CN211177490U - Air conditioner - Google Patents

Abstract

The utility model discloses an air conditioner, which comprises an outdoor unit and an indoor unit, wherein the outdoor unit comprises an enthalpy-increasing compression mechanism and an outdoor side heat exchanger, and the indoor unit comprises a first heat exchanger and a first throttling regulation device; the air conditioner further includes: a discharge pipe, a low-pressure suction pipe, a first piping, and a second piping; the outdoor unit further comprises a first switching device; the air conditioner also comprises an economizer which is arranged on a first pipe between the outdoor side heat exchanger and the first throttling device; a first refrigerant flow path and a second refrigerant flow path are arranged in the economizer, and the first refrigerant flow path is connected to a first piping through a refrigerant bridge circuit; one end of the second refrigerant flow path is communicated with the first pipe through a liquid taking pipe, and the other end of the second refrigerant flow path is simultaneously communicated with a medium-pressure suction inlet and a suction pipe of the compressor through a return pipe; so that the refrigerant flow directions in the first refrigerant flow path and the second refrigerant flow path are opposite. The utility model discloses technical scheme is favorable to improving the effect of getting liquid.

Description

Air conditioner

Technical Field

The utility model relates to an air conditioner technical field, in particular to air conditioner.

Background

Along with the increasing living standard and the energy-saving requirement of people, the enhanced vapor injection refrigerant system is more and more widely applied, in particular to the application of changing coal into electricity in the north and the application of multi-split air-conditioning systems. In addition, because a multi-split system or other refrigerant systems are applied by longer connecting pipes, and the throttling devices are arranged on the inner machine sides, a plurality of systems can be provided with two-stage supercooling devices so as to reduce the pressure loss of pipelines and the throttling noise of the inner machine. When a refrigerant system is applied and simultaneously needs enhanced vapor injection and secondary supercooling, the economizer can be shared, but the economizer is in forward flow heat exchange in one direction inevitably because the flow directions of refrigeration and heating refrigerants are opposite, so that the heat exchange temperature difference is small, and the heat exchange efficiency is reduced.

SUMMERY OF THE UTILITY MODEL

The main object of the present invention is to provide an air conditioner, which has a higher heating capacity in a low temperature environment under the premise of having a constant temperature dehumidification function.

In order to achieve the above object, the present invention provides an air conditioner, comprising an outdoor unit and an indoor unit, wherein the outdoor unit comprises an enthalpy-increasing compression mechanism and an outdoor side heat exchanger, and the indoor unit comprises a first heat exchanger and a first throttling regulation device;

the air conditioner further includes: a discharge pipe connected to a discharge side of the compression mechanism, a low-pressure suction pipe connected to a low-pressure suction side of the compression mechanism, a first pipe connecting the discharge pipe, the outdoor heat exchanger, the first throttle adjusting device, the first heat exchanger in this order, and a second pipe connecting the first heat exchanger and the low-pressure suction pipe, thereby forming a refrigerant circuit;

the outdoor unit further includes a first switching device that is switchable between a first switching device first switching state in which the first switching device communicates the first pipe with the suction pipe and communicates the second pipe with the discharge pipe, and a first switching device second switching state in which the first switching device communicates the first pipe with the discharge pipe and communicates the second pipe with the suction pipe;

the air conditioner also comprises an economizer which is arranged on a first pipe between the outdoor side heat exchanger and the first throttling device; a first refrigerant flow path and a second refrigerant flow path are arranged in the economizer, and the first refrigerant flow path is connected to the first distribution pipe through a refrigerant bridge circuit; one end of the second refrigerant flow path is communicated with the first pipe through a liquid taking pipe, and the other end of the second refrigerant flow path is simultaneously communicated with a medium-pressure suction inlet and a suction pipe of the compressor through a return pipe; so that the refrigerant flow directions in the first refrigerant flow path and the second refrigerant flow path are opposite.

Optionally, the refrigerant bridge circuit has a first port, a second port, and a refrigerant passage communicating the first port and the second port, and the refrigerant bridge circuit is connected to the first pipe through the first port and the second port.

Optionally, the refrigerant bridge circuit has a third port and a fourth port, and two ends of the first refrigerant flow path are respectively connected to the third port and the fourth port;

the first gap and the third gap are communicated through a first bridge section, and the first bridge section unidirectionally conducts the first gap to the third gap;

the third through port is communicated with the second through port through a second bridge section, and the second bridge section unidirectionally conducts the second through port to the third through port;

the second gap and the fourth gap are communicated through a third bridge section, and the third bridge section unidirectionally conducts the fourth gap to the second gap;

the fourth gap and the first gap are communicated through a fourth bridge section, and the fourth bridge section is communicated with the first gap from the fourth gap in a one-way mode.

Optionally, the refrigerant bridge circuit has a third port and a fourth port, and two ends of the first refrigerant flow path are respectively connected to the third port and the fourth port;

the first gap and the third gap are communicated through a first bridge section, and the first bridge section unidirectionally conducts the third gap to the first gap;

the third through port is communicated with the second through port through a second bridge section, and the second bridge section unidirectionally conducts the third through port to the second through port;

the second gap and the fourth gap are communicated through a third bridge section, and the third bridge section unidirectionally conducts the second gap to the fourth gap;

the fourth gap and the first gap are communicated through a fourth bridge section, and the fourth bridge section is communicated with the first gap to the fourth gap in a one-way mode.

Optionally, the first bridge section, the second bridge section, the third bridge section and the fourth bridge section are all provided with a check valve.

Optionally, a liquid taking throttle valve is arranged on the liquid taking pipe.

Optionally, the return pipe comprises a return pipe body, a first communicating pipe and a second communicating pipe;

one end of the first communicating pipe is communicated with the muffler body, and the other end of the first communicating pipe is communicated with a medium-pressure suction inlet of the compressor; a first control valve is arranged on the return pipe body or the first communication pipe;

one end of the second communicating pipe is communicated with the muffler body, the other end of the second communicating pipe is communicated with the suction pipe, and a second control valve is arranged on the second communicating pipe.

Optionally, the inflow end of the liquid taking pipe is communicated with a first pipe between the economizer and the outdoor side heat exchanger, or,

and the inflow end of the liquid taking pipe is communicated with a first pipe between the economizer and the first indoor throttling adjusting device.

Optionally, a connection between the inflow end of the liquid taking pipe and the first pipe has a liquid taking port located below the first pipe around the liquid taking port.

Optionally, the air conditioner further comprises a liquid taking structure, the liquid taking structure is provided with a liquid taking cavity, a first refrigerant port, a second refrigerant port and a liquid taking port, the first refrigerant port and the second refrigerant port are communicated with the liquid taking cavity, and the liquid taking port is located below the first refrigerant port and the second refrigerant port.

Optionally, the air conditioner further includes a second heat exchanger, a second throttling device, a third pipe, and a branch pipe branching from the discharge pipe, the third pipe sequentially connecting a first intersection of the first pipe, the second throttling device, the second heat exchanger, and the branch pipe, wherein the first intersection is located between the first throttling device and the outdoor side heat exchanger, and the economizer is located on the first pipe between the first intersection and the outdoor side heat exchanger.

Optionally, the third pipe is communicated with a branch pipe, and a third control valve is arranged on the branch pipe to control the on-off of the branch pipe; and the third piping is communicated with the low-pressure suction pipe or the second piping through a communicating pipe, and a fourth control valve is arranged on the communicating pipe to control the on-off of the first communicating pipe.

Optionally, the air conditioner further comprises a second switching device capable of switching between a third switching state and a fourth switching state of the second switching device,

in the third switching state, the second switching device causes the third pipe and the branch pipe to communicate with each other,

in the fourth switching state, the second switching device connects the third pipe and the suction pipe.

Optionally, the air conditioner further comprises an outdoor side throttling regulation device, and the outdoor side throttling regulation device is positioned on a first pipe between the economizer and the outdoor side heat exchanger.

Optionally, the air conditioner further comprises: a first connection pipe that branches off from a second intersection of the first pipe, and a second connection pipe that branches off from the second pipe, the second intersection being located between the first throttling device and the outdoor side heat exchanger, the air conditioner further including a plurality of indoor units that are connected in parallel on the first connection pipe and the second connection pipe. Optionally, the economizer includes a plate heat exchanger or a double pipe heat exchanger, the plate heat exchanger or the double pipe heat exchanger has a first end and a second end which are opposite to each other, the first refrigerant flow path enters from the first end and extends out from the second end, and the second refrigerant flow path enters from the second end and extends out from the first end;

or the first refrigerant flow path enters from the second end and extends out from the first end, and the second refrigerant flow path enters from the first end and extends out from the second end.

In the technical scheme of the utility model, through the refrigerant inflow end and the refrigerant bridge circuit connection with the first refrigerant flow path of economic ware, and set up the flow direction of second refrigerant flow path, make the refrigerant flow direction in first refrigerant flow path and the second refrigerant flow path always opposite (no matter be under the heating mode that the refrigerant flows to outdoor heat exchanger from indoor heat exchanger, still under the refrigeration mode that the refrigerant flows to indoor heat exchanger from outdoor heat exchanger), so, the abundant difference in temperature that has kept the refrigerant in first refrigerant flow path and the second refrigerant flow path, thereby the heat transfer effect of first refrigerant flow path and second refrigerant flow path has been guaranteed, be favorable to guaranteeing under the heating mode, the economic ware is to the tonifying qi effect of compressor, thereby guarantee the heating capacity of air conditioner under low temperature environment; meanwhile, the refrigerant liquefying effect (exhausting effect) of the economizer on the refrigerant is favorably ensured under the refrigeration mode, and the refrigerant entering the indoor throttling device is ensured to be in a liquid state, so that abnormal sound generated in the indoor throttling process is eliminated.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an embodiment of an air conditioner according to the present invention;

FIG. 2 is a schematic structural diagram of another embodiment of the air conditioner of the present invention;

FIG. 3 is a schematic diagram of the internal structure of the heating mode at A in FIG. 2;

FIG. 4 is a schematic diagram of the internal structure of the embodiment in the cooling mode A of FIG. 2;

FIG. 5 is a schematic structural diagram of another embodiment of the heating mode at A in FIG. 2;

FIG. 6 is a schematic structural diagram of another embodiment in a cooling mode at A in FIG. 2;

fig. 7 is a partially enlarged view of an embodiment of a connection between a liquid-taking tube and a first pipe of the air conditioner of the present invention;

fig. 8 is a partially enlarged view of another embodiment of the joint between the liquid-taking tube and the first pipe of the air conditioner of the present invention;

fig. 9 is a partially enlarged view of a further embodiment of the joint between the liquid-taking tube and the first pipe of the air conditioner of the present invention;

fig. 10 is a partial enlarged view of a connection between a liquid-taking pipe and a first pipe of an air conditioner according to still another embodiment of the present invention.

The reference numbers illustrate:

the objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

The specific structure of the air conditioner will be mainly described below.

Referring to fig. 1 to 4, first, the entire piping structure and component arrangement of the air conditioner will be described; in the embodiment of the present invention, the air conditioner includes an outdoor unit 100 and an indoor unit 200, the outdoor unit 100 includes a compressor 110 and an outdoor side heat exchanger 141, the indoor unit 200 includes a first heat exchanger 220 and a first throttling adjustment device 240;

the air conditioner further includes: a discharge pipe 111 connected to a discharge side of the compressor 110, a low pressure suction pipe 113 connected to a low pressure suction side of the compressor 110, a first pipe 140 connecting the discharge pipe 111, the outdoor heat exchanger 141, the first throttle controller 240, and the first heat exchanger 220 in this order, and a second pipe 150 connecting the first heat exchanger 220 and the low pressure suction pipe 113, thereby forming a refrigerant circuit;

the outdoor unit 100 further comprises first switching means 131, the first switching means 131 being switchable between a first switching state of the first switching means 131 and a second switching state of the first switching means 131,

in the first switching state, the first switching device 131 causes the first pipe 140 to communicate with the suction pipe and the second pipe 150 to communicate with the discharge pipe 111, and in the second switching state, the first switching device 131 causes the first pipe 140 to communicate with the discharge pipe 111 and the second pipe 150 to communicate with the suction pipe.

Through the arrangement of the first switching device 131, in the first switching state, the air conditioner is in a heating state, that is, the first heat exchanger 220 heats; in the second switching state, the air conditioner is in a cooling state. The first switching device 131 may be a four-way valve.

The air conditioner further includes an economizer 143, the economizer 143 being provided on the first piping 140 between the outdoor side heat exchanger 141 and the first throttling device; a first refrigerant flow path 143a and a second refrigerant flow path 143b are provided in the economizer 143, and the first refrigerant flow path 143a is connected to the first pipe 140 through a refrigerant bridge circuit 600; one end of the second refrigerant passage 143b is connected to the first pipe 140 through a liquid taking pipe 145, and the other end is connected to both the medium pressure suction port and the suction pipe of the compressor 110 through a return pipe 146; so that the refrigerant flows in the first refrigerant flow path 143a and the second refrigerant flow path 143b are opposite to each other.

In the heating mode, the discharge pipe 111 communicates with the second pipe 150 so that the high-temperature and high-pressure refrigerant passes through the discharge pipe 111 and the second pipe 150, enters the first heat exchanger 220 for heating, flows into the refrigerant bridge circuit 600 through the first pipe 140, enters the first refrigerant flow path 143a of the economizer 143 through the refrigerant bridge circuit 600, flows back to the first pipe 140 through the first refrigerant flow path 143a, passes through the outdoor throttle valve and the outdoor heat exchanger 141, and returns to the compressor 110 from the low-pressure suction port through the suction pipe. The second refrigerant passage 143b of the economizer 143 is returned to the medium-pressure suction pipe of the compressor 110 through the return pipe 146 after taking liquid and exchanging heat with the first refrigerant passage 143a through the plate heat exchanger. Meanwhile, the communication between the return pipe 146 and the suction pipe is cut off, so that the air is supplied to the compressor 110, and the heating capacity of the compressor 110 in a low-temperature environment is improved;

in the cooling mode, when the first switching device 131 is in the second state, the discharge pipe 111 is communicated with the first pipe 140, the high-temperature and high-pressure refrigerant enters the outdoor heat exchanger 141 through the discharge pipe 111 and the first pipe 140, passes through the outdoor heat exchanger 141, passes through the outdoor throttle valve, enters the first refrigerant flow path 143a of the economizer 143 through the refrigerant bridge circuit 600, passes through the plate heat exchanger, returns to the first pipe 140, enters the first indoor throttling device along the first pipe 140, and enters the first heat exchanger 220 for cooling; the inflow end of the second refrigerant fluid is communicated with the first pipe 140, and the refrigerant exchanges heat with the refrigerant in the first refrigerant flow path 143a through the plate heat exchanger (exchanges heat through the plate heat exchanger), and then returns to the low-pressure suction port of the compressor 110 through the return pipe 146 and the suction pipe, so that the refrigerant entering the room through the economizer 143 and the first pipe 140 is in a liquid state, and the indoor throttling device is prevented from generating harsh noise in the throttling process.

The economizer 143 includes a plate heat exchanger or a double pipe heat exchanger having a first end 510 and a second end 520 opposite to each other, the first refrigerant flow path 143a enters from the first end 510 and extends from the second end 520, and the second refrigerant flow path 143b enters from the second end 520 and extends from the first end 510; alternatively, the first cooling medium flow path 143a extends from the second end 520 to the first end 510, and the second cooling medium flow path 143b extends from the first end 510 to the second end 520. The refrigerant in the first refrigerant flow path 143a and the refrigerant in the second refrigerant flow path 143b exchange heat with each other by a plate heat exchanger or a double pipe heat exchanger. The first refrigerant flow path 143a and the second refrigerant flow path 143b flow in opposite directions, so that the temperature difference between the refrigerants in the first refrigerant flow path 143a and the second refrigerant flow path 143b is kept to be maximum, thereby ensuring the heat exchange effect.

Regarding the refrigerant bridge circuit 600, there may be many ways of the refrigerant bridge circuit 600 as long as the refrigerant flowing through the first piping 140 (whether the refrigerant flows from the indoor heat exchanger to the outdoor heat exchanger 141 or from the outdoor heat exchanger 141 to the indoor heat exchanger) always flows in the first refrigerant flow path 143a in the opposite direction to the refrigerant flowing through the second refrigerant flow path 143b to increase the temperature difference and ensure the heat exchange effect.

In this embodiment, the refrigerant inflow end of the first refrigerant flow path 143a of the economizer 143 is connected to the refrigerant bridge circuit 600, and the flow direction of the second refrigerant flow path 143b is set, so that the refrigerant flow directions in the first refrigerant flow path 143a and the second refrigerant flow path 143b are always opposite (no matter in a heating mode in which the refrigerant flows from the indoor heat exchanger to the outdoor heat exchanger 141, or in a cooling mode in which the refrigerant flows from the outdoor heat exchanger 141 to the indoor heat exchanger), and thus, the temperature difference between the refrigerant in the first refrigerant flow path 143a and the second refrigerant flow path 143b is sufficiently maintained, thereby ensuring the heat exchange effect of the first refrigerant flow path 143a and the second refrigerant flow path 143b, and being beneficial to ensuring the gas supplementing effect of the economizer 143 on the compressor 110 in the heating mode, thereby ensuring the heating capability of the air conditioner in a low temperature environment; meanwhile, the economizer 143 can be used for ensuring the liquefying effect (exhaust effect) of the refrigerant in the refrigerating mode, and the refrigerant entering the indoor throttling device is ensured to be in a liquid state, so that abnormal sound generated in the indoor throttling process is eliminated.

It should be noted that the concept of the present invention can be applied not only to the conventional air conditioner, but also to the case where a plurality of indoor heat exchangers are disposed in the same indoor unit 200, and can be applied to the case where a plurality of indoor units 200 are disposed in the refrigerant system. Because the complexity of single indoor unit 200 self structure increases, perhaps because the quantity of indoor unit 200 increases, all can increase the length of refrigerant pipeline, will make the utility model discloses an effect of eliminating the abnormal sound is more obvious.

The case where a plurality of indoor heat exchangers are provided in a single indoor unit 200 is described as follows:

the indoor unit 200 further includes a second heat exchanger 210, a second throttling device 230, and a heat circulating device for sending heat or cold of the indoor unit 200 into the room;

the air conditioner further includes a third pipe 160 and a branch pipe 112 branched from the discharge pipe 111, wherein the third pipe 160 sequentially connects a first intersection 211 of the first pipe 140, the second throttling device 230, the second heat exchanger 210, and the branch pipe 112 to form a refrigerant circuit, and the first intersection 211 is located between the first throttling device 240 and the outdoor heat exchanger 141. The economizer 143 is located on the first pipe 140 between the first junction 211 and the outdoor side heat exchanger 141.

Wherein, the thermal cycling device may be a wind wheel in some embodiments, and the wind wheel rotates to convey the air after exchanging heat with the primary heat exchanger and the secondary heat exchanger 210 to the indoor. Of course, in other embodiments, the heat circulation device may also be a water circulation device, and the first heat exchanger 220 and the second heat exchanger 210 send heat or cold to the indoor through the circulating water flowing in the water circulation device.

On the basis of the pipelines, the air conditioner can realize refrigeration of the first heat exchanger 220 and heating of the second heat exchanger 210, so that constant-temperature dehumidification can be realized. Wherein the first throttle adjusting device 240 comprises an electromagnetic throttle valve, such as an electromagnetic expansion valve, and the second throttle adjusting device 230 comprises an electromagnetic throttle valve, such as an electromagnetic expansion valve. In the second state, the first switching unit 131 performs cooling in the first heat exchanger 220, and at this time, the refrigerant is discharged from the discharge pipe 111, enters the second heat exchanger 210 through the branch pipe 112 and the third pipe 160, is heated in the second heat exchanger 210, flows out of the second heat exchanger 210, flows into the second pipe 150, passes through the refrigerant bridge circuit 600, the economizer 143, the outdoor heat exchanger 141, and the suction pipe along the second pipe 150, and returns to the low-pressure suction port of the compressor 110.

In some other embodiments, the air conditioner further includes a second switching device 132, the second switching device 132 being switchable between a third switching state of the second switching device 132, in which the second switching device 132 communicates the third piping 160 with the branch pipe 112, and a fourth switching state, in which the second switching device 132 communicates the third piping 160 with the suction pipe.

Through the setting of the second switching device 132, in the third switching state, the air conditioner is in the constant temperature dehumidification state; in the fourth switching state, the air conditioner is in a cooling state, that is, the first heat exchanger 220 and the second heat exchanger 210 cool simultaneously. The second switching device 132 may be a four-way valve. Also connected to the second switching device 132 is an auxiliary branch pipe which communicates with the suction pipe when the third piping 160 communicates with the branch pipe 112; when the third piping 160 communicates with the low pressure suction pipe 113, the auxiliary branch pipe communicates the low pressure suction pipe 113 and the branch pipe 112. The auxiliary branch pipe is provided with a filter and a capillary tube.

Of course, in some embodiments, the first switching device 131 and the second switching device 132 may exist at the same time, so that the air conditioner may be switched in three states of constant temperature dehumidification, single heating, and single cooling.

In order to better adjust the supercooling degree of the outdoor heat exchanger 141, the air conditioner further includes an outdoor throttle adjusting device 142, and the outdoor throttle adjusting device 142 is disposed on the first pipe 140 between the economizer 143 and the outdoor heat exchanger 141. The outdoor side throttle adjusting means 142 includes an outdoor throttle valve such as an electronic expansion valve.

The specific operation of the economizer 143 will be described again with reference to the first indoor heat exchanger and the second indoor heat exchanger being provided indoors:

the air conditioner further includes an economizer 143 in order to improve the ability of the air conditioner to heat at a low temperature; the economizer 143 is provided in the first pipe 140 between the outdoor heat exchanger 141 and the first junction 211, and a return pipe 146 of the economizer 143 communicates with the medium-pressure suction port of the compressor 110. The return pipe 146 may have various forms, and the return pipe 146 may include only the body of the return pipe 146, or may include the body of the return pipe 146 and a first communication pipe 148, one end of the first communication pipe 148 is communicated with the body of the return pipe 146, and the other end is communicated with the medium-pressure suction port of the compressor 110.

A first control valve 133 is provided on the return line 146 or on a first communication line 148 between the return line 146 and the medium pressure suction port of the compressor 110. The compressor 110 in this case is a vapor injection enthalpy compressor 110, and has a low pressure suction port and an intermediate pressure suction port. A liquid extraction throttle 144 is provided in the liquid extraction pipe 145. In this way, after the discharge air of the compressor 110 is switched by the first switching device 131 and the second switching device 132, the discharge air respectively enters the second heat exchanger 210 (where the refrigerant enters through the third pipe 160) and the first heat exchanger 220 (where the refrigerant enters through the first pipe 140) to perform heating, and the liquid refrigerant coming out of the second heat exchanger 210 and the first heat exchanger 220 is divided into two parts when passing through the economizer 143: the first part (through the refrigerant bridge circuit 600 and the first refrigerant flow path 143a) directly enters the outdoor heat exchanger 141 for evaporation and heat absorption after being throttled and depressurized by the outdoor throttling adjusting device 142 (electronic expansion valve), the second part (through the second refrigerant flow path 143b) enters the economizer 143 for heat absorption and evaporation after being throttled and depressurized by the liquid taking throttle valve 144 (electronic expansion valve) through the liquid taking pipe 145, and the evaporated medium-pressure saturated steam enters the medium-pressure suction port of the compressor 110 through the return pipe 146, the first control valve 133 and the connecting pipe and is compressed together with the refrigerant of the low-pressure suction port of the compressor 110 after being mixed with the refrigerant, so that the problems of small refrigerant flow, low return air pressure, high compression ratio and the like in a low-temperature environment are solved, and the reliability of the low-. Through the utility model discloses a technique, when outdoor ambient temperature is low temperature, through the system design of air injection enthalpy-increasing compressor 110 and economic ware 143, increases the refrigerant air suction volume under the compressor 110 low temperature environment, and then improves the low temperature heating volume, reduces the compression ratio under the low temperature environment simultaneously, can improve the reliability of system.

In order to improve the liquid taking effect, the inflow end of the liquid taking pipe 145 is communicated with the first pipe 140 between the economizer 143 and the outdoor side heat exchanger 141, and in other embodiments, the inflow end of the liquid taking pipe 145 may also be communicated with the first pipe 140 between the economizer 143 and the first cross point 211 (in the case where there is no first cross point 211, the inflow end of the liquid taking pipe 145 is communicated with the first pipe 140 between the economizer 143 and the first indoor throttling adjustment device). That is, the refrigerant flows in from the refrigerant outflow end of the economizer 143, which is advantageous for improving the reliability of liquid extraction.

The connection between the inflow end of the liquid taking pipe 145 and the first pipe 140 is called a liquid taking point, and regarding the selection of the liquid taking point, the selection of the corresponding liquid taking point under different working conditions is beneficial to different working conditions. When the inflow end of the liquid taking pipe 145 is communicated with the first pipe 140 between the economizer 143 and the outdoor side heat exchanger 141, the connection position is called a first liquid taking point 134, or an upstream liquid taking point; when the inflow end of the liquid take-off pipe 145 is located at the first pipe 140 communicating between the economizer 143 and the first cross point 211 (or the first indoor throttle adjusting means), the connection position is referred to as a second liquid take-off point 135, or a downstream liquid take-off point. When the indoor heat exchanger is used for heating and the enhanced vapor injection is needed to be started, the first liquid taking point 134 or the upstream liquid taking point is selected to supplement air for the compressor 110, so that the heating capacity of the compressor in the low-temperature environment is improved; when the indoor heat exchanger performs cooling or constant temperature dehumidification (or dehumidification and reheating), the second liquid taking point 135 or the downstream liquid taking point is selected to make the refrigerant entering the indoor unit 200 as liquid as possible, thereby avoiding noise generated during indoor throttling.

Referring to fig. 7 to 10, in some embodiments, in order to ensure the liquid extraction effect, a liquid extraction port 840 is provided at a connection between the inflow end of the liquid extraction pipe 145 and the first pipe 140, and the liquid extraction port 840 is located below the first pipe 140 around the liquid extraction port 840. By setting the position of the liquid taking port 840 to be lower than the first pipe 140, the liquid refrigerant flows along the lower pipe wall of the first pipe 140 (the density of the liquid refrigerant is higher than that of the gas refrigerant), so that the liquid refrigerant preferentially enters under the action of gravity when passing through the liquid taking port 840, and the refrigerant taken by the liquid taking port 840 is ensured to be in a liquid state.

The liquid outlet 840 may be formed in a variety of ways, for example, a liquid outlet structure 800 is disposed at the connection between the liquid outlet tube 145 and the first pipe 140, the liquid outlet structure 800 includes a liquid outlet chamber 810 and three refrigerant ports communicating with the liquid outlet chamber 810, namely, a first refrigerant port 830, a second refrigerant port 820 and a liquid outlet 840, and the liquid outlet 840 is located below the first refrigerant port 830 and the second refrigerant port 820. The first refrigerant port 830 and the second refrigerant port 820 are both communicated with the first pipe 140, and the liquid-taking port 840 is communicated with the inflow end of the liquid-taking tube 145. Specifically, the first refrigerant port 830 communicates with the first pipe 140 near the outdoor heat exchanger 141, and the second refrigerant port 820 communicates with the first pipe 140 near the first indoor throttle control device. Liquid extraction port 840 is located at the bottom of liquid extraction structure 800. The shape of the liquid-extracting structure 800 may be various, such as rectangular parallelepiped, cube, column, etc. The first refrigerant port 830 and the second refrigerant port 820 may be located at two ends or at the top of the liquid taking structure 800, and in some embodiments, the first pipe 140 may further extend into the liquid taking cavity 810 through the first refrigerant port 830 and the second refrigerant port 820.

In other embodiments, in order to avoid the unpleasant noise generated when the refrigerant in the vapor-liquid two-phase state passes through the indoor throttling device, the air conditioner further includes a gas-liquid separator 120 and an economizer 143, wherein the gas-liquid separator 120 is disposed on the low-pressure suction pipe 113; the economizer 143 is provided in the first pipe 140 between the outdoor heat exchanger 141 and the first junction 211, and a return pipe 146 of the economizer 143 communicates with the gas-liquid separator 120. The return pipe 146 may have various forms, and the return pipe 146 may include only the body of the return pipe 146, or may include the body of the return pipe 146 and a second connection pipe 147, where one end of the second connection pipe 147 is connected to the body of the return pipe 146, and the other end is connected to the gas-liquid separator 120. For convenience of control, in some examples, the return pipe 146 is communicated with the gas-liquid separator 120 through the low pressure suction pipe 113, and the return pipe 146 or a second connection pipe 250 between the return pipe 146 and the low pressure suction pipe 113 is provided with a second control valve 149.

The utility model discloses an adopt the system design who takes economic ware 143 on the basis of three controls, take liquid choke valve 144 (electronic expansion valve) of getting in the economic ware 143 system design return circuit through the control, further reduce the refrigerant condensation temperature of outdoor side heat exchanger 141 export, improve the super-cooled rate, make the refrigerant complete condensation be liquid, liquid refrigerant gets into indoor heat exchanger heat absorption evaporation after indoor electronic expansion valve throttle step-down, when the refrigerant through indoor throttling arrangement is full liquid, can solve the refrigerant abnormal sound that the two-phase attitude of gas-liquid produced.

After the exhaust gas of the compressor 110 is switched by the first switching device 131, the high-pressure and high-temperature gaseous refrigerant enters the outdoor heat exchanger 141 for condensation and heat exchange, and the gas-liquid two-phase medium-temperature and high-pressure refrigerant coming out of the outdoor heat exchanger 141 enters the economizer 143 and is divided into two parts: the first part is throttled and depressurized by the liquid taking throttle valve 144, then enters the economizer 143 through the liquid taking pipe 145 to absorb heat and evaporate, the evaporated gaseous refrigerant passes through the return pipe 146, the second control valve 149 (solenoid valve) and the connecting pipe enter the gas-liquid separator 120, and then is mixed with the gaseous refrigerant subjected to heat absorption and evaporation by the indoor heat exchanger, and then enters the air suction port of the compressor 110, the second part is further condensed and heat exchanged from the economizer 143, the gas-liquid two-phase refrigerant is changed into a pure liquid refrigerant, and the pure liquid refrigerant flows indoors, throttled and depressurized by the dehumidification throttle valve and the reheating throttle valve and then enters the first heat exchanger 220 and the second heat exchanger 210 to absorb heat and evaporate. The refrigerant entering the first throttling regulation device 240 and the second throttling regulation device 230 (electronic expansion valve) changes from a gas-liquid two-phase state to a pure liquid state, so that the problem of refrigerant noise generated when the gas-liquid two-phase refrigerant passes through the throttling device is solved.

In this embodiment, through the technical scheme of the utility model, can further reduce the refrigerant condensation temperature of outdoor side heat exchanger 141 export, improve the supercooling degree, make the refrigerant be liquid from the complete condensation of gas-liquid diphasic state, liquid refrigerant enters indoor heat exchanger endothermic evaporation after indoor electronic expansion valve (first throttle adjusting device 240 and second throttle adjusting device 230) throttle step-down, when the refrigerant through indoor throttle adjusting device (first throttle adjusting device 240 and second throttle adjusting device 230) is full liquid, can solve the gas-liquid diphasic state refrigerant produced through throttle device abnormal sound problem, improve user's satisfaction

It should be noted that in some embodiments, the return pipe 146 is connected to the intermediate-pressure suction port of the compressor 110 and the gas-liquid separator 120 through different connection pipes, and in this case, the first control valve 133 (close to the compressor 110) and the second control valve 149 (close to the gas-liquid separator 120) are respectively disposed on the two connection pipes (the first connection pipe 148 and the second connection pipe 147). The return line 146 in this case includes the body of the return line 146 and two communication pipes. In the heating mode, the second control valve 149 is closed, and the first control valve 133 is opened, so that the refrigerant flows into the compressor 110, thereby improving the heating capacity; in the cooling mode or the constant temperature dehumidification mode, the first control valve 133 is closed, and the second control valve 149 is opened to remove noise. Of course, in some embodiments, second control valve 149 may be closed and first control valve 133 may be opened as required by particular operating conditions. The arrangement is such that the air conditioner can adjust the first control valve 133 and the second control valve 149 according to specific conditions, thereby improving the heating capacity of the air conditioner in the heating mode and reducing noise in the cooling and constant temperature dehumidification modes.

Regarding the specific connection between the compressor 110 and the economizer 143, the compressor 110 is an enhanced vapor injection compressor 110, and the compressor 110 has a conventional high pressure discharge port P, a low pressure suction port S, and a medium pressure suction port M (i.e., a vapor injection port) through which medium pressure refrigerant vapor enters the compressor 110 to increase the effective flow rate of the refrigerant.

The port a of the economizer 143 is connected to the third port 630 of the refrigerant bridge circuit 600, the port b of the economizer 143 is connected to the fourth port 640 of the refrigerant bridge circuit 600, the port c of the economizer 143 is connected to the liquid taking pipe 145, the port d of the economizer 143 is connected to the return pipe 146, the liquid taking throttle valve 144 is connected in series to the liquid taking pipe 145, the first control valve 133 is connected in series to the connection pipe, the second control valve 149 is connected in series to another connection pipe, one end of the connection pipe is connected to the medium pressure suction port M of the compressor 110, and the other connection pipe is connected to the inlet end of the gas-liquid separator 120.

In some embodiments, the air conditioner further includes a plurality of indoor units 200, and the heat exchanger types included in the respective indoor units 200 may be different, such as one or more of an indoor unit with a constant temperature dehumidification function (having both the first heat exchanger 220 and the second heat exchanger 210), an ordinary cooling/heating indoor unit (having only one heat exchanger and a corresponding throttling device), and an indoor unit with a switching device capable of freely switching a cooling or heating state, so that the air conditioner can simultaneously perform a hybrid operation of constant temperature dehumidification, cooling, heating, and the like.

Specifically, the air conditioner further includes: a first connection pipe 260 branched from a second intersection 212 of the first pipe 140, and a second connection pipe 250 branched from the second pipe 150, the second intersection 212 being located between the first throttling device 240 and the outdoor side heat exchanger 141, the air conditioner further comprising a plurality of indoor units 200, the plurality of indoor units 200 being connected in parallel to the first connection pipe 260 and the second connection pipe 250.

In some embodiments, to improve the reliability of the second switching device 132, the second switching device 132 does not use a four-way valve, but is controlled using two solenoid valves. Specifically, the third pipe 160 communicates with the branch pipe 112 and with the low pressure suction pipe 113 or the second pipe 150, the branch pipe 112 is provided with a third control valve 310, the third pipe 160 communicates with the low pressure suction pipe 113 or the second pipe 150 through a communication pipe 114, and the communication pipe 114 is provided with a fourth control valve 320. Note that the end of the communication pipe 114 remote from the third pipe 160 may communicate with the second pipe 150 between the first switching device 131 and the indoor heat exchanger, or may communicate with the second pipe 150 between the first switching device 131 and the gas-liquid separator 120. Since the third control valve 310 and the fourth control valve 320 are separate control valves, the structure is simpler, and the stability and reliability are higher compared to a four-way valve. In addition, the third and fourth control valves 310 and 320 may be solenoid valves. The solenoid valve can still work stably and reliably under the condition that the liquid refrigerant enters, and if the liquid refrigerant enters the four-way valve, the working stability of the solenoid valve is affected, so that the stability and reliability of the operation and state switching of the air conditioner can be improved by using the independent third control valve 310 and the independent fourth control valve 320.

It should be noted that the third control valve 310 and the fourth control valve 320 may be set to the de-energized state according to actual operating condition requirements. Taking the third control valve 310 as an example, in the operation process of the air conditioner, the time for the third control valve 310 to maintain the normally open state is long, at this time, the third control valve 310 can be selected as a normally open valve, that is, in the power-off state, most of the work can be completed, and only when the state of the third control valve 310 needs to be switched, power needs to be supplied to the third control valve; similarly, if the third control valve 310 remains normally closed for a long time, it is selected as a normally closed valve. In this way, the electric energy consumed by the second switching device 132 (including the third control valve 310) during the operation of the air conditioner is reduced, thereby facilitating the rational utilization of the energy.

In some embodiments, the third piping 160, the branch pipe 112, and the communicating pipe 114 are connected to the first junction Q in order to simplify the piping structure, and of course, the low pressure suction pipe 113 may communicate with the other two pipes through the communicating pipe 114. In this case, a three-way valve may be provided at the first connection Q instead of two-way valves. The three-way valve realizes that the third piping 160 is respectively communicated with the communicating pipe 114 and the branch pipe 112, and can respectively control the on-off of the communicating pipe 114 and the branch pipe 112, so that the convenience of connecting the third piping 160, the communicating pipe 114 and the branch pipe 112 is improved.

A refrigeration mode:

the high-temperature and high-pressure refrigerant is discharged from the discharge pipe, passes through the first switching device 131, the first pipe 140, the outdoor heat exchanger 141, and the economizer 143 in this order, and then enters the evaporation heat exchanger and the first heat exchanger 220, respectively, to be cooled. A part of the effluent flows out of the first heat exchanger 220, passes through the second pipe 150 and the first switching device 131 (which may not be provided in some embodiments), and flows into the gas-liquid separator 120; the other part flows out of the evaporation heat exchanger, passes through the third pipe 160, enters the communicating pipe 114, and enters the gas-liquid separator 120 through the low-pressure suction pipe 113 when the communicating pipe 114 is communicated with the low-pressure suction pipe 113; when the communication pipe 114 communicates with the second pipe 150, the refrigerant flows into the second pipe 150 through the communication pipe 114, and flows into the gas-liquid separator 120 through the second pipe 150. During this process, the third control valve 310 is closed and the fourth control valve 320 is opened.

Heating mode:

the high-temperature and high-pressure refrigerant is discharged from the discharge pipe, and a part of the refrigerant passes through the first switching device 131 (which may not be provided in some embodiments) and the second piping 150 in sequence, enters the first heat exchanger 220 for heating, flows out of the first heat exchanger 220, and enters the first piping 140; the other portion enters the second heat exchanger 210 through the branch pipe 112 and the third pipe 160 in this order, is heated, flows out of the second heat exchanger 210, enters the first pipe 140, passes through the economizer 143, the outdoor heat exchanger 141, and the first switching device 131, and flows into the gas-liquid separator 120. During this process, the third control valve 310 is opened and the fourth control valve 320 is closed.

Constant temperature dehumidification mode:

the high-temperature and high-pressure refrigerant is discharged from the discharge pipe, and a portion of the refrigerant passes through the first switching device 131 (which may not be provided in some embodiments), the first pipe 140, the outdoor heat exchanger 141, and the economizer 143 in this order, enters the first heat exchanger 220 to be cooled, and then flows into the gas-liquid separator 120 through the second pipe 150 and the first switching device 131. The other portion passes through the branch pipe 112 and the third pipe 160 in this order, enters the second heat exchanger 210 to perform heating, and then flows into the first heat exchanger 220 to perform cooling. During this process, the third control valve 310 is opened and the fourth control valve 320 is closed.

The following description will be given, by way of example, with respect to the refrigerant bridge circuit 600:

the refrigerant bridge circuit 600 includes a first port 610, a second port 620, and a refrigerant passage communicating the first port 610 and the second port 620, and the refrigerant bridge circuit 600 is connected to the first pipe 140 through the first port 610 and the second port 620. Specifically, the first inlet 610 communicates with the first pipe 140 near the outdoor heat exchanger 141, and the second inlet 620 communicates with the first pipe 140 near the indoor unit 200. The refrigerant bridge circuit 600 further has a second port 620 and a fourth port 640, and the refrigerant bridge circuit 600 is connected to the first refrigerant line of the economizer 143 through the second port 620 and the fourth port 640. The refrigerant may enter the refrigerant bridge circuit 600 from the first port 610 or the second port 620, flow from the third port 630 (the fourth port 640) into the first refrigerant flow path 143a, pass through the first refrigerant flow path 143a, enter the refrigerant bridge circuit 600 from the fourth port 640 (the third port 630), and flow into the first pipe 140 from the second port 620 or the first port 610.

The adjacent through ports are in one-way conduction, and there are various specific conduction modes, which are described below by taking two specific examples:

first, the refrigerant bridge circuit 600 has a third port 630 and a fourth port 640, and both ends of the first refrigerant flow path 143a are connected to the third port 630 and the fourth port 640, respectively; the first through hole 610 and the third through hole 630 are communicated through a first bridge section 650, and the first bridge section 650 unidirectionally conducts the first through hole 610 to the third through hole 630; the third through hole 630 and the second through hole 620 are communicated through a second bridge section 660, and the second bridge section 660 unidirectionally conducts the second through hole 620 to the third through hole 630; the second through hole 620 is communicated with the fourth through hole 640 through a third bridge section 670, and the third bridge section 670 unidirectionally conducts the fourth through hole 640 to the second through hole 620; the fourth through-hole 640 communicates with the first through-hole 610 through a fourth bridge segment 680, and the fourth bridge segment 680 unidirectionally communicates the fourth through-hole 640 with the first through-hole 610.

Two examples are given below:

referring to fig. 3, in the indoor unit heating mode, liquid extraction is performed from first liquid extraction point 134 (upstream liquid extraction point):

the refrigerant flows out of the indoor heat exchanger, enters the first pipe 140, flows along the first pipe 140, enters the first bridge section 650 through the first port 610, flows out of the third port 630, enters the first refrigerant flow path 143a of the economizer 143, flows into the plate heat exchanger or the double pipe heat exchanger from the first end 510 (in some embodiments, the refrigerant may enter from the second end 520 and exit from the first end 510), exchanges heat with the heat exchanger, flows out of the second end 520, flows into the third bridge section 670 from the fourth port 640, flows out of the refrigerant bridge circuit 600 from the second port 620, enters the first pipe 140, and sequentially passes through the outdoor throttle adjustment device 142 and the outdoor heat exchanger 141.

The liquid taking pipe 145 takes liquid from the first liquid taking point 134, enters the plate heat exchanger or the double pipe heat exchanger from the second end 520 through the liquid taking throttle valve 144, flows out from the first end 510 (in some embodiments, the liquid may also enter from the first end 510, and the liquid may also exit from the second end 520, which is opposite to the first refrigerant flow path 143a), and then enters the return pipe 146, and returns to the medium pressure suction port of the compressor 110 along the return pipe 146.

Referring to fig. 4, in the cooling or dehumidification reheating mode of the indoor unit, liquid extraction is performed from second liquid extraction point 135 (downstream liquid extraction point):

the refrigerant flows out of the outdoor heat exchanger 141, enters the first pipe 140, flows along the first pipe 140, enters the second bridge section 660 through the second port 620, flows out of the third port 630, enters the first refrigerant flow path 143a of the economizer 143, enters the plate heat exchanger or the double pipe heat exchanger from the first end 510 (in some embodiments, the refrigerant may enter from the second end 520 and exit from the first end 510), exchanges heat with the heat exchanger, flows out of the second end 520, enters the fourth bridge section 680 from the fourth port 640, flows out of the refrigerant bridge circuit 600 from the first port 610, enters the first pipe 140, and enters the indoor heat exchanger.

The liquid taking pipe 145 takes liquid from the second liquid taking point 135, enters the plate heat exchanger or the double pipe heat exchanger from the second end 520 through the liquid taking throttle valve 144, flows out from the first end 510 (in some embodiments, the liquid may also enter from the first end 510, and the liquid may also exit from the second end 520, which is opposite to the first refrigerant flow path 143a), and then enters the return pipe 146, and returns to the medium pressure suction port of the compressor 110 along the return pipe 146.

Second, the refrigerant bridge circuit 600 has a third port 630 and a fourth port 640, and both ends of the first refrigerant flow path 143a are connected to the third port 630 and the fourth port 640, respectively; the first through hole 610 and the third through hole 630 are communicated through a first bridge section 650, and the first bridge section 650 unidirectionally conducts the third through hole 630 to the first through hole 610; the third through hole 630 and the second through hole 620 are communicated through a second bridge section 660, and the second bridge section 660 unidirectionally conducts the third through hole 630 to the second through hole 620; the second through hole 620 is communicated with the fourth through hole 640 through a third bridge section 670, and the third bridge section 670 unidirectionally conducts the second through hole 620 to the fourth through hole 640; the fourth passage 640 is communicated with the first passage 610 through a fourth bridge segment 680, and the fourth bridge segment 680 unidirectionally conducts the first passage 610 to the fourth passage 640.

Two examples are given below:

referring to fig. 5, in the indoor unit heating mode, liquid extraction is performed from first liquid extraction point 134 (upstream liquid extraction point):

the refrigerant flows out of the indoor heat exchanger, enters the first pipe 140, flows along the first pipe 140, enters the fourth bridge section 680 through the first port 610, flows out of the fourth port 640, enters the first refrigerant flow path 143a of the economizer 143, flows into the plate heat exchanger or the double pipe heat exchanger from the second end 520 (in some embodiments, the refrigerant may enter from the first end 510 and exit from the second end 520), exchanges heat with the heat exchanger, flows out of the first end 510, flows into the second bridge section 660 from the third port 630, flows out of the refrigerant bridge circuit 600 from the second port 620, enters the first pipe 140, and sequentially passes through the outdoor throttle adjustment device 142 and the outdoor heat exchanger 141.

The liquid taking pipe 145 takes liquid from the first liquid taking point 134, enters the plate heat exchanger or the double pipe heat exchanger from the first end 510 through the liquid taking throttle valve 144, exchanges heat with the heat, flows out from the second end 520 (in some embodiments, the liquid may enter from the second end 520, and the liquid may exit from the first end 510, which is opposite to the refrigerant flow direction of the first refrigerant flow path 143a), enters the return pipe 146, and returns to the medium pressure suction port of the compressor 110 along the return pipe 146.

Referring to fig. 6, in the cooling or dehumidification reheating mode of the indoor unit, liquid extraction is performed from second liquid extraction point 135 (downstream liquid extraction point):

the refrigerant flows out of the outdoor heat exchanger 141, enters the first pipe 140, flows along the first pipe 140, enters the third bridge 670 through the second port 620, flows out of the fourth port 640, enters the first refrigerant flow path 143a of the economizer 143, flows into the plate heat exchanger or the double pipe heat exchanger from the second end 520 (in some embodiments, the refrigerant may enter from the first end 510 and exit from the second end 520), exchanges heat with the heat exchanger, flows out of the first end 510, flows into the first bridge 650 from the third port 630, flows out of the refrigerant bridge 600 from the first port 610, enters the first pipe 140, and enters the indoor heat exchanger.

After the liquid is taken from the second liquid taking point 135, the liquid taking pipe 145 enters the plate heat exchanger or the double pipe heat exchanger from the first end 510 through the liquid taking throttle valve 144 to exchange heat, flows out from the second end 520 (in some embodiments, the liquid may also enter from the second end 520, and the liquid may also exit from the first end 510 in a direction opposite to the first refrigerant flow direction), and then enters the return pipe 146 to return to the medium-pressure suction port of the compressor 110 along the return pipe 146.

The one-way conduction mode may be various, for example, a one-way valve 690 is provided, and the first bridge section 650, the second bridge section 660, the third bridge section 670 and the fourth bridge section 680 are all provided with the one-way valve 690, so as to realize the one-way conduction of each bridge section.

The above only be the preferred embodiment of the utility model discloses a not consequently restriction the utility model discloses a patent range, all are in the utility model discloses a conceive, utilize the equivalent structure transform of what the content was done in the description and the attached drawing, or direct/indirect application all is included in other relevant technical field the utility model discloses a patent protection within range.

Claims (16)

1. An air conditioner is characterized by comprising an outdoor unit and an indoor unit, wherein the outdoor unit comprises an enthalpy-increasing compression mechanism and an outdoor side heat exchanger, and the indoor unit comprises a first heat exchanger and a first throttling regulation device;

the air conditioner further includes: a discharge pipe connected to a discharge side of the compression mechanism, a low-pressure suction pipe connected to a low-pressure suction side of the compression mechanism, a first pipe connecting the discharge pipe, the outdoor heat exchanger, the first throttle adjusting device, the first heat exchanger in this order, and a second pipe connecting the first heat exchanger and the low-pressure suction pipe, thereby forming a refrigerant circuit;

the outdoor unit further includes a first switching device that is switchable between a first switching device first switching state in which the first switching device communicates the first pipe with the suction pipe and communicates the second pipe with the discharge pipe, and a first switching device second switching state in which the first switching device communicates the first pipe with the discharge pipe and communicates the second pipe with the suction pipe;

the air conditioner also comprises an economizer which is arranged on a first pipe between the outdoor side heat exchanger and the first throttling device; a first refrigerant flow path and a second refrigerant flow path are arranged in the economizer, and the first refrigerant flow path is connected to the first distribution pipe through a refrigerant bridge circuit; one end of the second refrigerant flow path is communicated with the first pipe through a liquid taking pipe, and the other end of the second refrigerant flow path is simultaneously communicated with a medium-pressure suction inlet and a suction pipe of the compressor through a return pipe; so that the refrigerant flow directions in the first refrigerant flow path and the second refrigerant flow path are opposite.

2. The air conditioner as claimed in claim 1, wherein the refrigerant bridge circuit has a first port, a second port, and a refrigerant passage communicating the first port and the second port, and the refrigerant bridge circuit is connected to the first pipe through the first port and the second port.

3. The air conditioner as claimed in claim 2, wherein the refrigerant bridge circuit has a third port and a fourth port, and both ends of the first refrigerant flow path are connected to the third port and the fourth port, respectively;

the first gap and the third gap are communicated through a first bridge section, and the first bridge section unidirectionally conducts the first gap to the third gap;

the third through port is communicated with the second through port through a second bridge section, and the second bridge section unidirectionally conducts the second through port to the third through port;

the second gap and the fourth gap are communicated through a third bridge section, and the third bridge section unidirectionally conducts the fourth gap to the second gap;

the fourth gap and the first gap are communicated through a fourth bridge section, and the fourth bridge section is communicated with the first gap from the fourth gap in a one-way mode.

4. The air conditioner as claimed in claim 2, wherein the refrigerant bridge circuit has a third port and a fourth port, and both ends of the first refrigerant flow path are connected to the third port and the fourth port, respectively;

the first gap and the third gap are communicated through a first bridge section, and the first bridge section unidirectionally conducts the third gap to the first gap;

the third through port is communicated with the second through port through a second bridge section, and the second bridge section unidirectionally conducts the third through port to the second through port;

the second gap and the fourth gap are communicated through a third bridge section, and the third bridge section unidirectionally conducts the second gap to the fourth gap;

the fourth gap and the first gap are communicated through a fourth bridge section, and the fourth bridge section is communicated with the first gap to the fourth gap in a one-way mode.

5. The air conditioner according to claim 3 or 4, wherein check valves are provided on the first bridge section, the second bridge section, the third bridge section and the fourth bridge section.

6. The air conditioner as claimed in claim 1, wherein a liquid take-off throttle valve is provided on the liquid take-off pipe.

7. The air conditioner according to claim 1,

the backflow pipe comprises a backflow pipe body, a first communicating pipe and a second communicating pipe;

one end of the first communicating pipe is communicated with the muffler body, and the other end of the first communicating pipe is communicated with a medium-pressure suction inlet of the compressor; a first control valve is arranged on the return pipe body or the first communication pipe;

one end of the second communicating pipe is communicated with the muffler body, the other end of the second communicating pipe is communicated with the suction pipe, and a second control valve is arranged on the second communicating pipe.

8. The air conditioner according to claim 1, wherein the inflow end of the liquid take-out pipe communicates with a first pipe between the economizer and the outdoor side heat exchanger, or,

and the inflow end of the liquid taking pipe is communicated with a first pipe between the economizer and the first indoor throttling adjusting device.

9. The air conditioner according to claim 1, wherein a connection between the inflow end of the liquid extraction pipe and the first pipe has a liquid extraction port located below the first pipe in the vicinity thereof.

10. The air conditioner of claim 9, further comprising a liquid extraction structure having a liquid extraction chamber and a first refrigerant port, a second refrigerant port, and a liquid extraction port in communication with the liquid extraction chamber, the liquid extraction port being located below the first refrigerant port and the second refrigerant port.

11. The air conditioner according to claim 1, further comprising a second heat exchanger, a second throttling device, a third pipe, and a branch pipe branching from the discharge pipe, wherein the third pipe connects a first intersection of the first pipe, the second throttling device, the second heat exchanger, and the branch pipe in this order, wherein the first intersection is located between the first throttling device and the outdoor side heat exchanger, and wherein the economizer is located on the first pipe between the first intersection and the outdoor side heat exchanger.

12. The air conditioner according to claim 11, wherein the third pipe communicates with a branch pipe, and a third control valve is provided on the branch pipe to control on/off of the branch pipe; and the third piping is communicated with the low-pressure suction pipe or the second piping through a communicating pipe, and a fourth control valve is arranged on the communicating pipe to control the on-off of the first communicating pipe.

13. The air conditioner according to claim 11,

the air conditioner further includes a second switching device capable of switching between a third switching state and a fourth switching state of the second switching device,

in the third switching state, the second switching device causes the third pipe and the branch pipe to communicate with each other,

in the fourth switching state, the second switching device connects the third pipe and the suction pipe.

14. The air conditioner according to claim 1, further comprising an outdoor side throttling device provided on a first pipe between the economizer and the outdoor side heat exchanger.

15. The air conditioner according to claim 1,

the air conditioner further includes: a first connection pipe that branches off from a second intersection of the first pipe, and a second connection pipe that branches off from the second pipe, the second intersection being located between the first throttling device and the outdoor side heat exchanger, the air conditioner further including a plurality of indoor units that are connected in parallel on the first connection pipe and the second connection pipe.

16. An air conditioner according to any one of claims 1 to 15, wherein the economizer comprises a plate heat exchanger or a double pipe heat exchanger having first and second opposite ends, the first refrigerant flow path entering from the first end and extending from the second end, the second refrigerant flow path entering from the second end and extending from the first end;

or the first refrigerant flow path enters from the second end and extends out from the first end, and the second refrigerant flow path enters from the first end and extends out from the second end.

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