CN100587350C - Air conditioner fault detection method and system - Google Patents

Abstract

The invention discloses a fault detection method for an air conditioner, which includes: when the air conditioner is in a cooling state, obtaining the discharge temperature of the compressor and the temperature of the air port of the condenser behind the four-way valve, and the detection point of the temperature of the air port of the condenser is located between the four-way valve and the condenser If the difference between the compressor discharge temperature and the condenser air port temperature after the four-way valve is higher than the first preset value, it is determined that the air conditioner is faulty. The invention also discloses a fault detection system for an air conditioner, which includes a compressor, a four-way valve, a condenser, a throttling device and an evaporator, and also includes: a temperature sensor at the air port of the condenser, which is arranged between the four-way valve and the condenser on the pipeline between the compressors; the compressor discharge temperature sensor is arranged on the pipeline between the four-way valve and the compressor. The invention can accurately detect various faults in the working process of the air conditioner, so as to ensure the normal operation of the air conditioner.

Description

Air conditioner fault detection method and system

technical field

The invention relates to the field of air conditioners, in particular to an air conditioner fault detection method and system.

Background technique

The air conditioner is one of our most commonly used home appliances. The air conditioner uses the compressor to compress the refrigerant, and the refrigerant absorbs and releases heat to realize the cooling and heating functions. This requires the refrigerant to circulate repeatedly in the air conditioner in various states. It is easier to cause leakage. The leakage of refrigerant in the air conditioner will not only affect the cooling and heating effects, but also increase the workload of the air conditioner, increase the exhaust temperature of the compressor in the air conditioner, and even burn the compressor. Therefore, it is necessary to accurately detect failures such as refrigerant leakage of the air conditioner.

The existing air conditioner refrigerant leakage fault detection measure is to install a low pressure switch on the compressor intake pipe, and when the compressor suction pressure is lower than a certain value, an alarm will be given. Referring to Fig. 1, it is a schematic diagram of an existing air-conditioning fault detection system, including a compressor 11, a four-way valve 12, a condenser 13, a throttling device (electronic expansion valve or capillary tube) 14, an evaporator 15 and a low-pressure pressure switch 16, wherein the low-pressure The pressure switch 16 is connected with the control circuit and the early warning device. When the air conditioner has a failure such as refrigerant leakage, which causes the suction pressure of the compressor 11 to be lower than the set value, the low pressure switch 16 is turned on, and a corresponding electrical signal is output to the control circuit, the control circuit stops the compressor, and commands the early warning device Forewarning.

If the refrigerant in the air conditioner leaks, the circulating refrigerant will decrease, so that the return air pressure in the return air pipeline will drop, and the compressor 11 will not be able to suck enough refrigerant to work. When the return air pressure in the return air pipeline is lower than the set value, the low-pressure pressure switch 16 triggers the action, and by stopping the work of the compressor 11, an alarm and other modes are performed.

However, the set value of the low pressure of the air conditioner must be lower than the return air pressure value in the air return pipeline when the air conditioner works normally, and the set value is close to zero, so the low pressure switch 16 is difficult to detect accurately. Only when most of the refrigerant leaks occurs, the low-pressure pressure switch 16 can detect. When the refrigerant only partially leaks and the air conditioner continues to run, the low pressure switch 16 is difficult to detect. In this way, the refrigerant will continue to leak, affecting the cooling and heating effects of the air conditioner. Once the discharge temperature protection fails or there is no discharge temperature protection, the compressor may burn out due to excessive operating temperature.

When the air conditioner is switching between cooling and heating modes, there may be faults such as the four-way valve 12 not reversing, so that the air conditioner cannot work normally, and the low pressure switch 16 cannot detect this fault.

Contents of the invention

The technical problem to be solved by the present invention is to provide an air conditioner fault detection method and system, which can accurately detect various faults in the working process of the air conditioner and ensure the normal operation of the air conditioner.

The air conditioner fault detection method of the present invention comprises: when the air conditioner is in the cooling state, obtaining the discharge temperature of the compressor and the air port temperature of the condenser behind the four-way valve, and the detection point of the air port temperature of the condenser is located between the four-way valve and the condenser If the difference between the exhaust temperature of the compressor and the air port temperature of the condenser after the four-way valve is higher than the first preset value, it is determined that the air conditioner is faulty.

Preferably, the difference between the exhaust temperature of the compressor and the air port temperature of the condenser after the four-way valve is higher than the first preset value is: the difference between the exhaust temperature of the compressor and the air port temperature of the condenser after the four-way valve It is higher than the first preset value and lasts for the set time.

Preferably, the first preset value is 25.

Preferably, it also includes: when the air conditioner is in the heating state, obtain the compressor discharge temperature and the air port temperature of the condenser after the four-way valve; if the difference between the compressor discharge temperature and the air port temperature of the condenser after the four-way valve is lower than The second preset value determines that the air conditioner is faulty.

Preferably, the second preset value is 25.

Preferably, it also includes: the detection point of the discharge temperature of the compressor and the air port temperature of the condenser after the four-way valve is separated from the four-way valve.

An air conditioner fault detection system of the present invention includes a compressor, a four-way valve, a condenser, a throttling device, and an evaporator, and also includes: a temperature sensor at the air port of the condenser, arranged between the four-way valve and the condenser On the pipeline between; compressor discharge temperature sensor, is arranged on the pipeline between described four-way valve and described compressor; If the temperature difference detected by the air port temperature sensor is higher than the first preset value, it is determined that the air conditioner is faulty.

Preferably, the first preset value is 25.

Preferably, it also includes: when the air conditioner is in the heating state, if the difference between the detected temperature of the compressor discharge temperature sensor and the detected temperature of the condenser air outlet temperature sensor is lower than the second preset value, it is determined that the air conditioner has a fault .

Preferably, the second preset value is 25.

Compared with the prior art, the present invention has the following advantages:

In the present invention, a temperature sensor is arranged at the exhaust port of the compressor and the air port of the condenser after the four-way valve, and detects whether the refrigerant of the air conditioner leaks by detecting the temperature difference between the air outlet of the compressor exhaust port and the air port of the condenser after the four-way valve. In the cooling mode, if the air conditioner refrigerant leaks, the refrigerant in the gas compressed by the compressor is insufficient, and the temperature of the compressed gas is too high, so that the temperature difference between the compressor exhaust port and the condenser gas port after the four-way valve is larger than normal. , when the temperature difference exceeds the set value, it is confirmed that the air conditioner has faults such as insufficient refrigerant.

By detecting the temperature difference between the exhaust port of the compressor and the air port of the condenser after the four-way valve during refrigeration, the present invention can also accurately detect the reduction of refrigerant flow caused by abnormal throttling device or abnormal pressure loss in the pipeline system.

In the heating mode of the present invention, the temperature of the exhaust port of the compressor is relatively high, while the temperature of the air port of the condenser after the four-way valve is very low. Then it is determined that there are faults in the air conditioner such as the four-way valve not reversing or the air conditioner is still working in refrigeration.

Description of drawings

Fig. 1 is the schematic diagram of existing air conditioner fault detection system;

Fig. 2 is the flowchart of the air conditioner fault detection method embodiment of the present invention;

Fig. 3 is a schematic diagram of an embodiment of the air conditioner fault detection system of the present invention.

Detailed ways

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

The core idea of the present invention is to install a temperature sensor at the exhaust port of the compressor and the air port of the condenser after the four-way valve, and detect whether the refrigerant of the air conditioner is leakage. In the cooling mode, if the air conditioner refrigerant leaks, the refrigerant in the gas compressed by the compressor is insufficient, and the temperature of the compressed gas is too high, so that the temperature difference between the compressor exhaust port and the condenser gas port after the four-way valve is larger than normal. , when the temperature difference exceeds the set value, it is confirmed that the air conditioner has faults such as insufficient refrigerant.

In the cooling mode of the air conditioner, the compressor sucks low-temperature and low-pressure gas refrigerant. After compression, the refrigerant becomes high-temperature and high-pressure saturated gas, which is sent to the condenser through the four-way valve; the high-temperature and high-pressure saturated gas is cooled in the condenser to maintain When the pressure remains constant, heat is released outward, thereby condensing into a low-temperature and high-pressure liquid; the refrigerant is discharged from the condenser, and when it passes through the expansion valve, the pressure drops due to obstruction, causing part of the refrigerant liquid to become a gas, while absorbing the latent heat of vaporization. It also reduces its own temperature and becomes a low-temperature and low-pressure wet vapor; enters the evaporator, and in the evaporator, the refrigerant liquid absorbs the heat in the air under the condition of constant pressure, making the surrounding air colder, and at the same time, the refrigerant liquid is cooled by the fan. Air is blown into the room to achieve cooling effect.

In the refrigeration process, the high-temperature and high-pressure saturated refrigerant gas is discharged from the compressor and enters the condenser through the four-way valve. During this transmission process, the high-temperature and high-pressure saturated refrigerant gas will lose a small amount of heat, causing the temperature to drop slightly. Under normal circumstances, The temperature of the gas discharged from the compressor is generally as high as 80°C to 90°C, and when it reaches the gas port of the condenser after the four-way valve, the temperature is generally 75°C to 85°C (related to the specific operating environment temperature). At this time, the air inlet temperature of the condenser after the four-way valve is the air inlet temperature of the condenser. If the gas discharged from the compressor is high temperature and high pressure saturated refrigerant gas, the temperature difference between the compressor exhaust port and the condenser gas port after the four-way valve should be at least within the range of 25°C. If within a certain period of time, the temperature difference between the compressor discharge temperature and the condenser air port temperature after the four-way valve exceeds 25, it can be confirmed that the gas discharged from the compressor is not saturated refrigerant gas, and the air conditioner has failures such as insufficient refrigerant flow.

When the flow of refrigerant in the air conditioner is insufficient, the temperature of the gas discharged from the compressor will be higher than that during normal operation, and the heat will be easily lost during the process of transferring the condenser, which will cause the exhaust port of the compressor and the air port of the condenser after the four-way valve to The temperature difference is large. After the air conditioner is turned on for a period of time, the refrigeration system of the air conditioner begins to circulate normally. If the temperature difference exceeds the set temperature and lasts for a period of time, a fault signal will be sent to the air conditioner controller. The air conditioner controller will instruct the compressor to stop working and give a fault warning.

In the cooling mode, the present invention acquires the compressor exhaust temperature and the air port temperature of the condenser after the four-way valve. If the difference between the compressor exhaust temperature and the air port temperature of the condenser after the four-way valve exceeds the first preset value, then Confirm that there are faults such as insufficient refrigerant flow in the air conditioner. The present invention can accurately give early warning of refrigerant leakage and other failures of various types of air conditioners by adjusting the first preset value, and can give early warning in time when a small amount of refrigerant leaks to prevent the continued leakage of refrigerant, which is effective Ensure the cooling effect of the air conditioner, prevent the compressor from being burned due to lack of refrigerant and high operating temperature of the compressor, and at the same time, it can also detect whether there is abnormal pressure loss on the exhaust side, whether the four-way valve is working normally, and whether the throttling device is normal.

To switch from refrigeration mode to heating mode, the four-way valve needs to be reversed, and the compressor sucks low-temperature and low-pressure gas refrigerant. After compression, the refrigerant becomes high-temperature and high-pressure saturated gas, which is sent to the evaporator through the four-way valve; In the process, the refrigerant gas releases heat to the outside under the condition of constant pressure to heat the surrounding air, and at the same time, the fan blows cold air into the room to achieve the effect of heating. After the refrigerant releases heat, it condenses into a low-temperature and high-pressure liquid; the refrigerant is discharged from the evaporator, and when it passes through the expansion valve, the pressure drops due to obstruction, causing part of the refrigerant liquid to become a gas, and at the same time absorbs the latent heat of vaporization, making itself The temperature also drops and becomes a low-temperature and low-pressure wet vapor; the refrigerant enters the condenser, absorbs heat in the air in the condenser, becomes a low-temperature and low-pressure refrigerant gas, and is sucked into the compressor.

During the heating process, the temperature of the gas discharged from the compressor is about 80°C to 90°C, and at this time, the air inlet of the condenser in cooling mode becomes the air outlet, and the temperature of the air outlet is about 5°C to 10°C (related to the specific operating environment temperature), the temperature difference between the two is very large, if the difference between the temperature of the exhaust port of the compressor and the air port of the condenser behind the four-way valve is less than 25°C, it can be determined that the air conditioner has a four-way valve without reversing Wait for failure.

In the heating mode, the present invention obtains the exhaust temperature of the compressor and the air port temperature of the condenser after the four-way valve, if the difference between the exhaust temperature of the compressor and the air port temperature of the condenser after the four-way valve is less than the second preset value, Then confirm that there are faults such as the four-way valve and no reversing of the air conditioner.

Referring to Fig. 2, it is a flowchart of an air conditioner fault detection method embodiment of the present invention, and the specific steps are as follows:

Step 201, determine the working mode of the air conditioner;

After the air conditioner starts to run, the air port temperature of the condenser behind the four-way valve is detected, and the air port temperature is used to determine whether the air conditioner is in the cooling mode or the heating mode. In the cooling mode, the air port temperature of the condenser after the four-way valve is about 70 to 80 ° C; in the heating mode, the temperature of the condenser air port after the four-way valve is about 5 ° C to 10 ° C, the temperature difference is very obvious . Therefore, if the difference between the discharge temperature of the compressor and the air port temperature of the condenser after the four-way valve is less than the set temperature of 25°C, it is determined that the air conditioner is in cooling mode, and go to step 202; If the temperature difference between the air outlets of the air conditioner is greater than the set temperature of 25° C., it is determined that the air conditioner is in the heating mode, and the process goes to step 204 .

Step 202, calculating the difference between the discharge temperature of the compressor and the temperature of the condenser air port after the four-way valve;

When the air conditioner runs for 10 minutes, the refrigerant has started to circulate normally in the air conditioner. Obtain the compressor discharge temperature and the condenser air port temperature after the four-way valve, and calculate the difference between them.

Step 203, judging whether there is a fault in the air conditioner according to the difference;

If the difference is higher than the first preset value and lasts for more than 2 minutes, it is determined that the air conditioner is faulty; if the difference is lower than the preset value, it is determined that the air conditioner is working normally.

Under normal circumstances, the temperature of the gas discharged from the compressor is generally as high as 80°C to 90°C, and when it reaches the inlet of the condenser, the temperature is generally 75 to 80°C, that is, if the delivered gas is high-temperature and high-pressure saturated refrigerant gas, the compressor The temperature difference between the exhaust gas temperature and the air port temperature of the condenser after the four-way valve should be within the range of 25°C. The preset value can be preferably set to 25. If within a certain period of time, the temperature difference between the discharge temperature of the compressor and the air port temperature of the condenser after the four-way valve exceeds 25, it can be confirmed that the gas discharged from the compressor is not a saturated refrigerant gas. There are faults such as insufficient refrigerant.

Step 204, calculating the difference between the discharge temperature of the compressor and the air port temperature of the condenser after the four-way valve;

Obtain the compressor discharge temperature and the condenser air port temperature after the four-way valve, and calculate the difference between them. The detection point of compressor discharge temperature and condenser air port temperature after the four-way valve is separated from the four-way valve. In heating mode, the temperature of the condenser air port after the four-way valve is the temperature of the condenser exhaust port.

Step 205, judging whether there is a fault in the air conditioner according to the difference;

If the difference is lower than the second preset value, it is determined that the air conditioner is faulty; if the difference is higher than the second set value, it is determined that the air conditioner is working normally.

In the heating mode, the temperature of the gas discharged from the compressor is generally 80°C to 90°C, while the temperature of the gas outlet of the condenser is generally 5°C to 10°C, and the temperature difference between the two is large. The second preset value can be set to 25. If the temperature difference is lower than 25, it can be determined that the compressor has a fault such as a four-way valve without reversing.

The invention can accurately detect failures such as abnormality of the throttling device or abnormal pressure loss in the pipeline system resulting in reduced refrigerant flow by detecting the exhaust temperature of the compressor and the air port temperature of the condenser after the four-way valve in the cooling mode.

Referring to Fig. 3, it is a schematic diagram of an embodiment of an air-conditioning fault detection system of the present invention, including a compressor 11, a four-way valve 12, a condenser 13, a throttling device 14, an evaporator 15, a low pressure switch 16, a high pressure switch 17, a condenser Air port temperature sensor 31 and compressor discharge temperature sensor 32. The throttling device 14 may be an expansion valve or a capillary tube.

The condenser air port temperature sensor 31 is arranged on the pipeline between the four-way valve 12 and the second condenser 13 , at a position close to the condenser 13 . The condenser air port temperature sensor 31 is responsible for detecting the air port temperature of the condenser 13 behind the four-way valve 12, and transmits the temperature value to the air conditioner controller.

The compressor discharge temperature sensor 32 is arranged on the pipeline between the four-way valve 12 and the second compressor 11 , close to the position of the compressor 11 . The compressor discharge temperature sensor 32 is responsible for detecting the discharge temperature of the compressor 11 and sending the temperature value to the air conditioner controller.

When the air conditioner is in the cooling state, if the difference between the temperature detected by the compressor discharge temperature sensor 32 and the temperature detected by the condenser air port temperature sensor 31 is higher than the first preset value, it is determined that the air conditioner is faulty.

When the air conditioner runs for 10 minutes, the refrigerant has started to circulate normally in the air conditioner. The air conditioner controller obtains the compressor exhaust temperature and the condenser air port temperature after the four-way valve, and calculates the difference between the two. If the difference is higher than the preset value and lasts for more than 2 minutes, it is determined that the air conditioner exists. Faults such as insufficient refrigerant; if the difference is lower than the first preset value, it is determined that the air conditioner is working normally. The first preset value is preferably 25.

When the air conditioner is in the heating state, if the difference between the temperature detected by the compressor discharge temperature sensor 32 and the temperature detected by the condenser air port temperature sensor 31 is lower than a second preset value, it is determined that the air conditioner is faulty.

The air conditioner controller obtains the discharge temperature of the compressor and the air port temperature of the condenser after the four-way valve, and calculates the difference between them. If the difference is lower than the second preset value, it is determined that the four-way valve 12 of the air conditioner has not been replaced. If the difference is higher than the set value, it is determined that the air conditioner is working normally. The second preset value is preferably 25°C.

The air conditioner fault detection system of the present invention can also detect air conditioner faults through various methods. For example, first check whether the resistance values of the compressor discharge temperature sensor 32 and the condenser air port temperature sensor 31 are correct; if correct, obtain the compressor discharge temperature and the condenser air port temperature to determine whether the four-way valve 12 is working normally; The through valve 12 is normal, and the low pressure and high pressure are detected by the low pressure switch 16 and the high pressure switch 17. If the low pressure is lower than the normal pressure, and the high pressure is higher than the normal pressure, it is determined that the throttling device 14 is abnormal, and the expansion valve may be open. If the low pressure is lower than the normal working pressure, and the high pressure is also lower than the normal working pressure, it is determined that the refrigerant is leaking or the charge is insufficient, and leak detection is required And add refrigerant.

The above-mentioned air conditioner fault detection method and system can be completely applied to temperature control systems such as refrigerators, freezers, and heat preservation rooms. It is only necessary to install temperature sensors at corresponding positions in refrigerators, freezers, and heat preservation rooms to obtain the compressor exhaust temperature and four-way temperature. The air port temperature of the condenser after the valve can be used to judge whether the system is working normally by calculating the temperature difference.

The air conditioner fault detection method and system provided by the present invention have been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the present invention. The method of the invention and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. In summary, the content of this specification should not be understood To limit the present invention.

Claims (10)

1. An air conditioner fault detection method, characterized in that, comprising: When the air conditioner is in the cooling state, obtain the discharge temperature of the compressor and the air port temperature of the condenser after the four-way valve. The detection point of the air port temperature of the condenser is located on the pipeline between the four-way valve and the condenser; If the difference between the discharge temperature of the compressor and the air port temperature of the condenser after the four-way valve is higher than the first preset value, it is determined that the air conditioner is faulty. 2. The method according to claim 1, wherein the difference between the exhaust temperature of the compressor and the air port temperature of the condenser after the four-way valve is higher than the first preset value is: For example, the difference between the discharge temperature of the compressor and the air port temperature of the condenser after the four-way valve is higher than the first preset value and lasts for a set time. 3. The method according to claim 1 or 2, characterized in that the first preset value is greater than or equal to 25. 4. The method according to claim 1 or 2, further comprising: When the air conditioner is in the heating state, obtain the discharge temperature of the compressor and the temperature of the condenser after the four-way valve; If the difference between the discharge temperature of the compressor and the air port temperature of the condenser after the four-way valve is smaller than the second preset value, it is determined that the air conditioner is faulty. 5. The method according to claim 4, wherein the second preset value is less than or equal to 25. 6. The method according to claim 4, further comprising: The detection points of the discharge temperature of the compressor and the air port temperature of the condenser after the four-way valve are separated from the four-way valve. 7. An air conditioner fault detection system, comprising a compressor, a four-way valve, a condenser, a throttling device and an evaporator, characterized in that it also includes: A condenser air port temperature sensor is arranged on the pipeline between the four-way valve and the condenser; A compressor discharge temperature sensor is arranged on the pipeline between the four-way valve and the compressor; When the air conditioner is in the cooling state, if the difference between the temperature detected by the compressor discharge temperature sensor and the temperature detected by the condenser air outlet temperature sensor is greater than a first preset value, it is determined that the air conditioner is faulty. 8. The system according to claim 7, wherein the first preset value is 25. 9. The system according to claim 7 or 8, further comprising: When the air conditioner is in the heating state, if the difference between the temperature detected by the compressor discharge temperature sensor and the temperature detected by the condenser air outlet temperature sensor is lower than a second preset value, it is determined that the air conditioner is faulty. 10. The system according to claim 9, wherein the second preset value is 25.

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