Control method of air conditioning system and air conditioning system

Abstract

The invention relates to the technical field of air conditioning systems, and particularly provides a control method of an air conditioning system and the air conditioning system. The air conditioning system comprises an indoor unit, the indoor unit is provided with an air outlet and an air return port, and the air return port comprises an indoor air return port and an outdoor air inlet; the air conditioning system further comprises a first air duct and a second air duct, the air outlet communicates with the outdoor environment through the first air duct, the outdoor air inlet communicates with the outdoor environment through the second air duct, a first air valve is arranged in the first air duct, and a second air valve is arranged in the second air duct. The control method comprises the steps that when a defrosting mode is operated, the air conditioning system performs refrigeration operation; and the indoor fan rotates, and the first air valve and the second air valve are opened. In the defrosting process, residual heat of indoor air is recycled, heat of outdoor fresh air is fully utilized, and the indoor unit heat exchanger absorbs the heat of the indoor air and the heat of the outdoor fresh air, so that the evaporation pressure of the system is increased, energy consumption in the defrosting process is reduced, cold air is exhausted outdoors, and the indoor comfortable temperature is guaranteed.

Description

Technical Field

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

[0002] When the air conditioner is in the heating mode, when the outdoor ambient temperature is relatively low and the humidity is relatively high, condensed water in the air condenses into frost on the surface of the outdoor condenser. Existing air conditioners usually use the reverse cycle defrosting method. During the defrosting process, the air conditioner needs to switch to the cooling mode, and the heat that was originally sent to the indoor unit is sent to the outdoor condenser for defrosting. During the defrosting process, the indoor unit heat exchanger acts as an evaporator to absorb the indoor heat. When the air conditioner is in normal heating, the indoor fan rotates normally. However, during defrosting, in order to prevent cold air from being blown out by the indoor unit, the indoor fan usually stops rotating. However, since there is no air volume passing through the indoor unit heat exchanger, the evaporation temperature drops rapidly, and the low-pressure pressure drops, resulting in a slow rise in the exhaust temperature, poor defrosting effect, long defrosting cycle, high energy consumption, and affecting the user's comfort experience.

[0003] Therefore, in the defrosting process of some existing air conditioners, the indoor fan rotates and does not stop to improve the defrosting efficiency, and the auxiliary electric heating is turned on. When the air conditioner is in normal heating, the auxiliary electric heating can be selectively turned on. However, when the defrosting condition is reached, the air conditioner switches to the defrosting mode, and at the same time, the auxiliary electric heating of the indoor unit is turned on, and the indoor fan continues to rotate. At this time, the heat supply of the auxiliary electric heating should be greater than the cold quantity generated when the indoor unit heat exchanger evaporates to prevent cold air from being blown out. However, the energy consumption of the auxiliary electric heating is relatively high. Another method is that during the defrosting process of the air conditioner, the indoor fan rotates, and the cold air previously discharged into the room is discharged outdoors through a pipeline, so as to achieve defrosting without affecting the indoor temperature. However, since the cold air first passes through the indoor air supply pipeline, the pipeline temperature drops, and more heat needs to be consumed to raise the pipeline temperature during the next heating operation, so there is also the problem of high energy consumption.

[0004] Correspondingly, there is a need in the art for a new control method for an air conditioning system to solve the problem of high energy consumption in the existing air conditioning system when operating the defrosting function. Summary of the Invention

[0005] The present invention aims to solve the above technical problems, that is, to solve the problem of high energy consumption in the existing air conditioning system when operating the defrosting function.

[0006] The present invention provides a control method for an air conditioning system. The air conditioning system includes an indoor unit and an outdoor unit. An air outlet and an air return opening are provided on the indoor unit. The air return opening includes an indoor air return opening and an outdoor air inlet;

[0007] The air conditioning system further includes a first air duct and a second air duct. The air outlet and the outdoor environment are connected through the first air duct, and the outdoor air inlet and the outdoor environment are connected through the second air duct. A first air valve is arranged in the first air duct, and a second air valve is arranged in the second air duct;

[0008] The control method includes:

[0009] When the defrosting mode is running, the air conditioning system operates in a refrigeration mode and the indoor fan rotates;

[0010] The first air valve and the second air valve are opened.

[0011] In a preferred technical solution of the control method of the above air conditioning system, the air conditioning system further includes a third air duct. The air outlet and the indoor environment are connected through the third air duct, and a third air valve is arranged in the third air duct;

[0012] The control method includes:

[0013] When the defrosting mode is running, the air conditioning system operates in a refrigeration mode;

[0014] The indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve is closed.

[0015] In a preferred technical solution of the control method of the above air conditioning system, the steps of "when the defrosting mode is running, the air conditioning system operates in a refrigeration mode; the indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve is closed" further include:

[0016] After receiving the signal to run the defrosting mode, the indoor fan rotates, the first air valve is closed, the second air valve is opened, and the third air valve is opened;

[0017] Control the compressor to reduce the frequency to the defrosting entry frequency;

[0018] Control the air conditioning system to operate in a refrigeration mode;

[0019] The first air valve is opened, the second air valve is opened, and the third air valve is closed;

[0020] Control the compressor to increase the frequency to the defrosting target frequency.

[0021] In a preferred technical solution of the control method of the above air conditioning system, after the step of "control the compressor to increase the frequency to the defrosting target frequency", the control method further includes:

[0022] When receiving the signal that the defrosting mode ends, the compressor reduces the frequency to the defrosting exit frequency;

[0023] Control the air conditioning system to switch to heating operation;

[0024] The second air valve is closed, the first air valve is closed, and the third air valve is opened.

[0025] In a preferred technical solution of the control method of the above air conditioning system, the step of "controlling the air conditioning system to operate in cooling mode" further includes:

[0026] After the compressor maintains the defrosting entry frequency for a first preset duration, control the air conditioning system to operate in cooling mode; and / or,

[0027] The step of "controlling the compressor to increase the frequency to the defrosting target frequency" further includes:

[0028] After the compressor continues to maintain the defrosting entry frequency for a second preset duration, control the compressor to increase the frequency to the defrosting target frequency; and / or,

[0029] The step of "the second air valve is closed, the first air valve is closed, and the third air valve is opened" further includes:

[0030] After the second air valve is closed for a fourth preset duration, the first air valve is closed, and the third air valve and the fourth air valve are opened.

[0031] In a preferred technical solution of the control method of the above air conditioning system, the air conditioning system further includes a fourth air duct, the air outlet and the indoor environment are communicated through the fourth air duct, and a fourth air valve is arranged in the fourth air duct;

[0032] The control method includes:

[0033] When operating in the defrosting mode, the air conditioning system operates in cooling mode;

[0034] The indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve and / or the fourth air valve are closed; and / or,

[0035] When the air conditioning system operates in the cooling mode or the heating mode, the indoor fan rotates, the first air valve and the second air valve are closed, and the third air valve and / or the fourth air valve are opened.

[0036] In a preferred technical solution of the control method of the above air conditioning system, the control method includes:

[0037] When operating the fresh air function, the indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve is opened.

[0038] In the preferred technical solution of the control method of the above air-conditioning system, the step of "when the fresh air function is running, the indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve is opened" further includes:

[0039] When the fresh air function is running and when the air-conditioning system is operating in the defrost mode, the indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve is opened; wherein, the opening degree of the third air valve is a first preset opening degree;

[0040] When the fresh air function is running and when the air-conditioning system is operating in the heating mode, the indoor fan rotates, the first air valve and the second air valve are opened, the third air valve is opened, and the opening degree of the third air valve is a second preset opening degree; wherein, the first preset opening degree is less than the second preset opening degree; and / or,

[0041] When the air-conditioning system only runs the fresh air function, the indoor fan rotates, and the first air valve, the second air valve, and the third air valve are opened to the maximum opening degree; and / or,

[0042] When the fresh air function is running, the indoor fan rotates, the first air valve and the second air valve are opened, the third air valve is opened, the first air valve and / or the second air valve are opened for a first preset duration and then closed for a second preset duration and then reopened for the first preset duration, and after repeating the preset number of times, the first air valve and the second air valve are closed.

[0043] In the preferred technical solution of the control method of the above air-conditioning system, before the step of "running the fresh air function", the control method includes:

[0044] Obtain the carbon dioxide concentration in the indoor ambient air;

[0045] When the carbon dioxide concentration ≥ the preset concentration, run the fresh air function;

[0046] When the carbon dioxide concentration < the preset concentration, stop running the fresh air function.

[0047] The present invention also provides an air-conditioning system, which includes a memory and a processor. The memory is suitable for storing multiple program codes, and the program codes are suitable for being loaded and run by the processor to execute the control method of the air-conditioning system described in any one of the above technical solutions.

[0048] Those skilled in the art can understand that the air conditioning system of the present invention includes an indoor unit and an outdoor unit. The indoor unit is provided with an air outlet and an air return opening. The air return opening includes an indoor air return opening and an outdoor air inlet. The air conditioning system further includes a first air duct and a second air duct. The air outlet is communicated with the outdoor environment through the first air duct, and the outdoor air inlet is communicated with the outdoor environment through the second air duct. A first air valve is arranged in the first air duct, and a second air valve is arranged in the second air duct. The control method includes: when the defrosting mode is running, the air conditioning system operates in a refrigeration mode; the indoor fan rotates, and the first air valve and the second air valve are opened.

[0049] In the case of adopting the above technical solution, when the air conditioning system of the present invention is running in the defrosting mode, it controls the air conditioning system to switch to refrigeration operation, defrosts the outdoor unit heat exchanger through the high-temperature refrigerant in the outdoor unit heat exchanger, and at the same time of reverse defrosting operation, the indoor fan rotates, the first air valve and the second air valve are opened, outdoor fresh air enters the indoor unit air return opening through the second air valve, the indoor air and the outdoor fresh air are mixed and then blown to the indoor unit heat exchanger to exchange heat with the indoor unit heat exchanger, jointly improving the evaporation pressure and evaporation temperature during defrosting, improving the defrosting efficiency, and then discharging the cold air to the outside through the first air duct, reducing the indoor temperature fluctuation.

[0050] During the defrosting process, not only the residual heat of the indoor air is recovered, but also the characteristic that the temperature of the indoor unit heat exchanger is much lower than that of the outdoor fresh air during defrosting is utilized to make full use of the heat of the outdoor fresh air to further increase the evaporation temperature and evaporation pressure during defrosting, reduce the compression ratio during the defrosting process, ensure the oil return and reliability of the compressor, and reduce the power consumption during the defrosting process. At the same time, the air conditioning system does not require an electric heater, and the process of replacing fresh air does not require an additional fresh air fan. The fresh air can be input by the operation of the indoor fan, reducing the cost of the air conditioning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, in which:

[0052] Figure 1 is a schematic structural diagram of the air conditioning system of the present invention;

[0053] Figure 2 is a main step flow chart of the control method of the air conditioning system of the present invention;

[0054] Figure 3 is a step flow chart of the first embodiment of the control method of the air conditioning system of the present invention;

[0055] Figure 4 is a step flow chart of the second embodiment of the control method of the air conditioning system of the present invention;

[0056] Figure 5It is a flowchart of the steps of the third implementation manner of the control method of the air-conditioning system of the present invention. List of reference numerals: 1. Indoor unit; 2. Outdoor unit; 21. Return air inlet; 211. Indoor air return inlet; 212. Outdoor air inlet; 22. Air outlet; 3. First air duct; 31. First air valve; 4. Second air duct; 41. Second air valve; 5. Third air duct; 51. Third air valve; 6. Fourth air duct; 61. Fourth air valve. Specific implementation manner

[0057] The preferred implementation manners of the present invention 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 invention and are not intended to limit the protection scope of the present invention. Those skilled in the art can adjust it as needed to adapt to specific application scenarios. For example, the control method of the air-conditioning system in this application can be used for wall-mounted air conditioners, cabinet air conditioners, central air conditioners, or multi-connected air conditioners, etc. The present invention does not impose any restrictions on the type of air conditioner, and it can also be applied to equipment that needs defrosting other than air conditioners.

[0058] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the term "connection" 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; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood according to specific situations.

[0059] Specifically, referring to Figure 1 , the air-conditioning system of the present invention includes an indoor unit 1, an outdoor unit 2, a four-way valve, an electronic expansion valve, and a refrigerant circulation circuit provided between the indoor unit 1 and the outdoor unit 2. The four-way valve and the electronic expansion valve are arranged on the refrigerant circulation circuit. The indoor unit 1 includes an indoor unit heat exchanger and an indoor fan, and the outdoor unit 2 includes a compressor, an outdoor unit heat exchanger, and an outdoor fan. Of course, those skilled in the art can also set the types of the indoor unit heat exchanger and the outdoor unit heat exchanger according to needs, and the present invention does not impose any restrictions on this.

[0060] The compressor, the indoor heat exchanger, and the outdoor heat exchanger are all arranged on the refrigerant circulation loop. The refrigerant circulates between the indoor and outdoor through the refrigerant circulation loop to exchange heat with the indoor environment through the indoor heat exchanger, so as to meet the heat exchange needs of users. Further, the indoor unit 1 includes an indoor unit housing, on which there are an air outlet 22 and an air return opening 21. The indoor heat exchanger and the indoor fan are arranged inside the indoor unit housing and between the air outlet 22 and the air return opening 21, so that the air flowing into the air return opening 21 is discharged from the air outlet 22 after exchanging heat through the indoor heat exchanger.

[0061] The air-conditioning system further includes a first air duct 3, a second air duct 4, a third air duct 5, and a fourth air duct 6. One end of the first air duct 3 is connected to the air outlet 22, and the other end is communicated with the outdoor environment. The air outlet 22 and the outdoor environment are communicated through the first air duct 3. The air return opening 21 further includes an indoor air return opening 211 and an outdoor air inlet 212. One end of the second air duct 4 is connected to the outdoor air inlet 212, and the other end is communicated with the outdoor environment. The outdoor air inlet 212 and the outdoor environment are communicated through the second air duct 4. A first air valve 31 is arranged in the first air duct 3, and a second air valve 41 is arranged in the second air duct 4.

[0062] One ends of the third air duct 5 and the fourth air duct 6 are connected to the air outlet 22, and the other ends are communicated with the indoor environment. The air outlet 22 and the indoor environment are communicated through the third air duct 5 and the fourth air duct 6. A third air valve 51 is arranged in the third air duct 5, and a fourth air valve 61 is arranged in the fourth air duct 6.

[0063] The indoor air enters the indoor unit 1 through the indoor air return opening 211, and the outdoor fresh air enters the indoor unit 1 through the outdoor air inlet 212. Alternatively, the indoor air return opening 211 can also be arranged on the fourth air duct 6 and between the second air valve 41 and the air return opening 21. Those skilled in the art can set the position and structure of the indoor air return opening 211 according to needs, as long as the indoor air can flow back into the indoor unit 1, and all fall within the protection scope of the present invention.

[0064] The air valve includes an air valve body and a driving mechanism for driving the rotation of the air valve body. The following specifically describes the movement forms of the air valve. For example, taking the third air valve 51 as an example, the third air valve 51 includes a third air valve body and a third driving mechanism. The third air valve body includes a first position where the communication between the indoor environment and the air outlet 22 is closed, and a second position where the communication between the indoor environment and the air outlet 22 is fully opened. The air valve body can stay at any position between the first position and the second position. The opening degree of the air valve can be determined by adjusting the position of the air valve body. The larger the opening degree, the larger the opening for the airflow to flow between the air valve body and the air duct. Similarly, the smaller the opening degree, the smaller the opening for the airflow to flow between the air valve body and the air duct. Optionally, the driving mechanism can be a combination of a motor and a rack and pinion mechanism, or directly a rotating electric cylinder. However, it should be noted that there are many types and structures of air valves. Those skilled in the art can set the types and structures of air valves according to needs. The present invention does not impose any restrictions on the structure of the air valve, and all fall within the protection scope of the present invention.

[0065] Further, the air conditioning system further includes a controller that can control the operating state of the air conditioning system. For example, it can control the start and stop of the outdoor unit, the commutation of the four-way valve, the operation of the blower, and the frequency of the variable frequency compressor, etc. Those skilled in the art can understand that the present invention does not impose any restrictions on the specific structure and model of the controller, and the technician can set the structure and model of the controller according to actual usage requirements.

[0066] During the use process, the user can control the operation of the air conditioning system by setting the temperature. Those skilled in the art can understand that the present invention does not impose any restrictions on the specific structure of the air conditioning system, and the technician can set the specific structure of the air conditioning system according to actual usage requirements. Such a change in the specific application object does not deviate from the basic principle of the present invention and belongs to the protection scope of the present invention.

[0067] Referring to Figure 2 , to solve the problem of high energy consumption of the existing air conditioning system during the defrosting function operation, the control method of the air conditioning system of the present invention includes:

[0068] Step S10: When the defrosting mode is running, the air conditioning system operates in a refrigeration mode and the indoor blower rotates;

[0069] Step S20: The first air valve and the second air valve are opened.

[0070] The advantages of the above setting method are as follows: When the air conditioning system of the present invention operates in the defrosting mode, it is controlled to switch to refrigeration operation. The high-temperature refrigerant in the outdoor heat exchanger is used to defrost the outdoor heat exchanger. At the same time of reverse defrosting operation, the indoor fan rotates, the first air valve 31 and the second air valve 41 are opened, outdoor fresh air enters the return air port of the indoor unit through the second air valve, and the indoor air and the outdoor fresh air are mixed and then blown to the indoor heat exchanger to exchange heat with the indoor heat exchanger, jointly increasing the evaporation pressure and evaporation temperature during defrosting, improving the defrosting efficiency, and then discharging the cold air to the outside through the first air duct 3, reducing the indoor temperature fluctuation.

[0071] During the defrosting process, not only the residual heat of the indoor air is recovered, but also the fact that the temperature of the indoor heat exchanger is much lower than that of the outdoor fresh air during defrosting is utilized to make full use of the heat of the outdoor fresh air to further increase the evaporation temperature and evaporation pressure during defrosting, reduce the compression ratio during the defrosting process, ensure the oil return and reliability of the compressor, and reduce the power consumption during the defrosting process. At the same time, the air conditioning system does not require an electric heater, and no additional fresh air fan is needed for the fresh air replacement process. The fresh air can be input by the operation of the indoor fan, reducing the cost of the air conditioning system.

[0072] Refer to Figure 3 , in a possible implementation manner, the air conditioning system of the present invention can also synchronously replace the fresh air in the room while performing periodic defrosting, so that there is no need to separately set a fresh air mode. The control method of the air conditioning system specifically includes:

[0073] Step S31: After receiving the signal to operate the defrosting mode when the air conditioning system is operating in the heating mode, the indoor fan rotates, the first air valve is closed, the second air valve is opened, the third air valve and the fourth air valve are opened;

[0074] Step S32: Control the compressor to reduce the frequency to the defrosting entry frequency.

[0075] During the heating mode operation of the air conditioning system, when the outdoor heat exchanger frosts and certain conditions are met, the outdoor unit 2 sends a defrost signal to the indoor unit 1. The compressor reduces the current heating operation frequency to the defrost entry frequency. For example, the defrost entry frequency is set to 60HZ, and the indoor fan speed operates at the set wind speed. When the indoor unit 1 receives the defrost start signal, the second air valve 41 opens. At this time, the first air valve 31 is in the closed state, and the third air valve 51 and the fourth air valve 61 are in the open state. At this time, the outdoor fresh air and the indoor return air are mixed and first pass through the indoor heat exchanger. At this time, the temperature of the indoor heat exchanger is relatively high. After the fresh air absorbs heat, it enters the indoor space through the third air duct 5 and the fourth air duct 6, realizing the introduction of warm fresh air into the room. At the same time, because the temperature of the outdoor fresh air is lower than the indoor ambient temperature, introducing the outdoor fresh air to the outdoor heat exchanger can quickly reduce the exhaust pressure of the air conditioning system. At this time, the compressor does not need to be reduced to a very low frequency to achieve a reduction in the system pressure difference. When the defrost entry frequency does not need to be reduced very low, it can ensure that the subsequent four-way valve commutates stably at a relatively high frequency for refrigeration, reducing the time for the compressor to change from a reduced frequency to an increased frequency to the target defrost frequency during the defrost conversion period and improving the defrost efficiency.

[0076] Step S33: After the compressor maintains the defrost entry frequency for the first preset duration, control the air conditioning system to switch to refrigeration operation;

[0077] Step S331: Open the first air valve, open the second air valve, close the third air valve and the fourth air valve, and stop the outdoor fan;

[0078] Step S332: After the compressor continues to maintain the defrost entry frequency for the second preset duration, control the compressor to increase the frequency to the defrost target frequency.

[0079] When the compressor frequency is stable at the defrost entry frequency (60HZ) for the first preset duration, for example, the first preset duration is 60 seconds, the four-way valve loses power and commutates to refrigeration. At the same time, the first air valve 31 and the second air valve 41 open, the third air valve 51 and the fourth air valve 61 close, and the outdoor fan stops. Defrosting starts. When the air conditioning system defrosts, it does not send cold air into the room to prevent the indoor temperature from dropping. The indoor fan continues to operate at the set wind speed. After the heating operation switches to the refrigeration operation, to prevent the system load from changing violently during the pressure conversion period when switching from the heating operation to the refrigeration operation, the compressor maintains the defrost entry frequency and continues to operate for the second preset duration, and then the compressor increases the frequency to the defrost target frequency for defrosting. For example, the second preset duration is 20 seconds, and the defrost target frequency is 80HZ. The electronic expansion valve is at the set defrost opening to complete the defrosting of the outdoor heat exchanger.

[0080] After receiving the signal to operate in the defrost mode, the air conditioning system of the present invention only supplies fresh air to the indoor unit at the stage when defrosting starts. The fresh air absorbs the heat of the indoor unit heat exchanger, resulting in small indoor heat loss. Moreover, by utilizing the low-temperature characteristics of the fresh air, the exhaust pressure of the system is reduced, preparing for the subsequent commutation of the four-way valve. The defrosting entry frequency does not need to be lowered very much to meet the requirement of stable commutation and refrigeration operation of the four-way valve. It also does not take too long for the subsequent compressor to rise to the defrost target frequency, thereby improving the defrosting efficiency. During the defrosting stage, when the air conditioning system operates in refrigeration mode for defrosting, the third air valve 51 and the fourth air valve 61 are in the closed state, and no fresh air is supplied indoors. Also, the cold air does not pass through the indoor air supply duct. When heating operation resumes after defrosting, it is not necessary to consume a large amount of heat to increase the duct heat, ensuring a comfortable indoor temperature.

[0081] Step S34: When receiving the signal that the defrost mode ends, the compressor frequency is reduced to the defrost exit frequency;

[0082] Step S341: Control the air conditioning system to switch to heating operation;

[0083] Step S342: The outdoor fan rotates after the air conditioning system operates in heating mode for a third preset duration;

[0084] Step S343: The second air valve is closed;

[0085] Step S344: After the second air valve is closed for a fourth preset duration, the first air valve is closed, and the third air valve and the fourth air valve are opened.

[0086] When the defrosting operation reaches the defrost mode exit condition, the compressor is reduced from the current defrost target frequency to the defrost exit frequency. For example, the defrost exit frequency is 40HZ, and the four-way valve is re-energized and switched to heating operation. To prevent the problem of overcurrent caused by a sudden increase in the electrical load, the outdoor fan resumes operation after the air conditioning system operates in heating mode for a third preset duration. For example, the third preset duration is 3 seconds, and the electronic expansion valve enters the automatic opening degree.

[0087] When the air conditioning system switches back from cooling operation to heating operation, the indoor unit heat exchanger undergoes a change process from cold to hot. To prevent cold air from being blown into the room when the temperature of the indoor unit heat exchanger has not risen to an appropriate temperature, after the second air valve 41 is closed, the first air valve 31 is closed after a delay of a fourth preset duration to discharge the cold air from the first air duct 3 to the outside. For example, the fourth preset duration is 20 seconds. When the first air valve 31 is closed, the third air valve 51 and the fourth air valve 61 are opened simultaneously. After the defrosting mode ends, the compressor automatically operates, and the air conditioning system switches back to the heating mode. The above is the end of one cycle of defrosting synchronous fresh air replacement. When the next defrosting condition is met, the above process is repeated, thereby achieving fresh air replacement during defrosting. The air conditioning system of the present invention is different from having to go through a separate fresh air operation process. Instead, fresh air replacement is naturally introduced during the periodic defrosting process, and periodic defrosting synchronous fresh air replacement can be completed without separately setting an additional fresh air mode.

[0088] However, it should be noted that those skilled in the art can set the specific frequency values of the defrosting entry frequency, defrosting target frequency, and defrosting exit frequency as needed. The present invention does not make any restrictions on this, and they all fall within the protection scope of the present invention. In addition, the specific durations of the first preset duration to the fourth preset duration can also be set by those skilled in the art themselves and all fall within the protection scope of the present invention.

[0089] Refer to Figure 4 , in another possible implementation manner, the control method of the air conditioning system includes:

[0090] Step S41: The air conditioning system is powered on;

[0091] Step S42: When the air conditioning system operates in the heating mode, the indoor fan rotates, the first air valve and the second air valve are closed, and the third air valve and the fourth air valve are opened.

[0092] When the air conditioning system only operates in the heating mode, the indoor fan rotates, the first air valve 31 and the second air valve 41 are closed, and the third air valve 51 and the fourth air valve 61 are opened. Under the action of the indoor fan, indoor air enters the indoor unit heat exchanger from the indoor air return air inlet 211 for heat exchange. After the air absorbs heat, the hot air enters different indoor rooms from the third air duct 5 and the fourth air duct 6, thereby increasing the indoor temperature.

[0093] Step S43: When the air conditioning system operates in the cooling mode, the indoor fan rotates, the first air valve and the second air valve are closed, and the third air valve and the fourth air valve are opened.

[0094] When the outdoor temperature is relatively high in summer and the air conditioning system only operates in the cooling mode, the indoor fan rotates, the first air valve 31 and the second air valve 41 are closed, the third air valve 51 and the fourth air valve 61 are opened, indoor air enters the indoor unit heat exchanger from the indoor air return vent 211 for heat dissipation, and the cold air is discharged into the room through the air outlet 22 via the third air duct 5 and the fourth air duct 6 to cool the room.

[0095] Step S44: When receiving an instruction to operate the fresh air function, operate the fresh air function;

[0096] The steps of "operating the fresh air function" include:

[0097] Step S441: The indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve and the fourth air valve are opened.

[0098] When fresh air needs to be exchanged indoors, the fresh air function can be prioritized, that is, the air conditioning can maintain the current operating mode, the first air valve 31 and the second air valve 41 remain continuously open, the indoor fan rotates, outdoor fresh air continuously enters from the second air duct 4 into the outdoor air inlet 212, indoor air enters from the indoor air return vent 211, after the outdoor fresh air and the indoor air are mixed, a part of the mixed air enters the room through the third air duct 5 and the fourth air duct 6, thereby improving the indoor air quality, and another part of the mixed air is discharged outdoors through the first air duct 3. Directly blowing outdoor fresh air into the room will cause large fluctuations in the indoor temperature. In the present invention, the outdoor fresh air is mixed with the indoor air and then discharged into the room, so that the indoor air temperature fluctuates less and the user comfort is improved.

[0099] The user can send an instruction by pressing a button on the air conditioning system or through a terminal device such as a mobile phone APP; it can also be an instruction sent after the air conditioning system runs a certain program. For example, when the defrosting program is completed, an instruction to operate the fresh air function is automatically sent. After sending the instruction to operate the fresh air function, the air conditioning system receives the instruction to operate the fresh air function.

[0100] Step S441 further includes:

[0101] Step: The indoor fan rotates, the first air valve and the second air valve are opened, the third air valve and the fourth air valve are opened, the second air valve is closed after opening for a first preset duration and then reopened for a first preset duration after a second preset duration, and after repeating the preset number of times, the first air valve and the second air valve are closed.

[0102] When the air conditioning system is running, the heating or cooling demand and the fresh air volume demand can also be balanced by periodically changing the fresh air. By periodically controlling the opening and closing of the second air valve 41, heat loss and room temperature fluctuations can be reduced, and the air conditioning system can achieve timed or periodic fresh air change. For example, the second air valve is opened for 5 minutes, then closed for 5 minutes, reopened for 5 minutes, and after repeating this 5 times, it is closed. To achieve periodic fresh air change, step S441 may further include:

[0103] Steps: The indoor fan rotates, the first air valve and the second air valve are opened, the third air valve and the fourth air valve are opened. After the first air valve is opened for a first preset duration, it is closed for a second preset duration and then reopened for the first preset duration. After repeating the preset number of times, the first air valve and the second air valve are closed.

[0104] Refer to Figure 5 , in a possible implementation manner, the control method further includes:

[0105] Step S45: Obtain the carbon dioxide concentration in the indoor ambient air;

[0106] Step: When the carbon dioxide concentration ≥ the preset concentration, run the fresh air function;

[0107] Step S452: When the carbon dioxide concentration < the preset concentration, stop running the fresh air function.

[0108] A carbon dioxide concentration detector is set indoors. When the indoor carbon dioxide concentration is high, it indicates that the oxygen content in the indoor air decreases. Then, the fresh air function is automatically run to achieve intelligent fresh air change, sending outdoor fresh air into the room, increasing the oxygen content in the indoor air, and improving the indoor air quality. The fresh air function stops running until the indoor air carbon dioxide concentration is lower than the preset concentration.

[0109] Before the step of "running the fresh air function", the control method includes:

[0110] Step S451: When the carbon dioxide concentration ≥ the preset concentration, judge the current operating mode of the air conditioning system;

[0111] The step of "running the fresh air function" further includes:

[0112] Step S4511: Run the fresh air function and when the air conditioning system is in the defrosting mode, the indoor fan rotates, the first air valve and the second air valve are opened, the third air valve and the fourth air valve are opened, and the opening degrees of the third air valve and the fourth air valve are the first preset opening degrees;

[0113] Step S4512: Run the fresh air function and when the air conditioning system is in the heating mode, the indoor fan rotates, the first air valve and the second air valve are opened, the third air valve and the fourth air valve are opened, and the opening degrees of the third air valve and the fourth air valve are the second preset opening degrees; wherein, the first preset opening degree is less than the second preset opening degree;

[0114] Step S4513: When the fresh air function is running and when the air conditioning system is running in the cooling mode, the indoor fan rotates, the first air valve and the second air valve are opened, the third air valve and the fourth air valve are opened, and the opening degrees of the third air valve and the fourth air valve are the third preset opening degrees; wherein, the first preset opening degree is less than the third preset opening degree.

[0115] Although in the above embodiments, fresh air replacement is carried out at the defrosting entry stage, that is, when the outdoor unit heat exchanger has not been defrosted, and the cold air is discharged to the outside through the first air valve 31 to ensure the indoor temperature, however, if a fresh air function operation instruction is received during the defrosting mode, a small amount of fresh air mixed air can be discharged into the room for fresh air replacement. If the mixed air of outdoor fresh air and indoor air is directly blown into the room after cooling at the indoor unit heat exchanger, it usually causes a sudden drop in the indoor temperature. Therefore, in order to keep the indoor temperature suitable, when the user needs to replace fresh air in the room during the defrosting mode, the opening degree of the air valve is reduced so that a small amount of fresh air enters the room, that is, the opening degrees of the first air valve 31 and the second air valve 41 are less than those in the heating mode or the cooling mode, which can not only realize fresh air replacement in the room, but also ensure less heat loss in the room.

[0116] Step S4514: When the air conditioning system only runs the fresh air function, the indoor fan rotates, the first air valve and the second air valve are opened to the maximum opening degree, and the third air valve and the fourth air valve are opened to the maximum opening degree.

[0117] When the indoor temperature is suitable and there is no need for cooling or heating, the indoor-outdoor temperature difference is small. When the fresh air function is independently turned on to replace fresh air in the room, by appropriately increasing the opening degrees of the first air valve 31, the second air valve 41, the third air valve 51 and the fourth air valve 61, the fresh air replacement rate and the fresh air volume can be increased.

[0118] Of course, the specific operation mode of the fresh air function can also be manually set by the user to perform periodic fresh air replacement, continuous fresh air replacement or intelligent fresh air replacement. Those skilled in the art can set it according to their needs, and all control schemes using the same principle are within the protection scope of the present invention.

[0119] However, it should also be noted that although two air ducts for supplying air to the room are described in the above embodiments, that is, the third air duct 5 and the fourth air duct 6, those skilled in the art can set the number of air ducts for supplying air to the room according to their needs. In addition, although in the above embodiments, the third air valve 51 and the fourth air valve 61 are opened simultaneously to control the connection between the air duct and the indoor unit 1, those skilled in the art can set the opening or closing of the third air valve 51 and the fourth air valve 61 according to their needs. It can also be that one of them is opened and the other is closed, or the number of air valves can be changed as appropriate according to actual needs, and all fall within the protection scope of the present invention.

[0120] As described in the first paragraph of this section, the above embodiments are merely used to illustrate the principles of the present invention and are not intended to limit the protection scope of the present invention. Without departing from the principles of the present invention, those skilled in the art can adjust the above structures so that the present invention can be applied to more specific application scenarios.

[0121] In addition, the present invention also provides an air-conditioning system, which includes a memory and a processor. The memory is adapted to store multiple program codes, and the program codes are adapted to be loaded and run by the processor to execute the control method of the air-conditioning system described in any one of the above embodiments.

[0122] Those skilled in the art can understand that the above air-conditioning system also includes some other well-known structures, such as a processor, a controller, a memory, etc. Among them, the memory includes but is not limited to random access memory, flash memory, read-only memory, programmable read-only memory, volatile memory, non-volatile memory, serial memory, parallel memory or registers, etc. The processor includes but is not limited to CPLD / FPGA, DSP, ARM processor, MIPS processor, etc. To avoid unnecessarily obscuring the embodiments of the present disclosure, these well-known structures are not shown in the drawings.

[0123] In the above embodiments, although the steps are described in the above sequential order, those skilled in the art can understand that in order to achieve the effects of this embodiment, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in a reversed order, or a step can be split into multiple steps for execution. Those skilled in the art can set according to needs, and all fall within the protection scope of the present invention.

[0124] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, 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 all fall within the protection scope of the present invention.

Claims

1. A control method for an air conditioning system, characterized in that, The air conditioning system includes an indoor unit and an outdoor unit. An air outlet and an air return opening are provided on the indoor unit. The air return opening includes an indoor air return opening and an outdoor air inlet. The air conditioning system further includes a first air duct and a second air duct. The air outlet is communicated with the outdoor environment through the first air duct, and the outdoor air inlet is communicated with the outdoor environment through the second air duct. A first air valve is provided in the first air duct, and a second air valve is provided in the second air duct. The control method includes: When operating in the defrosting mode, the air conditioning system operates in the cooling mode, and the indoor fan rotates. The first air valve and the second air valve are opened.

2. The control method of the air conditioning system according to claim 1, wherein, The air conditioning system further includes a third air duct. The air outlet is communicated with the indoor environment through the third air duct. A third air valve is provided in the third air duct. The control method includes: When operating in the defrosting mode, the air conditioning system operates in the cooling mode. The indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve is closed.

3. The control method of the air conditioning system according to claim 2, wherein The steps of "when operating in the defrosting mode, the air conditioning system operates in the cooling mode; the indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve is closed" further include: After receiving the signal to operate in the defrosting mode, the indoor fan rotates, the first air valve is closed, the second air valve is opened, and the third air valve is opened. Control the compressor to reduce the frequency to the defrosting entry frequency. Control the air conditioning system to operate in the cooling mode. The first air valve is opened, the second air valve is opened, and the third air valve is closed. Control the compressor to increase the frequency to the defrosting target frequency.

4. The control method of the air-conditioning system according to claim 3, characterized in that, After the step of "control the compressor to increase the frequency to the defrosting target frequency", the control method further includes: When receiving the signal that the defrosting mode ends, the compressor reduces the frequency to the defrosting exit frequency. Control the air conditioning system to switch to the heating mode. The second air valve is closed, the first air valve is closed, and the third air valve is opened.

5. The control method of the air conditioning system according to claim 4, wherein The step of "control the air conditioning system to operate in the cooling mode" further includes: After the compressor maintains the defrosting entry frequency for a first preset duration, control the air conditioning system to operate in the cooling mode; and / or The step of "control the compressor to increase the frequency to the defrosting target frequency" further includes: After the compressor continues to maintain the defrosting entry frequency for a second preset duration, control the compressor to increase the frequency to the defrosting target frequency; and / or The step of "the second air valve is closed, the first air valve is closed, and the third air valve is opened" further includes: After the second air valve is closed for a fourth preset duration, the first air valve is closed, and the third air valve and the fourth air valve are opened.

6. The control method of the air conditioning system according to claim 2, characterized in that, The air conditioning system further includes a fourth air duct. The air outlet is communicated with the indoor environment through the fourth air duct. A fourth air valve is provided in the fourth air duct. The control method includes: When operating in the defrosting mode, the air conditioning system operates in the cooling mode. The indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve and / or the fourth air valve are closed; and / or When the air conditioning system operates in the cooling mode or the heating mode, the indoor fan rotates, the first air valve and the second air valve are closed, and the third air valve and / or the fourth air valve are opened.

7. The control method of the air-conditioning system according to claim 2, wherein The control method includes: When the fresh air function is operating, the indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve is opened.

8. The control method of the air conditioning system according to claim 7, characterized in that, The step of "when the fresh air function is operating, the indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve is opened" further includes: When the fresh air function is operating and when the air conditioning system operates in the defrosting mode, the indoor fan rotates, the first air valve and the second air valve are opened, and the third air valve is opened; wherein, the opening degree of the third air valve is a first preset opening degree; When the fresh air function is operating and when the air conditioning system operates in the heating mode, the indoor fan rotates, the first air valve and the second air valve are opened, the third air valve is opened, and the opening degree of the third air valve is a second preset opening degree; wherein the first preset opening degree is less than the second preset opening degree; and / or, When the air conditioning system only operates the fresh air function, the indoor fan rotates, and the first air valve, the second air valve, and the third air valve are opened to the maximum opening degree; and / or, When the fresh air function is operating, the indoor fan rotates, the first air valve and the second air valve are opened, the third air valve is opened, the first air valve and / or the second air valve are opened for a first preset duration and then closed for a second preset duration and then reopened for the first preset duration, and after repeating the preset number of times, the first air valve and the second air valve are closed.

9. The control method of the air conditioning system according to claim 7, wherein Before the step of "operating the fresh air function", the control method includes: Obtain the carbon dioxide concentration in the indoor ambient air; When the carbon dioxide concentration ≥ the preset concentration, operate the fresh air function; When the carbon dioxide concentration < the preset concentration, stop operating the fresh air function.

10. An air conditioning system, characterized in that, The air conditioning system includes a memory and a processor. The memory is adapted to store multiple program codes, and the program codes are adapted to be loaded and run by the processor to execute the control method of the air conditioning system according to any one of claims 1-9.

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