Indoor heat exchange structure, air conditioning system and control method thereof

Abstract

The present disclosure relates to an indoor heat exchange structure, an air conditioning system and a control method thereof. The indoor heat exchange structure for the air conditioning system includes: an air duct assembly having an air duct and a return air inlet and a lower air outlet connected to the air duct; an indoor heat exchanger group arranged in the air duct and configured to perform heat exchange with the air flow entering from the return air inlet and flowing through the indoor heat exchanger group; a fan arranged in the air duct and located between the lower air outlet and the indoor heat exchanger group, configured to inhale the air flow flowing through the indoor heat exchanger group and discharge the inhaled air flow downward through the lower air outlet; wherein the indoor heat exchanger group includes a first indoor heat exchanger and a second indoor heat exchanger, the first indoor heat exchanger being configured to heat the indoor return air entering from the return air inlet in a first mode of the air conditioning system, and the second indoor heat exchanger being configured to cool and dehumidify the indoor return air entering from the return air inlet in the first mode of the air conditioning system.

Description

Technical Field

[0001] The present disclosure relates to the technical field of air conditioning, and in particular to an indoor heat exchange structure, an air conditioning system and a control method thereof. Background Art

[0002] With the improvement of living standards, people's requirements for air conditioning are no longer simple cooling and heating, but have a variety of comfort needs, such as temperature control and dehumidification, heating without drying, etc. For the needs of temperature control and dehumidification, two methods are usually used in related technologies. Figure 1 (a) One method is to arrange the dehumidification heat exchanger and the regenerative heat exchanger in a front-to-back arrangement so that the indoor return air first passes through the dehumidification heat exchanger and then passes through the regenerative heat exchanger before being discharged; Figure 1 (b) Another method is to arrange the regenerative heat exchanger and the dehumidification heat exchanger in an upper and lower structure so that the indoor return air passes through the regenerative heat exchanger and the dehumidification heat exchanger respectively and then merges into one air outlet. Summary of the Invention

[0003] After research, the inventor found that in the structural form of the dehumidification heat exchanger and the regenerative heat exchanger arranged in front and behind in the related technology, when switched to heating mode, the high-temperature gaseous refrigerant first passes through the dehumidification heat exchanger and then through the regenerative heat exchanger, so that the refrigerant flow direction and the air flow direction form a parallel flow, resulting in a smaller heat exchange temperature difference, affecting the heating capacity and energy efficiency; and in the structural form of the regenerative heat exchanger and the dehumidification heat exchanger arranged up and down in the related technology, when the fan blows the indoor return air to the regenerative heat exchanger and the dehumidification heat exchanger, the hotter air flow flowing through the regenerative heat exchanger flows upward, and the colder air flow flowing through the dehumidification heat exchanger flows downward, thereby causing the natural separation of the hot and cold air flows. At this time, the air guide structure is required to achieve airflow mixing, otherwise it will cause hot air on the top and cold air on the bottom, making the user feel the temperature is too low and uncomfortable when using the temperature control dehumidification mode.

[0004] In view of this, embodiments of the present disclosure provide an indoor heat exchange structure, an air-conditioning system, and a control method thereof, which can improve the indoor air output of the air-conditioning system.

[0005] In one aspect of the present disclosure, there is provided an indoor heat exchange structure for an air conditioning system, comprising:

[0006] An air duct assembly, comprising an air duct and an air return port and a lower air outlet connected to the air duct;

[0007] an indoor heat exchanger group, disposed in the air duct and configured to perform heat exchange with the airflow entering from the return air port and flowing through the indoor heat exchanger group;

[0008] a fan, disposed in the air duct and located between the lower air outlet and the indoor heat exchanger group, configured to suck the air flowing through the indoor heat exchanger group and discharge the sucked air downward through the lower air outlet;

[0009] In which, the indoor heat exchanger group includes a first indoor heat exchanger and a second indoor heat exchanger. The first indoor heat exchanger is configured to heat the indoor return air entering from the return air inlet in the first mode of the air-conditioning system, and the second indoor heat exchanger is configured to cool and dehumidify the indoor return air entering from the return air inlet in the first mode of the air-conditioning system.

[0010] In some embodiments, the lower air outlet is located on the lower surface of the air duct assembly.

[0011] In some embodiments, the first indoor heat exchanger is located on an upper side of the second indoor heat exchanger.

[0012] In some embodiments, the indoor heat exchanger group further includes:

[0013] The water receiving tray is arranged in the air duct and is located at the lower side of the second indoor heat exchanger.

[0014] In some embodiments, the first indoor heat exchanger includes at least one row of first indoor heat exchangers, and the second indoor heat exchanger includes at least one row of second indoor heat exchangers corresponding to the at least one row of first indoor heat exchangers, and each row of first indoor heat exchangers and the corresponding second indoor heat exchanger are in the shape of a straight line, a "<" shape, or a ">" shape.

[0015] In some embodiments, the number of rows of the first indoor heat exchanger and the number of rows of the second indoor heat exchanger are both greater than or equal to 1 and less than or equal to 4.

[0016] In some embodiments, the first indoor heat exchanger and the second indoor heat exchanger both include tube-fin heat exchangers, and the number of U-shaped tubes included in each row of the first indoor heat exchanger is greater than or equal to the number of U-shaped tubes included in the corresponding second indoor heat exchanger.

[0017] In some embodiments, the first mode of the air-conditioning system is a dehumidification mode of the air-conditioning system.

[0018] In one aspect of the present disclosure, an air-conditioning system is provided, comprising: the aforementioned indoor heat exchange structure.

[0019] In some embodiments, the air conditioning system is a ducted air conditioning system.

[0020] In some embodiments, the air conditioning system further comprises:

[0021] The control valve group is configured to connect the refrigerant flow paths of the first indoor heat exchanger and the second indoor heat exchanger in series or in parallel, wherein the refrigerant flow path between the first indoor heat exchanger and the second indoor heat exchanger is opened or throttled in the series connection state, and the refrigerant flow path between the first indoor heat exchanger and the second indoor heat exchanger is disconnected in the parallel connection state.

[0022] In some embodiments, the control valve group includes:

[0023] a first on-off valve, wherein the first indoor heat exchanger and the first on-off valve are connected in series on a first refrigerant flow path;

[0024] a second on-off valve, the second indoor heat exchanger and the second on-off valve being connected in series on a second refrigerant flow path, the first refrigerant flow path and the second refrigerant flow path being connected in parallel; and

[0025] The first throttle element is provided on the third refrigerant flow path connected between the first refrigerant flow path and the second refrigerant flow path.

[0026] In some embodiments, the air-conditioning system also includes: a compressor, an outdoor heat exchanger, a second throttling element, a switching valve and the aforementioned indoor heat exchange structure, and the switching valve is configured to switch the circulation direction of the refrigerant circulation loop formed by the compressor, the outdoor heat exchanger, the second throttling element and the indoor heat exchange structure.

[0027] In one aspect of the present disclosure, a method for controlling the aforementioned air-conditioning system is provided, comprising:

[0028] Determine the temperature difference ΔT between the indoor ambient temperature and the set temperature;

[0029] According to the temperature difference level corresponding to the temperature difference ΔT, the air-conditioning system is switched between a heating mode, a cooling mode, and a dehumidification mode through the control valve group, the second throttling element, and the switching valve.

[0030] In some embodiments, the control method further includes:

[0031] During the startup phase of the air conditioning system, when switching to a cooling mode, the refrigerant flow paths of the first indoor heat exchanger and the second indoor heat exchanger are connected in parallel through the control valve group, and the refrigerant flow path between the first indoor heat exchanger and the second indoor heat exchanger is disconnected;

[0032] During the operation phase of the air-conditioning system, when switched to the cooling mode, the refrigerant flow paths of the first indoor heat exchanger and the second indoor heat exchanger are connected in series through the control valve group, and the refrigerant flow path between the first indoor heat exchanger and the second indoor heat exchanger is conducted.

[0033] In some embodiments, the step of switching the air-conditioning system between the heating mode, the cooling mode, and the dehumidification mode by the control valve group, the second throttling element, and the switching valve according to the temperature difference level corresponding to the temperature difference ΔT includes:

[0034] During the startup phase of the air conditioning system:

[0035] If the temperature difference ΔT is greater than or equal to a first temperature difference threshold C1, the air conditioning system is switched to a cooling mode through the control valve group, the second throttling element, and the switching valve;

[0036] If the temperature difference ΔT is less than the first temperature difference threshold C1 and greater than the second temperature difference threshold C2, the air conditioning system is switched to a dehumidification mode through the control valve group, the second throttling element, and the switching valve;

[0037] If the temperature difference ΔT is less than or equal to the second temperature difference threshold C2, the air conditioning system is switched to a heating mode through the control valve group, the second throttling element, and the switching valve;

[0038] The first temperature difference threshold C1 is smaller than the second temperature difference threshold C2.

[0039] In some embodiments, the step of switching the air-conditioning system between the heating mode, the cooling mode, and the dehumidification mode by the control valve group, the second throttling element, and the switching valve according to the temperature difference level corresponding to the temperature difference ΔT includes:

[0040] During the operation phase of the air conditioning system:

[0041] If the temperature difference ΔT is greater than or equal to a third temperature difference threshold C3, the air conditioning system is switched to a cooling mode through the control valve group, the second throttling element, and the switching valve;

[0042] If the temperature difference ΔT is less than or equal to a fourth temperature difference threshold C4 and greater than a fifth temperature difference threshold C5, the air conditioning system is switched to a dehumidification mode through the control valve group, the second throttling element, and the switching valve;

[0043] If the temperature difference ΔT is less than or equal to a sixth temperature difference threshold C6, the air conditioning system is switched to a heating mode through the control valve group, the second throttling element, and the switching valve;

[0044] The third temperature difference threshold C3 is greater than the fourth temperature difference threshold C4, the fourth temperature difference threshold C4 is greater than the fifth temperature difference threshold C5, and the fifth temperature difference threshold C5 is greater than the sixth temperature difference threshold C6.

[0045] In some embodiments, the step of switching the air-conditioning system between the heating mode, the cooling mode, and the dehumidification mode by the control valve group, the second throttling element, and the switching valve according to the temperature difference level corresponding to the temperature difference ΔT further includes:

[0046] During the operation phase of the air conditioning system:

[0047] When the air-conditioning system is in the cooling mode or the dehumidification mode, if the temperature difference ΔT is greater than the fourth temperature difference threshold C4 and less than the third temperature difference threshold C3, the air-conditioning system is maintained in the current mode through the control valve group, the second throttling element, and the switching valve;

[0048] When the air-conditioning system is in the heating mode or the dehumidification mode, if the temperature difference ΔT is greater than the sixth temperature difference threshold C6 and less than or equal to the fifth temperature difference threshold C5, the air-conditioning system maintains the current mode through the control valve group, the second throttling element and the switching valve.

[0049] In some embodiments, the control method further includes:

[0050] When the sleep function of the air-conditioning system is turned on, when it is switched to cooling mode, heating mode or dehumidification mode, the refrigerant flow paths of the first indoor heat exchanger and the second indoor heat exchanger are always connected in series through the control valve group, and the refrigerant flow path between the first indoor heat exchanger and the second indoor heat exchanger is always kept disconnected.

[0051] In some embodiments, the step of switching the air-conditioning system between the heating mode, the cooling mode, and the dehumidification mode by the control valve group, the second throttling element, and the switching valve according to the temperature difference level corresponding to the temperature difference ΔT includes:

[0052] When the sleep function of the air-conditioning system is turned on, when the air-conditioning system is in the startup stage, if the temperature difference ΔT is greater than or equal to the seventh temperature difference threshold C7, the air-conditioning system is switched to the cooling mode through the control valve group, the second throttling element and the switching valve; otherwise, the control valve group, the second throttling element and the switching valve switch the air-conditioning system to the dehumidification mode.

[0053] In some embodiments, the step of switching the air-conditioning system between the heating mode, the cooling mode, and the dehumidification mode by the control valve group, the second throttling element, and the switching valve according to the temperature difference level corresponding to the temperature difference ΔT includes:

[0054] When the sleep function of the air conditioning system is turned on and the air conditioning system is in the operation stage:

[0055] If the temperature difference ΔT is greater than or equal to an eighth temperature difference threshold C8, the air conditioning system is switched to a cooling mode through the control valve group, the second throttling element, and the switching valve;

[0056] If the temperature difference ΔT is less than or equal to a ninth temperature difference threshold C9, the air conditioning system is switched to a dehumidification mode through the control valve group, the second throttling element, and the switching valve;

[0057] When the air-conditioning system is in the cooling mode or the dehumidification mode, if the temperature difference ΔT is greater than a ninth temperature difference threshold value C9 and less than an eighth temperature difference threshold value C8, the air-conditioning system is maintained in the current mode through the control valve group, the second throttling element, and the switching valve;

[0058] The eighth temperature difference threshold C8 is greater than the ninth temperature difference threshold C9.

[0059] Therefore, according to the embodiment of the present disclosure, the fan in the indoor heat exchange structure is arranged between the indoor heat exchanger group and the lower air outlet, so that the fan sucks in the air flow flowing through the indoor heat exchanger group and discharges it downward through the lower air outlet. In this way, the air flow that is heated when flowing through the indoor heat exchanger can be mixed once in the fan, and when it is discharged downward through the lower air outlet, the hotter air flow that floats up of the insufficiently mixed air flow can be mixed for the second time with the cooler air flow that sinks and is subsequently discharged. The cooler air flow is used to cool the hotter air flow that floats up, thereby achieving more uniform indoor air outlet, thereby improving the user's comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0061] The present disclosure can be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0062] Figure 1 (a) and (b) are schematic diagrams of the front-to-back arrangement and top-to-bottom arrangement of the dehumidification heat exchanger and the heat recovery heat exchanger in the indoor heat exchange structure of the air conditioner in the related art, respectively;

[0063] Figure 2 is a schematic structural diagram of some embodiments of the indoor heat exchange structure disclosed herein;

[0064] Figure 3 yes Figure 2 Schematic diagram of working principle;

[0065] Figure 4 Schematic diagrams of structures of other embodiments of the indoor heat exchange structure disclosed herein;

[0066] Figure 5 is a schematic structural diagram of some embodiments of the air-conditioning system according to the present disclosure;

[0067] Figure 6-Figure 9 They are schematic diagrams of refrigerant circulation in different modes according to some embodiments of the air-conditioning system disclosed herein;

[0068] Figure 10 is a flowchart of some embodiments of the control method of the air-conditioning system according to the present disclosure;

[0069] Figure 11 is a flowchart of other embodiments of the control method of the air-conditioning system according to the present disclosure;

[0070] Figure 12 1 is a flow chart of some further embodiments of the control method of the air-conditioning system according to the present disclosure.

[0071] It should be understood that the size of each part shown in the drawings is not drawn according to the actual proportional relationship.In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0072] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure, its application, or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of parts and steps, the composition of materials, numerical expressions, and numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0073] The terms "first", "second" and similar terms used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The terms "include" or "comprises" and similar terms mean that the elements before the term include the elements listed after the term, and do not exclude the possibility of also including other elements. The terms "upper", "lower", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0074] In the present disclosure, when a specific device is described as being located between a first device and a second device, an intervening device may or may not be present between the specific device and the first device or the second device. When a specific device is described as being connected to another device, the specific device may be directly connected to the other device without an intervening device, or may be not directly connected to the other device but with an intervening device.

[0075] All terms (including technical or scientific terms) used in this disclosure have the same meaning as those understood by one of ordinary skill in the art to which this disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, general dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an idealized or highly formal sense, unless explicitly defined herein.

[0076] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0077] Figure 2 It is a structural schematic diagram of some embodiments of the indoor heat exchange structure according to the present disclosure. Figure 3 yes Figure 2 Schematic diagram of the working principle. Figure 2 and Figure 3 The present disclosure provides an indoor heat exchange structure for an air conditioning system. The indoor heat exchange structure includes an air duct assembly 10, an indoor heat exchanger group, and a fan 30. The air duct assembly 10 includes an air duct 11, a return air port 12, and a lower air outlet 13 connected to the air duct 11. The return air port 12 can be a side return air port, through which indoor return air enters the air duct 11.

[0078] The indoor heat exchanger group is disposed in the air duct 11 and is configured to perform heat exchange with the air flow entering from the return air port 12 and flowing through the indoor heat exchanger group.

[0079] The fan 30 is disposed in the air duct 11 and is located between the lower air outlet 13 and the indoor heat exchanger group. The fan 30 is configured to draw air flowing through the indoor heat exchanger group and discharge the drawn air downward through the lower air outlet 13. The fan 30 may be a cross-flow fan or other types of fans.

[0080] The indoor heat exchanger group includes a first indoor heat exchanger 21 and a second indoor heat exchanger 22. The first indoor heat exchanger 21 is configured to heat the indoor return air entering through the return air vent 12 in the first mode of the air conditioning system. The first indoor heat exchanger 21 can function as a regenerative heat exchanger to exchange heat with a portion of the return air entering through the return air vent 12, thereby being heated to a relatively high temperature.

[0081] The second indoor heat exchanger 22 is configured to cool and dehumidify the indoor return air entering from the return air vent 12 in the first mode of the air conditioning system. The second indoor heat exchanger 22 can function as a dehumidification heat exchanger to exchange heat with another portion of the return air entering from the return air vent 12, and be cooled into relatively dry cold air.

[0082] The first mode of the air conditioning system is at least one operational mode that the air conditioning system can implement, such as the dehumidification mode of the air conditioning system. Accordingly, in the first mode, the first indoor heat exchanger 21 and the second indoor heat exchanger 22 heat and cool the return air, respectively. In other modes of the air conditioning system, the first indoor heat exchanger 21 and the second indoor heat exchanger 22 may both heat or cool the return air.

[0083] refer to Figure 3 In this embodiment, the indoor return air F1 is sucked into the return air inlet 12 by the suction action of the fan 30. The indoor return air duct F1 flows through the first indoor heat exchanger 21 and the second indoor heat exchanger 22 under the action of the fan 30. The return air F2 that is heated by the first indoor heat exchanger 21 and the return air F3 that is cooled by the second indoor heat exchanger 22 are both sucked into the suction port of the fan 30 and mixed once in the fan 30.

[0084] The mixed air F4 obtained by mixing in the fan 30 is discharged downward through the lower air outlet. For the hot and cold airflows that were not completely mixed in the fan 30, when they are discharged from the lower air outlet, the hotter airflow that is not fully mixed will float relatively upward, while the cooler airflow that is not fully mixed will sink relatively downward. For the lower air outlet, the airflow is discharged continuously. The airflow F4 discharged at the current moment and the airflow F5 discharged at the next moment can be mixed twice. That is, the relatively rising hotter airflow discharged at the current moment can mix with the relatively sinking cooler airflow discharged at the next moment, and the relatively sinking cooler airflow discharged at the current moment can mix with the relatively rising hotter airflow discharged at the previous moment.

[0085] Compared with the structural form in the related art in which the indoor return air is blown to the dehumidification heat exchanger and the return air heat exchanger through the fan, this embodiment can effectively overcome the problem of outlet air temperature stratification, so that the outlet air can be more fully mixed, and the outlet air humidity can also be more uniform, thereby effectively improving the indoor air outlet of the air conditioning system and thus improving the user's comfort.

[0086] In order to guide the air downward through the lower air outlet 13 to achieve secondary mixing of the air, Figure 2 In the embodiment, the lower air outlet 13 may be located on the lower surface of the air duct assembly 10 .

[0087] refer to Figure 2 In some embodiments, the first indoor heat exchanger 21 is located on the upper side of the second indoor heat exchanger 22. This allows the second indoor heat exchanger 22, which is capable of cooling the return air, to more conveniently discharge condensed water during the cooling process. Figure 2In the embodiment, the indoor heat exchanger assembly may further include a water receiving pan 23 disposed in the air duct 11. The water receiving pan 23 is located below the second indoor heat exchanger 22. This allows condensed water to quickly enter the water receiving pan 23 under the action of gravity, preventing the condensed water from adversely affecting the heating function of the first indoor heat exchanger 21.

[0088] In the above embodiment, the first indoor heat exchanger 21 includes at least one row of first indoor heat exchangers 21, and the second indoor heat exchanger 22 includes at least one row of second indoor heat exchangers 22 corresponding to the at least one row of first indoor heat exchangers 21. Depending on heating or cooling needs, an appropriate number of rows of first indoor heat exchangers 21 and second indoor heat exchangers 22 can be selected. For example, the number of rows of the first indoor heat exchangers 21 and the number of rows of the second indoor heat exchangers 22 can both be greater than or equal to 1 and less than or equal to 4.

[0089] exist Figure 2 In the embodiment, a single row of first indoor heat exchangers 21 and a single row of second indoor heat exchangers 22 are used. In other embodiments, two, three, or four rows of first indoor heat exchangers 21 and second indoor heat exchangers 22 may be used. Fewer rows of heat exchangers can reduce space and weight while meeting heat exchange requirements, while more rows of heat exchangers can achieve greater heat exchange capacity. For multiple rows of first indoor heat exchangers 21 and second indoor heat exchangers 22, they can be arranged in intervals along the direction from the return air inlet 12 to the fan 30.

[0090] refer to Figure 2 In some embodiments, each row of first indoor heat exchangers 21 and the corresponding second indoor heat exchangers 22 form a ">" shape. This ">" shape indicates that the adjacent ends of each row of first indoor heat exchangers 21 and the corresponding second indoor heat exchangers 22 are connected or abutted, and the ends away from each other are open toward the fan.

[0091] The first indoor heat exchanger 21 and the second indoor heat exchanger 22 can be the same or different types of heat exchangers and can be the same or different in size. In some embodiments, both the first indoor heat exchanger 21 and the second indoor heat exchanger 22 comprise tube-and-fin heat exchangers. The number of U-shaped tubes in each row of the first indoor heat exchanger 21 is equal to or greater than the number of U-shaped tubes in the corresponding row of the second indoor heat exchanger 22. A greater number of U-shaped tubes in the second indoor heat exchanger helps reduce the difficulty of temperature control in the dehumidification mode of the air conditioning system.

[0092] Figure 4 Schematic diagram of some other embodiments of the indoor heat exchange structure according to the present disclosure. Figure 4In some embodiments, the first indoor heat exchanger 21 includes at least one row of first indoor heat exchangers 21, and the second indoor heat exchanger 22 includes at least one row of second indoor heat exchangers 22 corresponding to the at least one row of first indoor heat exchangers 21, and each row of first indoor heat exchangers 21 and the corresponding second indoor heat exchanger 22 form a straight line. Figure 4 The first indoor heat exchangers 21 and the second indoor heat exchangers 22 in the straight line can be arranged obliquely relative to the air duct 11. In other embodiments, each row of the first indoor heat exchangers 21 and the corresponding second indoor heat exchangers 22 can also be in the shape of a "<".

[0093] Figure 5 Schematic diagram of the structure of some embodiments of the air conditioning system according to the present disclosure. Figure 5 The present disclosure provides an air conditioning system, including the indoor heat exchange structure of any of the aforementioned embodiments. This air conditioning system can be a ducted air conditioning system or other forms of air conditioning system.

[0094] refer to Figure 5 In some embodiments, the air conditioning system further includes a control valve group. The control valve group is configured to connect the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 in series or in parallel. In the series connection state, the control valve group opens or throttles the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22, and in the parallel connection state, the control valve group disconnects the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22. The control valve group can connect the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 in series or in parallel depending on factors such as the specific operating mode and cooling efficiency of the air conditioning system.

[0095] Specifically, refer to Figure 5 The control valve group may include: a first on-off valve 24, a second on-off valve 25, and a first throttling element 26. The first indoor heat exchanger 21 and the first on-off valve 24 are connected in series on the first refrigerant flow path f1. The second indoor heat exchanger 22 and the second on-off valve 25 are connected in series on the second refrigerant flow path f2, and the first refrigerant flow path f1 and the second refrigerant flow path f2 are connected in parallel. The first throttling element 26 is provided on the third refrigerant flow path f3 connected between the first refrigerant flow path f1 and the second refrigerant flow path f2.

[0096] The first on-off valve 24 and the second on-off valve 25 can both be solenoid valves, or other types of on-off valves, such as electric valves, hydraulic control valves, etc. The first throttling element 26 can be an electronic expansion valve, or other types of throttling elements.

[0097] exist Figure 5In the embodiment, the air conditioning system further includes a compressor 41, an outdoor heat exchanger 42, a second throttling element 43, and a switching valve 44. The switching valve 44 is configured to switch the circulation direction of the refrigerant circulation loop formed by the compressor 41, the outdoor heat exchanger 42, the second throttling element 43, and the indoor heat exchange structure. The switching valve 44 may be a four-way valve, for example. The control valve assembly, the second throttling element 43, and the switching valve 44 can switch between multiple operating modes of the air conditioning system, for example, between a heating mode, a cooling mode, and a dehumidification mode.

[0098] Figure 6-Figure 9 These are schematic diagrams of refrigerant circulation in different modes according to some embodiments of the air-conditioning system disclosed herein. Figure 6 During the startup phase of the air-conditioning system, when switched to the cooling mode, the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in parallel through the control valve group, and the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22 is disconnected.

[0099] exist Figure 6 In the cooling mode shown, the first on-off valve 24 and the second on-off valve 25 are both open, allowing refrigerant to flow, while the first throttling element 26 is closed, preventing refrigerant from flowing. The first indoor heat exchanger 21 and the second indoor heat exchanger 22 are in parallel, both acting as evaporators to absorb heat, thereby achieving the cooling effect during the startup phase of the air conditioning system. At this time, the refrigerant flow direction is: compressor 41 → switching valve 44 → outdoor heat exchanger 42 (acting as a condenser) → second throttling element 43 (acting as a throttling unit) → parallel first indoor heat exchanger 21 and second indoor heat exchanger 22 (both acting as evaporators) → switching valve 44 → compressor 41. This parallel state of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 can shorten the heat exchange process and improve the heat exchange effect, thereby achieving a more efficient cooling effect.

[0100] refer to Figure 7 During the startup phase or operation phase of the air-conditioning system, when switched to the heating mode, the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in series through the control valve group, and the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22 is conducted.

[0101] exist Figure 7In the heating mode shown, the first on-off valve 24 and the second on-off valve 25 are both closed and no refrigerant circulates, while the first throttling element 26 is open and refrigerant can circulate. The first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in series and both act as condensers to release heat, thereby achieving a heating effect during the startup or operation phase of the air conditioning system. At this time, the refrigerant flow direction is: compressor 41 → switching valve 44 → second indoor heat exchanger 22 (acting as a condenser) → first throttling unit 26 (fully open and not throttling) → first indoor heat exchanger 21 (also acting as a condenser) → second throttling element 43 (acting as a throttling unit) → outdoor heat exchanger 42 (acting as an evaporator) → switching valve 44 → compressor 41.

[0102] refer to Figure 8 During the startup phase or operation phase of the air-conditioning system, when switched to the dehumidification mode, the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in series through the control valve group, and the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22 is conducted.

[0103] exist Figure 8 In the dehumidification mode shown, the first on-off valve 24 and the second on-off valve 25 are both closed, preventing refrigerant from flowing, while the first throttling element 26 is in a throttling state. The first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in series, with the first indoor heat exchanger 21 acting as a condenser, releasing heat, while the second indoor heat exchanger 22 acts as an evaporator, absorbing heat, thereby achieving temperature control and dehumidification during the startup or operation phase of the air conditioning system. At this time, the refrigerant flow is: compressor 41 → switching valve 44 → outdoor heat exchanger 42 (acting as a condenser) → second throttling element 43 (fully open, not throttling) → first indoor heat exchanger 21 (acting as a condenser) → first throttling element 26 (acting as a throttling unit) → second indoor heat exchanger 22 (acting as an evaporator) → switching valve 44 → compressor 41.

[0104] refer to Figure 9 During the operation phase of the air-conditioning system, when switched to the cooling mode, the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in series through the control valve group, and the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22 is conducted.

[0105] exist Figure 9In the cooling mode shown, the first on-off valve 24 and the second on-off valve 25 are both closed, with no refrigerant flowing, while the first throttling element 26 is open. The first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in series, and both act as evaporators to absorb heat, thereby achieving the cooling effect during the operation phase of the air conditioning system. At this time, the refrigerant flow is: compressor 41 → switching valve 44 → outdoor heat exchanger 42 (acting as a condenser) → second throttling element 43 (acting as a throttling unit) → first indoor heat exchanger 21 (acting as an evaporator) → first throttling element 26 (fully open, no throttling) → second indoor heat exchanger 22 (acting as an evaporator) → switching valve 44 → compressor 41.

[0106] In this way, it is no longer necessary to switch the first on-off valve 24 and the second on-off valve 25 during the operation phase of the air-conditioning system, thereby avoiding noise caused by frequent switching of the on-off valves, thereby improving user experience.

[0107] Figure 10 is a flow chart illustrating some embodiments of a control method for an air conditioning system according to the present disclosure. Based on the aforementioned embodiments of the air conditioning system according to the present disclosure, the present disclosure further provides a control method for an air conditioning system, comprising steps S1 and S2. In step S1, a temperature difference ΔT between the indoor ambient temperature and a set temperature is determined. In step S2, the air conditioning system is switched between heating mode, cooling mode, and dehumidification mode via the control valve assembly, the second throttling element 43, and the switching valve 44 based on the temperature difference level corresponding to the temperature difference ΔT.

[0108] In this embodiment, the temperature difference level corresponds to at least one pre-set temperature range for the air conditioning system. Different temperature difference levels represent the degree of difference between the indoor ambient temperature and the set temperature. Adopting corresponding air conditioning operating modes for different temperature differences can improve air conditioning performance, reduce energy consumption, and enhance user experience. The aforementioned air conditioning system control method can be executed by a controller within the air conditioning system or by a network control platform capable of communicating with the controller within the air conditioning system by sending commands to the controller.

[0109] For different working stages of the air conditioning system, different refrigerant flow paths may be used when switching to the cooling mode. For example, in some embodiments, the control method further includes: during the startup phase of the air conditioning system, when switching to the cooling mode, the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in parallel through the control valve group, and the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22 is disconnected (see Figure 6 This helps shorten the heat exchange process during the startup phase, improve the heat exchange effect, and thus achieve a more efficient cooling effect.

[0110] During the operation phase of the air conditioning system, when the system is switched to the cooling mode, the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in series through the control valve group, and the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22 is conducted (see Figure 9 This eliminates the need to switch the on-off valve in the control valve group, thereby avoiding the noise caused by frequent switching of the on-off valve and improving the user experience.

[0111] Figure 11 1 is a flow chart of other embodiments of the control method of the air-conditioning system according to the present disclosure. Figure 10 and Figure 11 In some embodiments, step S2 may include:

[0112] During the startup phase of the air conditioning system:

[0113] If the temperature difference ΔT is greater than or equal to the first temperature difference threshold C1, the air conditioning system is switched to the cooling mode through the control valve group, the second throttling element 43 and the switching valve 44. Figure 6 The refrigerant circulation path shown connects the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 in parallel, disconnects the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22, and the second throttling element 43 is in a throttling state and the first throttling element 25 is closed.

[0114] If the temperature difference ΔT is less than the first temperature difference threshold C1 and greater than the second temperature difference threshold C2, the air conditioning system is switched to the dehumidification mode through the control valve group, the second throttling element 43 and the switching valve 44. Figure 8 The refrigerant circulation path shown is such that the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in series, and the second throttling element 43 is open and the first throttling element 25 is in a throttling state;

[0115] If the temperature difference ΔT is less than or equal to the second temperature difference threshold C2, the air conditioning system is switched to the heating mode through the control valve group, the second throttling element 43 and the switching valve 44. Figure 7 The refrigerant circulation path shown connects the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 in series, and the second throttle element 43 is in a throttle state and the first throttle element 25 is open.

[0116] In this embodiment, the first temperature difference threshold C1 is smaller than the second temperature difference threshold C2, wherein C1 may be 2 to 5°C, and C2 may be -5 to -2°C.

[0117] refer to Figure 10 and Figure 11 In some embodiments, step S2 may include:

[0118] During the operation phase of the air conditioning system:

[0119] If the temperature difference ΔT is greater than or equal to the third temperature difference threshold C3, the air conditioning system is switched to the cooling mode through the control valve group, the second throttling element 43 and the switching valve 44. Figure 9 The refrigerant circulation path shown connects the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 in series, and the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22 is conductive, the second throttling element 43 is in a throttling state, and the first throttling element 25 is open;

[0120] If the temperature difference ΔT is less than or equal to the fourth temperature difference threshold C4 and greater than the fifth temperature difference threshold C5, the air conditioning system is switched to the dehumidification mode through the control valve group, the second throttling element 43 and the switching valve 44. Figure 8 The refrigerant circulation path shown is such that the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in series, and the second throttling element 43 is open and the first throttling element 25 is in a throttling state;

[0121] If the temperature difference ΔT is less than or equal to the sixth temperature difference threshold C6, the air conditioning system is switched to the heating mode through the control valve group, the second throttling element 43 and the switching valve 44. Figure 7 The refrigerant circulation path shown connects the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 in series, and the second throttle element 43 is in a throttle state and the first throttle element 25 is open.

[0122] In this embodiment, the third temperature difference threshold C3 is greater than the fourth temperature difference threshold C4, the fourth temperature difference threshold C4 is greater than the fifth temperature difference threshold C5, and the fifth temperature difference threshold C5 is greater than the sixth temperature difference threshold C6, wherein C3 can take a value of 2 to 5°C, C4 can take a value of -1 to 2°C, C5 can take a value of -1 to -2°C, and C6 can be less than -2°C.

[0123] In order to reduce the frequent switching of the air conditioning system working mode, refer to Figure 10-11 In some embodiments, step S2 may further include:

[0124] During the operation phase of the air conditioning system:

[0125] When the air conditioning system is in the cooling mode or the dehumidification mode, if the temperature difference ΔT is greater than the fourth temperature difference threshold C4 and less than the third temperature difference threshold C3, the air conditioning system is maintained in the current mode through the control valve group, the second throttling element 43, and the switching valve 44.

[0126] When the air-conditioning system is in the heating mode or the dehumidification mode, if the temperature difference ΔT is greater than the sixth temperature difference threshold C6 and less than or equal to the fifth temperature difference threshold C5, the air-conditioning system maintains the current mode through the control valve group, the second throttling element 43 and the switching valve 44.

[0127] Considering that the noise from the solenoid valves opening and closing during sleep can easily affect a user's sleep quality, when the air conditioning system's sleep function is enabled and the system switches to cooling, heating, or dehumidification mode, the control valve assembly maintains the refrigerant flow paths between the first and second indoor heat exchangers 21, 22 in series, while the refrigerant flow path between the first and second indoor heat exchangers 21, 22 remains disconnected. This eliminates the need to switch the on / off valves in the refrigerant flow paths between the first and second indoor heat exchangers 21, 22 when switching the air conditioning system's operating mode, thereby preventing noise from switching the on / off valves.

[0128] Figure 12 FIG. 1 is a flow chart of some other embodiments of the control method of the air-conditioning system according to the present disclosure. Figure 10 and Figure 12 In some embodiments, step S2 may include: when the sleep function of the air-conditioning system is turned on, when the air-conditioning system is in the startup stage, if the temperature difference ΔT is greater than or equal to the seventh temperature difference threshold C7, the air-conditioning system is switched to the cooling mode through the control valve group, the second throttling element 43 and the switching valve 44. At this time, Figure 9 The refrigerant circulation path shown connects the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 in series, and makes the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22 conductive, the second throttling element 43 is in a throttling state and the first throttling element 25 is open.

[0129] If the temperature difference ΔT is less than the seventh temperature difference threshold C7, the air conditioning system is switched to the dehumidification mode through the control valve group, the second throttling element 43 and the switching valve 44. Figure 8 The refrigerant circulation path shown connects the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 in series, and the second throttle element 43 is open and the first throttle element 25 is in a throttling state.

[0130] In this embodiment, the seventh temperature difference threshold C7 may be set to a value of 0-2°C.

[0131] refer to Figure 10 and Figure 12 In some embodiments, step S2 may include: when the sleep function of the air-conditioning system is turned on and the air-conditioning system is in the running stage:

[0132] If the temperature difference ΔT is greater than or equal to the eighth temperature difference threshold C8, the air conditioning system is switched to the cooling mode through the control valve group, the second throttling element 43 and the switching valve 44. Figure 9 The refrigerant circulation path shown connects the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 in series, and the refrigerant flow path between the first indoor heat exchanger 21 and the second indoor heat exchanger 22 is conductive, the second throttling element 43 is in a throttling state, and the first throttling element 25 is open;

[0133] If the temperature difference ΔT is less than or equal to the ninth temperature difference threshold C9, the air conditioning system is switched to the dehumidification mode through the control valve group, the second throttling element 43 and the switching valve 44. Figure 8 The refrigerant circulation path shown is such that the refrigerant flow paths of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 are connected in series, and the second throttling element 43 is open and the first throttling element 25 is in a throttling state;

[0134] When the air-conditioning system is in the cooling mode or the dehumidification mode, if the temperature difference ΔT is greater than the ninth temperature difference threshold C9 and less than the eighth temperature difference threshold C8, the air-conditioning system maintains the current mode through the control valve group, the second throttling element 43 and the switching valve 44.

[0135] In this embodiment, the eighth temperature difference threshold C8 is greater than the ninth temperature difference threshold C9, wherein C8 may be 0 to 2°C, and C9 may be -2 to 0°C.

[0136] Thus far, various embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details known in the art have not been described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0137] Although some specific embodiments of the present disclosure have been described in detail through examples, those skilled in the art will understand that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. Those skilled in the art will understand that the above embodiments may be modified or some technical features may be replaced with equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. An indoor heat exchange structure for an air conditioning system, characterized in that: include: An air duct assembly (10) comprises an air duct (11) and an air return port (12) and a lower air outlet (13) in communication with the air duct (11); an indoor heat exchanger group, disposed in the air duct (11), and configured to perform heat exchange with the air flow entering from the return air port (12) and flowing through the indoor heat exchanger group; a fan (30) disposed in the air duct (11) and located between the lower air outlet (13) and the indoor heat exchanger group, configured to suck in the airflow flowing through the indoor heat exchanger group and discharge the sucked airflow downward through the lower air outlet (13); The indoor heat exchanger group includes a first indoor heat exchanger (21) and a second indoor heat exchanger (22), wherein the first indoor heat exchanger (21) is configured to heat the indoor return air entering from the return air inlet (12) in the first mode of the air-conditioning system, and the second indoor heat exchanger (22) is configured to cool and dehumidify the indoor return air entering from the return air inlet (12) in the first mode of the air-conditioning system; the first indoor heat exchanger (21) is located on the upper side of the second indoor heat exchanger (22).

2. The indoor heat exchange structure according to claim 1, characterized in that: The lower air outlet (13) is located on the lower surface of the air duct assembly (10).

3. The indoor heat exchange structure according to claim 1, characterized in that: The indoor heat exchanger group also includes: A water receiving tray (23) is provided in the air duct (11) and is located on the lower side of the second indoor heat exchanger (22).

4. The indoor heat exchange structure according to claim 1, characterized in that: The first indoor heat exchanger (21) includes at least one row of first indoor heat exchangers (21), and the second indoor heat exchanger (22) includes at least one row of second indoor heat exchangers (22) corresponding to the at least one row of first indoor heat exchangers (21), and each row of first indoor heat exchangers (21) and the corresponding second indoor heat exchanger (22) are arranged in a straight line, a "<" shape, or a ">" shape.

5. The indoor heat exchange structure according to claim 4, characterized in that: The number of rows of the first indoor heat exchanger (21) and the number of rows of the second indoor heat exchanger (22) are both greater than or equal to 1 and less than or equal to 4.

6. The indoor heat exchange structure according to claim 1, characterized in that: The first indoor heat exchanger (21) and the second indoor heat exchanger (22) both comprise tube-fin heat exchangers, and the number of U-shaped tubes included in each row of the first indoor heat exchanger (21) is greater than or equal to the number of U-shaped tubes included in the corresponding second indoor heat exchanger (22).

7. The indoor heat exchange structure according to claim 1, characterized in that: The first mode of the air-conditioning system is a dehumidification mode of the air-conditioning system.

8. An air conditioning system, characterized in that: include: The indoor heat exchange structure according to any one of claims 1 to 7.

9. The air conditioning system according to claim 8, characterized in that The air conditioning system is a ducted air conditioning system.

10. The air conditioning system according to claim 8, characterized in that Also includes: The control valve group is configured to connect the refrigerant flow paths of the first indoor heat exchanger (21) and the second indoor heat exchanger (22) in series or in parallel, wherein the refrigerant flow path between the first indoor heat exchanger (21) and the second indoor heat exchanger (22) is opened or throttled in the series connection state, and the refrigerant flow path between the first indoor heat exchanger (21) and the second indoor heat exchanger (22) is disconnected in the parallel connection state.

11. The air conditioning system according to claim 10, characterized in that The control valve group includes: a first on-off valve (24), wherein the first indoor heat exchanger (21) and the first on-off valve (24) are connected in series on the first refrigerant flow path (f1); a second on-off valve (25), the second indoor heat exchanger (22) and the second on-off valve (25) are connected in series on the second refrigerant flow path (f2), and the first refrigerant flow path (f1) and the second refrigerant flow path (f2) are connected in parallel; and The first throttling element (26) is provided on a third refrigerant flow path (f3) connected between the first refrigerant flow path (f1) and the second refrigerant flow path (f2).

12. The air conditioning system according to claim 10 or 11, characterized in that: Also includes: A compressor (41), an outdoor heat exchanger (42), a second throttling element (43) and a switching valve (44), wherein the switching valve (44) is configured to switch the circulation direction of the refrigerant circulation loop formed by the compressor (41), the outdoor heat exchanger (42), the second throttling element (43) and the indoor heat exchange structure.

13. A control method for an air conditioning system according to claim 12, characterized in that: include: Determine the temperature difference ΔT between the indoor ambient temperature and the set temperature; According to the temperature difference level corresponding to the temperature difference ΔT, the air conditioning system is switched between a heating mode, a cooling mode and a dehumidification mode through the control valve group, the second throttling element (43) and the switching valve (44).

14. The control method according to claim 13, characterized in that: Also includes: During the startup phase of the air-conditioning system, when the system is switched to a cooling mode, the refrigerant flow paths of the first indoor heat exchanger (21) and the second indoor heat exchanger (22) are connected in parallel through the control valve group, and the refrigerant flow path between the first indoor heat exchanger (21) and the second indoor heat exchanger (22) is disconnected; During the operation phase of the air-conditioning system, when the system switches to the cooling mode, the refrigerant flow paths of the first indoor heat exchanger (21) and the second indoor heat exchanger (22) are connected in series through the control valve group, and the refrigerant flow path between the first indoor heat exchanger (21) and the second indoor heat exchanger (22) is conducted.

15. The control method according to claim 14, characterized in that: The step of switching between the heating mode, the cooling mode and the dehumidification mode of the air-conditioning system through the control valve group, the second throttling element (43) and the switching valve (44) according to the temperature difference level corresponding to the temperature difference ΔT comprises: During the startup phase of the air conditioning system: If the temperature difference ΔT is greater than or equal to a first temperature difference threshold C1, the air conditioning system is switched to a cooling mode through the control valve group, the second throttling element (43) and the switching valve (44); If the temperature difference ΔT is less than the first temperature difference threshold C1 and greater than the second temperature difference threshold C2, the air conditioning system is switched to a dehumidification mode through the control valve group, the second throttling element (43) and the switching valve (44); If the temperature difference ΔT is less than or equal to the second temperature difference threshold C2, the air conditioning system is switched to a heating mode through the control valve group, the second throttling element (43) and the switching valve (44); The first temperature difference threshold C1 is smaller than the second temperature difference threshold C2.

16. The control method according to claim 14, characterized in that: The step of switching between the heating mode, the cooling mode and the dehumidification mode of the air-conditioning system through the control valve group, the second throttling element (43) and the switching valve (44) according to the temperature difference level corresponding to the temperature difference ΔT comprises: During the operation phase of the air conditioning system: If the temperature difference ΔT is greater than or equal to a third temperature difference threshold C3, the air conditioning system is switched to a cooling mode through the control valve group, the second throttling element (43) and the switching valve (44); If the temperature difference ΔT is less than or equal to a fourth temperature difference threshold value C4 and greater than a fifth temperature difference threshold value C5, the air conditioning system is switched to a dehumidification mode through the control valve group, the second throttling element (43) and the switching valve (44); If the temperature difference ΔT is less than or equal to a sixth temperature difference threshold C6, the air conditioning system is switched to a heating mode through the control valve group, the second throttling element (43) and the switching valve (44); The third temperature difference threshold C3 is greater than the fourth temperature difference threshold C4, the fourth temperature difference threshold C4 is greater than the fifth temperature difference threshold C5, and the fifth temperature difference threshold C5 is greater than the sixth temperature difference threshold C6.

17. The control method according to claim 16, characterized in that: The step of switching between the heating mode, the cooling mode and the dehumidification mode of the air-conditioning system through the control valve group, the second throttling element (43) and the switching valve (44) according to the temperature difference level corresponding to the temperature difference ΔT further includes: During the operation phase of the air conditioning system: When the air conditioning system is in the cooling mode or the dehumidification mode, if the temperature difference ΔT is greater than the fourth temperature difference threshold value C4 and less than the third temperature difference threshold value C3, the air conditioning system is kept in the current mode through the control valve group, the second throttling element (43) and the switching valve (44); When the air-conditioning system is in the heating mode or the dehumidification mode, if the temperature difference ΔT is greater than the sixth temperature difference threshold C6 and less than or equal to the fifth temperature difference threshold C5, the air-conditioning system is kept in the current mode through the control valve group, the second throttling element (43) and the switching valve (44).

18. The control method according to claim 13, characterized in that: Also includes: When the sleep function of the air-conditioning system is turned on, when it is switched to cooling mode, heating mode or dehumidification mode, the refrigerant flow paths of the first indoor heat exchanger (21) and the second indoor heat exchanger (22) are always connected in series through the control valve group, and the refrigerant flow path between the first indoor heat exchanger (21) and the second indoor heat exchanger (22) is always kept disconnected.

19. The control method according to claim 18, characterized in that: The step of switching between the heating mode, the cooling mode and the dehumidification mode of the air-conditioning system through the control valve group, the second throttling element (43) and the switching valve (44) according to the temperature difference level corresponding to the temperature difference ΔT comprises: In the sleep function of the air-conditioning system, when the air-conditioning system is in the startup stage, if the temperature difference ΔT is greater than or equal to a seventh temperature difference threshold value C7, the air-conditioning system is switched to a cooling mode through the control valve group, the second throttling element (43) and the switching valve (44); otherwise, the air-conditioning system is switched to a dehumidification mode through the control valve group, the second throttling element (43) and the switching valve (44).

20. The control method according to claim 18, characterized in that: The step of switching between the heating mode, the cooling mode and the dehumidification mode of the air-conditioning system through the control valve group, the second throttling element (43) and the switching valve (44) according to the temperature difference level corresponding to the temperature difference ΔT comprises: When the sleep function of the air conditioning system is turned on and the air conditioning system is in the operation stage: If the temperature difference ΔT is greater than or equal to an eighth temperature difference threshold value C8, the air conditioning system is switched to a cooling mode through the control valve group, the second throttling element (43) and the switching valve (44); If the temperature difference ΔT is less than or equal to a ninth temperature difference threshold value C9, the air conditioning system is switched to a dehumidification mode through the control valve group, the second throttling element (43) and the switching valve (44); When the air conditioning system is in the cooling mode or the dehumidification mode, if the temperature difference ΔT is greater than a ninth temperature difference threshold value C9 and less than an eighth temperature difference threshold value C8, the air conditioning system is kept in the current mode through the control valve group, the second throttling element (43) and the switching valve (44); The eighth temperature difference threshold C8 is greater than the ninth temperature difference threshold C9.

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