Air conditioner and shut-off valve fault detection method thereof

Abstract

The present application proposes an air conditioner and a method for detecting a shutoff valve fault thereof. The air conditioner includes: an indoor heat exchanger; an outdoor unit; a shutoff valve and a controller. The controller is used to determine whether the shutoff valve detection condition is met when the air conditioner is powered on for the first time and the heating operation is started, and count the shutoff valve faults when the coil temperature and the initial coil temperature meet the preset conditions; after a fourth preset time, determine whether the shutoff valve detection condition is met again, and count the shutoff valve faults when the shutoff valve detection condition is met, until the shutoff valve fault count reaches a preset number of times, determining that the shutoff valve has failed. The present application avoids misjudgment of a fault caused by compressor shutdown due to usage scenarios such as indoor motor stall or ultra-low power supply voltage, and avoids misjudgment of a shutoff valve failure due to outdoor ambient temperature, thereby improving the accuracy of the shutoff valve failure while reducing user complaints caused by misjudgment.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioning, and in particular to an air conditioner and a method for detecting a stop valve failure thereof. Background Art

[0002] A split-type air conditioner consists of an indoor unit, an outdoor unit, and connecting pipes, which are connected as a whole during installation. In addition, there are situations where the air conditioner installation and the whole-machine debugging are separated. If the stop valve is not opened after the air conditioner is installed, and the debugging personnel do not check whether the stop valve is open when debugging the whole machine, if the air conditioner is operated for heating when the stop valve is not opened, it is easy for the compressor to be damaged in a short period of time, or even the pipeline to burst, thereby endangering personal safety.

[0003] At present, the protection method for the stop valve is usually to detect whether the stop valve meets the preset conditions. For example, in the stop valve protection control method of patent document CN113587359A, it is disclosed that after the air conditioner is turned on and running for a certain period of time, a first preset condition for judging the stop valve is met. If the condition is met, the air conditioner is controlled to stop for a certain period of time and then turned on again. After running for a period of time, it is determined whether the second preset condition for determining that the valve is abnormal is met. If the condition is met again, it is determined that the valve is shut off abnormally and the corresponding stop valve protection is triggered; and when judging whether the stop valve has a non-opening fault, the outdoor ambient temperature and the coil temperature of the outdoor heat exchanger at the time the air conditioner is turned on are detected, so as to judge whether the stop valve has a non-opening fault based on the outdoor ambient temperature and the coil temperature of the outdoor heat exchanger.

[0004] However, when the stop valve fault is detected by adopting the above method, even if the stop valve is opened, it is easy to cause an overcurrent fault due to problems such as indoor motor jam, indoor motor shutdown or ultra-low user power supply voltage. In addition, when judging the stop valve failure not being opened by using the outdoor ambient temperature and the coil temperature of the outdoor heat exchanger, the outdoor ambient temperature is easily affected by the solar radiation temperature, which can easily lead to misjudgment or omission of the stop valve failure. After a misjudgment occurs, the air conditioner is actively stopped and locked, which causes user complaints. Summary of the Invention

[0005] This application aims to solve at least one of the technical problems existing in the prior art.

[0006] To this end, one objective of the present application is to provide an air conditioner that avoids misjudgment of compressor shutdowns caused by scenarios such as indoor motor stall or extremely low power supply voltage, and misjudgment of shut-off valve failures caused by outdoor ambient temperature, thereby improving the accuracy of shut-off valve failure detection and reducing user complaints caused by misjudgment.

[0007] Therefore, the second object of the present application is to provide a method for detecting a stop valve failure of an air conditioner.

[0008] In order to achieve the above-mentioned purpose, an embodiment of the first aspect of the present application proposes an air conditioner, which includes: a refrigerant circulation loop, so that the refrigerant circulates in the circulation loop through a compressor, a condenser, an expansion valve and an evaporator; an outdoor heat exchanger and an indoor heat exchanger, wherein one works for the condenser and the other works for the evaporator; an indoor coil temperature sensor for detecting the indoor coil temperature; an outdoor unit, the outdoor unit including: an outdoor casing; a compressor, arranged in the outdoor casing, for compressing low-temperature and low-pressure refrigerant gas into high-temperature and high-pressure refrigerant gas and discharging it to the condenser; a stop valve, the stop valve being arranged in the outdoor unit casing, for opening or closing the refrigerant circulation loop; a controller for obtaining the indoor initial coil temperature at the start-up moment of the compressor when the power is first turned on and the air conditioner is turned on for heating. , and judge whether the stop valve detection condition is met, wherein the stop valve detection condition includes: detecting that the operating parameter of the compressor is greater than the first preset parameter threshold within a first preset time, and detecting that the overcurrent protection shutdown action of the compressor is triggered within a second preset time and a third preset time interval, and determining the indoor coil temperature and the indoor initial coil temperature at the instant before the overcurrent protection shutdown, and counting the stop valve faults when the indoor coil temperature and the indoor initial coil temperature meet the preset conditions; after the first low temperature preset time, judging whether the stop valve detection condition is met again, and counting the stop valve faults when the stop valve detection condition is met, until the stop valve fault count reaches a preset number, determining that the stop valve fault is present, wherein the third preset time is greater than the second preset time.

[0009] According to the air conditioner of some embodiments of the present application, when the air conditioner is powered on for the first time and the heating operation is started, the indoor initial coil temperature at the time of compressor startup is obtained, and the operating parameters of the compressor, the time when the compressor is shut down for overcurrent protection, the coil temperature of the indoor heat exchanger before shutdown, and the initial coil temperature are detected to determine whether the stop valve detection conditions are met, and when the stop valve detection conditions are met, the stop valve faults are counted until the fault count reaches a preset number of times, and it is determined that the stop valve has a non-opening fault. Since when the stop valve is not opened, the operating parameters of the compressor, the time when the compressor is shut down for overcurrent protection, and the coil temperature of the indoor heat exchanger before shutdown, and the initial coil temperature all meet the stop valve detection conditions, and when the indoor AC motor is blocked or shut down due to a fault, although the compressor overcurrent protection shutdown action and the compressor operating parameters are too large will occur, the time when the overcurrent protection shutdown occurs and the compressor operating parameters are compared with when the stop valve is not opened. There is an obvious difference, that is, the time of overcurrent protection shutdown is longer, and the operating parameters of the compressor are smaller; and, when the AC power supply voltage is ultra-low, there is a small probability that overcurrent protection shutdown will occur, but the shutdown time is significantly different from when the stop valve is not opened, and the operating parameters of the compressor are smaller than when the stop valve is not opened, thereby avoiding misjudgment of faults caused by compressor shutdown due to usage scenarios such as indoor motor stall or ultra-low power supply voltage, and using indoor coil temperature and indoor initial coil temperature as detection conditions for the stop valve not opening fault, without detecting the outdoor ambient temperature to detect the stop valve not opening fault, which can effectively avoid the situation when detecting whether the stop valve has a not opening fault based on the outdoor ambient temperature, due to the solar radiation causing the detected outdoor ambient temperature to be too high, resulting in misjudgment of the stop valve not opening fault, thereby improving the accuracy of the stop valve not opening fault while reducing user complaints caused by misjudgment.

[0010] In order to achieve the above-mentioned purpose, an embodiment of the second aspect of the present application proposes a stop valve fault detection method for an air conditioner, which detection method includes: when the power is turned on for the first time and the air conditioner starts heating operation, obtaining the indoor initial coil temperature at the time of compressor startup, and judging whether the stop valve detection condition is met, wherein the stop valve detection condition includes: within a first preset time, detecting that the operating parameter of the compressor is greater than the first preset parameter threshold, and detecting that the overcurrent protection shutdown action of the compressor is triggered within a second preset time and a third preset time interval, and determining the indoor coil temperature and the indoor initial coil temperature at the instant before the overcurrent protection shutdown, and counting the stop valve faults when the indoor coil temperature and the indoor initial coil temperature meet the preset conditions; after the first low temperature preset time, judging again whether the stop valve detection condition is met, and when the stop valve detection condition is met, counting the stop valve faults until the stop valve fault count reaches a preset number, determining the stop valve fault, wherein the third preset time is greater than the second preset time.

[0011] According to the shut-off valve fault detection method for air conditioners in some embodiments of the present application, when the air conditioner is powered on for the first time and the heating operation is started, the indoor initial coil temperature at the time of compressor startup is obtained, and the operating parameters of the compressor, the time when the compressor is shut down for overcurrent protection, the coil temperature of the indoor heat exchanger before shutdown, and the initial coil temperature are detected to determine whether the shut-off valve detection conditions are met. When the shut-off valve detection conditions are met, the shut-off valve faults are counted until the fault count reaches a preset number of times, and it is determined that the shut-off valve has a non-opening fault. Since when the shut-off valve is not opened, the operating parameters of the compressor, the time when the compressor is shut down for overcurrent protection, and the coil temperature of the indoor heat exchanger before shutdown, and the initial coil temperature all meet the shut-off valve detection conditions, and when the indoor AC motor is blocked or shut down due to a fault, although the compressor overcurrent protection shutdown action and the compressor operating parameters are too large will occur, the time when the overcurrent protection shutdown occurs and the compressor operating parameters are compared with the shut-off valve. There is a significant difference when the stop valve is not opened, that is, the overcurrent protection shutdown time is longer, and the operating parameters of the compressor are smaller; and, when the AC power supply voltage is ultra-low, there is a small probability that an overcurrent protection shutdown will occur, but the shutdown time is significantly different from when the stop valve is not opened, and the operating parameters of the compressor are smaller than when the stop valve is not opened, thereby avoiding misjudgment of faults caused by compressor shutdown due to usage scenarios such as indoor motor stalling or ultra-low power supply voltage, and using the indoor coil temperature and the indoor initial coil temperature as detection conditions for the stop valve not opening fault, there is no need to detect the stop valve not opening fault by detecting the outdoor ambient temperature, which can effectively avoid the situation where the outdoor ambient temperature is too high when detecting whether the stop valve has a not opening fault based on the outdoor ambient temperature, resulting in misjudgment of the stop valve not opening fault due to solar radiation causing the detected outdoor ambient temperature to be too high, thereby improving the accuracy of the stop valve not opening fault while reducing user complaints caused by misjudgment.

[0012] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0014] Figure 1 is a schematic structural diagram of an air conditioner in operation according to some embodiments of the present application;

[0015] Figure 2 (a) is a schematic diagram of the change curves of indoor coil temperature and outdoor coil temperature when the stop valve is open according to some embodiments of the present application;

[0016] Figure 2(b) is a schematic diagram of the curve changes of the exhaust pressure and the suction pressure when the shut-off valve is open according to some embodiments of the present application;

[0017] Figure 2 (c) is a schematic diagram of the curve change of the phase current when the stop valve is open according to some embodiments of the present application;

[0018] Figure 3 (a) is a schematic diagram of the change curves of indoor coil temperature and outdoor coil temperature when the stop valve is closed according to some embodiments of the present application;

[0019] Figure 3 (b) is a schematic diagram of the curve changes of the exhaust pressure and the suction pressure when the shut-off valve is closed according to some embodiments of the present application;

[0020] Figure 3 (c) is a schematic diagram of the curve change of the phase current when the stop valve is closed according to some embodiments of the present application;

[0021] Figure 4 (a) is a schematic diagram of the change in indoor coil temperature and outdoor coil temperature curve when the indoor motor is stopped or blocked and the stop valve is in an open state according to some embodiments of the present application;

[0022] Figure 4 (b) is a schematic diagram of the curve changes of the suction pressure and the exhaust pressure when the indoor motor is stopped or locked and the stop valve is in the open state according to some embodiments of the present application;

[0023] Figure 4 (c) is a schematic diagram of a curve change of the compressor phase current when the indoor motor is stopped or locked and the stop valve is in an open state according to some embodiments of the present application;

[0024] Figure 5 (a) is a schematic diagram of the curve changes of the indoor coil temperature and the outdoor coil temperature when the AC power voltage is extremely low and the stop valve is in the open state according to some embodiments of the present application;

[0025] Figure 5 (b) is a schematic diagram of curve changes of exhaust pressure and suction pressure when the AC power supply voltage is extremely low and the shut-off valve is in an open state according to some embodiments of the present application;

[0026] Figure 5 (c) is a schematic diagram of a curve variation of the compressor phase current when the AC power supply voltage is extremely low and the shut-off valve is in an open state according to some embodiments of the present application;

[0027] Figure 6 is a block diagram of an air conditioner according to some embodiments of the present application;

[0028] Figure 7 is a flow chart of a method for detecting a stop valve failure of an air conditioner according to some embodiments of the present application;

[0029] Figure 8 (a) is a schematic diagram of indoor coil temperature and outdoor coil temperature curves when the stop valve is closed according to some embodiments of the present application;

[0030] Figure 8 (b) is a schematic diagram of the curve changes of the exhaust pressure and the suction pressure when the shut-off valve is closed according to some embodiments of the present application;

[0031] Figure 8 (c) is a schematic diagram of the curve change of the phase current when the stop valve is closed according to some embodiments of the present application;

[0032] Figure 9 is a flow chart of a method for detecting a stop valve failure of an air conditioner according to some embodiments of the present application;

[0033] Figure 10 (a) is a schematic diagram of the change curves of indoor coil temperature and outdoor coil temperature when the stop valve is closed according to some embodiments of the present application;

[0034] Figure 10 (b) is a schematic diagram of the curve structure of the exhaust pressure and the suction pressure when the shut-off valve is closed according to some embodiments of the present application;

[0035] Figure 10 (c) is a schematic diagram of the curve change of the phase current when the stop valve is closed according to some embodiments of the present application;

[0036] Figure 11 is a flow chart of a method for detecting a fault of an air conditioner stop valve according to some embodiments of the present application;

[0037] Figure 12 4 is a flow chart of a method for detecting a fault of an air conditioner stop valve according to some embodiments of the present application. DETAILED DESCRIPTION

[0038] The embodiments of the present application are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present application are described in detail below.

[0039] The air conditioner in this application performs a refrigeration cycle of the air conditioner by using a compressor, a condenser, an expansion valve and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion and evaporation, and supplies refrigerant to the air that has been conditioned and heat exchanged.

[0040] 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.

[0041] The expansion valve expands the high-temperature, high-pressure liquid refrigerant condensed in the condenser to a lower-pressure liquid. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves cooling by utilizing the latent heat of evaporation to exchange heat with the material being cooled. Throughout this cycle, the air conditioner regulates the temperature of the indoor space.

[0042] The outdoor unit of the air conditioner refers to a portion of a refrigeration cycle including a compressor and an outdoor heat exchanger, the indoor unit of the air conditioner includes an indoor heat exchanger, and the expansion valve may be provided in the outdoor unit or the indoor unit.

[0043] 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 functions as a heater in heating mode, and when the indoor heat exchanger functions as an evaporator, the air conditioner functions as a cooler in cooling mode.

[0044] The stop valve is set inside the outdoor unit housing. By controlling the opening or closing of the stop valve, the opening or closing state of the refrigerant circulation circuit is controlled.

[0045] Based on the basic heating or cooling working principle of the air conditioner, the structure of the air conditioner during operation is illustrated below.

[0046] like Figure 1 The figure shows a schematic diagram of the structure of the air conditioner during operation in some embodiments of the present application. Figure 1 It can be seen that when the shut-off valve is not opened and the air conditioner is running, for example, when the air conditioner is running in heating mode, the compressor starts. After the compressor starts, the refrigerant, i.e., the refrigerant, will be sucked from the outdoor heat exchanger to the compressor suction port and continuously discharged from the compressor exhaust port, and the shut-off valve is closed. At this time, the refrigerant is squeezed between the compressor exhaust port and the shut-off valve. Since the space between the compressor exhaust port and the shut-off valve is very small, the exhaust pressure will rise rapidly, far exceeding the upper limit requirement of the compressor specification. Specifically, the suction pressure drops sharply to 0 atmosphere. At this time, the compression ratio also far exceeds the requirements of the compressor specification. For example, the R32 compressor has a maximum allowable exhaust pressure of ≤4.30MPa, a minimum allowable suction pressure of ≥0.23MPa, and a maximum compression ratio of ≤7.5, where compression ratio = exhaust pressure (absolute pressure) / suction pressure (absolute pressure), which will cause compressor damage in a short time.

[0047] Based on this, the following describes the situation of the stop valve under different working conditions.

[0048] The following example illustrates the changes in various parameters of an air conditioner when the stop valve is in the open state.

[0049] like Figure 2 (a) shows a schematic diagram of the curve changes of the indoor coil temperature and the outdoor coil temperature in some embodiments of the present application when the shut-off valve is open. When the air conditioner is operating in heating mode and the shut-off valves are fully open, the indoor coil temperature, i.e., the coil temperature of the indoor heat exchanger, slowly rises and stabilizes, and the maximum value does not exceed the maximum condensing temperature Tcmax. The outdoor coil temperature, i.e., the coil temperature of the outdoor heat exchanger, rapidly decreases and stabilizes, and the minimum value does not fall below the minimum evaporation temperature Temin. The indoor and outdoor ambient temperatures are both laboratory ambient temperatures and theoretically remain unchanged.

[0050] like Figure 2 (b) shows a schematic diagram of the curves of exhaust pressure and suction pressure when the shut-off valve is open in some embodiments of the present application. The exhaust pressure rises slowly and tends to be stable, and the maximum value will not exceed the maximum exhaust pressure Pdmax. The suction pressure first drops rapidly and tends to be stable, and the minimum value will not be lower than the minimum suction pressure Psmin. Among them, the indoor coil temperature is measured by the indoor coil temperature sensor, the outdoor coil temperature is measured by the outdoor coil temperature sensor, the indoor ambient temperature is measured by the indoor ambient sensor, the outdoor ambient temperature is measured by the outdoor ambient sensor, and the phase current of the compressor is measured by the compressor phase current detection circuit. Among them, the condensing temperature corresponding to the maximum exhaust pressure Pdmax is the maximum condensing temperature Tcmax. There are multiple detection circuits for the phase current of the compressor. The three-resistance circuit can directly collect the UVW three-phase current, and the single-resistance sampling circuit can collect the total current and then reconstruct the UVW three-phase current through an algorithm.

[0051] like Figure 2 Figure (c) shows the curve variation of the phase current when the shutoff valve is open in some embodiments of the present application. When the air conditioner is operating in heating mode with all shutoff valves open, the compressor phase current slowly rises and stabilizes, with the maximum value not exceeding the maximum phase current value Imax of the air conditioner.

[0052] Depend on Figure 2 It can be seen that when the stop valve is opened, the indoor coil temperature and the outdoor coil temperature change according to a certain change pattern, the exhaust pressure and the suction pressure also change according to a certain change pattern, and the compressor operating parameters, such as the compressor phase current, also change according to a certain pattern. If the above parameters do not change according to the pattern when the stop valve is opened, the above parameters are analyzed to determine the cause of the fault when the above parameters are abnormal.

[0053] It is understandable that when the indoor coil temperature, outdoor coil temperature, exhaust pressure, suction pressure and compressor operating parameters are abnormal, there are many situations that may cause the operating parameters of the above-mentioned air conditioner to become abnormal, such as operating parameter abnormalities caused by the shut-off valve not being opened, operating parameter abnormalities caused by the shut-off valve being opened but the indoor AC motor being stuck or the indoor AC motor being shut down due to a fault, and operating parameter abnormalities caused by the shut-off valve being opened but the user's AC power supply voltage being extremely low. In all of the above situations, compressor operating parameters such as increased phase current and compressor overcurrent protection shutdown will occur. However, in different situations, parameters such as the compressor phase current, indoor coil temperature change value, and compressor overcurrent protection shutdown time will vary significantly. Therefore, by analyzing parameters such as changes in indoor coil temperature, changes in compressor operating parameters, and the time when the compressor overcurrent protection shutdown occurs, the causes of abnormal air conditioner operating parameters in different situations can be distinguished, thereby avoiding abnormal air conditioner operating parameters caused by indoor AC motor stall or fault and extremely low AC power supply voltage, which may lead to misjudgment of the open or closed state of the shut-off valve.

[0054] The following are some examples of situations where abnormalities occur in the operating parameters of the air conditioner.

[0055] In some embodiments, when the shut-off valve is not open, the operating parameters of the air conditioner change as follows:

[0056] like Figure 3 (a) shows a schematic diagram of the change curve of the indoor coil temperature and the outdoor coil temperature when the stop valve is closed in some embodiments of the present application. Figure 1 and Figure 3 As shown in (a), when all the stop valves are closed, the refrigerant is compressed between the compressor exhaust port and the rough stop valve. At this time, no refrigerant flows through the indoor heat exchanger, and the refrigerant in the outdoor heat exchanger is quickly extracted. The indoor coil temperature, indoor ambient temperature, and outdoor ambient temperature are laboratory temperatures and theoretically remain unchanged. The outdoor coil temperature first drops rapidly and slightly, then rises slowly, and finally the outdoor coil temperature approaches the outdoor ambient temperature and is finally the same as the outdoor ambient temperature.

[0057] like Figure 3(b) shows a schematic diagram of the curve structure of the exhaust pressure and suction pressure in the closed state of the stop valve in some embodiments of the present application. When the air conditioner is in heating operation, all the stop valves are closed. Due to the abnormality of the air conditioner, the exhaust pressure of the compressor rises sharply, and the pressure difference between the suction pressure and the exhaust pressure increases sharply. Among them, the exhaust pressure rises sharply, and the maximum value before the protection shutdown far exceeds the maximum exhaust pressure Pdmax. The suction pressure drops sharply until it drops to 0 atmosphere and stabilizes at 0 atmosphere. At this time, it is equivalent to the outdoor heat exchanger side being in a vacuum state. If the fine stop valve is not sealed tightly or leaks slightly, air can easily be drawn in, further increasing the danger. At this time, 0 atmosphere is significantly lower than the minimum suction pressure Psmin.

[0058] like Figure 3 Figure (c) shows a schematic diagram of the phase current curve changes when the shutoff valve is closed in some embodiments of the present application. When the pressure difference between the compressor's suction and discharge pressures increases dramatically, the compressor motor load increases sharply, causing the compressor phase current to rise sharply, significantly exceeding the maximum phase current value Imax specified for the air conditioner. At the same time, the increased discharge pressure and pressure difference can easily exceed the operating requirements of the compressor or the controller, resulting in a rapid overcurrent protection fault and shutdown.

[0059] Depend on Figure 3 It can be seen that when the stop valve is not opened and the air conditioner is running in heating mode, since the stop valve is closed, no refrigerant flows through the indoor heat exchanger, the indoor coil temperature will not change significantly, and the pressure difference between the exhaust pressure and the suction pressure of the compressor will increase sharply, which will cause the load of the compressor motor to increase sharply, resulting in a sharp increase in the operating parameters of the compressor, such as the phase current of the compressor. It can be understood that when the stop valve is not opened, the indoor coil temperature, the operating parameters of the compressor and the operating status of the compressor will undergo obvious changes. Therefore, when detecting whether there is a stop valve failure that is not open, the indoor coil temperature, the operating parameters of the compressor and the operating status of the compressor are detected, and when the above parameter changes meet the parameter change rules when the stop valve is not open, it is determined whether the cause of the parameter abnormality is that the stop valve is not open.

[0060] In some embodiments, when the stop valve is in an open state but the indoor AC motor is blocked or shut down due to a fault, the changes in various parameters of the air conditioner are illustrated.

[0061] like Figure 4(a) shows a schematic diagram of the curve changes of the indoor coil temperature and the outdoor coil temperature when the shut-off valve is in the open state in some embodiments of the present application. When the indoor heat exchanger cannot force heat exchange, the indoor coil temperature will rise sharply, and the outdoor coil temperature will first drop, then slowly rise, and finally tend to the outdoor ambient temperature and be the same as the outdoor ambient temperature. It can be understood that the value of the compressor before shutdown will be significantly lower than the value when the shut-off valve is in the fully closed state, and the compressor shutdown time is also longer than the time when the shut-off valve is in the fully closed state. At this time, the outdoor coil temperature and suction pressure first drop rapidly, and then gradually stabilize, which is not much different from the curve when the shut-off valve is in the fully open state. Among them, the AC motor is open-loop controlled. Once the fault stops, the air conditioner can still operate normally.

[0062] like Figure 4 Figure (b) shows a schematic diagram of the changes in suction and exhaust pressure curves when the shutoff valves are open, according to some embodiments of the present application. When the air conditioner is operating in heating mode with all shutoff valves open, if the indoor AC motor stalls or fails, the air conditioner will continue to operate normally. However, since the indoor fan is stopped, the indoor heat exchanger cannot force heat exchange, causing the exhaust pressure and condensing temperature (i.e., the indoor coil temperature) to rise significantly, exceeding the maximum limit. At this point, an overcurrent fault or overload fault may be reported, causing the air conditioner to shut down.

[0063] like Figure 4 Figure (c) shows a schematic diagram of the compressor phase current curve when the shutoff valve is open, according to some embodiments of the present application. When the indoor AC motor stalls or fails, the air conditioner operates normally, the indoor fan stops, and the indoor heat exchanger is unable to force heat exchange, causing the compressor phase current to rise significantly.

[0064] Depend on Figure 4 It can be seen that when the air conditioner is running in heating mode, the stop valve is open and the indoor AC motor is blocked or shut down due to a fault, although the compressor operating parameters may be abnormal and the compressor may shut down due to an overcurrent fault, the operating parameters of the compressor before shutdown, such as the phase current, will be significantly lower than the phase current when the compressor shuts down when the stop valve is not open, and the shutdown time of the compressor is also significantly longer than the running time of the compressor when the stop valve is not open. Therefore, when the stop valve is open but the indoor AC motor is blocked or shuts down due to a fault, the operating parameters of the air conditioner are significantly different from the operating parameters of the air conditioner when the stop valve is not open. By detecting the operating parameters of the compressor, the indoor coil temperature and the shutdown action of the compressor, it can be distinguished whether the current fault is caused by the stop valve not being opened or by the indoor AC motor being blocked or shutting down due to a fault.

[0065] In some embodiments, the changes in various parameters of the air conditioner are exemplified when the shut-off valve is in an open state but the AC power voltage is extremely low.

[0066] like Figure 5 Figure (a) shows the curves of the indoor and outdoor coil temperatures when the shutoff valve is open, according to some embodiments of the present application. When the air conditioner is operating in heating mode with the shutoff valve open, the indoor coil temperature rises first, with its maximum value never exceeding the maximum condensing temperature, Tcmax. The outdoor coil temperature first decreases and then increases, with its minimum value never falling below the minimum evaporating temperature, Temin.

[0067] like Figure 5 Figure (b) shows a schematic diagram of the curve changes in exhaust pressure and suction pressure when the shutoff valve is open in some embodiments of the present application. When the air conditioner is operating in heating mode with the shutoff valve open, if the user's AC power supply voltage is extremely low, for example, below 140V, the speed of the indoor and outdoor fans will decrease, reducing the circulating air volume through the indoor and outdoor heat exchangers, thereby reducing the heat exchange rate. At this time, the exhaust pressure and condensing temperature will rise significantly, potentially exceeding the maximum limit.

[0068] like Figure 5 Figure (c) shows a schematic diagram of the compressor phase current curve when the shutoff valve is open, according to some embodiments of the present application. When the power supply voltage is extremely low, the AC current peak may be very large. In this case, there is a certain possibility of a current fault and shutdown, that is, a significant increase in the compressor phase current. Furthermore, the user's power supply voltage is always extremely low from the start, so there is a possibility of a sudden and significant power drop during air conditioning operation.

[0069] Depend on Figure 5 It can be seen that when the air conditioner is running in heating mode, the stop valve is open and the user's AC power supply voltage is extremely low, the phase current of the compressor will also be large, that is, there is a certain probability that the compressor will shut down and other abnormal conditions will occur. However, there are obvious differences between the parameters when the above-mentioned parameters are abnormal and the parameters when the stop valve is not open. Therefore, by detecting the operating parameters of the compressor, the indoor coil temperature and the overcurrent protection shutdown action of the compressor when the air conditioner is running in heating mode, it can be accurately determined whether the current parameter abnormality is caused by the stop valve not being opened, or the indoor AC motor being stuck or shutting down due to a fault, or the AC power supply voltage being extremely low, thereby avoiding misjudgment of the stop valve not being opened.

[0070] In some embodiments, by obtaining the indoor initial coil temperature at the time of compressor startup, the indoor coil temperature at the instant before the overcurrent protection shutdown, the size of the compressor operating parameters within the first preset time, and the time of the compressor overcurrent protection shutdown, the above operating parameters are analyzed to determine whether the stop valve detection conditions are met, and the number of times the stop valve detection conditions are met is counted until the stop valve fault count is greater than the preset number of times, it is accurately determined that the stop valve has a non-opening fault, avoiding missed judgments and misjudgments caused by indoor motor jams, indoor motor stops, or overcurrent protection shutdowns caused by ultra-low voltage of the user power supply, thereby improving the accuracy of the judgment of the stop valve non-opening fault and avoiding user complaints caused by misjudgment.

[0071] Reference below Figure 6 Describe the air conditioner according to some embodiments of the present application, such as Figure 6 As shown, the air conditioner 1 of some embodiments of the present application includes: a refrigerant circulation loop 11, an outdoor heat exchanger 12, an indoor heat exchanger 13, an indoor coil temperature sensor 14, an outdoor unit 15, an outdoor unit casing 16, a compressor 17, a stop valve 18 and a controller 19, wherein,

[0072] The refrigerant circulation loop 11 allows the refrigerant to circulate in the circulation loop through the compressor 17, condenser, expansion valve and evaporator; the outdoor heat exchanger 12 and the indoor heat exchanger 13, one of which works as a condenser and the other works as an evaporator; the indoor coil temperature sensor 14 is used to detect the indoor coil temperature; the outdoor unit 15 includes: an outdoor housing 16; a compressor 17; the outdoor heat exchanger 12 and a stop valve 18, wherein the compressor 17 is arranged in the outdoor housing 16 and is used to compress the low-temperature and low-pressure refrigerant gas into a high-temperature and high-pressure refrigerant gas and discharge it to the condenser; the stop valve 18 is arranged in the outdoor unit housing 16 and is used to open or close the refrigerant circulation loop 11; the controller 19 is used to obtain the indoor initial coil temperature at the start-up moment of the compressor 17 when the air conditioner is powered on for the first time and the heating operation is turned on. It can be understood that the fault of the stop valve 18 not being opened is only detected when the air conditioner is installed or the whole machine is debugged and separated. Therefore, when obtaining the indoor initial coil temperature, it is necessary to obtain it when the air conditioner outdoor controller 17 is powered on for the first time.

[0073] After obtaining the indoor initial coil temperature at the time of compressor startup, it is determined whether the stop valve detection conditions are met. The stop valve detection conditions include detecting the relationship between the compressor operating parameters, such as the compressor phase current, and the first preset parameter threshold within a first preset time, and detecting whether the compressor overcurrent protection shutdown action is triggered within a second preset time and a third preset time, and detecting the indoor coil temperature and the indoor initial coil temperature at the instant before the compressor overcurrent protection shutdown, and starting to count the stop valve faults when the indoor coil temperature and the indoor initial coil temperature meet the preset conditions. Among them, using the detection of the indoor coil temperature and the indoor initial coil temperature as the detection conditions for the stop valve fault can effectively avoid the situation where, when detecting whether the stop valve has a non-opening fault based on the outdoor ambient temperature, the detected outdoor ambient temperature may be too high due to solar radiation, resulting in a misjudgment of the stop valve not opening fault.

[0074] During different time periods, when it is detected that the indoor initial coil temperature and the operating parameters of the compressor, i.e., the compressor's overcurrent protection shutdown action, meet the shutoff valve detection conditions, shutoff valve faults are counted. After a first low-temperature preset time, it is determined whether the shutoff valve detection conditions are met again. That is, the indoor initial coil temperature and the operating parameters of the compressor, i.e., the compressor's overcurrent protection shutdown action, are again detected. When the shutoff valve detection conditions are again met, shutoff valve faults are counted until the shutoff valve fault count reaches a preset number of times, at which point a shutoff valve fault is determined. The third preset time is greater than the second preset time. By counting shutoff valve faults and determining that the shutoff valve has a non-opening fault when the shutoff valve fault count reaches a preset number of times, such as two, it can be avoided that occasional operating parameter anomalies may lead to a misjudgment of a shutoff valve non-opening fault.

[0075] In some embodiments, when the controller is powered on for the first time and the air conditioner is operating in heating mode, the indoor ambient temperature and the indoor initial coil temperature at the time of compressor startup are detected and stored, and it is determined whether the air conditioner meets the shut-off valve detection conditions, that is, whether the operating parameters of the compressor, the overcurrent protection shutdown action of the compressor, the indoor coil temperature before the overcurrent protection shutdown, and the indoor initial coil temperature at the time of compressor startup meet specific conditions.

[0076] For example, the air conditioner meets the stop valve detection condition, that is, within the first preset time, the operating parameter of the compressor exceeds the first preset parameter threshold, such as Figure 3As shown in (a), within a first preset time, for example, 0-t1 minutes, the operating parameter of the compressor is, for example, the phase current of the compressor, and the first preset parameter is recorded as I1, that is, within 0-t1 minutes, the phase current of the compressor is greater than I1, and the phase current of the compressor continues to increase with time, and the triggering of the compressor overcurrent protection shutdown is detected within the second preset time and the third preset time interval, for example, within t1-t2 minutes, the triggering of the overcurrent protection shutdown action is detected; and the indoor coil temperature at the instant before the overcurrent protection shutdown is recorded as Tc, and the indoor initial coil temperature is recorded as Tc0, and it is determined whether the indoor coil temperature Tc and the indoor initial coil temperature Tc0 meet the preset conditions. When the indoor coil temperature Tc and the indoor initial coil temperature Tc0 meet the preset conditions, and when all the above conditions are met, the shut-off valve faults are counted.

[0077] After the first low temperature preset time reaches, for example, 3 minutes, it is again determined whether the shutoff valve detection condition is satisfied. The compressor operating parameters, the compressor overcurrent protection shutdown action, the indoor heat exchanger coil temperature before the overcurrent protection shutdown, and the initial indoor heat exchanger coil temperature at the time of compressor startup are again checked to see whether they meet specific conditions. When the shutoff valve detection condition is again satisfied, shutoff valve failures are counted until the shutoff valve failure count reaches a preset number, for example, two times, and the shutoff valve is determined to be not open. It will be appreciated that when the air conditioner is in heating mode, the shutoff valve detection condition is determined to be satisfied by checking the compressor operating parameters, the indoor coil temperature, and the initial indoor coil temperature at the time of compressor startup during operation. When the shutoff valve detection condition is determined to be satisfied, shutoff valve failures are counted until the failure count reaches a preset number, and a shutoff valve failure is determined to be present. This allows for rapid and accurate determination of a shutoff valve failure.

[0078] According to the air conditioner of some embodiments of the present application, when the air conditioner is powered on for the first time and the heating operation is started, the indoor initial coil temperature at the time of compressor startup is obtained, and the operating parameters of the compressor, the time when the compressor is shut down for overcurrent protection, the coil temperature of the indoor heat exchanger before shutdown, and the initial coil temperature are detected to determine whether the stop valve detection conditions are met, and when the stop valve detection conditions are met, the stop valve faults are counted until the fault count reaches a preset number of times, and it is determined that the stop valve has a non-opening fault. Since the stop valve has a non-opening fault, the operating parameters of the compressor, the time when the compressor is shut down for overcurrent protection, and the coil temperature of the indoor heat exchanger before shutdown, and the initial coil temperature all meet the stop valve detection conditions. When the indoor AC motor is blocked or shut down due to a fault, although the compressor overcurrent protection shutdown action and the compressor operating parameters are too large will occur, the time when the overcurrent protection shutdown occurs and the compressor operating parameters are shorter than when the stop valve is not shut down. There is an obvious difference when it is opened, that is, the time for overcurrent protection shutdown is longer, and the operating parameters of the compressor are smaller. When the AC power supply voltage is ultra-low, there is a small probability that overcurrent protection shutdown will occur, but the shutdown time is significantly different from when the shut-off valve is not opened, and the operating parameters of the compressor are smaller than when the shut-off valve is not opened, thereby avoiding misjudgment of faults caused by compressor shutdown due to usage scenarios such as indoor motor stall or ultra-low power supply voltage. In addition, the indoor coil temperature and the indoor initial coil temperature are used as detection conditions for the shut-off valve not opening fault. There is no need to detect the shut-off valve not opening fault by detecting the outdoor ambient temperature. This can effectively avoid the situation where the shut-off valve not opening fault is misjudged due to the detected outdoor ambient temperature being too high due to solar radiation when detecting whether the shut-off valve has a not opening fault based on the outdoor ambient temperature. This improves the accuracy of the shut-off valve not opening fault while reducing user complaints caused by misjudgment.

[0079] In some embodiments, when the indoor coil temperature and the indoor initial coil temperature meet the preset conditions, the difference between the indoor coil temperature and the indoor initial coil temperature is calculated. By calculating the difference between the indoor coil temperature and the indoor initial coil temperature, when the difference does not exceed the second preset parameter threshold, it is determined that the indoor coil temperature and the indoor initial coil temperature meet the preset conditions. Since no refrigerant flows through the indoor heat exchanger when the stop valve is not opened, the refrigerant in the outdoor heat exchanger is quickly drawn away, and the indoor coil temperature theoretically remains unchanged. By calculating the difference between the indoor coil temperature and the indoor initial coil temperature, when the difference is less than the second preset parameter threshold, it is considered that the indoor coil temperature remains basically unchanged, and this is used as one of the stop valve detection conditions.

[0080] In some embodiments, the indoor coil temperature is recorded as Tc, the indoor initial coil temperature is recorded as Tc0, and the second preset parameter threshold is recorded as

[0081] ΔT1 determines whether the indoor coil temperature and the indoor initial coil temperature meet a preset condition. Specifically, the difference between the indoor coil temperature and the indoor initial coil temperature is calculated and compared with a second preset parameter threshold, ΔT1. If the difference does not exceed the second preset parameter threshold, for example, Tc-Tc0 ≤ ΔT1, the indoor coil temperature and the indoor initial coil temperature are considered to meet the preset condition. By testing the indoor coil temperature and the indoor initial coil temperature, the accuracy of shutoff valve fault detection is improved.

[0082] In some embodiments, when the overcurrent protection shutdown action of the compressor is not triggered within the second preset time and the third preset time interval, the compressor is controlled to continue running until the continuous running time of the compressor reaches the fourth movement preset time, and it is no longer judged whether the stop valve detection condition is met, wherein the fourth movement preset time is greater than the third preset time. If the compressor overcurrent protection shutdown action is not detected within the specified time, the running time of the compressor is counted. When the running time reaches the fourth movement preset time, it is considered that the stop valve detection condition is not met, and the stop valve does not have a non-opening fault.

[0083] In some embodiments, when the air conditioner is turned on for heating, if the compressor's overcurrent protection shutdown action is not detected within the second preset time and the third preset time interval, the compressor is controlled to remain on and the continuous operation time of the compressor is counted until the continuous operation time of the compressor reaches the fourth preset time, for example, 10 minutes. It is then considered that the shut-off valve has not failed to open. At this time, the compressor's operating parameters and the indoor coil temperature are no longer checked to see if they meet the preset conditions, that is, the shut-off valve is no longer judged to have failed to open, and all data related to the judgment of the shut-off valve failure is cleared. By obtaining the continuous operation time of the compressor and no longer judging whether the shut-off valve detection conditions are met when the continuous operation time of the compressor reaches the fourth preset time, it is possible to avoid misjudgments of shut-off valve failures caused by unknown external environments and unknown electromagnetic interference, thereby improving the reliability of shut-off valve judgments.

[0084] In some embodiments, when the stop valve detection condition is not met and the fault count of the stop valve has not reached a preset number of times, the compressor is controlled to continue running, and the running time of the compressor is counted until the cumulative running time of the compressor reaches a sixth preset time, and it is no longer judged whether the stop valve detection condition is met, wherein the sixth preset time is greater than the fourth preset time, wherein, when the stop valve detection condition is judged, it is necessary to detect the fault count of the stop valve. If the fault count of the stop valve does not reach the preset number of times, for example, when the fault count of the stop valve is 1, it is considered that the compressor has a shutdown action, but when it is judged again whether the stop valve condition is met, the compressor overcurrent protection shutdown action is not triggered, then the running time of the compressor is counted, and when the cumulative running time of the compressor reaches the sixth preset time, it is considered that the stop valve detection condition is not met and the stop valve does not have a non-opening fault.

[0085] In some embodiments, when the stop valve detection condition is not met and the stop valve fault count has not reached a preset number of times, the compressor is controlled to continue running, and the running time of the compressor is counted until the cumulative running time of the compressor reaches a sixth preset time, for example, 30 minutes. The operating parameters of the compressor and the indoor coil temperature value are no longer detected to see whether they meet the preset conditions. By obtaining the cumulative running time of the compressor and when the cumulative running time of the compressor reaches the sixth preset time, it is no longer determined whether the stop valve detection condition is met. This can avoid misjudgment of stop valve failure caused by external unknown environment and unknown electromagnetic interference, thereby improving the reliability of stop valve judgment.

[0086] It is understandable that, under normal circumstances, the shut-off valve failure may only occur once. When the air conditioner is not in use, the user will actively cut off the power to the air conditioner, or even if the indoor unit is powered on, when it is not turned on, the indoor controller will automatically cut off the power to the outdoor controller. Once the outdoor controller is powered off, the operating parameters of the compressor, the coil temperature value of the indoor heat exchanger, and the data of the air conditioner's execution of the shut-off valve protection strategy will be lost. Therefore, each time the outdoor controller is powered on again, the shut-off valve failure detection and judgment process will be carried out.

[0087] In some embodiments, when it is determined that the stop valve is faulty, an alarm signal of the stop valve fault is issued, and the compressor is controlled to stop and not automatically start again.

[0088] In some embodiments, when the stop valve failure count reaches a preset number of times, for example, twice, it is determined that the stop valve is not open, and an alarm message of stop valve failure is issued, and the compressor is controlled to no longer start automatically, and the stop valve failure judgment is no longer performed, and all data related to the judgment that the stop valve is not open is cleared.

[0089] In some embodiments, the operating parameter of the compressor includes any one of the phase current of the compressor, the input power of the compressor, the entire input power of the air conditioner, and the entire input current of the air conditioner.

[0090] In some embodiments, the operating parameters of the compressor can be any one of the effective value of the compressor, the compressor input power, the whole machine input power of the air conditioner and the whole machine input current of the air conditioner. It can be understood that when the air conditioner is running in heating mode, the stop valve is closed and the refrigerant is compressed in a very small space, causing the exhaust pressure to rise sharply and the suction pressure to drop sharply, causing the suction and exhaust pressure difference to increase sharply, thereby causing the system load to increase sharply and act on the compressor drive control. In the compressor drive control, the increase in load may cause the compressor input power to increase, the compressor phase current to increase at the same voltage, the whole machine input power to increase, the whole machine input current to increase at the same voltage, etc. Therefore, any one of the above can be selected as the operating parameter of the compressor.

[0091] At present, compressors use permanent magnet synchronous motors. The general FOC (field-oriented control) algorithm requires current coordinate transformation to convert the compressor phase current in the rotating coordinate system into D-axis and Q-axis currents in the stationary coordinate system, and control the D-axis and Q-axis currents. As the phase current of the compressor increases, the corresponding D-axis current and Q-axis current also increase accordingly. The essence of the FOC algorithm is to combine the three-directional current vectors and then decompose them into two components perpendicular and parallel to the stationary coordinate system. The D-axis current and Q-axis current can be obtained by calculating and transforming the phase current in the rotating coordinate system through a function. That is, the D-axis current and Q-axis current are the currents after the phase current has undergone coordinate transformation. Therefore, the D-axis current, Q-axis current, or a combination of the D-axis and Q-axis are used to judge the operating parameters of the compressor.

[0092] The compressor's phase current is typically a sinusoidal wave. Sine wave current values ​​can be described in two ways: RMS (effective value) and peak (peak). The RMS value is the RMS value of the current, while the peak value is the instantaneous maximum current over a specific period. When the controller controls based on the detected current, it continuously monitors the instantaneous phase current and compares it to the maximum instantaneous current over a specific period, i.e., the phase current peak value. The RMS value is also calculated based on the peak value to determine the compressor's operating parameters.

[0093] For example, within the first preset time, such as 40 seconds, if it is detected that the phase current of the compressor exceeds the first preset parameter threshold, such as exceeding 12A, the phase current of the compressor will continue to be detected; it is also possible that at 40 seconds, it is detected that the input power of the compressor exceeds the first preset parameter threshold, such as exceeding 4.2W, the input power of the compressor will continue to be detected; it is also possible that at 40 seconds, it is detected that the entire input power of the air conditioner exceeds the first preset parameter threshold, such as exceeding 4.3W, the entire input power of the air conditioner will continue to be detected; it is also possible that at 40 seconds, it is detected that the entire input current of the air conditioner exceeds the first preset parameter threshold, such as exceeding 18A, the entire input current of the air conditioner will continue to be detected; it is also possible that at 40 seconds, it is detected that the Q-axis current of the compressor exceeds the first preset parameter threshold, such as exceeding 10A, the Q-axis current of the compressor will continue to be detected.

[0094] The following example illustrates the fault detection of the stop valve. The parameter settings of the air conditioner are as follows:

[0095] The first preset time t1 = 1 min, the third preset time t2 = 2 min, the fourth movement preset time t3 = 10 min, the sixth preset time t4 = 30 min, the second preset parameter threshold ΔT1 = 3° C., and the first preset parameter threshold I1 = 12A.

[0096] In some embodiments, when the outdoor unit controller is powered on for the first time and the heating operation mode is turned on, the compressor starts. The controller detects the indoor ambient temperature Tin0 = 20°C, the coil temperature Tc0 of the indoor heat exchanger = 21°C, the outdoor ambient temperature Tout0 = 15°C, the coil temperature Te0 of the outdoor heat exchanger = 15°C, and the exhaust temperature Td0 = 15°C at the time of compressor startup. The compressor phase current is also detected in real time. If at 40s, it is less than the first preset time t1 = 1min, and the phase current is detected to be 12A, and this phase current is equal to the first preset parameter threshold I1 = 12A, then the phase current detection continues. At 65s, the controller triggers the overcurrent protection shutdown. The coil temperature Tc at the time of shutdown is detected to be 21.5°C. At this time, Tc-Tc0 = 21.5-21 = 0.5°C < ΔT1 = 3°C, and the count is 1.

[0097] After 3 minutes, the compressor restarts and continues to monitor phase currents and other data in real time. If the phase current is detected at 12.2A at 35 seconds, phase current monitoring continues. At 55 seconds, the controller triggers an overcurrent protection shutdown. At the time of shutdown, Tc = 21.5°C. At this point, Tc - Tc0 = 21.5 - 21 = 0.5°C < ΔT1 = 3°C. A count of 1 is performed, and the cumulative count is 2. A shutoff valve failure is reported, and the system will not restart automatically.

[0098] In some embodiments, when the outdoor unit controller is powered on for the first time, the heating mode is turned on and the compressor starts. The controller detects the indoor ambient temperature Tin0 = 20°C, the indoor heat exchanger temperature Tc0 = 21°C, the outdoor ambient temperature Tout0 = 15°C, the outdoor heat exchanger coil temperature Te0 = 15°C, and the exhaust temperature Td0 = 15°C at the time of startup. The compressor phase current is also detected in real time. If the phase current is detected to be 12A at 55s, the phase current is continuously detected. At 109s, the controller triggers the overcurrent protection shutdown. At the time of shutdown, Tc = 53°C. At this time, Tc-Tc0 = 53-21 = 32°C > ΔT1 = 3°C, and the count is 0.

[0099] After 3 minutes, the compressor is restarted and real-time monitoring of phase current and other data continues. At 5 minutes, the phase current is detected to be 12.2A. The compressor runs until 10 minutes, and no overcurrent shutdown fault is detected. Therefore, the shut-off valve failure is no longer detected.

[0100] According to the air conditioner of some embodiments of the present application, when the air conditioner is powered on for the first time and the heating operation is started, the indoor initial coil temperature at the time of compressor startup is obtained, and the operating parameters of the compressor, the time when the compressor is shut down for overcurrent protection, the coil temperature of the indoor heat exchanger before shutdown, and the initial coil temperature are detected to determine whether the stop valve detection conditions are met, and when the stop valve detection conditions are met, the stop valve faults are counted until the fault count reaches a preset number of times, and it is determined that the stop valve has a non-opening fault. Since when the stop valve is not opened, the operating parameters of the compressor, the time when the compressor is shut down for overcurrent protection, and the coil temperature of the indoor heat exchanger before shutdown, and the initial coil temperature all meet the stop valve detection conditions, and when the indoor AC motor is blocked or shut down due to a fault, although the compressor overcurrent protection shutdown action and the compressor operating parameters are too large will occur, the time when the overcurrent protection shutdown occurs and the compressor operating parameters are compared with when the stop valve is not opened. There is an obvious difference, that is, the time of overcurrent protection shutdown is longer, and the operating parameters of the compressor are smaller; and, when the AC power supply voltage is ultra-low, there is a small probability that overcurrent protection shutdown will occur, but the shutdown time is significantly different from when the stop valve is not opened, and the operating parameters of the compressor are smaller than when the stop valve is not opened, thereby avoiding misjudgment of faults caused by compressor shutdown due to usage scenarios such as indoor motor stall or ultra-low power supply voltage, and using indoor coil temperature and indoor initial coil temperature as detection conditions for the stop valve not opening fault, without detecting the outdoor ambient temperature to detect the stop valve not opening fault, which can effectively avoid the situation when detecting whether the stop valve has a not opening fault based on the outdoor ambient temperature, due to the solar radiation causing the detected outdoor ambient temperature to be too high, resulting in misjudgment of the stop valve not opening fault, thereby improving the accuracy of the stop valve not opening fault while reducing user complaints caused by misjudgment.

[0101] The following describes a method for detecting a stop valve failure of an air conditioner according to some embodiments of the present application.

[0102] like Figure 7 As shown, the method for detecting a stop valve failure of an air conditioner in some embodiments of the present application at least includes: steps S11 to S16.

[0103] Step S11 , when the air conditioner is powered on for the first time and starts heating operation, the indoor initial coil temperature at the time of compressor startup is obtained.

[0104] Step S12, determining whether the stop valve detection condition is met, wherein the stop valve detection condition includes: detecting that the operating parameter of the compressor is greater than the first preset parameter threshold within a first preset time, and detecting that the overcurrent protection shutdown action of the compressor is triggered within a second preset time and a third preset time interval, and determining the indoor coil temperature and the indoor initial coil temperature at the instant before the overcurrent protection shutdown.

[0105] Step S13: When the stop valve detection condition is met, count the stop valve failures.

[0106] Step S14: After the first low temperature preset time, it is determined again whether the stop valve detection condition is met.

[0107] Step S15: When the stop valve detection condition is met, the stop valve failure is counted until the stop valve failure count reaches a preset number of times, and the stop valve failure is determined, wherein the third preset time is greater than the second preset time.

[0108] Step S16: When it is determined again that the stop valve detection condition is not met, it is determined that the stop valve does not have a closed fault.

[0109] According to the shut-off valve fault detection method for air conditioners in some embodiments of the present application, when the air conditioner is powered on for the first time and the heating operation is started, the indoor initial coil temperature at the time of compressor startup is obtained, and the operating parameters of the compressor, the time when the compressor is shut down for overcurrent protection, the coil temperature of the indoor heat exchanger before shutdown, and the initial coil temperature are detected to determine whether the shut-off valve detection conditions are met. When the shut-off valve detection conditions are met, the shut-off valve faults are counted until the fault count reaches a preset number of times, and it is determined that the shut-off valve has a non-opening fault. Since the shut-off valve has a non-opening fault, the operating parameters of the compressor, the time when the compressor is shut down for overcurrent protection, and the coil temperature of the indoor heat exchanger before shutdown, and the initial coil temperature all meet the shut-off valve detection conditions. When the indoor AC motor is blocked or shut down due to a fault, although the compressor overcurrent protection shutdown action and the compressor operating parameters are too large will occur, the time when the overcurrent protection shutdown occurs and the compressor operating parameters are relatively large. There is a significant difference compared to when the stop valve is not opened, that is, the time for overcurrent protection shutdown is longer, and the operating parameters of the compressor are smaller; and, when the AC power supply voltage is ultra-low, there is a small probability that overcurrent protection shutdown will occur, but the shutdown time is significantly different compared to when the stop valve is not opened, and the operating parameters of the compressor are smaller than when the stop valve is not opened, thereby avoiding misjudgment of faults caused by compressor shutdown due to usage scenarios such as indoor motor stall or ultra-low power supply voltage, and using indoor coil temperature and indoor initial coil temperature as detection conditions for the stop valve not opening fault, there is no need to detect the stop valve not opening fault by detecting the outdoor ambient temperature, which can effectively avoid the situation when detecting whether the stop valve has a not opening fault based on the outdoor ambient temperature. Due to solar radiation, the detected outdoor ambient temperature will be too high, resulting in misjudgment of the stop valve not opening fault, thereby improving the accuracy of the stop valve not opening fault while reducing user complaints caused by misjudgment.

[0110] In some embodiments, determining whether the indoor coil temperature and the indoor initial coil temperature meet a preset condition includes: calculating a difference between the indoor coil temperature and the indoor initial coil temperature; and determining that the indoor coil temperature and the indoor initial coil temperature meet the preset condition when the difference does not exceed a preset parameter threshold.

[0111] In some embodiments, after the overcurrent protection shutdown of the compressor is not triggered within the second preset time and the third preset time interval, it also includes: controlling the compressor to continue running until the continuous running time of the compressor reaches the fourth movement preset time, and no longer judging whether the stop valve detection condition is met, wherein the fourth movement preset time is greater than the third preset time.

[0112] In some embodiments, after the stop valve detection condition is not met and the stop valve fault count has not reached a preset number of times, it also includes: controlling the compressor to continue running and timing the running time of the compressor until the cumulative running time of the compressor reaches a sixth preset time, and no longer judging whether the stop valve detection condition is met, wherein the sixth preset time is greater than the fourth preset time.

[0113] In some embodiments, as Figure 8 Figure 2 shows a schematic diagram of the changes in air conditioner operating parameters when the shutoff valve is not open in some embodiments of the present application. Due to the low-temperature shutoff valve detection condition in this application, after the compressor is restarted and preheated, the exhaust pressure and compressor operating parameters will rise sharply in a short period of time.

[0114] Some embodiments of the present application determine whether the low-temperature stop valve detection condition is met by obtaining the outdoor ambient temperature and the indoor initial coil temperature at the time of compressor startup. When the low-temperature stop valve detection condition is met, the compressor is controlled to stop and a temporary count of stop valve failures is performed. By adding the low-temperature detection condition of the outdoor ambient temperature, when determining that the stop valve has not opened, misjudgments of the stop valve caused by the outdoor ambient temperature being too low can be taken into account, thereby reducing missed judgments.

[0115] It is understandable that when the outdoor ambient temperature is too low, even if the stop valve does not open fault occurs, when the air conditioner is operated for the first time, the operating parameters of the air conditioner, such as the compressor operating parameters and the exhaust pressure, are established slowly, and it is impossible to determine whether the stop valve detection conditions are met within the specified time, resulting in inaccurate stop valve fault counting and missed judgments. Therefore, adding low-temperature stop valve detection conditions and temporarily counting stop valve faults can avoid missed judgments of stop valve faults caused by low outdoor temperatures, and determine whether the stop valve detection conditions are met to eliminate misjudgments of stop valve failures caused by outdoor motor jams or ultra-low power supply voltage. This improves the accuracy of stop valve failures while reducing user complaints caused by misjudgments.

[0116] Reference below Figure 6 Describe the air conditioner according to some embodiments of the present application, such as Figure 6 As shown, the air conditioner 1 of some embodiments of the present application includes: a refrigerant circulation loop 11, an outdoor heat exchanger 12, an indoor heat exchanger 13, an indoor coil temperature sensor 14, an outdoor unit 15, an outdoor unit casing 16, a compressor 17, a stop valve 18 and a controller 19, wherein,

[0117] The refrigerant circulation loop 11 allows the refrigerant to circulate in the circulation loop through the compressor 17, condenser, expansion valve and evaporator; the outdoor heat exchanger 12 and the indoor heat exchanger 13, wherein one works as a condenser and the other works as an evaporator; the indoor coil temperature sensor 14 is used to detect the indoor coil temperature; the outdoor unit 15 includes: an outdoor housing 16; a compressor 17; the outdoor heat exchanger 12 and a stop valve 18, wherein the compressor 17 is arranged in the outdoor housing 16 and is used to compress the low-temperature and low-pressure refrigerant gas into a high-temperature and high-pressure refrigerant gas and discharge it to the condenser; the stop valve 18 is arranged in the outdoor unit housing 16, Used to open or close the refrigerant circulation loop 11; the controller 19 is used to obtain the outdoor ambient temperature and the indoor initial coil temperature at the start-up time of the compressor 17 when the power is first turned on and the air conditioner is turned on for heating. After obtaining the outdoor ambient temperature, if the outdoor ambient temperature does not exceed the preset temperature threshold, it is considered that the current working condition is low temperature, and it is judged whether the low temperature stop valve detection condition is met. When the low temperature stop valve detection condition is met, the compressor 17 is controlled to stop, and the stop valve faults are temporarily counted. When the working condition is low temperature and the low temperature stop valve detection condition is met, the stop valve 18 faults are temporarily counted to avoid missed judgments caused by low temperature.

[0118] The stop valve is shut down, and after the first low-temperature preset time, the compressor is restarted to determine whether the stop valve detection conditions are met. When the stop valve detection conditions are met, the stop valve fault count is counted. After restarting the compressor, if the stop valve detection conditions are met, the stop valve temporary count is considered valid; after restarting the compressor, if the stop valve detection conditions are not met, the stop valve temporary count is considered invalid, and when the stop valve fault temporary count and the stop valve fault count meet the preset times, the stop valve fault is determined. Taking into account the low-temperature working conditions, increasing the stop valve temporary count can improve the accuracy of the stop valve non-opening fault.

[0119] In some embodiments, the indoor ambient temperature at the time of compressor startup is recorded as Tin0, the initial indoor coil temperature is recorded as Tc0, the outdoor ambient temperature is recorded as Tout0, the outdoor coil temperature is recorded as Te0, and the preset temperature threshold is recorded as T1. When the outdoor controller of the air conditioner is powered on for the first time and the air conditioner is running in heating mode, the outdoor ambient temperature Tout0 and the indoor initial coil temperature Tc0 at the time of compressor startup are obtained. If the outdoor ambient temperature does not exceed the preset temperature threshold, for example, when Tout0 < T1, it is considered that the outdoor ambient temperature is low. At this time, it is determined whether the low-temperature shut-off valve detection condition is met, that is, it is determined whether the operating parameters of the compressor exceed the first preset parameter threshold within the second preset time and the third preset time interval, and the indoor coil temperature When the indoor initial coil temperature meets the preset conditions and the operating frequency of the compressor exceeds the second preset parameter threshold, and the outdoor environment does not exceed the preset temperature threshold, the operating parameters of the compressor exceed the first preset parameter threshold, the indoor coil is stable, the indoor initial coil temperature meets the preset conditions, and the operating frequency of the compressor exceeds the second preset parameter threshold, it is considered that the low-temperature stop valve detection conditions are met. It can be understood that when the low-temperature stop valve detection conditions are met, the stop valve faults are temporarily counted, which can solve the problem of misjudgment of the stop valve not opening fault due to the outdoor temperature being too low and the exhaust pressure building up slowly when the compressor is cold-started for the first time, and the operating parameters of the compressor changing slowly, thereby reducing missed judgments. Therefore, when making a stop valve fault judgment, low-temperature detection is performed first to reduce the probability of missed judgments.

[0120] After determining that the low-temperature stop valve detection conditions are met, the compressor is controlled to shut down actively to avoid failure to trigger the compressor overcurrent protection shutdown action within the specified time, causing damage to the compressor, and restart the compressor after the first low-temperature preset time, for example, 3 minutes, and judge whether the stop valve detection conditions are met, and judge again whether the stop valve detection conditions are met. When it is determined that the stop valve detection conditions are met again, the stop valve fault temporary count is considered valid, otherwise, the stop valve fault temporary count is considered invalid.

[0121] Determine whether the stop valve detection condition is met, that is, determine whether the operating parameter of the compressor is detected to exceed the first preset parameter threshold within the fourth preset operating time; trigger the overcurrent protection shutdown within the fifth preset time and the sixth preset time interval; determine the indoor coil temperature and the indoor initial coil temperature at the instant before the overcurrent protection shutdown, and when the indoor coil temperature and the indoor initial coil temperature meet the preset conditions and the sixth preset time does not exceed the second preset time, determine that the stop valve condition is met. At this time, determine that the stop valve fault temporary count is valid, and count the stop valve times. When the stop valve temporary count and the stop valve fault count meet the preset times, for example, twice, determine that the stop valve is faulty.

[0122] For example, taking the compressor operating parameter as the compressor phase current as an example, the second preset time is recorded as t1, the third preset time is recorded as t2, the first preset parameter threshold is recorded as I1, the indoor coil temperature is recorded as Tc, the indoor initial coil temperature is recorded as Tc0, the compressor operating frequency is recorded as F, the second preset frequency parameter threshold is recorded as F1, the fourth movement preset time is, for example, 0-t3 minutes, the fifth preset time is t3, and the sixth preset time is t4.

[0123] When the air conditioner outdoor controller is powered on for the first time and the air conditioner is turned on for heating, if the outdoor ambient temperature Tout0 is less than T1, the compressor running time is within the range of t1 to t2, the compressor phase current is greater than or equal to I1, the indoor coil temperature and the indoor initial coil temperature meet the preset conditions, and the compressor operating frequency F is greater than or equal to F1, it is determined that the low-temperature stop valve detection conditions are met, and it is judged that the stop valve may have a closed fault, and the compressor is controlled to shut down actively.

[0124] After the first low-temperature preset time, the compressor is restarted. When the start-up time of the compressor is in the range of 0-t3 minutes, the phase current of the compressor is greater than or equal to the first preset parameter I1. After that, the current continues to increase with time. In the range of t3 to t4, it is detected that the overcurrent protection shutdown is triggered, and the indoor coil temperature and the indoor initial coil temperature before the overcurrent protection shutdown are obtained. When the indoor coil temperature and the indoor initial coil temperature meet the preset conditions and the sixth preset time t4 is less than or equal to the second preset time t1, it is considered that the stop valve temporary count is valid, and the number of stop valve failures is accumulated. At this time, it is considered that the stop valve failure count and the stop valve failure temporary count meet the preset number of times, for example, twice, and the stop valve failure is determined.

[0125] According to some embodiments of the air conditioner of the present application, when the air conditioner is first powered on and heating is started, the outdoor ambient temperature is detected to determine whether a low-temperature stop-valve detection condition is met. By determining whether the low-temperature stop-valve detection condition is met, a temporary stop-valve fault count is counted. This can solve the problem of misjudgment of a stop-valve failure due to slow exhaust pressure buildup and slow changes in compressor operating parameters during the first cold start of the compressor due to excessively low outdoor temperature, thereby reducing missed faults. After the low-temperature stop-valve detection condition is met, it is determined whether a stop-valve detection condition is met. If all of the above detection conditions are met, the stop-valve fault count is counted until the stop-valve fault count and the temporary stop-valve fault count reach a preset number, thereby determining that a stop-valve failure has occurred. When determining whether the stop-valve detection condition is met, since the operating parameters of the air conditioner when the stop-valve failure has occurred differ from the operating parameters when the indoor motor is stalled or the power supply voltage is extremely low, by detecting whether the stop-valve detection condition is met, misjudgment of a stop-valve failure due to compressor shutdown caused by usage scenarios such as indoor motor stalling or extremely low power supply voltage can be avoided, thereby improving the accuracy of the stop-valve failure failure and reducing user complaints caused by misjudgments.

[0126] In some embodiments, determining whether the low-temperature stop valve detection conditions are met includes: within the second preset time and the third preset time interval, the operating parameters of the compressor exceed the first preset parameter threshold, and the indoor coil temperature and the indoor initial coil temperature meet the preset conditions, and the operating frequency of the compressor exceeds the second preset frequency parameter threshold. By detecting the operating parameters of the compressor, the indoor coil temperature and the indoor initial coil temperature and the operating frequency of the compressor, it can be determined based on the above parameters whether the low-temperature stop valve detection conditions are met.

[0127] In some embodiments, under low temperature conditions in winter, if the stop valve is not opened, when the outdoor unit controller is powered on for the first time and the air conditioner starts the heating mode, the rising rate of the compressor's operating parameters is significantly lower than the rising rate of the compressor's operating parameters when it is restarted or started multiple times.

[0128] During low-temperature operation, when the compressor is first started from a cold state, the exhaust pressure builds relatively slowly, and the corresponding phase current of the compressor also rises erratically. In this case, the overcurrent protection shutdown will not be triggered within the specified time, for example, within the sixth and seventh preset time intervals. In this case, if the low-temperature shut-off valve detection conditions are not determined to be met, it is easy to determine that the shut-off valve has not been faulted during the air conditioner's first low-temperature operation, thereby missing the detection of the shut-off valve fault. It is understandable that during low-temperature or ultra-low-temperature operation, if the overcurrent protection shutdown is detected within the specified time period, a missed detection may occur, resulting in a late detection. Since a shut-off valve fault that has not been triggered is extremely dangerous, it is necessary to determine whether the compressor has been faulted within the shortest possible time.

[0129] After the compressor is started once, it has been preheated, and the exhaust pressure and the phase current of the compressor will rise sharply in a short period of time. In order to avoid misjudgment of the stop valve not opening fault, it is necessary to make relevant judgments based on the curve of the stop valve not opening fault under normal temperature conditions.

[0130] In some embodiments, when determining whether the stop valve detection conditions are met, the lengths of the sixth preset time and the second preset time need to be detected. If the sixth preset time exceeds the second preset time, it is determined that the temporary count of the stop valve failure is invalid, and it is determined again whether the stop valve detection conditions are met. When the number of stop valve failures meets the preset number, it is determined that the stop valve is faulty.

[0131] In some embodiments, when determining whether the shut-off valve detection condition is met, if the sixth preset time exceeds the second preset time, it is considered that no overcurrent protection shutdown is detected within the preset time period, or the duration of the overcurrent protection shutdown being detected is too long. At this time, it is determined that the temporary shut-off valve fault count is invalid, and then it is determined again whether the shut-off valve detection condition is met, and when the shut-off valve fault count reaches a preset number of times, for example, two times, the shut-off valve fault is determined.

[0132] In some embodiments, when the indoor coil temperature and the indoor initial coil temperature meet the preset conditions, the difference between the indoor coil temperature and the indoor initial coil temperature is calculated. By calculating the difference between the indoor coil temperature and the indoor initial coil temperature, when the difference is less than a second preset parameter threshold, it is determined that the indoor coil temperature and the indoor initial coil temperature meet the preset conditions. Since no refrigerant flows through the indoor heat exchanger when the stop valve is not opened, the refrigerant in the outdoor heat exchanger is quickly drawn away, and the indoor coil temperature theoretically remains unchanged. By calculating the difference between the indoor coil temperature and the indoor initial coil temperature, when the difference is less than the second preset parameter threshold, it is considered that the indoor coil temperature remains basically unchanged, and this is used as one of the stop valve detection conditions.

[0133] In some embodiments, whether the indoor coil temperature and the indoor initial coil temperature meet a preset condition is determined. That is, the difference between the indoor coil temperature and the indoor initial coil temperature, for example, Tc-Tc0, is calculated, and the difference is compared with a second preset parameter threshold, for example, the relationship between the difference and ΔT1. When Tc-Tc0≤ΔT1, it is considered that the indoor coil temperature and the indoor initial coil temperature meet the preset condition. By comparing the relationship between the difference between the indoor coil temperature and the indoor initial coil temperature and ΔT1, the accuracy of determining the shut-off valve failure can be improved.

[0134] In some embodiments, when the low-temperature stop valve detection condition is not met, the compressor is controlled to continue running until the continuous running time of the compressor reaches the seventh preset time, and the stop valve failure is no longer judged, wherein the seventh preset time is greater than the third preset time. If the compressor overcurrent protection shutdown action is not detected within the specified time, the running time of the compressor is counted. When the running time reaches the seventh preset time, it is considered that the stop valve detection condition is not met and the stop valve failure does not exist.

[0135] In some embodiments, when the air conditioner is turned on for heating operation, if the low-temperature shut-off valve detection condition is not met, the compressor is controlled to remain on and the continuous operation time of the compressor is counted until the continuous operation time of the compressor reaches a seventh preset time, for example, 10 minutes. It is then determined that the shut-off valve has not failed to open. At this time, the compressor operating parameters and the indoor coil temperature are no longer checked to see if they meet the preset conditions. That is, the shut-off valve is no longer determined to have failed to open, and all data related to the determination of the shut-off valve failure is cleared. By obtaining the continuous operation time of the compressor and no longer determining whether the shut-off valve detection condition is met when the continuous operation time of the compressor reaches the seventh preset time, it is possible to avoid misjudgments of shut-off valve failures caused by unknown external environments and unknown electromagnetic interference, thereby improving the reliability of shut-off valve determinations.

[0136] In some embodiments, when it is determined that the stop valve detection condition is not met, the compressor is controlled to continue running, and the running time of the compressor is counted until the cumulative running time of the compressor reaches the eighth preset time, and the stop valve non-opening fault is no longer judged, wherein the eighth preset time is greater than the seventh preset time, wherein, when the stop valve detection condition is judged, it is necessary to detect the fault count of the stop valve. If the fault count of the stop valve does not reach the preset number of times, for example, when the fault count of the stop valve is 1, it is considered that the compressor has a shutdown action, but when it is judged again whether the stop valve condition is met, the compressor overcurrent protection shutdown action is not triggered, then the running time of the compressor is counted, and when the cumulative running time of the compressor reaches the eighth preset time, it is considered that the stop valve detection condition is not met and the stop valve does not have a non-opening fault.

[0137] In some embodiments, when the stop valve detection condition is not met and the stop valve fault count has not reached a preset number of times, the compressor is controlled to continue running, and the running time of the compressor is counted until the cumulative running time of the compressor reaches the ninth preset time, for example, 30 minutes. The operating parameters of the compressor and the indoor coil temperature value are no longer detected to see whether they meet the preset conditions. By obtaining the cumulative running time of the compressor and when the cumulative running time of the compressor reaches the ninth preset time, it is no longer determined whether the stop valve detection condition is met. This can avoid misjudgment of stop valve failure caused by external unknown environment and unknown electromagnetic interference, thereby improving the reliability of stop valve judgment.

[0138] It is understandable that, under normal circumstances, the shut-off valve failure may only occur once. When the air conditioner is not in use, the user will actively cut off the power to the air conditioner, or even if the indoor unit is powered on, when it is not turned on, the indoor controller will automatically cut off the power to the outdoor controller. Once the outdoor controller is powered off, the operating parameters of the compressor, the coil temperature value of the indoor heat exchanger, and the data of the air conditioner's execution of the shut-off valve protection strategy will be lost. Therefore, each time the outdoor controller is powered on again, the shut-off valve failure detection and judgment process will be carried out.

[0139] In some embodiments, when it is determined that the stop valve is faulty, an alarm signal of the stop valve fault is issued, and the compressor is controlled to stop and not automatically start again.

[0140] In some embodiments, when the stop valve failure count reaches a preset number of times, for example, twice, it is determined that the stop valve is not open, and an alarm message of stop valve failure is issued, and the compressor is controlled to no longer start automatically, and the stop valve failure judgment is no longer performed, and all data related to the judgment that the stop valve is not open is cleared.

[0141] In some embodiments, the compressor operating parameter includes any one of: a phase current of the compressor, an input power of the compressor, a whole input power of the air conditioner, and a whole input current of the air conditioner.

[0142] In some embodiments, the operating parameters of the compressor can be any one of the effective value of the compressor, the compressor input power, the whole machine input power of the air conditioner and the whole machine input current of the air conditioner. It can be understood that when the air conditioner is running in heating mode, the stop valve is closed and the refrigerant is compressed in a very small space, causing the exhaust pressure to rise sharply and the suction pressure to drop sharply, causing the suction and exhaust pressure difference to increase sharply, thereby causing the system load to increase sharply and act on the compressor drive control. In the compressor drive control, the increase in load may cause the compressor input power to increase, the compressor phase current to increase at the same voltage, the whole machine input power to increase, the whole machine input current to increase at the same voltage, etc. Therefore, any one of the above can be selected as the operating parameter of the compressor.

[0143] At present, the compressor uses a permanent magnet synchronous motor. The general FOC algorithm needs to undergo current coordinate transformation to convert the compressor phase current in the rotating coordinate system into the D-axis and Q-axis currents in the stationary coordinate system, and control the D-axis and Q-axis currents. When the phase current of the compressor increases, the corresponding D-axis current and Q-axis current also increase accordingly. The essence of the FOC algorithm is to combine the three-directional current vectors and then decompose them into two components perpendicular and parallel to the stationary coordinate system. The D-axis current and Q-axis current can be obtained by calculating and transforming the phase current in the rotating coordinate system through a function, that is, the D-axis current and Q-axis current are the currents after the phase current has undergone coordinate transformation. Therefore, the D-axis current, Q-axis current, or a combination of the D-axis and Q-axis are used to judge the operating parameters of the compressor.

[0144] The compressor's phase current is typically a sinusoidal wave. Sine wave current values ​​can be described in two ways: RMS (effective value) and peak (peak). The RMS value is the RMS value of the current, while the peak value is the instantaneous maximum current over a specific period. When the controller controls based on the detected current, it continuously monitors the instantaneous phase current and compares it to the maximum instantaneous current over a specific period, i.e., the phase current peak value. The RMS value is also calculated based on the peak value to determine the compressor's operating parameters.

[0145] For example, within the first preset time, such as 40 seconds, if it is detected that the phase current of the compressor exceeds the first preset parameter threshold, such as exceeding 12A, the phase current of the compressor will continue to be detected; it is also possible that at 40 seconds, it is detected that the input power of the compressor exceeds the first preset parameter threshold, such as exceeding 4.2W, the input power of the compressor will continue to be detected; it is also possible that at 40 seconds, it is detected that the entire input power of the air conditioner exceeds the first preset parameter threshold, such as exceeding 4.3W, the entire input power of the air conditioner will continue to be detected; it is also possible that at 40 seconds, it is detected that the entire input current of the air conditioner exceeds the first preset parameter threshold, such as exceeding 18A, the entire input current of the air conditioner will continue to be detected; it is also possible that at 40 seconds, it is detected that the Q-axis current of the compressor exceeds the first preset parameter threshold, such as exceeding 10A, the Q-axis current of the compressor will continue to be detected.

[0146] The following example illustrates the fault detection of the stop valve. The parameter settings of the air conditioner are as follows:

[0147] The second preset time t1 = 3 min, the third preset time t2 = 6 min, the fourth motion preset time t3 = 1 min, the sixth preset time t4 = 3 min, the seventh preset time t5 = 10 min, the eighth preset time t6 = 30 min, the second preset parameter threshold △T1 = 3°C, the preset temperature threshold T1 = 0°C, the first preset parameter threshold I1 = 12A, and the second preset frequency parameter threshold F1 = 50 Hz.

[0148] In some embodiments, when the outdoor unit controller is powered on for the first time and the air conditioner starts heating, the controller detects the compressor startup time, indoor ambient temperature Tin0 = 10°C, indoor initial coil temperature Tc0 = 11°C, outdoor ambient temperature Tout0 = -7°C, outdoor coil temperature Te0 = -7°C, and exhaust temperature Td0 = -7°C. The compressor phase current is also detected in real time. If, 3 minutes later, at the 5th minute 25 seconds, the compressor phase current I = 12.2A is detected, the compressor operating frequency F = 90Hz, and the indoor coil temperature Tc = 10°C, that is, Tc-Tc0 = 10-11 = -1°C. Since 5 minutes 25 seconds is less than 6 minutes, and at this time I>12A, F>50Hz, and (Tc-Tc0) <3°C, the compressor is automatically shut down and temporarily counted once.

[0149] After 3 minutes, the compressor restarts and continues to monitor phase current and other data in real time. If, at 35 seconds, the phase current is less than the fifth preset time t3 = 1 minute and is detected to be 12.2A, phase current monitoring continues. If, at 55 seconds, the phase current is less than the seventh preset time t4 = 3 minutes, the controller triggers an overcurrent protection shutdown, and the shutdown time is detected as Tc = 21.5°C. At this time, Tc-Tc0 = 21.5-21 = 0.5°C < ΔT1 = 3°C, resulting in a count of 1. Since the fault shutdown time is 55 seconds less than the initial power-on active shutdown time of 5 minutes and 25 seconds, the first count is valid. At this point, the cumulative count reaches 2, reporting a shutoff valve failure, and the system will no longer restart.

[0150] In some embodiments, when the outdoor unit controller is powered on for the first time, the air conditioner starts heating and the compressor starts. The controller detects the indoor ambient temperature Tin0 = 10°C, the indoor initial coil temperature Tc0 = 11°C, the outdoor ambient temperature Tout0 = -7°C, the outdoor coil temperature Te0 = -7°C, and the exhaust temperature Td0 = -7°C at the start-up time. The compressor phase current is detected in real time. If the compressor phase current I = 12.2A, the compressor operating frequency F = 90Hz, and the indoor coil temperature Tc = 10°C at 5min25s after 3min, that is, Tc-Tc0 = 10-11 = -1°C, since 5min25s is less than 6min, and I>12A, F>50Hz at this time,

[0151] (Tc-Tc0)<3℃. Automatically stop the compressor and temporarily count once.

[0152] 3min to restart the compressor, continue to detect phase current and other data in real time. 8min, greater than the third preset time = 2min, detect the phase current

[0153] =12.2A, compressor operating frequency F =100Hz, indoor coil temperature Tc =35°C, the compressor runs for 10 minutes, which is equal to the eighth preset time t5 = 10 minutes, and no overcurrent shutdown fault is detected. Temporary count 1 is cleared to 0, and the shutoff valve closed fault is no longer detected.

[0154] According to some embodiments of the air conditioner of the present application, when the air conditioner is first powered on and heating is started, the outdoor ambient temperature is detected to determine whether a low-temperature stop-valve detection condition is met. By determining whether the low-temperature stop-valve detection condition is met, a temporary stop-valve fault count is counted. This can solve the problem of misjudgment of a stop-valve failure due to slow exhaust pressure buildup and slow changes in compressor operating parameters during the first cold start of the compressor due to excessively low outdoor temperature, thereby reducing missed faults. After the low-temperature stop-valve detection condition is met, it is determined whether a stop-valve detection condition is met. If all of the above detection conditions are met, the stop-valve fault count is counted until the stop-valve fault count and the temporary stop-valve fault count reach a preset number, thereby determining that a stop-valve failure has occurred. When determining whether the stop-valve detection condition is met, since the operating parameters of the air conditioner when the stop-valve failure has occurred differ from the operating parameters when the indoor motor is stalled or the power supply voltage is extremely low, by detecting whether the stop-valve detection condition is met, misjudgment of a stop-valve failure due to compressor shutdown caused by usage scenarios such as indoor motor stalling or extremely low power supply voltage can be avoided, thereby improving the accuracy of the stop-valve failure failure and reducing user complaints caused by misjudgments.

[0155] The following describes a method for detecting a stop valve failure of an air conditioner according to some embodiments of the present application.

[0156] like Figure 9 As shown, the method for detecting a stop valve failure of an air conditioner in some embodiments of the present application at least includes: steps S21 to S27.

[0157] Step S21 , when the air conditioner is powered on for the first time and starts heating operation, the outdoor ambient temperature and the indoor initial coil temperature at the time of compressor startup are obtained.

[0158] Step S22: When the outdoor ambient temperature does not exceed the preset temperature threshold, it is determined whether a low-temperature stop valve detection condition is met.

[0159] Step S23: If the low-temperature stop valve detection condition is met, the compressor is controlled to stop and the stop valve failure is temporarily counted.

[0160] Step S24: After the first preset time, determine whether the stop valve detection condition is met.

[0161] Step S25, when the stop valve detection condition is met, determine that the stop valve fault temporary count is valid, and count the stop valve times, and when the stop valve temporary count and the stop valve fault count meet the preset times, determine that the stop valve is faulty.

[0162] Step S26: Control the compressor to continue running.

[0163] Step S27 , determining that the temporary stop valve fault count is invalid, and determining again that the stop valve detection condition is met.

[0164] According to some embodiments of the present application, a method for detecting a stop valve fault in an air conditioner is used to detect the outdoor ambient temperature when the air conditioner is first powered on and heating is started. A temporary count of stop valve faults is performed based on the determination of whether the low-temperature stop valve detection condition is met. This method can address the problem of misjudgment of a stop valve failure due to slow exhaust pressure buildup and slow changes in compressor operating parameters during the initial cold start of the compressor caused by excessively low outdoor temperature, thereby reducing missed detections. After the low-temperature stop valve detection condition is met, a determination is made as to whether a stop valve detection condition is met. If all of the above detection conditions are met, stop valve faults are counted until the stop valve failure count and the temporary count of stop valve failures reach a preset number, thereby determining that a stop valve failure has occurred. When determining whether the stop valve detection condition is met, the operating parameters of the air conditioner differ from those in the case of an indoor motor stall or an extremely low power supply voltage when the stop valve failure has occurred. By detecting whether the stop valve detection condition is met, misjudgment of a stop valve failure due to compressor shutdown caused by scenarios such as an indoor motor stall or an extremely low power supply voltage can be avoided. This improves the accuracy of the stop valve failure failure and reduces user complaints caused by misjudgments.

[0165] In some embodiments, as Figure 10 , which is a schematic diagram of changes in operating parameters of an air conditioner when the stop valve is not opened in some embodiments of the present application.

[0166] like Figure 10Figure (a) shows the curves of indoor and outdoor coil temperatures when the shutoff valves are closed, as seen in some embodiments of the present application. When all shutoff valves are closed, the refrigerant is compressed between the compressor exhaust and the rough shutoff valve. No refrigerant flows through the test indoor heat exchanger, while refrigerant is rapidly withdrawn from the outdoor heat exchanger. The indoor coil temperature, indoor ambient temperature, and outdoor ambient temperature remain constant at the laboratory temperature. The outdoor coil temperature initially decreases rapidly and slightly, then slowly increases, eventually approaching and ultimately matching the outdoor ambient temperature.

[0167] like Figure 10 (b) shows a schematic diagram of the curve structure of the exhaust pressure and suction pressure in the closed state of the stop valve in some embodiments of the present application. When the air conditioner is in heating operation, all the stop valves are closed. Due to the abnormality of the air conditioner, the exhaust pressure of the compressor rises sharply, and the pressure difference between the suction pressure and the exhaust pressure increases sharply. Among them, the exhaust pressure rises sharply, and the maximum value before the protection shutdown far exceeds the maximum exhaust pressure Pdmax. The suction pressure drops sharply until it drops to 0 atmosphere and stabilizes at 0 atmosphere. At this time, it is equivalent to the outdoor heat exchanger side being in a vacuum state. If the fine stop valve is not sealed tightly or leaks slightly, air can easily be drawn in, further increasing the danger. At this time, 0 atmosphere is significantly lower than the minimum suction pressure Psmin.

[0168] like Figure 10 Figure (c) shows a schematic diagram of the phase current curve changes when the shutoff valve is closed in some embodiments of the present application. When the pressure difference between the compressor's suction and discharge pressures increases dramatically, the compressor motor load increases sharply, causing the compressor phase current to rise sharply, significantly exceeding the maximum phase current value Imax specified for the air conditioner. At the same time, the increased discharge pressure and pressure difference can easily exceed the operating requirements of the compressor or the controller, resulting in a rapid overcurrent protection fault and shutdown.

[0169] Depend on Figure 10It can be seen that when the stop valve is not open and the air conditioner is running in heating mode, since the stop valve is closed, no refrigerant flows through the indoor heat exchanger, the indoor coil temperature will not change significantly, and the pressure difference between the exhaust pressure and the suction pressure of the compressor increases sharply, causing the load of the compressor motor to increase sharply, resulting in a sharp increase in the operating parameters of the compressor, such as the phase current of the compressor, which greatly exceeds the maximum phase current value Imax specified by the entire platform. At the same time, the increased exhaust pressure and pressure difference are very likely to exceed the use requirements of the compressor or the use requirements of the controller, causing a rapid overcurrent protection fault alarm and shutdown. It can be understood that when the stop valve is not open, the indoor coil temperature, the operating parameters of the compressor and the operating status of the compressor will change significantly. Therefore, when detecting whether there is a stop valve failure that is not open, the indoor coil temperature, the operating parameters of the compressor and the operating status of the compressor are detected. When the above parameter changes meet the parameter change rules when the stop valve is not open, it is determined whether the cause of the parameter abnormality is that the stop valve is not open.

[0170] Some embodiments of the present application obtain the operating parameters of multiple compressors and multiple indoor coil temperatures, and detect the operating parameters of the compressors and the indoor coil temperatures to determine whether the stop valve has a fault. Since when the stop valve fails to open, the operating parameters of the compressor and the indoor coil temperatures have a specific change pattern, by detecting whether the operating parameters of multiple compressors and multiple indoor coil temperatures meet the preset conditions, it is possible to accurately determine whether the stop valve has a failure to open, avoid missed judgments and misjudgments caused by indoor motor jams, indoor motor failure shutdowns, or overcurrent protection shutdowns caused by ultra-low user power supply voltage, thereby improving the accuracy of the judgment of the stop valve failure to open and avoiding user complaints caused by misjudgments.

[0171] like Figure 6 As shown, the air conditioner 1 of some embodiments of the present application includes: a refrigerant circulation loop 11, an outdoor heat exchanger 12, an indoor heat exchanger 13, an indoor coil temperature sensor 14, an outdoor unit 15, an outdoor unit casing 16, a compressor 17, a stop valve 18 and a controller 19, wherein,

[0172] The refrigerant circulation loop 11 allows the refrigerant to circulate in the circulation loop through the compressor 17, condenser, expansion valve and evaporator; the outdoor heat exchanger 12 and the indoor heat exchanger 13, wherein one works as a condenser and the other works as an evaporator; the indoor coil temperature sensor 14 is used to detect the indoor coil temperature; the outdoor unit 15 includes: an outdoor housing 16; a compressor 17; the outdoor heat exchanger 12 and a stop valve 18, wherein the compressor 17 is arranged in the outdoor housing 16 and is used to compress the low-temperature and low-pressure refrigerant gas into a high-temperature and high-pressure refrigerant gas and discharge it to the condenser; the stop valve 18 is arranged in the outdoor unit casing 16, and is used to open or close the refrigerant circulation loop 11; the controller 19 is used to determine the operating parameters of N compressors 17 and the indoor coil temperatures of N indoor heat exchangers 13 when the power is turned on for the first time and the air conditioner is turned on for heating. Since the operating parameters of the compressor 17 will increase sharply, and the increase in its operating parameters presents a relatively obvious increasing trend, at the same time, since the stop valve 18 has a failure to open, no refrigerant flows through the indoor heat exchanger 13, and the indoor coil temperature remains basically unchanged. Therefore, the temperatures of multiple indoor coils are detected.

[0173] When the operating parameters of N compressors and the N indoor coil temperatures meet preset conditions, the compressors are controlled to stop. After the first low temperature preset time, the operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers are determined again. When the operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers meet the preset conditions for a preset number of times, a stop valve failure is determined, and the compressors are controlled to stop, so as to realize stop valve fault detection.

[0174] In some embodiments, when the controller is powered on for the first time and the air conditioner is operating in heating mode, the indoor ambient temperature and indoor coil temperature at the time the compressor is started are detected and stored. At this time, the operating parameters of N compressors and the indoor coil temperatures of N indoor heat exchangers are determined, and the operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers are detected to determine whether the operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers meet preset conditions. If the parameters meet the preset conditions, it is determined that the shutoff valve may not be open, and the compressor is controlled to shut down. At this time, the number of times the operating parameters of the compressors and the indoor coil temperatures of the indoor heat exchangers meet the preset conditions is counted. For example, the number of times the operating parameters of the compressors and the indoor coil temperatures meet the preset conditions is counted as 1.

[0175] After the compressor is controlled to shut down, the compressor is restarted after a first low temperature preset time, such as 3 minutes, has elapsed. The operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers are re-determined. The phase currents of the N compressors and the indoor coil temperatures of the N indoor heat exchangers are analyzed again. When the phase currents of the compressors and the indoor coil temperatures meet preset conditions, it is determined that the shutoff valve may not be open, and the compressor is controlled to shut down. At this time, the number of times the compressor operating parameters and the indoor coil temperature meet the preset conditions is counted again as 1. The shutoff valve is determined to be open when the compressor operating parameters and the indoor coil temperature meet the preset conditions a preset number of times, such as twice. When the air conditioner is turned on for heating operation, the operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers are analyzed. When the compressor operating parameters and the indoor coil temperature meet the preset conditions a preset number of times, it is determined that the shutoff valve is not open.

[0176] It is understandable that when the stop valve is not open, the changes in the indoor coil temperature and the operating parameters of the compressor are significantly different from the changes in the indoor coil temperature and the operating parameters of the compressor when the indoor motor is blocked or shut down due to a fault, and the AC power supply voltage is extremely low. Therefore, by detecting the indoor coil temperature and the operating parameters of the compressor, the stop valve failure can be quickly and accurately determined, and when the operating parameters of the compressor and the indoor coil temperature of the indoor heat exchanger meet the preset conditions, the compressor is controlled to shut down without waiting for the overcurrent protection shutdown, which can make the protection timing earlier.

[0177] For example, taking the compressor operating parameter as the compressor phase current, when the outdoor controller is powered on for the first time and the heating is running, the phase currents of N compressors and the indoor coil temperatures of N indoor heat exchangers are determined, and the phase currents of the N compressors are respectively recorded as I(1), I(2), ...I(n-1), I(n), and the indoor coil temperatures of the N indoor heat exchangers are, for example, recorded as Tc(1), Tc(2), ...Tc(n-1), Tc(n). At this time, it is judged whether the phase current of the compressor and the indoor coil temperature of the indoor heat exchanger meet the preset conditions. When the phase current of the compressor and the indoor coil temperature of the indoor heat exchanger meet the preset conditions, it is judged that the stop valve may not be opened, and the compressor is actively controlled to stop, and the number of times the phase current of the compressor and the indoor coil temperature of the indoor heat exchanger meet the preset conditions is counted as 1.

[0178] After the compressor is controlled to stop, after a first low temperature preset time, for example 3 minutes, the phase current of the compressor and the indoor coil temperature of the indoor heat exchanger are detected again, and when the phase current of the compressor and the indoor coil temperature of the indoor heat exchanger meet the preset conditions for a preset number of times, it is determined that the stop valve is not open.

[0179] According to the air conditioner of some embodiments of the present application, when the air conditioner is powered on for the first time and the heating operation is started, the operating parameters of N compressors and N indoor coil temperatures are analyzed. When the stop valve fails to open, the operating parameters of the compressor and the indoor coil temperature meet the preset conditions, while in other faults, such as the indoor AC motor is blocked or shut down due to a fault and the AC power supply voltage is extremely low, the operating parameters of the compressor and the indoor coil temperature do not meet the preset conditions. Therefore, by detecting the operating parameters of the compressor and the indoor coil temperature, and when the operating parameters of the compressor and the N indoor coil temperatures meet the preset conditions for a preset number of times, it is determined that the stop valve has not opened. This avoids misjudgment of the fault caused by the compressor shutdown due to usage scenarios such as indoor motor blocking or extremely low power supply voltage, thereby improving the accuracy of the stop valve failure that does not open, reducing the air conditioner lock caused by misjudgment, and reducing user complaints. When the compressor operating parameters and the indoor coil temperature of the indoor heat exchanger meet the preset conditions, the compressor is controlled to stop without waiting for the overcurrent protection shutdown, which can make the protection timing earlier.

[0180] In some embodiments, the operating parameters of N compressors and N indoor coil temperatures meet preset conditions, that is, the difference between the operating parameter value of the compressor at a later moment and the operating parameter of the compressor at a previous moment is a positive value, and the difference is greater than the second preset parameter threshold, and the operating parameter of the compressor is greater than the first preset parameter threshold, and the temperature difference between the indoor coil temperature and the indoor initial coil temperature does not exceed the third preset parameter threshold. It is considered that the operating parameters of the compressor and the indoor coil temperature meet the preset conditions.

[0181] Specifically, by calculating the difference between the operating parameter value of the compressor at a later moment and the operating parameter of the compressor at a previous moment, the difference between the operating parameters of N-1 compressors is obtained, and the temperature difference between N indoor coil temperatures and the indoor initial coil temperature is calculated to obtain the temperature difference of N compressors; and when the difference between the operating parameter of the compressor at a later moment and the operating parameter of the compressor at a previous moment is positive, and the operating parameters of the compressor are all greater than the first preset parameter threshold, and the difference between the N-1 operating parameters exceeds the second preset parameter threshold, and when the N temperature differences do not exceed the third preset parameter threshold, it is determined that the compressor operating parameter value and the coil temperature meet the preset conditions. By judging whether the operating parameters and the coil temperature of the compressor meet the preset conditions, it can be accurately judged whether there is a shut-off valve failure.

[0182] In some embodiments, when determining whether the compressor operating parameters and the indoor coil temperature meet the preset conditions, the compressor operating parameters and the indoor coil temperature are detected.

[0183] For example, taking the compressor operating parameter as the compressor phase current as an example, determine whether the compressor phase current and the indoor coil temperature meet the preset conditions. The compressor phase currents are respectively recorded as I(1), I(2), I(3)…I(n-1), I(n), and the indoor coil temperatures of the indoor heat exchanger are respectively recorded as Tc(1), Tc(2), Tc(3)…Tc(n-1), Tc(n). At this time, calculate the difference between the compressor phase current at the next moment and the compressor phase current at the previous moment, that is, calculate I(n)-I(n-1), I(3)-I(2), and so on to calculate I(2)-I(1), until the difference between the phase currents of N-1 compressors is obtained, and calculate the temperature difference between the N indoor coil temperatures and the indoor initial coil temperature, that is, calculate Tc(n)-Tc(0), Tc(n-1)-Tc(0), and so on to calculate Tc(1)-Tc (0), when the operating parameters of the compressor at the next moment are all greater than the operating parameters of the compressor at the previous moment, that is, the phase current of the compressor shows an increasing trend, and the operating parameters of the compressor are all greater than the first preset parameter threshold, for example, I(n)>I(n-1)>I(n-2)>…>I(1), and the difference between the phase currents of the N compressors exceeds the second preset parameter threshold, and I(n)-I(n-1)>I2, I(n-1)-I(n-2)>I2, and so on, until I(2)-I(1)>I2, and the N temperature differences do not exceed the third preset parameter threshold, that is, Tc(n)-Tc(0)≤△T1, Tc(n-1)-Tc(0)≤△T1, and so on, until Tc(1)-Tc(0)≤△T1, at this time, it is determined that the operating parameters of the compressor and the coil temperature meet the preset conditions, and when the preset conditions are met, the compressor is controlled to stop. By detecting the indoor coil temperature of the indoor heat exchanger and the operating parameters of the compressor, it is possible to distinguish between a shut-off valve failure and other shutdown conditions caused by overcurrent protection, such as an indoor motor stall or shutdown, or an overcurrent protection shutdown caused by an extremely low power supply voltage. This effectively reduces missed and misjudgments, thereby improving the accuracy of shut-off valve fault diagnosis.

[0184] In some embodiments, when determining the operating parameters of N compressors and the indoor coil temperatures of N indoor heat exchangers, within a second preset time, it is determined whether the operating parameters of the compressors are greater than a first preset parameter threshold; if so, a reference time for the compressor operation is determined; the operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers are determined based on the reference time, and the time when the operating parameters of the compressors are greater than the first preset parameter is used as the reference time for the compressor operation. Based on the operating parameters of the compressors and the indoor coil temperatures determined at the reference time, and using the operating parameters of the compressors and the indoor coil temperatures at the reference time as a reference, the operating parameters of the compressors and the indoor coil temperatures are obtained at regular intervals until the operating parameters of the N compressors and the N indoor coil temperatures are obtained.

[0185] In some embodiments, when determining the operating parameters of N compressors and the indoor coil temperatures of N indoor heat exchangers, it is necessary to detect the compressor phase current within a second preset time (e.g., within 0-t1 minutes) when the outdoor controller of the air conditioner is first powered on and in heating mode. When the compressor phase current is greater than a first preset parameter threshold, a reference time for compressor operation is determined. The first preset parameter threshold is, for example, denoted as I1. That is, when the compressor phase current ≥ I1, this time is used as the reference time for compressor operation, i.e., reference time 0. Based on this reference time 0, the operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers are determined. By determining whether the compressor operating parameters are greater than the second preset parameter threshold within the second preset time, the reference time for compressor operation is determined. The operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers are determined based on this reference time, thereby providing a basis for determining a shutoff valve fault.

[0186] In some embodiments, when determining operating parameters of N compressors and indoor coil temperatures of N indoor heat exchangers based on a reference time, the operating parameters of the compressors and the indoor coil temperatures at the reference time are determined; the operating parameters of N-1 compressors and the indoor coil temperatures are acquired at intervals of a third preset time interval, starting from the reference time; the operating parameters of N compressors are determined based on the operating parameters of the compressors at the reference time and the operating parameters of the N-1 compressors; and the indoor coil temperatures of the N indoor heat exchangers are determined based on the indoor coil temperatures at the reference time and the N-1 indoor coil temperatures, wherein the third preset time interval is less than the first low temperature preset time interval. The operating parameters of the compressors and the indoor coil temperatures of the indoor heat exchangers are acquired at every third preset time interval.

[0187] In some embodiments, after determining a reference time for the compressor, the reference time is used as reference time zero to detect the initial operating parameters and indoor coil temperature of the compressor at that time. Starting from the reference time, the compressor operating parameters and indoor coil temperature are detected and acquired at third preset intervals, starting at the reference time, until N-1 compressor operating parameter values ​​and N-1 indoor coil temperatures are obtained. Furthermore, N compressor operating parameter values ​​are determined based on the compressor operating parameters at the reference time and the N-1 compressor operating parameter values, and the indoor coil temperatures of N indoor heat exchangers are determined based on the indoor coil temperatures at the reference time and the N-1 indoor coil temperatures. By determining the reference time for the compressor and acquiring the operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers, a shutoff valve fault can be detected based on the operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers.

[0188] In some embodiments, when the operating parameters of N compressors and N indoor coil temperatures do not meet the preset conditions, the compressor is controlled to continue running until the continuous running time of the compressor reaches a third preset time, and the operating parameters of the compressor and the indoor coil temperature are no longer detected to see whether they meet the preset conditions, wherein the third preset time is greater than the first low temperature preset time. If the indoor coil temperature and the operating parameters of the compressor do not meet the preset conditions within the specified time, the running time of the compressor is timed. When the running time reaches the third preset time, it is considered that the stop valve detection condition is not met, and the stop valve does not have a non-opening fault.

[0189] In some embodiments, when the air conditioner is turned on for heating, the operating parameters of N compressors and the indoor coil temperatures of N indoor heat exchangers are determined. If the operating parameters of the compressors and the indoor coil temperatures of the indoor heat exchangers do not meet preset conditions, the compressors are controlled to remain on and the duration of continuous operation of the compressors is measured. When the continuous operation of the compressors reaches a third preset time, such as 10 minutes, it is determined that the shutoff valve has not experienced a closed-loop fault. At this time, the compressor operating parameters and the indoor coil temperatures are no longer checked to see if they meet the preset conditions, i.e., the shutoff valve is no longer determined to have a closed-loop fault, and all data related to determining a closed-loop fault is cleared. By obtaining the continuous operation time of the compressors and, when the continuous operation time of the compressors reaches the third preset time, no longer checking to see if the operating parameters of the compressors and the indoor coil temperatures meet the preset conditions, misjudgment of a shutoff valve fault caused by an unknown external environment or unknown electromagnetic interference can be avoided, thereby improving the reliability of shutoff valve determination.

[0190] In some embodiments, when the operating parameters of N compressors and the indoor coil temperatures of N indoor heat exchangers do not meet the preset conditions for a preset number of times, the controller is further configured to: control the compressor to continue running, and count the running time of the compressor until the cumulative running time of the compressor reaches the fourth movement preset time, and no longer detect whether the operating parameters of the compressor and the indoor coil temperature meet the preset conditions, wherein the fourth movement preset time is greater than the third preset time, wherein, when judging whether the operating parameters of the compressor and the indoor coil temperature meet the preset conditions, it is necessary to detect the fault count of the stop valve, if the fault count of the stop valve does not reach the preset number of times, for example, when the fault count of the stop valve is 1, the compressor is controlled to stop, but when judging whether the preset conditions are met again, it is detected that the operating parameters of the compressor and the indoor coil temperature do not meet the preset conditions, then the running time of the compressor is counted, and when the cumulative running time of the compressor reaches the fourth movement preset time, it is considered that the preset conditions are not met, and the stop valve does not have a non-opening fault.

[0191] In some embodiments, when the operating parameters of N compressors and the indoor coil temperatures of N indoor heat exchangers do not meet the preset conditions for a preset number of times, the compressor is controlled to continue running, and the running time of the compressor is counted until the cumulative running time of the compressor reaches a fourth movement preset time, for example, 30 minutes, and the operating parameters of the compressor and the indoor coil temperature are no longer detected to see whether they meet the preset conditions. By obtaining the cumulative running time of the compressor and when the cumulative running time of the compressor reaches the fourth movement preset time, the operating parameters of the compressor and the indoor coil temperature are no longer detected to see whether they meet the preset conditions, the misjudgment of the stop valve failure caused by the external unknown environment and unknown electromagnetic interference can be avoided, thereby improving the reliability of the stop valve judgment.

[0192] It is understandable that, under normal circumstances, the shut-off valve failure may only occur once. When the air conditioner is not in use, the user will actively cut off the power to the air conditioner, or even if the indoor unit is powered on, when it is not turned on, the indoor controller will automatically cut off the power to the outdoor controller. Once the outdoor controller is powered off, the operating parameters of the compressor, the indoor coil temperature of the indoor heat exchanger, and the data of the air conditioner's execution of the shut-off valve protection strategy will be lost. Therefore, each time the outdoor controller is powered on again, the shut-off valve failure detection and judgment process will be carried out.

[0193] In some embodiments, when the operating parameters of N compressors and the indoor coil temperatures of N indoor heat exchangers meet preset conditions for a preset number of times, after the compressors are controlled to stop, an alarm message of a shut-off valve failure is issued, and the compressors are controlled to stop and no longer start automatically.

[0194] In some embodiments, when the operating parameters of the compressor and the indoor coil temperature meet the preset conditions for a preset number of times, that is, the operating parameters of the compressor at the latter moment are greater than the operating parameters of the compressor at the previous moment, and the difference between the N-1 operating parameter values ​​exceeds the second preset parameter threshold, and the number of times that the N temperature differences do not exceed the third preset parameter threshold meets the preset number of times, for example, twice, at this time, it is determined that the stop valve is not open, and an alarm message of stop valve failure is issued, and the compressor is controlled to no longer start automatically.

[0195] In some embodiments, the operating parameter of the compressor includes any one of: an effective value of the compressor, an input power of the compressor, a whole machine input power of the air conditioner, and a whole machine input current of the air conditioner.

[0196] In some embodiments, the operating parameters of the compressor can be any one of the effective value of the compressor, the compressor input power, the whole machine input power of the air conditioner and the whole machine input current of the air conditioner. It can be understood that when the air conditioner is running in heating mode, the stop valve is closed and the refrigerant is compressed in a very small space, causing the exhaust pressure to rise sharply and the suction pressure to drop sharply, causing the suction and exhaust pressure difference to increase sharply, thereby causing the system load to increase sharply and act on the compressor drive control. In the compressor drive control, the increase in load may cause the compressor input power to increase, the compressor phase current to increase at the same voltage, the whole machine input power to increase, the whole machine input current to increase at the same voltage, etc. Therefore, any one of the above can be selected as the operating parameter of the compressor.

[0197] At present, the compressor uses a permanent magnet synchronous motor. The general FOC algorithm needs to undergo current coordinate transformation to convert the compressor phase current in the rotating coordinate system into the D-axis and Q-axis currents in the stationary coordinate system, and control the D-axis and Q-axis currents. When the phase current of the compressor increases, the corresponding D-axis current and Q-axis current also increase accordingly. The essence of the FOC algorithm is to combine the three-directional current vectors and then decompose them into two components perpendicular and parallel to the stationary coordinate system. The D-axis current and Q-axis current can be obtained by calculating and transforming the phase current in the rotating coordinate system through a function, that is, the D-axis current and Q-axis current are the currents after the phase current has undergone coordinate transformation. Therefore, the D-axis current, Q-axis current, or a combination of the D-axis and Q-axis are used to judge the operating parameters of the compressor.

[0198] The compressor's phase current is typically a sinusoidal wave. Sine wave current values ​​can be described in two ways: RMS (effective value) and peak (peak). The RMS value is the RMS value of the current, while the peak value is the instantaneous maximum current over a specific period. When the controller controls based on the detected current, it continuously monitors the instantaneous phase current and compares it to the maximum instantaneous current over a specific period, i.e., the phase current peak value. The RMS value is also calculated based on the peak value to determine the compressor's operating parameters.

[0199] For example, within the first preset time, such as 40 seconds, if it is detected that the phase current of the compressor exceeds the first preset parameter threshold, such as exceeding 12A, the phase current of the compressor will continue to be detected; it is also possible that at 40 seconds, it is detected that the input power of the compressor exceeds the first preset parameter threshold, such as exceeding 4.2W, the input power of the compressor will continue to be detected; it is also possible that at 40 seconds, it is detected that the entire input power of the air conditioner exceeds the first preset parameter threshold, such as exceeding 4.3W, the entire input power of the air conditioner will continue to be detected; it is also possible that at 40 seconds, it is detected that the entire input current of the air conditioner exceeds the first preset parameter threshold, such as exceeding 18A, the entire input current of the air conditioner will continue to be detected; it is also possible that at 40 seconds, it is detected that the Q-axis current of the compressor exceeds the first preset parameter threshold, such as exceeding 10A, the Q-axis current of the compressor will continue to be detected.

[0200] The following is an example of the fault detection of the stop valve, and the parameters of the air conditioner are set as follows.

[0201] The third preset interval time interval is recorded as △t, △t=1 second, the third preset time is recorded as t2, t2=10min, the fourth movement preset time is recorded as t3, t3=30min, the third preset parameter threshold is recorded as △T1, △T1=3℃, the first preset parameter threshold is recorded as I1, I1=12V, the second preset parameter threshold is recorded as I2, I2=1A, the preset number of times is recorded as i, i=2, and the above parameters can be set as needed.

[0202] In some embodiments, when the air conditioner's outdoor unit is powered on for the first time, the heating mode is enabled, and the compressor starts. At this point, the controller detects the indoor ambient temperature and indoor coil temperature at the time the compressor starts: indoor ambient temperature Tin0 = 20°C, indoor coil temperature Tc0 of the indoor heat exchanger = 21°C, outdoor ambient temperature Tout0 = 15°C, outdoor coil temperature Te0 = 15°C, and exhaust temperature Td0 = 15°C. The controller also detects the compressor's phase current in real time.

[0203] During the set time period, for example, at 40 seconds, the phase current of the compressor is detected to be 12A, which is equal to the fourth preset parameter threshold value I1=12A, recorded as I(1)=12A, and the indoor coil temperature is 21°C, recorded as Tc(1)=21°C. After 1 second, the phase current and the indoor coil temperature are detected and recorded as I(2)=13.2A>12A, Tc(2)=21°C respectively; after another 1 second, the phase current and the indoor coil temperature are detected and recorded as I(3)=14.6A>12A, Tc(3)=21°C respectively; after another 1 second, the phase current and the indoor coil temperature are detected and recorded as I(4 )=15.8A>12A, Tc(4)=21℃; calculate I(4)-I(3)=1.2A>1A, I(3)-I(2)=1.4A>1A, I(2)-I(1)=1.2A>1A and Tc(4)-Tc0=21-21=0℃<3℃, Tc(3)-Tc0=21-21=0℃<3℃, Tc(2)-Tc0=21-21=0℃<3℃, Tc(1)-Tc0=21-21=0℃<3℃ respectively. If the above preset conditions are met, there may be a stop valve failure, the compressor is controlled to stop, and the count is 1 time.

[0204] Restart the compressor after 3 minutes and continue to detect phase current and other data in real time. If at 28 seconds, the phase current is detected to be 12A, which is equal to the first preset parameter threshold value I1, recorded as I(1) = 12A, and the indoor coil temperature is 21°C, recorded as Tc(1) = 21°C. After 1 second, detect the phase current and the indoor coil temperature of the indoor heat exchanger, and record them as I(2) = 13.2A > 12A, Tc(2) = 21°C respectively; after another 1 second, detect the phase current and the indoor coil temperature of the indoor heat exchanger, and record them as I(3) = 14.6A > 12A, Tc(3) = 21°C respectively; after another 1 second, detect the phase current and the indoor coil temperature of the indoor heat exchanger, and record them as I(4) = 15.8A > 12A, Tc(4) = 21°C respectively; calculate I( 4)-I(3)=1.2A>1A, I(3)-I(2)=1.4A>1A, I(2)-I(1)=1.2A>1A and Tc(4)-Tc0=21-21=0℃<3℃, Tc(3)-Tc0=21-21=0℃<3℃, Tc(2)-Tc0=21-21=0℃<3℃, Tc(1)-Tc0=21-21=0℃<3℃. If the above preset conditions are met, it may be a stop valve failure, and the compressor will be automatically stopped. Count 1 time.

[0205] When the operating parameters of the compressor and the indoor coil temperature meet the preset conditions for a preset number of times, for example, twice, a stop valve failure is reported, and the compressor is no longer controlled to start automatically.

[0206] In some embodiments, when the outdoor unit of an air conditioner is powered on for the first time, the heating mode is enabled, and the compressor starts. The controller detects the indoor ambient temperature Tin0 = 20°C, the indoor coil temperature Tc0 of the indoor heat exchanger = 21°C, the outdoor ambient temperature Tout0 = 15°C, the outdoor coil temperature Te0 = 15°C, and the exhaust temperature Td0 = 15°C at the time of startup. The controller also detects the compressor phase current in real time.

[0207] If at 59 seconds, the phase current is detected to be 12A, which is equal to the first preset parameter threshold value I1=12A, recorded as I(1)=12A, and the indoor coil temperature is 45℃, recorded as Tc(1)=35℃. 1 second later, the phase current and the indoor coil temperature of the indoor heat exchanger are detected and recorded as I(2)=12.2A>12A, Tc(2)=46℃ respectively; 1 second later, the phase current and the indoor coil temperature of the indoor heat exchanger are detected and recorded as I(3)=12.4A>12A, Tc(3)=47℃ respectively; 1 second later, the phase current and the indoor coil temperature of the indoor heat exchanger are detected and recorded as I(4)=12.2A>12A, Tc(4)=48℃ respectively; calculate I(4)-I(3)=0.2A<1A, I(3)-I(2) respectively.

[0208] =0.2A<1A, I(2)-I(1)=-0.2A<1A and Tc(4)-Tc 0=48-21=27℃>3℃, Tc(3)-Tc 0=47-21=26℃>3℃, Tc(2)-Tc 0=46-21=25℃>3℃, Tc(1)-Tc 0=45-21=24℃>3℃, the above preset conditions are not met and the compressor continues to operate.

[0209] The compressor runs until 10 minutes, which is equal to the fourth movement preset time t3=10 minutes, and there is no abnormality. Then, the stop valve failure will no longer be determined.

[0210] According to the air conditioner of some embodiments of the present application, when the air conditioner is powered on for the first time and the heating operation is started, the operating parameters of N compressors and N indoor coil temperatures are analyzed. When the stop valve fails to open, the operating parameters of the compressor and the indoor coil temperature meet the preset conditions, while in other faults, such as the indoor AC motor is blocked or shut down due to a fault and the AC power supply voltage is extremely low, the operating parameters of the compressor and the indoor coil temperature do not meet the preset conditions. Therefore, by detecting the operating parameters of the compressor and the indoor coil temperature, and when the operating parameters of the compressor and the N indoor coil temperatures meet the preset conditions for a preset number of times, it is determined that the stop valve has not opened. This avoids misjudgment of the fault caused by the compressor shutdown due to usage scenarios such as indoor motor blocking or extremely low power supply voltage, thereby improving the accuracy of the stop valve failure that does not open, reducing the air conditioner lock caused by misjudgment, and reducing user complaints. When the compressor operating parameters and the indoor coil temperature of the indoor heat exchanger meet the preset conditions, the compressor is controlled to stop without waiting for the overcurrent protection shutdown, which can make the protection timing earlier.

[0211] The following describes the air conditioner stop valve fault detection method according to some embodiments of the present application with examples.

[0212] like Figure 11 As shown, the air conditioner stop valve fault detection method of some embodiments of the present application includes at least steps S31 to S37.

[0213] Step S31 : When the air conditioner is powered on for the first time and starts heating operation, the operating parameters of N compressors and the indoor coil temperatures of N indoor heat exchangers are determined.

[0214] In some embodiments, when the controller is powered on for the first time and the air conditioner operates in heating mode, the indoor ambient temperature and indoor coil temperature at the time of compressor startup are detected and stored. At this time, the operating parameters of N compressors and the indoor coil temperatures of N indoor heat exchangers are determined.

[0215] Step S32: Determine whether the operating parameters of the N compressors and the temperatures of the N indoor coils meet preset conditions.

[0216] In step S33, if the operating parameters of the N compressors and the N indoor coil temperatures meet the preset conditions, the compressors are controlled to stop, and after the first low temperature preset time, the operating parameters of the N compressors and the indoor coil temperatures of the N indoor heat exchangers are determined again.

[0217] Step S34 , determining whether the operating parameters of the N compressors and the temperatures of the indoor coils of the N indoor heat exchangers meet the preset conditions for a preset number of times.

[0218] Step S35: When the preset conditions are met for the preset number of times, it is determined that the stop valve is faulty and the compressor is controlled to shut down.

[0219] Step S36, controlling the compressor to continue running.

[0220] Step S37, detecting the running time of the compressor. When the running time of the compressor reaches the fourth movement preset time, no further detection is performed to determine whether the preset condition is met.

[0221] According to the air conditioner of some embodiments of the present application, when the air conditioner is powered on for the first time and the heating operation is started, the operating parameters of N compressors and N indoor coil temperatures are analyzed. When the stop valve fails to open, the operating parameters of the compressor and the indoor coil temperature meet the preset conditions, while in other faults, such as the indoor AC motor is blocked or shut down due to a fault and the AC power supply voltage is extremely low, the operating parameters of the compressor and the indoor coil temperature do not meet the preset conditions. Therefore, by detecting the operating parameters of the compressor and the indoor coil temperature, and when the operating parameters of the compressor and the N indoor coil temperatures meet the preset conditions for a preset number of times, it is determined that the stop valve has not opened. This avoids misjudgment of the fault caused by the compressor shutdown due to usage scenarios such as indoor motor blocking or extremely low power supply voltage, thereby improving the accuracy of the stop valve failure that does not open, reducing the air conditioner lock caused by misjudgment, and reducing user complaints. When the compressor operating parameters and the indoor coil temperature of the indoor heat exchanger meet the preset conditions, the compressor is controlled to stop without waiting for the overcurrent protection shutdown, which can make the protection timing earlier.

[0222] In some embodiments, when the operating parameters of N compressors and N indoor coil temperatures meet preset conditions, it includes: calculating the difference between the operating parameter value of the compressor at a later moment and the operating parameter of the compressor at a previous moment to obtain the difference between the operating parameters of N-1 compressors, and calculating the temperature difference between the N indoor coil temperatures and the indoor initial coil temperature to obtain the temperature difference of the N compressors; when the operating parameters of the compressor at a later moment are all greater than the operating parameters of the compressor at the previous moment, and are all greater than the first preset parameter threshold, and the differences of the N-1 operating parameters all exceed the second preset parameter threshold, and the N temperature differences do not exceed the third preset parameter threshold, it is determined that the compressor operating parameter values ​​and the coil temperature meet the preset conditions.

[0223] In some embodiments, when determining whether the compressor operating parameters and the indoor coil temperature meet the preset conditions, the compressor operating parameters and the indoor coil temperature are detected.

[0224] For example, taking the compressor operating parameter as the compressor phase current as an example, determine whether the compressor phase current and the indoor coil temperature meet the preset conditions. The compressor phase currents are respectively recorded as I(1), I(2), I(3)…I(n-1), I(n), and the indoor coil temperatures of the indoor heat exchanger are respectively recorded as Tc(1), Tc(2), Tc(3)…Tc(n-1), Tc(n). At this time, calculate the difference between the compressor phase current at the next moment and the compressor phase current at the previous moment, that is, calculate I(n)-I(n-1), I(3)-I(2), and so on to calculate I(2)-I(1), until the difference between the phase currents of N-1 compressors is obtained, and calculate the temperature difference between the N indoor coil temperatures and the indoor initial coil temperature, that is, calculate Tc(n)-Tc(0), Tc(n-1)-Tc(0), and so on to calculate Tc(1)-Tc (0), when the operating parameters of the compressor at the next moment are all greater than the operating parameters of the compressor at the previous moment, that is, the phase current of the compressor shows an increasing trend, and the operating parameters of the compressor are all greater than the first preset parameter threshold, for example, I(n)>I(n-1)>I(n-2)>…>I(1), and the difference between the phase currents of the N compressors exceeds the second preset parameter threshold, and I(n)-I(n-1)>I2, I(n-1)-I(n-2)>I2, and so on, until I(2)-I(1)>I2, and the N temperature differences do not exceed the third preset parameter threshold, that is, Tc(n)-Tc(0)≤△T1, Tc(n-1)-Tc(0)≤△T1, and so on, until Tc(1)-Tc(0)≤△T1, at this time, it is determined that the operating parameters of the compressor and the coil temperature meet the preset conditions, and when the preset conditions are met, the compressor is controlled to stop. By detecting the indoor coil temperature of the indoor heat exchanger and the operating parameters of the compressor, it is possible to distinguish between a shut-off valve failure and other shutdown conditions caused by overcurrent protection, such as an indoor motor stall or shutdown, or an overcurrent protection shutdown caused by an extremely low power supply voltage. This effectively reduces missed and misjudgments, thereby improving the accuracy of shut-off valve fault diagnosis.

[0225] In some embodiments, by obtaining the operating parameters of the compressor and the peak phase current of the compressor, and detecting the operating parameters of the compressor and the peak current of the compressor, it is determined whether the stop valve has a fault. Since when the stop valve fails to open, the operating parameters of the compressor and the peak phase current of the compressor have a specific change pattern, by detecting whether the operating parameters of multiple compressors and the peak phase current of the compressor meet the preset conditions, it is possible to accurately determine whether the stop valve has a failure to open, avoid missed judgments and misjudgments caused by indoor motor stalling, indoor motor failure shutdown or user power supply voltage being too low resulting in overcurrent protection shutdown, thereby improving the accuracy of the judgment of the stop valve failure not opening and avoiding user complaints caused by misjudgment.

[0226] like Figure 6 As shown, the air conditioner 1 of some embodiments of the present application includes: a refrigerant circulation loop 11, an outdoor heat exchanger 12, an indoor heat exchanger 13, an indoor coil temperature sensor 14, an outdoor unit 15, an outdoor unit casing 16, a compressor 17, a stop valve 18 and a controller 19, wherein,

[0227] The refrigerant circulation loop 11 allows the refrigerant to circulate in the circulation loop through the compressor 17, condenser, expansion valve and evaporator; the outdoor heat exchanger 12 and the indoor heat exchanger 13, one of which works for the condenser and the other works for the evaporator; the indoor coil temperature sensor 14 is used to detect the indoor coil temperature; the outdoor unit 15 includes: an outdoor casing 16; a compressor 17; the outdoor heat exchanger 12 and a stop valve 18, wherein the compressor 17 is arranged in the outdoor casing 16, and is used to compress the low-temperature and low-pressure refrigerant gas into a high-temperature and high-pressure refrigerant gas and discharge it to the condenser; the stop valve 18 is arranged in the outdoor unit casing 16, and is used to open or close the refrigerant circulation loop 11; when the controller 19 is powered on for the first time and the air conditioner starts heating operation, it determines the operating parameters of N compressors 17 and the phase current peak of the compressor 17. When the stop valve 18 fails to open, the current peak of the compressor 17 increases rapidly, and the operating parameters of the compressor 17 conform to specific rules.

[0228] When the operating parameters of N compressors and the peak value of the phase current of the compressors meet the preset conditions, it is considered that the stop valve may not be open. At this time, the compressor is controlled to stop and count is performed. After the first low-temperature preset time, the operating parameters of the N compressors and the peak value of the phase current of the compressors are determined again. When the operating parameters of the compressors and the peak value of the current of the compressors meet the preset conditions for a preset number of times, for example, when the preset conditions are met twice, it is determined that the stop valve is faulty and the compressor is controlled to stop.

[0229] In some embodiments, when the controller is powered on for the first time and the air conditioner is operating in heating mode, the operating parameters of N compressors and the phase current peaks of the compressors are determined, and the operating parameters of the N compressors and the phase current peaks of the compressors are detected to determine whether the operating parameters of the N compressors and the phase current peaks of the compressors meet preset conditions. When the above parameters meet the preset conditions, it is determined that the shut-off valve may not be open, and the compressor is controlled to stop. At this time, the number of times the operating parameters of the compressors and the current peaks of the compressors meet the preset conditions is counted.

[0230] After controlling the compressor to stop, the compressor is restarted after the first low temperature preset time, for example, 3 minutes later, and the operating parameters of the N compressors and the phase current peak values ​​of the compressors are determined again, and the operating parameters of the N compressors and the phase current peak values ​​of the compressors are detected again to determine whether the operating parameters of the N compressors and the phase current peak values ​​of the compressors meet the preset conditions, and when the operating parameters of the compressors and the current peak values ​​of the compressors meet the preset conditions for a preset number of times, for example, when the operating parameters of the compressors and the current peak values ​​of the compressors meet the preset conditions twice, it is determined that the shut-off valve is not open, so that the shut-off valve failure can be quickly and accurately judged, and when the operating parameters of the compressors and the phase current peak values ​​of the compressors meet the preset conditions, the compressor is controlled to stop without waiting for the overcurrent protection to shut down, which can make the protection timing earlier.

[0231] For example, taking the compressor operating parameter as the compressor phase current, when the outdoor controller is powered on for the first time and the heating is running, the phase currents of N compressors and the current peaks of the compressors are determined, and the phase currents of the N compressors are respectively recorded as I(1), I(2), ...I(n-1), I(n). At this time, it is judged whether the phase current of the compressor and the current peak of the compressor meet the preset conditions. When the phase current of the compressor and the current peak of the compressor meet the preset conditions, it is judged that the shut-off valve may not be opened, and the compressor is actively controlled to stop, and the number of times the phase current of the compressor and the current peak of the compressor meet the preset conditions is counted as 1.

[0232] After the compressor is controlled to stop, after the first low temperature preset time, for example 3 minutes, the phase current of the compressor and the current peak of the compressor are detected again, and when the phase current of the compressor and the current peak of the compressor meet the preset conditions for the preset number of times, it is determined that the shut-off valve is not open.

[0233] It can be understood that the operating parameters of the compressor can be any one of the phase current of the compressor, the input power of the compressor, the overall input power of the air conditioner and the overall input current of the air conditioner. The phase current of the compressor is usually a sine wave. Regarding the description of the size of the sine wave, one is the effective value of the current, and the other is the current peak. The effective value of the phase current is the root mean square value of the current, and the phase current peak is the instantaneous maximum value of the current within a certain period of time. A conventional controller will always detect the instantaneous value of the phase current and compare it to obtain the maximum value of the current within a certain time period, that is, the phase current peak; it will also perform root mean square calculation based on the peak value to obtain the effective value of the phase current.

[0234] According to some embodiments of the air conditioner of the present application, when the air conditioner is first powered on and heating operation is started, the operating parameters of N compressors and the peak values ​​of their phase currents are analyzed. Since the operating parameters and the peak values ​​of the compressor phase currents satisfy a specific pattern when the shut-off valve is not open, the operating parameters and the peak values ​​of the compressor phase currents are detected. Therefore, a shut-off valve failure is determined when the operating parameters and the peak values ​​of the compressor phase currents satisfy a preset condition for a preset number of times. Since the changes in the operating parameters and the phase currents of the compressors when the shut-off valve is not open are significantly different from the corresponding changes in the operating parameters and the phase currents when the indoor motor is stalled or the power supply voltage is extremely low, the shut-off valve failure is determined when the detecting parameters and the phase currents of the compressors satisfy the preset condition. This can avoid misjudgments of compressor shutdowns caused by usage scenarios such as indoor motor stalls or extremely low power supply voltages, thereby improving the accuracy of shut-off valve failure detection, reducing air conditioner lockouts caused by misjudgments, and reducing user complaints. Furthermore, the compressor is controlled to shut down when the operating parameters and the peak values ​​of the compressor currents satisfy the preset conditions, without having to wait for overcurrent protection to shut down, thus enabling earlier protection.

[0235] In some embodiments, it is determined whether the operating parameters of N compressors and the phase current peak of the compressors meet preset conditions. The difference between the operating parameters of the compressor at a later moment and the operating parameters of the compressor at a previous moment is calculated to obtain the difference between the operating parameters of N-1 compressors. When the difference between the operating parameters of the compressor at a later moment and the operating parameters of the compressor at a previous moment is positive, it is considered that the operating parameters of the compressor are on an increasing trend, and the operating parameters of the N compressors all exceed a first preset parameter threshold, and the differences of the N-1 operating parameter values ​​are all greater than a second preset parameter threshold, and the compressor current peak exceeds the preset current threshold, it is determined that the N compressor operating parameter values ​​and the compressor current peak meet the preset conditions. After determining the compressor operating parameters and the compressor current peak, the above parameters are compared with the first preset parameter threshold, and the difference between the operating parameters of two adjacent compressors is compared with the second preset parameter threshold. When the current peak of the compressor exceeds the preset current threshold, it is considered that the compressor operating parameters and the compressor phase current meet the preset conditions.

[0236] In some embodiments, taking the operating parameter of the compressor as the phase current of the compressor as an example, when judging whether the operating parameters of N compressors and the phase current peak of the compressor meet the preset conditions, the difference between the phase current of the compressor at the next moment and the phase current of the compressor at the previous moment is calculated, for example, the difference of I(n)-I(n-1), I(n-1)-I(n-2)...I(2)-I(1) is calculated, and the difference of the phase current of N-1 compressors is calculated by analogy. At this time, it is judged whether the above differences are all positive. If the above differences are all positive, it is considered that the phase current of the compressor at the next moment is greater than the phase current of the compressor at the previous moment, and the operation of the N compressors is The parameters of the operation all exceed the first preset parameter threshold, for example, the phase current of the compressor shows an increasing trend and I(n)>I(n-1)>I(n-2)>…I(1)>I1, and the difference between the phase current of the compressor at the latter moment and the phase current of the compressor at the previous moment is greater than the second preset parameter threshold, the second preset parameter threshold is recorded as I2, that is, I(n)-I(n-1)>I2, I(n-1)-I(n-2)>I2, and so on, I(2)-I(1)>I2, and the current peak of the compressor exceeds the preset current threshold, the preset current threshold is recorded as Imax, that is, the current peak of the compressor ≥Imax, that is, Figure 10 Based on the phase current variation pattern shown in (c), when all of the above conditions are met, it is determined that the operating parameter values ​​and the compressor current peak values ​​of the N compressors meet the preset conditions. By determining the compressor operating parameters and the compressor current peak values, fault detection of the shutoff valve can be performed based on the judgment results.

[0237] In some embodiments, when determining the operating parameters of N compressors and the phase current peak of the compressor, within a second preset time, it is determined whether the operating parameters of the compressor are greater than the first preset parameter threshold. If so, the reference time of the compressor operation is determined, and the reference time is used as the reference time 0 point. The operating parameters of the N compressors and the compressor current peak are determined according to the reference time. By determining the reference time when the operating parameters of the compressor are greater than the first preset parameter threshold, it is convenient to determine the operating parameters of the compressor according to the reference time.

[0238] In some embodiments, to determine the operating parameters and peak phase currents of the N compressors, it is necessary to detect the phase currents of the compressors within a second preset time, e.g., within 0-t1 minutes, when the outdoor controller of the air conditioner is first powered on and in heating mode. When the phase currents of the compressors are greater than a first preset parameter threshold, a reference time for compressor operation is determined. The first preset parameter threshold is, for example, denoted as I1. When the phase current of the compressors is ≥ I1, this time is used as the reference time for compressor operation, i.e., reference time 0. Based on this reference time 0, the operating parameters and peak currents of the N compressors are determined. By determining whether the operating parameters of the compressors are greater than the first preset parameter threshold within the second preset time, the reference time for compressor operation is determined. The operating parameters and peak currents of the N compressors are then determined based on this reference time, thereby providing a basis for determining a shutoff valve fault.

[0239] In some embodiments, when the operating parameters of N compressors and the peak current of the compressor are obtained based on the reference time, the operating parameters of the compressor at the reference time are determined; with the reference time as the time starting point and the third preset interval time as the interval, N-1 compressor operating parameters are obtained, and the compressor peak current is obtained; N compressor operating parameters are determined based on the compressor operating parameter values ​​at the reference time and the N-1 compressor operating parameters, wherein the third preset interval time is less than the first low temperature preset time.

[0240] In some embodiments, after determining the reference time of the compressor, the time is used as the reference time 0, and the operating parameters of the compressor at the time are detected. The operating parameters of the compressor at the reference time are, for example, recorded as I(1), and the reference time is used as the starting point, and the third preset time is used as the interval, for example, every △t time, the operating parameters of the compressor are detected and obtained. For example, the operating parameters of the compressor obtained every △t time are recorded as I(2), I(3)..., I(n), I(n-1), respectively, and N compressor operating parameter values ​​are determined based on the operating parameters of the compressor at the reference time and N-1 compressor operating parameter values, so as to facilitate the detection of the shut-off valve fault based on the operating parameters of the N compressors and the peak current of the compressor.

[0241] In some embodiments, when the operating parameters of N compressors and the phase current peak of the compressor do not meet the preset conditions, the compressor is controlled to continue running until the continuous running time of the compressor reaches a third preset time, and the operating parameters of the compressor and the phase current peak of the compressor are no longer detected to see whether they meet the preset conditions, wherein the third preset time is greater than the first low-temperature preset time. If the operating parameters of the compressor and the phase current of the compressor do not meet the preset conditions within the specified time, the running time of the compressor is timed. When the running time reaches the third preset time, it is considered that the stop valve detection condition is not met, and the stop valve does not have a non-opening fault.

[0242] In some embodiments, when the air conditioner is turned on for heating, the operating parameters of N compressors and the peak phase currents of the compressors are determined. If the operating parameters and the peak phase currents of the compressors do not meet preset conditions, the compressors are controlled to remain on and the continuous operation time of the compressors is measured. When the continuous operation time of the compressors reaches a third preset time, it is determined that the shutoff valve has not experienced a closed-loop fault. At this time, the operating parameters of the compressors and the peak currents of the compressors are no longer tested, i.e., the shutoff valve is no longer determined to have a closed-loop fault, and all data related to the determination of a closed-loop fault is cleared. By obtaining the continuous operation time of the compressors and, when the continuous operation time of the compressors reaches the third preset time, no longer controlling the air conditioner to execute the shutoff valve protection strategy, misjudgment of a shutoff valve fault caused by an unknown external environment or unknown electromagnetic interference can be avoided, thereby improving the reliability of the shutoff valve determination.

[0243] In some embodiments, when the operating parameters of the compressor and the current peak of the compressor do not meet the preset conditions for a preset number of times, the controller is further configured to: control the compressor to continue running, and count the running time of the compressor, until the cumulative running time of the compressor reaches the fourth movement preset time, and no longer detect whether the operating parameters of the compressor and the phase current peak of the compressor meet the preset conditions, wherein the fourth movement preset time is greater than the third preset time. If the fault count of the stop valve does not reach the preset number of times, for example, when the fault count of the stop valve is 1, the compressor is controlled to stop, but when it is judged again whether the preset conditions are met, it is detected that the operating parameters of the compressor and the phase current peak of the compressor do not meet the preset conditions, then the running time of the compressor is counted, and when the cumulative running time of the compressor reaches the fourth movement preset time, it is considered that the preset conditions are not met, and the stop valve does not have a non-opening fault.

[0244] In some embodiments, when the air conditioner detects the operating parameters of the compressor and the current peak of the compressor again, if the operating parameters of the compressor and the current peak of the compressor do not meet the preset conditions of the preset number of times, the compressor is controlled to continue running, and the running time of the compressor is counted until the cumulative running time of the compressor reaches the fourth movement preset time, and the operating parameters of the compressor and the current peak of the compressor are no longer detected. By obtaining the cumulative running time of the compressor and no longer controlling the air conditioner to execute the stop valve protection strategy when the cumulative running time of the compressor reaches the fourth movement preset time, the misjudgment of the stop valve failure caused by the external unknown environment and unknown electromagnetic interference can be avoided, thereby improving the reliability of the stop valve judgment.

[0245] It is understandable that, under normal circumstances, the shut-off valve failure may only occur once. When the air conditioner is not in use, the user will actively cut off the power to the air conditioner, or even if the indoor unit is powered on, when it is not turned on, the indoor controller will automatically cut off the power to the outdoor controller. Once the outdoor controller is powered off, the operating parameters of the compressor, the coil temperature value of the indoor heat exchanger, and the data of the air conditioner's execution of the shut-off valve protection strategy will be lost. Therefore, each time the outdoor controller is powered on again, the shut-off valve failure detection and judgment process will be carried out.

[0246] In some embodiments, when the operating parameters of the compressor and the current peak of the compressor meet the preset conditions for a preset number of times, after controlling the compressor to stop, the controller is also configured to: issue an alarm message of a shut-off valve failure, and control the compressor to stop and no longer start automatically.

[0247] In some embodiments, when the operating parameters of the compressor and the current peak of the compressor meet the preset conditions for a preset number of times, that is, the operating parameters of the compressor at a later moment are greater than the operating parameters of the compressor at a previous moment, and the difference between the N-1 operating parameter values ​​exceeds the first preset parameter threshold, and the number of times the compressor current peak exceeds the preset current peak meets the preset number, for example, twice, at this time, it is determined that the stop valve is not open, and an alarm message of stop valve failure is issued, and the compressor is controlled to no longer start automatically.

[0248] In some embodiments, the compressor operating parameter includes any one of the phase current of the compressor, the input power of the compressor, the entire input power of the air conditioner, and the entire input current of the air conditioner.

[0249] In some embodiments, the operating parameters of the compressor can be any one of the effective value of the compressor, the compressor input power, the whole machine input power of the air conditioner and the whole machine input current of the air conditioner. It can be understood that when the air conditioner is running in heating mode, the stop valve is closed and the refrigerant is compressed in a very small space, causing the exhaust pressure to rise sharply and the suction pressure to drop sharply, causing the suction and exhaust pressure difference to increase sharply, thereby causing the system load to increase sharply and act on the compressor drive control. In the compressor drive control, the increase in load may cause the compressor input power to increase, the compressor phase current to increase at the same voltage, the whole machine input power to increase, the whole machine input current to increase at the same voltage, etc. Therefore, any one of the above can be selected as the operating parameter of the compressor.

[0250] At present, compressors use permanent magnet synchronous motors. The general FOC algorithm needs to undergo current coordinate transformation to convert the compressor phase current in the rotating coordinate system into the D-axis and Q-axis currents in the stationary coordinate system, and control the D-axis and Q-axis currents. When the phase current of the compressor increases, the corresponding D-axis current and Q-axis current also increase accordingly. The essence of the FOC algorithm is to combine the three-directional current vectors and then decompose them into two components perpendicular and parallel to the stationary coordinate system. The D-axis current and Q-axis current can be obtained by calculating and transforming the phase current in the rotating coordinate system through functions, that is, the D-axis current and Q-axis current are the currents after the phase current has undergone coordinate transformation. Therefore, using the D-axis current, Q-axis current or a combination of the D-axis and Q-axis as the operating parameters of the compressor also has the same effect.

[0251] For example, within the first preset time, such as 40 seconds, if it is detected that the phase current of the compressor exceeds the first preset parameter threshold, such as exceeding 12A, the phase current of the compressor will continue to be detected; it is also possible that at 40 seconds, it is detected that the input power of the compressor exceeds the first preset parameter threshold, such as exceeding 4.2W, the input power of the compressor will continue to be detected; it is also possible that at 40 seconds, it is detected that the entire input power of the air conditioner exceeds the first preset parameter threshold, such as exceeding 4.3W, the entire input power of the air conditioner will continue to be detected; it is also possible that at 40 seconds, it is detected that the entire input current of the air conditioner exceeds the first preset parameter threshold, such as exceeding 18A, the entire input current of the air conditioner will continue to be detected; it is also possible that at 40 seconds, it is detected that the Q-axis current of the compressor exceeds the first preset parameter threshold, such as exceeding 10A, the Q-axis current of the compressor will continue to be detected.

[0252] The following is an example of the fault detection of the stop valve, and the parameters of the air conditioner are set as follows.

[0253] Detection cycle n = 4, second preset time t1 = 1 minute, third preset interval time interval Δt = 1 second, third preset time t2 = 10 minutes, fourth preset time t3 = 30 minutes, first preset parameter threshold I1 = 12A, second preset parameter threshold I2 = 1A, preset number of times i = 2, preset current threshold Imax = 25A. The above parameters can be set as needed. In some embodiments, when the outdoor controller is powered on for the first time and operates in heating mode, the compressor starts. The controller detects the indoor ambient temperature Tin0 = 20°C, the indoor coil temperature Tc0 = 21°C, the outdoor ambient temperature Tout0 = 15°C, the outdoor coil temperature Te0 = 15°C, and the exhaust temperature Td0 = 15°C at the time of startup, and detects the phase current of the compressor in real time. If at the moment of 40s, which is less than the second preset time t1=1min, the detected phase current I(1) is 12A, which is equal to the second preset parameter threshold value I1=12A, after the third preset time △t, the phase current is detected and recorded as I(2)=13.2A>12A; after another 1s, the phase current is detected and recorded as I(3)=14.6A>12A; after another 1s, the phase current is detected and recorded as I(4)=15.8A>12A, and I(4)-I(3)=1.2A>1A, I(3)-I(2)=1.4A>1A, I(2)-I(1)=1.2A>1A are calculated respectively, and at this time the peak current of the compressor is 26A greater than 25A, which satisfies all the possibilities that the shut-off valve is not open, and the compressor is actively stopped and counted once.

[0254] Restart the compressor 3 minutes later and continue to detect the phase current and other data of the compressor. If the phase current is 12A at 28 seconds, record it as I(1) = 12A. 1 second later, record the phase current as I(2) = 13.2A > 12A; 1 second later, record the phase current as I(3) = 14.6A > 12A; 1 second later, record the phase current as I(4) = 15.8A > 12A; calculate I(4) - I(3) = 1.2A > 1A, I(3) - I(2) = 1.4A > 1A, I(2) - I(1) = 1.2A > 1A, and at this time the compressor current peak is 26.5A > 25A, which satisfies all the possibilities of the shut-off valve not opening fault. Actively stop the compressor and count once until the preset number is reached, for example, 2 times, and report the shut-off valve not opening fault, and no longer restart automatically.

[0255] In some embodiments, when the outdoor unit controller is powered on for the first time and operates in heating mode, the compressor starts. The controller detects the indoor ambient temperature Tin0 = 20°C, the indoor coil temperature Tc0 = 21°C, the outdoor ambient temperature Tout0 = 15°C, the outdoor coil temperature Te0 = 15°C, and the exhaust temperature Td0 = 15°C at the start-up time, and detects the phase current of the compressor in real time.

[0256] If at 59 seconds, the phase current is detected to be 12A, recorded as I(1) = 12A; 1 second later, the phase current is detected as I(2) = 12.2A>12A; 1 second later, the phase current is detected as I(3) = 12.4A>12A; 1 second later, the phase current is detected as I(4) = 12.2A>12A; calculate I(4)-I(3) = 0.2A < 1A, I(3)-I(2) respectively.

[0257] =0.2A<1A, I(2)-I(1)=-0.2A<1A, but the peak current of the compressor is 24A, which is less than 25A. If all the conditions are not met, it may be that the stop valve is not opened, and the compressor continues to run.

[0258] The compressor runs until 10 minutes, the third preset time t2=10 minutes, and there is no abnormality. Then, the stop valve failure will no longer be determined.

[0259] According to some embodiments of the air conditioner of the present application, when the air conditioner is first powered on and heating operation is started, the operating parameters of N compressors and the peak values ​​of their phase currents are analyzed. Since the operating parameters and the peak values ​​of the compressor phase currents satisfy a specific pattern when the shut-off valve is not open, the operating parameters and the peak values ​​of the compressor phase currents are detected. Therefore, a shut-off valve failure is determined when the operating parameters and the peak values ​​of the compressor phase currents satisfy a preset condition for a preset number of times. Since the changes in the operating parameters and the phase currents of the compressors when the shut-off valve is not open are significantly different from the corresponding changes in the operating parameters and the phase currents when the indoor motor is stalled or the power supply voltage is extremely low, the shut-off valve failure is determined when the detecting parameters and the phase currents of the compressors satisfy the preset condition. This can avoid misjudgments of compressor shutdowns caused by usage scenarios such as indoor motor stalls or extremely low power supply voltages, thereby improving the accuracy of shut-off valve failure detection, reducing air conditioner lockouts caused by misjudgments, and reducing user complaints. Furthermore, the compressor is controlled to shut down when the operating parameters and the peak values ​​of the compressor currents satisfy the preset conditions, without having to wait for overcurrent protection to shut down, thus enabling earlier protection.

[0260] The following describes the air conditioner stop valve fault detection method according to some embodiments of the present application with examples.

[0261] like Figure 12 As shown, the air conditioner stop valve fault detection method of some embodiments of the present application includes at least step S41 and step S47.

[0262] Step S41 : When the air conditioner is powered on for the first time and starts heating operation, the operating parameters of N compressors and the phase current peak values ​​of the N compressors are determined.

[0263] Step S42 , determining whether the operating parameters of the N compressors and the phase current peak values ​​of the N compressors meet preset conditions.

[0264] Step S43: If the conditions are met, the compressor is controlled to stop, and after the first low temperature preset time, the operating parameters of the N compressors and the phase current peak values ​​of the N compressors are determined again.

[0265] Step S44 , determining whether the operating parameters of the N compressors and the phase current peaks of the N compressors meet preset conditions for a preset number of times.

[0266] Step S45: Determine that the stop valve is faulty and control the compressor to shut down.

[0267] Step S46: Control the compressor to continue running.

[0268] Step S47, detecting the running time of the compressor. When the running time of the compressor reaches the fourth movement preset time, no further detection is performed to determine whether the preset condition is met.

[0269] According to the shut-off valve fault detection method for air conditioners in some embodiments of the present application, when the air conditioner is powered on for the first time and the heating operation is turned on, the operating parameters of N compressors and the peak values ​​of the phase currents of the compressors are analyzed. Since the operating parameters of the compressors and the peak values ​​of the phase currents of the compressors satisfy a specific rule when the shut-off valves are not opened, the operating parameters of the compressors and the phase currents of the compressors are detected. When the operating parameters of the compressors and the peak values ​​of the phase currents of the compressors satisfy the preset conditions for the preset number of times, it is determined that the shut-off valves have not been opened. Since the changes in the operating parameters of the compressors and the phase currents of the compressors when the shut-off valves are not opened are consistent with the changes in the indoor motor blockage, When the rotation speed is too high or the power supply voltage is too low, there are obvious differences in the changes in the corresponding compressor operating parameters and compressor phase current. Therefore, by detecting the compressor operating parameters and compressor phase current, the stop valve fault is determined when it meets the preset conditions. This can avoid misjudgment of faults caused by compressor shutdown due to usage scenarios such as indoor motor jam or ultra-low power supply voltage, thereby improving the accuracy of the stop valve failure not opening, reducing the air conditioner lock caused by misjudgment, thereby reducing user complaints, and controlling the compressor to stop when the compressor operating parameters and the compressor current peak meet the preset conditions. There is no need to wait until the overcurrent protection shutdown, which can make the protection timing earlier.

[0270] In some embodiments, determining whether the operating parameters of N compressors and the phase current peak of the compressor meet preset conditions includes: calculating the difference between the operating parameters of the compressor at a later moment and the operating parameters of the compressor at a previous moment to obtain the difference between N-1 compressor operating parameters; when the difference between the operating parameters of the compressor at a later moment and the operating parameters of the compressor at a previous moment is positive, and the differences between the N-1 operating parameter values ​​are all greater than the first preset parameter threshold, and the compressor current peak exceeds the preset current peak, determining that the N compressor operating parameters and the compressor current peak meet the preset conditions.

[0271] In some embodiments, taking the operating parameter of the compressor as the phase current of the compressor as an example, when judging whether the operating parameters of N compressors and the peak value of the phase current of the compressor meet the preset conditions, the difference between the phase current of the compressor at the next moment and the phase current of the compressor at the previous moment is calculated, for example, the difference of I(n)-I(n-1), I(n-1)-I(n-2)...I(2)-I(1) is calculated, and the difference of the phase current of N-1 compressors is calculated by analogy. At this time, it is judged whether the above differences are all positive. If the above differences are all positive, it is considered that the phase current of the compressor at the next moment is greater than the phase current of the compressor at the previous moment. Current, that is, it is considered that the phase current of the compressor is in an increasing trend, for example, I(n)>I(n-1)>I(n-2)>…I(1), and the difference between the phase current of the compressor at the latter moment and the phase current of the compressor at the previous moment is greater than the first preset parameter threshold, the first preset parameter threshold is recorded as I2, that is, I(n)-I(n-1)>I2, I(n-1)-I(n-2)>I2, and so on, I(2)-I(1)>I2, and the current peak of the compressor exceeds the preset current peak, the preset current peak is recorded as Imax, that is, the current peak of the compressor ≥Imax, that is, Figure 7 The phase current variation pattern shown in FIG. 1 shows that, when all of the above conditions are met, the operating parameter values ​​and the compressor current peak values ​​of the N compressors are determined to meet the preset conditions. By determining the compressor operating parameters and the compressor current peak values, a shutoff valve fault can be detected based on the judgment results.

[0272] 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 application. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0273] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. An air conditioner, characterized in that: include: A refrigerant circulation loop allows the refrigerant to circulate through the compressor, condenser, expansion valve and evaporator in a circulation loop; an outdoor heat exchanger and an indoor heat exchanger, wherein one works as the condenser and the other works as the evaporator; Indoor coil temperature sensor, used to detect indoor coil temperature; An outdoor unit, the outdoor unit comprising: outdoor housing; A compressor, disposed in the outdoor housing, for compressing low-temperature, low-pressure refrigerant gas into high-temperature, high-pressure refrigerant gas and discharging the refrigerant gas to the condenser; a stop valve, the stop valve being arranged in the outdoor unit housing and being used to open or close the refrigerant circulation circuit; The controller is used to obtain the indoor initial coil temperature at the time of compressor startup when the air conditioner is powered on for the first time and the air conditioner is turned on for heating, and to determine whether the stop valve detection condition is met, wherein: The stop valve detection condition includes: detecting that the operating parameter of the compressor is greater than a first preset parameter threshold within a first preset time, and An overcurrent protection shutdown action of the compressor is detected and triggered within the second preset time and the third preset time interval, and determining the indoor coil temperature and the indoor initial coil temperature at the instant before the overcurrent protection shutdown, and counting the shut-off valve failures when the indoor coil temperature and the indoor initial coil temperature meet a preset condition; After the first low temperature preset time, determining again whether the stop valve detection condition is met, and if the stop valve detection condition is met, counting the stop valve failures until the stop valve failure count reaches a preset number of times, determining that the stop valve is faulty, wherein the third preset time is greater than the second preset time; When the overcurrent protection shutdown action of the compressor is not triggered within the second preset time and the third preset time interval, the controller is further configured to: control the compressor to continue to operate until the continuous operation time of the compressor reaches a fourth preset movement time, and no longer determine whether the stop valve detection condition is met, wherein the fourth preset movement time is greater than the third preset time; When the stop valve detection condition is not met and the fault count of the stop valve has not reached a preset number of times, the controller is further configured to: control the compressor to continue running, and count the running time of the compressor until the cumulative running time of the compressor reaches a sixth preset time, and no longer judge whether the stop valve detection condition is met, wherein the sixth preset time is greater than the fourth preset time.

2. The air conditioner according to claim 1, characterized in that When the indoor coil temperature and the indoor initial coil temperature meet a preset condition, the controller is configured to: Calculating the difference between the indoor coil temperature and the indoor initial coil temperature; When the difference does not exceed a second preset parameter threshold, it is determined that the indoor coil temperature and the indoor initial coil temperature meet a preset condition.

3. The air conditioner according to claim 1, characterized in that When it is determined that the stop valve is faulty, the controller is configured to: send an alarm signal of the stop valve failure, and control the compressor to stop and not start automatically.

4. The air conditioner according to claim 1, wherein: The operating parameters of the compressor include: any one of the phase current of the compressor, the input power of the compressor, the entire input power of the air conditioner, and the entire input current of the air conditioner.

5. A method for detecting a stop valve failure of an air conditioner, characterized in that: include: When the air conditioner is powered on for the first time and the heating mode is turned on, the indoor initial coil temperature at the time of compressor startup is obtained, and it is determined whether the stop valve detection conditions are met. The stop valve detection condition includes: detecting that the operating parameter of the compressor is greater than a first preset parameter threshold within a first preset time, and An overcurrent protection shutdown action of the compressor is detected and triggered within the second preset time and the third preset time interval, and determining the indoor coil temperature and the indoor initial coil temperature at the instant before the overcurrent protection shutdown, and counting the shut-off valve failures when the indoor coil temperature and the indoor initial coil temperature meet a preset condition; After the first low temperature preset time, determining again whether the stop valve detection condition is met, and if the stop valve detection condition is met, counting the stop valve failures until the stop valve failure count reaches a preset number of times, determining that the stop valve is faulty, wherein the third preset time is greater than the second preset time; After the compressor is not triggered to shut down due to overcurrent protection within the second preset time and the third preset time interval, the method further includes: controlling the compressor to continue to operate until the continuous operation time of the compressor reaches a fourth preset time, and no longer determining whether the stop valve detection condition is met, wherein the fourth preset time is greater than the third preset time; When the stop valve detection condition is not met and the fault count of the stop valve has not reached a preset number of times, it also includes: controlling the compressor to continue running and timing the running time of the compressor until the cumulative running time of the compressor reaches a sixth preset time, and no longer judging whether the stop valve detection condition is met, wherein the sixth preset time is greater than the fourth preset time.

6. The method for detecting a stop valve failure of an air conditioner according to claim 5, wherein: Determining whether the indoor coil temperature and the indoor initial coil temperature meet a preset condition includes: Calculating the difference between the indoor coil temperature and the indoor initial coil temperature; When the difference does not exceed a second preset parameter threshold, it is determined that the indoor coil temperature and the indoor initial coil temperature meet a preset condition.

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