CN115727397A - Air conditioner and outdoor unit control method thereof - Google Patents

Abstract

The invention discloses an air conditioner and an outdoor unit control method thereof, wherein the air conditioner comprises an indoor unit, an outdoor unit and a controller, wherein an outdoor fan, a compressor, a suction pressure sensor, an exhaust temperature sensor, a plurality of outdoor heat exchangers, an electronic expansion valve, an electromagnetic valve and an outer disc temperature sensor are arranged in the outdoor unit; the controller is configured to control an operation frequency of the compressor according to a suction pressure or a discharge pressure of the compressor; calculating the exhaust superheat degree of the compressor according to the exhaust temperature and the temperature of the outdoor coil pipe, and adjusting the opening degree of the electronic expansion valve; and adjusting the state of the electromagnetic valve according to the running frequency of the compressor to match the outdoor unit with the indoor unit. The outdoor unit of the invention adopts a plurality of heat exchangers, and controls the air-conditioning refrigeration system by utilizing the suction and exhaust pressure and the exhaust superheat degree, so that the same outdoor unit can realize the free matching of the indoor units, and the user requirements can be met without any arrangement when matching different indoor units.

Description

Air conditioner and outdoor unit control method thereof

Technical Field

The invention relates to the technical field of air conditioners, in particular to an air conditioner and an outdoor unit control method thereof.

Background

The outdoor unit of the air conditioner is installed in a worse environment than the indoor unit, and the damage probability is far higher than that of the indoor unit. The indoor set is generally secretly adorned in the furred ceiling for the cooperation fitment, and the change degree of difficulty is great, and the user generally only needs to change the off-premises station. The heat exchange area of the existing outdoor unit of the air conditioner is fixed, the outdoor unit can only adapt to the product requirement of one capacity section under the common condition, and the heat exchange area of the indoor unit which can be matched with the outdoor unit of the air conditioner also has certain range requirements. At present, an air conditioner is generally provided with 3 to 4 different outdoor units according to several indoor functional sections commonly seen in the market, and the outdoor units are matched according to the requirements of users, and the users are required to debug the outdoor units according to the conditions of the indoor units. Therefore, the development workload is increased, and for users, the purchased sample machines still need to be debugged for the second time, so that the user experience is poor.

Disclosure of Invention

The invention provides an air conditioner and an outdoor unit control method thereof, wherein the outdoor unit adopts a plurality of heat exchangers, and controls an air conditioning and cooling system by utilizing suction and discharge pressure and discharge superheat degree, so that the same outdoor unit can realize free collocation of indoor units, and can meet the requirements of users without any setting when indoor units with different capacity sections are collocated, thereby ensuring the running reliability of the air conditioner under different collocation conditions.

An air conditioner provided in a first embodiment of the present invention includes:

the indoor unit is internally provided with an indoor heat exchanger and an indoor fan;

the outdoor unit is internally provided with an outdoor fan, a compressor, a suction pressure sensor, an exhaust temperature sensor, a plurality of outdoor heat exchangers, an electronic expansion valve, an electromagnetic valve and an outer disc temperature sensor, wherein the electronic expansion valve, the electromagnetic valve, the outdoor heat exchangers and the indoor heat exchangers are connected through pipelines to form a refrigerant circulation loop;

the air suction pressure sensor is used for detecting the air suction pressure of the air suction port of the compressor;

the discharge pressure sensor is used for detecting the discharge pressure of the compressor discharge port;

the exhaust temperature sensor is used for detecting the exhaust temperature of the exhaust port of the compressor;

the outer plate temperature sensor is used for detecting the temperature of a coil pipe of the outdoor unit;

a controller configured to control an operating frequency of the compressor according to the suction pressure or the discharge pressure; calculating the exhaust superheat degree of the compressor according to the exhaust temperature and the coil temperature, and increasing the opening degree of the electronic expansion valve when the exhaust superheat degree is lower than a preset threshold value; when the exhaust superheat degree is higher than a preset threshold value, reducing the opening degree of the electronic expansion valve; and automatically adjusting the state of each electromagnetic valve according to the running frequency of the compressor so as to adapt the heat exchange area of the outdoor unit to the running requirement of the indoor unit.

A second embodiment of the present invention provides an air conditioner, wherein the outdoor unit includes a first outdoor heat exchanger, a second outdoor heat exchanger, and a third outdoor heat exchanger; one end of the first outdoor heat exchanger is connected with a first electromagnetic valve, and the other end of the first outdoor heat exchanger is connected with a first electronic expansion valve; one end of the second outdoor heat exchanger is connected with the second electromagnetic valve, and the other end of the second outdoor heat exchanger is connected with the second electronic expansion valve; and one end of the third outdoor heat exchanger is connected with the third electromagnetic valve, and the other end of the third outdoor heat exchanger is connected with the third electronic expansion valve.

In an air conditioner according to a third embodiment of the present invention, a heat exchange area of the first outdoor heat exchanger is larger than a heat exchange area of the second outdoor heat exchanger, and a heat exchange area of the second outdoor heat exchanger is larger than a heat exchange area of the third outdoor heat exchanger.

A fourth embodiment of the present invention provides an air conditioner wherein the controller is configured to:

when the suction pressure is detected to be lower than a first pressure threshold value or the discharge pressure is detected to be lower than a second pressure threshold value, controlling the running frequency of the compressor to be increased;

when the suction pressure is detected to be higher than a first pressure threshold value or the exhaust pressure is detected to be higher than a second pressure threshold value, controlling the running frequency of the compressor to be reduced;

controlling the compressor to operate at a first frequency when it is detected that the suction pressure is equal to a first pressure threshold or the discharge pressure is equal to a second pressure threshold.

A fifth embodiment of the present invention provides an air conditioner, wherein the controller is configured to:

when the running frequency of the compressor is detected to be lower than a preset frequency threshold value, controlling the first electromagnetic valve to be in a closed state, and controlling the second electromagnetic valve or the third electromagnetic valve to be in an open state;

and when the running frequency of the compressor is detected to be higher than a preset frequency threshold value, controlling the first electromagnetic valve to be in an open state, and controlling the second electromagnetic valve and/or the third electromagnetic valve to be in an open state.

A method for controlling an outdoor unit of an air conditioner according to a sixth embodiment of the present invention is applied to an air conditioner including an indoor heat exchanger, an indoor fan, an outdoor fan, a compressor, a suction pressure sensor, a discharge temperature sensor, a plurality of outdoor heat exchangers, and an electronic expansion valve, an electromagnetic valve, and an outdoor tray temperature sensor connected to each of the outdoor heat exchangers, and includes:

controlling an operation frequency of the compressor according to the suction pressure or the discharge pressure;

calculating the exhaust superheat degree of the compressor according to the exhaust temperature and the coil temperature, and increasing the opening degree of the electronic expansion valve when the exhaust superheat degree is lower than a preset threshold value; when the exhaust superheat degree is higher than a preset threshold value, reducing the opening degree of the electronic expansion valve;

and automatically adjusting the state of each electromagnetic valve according to the running frequency of the compressor so as to adapt the heat exchange area of the outdoor unit to the running requirement of the indoor unit.

In a method of controlling an outdoor unit of an air conditioner according to a seventh embodiment of the present invention, the outdoor unit includes a first outdoor heat exchanger, a second outdoor heat exchanger, and a third outdoor heat exchanger; one end of the first outdoor heat exchanger is connected with a first electromagnetic valve, and the other end of the first outdoor heat exchanger is connected with a first electronic expansion valve; one end of the second outdoor heat exchanger is connected with the second electromagnetic valve, and the other end of the second outdoor heat exchanger is connected with the second electronic expansion valve; and one end of the third outdoor heat exchanger is connected with a third electromagnetic valve, and the other end of the third outdoor heat exchanger is connected with a third electronic expansion valve.

In the method for controlling an outdoor unit of an air conditioner according to the eighth embodiment of the present invention, a heat exchange area of the first outdoor heat exchanger is larger than a heat exchange area of the second outdoor heat exchanger, and the heat exchange area of the second outdoor heat exchanger is larger than a heat exchange area of the third outdoor heat exchanger.

In a method for controlling an outdoor unit of an air conditioner according to a ninth embodiment of the present invention, the controlling an operating frequency of the compressor according to the suction pressure or the discharge pressure includes:

controlling the running frequency of the compressor to be increased when the suction pressure is detected to be lower than a first pressure threshold value or the discharge pressure is detected to be lower than a second pressure threshold value;

when the suction pressure is detected to be higher than a first pressure threshold value or the exhaust pressure is detected to be higher than a second pressure threshold value, controlling the running frequency of the compressor to be reduced;

controlling the compressor to operate at a first frequency when it is detected that the suction pressure is equal to a first pressure threshold, or the discharge pressure is equal to a second pressure threshold.

In a method for controlling an outdoor unit of an air conditioner according to a tenth embodiment of the present invention, the automatically adjusting a state of each of the electromagnetic valves according to an operating frequency of the compressor includes:

when the running frequency of the compressor is detected to be lower than a preset frequency threshold value, controlling the first electromagnetic valve to be in a closed state, and controlling the second electromagnetic valve or the third electromagnetic valve to be in an open state;

and when the running frequency of the compressor is detected to be higher than a preset frequency threshold value, controlling the first electromagnetic valve to be in an open state, and controlling the second electromagnetic valve and/or the third electromagnetic valve to be in an open state.

Compared with the prior art, the air conditioner and the outdoor unit control method thereof provided by the embodiment of the invention have the beneficial effects that: the outdoor unit of the air conditioner is internally provided with an outdoor fan, a compressor, a suction pressure sensor, an exhaust temperature sensor, a plurality of outdoor heat exchangers, an electronic expansion valve, an electromagnetic valve and an outer disc temperature sensor which are connected with each outdoor heat exchanger, wherein the compressor, the electronic expansion valve, the electromagnetic valve, the outdoor heat exchanger and the indoor heat exchanger are connected through pipelines to form a refrigerant circulation loop; the suction pressure sensor is used for detecting the suction pressure of the suction port of the compressor; the discharge pressure sensor is used for detecting the discharge pressure of the compressor discharge port; the exhaust temperature sensor is used for detecting the exhaust temperature of the exhaust port of the compressor; the outer coil temperature sensor is used for detecting the coil temperature of the outdoor unit; a controller configured to control an operating frequency of the compressor according to the suction pressure or the discharge pressure; calculating the exhaust superheat degree of the compressor according to the exhaust temperature and the coil temperature, and increasing the opening degree of the electronic expansion valve when the exhaust superheat degree is lower than a preset threshold value; when the exhaust superheat degree is higher than a preset threshold value, reducing the opening degree of the electronic expansion valve; and automatically adjusting the state of each electromagnetic valve according to the running frequency of the compressor so as to adapt the heat exchange area of the outdoor unit to the running requirement of the indoor unit. The outdoor unit of the embodiment of the invention adopts a plurality of heat exchangers, and controls the air conditioner cooling system by utilizing the suction and exhaust pressure and the exhaust superheat degree, so that the same outdoor unit can realize the free matching of the indoor units, and the requirements of users can be met without any arrangement when the indoor units with different capacity sections are matched, and the running reliability of the air conditioner under different matching conditions is ensured.

Drawings

Fig. 1 is an external perspective view of an air conditioner according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an air conditioner according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a refrigerant circulation circuit of an air conditioner according to an embodiment of the present invention;

fig. 4 is another schematic structural diagram of an air conditioner according to an embodiment of the present invention;

fig. 5 is a front view illustrating an outdoor heat exchanger of an air conditioner according to an embodiment of the present invention;

fig. 6 is a plan view of an outdoor heat exchanger in an air conditioner according to an embodiment of the present invention;

fig. 7 is a first flowchart illustrating a controller of an air conditioner according to an embodiment of the present invention;

fig. 8 is a second flowchart illustrating an operation of a controller in an air conditioner according to an embodiment of the present invention;

fig. 9 is a third flowchart illustrating operation of a controller in an air conditioner according to an embodiment of the present invention;

fig. 10 is a flowchart illustrating a method for controlling a motor of an air conditioner according to an embodiment of the present invention;

fig. 11 is a schematic flow chart illustrating a compressor frequency control method according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, 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 invention.

In the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present application.

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, "a plurality" means two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

Referring to fig. 1 to 2, fig. 1 is an external perspective view of an air conditioner according to an embodiment of the present invention, and fig. 2 is a schematic structural diagram of an air conditioner according to an embodiment of the present invention. An air conditioner 1 provided in an embodiment of the present invention includes:

an indoor unit 2 in which an indoor heat exchanger 21 and an indoor fan 22 are installed;

an outdoor unit 3 having an outdoor fan 31, a compressor 32, a suction pressure sensor, a discharge temperature sensor, a plurality of outdoor heat exchangers 33, and an electronic expansion valve 34, a solenoid valve 35, and an outer disk temperature sensor 36 connected to each of the outdoor heat exchangers, wherein the compressor 32, the electronic expansion valve 34, the solenoid valve 35, the outdoor heat exchangers 33, and the indoor heat exchangers 21 are connected by pipes to form a refrigerant circulation circuit;

the suction pressure sensor is used for detecting the suction pressure of the suction port of the compressor;

the discharge pressure sensor is used for detecting the discharge pressure of the compressor discharge port;

the exhaust temperature sensor is used for detecting the exhaust temperature of the exhaust port of the compressor;

the outer plate temperature sensor is used for detecting the temperature of a coil pipe of the outdoor unit;

a controller configured to control an operating frequency of the compressor according to the suction pressure or the discharge pressure; calculating the exhaust superheat degree of the compressor according to the exhaust temperature and the coil temperature, and increasing the opening degree of the electronic expansion valve when the exhaust superheat degree is lower than a preset threshold value; when the exhaust superheat degree is higher than a preset threshold value, reducing the opening degree of the electronic expansion valve; and automatically adjusting the state of each electromagnetic valve according to the running frequency of the compressor so as to adapt the heat exchange area of the outdoor unit to the running requirement of the indoor unit.

Specifically, the air conditioner 1 according to the embodiment of the present invention includes an indoor unit 2, such as an indoor unit (shown) that is generally mounted on an indoor wall surface or the like. For another example, an indoor cabinet (not shown) is also an indoor unit of the indoor unit. The outdoor unit 3 is generally installed outdoors and used for heat exchange in an indoor environment. In the illustration of fig. 1, the outdoor unit 3 is indicated by a broken line because the outdoor unit 3 is located outdoors on the opposite side of the indoor unit 2 with respect to the wall surface. The indoor unit 2 and the outdoor unit 3 are connected by a connection pipe 4. The indoor unit 2 includes an indoor heat exchanger 21 and an indoor fan 22. The indoor heat exchanger 21 is configured by a plurality of fins and a coil penetrating the plurality of fins, and the indoor heat exchanger 21 functions as an evaporator or a radiator depending on the operating state of the indoor unit 2, and exchanges heat between the refrigerant flowing through the coil and the air passing through the indoor heat exchanger 21. The indoor fan 22 is located at a substantially central portion inside the indoor unit casing, and the indoor fan 22 is a cross-flow fan having a substantially cylindrical shape elongated in the longitudinal direction (left-right direction) of the indoor unit 2. By rotationally driving the indoor fan 22, the conditioned air generated by the indoor heat exchanger 21 after the indoor air is sucked from the suction port and passes through the air filter is blown out from the discharge port into the room. The larger the rotation speed of the indoor fan 22 is, the larger the volume of conditioned air blown out from the outlet port is. When the air conditioner is in the cooling mode, the indoor heat exchanger 21 operates as an evaporator. The indoor heat exchanger 21 functions as an evaporator or a radiator according to the operating state of the indoor unit, and exchanges heat between the refrigerant flowing through the heat transfer tubes and the air passing through the indoor heat exchanger. The indoor fan 22 generates an airflow of the indoor air passing through the indoor heat exchanger 21 to promote heat exchange between the refrigerant flowing in the heat transfer tubes of the indoor heat exchanger 21 and the indoor air. The outdoor unit 3 is provided therein with an outdoor fan 31, a compressor 32, a suction pressure sensor, a discharge temperature sensor, a plurality of outdoor heat exchangers 33, and an electronic expansion valve 34, a solenoid valve 35, and an outer disk temperature sensor 36 connected to each of the outdoor heat exchangers. The outdoor fan 31 generates an airflow of outdoor air passing through the outdoor heat exchanger 33 to promote heat exchange between the refrigerant flowing through the heat transfer tubes and the outdoor air, and the outdoor fan 31 is driven by an outdoor motor capable of changing the rotation speed. When the air conditioner is in the cooling mode, the outdoor heat exchanger 33 operates as a condenser. The outdoor fan 31 generates an air flow of outdoor air passing through the outdoor heat exchanger 33 to promote heat exchange between the refrigerant flowing in the heat transfer tubes of the outdoor heat exchanger 33 and the outdoor air. The suction pressure sensor is used for detecting the suction pressure of the suction port of the compressor when the air conditioner runs in the refrigeration mode. The exhaust pressure sensor is used for detecting the exhaust pressure of the exhaust port of the compressor when the air conditioner operates in a heating mode. The exhaust temperature sensor is used for detecting the exhaust temperature of the exhaust port of the compressor. The outer-panel temperature sensor is used to detect the coil temperature of the outdoor unit 3.

Referring to fig. 3, fig. 3 is a schematic diagram of a refrigerant circulation circuit of an air conditioner according to an embodiment of the present invention. The compressor 32, the electronic expansion valve 34, the solenoid valve 35, the outdoor heat exchanger 33, and the indoor heat exchanger 21 are connected by piping to form a refrigerant circulation circuit. The indoor heat exchanger 21 and the outdoor heat exchanger 33 function as a condenser or an evaporator. When the indoor heat exchanger 21 functions as a condenser and the outdoor heat exchanger 33 functions as an evaporator, the air conditioner functions as a heater in a heating mode; when the indoor heat exchanger 21 functions as an evaporator and the outdoor heat exchanger 33 functions as a condenser, the air conditioner functions as a cooler in a cooling mode. The solenoid valve 35 is used to control the flow direction of the refrigerant in the refrigerant circulation circuit so that the outdoor heat exchanger and the indoor heat exchanger are switched between the functions of a condenser and an evaporator. When the air conditioner is in the cooling mode, the indoor heat exchanger 21 and the outdoor heat exchanger 33 operate as an evaporator and a condenser, respectively. The refrigerant is compressed by the compressor and converted into high-temperature and high-pressure gas, enters the outdoor heat exchanger of the outdoor unit through the electromagnetic valve, is changed into medium-temperature and high-pressure liquid after the heat absorption and the heat release of the outdoor heat exchanger, is changed into low-temperature and low-pressure liquid after passing through the electronic expansion valve, is changed into low-temperature and low-pressure gas after the heat absorption and the heat release of the indoor heat exchanger of the indoor unit, returns to the compressor through the electromagnetic valve, and then continues to circulate. By circulating the refrigerant in the refrigerant circuit, a vapor compression refrigeration cycle can be executed. Wherein the electronic expansion valve can change the opening degree, and the flow path resistance of the refrigerant passing through the electronic expansion valve is increased by reducing the opening degree; by increasing the opening degree, the flow path resistance of the refrigerant passing through the electronic expansion valve is decreased. Such an electronic expansion valve expands and decompresses the refrigerant flowing from the indoor heat exchanger to the outdoor heat exchanger during the cooling operation. Further, even if the states of other devices installed in the refrigerant circuit do not change, when the opening degree of the electronic expansion valve changes, the flow rate of the refrigerant flowing in the refrigerant circuit changes.

In the embodiment of the invention, a plurality of outdoor heat exchangers connected in parallel are arranged in the outdoor unit, and each outdoor heat exchanger is connected with a corresponding electronic expansion valve, a corresponding electromagnetic valve and a corresponding outer disk temperature sensor. In the embodiment of the invention, the signal of the indoor unit cannot be transmitted to the outdoor unit, and the system cannot detect the indoor environment temperature and the indoor coil temperature, so that the indoor operation condition is judged by utilizing the suction and exhaust pressure. In the process of refrigeration, the suction pressure can reflect the evaporating temperature of the coil pipe of the indoor unit, the exhaust pressure in the process of heating can reflect the condensing temperature of the coil pipe of the indoor unit, and the two pressures are utilized to reflect the running state of the indoor unit, so that the running frequency of the compressor of the outdoor unit is controlled. The outdoor unit comprises an outdoor unit, a compressor, an outdoor unit, an air conditioner, an air compressor, an air suction pressure sensor, an air discharge pressure sensor and an air discharge pressure sensor, wherein the outdoor unit is provided with an outdoor coil temperature Twp, the outdoor unit is provided with an outdoor coil temperature sensor, the outdoor coil temperature sensor is provided with an outdoor discharge temperature Tp, the air discharge temperature sensor is provided with an outdoor discharge port, the air suction pressure sensor is provided with an air suction pressure sensor, the air suction pressure sensor is used for detecting the air suction pressure Ps of an air suction port of the compressor when the air conditioner operates in a refrigeration mode, and the air discharge pressure sensor is used for detecting the exhaust pressure Ph of the outdoor discharge port of the compressor when the air conditioner operates in a heating mode. The controller controls the operating frequency of the compressor according to the suction pressure Ps or the discharge pressure Ph of the compressor. And calculating the exhaust superheat Dsh = Tp-Twp of the compressor according to the exhaust temperature Tp and the coil temperature Twp. When the exhaust superheat degree Dsh is lower than a preset threshold value, increasing the opening degree of the electronic expansion valve; and when the exhaust superheat Dsh is higher than a preset threshold value, reducing the opening of the electronic expansion valve. In the operation process of the air conditioner, the state of each electromagnetic valve is automatically adjusted according to the operation frequency of the compressor, so that the heat exchange area of the outdoor unit is matched with the operation requirement of the indoor unit.

The outdoor unit of the embodiment of the invention adopts a plurality of heat exchangers, and controls the air conditioning and cooling system by utilizing the suction and exhaust pressure and the exhaust superheat degree, so that the same outdoor unit can realize the free collocation of the indoor units, and can meet the requirements of users without any setting when the indoor units with different capacity sections are collocated, thereby ensuring the running reliability of the air conditioner under different collocation conditions.

Referring to fig. 4, fig. 4 is another schematic structural diagram of an air conditioner according to an embodiment of the present invention.

As an alternative embodiment, the outdoor unit includes a first outdoor heat exchanger, a second outdoor heat exchanger, and a third outdoor heat exchanger; one end of the first outdoor heat exchanger is connected with a first electromagnetic valve, and the other end of the first outdoor heat exchanger is connected with a first electronic expansion valve; one end of the second outdoor heat exchanger is connected with the second electromagnetic valve, and the other end of the second outdoor heat exchanger is connected with the second electronic expansion valve; and one end of the third outdoor heat exchanger is connected with a third electromagnetic valve, and the other end of the third outdoor heat exchanger is connected with a third electronic expansion valve.

Illustratively, the refrigeration system in the embodiment of the present invention includes a compressor 1, a suction pressure sensor 2, a discharge temperature sensor 3, a discharge pressure sensor 4, a first solenoid valve 5, a first outdoor heat exchanger 6, a first external disk temperature sensor 7, a first electronic expansion valve 8, a second solenoid valve 9, a second outdoor heat exchanger 10, a second external disk temperature sensor 11, a second electronic expansion valve 12, a third solenoid valve 13, a third external disk heat exchanger 14, a third external disk temperature sensor 15, a third electronic expansion valve 16, a liquid storage tank 17, and an indoor heat exchanger 18. The outdoor unit of the embodiment of the present invention includes at least three outdoor heat exchangers, i.e., a first outdoor heat exchanger 6, a second outdoor heat exchanger 10, and a third outdoor heat exchanger 14. One end of each outdoor heat exchanger is connected with a solenoid valve, and the other end of each outdoor heat exchanger is connected with an electronic expansion valve, namely, one end of a first outdoor heat exchanger 6 is connected with a first solenoid valve 5, and the other end of the first outdoor heat exchanger is connected with a first electronic expansion valve 8; one end of the second outdoor heat exchanger 10 is connected with the second electromagnetic valve 9, and the other end is connected with the second electronic expansion valve 12; one end of the third outdoor heat exchanger 14 is connected to the third solenoid valve 13, and the other end is connected to the third electronic expansion valve 16, and the corresponding outdoor heat exchanger is controlled by the solenoid valve and the electronic expansion valve. Each outdoor heat exchanger is further provided with an outer plate temperature sensor, that is, the first outdoor heat exchanger 6 is provided with a first outer plate temperature sensor 7, the second outdoor heat exchanger 10 is provided with a second outer plate temperature sensor 11, and the third outdoor heat exchanger 14 is provided with a third outer plate temperature sensor 15, which is used for detecting the coil temperature of the outdoor unit. The embodiment of the invention adopts three sections of outdoor heat exchangers, and 6 heat exchange areas of the outdoor heat exchanger can be combined through the structure, namely the outdoor heat exchanger 1, the outdoor heat exchanger 2, the outdoor heat exchanger 3, the outdoor heat exchanger 1+2 and the outdoor heat exchanger 1+2+3. Compared with the existing 4 outdoor units, the outdoor unit has wider coverage. Referring to fig. 5 and 6, fig. 5 is a front view of an outdoor heat exchanger in an air conditioner according to an embodiment of the present invention, and fig. 6 is a top view of the outdoor heat exchanger in the air conditioner according to an embodiment of the present invention. The embodiment of the invention adopts an arrangement structure of two rows of outdoor heat exchangers, and in order to ensure the best heat exchange effect, the overall flow direction of the refrigerant is that the refrigerant enters from bottom to top in the evaporation process and enters from top to bottom in the condensation process. Meanwhile, the refrigerant should form a counter flow with the air flow direction during the condensation process. Therefore, in the embodiment of the present invention, the first outdoor heat exchanger is disposed at the outside, the second outdoor heat exchanger is disposed at the inside upper side, and the third outdoor heat exchanger is disposed at the inside lower side. According to the arrangement structure, the best heat exchange effect can be realized by combining the control process.

It should be noted that the number of the outdoor heat exchangers in the embodiment of the present invention is not limited to three, and may be set according to actual needs. Accordingly, the number of the arrangement rows of the outdoor heat exchangers may also be adjusted according to the number of the outdoor heat exchangers. For example, the outdoor unit is provided with n outdoor heat exchangers and m rows are arranged, wherein n is more than or equal to 2,1 and less than or equal to m and less than or equal to n.

As an alternative embodiment, the heat exchange area of the first outdoor heat exchanger is larger than the heat exchange area of the second outdoor heat exchanger, and the heat exchange area of the second outdoor heat exchanger is larger than the heat exchange area of the third outdoor heat exchanger.

In an exemplary embodiment of the present invention, according to the current situation of the indoor unit actually installed and used in the current market, the outdoor heat exchanger is divided by unequal areas. According to the previous research and the current research, the area division ratio adopted in the embodiment is preferably 50% for the outdoor heat exchanger 1, 30% for the outdoor heat exchanger 2 and 20% for the outdoor heat exchanger 3, that is, the heat exchange area of the first outdoor heat exchanger is larger than that of the second outdoor heat exchanger, and the heat exchange area of the second outdoor heat exchanger is larger than that of the third outdoor heat exchanger. According to the proportion division, 6 combination schemes which can be realized by combining the embodiment of the invention can be matched with all indoor unit terminals in the current market.

It should be noted that, in the embodiment of the present invention, the plurality of outdoor heat exchangers are in a structural form with unequal areas, and the area division ratio is not limited to 5:3:2, the setting can be carried out according to actual needs.

As one of the alternative embodiments, the controller is configured to:

when the suction pressure is detected to be lower than a first pressure threshold value or the discharge pressure is detected to be lower than a second pressure threshold value, controlling the running frequency of the compressor to be increased;

controlling the operating frequency of the compressor to decrease when it is detected that the suction pressure is higher than a first pressure threshold or the discharge pressure is higher than a second pressure threshold;

controlling the compressor to operate at a first frequency when it is detected that the suction pressure is equal to a first pressure threshold or the discharge pressure is equal to a second pressure threshold.

Specifically, referring to fig. 7, fig. 7 is a first flowchart of a controller of an air conditioner according to an embodiment of the present invention. When the refrigeration system is started to operate, the first electromagnetic valve is opened by default, and the first electronic expansion valve operates at the initial opening degree. After the operation starts, a suction pressure sensor detects a suction pressure Ps at a suction port of the compressor, or a discharge pressure sensor detects a discharge pressure Ph at a discharge port of the compressor. When it is detected that the suction pressure Ps is lower than the first pressure threshold value Psd or the discharge pressure Ph is lower than the second pressure threshold value Phd in controlling the operating frequency of the compressor according to the suction pressure Ps or the discharge pressure Ph, the operating frequency of the compressor is controlled to be increased. When it is detected that the suction pressure Ps is higher than the first pressure threshold value Psd, or the discharge pressure Ph is higher than the second pressure threshold value Phd, the operating frequency of the compressor is controlled to decrease. When it is detected that the suction pressure Ps is equal to the first pressure threshold value Psd, or the discharge pressure Ph is equal to the second pressure threshold value Phd, the compressor is controlled to operate at the first frequency. In the present embodiment, the first pressure threshold value Psd is preferably 0.1Mpa to 0.3Mpa, and the second pressure threshold value Phd is preferably 2.6Mpa to 3.1Mpa.

As one of the optional embodiments, the controller is configured to:

when the running frequency of the compressor is detected to be lower than a preset frequency threshold value, controlling the first electromagnetic valve to be in a closed state, and controlling the second electromagnetic valve or the third electromagnetic valve to be in an open state;

and when the running frequency of the compressor is detected to be higher than a preset frequency threshold value, controlling the first electromagnetic valve to be in an open state, and controlling the second electromagnetic valve and/or the third electromagnetic valve to be in an open state.

Specifically, referring to fig. 8, fig. 8 is a second flowchart of a controller of an air conditioner according to an embodiment of the present invention. When the refrigeration system is started to operate in the embodiment of the invention, the first electromagnetic valve is opened by default, and the first electronic expansion valve operates at the initial opening degree. After the operation starts, a suction pressure sensor detects a suction pressure Ps at a suction port of the compressor, or a discharge pressure sensor detects a discharge pressure Ph at a discharge port of the compressor. When it is detected that the suction pressure Ps is lower than the first pressure threshold value Psd or the discharge pressure Ph is lower than the second pressure threshold value Phd in controlling the operating frequency of the compressor according to the suction pressure Ps or the discharge pressure Ph, the operating frequency of the compressor is controlled to be increased. When it is detected that the suction pressure Ps is higher than the first pressure threshold value Psd, or the discharge pressure Ph is higher than the second pressure threshold value Phd, the operating frequency of the compressor is controlled to decrease. When it is detected that the suction pressure Ps is equal to the first pressure threshold value Psd, or the discharge pressure Ph is equal to the second pressure threshold value Phd, the compressor is controlled to operate at the first frequency. When detecting that the operating frequency Hy of the compressor is lower than the preset frequency threshold Hs, in order to make the operating frequency Hy of the compressor approach the preset frequency threshold Hs, the heat exchange area of the outdoor unit needs to be reduced at this time. In the embodiment of the invention, the heat exchange area of the first outdoor heat exchanger is larger than that of the second outdoor heat exchanger, and the heat exchange area of the second outdoor heat exchanger is larger than that of the third outdoor heat exchanger. For example, the outdoor heat exchanger 1 accounts for 50%, the outdoor heat exchanger 2 accounts for 30%, and the outdoor heat exchanger 3 accounts for 20%. When the refrigeration system is started to operate, the first electromagnetic valve is opened by default, and if the heat exchange area of the outdoor unit needs to be reduced, the first electromagnetic valve needs to be closed, and the second electromagnetic valve or the third electromagnetic valve needs to be opened. If the second electromagnetic valve is opened, the heat exchange area is reduced by 20%; if the third electromagnetic valve is opened, the heat exchange area is reduced by 30%. It should be noted that, in the embodiment of the present invention, the heat exchange area of the outdoor unit can be gradually reduced according to the actual situation. For example, the second solenoid valve is opened first, the heat exchange area is reduced by 20%, and if the operating frequency Hy of the compressor is still lower than the preset frequency threshold Hs, the second solenoid valve may be closed, and then the third solenoid valve may be opened. When detecting that the operating frequency Hy of the compressor is higher than the preset frequency threshold Hs, in order to make the operating frequency Hy of the compressor approach the preset frequency threshold Hs, the heat exchange area of the outdoor unit needs to be increased. When the refrigeration system is started to operate, the first electromagnetic valve is opened by default, and if the heat exchange area of the outdoor unit needs to be increased, the first electromagnetic valve needs to be maintained in an open state, and then the second electromagnetic valve and/or the third electromagnetic valve is opened. If the second electromagnetic valve is opened, the heat exchange area is increased by 30%; if the third electromagnetic valve is opened, the heat exchange area is increased by 20%; if the second electromagnetic valve and the third electromagnetic valve are opened simultaneously, the heat exchange area is increased by 50%. It should be noted that, in the embodiment of the present invention, the heat exchange area of the outdoor unit can be gradually increased according to the actual situation. For example, the third electromagnetic valve is opened first, the heat exchange area is increased by 20%, if the operating frequency Hy of the compressor is still higher than the preset frequency threshold Hs, the third electromagnetic valve can be closed, and then the second electromagnetic valve is opened, and the heat exchange area is increased by 30%; if the running frequency Hy of the compressor is still higher than the preset frequency threshold Hs, the third electromagnetic valve can be opened again, and the heat exchange area is increased by 50 percent at the moment. During the operation, the 1 st and 2 nd electronic expansion valves regulate the opening degree of the valve again according to the exhaust superheat degree of the path, when the exhaust superheat degree is lower than a set value, the opening degree of the expansion valve is increased, and when the exhaust superheat degree is higher than the set value, the opening degree of the expansion valve is decreased. After the compressor is stabilized, parameters such as pressure, dsh and the like are continuously detected, adjustment is continuously carried out, if the operating frequency of the compressor is increased, 1,2,3 electromagnetic valves are required to be opened, and if the operating frequency of the compressor is reduced, 2 electromagnetic valves are closed, automatic adjustment is carried out according to the rule, and finally matching with an indoor unit is completed, and the system is balanced. It should be noted that the range of the preset frequency threshold Hs in the present embodiment is preferably 60-80Hz.

The following describes an operation flow of the air conditioner provided in this embodiment with reference to fig. 9, where fig. 9 is a third operation flow chart of a controller in the air conditioner provided in an embodiment of the present invention.

The embodiment of the invention takes a refrigeration mode as an example:

when the refrigeration system is started to operate, the first electromagnetic valve is opened by default, and the first electronic expansion valve operates at the initial opening degree. After the operation is started, the suction pressure sensor detects the suction pressure Ps of the suction port of the compressor, and the compressor controls the operation frequency of the compressor according to the suction pressure Ps. When the detected suction pressure Ps is lower than the set pressure Psd, controlling the operation frequency of the compressor to increase; and when the detected suction pressure Ps is higher than the set pressure Psd, controlling the running frequency of the compressor to be reduced. When the detected suction pressure Ps is equal to the set pressure Psd, the compressor is controlled to operate at a fixed frequency, where the operating frequency of the compressor is Hy. The exhaust temperature sensor and the outer disk temperature sensor detect temperatures Tp and Twp, and an exhaust superheat Dsh is calculated, wherein DSH = Tp-Twp. The opening degree of the electronic expansion valve is controlled through the exhaust superheat degree, and when the exhaust superheat degree is lower than a set value, the opening degree of the electronic expansion valve is increased; when the exhaust superheat degree is higher than a set value, the opening degree of the electronic expansion valve is reduced. Judging the running frequency of the compressor and a set frequency Hs1 in the running process, and when the running frequency is lower than the set frequency after the compressor is stabilized, closing the first electromagnetic valve, opening the second electromagnetic valve, closing the third electromagnetic valve, and enabling the second outdoor heat exchanger to work; if the operation frequency is higher than the set frequency, the first electromagnetic valve and the second electromagnetic valve are opened simultaneously, the third electromagnetic valve is closed, the first outdoor heat exchanger and the second outdoor heat exchanger work, and the second electronic expansion valve operates at the initial set opening degree. During the operation, the 1 st and 2 nd electronic expansion valves regulate the opening degree of the valve again according to the exhaust superheat degree of the path, when the exhaust superheat degree is lower than a set value, the opening degree of the expansion valve is increased, and when the exhaust superheat degree is higher than the set value, the opening degree of the expansion valve is decreased. After the compressor is stabilized, parameters such as pressure, dsh and the like are continuously detected, adjustment is continuously carried out, if the operating frequency of the compressor is increased, 1,2,3 electromagnetic valves are required to be opened, and if the operating frequency of the compressor is reduced, 2 electromagnetic valves are closed, automatic adjustment is carried out according to the rule, and finally matching with an indoor unit is completed, and the system is balanced.

Referring to fig. 10, fig. 10 is a flowchart illustrating a method for controlling an outdoor unit of an air conditioner according to an embodiment of the present invention. The control method of the outdoor unit of the air conditioner is applied to the air conditioner comprising an indoor heat exchanger, an indoor fan, an outdoor fan, a compressor, a suction pressure sensor, an exhaust temperature sensor, a plurality of outdoor heat exchangers, an electronic expansion valve, an electromagnetic valve and an outer disc temperature sensor, wherein the electronic expansion valve, the electromagnetic valve and the outer disc temperature sensor are connected with each outdoor heat exchanger; the compressor, the electronic expansion valve, the electromagnetic valve, the outdoor heat exchanger and the indoor heat exchanger are connected through pipelines to form a refrigerant circulation loop; the suction pressure sensor is used for detecting the suction pressure of the suction port of the compressor; the discharge pressure sensor is used for detecting the discharge pressure of the compressor discharge port; the exhaust temperature sensor is used for detecting the exhaust temperature of the exhaust port of the compressor; the outdoor unit control method includes the steps of:

s1, controlling the running frequency of the compressor according to the suction pressure or the exhaust pressure;

s2, calculating the exhaust superheat degree of the compressor according to the exhaust temperature and the coil pipe temperature, and increasing the opening degree of the electronic expansion valve when the exhaust superheat degree is lower than a preset threshold value; when the exhaust superheat degree is higher than a preset threshold value, reducing the opening degree of the electronic expansion valve;

and S3, automatically adjusting the state of each electromagnetic valve according to the running frequency of the compressor so as to adapt the heat exchange area of the outdoor unit to the running requirement of the indoor unit.

The outdoor unit of the embodiment of the invention adopts a plurality of heat exchangers, and controls the air conditioning and cooling system by utilizing the suction and exhaust pressure and the exhaust superheat degree, so that the same outdoor unit can realize the free collocation of the indoor units, and can meet the requirements of users without any setting when the indoor units with different capacity sections are collocated, thereby ensuring the running reliability of the air conditioner under different collocation conditions.

As an alternative embodiment, the outdoor unit includes a first outdoor heat exchanger, a second outdoor heat exchanger, and a third outdoor heat exchanger; one end of the first outdoor heat exchanger is connected with a first electromagnetic valve, and the other end of the first outdoor heat exchanger is connected with a first electronic expansion valve; one end of the second outdoor heat exchanger is connected with the second electromagnetic valve, and the other end of the second outdoor heat exchanger is connected with the second electronic expansion valve; and one end of the third outdoor heat exchanger is connected with a third electromagnetic valve, and the other end of the third outdoor heat exchanger is connected with a third electronic expansion valve.

As an alternative embodiment, the heat exchange area of the first outdoor heat exchanger is larger than the heat exchange area of the second outdoor heat exchanger, and the heat exchange area of the second outdoor heat exchanger is larger than the heat exchange area of the third outdoor heat exchanger.

Referring to fig. 11, fig. 11 is a schematic flow chart illustrating a compressor frequency control method according to an embodiment of the present invention.

As an alternative embodiment, the controlling the operating frequency of the compressor according to the suction pressure or the exhaust pressure specifically includes:

controlling the running frequency of the compressor to be increased when the suction pressure is detected to be lower than a first pressure threshold value or the discharge pressure is detected to be lower than a second pressure threshold value;

controlling the operating frequency of the compressor to decrease when it is detected that the suction pressure is higher than a first pressure threshold or the discharge pressure is higher than a second pressure threshold;

controlling the compressor to operate at a first frequency when it is detected that the suction pressure is equal to a first pressure threshold or the discharge pressure is equal to a second pressure threshold.

As an optional embodiment, the automatically adjusting the state of each electromagnetic valve according to the operating frequency of the compressor specifically includes:

when the running frequency of the compressor is detected to be lower than a preset frequency threshold value, controlling the first electromagnetic valve to be in a closed state, and controlling the second electromagnetic valve or the third electromagnetic valve to be in an open state;

and when the running frequency of the compressor is detected to be higher than a preset frequency threshold value, controlling the first electromagnetic valve to be in a closed state, and controlling the second electromagnetic valve or the third electromagnetic valve to be in an open state.

The embodiment of the invention provides an air conditioner and an outdoor unit control method thereof, wherein an outdoor unit of the air conditioner is internally provided with an outdoor fan, a compressor, a suction pressure sensor, an exhaust temperature sensor, a plurality of outdoor heat exchangers, an electronic expansion valve, an electromagnetic valve and an outer disc temperature sensor, wherein the electronic expansion valve, the electromagnetic valve, the outdoor heat exchangers and the indoor heat exchangers are connected through pipelines to form a refrigerant circulation loop; the suction pressure sensor is used for detecting the suction pressure of the suction port of the compressor; the discharge pressure sensor is used for detecting the discharge pressure of the compressor discharge port; the exhaust temperature sensor is used for detecting the exhaust temperature of the exhaust port of the compressor; the outer plate temperature sensor is used for detecting the temperature of a coil pipe of the outdoor unit; a controller configured to control an operating frequency of the compressor according to the suction pressure or the discharge pressure; calculating the exhaust superheat degree of the compressor according to the exhaust temperature and the coil temperature, and increasing the opening degree of the electronic expansion valve when the exhaust superheat degree is lower than a preset threshold value; when the exhaust superheat degree is higher than a preset threshold value, reducing the opening degree of the electronic expansion valve; and automatically adjusting the state of each electromagnetic valve according to the running frequency of the compressor so as to adapt the heat exchange area of the outdoor unit to the running requirement of the indoor unit. The outdoor unit of the embodiment of the invention adopts a plurality of heat exchangers, and controls the air conditioning and cooling system by utilizing the suction and exhaust pressure and the exhaust superheat degree, so that the same outdoor unit can realize the free collocation of the indoor units, and can meet the requirements of users without any setting when the indoor units with different capacity sections are collocated, thereby ensuring the running reliability of the air conditioner under different collocation conditions.

It should be noted that the above-described system embodiments are merely illustrative, where the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. In addition, in the drawings of the embodiment of the system provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, and may be specifically implemented as one or more communication buses or signal lines. One of ordinary skill in the art can understand and implement it without inventive effort.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims (10)

1. An air conditioner, comprising:

the indoor unit is internally provided with an indoor heat exchanger and an indoor fan;

the outdoor unit is internally provided with an outdoor fan, a compressor, a suction pressure sensor, an exhaust temperature sensor, a plurality of outdoor heat exchangers, an electronic expansion valve, an electromagnetic valve and an outer disc temperature sensor, wherein the electronic expansion valve, the electromagnetic valve, the outdoor heat exchangers and the indoor heat exchangers are connected through pipelines to form a refrigerant circulation loop;

the suction pressure sensor is used for detecting the suction pressure of the suction port of the compressor;

the discharge pressure sensor is used for detecting the discharge pressure of the compressor discharge port;

the exhaust temperature sensor is used for detecting the exhaust temperature of the exhaust port of the compressor;

the outer plate temperature sensor is used for detecting the temperature of a coil pipe of the outdoor unit;

a controller configured to control an operating frequency of the compressor according to the suction pressure or the discharge pressure; calculating the exhaust superheat degree of the compressor according to the exhaust temperature and the coil temperature, and increasing the opening degree of the electronic expansion valve when the exhaust superheat degree is lower than a preset threshold value; when the exhaust superheat degree is higher than a preset threshold value, reducing the opening degree of the electronic expansion valve; and automatically adjusting the state of each electromagnetic valve according to the running frequency of the compressor so as to adapt the heat exchange area of the outdoor unit to the running requirement of the indoor unit.

2. The air conditioner as claimed in claim 1, wherein the outdoor unit includes a first outdoor heat exchanger, a second outdoor heat exchanger and a third outdoor heat exchanger; one end of the first outdoor heat exchanger is connected with a first electromagnetic valve, and the other end of the first outdoor heat exchanger is connected with a first electronic expansion valve; one end of the second outdoor heat exchanger is connected with the second electromagnetic valve, and the other end of the second outdoor heat exchanger is connected with the second electronic expansion valve; and one end of the third outdoor heat exchanger is connected with the third electromagnetic valve, and the other end of the third outdoor heat exchanger is connected with the third electronic expansion valve.

3. The air conditioner as claimed in claim 2, wherein said first outdoor heat exchanger has a heat exchange area larger than that of said second outdoor heat exchanger, and said second outdoor heat exchanger has a heat exchange area larger than that of said third outdoor heat exchanger.

4. The air conditioner of claim 3, wherein the controller is configured to:

controlling the running frequency of the compressor to be increased when the suction pressure is detected to be lower than a first pressure threshold value or the discharge pressure is detected to be lower than a second pressure threshold value;

when the suction pressure is detected to be higher than a first pressure threshold value or the exhaust pressure is detected to be higher than a second pressure threshold value, controlling the running frequency of the compressor to be reduced;

controlling the compressor to operate at a first frequency when it is detected that the suction pressure is equal to a first pressure threshold or the discharge pressure is equal to a second pressure threshold.

5. The air conditioner of claim 4, wherein the controller is configured to:

when the running frequency of the compressor is detected to be lower than a preset frequency threshold value, controlling the first electromagnetic valve to be in a closed state, and controlling the second electromagnetic valve or the third electromagnetic valve to be in an open state;

and when the running frequency of the compressor is detected to be higher than a preset frequency threshold value, controlling the first electromagnetic valve to be in an open state, and controlling the second electromagnetic valve and/or the third electromagnetic valve to be in an open state.

6. An outdoor unit control method of an air conditioner, the method being applied to an air conditioner including an indoor heat exchanger, an indoor fan, an outdoor fan, a compressor, a suction pressure sensor, a discharge temperature sensor, a plurality of outdoor heat exchangers, and an electronic expansion valve, a solenoid valve, and an outdoor tray temperature sensor connected to each outdoor heat exchanger, the outdoor unit control method comprising:

controlling an operation frequency of the compressor according to the suction pressure or the discharge pressure;

calculating the exhaust superheat degree of the compressor according to the exhaust temperature and the coil temperature, and increasing the opening degree of the electronic expansion valve when the exhaust superheat degree is lower than a preset threshold value; when the exhaust superheat degree is higher than a preset threshold value, reducing the opening degree of the electronic expansion valve;

and automatically adjusting the state of each electromagnetic valve according to the running frequency of the compressor so as to adapt the heat exchange area of the outdoor unit to the running requirement of the indoor unit.

7. The outdoor unit control method of claim 6, wherein the outdoor unit comprises a first outdoor heat exchanger, a second outdoor heat exchanger and a third outdoor heat exchanger; one end of the first outdoor heat exchanger is connected with a first electromagnetic valve, and the other end of the first outdoor heat exchanger is connected with a first electronic expansion valve; one end of the second outdoor heat exchanger is connected with the second electromagnetic valve, and the other end of the second outdoor heat exchanger is connected with the second electronic expansion valve; and one end of the third outdoor heat exchanger is connected with a third electromagnetic valve, and the other end of the third outdoor heat exchanger is connected with a third electronic expansion valve.

8. The outdoor unit control method of claim 7, wherein the heat exchange area of the first outdoor heat exchanger is larger than the heat exchange area of the second outdoor heat exchanger, and the heat exchange area of the second outdoor heat exchanger is larger than the heat exchange area of the third outdoor heat exchanger.

9. The method as claimed in claim 8, wherein the controlling the operating frequency of the compressor according to the suction pressure or the discharge pressure comprises:

controlling the running frequency of the compressor to be increased when the suction pressure is detected to be lower than a first pressure threshold value or the discharge pressure is detected to be lower than a second pressure threshold value;

controlling the operating frequency of the compressor to decrease when it is detected that the suction pressure is higher than a first pressure threshold or the discharge pressure is higher than a second pressure threshold;

controlling the compressor to operate at a first frequency when it is detected that the suction pressure is equal to a first pressure threshold, or the discharge pressure is equal to a second pressure threshold.

10. The method as claimed in claim 9, wherein the automatically adjusting the state of each of the solenoid valves according to the operating frequency of the compressor comprises:

when the running frequency of the compressor is detected to be lower than a preset frequency threshold value, controlling the first electromagnetic valve to be in a closed state, and controlling the second electromagnetic valve or the third electromagnetic valve to be in an open state;

and when the running frequency of the compressor is detected to be higher than a preset frequency threshold value, controlling the first electromagnetic valve to be in an open state, and controlling the second electromagnetic valve and/or the third electromagnetic valve to be in an open state.

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