Air treatment system

Abstract

The invention discloses an air treatment system, and belongs to the technical field of air treatment. The air treatment system includes: a compressor; an outdoor heat exchanger; the indoor heat exchanger comprises an indoor unit heat exchanger and a fresh air heat exchanger, the indoor unit heat exchanger is used for executing heat exchange between indoor air and a refrigerant, and the fresh air heat exchanger is used for executing heat exchange between outdoor fresh air and the refrigerant; the air conditioner electronic expansion valve and the indoor unit heat exchanger are connected in series to form an indoor unit branch, the fresh air electronic expansion valve and the fresh air heat exchanger are connected in series to form a fresh air branch, and the fresh air branch and the indoor unit branch are connected in parallel. Wherein the compressor, the outdoor heat exchanger and the four-way valve are arranged in the outdoor unit; the indoor unit heat exchanger is arranged in the indoor unit; the fresh air heat exchanger is arranged in the fresh air machine. According to the air treatment system, the problems of complex system design and high cost caused by adopting two sets of refrigerating systems are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air treatment, in particular to an air treatment system. BACKGROUND

[0002] With the improvement of people's requirements for indoor air quality, it is no longer just to meet the requirements of indoor temperature, therefore, the situation of simultaneous use of air conditioners and fresh air machines is increasing. The air conditioner is mainly used for adjusting the temperature in the room, and the fresh air machine can adjust the humidity of the air while sending outdoor fresh air into the room.

[0003] The air conditioner and the fresh air machine each have a set of refrigeration system, and the two sets of refrigeration system bring the problem of high cost. SUMMARY

[0004] The present application provides an air treatment system, which adopts one refrigeration system to realize temperature and humidity control, avoiding the problems of system design complexity and high cost caused by adopting two sets of refrigeration system.

[0005] In one aspect of the present application, an air treatment system comprises: a compressor configured to compress refrigerant; an outdoor heat exchanger configured to perform heat exchange between outdoor air and the refrigerant; an indoor heat exchanger comprising an indoor unit heat exchanger and a fresh air heat exchanger, the indoor unit heat exchanger being configured to perform heat exchange between indoor air and the refrigerant, and the fresh air heat exchanger being configured to perform heat exchange between outdoor fresh air and the refrigerant; a four-way valve configured to guide the refrigerant compressed in the compressor to the outdoor heat exchanger or the indoor heat exchanger according to whether the air treatment system is in a cooling mode or a heating mode; an air conditioner electronic expansion valve connected in series between the outdoor heat exchanger and the indoor unit heat exchanger; a fresh air electronic expansion valve connected in series between the outdoor heat exchanger and the fresh air heat exchanger; the air conditioner electronic expansion valve and the indoor unit heat exchanger being connected in series to form an indoor unit branch, the fresh air electronic expansion valve and the fresh air heat exchanger being connected in series to form a fresh air branch, and the fresh air branch and the indoor unit branch being connected in parallel.

[0006] The compressor, the outdoor heat exchanger and the four-way valve are arranged in an outdoor unit; the indoor unit heat exchanger is arranged in an indoor unit; the fresh air heat exchanger is arranged in a fresh air unit; the air conditioner electronic expansion valve and the fresh air electronic expansion valve are arranged in the outdoor unit; or the air conditioner electronic expansion valve is arranged in the indoor unit, and the fresh air electronic expansion valve is arranged in the fresh air unit.

[0007] In some embodiments, the air treatment system further comprises a controller configured to: calculate the required evaporation pressure of the indoor unit according to the temperature of the indoor unit heat exchanger; calculate the required temperature of the fresh air heat exchanger according to the dew point temperature of the fresh air; obtain the required evaporation pressure of the fresh air unit according to the required temperature of the fresh air heat exchanger; and control the frequency of the compressor according to the required evaporation pressure of the indoor unit and the required evaporation pressure of the fresh air unit.

[0008] In some embodiments, the target evaporating pressure is calculated according to the required evaporating pressure of the indoor unit and the required evaporating pressure of the fresh air unit; and the frequency of the compressor is controlled according to the target evaporating pressure.

[0009] wherein the target evaporating pressure P0 = sensible heat ratio * required evaporating pressure of the indoor unit + (1-sensible heat ratio) * required evaporating pressure of the fresh air unit.

[0010] In some embodiments, the controller is configured to control the opening degree of the air conditioning electronic expansion valve to be [(required evaporating pressure of the indoor unit-target evaporating pressure) / target evaporating pressure] * initial opening degree.

[0011] The opening degree of the fresh air electronic expansion valve is controlled to be [(target evaporating pressure-required evaporating pressure of the fresh air unit) / target evaporating pressure] * initial opening degree.

[0012] In some embodiments, the indoor unit has a plurality of indoor units; each indoor unit comprises an indoor electronic expansion valve connected in series on an indoor unit branch and connected between an indoor unit heat exchanger and the air conditioning electronic expansion valve.

[0013] The controller is configured to perform a sensible heat control step of determining whether the difference between the current evaporating pressure of the indoor unit and the required evaporating pressure of the indoor unit is less than the lower limit value of a preset range, and if so, decreasing the opening degree of the indoor electronic expansion valve; and determining whether the difference between the current evaporating pressure of the indoor unit and the required evaporating pressure of the indoor unit is greater than the upper limit value of the preset range, and if so, increasing the opening degree of the indoor electronic expansion valve.

[0014] In some embodiments, the fresh air unit comprises a fresh air flow valve connected in series on a fresh air branch for adjusting the refrigerant flow of the fresh air branch.

[0015] The controller is configured to perform a latent heat control step of determining whether the difference between the current evaporating pressure of the fresh air unit and the required evaporating pressure of the fresh air unit is less than the lower limit value of a preset range, and if so, decreasing the opening degree of the fresh air flow valve.

[0016] The controller is configured to perform a latent heat control step of determining whether the difference between the current evaporating pressure of the fresh air unit and the required evaporating pressure of the fresh air unit is greater than the upper limit value of a preset range, and if so, increasing the opening degree of the fresh air flow valve.

[0017] In some embodiments, the controller is further configured to perform a sensible heat control step of determining whether the temperature of the indoor unit heat exchanger is not less than the sum of the return air dew point temperature and a preset temperature value, and if not, increasing the opening degree of the air conditioning electronic expansion valve.

[0018] The controller is configured to perform a latent heat control step of determining whether the temperature of the fresh air heat exchanger is not greater than the difference between the fresh air dew point temperature and a preset temperature value, and if not, increasing the frequency of the compressor; and if so, maintaining the current state of the compressor.

[0019] In some embodiments, the indoor unit comprises: an indoor unit flow valve connected in series on the indoor unit branch, for adjusting the refrigerant flow of the indoor unit branch;

[0020] The fresh air unit comprises: a fresh air flow valve connected in series on the fresh air branch, for adjusting the refrigerant flow of the fresh air branch;

[0021] The controller is further configured to: in the sensible heat control step, if the temperature of the indoor heat exchanger is not less than the sum of the return air dew point temperature and the preset temperature value, determine whether the indoor temperature is not greater than the difference between the set temperature and the preset temperature value; if yes, decrease the opening degree of the indoor unit flow valve; if no, increase the opening degree of the indoor unit flow valve;

[0022] In the latent heat control step, it is determined whether the indoor humidity is not greater than the difference between the set humidity and the preset humidity value, if yes, the opening degree of the fresh air flow valve is decreased; if no, the opening degree of the fresh air flow valve is increased.

[0023] In some embodiments, the controller is configured to: determine whether the indoor temperature is not greater than the difference between the set temperature and the preset temperature value, and whether the indoor humidity is not greater than the difference between the set humidity and the preset humidity value; if no, the compressor maintains the current state; if yes, the compressor is stopped.

[0024] In another aspect of the present application, an air handling system comprises: a compressor for compressing refrigerant; an outdoor heat exchanger for performing heat exchange between outdoor air and refrigerant; an indoor heat exchanger comprising an indoor unit heat exchanger for performing heat exchange between indoor air and refrigerant, and a fresh air heat exchanger for performing heat exchange between outdoor fresh air and refrigerant; a four-way valve for guiding the refrigerant compressed in the compressor to the outdoor heat exchanger or the indoor heat exchanger according to whether the air handling system is in a cooling mode or a heating mode; an air conditioning electronic expansion valve connected in series between the outdoor heat exchanger and the indoor unit heat exchanger; a fresh air electronic expansion valve connected in series between the outdoor heat exchanger and the fresh air heat exchanger; a subcooling heat exchanger connected in series between the outdoor heat exchanger and the fresh air electronic expansion valve; the air conditioning electronic expansion valve and the indoor unit heat exchanger form an indoor unit branch, the fresh air electronic expansion valve, the subcooling heat exchanger and the fresh air heat exchanger form a fresh air branch, and the fresh air branch and the indoor unit branch are connected in parallel;

[0025] The compressor, the outdoor heat exchanger and the four-way valve are arranged in an outdoor unit; the indoor unit heat exchanger is arranged in an indoor unit; the fresh air heat exchanger is arranged in a fresh air unit; the air conditioning electronic expansion valve, the fresh air electronic expansion valve and the subcooling heat exchanger are arranged in the outdoor unit; or the air conditioning electronic expansion valve is arranged in the indoor unit, and the fresh air electronic expansion valve and the subcooling heat exchanger are arranged in the fresh air unit. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1A schematic diagram of an air handling system according to some embodiments is shown;

[0027] Figure 2 A schematic diagram of an outdoor unit of an air handling system according to some embodiments is shown;

[0028] Figure 3 A schematic diagram of an indoor unit of an air handling system according to some embodiments is shown;

[0029] Figure 4 A schematic diagram of a fresh air unit of an air handling system according to some embodiments is shown;

[0030] Figure 5 A schematic diagram of a refrigeration system of an air handling system according to some embodiments is shown;

[0031] Figure 6 A control flow of an air handling system according to some embodiments is shown Figure 1 ;

[0032] Figure 7 A control flow of an air handling system according to some embodiments is shown Figure 2 ;

[0033] Figure 8 A schematic diagram of an air handling system in an application scenario according to some other embodiments is shown;

[0034] Figure 9 A schematic diagram of an air handling system according to some other embodiments is shown;

[0035] Figure 10 A schematic diagram of a refrigeration system of an air handling system according to some other embodiments is shown;

[0036] Figure 11 A schematic diagram of a fresh air unit and a solar system combined in an air handling system according to some further embodiments is shown;

[0037] Figure 12 A schematic diagram of a refrigeration system of an air handling system according to some further embodiments is shown;

[0038] Figure 13 A schematic diagram of an air handling system in an application scenario according to some further embodiments is shown;

[0039] Figure 14 A schematic diagram of a refrigeration system of an air handling system according to some further embodiments is shown Figure 1 ;

[0040] Figure 15 A schematic diagram of a refrigeration system of an air handling system according to some further embodiments is shown Figure 2 ;

[0041] Figure 16 schematic diagram of a refrigeration system of an air handling system according to still further embodiments is shown Figure 3 ;

[0042] Figure 17 schematic diagram of a refrigeration system of an air handling system according to still further embodiments is shown Figure 4 . DETAILED DESCRIPTION

[0043] For the purpose of clarity and a thorough understanding of the present application, the exemplary embodiments of the present application will be described in detail with reference to the accompanying drawings. It is apparent that the following exemplary embodiments are only a part of the embodiments of the present application, and are not all of the embodiments.

[0044] In the description of the present application, it needs to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0045] The terms "first", "second", are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "a plurality of" means two or more.

[0046] In the description of the present application, it needs to be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0047] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0048] With reference to Figure 1 , the air handling system 100 of the embodiments of the present application includes an air conditioner having an outdoor unit 110 and an indoor unit 120, and a fresh air machine 130.

[0049] The outdoor unit 110 and the indoor unit 120 in the air conditioner can be a two-body structure, or the outdoor unit 110 and the indoor unit 120 can be installed in a one-body unit in a housing.

[0050] In this application, the outdoor unit 110 and the indoor unit 120 in a two-body structure are taken as an example for introduction:

[0051] The outdoor unit 110 is located in an outdoor space, and is configured to perform heat exchange between refrigerant and outdoor air.

[0052] In combination with Figure 1 and Figure 2 , the outdoor unit 110 includes an outdoor unit housing 1101, which forms the appearance of the outdoor unit 110.

[0053] The outdoor unit 110 includes a compressor 111 configured to suck in and compress refrigerant into a high-temperature and high-pressure state. A four-way valve 113 configured to switch a refrigerant flow path in a cooling mode and a refrigerant flow path in a heating mode. An outdoor heat exchanger 112 configured to perform heat exchange between outdoor air and refrigerant, the outdoor heat exchanger 112 condenses the refrigerant compressed by the compressor 111 in the cooling mode, and evaporates the refrigerant depressurized by the indoor unit 120 in the heating mode.

[0054] The outdoor unit 110 further includes an outdoor fan 114 configured to blow outdoor air to the outdoor heat exchanger 112.

[0055] The outdoor unit 110 includes an air conditioner electronic expansion valve 115 configured to depressurize the refrigerant. The air conditioner electronic expansion valve 115 can be provided in the outdoor unit 110 or in the indoor unit 120.

[0056] In combination with Figure 1 and Figure 3 , the indoor unit 120 is located in an indoor space, and is configured to perform heat exchange between refrigerant and indoor air.

[0057] The indoor unit 120 includes an indoor unit housing 1201, which forms the appearance of the indoor unit 120.

[0058] The indoor unit 120 includes an indoor heat exchanger 121. The indoor heat exchanger 121 is configured to perform heat exchange between refrigerant and indoor air. The indoor heat exchanger 121 evaporates low-pressure liquid refrigerant in the cooling mode, and condenses high-pressure gaseous refrigerant in the heating mode.

[0059] The indoor unit 120 further includes an indoor fan 123 configured to blow air, which has been heat-exchanged with the refrigerant by the indoor heat exchanger 121, to the indoor space.

[0060] In some embodiments, the air conditioner of the present application can be a multi-split type multi-connected unit, i.e., the indoor unit 120 has multiple indoor units to be applied in places such as shopping malls, office buildings, factories, etc. The indoor heat exchangers 121 in the multiple indoor units 120 are connected in parallel in the refrigeration system.

[0061] Referring to Figure 5 , the indoor unit 120 can include an indoor flow valve 122, which can be connected in series on the branch where the corresponding indoor heat exchanger 121 is located.

[0062] The indoor flow valve 122 can be an electronic expansion valve or a solenoid valve. By adjusting the opening degree of the indoor flow valve 122, the refrigerant flow at the indoor heat exchanger 121 of the corresponding branch can be controlled.

[0063] The compressor 111, the four-way valve 113, the outdoor heat exchanger 114, the air conditioning electronic expansion valve 115, and the indoor heat exchanger are connected by refrigerant pipelines to form a refrigeration system. It should be noted that the gas-liquid separator, oil separator, etc. in the refrigeration system are omitted in the present application to simplify the description of the present application.

[0064] In the refrigeration system, the discharge end of the compressor 111 is connected to the d pipe of the four-way valve 113, the e pipe and the c pipe of the four-way valve 113 are connected to the outdoor heat exchanger 112 and the indoor heat exchanger 121 respectively, and the s pipe of the four-way valve 113 is connected to the suction end of the compressor 111. The outdoor heat exchanger 112, the air conditioning electronic expansion valve 115, and the indoor heat exchanger 121 are connected in series.

[0065] The four-way valve 113 guides the refrigerant compressed by the compressor 111 to the outdoor heat exchanger 112 in the refrigeration mode, and guides the refrigerant compressed by the compressor 111 to the indoor heat exchanger 121 in the heating mode.

[0066] The working modes of the air conditioner will be introduced below in combination with the refrigeration system:

[0067] Refrigeration mode: The compressor 111 of the outdoor unit 110 compresses the refrigerant, and the compressed refrigerant at high temperature and high pressure continues to flow to the outdoor heat exchanger 112 through the four-way valve 113. The outdoor heat exchanger 112 condenses the refrigerant into a liquid state, and the liquid refrigerant flows to the indoor unit 120 after passing through the air conditioning electronic expansion valve 115.

[0068] After the indoor electronic expansion valve 124 of each branch depressurizes and cools the liquid refrigerant, the indoor heat exchanger 121 of the indoor unit 120 evaporates the depressurized and cooled liquid refrigerant into a gas state. The gaseous refrigerant continues to flow to the outdoor unit 110 after passing through the indoor flow valve 122.

[0069] The gaseous refrigerant returns to the compressor 111 via the four-way valve 113 of the outdoor unit 110.

[0070] In the above cooling mode, the refrigerant generated in the indoor heat exchanger 121 exchanges heat with the indoor air, so that the indoor air is cooled.

[0071] Heating mode: The compressor 111 of the outdoor unit 110 compresses the refrigerant, and the refrigerant compressed to high temperature and high pressure continues to flow to the indoor unit 120 through the four-way valve 113 and the indoor unit flow valve 122. Then, the indoor heat exchanger 121 condenses the refrigerant into a liquid state, and then flows to the indoor electronic expansion valve 124, and then to the outdoor unit 110.

[0072] The air conditioning electronic expansion valve 115 of the outdoor unit 110 depressurizes and cools the liquid refrigerant, and the outdoor heat exchanger 112 evaporates the depressurized and cooled liquid refrigerant into a gas state. The gaseous refrigerant returns to the compressor 111 via the four-way valve 113.

[0073] In the above heating mode, the refrigerant generated in the indoor heat exchanger 121 exchanges heat with the indoor air, so that the indoor air is heated.

[0074] The following briefly introduces the fresh air machine:

[0075] Referring to Figure 4 , the fresh air machine 130 is a device capable of discharging indoor dirty air and sending outdoor air into the room.

[0076] In an embodiment of the fresh air machine 130: the fresh air machine 130 includes a fresh air machine shell 1301, a heat exchange core 131, a supply air fan 132, and an exhaust air fan 133.

[0077] The fresh air machine shell 1301 forms the general appearance of the fresh air machine, and is generally in the shape of a rectangular cuboid. The fresh air machine shell 1301 is provided with a fresh air inlet OA, a supply air inlet SA, a return air inlet RA, and an exhaust air outlet EA.

[0078] The heat exchange core 131 is arranged in the shell and is used to realize heat exchange between indoor air and outdoor fresh air.

[0079] The fresh air machine shell 1301 forms a fresh air duct and an exhaust air duct therein, and the fresh air duct and the exhaust air duct are respectively communicated with the heat exchange core 131.

[0080] The fresh air duct communicates the fresh air inlet OA and the supply air inlet SA, and is used to circulate outdoor fresh air; the exhaust air duct communicates the return air inlet RA and the exhaust air outlet EA, and is used to circulate indoor air.

[0081] The supply air fan 132 is arranged in the fresh air duct corresponding to the supply air inlet SA, and is used to forcibly flow outdoor fresh air; the exhaust air fan 133 is arranged in the exhaust air duct corresponding to the exhaust air outlet EA, and is used to forcibly flow indoor air.

[0082] When the fresh air machine 130 is working, under the action of the supply air fan 132 and the exhaust air fan 133, indoor air from the return air port RA flows through the heat exchange core 131 in the exhaust air duct, outdoor fresh air from the outdoor air port OA flows through the heat exchange core 131 in the fresh air duct, and the two air flows exchange heat at the total heat exchange core 131. The indoor air after heat exchange blows to the exhaust air port EA, and the outdoor fresh air after heat exchange blows to the supply air port SA.

[0083] Exemplarily, when the fresh air machine is running in the summer cooling period, the outdoor fresh air obtains cold energy from the indoor air to reduce the temperature; and when the fresh air machine is running in the winter heating period, the outdoor fresh air obtains heat energy from the indoor air to increase the temperature.

[0084] In some application scenarios of the fresh air machine, the supply air port SA and the return air port RA are respectively connected to the indoor space through air ducts, and the exhaust air port EA and the outdoor air port OA are respectively connected to the outdoor space through air ducts.

[0085] In some application scenarios of the fresh air machine, the supply air port SA and the return air port RA are respectively connected to the indoor space through air ducts, and the exhaust air port EA and the outdoor air port OA are respectively connected to the outdoor space through air ducts.

[0086] The fresh air machine of the present application combines a refrigeration system to refrigerate and dehumidify or heat the fresh air.

[0087] The refrigeration system in the fresh air machine 130 can refer to the refrigeration system of an air conditioner, wherein the indoor heat exchanger in the refrigeration system is arranged at the air outlet side of the heat exchange core 131 in the fresh air duct. In order to distinguish the indoor heat exchanger of the air conditioner from the indoor heat exchanger of the fresh air machine, the indoor heat exchanger in the fresh air machine 130 is referred to as the fresh air heat exchanger 134, and the indoor heat exchanger in the air conditioner is referred to as the indoor heat exchanger 121 of the indoor unit.

[0088] The fresh air heat exchanger 134 can refrigerate and dehumidify the fresh air when used as an evaporator, and can heat the fresh air when used as a condenser.

[0089] In the prior art, the air conditioner and the fresh air machine 130 each have a refrigeration system, and two sets of refrigeration systems will cause high cost.

[0090] In order to solve this problem, in the air handling system of the present application, the fresh air machine 130 and the air conditioner share one set of refrigeration system to avoid the problem of high cost caused by using two sets of refrigeration systems.

[0091] In some embodiments of the present application, with reference to Figure 5The outdoor unit 110 includes a compressor 111, an outdoor heat exchanger 112, a four-way valve 113, an air conditioning electronic expansion valve 115, and a fresh air electronic expansion valve 116; the indoor unit 120 includes an indoor heat exchanger 121; the fresh air unit 130 includes a fresh air heat exchanger 134.

[0092] In the refrigeration system of the present application, the discharge end of the compressor 111 is connected to the d pipe of the four-way valve 113; one end of the outdoor heat exchanger 112 is connected to the e pipe of the four-way valve 113; the air conditioning electronic expansion valve 115 and the indoor heat exchanger 121 are connected in series to form an indoor unit branch; the fresh air electronic expansion valve 116 and the fresh air heat exchanger 134 are connected in series to form a fresh air branch.

[0093] The indoor unit branch and the fresh air branch are connected in parallel between the other end of the outdoor heat exchanger 112 and the c pipe of the four-way valve 113. The air conditioning electronic expansion valve 115 is located between the outdoor heat exchanger 112 and the indoor heat exchanger 121; the fresh air electronic expansion valve 116 is located between the outdoor heat exchanger 112 and the fresh air heat exchanger 134.

[0094] In the present application, by connecting the indoor heat exchanger 121 of the indoor unit and the fresh air heat exchanger 134 of the fresh air unit 130 in parallel between the outdoor heat exchanger 112 and the c pipe of the four-way valve 113, and by adjusting the opening degree of the air conditioning electronic expansion valve 115 to regulate the evaporation pressure of the air conditioner, and by adjusting the opening degree of the fresh air electronic expansion valve 116 to regulate the evaporation pressure of the fresh air unit, it is realized to control two evaporation pressures with one refrigeration system to create two evaporation temperatures to realize independent control of the air conditioner and the fresh air unit, avoiding the problem of complex system design and high cost caused by using two sets of refrigeration systems.

[0095] In some embodiments, an indoor unit flow valve 122 is connected in series on the indoor unit branch. The indoor unit flow valve 122 can be located between the indoor heat exchanger 121 and the c pipe of the four-way valve 113. The indoor unit flow valve 122 can be used to adjust the refrigerant flow in the indoor heat exchanger 121 to ensure proper heat exchange at the indoor heat exchanger 121.

[0096] A fresh air flow valve 135 is connected in series on the fresh air branch. The fresh air flow valve 135 can be located between the fresh air heat exchanger 134 and the c pipe of the four-way valve 113. The fresh air flow valve 135 can be used to adjust the refrigerant flow at the fresh air heat exchanger 134 to ensure proper heat exchange at the fresh air heat exchanger 134.

[0097] In some embodiments, the indoor unit 120 can include an indoor electronic expansion valve 124 connected in series on the branch where the corresponding indoor heat exchanger 121 is located. By adjusting the opening degree of the indoor electronic expansion valve 124, the pressure of the corresponding branch can be controlled. The indoor electronic expansion valve 124 can be located between the air conditioning electronic expansion valve 115 and the indoor heat exchanger 121.

[0098] Exemplarily, the indoor unit has i=4, 4 indoor heat exchanger markers are 121-1, 121-2, 121-3, 121-4 respectively. Among them, the indoor heat exchanger (121-1) branch corresponds to the indoor flow valve (122-1), the indoor electronic expansion valve (124-1); the indoor heat exchanger (121-2) branch corresponds to the indoor flow valve (122-2), the indoor electronic expansion valve (124-2); the indoor heat exchanger (121-3) branch corresponds to the indoor flow valve (122-3), the indoor electronic expansion valve (124-3); the indoor heat exchanger (121-4) branch corresponds to the indoor flow valve (122-4), the indoor electronic expansion valve (124-4).

[0099] In some embodiments, the air handling system can include a subcooling heat exchanger 117. The subcooling heat exchanger 117 is provided in the outdoor unit 110, and is connected in series on the fresh air branch between the outdoor heat exchanger 112 and the fresh air electronic expansion valve 116. When the refrigerant passes through the subcooling heat exchanger 117, heat is transferred to the outdoor air.

[0100] The provision of the subcooling heat exchanger 117 can generate sufficient subcooling degree to overcome the longer piping pressure drop between the outdoor unit 110 and the fresh air unit 130, avoiding the pipe resistance causing the liquid refrigerant to flash.

[0101] The following describes the cycle process of the refrigeration system of the present application for summer temperature and humidity control:

[0102] The high-temperature and high-pressure refrigerant is discharged from the discharge port of the compressor 111, passes through the four-way valve 113 to the outdoor heat exchanger 112 (used as a condenser), transfers heat to the outdoor air, and becomes high-temperature and low-pressure two-phase state refrigerant, which is then divided into two paths:

[0103] The first path: after passing through the air conditioning electronic expansion valve 115, the low-temperature and low-pressure liquid refrigerant is throttled and depressurized by the indoor electronic expansion valve 124 of each branch, and then flows to each indoor heat exchanger 121. The refrigerant flow rate of each indoor unit is determined by the opening degree of the indoor flow valve 122. The indoor air is cooled by heat exchange with the indoor air at the indoor heat exchanger 121, and the refrigerant absorbs the heat of the indoor air to become low-temperature and low-pressure gaseous refrigerant;

[0104] The second path: the low-temperature and low-pressure liquid refrigerant is throttled and depressurized by the fresh air electronic expansion valve 116 after transferring heat to the outdoor air at the subcooling heat exchanger 117, and then reaches the fresh air heat exchanger 134. Since the fresh air needs to be dehumidified, the evaporation temperature of this path needs to be controlled by the required dew point temperature. The refrigerant in this path exchanges heat with the fresh air, absorbs the heat of the fresh air, and becomes low-temperature and low-pressure gaseous refrigerant.

[0105] The two refrigerants are then mixed and flow to the four-way valve 113, and finally return to the compressor 111.

[0106] Hereinafter, the signal flow between the components included in the air handling system will be described.

[0107] The controller receives the detection data of the air conditioner and the fresh air machine 130, and controls the operation of the air conditioner and the fresh air machine 130 after calculation.

[0108] The memory stores programs and data related to the operation of the air handling system; the memory can be implemented by at least one of a non-volatile memory (for example, a cache, a read only memory (ROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), and a flash memory), a volatile memory (for example, a random access memory (RAM)), or a storage medium such as a hard disk drive (HDD) and a CD-ROM, but is not limited thereto.

[0109] The communication module enables communication between the controller and the air conditioner, and between the controller and the fresh air machine 130; for example, the detection information of the temperature and humidity of the air conditioner and the fresh air machine 130 can be shared to the controller through the communication module.

[0110] The communication module can be wired communication or wireless communication. The wireless communication can use at least one of fifth generation (5G) mobile communication, long term evolution (LTE), LTE-advanced (LTE-A), code division multiple access (CDMA), wideband CDMA (WCDMA), universal mobile telecommunications system (UMTS), wireless broadband (WiBro), or global system for mobile communications (GSM) as a cellular communication protocol; in addition, the wireless communication can include local communication, and the local communication can include at least one of wireless fidelity (WiFi), Bluetooth, or near field communication (NFC); the wired communication can include at least one of a universal serial bus (USB), a high definition multimedia interface (HDMI), a recommended standard 132 (RS-132), or a plain old telephone service (POTS).

[0111] The input unit can receive an input from a user, and can include a button type switch, a membrane switch, or a touch panel, etc. for receiving an operation command for the air handling system. Specifically, the input unit can receive an indoor set temperature and humidity from the user.

[0112] The return air temperature and humidity sensor can be provided at the air inlet of the indoor unit, and detects the temperature and humidity of the return air.

[0113] The outlet temperature sensor can be provided at the outlet of the indoor heat exchanger 121, and detects the temperature of the outlet of the indoor heat exchanger 121.

[0114] An indoor unit heat exchanger temperature sensor can be arranged on the indoor unit heat exchanger 121 to detect the temperature of the indoor unit heat exchanger 121.

[0115] A pressure sensor can be arranged at the inlet of the indoor unit heat exchanger 121 to detect the pressure.

[0116] A fresh air temperature and humidity sensor can be arranged at the windward side of the fresh air heat exchanger 134, i.e. in the fresh air duct between the fresh air heat exchanger 134 and the heat exchange core 131, to detect the temperature and humidity of the fresh air at the windward side of the fresh air heat exchanger 134.

[0117] A fresh air heat exchanger temperature sensor can be arranged on the fresh air heat exchanger 134 to detect the temperature of the fresh air heat exchanger 134.

[0118] The air handling system of the present application can realize independent temperature and humidity control, i.e. temperature control by the indoor unit and humidity control by the fresh air unit.

[0119] In the following, a method for the air handling system to realize independent temperature and humidity control will be described, referring to Figure 6 :

[0120] S1, calculate the required evaporation pressure P1 of the indoor unit and the required evaporation pressure P2 of the fresh air unit.

[0121] In the above step, the required evaporation pressure P1 of the indoor unit is calculated from the temperature Tfz of the indoor unit heat exchanger.

[0122] Specifically, the temperature Tfz of the indoor unit heat exchanger can be obtained from the detection value of the indoor unit heat exchanger temperature sensor. If the indoor unit is a multi-split unit, Tfz is the average temperature of all indoor unit heat exchangers. The temperature Tfz+YO of the refrigerant in the indoor unit heat exchanger can be estimated by adding a preset correction value YO to the temperature Tfz of the indoor unit heat exchanger. According to the refrigerant temperature and pressure correspondence table, the required evaporation pressure P1 of the indoor unit can be obtained.

[0123] In the above step, the required evaporation temperature P2 of the fresh air unit can be calculated from the required temperature of the fresh air heat exchanger.

[0124] Specifically, the temperature and relative humidity of the fresh air can be obtained from the fresh air temperature and humidity sensor at the windward side of the fresh air heat exchanger, and the dew point temperature TLoa of the fresh air can be calculated from the fresh air temperature and relative humidity.

[0125] Since the fresh air heat exchanger is mainly used for dehumidification, the temperature at the fresh air heat exchanger needs to be lower than the dew point temperature to ensure that water in the fresh air is removed, and thus the required temperature Ts2 of the fresh air heat exchanger is lower than (TLoa-A), where A represents a preset value, for example, A=2. Exemplarily, Ts2 can be calculated according to TLoa-A.

[0126] The required evaporation pressure P2 of the fresh air fan can be calculated according to the required temperature Ts2 of the fresh air heat exchanger. The specific calculation manner can refer to the calculation manner of Tfz to P1, which is not described herein again.

[0127] S2, controlling the frequency of the compressor according to the required evaporation pressure P1 of the indoor unit and the required evaporation pressure P2 of the fresh air fan.

[0128] The specific steps of S2 are: calculating a target evaporation pressure P0 according to the required evaporation pressure P1 of the indoor unit and the required evaporation pressure P2 of the fresh air fan; and adjusting the frequency of the compressor according to the target evaporation pressure P0.

[0129] Wherein, the target evaporation pressure P0 = α * the required evaporation pressure P1 of the indoor unit + (1-α) * the required evaporation pressure P2 of the fresh air fan. α represents a sensible heat ratio.

[0130] The sensible heat ratio α is the proportion of the sensible heat load to the total load. The sensible heat load = indoor load + fresh air sensible heat load; wherein, the indoor load = room area * load index; the fresh air sensible heat load = fresh air volume * density * (Tαa-Tset), Toa-Tset represents the difference between the fresh air temperature and the indoor set temperature.

[0131] The latent heat load = fresh air volume * density * (doa-dset), doa-dset represents the difference between the humidity of the fresh air and the humidity content of the indoor set humidity. The total load = sensible heat load + latent heat load.

[0132] In this application, the target evaporation pressure P0 is calculated according to the sensible heat ratio α, the required evaporation pressure P1 of the indoor unit, and the required evaporation pressure P2 of the fresh air fan, i.e., the target evaporation pressure P0 is calculated according to the weight of the sensible heat load and the latent heat load, which can make the calculation of the target evaporation pressure more accurate and reasonable.

[0133] In the above steps, the target frequency of the compressor obtained according to the target evaporation pressure P0 is applicable to the calculation manner of the prior art, which is not described herein again.

[0134] S3, adjusting the opening degree of the electronic expansion valve of the air conditioner according to the difference between the required evaporation pressure P1 of the indoor unit and the target evaporation pressure P0; and adjusting the opening degree of the electronic expansion valve of the fresh air according to the difference between the required evaporation pressure P2 of the fresh air fan and the target evaporation pressure P0.

[0135] The opening degree of the air-conditioning electronic expansion valve = [(the required evaporation pressure P1 of the indoor unit - the target evaporation pressure P0) / the target evaporation pressure P0] * the initial opening degree.

[0136] The opening degree of the fresh air electronic expansion valve = [(the target evaporation pressure P0 - the required evaporation pressure P2 of the fresh air unit) / the target evaporation pressure P0] * the initial opening degree.

[0137] S4, sensible heat control step: determining whether the difference between the current evaporation pressure P1i of the indoor unit and the required evaporation pressure P1 of the indoor unit is within a preset range, if yes, maintaining the current state; if no, and P1i - P1 is less than the lower limit value of the preset range, reducing the opening degree of the indoor electronic expansion valve; if no, and P1i - P1 is greater than the upper limit value of the preset range, increasing the opening degree of the indoor electronic expansion valve.

[0138] The current evaporation pressure P1i of the indoor unit can be detected by a pressure sensor at the inlet of the indoor heat exchanger.

[0139] Exemplarily, when -0.1 ≤ P1i - P1 ≤ 0.1, it is indicated that P1i - P1 is within the preset range, and the current evaporation pressure of the indoor unit is close to or equal to the required evaporation pressure, so that the opening degree of the indoor electronic expansion valve does not need to be adjusted.

[0140] When P1i - P1 < -0.1, it is indicated that the current evaporation pressure P1i of the indoor unit is relatively small, and the opening degree of the indoor electronic expansion valve can be reduced to increase the pressure P1i.

[0141] When P1i - P1 > 0.1, it is indicated that the current evaporation pressure P1i of the indoor unit is relatively large, and the opening degree of the indoor electronic expansion valve can be increased to reduce the pressure P1i.

[0142] After increasing or reducing the opening degree of the indoor electronic expansion valve, it is determined whether the difference between the current evaporation pressure P1i of the indoor unit and the required evaporation pressure P1 of the indoor unit is within the preset range in a timely manner until P1i - P1 is within the preset range.

[0143] In some embodiments, the sensible heat control step further comprises: controlling the opening degree of the indoor flow valve 122 according to the temperature of the refrigerant and the temperature at the outlet of the indoor heat exchanger.

[0144] The opening degree EVI (122-i) of the indoor flow valve = E * (TLi - TBLi) + F * (G (122-i) / ∑G (122-i).

[0145] Wherein, E and F are constants; TLi is the temperature value at the outlet of each indoor heat exchanger; TBLi is the saturation temperature corresponding to the evaporation pressure P1; G (122-i) is the capacity of each indoor heat exchanger; and ∑G (122-i) is the sum of the capacities of all indoor heat exchangers.

[0146] S5, latent heat control step: judging whether the difference between the current evaporating pressure P2i of the fresh air machine and the required evaporating pressure P2 of the fresh air machine is within a preset range, if yes, maintaining the current state; if no, and P2i-P2 is less than the lower limit value of the preset range, then reducing the opening degree of the fresh air flow valve; if no, and P1i-P1 is greater than the upper limit value of the preset range, then increasing the opening degree of the fresh air flow valve of the indoor unit.

[0147] The current evaporating pressure P2i of the fresh air machine can be detected by a pressure sensor at the inlet of the fresh air heat exchanger.

[0148] In the S4 and S5 steps, the sensible heat control is completed by the indoor unit, and the latent heat control is completed by the fresh air machine. After the S4 or S5 step, the S6 step is entered.

[0149] S6, judging whether the indoor temperature Tin is not greater than the difference between the indoor set temperature Tset and a preset temperature value, and the indoor humidity din is not greater than the difference between the indoor set humidity dset and a preset humidity value, if yes, the compressor is stopped; if no, the compressor maintains the current state.

[0150] Exemplarily, if the conditions of Tin≤Tset-1 and din≤dset-0.5 are met, it means that the indoor temperature and humidity are within the preset range; if Tin≤Tset-1 is not met, it means that the indoor temperature is not within the preset range; if din≤dset-0.5 is not met, it means that the indoor humidity is not within the preset range.

[0151] In this step, if the indoor temperature and humidity Tin is close to or equal to the indoor set temperature and humidity Tset, it means that the indoor temperature and humidity Tin is appropriate, at this time, the compressor can be controlled to stop to save energy; if the indoor temperature Tin and the set temperature Tset differ greatly, or the indoor humidity din and the set humidity dset differ greatly, it means that the temperature and humidity control needs to be continued, at this time, the compressor continues to work.

[0152] In the following, a second method of the air handling system for temperature and humidity independent control will be described, referring to Figure 7 :

[0153] Sensible heat control:

[0154] S11, judging whether the temperature Tfz of the indoor heat exchanger is not less than the sum of the return air dew point temperature TLin and a preset temperature value, if no, increasing the opening degree of the air conditioning electronic expansion valve; if yes, entering S12.

[0155] In the S11 step, the return air temperature and relative humidity can be detected by the temperature and humidity sensor at the return air inlet of the indoor unit, and the return air dew point temperature TLin can be calculated according to the return air temperature and relative humidity.

[0156] For example, the preset temperature value = 1. When the temperature Tfz of the indoor heat exchanger is greater than TLin+1, it indicates that the temperature of the indoor heat exchanger is greater than the dew point temperature, and the return air will not condense water when passing through the indoor heat exchanger, thereby achieving the purpose of temperature control of the indoor unit.

[0157] If the temperature Tfz of the indoor heat exchanger is not greater than TLin+1, it indicates that the temperature of the indoor heat exchanger is lower than the dew point temperature of the return air, and the return air may condense water when passing through the indoor heat exchanger. In order to avoid the indoor unit handling latent heat, the opening of the electronic expansion valve of the air conditioner can be increased, thereby increasing the temperature at the indoor heat exchanger.

[0158] After increasing the opening of the electronic expansion valve of the air conditioner, it is returned to continue to determine whether the temperature Tfz of the indoor heat exchanger is greater than TLin+1 until the determination is true.

[0159] S12, determine whether the indoor temperature Tin is not greater than the difference between the indoor set temperature Tset and the preset temperature value, if yes, reduce the opening of the indoor flow valve, and reduce the refrigerant flow; if not, increase the opening of the indoor flow valve.

[0160] Latent heat control:

[0161] S13, determine whether the temperature Tz of the fresh air heat exchanger is not less than the difference between the fresh air dew point temperature TLoa and the preset temperature value, if not, the compressor is frequency increased; if yes, the compressor maintains the current state.

[0162] For example, when Tz≤TLoa-1, it indicates that the difference between the temperature of the fresh air heat exchanger and the fresh air dew point temperature is within the preset range. Under this condition, the temperature of the fresh air heat exchanger is less than the fresh air dew point temperature, which can ensure the dehumidification effect of the fresh air heat exchanger.

[0163] If the condition is not met, it indicates that the temperature of the fresh air heat exchanger is not less than the fresh air dew point temperature, and the purpose of dehumidifying the fresh air cannot be achieved, and the compressor needs to be frequency increased to reduce the temperature at the fresh air heat exchanger.

[0164] After the compressor is frequency increased, it is returned to determine whether the temperature Tz of the fresh air heat exchanger is not less than the difference between the fresh air dew point temperature TLoa and the preset temperature value at a certain time, until the condition is met.

[0165] S14, determine whether the indoor humidity din is not greater than the difference between the set humidity dset and the preset humidity value, if yes, reduce the opening of the fresh air flow valve; if not, increase the opening of the fresh air flow valve.

[0166] Exemplarily, when the indoor humidity din≤dset-0.5 is established, it indicates that the indoor humidity is appropriate, at this time, the opening degree of the fresh air flow valve can be reduced; if not, it indicates that the indoor humidity is larger, the opening degree of the fresh air flow valve can be increased, and the dehumidification efficiency is improved.

[0167] After reducing the opening degree of the fresh air flow valve, it is determined whether the indoor humidity din is not greater than the difference between the set humidity dset and the preset humidity value in time until the condition is established.

[0168] After step S12 or step S14, S15 is entered.

[0169] S15, it is determined whether the indoor temperature Tin is not greater than the difference between the indoor set temperature Tset and the preset temperature value, and the indoor humidity din is not greater than the difference between the indoor set humidity dset and the preset humidity value, if yes, the compressor is stopped; if not, the compressor maintains the current state.

[0170] Exemplarily, when the conditions of Tin≤Tset-1 and din≤dset-0.5 are met, it indicates that the indoor temperature and humidity are in the preset range; if Tin≤Tset-1 is not met, it indicates that the indoor temperature is not in the preset range; if din≤dset-0.5 is not met, it indicates that the indoor humidity is not in the preset range.

[0171] In this step, if the indoor temperature and humidity are close to or equal to the indoor set temperature and humidity, it indicates that the indoor temperature and humidity are appropriate, at this time, the compressor can be controlled to stop to save energy; if the indoor temperature and the set temperature differ greatly, or the indoor humidity and the set humidity differ greatly, it indicates that the temperature and humidity control needs to be continued, at this time, the compressor continues to work.

[0172] In this application, by connecting the indoor heat exchanger 121 of the indoor unit and the fresh air heat exchanger 134 of the fresh air unit 130 in parallel between the outdoor heat exchanger 112 and the c pipe of the four-way valve 113, and adjusting the evaporation pressure of the air conditioner through the opening degree of the air conditioning electronic expansion valve 115 and adjusting the evaporation pressure of the fresh air unit through the opening degree of the fresh air electronic expansion valve 116, the independent control of the air conditioner and the fresh air unit is realized by using one refrigeration system to control two evaporation pressures to create two evaporation temperatures, which avoids the problems of complex system design and high cost caused by using two sets of refrigeration systems.

[0173] In this application, by controlling the evaporation pressure of the indoor unit and the evaporation pressure of the fresh air unit, the independent control of the temperature and humidity of the indoor unit and the fresh air unit is realized, which avoids the problem of high energy consumption when the indoor unit handles latent heat.

[0174] In the present application, the target evaporating pressure is calculated according to the sensible heat ratio, the required evaporating pressure P1 of the indoor unit, and the required evaporating pressure P2 of the fresh air unit. That is, the target evaporating pressure is calculated according to the sensible heat load and the weight of the sensible heat load, so that the calculation of the target evaporating pressure is more accurate and reasonable.

[0175] In the present application, for a multi-split air conditioner, an indoor electronic expansion valve is arranged on the indoor unit branch, and the evaporating pressure of a single indoor unit is adjusted by controlling the indoor electronic expansion valve.

[0176] In the present application, by adjusting the opening degree of the air conditioner electronic expansion valve, the temperature of the heat exchanger of the indoor unit is controlled to be higher than the dew point temperature of the return air, so that the indoor unit only handles sensible heat. By controlling the frequency of the compressor, the temperature of the fresh air heat exchanger of the fresh air unit is controlled to be lower than the dew point temperature of the fresh air, so that the fresh air unit handles latent heat, and independent control of temperature and humidity is realized.

[0177] In some embodiments of the present application, with reference to Figure 8 , Figure 9 , the fresh air unit 130 can include a fresh air side heat exchanger 1371. The fresh air side heat exchanger 1371 is arranged in the fresh air duct. The fresh air side heat exchanger 1371 cools the fresh air when used as an evaporator, and heats the fresh air when used as a condenser.

[0178] In some embodiments, the fresh air unit 130 can include an exhaust air side heat exchanger 1372. The exhaust air side heat exchanger 1372 is arranged in the exhaust air duct. The exhaust air side heat exchanger 1372 heats the indoor exhaust air when used as a condenser, and cools the indoor exhaust air when used as an evaporator.

[0179] In some embodiments, the fresh air unit 130 can include an adsorption runner 138. The adsorption runner 138 is rotatably connected in the fresh air unit housing 1301, a part of the adsorption runner 138 is located in the exhaust air duct and on the air outlet side of the exhaust air side heat exchanger 1372, and another part of the adsorption runner 138 is located in the fresh air duct and on the air outlet side of the fresh air side heat exchanger 1371.

[0180] Low-temperature air passing through the adsorption runner 138 can be absorbed by the adsorption runner 138, and high-temperature air passing through the adsorption runner 138 can remove moisture to regenerate the adsorption runner 138.

[0181] In some embodiments, with reference to Figure 9 and Figure 10 , in the refrigeration system of the air treatment system, the exhaust port of the compressor 111 is connected to the d pipe of the four-way valve 113, and the s pipe of the four-way valve 113 is connected to the suction port of the compressor 11.

[0182] The e pipe of the four-way valve 113 is connected to one end of the outdoor heat exchanger 112. The c pipes of the four-way valve 113 are respectively connected to one end of the indoor heat exchanger 121 and one end of the fresh air side heat exchanger 1371.

[0183] The four-way valve 113 can selectively guide the refrigerant compressed by the compressor to the outdoor heat exchanger 112 or to the indoor heat exchanger 121 and the fresh air side heat exchanger 1371. Specifically, in the cooling mode, the refrigerant compressed by the compressor 111 flows to the outdoor heat exchanger 112 through the four-way valve 113; in the heating mode, the refrigerant compressed by the compressor 111 flows to the indoor heat exchanger 121 and the fresh air side heat exchanger 1371 through the four-way valve 113.

[0184] The first branch and the second branch are connected in parallel between the other end of the outdoor heat exchanger 112 and the c pipe of the four-way valve 113.

[0185] The air conditioning electronic expansion valve 115 and the indoor heat exchanger 121 are connected in series on the first branch, and the air conditioning electronic expansion valve 115 is located between the outdoor heat exchanger 112 and the indoor heat exchanger 121.

[0186] The exhaust air side heat exchanger 1372, the seventh electronic expansion valve 1392, and the fresh air side heat exchanger 1371 are connected in series on the second branch, and the exhaust air side heat exchanger 1372 is located between the outdoor heat exchanger 112 and the seventh electronic expansion valve 1392.

[0187] In the cooling mode, the refrigerant of the refrigeration system flows as follows:

[0188] The high-temperature and high-pressure refrigerant is discharged from the exhaust port of the compressor 111, reaches the outdoor heat exchanger 112 through the four-way valve 113, and transfers heat to the outdoor air to become high-temperature and low-pressure two-phase state refrigerant, and then is divided into two paths:

[0189] The first path: flows to the exhaust air side heat exchanger 1372, then exchanges heat with the exhaust air, and the temperature of the refrigerant continues to drop, then passes through the seventh electronic expansion valve 1392 to throttle and decompress to become low-temperature and low-pressure liquid refrigerant, flows into the fresh air side heat exchanger 1371, exchanges heat with the fresh air, absorbs the heat of the fresh air to become high-temperature and low-pressure gaseous refrigerant, then flows to the gas pipe of the indoor unit, and the refrigerant at the outlet of the indoor unit converges to flow back to the four-way valve 113, and finally returns to the compressor.

[0190] The second path: passes through the air conditioning electronic expansion valve 115 to throttle and decompress to become low-temperature and low-pressure liquid refrigerant, then reaches the indoor heat exchanger 121, exchanges heat with the indoor air, absorbs the heat of the indoor air to become high-temperature and low-pressure gaseous refrigerant, and then converges with the refrigerant of the fresh air machine to flow back to the four-way valve 113, and finally returns to the compressor.

[0191] Air flow path in fresh air machine 130:

[0192] Fresh air: exchanges heat with indoor exhaust air when passing through heat return core 131, temperature decreases, continues to pass through fresh air side heat exchanger 1371 (used as evaporator), is dehumidified and cooled, continues to pass through adsorption runner 138, is dehumidified and heated, and is then sent into the room.

[0193] Exhaust air: exchanges heat with outdoor fresh air when passing through heat return core 131, temperature increases, continues to pass through exhaust air side heat exchanger 134 (used as condenser), is heated and warmed, continues to pass through adsorption runner 138, takes away moisture of adsorption runner 138, and is finally exhausted to the outside.

[0194] In the embodiments of the present application, by connecting indoor unit heat exchanger 121 of indoor unit 120, exhaust air side heat exchanger 1372 in fresh air machine 130, and fresh air side heat exchanger 1371 in series in the refrigeration system, the air conditioner and the fresh air machine share one set of refrigeration system, and the cost is reduced.

[0195] In some embodiments, the refrigeration system includes a supercooling heat exchanger 117 connected in series on the first branch between outdoor heat exchanger 112 and air conditioner electronic expansion valve 115. Supercooling heat exchanger 117 is used to exchange heat with outdoor air.

[0196] When outdoor unit 110 is far away from indoor unit 120, the pipe is long, and the pipe resistance may cause the flash of liquid refrigerant flowing out of outdoor heat exchanger 114. Supercooling heat exchanger 117 can avoid the flash of refrigerant.

[0197] In some embodiments, indoor unit 120 has multiple indoor units 120, and indoor unit heat exchangers 121 in multiple indoor units 120 are connected in parallel in the refrigeration system.

[0198] A flow valve is connected in series on the branch where each indoor unit heat exchanger 121 is located, and the flow valve can be arranged in indoor unit 120 to adjust the refrigerant flow of the branch.

[0199] The flow valve can be a solenoid valve or an electronic expansion valve. In the present application, the eighth electronic expansion valve is taken as an example for introduction.

[0200] For example, indoor unit 120 has i indoor units 120. When i = 3, the eighth electronic expansion valves in the three indoor units 120 are respectively marked as eighth electronic expansion valve (126-1), eighth electronic expansion valve (126-2), and eighth electronic expansion valve (126-3).

[0201] In some embodiments, the refrigeration system can include a fresh air flow valve connected in series with fresh air side heat exchanger 1371 to adjust the refrigerant flow at fresh air side heat exchanger 1371.

[0202] The fresh air flow valve can be arranged in the fresh air machine 130 or on the refrigerant pipeline outside the machine.

[0203] The fresh air flow valve can be a solenoid valve or an electronic expansion valve. In this application, the ninth electronic expansion valve 1391 is taken as an example for demonstration.

[0204] In some embodiments, referring to Figure 11 , the fresh air machine 130 can be combined with the solar system 140.

[0205] The solar system 140 includes a heat collector 141 for receiving solar energy to heat the water inside. The heat collector 141 is connected with a water supplement pipe, and the other end of the water supplement pipe is connected with a water source for supplying water to the heat collector 141.

[0206] The solar system 140 includes a water heat exchanger 142 in which water flows. When air flows through the water heat exchanger 142, the water heat exchanger 142 can perform heat exchange between water and air.

[0207] The heat collector 141 and the water heat exchanger 142 are connected by a water pipe to form a water circulation.

[0208] The water heat exchanger 142 can be arranged in the exhaust air duct of the fresh air machine 130 and located at the windward side of the adsorption runner 138.

[0209] When the heat collector 141 circulates hot water to the water heat exchanger 142, the water heat exchanger 142 can heat the exhaust air in the fresh air machine 130, and the high-temperature exhaust air continues to pass through the adsorption runner 138, which is beneficial to the regeneration of the adsorption runner 138.

[0210] In the embodiments provided in this application, the water heat exchanger 142 of the solar system 140 is combined into the fresh air machine 130, and the water heat exchanger 142 is used as a regeneration heat source of the adsorption runner 138, which can improve the regeneration efficiency.

[0211] In some embodiments, the water heat exchanger 142 can replace the exhaust air side heat exchanger 1372, that is, when the solar system 140 works, the exhaust air side heat exchanger 1372 can not work, and the solar energy can replace part of the energy of the refrigeration system, which can play a role in energy saving.

[0212] Referring to Figure 12 , the refrigeration system can include a first switch valve connected in series on the second branch and located between the outdoor heat exchanger 112 and the exhaust air side heat exchanger 1372, for controlling the on-off of the refrigerant at the exhaust air side heat exchanger 1372. The first switch valve can be a solenoid valve or an electronic expansion valve.

[0213] Take the first switch valve as an example, which is the first electromagnetic valve 1191: when the first electromagnetic valve 1191 is opened, the outdoor heat exchanger 112 is in communication with the exhaust heat exchanger 1372, and the refrigerant can flow into the exhaust heat exchanger 1372; when the first electromagnetic valve 1191 is closed, the outdoor heat exchanger 112 is not in communication with the exhaust heat exchanger 1372, and the exhaust heat exchanger 1372 does not work.

[0214] The refrigeration system can include a second switch valve, one end of which is connected between the air conditioning electronic expansion valve 115 and the indoor heat exchanger 121, and the other end is connected between the seventh electronic expansion valve 1392 and the fresh air heat exchanger 1371. The second switch valve can be an electromagnetic valve or an electronic expansion valve.

[0215] Take the second switch valve as an example, which is the second electromagnetic valve 1192: when the first electromagnetic valve 1191 is closed and the second electromagnetic valve 1192 is opened, the exhaust heat exchanger 1372 is closed, the fresh air heat exchanger 1371 is connected in parallel with the indoor heat exchanger 121, and the fresh air heat exchanger 1371 flows through the refrigerant; when the first electromagnetic valve 1191 is opened and the second electromagnetic valve 1192 is closed, the first branch and the second branch are connected in parallel.

[0216] Therefore, by changing the on-off state of the first electromagnetic valve 1191 and the second electromagnetic valve 1192, three working modes can be realized.

[0217] The first is the dehumidification cycle without using solar energy, the first electromagnetic valve 1191 is opened, and the second electromagnetic valve 1192 is closed:

[0218] The high-temperature and high-pressure refrigerant is discharged from the exhaust port of the compressor 111, passes through the four-way valve 112 to the outdoor heat exchanger 112, and transfers heat to the outdoor air to become high-temperature and low-pressure two-phase state refrigerant, and then is divided into two paths:

[0219] The first path: through the first electromagnetic valve 1191 to the exhaust heat exchanger 1372, then exchanges heat with the exhaust air, and then the temperature of the refrigerant continues to drop, then passes through the seventh electronic expansion valve 1392 to throttle and decompress to become low-temperature and low-pressure liquid refrigerant, flows into the fresh air heat exchanger 1371, exchanges heat with the fresh air, absorbs the heat of the fresh air to become high-temperature and low-pressure gaseous refrigerant, and then flows to the indoor machine gas pipe, and the refrigerant at the outlet of the indoor machine is combined to flow back to the four-way valve 113, and finally returns to the compressor.

[0220] The second path: flows to the supercooling heat exchanger 117, continues to exchange heat with outdoor air, and then passes through the air conditioning electronic expansion valve 115 to be throttled and decompressed into low-temperature and low-pressure liquid refrigerant, and then flows to each indoor unit heat exchanger 121 to exchange heat with indoor air, absorbs heat of the indoor air to become high-temperature and low-pressure gaseous refrigerant, and then flows to the eighth electronic expansion valve (126-1), (123-2), (123-3) of each indoor unit, the refrigerant at the outlets of all indoor units is combined with the refrigerant of the fresh air machine, flows back to the four-way valve 113, and finally returns to the compressor.

[0221] The second kind is a dehumidification cycle using solar energy and not using condensation heat, the first electromagnetic valve 1191 is turned off, and the second electromagnetic valve 1192 is turned on.

[0222] The high-temperature and high-pressure refrigerant is discharged from the discharge port of the compressor 111, reaches the outdoor heat exchanger 112 through the four-way valve 113, transmits heat to outdoor air to become high-temperature and low-pressure two-phase refrigerant, and then flows to the supercooling heat exchanger 117 to continue to exchange heat with outdoor air, and then passes through the air conditioning electronic expansion valve 115 to be throttled and decompressed into low-temperature and low-pressure liquid refrigerant, and then reaches the indoor unit heat exchanger 121 and the fresh air side heat exchanger 1371 to process indoor air and fresh air.

[0223] The indoor unit side: the refrigerant exchanges heat with indoor air through each indoor unit heat exchanger 121, absorbs heat of the indoor air to become high-temperature and low-pressure gaseous refrigerant, and then flows to the eighth electronic expansion valve (126-1), (123-2), (123-3) of each indoor unit, the refrigerant at the outlets of all indoor units is combined with the refrigerant of the fresh air machine, flows back to the four-way valve 113, and finally returns to the compressor.

[0224] The fresh air machine side: the refrigerant flows to the fresh air side heat exchanger 1371 through the second electromagnetic valve 1192, exchanges heat with fresh air to absorb heat of the fresh air to become high-temperature and low-pressure gaseous refrigerant, and then flows to the ninth electronic expansion valve 1391, is combined with the refrigerant at the outlets of the indoor units, flows back to the four-way valve 113 together, and finally returns to the compressor.

[0225] At this time, the solar energy system works, hot water at the water heat exchanger 142 heats exhaust air, and then the temperature of the exhaust air decreases and returns to the collector to complete a cycle of heating.

[0226] The third kind is to simultaneously use solar energy and condensation heat: the solar energy system is turned on, the first electromagnetic valve 1191 is turned on, and the second electromagnetic valve 1192 is turned off. When solar energy and condensation heat are simultaneously used, the regeneration efficiency of the adsorption wheel 138 is higher.

[0227] According to the embodiments of the present application, the above-mentioned embodiments are described with reference to Figure 11The solar energy system 140 comprises a water pump 145 for pumping water to circulate water flow in the solar energy system.

[0228] The water pipe comprises a water supply pipe 143 connected between the outlet of the heat collector 141 and the inlet of the water heat exchanger 142.

[0229] The water pipe comprises a water return pipe 144 connected between the outlet of the water heat exchanger 143 and the inlet of the heat collector 141.

[0230] The water pump 145 can be connected to the water supply pipe 143, and under the drive of the water pump 145, the hot water in the heat collector 141 flows into the water heat exchanger 142 along the water supply pipe 143, and then continues to flow back to the heat collector 141 from the water return pipe 144.

[0231] In some embodiments, the solar energy system 140 comprises a water flow switch 146. The water flow rate can be adjusted by controlling the opening degree of the water flow switch 146. The water flow switch 146 can be connected to the water supply pipe 143.

[0232] The solar energy system 140 can comprise a pressure sensor 147. The pressure sensor 147 can be arranged on the water supply pipe 143 to play a protection role when the pressure is large.

[0233] In the present application, by connecting the indoor unit 120, the exhaust side heat exchanger 1372 in the fresh air machine 130, and the fresh air side heat exchanger 1371 in parallel in the refrigeration system, the air conditioner and the fresh air machine share a set of refrigeration system, and the cost is reduced.

[0234] In the present application, by combining the water heat exchanger 142 of the solar energy system 140 into the fresh air machine 130, and using the water heat exchanger 142 as the regeneration heat source of the adsorption runner 138, the regeneration efficiency can be improved.

[0235] In the present application, by combining the water heat exchanger 142 of the solar energy system 140 into the fresh air machine 130, and using the water heat exchanger 142 as the regeneration heat source of the adsorption runner 138, the exhaust side heat exchanger 1372 is replaced, that is, when the solar energy system 140 works, the exhaust side heat exchanger 135 can not work, and the solar energy replaces part of the energy of the refrigeration system, which can play a role in energy saving.

[0236] In the present application, by arranging the first electromagnetic valve 1191 and the second electromagnetic valve 1192 on the refrigeration system, and by the different on-off states of the first electromagnetic valve 1191 and the second electromagnetic valve 1192, three working modes can be realized: dehumidification cycle without using solar energy, dehumidification cycle using solar energy and not using condensation heat, and initial cycle using solar energy and condensation heat. The system can select the corresponding working mode according to the actual state of sunlight, and save energy as much as possible under the premise of ensuring the dehumidification effect.

[0237] In some embodiments, with reference to Figure 13 and Figure 14 , the fresh air machine 130 is a device capable of sending outdoor air into the room.

[0238] The fresh air machine 130 includes a first fresh air heat exchanger 1341 located on the flow path of fresh air, which can cool and dehumidify the fresh air when used as an evaporator. The first fresh air heat exchanger 1341 can heat the fresh air when used as a condenser.

[0239] In the refrigeration system of the present application, the compressor 111 adopts a double-suction compressor, which has a first suction port 1111 and a second suction port 1112. Among them, the first suction port 1111 can be connected to the low-pressure cavity of the compressor 111, and the second suction port 1112 can be connected to the medium-pressure cavity of the compressor 111.

[0240] There are two four-way valves, which are the first four-way valve 1131 and the second four-way valve 1132. The first four-way valve 1131 is used to guide the refrigerant compressed by the compressor to the outdoor heat exchanger 112 in the refrigeration mode, and to the first fresh air heat exchanger 1341 in the heating mode. The second four-way valve 1132 is used to guide the refrigerant compressed by the compressor to the outdoor heat exchanger 112 in the refrigeration mode, and to the indoor heat exchanger 121 in the heating mode.

[0241] According to the embodiments of the present application, in the refrigeration system, the exhaust port of the compressor 111 is connected to the d pipe of the first four-way valve 1131. The s pipe of the first four-way valve 1131 is connected to the first suction port 1111 of the compressor 111.

[0242] The e pipe of the first four-way valve 1131 is connected to one end of the outdoor heat exchanger 112, and the other end of the outdoor heat exchanger 112 is sequentially connected in series with the first electronic expansion valve 1182, the first fresh air heat exchanger 1341, and the c pipe of the first four-way valve 1131.

[0243] The exhaust port of the compressor 111 is connected to the d pipe of the second four-way valve 1132. The s pipe of the second four-way valve 1132 is connected to the second suction port 1112 of the compressor 111.

[0244] The e pipe of the second four-way valve 1132 is connected to one end of the outdoor heat exchanger 112, and the other end of the outdoor heat exchanger 112 is sequentially connected in series with the air conditioning electronic expansion valve 115, the indoor heat exchanger 121, and the c pipe of the second four-way valve 1132.

[0245] The flow direction of the refrigeration system is introduced below taking summer operation as an example:

[0246] The high-temperature and high-pressure refrigerant is discharged from the exhaust port of the compressor 111, and then is divided into two paths: one path flows to the first four-way valve 1131 to reach the outdoor heat exchanger 112; and the other path flows to the second four-way valve 1132 to reach the outdoor heat exchanger 112; the refrigerant becomes low-temperature and high-pressure two-phase state refrigerant after transferring heat to outdoor air at the outdoor heat exchanger 112, and then is divided into two paths:

[0247] The first path: the low-temperature and low-pressure two-phase state refrigerant after throttling and pressure reduction by the first electronic expansion valve 1182 flows to the first fresh air heat exchanger 1341, and then exchanges heat with fresh air to become high-temperature and low-pressure gaseous refrigerant, and then flows to the first four-way valve 1131 to return to the low-pressure cavity of the compressor 111 through the first suction port 1111.

[0248] The second path: the low-temperature and low-pressure two-phase state refrigerant after throttling and pressure reduction by the air conditioning electronic expansion valve 115 flows to the indoor unit heat exchanger 121, exchanges heat with indoor air, absorbs heat of the indoor air to become high-temperature and low-pressure gaseous refrigerant, and then flows to the second four-way valve 1132 to return to the medium-pressure cavity of the compressor through the second suction port 1112.

[0249] The refrigerant in the low-pressure cavity and the medium-pressure cavity is compressed into high-temperature and high-pressure refrigerant gas inside the compressor.

[0250] In the fresh air machine 130, outdoor fresh air is sent to the indoor after being cooled and dehumidified by the first fresh air heat exchanger 1341. In the indoor unit 120, indoor air is sent to the indoor after being cooled by the indoor unit heat exchanger 121.

[0251] The air treatment system provided by the embodiments of the present application uses a double-suction compressor 111, so that the refrigerant in the circuit in which the first fresh air heat exchanger 1341 of the fresh air machine 130 is located flows back to the low-pressure cavity of the compressor 111, and the refrigerant in the circuit in which the indoor unit heat exchanger 121 of the indoor unit 120 is located flows back to the medium-pressure cavity of the compressor 111, so that double-evaporation temperatures can be realized by using one refrigeration system, and the problems of complex system design and high cost caused by using two sets of refrigeration systems are avoided. In addition, the present application can realize separate treatment of sensible heat and latent heat, that is, the high-temperature evaporator of the indoor unit 120 treats sensible heat, and the low-temperature evaporator of the fresh air machine 130 treats latent heat, so that the system energy efficiency can be improved.

[0252] In some embodiments, with reference to Figure 15 , the fresh air machine 130 can include a second fresh air heat exchanger 1342, which can be arranged on the air outlet side of the first fresh air heat exchanger 1341. The second fresh air heat exchanger 1342 can cool fresh air when used as an evaporator. The second fresh air heat exchanger 1342 can heat fresh air when used as a condenser.

[0253] In the refrigeration system, the second fresh air heat exchanger 1342 can be connected in series with the indoor unit heat exchanger 121.

[0254] In this embodiment, the refrigerant flow direction during summer operation is as follows:

[0255] First path: After throttling and pressure reduction by the first electronic expansion valve 1182, the two-phase state refrigerant becomes low-temperature and low-pressure, flows to the first fresh air heat exchanger 1341, exchanges heat with fresh air to become high-temperature and low-pressure gaseous refrigerant, and then flows to the first four-way valve 1131 and returns to the low-pressure cavity of the compressor 111 through the first suction port 1111.

[0256] Second path: After throttling and pressure reduction by the air conditioning electronic expansion valve 115, the two-phase state refrigerant becomes low-temperature and low-pressure, flows to the second fresh air heat exchanger 1342, exchanges heat with fresh air to become high-temperature and low-pressure gaseous refrigerant, and then flows into the indoor unit heat exchanger 121, exchanges heat with indoor air, absorbs heat from the indoor air to become high-temperature and low-pressure gaseous refrigerant, and then flows to the second four-way valve 1132 and returns to the medium-pressure cavity of the compressor through the second suction port 1112.

[0257] In the fresh air machine 130, outdoor fresh air is cooled and dehumidified by the first fresh air heat exchanger 1341, and then sent to the indoor after being cooled and dehumidified by the second fresh air heat exchanger 1342.

[0258] In some embodiments, with reference to Figure 16 , the air handling system further includes a third electronic expansion valve 1183. The third electronic expansion valve 1183 can be arranged in the fresh air machine 130, or the third electronic expansion valve 1183 can be arranged in the indoor unit.

[0259] The air conditioning electronic expansion valve 115, the second fresh air heat exchanger 1342, the third electronic expansion valve 1183, and the indoor unit heat exchanger 121 are connected in series between the outdoor heat exchanger 112 and the c pipe of the second four-way valve 1132.

[0260] In this embodiment, the refrigerant flow direction during summer operation is as follows:

[0261] First path: After throttling and pressure reduction by the first electronic expansion valve 1182, the two-phase state refrigerant becomes low-temperature and low-pressure, flows to the first fresh air heat exchanger 1341, exchanges heat with fresh air to become high-temperature and low-pressure gaseous refrigerant, and then flows to the first four-way valve 1131 and returns to the low-pressure cavity of the compressor 111 through the first suction port 1111.

[0262] Route 2: flows through the air conditioner electronic expansion valve 115 (full opening) to the second fresh air heat exchanger 1342, exchanges heat with fresh air to become high-temperature low-pressure liquid refrigerant, and then reaches the third electronic expansion valve 1183. The third electronic expansion valve 1183 throttles and depressurizes to become low-temperature low-pressure liquid refrigerant, flows into the indoor heat exchanger 121, exchanges heat with indoor air, absorbs the heat of indoor air to become high-temperature low-pressure gaseous refrigerant, and then flows to the second four-way valve 1132 and returns to the medium-pressure cavity of the compressor through the second suction port 1112.

[0263] In the fresh air machine 130, the outdoor fresh air is cooled and dehumidified by the first fresh air heat exchanger 1341, and then heated by the second fresh air heat exchanger 1342 and sent to the indoor.

[0264] Since the air conditioner electronic expansion valve 115 is fully opened and does not play a role in throttling and depressurizing, the second fresh air heat exchanger 1342 functions as a condenser and can heat the fresh air.

[0265] In order to avoid the temperature of the fresh air being too low after being cooled and dehumidified by the first fresh air heat exchanger 1341, the heating function of the second fresh air heat exchanger 1342 can be realized by fully opening the air conditioner electronic expansion valve 115, and the third electronic expansion valve 1183 throttles and depressurizes to achieve the purpose of dehumidification and reheating of the fresh air.

[0266] In the embodiments provided in the present application, a third electronic expansion valve 1183 is connected in series between the second fresh air heat exchanger 1342 and the indoor heat exchanger 121. By controlling the air conditioner electronic expansion valve 115 to be fully opened, the third electronic expansion valve 1183 throttles and depressurizes, which realizes the dehumidification and reheating of the fresh air without affecting the refrigeration function of the indoor unit 120.

[0267] In some embodiments, with reference to Figure 17 In the refrigeration system, the second fresh air heat exchanger 1342 and the indoor heat exchanger 121 are connected in parallel, and both are connected in parallel between the air conditioner electronic expansion valve 115 and the c pipe of the second four-way valve 1132.

[0268] The air handling system can include a first flow valve, which can be arranged in the fresh air machine 130.

[0269] The first flow valve can be a solenoid valve or an electronic expansion valve. In the present embodiment, the first flow valve is taken as an example of the fourth electronic expansion valve 1184.

[0270] The fourth electronic expansion valve 1184 is connected in series on the branch of the second fresh air heat exchanger 1342, and is used to adjust the flow of refrigerant at the second fresh air heat exchanger 1342.

[0271] The air handling system can include a second flow valve, which can be arranged in the indoor unit 120.

[0272] The second flow valve can be an electromagnetic valve or an electronic expansion valve. In this embodiment, the second flow valve is taken as an example of the fifth electronic expansion valve 1185.

[0273] The fifth electronic expansion valve 1185 is connected in series on the branch of the indoor heat exchanger 121, and is used to adjust the refrigerant flow at the indoor heat exchanger 121.

[0274] In the embodiments provided in this application, the second fresh air heat exchanger 1342 and the indoor heat exchanger 121 are connected in parallel, and the flow of the corresponding branch is controlled by the fourth electronic expansion valve 1184 and the fifth electronic expansion valve 1185, so that the refrigerant flow corresponds to the actual air volume, which can improve the efficiency of the system.

[0275] According to the embodiments of the present application, the air handling system can include a fresh air temperature and humidity sensor 136. The fresh air temperature and humidity sensor 136 can be arranged on the windward side of the first fresh air heat exchanger 1341, and is used to detect the temperature and humidity of the fresh air on the windward side of the first fresh air heat exchanger 1341.

[0276] The air handling system can include a return air temperature and humidity sensor 125. The return air temperature and humidity sensor 125 is arranged on the windward side of the indoor heat exchanger 121, and is used to detect the temperature and humidity of the indoor air.

[0277] The fresh air dew point temperature TL1 can be calculated from the detection value of the fresh air temperature and humidity sensor 136, and the temperature of the first fresh air heat exchanger 1341 = TL1-ΔT. ΔT is a constant.

[0278] Since the first fresh air heat exchanger 1341 needs to dehumidify the fresh air, the temperature of the first fresh air heat exchanger 1341 cannot be lower than the fresh air dew point temperature TL1.

[0279] The indoor air dew point temperature TL2 can be calculated from the detection value of the return air temperature and humidity sensor 125, and the minimum temperature of the indoor heat exchanger 121 = TL2+ΔT.

[0280] Since the indoor heat exchanger 121 is only used to process sensible heat, the temperature of the indoor heat exchanger 121 cannot be lower than the indoor air dew point temperature TL2.

[0281] The opening ratio of the first electronic expansion valve 1182 and the air conditioning electronic expansion valve 115 ≥ (TL1-ΔT):(TL2+ΔT).

[0282] In some embodiments, the opening ratio of the fourth electronic expansion valve 1184 and the fifth electronic expansion valve 1185 = (the area of the second fresh air heat exchanger * the air volume of the fresh air machine):(the area of the indoor heat exchanger * the air volume of the indoor machine), so that the refrigerant flow of the parallel branch can be adapted to the air volume.

[0283] In the present application, by using the double-suction compressor 111, the refrigerant in the circuit where the first fresh air heat exchanger 1341 of the fresh air machine 130 is located flows back to the low-pressure cavity of the compressor 111, and the refrigerant in the circuit where the indoor unit heat exchanger 121 of the indoor unit 120 is located flows back to the medium-pressure cavity of the compressor 111, so that double evaporation temperatures can be realized by using one refrigeration system, and the problems of complex system design and high cost caused by using two sets of refrigeration systems are avoided.

[0284] In the present application, by using the double-suction compressor 111, the refrigerant in the circuit where the first fresh air heat exchanger 1341 of the fresh air machine 130 is located flows back to the low-pressure cavity of the compressor 111, and the refrigerant in the circuit where the indoor unit heat exchanger 121 of the indoor unit 120 is located flows back to the medium-pressure cavity of the compressor 111, so that double evaporation temperatures can be realized by using one refrigeration system, and the problems of complex system design and high cost caused by using two sets of refrigeration systems are avoided.

[0285] In the present application, by connecting a third electronic expansion valve 1183 in series between the second fresh air heat exchanger 1342 and the indoor unit heat exchanger 121, and by controlling the air conditioning electronic expansion valve 115 to be fully open and the third electronic expansion valve 1183 to throttle and depressurize, dehumidification and reheating of fresh air are realized, and at the same time, the refrigeration function of the indoor unit 120 is not affected.

[0286] In the present application, by connecting the second fresh air heat exchanger 1342 and the indoor unit heat exchanger 121 in parallel, and by controlling the flow of the corresponding branch through the fourth electronic expansion valve 1184 and the fifth electronic expansion valve 1185, so that the refrigerant flow corresponds to the actual air volume, the efficiency of the system can be improved.

[0287] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

[0288] In order to facilitate explanation, the above description has been made in conjunction with specific embodiments. However, the above exemplary discussion is not intended to exhaust or limit the embodiments to the specific forms disclosed above. Various modifications and variations can be derived according to the above teachings. The selection and description of the above embodiments are for better explanation of the principles and practical applications, so that those skilled in the art can better use the embodiments and various different modified embodiments suitable for specific use considerations.

Claims

1. An air handling system, characterized in that, include: A compressor is used to compress refrigerant; An outdoor heat exchanger is used to perform heat exchange between outdoor air and the refrigerant. An indoor heat exchanger includes an indoor unit heat exchanger and a fresh air heat exchanger, wherein the indoor unit heat exchanger is used to perform heat exchange between indoor air and the refrigerant, and the fresh air heat exchanger is used to perform heat exchange between outdoor fresh air and the refrigerant; A four-way valve is used to direct the refrigerant compressed in the compressor to the outdoor heat exchanger or the indoor heat exchanger, depending on whether the air handling system is in cooling mode or heating mode. An air conditioning electronic expansion valve is connected in series between the outdoor heat exchanger and the indoor heat exchanger; A fresh air electronic expansion valve is connected in series between the outdoor heat exchanger and the fresh air heat exchanger; The air conditioning electronic expansion valve and the indoor unit heat exchanger are connected in series to form the indoor unit branch, the fresh air electronic expansion valve and the fresh air heat exchanger are connected in series to form the fresh air branch, and the fresh air branch and the indoor unit branch are connected in parallel. The compressor, the outdoor heat exchanger, and the four-way valve are located inside the outdoor unit; the indoor heat exchanger is located inside the indoor unit; and the fresh air heat exchanger is located inside the fresh air unit. The air conditioning electronic expansion valve and the fresh air electronic expansion valve are located inside the outdoor unit; or, the air conditioning electronic expansion valve is located inside the indoor unit, and the fresh air electronic expansion valve is located inside the fresh air unit.

2. The air handling system according to claim 1, characterized in that, Also includes: Controller, used for: The required evaporation pressure for the indoor unit is calculated based on the temperature of the indoor unit's heat exchanger. Calculate the required temperature of the fresh air heat exchanger based on the dew point temperature of the fresh air; obtain the required evaporation pressure of the fresh air unit based on the required temperature of the fresh air heat exchanger. The compressor frequency is controlled according to the evaporation pressure required by the indoor unit and the fresh air unit.

3. The air handling system according to claim 2, characterized in that, The target evaporation pressure is calculated based on the evaporation pressure required by the indoor unit and the fresh air unit; the compressor frequency is then controlled based on the target evaporation pressure. Wherein, the target evaporation pressure P0 = sensible heat ratio * evaporation pressure required by the indoor unit + (1 - sensible heat ratio) * evaporation pressure required by the fresh air unit.

4. The air handling system according to claim 3, characterized in that, The controller is used for: The opening degree of the air conditioner's electronic expansion valve is controlled by: [(required evaporation pressure of the indoor unit - target evaporation pressure) / target evaporation pressure] * initial opening degree; The opening degree of the electronic expansion valve for fresh air is controlled as: [(target evaporation pressure - required evaporation pressure of the fresh air unit) / target evaporation pressure] * initial opening degree.

5. The air handling system according to claim 2, characterized in that, The indoor unit has multiple units; the indoor unit includes: An indoor unit electronic expansion valve is connected in series in the indoor unit branch circuit and between the indoor unit heat exchanger and the air conditioning electronic expansion valve; The controller is used for: Sensible heat control steps: Determine whether the difference between the current evaporation pressure of the indoor unit and the required evaporation pressure of the indoor unit is less than the lower limit of the preset range. If so, reduce the opening of the electronic expansion valve of the indoor unit. Determine if the difference between the current evaporation pressure of the indoor unit and the required evaporation pressure of the indoor unit is greater than the upper limit of the preset range. If so, increase the opening of the electronic expansion valve of the indoor unit.

6. The air handling system according to claim 2, characterized in that, The fresh air unit includes: A fresh air flow valve is connected in series in the fresh air branch line to regulate the refrigerant flow rate of the fresh air branch line. The controller is used for: Latent heat control steps: Determine whether the difference between the current evaporation pressure of the fresh air unit and the required evaporation pressure of the fresh air unit is less than the lower limit of the preset range. If so, reduce the opening of the fresh air flow valve. Determine whether the difference between the current evaporation pressure of the fresh air unit and the required evaporation pressure of the fresh air unit is greater than the upper limit of the preset range. If so, increase the opening of the fresh air flow valve.

7. The air handling system according to claim 1, characterized in that, Also includes: Controller, used for: Sensible heat control steps: Determine whether the temperature of the indoor unit heat exchanger is not less than the sum of the return air dew point temperature and the preset temperature value. If not, increase the opening of the air conditioner electronic expansion valve. Latent heat control steps: Determine whether the temperature of the fresh air heat exchanger is not greater than the difference between the fresh air dew point temperature and the preset temperature value. If not, increase the compressor frequency. If so, the compressor will remain in its current state.

8. The air handling system according to claim 7, characterized in that, The indoor unit includes: An indoor unit flow valve is connected in series in the indoor unit branch circuit to regulate the refrigerant flow rate in the indoor unit branch circuit. The fresh air unit includes: A fresh air flow valve is connected in series in the fresh air branch line to regulate the refrigerant flow rate of the fresh air branch line. The controller is also used for: In the sensible heat control step, if the temperature of the indoor unit heat exchanger is not less than the sum of the return air dew point temperature and the preset temperature value, then it is determined whether the indoor temperature is not greater than the difference between the set temperature and the preset temperature value; if so, the opening of the indoor unit flow valve is reduced; if not, the opening of the indoor unit flow valve is increased. In the latent heat control step, it is determined whether the indoor humidity is not greater than the difference between the set humidity and the preset humidity value. If so, the opening of the fresh air flow valve is reduced; if not, the opening of the fresh air flow valve is increased.

9. The air handling system according to claim 1, characterized in that: The controller is used for: Determine whether the indoor temperature is not greater than the difference between the set temperature and the preset temperature value, and whether the indoor humidity is not greater than the difference between the set humidity and the preset humidity value; if not, the compressor maintains its current state; if so, the compressor shuts down.

10. An air handling system, characterized in that, include: A compressor is used to compress refrigerant; An outdoor heat exchanger is used to perform heat exchange between outdoor air and the refrigerant. An indoor heat exchanger includes an indoor unit heat exchanger and a fresh air heat exchanger, wherein the indoor unit heat exchanger is used to perform heat exchange between indoor air and the refrigerant, and the fresh air heat exchanger is used to perform heat exchange between outdoor fresh air and the refrigerant; A four-way valve is used to direct the refrigerant compressed in the compressor to the outdoor heat exchanger or the indoor heat exchanger, depending on whether the air handling system is in cooling mode or heating mode. An air conditioning electronic expansion valve is connected in series between the outdoor heat exchanger and the indoor heat exchanger; A fresh air electronic expansion valve is connected in series between the outdoor heat exchanger and the fresh air heat exchanger; A subcooling heat exchanger is connected in series between the outdoor heat exchanger and the fresh air electronic expansion valve; The air conditioning electronic expansion valve and the indoor unit heat exchanger form an indoor unit branch, and the fresh air electronic expansion valve, the subcooling heat exchanger and the fresh air heat exchanger form a fresh air branch. The fresh air branch and the indoor unit branch are connected in parallel. The compressor, the outdoor heat exchanger, and the four-way valve are located inside the outdoor unit; the indoor heat exchanger is located inside the indoor unit; and the fresh air heat exchanger is located inside the fresh air unit. The air conditioning electronic expansion valve, the fresh air electronic expansion valve, and the subcooling heat exchanger are located inside the outdoor unit; or, the air conditioning electronic expansion valve is located inside the indoor unit, and the fresh air electronic expansion valve and the subcooling heat exchanger are located inside the fresh air unit.

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