CN218269335U

CN218269335U - Air conditioning system

Info

Publication number: CN218269335U
Application number: CN202222417966.8U
Authority: CN
Inventors: 李庆辉; 王振; 宁明辉; 黄曙良; 侯志辉; 杨伟茂; 刘昕昕
Original assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Current assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Priority date: 2022-09-13
Filing date: 2022-09-13
Publication date: 2023-01-10
Anticipated expiration: 2032-09-13

Abstract

The application provides an air conditioning system includes an outdoor unit, and the outdoor unit is provided with a gas-liquid separator, a main outdoor heat exchanger and an auxiliary outdoor heat exchanger. The gas-liquid separator is configured to separate and store a liquid refrigerant, and is connected to a suction side of the compressor via a pipe. The main outdoor heat exchanger is configured to be connected with a main four-way valve, and the auxiliary outdoor heat exchanger is configured to be connected with an auxiliary four-way valve; in addition, a switching control valve is provided, the first end of the switching control valve is connected with the indoor unit through a pipe, one path of the second end of the switching control valve is connected with the auxiliary four-way valve through a pipe, the other path of the second end of the switching control valve is connected with the gas-liquid separator through a pipe, and the switching control valve is configured to turn on or off a refrigerant loop of the auxiliary outdoor heat exchanger, so that the load of the air conditioning system is automatically adjusted.

Description

Air conditioning system

Technical Field

The present application relates to the field of air conditioning technology, and more particularly, to an air conditioning system.

Background

The multi-split air conditioning system is an air conditioning system with multi-split type, variable refrigerant quantity and variable indoor unit capacity. One outdoor unit can be connected with a plurality of indoor units, and has the advantages of convenient installation, small occupied area, long service life, low maintenance cost and the like. Wherein the ratio of the internal volume to the external volume is usually 50-150%. Among the current air conditioning duty ratios, most systems operate at partial load and the outdoor ambient temperature span is wider (such as low-temperature refrigeration and high-temperature heating).

At present, the multi-split system basically adopts an outdoor heat exchanger as a constant volume; when the system operates under a small load, the capacities of the indoor heat exchanger and the outdoor heat exchanger are not matched (the capacity of the outdoor heat exchanger is far greater than that of the indoor heat exchanger), the system is easy to be frequently turned on and off, so that the energy consumption is high, the comfort of the indoor machine is reduced, the system pressure ratio and pressure are abnormal, and the reliability of the compressor is reduced due to the reduction of the oil return efficiency of the system.

Disclosure of Invention

In some embodiments of the present application, an outdoor unit is provided with a first outdoor heat exchanger and a second outdoor heat exchanger, wherein the first outdoor heat exchanger is a main heat exchanger and the second outdoor heat exchanger is an auxiliary heat exchanger; a first four-way valve connected with the first outdoor heat exchanger is a main four-way valve, and a second four-way valve connected with the second outdoor heat exchanger is an auxiliary four-way valve; the outdoor unit is connected to the indoor unit through an air pipe and a liquid pipe, wherein the first end of the switching control valve is connected with the air pipe.

In some embodiments of the present application, the outdoor unit further includes first and second electronic expansion valves; one end of the first electronic expansion valve is connected with the liquid pipe, and the other end of the first electronic expansion valve is connected with the first outdoor heat exchanger; one end of the second electronic expansion valve is connected with the liquid pipe, and the other end of the second electronic expansion valve is connected with the second outdoor heat exchanger.

In some embodiments of the present application, the air conditioning system operates in a first cooling mode, i.e., a high-load full cooling mode, the first four-way valve and the second four-way valve operate in a first state, the switching control valve is turned on, the first electronic expansion valve and the second electronic expansion valve are maintained at a maximum opening degree, and the first outdoor heat exchanger and the second outdoor heat exchanger operate in a condensing state at the same time.

In some embodiments of the present application, the air conditioning system operates in the second cooling mode, i.e., the low load cooling mode, the first four-way valve operates in the first state, the second four-way valve operates in the second state, the switching control valve is turned off, the first electronic expansion valve is maintained at the maximum opening degree, the second electronic expansion valve is maintained at the minimum opening degree, the first outdoor heat exchanger operates in the condensing state, and the refrigerant circuit of the second outdoor heat exchanger is turned off.

In some embodiments of the present application, the air conditioning system operates in a first heating mode, i.e., a high-load full heating mode, the first four-way valve and the second four-way valve operate in a second state, the switching control valve is turned on, the first electronic expansion valve and the second electronic expansion valve operate in a throttling state, and the first outdoor heat exchanger and the second outdoor heat exchanger operate in an evaporating state simultaneously.

In some embodiments of the present application, the air conditioning system operates in a second heating mode, i.e., a low load heating mode, the first four-way valve and the second four-way valve operate in a second state, the switching control valve is turned off, the first electronic expansion valve operates in a throttling state, the second electronic expansion valve is maintained at a minimum opening degree, and the first outdoor heat exchanger and the second outdoor heat exchanger operate in an evaporating state simultaneously.

The air conditioning system also comprises a bypass throttling element, wherein one path of the first end of the bypass throttling element is connected with the second end of the switching control valve, and the other path of the bypass throttling element is connected with an auxiliary four-way valve; the second end of the bypass throttling element is connected with the gas-liquid separator.

In some embodiments of the present application, the switching control valve is a solenoid valve.

In some embodiments of the present application, the switching valve is a first check valve that is in one-way communication from the indoor unit to the gas-liquid separator.

In some embodiments of the present application, to enable automatic switching of large load and small load refrigeration, the air conditioning system further includes a control unit configured to receive a refrigeration mode start signal to generate a first set of refrigeration driving signals to the first four-way valve, the second four-way valve, the switching control valve, the first electronic expansion valve, and the second electronic expansion valve, so that the air conditioning system operates in a first refrigeration mode; or receiving a refrigeration environment temperature detection signal or a refrigeration compressor exhaust pressure detection signal to generate a second group of refrigeration driving signals to the first four-way valve, the second four-way valve, the switching control valve, the first electronic expansion valve and the second electronic expansion valve, so that the air conditioning system works in a second refrigeration mode.

In some embodiments of the present application, automatic switching between large load and small load heating is achieved, and the control unit is further configured to receive a heating mode starting signal to generate a first set of heating driving signals to the first four-way valve, the second four-way valve, the switching control valve, the first electronic expansion valve and the second electronic expansion valve, so that the air conditioning system operates in the first heating mode; or receiving a heating environment temperature detection signal or a heating compressor exhaust pressure detection signal to generate a second set of heating driving signals to the first four-way valve, the second four-way valve, the switching control valve, the first electronic expansion valve and the second electronic expansion valve, so that the air-conditioning system works in a second heating mode.

In some embodiments of the present application, the air conditioning system further comprises an oil separator, a first end of the oil separator is connected to the discharge side of the compressor, a second end is connected to the first four-way valve and the second four-way valve via a second check valve, respectively, and a third end is connected to the gas-liquid separator via a filter; and the third end of the oil separator is positioned at the bottom of the oil separator.

In some embodiments of the present application, the air conditioning system further comprises a bypass solenoid valve connected between the second end of the oil separator and the suction side of the compressor by piping.

In the embodiment, through the configuration, the system capacity is matched with the load, and the problems of frequent startup and shutdown, reduced comfort of the indoor unit, abnormal system pressure ratio and pressure, reduced system oil return efficiency and the like are avoided.

Drawings

FIG. 1 shows a schematic block diagram of an air conditioning system;

FIG. 2 illustrates a refrigerant circuit schematic of some embodiments of an air conditioning system;

FIG. 3 illustrates a schematic diagram of the operation of various valve elements in some embodiments of an air conditioning system;

FIG. 4 illustrates a refrigerant circuit schematic of some embodiments of an air conditioning system;

FIG. 5 illustrates a schematic diagram of the operation of various valve elements in some embodiments of an air conditioning system;

FIG. 6 illustrates a refrigerant circuit schematic of some embodiments of an air conditioning system;

FIG. 7 illustrates a schematic diagram of the operation of various valve elements in some embodiments of an air conditioning system;

FIG. 8 illustrates a refrigerant circuit schematic of some embodiments of an air conditioning system;

FIG. 9 illustrates a schematic diagram of the operation of various valve elements in some embodiments of an air conditioning system;

10-13 illustrate refrigerant circuit schematics of some embodiments of an air conditioning system wherein the switching control valve is a first check valve;

fig. 14-17 show schematic block circuit diagrams of some embodiments of air conditioning systems.

Detailed Description

To make the purpose and embodiments of the present application clearer, the following will clearly and completely describe the exemplary embodiments of the present application with reference to the attached drawings in the exemplary embodiments of the present application, and it is obvious that the described exemplary embodiments are only a part of the embodiments of the present application, and not all of the embodiments.

It should be noted that the brief descriptions of the terms in the present application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of the present application. These terms should be understood in their ordinary and customary meaning unless otherwise indicated.

The terms "first," "second," "third," and the like in the description and claims of this application and in the above-described drawings are used for distinguishing between similar or analogous objects or entities and not necessarily for describing a particular sequential or chronological order, unless otherwise indicated. It is to be understood that the terms so used are interchangeable under appropriate circumstances.

The terms "comprises" and "comprising," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a product or apparatus that comprises a list of elements is not necessarily limited to all elements expressly listed, but may include other elements not expressly listed or inherent to such product or apparatus.

Aiming at the problem that the outdoor heat exchanger is basically constant in volume in the existing multi-split system; when the multi-split air conditioning system runs under a low load, the capacity of the indoor heat exchanger and the capacity of the outdoor heat exchanger are not matched (the capacity of the outdoor heat exchanger is far larger than that of the indoor heat exchanger), the air conditioning system is easy to have the problems of high energy consumption, reduced comfort of the indoor unit, abnormal pressure ratio and pressure of the system and reduced reliability of a compressor caused by reduced oil return efficiency due to frequent startup and shutdown, and the air conditioning system is designed and provided.

Fig. 1 is a schematic diagram of a refrigerant circuit of an air conditioning system 1 provided in the present embodiment. The air conditioning system 1 employs a compression refrigeration cycle, and includes four main components, i.e., a compressor 10, a condenser 12 (high-temperature heat source), a throttling element 14, and an evaporator 16 (low-temperature heat source), to form a refrigerant circuit, in which a refrigerant circulates sequentially through the compressor 10, the condenser 12, the throttling element 14, and the evaporator 16.

In the present embodiment, the cooling and heating cycle of the air conditioning system 1 includes a series of processes involving compression, condensation, expansion, and evaporation to cool or heat the indoor space.

The low-temperature and low-pressure refrigerant enters the compressor 10, and the compressor 10 compresses the refrigerant gas in a high-temperature and high-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser 12. The condenser 12 condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

The expansion element 14, which is exemplified by an electronic expansion valve, expands the high-temperature, high-pressure liquid-phase refrigerant condensed in the condenser 12 into a low-pressure liquid-phase refrigerant. The evaporator 16 evaporates the refrigerant expanded in the electronic expansion valve and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor 10. The evaporator 16 can achieve a cooling effect by heat-exchanging with a material to be cooled using latent heat of evaporation of a refrigerant. The air conditioning system 1 can adjust the temperature of the indoor space throughout the cycle.

The outdoor unit of the air conditioning system 1 refers to a portion of the refrigeration cycle including the compressor 10, the outdoor heat exchanger, and the outdoor fan, the indoor unit of the air conditioning system 1 refers to a portion including the indoor heat exchanger and the indoor fan, and the throttling element 14 may be provided in the indoor unit or the outdoor unit.

An indoor heat exchanger and an outdoor heat exchanger are used as the condenser 12 or the evaporator 16. When the indoor heat exchanger is used as the condenser 12, the air conditioning system 1 performs a heating mode, and when the indoor heat exchanger is used as the evaporator 16, the air conditioning system 1 performs a cooling mode.

The indoor heat exchanger and the outdoor heat exchanger are switched to be used as the condenser 12 or the evaporator 16, and a four-way valve is generally used, and the contents of the indoor heat exchanger and the outdoor heat exchanger will be further described below.

The working principle of the refrigeration operation of the air conditioning system 1 is as follows: the compressor 10 works to make the interior of the indoor heat exchanger (in the indoor unit, the evaporator 16 at this time) be in an ultra-low pressure state, the liquid refrigerant in the indoor heat exchanger is quickly evaporated to absorb heat, the air blown out by the indoor fan is cooled by the coil pipe of the indoor heat exchanger and then becomes cold air to be blown into the room, the evaporated and vaporized refrigerant is compressed by the compressor 10 and then is condensed into liquid in the high-pressure environment in the outdoor heat exchanger (in the outdoor unit, the condenser 12 at this time) to release heat, the heat is dissipated into the atmosphere through the outdoor fan, and the refrigeration effect is achieved by the circulation.

The heating operation principle of the air conditioning system 1 is as follows: the gaseous refrigerant is pressurized by the compressor 10 to become a high-temperature and high-pressure gas, and the high-temperature and high-pressure gas enters the indoor heat exchanger (in this case, the condenser 12), is condensed, liquefied, releases heat, becomes a liquid, and heats indoor air, thereby achieving the purpose of increasing the indoor temperature. The liquid refrigerant is decompressed by the throttling element 14, enters the outdoor heat exchanger (in this case, the evaporator 16), evaporates, absorbs heat, becomes gas, and simultaneously absorbs heat of outdoor air (the outdoor air becomes cooler), becomes gaseous refrigerant, and enters the compressor 10 again to start the next cycle.

The air conditioning system 1 further includes a gas-liquid separator configured to separate and store the liquid refrigerant flowing out of the evaporator 16, and the gas-liquid separator is connected between the evaporator 16 and the suction side of the compressor 10 by a pipe.

In an alternative embodiment, the air conditioning system 1 may comprise a plurality of indoor units. The indoor units and the outdoor units work in a matching way, for example, work in a mode of 'one driving more'.

In an alternative embodiment, the air conditioning system 1 may include a plurality of outdoor units. Each outdoor unit can work independently or be configured to work in groups, such as two outdoor units, four outdoor units, and so on. Each or each group of outdoor units is provided with an indoor unit corresponding to the outdoor unit in a matching way.

In an alternative embodiment, one compressor 10 or a plurality of compressors 10 may be provided in each outdoor unit, and ac power is supplied to the compressor 10 in an operating state through an inverter. When the output frequency of the inverter device is changed, the rotation speed of the compressor 10 is changed, thereby realizing different air conditioning capacities.

In an alternative embodiment, the indoor unit may adopt an independent air supply structure, such as a wall-mounted air supply structure, a floor-mounted air supply structure, an air duct type air supply structure, or an air supply structure embedded in a ceiling.

In an optional implementation mode, the indoor unit is correspondingly provided with a wire controller in a matching way, and the wire controller is fixedly installed on the wall of the air-conditioning room. The wire controller is provided with an operation interface for inputting set temperature and operation mode and a display interface for displaying the real-time temperature of the air-conditioning room and the running state of the air-conditioning system 1.

In an optional implementation manner, a remote controller is correspondingly arranged in a matching manner in the indoor unit, the remote controller is in communication connection with the indoor unit, and the remote controller is provided with keys for inputting a set temperature and an operation mode, and a display interface for displaying a real-time temperature of an air conditioning room and an operation state of the air conditioning system 1.

In an optional implementation manner, the indoor unit is correspondingly provided with a mobile control terminal in a matching manner, the mobile control terminal is in communication connection with the indoor unit, the mobile control terminal is provided with an application interface, and the set temperature and the operation mode can be input through the application interface and the real-time temperature or the operation state of the air-conditioning room can be displayed.

In an alternative embodiment, the mobile control terminal may be a computer, a tablet computer, a smart phone, a wearable device, or the like.

In an optional embodiment, an outdoor unit main board is disposed in the outdoor unit. The outdoor unit main board is preferably provided with an internal controller. The internal controller is configured to drive the frequency conversion device to operate, receive and process sampling signals of various sensors and realize necessary communication functions, drive the outdoor fan to operate, drive the throttling element 14 to operate, drive the four-way valve to switch between different operating positions, and the like.

In an alternative embodiment, the internal controller includes electrical components such as a memory unit, a processor, an input/output interface, and a communication interface.

The storage unit may include a volatile memory and/or a nonvolatile memory, among others. The storage unit is configured to store instructions or data, such as an application program, associated with at least one component of the outdoor unit. For example, the application program may be a heating operation or a cooling operation of the air conditioning system 1 by controlling the compressor 10 and the four-way valve.

The processor may be a dedicated processor, a Central Processing Unit (CPU), or the like. The processor may access the memory unit to execute instructions stored in the memory unit to perform the associated functions.

The input/output port may be a serial communication interface.

The communication interface may be a software interface supporting different wireless communication protocols.

The outdoor unit main board is usually integrated with a switching power supply circuit.

In an alternative embodiment, the internal controller may be communicatively coupled to the cloud control platform.

An indoor unit main board is arranged in the indoor unit, and an indoor controller is preferably arranged on the indoor unit main board. The indoor controller is configured to drive the indoor fan to work, display various parameters on the display panel, interact with human-computer, receive and process sampling signals of various sensors and realize necessary communication functions.

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

The memory unit may include volatile memory and/or nonvolatile memory. The storage unit is configured to store cooling or data associated with at least one component of the indoor unit, such as storing an application. For example, the application program may adjust the temperature of the air-conditioned room by the gear of different rotation speeds of the indoor fan.

The input/output interface may be a serial communication interface, for example, connected to a room temperature sensor, a tube temperature sensor, etc. to receive a sampling signal of the sensor, or connected to an indicator light, a buzzer, a stepping motor, etc. to output a control signal. The stepper motor may be a drive member for the air deflector.

The communication interface may be a software interface supporting different wireless communication protocols, such as WiFi, bluetooth, etc.

The main board of the indoor unit is also provided with a power circuit to provide 5V and 12V voltage.

And the internal controller on the outdoor unit mainboard is in communication connection with the internal controller on the indoor unit mainboard.

Hereinafter, examples of the present application will be described in detail.

The outdoor unit of the air conditioning system is provided with a main outdoor heat exchanger and an auxiliary outdoor heat exchanger, wherein the main outdoor heat exchanger is provided with a main four-way valve in a matching manner, and the auxiliary outdoor heat exchanger is provided with an auxiliary four-way valve in a matching manner. The outdoor unit of the air conditioning system is also provided with a switching control valve, the first end of the switching control valve is connected with the indoor unit through a pipe, one path of the second end of the switching control valve is connected with the auxiliary four-way valve through a pipe, and the other path of the second end of the switching control valve is connected with the gas-liquid separator through a pipe. The switching control valve is configured to turn on or off the refrigerant circuit of the auxiliary outdoor heat exchanger. When the refrigerant loop of the auxiliary outdoor heat exchanger is turned off, only the main outdoor heat exchanger works, and when the refrigerant loop of the auxiliary outdoor heat exchanger is turned on, the main outdoor heat exchanger and the auxiliary outdoor heat exchanger work simultaneously, so that the system capacity and the load are matched, and the problems of frequent startup and shutdown, reduced comfort of an indoor unit, abnormal system pressure ratio and pressure, reduced system oil return efficiency and the like are avoided.

The air conditioning system of some embodiments of the present application will be further described using fig. 2 to 17.

Fig. 2-9 are schematic diagrams of refrigerant cycles in some embodiments of air conditioning systems. The refrigerant cycle of the indoor heat exchanger of the indoor unit portion is the same as that of the related art, and therefore, redundant description is omitted.

In the example of fig. 2 to 9, the outdoor unit 18 is one, but may be another number.

In the example of fig. 3 to 9, the outdoor heat exchanger is implemented by a first outdoor heat exchanger 24 and a second outdoor heat exchanger 26 arranged in parallel in a set, matching the first outdoor heat exchanger 24 and the second outdoor heat exchanger 26, and further includes a first four-way valve 28 and a second four-way valve 30 arranged in a set. In addition, the outdoor unit 18 is provided with a gas-liquid separator and a compressor.

In the example of fig. 2 to 9, one compressor is provided.

In the example of fig. 2 to 9, the first outdoor heat exchanger 24 is defined as a main heat exchanger, and the second outdoor heat exchanger 26 is defined as an auxiliary heat exchanger. The first four-way valve 28 connected to the first outdoor heat exchanger 24 is a main four-way valve, and the second four-way valve 30 connected to the second outdoor heat exchanger 26 is an auxiliary four-way valve. Of course, the second outdoor heat exchanger 26 may be a main heat exchanger and the first outdoor heat exchanger 24 may be an auxiliary heat exchanger, which is similar to the first case and will not be described again.

The outdoor unit 18 and the indoor unit are connected by piping, specifically, by a liquid pipe 22 and an air pipe 20.

In some embodiments of the present application, the liquid tube 22 and the gas tube 20 are both metal copper tubes.

The liquid pipe 22 and the gas pipe 20 are defined with the state of the refrigerant as a reference; for example, during the heating operation, the gas refrigerant flowing into the indoor heat exchanger exchanges heat with indoor air and condenses to become a high-pressure two-phase refrigerant or a high-pressure supercooled refrigerant, and is sent to the outdoor unit 18 through the liquid pipe 22. The indoor unit and the outdoor unit 18 are connected to each other through an air pipe 20, and high-temperature and high-pressure air compressed by the compressor is supplied to the indoor through the air pipe 20 during the heating operation.

The first end of the switching control valve 32-1 is connected with the indoor unit through an air pipe 20, one path of the second end of the switching control valve 32-1 is connected with the second four-way valve 30, and the other path is connected with the gas-liquid separator.

In some embodiments of the present application, a first electronic expansion valve 34 and a second electronic expansion valve 36 are also provided in the air conditioning system, in concert with the first four-way valve 28, the second four-way valve 30, and the switching control valve 32-1. One end of the first electronic expansion valve 34 is connected to the liquid pipe 22, the other end is connected to the first outdoor heat exchanger 24, and one end of the second electronic expansion valve 36 is connected to the liquid pipe 22, and the other end is connected to the second outdoor heat exchanger 26. The first electronic expansion valve 34 and the second electronic expansion valve 36 can each function as a throttling element as shown in fig. 1, but in an air conditioning system, the throttling element can also have a larger number of electronic expansion valves or capillary tubes, which can be disposed in the indoor unit or the outdoor unit 18 and follow a manner well-known in the art, and will not be described again here.

At least four modes of operation are possible with the air conditioning system as shown.

The air conditioning system operates in the first cooling mode, the first four-way valve 28 and the second four-way valve 30 operate in the first state, the switching control valve 32-1 is turned on, the first electronic expansion valve 34 and the second electronic expansion valve 36 are maintained at the maximum opening degree, and the first outdoor heat exchanger 24 and the second outdoor heat exchanger 26 operate in the condensing state at the same time.

The first cooling mode of the air conditioning system is a full cooling mode.

As shown in fig. 2 and 3, the refrigerant circuit and the valve set in the full cooling mode operate such that the interior of the indoor heat exchanger (in the indoor unit, the evaporator at this time) is in an ultra-low pressure state, the liquid refrigerant in the indoor heat exchanger evaporates and absorbs heat rapidly, the blown air is cooled by the coil of the indoor heat exchanger and then becomes cold air to be blown into the room, and the evaporated and vaporized refrigerant enters the outdoor unit 18 through the air pipe 20, specifically: one path enters the gas-liquid separator through the first four-way valve 28 (working in a first state, such as a power-off state, at this time), the other path enters the gas-liquid separator through the conducted switching control valve 32-1, the two paths of evaporated and vaporized refrigerants are merged in the gas-liquid separator, the gaseous refrigerant separated by the gas-liquid separator is pressurized by the compressor, one path enters the first outdoor heat exchanger 24 through the first four-way valve 28 (working in the first state, such as the power-off state, at this time), the other path enters the second outdoor heat exchanger 26 through the second four-way valve 30 (working in the first state, such as the power-off state, at this time), the high-pressure environment in the first outdoor heat exchanger 24 (in the outdoor unit 18, in this time, a condenser) and the second outdoor heat exchanger 26 (in the outdoor unit 18, in this time, the condenser) is condensed into a liquid state, heat is released, and the heat is dissipated into the atmosphere through the outdoor fan. The liquid refrigerant condensed, liquefied, and released heat to become liquid passes through the first electronic expansion valve 34 and the second electronic expansion valve 36, which are maintained at the maximum opening degree, and is merged into the liquid inlet pipe 22, and is returned to the indoor unit. The cycle (as indicated by arrow F1 in fig. 2 and 3) achieves the effect of full cooling mode with large load.

The air conditioning system operates in the second cooling mode, the first four-way valve 28 operates in the first state, the second four-way valve 30 operates in the second state, the switching control valve 32-1 is turned off, the first electronic expansion valve 34 is maintained at the maximum opening degree, the second electronic expansion valve 36 is maintained at the minimum opening degree, the first outdoor heat exchanger 24 operates in the condensing state, and the refrigerant circuit of the second outdoor heat exchanger 26 is turned off.

The second cooling mode of the air conditioning system is a low load cooling mode.

As shown in fig. 4 and 5, the compressor operates to place the interior of the indoor heat exchanger (in the indoor unit, the evaporator at this time) in an ultra-low pressure state, the liquid refrigerant in the indoor heat exchanger evaporates quickly to absorb heat, the blown air is cooled by the indoor heat exchanger coil and becomes cool air to blow into the room, the evaporated and vaporized refrigerant enters the outdoor unit 18 through the air pipe 20, the refrigerant enters the gas-liquid separator through the first four-way valve 28 (operating in the first state, e.g., the power-off state at this time) due to the switching control valve 32-1 being turned off, the gaseous refrigerant separated by the gas-liquid separator is pressurized by the compressor, one path of the refrigerant enters the first outdoor heat exchanger 24 through the first four-way valve 28 (operating in the first state, e.g., the power-off state at this time), and the other path of the refrigerant cannot enter the second outdoor heat exchanger 26 through the second four-way valve 30 due to the switching control valve 32-1 being turned off and the second four-way valve 30 operating in the second state (e.g., the power-on state at this time), the other path of the refrigerant cannot enter the second outdoor heat exchanger 26, and the refrigerant circuit is cut off, and this portion of the refrigerant is returned to the gas-liquid separator through the pressure reducing throttle. Another portion of the refrigerant condenses to a liquid state in the high pressure environment in the first outdoor heat exchanger 24 (in the outdoor unit 18, which is a condenser in this case), and releases heat, which is dissipated to the atmosphere by the outdoor fan. The liquid refrigerant, which has condensed, liquefied, and released heat to become liquid, returns to the liquid pipe 22 through the first electronic expansion valve 34 maintained at the maximum opening degree, and further returns to the indoor unit. This cycle (as indicated by arrow F2 in fig. 4 and 5) achieves the effect of the light load cooling mode. Since the refrigerant circuit of the second outdoor heat exchanger 26 is shut off, the second electronic expansion valve 36 is maintained at the minimum opening degree.

The air conditioning system operates in the first heating mode, the first four-way valve 28 and the second four-way valve 30 operate in the second state, the switching control valve 32-1 is turned on, the first electronic expansion valve 34 and the second electronic expansion valve 36 operate in the throttling state, and the first outdoor heat exchanger 24 and the second outdoor heat exchanger 26 operate in the evaporating state simultaneously.

The first heating mode of the air conditioning system is a full heating mode.

The operation modes of the refrigerant circuit and the valve set in the full heating mode are as shown in fig. 6 and 7, the gaseous refrigerant is pressurized by the compressor to become high-temperature high-pressure gas, the high-temperature high-pressure gas is divided into two branches, one branch passes through the first four-way valve 28 (working in a second state, such as a power-on state at this time) to enter the indoor heat exchanger (a condenser at this time), and the high-temperature high-pressure gas is condensed, liquefied and released heat to become liquid, and simultaneously heats indoor air, so that the purpose of increasing the indoor temperature is achieved; the other path passes through a second four-way valve 30 (which works in a second state, such as a power-on state) and a conducting switching control valve 32-1, enters an indoor heat exchanger (which is a condenser), is condensed, liquefied and released heat to form liquid, and simultaneously heats indoor air so as to achieve the purpose of increasing the indoor temperature, liquid refrigerant flowing out of the indoor heat exchanger flows into a liquid pipe 22, is decompressed by a first electronic expansion valve 34 and a second electronic expansion valve 36 which work in a throttling state, returns to the first outdoor heat exchanger 24 and the second outdoor heat exchanger 26 respectively, is evaporated, absorbed and becomes gas, and flows out of the first outdoor heat exchanger 24 and the second outdoor heat exchanger 26 respectively, further passes through a first four-way valve 28 and a second four-way valve 30 which are connected with a gas-liquid separator, and gas refrigerant separated by the gas-liquid separator returns to the suction side of the compressor. The circulation (as shown by an arrow F3 in fig. 6 and 7) achieves the effect of the full heating mode with large load.

The air conditioning system operates in the second heating mode, the first four-way valve 28 and the second four-way valve 30 operate in the second state, the switching control valve 32-1 is turned off, the first electronic expansion valve 34 operates in the throttling state, and the second electronic expansion valve 36 is maintained at the minimum opening degree.

The first heating mode of the air conditioning system is a small load heating mode.

The refrigerant circuit and the valve group of the small load heating mode are operated as shown in the figure and the drawing, the gaseous refrigerant is pressurized by the compressor to become high-temperature high-pressure gas, the high-temperature high-pressure gas is divided into two branches, one branch of the high-temperature high-pressure gas passes through the first four-way valve 28 (working in a second state, such as a power-on state at the moment) to enter the indoor heat exchanger (a condenser at the moment), and the high-temperature high-pressure gas is condensed, liquefied and released heat to become liquid, and meanwhile, the indoor air is heated, so that the purpose of improving the indoor temperature is achieved; and the other path through second four-way valve 30 (now operating in a second state, e.g., an energized state). Since the switching control valve 32-1 is in the off state, it cannot enter the indoor heat exchanger (in this case, the condenser), the refrigerant circuit of the second outdoor heat exchanger 26 is cut off, and this portion of the refrigerant is throttled and decompressed and returned to the gas-liquid separator. The other part of the refrigerant entering the indoor heat exchanger (in this case, a condenser) is condensed, liquefied, and released heat to become liquid, and at the same time, the indoor air is heated to raise the indoor temperature, and the liquid refrigerant flowing out of the indoor heat exchanger flows into the liquid pipe 22, is decompressed by the first electronic expansion valve 34 operating in a throttled state, returns to the first outdoor heat exchanger 24, evaporates, vaporizes, absorbs heat, becomes gas, flows out of the first outdoor heat exchanger 24 to the gas-liquid separator, and the gas refrigerant separated by the gas-liquid separator returns to the suction side of the compressor. The heating mode with small load effect is achieved by this cycle (as indicated by arrow F4 in fig. 8 and 9). Since the refrigerant circuit of the second outdoor heat exchanger 26 is closed, the second electronic expansion valve 36 is maintained at the minimum opening degree.

In some embodiments of the present application, as shown in fig. 2 to 9, the switching control valve 32-1 is a solenoid valve.

In some embodiments of the present application, as shown in fig. 10 to 13, the switching control valve is a first check valve 32-2 that unidirectionally communicates from the indoor unit to the gas-liquid separator.

The refrigerant that cannot enter the indoor heat exchanger or the second outdoor heat exchanger 26 is throttled down by the bypass throttling element 38 due to the action of the switching control valve 32-1. One path of the first end of the bypass throttling element 38 is connected to the second end of the switching control valve 32-1, and the other path is connected to the auxiliary four-way valve. A second end of the bypass restriction member 38 is connected to the gas-liquid separator.

In some embodiments of the present application, the bypass restriction element 38 is a bypass capillary tube.

In some embodiments of the present application, an ambient temperature sensor is also included in the parameter detection. The ambient temperature sensor is used for detecting the temperature of the air-conditioned room.

In some embodiments of the present application, a control unit 62 is also included in the air conditioning system. The control unit 62 is preferably implemented by an internal controller in the outdoor unit 18.

FIG. 14 is a schematic block diagram of an electrical circuit of some embodiments of an air conditioning system. In the air conditioning system as shown in fig. 14, the control unit 62 is configured to generate a first set of cooling driving signals to the first four-way valve 28, the second four-way valve 30, the switching control valve 32-1, the first electronic expansion valve 34 and the second electronic expansion valve 36 after receiving the cooling mode start signal, so that the air conditioning system operates in the first cooling mode, that is, the first four-way valve 28 and the second four-way valve 30 operate in the first state, the switching control valve 32-1 is turned on, the first electronic expansion valve 34 and the second electronic expansion valve 36 are maintained at the maximum opening degree, and the air conditioning system operates in the full-cooling large-load cooling mode. After a period of operation, for example, when a condition that the ambient temperature is not higher than the set temperature is satisfied, the control unit 62 receives the cooling ambient temperature detection signal, and generates a second set of cooling driving signals to the first four-way valve 28, the second four-way valve 30, the switching control valve 32-1, the first electronic expansion valve 34, and the second electronic expansion valve 36, so that the air conditioning system operates in the second cooling mode, that is, the first four-way valve 28 operates in the first state, the second four-way valve 30 operates in the second state, the switching control valve 32-1 is turned off, the first electronic expansion valve 34 is maintained at the maximum opening degree, the second electronic expansion valve 36 is maintained at the minimum opening degree, and the air conditioning system automatically switches to the small-load cooling mode. The comparison of the ambient temperature and the set temperature is preferably performed by a comparator circuit, which outputs a refrigerated ambient temperature detection signal, which may be integrated in the ambient temperature sensor or in the internal controller.

FIG. 15 is a schematic block diagram of an electrical circuit of some embodiments of an air conditioning system. In the air conditioning system as shown in fig. 15. The control unit 62 is configured to receive the cooling mode start signal and then generate a first set of cooling driving signals to the first four-way valve 28, the second four-way valve 30, the switching control valve 32-1, the first electronic expansion valve 34 and the second electronic expansion valve 36, so that the air conditioning system operates in the first cooling mode, that is, the first four-way valve 28 and the second four-way valve 30 operate in the first state, the switching control valve 32-1 is turned on, the first electronic expansion valve 34 and the second electronic expansion valve 36 are maintained at the maximum opening degree, and the air conditioning system operates in the full-cooling large-load cooling mode. After a period of operation, for example, when a condition that the compressor discharge pressure is not higher than a set pressure is satisfied, the control unit 62 receives a refrigerant compressor discharge pressure detection signal, and generates a second set of refrigeration driving signals to the first four-way valve 28, the second four-way valve 30, the switching control valve 32-1, the first electronic expansion valve 34, and the second electronic expansion valve 36, so that the air conditioning system operates in the second refrigeration mode, that is, the first four-way valve 28 operates in the first state, the second four-way valve 30 operates in the second state, the switching control valve 32-1 is turned off, the first electronic expansion valve 34 is maintained at the maximum opening degree, the second electronic expansion valve 36 is maintained at the minimum opening degree, and the air conditioning system automatically switches to the small-load refrigeration mode. The comparison of the compressor discharge pressure and the set pressure is preferably performed by a comparator circuit that outputs a refrigerant compressor discharge pressure detection signal, which may be integrated in the compressor discharge pressure sensor or in an internal controller.

In the two embodiments, the full refrigeration mode is executed first, and then the small-load refrigeration mode is executed, so that automatic switching and automatic matching of loads are realized.

FIG. 16 is a schematic block diagram of an electrical circuit of some embodiments of an air conditioning system. In the air conditioning system as shown in fig. 16, the control unit 62 is configured to generate a first set of heating driving signals to the first four-way valve 28, the second four-way valve 30, the switching control valve 32-1, the first electronic expansion valve 34 and the second electronic expansion valve 36 after receiving the heating mode starting signal, so that the air conditioning system operates in the first heating mode, that is, the first four-way valve 28 and the second four-way valve 30 operate in the second state, the switching control valve 32-1 is turned on, the first electronic expansion valve 34 and the second electronic expansion valve 36 operate in the throttling state, and the air conditioning system operates in the heating only large load heating mode. After a period of operation, for example, when a condition that the ambient temperature is not lower than the set temperature is satisfied, the control unit 62 receives the heating ambient temperature detection signal, and generates a second set of heating driving signals to the first four-way valve 28, the second four-way valve 30, the switching control valve 32-1, the first electronic expansion valve 34, and the second electronic expansion valve 36, so that the air conditioning system operates in the second heating mode, that is, the first four-way valve 28 and the second four-way valve 30 operate in the second state, the switching control valve 32-1 is turned off, the first electronic expansion valve 34 operates in the throttling state, the second electronic expansion valve 36 is maintained at the minimum opening degree, and the air conditioning system automatically switches to the small-load heating mode. The comparison of the ambient temperature and the set temperature is preferably performed by a comparator circuit that outputs a heating ambient temperature detection signal, which may be integrated in the ambient temperature sensor or in an internal controller.

FIG. 17 is a schematic block diagram of an electrical circuit of some embodiments of an air conditioning system. In the air conditioning system as shown in fig. 17, the control unit 62 is configured to generate a first set of heating driving signals to the first four-way valve 28, the second four-way valve 30, the switching control valve 32-1, the first electronic expansion valve 34 and the second electronic expansion valve 36 after receiving the heating mode starting signal, so that the air conditioning system operates in the first heating mode, that is, the first four-way valve 28 and the second four-way valve 30 operate in the second state, the switching control valve 32-1 is turned on, the first electronic expansion valve 34 and the second electronic expansion valve 36 operate in the throttling state, and the air conditioning system operates in the heating only large load heating mode. After a period of operation, for example, when a condition that the compressor discharge pressure is not lower than a set pressure is satisfied, the control unit 62 receives a heating compressor discharge pressure detection signal, generates a second set of heating driving signals to the first four-way valve 28, the second four-way valve 30, the switching control valve 32-1, the first electronic expansion valve 34, and the second electronic expansion valve 36, so that the air conditioning system operates in the second heating mode, that is, the first four-way valve 28 and the second four-way valve 30 operate in the second state, the switching control valve 32-1 is turned off, the first electronic expansion valve 34 operates in the throttling state, the second electronic expansion valve 36 is maintained at the minimum opening degree, and the air conditioning system automatically switches to the small-load heating mode for operation. The comparison of the compressor discharge pressure and the set pressure is preferably performed by a comparator circuit that outputs a heating compressor discharge pressure detection signal, which may be integrated in the compressor discharge pressure sensor or in an internal controller.

In an alternative embodiment, the air conditioning system further includes a first outdoor heat exchanger temperature sensor 58, the first outdoor heat exchanger temperature sensor 58 being disposed between the first outdoor heat exchanger 24 and the first four-way valve 28, and being operable to calculate the degree of superheat of the exhaust air and to control the opening degree of the first electronic expansion valve 34 in the throttled state based on the degree of superheat of the exhaust air.

In an alternative embodiment, the air conditioning system further includes a first outdoor heat exchanger temperature sensor 60, the first outdoor heat exchanger temperature sensor 60 being disposed between the second outdoor heat exchanger 26 and the second four-way valve 30, and being operable to calculate the degree of superheat of the exhaust air and to control the opening degree of the second electronic expansion valve 36 in the throttling state based on the degree of superheat of the exhaust air.

In an alternative embodiment, the air conditioning system further comprises an oil separator 42, a first end of the oil separator 42 is connected to the discharge side of the compressor, a second end is connected to the first four-way valve 28 and the second four-way valve 30 via check valves, respectively, and a third end is connected to the gas-liquid separator via a filter 48; wherein the third end is located at the bottom of the oil separator 42. The oil separator 42 separates the lubricating oil from the high pressure vapor discharged from the compressor to ensure safe and efficient operation of the apparatus.

In an alternative embodiment, the air conditioning system further includes a bypass solenoid valve 40, the bypass solenoid valve 40 being connected between the second end of the oil separator 42 and the suction side of the compressor by piping. The bypass solenoid valve 40 is turned on under the protection condition to directly return a part of the refrigerant discharged from the discharge side of the compressor to the low pressure side of the compressor, thereby ensuring the normal operation of the air conditioning system.

In an alternative embodiment, the air conditioning system further comprises a low pressure sensor 52 disposed on the suction side of the compressor and configured to detect the suction pressure of the compressor, and a high pressure sensor 44 disposed on the discharge side of the compressor and configured to detect the discharge pressure of the compressor, and a high pressure switch disposed on the discharge side of the compressor and configured to perform protection control on the compressor according to the actual pressure.

In an alternative embodiment, the air conditioning system further comprises a liquid side stop valve 54 disposed on the liquid pipe 22 and a gas side stop valve 56 disposed on the gas pipe 20.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

The foregoing description, for purposes of explanation, has been presented in conjunction with specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed above. Many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles and the practical application, to thereby enable others skilled in the art to best utilize the embodiments and various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. An air conditioning system comprising:

an outdoor unit provided with:

a gas-liquid separator configured to separate and store a liquid refrigerant, the gas-liquid separator being connected to a suction side of the compressor through a pipe;

the outdoor unit further includes:

a main outdoor heat exchanger configured to be connected to a main four-way valve;

an auxiliary outdoor heat exchanger configured to be connected with an auxiliary four-way valve; and

a switching control valve, the first end of which is connected with the indoor unit through a pipe, the second end of which is connected with the auxiliary four-way valve through a pipe in one path and is connected with the gas-liquid separator through a pipe in the other path;

the switching control valve is configured to turn on or off a refrigerant circuit of the auxiliary outdoor heat exchanger.

2. The air conditioning system of claim 1, wherein:

the outdoor unit is provided with a first outdoor heat exchanger and a second outdoor heat exchanger, wherein the first outdoor heat exchanger is a main heat exchanger, and the second outdoor heat exchanger is an auxiliary heat exchanger; a first four-way valve connected with the first outdoor heat exchanger is a main four-way valve, and a second four-way valve connected with the second outdoor heat exchanger is an auxiliary four-way valve; the outdoor unit is connected with the indoor unit through an air pipe and a liquid pipe, wherein the first end of the switching control valve is connected with the air pipe;

the outdoor unit further comprises:

one end of the first electronic expansion valve is connected with the liquid pipe, and the other end of the first electronic expansion valve is connected with the first outdoor heat exchanger; and

and one end of the second electronic expansion valve is connected with the liquid pipe, and the other end of the second electronic expansion valve is connected with the second outdoor heat exchanger.

3. The air conditioning system of claim 2, wherein:

the air conditioning system works in a first refrigeration mode, the first four-way valve and the second four-way valve work in a first state, the switching control valve is conducted, the first electronic expansion valve and the second electronic expansion valve are maintained at the maximum opening degree, and the first outdoor heat exchanger and the second outdoor heat exchanger work in a condensation state simultaneously; or

The air conditioning system works in a second refrigeration mode, the first four-way valve works in a first state, the second four-way valve works in a second state, the switching control valve is turned off, the first electronic expansion valve is maintained at the maximum opening degree, the second electronic expansion valve is maintained at the minimum opening degree, the first outdoor heat exchanger works in a condensation state, and a refrigerant loop of the second outdoor heat exchanger is turned off.

4. The air conditioning system of claim 2, wherein:

the air conditioning system works in a first heating mode, the first four-way valve and the second four-way valve work in a second state, the switching control valve is conducted, the first electronic expansion valve and the second electronic expansion valve work in a throttling state, and the first outdoor heat exchanger and the second outdoor heat exchanger work in an evaporation state simultaneously; or

The air conditioning system works in a second heating mode, the first four-way valve and the second four-way valve work in a second state, the switching control valve is turned off, the first electronic expansion valve works in a throttling state, the second electronic expansion valve is maintained at a minimum opening degree, and the first outdoor heat exchanger and the second outdoor heat exchanger work in an evaporation state simultaneously.

5. The air conditioning system according to any one of claims 1 to 4, characterized in that:

the air conditioning system further includes:

one path of the first end of the bypass throttling element is connected with the second end of the switching control valve, and the other path of the first end of the bypass throttling element is connected with the auxiliary four-way valve; and the second end of the bypass throttling element is connected with the gas-liquid separator.

6. The air conditioning system of claim 4, wherein:

the switching control valve is an electromagnetic valve or a first one-way valve which is communicated from the indoor unit to the gas-liquid separator in one way.

7. The air conditioning system of claim 5, wherein:

further comprising:

a control unit configured to receive a refrigeration mode start signal to generate a first set of refrigeration driving signals to the first four-way valve, the second four-way valve, the switching control valve, the first electronic expansion valve and the second electronic expansion valve, so that the air conditioning system operates in a first refrigeration mode; or receiving a refrigeration environment temperature detection signal or a refrigeration compressor exhaust pressure detection signal to generate a second group of refrigeration driving signals to the first four-way valve, the second four-way valve, the switching control valve, the first electronic expansion valve and the second electronic expansion valve, so that the air conditioning system works in a second refrigeration mode.

8. The air conditioning system of claim 7, wherein:

the control unit is also configured to receive a heating mode starting signal to generate a first set of heating driving signals to the first four-way valve, the second four-way valve, the switching control valve, the first electronic expansion valve and the second electronic expansion valve so as to enable the air-conditioning system to work in a first heating mode; or receiving a heating environment temperature detection signal or a heating compressor exhaust pressure detection signal to generate a second set of heating driving signals to the first four-way valve, the second four-way valve, the switching control valve, the first electronic expansion valve and the second electronic expansion valve, so that the air-conditioning system works in a second heating mode.

9. The air conditioning system of claim 5, further comprising:

an oil separator having a first end connected to a discharge side of the compressor, a second end connected to the first four-way valve and the second four-way valve via a second check valve, and a third end connected to the gas-liquid separator via a filter; wherein the third end of the oil separator is positioned at the bottom of the oil separator.

10. The air conditioning system as claimed in claim 9, further comprising:

a bypass solenoid valve connected between the second end of the oil separator and the suction side of the compressor by a pipe.