Control method of multi-split air conditioning system

Abstract

The invention relates to the technical field of multi-split air conditioning systems, particularly provides a control method of a multi-split air conditioning system, and aims to solve the problem that refrigerant leakage misjudgment is easy to occur in an existing multi-split air conditioning system. In order to achieve the purpose, according to the control method of the multi-split air conditioning system, the indoor first refrigerant concentration and the indoor second refrigerant concentration before and after the set time are compared with the preset concentration threshold value so as to judge whether the condition of refrigerant leakage exists in the multi-split air conditioning system or not; therefore, the accuracy of refrigerant leakage detection and the reliability of the multi-split air conditioning system are improved. Besides, under the condition that it is determined that the refrigerant leaks, the first electric control valve is opened, the refrigerant in the refrigerant flow path is discharged outdoors, indoor refrigerant concentration accumulation is effectively prevented, and therefore the safety of the multi-split air conditioning system is improved.

Description

Technical Field

[0001] The present invention relates to the field of multi-connected air-conditioning systems, and specifically provides a control method for a multi-connected air-conditioning system. Background Art

[0002] Refrigerant plays a crucial role in the operation of a multi-connected air-conditioning system. However, most refrigerant substances, such as R32 refrigerant, R290 refrigerant, etc., are highly flammable. Once the refrigerant leaks, it may pose a serious threat to the safety of users. Therefore, timely monitoring and control of refrigerant leakage is an important task in the air-conditioning manufacturing industry.

[0003] Currently, although the multi-connected air-conditioning system is equipped with a concentration detection component to give an early warning of refrigerant leakage faults, the detection and determination method is relatively single, and there is a high risk of misjudgment. If misjudgment occurs, the system often needs to be shut down for maintenance, which not only affects the normal heat exchange of the multi-connected air-conditioning system but also directly reduces the comfort experience of users.

[0004] Therefore, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0005] In order to solve at least one problem in the prior art, that is, to solve the problem that the existing multi-connected air-conditioning system is prone to misjudgment of refrigerant leakage. The present application provides a control method for a multi-connected air-conditioning system. The multi-connected air-conditioning system includes an indoor unit and a refrigerant discharge pipe connected to the refrigerant flow path in the indoor unit. The other end of the refrigerant discharge pipe passes through the indoor unit and extends to the outside, and a first electric control valve is provided thereon. The control method includes:

[0006] Obtain the first refrigerant concentration and the second refrigerant coldness in the room before and after the set time;

[0007] Based on the first refrigerant concentration and the second refrigerant concentration, determine whether the multi-connected air-conditioning system meets the preset refrigerant leakage conditions;

[0008] Based on the judgment result, selectively open the first electric control valve;

[0009] The preset refrigerant leakage conditions include:

[0010] Both the first refrigerant concentration and the second refrigerant concentration are greater than the preset concentration threshold.

[0011] In a preferred technical solution of the above control method, the step of "based on the judgment result, selectively open the first electric control valve" further includes:

[0012] When both the first refrigerant concentration and the second refrigerant concentration are greater than the preset concentration threshold, open the first electric control valve.

[0013] In a preferred technical solution of the above control method, before, after or at the same time as the step of "opening the first electronic control valve", the following steps are further included:

[0014] Control the fan in the indoor unit to start running to discharge the refrigerant in the room to the outside.

[0015] In a preferred technical solution of the above control method, the multi-connected air-conditioning system further includes a refrigerant liquid pipe and a refrigerant gas pipe that are respectively connected to the refrigerant flow path and are located in the refrigerant circulation loop. A second electronic control valve is provided on the refrigerant liquid pipe, and a third electronic control valve is provided on the refrigerant gas pipe. Before the step of "opening the first electronic control valve", the following steps are further included:

[0016] When the first refrigerant concentration is greater than the preset concentration threshold, close the second electronic control valve and the third electronic control valve.

[0017] In a preferred technical solution of the above control method, before, after or at the same time as the step of "closing the second electronic control valve and the third electronic control valve", the following steps are further included:

[0018] Send out a fault alarm for refrigerant leakage.

[0019] In a preferred technical solution of the above control method, after the step of "closing the second electronic control valve and the third electronic control valve", the following steps are further included:

[0020] When the first refrigerant concentration is greater than the preset concentration threshold and the second refrigerant concentration is less than or equal to the preset concentration threshold, obtain the operation data of the concentration detection component for detecting the refrigerant concentration;

[0021] Based on the operation data, judge whether the concentration detection component is abnormal;

[0022] When the concentration detection component is abnormal, open the second electronic control valve and the third electronic control valve.

[0023] In a preferred technical solution of the above control method, the control method further includes:

[0024] When the concentration detection component is not abnormal, close the first electronic control valve.

[0025] In a preferred technical solution of the above control method, before, after or at the same time as the step of "opening the second electronic control valve and the third electronic control valve", the following steps are further included:

[0026] Send out an alarm that the concentration detection component is abnormal.

[0027] In a preferred technical solution of the above control method, when the multi-connected air-conditioning system further includes a refrigerant replenishing device, the control method further includes:

[0028] After the fault of refrigerant leakage is eliminated, control the refrigerant replenishing device to charge refrigerant into the refrigerant flow path;

[0029] Preferably, when the multi-connected air-conditioning system further includes a vacuum pumping device, before the step of "controlling the refrigerant replenishing device to charge refrigerant into the refrigerant flow path", it further includes:

[0030] After the fault of refrigerant leakage is eliminated, control the vacuum pumping device to perform a vacuum pumping treatment on the refrigerant flow path.

[0031] In a preferred technical solution of the above control method, after the step of "opening the first electronic control valve", it further includes:

[0032] Obtain the third refrigerant concentration in the room;

[0033] Compare the size of the third refrigerant concentration with the preset concentration threshold;

[0034] When the third refrigerant concentration is less than or equal to the preset concentration threshold, close the first electronic control valve.

[0035] Those skilled in the art can understand that the control method of the multi-connected air-conditioning system of the present application compares the first refrigerant concentration and the second refrigerant in the room before and after the set time with the preset concentration threshold respectively to determine whether there is refrigerant leakage in the multi-connected air-conditioning system, thereby improving the accuracy of refrigerant leakage detection and the reliability of the multi-connected air-conditioning system. In addition, when it is determined that refrigerant leakage occurs, the first electronic control valve is opened to discharge the refrigerant in the refrigerant flow path to the outside, effectively preventing the accumulation of indoor refrigerant concentration, thereby improving the safety of the multi-connected air-conditioning system.

[0036] Furthermore, when both the first refrigerant concentration and the second refrigerant concentration are greater than the preset concentration threshold, opening the first electronic control valve can discharge the refrigerant in the refrigerant flow path to the outside, which helps to reduce the indoor refrigerant concentration, and further reduces the potential safety hazards caused by refrigerant leakage, improving the safety of the multi-connected air-conditioning system.

[0037] Furthermore, by controlling the fan to start running before, after or at the same time as opening the first electronic control valve, the refrigerant in the room can be discharged to the outside, which helps to dilute the indoor refrigerant concentration and reduce the potential safety risks.

[0038] Furthermore, by closing the second electronic control valve and the third electronic control valve when the concentration of the first refrigerant is greater than the preset concentration threshold, the connection between the indoor unit and other devices in the multi-connected air-conditioning system can be cut off, so as to reduce the potential risks and damages of refrigerant leakage to other parts of the system.

[0039] Furthermore, by sending a fault alarm for refrigerant leakage before, after or at the same time as the step of closing the second electronic control valve and the third electronic control valve, the situation of refrigerant leakage can be notified to relevant personnel in time, which is convenient for quickly taking countermeasures, thereby further reducing the damages that may be caused by refrigerant leakage.

[0040] Furthermore, when the concentration of the first refrigerant is greater than the preset concentration threshold and the concentration of the second refrigerant is less than or equal to the preset concentration threshold, the operating data of the concentration detection component is obtained, and based on the operating data, it is judged whether the concentration detection component is abnormal. When the concentration detection component is abnormal, it indicates that there is no refrigerant leakage in the multi-connected air-conditioning system. At this time, by opening the second electronic control valve and the third electronic control valve, the multi-connected air-conditioning system can work normally, thereby improving the accuracy of refrigerant leakage detection and the reliability of the multi-connected air-conditioning system.

[0041] Furthermore, by obtaining the concentration of the third refrigerant in the room again after opening the first electronic control valve and closing the first electronic control valve when the concentration of the third refrigerant is less than or equal to the preset concentration threshold, it can not only ensure indoor safety, but also reduce unnecessary refrigerant waste. Description of the Drawings

[0042] The preferred embodiments of the present invention will be described below with reference to the drawings, in which:

[0043] Figure 1 is the system diagram of the multi-connected air-conditioning system of the present application;

[0044] Figure 2 is the flowchart of the control method of the multi-connected air-conditioning system of the present application;

[0045] Figure 3 is the logic diagram of a possible implementation manner of the control method of the multi-connected air-conditioning system of the present application.

[0046] Description of the Reference Numerals:

[0047] 1. Indoor unit; 11. Body; 12. Heat exchanger; 13. Refrigerant concentration sensor; 14. Expansion valve; 15. First electric control valve; 2. Refrigerant discharge pipe; 21. First refrigerant discharge pipe; 211. First stop valve; 22. Second refrigerant discharge pipe; 3. Refrigerant liquid pipe; 31. First refrigerant liquid pipe; 311. Second stop valve; 32. Second refrigerant liquid pipe; 4. Refrigerant gas pipe; 41. First refrigerant gas pipe; 411. Third stop valve; 42. Second refrigerant gas pipe; 5. Valve box; 51. Box body; 52. Second electric control valve; 53. Third electric control valve. Detailed implementation manners

[0048] The preferred implementation manners of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principle of the present application and are not intended to limit the protection scope of the present application.

[0049] It should be noted that in the description of the present application, the terms indicating the direction or positional relationship, such as "upper", "lower", "inner", "bottom", "end", etc., are based on the direction or positional relationship shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.

[0050] In addition, it should be noted that in the description of the present application, unless otherwise clearly specified and limited, the terms "set", "connected", "communicated" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0051] First, in combination with Figure 1 , the multi-split air conditioning system of the present application will be introduced.

[0052] The multi-split air conditioning system of the present application includes an indoor unit 1 and a refrigerant discharge pipe 2. The refrigerant discharge pipe 2 is communicated with the refrigerant flow path in the indoor unit 1, and the other end of the refrigerant discharge pipe 2 extends to the outside of the room, so that the refrigerant in the refrigerant flow path can be discharged to the outside through the refrigerant discharge pipe 2. A first electric control valve 15 is provided on the refrigerant discharge pipe 2. When a refrigerant leakage fault occurs in the multi-split air conditioning system, by opening the first electric control valve 15, the refrigerant in the refrigerant flow path is discharged to the outside, which helps to dilute the indoor refrigerant concentration and improve the safety of the multi-split air conditioning system.

[0053] It should be noted that the present application does not limit the specific type of the first electronic control valve 15, as long as it can discharge the refrigerant in the multi-connected air conditioning system to the outside when it is in the open state. For example, the first electronic control valve 15 can be a solenoid valve or an electric valve.

[0054] Next, refer to Figure 1 , the multi-connected air conditioning system further includes a refrigerant liquid pipe 3, a refrigerant gas pipe 4, and a valve box 5. The refrigerant liquid pipe 3 and the refrigerant gas pipe 4 are both connected to the refrigerant flow path in the indoor unit 1, so that the refrigerant liquid pipe 3, the refrigerant gas pipe 4, and the refrigerant flow path are all located on the refrigerant circulation loop. The valve box 5 includes a box body 51, and a second electronic control valve 52 and a third electronic control valve 53 arranged in the box body 51. The second electronic control valve 52 is arranged on the refrigerant liquid pipe 3, and the third electronic control valve 53 is arranged on the refrigerant gas pipe 4. By opening or closing the second electronic control valve 52 and the third electronic control valve 53, the flow of the refrigerant in the refrigerant circulation loop can be adjusted, and thus the on-off of the leaking indoor unit 1 and other components in the multi-connected air conditioning system can be realized.

[0055] It should be noted that the present application does not limit the specific setting types of the second electronic control valve 52 and the third electronic control valve 53, as long as the on-off of the leaking indoor unit 1 and other components in the multi-connected air conditioning system can be realized when the second electronic control valve 52 and the third electronic control valve 53 are closed. For example, the second electronic control valve 52 can be an electric valve or a solenoid valve. And / or, the third electronic control valve 53 can be an electric valve or a solenoid valve.

[0056] Next, refer to Figure 1, the indoor unit 1 includes a body 11, a heat exchanger 12 and a concentration detector disposed within the body 11. The refrigerant liquid pipe 3 includes a first refrigerant liquid pipe 31 and a second refrigerant liquid pipe 32. The first end of the first refrigerant liquid pipe 31 is connected to the first refrigerant connection port of the heat exchanger 12 through an expansion valve 14, and the second end passes through the body 11 and extends outside the body 11 to communicate with the first end of the second refrigerant liquid pipe 32. The refrigerant discharge pipe 2 includes a first refrigerant discharge pipe 21 and a second refrigerant discharge pipe 22. The first end of the first refrigerant discharge pipe 21 is connected to the first refrigerant liquid pipe 31 between the expansion valve 14 and the first refrigerant connection port, and the second end passes through the body 11 and extends outside the body 11 to communicate with the first end of the second refrigerant discharge pipe 22. The second end of the second refrigerant discharge pipe 22 extends to the outside. The refrigerant gas pipe 4 includes a first refrigerant gas pipe 41 and a second refrigerant gas pipe 42. The first end of the first refrigerant gas pipe 41 is connected to the second refrigerant connection port of the heat exchanger 12, and the second end passes through the body 11 and extends outside the body 11 to communicate with the first end of the second refrigerant gas pipe 42. The second end of the second refrigerant gas pipe 42 is connected to the fourth refrigerant connection port of the outdoor unit. Wherein, the second ends of the second refrigerant liquid pipe 32 and the second refrigerant gas pipe 42 are respectively connected to different refrigerant connection ports on the outdoor unit of the multi-split air-conditioning system, so that the indoor unit 1 and the outdoor unit can form a refrigerant circulation circuit under the action of the refrigerant liquid pipe 3 and the refrigerant gas pipe 4.

[0057] It should be noted that the present application does not limit the specific type of the concentration detector, as long as it can detect the refrigerant concentration. For example, the concentration detector can be a refrigerant concentration sensor 13. Among them, the multi-split air-conditioning system can also include a refrigerant replenishing device and a vacuum pumping device. After the refrigerant is discharged to the outside through the refrigerant discharge pipe 2 and the refrigerant leakage fault is effectively eliminated, in order to ensure the normal operation of the indoor unit 1 where leakage has occurred, it is necessary to replenish the refrigerant into the refrigerant flow path. Among them, the vacuum pumping device is used to pump out the air and moisture in the refrigerant flow path to ensure that the inside of the system is in a vacuum state. The refrigerant replenishing device is used to inject refrigerant into the refrigerant flow path so that the indoor unit 1 can operate normally.

[0058] Next, refer to Figure 1 , a first stop valve 211 is provided at the second end of the first refrigerant discharge pipe 21, and the first refrigerant discharge pipe 21 and the second refrigerant discharge pipe 22 are connected through the first stop valve 211. A second stop valve 311 is provided at the second end of the first refrigerant liquid pipe 31, and the first refrigerant liquid pipe 31 and the second refrigerant liquid pipe 32 are connected through the second stop valve 311. A third stop valve; 411 is provided at the second end of the first refrigerant gas pipe 41, and the first refrigerant gas pipe 41 and the second refrigerant gas pipe 42 are connected through the third stop valve; 411. Among them, the first stop valve 211, the second stop valve 311 and the third stop valve; 411 are all mechanical valves, and these three stop valves are always in the open state, and their main function is to connect the pipes.

[0059] In other preferred embodiments, the first stop valve 211, the second stop valve 311, and the third stop valve 411 are not necessarily provided, and those skilled in the art can make selections according to needs. In the case where the first stop valve 211, the second stop valve 311, and the third stop valve 411 are not provided, those skilled in the art can connect the first refrigerant discharge pipe 21 and the second refrigerant discharge pipe 22 through the first connector, connect the first refrigerant liquid pipe 31 and the second refrigerant liquid pipe 32 through the second connector, and connect the first refrigerant gas pipe 41 and the second refrigerant gas pipe 42 through the third connection port.

[0060] As Figure 2 shown, based on the above setting method, the control method of the multi-connected air-conditioning system of the present application includes:

[0061] S101. Obtain the first refrigerant concentration and the second refrigerant coldness in the room before and after the set time. For example, a refrigerant sensor can be set in the indoor unit 1, and the first refrigerant concentration and the second refrigerant concentration in the room before and after the set time can be obtained through the refrigerant concentration sensor 13.

[0062] S102. Based on the first refrigerant concentration and the second refrigerant concentration, determine whether the multi-connected air-conditioning system meets the preset refrigerant leakage condition. For example, after obtaining the first refrigerant concentration and the second refrigerant concentration, the difference between the first refrigerant concentration and the preset concentration threshold can be compared to determine whether it is greater than 0, or the ratio between the two can be compared to determine whether it is greater than 1, and the difference between the second refrigerant concentration and the preset concentration threshold can be compared to determine whether it is greater than 0, or the ratio between the two can be compared to determine whether it is greater than 1, so as to determine whether the multi-connected air-conditioning system meets the preset refrigerant leakage condition.

[0063] S103. Based on the judgment result, selectively open the first electromagnetic valve 15. For example, after determining that the multi-connected air-conditioning system meets the preset refrigerant leakage condition, the first electromagnetic valve 15 can be opened to discharge the refrigerant in the refrigerant flow path to the outside.

[0064] Among them, the preset refrigerant leakage condition includes:

[0065] Both the first refrigerant concentration and the second refrigerant concentration are greater than the preset concentration threshold.

[0066] The control method of the multi-connected air-conditioning system of the present application compares the first refrigerant concentration and the second refrigerant indoors before and after the set time with a preset concentration threshold respectively to determine whether there is refrigerant leakage in the multi-connected air-conditioning system, thereby improving the accuracy of refrigerant leakage detection and the reliability of the multi-connected air-conditioning system. And when it is determined that refrigerant leakage occurs, the first electric control valve 15 is opened to discharge the refrigerant in the refrigerant flow path to the outside, effectively preventing the accumulation of indoor refrigerant concentration, thereby improving the safety of the multi-connected air-conditioning system.

[0067] The preferred embodiments of the control method of the multi-connected air-conditioning system of the present application will be introduced below.

[0068] In one embodiment, before the step of "opening the first electric control valve 15", it further includes:

[0069] When the first refrigerant concentration is greater than the preset concentration threshold, the second electric control valve 52 and the third electric control valve 53 are closed.

[0070] It should be noted that when the first refrigerant concentration is greater than the preset concentration threshold, it indicates that there is a risk of refrigerant leakage in the multi-connected air-conditioning system. In order to reduce the potential risks and damages of refrigerant leakage to other parts of the system, it is necessary to cut off the connection between the indoor unit 1 where refrigerant leakage occurs and the outdoor unit in the multi-connected air-conditioning system, that is, to close the second electric control valve 52 and the third electric control valve 53.

[0071] For example, taking the concentration detection component as the refrigerant concentration sensor 13 and the preset concentration threshold as 0.3 kg / m 3 for illustration. When the refrigerant concentration sensor 13 detects that the first refrigerant concentration is greater than 0.3 kg / m 3 , it indicates that there is a risk of refrigerant leakage in the multi-connected air-conditioning. In order to cut off the connection between the indoor unit 1 where refrigerant leakage occurs and the outdoor unit, it is necessary to close the second electric control valve 52 and the third electric control valve 53. Therefore, when the first refrigerant concentration is greater than 0.3 kg / m 3 , the second electric control valve 52 and the third electric control valve 53 are closed.

[0072] Furthermore, before, after or at the same time as the step of "closing the second electric control valve 52 and the third electric control valve 53", it further includes:

[0073] Issuing a fault alarm for refrigerant leakage.

[0074] It should be noted that when there is a risk of refrigerant leakage in the multi-connected air-conditioning system, in order to ensure timely notification of relevant personnel and prompt adoption of countermeasures to reduce potential damage, before, after or at the same time as the step of closing the second electric control valve 52 and the third electric control valve 53, a fault alarm for refrigerant leakage can also be included. Among them, the present application places no restrictions on the way of sending the alarm, as long as it can remind relevant personnel. For example, relevant personnel can be reminded through an audible and visual alarm, or a text message alarm can be sent to a preset mobile phone number to achieve the reminder function.

[0075] In one embodiment, the step of "selectively opening the first electric control valve 15 based on the judgment result" further includes:

[0076] When both the first refrigerant concentration and the second refrigerant concentration are greater than the preset concentration threshold, the first electric control valve 15 is opened.

[0077] It should be noted that before and after the set time, both the first refrigerant concentration and the second refrigerant concentration are greater than the preset concentration threshold, indicating that the refrigerant concentration detector is not abnormal, so there is no misjudgment. Therefore, it can be determined that a refrigerant leakage fault has occurred in the indoor unit 1.

[0078] For example, taking the concentration detection element as the refrigerant concentration sensor 13, the preset concentration threshold is 0.3 kg / m 3 , and the set time is 10 min for illustration. When the first refrigerant concentration is greater than 0.3 kg / m 3 , and after 10 min, the second refrigerant concentration is still greater than 0.3 kg / m 3 , it indicates that in two consecutive detections, it is found that the refrigerant concentration in the room exceeds the standard, which is sufficient to prove that there is indeed a refrigerant leakage in the multi-connected air-conditioning system. At this time, opening the first electric control valve 15 can enable the refrigerant in the refrigerant flow path to be discharged outdoors, which helps to reduce the refrigerant concentration in the room, and further reduces the potential safety hazards caused by refrigerant leakage, improving the safety of the multi-connected air-conditioning system.

[0079] Another example, taking the concentration detection element as the refrigerant concentration sensor 13, the preset concentration threshold is 0.3 kg / m 3 , and the set time is 10 min for illustration. When the first refrigerant concentration is greater than 0.3 kg / m 3 , the second electric control valve 52 and the third electric control valve 53 are closed to cut off the connection between the indoor unit 1 where the refrigerant leakage occurs and the outdoor unit. After 10 min, the second refrigerant concentration is still greater than 0.3 kg / m 3 , then the first electric control valve 15 is opened to discharge the refrigerant in the refrigerant flow path outdoors.

[0080] Furthermore, before, after or at the same time as the step of "opening the first electric control valve 15", it further includes:

[0081] Control the fan in indoor unit 1 to start running.

[0082] It should be noted that when a refrigerant leakage occurs in a multi-split air-conditioning system, in order to dilute the refrigerant concentration in the room and reduce potential safety risks, the fan in the indoor unit 1 can be controlled to start running so that the indoor refrigerant can be discharged to the outside through the discharge port on the body 11 under the action of the fan.

[0083] In one embodiment, after the step of “opening the first electrically controlled valve 15”, the method further includes:

[0084] Obtaining the third refrigerant concentration in indoor unit 1;

[0085] Comparing the third refrigerant concentration with a preset concentration threshold;

[0086] When the third refrigerant concentration is less than or equal to the preset concentration threshold, the first electrically controlled valve 15 is closed.

[0087] It should be noted that by opening the first electrically controlled valve 15 to discharge the refrigerant in the refrigerant flow path to the outdoors, it helps to reduce the indoor refrigerant concentration. When the indoor refrigerant concentration is reduced to below the preset concentration threshold, it means that the indoor refrigerant concentration is already within a safe and normal range. At this time, closing the first electrically controlled valve 15 can not only ensure indoor safety, but also reduce unnecessary waste of refrigerant. It should also be noted that the indoor refrigerant concentration is already within a safe and normal range, so the refrigerant leakage fault is resolved, and the refrigerant leakage alarm can be released at this time. For example, when the alarm mode is an audible and visual alarm generated by an audible and visual alarm, the audible and visual alarm is controlled to stop emitting an audible and visual alarm. Alternatively, if the alarm mode is to send information about a refrigerant leak to a preset mobile phone number, a text message that the refrigerant leakage fault has been resolved is sent to the preset mobile phone.

[0088] For example, the preset concentration threshold is 0.3kg / m 3 When the concentration of the third refrigerant is less than or equal to 0.3 kg / m 3 , indicating that the indoor refrigerant concentration is within a safe and normal range, and there is no need to discharge the refrigerant in the refrigerant flow path to the outside. Therefore, when the third refrigerant concentration is less than or equal to 0.3kg / m 3 , the first electrically controlled valve 15 can be closed.

[0089] Furthermore, before, after or simultaneously with the step of “closing the first electrically controlled valve 15”, the following steps may also be included:

[0090] Control the fan to stop running.

[0091] It should be noted that when the concentration of the third refrigerant is less than the preset concentration threshold, it indicates that the refrigerant concentration in the room is within the safe and normal range. At this time, there is no need to accelerate the discharge of the refrigerant in the indoor unit 1 to the outside through the fan. Therefore, before, after, or at the same time as closing the first electronic control valve 15, the fan can be controlled to stop running.

[0092] In one embodiment, after the step of "closing the second electronic control valve 52 and the third electronic control valve 53", the method further includes:

[0093] When the concentration of the first refrigerant is greater than the preset concentration threshold and less than or equal to the preset concentration threshold, obtain the operation data of the concentration detection component for detecting the refrigerant concentration;

[0094] Based on the operation data, determine whether the concentration detection component is abnormal;

[0095] When the concentration detection component is abnormal, open the second electronic control valve 52 and the third electronic control valve 53.

[0096] It should be noted that before the set time, the concentration of the first refrigerant is greater than the preset concentration threshold, and after the set time, the concentration of the second refrigerant is less than or equal to the preset concentration threshold. This abnormal change usually does not occur when there is a refrigerant leak in the multi-connected air-conditioning system because the refrigerant concentration often accumulates and increases over time. However, the current situation indicates that there is an abnormality in the concentration detection component and there is no refrigerant leak in the indoor unit 1. Therefore, by opening the second electronic control valve 52 and the third electronic control valve 53, the multi-connected air-conditioning system is restored to the normal working state to avoid the situation that the multi-connected air-conditioning system affects its normal heat exchange work due to misjudgment of refrigerant leakage and reduces the user experience.

[0097] For example, taking the preset concentration threshold as 0.3 kg / m 3 for illustration. When the concentration of the first refrigerant is greater than 0.3 kg / m 3 , close the second electronic control valve 52 and the third electronic control valve 53. After 10 minutes, obtain the concentration of the second refrigerant again. When the concentration of the second refrigerant is less than or equal to 0.3 kg / m 3 , it indicates that there is an abnormality in the refrigerant concentration sensor 13 and there is no refrigerant leak in the multi-connected air-conditioning system. At this time, open the second electronic control valve 52 and the third electronic control valve 53 to make the multi-connected air-conditioning system return to normal operation.

[0098] In one embodiment, when the multi-connected air-conditioning system further includes a refrigerant replenishing device, the control method further includes:

[0099] When the fault of refrigerant leakage is eliminated, control the refrigerant replenishing device to charge the refrigerant into the refrigerant flow path.

[0100] It should be noted that when refrigerant leakage occurs in the multi-connected air-conditioning system, the first electric control valve 15 needs to be opened to discharge the refrigerant in the refrigerant flow path to the outside. Therefore, due to the reduction of the refrigerant amount, the system cannot work properly. Therefore, after the refrigerant leakage fault is eliminated, it is necessary to control the refrigerant replenishing device to fill the refrigerant flow path with refrigerant. Among them, in order to facilitate filling the refrigerant into the refrigerant flow path, the refrigerant replenishing device can be connected to the refrigerant discharge pipe 2.

[0101] Furthermore, when the multi-connected air-conditioning system further includes a vacuum pumping device, before the step of "controlling the refrigerant replenishing device to fill the refrigerant flow path with refrigerant", the following steps are also included:

[0102] When the refrigerant leakage fault is eliminated, control the vacuum pumping device to perform vacuum pumping on the refrigerant flow path.

[0103] It should be noted that before filling the refrigerant into the air-conditioning system, in order to remove the air and moisture in the refrigerant flow path and ensure the tightness of the refrigerant flow path, it is necessary to use a vacuum pumping device to perform vacuum pumping on the refrigerant flow path. Among them, in order to facilitate vacuum pumping of the refrigerant flow path, the vacuum pumping device can be communicated with the refrigerant discharge pipe 2. There is no limitation on the vacuum pumping device in this application, as long as the refrigerant flow path can be in a vacuum state. For example, the vacuum pumping device is a vacuum pump.

[0104] The following combines Figure 3 , and briefly describes a possible operation process of the control method of the multi-connected air-conditioning system of this application. Figure 3 It is a logic diagram of a possible implementation manner of the control method of the multi-connected air-conditioning system of this application.

[0105] S201. Obtain the first refrigerant concentration in the indoor unit 1.

[0106] S202. Determine whether the first refrigerant concentration is greater than 0.3 kg / m 3 ? If so, execute S203; otherwise, execute S201.

[0107] S203. Close the second electric control valve 52 and the third electric control valve 53, and at the same time issue a refrigerant leakage alarm, and then execute S204.

[0108] S204. After 10 minutes, obtain the second refrigerant concentration in the indoor unit 1 again, and then execute S205.

[0109] S205. Determine whether the second refrigerant concentration is greater than 0.3 kg / m 3 ? If so, execute S206; otherwise, execute S210.

[0110] S206. Open the first electric control valve 15, and at the same time control the fan to start running, and then execute S207.

[0111] S207. Obtain the third refrigerant concentration in the indoor unit 1 again, and then execute S208.

[0112] S208: Determine whether the concentration of the third refrigerant is less than or equal to 0.3 kg / m 3 If yes, execute S209; otherwise, execute S206.

[0113] S209, close the first electrically controlled valve 15, control the fan to stop running and release the refrigerant leakage alarm, and then execute S213.

[0114] S210, obtaining the operating data of the refrigerant concentration sensor 13, and then executing S211.

[0115] S211. Determine whether the refrigerant concentration sensor 13 is abnormal. If yes, execute S212; otherwise, execute S213.

[0116] S212, open the second electrically controlled valve 52 and the third electrically controlled valve 53, and issue an alarm indicating that the refrigerant concentration sensor 13 is abnormal.

[0117] S213. When the refrigerant leakage fault is resolved, control the vacuum pump to evacuate the refrigerant flow path, and then execute S214.

[0118] S214: After the vacuuming is completed, the refrigerant replenishing device is controlled to charge the refrigerant into the refrigerant circulation loop, and then S215 is executed.

[0119] S215 , open the second electrically controlled valve 52 and the third electrically controlled valve 53 , and then execute S201 .

[0120] Those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims of the present application, any one of the claimed embodiments may be used in any combination.

[0121] So far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present application.

Claims

1. A control method for a multi-connected air-conditioning system, characterized in that The multi-connected air-conditioning system includes an indoor unit (1) and a refrigerant discharge pipe (2) connected to the refrigerant flow path in the indoor unit (1). The other end of the refrigerant discharge pipe (2) extends outside the indoor unit (1) through the indoor unit (1), and a first electric control valve (15) is provided thereon. The control method includes: Obtain the first refrigerant concentration and the second refrigerant coldness indoors before and after the set time; Based on the first refrigerant concentration and the second refrigerant concentration, determine whether the multi-connected air-conditioning system meets the preset refrigerant leakage condition; Based on the judgment result, selectively open the first electric control valve (15); The preset refrigerant leakage condition includes: Both the first refrigerant concentration and the second refrigerant concentration are greater than the preset concentration threshold.

2. The control method according to claim 1, characterized in that, The step of "selectively opening the first electric control valve (15) based on the judgment result" further includes: When both the first refrigerant concentration and the second refrigerant concentration are greater than the preset concentration threshold, open the first electric control valve (15).

3. The control method according to claim 2, wherein, Before, after or at the same time as the step of "opening the first electric control valve (15)", it further includes: Control the fan in the indoor unit (1) to start running to discharge the refrigerant indoors to the outside.

4. The control method according to claim 2, characterized in that, The multi-connected air-conditioning system further includes a refrigerant liquid pipe (3) and a refrigerant gas pipe (4) respectively connected to the refrigerant flow path and located in the refrigerant circulation loop. A second electric control valve (52) is provided on the refrigerant liquid pipe (3), and a third electric control valve (53) is provided on the refrigerant gas pipe (4). Before the step of "opening the first electric control valve (15)", it further includes: When the first refrigerant concentration is greater than the preset concentration threshold, close the second electric control valve (52) and the third electric control valve (53).

5. The control method according to claim 4, wherein Before, after or at the same time as the step of "closing the second electric control valve (52) and the third electric control valve (53)", it further includes: Send out a fault alarm for refrigerant leakage.

6. The control method according to claim 4, wherein After the step of "closing the second electric control valve (52) and the third electric control valve (53)", it further includes: When the first refrigerant concentration is greater than the preset concentration threshold and the second refrigerant concentration is less than or equal to the preset concentration threshold, obtain the operation data of the concentration detection component for detecting the refrigerant concentration; Based on the operation data, determine whether the concentration detection component is abnormal; When the concentration detection component is abnormal, open the second electric control valve (52) and the third electric control valve (53).

7. The control method according to claim 6, wherein The control method further includes: When the concentration detection component is not abnormal, close the first electric control valve (15).

8. The control method according to claim 6, characterized in that Before, after or at the same time as the step of "opening the second electric control valve (52) and the third electric control valve (53)", it further includes: Send out an alarm that the concentration detection component is abnormal.

9. The control method according to claim 7 or 8, characterized in that, When the multi-connected air-conditioning system further includes a refrigerant replenishment device, the control method further includes: When the refrigerant leakage fault is eliminated, control the refrigerant replenishment device to fill the refrigerant into the refrigerant flow path; Preferably, when the multi-connected air-conditioning system further includes a vacuum pumping device, before the step of "controlling the refrigerant replenishment device to fill the refrigerant into the refrigerant flow path", it further includes: Control the vacuum device to perform vacuum treatment on the refrigerant flow path.

10. The control method according to claim 2, characterized in that After the step of "opening the first electronic control valve (15)", the following steps are further included: Obtain the third refrigerant concentration in the room; Compare the size of the third refrigerant concentration with the preset concentration threshold; When the third refrigerant concentration is less than or equal to the preset concentration threshold, close the first electronic control valve (15).

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