Air conditioning system

Abstract

An air conditioning system (100), comprising an outdoor unit (10), a first indoor unit (201), and a second indoor unit (202). The first indoor unit (201) and the second indoor unit (202) are separately connected to the outdoor unit (10). The outdoor unit (10) comprises an outdoor heat exchanger (107-1, 107-2) and a compressor (101-1, 102-2). The first indoor unit (201) comprises a first indoor heat exchanger (201-1), and the second indoor unit (202) comprises a second indoor heat exchanger (202-1). During operation of the air conditioning system (100), the second indoor heat exchanger (202-1) satisfies one of the following: the second indoor heat exchanger (202-1) serves as an evaporator; or the second indoor heat exchanger (202-1) serves as a condenser. During operation of the air conditioning system (100), the first indoor heat exchanger (201-1) and the outdoor heat exchanger (107-1, 107-2) satisfy one of the following: the first indoor heat exchanger (201-1) serves as a condenser, and the outdoor heat exchanger (107-1, 107-2) serves as a condenser; or the first indoor heat exchanger (201-1) serves as an evaporator, and the outdoor heat exchanger (107-1, 107-2) serves as an evaporator.

Description

Air conditioning system

[0001] This application claims priority to Chinese Patent Application No. 202410429124.5, filed on April 10, 2024, Chinese Patent Application No. 202410429004.5, filed on April 10, 2024, Chinese Patent Application No. 202420734164.6, filed on April 10, 2024, and Chinese Patent Application No. 202420734191.3, filed on April 10, 2024, the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present disclosure relates to the field of air conditioning technology, and in particular, to an air conditioning system. BACKGROUND

[0003] With the continuous progress of science and technology and the improvement of people's living standards, air conditioners have become an indispensable appliance in daily life.

[0004] A multi-split air conditioning system is a system for providing cooling and heating air conditioning for a building or a room, which usually includes an outdoor unit and multiple indoor units. Each indoor unit can independently control the temperature, and therefore, multiple indoor units can be installed in different rooms or areas to meet the needs of different rooms.

[0005] SUMMARY

[0006] An air conditioning system is provided, which includes an outdoor unit, a first pipe, a second pipe, a first indoor unit, a third pipe, a fourth pipe, and a second indoor unit. The outdoor unit includes an outdoor heat exchanger and a compressor. The first indoor unit is connected to the outdoor unit through the first pipe and the second pipe; the first indoor unit includes a first housing and a first indoor heat exchanger disposed in the first housing. The second indoor unit includes a second housing and a second indoor heat exchanger disposed in the second housing; the first indoor heat exchanger and the second indoor heat exchanger are respectively connected to the first pipe; the second indoor unit satisfies one of the following: the second indoor unit is connected to the outdoor unit through the first pipe and the third pipe; and the second indoor unit is connected to the outdoor unit through the first pipe, the third pipe, and the fourth pipe. During operation of the air conditioning system, the second indoor heat exchanger satisfies one of the following: the second indoor heat exchanger serves as an evaporator; and the second indoor heat exchanger serves as a condenser. During operation of the air conditioning system, the first indoor heat exchanger and the outdoor heat exchanger satisfy one of the following: the first indoor heat exchanger serves as a condenser, and the outdoor heat exchanger serves as a condenser; and the first indoor heat exchanger serves as an evaporator, and the outdoor heat exchanger serves as an evaporator. BRIEF DESCRIPTION OF DRAWINGS

[0007] FIG. 1 is a structural diagram of an air conditioning system according to some embodiments;

[0008] FIG. 2 is a block diagram of an air conditioning system according to some embodiments;

[0009] FIG. 3 is a structural diagram of an air conditioning system performing a cooling mode according to some embodiments;

[0010] FIG. 4 is a structural diagram of an air conditioning system performing a heating mode according to some embodiments;

[0011] FIG. 5 is a structural diagram of an air conditioning system of FIG. 1 including a controller according to some embodiments;

[0012] FIG. 6 is a structural diagram of another air conditioning system according to some embodiments;

[0013] FIG. 7 is a block diagram of another air conditioning system according to some embodiments;

[0014] FIG. 8 is a structural diagram of another air conditioning system performing a cooling mode (full load) according to some embodiments;

[0015] FIG. 9 is a structural diagram of another air conditioning system performing a cooling mode (partial load) according to some embodiments;

[0016] FIG. 10 is a structural diagram of another air conditioning system performing a dehumidification without cooling mode according to some embodiments;

[0017] FIG. 11 is a structural diagram of another air conditioning system performing another dehumidification without cooling mode according to some embodiments;

[0018] FIG. 12 is a structural diagram of another air conditioning system of FIG. 6 including a controller according to some embodiments;

[0019] FIG. 13 is a control flow diagram of an air conditioning system according to some embodiments. DETAILED DESCRIPTION

[0020] Some embodiments of the present disclosure will be described clearly and completely with reference to the drawings, obviously, the described embodiments are only some embodiments of the present disclosure, but not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present disclosure.

[0021] Unless the context clearly requires otherwise, throughout the description and the claims, the term "comprise," and variations thereof (e.g., "comprises" and "comprising"), will be construed both to cover the containing feature or features and additional feature or features not described. In describing some embodiments, it will be understood that the terms "connect," "exhibiting," "including," and "including," among others, are used to describe particular structures and are not to be construed as requiring such connectedness or composition. Rather, such associated terminology can be used to describe a relationship between one piece or component and another piece or component that can or can not exist.

[0022] Hereinafter, the terms "first", "second", etc. are used only for the purpose of description, and should not be construed as indicating or implying relative importance or implying the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0023] In describing some embodiments, the term "connected" and variations thereof can be used. The term "connected" is used in a broad sense and can mean fixedly connected, detachably connected, or integrated; directly connected or indirectly connected through an intermediate medium.

[0024] "A, B, and C at least one of" has the same meaning as "at least one of A, B, or C", and includes the following combinations of A, B, and C: only A, only B, only C, a combination of A and B, a combination of A and C, a combination of B and C, and a combination of A, B, and C.

[0025] "A and / or B" includes the following three combinations: only A, only B, and a combination of A and B.

[0026] The use of "adapted to" or "configured to" herein means open and inclusive language that does not exclude additional tasks or steps not described.

[0027] As used herein, "about," "approximately," or "around" includes the value recited and the average value within an acceptable range of deviation, as determined by one of ordinary skill in the art considering the measurement in question and the error intended to be introduced by the particular quantity measured (i.e., the limitations of the measurement system).

[0028] As used herein, "parallel," "perpendicular," "equal" includes the recited condition and conditions approximating the recited condition within an acceptable range of deviation, as determined by one of ordinary skill in the art considering the measurement in question and the error intended to be introduced by the particular quantity measured (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallel and near parallel, where near parallel can have an acceptable range of deviation of, for example, within 5°; "perpendicular" includes absolute perpendicular and near perpendicular, where near perpendicular can also have an acceptable range of deviation of, for example, within 5°. "Equal" includes absolute equality and near equality, where near equality can have an acceptable range of deviation of, for example, a difference between the two less than or equal to 5% of either.

[0029] With the continuous progress of science and technology and the improvement of people's living standards, air conditioners have become an indispensable appliance in daily life. A multi-split air conditioning system is a system for providing cooling and heating air conditioning for a building or a room, which usually includes an outdoor unit and multiple indoor units. Each indoor unit can independently control the temperature (such as independently performing refrigeration or heating), and therefore, multiple indoor units can be installed in different rooms or areas, so as to meet the needs of different rooms.

[0030] Generally, a multi-split air conditioning system realizes the function of independent temperature control of each indoor unit through a piping system and a valve control, for example, by connecting the outdoor unit and the indoor unit through a low-pressure gas pipe, a high-low-pressure gas pipe, and a liquid pipe, and by controlling the flow direction and flow rate of the refrigerant in the pipe through a valve, so as to control whether each indoor unit performs refrigeration or heating.

[0031] To realize the above function, some multi-split air conditioning systems realize waste heat recovery through a built-in cold-heat switching device, which includes multiple valves, has a complex structure, is not convenient to install, and has a high cost.

[0032] To solve the above technical problems, some embodiments of the present disclosure provide an air conditioning system 100, which can realize separate control of the working modes of multiple indoor units through the cooperation of pipes and valves, thereby omitting structures such as a cold-heat switching device, which is conducive to simplifying the structure of the air conditioning system 100, reducing the cost, and facilitating installation. For example, the air conditioning system 100 is a four-pipe multi-scene convertible heat exchanger heat recovery system.

[0033] In some embodiments, referring to FIGS. 1 and 2, the air conditioning system 100 includes a first indoor unit 201. The first indoor unit 201 is configured to perform a cooling mode or a heating mode.

[0034] The air conditioning system 100 further includes a second indoor unit 202. The second indoor unit 202 is configured to perform a cooling mode or a heating mode. The second indoor unit 202 is further configured to perform a cooling, heating, or dehumidifying process on air and supply the processed air into an air conditioning room.

[0035] For example, the first indoor unit 201 and the second indoor unit 202 can exchange heat with air, or the first indoor unit 201 and the second indoor unit 202 can exchange heat with other medium (e.g., water) to perform a cooling mode or a heating mode.

[0036] In some embodiments, referring to FIGS. 1 and 2, the air conditioning system 100 further includes a first pipe 30 (a liquid pipe) configured to flow a refrigerant in a liquid state.

[0037] The air conditioning system 100 further includes a second pipe 40 (a heat recovery pipe) configured to flow a refrigerant.

[0038] The air conditioning system 100 further includes a third pipe 50 (a high-low pressure gas pipe) configured to flow a high-pressure gaseous refrigerant and a low-pressure gaseous refrigerant.

[0039] The air conditioning system 100 further includes a fourth pipe 60 (a low-pressure gas pipe) configured to flow a low-pressure gaseous refrigerant.

[0040] The air conditioning system 100 further includes an outdoor unit 10. The first pipe 30, the second pipe 40, the third pipe 50, and the fourth pipe 60 are connected to the outdoor unit 10, respectively.

[0041] For example, the outdoor unit 10 includes a first compressor 101-1 and a second compressor 101-2. The first compressor 101-1 and the second compressor 101-2 each include a motor and are configured in a hermetic structure. The first compressor 101-1 and the second compressor 101-2 can compress a low-temperature and low-pressure refrigerant into a high-temperature and high-pressure refrigerant gas and discharge the same.

[0042] The first compressor 101-1 and the second compressor 101-2 each include a refrigerant oil configured to reduce friction and abrasion of the first compressor 101-1 and the second compressor 101-2 to improve reliability of operation of the first compressor 101-1 and the second compressor 101-2.

[0043] In some embodiments, the outdoor unit 10 can also include two or more compressors connected in parallel, or in groups, with more compressors. In this case, the outdoor unit 10 can assign an actual operating frequency to each compressor according to the cumulative operating time of each compressor and a preset rotation order.

[0044] In some embodiments, referring to FIG. 1, the discharge end of the first compressor 101-1 is provided with a first switch 102-1 (first high-pressure switch), and the discharge end of the second compressor 101-2 is provided with a second switch 102-2 (second high-pressure switch). The first switch 102-1 and the second switch 102-2 are used to monitor the pressure in the system. When the pressure in the system exceeds a first threshold value, at least one of the first switch 102-1 or the second switch 102-2 automatically cuts off the power supply to stop at least one of the first compressor 101-1 or the second compressor 101-2 from operating, so as to protect the components in the system from damage caused by high pressure. The first threshold value can be set according to the design parameters and operating conditions of the air conditioning system 100.

[0045] For example, when the pressure in the system decreases to a second threshold value, at least one of the first switch 102-1 or the second switch 102-2 restores the power supply to restart at least one of the first compressor 101-1 or the second compressor 101-2. The second threshold value can be set according to the design parameters and operating conditions of the air conditioning system 100.

[0046] In some embodiments, referring to FIG. 1, the outdoor unit 10 further includes two oil separators, which are a first oil separator 103-1 and a second oil separator 103-2. The first oil separator 103-1 is arranged at the discharge end of the first compressor 101-1, and the second oil separator 103-2 is arranged at the discharge end of the second compressor 101-2. The first oil separator 103-1 and the second oil separator 103-2 are configured to separate refrigeration oil from refrigerant.

[0047] For example, the first oil separator 103-1 and the second oil separator 103-2 separate the refrigeration oil from the refrigerant by physical means, such as centrifugal force or gravity. The separated refrigeration oil is recycled and reused, while the refrigerant continues to flow.

[0048] In some embodiments, referring to FIG. 1, a first one-way valve 104-1 is arranged downstream of the first oil separator 103-1, and a second one-way valve 104-2 is arranged downstream of the second oil separator 103-2, so as to prevent the refrigerant from flowing back.

[0049] The outdoor unit 10 further includes a first pressure reducer 105-1 (e.g., a first capillary tube) that is matched with the first oil separator 103-1. The outdoor unit 10 further includes a second pressure reducer 105-2 (e.g., a second capillary tube) that is matched with the second oil separator 103-2. The first pressure reducer 105-1 is connected between the first compressor 101-1 and the first oil separator 103-1, and the second pressure reducer 105-2 is connected between the second compressor 101-2 and the second oil separator 103-2. The first pressure reducer 105-1 and the second pressure reducer 105-2 are configured to recover and direct (e.g., by adsorption) the deposited refrigerant oil into the lubrication system of the first compressor 101-1 and the second compressor 101-2, enabling the recycling of the refrigerant oil.

[0050] In some embodiments, the first oil separator 103-1 and the second oil separator 103-2 can be in series with a filter, respectively.

[0051] In some embodiments, referring to FIG. 1, the second switching valve 106-2 (e.g., a four-way valve) receives the refrigerant discharged from the first compressor 101-1 and the second compressor 101-2 through the first oil separator 103-1 and the second oil separator 103-2.

[0052] The second switching valve 106-2 includes a fifth port A2 (a second switching valve first port) that has a first path connected to the first oil separator 103-1 and the second oil separator 103-2, and a second path connected to the first switching valve 106-1.

[0053] The second switching valve 106-2 further includes a sixth port B2 (a second switching valve second port) that is connected to a seventh port C2. For example, the air conditioning system 100 further includes a second solenoid valve 114-2 that is disposed between the sixth port B2 and the seventh port C2. For example, the air conditioning system 100 further includes a fourth pressure reducer 105-4 that is disposed between the seventh port C2 and the second solenoid valve 114-2. For example, the sixth port B2 is connected to the seventh port C2 through the second solenoid valve 114-2 and the fourth pressure reducer 105-4.

[0054] The second switching valve 106-2 further includes a seventh port C2 (a second switching valve third port) that is connected to the suction ports of the first compressor 101-1 and the second compressor 101-2.

[0055] The second switching valve 106-2 further includes an eighth port D2 (a second switching valve fourth port) that has a first path connected to the first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2, and a second path connected to the second pipe 40.

[0056] The first switching valve 106-1 (e.g., a four-way valve) includes a first port A1 (first switching valve first port), a first path of the first port A1 connecting the first oil separator 103-1 and the second oil separator 103-2, and a second path of the first port A1 connecting a second switching valve first port A1.

[0057] The first switching valve 106-1 further includes a second port B1 (first switching valve second port) connecting a third port C1. For example, the air conditioning system 100 further includes a first solenoid valve 114-1 disposed between the second port B1 and the third port C1. For example, the air conditioning system 100 further includes a third pressure reducer 105-3 disposed between the third port C1 and the first solenoid valve 114-1. For example, the second port B1 connects the third port C1 through the first solenoid valve 114-1 and the third pressure reducer 105-3.

[0058] The first switching valve 106-1 further includes a third port C1 (first switching valve third port) connecting suction ports of the first compressor 101-1 and the second compressor 101-2.

[0059] The first switching valve 106-1 further includes a fourth port D1 (first switching valve fourth port) connecting the third pipe 50.

[0060] The switching valves (e.g., the first switching valve 106-1 and the second switching valve 106-2) can be switched between an ON state and an OFF state.

[0061] When the first switching valve 106-1 is in the ON state, a flow path between the first port A1 and the second port B1 is conducted, and a flow path between the third port C1 and the fourth port D1 is conducted. Similarly, when the second switching valve 106-2 is in the ON state, a flow path between the fifth port A2 and the sixth port B2 is conducted, and a flow path between the seventh port C2 and the eighth port D2 is conducted.

[0062] When the first switching valve 106-1 is in the OFF state, a flow path between the first port A1 and the fourth port D1 is conducted, and a flow path between the second port B1 and the third port C1 is conducted. Similarly, when the second switching valve 106-2 is in the OFF state, a flow path between the fifth port A2 and the eighth port D2 is conducted, and a flow path between the sixth port B2 and the seventh port C2 is conducted.

[0063] In some embodiments, the outdoor unit 10 includes multiple outdoor heat exchangers arranged in parallel, for example, the outdoor unit 10 includes a first outdoor heat exchanger 107-1 and a second outdoor heat exchanger 107-2. The first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 are connected to the eighth port D2 in parallel.

[0064] The outdoor unit 10 further includes a first throttling element 108-1 (first outdoor throttling element) matched with the first outdoor heat exchanger 107-1. The outdoor unit 10 further includes a second throttling element 108-2 (second outdoor throttling element) matched with the second outdoor heat exchanger 107-2. The fifth throttling element 201-2 is arranged on the side of the first indoor heat exchanger 201-1 connected to the first pipe 30, and the sixth throttling element 202-2 is arranged on the side of the second indoor heat exchanger 202-1 connected to the first pipe 30.

[0065] In some embodiments, the outdoor unit 10 further includes a subcooler 110 connected to the first throttling element 108-1 and the second throttling element 108-2 respectively. The outdoor unit 10 further includes a fourth throttling element 111 (fourth outdoor throttling element) connected to the subcooler 110. For example, the fourth throttling element 111 is an electronic expansion valve.

[0066] For example, the subcooler 110 is a heat exchanger, the refrigerant flowing to the first pipe 30 through the first throttling element 108-1 and the second throttling element 108-2 is bypassed by the subcooler 110, and then flows into the subcooler 110 again after passing through the fourth throttling element 111, so that the refrigerant flowing to the first pipe 30 is cooled.

[0067] For example, the outdoor unit 10 further includes a liquid accumulator 112 connected to the suction end of the first compressor 101-1 and the second compressor 101-2 respectively. The bypassed refrigerant can return to the suction end of the first compressor 101-1 and the second compressor 101-2, for example, return to the liquid accumulator 112.

[0068] In some embodiments, the outdoor unit 10 further includes a first outdoor fan and a second outdoor fan, and the start-stop and rotation speed of the first outdoor fan and the second outdoor fan can be independently controlled to change the air flow of the first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 by adjusting the rotation speed. The first outdoor fan and the second outdoor fan can be axial flow fans, cross flow fans or other fans. The first outdoor fan is arranged close to the first outdoor heat exchanger 107-1, and the second outdoor fan is arranged close to the second outdoor heat exchanger 107-2.

[0069] In some embodiments, as shown in FIG. 2, the first indoor unit 201 has a first shell 204, and a first indoor heat exchanger 201-1 is arranged in the first shell 204. The first shell 204 is provided with a first return air inlet and a first air outlet, and the air after heat exchange with the first indoor heat exchanger 201-1 can enter the indoor space through the first air outlet or be discharged to the external space.

[0070] In some embodiments, as shown in FIG. 1 and FIG. 2, the first indoor heat exchanger 201-1 is connected to the outdoor unit 10 through the second pipe 40 (such as a bend pipe) and the first pipe 30, respectively. The first indoor unit 201 further comprises a fifth throttling element 201-2 (first indoor throttling element), which is connected to the first indoor heat exchanger 201-1 and matched with the first indoor heat exchanger 201-1.

[0071] In some embodiments, the first indoor unit 201 is further provided with a first indoor fan, which can be an axial fan or a cross-flow fan.

[0072] In some embodiments, the first indoor heat exchanger 201-1 can also exchange heat with other medium, such as water.

[0073] In some embodiments, as shown in FIG. 2, the second indoor unit 202 has a second shell 205, and a second indoor heat exchanger 202-1 is arranged in the second shell 205. The second shell 205 is provided with a second return air inlet and a second air outlet, and the air after heat exchange with the second indoor heat exchanger 202-1 can enter the indoor space through the second air outlet.

[0074] In some embodiments, as shown in FIG. 1 and FIG. 2, the second indoor heat exchanger 202-1 is connected to the outdoor unit 10 through the third pipe 50 and the first pipe 30, respectively. The second indoor unit 202 further comprises a sixth throttling element 202-2 (second indoor throttling element), which is connected to the second indoor heat exchanger 202-1 and matched with the second indoor heat exchanger 202-1.

[0075] In some embodiments, the second indoor unit 202 is further provided with a second indoor fan, which can be an axial fan or a cross-flow fan.

[0076] In some embodiments, the first shell 204 is arranged in a first space, and the first indoor heat exchanger 201-1 can exchange heat with the medium in the first space.

[0077] The second shell 205 is arranged in a second space, and the first space and the second space are independently arranged, and the second indoor heat exchanger 202-1 can exchange heat with the medium in the second space.

[0078] In some embodiments, the first casing 204 is arranged in a first space, and the first air supply port is in communication with an external space.

[0079] In some embodiments, the air that is sent into the indoor space via the second air supply port for heat exchange can be further introduced into the first casing 204 via the first air return port, and then discharged to the outdoor space after heat exchange with the first indoor heat exchanger 201-1.

[0080] In some embodiments, the air conditioning system 100 further comprises a control terminal 70 connected to and matched with the second indoor unit 202. The control terminal 70 is configured to control the air conditioning system 100, for example, the control of the air conditioning system 100 includes start-stop control, set temperature adjustment, set air volume adjustment, receiving user output mode selection instruction, mode switching, etc. The control terminal 70 is fixedly installed indoors and comprises a touch screen or a button and is equipped with a display screen for displaying system running state and alarm information. The control terminal 70 can also be a remote controller, including but not limited to an infrared remote controller, a smart phone, and a smart control terminal, etc.

[0081] In some embodiments, when the air conditioning system 100 receives a heating mode instruction, the second indoor heat exchanger 202-1 works as a condenser, and the first indoor heat exchanger 201-1 and the outdoor heat exchanger work as evaporators. When the air conditioning system 100 receives a cooling mode instruction, the second indoor heat exchanger 202-1 works as an evaporator, and the first indoor heat exchanger 201-1 and the outdoor heat exchanger work as condensers.

[0082] For example, when the control terminal receives a heating mode instruction, the second indoor heat exchanger works as a condenser, and the first indoor heat exchanger and the outdoor heat exchanger work as evaporators; when the control terminal receives a cooling mode instruction, the second indoor heat exchanger works as an evaporator, and the first indoor heat exchanger and the outdoor heat exchanger work as condensers.

[0083] In some embodiments, as shown in FIG. 3, when the user controls the air conditioning system 100 to execute a cooling mode through the control terminal 70, the second indoor heat exchanger 202-1 works as an evaporator, and the first indoor heat exchanger 201-1 and the outdoor heat exchanger work as condensers.

[0084] From the principle point of view, low temperature and low pressure refrigerant enters the first compressor 101-1 and the second compressor 101-2, the first compressor 101-1 and the second compressor 101-2 compress the low temperature and low pressure refrigerant into high temperature and high pressure state refrigerant gas and discharge the compressed refrigerant gas. In this case, the first switching valve 106-1 is in the ON state, the second switching valve 106-2 is in the OFF state, the compressed refrigerant gas flows into the first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 through the fifth port A2 and the eighth port D2, the first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 act as condensers, and the compressed refrigerant is condensed into high temperature and high pressure liquid phase refrigerant. The heat released by the refrigerant is released to the surrounding environment through the condensation process.

[0085] Next, the high temperature and high pressure liquid phase refrigerant flows through the subcooler 110 into the first pipe 30 and enters the second indoor unit 202, in this process, the first throttling element 108-1, the second throttling element 108-2 and the sixth throttling element 202-2 expand the high temperature and high pressure state liquid phase refrigerant formed in the condenser into low pressure liquid phase refrigerant.

[0086] The refrigerant passing through the fifth port A2 and the eighth port D2 also enters the first indoor unit 201 through the second pipe 40, that is, enters the first indoor heat exchanger 201-1, the first indoor heat exchanger 201-1 acts as a condenser, and the first indoor heat exchanger 201-1 condenses the compressed refrigerant into a liquid phase, and the heat released by the refrigerant is released to the surrounding environment through the condensation process. In this way, the first indoor unit 201 realizes heating.

[0087] The high temperature and high pressure state liquid phase refrigerant formed in the first indoor heat exchanger 201-1 flows through the fifth throttling element 201-2, the fifth throttling element 201-2 expands the high temperature and high pressure state liquid phase refrigerant formed in the first indoor heat exchanger 201-1 into low pressure liquid phase refrigerant.

[0088] The expanded low pressure liquid phase refrigerant converges and enters the second indoor heat exchanger 202-1. The second indoor heat exchanger 202-1 acts as an evaporator, the second indoor heat exchanger 202-1 evaporates the refrigerant expanded in the first throttling element 108-1, the second throttling element 108-2, the sixth throttling element 202-2 and the fifth throttling element 201-2, and makes the refrigerant in the low temperature and low pressure state return to the first compressor 101-1 and the second compressor 101-2 through the third pipe 50, the fourth port D1, the third port C1 and the liquid accumulator 112. The second indoor heat exchanger 202-1 can exchange heat with the material to be cooled to realize the refrigeration effect.

[0089] It can be understood that in the above process, part of the heat originally dissipated by the outdoor unit 10 to the environment in the cooling mode is recovered, and the first indoor unit 201 uses the recovered heat to realize heating of the indoor space (such as the first space) where it is located, thereby improving the working efficiency of the air conditioning system 100 and reducing energy consumption.

[0090] For example, in the process of the air conditioning system 100 performing the cooling mode, the air sent into the indoor (such as the second space) by the second air outlet for heat exchange is further introduced into the first shell 204 through the first air return outlet, and is discharged to the outdoor after heat exchange with the first indoor heat exchanger 201-1. The temperature of the air sent into the indoor for heat exchange through the second air outlet is relatively low, and compared with the outdoor heat exchanger in a high temperature and working in a condensing state, the condensing effect and capacity of the first heat exchanger as a condenser are obviously improved, so that the air conditioning system 100 can achieve the same cooling and heating effect with less energy consumption, thereby facilitating the reduction of energy consumption of the air conditioning system 100.

[0091] The first indoor fan and the second indoor fan are controlled in linkage, that is, when the second indoor fan is on standby or stopped, the first indoor fan also stops running.

[0092] In some embodiments, as shown in FIG. 4, when the user controls the air conditioning system 100 to perform the heating mode through the control terminal 70, the second indoor heat exchanger 202-1 works as a condenser, and the first indoor heat exchanger 201-1 and the outdoor heat exchanger work as evaporators.

[0093] From the principle point of view, the first compressor 101-1 and the second compressor 101-2 compress the low-temperature and low-pressure refrigerant into high-temperature and high-pressure refrigerant gas and discharge it. In this case, the first switching valve 106-1 is in the OFF state, and the second switching valve 106-2 is in the ON state. The discharged refrigerant gas enters the third pipe 50 through the first port A1 and the fourth port D1, and then enters the second indoor unit 202, flows into the second indoor heat exchanger 202-1, and the second indoor heat exchanger 202-1 works as a condenser. The second indoor heat exchanger 202-1 condenses the compressed refrigerant into liquid-phase refrigerant, and the heat of the refrigerant is released to the surrounding environment through the condensing process.

[0094] The high-temperature and high-pressure liquid-phase refrigerant formed in the condenser is condensed and returned to the outdoor unit 10 side through the first pipe 30. In this process, the sixth throttling element 202-2, the first throttling element 108-1, and the second throttling element 108-2 expand the high-temperature and high-pressure liquid-phase refrigerant formed in the condenser into low-pressure liquid-phase refrigerant. The first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 serve as evaporators, evaporate the refrigerant expanded in the sixth throttling element 202-2, the first throttling element 108-1, and the second throttling element 108-2, and return the refrigerant in a low-temperature and low-pressure state to the first compressor 101-1 and the second compressor 101-2 through the eighth port D2, the seventh port C2, and the accumulator 112.

[0095] The high-temperature and high-pressure liquid-phase refrigerant formed in the condenser flows into the first indoor unit 201. In this process, the fifth throttling element 201-2 expands the high-temperature and high-pressure liquid-phase refrigerant into low-pressure liquid-phase refrigerant. The first indoor heat exchanger 201-1 serves as an evaporator, evaporates the refrigerant expanded in the fifth throttling element 201-2. In this case, the refrigerant flowing through the first indoor heat exchanger 201-1 is evaporated to absorb heat in the ambient air, thereby achieving refrigeration of the indoor space (e.g., the first space) in which the first indoor unit 201 is located.

[0096] Next, the refrigerant in a low-temperature and low-pressure state returns to the first compressor 101-1 and the second compressor 101-2 through the eighth port D2 and the seventh port C2, the accumulator 112.

[0097] It can be understood that in the above process, part of the heat originally dissipated by the outdoor unit 10 to the environment in the heating mode is recovered, and the first indoor unit 201 uses this part of the recovered heat to achieve refrigeration of the indoor space (e.g., the first space) in which it is located, thereby improving the working efficiency of the air conditioning system 100 and reducing energy consumption.

[0098] For example, in the process of the air conditioning system 100 performing the heating mode, the air that has been sent into the room for heat exchange through the first air supply port is further introduced into the second housing 205 through the second return air port, and is discharged to the outside after heat exchange with the second indoor heat exchanger 202-1. The temperature of the air that has been sent into the room for heat exchange through the first air supply port is relatively high, thereby improving the evaporation effect and capacity of the first heat exchanger as an evaporator, so that the air conditioning system 100 can achieve the same refrigeration or heating effect with less energy consumption, thereby facilitating the reduction of energy consumption of the air conditioning system 100.

[0099] It can be understood that the cooperation of the first throttling element 108-1 and the second throttling element 108-2 can enable the first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 to achieve refrigerant storage, refrigerant release, and refrigerant locking, variable storage of refrigerant, and keep the refrigerant in the air conditioning system 100 at a suitable level (for example, the amount of refrigerant is within a preset range).

[0100] In the above process, the first indoor unit 201 and the second indoor unit 202 are jointly controlled by the control terminal 70, without the participation of the cold-heat switching device, which is convenient for user operation.

[0101] In the above process, the fourth pipe 60 remains closed. The first pipe 30 is provided with a first closed valve 31. The third pipe 50 is provided with a third closed valve 61. The second pipe 40 is provided with a second closed valve 41.

[0102] It can be understood that the first indoor unit 201 and the second indoor unit 202 are shown in the drawings of the present disclosure, and the air conditioning system can also be configured with two or more first indoor units 201 and second indoor units 202 using the same connection mode. Some embodiments of the present disclosure do not limit the number of first indoor units 201 and second indoor units 202.

[0103] In some embodiments, at least one of the plurality of parallelly arranged outdoor heat exchangers is provided with a third throttling element 109 (third outdoor throttling element) between the fourth port. For example, the second outdoor heat exchanger 107-2 and the fourth port D1 are provided with the third throttling element 109.

[0104] In some embodiments, as shown in FIGS. 6 and 7, the second indoor unit 202 includes a second indoor heat exchanger 202-1 and a third indoor heat exchanger 203-1, which are arranged in a second housing 205. The third indoor heat exchanger 203-1 is connected to the outdoor unit 10 through the fourth pipe 60 and the first pipe 30, and the first indoor heat exchanger 201-1, the second indoor heat exchanger 202-1, and the third indoor heat exchanger 203-1 are connected to the first pipe 30. The third indoor heat exchanger 203-1 can act as an evaporator, thereby having a combination of a plurality of working modes shown in FIGS. 8 to 11.

[0105] For example, when the control terminal receives a heating mode instruction, the second indoor unit is configured to cause the second indoor heat exchanger to act as a condenser, and the first indoor heat exchanger and the outdoor heat exchanger to act as evaporators.

[0106] When the control terminal receives the dehumidification instruction, the second indoor unit is configured to make the second indoor heat exchanger as a condenser and the third indoor heat exchanger as an evaporator; the second indoor unit is further configured to make the first indoor heat exchanger and the outdoor heat exchanger as evaporators, or make the first indoor heat exchanger and the outdoor heat exchanger as condensers.

[0107] When the control terminal receives the dehumidification instruction, the second indoor unit is configured to make the second indoor heat exchanger as a condenser and the third indoor heat exchanger as an evaporator; the second indoor unit is further configured to make the first indoor heat exchanger and the outdoor heat exchanger as evaporators, or make the first indoor heat exchanger and the outdoor heat exchanger as condensers.

[0108] The first working mode is shown in FIG. 8. The user controls the air conditioning system 100 to execute the cooling mode (full load) through the control terminal 70.

[0109] From the principle point of view, the first compressor 101-1 and the second compressor 101-2 compress the low-temperature and low-pressure refrigerant into a high-temperature and high-pressure state of refrigerant gas and discharge it. In this case, the first switching valve 106-1 is in the ON state, and the second switching valve 106-2 is in the OFF state. The high-temperature and high-pressure state of refrigerant gas flows into the first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 through the fifth port A2 and the eighth port D2, and the first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 act as condensers. The first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 condense the compressed refrigerant into a liquid phase of refrigerant, and the heat of the refrigerant is released to the surrounding environment through the condensation process. The high-temperature and high-pressure state of liquid phase refrigerant formed in the condenser flows through the subcooler 110 into the first pipe 30. In this process, the first throttling element 108-1 and the second throttling element 108-2 expand the high-temperature and high-pressure state of liquid phase refrigerant formed in the condenser into a low-pressure liquid phase refrigerant.

[0110] The refrigerant passing through the fifth port A2 and the eighth port D2 also enters the first indoor heat exchanger 201-1 through the second pipe 40, and the first indoor heat exchanger 201-1 acts as a condenser. The first indoor heat exchanger 201-1 condenses the compressed refrigerant into a liquid phase of refrigerant, and the heat of the refrigerant is released to the surrounding environment through the condensation process, so that the first indoor unit 201 realizes heating of the space. The high-temperature and high-pressure state of liquid phase refrigerant formed in the first indoor heat exchanger 201-1 flows through the fifth throttling element 201-2.

[0111] After passing through the sixth throttling element 202-2 and the seventh throttling element 203-2 (third indoor throttling element) respectively, the expanded low-pressure liquid-phase refrigerant enters the second indoor heat exchanger 202-1 and the third indoor heat exchanger 203-1 respectively. The second indoor heat exchanger 202-1 and the third indoor heat exchanger 203-1 serve as evaporators and are configured to evaporate the expanded refrigerant. The second indoor heat exchanger 202-1 causes the refrigerant in a low-temperature and low-pressure state to return to the first compressor 101-1 and the second compressor 101-2 via the third pipe 50, the fourth port D1, the third port C1, and the accumulator 112. The third indoor heat exchanger 203-1 causes the refrigerant in a low-temperature and low-pressure state to return to the first compressor 101-1 and the second compressor 101-2 via the accumulator 112.

[0112] It can be understood that, in the first working mode, the air conditioning system 100 operates at full load, so as to improve the refrigeration capacity of the air conditioning system 100.

[0113] The second working mode, as shown in FIG. 9, the user controls the air conditioning system 100 to execute the cooling mode (partial load) through the control terminal 70, the air conditioning system 100 operates at partial load, the refrigerant flow path of the third indoor heat exchanger 203-1 is cut off, and the third indoor heat exchanger 203-1 stops operating. The working mode of the second heat exchanger is the same as that in the cooling mode in the first embodiment, and will not be described here.

[0114] The third working mode, the user controls the air conditioning system 100 to execute the heating mode through the control terminal 70, the air conditioning system 100 cuts off the refrigerant flow path of the third indoor heat exchanger 203-1, and the third indoor heat exchanger 203-1 stops operating. The working mode of the second heat exchanger is the same as that when the air conditioning system 100 executes the heating mode, and will not be described here.

[0115] The fourth working mode, as shown in FIG. 10, the user controls the air conditioning system 100 to execute a dehumidification without cooling mode through the control terminal 70.

[0116] From a principle point of view, the first compressor 101-1 and the second compressor 101-2 compress the low-temperature and low-pressure refrigerant into a high-temperature and high-pressure refrigerant gas and discharge the compressed refrigerant gas. In this case, the first switching valve 106-1 is in an OFF state, the second switching valve 106-2 is in an ON state, the compressed refrigerant gas passes through the first port A1, the fourth port D1, enters the third pipe 50, and then flows into the second indoor heat exchanger 202-1, which acts as a condenser. The second indoor heat exchanger 202-1 condenses the compressed refrigerant into a high-temperature and high-pressure liquid-phase refrigerant, and the heat in the refrigerant is released to the surrounding environment through the condensation process. In this way, the temperature of the surrounding environment of the second indoor heat exchanger 202-1 can be increased, so that heating of the indoor space where the second indoor unit 202 is located can be achieved.

[0117] The high-temperature and high-pressure liquid-phase refrigerant formed in the condenser returns to the outdoor unit 10 side through the first pipe 30. In this process, the sixth throttling element 202-2, the first throttling element 108-1, and the second throttling element 108-2 expand the high-temperature and high-pressure liquid-phase refrigerant formed in the condenser into a low-pressure liquid-phase refrigerant. The first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 act as evaporators, evaporate the refrigerant expanded in the sixth throttling element 202-2, the first throttling element 108-1, and the second throttling element 108-2, and make the refrigerant in a low-temperature and low-pressure state return to the first compressor 101-1 and the second compressor 101-2 through the eighth port D2 and the seventh port C2, and the accumulator 112.

[0118] The high-temperature and high-pressure liquid-phase refrigerant formed in the condenser flows into the third indoor heat exchanger 203-1. In this process, the seventh throttling element 203-2 expands the high-temperature and high-pressure liquid-phase refrigerant formed in the condenser into a low-pressure liquid-phase refrigerant. The third indoor heat exchanger 203-1 acts as an evaporator, evaporates the refrigerant expanded in the seventh throttling element 203-2, and makes the refrigerant in a low-temperature and low-pressure state return to the first compressor 101-1 and the second compressor 101-2 through the fourth pipe 60 and the accumulator 112. The third indoor heat exchanger 203-1 can exchange heat with the material to be cooled (such as indoor air) to achieve a dehumidification effect, in which case the second indoor heat exchanger 202-1 is in a heating state, so that the second indoor unit 202 can dehumidify the indoor environment where it is located without lowering the temperature of the indoor environment.

[0119] In the process of condensing the formed high-temperature and high-pressure state liquid-phase refrigerant into the first indoor unit 201, the fifth throttling element 201-2 expands the high-temperature and high-pressure state liquid-phase refrigerant formed in the condenser into low-pressure liquid-phase refrigerant. The first indoor heat exchanger 201-1 acts as an evaporator, evaporates the refrigerant expanded in the fifth throttling element 201-2, and returns the refrigerant in a low-temperature and low-pressure state to the first compressor 101-1 and the second compressor 101-2 through the eighth port D2 and the seventh port C2, the accumulator 112.

[0120] On the basis of the fourth working mode, in the fifth working mode, the operation of the third indoor heat exchanger 203-1 can be stopped alone, and the heating operation of the second indoor heat exchanger 202-1 is retained, in which case the working states of the first switching valve 106-1 and the second switching valve 106-2 are maintained, and the first indoor unit 201 cools.

[0121] The sixth working mode, as shown in FIG. 11, is another dehumidification without temperature reduction mode controlled by the user through the control terminal 70.

[0122] From the principle point of view, in the sixth working mode, the first compressor 101-1 and the second compressor 101-2 compress the low-temperature and low-pressure refrigerant into high-temperature and high-pressure refrigerant gas and discharge the compressed refrigerant gas. In this case, the first switching valve 106-1 is in the OFF state, the second switching valve 106-2 is in the OFF state, the compressed refrigerant gas flows into the first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 through the fifth port A2 and the eighth port D2, the first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 act as condensers, and the first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 condense the compressed refrigerant into liquid phase, and the heat in the refrigerant is released to the surrounding environment through the condensation process.

[0123] In the process of condensing the formed high-temperature and high-pressure state liquid-phase refrigerant into the first indoor unit 201, the fifth throttling element 201-2 expands the high-temperature and high-pressure state liquid-phase refrigerant formed in the condenser into low-pressure liquid-phase refrigerant. The first indoor heat exchanger 201-1 acts as an evaporator, evaporates the refrigerant expanded in the fifth throttling element 201-2, and returns the refrigerant in a low-temperature and low-pressure state to the first compressor 101-1 and the second compressor 101-2 through the eighth port D2 and the seventh port C2, the accumulator 112.

[0124] The refrigerant passing through the fifth port A2 and the eighth port D2 also enters the first indoor heat exchanger 201-1 through the second pipe 40. The first indoor heat exchanger 201-1 functions as a condenser, and the first indoor heat exchanger 201-1 condenses the compressed refrigerant into liquid-phase refrigerant in a high-temperature and high-pressure state. The heat in the refrigerant is released to the ambient environment through the condensation process, so that the first indoor unit 201 achieves heating of the indoor space where it is located. The liquid-phase refrigerant in a high-temperature and high-pressure state formed by condensation in the first indoor heat exchanger 201-1 flows through the fifth throttling element 201-2.

[0125] The refrigerant gas discharged by the compressor enters the second indoor heat exchanger 202-1 through the first port A1, the fourth port D1, and the third pipe 50. The second indoor heat exchanger 202-1 functions as a condenser, and the second indoor heat exchanger 202-1 condenses the compressed refrigerant into liquid-phase refrigerant. The heat in the refrigerant is released to the ambient environment through the condensation process to increase the temperature of the indoor space where the second indoor heat exchanger 202-1 is located. The liquid-phase refrigerant in a high-temperature and high-pressure state formed by condensation in the second indoor heat exchanger 202-1 flows through the seventh throttling element 203-2.

[0126] After passing through the fifth throttling element 201-2 and the seventh throttling element 203-2, respectively, the expanded low-pressure liquid-phase refrigerant further enters the third indoor heat exchanger 203-1. The third indoor heat exchanger 203-1 functions as an evaporator, and evaporates the expanded refrigerant, so that the refrigerant absorbs heat from the ambient air to lower the temperature of the air and cause water in the air to be separated out, achieving the effect of dehumidification. The third indoor heat exchanger 203-1 causes the refrigerant in a low-temperature and low-pressure state to return to the first compressor 101-1 and the second compressor 101-2 via the fourth pipe 60 and the liquid accumulator 112.

[0127] It can be understood that in the sixth working mode, the second indoor heat exchanger 202-1 can increase the temperature of the indoor space where it is located, and the third indoor heat exchanger 203-1 can decrease the temperature and dehumidify the indoor space where it is located, so that the second indoor unit 202 can achieve dehumidification and non-cooling of the indoor space where it is located.

[0128] On the basis of the sixth working mode, the seventh working mode can stop the operation of the second indoor heat exchanger 202-1 alone, and only keep the third indoor heat exchanger 203-1 refrigeration (dehumidification) running. In this case, the working states of the first switching valve 106-1 and the second switching valve 106-2 remain unchanged, and the first indoor unit 201 heats.

[0129] It can be understood that only one first indoor unit 201 and one second indoor unit 202 are shown in the figure, and the same connection mode can be adopted, and the first indoor unit 201 and the second indoor unit 202 can also be configured with more units, and the number of the first indoor unit 201 and the second indoor unit 202 is not limited in some embodiments of the present disclosure.

[0130] In some embodiments, as shown in FIG. 1, the air conditioning system 100 further comprises a plurality of filters 113. The plurality of filters 113 are respectively arranged in the refrigerant pipelines in the first indoor unit 201, the second indoor unit 202 and the outdoor unit 10, and are configured to filter impurities in the flowing refrigerant. For example, the filter 113 is a filter screen.

[0131] In some embodiments, as shown in FIGS. 5 and 12, the air conditioning system 100 further comprises a controller 90. The controller 90 is arranged in a closed shell, for example, the shell is a metal piece, so as to improve the heat conduction performance and facilitate the heat dissipation of the controller 90.

[0132] The controller 90 comprises a processor and a memory. The processor can be a special-purpose processor, a central processing unit (CPU) or the like. The processor can access the memory to execute instructions or application programs stored in the memory to realize related functions, for example, driving the frequency of the compressor through the program. The memory can include volatile memory and / or non-volatile memory.

[0133] The controller 90 further comprises a plurality of interfaces. The plurality of interfaces can be in communication connection with various types of sensors described above to receive detection values of various types of sensors. The plurality of interfaces are also in communication connection with devices such as the first compressor 101-1 and the second compressor 101-2 to output control instructions generated by the processor. For example, the plurality of interfaces include input interfaces and output interfaces.

[0134] The controller 90 further comprises a communication interface, which can support different wireless communication protocols, such as wireless fidelity (Wi-Fi), Bluetooth, near field communication, narrow band internet of things (NB-IoT), etc., to be in communication connection with other electronic devices, including but not limited to a cloud server, a programmable logic controller, a computer (upper computer), a smart phone, a tablet computer, a personal digital assistant (PDA), a smart control tool, a wearable device and a vehicle-mounted device, etc.

[0135] In some embodiments, when the air conditioning system 100 operates in the heating mode, the second outdoor heat exchanger 107-2 can achieve corresponding control of refrigerant storage, refrigerant release and refrigerant locking through the second throttling element 108-2 and the third throttling element 109, and the second outdoor heat exchanger 107-2 can variably store refrigerant, so that the refrigerant in the air conditioning system 100 is always at a suitable level.

[0136] It should be noted that the air conditioning system 100 operates in the heating mode means that the heating load of the air conditioning system 100 is greater than the cooling load, and the outdoor unit 10 operates in the heating operation, that is, the first outdoor heat exchanger 107-1 and the second outdoor heat exchanger 107-2 act as evaporators.

[0137] In some embodiments, as shown in FIGS. 5, 12 and 13, the controller 90 is configured to perform steps S1 to S8 to achieve corresponding control of refrigerant storage, refrigerant release and refrigerant locking.

[0138] In step S1, the opening degree of the second throttling element 108-2 is controlled according to the superheat degree, and the third throttling element 109 is kept fully open.

[0139] In step S2, it is judged whether the relationship between the heating load rate, the set lower threshold value and the set upper threshold value, when the heating load rate is lower than the set lower threshold value, step S3 is performed, when the heating load rate is higher than the set upper threshold value, step S5 is performed, and when the heating load rate is between the set lower threshold value and the set upper threshold value, step S7 is performed.

[0140] For example, the heating load rate is between the set lower threshold value and the set upper threshold value means that the heating load rate is less than or equal to the upper threshold value, and greater than or equal to the set lower threshold value.

[0141] In step S3, it is judged whether the real-time working condition meets the refrigerant storage condition; if yes, step S4 is performed.

[0142] For example, judging whether the real-time working condition meets the refrigerant storage condition includes judging whether the compressor discharge pressure, the compressor operating frequency, and the temperature difference between the compressor discharge temperature and the corresponding saturated temperature of the compressor discharge pressure meet the refrigerant storage condition.

[0143] In step S4, the second throttling element 108-2 is controlled to be fully open, and the third throttling element 109 is controlled to be fully closed, so as to store excess refrigerant through the second outdoor heat exchanger 107-2.

[0144] In step S5, it is judged whether the real-time working condition meets the refrigerant release condition; if yes, step S6 is performed.

[0145] For example, the determination of whether the real-time working condition satisfies the refrigerant releasing condition includes the determination of whether the compressor discharge pressure, the compressor operating frequency, and the temperature difference between the compressor discharge temperature and the saturation temperature corresponding to the compressor discharge pressure satisfy the refrigerant releasing condition.

[0146] At step S6, the second throttling element 108-2 is controlled to be fully closed, the third throttling element 109 is controlled to be fully closed, and the third throttling element 109 is controlled to perform a gradual valve opening operation from the fully closed state, so that the second outdoor heat exchanger releases the refrigerant.

[0147] For example, during the opening of the third throttling element 109, if the real-time working condition no longer satisfies the refrigerant releasing condition, the current valve opening degree of the third throttling element 109 is maintained.

[0148] For example, the controller 90 is further configured to, during the opening of the third throttling element 109, determine whether the third throttling element 109 reaches the maximum opening degree, and if the third throttling element 109 reaches the maximum opening degree, control the opening degree of the second throttling element 108-2 according to the superheat degree, maintain the third throttling element 109 fully open, and release the excess refrigerant through the second outdoor heat exchanger 107-2.

[0149] At step S7, it is determined whether the real-time working condition satisfies the refrigerant locking condition, and if yes, step S8 is performed.

[0150] For example, the determination of whether the real-time working condition satisfies the refrigerant locking condition includes the determination of whether the compressor discharge pressure, the compressor operating frequency, and the temperature difference between the compressor discharge temperature and the saturation temperature corresponding to the compressor discharge pressure satisfy the refrigerant locking condition.

[0151] At step S8, the second throttling element 108-2 is controlled to be fully closed, and the third throttling element 109 is controlled to be fully closed, so as to lock the excess refrigerant through the second outdoor heat exchanger 107-2.

[0152] In some embodiments, when the air conditioning system 100 is not operating in the heating mode (e.g., operating in the cooling mode), the second throttling element 108-2 and the third throttling element 109 are both controlled to be fully open.

[0153] In some embodiments, the refrigerant storage condition includes that the compressor discharge pressure is higher than the first corrected target pressure maximum value, the actual compressor operating frequency is lower than the first set compressor frequency threshold, and the temperature difference between the compressor discharge temperature and the saturation temperature corresponding to the compressor discharge pressure is lower than the first set temperature difference threshold.

[0154] For example, the maximum target pressure is generated based on the temperature difference between the set temperature and the return air temperature of the heating indoor unit. A larger temperature difference between the set temperature and the return air temperature indicates a larger maximum target pressure. The first corrected maximum target pressure is the sum of the maximum target pressure and the corrected value. The first set compressor frequency threshold is generated based on the calculated compressor frequency. The calculated compressor frequency is the compressor operating frequency calculated based on an empirical formula based on the current operating load and the corresponding indoor demand.

[0155] For example, the compressor frequency can be calculated using the empirical formula (1):

[0156] In formula (1), C on (i) is the total operating capacity (HP) of the i-th cooling Thermo ON indoor unit, H on (j) is the total operating capacity of the jth heating Thermo ON indoor unit; HTh off (k) is the total capacity of the kth heating Thermo OFF indoor unit, expressed in HP; H off (m) is the total capacity of the mth indoor unit with heating stopped, expressed in HP, where A, B, C and D are constants.

[0157] In formula (1), Khp is the exhaust pressure correction coefficient; when P d ≥P do When Khp=E-(P dmax -P do )×F, and 0.1≤Khp≤1; otherwise Khp=1. KT is the outdoor ambient temperature correction coefficient, KT=G×T a +H, and G and H are constant. K c (i) and K h (j) is the temperature difference capacity correction coefficient of the i-th indoor unit, K c (i) and K h (j) Based on the difference between the return air temperature and the set temperature, the greater the absolute value of the difference between the return air temperature and the set temperature, the higher the K c (i) and K h (j) is also larger. The first set compressor frequency threshold is calculated by multiplying the compressor frequency by a first proportional coefficient. The first proportional coefficient is a constant obtained under experimental conditions and stored as a constant for easy access at any time. The first proportional coefficient can be set to be less than 1. The first set temperature difference threshold is a constant. The first set temperature difference threshold is pre-set and stored.

[0158] In some embodiments, the refrigerant release condition comprises: the compressor discharge pressure is lower than a second corrected target pressure maximum value, the actual compressor operating frequency is higher than a second set compressor frequency threshold, and a temperature difference between the compressor discharge temperature and a saturation temperature corresponding to the compressor discharge pressure is higher than a second set temperature difference threshold.

[0159] For example, the target pressure maximum value is generated based on a temperature difference between a set temperature of the heating indoor unit and a return air temperature, and the greater the temperature difference between the set temperature and the return air temperature, the greater the target pressure maximum value. The second corrected target pressure maximum value is the difference between the target pressure maximum value and a correction value. The set compressor frequency threshold is generated based on a calculated compressor frequency. The calculated compressor frequency is a compressor operating frequency calculated based on an empirical formula according to a current starting load and a corresponding indoor demand condition.

[0160] It should be noted that the compressor frequency can be calculated by the above formula (1), which will not be described here.

[0161] The second set compressor frequency threshold is the product of the calculated compressor frequency and a second proportional coefficient, and the second proportional coefficient is a constant obtained under experimental conditions and stored in the form of a constant for ready use. The second proportional coefficient can be set to be greater than 1.

[0162] The second set temperature difference threshold is a constant, and the second set temperature difference threshold is pre-set and stored. The second set temperature difference threshold is higher than the first set temperature difference threshold.

[0163] When neither the refrigerant storage condition nor the refrigerant release condition is met, it is determined that the refrigerant locking condition is met.

[0164] It should be noted that any one of the technical solutions disclosed in the present disclosure can solve one or more of the above technical problems and achieve certain disclosed purposes to some extent; multiple technical disclosures can also be combined into one overall scheme to solve one or more of the above technical problems and achieve certain disclosed purposes; or part of the technical disclosures can be combined into one overall scheme, while related technologies and degraded schemes are used, but the degraded trend can be compensated by the technical disclosure means, and the overall technical problems and the disclosed purposes are solved to some extent; each technical disclosure is combined into a complete technical scheme, which constitutes an organic and indivisible overall scheme, and solves the technical problems and achieves certain disclosed purposes.

[0165] Any technical disclosure in the present disclosure, and the recombination of multiple technical disclosures can form a complete technical scheme, and can solve one or more of the above technical problems to achieve the disclosed purposes, which belongs to the content of the present disclosure and is directly and without doubt determined according to the content of the present disclosure.

[0166] The above merely provides the specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto, any person skilled in the art can think of the changes or replacements within the technical range disclosed by the present disclosure, which should be covered in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. An air conditioning system comprising: an outdoor unit, the outdoor unit comprising an outdoor heat exchanger and a compressor; First tube; Second tube; a first indoor unit connected to the outdoor unit via the first pipe and the second pipe; the first indoor unit comprising a first shell and a first indoor heat exchanger disposed in the first shell; The third tube; Fourth tube; A second indoor unit, comprising a second shell and a second indoor heat exchanger disposed in the second shell; the first indoor heat exchanger and the second indoor heat exchanger are respectively connected to the first pipe; the second indoor unit satisfies one of the following conditions: The second indoor unit is connected to the outdoor unit via the first pipe and the third pipe; or The second indoor unit is connected to the outdoor unit via the first pipe, the third pipe and the fourth pipe; Wherein, during the operation of the air-conditioning system, the second indoor heat exchanger satisfies one of the following conditions: The second indoor heat exchanger serves as an evaporator; and The second indoor heat exchanger serves as a condenser; During operation of the air-conditioning system, the first indoor heat exchanger and the outdoor heat exchanger satisfy one of the following conditions: The first indoor heat exchanger serves as a condenser, and the outdoor heat exchanger serves as a condenser; and The first indoor heat exchanger serves as an evaporator, and the outdoor heat exchanger serves as an evaporator.

2. The air conditioning system according to claim 1, further comprising a control terminal, the control terminal being matched with the second indoor unit and configured to receive a mode selection instruction input by a user; in, When the control terminal receives a heating mode instruction, the second indoor heat exchanger serves as a condenser, and the first indoor heat exchanger and the outdoor heat exchanger serve as evaporators; When the control terminal receives a cooling mode instruction, the second indoor heat exchanger serves as an evaporator, and the first indoor heat exchanger and the outdoor heat exchanger serve as condensers.

3. The air conditioning system according to claim 1 or 2, wherein: The first housing is disposed in a first space, and the first indoor heat exchanger is configured to exchange heat with a medium in the first space; The second housing is disposed in a second space, and the second indoor heat exchanger is configured to exchange heat with a medium in the second space; The first space and the second space are independently arranged.

4. The air conditioning system according to any one of claims 1 to 3, wherein: The first indoor unit further includes a first indoor fan, which is disposed in the first housing; the first housing is disposed in the first space and includes a first return air port and a first air supply port, the first air supply port being connected to the external space; The second housing is disposed in a second space, and the second indoor heat exchanger is configured to exchange heat with a medium in the second space; The first return air inlet is connected to the second space, and the return air from the second space enters the first shell from the first return air inlet, exchanges heat with the first indoor heat exchanger, and is discharged to the external space. 5 . The air conditioning system according to claim 1 , further comprising a fifth throttling element provided on a side of the first indoor heat exchanger connected to the first pipe. 6 . The air conditioning system according to claim 1 , further comprising a sixth throttling element provided on a side of the second indoor heat exchanger connected to the first pipe.

7. The air conditioning system according to any one of claims 1 to 6, wherein: The second indoor unit further includes a third indoor heat exchanger, the third indoor heat exchanger is disposed in the second shell, and the first indoor heat exchanger, the second indoor heat exchanger and the third indoor heat exchanger are respectively connected to the first pipe; Wherein, during the operation of the air-conditioning system, the third indoor heat exchanger serves as an evaporator.

8. The air conditioning system according to claim 7, further comprising a control terminal, the control terminal being matched with the second indoor unit and configured to receive a mode selection instruction input by a user; in, When the control terminal receives a heating mode instruction, the second indoor unit is configured to: use the second indoor heat exchanger as a condenser, and use the first indoor heat exchanger and the outdoor heat exchanger as evaporators; When the control terminal receives a cooling mode instruction, the second indoor unit is configured to: use the second indoor heat exchanger as an evaporator, or use the second indoor heat exchanger and the third indoor heat exchanger as evaporators; The second indoor unit is further configured to: use the first indoor heat exchanger and the outdoor heat exchanger as a condenser; When the control terminal receives a dehumidification instruction, the second indoor unit is configured to: use the second indoor heat exchanger as a condenser and the third indoor heat exchanger as an evaporator; the second indoor unit is also configured to: use the first indoor heat exchanger and the outdoor heat exchanger as an evaporator, or use the first indoor heat exchanger and the outdoor heat exchanger as a condenser. 9 . The air conditioning system according to claim 8 , further comprising a seventh throttling element provided on a side of the third indoor heat exchanger connected to the first pipe.

10. The air conditioning system according to any one of claims 1 to 9, further comprising: a first solenoid valve; a third pressure reducer; The first switching valve includes: a first port connected to a discharge end of the compressor; The second port is connected to the third port via the first solenoid valve and the third pressure reducer; The third port is connected to the suction end of the compressor; and a fourth port connected to the third tube; a second solenoid valve; a fourth pressure reducer; and The second switching valve includes: a first port connected to the exhaust port of the compressor; The second port is connected to the third port via the second solenoid valve and the fourth pressure reducer; The third port is connected to the suction end of the compressor; and The fourth port is connected to the outdoor heat exchanger and the second pipe.

Images