Fresh air humidity-adjustable multi-connected air conditioner

Abstract

The present application discloses a fresh air humidity control multi-connected air conditioner, which includes: m humidity control indoor units. Each humidity control indoor unit includes: a first air duct and a second air duct; a first fan is arranged in the first air duct, and a second fan is arranged in the second air duct; a first heat exchanger coated with an adsorption material is arranged in the first air duct, and a second heat exchanger coated with an adsorption material is arranged in the second air duct; the humidity control indoor unit can achieve the transformation between two states: in one state, the first fan makes the return air discharged to the outside through the first air duct; the second fan makes the fresh air sent to the indoor through the second air duct; in another state, the first fan changes its rotation direction, making the fresh air flow into the indoor through the first air duct; the second fan changes its rotation direction, making the return air flow to the outside through the second air duct; wherein, in each humidity control indoor unit, the first heat exchanger and the second heat exchanger are connected in series to form a heat exchange branch; m heat exchange branches are connected in parallel between the C pipe and the E pipe of the four-way valve. The fresh air humidity control multi-connected air conditioner realizes continuous dehumidification and humidification through the forward and reverse rotation of the fan.

Description

Technical Field

[0001] This application relates to the technical field of air treatment, and particularly to a fresh air humidity-adjusting multi-connected unit. Background Art

[0002] The fresh air humidity-adjusting machine is mainly used to introduce the humidity-adjusted fresh air into the room to adjust the indoor air. During dehumidification in summer, the fresh air is cooled by the evaporator, and the moisture it carries is adsorbed on the adsorption material to dehumidify the fresh air; under certain conditions, the air duct is switched, and the evaporator becomes a condenser. The indoor return air is heated by the condenser, and then the moisture inside the adsorption material is dried out and taken away; during moisturization in winter, the principle is opposite. The indoor return air is cooled by the evaporator, and the moisture it carries is adsorbed onto the adsorption material for storage; under certain conditions, the air duct is switched, and the evaporator becomes a condenser. The fresh air is heated by the condenser, and the moisture on the adsorption material is dried out and sent into the room to humidify the fresh air.

[0003] In the above fresh air humidity-adjusting machine, two air valve switching devices are required to switch the air duct, and the air valve switching device usually has a relatively complex structure and a relatively large volume. Summary of the Invention

[0004] This application provides a fresh air humidity-adjusting multi-connected unit, which realizes continuous dehumidification and humidification through the forward and reverse rotation of the fan, and does not require an air valve switching device.

[0005] A fresh air humidity-adjusting multi-connected unit includes: m humidity-adjusting indoor units, where m≥2; the humidity-adjusting indoor unit includes: a housing, on which a first outdoor air outlet, a first indoor air outlet, a second outdoor air outlet, and a second indoor air outlet are provided. Among them, a first air duct is formed by connecting the first outdoor air outlet and the first indoor air outlet, and a second air duct is formed by connecting the second outdoor air outlet and the second indoor air outlet; a first fan and a second fan, the first fan is arranged in the first air duct, and the second fan is arranged in the second air duct; a first heat exchanger and a second heat exchanger, on which adsorption materials are coated, the first heat exchanger is arranged in the first air duct, and the second heat exchanger is arranged in the second air duct.

[0006] The humidity-adjusting indoor unit can realize the transformation between two states:

[0007] In one state, the first fan is used as an exhaust fan, so that the return air is exhausted to the outside through the first air duct. At this time, the first air duct is the exhaust air duct; the second fan is used as a supply fan, so that the fresh air is sent into the room through the second air duct. At this time, the second air duct is the fresh air duct.

[0008] When changing from one state to another state, the first fan changes its rotation direction and is used as a supply fan, so that the fresh air flows into the room through the first air duct. At this time, the first air duct is the fresh air duct; the second fan changes its rotation direction and is used as an exhaust fan, so that the return air flows to the outside through the second air duct. At this time, the second air duct is the exhaust air duct.

[0009] Among them, in each humidity-adjusting indoor unit, the first heat exchanger and the second heat exchanger are connected in series to form a heat exchange branch;

[0010] The fresh air humidity-adjusting multi-connected air conditioner further includes: a compressor and a four-way valve; the exhaust port of the compressor is connected to the D pipe of the four-way valve, m heat exchange branches are connected in parallel between the C pipe and the E pipe of the four-way valve, and the suction port of the compressor is connected to the S pipe of the four-way valve.

[0011] In some embodiments, it further includes: a controller for: calculating the change rate of the moisture content of the air supply of each humidity-adjusting indoor unit according to the indoor and outdoor temperature and humidity respectively judging the average value of the change rates of the moisture content of the air supply of m humidity-adjusting indoor units whether it satisfies If it is satisfied, the four-way valve changes direction; if it is not satisfied, it continues to operate;

[0012] where θ is a preset constant.

[0013] In some embodiments, it further includes: a controller for: calculating the change rate of the moisture content of the air supply of each humidity-adjusting indoor unit according to the indoor and outdoor temperature and humidity respectively judging among m humidity-adjusting indoor units the maximum value or the minimum value or and whether the average value is less than a preset value. If it holds, the four-way valve changes direction; if it does not hold, it continues to operate.

[0014] In some embodiments, in the dehumidification mode, in the humidification mode,

[0015] where d i-1 represents the moisture content of the air at the air outlet of the fresh air duct at the (i-1)th moment; d i represents the moisture content of the air at the air outlet of the fresh air duct at the ith moment; d i+1 represents the moisture content of the air at the air outlet of the fresh air duct at the (i+1)th moment; represents a preset time period.

[0016] In some embodiments, it further includes: a controller for controlling the frequency Fx of the compressor according to the following formula:

[0017]

[0018] where doa is the moisture content of outdoor fresh air, ds is the indoor set moisture content, Toa is the outdoor fresh air temperature, Ts is the indoor set temperature, and A and B are constants.

[0019] In some embodiments, the controller is further configured to: after power-on, control the compressor to start at an initial frequency F0; in the next cycle of state transformation, control the frequency Fx of the compressor to be executed according to a formula.

[0020] In some embodiments, it further includes: a controller, configured to: when operating in a dehumidification mode after power-on,

[0021] judge whether the temperature T4 at the second indoor air outlet and the temperature T2 at the second outdoor air outlet satisfy: T4 < T2 - β. If satisfied, continue; if not satisfied, change the rotation direction of the second fan;

[0022] judge whether the temperature T3 at the first indoor air outlet and the temperature T1 at the first outdoor air outlet satisfy: T3 < T1 - α; if satisfied, continue; if not satisfied, change the rotation direction of the first fan;

[0023] When operating in a humidification mode after power-on,

[0024] judge whether the temperature T3 at the first indoor air outlet and the temperature T1 at the first outdoor air outlet satisfy: T3 > T1 + α0; if satisfied, continue; if not satisfied, change the rotation direction of the first fan;

[0025] judge whether the temperature T4 at the second indoor air outlet and the temperature T2 at the second outdoor air outlet satisfy: T4 > T2 + β0; if satisfied, continue; if not satisfied, change the rotation direction of the second fan;

[0026] wherein, α, β, α0, β0 are preset values.

[0027] In some embodiments, it further includes: a controller, configured to: during the dehumidification mode, after the compressor restarts, judge whether the temperature T4 at the second indoor air outlet and the temperature T2 at the second outdoor air outlet satisfy: T4 < T2 - β1, and / or judge whether the temperature T3 at the first indoor air outlet and the temperature T1 at the first outdoor air outlet satisfy T3 < T1 - β3; if satisfied, continue; if not satisfied, control the four-way valve to change its direction;

[0028] During the humidification mode, after the compressor restarts, judge whether the temperature T2 at the second outdoor air outlet and the temperature T4 at the second indoor air outlet satisfy: T4 > T2 + β2, and / or judge whether the temperature T3 at the first indoor air outlet and the temperature T1 at the first outdoor air outlet satisfy T3 > T1 + β4; if satisfied, continue; if not satisfied, control the four-way valve to change its direction;

[0029] wherein, β1, β2, β3, β4 are preset values.

[0030] In some embodiments, temperature and humidity sensors are respectively provided at the first outdoor air outlet, the first indoor air outlet, the second outdoor air outlet, and the second indoor air outlet.

[0031] In some embodiments, the m heat exchange branches are respectively connected to the C pipe and the E pipe of the four-way valve through distributors. Description of the Drawings

[0032] Figure 1 Shows a schematic diagram of the humidity-adjusting indoor unit in the fresh air humidity-adjusting multi-connected air conditioner according to some embodiments;

[0033] Figure 2 Shows a schematic diagram of the humidity-adjusting indoor unit in the fresh air humidity-adjusting multi-connected air conditioner according to some embodiments in one state;

[0034] Figure 3 Shows a schematic diagram of the humidity-adjusting indoor unit in the fresh air humidity-adjusting multi-connected air conditioner according to some embodiments in another state;

[0035] Figure 4 Shows the first state diagram of the fresh air humidity-adjusting multi-connected air conditioner in the dehumidification mode according to some embodiments;

[0036] Figure 5 Shows the second state diagram of the fresh air humidity-adjusting multi-connected air conditioner in the dehumidification mode according to some embodiments;

[0037] Figure 6 Shows the first state diagram of the fresh air humidity-adjusting multi-connected air conditioner in the humidification mode according to some embodiments;

[0038] Figure 7 Shows the second state diagram of the fresh air humidity-adjusting multi-connected air conditioner in the humidification mode according to some embodiments;

[0039] Figure 8 Shows the flow chart of the four-way valve state detection when the compressor restarts in the fresh air humidity-adjusting multi-connected air conditioner according to some embodiments;

[0040] Figure 9 Shows the flow chart of the commutation control in the dehumidification mode of the fresh air humidity-adjusting multi-connected air conditioner according to some embodiments;

[0041] Figure 10 Shows the flow chart of the commutation control in the humidification mode of the fresh air humidity-adjusting multi-connected air conditioner according to some embodiments;

[0042] In the above figures, 101 is the first humidity-adjusting indoor unit; 102 is the second humidity-adjusting indoor unit; 103 is the third humidity-adjusting indoor unit; 1 is the housing; 11 is the first outdoor air outlet; 12 is the second outdoor air outlet; 13 is the first indoor air outlet; 14 is the second indoor air outlet; 21 is the first fan; 22 is the second fan; 3 is the first filter; 4 is the second filter; 5 is the first heat exchanger; 6 is the second heat exchanger; 7 is the compressor; 8 is the four-way valve; 9 is the electronic expansion valve. Detailed implementation manners

[0043] To make the purpose and implementation manners of this application clearer, the following will clearly and completely describe the exemplary implementation manners of this application with reference to the accompanying drawings in the exemplary embodiments of this application. Obviously, the described exemplary embodiments are only a part of the embodiments of this application, rather than all the embodiments.

[0044] In the description of this application, it should be understood that the orientation or positional relationships indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0045] The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0046] In the description of this application, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0047] The following introduces the implementation manners of this application in detail with reference to the accompanying drawings.

[0048] The fresh air humidity-adjusting multi-connected air conditioner according to the implementation manner of this application includes m humidity-adjusting indoor units, where m is a positive integer greater than or equal to 2.

[0049] The following first introduces the humidity-adjusting indoor unit:

[0050] Reference Figures 1 to 3 As shown in Figures 1 to 3 , the humidity conditioning indoor unit includes a housing 1. The housing 1 forms the general appearance of the humidity conditioning indoor unit and is roughly rectangular in shape. Four air vents are provided on the side wall of the housing 1, namely a first outdoor air vent 11, a second outdoor air vent 12, a first indoor air vent 13, and a second indoor air vent 14.

[0051] Among them, the first outdoor air vent 11 and the second outdoor air vent 12 are respectively connected to the outside through air ducts and serve as the inlet of fresh air or the outlet of return air. The first indoor air vent 13 and the second indoor air vent 14 are respectively connected to the inside through air ducts and serve as the outlet of fresh air or the inlet of return air.

[0052] The air ducts are separated in the housing 1 by partitions. The air ducts include a first air duct and a second air duct. The first outdoor air vent 11 and the first indoor air vent 13 are connected to form the first air duct, and the second outdoor air vent 12 and the second indoor air vent 14 are connected to form the second air duct.

[0053] The humidity conditioning indoor unit further includes a first fan 21 and a second fan 22. The first fan 21 is arranged in the first air duct, and the second fan 22 is arranged in the second air duct.

[0054] The humidity conditioning indoor unit can be switched between two states:

[0055] In one state, in the first air duct, the first fan 21 rotates reversely, and the indoor return air enters the first air duct from the first indoor air vent 13 and is discharged to the outside through the first outdoor air vent 11. In the second air duct, the second fan 22 rotates forward, and the outdoor fresh air enters the second air duct from the second outdoor air vent 12 and is sent to the inside through the second indoor air vent 14.

[0056] At this time, the first fan 21 serves as an exhaust fan, and the first air duct serves as a return air duct; the second fan 22 serves as a supply fan, and the second air duct serves as a fresh air duct.

[0057] In another state, in the first air duct, the first fan 21 rotates forward, and the outdoor fresh air enters the first air duct from the first outdoor air vent 11 and is sent to the inside through the first indoor air vent 13. In the second air duct, the second fan 22 rotates reversely, and the indoor return air enters the second air duct from the second indoor air vent 14 and is discharged to the outside through the second outdoor air vent 12.

[0058] At this time, the first fan 21 serves as a fresh air fan, and the first air duct serves as a fresh air duct; the second fan 22 serves as an exhaust fan, and the second air duct serves as a return air duct.

[0059] It should be noted that in this application, the forward and reverse rotations of the fan are only for the description of opposite rotations and do not specifically refer to the forward and reverse rotations of the fan in the actual working conditions.

[0060] Compared with the problems of complex structure and large volume caused by changing the air duct through two air valve switching devices in the prior art, the humidity-adjusting indoor unit of the present application realizes the transformation of the fresh air duct and the return air duct by the forward and reverse rotation of the fan, omits the air valve switching device, simplifies the product structure, reduces the cost, makes the product volume more compact, and saves the occupied space.

[0061] In addition, omitting the air valve switching device also reduces the resistance inside the unit, improves the working efficiency of the unit, and reduces the energy consumption.

[0062] According to an embodiment of the present application, the humidity-adjusting indoor unit further includes a first heat exchanger 5 and a second heat exchanger 6. Among them, the first heat exchanger 5 is arranged in the first air duct, and the second heat exchanger 6 is arranged in the second air duct. Adsorbent materials are coated on both the first heat exchanger 5 and the second heat exchanger 6. When the first heat exchanger 5 is used as an evaporator, the second heat exchanger 6 is used as a condenser; when the first heat exchanger 5 is used as a condenser, the second heat exchanger 6 is used as an evaporator.

[0063] The heat exchanger used as an evaporator cools the air and absorbs water through the adsorption action of the adsorbent material, thereby drying the air. The heat exchanger used as a condenser heats the adsorbent material and evaporates water from the adsorbent material through the regeneration action of the adsorbent material, thereby humidifying the air.

[0064] The humidity-adjusting indoor unit further includes an electronic expansion valve 9, and the electronic expansion valve 9 is connected in series between the first heat exchanger 5 and the second heat exchanger 6.

[0065] In the embodiment of the present application, the first air duct and the second air duct are symmetric about the lateral center of the housing 1, so that the first air duct and the second air duct are exactly the same.

[0066] Since the first air duct and the second air duct need to be periodically transformed between the fresh air duct and the exhaust air duct, if the two are different, it will cause obvious unequal air pressures between the two, which will bring the risk of air leakage, further reduce the working efficiency of the humidity-adjusting machine, and increase the energy consumption.

[0067] The humidity-adjusting indoor unit is also provided with a first filter screen 3 and a second filter screen 4. Among them, the first filter screen 3 is located in the first air duct, and the second filter screen 4 is located in the second air duct, and is used for filtering and purifying the flowing air.

[0068] The fresh air humidity-adjusting multi-connected unit will be introduced below with m = 3 as an example:

[0069] Refer to Figure 4 and Figure 5 , the fresh air humidity-adjusting multi-connected unit according to the embodiment of the present application includes a first humidity-adjusting indoor unit 101, a second humidity-adjusting indoor unit 102 and a third humidity-adjusting indoor unit 103.

[0070] In each humidity-adjusting indoor unit, the first heat exchanger 5, the electronic expansion valve 9, and the second heat exchanger 6 are connected in series to form a heat exchange branch.

[0071] The fresh air humidity-adjusting multi-connected unit further includes a refrigerant circuit, and the three heat exchange branches are connected in parallel in the refrigerant circuit.

[0072] Specifically, the refrigerant circuit further includes a compressor 7 and a four-way valve 8. The exhaust port of the compressor 7 is connected to the D pipe of the four-way valve 8, the suction port of the compressor 7 is connected to the S pipe of the four-way valve 8, and the three heat exchange branches are connected in parallel between the C pipe and the E pipe of the four-way valve 8.

[0073] When the four-way valve 8 changes between two states, the use of the heat exchanger can be changed. In one state, the first heat exchanger 5 functions as an evaporator, and the second heat exchanger 6 functions as a condenser; in another state, the first heat exchanger 5 functions as a condenser, and the second heat exchanger 6 functions as an evaporator.

[0074] In this application, continuous humidification or dehumidification of the unit is achieved by the commutation of the four-way valve 8 and the forward and reverse rotation of the fan.

[0075] In some embodiments of this application, the three heat exchange branches are respectively connected to the C pipe of the four-way valve and the E pipe of the four-way valve through distributors.

[0076] In this application, the compressor 7, the four-way valve 8, and the distributor are arranged outside the humidity-adjusting indoor unit. For example, the external compressor, four-way valve, and distributor are arranged in the equipment room, which can reduce the number of components inside the indoor unit, thereby optimizing the air duct structure inside the indoor unit, further reducing the air resistance, and improving the working efficiency of the indoor unit.

[0077] <Summer dehumidification mode>

[0078] Refer to Figure 2 and Figure 4 , the first state: the first heat exchanger 5 is used as a condenser, and the second heat exchanger 6 is used as an evaporator; the first fan 21 rotates in the reverse direction and functions as an exhaust fan, and the second fan 22 rotates in the forward direction and functions as a supply fan.

[0079] The second air duct (fresh air duct): Fresh air enters from the second outdoor air outlet 12. Driven by the second fan 22, it first passes through the second filter screen 4 for purification, and then passes through the second heat exchanger 6 (evaporator). The fresh air is cooled, dehumidified, and the moisture in the fresh air is adsorbed by the adsorption material on the surface of the second heat exchanger 6 (adsorption process), and then reaches the second indoor air outlet 14 and is sent into the room to complete the dehumidification process of the fresh air once.

[0080] The first air duct (exhaust air duct): Indoor air enters from the first indoor air outlet 13, first passes through the first heat exchanger 5 (condenser), takes away the heat of the first heat exchanger 5 and the moisture in the adsorption material (regeneration process), then is purified by the first filter 3, and then, driven by the first fan 21, finally reaches the first outdoor air outlet 11 and is discharged outdoors, completing an exhaust air process.

[0081] Refrigerant circuit: The exhaust port of the compressor 7 transports the high-temperature and high-pressure refrigerant. First, it passes through the four-way valve 8 (in the OFF state at this time) and reaches the diverter 10-1, and then is divided into three indoor units (the flow rate of each indoor unit is determined by the electronic expansion valves 9-1, 9-2, and 9-3 respectively). The refrigerant reaches the first heat exchanger 5 of each indoor unit, transfers the heat to the exhaust air, and the refrigerant becomes a low-temperature and high-pressure two-phase refrigerant. Then it flows to the electronic expansion valve 9, is throttled and depressurized to become a low-temperature and low-pressure liquid refrigerant, and then flows to the second heat exchanger 6 of each humidity control indoor unit, absorbs the heat of the air outside the pipe and becomes a low-temperature and low-pressure gaseous refrigerant. Then it converges at the diverter 10-2, then flows to the E pipe of the four-way valve 8, and then returns to the suction port of the compressor 7 through the S pipe of the four-way valve 8, thus completing a refrigerant cycle.

[0082] When the state change conditions are met, referring to Figure 3 and Figure 5 , the four-way valve 8 changes its direction, the first heat exchanger 5 is used as an evaporator, and the second heat exchanger 6 is used as a condenser; the first fan 21 rotates forward and is used as a supply fan, and the second fan 22 rotates reversely and is used as an exhaust fan.

[0083] The first air duct (fresh air duct): Fresh air enters from the first outdoor air outlet 11, and under the drive of the first fan 21, first passes through the first filter 3 for purification, and then passes through the first heat exchanger 5 (evaporator). The fresh air is cooled, dehumidified, and the moisture in the fresh air is adsorbed by the adsorption material on the surface of the first heat exchanger 5 (adsorption process). Then it reaches the first indoor air outlet 13 and is sent into the room, completing a dehumidification process of the fresh air.

[0084] The second air duct (exhaust air duct): Indoor air enters from the second indoor air outlet 14, first passes through the second heat exchanger 6 (condenser), takes away the heat of the second heat exchanger 6 and the moisture in the adsorption material (regeneration process), then is purified by the second filter 4, and then, driven by the second fan 22, finally reaches the second outdoor air outlet 12 and is discharged outdoors, completing an exhaust air process.

[0085] Refrigerant circuit: The exhaust port of the compressor 7 delivers high-temperature and high-pressure refrigerant. First, it passes through the four-way valve 8 (in the ON state at this time) and reaches the diverter 10-2, and then flows to each humidity control indoor unit (the flow rate of each indoor unit is determined by the electronic expansion valves 9-1, 9-2, and 9-3 respectively). The refrigerant reaches the second heat exchanger 6 of each humidity control indoor unit, transfers heat to the exhaust air, and the refrigerant becomes a low-temperature and high-pressure two-phase refrigerant. Then it flows to the electronic expansion valve 9, is throttled and depressurized to become a low-temperature and low-pressure liquid refrigerant, and then flows to the first heat exchanger 5 of each humidity control indoor unit, absorbs the heat of the air outside the pipe and becomes a low-temperature and low-pressure gaseous refrigerant. Then it converges at the diverter 10-1, flows to the C pipe of the four-way valve 8, and then returns to the suction port of the compressor 7 through the S pipe of the four-way valve 8, thus completing one refrigerant cycle.

[0086] In this way, the dehumidification process continuously cycles between the first state and the second state.

[0087] <Winter humidification mode>

[0088] Refer to Figure 3 and Figure 6 , the first state: The first heat exchanger 5 is used as a condenser, and the second heat exchanger 6 is used as an evaporator;

[0089] The first fan 21 rotates forward and is used as a supply fan, and the second fan 22 rotates reversely and is used as an exhaust fan.

[0090] The first air duct (fresh air duct): Fresh air enters from the first outdoor air outlet 11. Driven by the first fan 21, it first passes through the first filter screen 3 for purification, and then passes through the first heat exchanger 5 (condenser). The fresh air is heated and its temperature rises. At the same time, the moisture in the adsorption material on the surface of the first heat exchanger 5 is regenerated and mixed into the fresh air, increasing the humidity of the fresh air. Then it reaches the first indoor air outlet 13 and is sent into the room, completing one fresh air humidification process;

[0091] The second air duct (exhaust air duct): Indoor return air enters from the second indoor air outlet 14, first passes through the second heat exchanger 6 (evaporator), the return air is cooled, and at the same time the moisture carried is adsorbed by the adsorption material on the surface of the second heat exchanger 6 inside, so that the return air is cooled and dehumidified. Then it passes through the second filter screen 4 for purification, and then driven by the second fan 22, it reaches the second outdoor air outlet 12 and is discharged to the outside, completing one exhaust air process;

[0092] Refrigerant circuit: The exhaust port of the compressor 7 delivers the high-temperature and high-pressure refrigerant. First, it passes through the four-way valve 8 (in the OFF state at this time) and reaches the diverter 10-1, and then is diverted to each humidity-adjusting indoor unit (the flow rate of each indoor unit is determined by the electronic expansion valves 9-1, 9-2, and 9-3 respectively). The refrigerant reaches the first heat exchanger 5 of each humidity-adjusting indoor unit, transfers heat to the fresh air, and the refrigerant becomes a low-temperature and high-pressure two-phase refrigerant. Then it flows to the electronic expansion valve 9, is throttled and depressurized to become a low-temperature and low-pressure liquid refrigerant, and then flows to the second heat exchanger 6 of each humidity-adjusting indoor unit, absorbs the heat of the air outside the pipe and becomes a low-temperature and low-pressure gaseous refrigerant. Then it converges at the diverter 10-2, and then flows to the E pipe of the four-way valve 8, and then returns to the suction port of the compressor 7 through the S pipe of the four-way valve 8, thus completing one refrigerant cycle.

[0093] When the state change condition is satisfied, referring to Figure 2 and Figure 7 , the four-way valve 8 changes its direction, the first heat exchanger 5 is used as an evaporator, and the second heat exchanger 6 is used as a condenser; the first fan 21 rotates in reverse and is used as an exhaust fan; the second fan 22 rotates forward and is used as a supply fan.

[0094] Second state:

[0095] Second air duct (fresh air duct): Fresh air enters from the second outdoor air outlet 12. Driven by the second fan 22, it first passes through the second filter screen 4 for purification, and then passes through the second heat exchanger 6 (condenser). The fresh air is heated and its temperature rises. At the same time, the moisture in the adsorption material on the surface of the second heat exchanger 6 is regenerated and mixed into the fresh air, increasing the humidity of the fresh air. Then it reaches the second indoor air outlet 14 and is sent into the room, completing one humidification process of the fresh air;

[0096] First air duct (exhaust air duct): Indoor return air enters from the first indoor air outlet 13, first passes through the first heat exchanger 5 (evaporator), the return air is cooled, and at the same time the moisture carried is adsorbed by the adsorption material on the surface of the first heat exchanger 5 inside, so the return air is cooled and dehumidified. Then it passes through the first filter screen 3 for purification, and then driven by the first fan 21, it reaches the first outdoor air outlet 11 and is exhausted to the outside, completing one exhaust process;

[0097] Refrigerant circuit: The exhaust port of the compressor 7 delivers high-temperature and high-pressure refrigerant. First, it passes through the four-way valve 8 (which is in the ON state at this time), and then flows from the flow divider 10-2 to each humidity-adjusting indoor unit (the flow rate of each indoor unit is determined by the electronic expansion valves 9-1, 9-2, and 9-3 respectively). The refrigerant reaches the second heat exchanger 6 of each humidity-adjusting indoor unit, transfers heat to the fresh air, and the refrigerant becomes a low-temperature and high-pressure two-phase refrigerant. Then it flows to the electronic expansion valve 9, is throttled and depressurized to become a low-temperature and low-pressure liquid refrigerant, and then flows to the first heat exchanger 5 of each humidity-adjusting indoor unit, absorbs the heat of the air outside the pipe and becomes a low-temperature and low-pressure gaseous refrigerant. Then it converges at the flow divider 10-1 and flows together to the C pipe of the four-way valve 8, and then returns to the compressor 7 through the S pipe of the four-way valve 8, thus completing one refrigerant cycle.

[0098] In this way, the humidification process continuously cycles between the first state and the second state.

[0099] In some embodiments of the present application, the unit has a function of automatically detecting whether the startup state is correct.

[0100] Specifically, temperature and humidity sensors are respectively provided at the first outdoor air outlet 11, the second outdoor air outlet 12, the first indoor air outlet 13, and the second indoor air outlet 14 to detect the temperature and humidity at the corresponding air outlets. For example, referring to Figures 1 to 3 , the temperature T1 and humidity H1 of the air at the first outdoor air outlet 11 can be obtained through the temperature and humidity sensor 200-1, the temperature T2 and humidity H2 of the air at the second outdoor air outlet 12 can be obtained through the temperature and humidity sensor 200-2, the temperature T3 and humidity H3 of the air at the first indoor air outlet 13 can be obtained through the temperature and humidity sensor 200-3, and the temperature T4 and humidity H4 of the air at the second indoor air outlet 14 can be obtained through the temperature and humidity sensor 200-4.

[0101] After startup, enter the dehumidification mode, and the four-way valve starts in the default OFF state;

[0102] Judge whether T4 < T2 - β is satisfied. If so, it means that the state of the second fan is correct and continue to run; if not, it means that the state of the second fan is incorrect, and control the second fan to change the rotation direction;

[0103] At the same time, judge whether T3 < T1 - α is satisfied. If so, it means that the state of the first fan is correct and continue to run; if not, it means that the state of the first fan is incorrect, and control the first fan to change the rotation direction.

[0104] In the above steps, when the four-way valve 8 is in the OFF state, the first heat exchanger 5 serves as a condenser, and the second heat exchanger 6 serves as an evaporator; the second air duct is a fresh air duct, and fresh air enters the second air duct from the second outdoor air outlet 12, and after being cooled by the evaporator, it flows to the second indoor air outlet 14. Therefore, the temperature T4 at the second indoor air outlet 14 should be lower than the temperature T2 at the second outdoor air outlet 12;

[0105] The first air duct is an exhaust air duct, and indoor return air enters the first air duct from the first indoor air outlet 13, and after being heated by the condenser, it flows to the first indoor air outlet 11. Therefore, the temperature T3 at the first indoor air outlet 13 should be lower than the temperature T1 at the first outdoor air outlet 11.

[0106] Similarly, after starting up, when entering the humidification mode, the four-way valve is default to start in the OFF state;

[0107] Judge whether T3 > T1 + α0 is satisfied. If so, it means that the state of the first fan is correct and continue to run; if not, it means that the state of the first fan is incorrect, and control the first fan to change its rotation direction;

[0108] At the same time, judge whether T4 > T2 + β0 is satisfied. If so, it means that the state of the second fan is correct and continue to run; if not, it means that the state of the second fan is incorrect, and control the second fan to change its rotation direction.

[0109] It should be noted that the four-way valve can also be default to start in the ON state, or the four-way valve is default to start in one of the OFF and ON states in the dehumidification mode, and is default to start in the other state of OFF and ON in the humidification mode;

[0110] The above α, β, α0, and β0 are all preset constants.

[0111] In some embodiments of the present application, the frequency Fx of the compressor can be calculated according to the following formula:

[0112]

[0113] Wherein, doa represents the moisture content of outdoor fresh air, ds represents the indoor set moisture content, Toa represents the outdoor fresh air temperature, Ts represents the indoor set temperature, and A and B are constants.

[0114] doa can be calculated according to the detected values of the temperature and humidity of outdoor fresh air.

[0115] In the present application, the frequency Fx of the compressor is correlated with the temperature and humidity outdoors and the temperature and humidity set indoors. In this way, the frequency Fx of the compressor can always exactly meet the requirements of dehumidification / humidification without causing waste of energy.

[0116] After startup, the compressor can start at the preset initial frequency F0; then, based on the detection data of the temperature and humidity sensor and the above formula, calculate the frequency of the compressor, and control the frequency Fx of the compressor to execute according to the formula after commutation (the next cycle).

[0117] In some embodiments of the present application, the compressor may stop due to problems such as temperature rise, overcurrent, or out-of-step faults, while the fan will continue to operate; after the fault is cleared, the compressor will automatically restart, and at this time, there may be a problem that the cumulative time of the four-way valve and the fan is different.

[0118] To address this issue, the unit of the present application has the function of automatic adjustment control:

[0119] Refer to Figure 8 During the dehumidification process, the compressor stops due to a fault and restarts after the fault is automatically cleared. The four-way valve works in the default state OFF.

[0120] Judge whether T4 < T2 - β1 is satisfied; if it is satisfied, it means that the state of the four-way valve is correct and continue to operate; if it is not satisfied, it means that the state of the four-way valve is incorrect and the four-way valve needs to be controlled to commutate.

[0121] The four-way valve starts with OFF. The first heat exchanger in the first air duct is the condenser, and the second heat exchanger in the second air duct is the evaporator; during dehumidification, the fresh air needs to be cooled. Therefore, if the second fan rotates forward and the second air duct is used as the air supply duct, the state of the fan exactly matches the state of the four-way valve.

[0122] Therefore, judge whether T4 < T2 - β1 in the second air duct is satisfied. If it is satisfied, it means that the second fan rotates forward and the fan state matches the four-way valve state; if it is not satisfied, it means that the second fan rotates in the reverse state and does not match the four-way valve state, and the four-way valve needs to commutate.

[0123] It should be noted that it can also be judged whether T3 < T1 - β3 in the first air duct is satisfied. If it is not satisfied, it means that the first fan rotates forward and does not match the four-way valve state, and the four-way valve needs to commutate.

[0124] Similarly, in the humidification mode, the compressor stops due to a fault and restarts after the fault is automatically cleared. The four-way valve works in the default state OFF.

[0125] Judge whether T3 > T1 + β4 is satisfied; if it is satisfied, it means that the state of the four-way valve is correct and continue to operate; if it is not satisfied, it means that the state of the four-way valve is incorrect and the four-way valve needs to be controlled to commutate.

[0126] The four-way valve starts in the OFF state. The first heat exchanger in the first air duct serves as the condenser, and the second heat exchanger in the second air duct serves as the evaporator. When humidifying, the fresh air needs to be heated. Therefore, if the first fan rotates forward, and the first air duct is used as the supply air duct, then the state of the fan exactly matches the state of the four-way valve.

[0127] Therefore, it is judged whether T3 > T1 + β4 in the first air duct. If it is satisfied, it indicates that the first fan rotates forward and the fan state matches the four-way valve state. If it is not satisfied, it indicates that the first fan rotates in the reverse state, which matches the four-way valve state, and the four-way valve needs to change its direction.

[0128] It should be noted that it can also be judged whether T4 > T2 + β2 in the second air duct is satisfied. If it is not satisfied, it indicates that the second fan rotates forward, which does not match the state of the four-way valve, and the four-way valve needs to change its direction.

[0129] β1, β2, β3, and β4 are preset constants.

[0130] In the above embodiments, when the compressor stops due to a fault and then the fault is automatically cleared, the compressor can be restarted again after receiving the direction-changing instruction. This can ensure that the cumulative time of the four-way valve and the fan in the new cycle is the same.

[0131] Exemplarily, the unit operates in a fixed cycle in each state. If the compressor is restarted after changing the direction, it can ensure that the cumulative time of the four-way valve and the fan in the upcoming cycle is the same.

[0132] In some embodiments of the present application, the conversion (direction change) between the first state and the second state can be controlled according to the change rate of the moisture content of the supply air.

[0133] According to the temperature T and humidity H detected by the temperature and humidity sensor, the moisture content d of the air at the corresponding air outlet can be obtained. Then, it is judged whether a direction change is needed according to the change rate of the moisture content of the supply air.

[0134] Specifically, referring to Figure 9 , in the dehumidification mode, the direction change control can be carried out according to the following steps:

[0135] S1. Determine the state of the unit: If the four-way valve is in the OFF state, enter S2; if the four-way valve is in the ON state, enter S4;

[0136] That is, it is necessary to judge whether the current unit is in the first state or the second state. The state can be judged according to the state of the four-way valve 8: when the four-way valve 8 is in the OFF state, it is judged that the unit is in the first state, and when the four-way valve 8 is in the ON state, it is judged that the unit is in the second state.

[0137] When the four-way valve 8 is in the OFF state, the first heat exchanger 5 functions as a condenser, and the second heat exchanger 6 functions as an evaporator; when the four-way valve 8 is in the ON state, the first heat exchanger 5 functions as an evaporator, and the second heat exchanger 6 functions as a condenser.

[0138] S2. Calculate the change rate of the moisture content of the air supplied by each humidity-adjusting indoor unit respectively Judge the average value of the change rates of the moisture content of the air supplied by m indoor units Whether it satisfies θ is a preset constant. If it is satisfied, go to S3; if it is not satisfied, continue to run;

[0139] In this step, when the four-way valve is OFF, it means that the second air duct is the fresh air duct, the second outdoor air outlet 12 is the inlet of fresh air, and the second indoor air outlet 14 is the outlet of fresh air; at this time, the change rate of the moisture content of the air supply is the change rate of the moisture content of the air at the second indoor air outlet 14

[0140] Among them, d14 i-1 represents the moisture content of the air supply at the (i - 1)-th moment; d14 i represents the moisture content of the air supply at the i-th moment; represents the time period, such as 60 s or 100 s;

[0141] S3. Control the four-way valve to change direction. The fan starts to prepare for changing direction. After the four-way valve changes direction for 30 s, the fan completes the direction change, and then enters S4;

[0142] S4. Calculate the change rate of the moisture content of the air supplied by each indoor unit Judge the average value of the change rates of the moisture content of the air supplied by m indoor units Whether it satisfies θ is a preset constant. If it is satisfied, go to S5; if it is not satisfied, continue to run;

[0143] In this step, since the four-way valve has changed direction and the first fan and the second fan have changed direction, the first air duct is used as the fresh air duct, the first outdoor air outlet 11 is the fresh air inlet, and the first indoor air outlet 13 is the fresh air outlet; at this time, the change rate of the moisture content of the air supply is the change rate of the moisture content of the air at the first indoor air outlet 13

[0144] S5. Control the four-way valve to change direction. The fan starts to prepare for changing direction. After the four-way valve changes direction for 30 s, the fan completes the direction change, and then enters S2.

[0145] Similarly, referring to Figure 10 , in the humidification mode, the reverse control can be carried out according to the following steps:

[0146] S11. Determine the state of the unit: If the four-way valve is in the OFF state, enter S21; if the four-way valve is in the ON state, enter S41;

[0147] Among them, when the four-way valve 8 is in the OFF state, the first heat exchanger 5 is used as a condenser, and the second heat exchanger 6 is used as an evaporator; when the four-way valve 8 is in the ON state, the first heat exchanger 5 is used as an evaporator, and the second heat exchanger 6 is used as a condenser.

[0148] S21. Calculate the change rate of the moisture content of the air supply of each humidity-adjusting indoor unit Judge the average value of the change rates of the moisture content of the air supply of m indoor units Whether it satisfies θ is a preset constant. If it is satisfied, enter S31; if it is not satisfied, continue to run;

[0149] In this step, when the four-way valve is OFF, it means that the first air duct is the fresh air duct, the first outdoor air outlet 11 is the inlet of the fresh air, and the first indoor air outlet 13 is the outlet of the fresh air; at this time, the change rate of the moisture content of the air supply is the change rate of the moisture content of the air at the first indoor air outlet 13

[0150] d13 i+1 represents the moisture content of the air supply at the (i + 1)-th moment; d13 i represents the moisture content of the air supply at the i-th moment.

[0151] S31. Control the four-way valve to change direction, the fan starts to prepare for changing direction, and after the four-way valve changes direction for 30 s, the fan completes the change of direction, and then enters S41;

[0152] S41. Calculate the change rate of the moisture content of the air supply of each indoor unit Judge the average value of the change rates of the moisture content of the air supply of m indoor units Whether it satisfies θ is a preset constant. If it is satisfied, enter S51; if it is not satisfied, continue to run;

[0153] In this step, since the four-way valve has changed direction and the first fan and the second fan have changed direction, the second air duct is used as the fresh air duct, the second outdoor air outlet 12 is the fresh air inlet, and the second indoor air outlet 14 is the fresh air outlet; at this time, the change rate of the moisture content of the air supply is the change rate of the moisture content of the air at the second indoor air outlet 14

[0154] S51. Control the four-way valve to change direction, the fan starts to prepare for changing direction, and after the four-way valve changes direction for 30 s, the fan completes the change of direction, and then enters S21.

[0155] It should be noted that in other embodiments, the average value of the change rate of the moisture content in the supply air can also be replaced with the maximum value of the change rate of the moisture content in the supply air or replaced with the minimum value of the change rate of the moisture content in the supply air or replaced with the maximum value of the change rate of the moisture content in the supply air and the minimum value of the average value.

[0156] In the present application, by using the change rate of the moisture content in the supply air as the basis for commutation control, it can be directly related to the adsorption effect of the adsorption material. When the change rate of the moisture content in the supply air is small, it indicates that the adsorption or regeneration effect of the current adsorption material is weakened, and it is more suitable to change the air duct so that the adsorption material of another heat exchanger comes into play.

[0157] The first concept of the present application is to realize the switching between the fresh air duct and the return air duct by the forward and reverse rotation of the fan, without a wind valve switching device, which simplifies the product structure, reduces the cost, and also makes the product more compact and saves the occupied space.

[0158] The second concept of the present application is to realize the switching between the fresh air duct and the return air duct by the forward and reverse rotation of the fan, without a wind valve switching device. The reduction of components results in a small internal resistance of the unit, improves the working efficiency of the unit, and reduces the energy consumption.

[0159] The third concept of the present application is to realize the switching between the fresh air duct and the return air duct by the forward and reverse rotation of the fan, and to realize humidification or dehumidification by coating an adsorption material on the heat exchanger, making the product structure more compact.

[0160] The fourth concept of the present application is to judge whether the state of the fan after startup is correct by comparing the temperatures at the two air outlets of the air duct, and has the function of automatically detecting the state of the fan after startup.

[0161] The fifth concept of the present application is to judge whether the states of the fan and the four-way valve match after the compressor fails and restarts by comparing the temperatures at the two air outlets of the air duct, and has the function of automatically detecting whether the states of the four-way valve and the fan match after the compressor fails and restarts.

[0162] The sixth concept of the present application is to control the frequency of the compressor according to the temperature and humidity of the outdoor fresh air and the set temperature and humidity indoors, so that the frequency Fx of the compressor can always exactly meet the requirements of dehumidification / humidification without causing waste of energy.

[0163] The seventh concept of the present application is to use the change rate of the moisture content in the supply air as the basis for commutation control, which can be directly related to the adsorption effect of the adsorption material, making the commutation time more reasonable and ensuring the dehumidification / humidification efficiency of the unit.

[0164] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present application.

[0165] For the sake of explanation, the above description has been made in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. According to the above teachings, various modifications and variations can be obtained. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, so that those skilled in the art can better use the embodiments and various different variations of the embodiments suitable for specific use considerations.

Claims

1. A fresh air humidity-adjustable multi-connected air conditioner, characterized in that Including: m humidity-adjusting indoor units, where m≥2; The humidity-adjusting indoor unit includes: A housing, on which there are a first outdoor air outlet, a first indoor air outlet, a second outdoor air outlet, and a second indoor air outlet. Among them, a first air duct is formed by connecting the first outdoor air outlet and the first indoor air outlet, and a second air duct is formed by connecting the second outdoor air outlet and the second indoor air outlet; A first fan and a second fan, where the first fan is arranged in the first air duct, and the second fan is arranged in the second air duct; A first heat exchanger and a second heat exchanger, both of which are coated with an adsorption material. The first heat exchanger is arranged in the first air duct, and the second heat exchanger is arranged in the second air duct; The humidity-adjusting indoor unit can achieve the transformation between two states: In one state, the first fan is used as an exhaust fan, so that the return air is exhausted outdoors through the first air duct. At this time, the first air duct is the exhaust air duct; the second fan is used as a supply fan, so that the fresh air is sent indoors through the second air duct. At this time, the second air duct is the fresh air duct; When changing from one state to another state, the first fan changes its rotation direction and is used as a supply fan, so that the fresh air flows indoors through the first air duct. At this time, the first air duct is the fresh air duct; the second fan changes its rotation direction and is used as an exhaust fan, so that the return air flows outdoors through the second air duct. At this time, the second air duct is the exhaust air duct; Among them, in each humidity-adjusting indoor unit, the first heat exchanger and the second heat exchanger are connected in series to form a heat exchange branch; The fresh air humidity-adjusting multi-connected air conditioner further includes: a compressor and a four-way valve; the exhaust port of the compressor is connected to the D pipe of the four-way valve, and m heat exchange branches are connected in parallel between the C pipe and the E pipe of the four-way valve, and the suction port of the compressor is connected to the S pipe of the four-way valve; It also includes: a controller, used for: After starting up and running in the dehumidification mode, Judging whether the temperature T4 at the second indoor air outlet and the temperature T2 at the second outdoor air outlet satisfy: T4<T2-β. If satisfied, continue; if not satisfied, change the rotation direction of the second fan; Judging whether the temperature T3 at the first indoor air outlet and the temperature T1 at the first outdoor air outlet satisfy: T3<T1-α; if satisfied, continue; if not satisfied, change the rotation direction of the first fan; After starting up and running in the humidification mode, Judging whether the temperature T3 at the first indoor air outlet and the temperature T1 at the first outdoor air outlet satisfy: T3>T1+α0; if satisfied, continue; if not satisfied, change the rotation direction of the first fan; Judging whether the temperature T4 at the second indoor air outlet and the temperature T2 at the second outdoor air outlet satisfy: T4>T2+β0; if satisfied, continue; if not satisfied, change the rotation direction of the second fan; Among them, α, β, α0, and β0 are preset values.

2. The fresh air humidity-adjusting multi-connected unit according to claim 1, characterized in that, The controller, used for: Calculating the change rate of the moisture content ⊿d of the air supply of each humidity-adjusting indoor unit according to the indoor and outdoor temperature and humidity respectively; judging whether the average value ⊿dp of the change rates of the moisture content of the air supply of m humidity-adjusting indoor units satisfies ⊿dp≤θ. If satisfied, the four-way valve changes its direction; if not satisfied, continue to run; Among them, θ is a preset constant.

3. The fresh air humidity-adjusting multi-connected unit according to claim 1, characterized in that, The controller, used for: Calculate the change rate of moisture content in the air supply of each humidity-adjusting indoor unit, Δd, based on the indoor and outdoor temperature and humidity; determine the maximum value MAXΔd, or the minimum value MINΔd, or the average value of MAXΔd and MINΔd among the m humidity-adjusting indoor units, and check if it is less than a preset value. If so, reverse the four-way valve; if not, continue to operate.

4. The fresh air humidity-adjusting multi-connected unit according to claim 2 or 3, characterized in that, In the dehumidification mode, ; In the humidification mode, ; where, d i-1 represents the moisture content of the air at the air outlet of the fresh air duct at the (i - 1)-th moment; d i represents the moisture content of the air at the air outlet of the fresh air duct at the i-th moment; d i+1 represents the moisture content of the air at the air outlet of the fresh air duct at the (i + 1)-th moment; Δt represents the preset time period.

5. The fresh air humidity-adjusting multi-connected unit according to claim 1, wherein A controller for controlling the frequency Fx of the compressor according to the following formula: where doa is the moisture content of outdoor fresh air, ds is the indoor set moisture content, Toa is the outdoor fresh air temperature, Ts is the indoor set temperature, and A and B are constants.

6. The fresh air humidity-adjusting multi-connected air conditioner according to claim 5, characterized in that, The controller is further configured to: After startup, control the compressor to start at the initial frequency F0; in the next cycle of state change, control the frequency Fx of the compressor to be executed according to the formula.

7. The fresh air humidity-adjusting multi-connected air conditioner according to claim 1, wherein A controller for: During the dehumidification mode, after the compressor restarts, determine whether the temperature T4 at the second indoor air outlet and the temperature T2 at the second outdoor air outlet satisfy: T4 < T2 - β1, and / or determine whether the temperature T3 at the first indoor air outlet and the temperature T1 at the first outdoor air outlet satisfy T3 < T1 - β3; if satisfied, continue; if not, control the four-way valve to reverse; During the humidification mode, after the compressor restarts, determine whether the temperature T2 at the second outdoor air outlet and the temperature T4 at the second indoor air outlet satisfy: T4 > T2 + β2, and / or determine whether the temperature T3 at the first indoor air outlet and the temperature T1 at the first outdoor air outlet satisfy T3 > T1 + β4; if satisfied, continue; if not, control the four-way valve to reverse; where β1, β2, β3, and β4 are preset values.

8. The fresh air humidity-adjusting multi-connected air conditioner according to claim 1, wherein Temperature and humidity sensors are respectively provided at the first outdoor air outlet, the first indoor air outlet, the second outdoor air outlet, and the second indoor air outlet.

9. The fresh air humidity-adjusting multi-connected air conditioner according to claim 1, wherein m heat exchange branches are respectively connected to the C pipe and the E pipe of the four-way valve through distributors.

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