first preset duration (e.g., 10 minutes) can be waited for the refrigerant circulation and oil circuit distribution to reach dynamic equilibrium again before re-collecting compressor operating data for fault detection.

[0052] Operating data includes key operating parameters of the compressor, such as compressor speed, suction pressure, discharge pressure, input current, and input power. The above-mentioned actual input electrical parameters are the current parameters or power parameters.

[0053] S305. Based on the operating data, determine the theoretical input electrical parameters of the compressor under the corresponding operating conditions. The actual input electrical parameters and theoretical input electrical parameters include current parameters or power parameters.

[0054] This can be achieved using methods such as the compressor ten-coefficient method or the CC method. Based on the compressor's operating data (e.g., compressor speed, suction pressure, discharge pressure), the theoretical input electrical parameters (current or power parameters) of the compressor under corresponding operating conditions can be calculated. For example, with the compressor ten-coefficient method, the compressor speed, suction pressure, and discharge pressure can be input to calculate the theoretical input power of the compressor under corresponding operating conditions. With the CC method, the compressor's rated parameters can be used as a benchmark, combined with an operating condition correction factor K, to estimate the theoretical input power. Then, the collected actual input electrical parameters are compared with the calculated theoretical input electrical parameters to reassess whether the compressor's operation is abnormal.

[0055] S306. Based on the theoretical input electrical parameters and the actual input electrical parameters, control the triggering operation for compressor abnormality warning signals.

[0056] In some embodiments, step S306 specifically includes: Calculate the deviation between the actual input electrical parameters and the theoretical input electrical parameters; Determine whether the ratio between the deviation value and the theoretical input electrical parameter is greater than a first preset value, or whether it is greater than a second preset value for a continuous period of time, wherein the first preset value is greater than the second preset value; If so, the compressor abnormality warning signal will be triggered, and the first cumulative trigger count will be updated.

[0057] The first preset value, second preset value, and second preset duration are manually set. For example, the first preset value is 0.5, the second preset value is 0.3, and the second preset duration is 5 minutes. For instance, taking a scenario where both the actual and theoretical input electrical parameters are power parameters, the deviation value Deta_W between the actual input power w and the theoretical input power w' can be calculated first. If the deviation value Deta_W is greater than 0.5w' (i.e., the ratio between the deviation value Deta_W and the theoretical input power w' is greater than 0.5), or if it remains greater than 0.3w' for the second preset duration, the compressor's operating state can be determined to be abnormal, triggering a compressor abnormality warning signal and updating the first cumulative trigger count of this signal accordingly, for example, by incrementing it by 1. Conversely, if the deviation value does not meet any of the above conditions, the current fluctuation is considered to be a normal operating condition disturbance or sensor noise, and the compressor abnormality warning signal is not triggered; the system continues to maintain a normal monitoring cycle.

[0058] Furthermore, when the deviation value does not meet any of the above conditions and the compressor abnormality warning signal is not triggered, a compressor normal operation signal can be triggered to indicate that the compressor is operating normally at the current moment. That is, after the above step of "determining whether the ratio between the deviation value and the theoretical input electrical parameter is greater than the first preset value, or continuously greater than the second preset value within the second preset time period", the fault detection method of the air conditioning system may further include: If not, the compressor normal operation signal is triggered, and the second cumulative trigger count of the compressor normal operation signal is updated; Determine whether the updated second cumulative trigger count is greater than the second preset count; When the second cumulative trigger count is greater than the second preset count, the first cumulative trigger count is reset to zero.

[0059] The second preset number of triggers can be an empirical value set based on the system sampling period and fault recovery confirmation time (e.g., set to 5 times, corresponding to approximately 5-10 minutes of continuous normal operation time). The compressor's normal operation signal needs to be triggered continuously for the second cumulative trigger count to accumulate. Once a compressor abnormal operation signal is triggered during the accumulation period, the second cumulative trigger count must be reset to zero. Simultaneously, when the second cumulative trigger count reaches the second preset number, it indicates that the compressor has been running stably for a period of time. At this point, the trigger count for the compressor abnormal warning signal (the first cumulative trigger count) can be reset to zero.

[0060] In this embodiment, by introducing a mechanism to reset the trigger counts of the compressor's normal operation signal and compressor abnormal warning signal, on the one hand, "continuous verification" of the compressor's fault recovery status is achieved. This avoids directly resetting the accumulated abnormal count (i.e., the aforementioned first accumulated trigger count) due to a brief period of normal operation caused by a single fluctuation in operating conditions. It ensures that the fault is only determined to be completely recovered after the compressor has been running continuously and stably for a period of time, thus improving the reliability of fault recovery judgment. On the other hand, by resetting the first accumulated trigger count after the second accumulated trigger count reaches a threshold, the abnormal diagnostic status of the compressor can be reset in a timely manner, avoiding interference from historical accumulated abnormal counts on the diagnosis of subsequent normal operation phases, and ensuring the real-time performance and accuracy of fault detection. At the same time, this design further optimizes the closed-loop nature of the diagnostic process, identifying persistent faults through the accumulated abnormal count and confirming fault recovery through the accumulated normal count, making the fault detection of the air conditioning system more intelligent and fault-tolerant, effectively reducing misjudgments and unnecessary downtime caused by occasional fluctuations in operating conditions.

[0061] In addition, the fault detection method for this air conditioning system before triggering the compressor malfunction warning signal also includes: Determine whether the air conditioning system is currently in a preset operating state; If the air conditioning system is not currently in the preset working state, then the operation of triggering the compressor abnormality warning signal will be executed.

[0062] Preset operating states refer to special operating conditions that the air conditioning system enters due to its own operational needs, causing the compressor's operating parameters to temporarily deviate from normal thresholds. These operating conditions are part of the normal process designed for the system and are not compressor malfunctions. Therefore, they need to be eliminated during fault detection to avoid misjudgment. For example, preset operating states include, but are not limited to, normal oil return control state, defrosting state, and start-up state. When the compressor's operating data determines that the compressor's operating state is abnormal, and the compressor is not currently in a special operating condition, a compressor abnormality warning signal can be triggered.

[0063] S307. Generate fault detection results indicating abnormal compressor operation.

[0064] The steps S307 and S203 are the same as those described above, and will not be repeated here.

[0065] Based on the method described in the above embodiments, this application also provides a fault detection device for an air conditioning system, used to perform the steps in the fault detection method for the air conditioning system described above. Please refer to... Figure 5 , Figure 5This is a schematic diagram of the structure of a fault detection device for an air conditioning system provided as an exemplary embodiment of this application. Specifically, the air conditioning system includes a compressor, and the fault detection device 500 for the air conditioning system includes a judgment unit 401, a control unit 402, and a generation unit 403, wherein: The judgment unit 401 is used to determine whether the first cumulative number of triggers of the compressor abnormality warning signal is less than the first preset number when a triggered compressor abnormality warning signal is detected. The control unit 402 is configured to perform oil return control on the air conditioning system if the first cumulative trigger count is less than the first preset count, and control the triggering operation for the compressor abnormal warning signal based on the compressor's operating data after the oil return control ends, and return to execute the operation of determining whether the first cumulative trigger count of the compressor abnormal warning signal is less than the first preset count when the triggered compressor abnormal warning signal is detected. The generation unit 403 is used to generate a fault detection result indicating that the compressor is operating abnormally if the first cumulative trigger count is greater than or equal to the first preset count.

[0066] In some embodiments, the air conditioning system includes a refrigerant circulation loop, in which the compressor, a four-way valve, and a throttling device are disposed, and the control unit 402 is specifically used for: Determine the current operating mode of the air conditioning system and the target oil return frequency of the compressor; Adjust the compressor's operating frequency according to the target oil return frequency, and adjust the four-way valve and the throttling device according to the working mode so that the lubricating oil in the pipeline of the refrigerant circulation loop flows back to the compressor.

[0067] In some embodiments, the throttling device includes an indoor throttling device and an outdoor throttling device, and the control unit 402 is specifically configured to: When the operating mode is indicated as cooling mode, increase the opening of the indoor throttling device. When the operating mode is indicated as heating mode, the four-way valve is switched to cooling connection mode, and the opening of the outdoor throttling device is increased.

[0068] In some embodiments, the control unit 402 is specifically used for: Obtain the pressure and temperature values ​​of the refrigerant in the refrigerant circulation loop; Based on a pre-defined thermodynamic model, the Froude constant is determined according to the detected pressure and temperature values. The target oil return frequency of the compressor is determined based on the Froude constant.

[0069] In some embodiments, the control unit 402 is specifically used for: When the oil return control ends and the first preset time has elapsed, the compressor's operating data is acquired, including the actual input electrical parameters. Based on the operating data, the theoretical input electrical parameters of the compressor under the corresponding operating conditions are determined. The actual input electrical parameters and the theoretical input electrical parameters include current parameters or power parameters. Based on the theoretical input electrical parameters and the actual input electrical parameters, the system controls the triggering operation for the compressor's abnormal warning signal.

[0070] In some embodiments, the control unit 402 is specifically used for: Calculate the deviation between the actual input electrical parameter and the theoretical input electrical parameter; Determine whether the ratio between the deviation value and the theoretical input electrical parameter is greater than a first preset value, or whether it is greater than a second preset value for a continuous period of time, wherein the first preset value is greater than the second preset value; If so, the compressor abnormality warning signal will be triggered, and the first cumulative trigger count will be updated.

[0071] In some embodiments, after determining whether the ratio between the deviation value and the theoretical input electrical parameter is greater than a first preset value, or remains greater than the second preset value for a second preset duration, the control unit 402 is further configured to: If not, the compressor normal operation signal is triggered, and the second cumulative trigger count of the compressor normal operation signal is updated; Determine whether the updated second cumulative trigger count is greater than the second preset count; When the second cumulative trigger count is greater than the second preset count, the first cumulative trigger count is reset to zero.

[0072] In some embodiments, before triggering the compressor malfunction warning signal, the control unit 402 is further configured to: Determine whether the air conditioning system is currently in a preset operating state; If the air conditioning system is not currently in the preset working state, then the operation of triggering the compressor abnormality warning signal will be executed.

[0073] It should be noted that the division of the unit modules in the above-described air conditioning system fault detection device 400 is only for illustrative purposes. In other embodiments, the air conditioning system fault detection device 400 can be divided into different unit modules as needed to complete all or part of the functions of the air conditioning system fault detection device 400. The implementation of each unit module in the air conditioning system fault detection device 400 provided in the embodiments of this specification can be in the form of a computer program. This computer program can run on a terminal or server. The program modules constituted by this computer program can be stored in the memory of the terminal or server. When the computer program is executed by a processor, it implements all or part of the steps of the air conditioning system fault detection method described in the embodiments of this specification.

[0074] As described above, the fault detection device 400 for the air conditioning system provided in this embodiment, when detecting a triggered compressor abnormality warning signal, determines through the judgment unit 401 whether the first cumulative trigger count of the compressor abnormality warning signal is less than a first preset count; if the first cumulative trigger count is less than the first preset count, the control unit 402 performs oil return control on the air conditioning system, and controls the triggering operation for the compressor abnormality warning signal based on the compressor's operating data after the oil return control ends, and returns to execute the operation of determining whether the first cumulative trigger count of the compressor abnormality warning signal is less than the first preset count when the triggered compressor abnormality warning signal is detected; if the first cumulative trigger count is greater than or equal to the first preset count, the generation unit 403 generates a fault detection indicator indicating compressor abnormality. The test results show that, each time a compressor abnormality warning signal is triggered, on the one hand, the cumulative number of abnormalities is used to filter out occasional, non-continuous abnormal interference; on the other hand, the oil return control is actively executed, and after the oil return control ends, a secondary verification of the actual input electrical parameters (such as input current or input power) is introduced to evaluate the effectiveness of the oil return control. This indirectly verifies whether the previous abnormality was a recoverable abnormality caused by temporary lubricating oil retention or other substantial faults. Therefore, accurate detection of compressor faults can be achieved without replacing the compressor or external testing equipment. This not only reduces fault detection costs, simplifies the detection process, and improves detection efficiency, but also minimizes unnecessary downtime caused by occasional fluctuations in operating conditions, significantly improving the operational continuity of the air conditioning system and the user experience.

[0075] Please see below. Figure 6 This document provides a schematic diagram of an air conditioning system as an embodiment of this application. Figure 6 As shown, the air conditioning system 600 may include: at least one processor 610, at least one network interface 620, user interface 630, memory 640, and at least one communication bus 650.

[0076] The communication bus 650 is used to enable communication between these components.

[0077] The network interface 620 may include, but is not limited to, a low-power Bluetooth module, a near field communication (NFC) module, a wireless Fidelity (Wi-Fi) module, etc.

[0078] The user interface 630 may include a display screen and a camera. Optionally, the user interface 630 may also include a standard wired interface and a wireless interface.

[0079] The processor 610 may include one or more processing cores. The processor 610 connects to various parts of the air conditioning system 600 using various interfaces and lines, and performs various functions and processes data of the air conditioning system 600 by running or executing instructions, programs, code sets, or instruction sets stored in the memory 640, and by calling data stored in the memory 640. Optionally, the processor 610 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 610 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content to be displayed on the screen; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the processor 610 and may be implemented as a separate chip.

[0080] The memory 640 may include random access memory (RAM) or read-only memory (ROM). Optionally, the memory 640 may include a non-transitory computer-readable storage medium. The memory 640 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 640 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for at least one function (such as voiceprint direction recognition, voice separation, personalized data storage, etc.), and instructions for implementing the various method embodiments described above. The data storage area may store data involved in the various method embodiments described above. Optionally, the memory 640 may also be at least one storage device located remotely from the aforementioned processor 610. Figure 6 As shown, the memory 640, which serves as a computer storage medium, may include an operating system, a network communication module, a user interface module, and program instructions.

[0081] exist Figure 6 In the air conditioning system 600 shown, the user interface 630 is mainly used to provide an input interface for the user and to obtain user input data; while the processor 610 can be used to call program instructions stored in the memory 640. The air conditioning system 600 can be, but is not limited to, for example... Figure 5 The fault detection device 500 for the air conditioning system shown herein, and the fault detection method for the air conditioning system described in any of the above embodiments.

[0082] This application also provides a computer storage medium storing instructions that, when executed on a computer or processor, cause the computer or processor to perform one or more steps of any of the above methods. If the constituent modules of the above-described air conditioning system fault detection device are implemented as software functional units and sold or used as independent products, they can be stored in this storage medium.

[0083] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. This computer program product includes one or more computer instructions. When these computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in or transmitted through a computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., Digital Versatile Discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0084] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks. Unless otherwise specified, the technical features of this embodiment and its implementation can be combined arbitrarily.

[0085] The above embodiments are merely descriptions of preferred embodiments of this application and are not intended to limit the scope of this application. Any modifications and improvements made by those skilled in the art to the technical solutions of this application without departing from the spirit of this application should fall within the protection scope defined by the claims of this application.

Claims

1. A fault detection method for an air conditioning system, characterized in that, The air conditioning system includes a compressor, and the method includes: When a compressor abnormality warning signal is detected, it is determined whether the first cumulative number of triggers of the compressor abnormality warning signal is less than a first preset number; If the first cumulative trigger count is less than the first preset count, then the air conditioning system is controlled to return oil, and the compressor's operating data after the return oil control is completed is used to control the triggering operation for the compressor abnormal warning signal, and the operation of determining whether the first cumulative trigger count of the compressor abnormal warning signal is less than the first preset count is returned to be executed when the triggered compressor abnormal warning signal is detected. If the first cumulative trigger count is greater than or equal to the first preset count, a fault detection result indicating abnormal compressor operation is generated.

2. The method according to claim 1, characterized in that, The air conditioning system includes a refrigerant circulation loop, in which the compressor, a four-way valve, and a throttling device are installed. The oil return control of the air conditioning system includes: Determine the current operating mode of the air conditioning system and the target oil return frequency of the compressor; The compressor's operating frequency is adjusted according to the target oil return frequency, and the four-way valve and the throttling device are adjusted according to the working mode to allow the lubricating oil in the refrigerant circulation loop to flow back into the compressor.

3. The method according to claim 2, characterized in that, The throttling device includes an indoor throttling device and an outdoor throttling device. Adjusting the four-way valve and the throttling device according to the operating mode includes: When the operating mode is indicated as cooling mode, increase the opening of the indoor throttling device; When the operating mode is indicated as heating mode, the four-way valve is switched to cooling connection mode, and the opening of the outdoor throttling device is increased.

4. The method according to claim 2, characterized in that, Determining the target oil return frequency of the compressor includes: Obtain the pressure and temperature values ​​detected for the refrigerant in the refrigerant circulation loop; Based on a preset thermodynamic model, the Froude constant is determined according to the detected pressure and temperature values; The target oil return frequency of the compressor is determined based on the Froude constant.

5. The method according to any one of claims 1-4, characterized in that, The operation of triggering the compressor abnormality warning signal based on the compressor's operating data control after the oil return control is completed includes: When the oil return control ends and a first preset time has elapsed, the operating data of the compressor is acquired, including the actual input electrical parameters; The theoretical input electrical parameters of the compressor under the corresponding operating state are determined based on the operating data. The actual input electrical parameters and the theoretical input electrical parameters include current parameters or power parameters. Based on the theoretical input electrical parameters and the actual input electrical parameters, the triggering operation for the compressor abnormality warning signal is controlled.

6. The method according to claim 5, characterized in that, The step of controlling the triggering operation for the compressor abnormality warning signal based on the theoretical input electrical parameters and the actual input electrical parameters includes: Calculate the deviation between the actual input electrical parameters and the theoretical input electrical parameters; Determine whether the ratio between the deviation value and the theoretical input electrical parameter is greater than a first preset value, or whether it is greater than a second preset value for a second preset period of time, wherein the first preset value is greater than the second preset value; If so, the compressor abnormality warning signal is triggered, and the first cumulative trigger count is updated.

7. The method according to claim 6, characterized in that, After determining whether the ratio between the deviation value and the theoretical input electrical parameter is greater than a first preset value, or remains greater than the second preset value for a second preset duration, the method further includes: If not, then the compressor normal operation signal is triggered, and the second cumulative trigger count of the compressor normal operation signal is updated; Determine whether the updated second cumulative trigger count is greater than the second preset count; When the second cumulative trigger count is greater than the second preset count, the first cumulative trigger count is reset to zero.

8. The method according to claim 6, characterized in that, Before triggering the compressor malfunction warning signal, the method further includes: Determine whether the air conditioning system is currently in a preset operating state; If the air conditioning system is not currently in the preset working state, then the operation of triggering the compressor abnormality warning signal is executed.

9. A fault detection device for an air conditioning system, characterized in that, The air conditioning system includes a compressor, and the device includes: The judgment unit is used to determine whether the first cumulative number of times the compressor abnormality warning signal is triggered is less than a first preset number when a triggered compressor abnormality warning signal is detected. The control unit is configured to perform oil return control on the air conditioning system if the first cumulative trigger count is less than the first preset count, and control the triggering operation for the compressor abnormal warning signal based on the compressor's operating data after the oil return control ends, and return to execute the operation of determining whether the first cumulative trigger count of the compressor abnormal warning signal is less than the first preset count when the triggered compressor abnormal warning signal is detected. The generation unit is used to generate a fault detection result indicating that the compressor is operating abnormally if the first cumulative trigger count is greater than or equal to the first preset count.

10. An air conditioning system, characterized in that, include: Memory, used to store executable program code; A processor is configured to call and run the executable program code from the memory, causing the air conditioning system to perform the fault detection method for the air conditioning system as described in any one of claims 1 to 8.

11. A computer storage medium, characterized in that, The computer storage medium stores multiple instructions, which are adapted to be loaded by a processor and executed as described in any one of claims 1-8.

12. A computer program product, characterized in that, The computer program product includes computer program code, which, when run on a computer, causes the computer to perform the fault detection method for the air conditioning system as described in any one of claims 1 to 8.

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