CN113280470B - A four-way valve fault detection method, device and air conditioner - Google Patents

Abstract

The invention provides a four-way valve fault detection method, device and air conditioner, and relates to the technical field of air conditioners. The four-way valve fault detection method includes: obtaining the temperature of the exhaust port compressed before the compressor is turned on to obtain the first initial temperature; obtaining the temperature of the heat exchanger of the indoor unit or the outdoor unit before the compressor is turned on, and obtaining the first initial temperature 2. Initial temperature; after the compressor is turned on, obtain the real-time temperature of the exhaust port to obtain the real-time exhaust temperature; selectively obtain the real-time heat exchange temperature of the heat exchanger according to the real-time exhaust temperature and the first initial temperature; according to the real-time heat exchange The temperature and the second initial temperature determine whether the four-way valve of the air conditioner is faulty. The four-way valve fault detection method provided by the present invention can automatically identify the four-way valve fault, thereby improving maintenance convenience.

Description

A four-way valve fault detection method, device and air conditioner

technical field

The present invention relates to the technical field of air conditioners, and in particular, to a fault detection method for a four-way valve and an air conditioner.

Background technique

The four-way valve is an important component in the air conditioner, which is usually used to control the flow direction of the refrigerant in the system, so as to realize the switching between cooling and heating modes. In the actual use process, if the four-way valve fails to change direction or crosses the air, it will have a great impact on the cooling and heating effect.

Since the four-way valve is installed inside the air conditioner, it is difficult to detect in time when the four-way valve fails, and the continuous operation of the air conditioner brings a very poor experience to the user.

SUMMARY OF THE INVENTION

The problem solved by the present invention is that it is difficult to find out the failure of the four-way valve in time.

In order to solve the above problems, the present invention provides a four-way valve fault detection method, which can automatically identify the four-way valve fault, thereby improving maintenance convenience.

A fault detection method for a four-way valve, applied to an air conditioner, comprising:

Obtain the temperature of the exhaust port of the compressor before the compressor is turned on, and obtain the first initial temperature;

obtaining the temperature of the heat exchanger of the indoor unit or the outdoor unit before the compressor is turned on, to obtain the second initial temperature;

After the compressor is turned on, obtain the real-time temperature of the exhaust port to obtain the real-time exhaust temperature;

Selectively obtain the real-time heat exchange temperature of the heat exchanger according to the real-time exhaust temperature and the first initial temperature;

Whether the four-way valve of the air conditioner is faulty is determined according to the real-time heat exchange temperature and the second initial temperature.

In an optional embodiment, the step of selectively acquiring the real-time heat exchange temperature of the heat exchanger according to the real-time exhaust gas temperature and the first initial temperature includes:

comparing the real-time exhaust temperature with a first preset threshold;

If the real-time exhaust temperature is greater than the first preset threshold, comparing the difference between the real-time exhaust temperature and the first initial temperature with a second preset threshold;

If the difference between the real-time exhaust gas temperature and the first initial temperature is greater than the second preset threshold, obtain the real-time heat exchange temperature of the heat exchanger.

In an optional implementation manner, the step of judging whether the four-way valve of the air conditioner is faulty according to the real-time heat exchange temperature and the second initial temperature includes:

Calculate the difference between the real-time heat exchange temperature and the second initial temperature to obtain the heat exchange temperature difference;

comparing the heat exchange temperature difference with a third preset threshold;

Whether the four-way valve of the air conditioner is faulty is determined according to the comparison result between the heat exchange temperature difference and the third preset threshold.

In an optional embodiment, the step of judging whether the four-way valve of the air conditioner is faulty according to the comparison result of the heat exchange temperature difference and the third preset threshold value includes:

If the heat exchange temperature difference is less than the third preset threshold, it is determined that the four-way valve is faulty;

If the heat exchange temperature difference is greater than or equal to the third preset threshold, it is determined that the four-way valve is not faulty.

In an optional implementation manner, after the step of determining that the four-way valve is faulty if the heat exchange temperature difference is less than the third preset threshold, the method further includes:

comparing the heat exchange temperature difference with a fourth preset threshold, wherein the fourth preset threshold is smaller than the third preset threshold;

The failure type of the four-way valve is determined according to the comparison result between the heat exchange temperature difference and the fourth preset threshold.

In an optional implementation manner, the step of determining the fault type of the four-way valve according to the comparison result of the heat exchange temperature difference and the fourth preset threshold includes:

If the heat exchange temperature difference is less than the fourth preset threshold, it is determined that the four-way valve has a switching failure;

If the heat exchange temperature difference is greater than or equal to the fourth preset threshold, it is determined that the four-way valve has a cross-gas failure.

In an optional implementation manner, after the step of determining the failure type of the four-way valve according to the comparison result between the heat exchange temperature difference and the fourth preset threshold, the method further includes:

controlling the compressor to stop for a preset time;

Begin with the step of obtaining the first initial temperature by obtaining the temperature of the exhaust port of the compressor before the compressor is turned on, and cycle the subsequent steps;

If it is still determined that a corresponding type of failure occurs in the four-way valve after a preset number of cycles, a failure alarm signal corresponding to the failure type is issued.

An embodiment of the present invention also provides a four-way valve fault detection device, which is applied to an air conditioner, including:

an obtaining module, configured to obtain the temperature of the exhaust port of the compressor before the compressor is turned on, to obtain a first initial temperature, and used to obtain the temperature of the heat exchanger of the indoor unit or the outdoor unit before the compressor is turned on, Obtain the second initial temperature, and be used to obtain the real-time temperature of the exhaust port after the compressor is turned on, obtain the real-time exhaust temperature, and also be used to select according to the real-time exhaust temperature and the first initial temperature Obtain the real-time heat exchange temperature of the heat exchanger;

A judgment module, configured to judge whether the four-way valve of the air conditioner is faulty according to the real-time heat exchange temperature and the second initial temperature.

In an optional implementation manner, the obtaining module includes:

A first comparison sub-module, configured to compare the real-time exhaust temperature with a first preset threshold, and to compare the real-time exhaust temperature with the first preset threshold when the real-time exhaust temperature is greater than the first preset threshold. comparing the difference between the real-time exhaust temperature and the first initial temperature with a second preset threshold;

An obtaining submodule, configured to obtain the real-time heat exchange temperature of the heat exchanger when the difference between the real-time exhaust gas temperature and the first initial temperature is greater than the second preset threshold.

In an optional implementation manner, the judging module includes:

a calculation sub-module for calculating the difference between the real-time heat exchange temperature and the second initial temperature to obtain the heat exchange temperature difference;

a second comparison sub-module, configured to compare the heat exchange temperature difference with a third preset threshold;

a judging sub-module for determining that the four-way valve is faulty when the heat exchange temperature difference is less than the third preset threshold, and for determining that the heat exchange temperature difference is greater than or equal to the third preset threshold In the case of the threshold value, it is determined that the four-way valve is not malfunctioning.

An embodiment of the present invention also provides an air conditioner, including a controller, where the controller is configured to execute the four-way valve fault detection method, and the four-way valve fault detection method includes:

Obtain the temperature of the exhaust port of the compressor before the compressor is turned on, and obtain the first initial temperature;

obtaining the temperature of the heat exchanger of the indoor unit or the outdoor unit before the compressor is turned on, to obtain the second initial temperature;

After the compressor is turned on, obtain the real-time temperature of the exhaust port to obtain the real-time exhaust temperature;

Selectively obtain the real-time heat exchange temperature of the heat exchanger according to the real-time exhaust temperature and the first initial temperature;

Whether the four-way valve of the air conditioner is faulty is determined according to the real-time heat exchange temperature and the second initial temperature.

Description of drawings

1 is a flowchart of a four-way valve fault detection method provided by an embodiment of the present invention;

Fig. 2 is a sub-step flowchart of step S104 in Fig. 1;

Fig. 3 is a sub-step flowchart of step S105 in Fig. 1;

Fig. 4 is a sub-step flowchart of sub-step S1053 in Fig. 3;

5 is a structural block diagram of a four-way valve fault detection device provided by an embodiment of the present invention;

Fig. 6 is the structural block diagram of acquisition module in Fig. 5;

FIG. 7 is a structural block diagram of the judgment module in FIG. 5 .

Description of reference numbers:

100-four-way valve fault detection device; 110-acquisition module; 111-first comparison sub-module; 113-acquisition sub-module; 130-judgment module; 131-calculation sub-module; 133-second comparison sub-module; 135 - Judgment submodule.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Please refer to FIG. 1 . FIG. 1 shows a flowchart of a method for detecting a fault of a four-way valve according to an embodiment of the present application. The four-way valve fault detection method is applied to the air conditioner, and can automatically identify the fault of the four-way valve of the air conditioner, thereby improving maintenance convenience and user experience. The four-way valve fault detection method includes the following steps:

In step S101, the temperature of the exhaust port of the compressor before the compressor is turned on is obtained to obtain a first initial temperature.

In this embodiment, a temperature sensor is provided at the position of the exhaust port of the compressor, and the temperature sensor acquires the temperature of the exhaust port of the compressor in real time.

Further, the four-way valve fault detection method also includes:

Step S102, obtaining the temperature of the heat exchanger of the indoor unit or the outdoor unit before the compressor is turned on, to obtain the second initial temperature.

It should be noted that, in the method for detecting a fault of a four-way valve provided in this embodiment, the detection data can be obtained from the heat exchanger of the indoor unit or the heat exchanger of the outdoor unit.

Further, the four-way valve fault detection method also includes:

Step S103, after the compressor is turned on, obtain the real-time temperature of the exhaust port to obtain the real-time exhaust temperature.

Further, the four-way valve fault detection method also includes:

Step S104, selectively acquiring the real-time heat exchange temperature of the heat exchanger according to the real-time exhaust gas temperature and the first initial temperature.

According to the real-time exhaust temperature and the first initial temperature, ensure that the compressor works normally and has a certain pressure difference, and at the same time avoid the risk of false alarms due to the fact that the exhaust temperature does not drop in time or the ambient temperature is too high during startup. Therefore, other factors affecting the judgment result are excluded through step S104.

Please refer to FIG. 2. FIG. 2 shows a sub-step flowchart of step S104. Step S104 may include:

Sub-step S1041, compare the real-time exhaust temperature with the first preset threshold.

Actually, according to the current operating mode of the air conditioner, the first preset threshold has different settings. If the air conditioner is currently running in the heating mode, the setting range of the first preset threshold is 0°C to 40°C, preferably 20°C; if the air conditioner is currently running in the cooling mode, the setting range of the first preset threshold is 20°C °C to 60 °C, preferably 40 °C.

Sub-step S1042, if the real-time exhaust temperature is greater than the first preset threshold, compare the difference between the real-time exhaust temperature and the first initial temperature with the second preset threshold.

The setting range of the second preset threshold is 0°C to 30°C, preferably 15°C.

Sub-step S1043, if the difference between the real-time exhaust temperature and the first initial temperature is greater than the second preset threshold, obtain the real-time heat exchange temperature of the heat exchanger.

If the difference between the real-time exhaust temperature and the first initial temperature is greater than the second preset threshold, it indicates that the compressor is working normally, and has been running for a period of time, eliminating the influence of the ambient temperature. In this case, to obtain the real-time heat exchange temperature of the heat exchanger, it may be the heat exchanger of the indoor unit or the heat exchanger of the outdoor unit.

Please continue to refer to FIG. 1, further, the four-way valve fault detection method further includes:

Step S105, according to the real-time heat exchange temperature and the second initial temperature, determine whether the four-way valve of the air conditioner is faulty.

After the influence of factors such as compressor failure and ambient temperature is exhausted through step S104, it is determined whether the four-way valve fails according to the temperature change trend of the heat exchanger.

Please refer to FIG. 3. FIG. 3 shows a flowchart of a sub-step of step S105. Step S105 may include:

Sub-step S1051, calculate the difference between the real-time heat exchange temperature and the second initial temperature to obtain the heat exchange temperature difference.

Sub-step S1052, comparing the heat exchange temperature difference with a third preset threshold.

In the case where the detection object is the heat exchanger of the indoor unit, if the air conditioner operates in the heating mode, the heat exchanger of the indoor unit is equivalent to the condenser, and its heat exchange temperature difference must be smaller than the temperature difference of the compressor discharge temperature. Therefore, the first The three preset thresholds have a proportional relationship with the second preset threshold. In this embodiment, the third preset threshold is equal to the second preset threshold multiplied by the proportional coefficient 0.2. In other embodiments, the proportional coefficient may also be between 0 and 1. Select other values within the range. If the air conditioner operates in cooling mode, the heat exchanger of the indoor unit is equivalent to the evaporator. At this time, the heat exchange temperature difference has nothing to do with the exhaust gas temperature. In this case, the third preset threshold is taken in the range of 0°C to 10°C. value, preferably 3°C.

When the detection object is the heat exchanger of the outdoor unit, if the air conditioner operates in the heating mode, the outdoor heat exchanger is equivalent to the evaporator. At this time, the heat exchange temperature difference has nothing to do with the exhaust temperature. In this case, the third The preset threshold value ranges from 0°C to 10°C, preferably 3°C. If the air conditioner operates in the cooling mode, the heat exchanger of the outdoor unit is equivalent to the condenser. Similarly, the third preset threshold is equal to the second preset threshold multiplied by the proportional coefficient 0.2. In other embodiments, the proportional coefficient may also be 0 Choose another value in the range to 1.

Sub-step S1053, according to the comparison result between the heat exchange temperature difference and the third preset threshold, determine whether the four-way valve of the air conditioner is faulty.

Please refer to FIG. 4. FIG. 4 shows a sub-step flowchart of sub-step S1053. Sub-step S1053 may include:

Sub-step S1053a, if the heat exchange temperature difference is less than the third preset threshold, it is determined that the four-way valve is faulty.

If the heat exchange temperature difference is less than the third preset threshold, it indicates that the heat exchange temperature difference is too small, and it is determined that the four-way valve is faulty when the influence of the compressor and the ambient temperature is excluded. If the heat exchange temperature difference is greater than or equal to the third preset threshold, it indicates that the heat exchange temperature difference is normal, and it is determined that the four-way valve is not faulty.

Sub-step S1053b, comparing the heat exchange temperature difference with a fourth preset threshold, where the fourth preset threshold is smaller than the third preset threshold.

The value range of the fourth preset threshold is -10°C to 0°C, and preferably -2°C in this embodiment. On the premise of judging the failure of the four-way valve, the specific failure type of the four-way valve is further judged by the size of the heat exchange temperature difference of the heat exchanger.

In sub-step S1053c, if the heat exchange temperature difference is less than the fourth preset threshold, it is determined that the four-way valve has a switching failure.

If the heat exchange temperature difference is less than the fourth preset threshold, and the heat exchange amount is too small, it means that the four-way valve cannot be switched, and it is determined that the four-way valve has a switching failure.

Sub-step S1053d, if the heat exchange temperature difference is greater than or equal to the fourth preset threshold, it is determined that the four-way valve has a cross-gas failure.

The heat exchange temperature difference is less than the third preset threshold value and greater than or equal to the fourth preset threshold value, and the heat exchange amount is small, indicating that the four-way valve is connected in series, and it is determined that the four-way valve has a cross-gas failure.

Sub-step S1053e, control the compressor to stop for a preset time.

It is understandable that the single judgment result is not convincing, and there may be detection errors. Therefore, after the failure type is determined once, the compressor is controlled to stop for a preset time and then another round of determination is performed. In this embodiment, the preset time is 3 minutes.

Sub-step S1053f starts with the step of obtaining the temperature of the exhaust port of the compressor before the compressor is turned on, and obtaining the first initial temperature, and the subsequent steps are cycled.

In sub-step S1053g, if it is still determined that a corresponding type of failure occurs in the four-way valve after the preset number of cycles, a failure alarm signal corresponding to the failure type is issued.

After sub-step S1053f and sub-step S1053g, if the multiple determination results show that the four-way valve has a corresponding type of failure, it is determined that the four-way valve has this type of failure. The fault alarm is carried out to remind the user to carry out the corresponding maintenance.

In order to perform the corresponding steps in the foregoing method embodiments and possible implementation manners, an implementation manner of a four-way valve fault detection apparatus 100 is given below. Referring to FIG. 5 , FIG. 5 shows a schematic block diagram of a four-way valve fault detection apparatus 100 provided by an embodiment of the present application. The four-way valve fault detection apparatus 100 is applied to an air conditioner, and the four-way valve fault detection apparatus 100 includes an acquisition module 110 and a judgment module 130 .

The obtaining module 110 is used to obtain the temperature of the exhaust port of the compressor before the compressor is turned on, to obtain the first initial temperature, and to obtain the temperature of the heat exchanger of the indoor unit or the outdoor unit before the compressor is turned on, to obtain the second initial temperature. The initial temperature is used to obtain the real-time temperature of the exhaust port after the compressor is turned on to obtain the real-time exhaust temperature, and is also used to selectively obtain the real-time heat exchange temperature of the heat exchanger according to the real-time exhaust temperature and the first initial temperature. The obtaining module 110 is configured to perform steps S101 to S104 of the foregoing four-way valve fault detection method.

The judgment module 130 is used for judging whether the four-way valve of the air conditioner is faulty according to the real-time heat exchange temperature and the second initial temperature. The judgment module 130 is configured to execute step S105 of the foregoing four-way fault detection method.

Please refer to FIG. 6 . FIG. 6 shows a structural block diagram of the acquisition module 110 . The acquisition module 110 includes a first comparison sub-module 111 and an acquisition sub-module 113 .

The first comparison sub-module 111 is used to compare the real-time exhaust temperature with the first preset threshold, and is used to compare the real-time exhaust temperature with the first preset threshold when the real-time exhaust temperature is greater than the first preset threshold. The difference of the initial temperature is compared with a second preset threshold. The first comparison module is used for executing the aforementioned sub-step S1041 and sub-step S1042.

The obtaining sub-module 113 is configured to obtain the real-time heat exchange temperature of the heat exchanger when the difference between the real-time exhaust temperature and the first initial temperature is greater than the second preset threshold. The obtaining sub-module 113 is configured to perform sub-step S1043 of the foregoing four-way fault detection method.

Please refer to FIG. 7 . FIG. 7 shows a structural block diagram of the judgment module 130 . The judgment module 130 includes a calculation sub-module 131 , a second comparison sub-module 133 and a judgment sub-module 135 .

The calculation sub-module 131 is configured to calculate the difference between the real-time heat exchange temperature and the second initial temperature to obtain the heat exchange temperature difference. The calculation sub-module 131 is configured to execute the sub-step S1051 of the foregoing four-way fault detection method.

The second comparison sub-module 133 is configured to compare the heat exchange temperature difference with the third preset threshold. The second comparison sub-module 133 is configured to perform sub-step S1052 of the foregoing four-way fault detection method.

The judgment sub-module 135 is used for judging that the four-way valve is faulty when the heat exchange temperature difference is less than the third preset threshold, and is used to judge the four-way valve when the heat exchange temperature difference is greater than or equal to the third preset threshold No failure occurred. The judging sub-module 135 is configured to execute the sub-step S1053 of the foregoing four-way fault detection method, and the sub-steps S1053a to S1053g.

An embodiment of the present application further provides an air conditioner, the air conditioner includes a controller, and the controller is configured to execute the four-way valve fault detection method in the foregoing steps S101 to S105, and the controller is further configured to execute the four-way valve failure Multiple sub-steps corresponding to multiple steps of the detection method respectively.

To sum up, the four-way valve fault detection method, the four-way valve fault detection device 100 and the air conditioner provided in this embodiment use the temperature difference of the exhaust gas to eliminate the interference of the compressor and the ambient temperature, etc. The heat exchange temperature difference is used to determine whether the four-way valve is faulty, and further determine the type of fault that occurs. The automatic identification of the fault of the four-way valve of the air conditioner is realized, the maintenance convenience of the air conditioner is improved, and the user experience is further improved.

Although the present invention is disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be based on the scope defined by the claims.

Claims (7)

1. A four-way valve fault detection method is applied to an air conditioner and is characterized by comprising the following steps:

acquiring the temperature of an exhaust port of a compressor before the compressor is started to obtain a first initial temperature;

obtaining the temperature of a heat exchanger of an indoor unit or an outdoor unit before the compressor is started to obtain a second initial temperature;

after the compressor is started, acquiring the real-time temperature of the exhaust port to obtain the real-time exhaust temperature;

acquiring the real-time heat exchange temperature of the heat exchanger according to the real-time exhaust temperature and the first initial temperature;

judging whether a four-way valve of the air conditioner breaks down or not according to the real-time heat exchange temperature and the second initial temperature;

the step of obtaining the real-time heat exchange temperature of the heat exchanger according to the real-time exhaust temperature and the first initial temperature comprises the following steps:

comparing the real-time exhaust temperature with a first preset threshold;

if the real-time exhaust temperature is greater than the first preset threshold, comparing the difference value between the real-time exhaust temperature and the first initial temperature with a second preset threshold;

if the difference value between the real-time exhaust temperature and the first initial temperature is larger than the second preset threshold value, acquiring the real-time heat exchange temperature of the heat exchanger;

the step of judging whether a four-way valve of the air conditioner breaks down according to the real-time heat exchange temperature and the second initial temperature comprises the following steps:

calculating the difference value between the real-time heat exchange temperature and the second initial temperature to obtain a heat exchange temperature difference;

comparing the heat exchange temperature difference with a third preset threshold value;

and judging whether a four-way valve of the air conditioner breaks down or not according to a comparison result of the heat exchange temperature difference and the third preset threshold value.

2. The method for detecting the four-way valve fault according to claim 1, wherein the step of judging whether the four-way valve of the air conditioner has the fault according to the comparison result of the heat exchange temperature difference and the third preset threshold comprises the following steps of:

if the heat exchange temperature difference is smaller than the third preset threshold value, judging that the four-way valve breaks down;

and if the heat exchange temperature difference is greater than or equal to the third preset threshold value, judging that the four-way valve fails.

3. The four-way valve fault detection method according to claim 1, wherein after the step of determining that the four-way valve is faulty if the heat exchange temperature difference is smaller than the third preset threshold, the method further comprises:

comparing the heat exchange temperature difference with a fourth preset threshold value, wherein the fourth preset threshold value is smaller than the third preset threshold value;

and judging the fault type of the four-way valve according to the comparison result of the heat exchange temperature difference and the fourth preset threshold value.

4. The four-way valve fault detection method according to claim 3, wherein the step of determining the fault type of the four-way valve according to the comparison result between the heat exchange temperature difference and the fourth preset threshold value comprises:

if the heat exchange temperature difference is smaller than the fourth preset threshold value, judging that the four-way valve has a switching fault; and if the heat exchange temperature difference is greater than or equal to the fourth preset threshold value, judging that the four-way valve has a gas leakage fault.

5. The four-way valve fault detection method according to claim 3, wherein after the step of determining the fault type of the four-way valve according to the comparison result between the heat exchange temperature difference and the fourth preset threshold, the method further comprises:

controlling the compressor to stop for a preset time;

starting with the step of obtaining the temperature of the exhaust port of the compressor before the compressor is started to obtain a first initial temperature, and circulating the subsequent steps;

and if the four-way valve is still judged to have faults of corresponding types after circulating for the preset times, sending fault alarm signals of corresponding fault types.

6. The utility model provides a cross valve fault detection device, is applied to the air conditioner, its characterized in that includes: the system comprises an acquisition module (110), a control module and a control module, wherein the acquisition module is used for acquiring the temperature of an exhaust port of a compressor before the compressor is started to obtain a first initial temperature, acquiring the temperature of a heat exchanger of an indoor unit or an outdoor unit before the compressor is started to obtain a second initial temperature, acquiring the real-time temperature of the exhaust port after the compressor is started to obtain the real-time exhaust temperature, and acquiring the real-time heat exchange temperature of the heat exchanger according to the real-time exhaust temperature and the first initial temperature;

the judging module (130) is used for judging whether a four-way valve of the air conditioner breaks down or not according to the real-time heat exchange temperature and the second initial temperature;

the acquisition module (110) comprises:

the first comparison sub-module (111) is used for comparing the real-time exhaust temperature with a first preset threshold value, and comparing the difference value between the real-time exhaust temperature and the first initial temperature with a second preset threshold value under the condition that the real-time exhaust temperature is greater than the first preset threshold value;

the obtaining submodule (113) is used for obtaining the real-time heat exchange temperature of the heat exchanger under the condition that the difference value between the real-time exhaust temperature and the first initial temperature is larger than the second preset threshold value;

the determining means (130) comprises:

the calculation submodule (131) is used for calculating the difference value between the real-time heat exchange temperature and the second initial temperature to obtain a heat exchange temperature difference;

the second comparison submodule (133) is used for comparing the heat exchange temperature difference with a third preset threshold value;

and the judging submodule (135) is used for judging that the four-way valve fails under the condition that the heat exchange temperature difference is smaller than a third preset threshold value, and is used for judging that the four-way valve fails under the condition that the heat exchange temperature difference is larger than or equal to the third preset threshold value.

7. An air conditioner comprising a controller for performing the four-way valve malfunction detection method according to any one of claims 1 to 5.

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