Control method for air conditioning system and air conditioning system

Abstract

The present invention relates to the technical field of air conditioning systems, and particularly provides a control method for 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 port and an air return port, and the air return port comprises an indoor air return port and an outdoor air inlet port; the air conditioner system further comprises a first air duct and a second air duct, the air outlet port is communicated with the outdoor environment by means of the first air duct, the outdoor air inlet is communicated with the outdoor environment by means of 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: in a defrosting mode, an air conditioning system performs a cooling operation, and an indoor fan rotates; and a first air valve and a second air valve open. Residual heat of indoor air is recovered during the defrosting process, heat of outdoor fresh air is fully utilized, a heat exchanger of the indoor unit absorbs heat of the indoor air and the outdoor fresh air, so as to improve the evaporation pressure of the system, reduce the energy consumption during the defrosting process, and discharge the cold air outdoors, thereby ensuring comfortable indoor temperature.

Description

Air conditioning system control method and air conditioning system This application claims priority to Chinese patent application No. 202311836767.3 filed on December 28, 2023, with the invention name “Control method and air conditioning system of air conditioning system”. The full text of the above Chinese patent application is incorporated into this application by reference. Technical Field

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

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

[0003] Therefore, some existing air conditioners rotate the indoor fan during the defrost process, and the indoor fan does not stop to improve the defrost efficiency and turn on the auxiliary electric heating. When the air conditioner is heating normally, the auxiliary electric heating can be turned on selectively, but when the defrost conditions are met, the air conditioner switches to the defrost mode, and the auxiliary electric heating of the indoor unit is turned on, and the indoor fan continues to run. At this time, the heating supply of the auxiliary electric heating must be greater than the cooling capacity generated by the evaporation of the indoor unit heat exchanger to prevent cold air from being blown out, but the energy consumption of the auxiliary electric heating is high. Another way is that the indoor fan rotates during the defrost process of the air conditioner, and the cold air previously discharged into the room is discharged to the outside through the pipe, thereby achieving defrost without affecting the indoor temperature, but the cold air passes through the indoor air supply duct first, causing the pipe temperature to drop. The next time heating is run, more heat is needed to increase the pipe temperature, so there is also the problem of high energy consumption.

[0004] Accordingly, the art requires a new control method for an air-conditioning system to solve the problem of high energy consumption when the existing air-conditioning system operates the defrost function. Summary of the Invention

[0005] The present invention aims to solve the above technical problem, that is, to solve the problem of high energy consumption of the existing air-conditioning system when running the defrost function.

[0006] The present invention provides a control method for an air conditioning system, wherein the air conditioning system includes an indoor unit and an outdoor unit, wherein the indoor unit is provided with an air outlet and an air return outlet, and the air return outlet includes an indoor air return outlet and an outdoor air inlet;

[0007] The air conditioning system further includes a first air duct and a second air duct, the air outlet is connected to the outdoor environment through the first air duct, the outdoor air inlet is connected to 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;

[0008] The control method includes:

[0009] When the defrost mode is in operation, the air conditioning system operates in cooling mode and the indoor fan rotates;

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

[0011] In the 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 provided in the third air duct;

[0012] The control method includes:

[0013] When running in defrost mode, the air conditioning system operates in cooling 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 the preferred technical solution of the control method of the above air-conditioning system, the step of "when operating in the defrost mode, the air-conditioning system operates in 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 includes:

[0016] After receiving the signal for running the defrost 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 defrost entry frequency;

[0018] Controlling the cooling operation of the air conditioning system;

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

[0020] The compressor is controlled to increase the frequency to the defrost target frequency.

[0021] In a preferred technical solution of the control method of the air-conditioning system, after the step of “controlling the compressor to increase the frequency to the defrost target frequency”, the control method further includes:

[0022] Upon receiving a signal indicating that the defrost mode has ended, the compressor reduces its frequency to a defrost exit frequency;

[0023] Controlling 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 the preferred technical solution of the above-mentioned method for controlling the air-conditioning system, the step of "controlling the cooling operation of the air-conditioning system" further includes:

[0026] After the compressor maintains the defrost entry frequency for a first preset time, the air conditioning system is controlled to operate in a cooling mode; and / or,

[0027] The step of “controlling the compressor to increase the frequency to the defrost target frequency” further includes:

[0028] After the compressor continues to maintain the defrost entry frequency for a second preset time, controlling the compressor to increase the frequency to the defrost target frequency; and / or,

[0029] The step of “closing the second air valve, closing the first air valve, and opening the third air valve” further includes:

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

[0031] In the 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 connected through the fourth air duct, and a fourth air valve is provided in the fourth air duct;

[0032] The control method includes:

[0033] When running in defrost 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 cooling mode or 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 the preferred technical solution of the control method of the above air-conditioning system, the control method includes:

[0037] 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.

[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 the air conditioning system is running 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 the air conditioning system is running in 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 smaller than the second preset opening degree; and / or,

[0041] When the air conditioning system operates only in 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; 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, and the third air valve is opened. The first air valve and / or the second air valve are opened for a first preset time, then closed for a second preset time, and then reopened for the first preset time. 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 "operating 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 is ≥ the preset concentration, the fresh air function is activated;

[0046] When the carbon dioxide concentration is less than the preset concentration, the fresh air function will stop running.

[0047] The present invention also provides an air-conditioning system, which includes a memory and a processor, wherein 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 of the above technical solutions.

[0048] Those skilled in the art will appreciate 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 a return air outlet, the return air outlet includes an indoor air return air outlet and an outdoor air inlet; the air-conditioning system also includes a first air duct and a second air duct, the air outlet and the outdoor environment are connected through the first air duct, the outdoor air inlet and the outdoor environment are connected 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 defrost mode, the air-conditioning system operates in a cooling mode; the indoor fan rotates, and the first air valve and the second air valve are opened.

[0049] When the above technical solution is adopted, when the air-conditioning system of the present invention is running in the defrost mode, the air-conditioning system is controlled to switch to cooling operation, and the outdoor unit heat exchanger is defrosted by the high-temperature refrigerant in the outdoor unit heat exchanger. While running in reverse to defrost, the indoor fan rotates, the first air valve and the second air valve are opened, and the outdoor fresh air enters the indoor unit return air inlet through the second air valve. The indoor air and the outdoor fresh air are mixed and blown to the indoor unit heat exchanger and exchange heat with the indoor unit heat exchanger, thereby jointly increasing the evaporation pressure and evaporation temperature during defrosting, improving the defrosting efficiency, and then the cold air is discharged to the outside through the first air duct to reduce indoor temperature fluctuations.

[0050] During the defrost process, the system not only recovers the residual heat from the indoor air, but also utilizes the fact that the temperature of the indoor unit's heat exchanger is much lower than that of the outdoor fresh air during defrost, fully utilizing the heat from the outdoor fresh air to further increase the evaporation temperature and pressure during defrost. This reduces the compression ratio during the defrost process, ensures oil return and reliability of the compressor, and reduces power consumption during the defrost process. Furthermore, the air conditioning system eliminates the need for an electric heater, and the fresh air exchange process also eliminates the need for an additional fresh air fan. Fresh air input is achieved through 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 are described below with reference to the accompanying drawings, in which:

[0052] FIG1 is a schematic structural diagram of an air-conditioning system of the present invention;

[0053] FIG2 is a flow chart of the main steps of the control method of the air-conditioning system of the present invention;

[0054] 3 is a flowchart of the steps of a first embodiment of a method for controlling an air-conditioning system according to the present invention;

[0055] 4 is a flowchart of the steps of a second embodiment of a method for controlling an air-conditioning system according to the present invention;

[0056] Figure 5 is a flowchart of the steps of a third embodiment of the control method for an air conditioning system according to the present invention. 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. DETAILED DESCRIPTION

[0057] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are merely used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art may make adjustments as needed to adapt to specific applications. For example, the control method of the air-conditioning system in this application may be used for wall-mounted air conditioners, cabinet air conditioners, central air conditioners, or multi-split air conditioners, etc. The present invention does not impose any restrictions on the type of air conditioner, and it may also be applied to equipment other than air conditioners that require defrosting.

[0058] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified or 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 a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] Specifically, referring to FIG1 , 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 loop disposed between the indoor unit 1 and the outdoor unit 2. The four-way valve and the electronic expansion valve are disposed in the refrigerant circulation loop. The indoor unit 1 includes an indoor heat exchanger and an indoor fan, and the outdoor unit 2 includes a compressor, an outdoor heat exchanger, and an outdoor fan. Of course, those skilled in the art may also customize the types of the indoor and outdoor heat exchangers as needed, and the present invention does not impose any limitations thereto.

[0060] The compressor, indoor heat exchanger, and outdoor heat exchanger are all installed in a refrigerant circulation loop. Refrigerant circulates between the indoor and outdoor areas through the refrigerant circulation loop, exchanging heat with the indoor environment through the indoor heat exchanger, thereby meeting the user's heat exchange needs. Furthermore, the indoor unit 1 includes an indoor casing, which is provided with an air outlet 22 and a return air outlet 21. The indoor heat exchanger and indoor fan are installed within the indoor casing and located between the air outlet 22 and the return air outlet 21. Airflow entering the return air outlet 21 is then discharged from the air outlet 22 after passing through the indoor heat exchanger for heat exchange.

[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 connected to the outdoor environment. The air outlet 22 is connected to the outdoor environment through the first air duct 3. The return air duct 21 also includes an indoor air return duct 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 connected to the outdoor environment. The outdoor air inlet 212 is connected to the outdoor environment through the second air duct 4. A first air valve 31 is provided in the first air duct 3, and a second air valve 41 is provided in the second air duct 4.

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

[0063] Indoor air enters the indoor unit 1 through the indoor air return vent 211, and outdoor fresh air enters the indoor unit 1 through the outdoor air inlet 212. Alternatively, the indoor air return vent 211 may be disposed on the fourth air duct 6 and between the second air valve 41 and the return air vent 21. Persons skilled in the art may adjust the position and structure of the indoor air return vent 211 as needed, as long as the indoor air can flow back into the indoor unit 1, and all such adjustments fall within the scope of the present invention.

[0064] The damper includes a damper body and a drive mechanism for rotating the damper body. The following describes the motion of the damper in detail. For example, taking the third damper 51 as an example, the third damper 51 includes a third damper body and a third drive mechanism. The third damper body can have a first position that closes the connection between the indoor environment and the air outlet 22, and a second position that fully opens the connection between the indoor environment and the air outlet 22. The damper body can be positioned anywhere between the first and second positions. The damper opening can be determined by adjusting the position of the damper body. A larger opening increases the opening for air flow between the damper body and the air duct. Similarly, a smaller opening decreases the opening for air flow between the damper body and the air duct. Alternatively, the drive mechanism can be a combination of a motor and a rack-and-pinion mechanism, or simply a rotary electric cylinder. It should be noted that there are many types and structures of dampers, and those skilled in the art can customize the type and structure of the damper according to their needs. The present invention does not impose any limitations on the structure of the damper, and all such structures fall within the scope of the present invention.

[0065] Furthermore, the air conditioning system also includes a controller capable of controlling the operating status of the air conditioning system, such as starting and stopping the outdoor unit, reversing the direction of the four-way valve, operating the fan, and controlling the frequency of the variable-frequency compressor. Those skilled in the art will appreciate that the present invention does not impose any limitations on the specific structure and model of the controller, and those skilled in the art may customize the structure and model of the controller based on actual usage requirements.

[0066] During use, the user can control the operation of the air conditioning system by setting the temperature. Those skilled in the art will appreciate that the present invention does not impose any limitations on the specific structure of the air conditioning system. Those skilled in the art may customize the specific structure of the air conditioning system based on actual usage requirements. Such changes in specific application targets do not deviate from the basic principles of the present invention and fall within the scope of protection of the present invention.

[0067] 2 , in order to solve the problem of high energy consumption of the existing air conditioning system when running the defrost function, the control method of the air conditioning system of the present invention includes:

[0068] Step S10: When the defrost mode is in operation, the air conditioning system operates in cooling mode and the indoor fan rotates;

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

[0070] The advantage of the above-mentioned setting method is that when the air-conditioning system of the present invention is running in the defrost mode, the air-conditioning system is controlled to switch to cooling operation, and the outdoor unit heat exchanger is defrosted by the high-temperature refrigerant in the outdoor unit heat exchanger. While running in reverse to defrost, the indoor fan rotates, the first air valve 31 and the second air valve 41 are opened, and the outdoor fresh air enters the indoor unit return air inlet through the second air valve. The indoor air and the outdoor fresh air are mixed and blown to the indoor unit heat exchanger and exchange heat with the indoor unit heat exchanger, thereby jointly increasing the evaporation pressure and evaporation temperature during defrosting, improving the defrosting efficiency, and then the cold air is discharged to the outside through the first air duct 3 to reduce indoor temperature fluctuations.

[0071] During the defrost process, the system not only recovers the residual heat from the indoor air, but also utilizes the fact that the temperature of the indoor unit's heat exchanger is much lower than that of the outdoor fresh air during defrost, fully utilizing the heat from the outdoor fresh air to further increase the evaporation temperature and pressure during defrost. This reduces the compression ratio during the defrost process, ensures oil return and reliability of the compressor, and reduces power consumption during the defrost process. Furthermore, the air conditioning system does not require an electric heater, and the fresh air exchange process does not require an additional fresh air fan. Fresh air input can be achieved through the operation of the indoor fan, reducing the cost of the air conditioning system.

[0072] 3 , in one possible embodiment, the air conditioning system of the present invention can also simultaneously achieve indoor fresh air exchange while periodically defrosting, thereby eliminating the need to set a separate fresh air mode. The control method of the air conditioning system specifically includes:

[0073] Step S31: When the air conditioning system is in heating mode and receives a signal to operate in defrost mode, the indoor fan rotates, the first air valve is closed, the second air valve is opened, and the third and fourth air valves are opened;

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

[0075] When the air-conditioning system is operating in heating mode, when the outdoor unit heat exchanger is frosted and certain conditions are met, the outdoor unit 2 sends a defrost signal to the indoor unit 1, and 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 runs 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 pass through the indoor unit heat exchanger first. At this time, the temperature of the indoor unit heat exchanger is higher. After the fresh air absorbs heat, it enters the indoor space through the third air duct 5 and the fourth air duct 6, so that warm fresh air is introduced into the room. At the same time, since the outdoor fresh air temperature is lower than the indoor ambient temperature, introducing outdoor fresh air into the outdoor unit 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 lower frequency to reduce the system pressure difference. The defrost entry frequency does not need to be reduced very low, and the subsequent four-way valve can be guaranteed to stably switch at a relatively high frequency for cooling, reducing the time it takes for the compressor to go from frequency reduction to frequency increase to the target defrost frequency during the defrost conversion period, thereby improving the defrost efficiency.

[0076] Step S33: After the compressor maintains the defrost entry frequency for a first preset time, the air conditioning system is controlled to switch to cooling operation;

[0077] Step S331: the first air valve is opened, the second air valve is opened, the third air valve and the fourth air valve are closed, and the outdoor fan is stopped;

[0078] Step S332: After the compressor continues to maintain the defrost entry frequency for a second preset period of time, the compressor is controlled to increase the frequency to the defrost target frequency.

[0079] When the compressor frequency stabilizes at the defrost entry frequency (60HZ) for the first preset time, for example, the first preset time is 60 seconds, the four-way valve is powered off and switched to cooling, and at the same time the first air valve 31 and the second air valve 41 are opened, the third air valve 51 and the fourth air valve 61 are closed, the outdoor fan stops, and defrosting begins. The air-conditioning system does not supply cold air to the room during defrosting 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 cooling operation, in order to prevent the system load from changing drastically during the pressure conversion when the heating operation switches to the cooling operation, the compressor maintains the defrost entry frequency and continues to operate for the second preset time. The compressor then increases the frequency to the defrost target frequency for defrosting. For example, the second preset time is 20 seconds, the defrost target frequency is 80HZ, and the electronic expansion valve completes the defrosting of the outdoor unit heat exchanger according to the set defrost opening.

[0080] After receiving the signal to operate in defrost mode, the air conditioning system of the present invention only exchanges fresh air for the room at the beginning of the defrost operation. The fresh air absorbs the heat of the indoor unit heat exchanger, resulting in low indoor heat loss. The low temperature characteristic of the fresh air is used to reduce the exhaust pressure of the system, preparing for the subsequent reversal of the four-way valve. The defrost entry frequency does not need to be reduced very low to meet the requirements of the stable reversal of the four-way valve for refrigeration operation. It also does not take too long for the subsequent compressor to rise to the defrost target frequency, thereby improving the defrost efficiency. In the defrost stage, when the air conditioning system is in refrigeration operation and defrosting, the third air valve 51 and the fourth air valve 61 are in the closed state, and fresh air is not exchanged indoors. The cold air does not pass through the indoor air supply duct. When the heating is operated again after the defrost is completed, there is no need to consume a lot of heat to increase the heat in the duct, thereby ensuring a comfortable indoor temperature.

[0081] Step S34: upon receiving a signal indicating that the defrost mode has ended, the compressor frequency is reduced to a defrost exit frequency;

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

[0083] Step S342: The outdoor fan of the air conditioning system rotates after the heating operation of the air conditioning system is performed for a third preset time period;

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

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

[0086] When the defrost 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 powered on again and switched to heating operation. To prevent overcurrent problems caused by a sudden increase in power load, the outdoor fan resumes operation after the third preset time of heating operation, for example, the third preset time is 3 seconds, and the electronic expansion valve enters automatic opening.

[0087] Since the air conditioning system switches back to heating operation from cooling operation, the indoor unit heat exchanger has a change process from cold to hot. In order to prevent the indoor unit heat exchanger temperature from rising to the appropriate temperature and blowing cold air into the room, after the second air valve 41 is closed, the first air valve 31 is closed after a fourth preset time delay to discharge the cold air from the first air duct 3 to the outside. For example, the fourth preset time is 20 seconds. The first air valve 31 is closed and the third air valve 51 and the fourth air valve 61 are opened. After the defrost mode is completed, the compressor automatically operates and the air conditioning system returns to the heating mode. The above is the end of a cycle of defrosting and synchronous fresh air exchange. When the next defrost condition is met, the above process is repeated, thereby completing the fresh air exchange during the defrost period. The air conditioning system of the present invention is different from the system that must go through a separate fresh air operation process. Instead, it naturally introduces fresh air during the periodic defrost process, and can complete the periodic defrost and synchronous fresh air exchange without setting an additional fresh air mode.

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

[0089] 4 , in another possible implementation, the method for controlling the air-conditioning system includes:

[0090] Step S41: Turn on the air conditioning system;

[0091] Step S42: When the air conditioning system operates in 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 operates only in 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, the 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 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 high in summer and the air conditioning system only operates in 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, and the indoor air enters the indoor unit heat exchanger from the indoor air return air inlet 211 for heat dissipation, and the cold air is discharged into the room through the air outlet 22 from the third air duct 5 and the fourth air duct 6 to cool the room.

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

[0096] The steps for running 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 it is necessary to exchange fresh air for the indoor space, the fresh air function can be given priority, that is, the air conditioner can maintain the current operating mode, the first air valve 31 and the second air valve 41 remain continuously open, the indoor fan rotates, and the outdoor fresh air continuously enters the outdoor air inlet 212 from the second air duct 4, and the indoor air enters from the indoor air return air outlet 211. After the outdoor fresh air and the indoor air are mixed, a part of the mixed air enters the room from the third air duct 5 and the fourth air duct 6, thereby improving the indoor air quality, and the other part of the mixed air is discharged to the outdoors from the first air duct 3. The outdoor fresh air directly blown into the room will cause large fluctuations in the indoor temperature. The present invention mixes the outdoor fresh air with the indoor air and discharges it into the room, so that the indoor air temperature fluctuation is smaller, thereby improving user comfort.

[0099] Users can send commands by pressing a button on the air conditioning system or through a terminal device such as a mobile phone app. They can also send commands after the air conditioning system completes a certain program, for example, automatically sending a command to run the fresh air function after the defrost program is completed. When the command to run the fresh air function is sent, the air conditioning system receives the command to run the fresh air function.

[0100] Step S441 further includes:

[0101] 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, the second air valve is opened for a first preset time, then closed for a second preset time, and then reopened for the first preset time. After repeating the preset number of times, the first air valve and the second air valve are closed.

[0102] While the air conditioning system is operating, periodic fresh air exchange can be used to balance heating or cooling needs with fresh air volume requirements. By periodically controlling the opening and closing of the second air valve 41, heat loss and room temperature fluctuations can be reduced, thereby achieving timed or periodic fresh air exchange for the air conditioning system. For example, the second air valve may be opened for 5 minutes, closed for 5 minutes, reopened for 5 minutes, and then closed after 5 cycles. To achieve periodic fresh air exchange, 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, the first air valve is opened for a first preset time, then closed for a second preset time, and then reopened for the first preset time. After repeating the preset number of times, the first air valve and the second air valve are closed.

[0104] 5 , in one possible implementation, the control method further includes:

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

[0106] Steps: When the carbon dioxide concentration is ≥ the preset concentration, the fresh air function is operated;

[0107] Step S452: When the carbon dioxide concentration is less than the preset concentration, the fresh air function is stopped.

[0108] A carbon dioxide concentration detector is installed indoors. When the indoor carbon dioxide concentration is high, it means that the oxygen content in the indoor air is reduced. The fresh air function will be automatically operated to realize intelligent fresh air exchange, and the outdoor fresh air will be sent into the room to increase the indoor air oxygen content and improve the indoor air quality. The fresh air function will be stopped 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 is greater than or equal to the preset concentration, determining the current operating mode of the air conditioning system;

[0111] The steps of “operating the fresh air function” further include:

[0112] Step S4511: When the fresh air function is running and the air conditioning system is in defrost mode, 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. The opening degrees of the third air valve and the fourth air valve are first preset opening degrees.

[0113] Step S4512: When the fresh air function is running and the air conditioning system is in heating mode, 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. The openings of the third air valve and the fourth air valve are set to a second preset opening; wherein the first preset opening is smaller than the second preset opening.

[0114] Step S4513: When the fresh air function is running and the air-conditioning system is running in 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 of the third air valve and the fourth air valve is the third preset opening; wherein the first preset opening is smaller than the third preset opening.

[0115] Although the above embodiment has described that fresh air is exchanged during the defrost entry phase, i.e., before the outdoor heat exchanger is defrosted, and the cold air is discharged outdoors through the first air valve 31 to maintain the indoor temperature, if a command to operate the fresh air function is received while the defrost mode is in operation, a small amount of fresh air mixed air can be discharged indoors to exchange fresh air. If the mixed air of outdoor fresh air and indoor air is directly blown into the room after being cooled at the indoor heat exchanger, it will usually cause a sudden drop in indoor temperature. Therefore, in order to maintain a suitable indoor temperature, when the user needs to exchange fresh air for the room during the defrost mode, the opening of the air valve is reduced to allow a small amount of fresh air to enter the room. That is, the opening of the first air valve 31 and the second air valve 41 is smaller than the opening in the heating mode or the cooling mode. This can achieve fresh air exchange for the room while ensuring that indoor heat loss is small.

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

[0117] When the indoor temperature is suitable and no cooling or heating is required, the temperature difference between indoor and outdoor is not large. When the fresh air function is turned on alone to exchange fresh air for the indoor air, the opening of the first air valve 31, the second air valve 41, the third air valve 51 and the fourth air valve 61 is appropriately increased to increase the fresh air exchange rate and the fresh air volume.

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

[0119] However, it should be noted that although the above embodiment describes the provision of two air ducts for supplying air to the indoor space, namely the third air duct 5 and the fourth air duct 6, those skilled in the art may set the number of air ducts for supplying air to the indoor space as needed. In addition, although the above embodiment uses the third air valve 51 and the fourth air valve 61 to be opened simultaneously to control the connection between the air duct and the indoor unit 1, those skilled in the art may set the opening or closing of the third air valve 51 and the fourth air valve 61 as needed, or may set one of the two air valves to be opened and the other to be closed, or may change the number of air valves as appropriate according to actual needs, and all of these fall within the scope of protection of the present invention.

[0120] As stated in the first paragraph of this section, the above implementation mode is only used to illustrate the principles of the present invention and is not intended to limit the scope of protection of the present invention. Without departing from the principles of the present invention, those skilled in the art can adjust the above structure 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 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 of the above embodiments.

[0122] Those skilled in the art will appreciate that the aforementioned air conditioning system also includes some other well-known structures, such as a processor, a controller, and a memory. 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. The processor includes, but is not limited to, CPLD / FPGA, DSP, ARM processor, MIPS processor, etc. To unnecessarily obscure the embodiments of the present disclosure, these well-known structures are not shown in the drawings.

[0123] Although the various steps in the above embodiment are described in the above-mentioned order, those skilled in the art will understand that in order to achieve the effect 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 reverse order, or one step can be split into multiple steps for execution. Those skilled in the art can set them according to their needs, and they all fall within the scope of protection of the present invention.

[0124] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection 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 may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection 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 communicates with the outdoor environment through the first air duct, and the outdoor air inlet communicates 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 the defrosting mode is running, the air conditioning system operates in a 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 communicates with the indoor environment through the third air duct, and a third air valve is provided in the third air duct; The control method includes: When the defrosting mode is running, the air conditioning system operates in a 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 the defrosting mode is running, the air conditioning system operates in a 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 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; Control the compressor to reduce the frequency to the defrosting entry frequency; Control the air conditioning system to operate in a 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, control the compressor to reduce the frequency to the defrosting exit frequency; Control the air conditioning system to switch to a 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 a 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 a 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 communicates with the indoor environment through the fourth air duct, and a fourth air valve is provided in the fourth air duct; The control method includes: When the defrosting mode is running, the air conditioning system operates in a 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, characterized in that, 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, characterized in that, 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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