Air conditioning equipment

Abstract

The air conditioning device includes: an outdoor unit with a compressor and an outdoor heat exchanger, an indoor unit with an indoor heat exchanger, a gas-liquid separator storing liquid refrigerant, a refrigerant circuit for the refrigerant to circulate in sequence; a first valve element for sealing the refrigerant into the liquid pipe on one side of the indoor heat exchanger before the indoor unit is shut down during heating operation; a condenser and an evaporator are outdoor and indoor heat exchangers respectively; and a control unit is configured to not perform defrosting control but perform heating operation control to shut down the compressor when a first system parameter including the mass flow rate of the refrigerant in the outdoor liquid pipe section meets a forced defrosting condition and a second system parameter including the liquid level of the refrigerant in the gas-liquid separator meets a regulation control condition, and restart the compressor from the start of the shutdown to a preset shutdown time. The present invention can prevent the excessive liquid refrigerant stored in the gas-liquid separator from entering the compressor during multiple starts and stops and defrosting, causing damage.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioning equipment, and in particular to an air conditioning equipment. Background Art

[0002] In recent years, with the continuous improvement of people's living standards and the continuous development of the real estate industry, more and more air-conditioning products are equipped with large-capacity units, and the corresponding compressor displacement is also getting larger and larger. At the same time, due to the increase in urban population, the increase in building density, and the increasingly complex and diverse outdoor environment, higher requirements are placed on the stable and reliable operation of air-conditioning outdoor units. The compressor is the core component of the air-conditioning outdoor unit. Among the causes of compressor wear, the compressor sucking too much liquid refrigerant is one of the main reasons for the damage caused by the compressor liquid compression.

[0003] Most multi-split units have one outdoor unit that connects many indoor units. If there is a modular combination, there will be more indoor units connected. Depending on the usage scenario, the pipe connections of the indoor units are complex and diverse. At the same time, different users use them in different ways. Therefore, the connection method of the indoor units and the user's usage habits will have a certain impact on the reliability of the outdoor units. In order to cope with the different usage habits of users and improve the reliability of the unit operation, during the product development stage, repeated tests and verifications will be carried out according to different environmental conditions, such as continuous start and stop (ON / OFF) tests of the indoor units.

[0004] During the actual operation of the multi-split unit in the heating mode, before the unit is shut down, the refrigerant is generally brought from the low-pressure side piping of the system to the high-pressure side piping. The main purpose of this operation mode is to prevent the compressor from sucking too much liquid refrigerant from the low-pressure side when the unit is started next time, thereby causing the compressor to be compressed. When the air-conditioning unit is in heating operation, generally, a forced defrost will be performed when the heating operation accumulates to a certain time. The main purpose is to prevent excessive frost on the heat exchanger of the air-conditioning outdoor unit, which affects the heat exchange efficiency of the unit.

[0005] Combined with the actual operation of the multi-split unit, it is found that the unit will have the following situation: when the air-conditioning unit is in heating operation and the indoor unit is turned on and off every few minutes, the outdoor unit will repeatedly introduce the refrigerant from the low-pressure side piping of the system to the high-pressure side piping, so that the refrigerant accumulated in the indoor unit will gradually increase. As time goes by, the cumulative time of heating operation meets the conditions for forced defrosting. When the unit is started again, the four-way valve will immediately switch to defrost operation. At this time, a large amount of refrigerant accumulated in the indoor unit will enter the gas-liquid separator and then enter the compressor. Because there is too much liquid refrigerant, the gas-liquid separator cannot be separated in time, and the compressor will inhale too much liquid refrigerant, causing liquid compression to damage the compressor, seriously affecting the service life of the compressor. Summary of the invention

[0006] The first aspect of the present application provides an air conditioning device, which includes an outdoor unit, an indoor unit, a gas-liquid separator, and a refrigerant circuit for circulating refrigerant. The outdoor unit has a compressor and an outdoor heat exchanger, and the indoor unit has an indoor heat exchanger. In the refrigerant circuit, the refrigerant circulates in sequence through the compressor, the condenser, the throttling element, and the evaporator; one of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger; the gas-liquid separator is configured to store liquid refrigerant flowing out of the evaporator and is connected between the evaporator and the suction side of the compressor through piping. The refrigerant circuit is also provided with a first valve element, which is used to seal the refrigerant into the liquid pipe on one side of the indoor heat exchanger before the indoor unit is shut down during heating operation. The control unit of the air-conditioning equipment is configured to execute heating operation control by shutting down the compressor instead of executing defrost control, and restarting the compressor from the start of shutdown to a preset shutdown time when a first system parameter including the mass flow rate of the refrigerant in the outdoor liquid pipe section meets the forced defrost condition and a second system parameter including the liquid level of the refrigerant in the gas-liquid separator meets the regulation control condition.

[0007] In some embodiments of the present invention, the control unit is configured to perform defrost control during heating operation when the first system parameter satisfies the forced defrost condition and the second system parameter does not satisfy the regulation control condition.

[0008] In some embodiments of the present invention, the defrost control of the control unit specifically includes: when the mass flow rate of the refrigerant in the outdoor liquid pipe section is below the set mass flow rate, the cumulative heating operation time is above the set heating operation cumulative time, the compressor operation time is above the set compressor operation time, the minimum outdoor ambient temperature is below the set ambient temperature, and the minimum temperature of the refrigerant in the outdoor liquid pipe section is below the set refrigerant temperature, the first forced defrost condition is met, and the control of circulating the refrigerant in the refrigerant circuit in reverse order of the refrigeration operation is executed to defrost the outdoor heat exchanger.

[0009] In some embodiments of the present invention, the defrost control of the control unit specifically includes: when the mass flow rate of the refrigerant in the outdoor liquid pipe section is above the set mass flow rate, the cumulative heating operation time is above the set heating operation cumulative time, the compressor operation time is above the set compressor operation time, the heating operation continuous operation time is above the set heating operation continuous operation time, the minimum outdoor ambient temperature is below the set ambient temperature, and the minimum temperature of the refrigerant in the outdoor liquid pipe section is below the set refrigerant temperature, when the second forced defrost condition is met, control is executed to circulate the refrigerant in the refrigerant circuit in reverse order of the refrigeration operation to defrost the outdoor heat exchanger.

[0010] In order to further accurately determine the start time of defrost control, in some embodiments of the present invention, the minimum temperature of the refrigerant in the outdoor liquid pipe section is the minimum temperature of the refrigerant in the outdoor liquid pipe section at the end of the start-up phase of heating operation of the air-conditioning equipment.

[0011] In some embodiments of the present invention, the minimum temperature value of the refrigerant in the outdoor liquid pipe section is the minimum temperature value of the refrigerant in the outdoor liquid pipe section when the air conditioner ends defrosting control once and restarts heating operation.

[0012] In some embodiments of the present invention, the second system parameter also includes a minimum compressor exhaust temperature, and the control unit is configured to, when the liquid level of the refrigerant in the gas-liquid separator and the minimum compressor exhaust temperature both meet the regulation control conditions, not perform defrost control but perform heating operation control to shut down the compressor, and restart the compressor from the start of shutdown to a preset shutdown time.

[0013] In some embodiments of the present invention, the conditions for entering the regulation control are specifically: when the liquid level of the refrigerant in the gas-liquid separator is above the set liquid level, the minimum exhaust temperature of the compressor is below the set exhaust temperature and the maintenance time reaches the set maintenance time, the first regulation control condition is met, and the defrost control is not performed but the compressor is shut down, and the heating operation control is performed from the start of shutdown to the preset shutdown time to restart the compressor.

[0014] In some embodiments of the present invention, the conditions for entering the regulation and control are specifically: when the liquid level of the refrigerant in the gas-liquid separator is above the set liquid level, the minimum exhaust temperature of the compressor is below the set exhaust temperature and the cumulative maintenance time within the set cycle duration reaches the set maintenance time, the second regulation and control condition is met, and the defrost control is not performed but the compressor is shut down, and the heating operation control of the compressor is started from the start of the shutdown to the preset shutdown time.

[0015] In some embodiments of the present invention, the exhaust temperature is set to be greater than the refrigerant saturation temperature corresponding to the compressor exhaust pressure.

[0016] In some embodiments of the present invention, the control unit is configured such that, when executing regulation control, when the actual timing duration reaches the set period length, the set period is reset to zero and the accumulated maintenance time is reset to zero.

[0017] In some embodiments of the present invention, the control unit is configured to reset the setting cycle to zero when performing defrost control.

[0018] In some embodiments of the present invention, the control unit is configured to: when executing the regulation control, not execute the defrost control but execute the heating operation control of stopping the compressor, resetting the throttling element to the set opening of the heating operation, and restarting the compressor from the start of the shutdown to the preset shutdown time.

[0019] In some embodiments of the present invention, the set opening is smaller than the opening of the throttling element generated during the heating operation.

[0020] In some embodiments of the present invention, the opening degree is set to 75% of the opening degree of the throttling element generated by the heating operation.

[0021] In some embodiments of the present invention, the control unit is configured to: when executing the regulation control, after the compressor is restarted, if the liquid level of the refrigerant in the gas-liquid separator is above the set liquid level, execute the control of reducing the opening of the throttling element from the set opening until the liquid level of the refrigerant in the gas-liquid separator is below the set liquid level.

[0022] In some embodiments of the present invention, the control unit is configured to: when executing regulation control, execute the control of reducing the opening of the throttling element from the set opening until the liquid level of the refrigerant in the gas-liquid separator is below the set liquid level, and maintain the current opening of the throttling element until the compressor exhaust temperature no longer meets the regulation control conditions.

[0023] In some embodiments of the present invention, the air conditioning device further comprises:

[0024] A plate heat exchanger, the plate heat exchanger is arranged in the outdoor unit;

[0025] The plate heat exchanger is fluidly connected to an auxiliary heat exchange pipeline provided with an auxiliary electronic expansion valve. The refrigerant in the refrigerant circuit circulates into the first heat exchange pipeline of the plate heat exchanger. The refrigerant flowing out of the auxiliary electronic expansion valve circulates into the second heat exchange pipeline of the plate heat exchanger and exchanges heat with the refrigerant in the first heat exchange pipeline.

[0026] The present invention provides an air-conditioning device. On the one hand, the air-conditioning device adds the mass flow rate of the refrigerant in the outdoor liquid pipe section to the first system parameter used to determine the forced defrost, and judges whether further intervention is needed for the defrost control according to the mass flow rate of the refrigerant in the outdoor liquid pipe section; on the other hand, when the forced defrost condition is met, the defrost is temporarily suspended, and it is further judged whether the second system parameter including the liquid level of the refrigerant in the gas-liquid separator meets the regulation and control condition, and corresponding control is performed according to the liquid level height of the refrigerant in the gas-liquid separator. When the liquid level height of the refrigerant meets the regulation and control condition, the defrost control is not performed but the compressor is shut down, and the heating operation control of restarting the compressor from the start of the shutdown to a preset shutdown time is performed, so as to protect the compressor and enable the unit to operate stably and reliably. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic structural block diagram of an air conditioning device according to some embodiments is shown;

[0028] Figure 2 A schematic diagram of a refrigerant cycle for cooling operation of an air-conditioning device according to some embodiments is shown;

[0029] Figure 3 A schematic diagram of a refrigerant cycle of a heating operation of an air-conditioning device according to some embodiments is shown;

[0030] Figure 4 shows a flow chart of a control unit according to some embodiments;

[0031] Figure 5 shows a flow chart of a control unit according to some embodiments;

[0032] Figure 6 shows a flow chart of a control unit according to some embodiments;

[0033] Figure 7 shows a flow chart of a control unit according to some embodiments;

[0034] Figure 8 shows a flow chart of a control unit according to some embodiments;

[0035] Fig. 9 shows a flow chart of a control unit according to some embodiments;

[0036] Fig.10 A schematic block diagram of a circuit structure of an air conditioning device according to some embodiments is shown;

[0037] Fig.11 shows a flow chart of a control unit according to some embodiments;

[0038] Fig.12 shows a flow chart of a control unit according to some embodiments;

[0039] Fig.13 A schematic block diagram of a circuit structure of an air conditioning device according to some embodiments is shown;

[0040] Fig.14 shows a flow chart of a control unit according to some embodiments;

[0041] Fig.15 shows a flow chart of a control unit according to some embodiments;

[0042] Fig.16shows a flow chart of a control unit according to some embodiments;

[0043] Fig.17 A schematic block diagram of a circuit structure of an air conditioning device according to some embodiments is shown;

[0044] Fig.18 A schematic block diagram of a circuit structure of an air conditioning device according to some embodiments is shown. DETAILED DESCRIPTION

[0045] In order to make the purpose and implementation method of the present application clearer, the exemplary implementation method of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0046] It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their common and usual meanings.

[0047] The terms "first", "second", "third", etc. in the specification and claims of this application and the above drawings are used to distinguish similar or similar objects or entities, and do not necessarily mean to limit a specific order or sequence, unless otherwise noted. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances.

[0048] The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device comprising a list of components is not necessarily limited to all the components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0049] In view of the problem that the indoor unit is constantly started and stopped (ON / OFF) during heating operation, for example, when it is started and stopped (ON / OFF) every few minutes, the refrigerant will be introduced from the low-pressure side piping of the system to the high-pressure side piping many times, resulting in a gradual increase in the refrigerant accumulated in the indoor unit. When the cumulative heating operation time meets the forced defrosting conditions, a large amount of refrigerant accumulated in the indoor unit enters the gas-liquid separator and then enters the compressor, causing the compressor to inhale too much liquid refrigerant, causing liquid compression to damage the compressor, and affecting the service life of the compressor, an air-conditioning device 10 is designed and provided.

[0050] Figure 11 is a schematic diagram of the refrigerant circuit of the air conditioning device 10 provided in this embodiment. The air conditioning device 10 adopts a compression refrigeration cycle, and has four main components, namely, a compressor 100, a condenser (high-temperature heat source), a throttling element 102, and an evaporator (low-temperature heat source), to form a refrigerant circuit. In the refrigerant circuit, the refrigerant circulates sequentially through the compressor 100, the condenser, the throttling element 102, and the evaporator.

[0051] In this embodiment, the cooling and heating cycle of the air conditioning device 10 includes a series of processes involving compression, condensation, expansion and evaporation to cool or heat the indoor space.

[0052] The low-temperature and low-pressure refrigerant enters the compressor 100, which compresses it into a high-temperature and high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

[0053] The throttling element 102, for example, an electronic expansion valve, expands the high-temperature and high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant expanded in the electronic expansion valve and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor 100. The evaporator can achieve a refrigeration effect by utilizing the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled. In the entire cycle, the air conditioning device 10 can adjust the temperature of the indoor space.

[0054] The outdoor unit 30 of the air-conditioning device 10 refers to a part of the refrigeration cycle including the compressor 100, the outdoor heat exchanger 300 and the outdoor fan, the indoor unit 20 of the air-conditioning device 10 includes a part of the indoor heat exchanger 200 and the indoor fan, and a throttling element 102 (such as a capillary tube or an electronic expansion valve) can be provided in the indoor unit 20 or the outdoor unit 30.

[0055] In an optional embodiment, if Figure 1 As shown, the throttling element 102 is provided in the outdoor unit 30 .

[0056] The indoor heat exchanger 200 and the outdoor heat exchanger 300 function as a condenser or an evaporator. When the indoor heat exchanger 200 functions as a condenser, the air conditioning apparatus 10 performs a heating mode, and when the indoor heat exchanger 200 functions as an evaporator, the air conditioning apparatus 10 performs a cooling mode.

[0057] The indoor heat exchanger 200 and the outdoor heat exchanger 300 are switched to function as a condenser or an evaporator, generally using a four-way valve 103 . For details, please refer to the configuration of the conventional air conditioning device 10 , which will not be described in detail here.

[0058] The refrigeration operation working principle of the air-conditioning equipment 10 is: the compressor 100 works to make the indoor heat exchanger 200 (in the indoor unit 20, it is the evaporator at this time) in an ultra-low pressure state, and the liquid refrigerant in the indoor heat exchanger 200 evaporates rapidly to absorb heat. The wind blown by the indoor fan is cooled by the indoor heat exchanger 200 coil and becomes cold wind to be blown into the room. The evaporated refrigerant is pressurized by the compressor 100 and condensed into liquid under the high pressure environment of the outdoor heat exchanger 300 (in the outdoor unit 30, it is the condenser at this time), releasing heat, and dissipating the heat into the atmosphere through the outdoor fan. Such a cycle achieves the cooling effect.

[0059] Figure 2 The refrigerant cycle process of the refrigeration operation is shown. As shown by the arrow Fcool_1 in the figure, the low-temperature and low-pressure refrigerant enters the compressor 100, and the compressor 100 compresses it into a refrigerant gas in a high-temperature and high-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the outdoor heat exchanger 300. The outdoor heat exchanger 300 condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process. The throttling element 102, taking the electronic expansion valve as an example, expands the liquid phase refrigerant in a high-temperature and high-pressure state condensed in the outdoor heat exchanger 300 into a low-pressure liquid phase refrigerant. The indoor heat exchanger 200 evaporates the refrigerant expanded in the electronic expansion valve, and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor 100. The indoor heat exchanger 200 can achieve a refrigeration effect by utilizing the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled.

[0060] The heating working principle of the air conditioning device 10 is as follows: the gaseous refrigerant is pressurized by the compressor 100 to become a high-temperature and high-pressure gas, enters the indoor heat exchanger 200 (the condenser at this time), condenses and liquefies to release heat, becomes a liquid, and heats the indoor air at the same time, thereby achieving the purpose of increasing the indoor temperature. The liquid refrigerant is decompressed by the throttling element 102 and enters the outdoor heat exchanger 300 (the evaporator at this time), evaporates and vaporizes to absorb heat, becomes a gas, and absorbs heat from the outdoor air (the outdoor air becomes colder), becomes a gaseous refrigerant, and enters the compressor 100 again to start the next cycle.

[0061] Figure 3The refrigerant cycle process of the heating operation is shown. As shown by the arrow Fheat_1 in the figure, the low-temperature and low-pressure refrigerant enters the compressor 100, and the compressor 100 compresses it into a high-temperature and high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the indoor heat exchanger 200. The indoor heat exchanger 200 condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process. The throttling element 102, taking the electronic expansion valve as an example, expands the liquid phase refrigerant in the high-temperature and high-pressure state condensed in the indoor heat exchanger 200 into a low-pressure liquid phase refrigerant. The outdoor heat exchanger 300 evaporates the refrigerant expanded in the electronic expansion valve and returns the refrigerant gas in the low-temperature and low-pressure state to the compressor 100. In the whole cycle, the air conditioning device 10 can adjust the temperature of the indoor space. Since the outdoor heat exchanger 300 operates outdoors and the ambient temperature is low, a frost layer will appear on its surface. The frost layer needs to be processed to ensure the heat exchange efficiency of the outdoor heat exchanger 300.

[0062] In an optional embodiment, if Figure 1 As shown, the air conditioning device 10 further includes a gas-liquid separator 104 , which is configured to store liquid refrigerant flowing out of the evaporator. The gas-liquid separator 104 is connected between the evaporator and the suction side of the compressor 100 through a pipe.

[0063] In an optional embodiment, the air conditioning device 10 may include a plurality of indoor units 20, and the plurality of indoor units 20 work in conjunction with an outdoor unit 30, such as a "one-to-many" air conditioning unit.

[0064] In another optional embodiment, the air conditioning device 10 may include a plurality of outdoor units 30. The outdoor units 30 may be configured to work in groups, for example, two units are grouped together, and the corresponding indoor units 20 are provided. Each outdoor unit 30 may be provided with one or more compressors, and AC power is supplied to the compressors through a frequency conversion device. When the output frequency of the frequency conversion device changes, the speed of the compressor changes, and different air conditioning capacities are achieved.

[0065] In an optional embodiment, the indoor unit 20 may adopt an independent air supply structure, such as a wall-mounted air supply structure, a floor-standing air supply structure, a duct-type air supply structure, or an air supply structure embedded in the ceiling, etc.

[0066] Each indoor unit 20 is correspondingly provided with a wired controller, and the wired controller is provided with an operation interface for inputting a set temperature and an operation mode, and a display interface for displaying the real-time temperature or operation status of the air-conditioned room.

[0067] In an optional implementation, each indoor unit 20 is provided with a corresponding remote controller, and the remote controller is provided with buttons for inputting set temperature and operation mode.

[0068] In an optional embodiment, each indoor unit 20 is correspondingly connected to a mobile terminal for communication. The mobile terminal has an application interface, through which the set temperature and operation mode can be input and the real-time temperature or operation status of the air-conditioned room can be displayed.

[0069] In an optional implementation, an outdoor heat exchanger 300 is provided in each outdoor unit 30, and the refrigerant in the outdoor heat exchanger 300 can exchange heat with an external medium, and the external medium can be water or air.

[0070] In an optional embodiment, the number of the electronic expansion valve and the four-way valve 103 as the throttling element 102 can be designed according to functional requirements. In this embodiment, one electronic expansion valve and one four-way valve 103 as the throttling element 102 are provided.

[0071] The outdoor unit 30 is provided with an outdoor mainboard, and the outdoor mainboard is preferably provided with an internal controller. The internal controller is configured to drive the frequency conversion device to work, receive and process sampling signals of various sensors, and realize necessary communication functions.

[0072] In an optional embodiment, the sensor includes a flow detector and a temperature sensor 108 arranged on the liquid pipe connecting the indoor heat exchanger 200 and the outdoor heat exchanger 300 and located on one side of the outdoor unit 30, a liquid level sensor arranged in the gas-liquid separator 104 to detect the liquid level of the liquid refrigerant, a temperature sensor 112 arranged in the outdoor unit 30 to detect the outdoor ambient temperature, a temperature sensor 114 and a pressure sensor 116 arranged on the exhaust side of the compressor 100, etc.

[0073] The internal controller includes electrical components such as a storage unit, a processor, an input / output interface, and a communication interface.

[0074] The storage unit may include a volatile memory and / or a non-volatile memory. The storage unit is configured to store instructions or data associated with at least one component of the outdoor unit 30, such as storing an application program. Exemplarily, the application program may be to control the throttling element 102, the compressor 100, and the four-way valve 103 to make the air conditioning device 10 perform heating operation or cooling operation.

[0075] The processor may be a dedicated processor, a central processing unit (CPU), etc. The processor may access the storage unit to execute instructions stored in the storage unit to implement relevant functions.

[0076] The input / output interface may be a serial communication interface.

[0077] The communication interface can be a software interface that supports different wireless communication protocols, such as 4G, 5G, NB-IoT, WiFi, Bluetooth, near-field communication, etc.

[0078] The outdoor unit mainboard usually also integrates a filter circuit and a switching power supply circuit.

[0079] In an optional implementation, the internal controller may be communicatively connected to the cloud control platform.

[0080] The indoor unit 20 is provided with an indoor mainboard, and the indoor mainboard is preferably provided with an indoor controller. The indoor controller is configured to drive the indoor fan to work, receive and process sampling signals of various sensors, and realize necessary communication functions.

[0081] The indoor controller also includes electrical components such as a storage unit, a processor, an input / output interface, and a communication interface.

[0082] The storage unit may include a volatile memory and / or a non-volatile memory. The storage unit is configured to store instructions or data associated with at least one component of the indoor unit 20, such as storing an application. For example, the application may be for adjusting the temperature of the air-conditioned room through different speed gears of the indoor fan.

[0083] The processor may be a dedicated processor, a central processing unit (CPU), etc. The processor may access the storage unit to execute instructions stored in the storage unit to implement relevant functions.

[0084] The input / output interface can be a serial communication interface, for example, connected to a room temperature sensor, a pipe temperature sensor, etc. to receive a sampling signal from the sensor, or connected to components such as an indicator light, a buzzer, a stepper motor, etc. to output a control signal.

[0085] The communication interface may be a software interface that supports different wireless communication protocols, such as communicating with a mobile terminal via WiFi.

[0086] A power supply circuit is usually also provided on the indoor unit mainboard to provide DC 12V and 5V voltages.

[0087] like Figure 1 As shown, a gas-side stop valve 302 and a liquid-side stop valve 304 are also provided in the refrigerant circuit.

[0088] See also Figure 1, a first valve element 202 is also provided in the refrigerant circuit. The first valve element 202 is configured to seal the refrigerant into the indoor liquid pipe section 204 before the indoor unit 20 is shut down. The above working mode of the first valve element 202 can prevent the liquid refrigerant from migrating and returning to the compressor 100 under non-circulation conditions, and prevent the liquid refrigerant from naturally balancing and moving to the part with the lowest ambient temperature in the refrigerant circuit, such as gathering in the chassis of the compressor 100. Especially under the condition of low outdoor ambient temperature, since the compressor 100 is arranged outdoors and the ambient temperature is lower than that of the room, the liquid refrigerant in the refrigerant circuit will gradually migrate to the compressor 100. At the next startup, the compressor 100 is prone to blockage and damage.

[0089] The first valve element 202 may be an electronic expansion valve or a solenoid valve. Taking the example of setting an indoor unit 20 and an electronic expansion valve, when the indoor unit 20 is in heating operation, after receiving a shutdown command (such as Figure 4 As shown in step S1 in the figure, the first valve element 202 is closed, the refrigerant is sealed into the liquid pipe on one side of the indoor heat exchanger (working in the condensing state), and the refrigerant stops flowing into the outdoor heat exchanger 300 (working in the evaporating state) (as shown in the figure). Figure 4 At this time, the compressor 100 that remains in operation continues to operate, the refrigerant is drawn from the outdoor heat exchanger 300, and the suction pressure of the compressor 100 decreases. When the suction pressure drops to the low-pressure control set point (exemplarily under the control of the low-pressure switch), the compressor 100 stops. In this way, under the non-circulating condition of the compressor 100 being stopped, the refrigerant on the low-pressure side of the refrigerant circuit is removed and replaced by the high-pressure side, avoiding the migration of the liquid refrigerant in the natural equilibrium state. After receiving the heating operation start instruction again (such as Figure 4 As shown in step S3 in the figure, since the refrigerant temperature in the indoor liquid pipe section 204 has not reached the target temperature, the first valve element 202 is switched on (as shown in step S4). Figure 4 As shown in step S4, the refrigerant flows from the liquid pipe 204 on the indoor heat exchanger side to the liquid pipe 306 on the outdoor heat exchanger side, and the compressor 100 can operate normally.

[0090] Since the indoor unit 20 needs to be started and stopped several times in a row at intervals of several minutes under certain working conditions, the first valve element 202 will also repeatedly switch between the closed and open states, and the refrigerant in the liquid pipe of the indoor unit 20 will also accumulate. After the heating operation reaches a certain time, the outdoor heat exchanger 300 needs to be defrosted, that is, the control of the refrigerant in the refrigerant circuit is executed in the reverse order of the refrigeration operation, so that the high-temperature refrigerant flows into the outdoor heat exchanger 300 to melt the surface frost layer. After the four-way valve 103 is reversed, a large amount of refrigerant accumulated in the indoor heat exchanger will enter the gas-liquid separator 104 and then enter the compressor 100. Because there is too much refrigerant, the gas-liquid separator 104 cannot be separated in time, and the compressor 100 will suck in too much liquid refrigerant, causing liquid compression.

[0091] In order to avoid liquid compression and ensure that the first valve element 202 functions normally and maintains normal defrosting under the condition of multiple consecutive starts and stops at intervals of several minutes, in this embodiment, the control unit 400 is configured to, when the first system parameter including the mass flow rate of the refrigerant in the outdoor liquid pipe section 306 meets the forced defrosting condition and the second system parameter including the liquid level of the refrigerant in the gas-liquid separator 104 meets the regulation control adjustment (such as Figure 4 As shown in steps S5 and S6 in the above, the defrosting control is not performed but the compressor 100 is stopped and the heating operation control is performed to restart the compressor 100 after the preset stop time H from the start of the stop (such as Figure 4 (as shown in step S7 in FIG. 1 ).

[0092] In an alternative embodiment, the control unit 400 may be implemented by an internal controller disposed in the outdoor unit 30 .

[0093] On the one hand, the mass flow rate of the refrigerant in the outdoor liquid pipe section 306 is added to the first system parameter for determining forced defrost. If the mass flow rate of the refrigerant in the outdoor liquid pipe section 306 is relatively low when the machine is shut down and restarted after the first valve element 202 is closed, it means that the amount of liquid refrigerant is controllable at this time, and forced defrost is relatively safe; if the mass flow rate of the refrigerant in the outdoor liquid pipe section 306 is relatively high when the machine is shut down and restarted after the first valve element 202 is closed, it means that the amount of liquid refrigerant deviates from a controllable state, and further intervention in defrost control is required.

[0094] Secondly, when the forced defrost conditions are met, defrosting is temporarily suspended, and it is further determined whether the second system parameter including the liquid level of the refrigerant in the gas-liquid separator 104 meets the regulation and control conditions. Corresponding control is performed according to the liquid level of the refrigerant in the gas-liquid separator 104. When the liquid level of the refrigerant meets the regulation and control conditions, defrost control is not performed but the compressor 100 is shut down, and heating operation control is performed from the start of shutdown to the preset shutdown time H to restart the compressor 100, so as to protect the compressor 100 and enable the unit to operate stably and reliably.

[0095] In an optional embodiment, the control unit 400 is configured to perform defrost control during heating operation when the first system parameter meets the forced defrost condition and the second system parameter does not meet the regulation control condition.

[0096] Specifically, the control unit 400 is configured to perform defrosting control in the heating operation in the following manner. The control unit 400 samples the mass flow rate of the refrigerant in the outdoor liquid pipe section 306 (eg Figure 5 As shown in step S105), the cumulative heating operation time (such as Figure 5 As shown in step S106), compressor operation time (as shown in step S106 Figure 5 As shown in step S107), the continuous operation time of heating operation (such as Figure 5 As shown in step S108), the minimum outdoor ambient temperature (such as Figure 5 9) and the minimum temperature of the refrigerant in the outdoor liquid pipe section 306 (as shown in step S109). Figure 5 As shown in step S110), and when the above parameters meet the forced defrosting conditions (such as Figure 5 As shown in step S111 in the figure, the refrigerant is controlled to circulate in the refrigerant circuit in reverse order according to the refrigeration operation to defrost the outdoor heat exchanger (such as Figure 5 (as shown in step S112).

[0097] In an optional embodiment, the control unit 400 is configured to sample the interval time of the first valve element 202 being closed for multiple times (at least twice) in a row. If the interval time of the multiple times (twice) being closed in a row is less than the set interval time, the control unit 400 is configured to perform the defrosting control as described above in the heating operation, that is, when the mass flow rate of the refrigerant in the outdoor liquid pipe section 306, the cumulative heating operation time, the compressor operation time, the continuous operation time of the heating operation, the minimum value of the outdoor ambient temperature, and the minimum value of the temperature of the refrigerant in the outdoor liquid pipe section 306 meet the forced defrosting conditions, the control of making the refrigerant circulate in the refrigerant circuit in the reverse order of the cooling operation to defrost the outdoor heat exchanger. If the interval time of the multiple times (twice) being closed in a row is more than the set interval time, the control unit 400 can be configured to make the refrigerant circulate in the refrigerant circuit in the reverse order of the cooling operation to defrost the outdoor heat exchanger after the heating operation starts and the preset cumulative heating time.

[0098] In an optional embodiment, two different forced defrost conditions are established according to different states of the refrigerant in the outdoor liquid pipe section 306 .

[0099] like Figure 6 and Fig.13 As shown, the first forced defrosting condition is: during the heating operation, when the mass flow rate C of the refrigerant in the outdoor liquid pipe section 306 is below the set mass flow rate A (such as Figure 6 As shown in step S201), the cumulative heating operation time is greater than the set cumulative heating operation time B (in minutes) (such as Figure 6 As shown in step S202), the compressor operation time is greater than the set compressor operation time C (in seconds) (such as Figure 6 As shown in step S203), the minimum outdoor ambient temperature Tamin is below the set ambient temperature a℃ (such as Figure 6 As shown in step S204), and the minimum temperature of the refrigerant in the outdoor liquid pipe section 306 is below the set refrigerant temperature b°C (as shown in step S204). Figure 6 In the case of step S205 in the above example, it is considered that the first forced defrosting condition (such as Figure 6 As shown in step S206, the refrigerant is controlled to circulate in the refrigerant circuit in reverse order according to the refrigeration operation to defrost the outdoor heat exchanger (such as Figure 6 That is, if the mass flow rate of the refrigerant in the outdoor liquid pipe section 306 is low when the heating operation is started again after the first valve element 202 is closed, it means that the amount of liquid refrigerant is controllable and forced defrosting is relatively safe. If the cumulative heating operation time is greater than the set cumulative heating operation time B, defrosting can be allowed at the first level.

[0100] In an optional embodiment, if Figure 7 As shown, the control unit 400 determines whether the first forced defrosting condition (such as Figure 7 If otherwise, heating operation is performed (such as Figure 7 If so, it is further determined whether the control condition is met (such as Figure 7 If the control condition is not met, the defrost control is performed (eg Figure 7 As shown in step S404 in the figure), if the regulation control condition is met, the compressor is shut down and the heating operation control is performed to restart the compressor after the preset shutdown time H from the start of the shutdown (such as Figure 7 (as shown in step S405).

[0101] The second forced defrosting condition is: during the heating operation, when the mass flow rate of the refrigerant in the outdoor liquid pipe section 306 is above the set mass flow rate A (such as Figure 8 As shown in step S301), the cumulative heating operation time is greater than the set cumulative heating operation time B (such as Figure 8 As shown in step S302), the compressor operation time is greater than the set compressor operation time C (such as Figure 8 As shown in step S303), the continuous operation time of the heating operation is longer than the set continuous operation time D (in minutes) of the heating operation (as shown in step S303). Figure 8 As shown in step S304), the minimum outdoor ambient temperature is below the set ambient temperature a°C (such as Figure 8 As shown in step S305), and the minimum temperature of the refrigerant in the outdoor liquid pipe section 306 is below the set refrigerant temperature b°C (as shown in step S305). Figure 8 In the case of step S306 in the above example, it is considered that the second forced defrosting condition (such as Figure 8 As shown in step S307, the refrigerant is controlled to circulate in the refrigerant circuit in reverse order according to the refrigeration operation to defrost the outdoor heat exchanger (such as Figure 8 That is, if the mass flow of the refrigerant in the outdoor liquid pipe section 306 is relatively high when the first valve element 202 is shut down and restarted, indicating that the amount of liquid refrigerant at this time deviates from the controllable state, then on the basis of the accumulated heating operation time, the condition that the continuous operation time of the heating operation is greater than the set continuous operation time of the heating operation D (in minutes) is added. This intervention method can avoid the immediate entry into defrosting when the first valve element 202 is shut down and restarted, that is, the air conditioner is allowed to perform heating operation for at least a certain period of time after restarting so that the liquid refrigerant in the indoor unit 20 enters the circulation state, and then defrosting is allowed at the first level.

[0102] In an optional embodiment, if Fig. 9 As shown, the control unit 400 determines whether the first forced defrosting condition (such as Fig. 9 If otherwise, heating operation is performed (such as Fig. 9 If so, it is further determined whether the control condition is met (such as Fig. 9 If the control condition is not met, the defrost control is performed (eg Fig. 9 As shown in step S504 in the figure), if the regulation control condition is met, the compressor is shut down and the heating operation control is performed to restart the compressor after the preset shutdown time H from the start of the shutdown (such as Fig. 9 (as shown in step S505).

[0103] In an optional embodiment, the minimum temperature value of the refrigerant in the outdoor liquid pipe section 306 is the minimum temperature value of the refrigerant in the outdoor liquid pipe section 306 when the start-up phase of the air-conditioning device heating operation ends (the compressor protection phase ends) or the minimum temperature value of the refrigerant in the outdoor liquid pipe section 306 when the air-conditioning device starts heating operation again after one defrosting control ends. The minimum value may be the minimum temperature value in the set continuous sampling times. The minimum value of the outdoor ambient temperature may be the minimum value of the outdoor ambient temperature or the minimum temperature value in the set continuous sampling times.

[0104] The timing unit in the control unit 400 is implemented by the crystal oscillator of the processor.

[0105] When defrosting is allowed or after entering defrost control, the refrigerant level in the gas-liquid separator is too high or the refrigerant level in the gas-liquid separator rises as defrost control progresses. At the second level, the air-conditioning equipment will make adjustments and controls based on the refrigerant level height, temperature and time conditions in the gas-liquid separator detected by the level sensor.

[0106] In an optional embodiment, the control unit 400 is configured to sample the liquid level H of the refrigerant in the gas-liquid separator and the minimum value Tdmin of the compressor exhaust temperature, such as Fig.10 When the liquid level of the refrigerant in the gas-liquid separator and the minimum value of the compressor exhaust temperature both meet the regulation control conditions, the defrosting control is not performed but the compressor is shut down and the heating operation control is performed to restart the compressor after the preset shutdown time H from the start of the shutdown.

[0107] In an optional implementation, a first regulation and control condition and a second regulation and control condition are configured.

[0108] The control unit 400 is configured to, when the liquid level of the refrigerant in the gas-liquid separator is above the set liquid level E (e.g. Fig.11As shown in step S601, the minimum value of the compressor exhaust temperature is below the set exhaust temperature (such as Fig.11 As shown in step S602) and the holding time reaches the set holding time (such as Fig.11 In the case of step S603 in the above example, it is considered that the first regulation control condition (such as Fig.11 As shown in step S604, the defrosting control is not performed but the compressor is stopped and the heating operation control is performed to restart the compressor after the preset stop time H from the start of the stop (such as Fig.11 , as shown in step S605).

[0109] As another parallel method, the control unit 400 is configured to, when the liquid level of the refrigerant in the gas-liquid separator is above the set liquid level E (such as Fig.12 As shown in step S701, the minimum value of the compressor exhaust temperature is below the set exhaust temperature (such as Fig.12 In the case where the cumulative maintenance time F (in minutes) within the set period G (in minutes) reaches the set maintenance time (as shown in step S702 in FIG. Fig.12 As shown in step S703, the second control condition is met (such as Fig.12 As shown in step S704, the defrosting control is not performed but the compressor is stopped, and the compressor is started in the heating operation control (such as Fig.12 (as shown in step S705).

[0110] In an optional embodiment, the exhaust temperature is set to be greater than the refrigerant saturation temperature corresponding to the compressor exhaust pressure, for example, the minimum value Tdmin of the compressor exhaust temperature satisfies Tdmin≤Tc+c℃, Tc is the refrigerant saturation temperature corresponding to the compressor exhaust pressure, which can be stored in the storage unit to be called according to the actual compressor exhaust pressure. The minimum value Tdmin of the compressor exhaust temperature is the lowest temperature monitored by the compressor exhaust temperature sensor during the operation of the air-conditioning equipment.

[0111] In an optional embodiment, the control unit 400 is configured to start timing when the regulation control is started (eg Fig.14 As shown in step S801 in the figure, when the actual timing duration reaches the set duration (such as Fig.14 As shown in step S802, set the cycle G to zero (such as Fig.14 As shown in step S803, the accumulated maintenance time F is reset (eg Fig.14 , as shown in step S804).

[0112] In an optional implementation, when the defrost control is performed, the cycle G is set to zero.

[0113] In an optional embodiment, the control unit 400 is configured to: when performing regulation control, not perform defrost control but perform compressor shutdown (such as Fig.15 As shown in step S405 in the figure), the throttling element is reset to the set opening degree for heating operation (such as Fig.15 As shown in step S406, and the heating operation control of restarting the compressor after the preset shutdown time H from the start of shutdown (such as Fig.15 As shown in step S407); the opening is set to be smaller than the throttling element opening generated during heating operation.

[0114] In an optional embodiment, the opening is set to 75% of the throttling element generated by the heating operation, that is, the adjusted reduction is 25% of the opening of the throttling element generated by the heating operation, so as to avoid the failure of low exhaust superheat when the compressor is restarted after a preset downtime H.

[0115] In an optional embodiment, if Fig.17 As shown, when the control is executed, after the compressor is restarted, if the liquid level of the refrigerant in the gas-liquid separator is above the set liquid level E (such as Fig.16 As shown in step S904, the control of reducing the opening of the throttling element from the set opening is executed (such as Fig.16 until the liquid level of the refrigerant in the gas-liquid separator is below the set liquid level E (as shown in step S905). Fig.16 The liquid level of the refrigerant in the gas-liquid separator is adjusted by the opening of the throttling element so that the liquid level is kept below the set liquid level E.

[0116] In an optional embodiment, when performing the regulation control, the control of reducing the opening of the throttling element from the set opening is performed until the liquid level of the refrigerant in the gas-liquid separator is below the set liquid level E, and the current opening of the throttling element (such as Fig.16 until the compressor exhaust temperature no longer meets the regulation control condition (such as Fig.16 , as shown in step S907).

[0117] like Figures 1 to 3 As shown, in an optional embodiment, the refrigerant circuit further includes a plate heat exchanger 500. The plate heat exchanger 500 is disposed in the outdoor unit 30. The plate heat exchanger 500 is fluidically connected to an auxiliary heat exchange pipeline 502 provided with an auxiliary electronic expansion valve 504, and the refrigerant in the refrigerant circuit circulates into the first heat exchange pipeline of the plate heat exchanger 500, and the refrigerant flowing out of the auxiliary electronic expansion valve 504 circulates into the second heat exchange pipeline of the plate heat exchanger 500 and heat exchanges with the refrigerant in the first heat exchange pipeline.

[0118] Taking refrigeration operation as an example, when the refrigerant in the refrigerant circuit circulates into the first heat exchange pipeline of the plate heat exchanger 500, a part of the refrigerant will enter the auxiliary heat exchange pipeline 502. The refrigerant in the auxiliary heat exchange pipeline 502 passes through the auxiliary electronic expansion valve 504, throttling and reducing the pressure, and the temperature is reduced, and then flows through the second heat exchange pipeline of the plate heat exchanger 500 (such as Figure 2 The plate heat exchanger 500 in the heating operation has a similar circulation principle to that in the cooling operation (as shown in FIG. 3 , which corresponds to Fcool_2), and will not be described in detail here.

[0119] In an optional embodiment, the plate heat exchanger 500 may not be provided, and the refrigerant circuit of the plate heat exchanger 500 may not be provided. Fig.18 shown.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0121] For ease of explanation, the above description has been made in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations can be obtained. The selection and description of the above embodiments are intended to better explain the principles and practical applications, so that those skilled in the art can better use the embodiments and various different variations of the embodiments suitable for specific use considerations.

Claims

1. Air conditioning equipment, including: an outdoor unit having at least a compressor and an outdoor heat exchanger; one or more indoor units having at least an indoor heat exchanger; A refrigerant circuit, in which the refrigerant circulates sequentially through a compressor, a condenser, a throttling element, and an evaporator; one of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger; and a gas-liquid separator configured to store liquid refrigerant flowing out of the evaporator; It is characterized by further comprising: a first valve element configured to seal the refrigerant into the liquid pipe on one side of the indoor heat exchanger before the indoor unit is shut down during heating operation; and A control unit is configured to execute heating operation control such that the compressor is shut down instead of the defrost control when a first system parameter including the mass flow rate of the refrigerant in the outdoor liquid pipe section meets the forced defrost condition and a second system parameter including the liquid level of the refrigerant in the gas-liquid separator meets the regulation control condition, and the compressor is restarted from the start of the shutdown to a preset shutdown time.

2. The air conditioning device according to claim 1, characterized in that: The control unit is configured to perform defrost control when the first system parameter satisfies the forced defrost condition and the second system parameter does not satisfy the regulation control condition during heating operation: When the mass flow rate of the refrigerant in the outdoor liquid pipe section is below the set mass flow rate, the cumulative heating operation time is above the set heating operation cumulative time, the compressor operation time is above the set compressor operation time, the minimum outdoor ambient temperature is below the set ambient temperature, and the minimum temperature of the refrigerant in the outdoor liquid pipe section is below the set refrigerant temperature, the first forced defrosting condition is satisfied, and control is performed to make the refrigerant circulate in the refrigerant circuit in the reverse order of the refrigeration operation to defrost the outdoor heat exchanger; or When the mass flow rate of the refrigerant in the outdoor liquid pipe section is above the set mass flow rate, the cumulative heating operation time is above the set heating operation cumulative time, the compressor operation time is above the set compressor operation time, the heating operation continuous operation time is above the set heating operation continuous operation time, the minimum outdoor ambient temperature is below the set ambient temperature, and the minimum temperature of the refrigerant in the outdoor liquid pipe section is below the set refrigerant temperature, and the second forced defrost condition is met, control is performed to circulate the refrigerant in the refrigerant circuit in reverse order of the refrigeration operation to defrost the outdoor heat exchanger.

3. The air conditioning device according to claim 2, characterized in that: The minimum temperature value of the refrigerant in the outdoor liquid pipe section is the minimum temperature value of the refrigerant in the outdoor liquid pipe section at the end of the start-up phase of the heating operation of the air-conditioning equipment, or the minimum temperature value of the refrigerant in the outdoor liquid pipe section when the air-conditioning equipment starts heating operation again after one defrost control is completed.

4. The air conditioning device according to any one of claims 1 to 3, characterized in that: The control unit is configured to execute heating operation control by shutting down the compressor instead of executing defrost control when the liquid level of the refrigerant in the gas-liquid separator and the minimum exhaust temperature of the compressor both meet the regulation control conditions, and restarting the compressor from the start of shutdown to a preset shutdown time.

5. The air conditioning device according to claim 4, characterized in that: The control unit is configured as follows: When the liquid level of the refrigerant in the gas-liquid separator is above the set liquid level, and the minimum value of the compressor exhaust temperature is below the set exhaust temperature and the maintenance time reaches the set maintenance time, the first regulation control condition is met, and the defrosting control is not performed but the compressor is stopped, and the heating operation control is performed to restart the compressor from the start of the shutdown to the preset shutdown time; or When the liquid level of the refrigerant in the gas-liquid separator is above the set liquid level, the minimum value of the compressor exhaust temperature is below the set exhaust temperature and the accumulated maintenance time within the set cycle time reaches the set maintenance time, the second regulation control condition is met, and the defrosting control is not performed but the compressor is stopped, and the heating operation control is performed from the start of the shutdown to the preset shutdown time when the compressor is restarted; The set exhaust temperature is greater than the refrigerant saturation temperature corresponding to the compressor exhaust pressure.

6. The air conditioning device according to claim 5, characterized in that: The control unit is configured as follows: When executing regulation and control, when the actual timing duration reaches the set period length, the set period is reset to zero and the accumulated maintenance time is reset to zero; When the defrost control is executed, the set cycle is cleared.

7. The air conditioning device according to claim 4, characterized in that: The control unit is configured as follows: When performing regulation control, the defrosting control is not performed but the heating operation control is performed by stopping the compressor, resetting the throttling element to the set opening degree of the heating operation, and restarting the compressor after a preset stop time from the start of the stop; The set opening is smaller than the throttling element opening generated during heating operation.

8. The air conditioning device according to claim 7, characterized in that: The control unit is configured as follows: When executing regulation control, after the compressor is restarted, under the condition that the liquid level of refrigerant in the gas-liquid separator is above the set liquid level, the control of reducing the opening of the throttling element from the set opening is executed until the liquid level of refrigerant in the gas-liquid separator is below the set liquid level.

9. The air conditioning device according to claim 8, characterized in that: The control unit is configured as follows: When performing regulation control, the opening of the throttling element is reduced from the set opening until the liquid level of the refrigerant in the gas-liquid separator is below the set liquid level, and the current opening of the throttling element is maintained until the compressor exhaust temperature no longer meets the regulation control conditions.

10. The air conditioning device according to claim 1, characterized in that: Also includes: A plate heat exchanger, wherein the plate heat exchanger is arranged in the outdoor unit; The plate heat exchanger is fluidly connected to an auxiliary heat exchange pipeline provided with an auxiliary electronic expansion valve, the refrigerant in the refrigerant circuit circulates into the first heat exchange pipeline of the plate heat exchanger, and the refrigerant flowing out of the auxiliary electronic expansion valve circulates into the second heat exchange pipeline of the plate heat exchanger and exchanges heat with the refrigerant in the first heat exchange pipeline.

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