CN115654775A - Air conditioning system and control method thereof - Google Patents

Abstract

The application provides an air conditioning system and a control method thereof, relates to the technical field of air conditioners, and is used for reducing the probability of damage of a compressor during heating starting. The controller is configured to: responding to a heating starting instruction of an air conditioning system, and acquiring the outdoor environment temperature and the working state of a four-way valve; under the conditions that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in a first working state, controlling the outdoor expansion valve to be opened to a preset initial opening degree, controlling the compressor to perform frequency-up operation to a target frequency, and controlling the bypass valve to be closed; when the reversing condition of the four-way valve is met, controlling the four-way valve to be switched from a first working state to a second working state, and simultaneously controlling the expansion valve to be closed; after the four-way valve is switched to the second working state, the opening degree of the expansion valve is controlled based on the exhaust superheat degree of the compressor, and the opening and closing of the bypass valve are controlled based on the suction pressure of the compressor.

Description

Air conditioning system and control method thereof

Technical Field

The application relates to the technical field of air conditioners, in particular to an air conditioning system and a control method thereof.

Background

With the improvement of living standard, the air conditioner has gone into every family and becomes an indispensable household appliance in people's life. Based on the demand of the public for temperature comfort, consumers expect that the air conditioner can normally operate in a relatively wide temperature range, and some export countries have also clearly required that the air conditioner can normally heat and start to operate at minus 25 ℃.

In the heating starting process of the air-conditioning system at the present stage, the outdoor electronic expansion valve is fully opened, and a large amount of refrigerant can flow back to the gas-liquid separator, so that the circulation time of the refrigerant can be reduced, and the air outlet time of the air conditioner can be accelerated. However, when the volume of the gas-liquid separator is not large enough, liquid refrigerant in the air conditioning system may enter the compressor during the heating start process, and the compressor is thus subjected to liquid compression, so that the compressor is damaged.

Disclosure of Invention

The application provides an air conditioning system and a control method thereof, which are used for reducing the probability of damage of a compressor during heating starting.

In a first aspect, an air conditioning system is provided, comprising: the refrigerant circulation loop is used for circulating the refrigerant in a loop formed by the compressor, the condenser, the expansion valve, the evaporator, the four-way valve and the gas-liquid separator;

the compressor is used for compressing low-temperature and low-pressure refrigerant gas into high-temperature and high-pressure refrigerant gas and discharging the high-temperature and high-pressure refrigerant gas to the condenser;

an outdoor heat exchanger and an indoor heat exchanger, wherein one of the heat exchangers operates as a condenser and the other operates as an evaporator;

the four-way valve is used for controlling the flow direction of refrigerant in the refrigerant loop; when the four-way valve is in a first working state, the outdoor heat exchanger works as a condenser; when the four-way valve is in a second working state, the outdoor heat exchanger works as an evaporator;

a bypass branch, which is arranged between the inlet of the gas-liquid separator and the exhaust port of the compressor, is used for dividing part of the refrigerant flowing to the condenser from the compressor and converging the refrigerant flowing to the inlet of the gas-liquid separator;

the bypass valve is arranged on the bypass branch and used for controlling the on-off of the bypass branch;

and a controller configured to:

responding to a heating starting instruction of an air conditioning system, and acquiring the outdoor environment temperature and the working state of a four-way valve;

under the conditions that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in a first working state, controlling the outdoor expansion valve to be opened to a preset initial opening degree, controlling the compressor to perform frequency-up operation to a target frequency, and controlling the bypass valve to be closed;

when the reversing condition of the four-way valve is met, controlling the four-way valve to be switched from a first working state to a second working state, and simultaneously controlling the expansion valve to be closed;

after the four-way valve is switched to the second working state, the opening degree of the expansion valve is controlled based on the exhaust superheat degree of the compressor, and the opening and closing of the bypass valve is controlled based on the suction pressure of the compressor.

The technical scheme provided by the embodiment of the application at least has the following beneficial effects: the embodiment of the application provides an air conditioning system, when control cross valve switches into the second operating condition from first operating condition, closes the expansion valve, prevents that liquid refrigerant in the outdoor heat exchanger from entering into the compressor through the expansion valve, causing the damage of compressor. The bypass valve is controlled to be opened and closed based on the suction pressure of the compressor, so that the bypass branch is connected, at the moment, a part of high-temperature and high-pressure gaseous refrigerant in the compressor can be branched out and enter the gas-liquid separator through the bypass branch, so that the liquid refrigerant in the gas-liquid separator is evaporated into the gaseous refrigerant and then enters the compressor, the refrigerant between the compressor and the gas-liquid separator forms internal circulation, and the liquid refrigerant in the gas-liquid separator is reduced. When the exhaust superheat degree of the compressor is detected to reach a first preset threshold value, the outdoor fan is controlled to operate at a target rotating speed, the heat exchange rate of the outdoor heat exchanger is improved, the liquid refrigerant in the outdoor heat exchanger is quickly evaporated into the gaseous refrigerant, and the content of the liquid refrigerant in the outdoor heat exchanger is reduced. When the compressor is detected to reach the second superheat degree threshold value, the compressor has established a certain superheat degree, only a small amount of liquid refrigerant exists in the outdoor heat exchanger, the expansion valve is opened at the moment, the liquid refrigerant enters the gas-liquid separator, the gaseous refrigerant enters the compressor, the content of the liquid refrigerant in the air-conditioning system is reduced, when the gas-liquid separator is not large enough, the liquid refrigerant can be prevented from entering the compressor due to the fact that the liquid refrigerant is too much in the heating starting process, and the probability of damage to the compressor when the air-conditioning system is heated and started is reduced.

In some embodiments, the air conditioning system further comprises: an outdoor fan for radiating heat of the outdoor heat exchanger; the controller is further configured to: controlling an outdoor fan to stop running under the condition that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in a first working state; after the four-way valve is switched to a second working state, controlling the outdoor fan to stop running when the exhaust superheat degree of the compressor is lower than a first preset superheat degree; and when the exhaust superheat degree of the compressor is increased to reach a first superheat degree threshold value, controlling the outdoor fan to operate at a target rotating speed.

In some embodiments, the controller is configured to control the opening degree of the expansion valve based on a degree of superheat of exhaust gas of the compressor after the four-way valve is switched to the second operation state, and includes: after the four-way valve is switched to a second working state, when the exhaust superheat degree of the compressor is lower than a second superheat degree threshold value, controlling the expansion valve to keep a closed state, wherein the second superheat degree threshold value is higher than the first superheat degree threshold value; and when the exhaust superheat degree of the compressor is increased to reach a second superheat degree threshold value, controlling the expansion valve to be opened to a preset initial opening degree.

In some embodiments, the controller is further configured to: after the start control end condition is satisfied, the opening degree of the expansion valve is adjusted so that the discharge superheat degree of the compressor reaches a target discharge superheat degree, or the suction superheat degree of the compressor reaches a target suction superheat degree.

In some embodiments, the controller is configured to control the switching of the bypass valve based on a suction pressure of the compressor after the four-way valve is switched to the second operating state, and includes: after the four-way valve is switched to a second working state, when the suction pressure of the compressor is lower than a preset pressure threshold value, controlling the opening of the bypass valve; and controlling the bypass valve to be closed after the suction pressure of the compressor reaches a preset pressure threshold value.

In some embodiments, the controller is further configured to: after the start control end condition is satisfied, the bypass valve is controlled to be closed.

In some embodiments, the start control end condition includes any one of: the opening duration of the bypass valve reaches a preset duration; or when the exhaust superheat degree of the compressor reaches a third superheat degree threshold value, the third superheat degree threshold value is larger than the second superheat degree threshold value.

In some embodiments, the controller is further configured to: under the conditions that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in a second working state, the expansion valve is controlled to be closed, and the compressor is controlled to perform frequency rising operation to the target frequency; the opening degree of the expansion valve is controlled based on the degree of superheat of the discharge gas of the compressor, and the opening and closing of the bypass valve is controlled based on the suction pressure of the compressor.

In some embodiments, the air conditioning system further comprises: an outdoor fan for radiating heat of the outdoor heat exchanger; the controller is further configured to: when the outdoor environment temperature is lower than the preset temperature and the four-way valve is in a second working state, controlling the outdoor fan to stop running; and when the exhaust superheat degree of the compressor is increased to reach a first superheat degree threshold value, controlling the outdoor fan to operate at a target rotating speed.

In a second aspect, there is provided a control method of an air conditioning system, the method including: responding to a heating starting instruction of an air conditioning system, and acquiring the outdoor environment temperature and the working state of a four-way valve; under the conditions that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in a first working state, controlling the outdoor expansion valve to be opened to a preset initial opening degree, controlling the compressor to perform frequency-up operation to a target frequency, and controlling the bypass valve to be closed; when the reversing condition of the four-way valve is met, controlling the four-way valve to be switched from a first working state to a second working state, and simultaneously controlling the expansion valve to be closed; after the four-way valve is switched to the second working state, the opening degree of the expansion valve is controlled based on the exhaust superheat degree of the compressor, and the opening and closing of the bypass valve are controlled based on the suction pressure of the compressor.

In a third aspect, an embodiment of the present application provides a controller, including: one or more processors; one or more memories; wherein the one or more memories are configured to store computer program code comprising computer instructions, and the controller executes the control method of the air conditioning system provided by the second aspect when the one or more processors execute the computer instructions.

In a fourth aspect, embodiments of the present application provide a computer-readable storage medium, which includes computer instructions, when the computer instructions are executed on a computer, the computer is caused to execute the control method of the air conditioning system provided in the second aspect.

In a fifth aspect, an embodiment of the present invention provides a computer program product, which is directly loadable into a memory and contains software codes, and the computer program product can be loaded into and executed by a computer to implement the control method of the air conditioning system provided in the second aspect.

It should be noted that all or part of the computer instructions may be stored on the computer readable storage medium. The computer readable storage medium may be packaged with or separately from a processor of the controller, which is not limited in this application.

The beneficial effects described in the second aspect to the fifth aspect in the present application may refer to the beneficial effect analysis of the first aspect, and are not described herein again.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the example serve to explain the principles of the invention and not to limit the invention.

Fig. 1 is a schematic composition diagram of an air conditioning system according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a refrigerant circulation loop of an air conditioning system according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of an outdoor unit according to an embodiment of the present disclosure;

fig. 4 is a block diagram of a hardware configuration of an air conditioning system according to an embodiment of the present disclosure;

fig. 5 is a schematic flowchart of a control method of an air conditioning system according to an embodiment of the present disclosure;

fig. 6 is a flowchart illustrating another control method for an air conditioning system according to an embodiment of the present disclosure;

fig. 7 is a schematic flowchart of another control method for an air conditioning system according to an embodiment of the present disclosure;

fig. 8 is a schematic flowchart of another control method for an air conditioning system according to an embodiment of the present disclosure;

fig. 9 is a schematic flowchart of another control method for an air conditioning system according to an embodiment of the present disclosure;

fig. 10 is a schematic flowchart of another control method for an air conditioning system according to an embodiment of the present application;

fig. 11 is a flowchart illustrating another control method for an air conditioning system according to an embodiment of the present disclosure;

fig. 12 is a flowchart illustrating another control method for an air conditioning system according to an embodiment of the present disclosure;

fig. 13 is a schematic hardware structure diagram of a controller according to an embodiment of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that all directional indicators (such as up, down, left, right, front, and back \8230;) in the embodiments of the present invention are only used to explain the relative positional relationship between the components, the motion situation, etc. in a specific posture (as shown in the attached drawings), and if the specific posture is changed, the directional indicators are changed accordingly.

The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, the meaning of "a plurality" is two or more unless otherwise specified.

In the description of the present application, it should be noted that the terms "connected" and "connected" are to be construed broadly and may include, for example, a fixed connection, a detachable connection, or an integral connection unless otherwise explicitly stated or limited. The specific meaning of the above terms in this application will be understood to be a specific case for those of ordinary skill in the art. In addition, when a pipeline is described, the terms "connected" and "connected" are used in this application to have a meaning of conducting. The specific meaning is to be understood in conjunction with the context.

In the embodiments of the present application, the words "exemplary" or "such as" are used herein to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

As described in the above background art, when the volume of the gas-liquid separator is not large enough, liquid refrigerant in the air conditioning system may enter the compressor during the heating start process, and the compressor may be compressed by the liquid refrigerant, so that the compressor may be damaged.

Based on this, the embodiment of the application provides an air conditioning system and a control method thereof, in the case that the outdoor environment is lower than the preset temperature and the four-way valve is in the first working state, the flow of the refrigerant is controlled by controlling the opening degree of the outdoor expansion valve, so that the pressures at two ends of the four-way valve are different due to different flows, when the pressure difference at two ends of the four-way valve reaches the reversing condition, the four-way valve is switched to the second working state, and the expansion valve is controlled to be closed at the same time, so that the refrigerant does not rapidly circulate in the air conditioning system any more. When the suction pressure of the compressor is detected to be lower than the pressure threshold value, the bypass valve is opened to enable the bypass branch to be connected, at the moment, a part of high-temperature and high-pressure gaseous refrigerant in the compressor can be divided and enter the gas-liquid separator through the bypass branch, so that the refrigerant in the gas-liquid separator is converted into the gaseous refrigerant and then enters the compressor, and internal circulation between the compressor and the gas-liquid separator is formed. When the exhaust superheat degree of the compressor is detected to reach a first preset threshold value, the outdoor fan is turned on, the heat exchange efficiency of the outdoor heat exchanger is improved, the liquid refrigerant in the outdoor heat exchanger is quickly converted into the gaseous refrigerant, and the content of the liquid refrigerant in the outdoor heat exchanger is reduced. When the compressor reaches the second superheat degree threshold value, only a small amount of liquid refrigerant exists in the outdoor heat exchanger, the expansion valve is opened at the moment, and even if the volume of the gas-liquid separator is not large enough, the liquid refrigerant cannot enter the compressor, so that the liquid return phenomenon of the system is reduced, and the compressor is prevented from being damaged due to liquid compression.

To further describe the solution of the present application, as shown in fig. 1, a schematic composition diagram of an air conditioning system provided in an embodiment of the present application is shown, and as shown in fig. 1, the air conditioning system 10 includes an outdoor unit 11, a plurality of indoor units 12, and a controller 13 (not shown in fig. 1).

The outdoor unit 11 is generally installed outdoors to exchange heat with an outdoor environment. The outdoor unit 11 is located outdoors on the opposite side of the indoor units 12 with respect to the wall surface.

The indoor units 12, for example, one indoor unit 12, are usually disposed indoors, and are used for exchanging heat with an indoor environment to achieve heating or cooling effects.

Wherein, there is a pipe connection between the outdoor unit 11 and the indoor unit 12, the pipe, also called gas-liquid pipe, includes: a gas pipe for conveying gaseous refrigerant and a liquid pipe for conveying two-phase refrigerant.

In some embodiments, the controller 13 refers to a device that can generate an operation control signal according to the command operation code and the timing signal, and instruct the air conditioning system to execute the control command. For example, the controller may be a Central Processing Unit (CPU), a general purpose processor Network (NP), a Digital Signal Processor (DSP), a microprocessor, a microcontroller, a Programmable Logic Device (PLD), or any combination thereof. The controller may also be other devices with processing functions, such as a circuit, a device, or a software module, which is not limited in any way by the embodiments of the present application.

In addition, the controller 13 may be configured to control operations of various components within the air conditioning system 10 to enable the various components of the air conditioning system 10 to perform various predetermined functions of the air conditioning system.

In some embodiments, the air conditioning system may further include a remote controller, which may be independently located outside the air conditioning system, and a plurality of buttons are provided on the remote controller, wherein different buttons may adjust the state of the air conditioning system.

Fig. 2 is a schematic structural diagram of a refrigerant circulation loop of an air conditioning system according to an embodiment of the present disclosure. As shown in fig. 2, the circulation circuit of the air conditioning system 10 includes a compressor 111, a four-way valve 112, a gas-liquid separator 113, an outdoor heat exchanger 114, an expansion valve 115, and an indoor heat exchanger 116.

In some embodiments, the compressor 111 is connected to the controller 13. The compressor 111 is disposed between the four-way valve 112 and the gas-liquid separator 113, and compresses the refrigerant sent from the gas-liquid separator 113, and sends the compressed refrigerant to the air conditioning system via the four-way valve 112. The compressor 111 may be an inverter compressor with variable capacity that performs rotational speed control by an inverter.

In some embodiments, four-way valve 112 is connected to controller 13. The four-way valve 112 is a control valve having four oil ports, and the four oil ports are connected to the compressor 111, the gas-liquid separator 113, the outdoor heat exchanger 114, and the indoor heat exchanger 116, respectively. The four-way valve 112 is used for realizing interconversion between cooling and heating by changing the flow direction of the refrigerant in the system pipeline.

In some embodiments, a solenoid coil on the four-way valve is energized and in an open state. The leading slide valve overcomes the tension of a compression spring and moves right under the action of magnetic force generated by an electromagnetic coil, high-pressure gas enters a left-end piston cavity after entering a capillary tube, the gas in the right-end piston cavity on the other reverse side is exhausted, and due to the pressure difference between two ends of the piston, the piston and the main slide valve move right, so that an exhaust pipe is communicated with an indoor unit connecting pipe, and the other two connecting pipes are communicated to form a heating cycle.

In some embodiments, the gas-liquid separator 113 is connected to the compressor 111 at one end and to the four-way valve 112 at the other end. In the gas-liquid separator 113, the refrigerant flowing from the outdoor heat exchanger 114 to the compressor 111 via the four-way valve 112 is separated into a gas refrigerant and a liquid refrigerant. The gas-liquid separator 113 mainly supplies a gaseous refrigerant to the suction port of the compressor 111.

In some embodiments, the outdoor heat exchanger 114 is connected to the controller 13. One end of the outdoor heat exchanger 114 is connected to the four-way valve 112, and the other end is connected to an expansion valve 115. The outdoor heat exchanger 114 is typically disposed outdoors for exchanging heat with the outdoor environment. In the cooling mode, the gaseous refrigerant in the outdoor heat exchanger 114 releases heat and is converted into a liquid refrigerant, and the liquid refrigerant serves as a condenser to work; in the heating mode, the liquid refrigerant of the outdoor heat exchanger 114 absorbs heat and is converted into a gaseous refrigerant, which serves as an evaporator.

In some embodiments, the expansion valve 115 is connected to the controller 13. The expansion valve 115 is disposed between the outdoor heat exchanger 114 and the indoor heat exchanger 116. The expansion valve 115 is composed of a valve body and a coil, has a function of expanding and decompressing the refrigerant flowing through the expansion valve 115, and can be used to adjust the supply amount of the refrigerant in the pipe. When the expansion valve 115 is opened to a smaller degree, the flow resistance of the refrigerant passing through the expansion valve 115 increases. When the expansion valve 115 is opened to a larger degree, the flow path resistance of the refrigerant passing through the expansion valve 115 is reduced. Thus, even if the state of other components in the circuit does not change, the refrigerant flow rate in the air conditioning system changes when the opening degree of the electronic expansion valve 115 changes.

In some embodiments, the indoor heat exchanger 116 is connected to a controller. One end of the indoor heat exchanger 116 is connected to the expansion valve, and the other end is connected to the four-way valve. The indoor heat exchanger 116 is typically disposed indoors for exchanging heat with an indoor environment. In the cooling mode, the liquid refrigerant in the indoor heat exchanger 116 absorbs heat and is converted into a gaseous refrigerant, and the gaseous refrigerant serves as an evaporator to work; in the heating mode, the gaseous refrigerant in the indoor heat exchanger 116 releases heat and is converted into a liquid refrigerant, and the liquid refrigerant operates as a condenser.

Fig. 3 is a schematic structural diagram of an outdoor unit 11 according to an embodiment of the present application. As shown in fig. 3, the outdoor unit 11 includes a compressor 111, a four-way valve 112, a gas-liquid separator 113, an outdoor heat exchanger 114, an expansion valve 115, a bypass valve 117, an outdoor fan 118, an air cut-off valve 119, a liquid cut-off valve 120, a first pressure sensor 121, a second pressure sensor 122, and a temperature sensor 123 (not shown).

The description of the compressor 111, the four-way valve 112, the gas-liquid separator 113, the outdoor heat exchanger 114, and the expansion valve 115 can refer to the description of fig. 2, and will not be repeated herein.

In some embodiments, as shown in fig. 3, a bypass branch is provided between the inlet of the gas-liquid separator 113 and the discharge port of the compressor, and the bypass branch is used for dividing part of the refrigerant flowing from the compressor 111 to the condenser (i.e., the outdoor heat exchanger 114) and merging with the refrigerant flowing to the inlet of the gas-liquid separator.

In some embodiments, a bypass valve 117 is disposed in the bypass branch for controlling the opening and closing of the bypass branch. When the bypass valve is in an open state, high-temperature and high-pressure gaseous refrigerant discharged by the compressor can enter the gas-liquid separator through the bypass branch, the refrigerant in the gas-liquid separator is heated into gaseous refrigerant, and the gaseous refrigerant in the gas-liquid separator flows back to the compressor through the air suction port of the compressor to form internal circulation.

In some embodiments, as shown in FIG. 3, a bypass capillary tube is connected to one end of bypass valve 117.

In some embodiments, the outdoor fan 118 generates an airflow of outdoor air through the outdoor heat exchanger 114 to facilitate heat exchange between the refrigerant in the outdoor heat exchanger and the outdoor environment.

In some embodiments, the air shutoff valve 119 is connected to the controller 13 and disposed on an air pipe of the outdoor unit 11 for controlling the connection and disconnection of the air pipe.

In some embodiments, the liquid stop valve 120 is connected to the controller 13 and disposed on a liquid pipe of the outdoor unit 11 for controlling connection and disconnection of the liquid pipe.

In some embodiments, the first pressure sensor 121 is connected to the controller 13, disposed at the exhaust port of the compressor 111, and configured to detect a pressure value of the exhaust gas at the exhaust port of the compressor and send the detected pressure value of the exhaust gas to the controller 13.

In some embodiments, the second pressure sensor 122 is connected to the controller 13, disposed at the suction port of the compressor 111, and configured to detect a suction pressure value at the suction port of the compressor and send the detected suction pressure value to the controller 13.

In some embodiments, the temperature sensor 123 is connected to the controller 13, and may be disposed on the outdoor unit 11, and configured to detect a temperature value of an environment of the outdoor unit 11 and send the detected temperature value of the environment of the outdoor unit 11 to the controller 13.

Fig. 4 is a block diagram illustrating a hardware configuration of an air conditioning system according to an embodiment of the present application. As shown in fig. 4, the air conditioning system 10 may further include one of: a communicator 130 and a memory 140.

In some embodiments, the communicator 130 is configured to establish a communication connection with other network entities, such as a terminal device. The communicator 130 may include a Radio Frequency (RF) module, a cellular module, a wireless fidelity (WIFI) module, a GPS module, and the like. Taking the RF module as an example, the RF module can be used for receiving and transmitting signals, and particularly, transmitting the received information to the controller 13 for processing; in addition, the signal generated by the controller 13 is sent out. In general, the RF circuit may include, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a Low Noise Amplifier (LNA), a duplexer, and the like.

Memory 140 may be used to store software programs and data. The controller 13 executes various functions of the air conditioning system 10 and data processing by executing software programs or data stored in the memory 140. The memory 140 may include high speed random access memory and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device. The memory 140 stores an operating system that enables the air conditioning system 10 to operate. The memory 140 may store an operating system and various application programs, and may also store codes for executing the control method of the air conditioning system provided in the embodiment of the present application.

Those skilled in the art will appreciate that the hardware configuration shown in FIG. 4 does not constitute a limitation of air conditioning systems, which may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components.

The embodiments provided in the present application will be described in detail below with reference to the accompanying drawings.

The embodiment of the present application provides a control method for an air conditioning system, where the method is applied to a controller, and the controller may be the controller 13 shown in fig. 4, as shown in fig. 5, the method includes the following steps:

s101, responding to a heating starting instruction of the air conditioning system, and acquiring the outdoor environment temperature and the working state of the four-way valve.

In some embodiments, when a user needs to use the air conditioning system for heating, the user may issue a heating start instruction to the air conditioning system through the terminal device or a remote controller of the air conditioning system, and after receiving the heating start instruction, the controller controls the air conditioning system to enter a heating start state in response to the heating start instruction of the air conditioning system.

In some embodiments, when the air conditioning system enters a heating starting state, the controller acquires the outdoor environment temperature through the temperature sensor and acquires the working state of the four-way valve. The working state of the four-way valve comprises a first working state and a second working state, wherein the first working state can be a closing state, and the second working state can be an opening state.

S102, under the condition that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in the first working state, the outdoor expansion valve is controlled to be opened to the preset initial opening degree, the compressor is controlled to run in an up-conversion mode to the target frequency, and the bypass valve is controlled to be closed.

The preset temperature is preset when the air conditioning system leaves a factory, for example, the preset temperature is minus 5 ℃.

It can be understood that, when the outdoor environment temperature is detected to be lower than the preset temperature and the four-way valve is in the first working state, the outdoor environment is a low-temperature environment, the four-way valve is in a closed state, and the air conditioning system needs to be started for heating in the low-temperature environment, based on which, the controller controls the outdoor expansion valve to be opened to a preset initial opening degree, controls the compressor to be operated at a target frequency in an up-conversion mode, and controls the bypass valve to be closed.

It can be understood that the controller controls the outdoor expansion valve to be opened to the preset initial opening degree, so that the resistance of a refrigerant flow path of the outdoor expansion valve is increased, the refrigerant circulation volume is reduced, the four-way valve can be closed in time after being switched to the second working state, and the liquid refrigerant is prevented from entering the compressor.

Illustratively, the preset initial opening degree of the expansion valve is preset at the time of factory shipment, for example, the preset initial opening degree of the expansion valve is 10% of the maximum opening degree.

In some embodiments, the controller controls the compressor to perform up-conversion operation to a target frequency, and may compress a refrigerant entering the compressor through the outdoor expansion valve and discharge a compressed high-temperature and high-pressure gaseous refrigerant. After the compressor discharges high-temperature and high-pressure gaseous refrigerant, the discharge pressure on the discharge side of the compressor is increased, and the suction pressure on the suction side of the compressor is not changed, so that the pressure difference between the discharge side and the suction side is increased along with the increase of the working time of the compressor. And the compressor exhaust side is connected with an oil port of the four-way valve, the air suction side of the compressor is connected with another oil port of the four-way valve, and the pressure difference between the compressor exhaust side and the air suction side, namely the pressure difference between the two oil ports of the four-way valve.

In some embodiments, the bypass valve is controlled to be closed, the bypass branch is disconnected, and the high-temperature and high-pressure gaseous refrigerant discharged from the compressor is not shunted, so that the performance of the unit capacity is facilitated.

And S103, when the reversing condition of the four-way valve is met, controlling the four-way valve to be switched from the first working state to the second working state, and simultaneously controlling the expansion valve to be closed.

The four-way valve reversing condition may be preset when the air conditioning system leaves a factory, for example, when the pressure difference of the four-way valve is 1 megapascal (MPa), the four-way valve reverses.

In some embodiments, after the controller detects that the pressure difference between two sides of the four-way valve reaches the reversing pressure difference, the controller controls the four-way valve to reverse, and the four-way valve is switched from the first working state to the second working state. The second working state is an opening state, namely the four-way valve is switched from a closing state to an opening state. After the four-way valve is switched to the opening state, high-temperature and high-pressure gaseous refrigerants discharged by the compressor enter the indoor heat exchanger through the four-way valve, the high-temperature and high-pressure gaseous refrigerants are condensed in the indoor heat exchanger to release heat, and at the moment, the air conditioning system is switched from the refrigeration mode to the heating mode.

In some embodiments, the controller controls the expansion valve to close when the four-way valve is switched to the second working state. After the expansion valve is closed, the liquid refrigerant in the indoor heat exchanger can not flow into the outdoor heat exchanger through the expansion valve, so that the liquid refrigerant in the outdoor heat exchanger is reduced, and the liquid refrigerant entering the gas-liquid separator from the outdoor heat exchanger is reduced.

And S104, after the four-way valve is switched to the second working state, controlling the opening degree of the expansion valve based on the exhaust superheat degree of the compressor, and controlling the opening and closing of the bypass valve based on the suction pressure of the compressor.

In some embodiments, after the four-way valve is controlled to be switched to the second working state, that is, the four-way valve is in an open state, the opening degree of the expansion valve is controlled according to the exhaust superheat degree of the compressor, so that the liquid refrigerant in the indoor heat exchanger is prevented from entering the compressor, and the compressor is prevented from being damaged.

In some embodiments, the bypass valve is controlled to open and close based on the suction pressure of the compressor. The bypass valve is closed, and the bypass branch is disconnected; the bypass valve is opened, and the bypass branch is communicated.

Optionally, as shown in fig. 6, the step S104 may be implemented as the following steps:

and S1041, after the four-way valve is switched to the second working state, controlling the bypass valve to open when the suction pressure of the compressor is lower than a preset pressure threshold value.

In some embodiments, the controller detects that the suction pressure of the compressor is lower than a preset pressure threshold, and controls the bypass valve to open if the bypass valve is not opened. And if the bypass valve is opened, controlling the bypass valve to be continuously opened. After the bypass valve is opened, the bypass branch is communicated, and the high-temperature high-pressure gaseous refrigerant discharged from the compressor can be divided into partial high-temperature high-pressure gaseous refrigerant to be converged with the refrigerant flowing to the gas-liquid separator. And the high-temperature and high-pressure gas refrigerant after being converged enters the gas-liquid separator, the liquid refrigerant in the gas-liquid separator is evaporated into the gas refrigerant, and then the gas refrigerant flows into the compressor again, and the internal circulation of the refrigerant is formed between the compressor and the gas-liquid separator, so that a small amount of liquid refrigerant exists in the gas-liquid separator.

S1042, after the suction pressure of the compressor reaches a preset pressure threshold, controlling the bypass valve to close.

In some embodiments, the controller controls the bypass valve to close after detecting that the suction pressure of the compressor reaches a preset pressure threshold through the second pressure sensor.

The preset pressure threshold may be preset when the air conditioning system leaves a factory. For example, the preset pressure threshold is 0.2MPa.

And S1043, controlling the outdoor fan to stop running under the conditions that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in the second working state.

In some embodiments, under the condition that the controller detects that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in the second working state, if the outdoor fan is in the running state, the outdoor fan is controlled to stop running; and if the outdoor fan is in the running stop state, controlling the outdoor fan to be in the running stop state continuously.

And S1044, controlling the outdoor fan to operate at the target rotating speed when the exhaust superheat degree of the compressor is increased to reach a first superheat degree threshold value.

The first superheat threshold may be preset when the air conditioning system is shipped from a factory. For example, the first superheat threshold is 5 ℃.

In some embodiments, the compressor is controlled to run at an up-frequency, and the degree of superheat of the exhaust gas is gradually increased. And when the discharge superheat degree of the compressor reaches a first superheat degree threshold value, controlling the outdoor fan to operate at a target rotating speed. The outdoor fan operates at the target rotating speed, so that the heat exchange rate between the outdoor heat exchanger and the outdoor environment can be improved, the rate of the liquid refrigerant in the outdoor heat exchanger absorbing heat and evaporating into the gaseous refrigerant is further improved, and the content of the liquid refrigerant in the outdoor heat exchanger is reduced.

Illustratively, the target rotating speed is determined by the outdoor environment temperature, and the lower the outdoor environment temperature is, the faster the outdoor fan rotating speed is; the higher the outdoor ambient temperature, the slower the outdoor fan speed.

And S1045, after the four-way valve is switched to the second working state, controlling the expansion valve to keep a closed state when the exhaust superheat degree of the compressor is lower than a second superheat degree threshold value.

Illustratively, the second threshold degree of superheat is higher than the first threshold degree of superheat. For example, the second superheat threshold is 10 ℃.

In some embodiments, when the controller detects that the degree of superheat of the exhaust gas is lower than the second degree of superheat threshold value, the expansion valve is controlled to be kept in a closed state, so that the liquid refrigerant in the outdoor heat exchanger is prevented from flowing through the expansion valve and finally entering the compressor, and the compressor is prevented from being damaged.

And S1046, when the exhaust superheat degree of the compressor is increased to reach a second superheat degree threshold value, controlling the expansion valve to be opened to a preset initial opening degree.

The preset initial opening may be preset when the air conditioning system leaves a factory. For example, the initial preset opening is 8% of the maximum opening.

In some embodiments, when the controller detects that the degree of superheat of the exhaust gas of the compressor reaches the second degree of superheat threshold value, the time consumed in the process is long, the liquid refrigerant in the outdoor heat exchanger is evaporated into the gaseous refrigerant, the liquid refrigerant in the gas-liquid separator is also evaporated into the gaseous refrigerant, at this time, the expansion valve is opened to the preset initial opening degree, and only a small amount of liquid refrigerant existing in the indoor heat exchanger enters the gas-liquid separator and does not enter the compressor.

In some embodiments, as shown in fig. 7, after step S104, the method further comprises the steps of:

and S105, finishing the starting control ending condition, finishing the heating starting of the air conditioning system, and ending the starting control.

Optionally, the starting control end condition may be that the opening duration of the bypass valve reaches a preset duration, at this time, the compressor is started completely, a large amount of gaseous refrigerant exists in the air conditioning system, a small amount of liquid refrigerant flows from the outdoor unit to the gas-liquid separator, and the situation that the liquid refrigerant flows to the compressor does not occur.

The preset time period is preset when the air conditioning system leaves a factory, and for example, the preset time period is 10 minutes.

Optionally, the starting control end condition may be that the discharge superheat degree of the compressor reaches a third superheat degree threshold value, at this time, the starting of the compressor is completed, and after the air conditioning system establishes a certain superheat degree, the refrigerant entering the compressor does not have a liquid refrigerant.

In some embodiments, after the start-up control end condition is met, the air conditioning system establishes a certain superheat degree, controls the bypass valve to be closed, and disconnects the bypass branch. The high-temperature high-pressure gaseous refrigerant in the compressor does not need to enter the gas-liquid separator through the bypass branch, and the refrigerant entering the compressor does not have a liquid refrigerant. The bypass valve is opened and still can cause the noise, and after satisfying the start-up end condition, close the bypass valve and can also reduce the noise, promote user experience.

In some embodiments, after the start control end condition is satisfied, the refrigerant flow rate may be adjusted by adjusting the opening degree of the expansion valve, so as to adjust the exhaust superheat degree. The opening degree of the expansion valve is large, the flow resistance of the refrigerant is small, the refrigerant flow of the air conditioning system is large, the exhaust superheat degree is small, and the opening degree of the expansion valve is adjusted to be reduced at the moment, so that the exhaust superheat degree is increased; the opening degree of the expansion valve is small, the flow resistance of the refrigerant is large, the refrigerant flow of the air conditioning system is small, the exhaust superheat degree is large, and the opening degree of the expansion valve is adjusted to be increased, so that the exhaust superheat degree is reduced.

Based on the embodiment shown in fig. 5, at least the following advantages are brought: the embodiment of the application provides an air conditioning system and a control method thereof. The exhaust pressure of the exhaust side of the compressor is high and is connected with one oil port of the four-way valve, the suction pressure of the suction side of the compressor is low and is connected with the other oil port of the four-way valve, so that pressure difference exists between the two oil ports of the four-way valve. And when the pressure difference between the two oil ports of the four-way valve is detected to reach the reversing condition, the four-way valve is controlled to be switched to the opening state. And meanwhile, the expansion valve is controlled to be closed, so that the liquid refrigerant in the outdoor heat exchanger is prevented from entering the compressor to cause damage to the compressor. When the controller acquires that the suction pressure of the compressor is lower than a pressure threshold value through the second pressure sensor, the bypass valve is controlled to be opened to enable the bypass branch to be connected, at the moment, a part of high-temperature and high-pressure gaseous refrigerant in the compressor can be branched out and enter the gas-liquid separator through the bypass branch, so that the liquid refrigerant in the gas-liquid separator is evaporated into the gaseous refrigerant and then enters the compressor, and the refrigerant between the compressor and the gas-liquid separator forms internal circulation. When the exhaust superheat degree of the compressor is detected to reach a first preset threshold value, the outdoor fan is controlled to operate at a target rotating speed, the heat exchange efficiency of the outdoor heat exchanger is improved, the liquid refrigerant in the outdoor heat exchanger is quickly evaporated into the gaseous refrigerant, and the content of the liquid refrigerant in the outdoor heat exchanger is reduced. When the compressor is detected to reach the second superheat degree threshold value, a certain superheat degree is established in the compressor at the moment, a small amount of liquid refrigerant exists in the outdoor heat exchanger, the expansion valve is opened at the moment, the liquid refrigerant enters gas-liquid separation, the gaseous refrigerant enters the compressor, the content of the liquid refrigerant in the air-conditioning system is reduced, when the gas-liquid separator is not large enough, the situation that the liquid refrigerant enters the compressor due to excessive liquid refrigerant in the heating starting process can be prevented, and the probability that the compressor is damaged during the heating starting of the air-conditioning system is reduced.

The above embodiments have focused on the description that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in the off state in the air conditioning system and the control method thereof provided in the embodiments of the present application, and in some embodiments, the description that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in the on state is provided in the embodiments of the present application, as shown in fig. 8, the method further includes the following steps:

s201, responding to a heating starting instruction of the air conditioning system, and acquiring the outdoor environment temperature and the working state of the four-way valve.

Regarding the description of S201 shown in fig. 8, reference may be made to the description of step S101, which is not repeated herein.

S202, under the condition that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in the second working state, the expansion valve is controlled to be closed, and the compressor is controlled to be in the frequency-up operation to the target frequency.

It can be understood that, in the case that the outdoor environment temperature is detected to be lower than the preset temperature and the four-way valve is in the second working state, the outdoor environment represents a low-temperature environment, and the air conditioning system needs to be heated and started in the low-temperature environment, based on which, the controller controls the outdoor expansion valve to be closed and controls the compressor to perform the up-conversion operation to the target frequency.

As can be appreciated, the controller controls the expansion valve to close, so that the liquid refrigerant in the indoor heat exchanger cannot flow into the outdoor heat exchanger through the expansion valve, thereby reducing the liquid refrigerant in the outdoor heat exchanger, and further reducing the liquid refrigerant entering the gas-liquid separator from the outdoor heat exchanger.

In some embodiments, the compressor is controlled to perform up-conversion operation to a target frequency, a refrigerant flowing into the compressor can be compressed, and a high-temperature and high-pressure gaseous refrigerant obtained by compression is discharged, so that the compressor establishes a certain superheat degree.

And S203, controlling the bypass valve to be opened when the suction pressure of the compressor is lower than a preset pressure threshold value.

In some embodiments, the controller controls the bypass valve to open when the second pressure sensor detects that the suction pressure of the compressor is lower than a preset pressure threshold. The bypass valve is opened, the bypass branch is communicated, and the high-temperature and high-pressure gaseous refrigerant discharged from the compressor can be divided into a part to be merged with the refrigerant flowing to the gas-liquid separator. And the high-temperature and high-pressure gas refrigerant after being converged enters a gas-liquid separator, the liquid refrigerant in the gas-liquid separator is evaporated into the gas refrigerant, the gas refrigerant flows into the compressor again, and the refrigerant between the compressor and the gas-liquid separator forms internal circulation, so that a small amount of liquid refrigerant exists in the gas-liquid separator.

And S204, controlling the outdoor fan to operate at the target rotating speed when the exhaust superheat degree of the compressor is increased to reach a first superheat degree threshold value.

In some embodiments, the controller controls the compressor to run at an up-conversion rate, and the superheat degree of the exhaust gas is gradually increased, so that the stability of the compressor is improved. And when detecting that the discharge superheat degree of the compressor reaches a first superheat degree threshold value, controlling the outdoor fan to operate at a target rotating speed. The outdoor fan operates at a target rotating speed, so that the heat exchange efficiency of the outdoor heat exchanger and the outdoor environment can be improved, the rate of the liquid refrigerant in the outdoor heat exchanger absorbing heat and evaporating into the gaseous refrigerant is further improved, and the content of the liquid refrigerant in the outdoor heat exchanger is reduced.

And S205, when the exhaust superheat degree of the compressor is increased to reach a second superheat degree threshold value, controlling the expansion valve to be opened to a preset initial opening degree.

The second superheat degree threshold value and the preset initial opening degree can be preset when the air-conditioning system leaves a factory. For example, the second superheat threshold is 10 ℃, and the initial preset opening degree is 8% of the maximum opening degree.

It can be understood that when the controller detects that the exhaust superheat degree of the compressor reaches the second superheat degree threshold value, the time consumed in the process is long, the liquid refrigerant in the outdoor heat exchanger is evaporated into the gaseous refrigerant, the liquid refrigerant in the gas-liquid separator is also evaporated into the gaseous refrigerant, at the moment, the expansion valve is opened to the preset initial opening degree, a small amount of liquid refrigerant existing in the outdoor heat exchanger can enter the gas-liquid separator and cannot enter the compressor, and after the expansion valve is opened, the circulation resistance of the refrigerant is reduced, the refrigerant flow of the air conditioning system is large, the refrigerant flow entering the compressor is increased, and the exhaust superheat degree of the compressor is favorably improved.

And S206, finishing the starting control ending condition, finishing the heating starting of the air conditioning system, and ending the starting control.

Regarding the description of step S206, reference may be made to the above description of step S105, which is not repeated herein.

Based on the embodiment shown in fig. 8, at least the following advantages are brought: the embodiment of the application provides an air conditioning system and a control method thereof, when a controller detects that the outdoor environment temperature is lower than a preset temperature and a four-way valve is in an opening state, the controller controls a compressor to perform frequency-up operation to a target frequency, and the superheat degree of the compressor is improved. When the suction pressure of the compressor is detected to be lower than the pressure threshold value, the bypass valve is opened to enable the bypass branch to be connected, at the moment, a part of high-temperature and high-pressure gaseous refrigerant in the compressor can be divided and enter the gas-liquid separator through the bypass branch, so that the liquid refrigerant in the gas-liquid separator is evaporated into the gaseous refrigerant and then enters the compressor, and the refrigerant between the compressor and the gas-liquid separator forms internal circulation. When the exhaust superheat degree of the compressor is detected to reach a first preset threshold value, the outdoor fan is controlled to operate at a target rotating speed, the heat exchange rate of the outdoor heat exchanger is improved, the liquid refrigerant in the outdoor heat exchanger is quickly evaporated into the gaseous refrigerant, and the content of the liquid refrigerant in the outdoor heat exchanger is reduced. When the compressor is detected to reach the second superheat degree threshold value, the compressor has established a certain superheat degree, only a small amount of liquid refrigerant exists in the outdoor heat exchanger, the expansion valve is opened at the moment, the liquid refrigerant enters gas-liquid separation, the gaseous refrigerant enters the compressor, the content of the liquid refrigerant in the air-conditioning system is reduced, when the gas-liquid separator is not large enough, the liquid refrigerant can be prevented from entering the compressor due to the fact that the liquid refrigerant is too much in the heating starting process, and the probability of damage to the compressor when the air-conditioning system is heated and started is reduced.

The above embodiments have focused on the description that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in the on state in the air conditioning system and the control method thereof provided in the embodiments of the present application, and in some embodiments, the description that the outdoor environment temperature is higher than the preset temperature and the four-way valve is in the off state is provided in the embodiments of the present application, as shown in fig. 9, the method further includes the following steps:

s301, responding to a heating starting instruction of the air conditioning system, and acquiring the outdoor environment temperature and the working state of the four-way valve.

Regarding the description of S301 shown in fig. 9, reference may be made to the above description of step S101, which is not repeated herein.

S302, under the condition that the outdoor environment temperature is higher than the preset temperature and the four-way valve is in the first working state, the outdoor expansion valve is controlled to be opened to the preset initial opening degree, the compressor is controlled to run in an up-conversion mode to the target frequency, and the bypass valve is controlled to be closed.

It can be understood that, in the case that the outdoor environment temperature is detected to be higher than the preset temperature and the four-way valve is in the first working state, the outdoor environment is a high-temperature environment, the air conditioning system needs to be heated and started in a low-temperature environment, based on the situation, the controller controls the outdoor expansion valve to be opened to the preset opening degree, controls the compressor to be operated in an up-conversion mode to the target frequency, and controls the bypass valve to be closed.

It can be understood that the controller controls the expansion valve to be opened to the preset opening degree, so that the resistance of a refrigerant flow path of the outdoor expansion valve is increased, the refrigerant circulation volume is reduced, the four-way valve can be closed in time after being switched to the second working state, and the liquid refrigerant is prevented from entering the compressor.

For example, when the expansion valve is controlled to be opened, the expansion valve may be controlled to adjust the opening degree to the maximum opening degree.

In some embodiments, the compressor is controlled to perform up-conversion operation to a target frequency, and the refrigerant circulated through the outdoor expansion valve may be compressed and then the compressed high-temperature and high-pressure gaseous refrigerant may be discharged. After the compressor discharges high-temperature and high-pressure gaseous refrigerant, the discharge pressure at the discharge side of the compressor is increased, and the suction pressure at the suction side of the compressor is not changed, so that the pressure difference between the discharge side and the suction side is increased along with the increase of the working time of the compressor. And the compressor exhaust side is connected with an oil port of the four-way valve, the air suction side of the compressor is connected with another oil port of the four-way valve, and the pressure difference between the compressor exhaust side and the air suction side, namely the pressure difference between the two sides of the four-way valve.

In some embodiments, the controller controls the bypass valve to close if it detects that the bypass valve is in the open state and to remain in the closed state if it detects that the bypass valve is in the closed state. The bypass valve is closed, the bypass branch is disconnected, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor cannot be shunted, and the pressure difference between the exhaust side and the suction side of the compressor is prevented from being reduced.

And S303, controlling the four-way valve to be switched from the first working state to the second working state when the reversing condition of the four-way valve is met.

Regarding the description of the commutation condition of the four-way valve, reference may be made to the description of the commutation condition of the four-way valve in step S103, which is not repeated herein.

In some embodiments, after the controller detects that the pressure difference between two sides of the four-way valve reaches the reversing pressure difference, the four-way valve is controlled to be switched from the first working state to the second working state, namely, the four-way valve is controlled to be reversed. The second working state is an opening state, namely the four-way valve is switched from a closing state to an opening state. After the four-way valve is switched to the opening state, high-temperature and high-pressure gaseous refrigerants discharged by the compressor enter the indoor heat exchanger through the four-way valve, the high-temperature and high-pressure gaseous refrigerants are condensed in the indoor heat exchanger to release heat, and at the moment, the air conditioning system enters a heating mode.

And S304, after the four-way valve is switched to the second working state, controlling the outdoor fan to operate at the target rotating speed, controlling the opening degree of the expansion valve based on the exhaust superheat degree of the compressor, and controlling the opening and closing of the bypass valve based on the suction pressure of the compressor.

In some embodiments, after the four-way valve is opened, the air conditioning system enters a heating mode, and the controller controls the outdoor fan to operate at a target rotating speed, so that the heat exchange efficiency between the outdoor heat exchanger and the outdoor environment is improved, the rate of the liquid refrigerant in the outdoor heat exchanger absorbing heat and evaporating into the gaseous refrigerant is increased, and the content of the refrigerant circulating in the air conditioning system is increased.

For example, the target rotation speed is determined by the outdoor ambient temperature, for example, the target rotation speed is in a negative correlation with the outdoor ambient temperature, that is, the lower the outdoor ambient temperature is, the faster the outdoor fan rotation speed is; the higher the outdoor ambient temperature, the slower the outdoor fan speed.

Optionally, as shown in fig. 10, the step S304 may be implemented as the following steps:

s3041, when the suction pressure of the compressor is lower than a preset pressure threshold value, controlling the bypass valve to be opened.

For the description of S3041, reference may be made to the above description of step S1041, which is not repeated herein.

S3042, controlling the expansion valve to be opened to a preset initial opening degree.

In some embodiments, after the four-way valve is opened, the controller controls the expansion valve to be opened to a preset opening degree. Under the high-temperature environment, the expansion valve is opened to a preset opening degree, and the refrigerant circulates in the air conditioning system, so that the compressor can quickly establish the superheat degree. After the compressor establishes certain superheat degree, only gaseous refrigerant enters the compressor, the condition that liquid refrigerant enters the compressor can not occur, and the compressor is prevented from being damaged due to hydraulic compression.

The preset initial opening may be preset when the air conditioning system leaves a factory. For example, the initial preset opening is 8% of the maximum opening.

And S305, finishing the starting control ending condition, finishing the heating starting of the air conditioning system, and ending the starting control.

Regarding the description of S305 shown in fig. 9, reference may be made to the description of step S105, which is not repeated herein.

The embodiment based on fig. 9 brings at least the following advantages: the embodiment of the application provides an air conditioning system and a control method thereof, when a controller detects that outdoor environment temperature is higher than preset temperature and a four-way valve is in a closed state, the controller controls a compressor to perform frequency-up operation to a target frequency, the exhaust pressure of the exhaust side of the compressor is high and is connected with one oil port of the four-way valve, the suction pressure of the suction side of the compressor is low and is connected with the other oil port of the four-way valve, so that pressure difference exists between the two oil ports of the four-way valve, and when the pressure difference between the two oil ports of the four-way valve reaches a reversing condition, the four-way valve is controlled to be switched to an open state. After the four-way valve is switched to the on state, the outdoor fan is controlled to run at the target rotating speed, the heat exchange efficiency of the outdoor heat exchanger is improved, and then the number of gaseous refrigerants and the number of liquid refrigerants circulating in the air-conditioning system are increased; and meanwhile, the expansion valve is controlled to be opened to a preset initial opening degree, the flow of the refrigerant flowing in the air conditioning system is increased, and the superheat degree of the compressor can be quickly established. After the compressor establishes a certain exhaust superheat degree, the stability of the compressor is improved, and the air-conditioning system only has a small amount of liquid refrigerant, so that the phenomenon that the liquid refrigerant enters the compressor cannot occur, and the compressor is prevented from being damaged.

The foregoing embodiments have focused on the description that the outdoor environment temperature is higher than the preset temperature and the four-way valve is in the off state in the air conditioning system and the control method thereof provided in the embodiments of the present application, and in some embodiments, the description that the outdoor environment temperature is higher than the preset temperature and the four-way valve is in the on state is provided in the embodiments of the present application, as shown in fig. 11, the method further includes the following steps:

s401, responding to a heating starting instruction of the air conditioning system, and acquiring the outdoor environment temperature and the working state of the four-way valve.

Regarding the description of S401 shown in fig. 11, reference may be made to the above description of step S101, which is not repeated herein.

S402, under the condition that the outdoor environment temperature is higher than the preset temperature and the four-way valve is in the second working state, the outdoor fan is controlled to operate at the target rotating speed for a first preset time.

It can be understood that, when the outdoor environment temperature is detected to be higher than the preset temperature and the four-way valve is in the second working state, the outdoor environment is represented as a high-temperature environment, the air conditioning system needs to be heated and started in the high-temperature environment, and based on the situation, the controller controls the outdoor fan to operate at the target rotating speed for the first preset time.

It can be understood that the controller controls the outdoor fan to operate at the target rotating speed for the first preset time, so that the heat exchange efficiency of the outdoor heat exchanger and the outdoor environment is improved, the rate of the liquid refrigerant in the outdoor heat exchanger absorbing heat and evaporating into the gaseous refrigerant is further improved, and the refrigerant flow in the air conditioning system is increased.

The first preset duration may be set at the time of factory shipment. For example, the first preset time period is 10 seconds.

It can be understood that the refrigerant flow in the air conditioning system is increased, the refrigerant flow entering the compressor is increased, and the compressor can quickly build the superheat degree.

And S403, controlling the compressor to perform frequency raising operation to a target frequency.

In some embodiments, the controller detects that the outdoor environment is a high-temperature environment through the temperature sensor, and detects that the working state of the four-way valve is an open state. The frequency rising operation of the compressor is controlled to the target frequency, after the compressor operates and discharges high-temperature and high-pressure gaseous refrigerants, the exhaust pressure of the compressor is increased, and further the exhaust superheat degree of the compressor is increased, so that the compressor establishes a certain exhaust superheat degree.

S404, controlling the opening degree of the expansion valve based on the exhaust superheat degree of the compressor, and controlling the opening and closing of the bypass valve based on the suction pressure of the compressor.

In some embodiments, the refrigerant entering the compressor is only gaseous refrigerant after the compressor has established a discharge superheat. The opening degree of the expansion valve is controlled based on the exhaust superheat degree of the compressor, so that the flow of the refrigerant in the air-conditioning system is increased, the flow of the refrigerant entering the compressor is increased, the superheat degree of the compressor is quickly established, and the stability of the compressor is improved.

In some embodiments, the controller controls the bypass valve to open when the second pressure sensor detects that the suction pressure of the compressor is lower than a preset pressure threshold. After the bypass valve is opened, the bypass branch is communicated, and the high-temperature high-pressure gaseous refrigerant discharged from the compressor can be divided into partial high-temperature high-pressure gaseous refrigerant to be converged with the refrigerant flowing to the gas-liquid separator. And the high-temperature and high-pressure gas refrigerant after being converged enters a gas-liquid separator, and the liquid refrigerant in the gas-liquid separator is evaporated into the gas refrigerant, so that the flow of the refrigerant entering the compressor is increased.

And S405, finishing a starting control ending condition, finishing heating starting of the air conditioning system, and ending the starting control.

For the description of S405 shown in fig. 11, reference may be made to the description of S105 described above, and details are not repeated here.

The embodiment based on fig. 11 brings at least the following advantages: the embodiment of the application provides an air conditioning system and a control method thereof, when a controller detects that the temperature of outdoor environment is higher than a preset temperature and a four-way valve is in an open state, an outdoor fan is controlled to operate at a target rotating speed, the heat exchange efficiency of an outdoor heat exchanger and the outdoor environment is improved, and therefore gaseous refrigerants and liquid refrigerants circulating in the air conditioning system are increased; in the process of controlling the compressor to operate according to the target frequency rise, after the high-temperature high-pressure gaseous refrigerant is discharged, the discharge pressure of the compressor is increased, and further the discharge superheat degree of the compressor is increased. The opening degree of the expansion valve is controlled according to the exhaust superheat degree, the exhaust superheat degree is low, the expansion valve is controlled to increase the opening degree, the flow of the refrigerant flowing in the air conditioning system is increased, the flow of the refrigerant entering the compressor is increased, and the compressor can establish higher exhaust superheat degree. After the compressor establishes a certain exhaust superheat degree, the stability of the compressor is improved, and the air-conditioning system only has a small amount of liquid refrigerant, so that the phenomenon that the liquid refrigerant enters the compressor cannot occur, and the compressor is prevented from being damaged.

The following describes an example of a control method of an air conditioning system according to an embodiment of the present application with reference to a specific example. As shown in fig. 12, after the user controls the air conditioning system to heat and start, the controller first determines whether the outdoor environment temperature is lower than the preset temperature, and determines whether the four-way valve is turned on or off when the outdoor environment temperature is lower than the preset temperature.

When the four-way valve is in an opening state, the controller controls the expansion valve to be opened according to a preset opening degree, controls the compressor to perform frequency-up operation to a target frequency, controls the outdoor fan to be closed, and controls the bypass valve to be closed. After the four-way valve is opened, the compressor is controlled to run according to the target frequency, the expansion valve is closed, the bypass valve is controlled according to the suction pressure, and the outdoor fan is closed. When the detected exhaust superheat degree is more than 5 ℃, the outdoor fan is controlled to operate at the target rotating speed, and the compressor, the bypass valve and the expansion valve are controlled to keep the original state. When the exhaust superheat degree is higher than 10 ℃, the expansion valve is controlled to be opened to a preset initial opening degree, and the compressor, the outdoor fan and the bypass valve are controlled to keep in an original state. When the startup exit condition is reached, the startup control ends. When the four-way valve is in a closed state, the controller controls the expansion valve to be closed, controls the compressor to perform frequency-up operation to a target frequency, controls the outdoor fan to be closed, and controls the bypass valve to be closed. When the detected exhaust superheat degree is more than 5 ℃, the outdoor fan is controlled to operate at the target rotating speed, and the compressor, the bypass valve and the expansion valve are controlled to keep the original state. When the exhaust superheat degree is higher than 10 ℃, the expansion valve is controlled to be opened to a preset initial opening degree, and the compressor, the outdoor fan and the bypass valve are controlled to be kept in an original state. When the startup exit condition is reached, the startup control ends.

And under the condition that the outdoor environment temperature is higher than the preset temperature, judging whether the four-way valve is opened or closed, controlling the compressor to perform frequency-up operation to the target frequency when the four-way valve is in an open state, controlling the expansion valve to be opened according to the preset opening degree, controlling the outdoor fan to be closed, and controlling the bypass valve to be closed. After the four-way valve is opened, the compressor is controlled to run according to a target frequency, the expansion valve is controlled according to the exhaust superheat degree, the outdoor fan is controlled to run at a target rotating speed, and the bypass valve is controlled according to the suction pressure. When the startup exit condition is reached, the startup control ends.

When the four-way valve is in an open state, outdoor air is controlled to run at a target rotating speed, the compressor is controlled to run at a target frequency in an up-conversion mode, the expansion valve is controlled according to the exhaust superheat degree, and the bypass valve is controlled according to the suction pressure. When the startup exit condition is reached, the startup control ends.

It can be seen that the foregoing describes the solution provided by the embodiments of the present application primarily from a methodological perspective. In order to implement the functions described above, the embodiments of the present application provide corresponding hardware structures and/or software modules for performing the respective functions. Those of skill in the art will readily appreciate that the various illustrative modules and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the embodiment of the present application, the controller may be divided into the functional modules according to the above method example, for example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. Optionally, the division of the modules in the embodiment of the present application is schematic, and is only a logic function division, and there may be another division manner in actual implementation.

As shown in fig. 13, the controller 3000 includes a processor 3001, and optionally, a memory 3002 and a communication interface 3003, which are connected to the processor 3001. The processor 3001, memory 3002, and communication interface 3003 are connected by a bus 3004.

The processor 3001 may be a Central Processing Unit (CPU), a general purpose processor Network Processor (NP), a Digital Signal Processor (DSP), a microprocessor, a microcontroller, a Programmable Logic Device (PLD), or any combination thereof. The processor 3001 may also be any other means having a processing function, such as a circuit, a device, or a software module. The processor 3001 may include a plurality of CPUs, and the processor 3001 may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, or processing cores that process data, such as computer program instructions.

The memory 3002 may be a read-only memory (ROM) or other types of static storage devices that may store static information and instructions, a Random Access Memory (RAM) or other types of dynamic storage devices that may store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compact disc, laser disc, optical disc, digital versatile disc, blu-ray disc, etc.), a magnetic disc storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, which are not limited by the embodiments of the present application. The memory 3002 may be separate or integrated with the processor 3001. The memory 3002 may have computer program code embodied therein. The processor 3001 is configured to execute the computer program code stored in the memory 3002, so as to implement a control method of the air conditioning system provided by the embodiment of the present application.

Communication interface 3003 may be used to communicate with other devices or communication networks (e.g., ethernet, radio Access Network (RAN), wireless Local Area Networks (WLAN), etc.). Communication interface 3003 may be a module, circuitry, transceiver, or any device capable of enabling communication.

The bus 3004 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus 3004 may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 13, but this is not intended to represent only one bus or type of bus.

An embodiment of the present invention further provides a computer-readable storage medium, where the computer-readable storage medium includes computer-executable instructions, and when the computer-executable instructions run on a computer, the computer is enabled to execute the control method of the air conditioning system provided in the foregoing embodiment.

Embodiments of the present invention further provide a computer program product, where the computer program product may be directly loaded into a memory and contains a software code, and after the computer program product is loaded and executed by a computer, the control method of an air conditioning system provided in the foregoing embodiments can be implemented.

Those skilled in the art will recognize that the functionality described in this disclosure may be implemented in hardware, software, firmware, or any combination thereof, in one or more of the examples described above. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

Through the above description of the embodiments, it is clear to those skilled in the art that, for convenience and simplicity of description, the foregoing division of the functional modules is merely used as an example, and in practical applications, the above function distribution may be completed by different functional modules according to needs, that is, the internal structure of the device may be divided into different functional modules to complete all or part of the above described functions.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the modules or units is only one logical function division, and there may be other division ways in actual implementation. For example, various elements or components may be combined or may be integrated into another device, or some features may be omitted, or not implemented. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form. Units described as separate parts may or may not be physically separate, and parts displayed as units may be one physical unit or a plurality of physical units, may be located in one place, or may be distributed to a plurality of different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit. The integrated unit, if implemented as a software functional unit and sold or used as a separate product, may be stored in a readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be essentially or partially contributed to by the prior art, or all or part of the technical solutions may be embodied in the form of a software product, where the software product is stored in a storage medium and includes several instructions to enable a device (which may be a single chip, a chip, or the like) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a U disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. An air conditioning system, comprising:

the refrigerant circulation loop is used for circulating the refrigerant in a loop formed by the compressor, the condenser, the expansion valve, the evaporator, the four-way valve and the gas-liquid separator;

the compressor is used for compressing low-temperature and low-pressure refrigerant gas into high-temperature and high-pressure refrigerant gas and discharging the high-temperature and high-pressure refrigerant gas to the condenser;

an outdoor heat exchanger and an indoor heat exchanger, wherein one of the heat exchangers operates as a condenser and the other operates as an evaporator;

the four-way valve is used for controlling the flow direction of the refrigerant in the refrigerant loop; when the four-way valve is in a first working state, the outdoor heat exchanger works as a condenser; when the four-way valve is in a second working state, the outdoor heat exchanger works as an evaporator;

a bypass branch, disposed between an inlet of the gas-liquid separator and an exhaust port of the compressor, for dividing a part of the refrigerant flowing from the compressor to the condenser, and merging with the refrigerant flowing to the inlet of the gas-liquid separator;

the bypass valve is arranged on the bypass branch and used for controlling the on-off of the bypass branch;

and a controller configured to:

responding to a heating starting instruction of the air conditioning system, and acquiring the outdoor environment temperature and the working state of the four-way valve;

under the conditions that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in a first working state, controlling the outdoor expansion valve to be opened to a preset initial opening degree, controlling the compressor to run at a target frequency in an up-conversion mode, and controlling the bypass valve to be closed;

when the reversing condition of the four-way valve is met, controlling the four-way valve to be switched from a first working state to a second working state, and simultaneously controlling the expansion valve to be closed;

after the four-way valve is switched to the second working state, the opening degree of the expansion valve is controlled based on the exhaust superheat degree of the compressor, and the opening and closing of the bypass valve are controlled based on the suction pressure of the compressor.

2. The air conditioning system of claim 1, further comprising:

an outdoor fan for radiating heat of the outdoor heat exchanger;

the controller is further configured to:

controlling the outdoor fan to stop running under the condition that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in a first working state;

after the four-way valve is switched to a second working state, when the exhaust superheat degree of the compressor is lower than a first preset superheat degree, controlling the outdoor fan to stop running;

and controlling the outdoor fan to operate at a target rotating speed when the exhaust superheat degree of the compressor is increased to reach a first superheat degree threshold value.

3. The air conditioning system of claim 2,

the controller is configured to control the opening degree of the expansion valve based on a discharge superheat degree of the compressor after the four-way valve is switched to the second operation state, and includes:

after the four-way valve is switched to the second working state, controlling the expansion valve to keep a closed state when the exhaust superheat degree of the compressor is lower than a second superheat degree threshold value, wherein the second superheat degree threshold value is higher than the first superheat degree threshold value;

and when the exhaust superheat degree of the compressor is increased to reach the second superheat degree threshold value, controlling the expansion valve to be opened to a preset initial opening degree.

4. Air conditioning system according to claim 3,

the controller is further configured to:

after the starting control end condition is met, adjusting the opening degree of the expansion valve so that the discharge superheat degree of the compressor reaches a target discharge superheat degree, or the suction superheat degree of the compressor reaches a target suction superheat degree.

5. Air conditioning system according to any of claims 1 to 3,

the controller is configured to control the switch of the bypass valve based on a suction pressure of the compressor after the four-way valve is switched to the second operation state, and includes:

after the four-way valve is switched to the second working state, when the suction pressure of the compressor is lower than a preset pressure threshold value, controlling the bypass valve to be opened;

and controlling the bypass valve to be closed after the suction pressure of the compressor reaches a preset pressure threshold value.

6. The air conditioning system of claim 5,

the controller is further configured to:

and controlling the bypass valve to be closed after the starting control end condition is met.

7. The air conditioning system according to claim 4 or 6, wherein the start control end condition includes any one of:

the opening time of the bypass valve reaches a preset time; alternatively, the first and second liquid crystal display panels may be,

and when the exhaust superheat degree of the compressor reaches a third superheat degree threshold value, the third superheat degree threshold value is larger than the second superheat degree threshold value.

8. The air conditioning system of claim 1,

the controller is further configured to:

under the condition that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in a second working state, controlling the expansion valve to be closed, and controlling the compressor to perform frequency-up operation to a target frequency;

the opening degree of the expansion valve is controlled based on the discharge superheat degree of the compressor, and the opening and closing of the bypass valve is controlled based on the suction pressure of the compressor.

9. The air conditioning system of claim 8, further comprising:

an outdoor fan for radiating heat of the outdoor heat exchanger;

the controller is further configured to:

when the outdoor environment temperature is lower than the preset temperature and the four-way valve is in a second working state, controlling the outdoor fan to stop running;

and controlling the outdoor fan to operate at a target rotating speed when the exhaust superheat degree of the compressor is increased to reach a first superheat degree threshold value.

10. A control method of an air conditioning system, characterized by being applied to the air conditioning system of any one of claims 1 to 9, the method comprising:

responding to a heating starting instruction of the air conditioning system, and acquiring the outdoor environment temperature and the working state of the four-way valve;

under the condition that the outdoor environment temperature is lower than the preset temperature and the four-way valve is in a first working state, controlling the outdoor expansion valve to be opened to a preset initial opening degree, controlling the compressor to perform frequency-up operation to a target frequency, and controlling the bypass valve to be closed;

when the reversing condition of the four-way valve is met, controlling the four-way valve to be switched from a first working state to a second working state, and simultaneously controlling the expansion valve to be closed;

after the four-way valve is switched to the second working state, the opening degree of the expansion valve is controlled based on the exhaust superheat degree of the compressor, and the opening and closing of the bypass valve are controlled based on the suction pressure of the compressor.

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