DETECTION METHOD, CONTROL DEVICE AND AIR CONDITIONING SYSTEM OF AIR CONDITIONING SYSTEM

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of Chinese Patent Application No. 202411215121.8 filed on Aug. 30, 2024, and all the benefits accruing therefrom under 35 U.S.C. § 119, the contents of which in their entirety are herein incorporated by reference.

BACKGROUND

After mounting of a multi-split air conditioning system is completed, each component in the multi-split air conditioning system needs to be tested or debugged, different components of a plurality of indoor units in the multi-split air conditioning system are manually detected or debugged one by one, and mounting and detection time and labor cost of the air conditioning system are increased to a certain extent.

In the existing automatic detection or debugging technology, it is necessary to comprehensively consider operating conditions of different air conditioning systems to determine whether fans and expansion valves of each indoor unit in the multi-split air conditioning system are operating normally, so that a plurality of sensing devices need to be additionally arranged in the multi-split air conditioning system to acquire different operating condition parameters of the multi-split air conditioning system, and manufacturing and mounting cost of the air conditioning system is increased while internal space of the multi-split air conditioning system is occupied.

SUMMARY

An object of this application is to provide a detection method and control device of an air conditioning system, and an air conditioning system using the detection method or including the control device, so that some problems can be resolved or alleviated.

This application provides a detection method of an air conditioning system, and an air conditioning system suitable for the detection method includes a compressor, an outdoor unit, a first indoor unit and a second indoor unit connected to the compressor through a refrigerant circulation loop, and a first expansion valve and a second expansion valve respectively provided corresponding to the first indoor unit and the second indoor unit. The detection method according to this application includes: an air conditioning system operation mode determination step of determining whether the air conditioning system is in a specified mode; a compressor first rotating speed operating control step of maintaining the compressor to operate at a first specified rotating speed for a first specified duration, instructing a fan of the first indoor unit and a fan of the second indoor unit to maintain the same specified fan rotating speed within the first specified duration, and instructing opening degrees of the first expansion valve and the second expansion valve to maintain the same first specified expansion valve opening degree; an indoor unit fan operating condition detection step of, within the first specified duration, separately detecting a return air temperature of the first indoor unit and a heat exchanger coil temperature of the first indoor unit and comparing a difference therebetween, and detecting a return air temperature of the second indoor unit and a heat exchanger coil temperature of the second indoor unit and comparing a difference therebetween; an indoor unit fan operating condition determination step of determining whether the fan of the first indoor unit and the fan of the second indoor unit operate normally according to detection and comparison results in the indoor unit fan operating condition detection step; a compressor second rotating speed operating control step of instructing the compressor to operate at a second specified rotating speed higher than the first specified rotating speed after the first specified duration has elapsed; a first expansion valve adjustment step of instructing the first expansion valve to close, instructing the first expansion valve to be adjusted to a second specified expansion valve opening degree after the first expansion valve is closed and a second specified duration has elapsed, and maintaining the second specified expansion valve opening degree for a third specified duration; a first expansion valve operating condition detection step of, within the second specified duration and the third specified duration, separately detecting return air temperature of the first indoor unit and acquiring a return air temperature difference of the first indoor unit, and detecting heat exchanger coil temperature of the first indoor unit and acquiring a heat exchanger coil temperature difference of the first indoor unit; and a first expansion valve operating condition determination step of determining that the first expansion valve is faulty when a first difference between the return air temperature difference of the first indoor unit and the heat exchanger coil temperature difference of the first indoor unit is less than a specified expansion valve determination threshold.

In one or more embodiments, the detection method further includes: a second expansion valve adjustment step of instructing the second expansion valve to close, instructing the second expansion valve to be adjusted to the second specified expansion valve opening degree after the second expansion valve is closed and the second specified duration has elapsed, and maintaining the second specified expansion valve opening degree for the third specified duration; a second expansion valve operating condition detection step of, within the second specified duration and the third specified duration, separately detecting the return air temperature of the second indoor unit and acquiring a return air temperature difference of the second indoor unit, and detecting the heat exchanger coil temperature of the second indoor unit and acquiring a heat exchanger coil temperature difference of the second indoor unit; and a second expansion valve operating condition determination step of determining that the second expansion valve is faulty when a second difference between the return air temperature difference of the second indoor unit and the heat exchanger coil temperature difference of the second indoor unit is less than the specified expansion valve determination threshold.

In one or more embodiments, when the second expansion valve adjustment step is executed, an opening degree of the first expansion valve is instructed to be adjusted to a third specified expansion valve opening degree greater than the second specified expansion valve opening degree.

In one or more embodiments, the specified mode is a cooling mode.

In one or more embodiments, in the indoor unit fan operating condition determination step, when the difference between the return air temperature of the first indoor unit and the heat exchanger coil temperature of the first indoor unit, or the difference between the return air temperature of the second indoor unit and the heat exchanger coil temperature of the second indoor unit is greater than a specified fan determination threshold, it is determined that the fan of the first indoor unit or the fan of the second indoor unit is faulty.

In one or more embodiments, the second specified expansion valve opening degree is a minimum opening degree of the first expansion valve and/or the second expansion valve.

In one or more embodiments, the first specified expansion valve opening degree is a specified opening degree between a maximum opening degree and the minimum opening degree of the first expansion valve and/or the second expansion valve.

In one or more embodiments, the specified fan rotating speed is a highest rotating speed of the fan of the first indoor unit and the fan of the second indoor unit.

In one or more embodiments, the air conditioning system further includes: a third indoor unit and a fourth indoor unit connected to the compressor through a refrigerant circulation loop; and a third expansion valve and a fourth expansion valve respectively provided corresponding to the third indoor unit and the fourth indoor unit, and the detection method further includes: a third expansion valve adjustment step and a fourth expansion valve adjustment step; a third expansion valve operating condition detection step and a fourth expansion valve detection step; and a third expansion valve operating condition determination step and a fourth expansion valve operating condition determination step.

Another aspect of this application further provides a control device of an air conditioning system, the air conditioning system using the control device includes a compressor, an outdoor unit, a first indoor unit and a second indoor unit connected to the compressor through a refrigerant circulation loop, and a first expansion valve and a second expansion valve respectively provided corresponding to the first indoor unit and the second indoor unit. The control device includes: an air conditioning system operating mode determination module configured to determine whether the air conditioning system is in a specified mode; a compressor first rotating speed operating control module configured to maintain the compressor to operate at a first specified rotating speed for a first specified duration, instruct a fan of the first indoor unit and a fan of the second indoor unit to maintain the same specified fan rotating speed within the first specified duration, and instruct opening degrees of the first expansion valve and the second expansion valve to maintain the same first specified expansion valve opening degree; an indoor unit fan operating condition detection module configured to, within the first specified duration, separately detect a return air temperature of the first indoor unit and a heat exchanger coil temperature of the first indoor unit and compare a difference therebetween, and detect a return air temperature of the second indoor unit and a heat exchanger coil temperature of the second indoor unit and compare a difference therebetween; an indoor unit fan operating condition determination module configured to determine whether the fan of the first indoor unit and the fan of the second indoor unit operate normally according to detection and comparison results in the indoor unit fan operating condition detection module; a compressor second rotating speed operating control module configured to instruct the compressor to operate at a second specified rotating speed higher than the first specified rotating speed after the first specified duration has elapsed; a first expansion valve adjustment module configured to instruct to close the first expansion valve, instruct the first expansion valve to be adjusted to a second specified expansion valve opening degree after the first expansion valve is closed and a second specified duration has elapsed, and maintain the second specified expansion valve opening degree for a third specified duration; a first expansion valve operating condition detection module configured to, within the second specified duration and the third specified duration, separately detect the return air temperature of the first indoor unit and acquire a return air temperature difference of the first indoor unit, and detect the heat exchanger coil temperature of the first indoor unit and acquire a heat exchanger coil temperature difference of the first indoor unit; and a first expansion valve operating condition determination module configured to determine that the first expansion valve is faulty when a first difference between the return air temperature difference of the first indoor unit and the heat exchanger coil temperature difference of the first indoor unit is less than a specified expansion valve determination threshold.

Another aspect of this application further provides an air conditioning system including a memory and a controller, in which the controller executes any one of the above detection methods of an air conditioning system.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic diagram of modules of an air conditioning system in one or more embodiments of this application;

FIG. 2 is a schematic diagram of steps executed in a detection method of an air conditioning system in one or more embodiments of this application;

FIG. 3 is a timing diagram of executing a detection method of an air conditioning system in one or more embodiments of this application;

FIG. 4 is a schematic diagram of steps executed in a detection method of an air conditioning system in another embodiment of this application;

FIG. 5 is a schematic diagram of modules of an air conditioning system in another embodiment of this application;

FIG. 6 is a schematic diagram of steps executed in a detection method of an air conditioning system in another embodiment of this application; and

FIG. 7 is a schematic diagram of modules of a control device of an air conditioning system in one or more embodiments of this application.

Reference numerals: air conditioning system 1, compressor 101, outdoor unit 102, first indoor unit 103, first heat exchanger coil 1031, first fan 1032, second indoor unit 104, second heat exchanger coil 1041, second fan 1042, first expansion valve 105, second expansion valve 106, refrigerant pipeline 107, third indoor unit 108, third heat exchanger coil 1081, third fan 1082, fourth indoor unit 109, fourth heat exchanger coil 1091, fourth fan 1092, third expansion valve 110, fourth expansion valve 111, control device 10, air conditioning system operating mode determination module 11, compressor first rotating speed operating control module 12, indoor unit fan operating condition detection module 13, indoor unit fan operating condition determination module 14, compressor second rotating speed operating control module 15, first expansion valve adjustment module 16, first expansion valve operating condition detection module 17, first expansion valve operating condition determination module 18.

DETAILED DESCRIPTION OF THE DISCLOSURE

It should be noted that working principles, features, advantages, and the like of a refrigeration apparatus according to this application will be explained below by way of embodiments. However, it should be understood that all descriptions are only given for exemplification and therefore these embodiments should not be understood as forming any limitation on this application.

In addition, for any single technical feature described or implicit in some embodiments mentioned herein, or any single technical feature shown or implicit in the drawings, this application still allows any combination or deletion between these technical features (or their equivalents) without any technical obstacles, thereby acquiring more other embodiments of this application that may not be directly mentioned herein.

FIG. 1 is a schematic diagram of modules of an air conditioning system according to one or more embodiments of this application. Referring to FIG. 1, an air conditioning system 1 includes a compressor 101, an outdoor unit 102, a first indoor unit 103, a second indoor unit 104, a first expansion valve 105, a second expansion valve 106, and a refrigerant pipeline 107.

As shown in FIG. 1, the first indoor unit 103 and the second indoor unit 104 are connected to the compressor 101 and the outdoor unit 102 through the refrigerant pipeline 107. The first expansion valve 105 is provided corresponding to the first indoor unit 103, and the second expansion valve 106 is provided corresponding to the second indoor unit 104. In addition, a first heat exchanger coil 1031 for heat exchange and a first fan 1032 of the first indoor unit are further provided corresponding to the first indoor unit 103, and a second heat exchanger coil 1041 for heat exchange and a second fan 1042 of the second indoor unit are further provided corresponding to the second indoor unit 104.

FIG. 2 is a schematic diagram of steps executed in a detection method of the air conditioning system 1 shown in FIG. 1 in one or more embodiments of this application. Referring to FIG. 2, the detection method of the air conditioning system according to this embodiment includes: an air conditioning system operation mode determination step S1, a compressor first rotating speed operating control step S2, an indoor unit fan operating condition detection step S3, an indoor unit fan operating condition determination step S4, a compressor second rotating speed operating control step S5, a first expansion valve adjustment step S6, a first expansion valve operating condition detection step S7, and a first expansion valve operating condition determination step S8.

FIG. 3 is a timing diagram of executing the detection method of the air conditioning system shown in FIG. 2 in this application. The following further describes, with reference to FIG. 1, FIG. 2, and FIG. 3, execution cases of actions and steps of each component when the detection method of the air conditioning system is executed.

Specifically, when the air conditioning system 1 receives an instruction to start test operation, the air conditioning system operation mode determination step S1 is executed to determine whether the air conditioning system 1 is set to a specified mode, when the air conditioning system 1 is set to the specified mode, that is, the air conditioning system 1 operates in a cooling mode, and it is necessary to detect an expansion valve and the fan of the indoor unit of the air conditioning system 1, as shown in FIG. 2 and FIG. 3, the compressor first rotating speed operating control step S2 is executed to control the compressor 101 to operate at a first specified rotating speed N1 for a first specified duration T1, the first fan 1032 of the first indoor unit 103 and the second fan 1042 of the second indoor unit 104 are instructed to maintain the same specified fan rotating speed R within the first specified duration T1, and opening degrees of the corresponding first expansion valve 105 and the second expansion valve 106 are instructed to maintain the same first specified expansion valve opening degree V1.

Within the first specified duration T1, the indoor unit fan operating condition detection step S3 is executed to detect a return air temperature of the first indoor unit 103 and a first heat exchanger coil temperature of the first indoor unit 103 in real time and compare them to acquire a difference Δt1, and at the same time, detect a return air temperature of the second indoor unit 104 and a heat exchanger coil temperature of the second indoor unit 104 and compare them to acquire a difference Δt2. The return air temperature of the first indoor unit 103 (or the second indoor unit 104) and the first heat exchanger coil temperature (or the second heat exchanger coil temperature) are detected in real time by sensors. The sensors can include temperature sensors or other suitable sensors. At this time, when the first fan 1032 (or the second fan 1042) of the first indoor unit 103 (or the second indoor unit 104) is faulty and does not operate at the specified fan rotating speed R according to the instruction but is in a faulty state, in the first heat exchanger coil 1031 (or the second heat exchanger coil 1041) portion of the first indoor unit 103 (or the second indoor unit 104), a refrigerant does not exchange heat with the outside air under flow of a wind speed, the heat exchanger coil temperature of the first indoor unit 103 (or the second indoor unit 104) continuously decreases, and the return air temperature of each indoor unit within the first specified duration T1 does not change greatly, so that the difference Δt1 (or the difference Δt2) between the return air temperature of the first indoor unit 103 (or the second indoor unit 104) and the heat exchanger coil temperature of the first indoor unit 103 (or the second indoor unit 104) increases, and therefore, whether the first fan 1032 (or the second fan 1042) of the first indoor unit 103 (or the second indoor unit 104) is in normal operation or faulty may be determined according to an increase degree of the difference Δt1 (or the difference Δt2).

For example, when a value of the difference Δt1 or the difference Δt2 is greater than or equal to a preset specified threshold Δt, it may be determined that the first fan 1032 of the first indoor unit 103 or the second fan 1042 of the second indoor unit 104 fails to operate normally according to the instruction. On the contrary, when values of the difference Δt1 and the difference Δt2 are both less than the preset specified threshold Δt, it may be determined that both the first fan 1032 of the first indoor unit 103 and the second fan 1042 of the second indoor unit 104 operate normally, thereby completing a test of the fan of the indoor unit.

When it is determined in the indoor unit fan operating condition determination step S4 that the first fan 1032 of the first indoor unit 103 or the second fan 1042 of the second indoor unit 104 operates normally, after the first specified duration T1 has elapsed, the compressor second rotating speed operating control step S5 is executed, that is, the compressor 101 is controlled to operate at a second specified rotating speed N2 higher than the first specified rotating speed N1. At this time, the first expansion valve adjustment step S6 is executed to instruct to close the first expansion valve 105, a low-temperature refrigerant cannot enter the first heat exchanger coil 1031 of the first indoor unit 103 through the first expansion valve 105 to complete processes of expansion, decompression, evaporation and heat absorption, but the first fan 1032 of the first indoor unit 103 still continues to maintain the specified fan rotating speed R to operate, and air entering the first indoor unit 103 continues to exchange heat with a refrigerant remaining in the first heat exchanger coil 1031 of the first indoor unit 103, so that the heat exchanger coil temperature of the first indoor unit 103 tends to rise within the second specified duration T2. After the second specified duration T2 has elapsed, the first expansion valve 105 is instructed to adjust to a second specified opening degree V2 of the expansion valve, and the second specified opening degree V2 of the expansion valve is maintained for a third specified duration T3. After the third specified duration T3 has elapsed, an opening degree of the first expansion valve 105 may be adjusted to a third specified opening degree V3 of the expansion valve. A size of the third specified opening degree V3 of the expansion valve may be set according to a debugging requirement of the air conditioning system 1, and after the opening degree of the first expansion valve 105 is adjusted to the third specified opening degree V3 of the expansion valve, an expansion valve automatic adjustment mode is entered, and the opening degree of the first expansion valve 105 is adjusted according to a target superheat degree of the first indoor unit 103 to ensure that a refrigerant at an outlet of the first indoor unit 103 has a certain superheat degree to protect normal operation of the compressor 101.

When the first expansion valve 105 is adjusted to the second specified opening degree V2 of the expansion valve, a low-temperature and low-pressure refrigerant re-enters the first indoor unit 103 through the first expansion valve 105, and evaporates and absorbs heat in the first heat exchanger coil 1031 of the first indoor unit 103, so that the heat exchanger coil temperature of the first indoor unit 103 is reduced compared with that when the first expansion valve 105 is closed, and the return air temperature of the first indoor unit 103 may also be gradually reduced.

Meanwhile, the first expansion valve operating condition detection step S7 is executed, that is, the return air temperature of the first indoor unit 103 and the heat exchanger coil temperature of the first indoor unit 103 are respectively detected within the second specified duration T2. The return air temperature of the first indoor unit 103 and the heat exchanger coil temperature of the first indoor unit 103 are respectively detected within the third specified duration T3, and a return air temperature difference ΔWt1 in the first indoor unit 103 within the second specified duration T2 and the third specified duration T3 and a heat exchanger coil temperature difference ΔHt1 in the first indoor unit 103 within the second specified duration T2 and the third specified duration T3 are acquired by calculation.

After the return air temperature difference ΔWt1 and the heat exchanger coil temperature difference ΔHt1 are acquired, the first expansion valve operating condition determination step S8 is executed, that is, a difference between the return air temperature difference ΔWt1 of the first indoor unit 103 and the heat exchanger coil temperature difference ΔHt1 of the first indoor unit 103 is taken as a first difference X1 (i.e., X1=ΔHt1−ΔWt1), when the first difference X1 is less than or equal to a specified expansion valve determination threshold Δxt, it is determined that the first expansion valve 105 fails to correctly execute an instruction of closing or adjusting to the second specified opening degree V2 of the expansion valve, and accordingly, it is determined that the first expansion valve 105 is faulty.

At this time, the specified expansion valve determination threshold Δxt may be the same as or different from the specified threshold Δt, and may be appropriately set according to the actual configuration of the air conditioning system 1, which is not particularly limited.

On the contrary, when the first difference X1 is greater than the specified expansion valve determination threshold Δxt, it is determined that the first expansion valve 105 operates normally.

Through the above manner, when the air conditioning system 1 operates in a specified mode and needs to detect expansion valves of a plurality of indoor units including the first indoor unit 103 and the second indoor unit 104 and fans of a plurality of indoor units of the air conditioning system 1, the fans of all the indoor units are detected first, and the compressor 101 is controlled to operate at the lower first specified rotating speed N1 within the first specified duration T1, at this time, the expansion valves of all the indoor units are opened to the first specified opening degree V1, and the fans of all the indoor units instruct to maintain the same specified fan rotating speed R. Therefore, when the first fan 1032 (or the second fan 1042) of the first indoor unit 103 (or the second indoor unit 104) is faulty, the return air temperature of the first indoor unit 103 (or the second indoor unit 104) and the heat exchanger coil temperature of the first indoor unit 103 (or the second indoor unit 104) will be different, and specifically, based on a difference between the return air temperature of the first indoor unit 103 (or the second indoor unit 104) and the heat exchanger coil temperature of the first indoor unit 103 (or the second indoor unit 104), it is determined whether the first fan 1032 of the first indoor unit 103 (or the second fan 1042 of the second indoor unit 104) operates normally.

After it is determined that both the first fan 1032 of the first indoor unit 103 and the second fan 1042 of the second indoor unit 104 operate normally, the compressor second rotating speed operating control step S5, the first expansion valve adjustment step S6, the first expansion valve operating condition detection step S7, and the first expansion valve operating condition determination step S8 can be continuously executed without stopping to detect the first expansion valve 105. Specifically, after an opening degree of the first expansion valve 105 is changed by an instruction, within the second specified duration T2 and the third specified duration T3, that is, when the first expansion valve 105 is in different opening degrees, the difference between the return air temperature difference ΔWt1 of the first indoor unit 103 and the heat exchanger coil temperature difference ΔHt1 of the first indoor unit 103 is detected and acquired, that is, the first difference X1=ΔHt1−ΔWt1, and when the first difference X1 is less than the specified expansion valve determination threshold Δxt, it is determined that the first expansion valve 105 fails to correctly execute the opening degree adjustment instruction and is in a fault state.

Therefore, according to the above detection and comparison results, continuous automatic adjustment of the fans and the expansion valves of the plurality of indoor units of the air conditioning system 1 is realized, and a problem that automatic adjustment relies on manual inspection of the plurality of indoor units of the air conditioning system 1 one by one and results in low inspection and adjustment efficiency is avoided. Meanwhile, by using the detection method in some embodiments of this application, automatic detection or debugging can be performed on the fans and the expansion valves of the indoor units in the air conditioning system 1 only by detecting a return air temperature and an indoor coil temperature of the indoor unit, and calculating a corresponding difference, thereby avoiding a problem that an automatic detection or debugging method is more cumbersome and requires acquiring more operating parameters, or mounting of more sensor detection devices inside the air conditioning system 1 leads to increased costs.

In some embodiments of this application, the specified fan rotating speed R is the highest rotating speed of the first fan 1032 of the first indoor unit 103 and the second fan 1042 of the second indoor unit 104. At the highest rotating speed, the first fan 1032 of the first indoor unit 103 and the second fan 1042 of the second indoor unit 104 can provide the maximum air heat exchange amount, so that the difference Δt1 (or the difference Δt2) between the return air temperature of the first indoor unit 103 (or the second indoor unit 104)) and the heat exchanger coil temperature of the first indoor unit 103 (or the second indoor unit 104) is more significant, which is convenient for determining whether the first fan 1032 (or the second fan 1042) of the first indoor unit 103 (or the second indoor unit 104) operates normally.

In some embodiments of this application, the first specified expansion valve opening degree V1 is a specified opening degree between a maximum opening degree and a minimum opening degree of the first expansion valve 105 and/or the second expansion valve 106.

In some embodiments of this application, in the indoor unit fan operating condition determination step S4, when the difference Δt1 between the return air temperature of the first indoor unit 103 and the heat exchanger coil temperature of the first indoor unit 103 or the difference Δt2 between the return air temperature of the second indoor unit 104 and the heat exchanger coil temperature of the second indoor unit 104 is greater than or equal to the specified fan determination threshold, it is determined that the first fan 1032 of the first indoor unit 103 or the second fan 1042 of the second indoor unit 104 is faulty.

Through the above manner, in the indoor unit fan operating condition determination step S4, whether the fan of the indoor unit is faulty can be quickly determined only based on the difference between the return air temperature of the indoor unit and the heat exchanger coil temperature of the indoor unit, thereby avoiding problems in the automatic detection method that it is more complicated and less efficient to comprehensively consider multiple operating condition parameters to determine whether the fan is faulty. Meanwhile, the problem of increasing costs due to the need to mount more sensor detection devices in the air conditioning system 1 is also avoided.

In some embodiments of this application, the specified fan determination threshold is not limited, and the fan determination threshold may be the specified threshold Δt in the above embodiments, or may be a threshold acquired through an experiment, or a manner of flexibly setting different specified fan determination thresholds by comprehensively considering indoor and external environment parameters, different models of the air conditioning system 1, operating parameters, and the like when the air conditioning system 1 operates, all of the above shall be included in the protection scope of this application.

In addition, in some embodiments of this application, the second specified opening degree V2 of the expansion valve is the minimum opening degree of the first expansion valve 105 and/or the second expansion valve 106.

In the first expansion valve adjustment step S6, the first expansion valve 105 is instructed to be closed, and after the first expansion valve 105 is closed and the second specified duration T2 has elapsed, the first expansion valve 105 is instructed to be adjusted to the second specified opening degree V2 of the expansion valve, that is, the minimum opening degree of the first expansion valve 105, and the second specified opening degree V2 of the expansion valve, that is, the minimum opening degree of the first expansion valve 105, is maintained for the third specified duration T3.

In some embodiments, when the first expansion valve 105 is detected, the first expansion valve 105 is instructed to be closed within the second specified duration, and a refrigerant flowing out of a condenser cannot enter the first heat exchanger coil 1031 of the first indoor unit 103 through the first expansion valve 105, at this time, the first fan 1032 of the first indoor unit 103 still maintains the highest rotating speed, and a refrigerant remaining in the first heat exchanger coil 1031 of the first indoor unit 103 absorbs heat and evaporates, and the temperature thereof rises. Therefore, within the second specified duration T2, the heat exchanger coil temperature of the first indoor unit 103 and the return air temperature of the first indoor unit 103 will both rise. After the second specified duration T2 has elapsed, the first expansion valve 105 is controlled to open to the second specified expansion valve opening degree, that is, the minimum opening degree of the first expansion valve 105, and maintained for the third specified duration T3, at this time, the refrigerant flows into the heat exchanger of the first indoor unit 103 through the first expansion valve 105 again, so that the heat exchanger coil temperature of the first indoor unit 103 decreases. By controlling the second specified opening degree V2 of the expansion valve to be the minimum opening degree of the first expansion valve 105 and/or the second expansion valve 106, a flow rate of a refrigerant flowing into the first indoor unit 103 through the first expansion valve 105 when the first expansion valve 105 is switched from a closed state to an open state is reduced, thereby ensuring that the refrigerant flowing through the first indoor unit 103 can be fully evaporated and vaporized, and also avoiding a problem that a refrigerant flowing into the compressor 101 carries droplets and affects the service life of the compressor 101.

In some embodiments of this application, the specified expansion valve determination threshold Δxt is not limited, and the specified expansion valve determination threshold Δxt is a threshold acquired through an experiment, or a manner of flexibly setting different specified expansion valve determination thresholds Δxt by comprehensively considering indoor and external environment parameters, different models of the air conditioning system 1, operating parameters, and the like when the air conditioning system 1 operates, all of the above shall be included in the protection scope of this application.

FIG. 4 is a schematic diagram of steps executed in the detection method of an air conditioning system in some embodiments of this application. Referring to FIG. 4, in some embodiments the detection method of an air conditioning system further includes a second expansion valve adjustment step S9, a second expansion valve operating condition detection step S10, and a second expansion valve operating condition determination step S11.

In some embodiments of this application, after the first expansion valve operating condition determination step S8 is completed, the second expansion valve adjustment step S9 can be executed without stopping, the second expansion valve 106 is instructed to be closed, the low-temperature refrigerant cannot enter the second heat exchanger coil 1041 of the second indoor unit 104 through the second expansion valve 106 to complete processes of expansion, decompression, evaporation, and heat absorption, but the second fan 1042 of the second indoor unit 104 still continues to maintain the specified fan rotating speed R to operate, and air entering the second indoor unit 104 continues to exchange heat with a refrigerant remaining in the second heat exchanger coil 1041 of the second indoor unit 104, so that the heat exchanger coil temperature of the second indoor unit 104 tends to rise within the second specified duration T2. After the second specified duration T2 has elapsed, the second expansion valve 106 is instructed to adjust to a second specified opening degree V2 of the expansion valve, and the second specified opening degree V2 of the expansion valve is maintained for a third specified duration T3. After the third specified duration T3 has elapsed, an opening degree of the second expansion valve 106 may be adjusted to the third specified opening degree V3 of the expansion valve. A size of the third specified opening degree V3 of the expansion valve may be set according to a debugging requirement of the air conditioning system 1, and after the opening degree of the second expansion valve 106 is adjusted to the third specified opening degree V3 of the expansion valve, an expansion valve automatic adjustment mode is entered, and the opening degree of the second expansion valve 106 is adjusted according to a target superheat degree of the second indoor unit 104 to ensure that a refrigerant at an outlet of the second indoor unit 104 has a certain superheat degree to protect normal operation of the compressor 101.

When the second expansion valve 106 is adjusted to the second specified opening degree V2 of the expansion valve, a refrigerant re-enters the second indoor unit 104 through the second expansion valve 106, and evaporates and absorbs heat in the second heat exchanger coil 1041 of the second indoor unit 104, so that the heat exchanger coil temperature of the second indoor unit 104 is reduced compared with that when the second expansion valve 106 is closed, and the return air temperature of the second indoor unit 104 may also be gradually reduced.

Meanwhile, the second expansion valve operating condition detection step S10 is executed, that is, the return air temperature of the second indoor unit 104 and the heat exchanger coil temperature of the second indoor unit 104 are respectively detected within the second specified duration T2. The return air temperature of the second indoor unit 104 and the heat exchanger coil temperature of the second indoor unit 104 are respectively detected within the third specified duration T3, and a return air temperature difference ΔWt2 in the second indoor unit 104 within the second specified duration T2 and the third specified duration T3 and a heat exchanger coil temperature difference ΔHt2 in the second indoor unit 104 within the second specified duration T2 and the third specified duration T3 are acquired by calculation.

After the return air temperature difference ΔWt2 and the heat exchanger coil temperature difference ΔHt2 are acquired, the second expansion valve operating condition determination step S11 is executed, that is, a difference between the return air temperature difference ΔWt2 of the second indoor unit 104 and the heat exchanger coil temperature difference ΔHt2 of the second indoor unit 104 is taken as a second difference X2 (i.e., X2=ΔHt2−ΔWt2), when the second difference X2 is less than or equal to the specified expansion valve determination threshold Δxt, it is determined that the second expansion valve 106 fails to correctly execute the instruction of closing or adjusting to the second specified opening degree V2 of the expansion valve, and accordingly, it is determined that the second expansion valve 106 is faulty.

In some embodiments of this application, when the second expansion valve adjustment step S9 is executed, the opening degree of the first expansion valve 105 is instructed to be adjusted to the third specified opening degree V3 of the expansion valve greater than the second specified opening degree V2 of the expansion valve.

Through the above manner, when the second expansion valve 106 is adjusted to the closed state, the refrigerant cannot flow continuously after flowing to a position where the second expansion valve 106 is located, a pressure at the second expansion valve 106 rises, and more refrigerant flows to the first expansion valve 105 with a lower pressure; and when the second expansion valve adjustment step S9 is executed, the first expansion valve 105 is controlled to be adjusted to the third specified expansion valve opening degree greater than the second specified expansion valve opening degree, so that more refrigerant flows into the first indoor unit 103 through the first expansion valve 105, thereby avoiding a problem that a pressure at the first expansion valve 105 or the second expansion valve 106 is too high or the refrigerant cannot be reasonably distributed, thereby affecting the service life of the air conditioning system 1.

FIG. 5 is a schematic diagram of modules of an air conditioning system in one or more embodiments of this application. Referring to FIG. 5, the air conditioning system 1 further includes a third indoor unit 108, a fourth indoor unit 109, a third expansion valve 110, and a fourth expansion valve 111.

As shown in FIG. 5, the third indoor unit 108 and the fourth indoor unit 109 are connected in parallel and connected to the compressor 101 and the outdoor unit 102 through the refrigerant pipeline 107. The third expansion valve 110 is provided corresponding to the third indoor unit 108, and the fourth expansion valve 111 is provided corresponding to the fourth indoor unit 109. In addition, a third heat exchanger coil 1081 for heat exchange and a third fan 1082 of the third indoor unit are further provided corresponding to the third indoor unit 108, and a fourth heat exchanger coil 1091 for heat exchange and a fourth fan 1092 of the fourth indoor unit are further provided corresponding to the fourth indoor unit 109.

FIG. 6 is a schematic diagram of steps executed in the detection method of an air conditioning system in some embodiments of this application. Referring to FIG. 6, in some embodiments the detection method of an air conditioning system further includes: a third expansion valve adjustment step S12, a third expansion valve operating condition detection step S13, a third expansion valve operating condition determination step S14, a fourth expansion valve adjustment step S15, a fourth expansion valve detection step S16, and a fourth expansion valve operating condition determination step S17.

In some embodiments of this application, after the second expansion valve operating condition determination step S11 is completed, the third expansion valve adjustment step S12 can be executed without stopping, the third expansion valve 110 is instructed to be closed, the low-temperature refrigerant cannot enter the third heat exchanger coil 1081 of the third indoor unit 108 through the third expansion valve 110 to complete processes of expansion, decompression, evaporation, and heat absorption, but the third fan 1082 of the third indoor unit 108 still continues to maintain the specified fan rotating speed R to operate, and air entering the third indoor unit 108 continues to exchange heat with a refrigerant remaining in the third heat exchanger coil 1081 of the third indoor unit 108, so that the heat exchanger coil temperature of the third indoor unit 108 tends to rise within the second specified duration T2. After the second specified duration T2 has elapsed, the third expansion valve 110 is instructed to adjust to a second specified opening degree V2 of the expansion valve, and the second specified opening degree V2 of the expansion valve is maintained for a third specified duration T3. After the third specified duration T3 has elapsed, an opening degree of the third expansion valve 110 may be adjusted to the third specified opening degree V3 of the expansion valve. A size of the third specified opening degree V3 of the expansion valve may be set according to the debugging requirement of the air conditioning system 1, and after the opening degree of the third expansion valve 110 is adjusted to the third specified opening degree V3 of the expansion valve, the expansion valve automatic adjustment mode is entered, and the opening degree of the third expansion valve 110 is adjusted according to a target superheat degree of the third indoor unit 108 to ensure that a refrigerant at an outlet of the third indoor unit 108 has a certain superheat degree to protect the normal operation of the compressor 101.

When the third expansion valve 110 is adjusted to the second specified opening degree V2 of the expansion valve, the low-temperature and low-pressure refrigerant re-enters the third indoor unit 108 through the third expansion valve 110, and evaporates and absorbs heat in the third heat exchanger coil 1081 of the third indoor unit 108, so that the heat exchanger coil temperature of the third indoor unit 108 is reduced compared with that when the third expansion valve 110 is closed, and the return air temperature of the third indoor unit 108 may also be gradually reduced.

Meanwhile, the third expansion valve operating condition detection step S13 is executed, that is, the return air temperature of the third indoor unit 108 and the heat exchanger coil temperature of the third indoor unit 108 are respectively detected within the second specified duration T2. The return air temperature of the third indoor unit 108 and the heat exchanger coil temperature of the third indoor unit 108 are respectively detected within the third specified duration T3, and a return air temperature difference ΔWt3 in the third indoor unit 108 within the second specified duration T2 and the third specified duration T3 and a heat exchanger coil temperature difference ΔHt3 in the third indoor unit 108 within the second specified duration T2 and the third specified duration T3 are acquired by calculation.

After the return air temperature difference ΔWt3 and the heat exchanger coil temperature difference ΔHt3 are acquired, the third expansion valve operating condition determination step S14 is executed, that is, a difference between the return air temperature difference ΔWt3 of the third indoor unit 108 and the heat exchanger coil temperature difference ΔHt3 of the third indoor unit 108 is taken as a third difference X3 (that is, X3=ΔHt3−ΔWt3), when the third difference X3 is less than or equal to the specified expansion valve determination threshold Δxt, it is determined that the third expansion valve 110 fails to correctly execute the instruction of closing or adjusting to the second specified opening degree V2 of the expansion valve, and accordingly, it is determined that the third expansion valve 110 is faulty.

After detection of the third expansion valve 110 is completed, the fourth expansion valve adjustment step S15, the fourth expansion valve detection step S16 and the fourth expansion valve operating condition determination step S17 are executed to detect an operating condition of the fourth expansion valve 111.

Through the above embodiment, when the air conditioning system 1 operates in a cooling mode and it is necessary to detect the fan and the expansion valve of the air conditioning system 1, the compressor first rotating speed operating control step S2, the indoor unit fan operating condition detection step S3 and the indoor unit fan operating condition determination step S4 are firstly executed to detect the fans of all the indoor units, and when it is determined that the fans of the indoor units operate normally, the expansion valves of the air conditioning system 1 are detected one by one to avoid a problem that the expansion valves of the air conditioning system 1 are closed or adjusted to the second specified expansion valve opening degree at the same time, so that the pressure of the expansion valves rises or the refrigerant cannot be reasonably distributed to affect the service life of the air conditioning system 1.

Although the embodiments of this application are described in the form of the first expansion valve 105, the second expansion valve 106, the third expansion valve 110, and the fourth expansion valve 111, and their corresponding first indoor unit 103, the second indoor unit 104, the third indoor unit 108, and the fourth indoor unit 109, this application is not limited thereto, more or fewer expansion valves and the corresponding indoor units are connected in parallel in the air conditioning system 1, as long as it is determined that after the fan of the indoor unit operates normally, the expansion valves are adjusted one by one or sequentially grouped, and a difference between the return air temperature difference of the indoor unit and the heat exchanger coil temperature difference of the indoor unit is compared with the specified expansion valve determination threshold to determine whether the expansion valve is faulty, all of the above shall be included in the protection scope of this application. For example, it is assumed that 20 indoor units are connected in parallel in the air conditioning system 1 and divided into four groups, a first group is set as the first expansion valve 105 and the first indoor unit 103, a second group is set as the second expansion valve 106 and the second indoor unit 104, a third group is set as the third expansion valve 110 and the third indoor unit 108, and a fourth group is set as the fourth expansion valve 111 and the fourth indoor unit 109, and settings of the detection method of the air conditioning system 1 according to the embodiments of this application are executed on the 20 indoor units, which shall also be included in the protection scope of this application.

It should be noted that, although the plurality of indoor units connected in parallel are grouped for testing in the above embodiments, each group includes a plurality of indoor units and correspondingly includes a plurality of indoor fans and expansion valves, determination is still performed independently according to parameters of each indoor unit in a detection process, rather than determination for the entire group.

FIG. 7 is a schematic diagram of modules of a control device of an air conditioning system in one or more embodiments of this application. As shown in FIG. 7, a control device 10 of the air conditioning system 1 according to this embodiment includes: an air conditioning system operating mode determination module 11, a compressor first rotating speed operating control module 12, an indoor unit fan operating condition detection module 13, an indoor unit fan operating condition determination module 14, a compressor second rotating speed operating control module 15, a first expansion valve adjustment module 16, a first expansion valve operating condition detection module 17, and a first expansion valve operating condition determination module 18.

In some embodiments of this application, when the air conditioning system 1 receives an instruction to start test operation, the air conditioning system operating mode determination module 11 executes the air conditioning system operation mode determination step S1 of determining whether the air conditioning system 1 is set to a specified mode, and when the air conditioning system 1 is set to the specified mode, that is, the air conditioning system 1 operates in a cooling mode, and it is necessary to detect the expansion valve and the fan of the indoor unit of the air conditioning system 1, the compressor first rotating speed operating control module 12 executes the compressor first rotating speed operating control step S2 of controlling the compressor 101 to operate at the first specified rotating speed N1 for the first specified duration T1, instructing the first fan 1032 of the first indoor unit 103 and the second fan 1042 of the second indoor unit 104 to maintain the same specified fan rotating speed R within the first specified duration T1, and instructing the opening degrees of the corresponding first expansion valve 105 and the second expansion valve 106 to maintain the same first specified expansion valve opening degree V1.

Within the first specified duration T1, the indoor unit fan operating condition detection module 13 executes the indoor unit fan operating condition detection step S3 of detecting the return air temperature of the first indoor unit 103 and the heat exchanger coil temperature of the first indoor unit 103 and comparing them to acquire the difference Δt1, and detecting the return air temperature of the second indoor unit 104 and the heat exchanger coil temperature of the second indoor unit 104 and comparing them to acquire the difference Δt2. After the detection is completed, the indoor unit fan operating condition determination module 14 executes the indoor unit fan operating condition determination step S4 of determining whether the first fan 1032 of the first indoor unit 103 and the second fan 1042 of the second indoor unit 104 operate normally according to detection and comparison results in the indoor unit fan operating condition detection module 13.

When the indoor unit fan operating condition determination module 14 determines that the first fan 1032 of the first indoor unit 103 and the second fan 1042 of the second indoor unit 104 are operates normally, after the first specified duration T1 has elapsed, the compressor second rotating speed operating control module 15 executes the compressor second rotating speed operating control step S5, that is, controls the compressor 101 to operate at the second specified rotating speed N2 higher than the first specified rotating speed N1. At this time, the first expansion valve adjustment module 16 executes the first expansion valve adjustment step S6 of controlling the first expansion valve 105 to be closed, controlling the first expansion valve 105 to be adjusted to the second specified opening degree V2 of the expansion valve after the first expansion valve 105 is closed and the second specified duration T2 has elapsed, and maintaining the second specified opening degree V2 of the expansion valve for the third specified duration T3.

Meanwhile, the first expansion valve operating condition detection module 17 executes the first expansion valve operating condition detection step S7, that is, the return air temperature of the first indoor unit 103 and the heat exchanger coil temperature of the first indoor unit 103 are respectively detected within the second specified duration T2. The return air temperature of the first indoor unit 103 and the heat exchanger coil temperature of the first indoor unit 103 are respectively detected within the third specified duration T3, and a return air temperature difference ΔWt1 in the first indoor unit 103 within the second specified duration T2 and the third specified duration T3 and a heat exchanger coil temperature difference ΔHt1 in the first indoor unit 103 within the second specified duration T2 and the third specified duration T3 are acquired by calculation. After the return air temperature difference ΔWt1 and the heat exchanger coil temperature difference ΔHt1 are acquired, the first expansion valve operating condition determination module 18 executes the first expansion valve operating condition determination step S8, that is, the difference between the return air temperature difference ΔWt1 of the first indoor unit 103 and the heat exchanger coil temperature difference ΔHt1 of the first indoor unit 103 is taken as the first difference X1 (i.e., X1=ΔHt1−ΔWt1), when the first difference X1 is less than or equal to a specified expansion valve determination threshold Δxt, it is determined that the first expansion valve 105 fails to correctly execute an instruction of closing or adjusting to the second specified opening degree V2 of the expansion valve, and accordingly, it is determined that the first expansion valve 105 is faulty.

Specifically, in some embodiments, the air conditioning system operating mode determination module 11 is controlled to execute the air conditioning system operation mode determination step S1 of any one of the one or more embodiments. Similarly, the compressor first rotating speed operating control module 12 is controlled to execute the compressor first rotating speed operating control step S2, the indoor unit fan operating condition detection module 13 is controlled to execute the indoor unit fan operating condition detection step S3, the indoor unit fan operating condition determination module 14 is controlled to execute the indoor unit fan operating condition determination step S4, the compressor second rotating speed operating control module 15 is controlled to execute the compressor second rotating speed operating control step S5, the first expansion valve adjustment module 16 is controlled to execute the first expansion valve adjustment step S6, the first expansion valve operating condition detection module 17 is controlled to execute the first expansion valve operating condition detection step S7, and the first expansion valve operating condition determination module 18 is controlled to execute the first expansion valve operating condition determination step S8.

One or more embodiments of this application further provide an air conditioning system including a memory and a controller, in which the controller executes any one of the above detection methods of an air conditioning system.

The above embodiments are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application shall be included in the protection scope of this application.