WO2021208584A1

WO2021208584A1 - Air-cooled heat pump air conditioning system for efficient heat production

Info

Publication number: WO2021208584A1
Application number: PCT/CN2021/076511
Authority: WO
Inventors: 张洪亮; 任滔; 张捷; 赵雷; 谢吉培; 徐志强; 张国成
Original assignee: 青岛海尔空调电子有限公司; 海尔智家股份有限公司
Priority date: 2020-04-13
Filing date: 2021-02-10
Publication date: 2021-10-21
Also published as: CN113531696B; CN113531696A

Abstract

The present invention relates to air conditioning technology, and specifically provides an air-cooled heat pump air conditioning system for efficient heat production, which aims to solve the problem of uneven distribution of refrigerants in gas and liquid phases within existing air conditioning heat exchangers. Thus, the air conditioning system according to the present invention comprises a compressor, a first heat exchanger, a second heat exchanger, a directional control valve, a main circuit expansion valve and a gas-liquid separator. The second heat exchanger is divided into an upper circuit and a lower circuit which are independent of each other, and the flow of the upper circuit is larger than that of the lower circuit. Under a heating condition, a gas-liquid phase refrigerant formed by the throttling of the main circuit expansion valve is separated into a gas refrigerant and a liquid refrigerant in the gas-liquid separator, and then flows into the lower circuit and the upper circuit in the second heat exchanger respectively. Since the flow of the upper circuit is greater than that of the lower circuit, the liquid refrigerant in the second heat exchanger may carry out heat exchange more fully and is thus evaporated more fully, thereby enhancing the heating capacity of the air conditioning system under various conditions.

Description

Air-cooled heat pump air-conditioning system with high-efficiency heating

Technical field

The invention belongs to the technical field of air conditioning, and specifically provides an air-cooled heat pump air-conditioning system for efficient heating.

Background technique

The air-cooled heat pump air-conditioning system is an air-conditioning system unit that is different from the air-cooled cold water system in the air-conditioning industry. In addition to the function of the air-cooled cold water system to produce cold water, the air-cooled heat pump air conditioning system can also switch to heating conditions to produce hot water. The basic principle of the air-cooled heat pump air conditioning system is based on a compression refrigeration cycle, using refrigerant as a carrier, through forced heat exchange by a fan, to absorb heat from the atmosphere or discharge heat to meet the requirements of cooling or heating.

In actual use, when the air-cooled heat pump air conditioning system is under heating conditions, uneven frosting often occurs on the surface of the heat exchanger, which will reduce the heating performance of the system. Those skilled in the art found that the reason for this phenomenon is that the refrigerant changes from a high-temperature liquid refrigerant to a gas-liquid two-phase state after passing through the throttling device. No matter how well-designed the separator is, it is difficult to mix the gas and liquid. The two-phase fluid is evenly distributed to the heat exchanger. The uneven distribution of refrigerant results in excessive distribution of liquid refrigerant in some circuits of the heat exchanger. The excessive liquid refrigerant cannot be completely evaporated during the heat exchange process, which in turn makes the frost layer on the surface of the heat exchanger where this part of the circuit is located is relatively high. thick.

In order to fully evaporate the refrigerant in the circuit with more liquid refrigerant distribution, the prior art increases the saturation evaporation temperature and the heat exchange temperature difference of the air by reducing the opening of the expansion valve and reducing the suction pressure. However, the reduction in suction pressure will reduce the density of the low-pressure side refrigerant, and then reduce the quality and flow of the refrigerant sucked by the compressor, resulting in a decrease in the unit's heating capacity and poor energy efficiency.

Therefore, those skilled in the art urgently need to find another way to find a new technical method to solve the problem of uneven distribution of the gas-liquid two-phase refrigerant in the heat exchanger.

Summary of the invention

In order to solve the above technical problems, the present invention provides an air-cooled heat pump air-conditioning system with high-efficiency heating. The air-conditioning system includes a compressor, a first heat exchanger, a second heat exchanger, a directional control valve, and a main expansion valve. The air conditioning system further includes a gas-liquid separator; the second heat exchanger is divided into an upper circuit and a lower circuit that are independent of each other, the upper circuit is connected to the liquid phase port of the gas-liquid separator, and the lower circuit Connected with the gas-phase port of the gas-liquid separator, the main circuit expansion valve connects the first heat exchanger and the gas-liquid mixing port of the gas-liquid separator, and the flow of the upper loop is larger than that of the lower portion The flow of the circuit; under refrigeration conditions, the directional control valve is located in the first working position to control the high-pressure side of the compressor to communicate with both the upper circuit and the lower circuit, and the low-pressure of the compressor Side is connected to the first heat exchanger; under heating conditions, the directional control valve is located in the second working position to control the high-pressure side of the compressor to communicate with the first heat exchanger. The low pressure side of the compressor communicates with both the upper circuit and the lower circuit.

Preferably, the lower circuit and the gas-liquid separator are connected by a flow control device, and the flow control device is used to throttle the refrigerant flowing from the lower circuit into the gas-liquid separator under refrigeration conditions, And under heating conditions, the refrigerant flowing from the gas-liquid separator into the lower circuit is directly connected.

Preferably, the flow control device is a parallel assembly of a one-way valve and a capillary tube, and the capillary tube is used to throttle the refrigerant flowing from the lower loop into the gas-liquid separator under refrigeration conditions, and the one-way The valve is used to directly conduct the refrigerant flowing from the gas-liquid separator into the lower circuit under heating conditions.

Preferably, the number of the second heat exchangers is two or more, and two or more of the second heat exchangers are arranged in parallel.

Preferably, the number of the second heat exchanger is two or more, and the air conditioning system further includes a three-way valve, a defrost switch valve, and the air conditioning system corresponding to each of the second heat exchangers. Liquid separator; the three-way valve is arranged between the high-pressure side of the compressor, the directional control valve and the corresponding second heat exchanger, and is used to control the second heat exchanger Selectively communicate with the high-pressure side of the compressor or communicate with the directional control valve; the defrost switch valve is arranged between the high-pressure side of the compressor and the three-way valve for controlling the compression The high-pressure side of the engine is cut off or connected to the three-way valve.

Preferably, the inlet of each of the gas-liquid separators and the main circuit expansion valve are connected by a parallel assembly composed of a forward check valve and a reverse check valve; wherein, the forward check valve allows the refrigerant to pass through The corresponding gas-liquid separator flows to the main circuit expansion valve, and the reverse check valve allows the refrigerant to flow from the main circuit expansion valve to the corresponding gas-liquid separator.

Preferably, the air-conditioning system further includes a refrigeration switch valve and a bypass expansion valve assembly arranged in parallel, and the refrigeration switch valve and bypass expansion valve assembly arranged in parallel are used to connect each of the forward check valves in series with the bypass expansion valve assembly. The main circuit expansion valve; when each of the second heat exchangers is in a cooling mode, the cooling switch valve is opened, and the second expansion valve is closed; each of the second heat exchangers is located in the heating Under working conditions, the refrigeration on-off valve is closed and the second expansion valve is closed; when at least one of the second heat exchangers is in a defrosting state, the refrigeration on-off valve is closed and the second expansion valve is activated.

Preferably, each of the lower circuits and the corresponding gas-liquid separator are connected by a flow control device, and the flow control device is used to throttle the flow from the lower circuit into the gas-liquid separator under refrigeration conditions. The refrigerant that flows into the lower circuit from the gas-liquid separator is directly conducted under heating conditions.

Preferably, the flow control device is a parallel assembly of a one-way valve and a capillary tube, and the capillary tube is used to throttle the refrigerant flowing from the lower circuit into the gas-liquid separator under refrigeration conditions. The valve is used to directly conduct the refrigerant flowing from the gas-liquid separator into the lower circuit under heating conditions.

Preferably, the liquid-phase port of the gas-liquid separator is arranged at the bottom thereof, the gas-phase port of the gas-liquid separator is arranged on the top thereof, and the gas-liquid mixing port of the gas-liquid separator is arranged at its middle part.

Compared with the prior art, in the air conditioning system provided by the present invention, under heating conditions, the gas-liquid two-phase refrigerant formed by the main circuit expansion valve throttling is separated into gaseous refrigerant and liquid in the gas-liquid separator After the refrigerant, it flows into the independent upper and lower circuits of the second heat exchanger to participate in heat exchange, ensuring that the upper circuit is basically pure liquid refrigerant, and the lower circuit is basically pure gaseous refrigerant. Ground, because the flow of the upper circuit is greater than the flow of the lower circuit, the liquid refrigerant can more fully exchange heat and thus be more thoroughly evaporated, thereby improving the heating capacity of the air conditioning system under various working conditions.

Description of the drawings

Fig. 1 is a schematic structural diagram of a first embodiment of an air-cooled heat pump air-conditioning system with high-efficiency heating according to the present invention.

Fig. 2 is a schematic structural diagram of a second embodiment of the air-cooled heat pump air-conditioning system for efficient heating of the present invention.

Fig. 3 is a schematic structural diagram of a third embodiment of the air-cooled heat pump air-conditioning system for efficient heating of the present invention.

Fig. 4 is a schematic structural diagram of a fourth embodiment of the air-cooled heat pump air-conditioning system for efficient heating of the present invention.

Detailed ways

The preferred embodiments of the present invention will be described below with reference to the drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention, and are not intended to limit the protection scope of the present invention.

It should be noted that in the description of the present invention, the terms "upper", "lower", and other terms indicating the direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for ease of description. It does not indicate or imply that the device or element must have a specific orientation, be configured and operate in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance.

As shown in FIG. 1, the figure is a schematic structural diagram of a first embodiment of an air-cooled heat pump air-conditioning system with high-efficiency heating according to the present invention. The air-cooled heat pump air conditioning system includes a compressor CP, a first heat exchanger EH1, a second heat exchanger EH2, a directional control valve, a main expansion valve XV1, and a gas-liquid separator GLS.

Among them, the second heat exchanger EH2 is divided into separate upper loop EH2U and lower loop EH2B; the upper loop EH2U is connected with the liquid phase port of the gas-liquid separator GLS, and the lower loop EH2B is connected with the gas phase port of the gas-liquid separator GLS, The main expansion valve XV1 connects the gas-liquid mixing port of the first heat exchanger EH1 and the gas-liquid separator GLS, and the flow of the upper loop EH2U is greater than the flow of the lower loop EH2B, which refers to the length of the upward flow path along the refrigerant flow.

Continuing to refer to 1, the directional control valve is preferably a four-way valve 4DCV. The four-way valve 4DCV has four ports. The four ports are the first port, the second port, the third port, and the fourth port. The first port It is connected with the high pressure side of the compressor CP through a pipeline, the second interface is connected with the port of the first heat exchanger EH1 through a pipeline, and the third interface is connected with the port of the upper circuit EH2U and the port of the lower circuit EH2B through a pipeline. , The fourth interface and the low pressure side of the compressor CP are connected by pipelines.

The four-way valve 4DCV has two working positions, which are a first working position and a second working position, respectively.

When the four-way valve 4DCV is in the first working position, the spool moves relative to the valve body until the first port and the third port are connected, and the second port and the fourth port are connected. At this time, the high-pressure side and the upper part of the compressor CP The circuit EH2U and the lower circuit EH2B are connected, the low pressure side of the compressor CP is connected with the first heat exchanger EH1, and the air-cooled heat pump air conditioning system enters the refrigeration mode.

In refrigeration conditions, the refrigerant circulation process is: compressor CP→four-way valve 4DCV→divided into two paths, one flow into the upper circuit EH2U, the other flow into the lower circuit EH2B→gas-liquid separator GLS→main circuit expansion valve XV1→first heat exchanger EH1→four-way valve 4DCV→compressor CP.

The working principle of the refrigeration condition of this air conditioning system is: the low-temperature and low-pressure refrigerant vapor is compressed into high-temperature, high-pressure and superheated vapor through the compressor CP, and the gaseous refrigerant flow enters the upper part of the second heat exchanger EH2 after passing through the four-way valve 4DCV The circuit EH2U and the lower circuit EH2B transfer heat to the air through heat exchange. The refrigerant is condensed into a high-temperature and high-pressure liquid, flows through the gas-liquid separator GLS, and is throttled by the main circuit expansion valve XV1 to become saturated refrigeration. Then it enters the first heat exchanger EH1 to evaporate and absorb heat into low-temperature superheated vapor, and then return to the compressor CP through the four-way valve 4DCV. The air-conditioning system continuously circulates to produce cold water and dissipate heat into the air.

When the four-way valve 4DCV is switched to the second working position, the spool moves relative to the valve body to communicate with the first port and the second port, and the third port is connected with the fourth port, that is, the high-pressure side of the compressor CP is connected to the first port. The heater EH1 is connected, and the low pressure side of the compressor CP is connected to both the upper circuit EH2U and the lower circuit EH2B, and the air conditioning system enters the heating mode.

Under heating conditions, the refrigerant circulation process is: compressor CP→four-way valve DCV4→first heat exchanger EH1→main expansion valve XV1→gas-liquid separator GLS→divided into two paths, one flow into the upper part The circuit EH2U, the other way flows into the lower circuit EH2B→four-way valve 4DCV→compressor CP.

The working principle of the heating condition of the air conditioning system is: the low-temperature and low-pressure refrigerant vapor is compressed into high-temperature, high-pressure superheated vapor through the compressor CP, and the gaseous refrigerant flow enters the first heat exchanger EH1 after passing through the four-way valve 4DCV, The heat is transferred to the circulating water through heat exchange. The refrigerant is condensed into a high-temperature and high-pressure liquid, which is throttled by the main expansion valve XV1 to form a gas-liquid two-phase refrigerant, which is then separated into a gas-liquid refrigerant by the gas-liquid separator GLS Liquid refrigerant and gaseous refrigerant. Among them, the liquid refrigerant flows into the upper circuit EH2U of the second heat exchanger EH2, exchanges heat with the external environment, absorbs heat and evaporates to form a gaseous refrigerant; at the same time, the gaseous refrigerant sequentially flows through the lower circuit EH2B and the four-way valve 4DCV It is then sucked into the compressor CP. The air-conditioning system continuously circulates to produce hot water and absorb heat from the air.

Continuing to refer to FIG. 1, the liquid phase port of the gas-liquid separator GLS is arranged at its bottom, the gas phase port of the gas-liquid separator GLS is arranged at the top thereof, and the gas-liquid mixing port of the gas-liquid separator GLS is arranged at its middle part.

Refer to FIG. 2, which is a schematic structural diagram of a second embodiment of an air-cooled heat pump air-conditioning system with high-efficiency heating according to the present invention. The air-cooled heat pump air conditioning system includes a compressor CP, a first heat exchanger EH1, a second heat exchanger EH2, a directional control valve, a main expansion valve XV1, a gas-liquid separator GLS, and a flow control device.

Among them, the second heat exchanger EH2 is divided into an upper loop EH2U and a lower loop EH2B that are independent of each other, and the flow of the upper loop EH2U is greater than the flow of the lower loop EH2B. The upper circuit EH2U is connected with the liquid phase port of the gas-liquid separator GLS, and the lower circuit EH2B is connected with the gas-phase port of the gas-liquid separator GLS through a flow control device. The flow control device is used for throttling by the lower circuit EH2B under refrigeration conditions. The refrigerant flowing into the gas-liquid separator GLS and the refrigerant flowing from the gas-liquid separator GLS into the lower circuit EH2B are directly conducted under heating conditions.

Preferably, the flow control device in this embodiment is a parallel assembly of a one-way valve CV and a capillary tube MV; wherein the capillary tube MV is used to throttle the refrigerant flowing from the lower loop EH2B into the gas-liquid separator GLS under refrigeration conditions. The valve CV is used to directly conduct the refrigerant flowing from the gas-liquid separator GLS into the lower circuit EH2B under heating conditions.

It can be understood that the parallel assembly of the one-way valve CV and the capillary tube MV is used in this embodiment to flexibly realize the flow control of the refrigerant in different flow directions between the lower loop EH2B and the gas-liquid separator GLS, with simple structure and low cost. Of course, the flow control device can also be a flow control valve such as an electronic expansion valve on the basis of satisfying the flow control function when the refrigerant flows in different directions between the lower circuit and the gas-liquid separator GLS.

Continuing to refer to Figure 2, in this embodiment, the directional control valve is preferably a four-way valve 4DCV. The four-way valve 4DCV has four ports. The four ports are the first port, the second port, the third port, and the fourth port. ; Among them, the first interface and the high pressure side of the compressor CP are connected by pipelines, the second interface and the port of the first heat exchanger EH1 are connected by pipelines, and the third interface is connected to the port of the upper circuit EH2U and the port of the lower circuit EH2B The two are connected by pipelines, and the fourth port and the low pressure side of the compressor CP are connected by pipelines.

The four-way valve 4DCV has two working positions, which are a first working position and a second working position, respectively. When the four-way valve 4DCV is in the first working position, the spool moves relative to the valve body to communicate with the first port and the third port. At this time, the high-pressure side of the compressor CP communicates with both the upper circuit EH2U and the lower circuit EH2B, compressing The low pressure side of the engine CP is connected to the first heat exchanger EH1, and the air conditioning system enters the cooling mode.

Under refrigeration conditions, the refrigerant circulation process is: compressor CP→four-way valve 4DCV→divided into two paths, one flowing through the upper circuit EH2U, and the other flowing through the lower circuit EH2B and capillary MV in turn→gas-liquid separator GLS→main expansion valve XV1→first heat exchanger EH1→four-way valve 4DCV→compressor CP.

The working principle of the refrigeration conditions of this system is: the low-temperature and low-pressure refrigerant vapor is compressed into high-temperature, high-pressure and superheated vapor through the compressor CP, and the gaseous refrigerant flows into the upper circuit of the second heat exchanger EH2 after passing through the four-way valve 4DCV. EH2U and the lower circuit EH2B, one refrigerant flows directly into the gas-liquid separator GLS after heat exchange in the upper circuit EH2U, and the other refrigerant flows into the gas-liquid separator GLS after heat exchange through the capillary MV after the heat exchange in the lower circuit EH2B. After merging, it flows into the main circuit expansion valve XV1, and becomes saturated refrigerant after throttling. The refrigerant flows into the first heat exchanger EH1 to evaporate the heat-trapped gas and turn it into low-temperature superheated vapor, and finally flows back through the four-way valve 4DCV Compressor CP. The air-conditioning system continuously circulates to produce cold water and dissipate heat into the air.

When the four-way valve 4DCV is switched to the second working position, the spool moves relative to the valve body to communicate with the first port and the second port, and the third port is connected with the fourth port, that is, the high-pressure side of the compressor CP is connected to the first port. The heater EH1 is connected, the low pressure side of the compressor CP is connected with both the upper circuit EH2U and the lower circuit EH2B, and the air conditioning system enters the heating mode.

Under heating conditions, the refrigerant circulation process is: compressor CP→four-way valve 4DCV→first heat exchanger EH1→main expansion valve XV1→gas-liquid separator GLS→divided into two paths, one flow into the upper part In the circuit EH2U, the other circuit flows through the one-way valve CV and the lower circuit EH2B→four-way valve DCV4→compressor CP in turn.

The working principle of the heating condition of this system is: the low-temperature and low-pressure refrigerant vapor is compressed into high-temperature and high-pressure superheated vapor through the compressor CP, and the gaseous refrigerant flow enters the first heat exchanger EH1 after passing through the four-way valve 4DCV. The heat exchange transfers heat to the circulating water. The refrigerant is condensed into a high-temperature and high-pressure liquid, which is throttled by the main expansion valve XV1 to form a gas-liquid two-phase refrigerant, which is then processed into a gas-liquid two-phase refrigerant by the gas-liquid separator GLS Liquid refrigerant and gaseous refrigerant. Among them, the liquid refrigerant flows into the upper circuit EH2U of the second heat exchanger EH2 and exchanges heat with the external environment, absorbing heat and evaporating to form a gaseous refrigerant; at the same time, the gaseous refrigerant flows through the check valve CV, the lower circuit EH2B and The four-way valve 4DCV is sucked into the compressor CP. The air-conditioning system continuously circulates to produce hot water and absorbs heat from the air.

Refer to FIG. 3, which is a schematic structural diagram of a third embodiment of a separate cooling heat pump air-conditioning system with high-efficiency heating according to the present invention. It should be noted that, in order to improve the readability of this article, this article only elaborates on the differences between the third embodiment and the second embodiment. For the similarities, please refer to the relevant records of the aforementioned second embodiment. Those skilled in the art can realize this scheme without any doubt.

The difference between the third embodiment and the second embodiment is: the number of second heat exchangers of the air conditioning system provided by the third embodiment is two, and the two second heat exchangers are arranged in parallel. Each second heat exchanger is divided into an upper circuit and a lower circuit independent of each other.

For the convenience of explanation, this article uses the location words "front" and "rear" to distinguish the two second heat exchangers, and the location words "front" and "rear" are set based on the compressor in Figure 3 Among the two second heat exchangers, the second heat exchanger on the compressor side is the front second heat exchanger EH2f, and the second heat exchanger far from the compressor is the rear second heat exchanger EH2b. It should be noted that the orientation words "front" and "rear" are only set to distinguish the two second heat exchangers, and the setting of these orientation words does not limit the scope of protection of this patent.

In detail, the upper circuit of the front second heat exchanger EH2f has two connection ports, namely the first upper connection port and the second upper connection port; the lower circuit of the front second heat exchanger EH2f also has two connections Ports are the first lower connection port and the second lower connection port; the upper circuit of the second rear heat exchanger EH2b has two connection ports, the third upper connection port and the fourth upper connection port, respectively; The lower circuit of the second heat exchanger EH2b also has two connection ports, namely the third lower connection port and the fourth lower connection port.

Wherein, the first upper connection port, the first lower connection port, the third upper connection port and the third lower connection port are respectively connected to the first port, the second port, the third port and the fourth port of the first collecting valve through pipelines. Interface connection, the fourth interface of the four-way valve 4DCV is connected to the fifth interface of the first collecting valve through a pipeline.

With this arrangement, under cooling conditions, the refrigerant from the compressor CP flows into the first collecting valve through the four-way valve 4DCV, and is divided into four paths in the collecting valve, and then flows into the upper part of the front second heat exchanger EH2f. The circuit, the lower circuit of the front second heat exchanger EH2f, the upper circuit of the rear second heat exchanger EH2b, and the lower circuit of the rear second heat exchanger EH2b. Conversely, under heating conditions, the upper circuit of the front second heat exchanger EH2f, the lower circuit of the front second heat exchanger EH2f, the upper circuit of the rear second heat exchanger EH2b, and the rear second heat exchanger The refrigerant in the lower circuit of the heater EH2b flows into the first collecting valve through the corresponding four pipelines, flows into the four-way valve 4DCV after the first collecting valve merges, and is finally sucked into the compressor CP.

Both the upper circuit of the front second heat exchanger EH2f and the upper circuit of the rear second heat exchanger EH2b are connected to the gas-liquid separator through a second collecting valve. In detail, the second upper connection port is connected to the first port of the second collecting valve, the fourth upper connection port is connected to the second connection port of the second collecting valve, and the liquid phase port of the gas-liquid separator GLS is connected to the second connection port of the second collecting valve. The third connection port of the collecting valve communicates.

Both the lower circuit of the front second heat exchanger EH2f and the lower circuit of the rear second heat exchanger EH2b are connected in parallel with the check valve CV and the capillary MV through a third collecting valve. In detail, the second lower connecting port is connected to the first port of the third collecting valve, the fourth lower connecting port is connected to the second port of the third collecting valve, and the cut-off port of the one-way valve CV is connected to the third collecting valve. The third port of the valve is in communication, and a port of the capillary tube MV is in communication with the fourth port of the third collecting valve.

The parallel assembly of the check valve CV and the capillary MV is connected to the gas-liquid separator GLS through the fourth collecting valve. In detail, the conduction port of the one-way valve CV communicates with the first port of the fourth collecting valve, the other port of the capillary MV communicates with the second port of the fourth collecting valve, and the gas-phase port of the gas-liquid separator GLS communicates with The third port of the fourth collecting valve is in communication.

So set up, in the cooling condition: the refrigerant in the upper circuit of the front second heat exchanger EH2f and the upper circuit of the rear second heat exchanger EH2b flows into the second collecting valve, in the second collecting valve After being collected, it flows into the gas-liquid separator through the liquid phase outlet; the refrigerant in the lower circuit of the front second heat exchanger EH2f and the lower circuit of the rear second heat exchanger EH2b flows into the third collecting valve, After the flow in the collecting valve is converged, it is throttled by the capillary MV and then flows into the fourth collecting valve, and then flows into the gas-liquid separator GLS from the fourth collecting valve.

Conversely, under heating conditions: After the refrigerant in the gas-liquid separator GLS is separated from the gas and liquid, the gaseous refrigerant flows through the fourth collecting valve and the check valve CV in turn into the third collecting valve. The three-collecting valve flows into the lower circuit of the second heat exchanger EH2f at the front and the lower circuit of the second heat exchanger EH2b at the rear. The liquid refrigerant flows into the second collecting valve and flows into the second collecting valve. After being split, it flows into the upper circuit of the front second heat exchanger EH2f and the upper circuit of the rear second heat exchanger EH2b.

Obviously, the air-cooled heat pump air conditioning system in the third embodiment adopts two sets of second heat exchangers, which has the characteristics of large heat exchange area and high heating performance.

It should be noted that the air-cooled heat pump air conditioning system in this embodiment includes two second heat exchangers. It is understandable that the number of second heat exchangers is not limited to two. According to actual needs, the air-cooled heat pump air-conditioning system may use multiple second heat exchangers, and each second heat exchanger is arranged in parallel. Among them, multiple refers to an integer greater than or equal to 3, such as 3, 4, 5, 6, 7, and so on. In addition, when the air-cooled heat pump air conditioning system includes multiple second heat exchangers, the connection relationship between each second heat exchanger and other devices is similar to that of the aforementioned two second heat exchangers. The description of can be realized without any doubt, so this article will not repeat it here.

4, this figure is a fourth embodiment of an air-cooled heat pump air-conditioning system with high-efficiency heating according to the present invention. The air-conditioning system includes a compressor CP, a first heat exchanger EH1, a directional control valve, and a main expansion valve XV1, and Three second heat exchangers are arranged in parallel with each other, and each second heat exchanger is divided into an upper circuit and a lower circuit independent of each other.

For ease of explanation, this article uses the location words "front", "中" and "后" to distinguish the three second heat exchangers, and the location words "front", "中" and "后" are shown in Figure 4 Set based on the middle compressor, among the three second heat exchangers, the second heat exchanger on the compressor side is the front second heat exchanger EH2f, and the second heat exchanger far away from the compressor is the rear The second heat exchanger EH2b, located between the front second heat exchanger EH2f and the rear second heat exchanger EH2b is the middle second heat exchanger EH2m. It should be noted that the orientation words "front", "middle" and "rear" are only set to distinguish the three second heat exchangers, and these orientation words do not limit the scope of protection of this patent.

Continuing to refer to Figure 4, the air conditioning system also includes a first three-way valve 3DCV1 and a second three-way valve 3DCV1 and a second three-way valve respectively corresponding to the front second heat exchanger EH2f, the middle second heat exchanger EH2m, and the rear second heat exchanger EH2b. The three-way valve 3DCV2 and the third three-way valve 3DCV3, as well as the first defrost switch valve SV1 respectively corresponding to the front second heat exchanger EH2f, the middle second heat exchanger EH2m and the rear second heat exchanger EH2b. The second defrost switch valve SV2 and the third defrost switch valve SV3.

Among them, the first three-way valve DCV31 is arranged between the high pressure side of the compressor CP, the directional control valve and the front second heat exchanger EH2f to control the front second heat exchanger EH2f to be selectively connected to the compressor The high-pressure side of the CP may be connected to the directional control valve. The first defrost switch valve SV1 is arranged between the high-pressure side of the compressor CP and the first three-way valve 3DCV1 to control the high-pressure side of the compressor CP and the first three-way valve 3DCV1 to cut off or conduct.

In the same way, the second three-way valve 3DCV2 is set between the high pressure side of the compressor CP, the four-way valve 4DCV and the second heat exchanger EH2m in the middle to control the second heat exchanger EH2m in the middle to be selectively connected to the compressor The high pressure side of the CP or the directional control valve is connected. The second defrost switch valve SV2 is arranged between the high-pressure side of the compressor CP and the second three-way valve 3DCV2 to control the high-pressure side of the compressor CP and the second three-way valve 3DCV2 to cut off or conduct.

The third three-way valve 3DCV3 is arranged between the high pressure side of the compressor CP, the directional control valve and the third second heat exchanger EH3 to control the rear second heat exchanger EH2b to be selectively connected to the compressor CP The high-pressure side or the four-way valve 4DCV is connected. The third defrost switch valve SV3 is arranged between the high-pressure side of the compressor CP and the third three-way valve 3DCV3 to control the high-pressure side of the compressor CP and the third three-way valve 3DCV3 to cut off or conduct.

The air conditioning system also includes a first gas-liquid separator GLS1 and a second gas-liquid separator GLS2 respectively corresponding to the front second heat exchanger EH2f, the middle second heat exchanger EH2m, and the rear second heat exchanger EH2b. And the third gas-liquid separator GLS3; among them, the gas-liquid mixing port of the first gas-liquid separator GLS1 is connected to the main expansion valve XV1, and the liquid-phase port of the first gas-liquid separator GLS1 is connected to the front second heat exchanger The upper loop of EH2f is connected; in the same way, the gas-liquid mixing port of the second gas-liquid separator GLS2 is connected to the main expansion valve XV1, and the liquid port of the second gas-liquid separator GLS2 is connected to the upper part of the second heat exchanger EH2m in the middle. The circuit is connected; the gas-liquid mixing port of the third gas-liquid separator GLS3 communicates with the main expansion valve XV1, and the liquid-phase port of the third gas-liquid separator GLS3 communicates with the upper circuit of the rear second heat exchanger EH2b.

Continuing to refer to Figure 4, the air conditioning system also includes a first flow control device; the first flow control device is arranged between the lower loop of the front second heat exchanger EH2f and the gas phase port of the first gas-liquid separator GLS1 for Under refrigeration conditions, the refrigerant that flows from the lower loop of the front second heat exchanger EH2f to the first gas-liquid separator GLS1 is throttled, and under heating conditions, it is directly connected to the first gas-liquid separator GLS1. The refrigerant in the lower circuit of the front second heat exchanger EH2f.

The air conditioning system also includes a second flow control device, which is arranged between the lower loop of the second heat exchanger EH2m in the middle and the gas phase port of the second gas-liquid separator GLS2, and is used for cooling under cooling conditions. The refrigerant flows from the lower loop of the second heat exchanger EH2m in the middle to the second gas-liquid separator GLS2, and in heating conditions, it is directly connected from the second gas-liquid separator GLS2 to the lower part of the second heat exchanger EH2m in the middle. The refrigerant in the circuit.

The air-cooled heat pump air conditioning system also includes a third flow control device; the third flow control device is arranged between the lower loop of the second rear heat exchanger EH2b and the gas-phase port of the third gas-liquid separator GLS3 for cooling Under working conditions, the refrigerant flowing from the lower circuit of the second rear heat exchanger EH2b to the third gas-liquid separator GLS3 is throttled, and under heating conditions, it is directly connected from the third gas-liquid separator GLS3 to the rear second gas-liquid separator. The refrigerant in the lower circuit of the second heat exchanger EH2b.

Continuing to refer to Figure 4, the first flow control device in this embodiment preferably adopts a parallel assembly of the first check valve CV1 and the first capillary tube MV1. A gas-liquid separator GLS1 flows into the refrigerant in the lower circuit of the front second heat exchanger EH2f. The first capillary tube MV1 is used to throttle the flow from the lower circuit of the front second heat exchanger EH2f to the first under cooling conditions. The refrigerant in the gas-liquid separator GLS1.

In the same way, the second flow control device also preferably adopts the parallel assembly of the second one-way valve CV2 and the second capillary tube MV2. The second one-way valve CV2 is used to directly conduct the second gas-liquid separator under heating conditions GLS2 flows into the refrigerant in the lower circuit of the second heat exchanger EH2m in the middle. The second capillary MV2 is used to throttle the refrigerant flowing from the lower circuit of the second heat exchanger EH2m in the middle to the second gas-liquid separator GLS2 under cooling conditions. .

The third flow control device also preferably adopts a parallel assembly of a third check valve CV3 and a third capillary MV3. The third check valve CV3 is used for heating conditions and is directly connected to the rear by the third gas-liquid separator GLS3 The refrigerant in the lower circuit of the second heat exchanger EH2b, and the third capillary MV3 is used to throttle the refrigerant flowing from the lower circuit of the rear second heat exchanger EH2b to the third gas-liquid separator GLS3 under cooling conditions.

Further, continuing to refer to FIG. 4, the gas-liquid mixing port of the first gas-liquid separator GLS1 and the main expansion valve XV1 are connected through a parallel assembly formed by a fourth forward check valve CV4 and a fifth reverse check valve CV5; Among them, the fourth positive check valve CV4 allows the refrigerant to flow from the first gas-liquid separator GLS1 to the main expansion valve XV1, and the fifth reverse check valve CV5 allows the refrigerant to flow from the main expansion valve XV1 to the first gas-liquid Separator GLS1.

In the same way, the gas-liquid mixing port of the second gas-liquid separator GLS2 is connected to the main expansion valve XV1 through the parallel assembly formed by the sixth positive check valve CV6 and the seventh reverse check valve CV7; among them, the sixth positive The check valve CV6 allows the refrigerant to flow from the second gas-liquid separator GLS2 to the main expansion valve XV1, and the seventh reverse check valve CV7 allows the refrigerant to flow from the main expansion valve XV1 to the second gas-liquid separator GLS2.

The gas-liquid mixing port of the third gas-liquid separator GLS3 is connected to the main expansion valve XV1 through the parallel assembly formed by the eighth forward check valve CV8 and the ninth reverse check valve CV9; wherein, the eighth forward one-way The valve CV8 allows the refrigerant to flow from the third gas-liquid separator GLS3 to the main expansion valve XV1, and the ninth reverse check valve CV9 allows the refrigerant to flow from the main expansion valve XV1 to the third gas-liquid separator GLS3.

Further, continuing to refer to Figure 4, the air conditioning system of this embodiment further includes a refrigeration switching valve SV4 and a bypass expansion valve XV2 assembly arranged in parallel, and the refrigeration switching valve SV4 and a bypass expansion valve XV2 assembly arranged in parallel are used for connecting each component in series. Positive check valve and main circuit expansion valve. When the three second heat exchangers are in the cooling mode, the cooling switch valve SV4 is opened, and the bypass expansion valve XV2 is closed; when the three second heat exchangers are all in the heating mode, the cooling switch valve SV4 is closed, and the bypass The expansion valve XV2 is closed; when at least one of the three second heat exchangers is in the defrosting state, the refrigeration switch valve SV4 is closed, and the bypass expansion valve XV2 starts throttling.

In this embodiment, the directional control valve is preferably a four-way valve 4DCV. The four-way valve 4DCV has four ports. The four ports are the first port, the second port, the third port, and the fourth port. The first port It communicates with the high-pressure side of the compressor CP through a pipeline, the second interface communicates with the port of the first heat exchanger EH1 through a pipeline, and the third interface communicates with the front second heat exchanger EH2f, the middle second heat exchanger EH2m and The rear second heat exchanger EH2b is in communication, and the fourth port is in communication with the low pressure side of the compressor CP through a pipeline.

The four-way valve 4DCV has two working positions, which are a first working position and a second working position, respectively. When the four-way valve 4DCV is in the first working position, the spool moves relative to the valve body to communicate with the first port and the third port. At this time, the high-pressure side of the compressor CP is connected to the front second heat exchanger EH2f, and the middle second heat exchanger EH2f. The heat exchanger EH2m and the rear second heat exchanger EH2b are connected, the low pressure side of the compressor CP is connected with the first heat exchanger EH1, and the air-cooled heat pump air conditioning system enters the cooling mode.

Under refrigeration conditions, the first defrost switch valve SV1, the second defrost switch valve SV2, the third defrost switch valve SV3, and the bypass main circuit expansion valve XV12 are all in the closed state, and the refrigeration switch valve SV4 is opened.

The refrigerant cycle process is: compressor CP→4 four-way valve DCV→first three-way valve 3DCV1, second three-way valve 3DCV2 and third three-way valve 3DCV3→divided into two ways, one way flows into the front part of the second heat exchange The upper circuit of the heat exchanger EH2f, the upper circuit of the middle second heat exchanger EH2m and the upper circuit of the rear second heat exchanger EH2b, the other one flows into the lower circuit of the front second heat exchanger EH2f and the first capillary MV1 in turn, The lower circuit of the second heat exchanger EH2m in the middle and the second capillary MV2, the lower circuit of the second heat exchanger EH2b in the rear and the third capillary MV3 → the first gas-liquid separator GLS1, the second gas-liquid separator GLS2 and the second Three gas-liquid separator GLS3→fourth positive one-way valve CV4, sixth positive one-way valve CV6, eighth positive one-way valve CV8→bypass expansion valve XV2→main expansion valve XV1→first heat exchange EH1→four-way valve 4DCV→compressor CP.

The working principle of the refrigeration mode of the air conditioning system is: the low-temperature and low-pressure refrigerant vapor is compressed into high-temperature, high-pressure and superheated vapor through the compressor CP. A second heat exchanger transfers heat to the air through heat exchange, and the refrigerant is condensed into a high-temperature and high-pressure liquid refrigerant; then the refrigerant flows through the capillary tubes, gas-liquid and gas-liquid corresponding to the second heat exchangers. The separator refrigerant and the check valve flow into the main expansion valve XV1 through the refrigeration switch valve SV4. After converging in the main expansion valve XV1, the refrigerant that becomes saturated is throttled and enters the first heat exchanger. EH1 evaporates and absorbs heat into low-temperature superheated vapor, and finally returns to the compressor CP through the four-way valve 4DCV. The air-conditioning system continuously circulates to produce cold water and dissipate heat into the air.

Under heating conditions, the first defrost switch valve SV1, the second defrost switch valve SV2, the third defrost switch valve SV3, the refrigeration switch valve SV4, and the bypass valve XV2 are all in a closed state.

The refrigerant cycle process is: compressor CP→four-way valve 4DCV→first heat exchanger EH1→main expansion valve XV1→fifth reverse check valve CV5, seventh reverse check valve CV7, ninth reverse One-way valve CV9→first gas-liquid separator GLS1, second gas-liquid separator GLS2, and third gas-liquid separator GLS3→divided into two paths, one way flows into the upper circuit of the front second heat exchanger EH2f, the middle part The upper circuit of the second heat exchanger EH2m and the upper circuit of the rear second heat exchanger EH2b, the other one flows through the first check valve CV1 and the lower circuit of the front second heat exchanger EH2f, and the second check valve CV2 and the lower circuit of the second heat exchanger EH2m in the middle, the lower circuit of the third check valve CV3 and the second heat exchanger EH2b in the rear → the first three-way valve 3DCV1, the second three-way valve 3DCV2 and the third three-way Valve 3DCV3→four-way valve 4DCV→compressor CP.

The working principle of the heating mode of the air conditioning system is: the low-temperature and low-pressure refrigerant vapor is compressed into high-temperature, high-pressure superheated vapor through the compressor CP, and the gaseous refrigerant flow enters the first heat exchanger EH1 after passing through the four-way valve 4DCV, The heat is transferred to the circulating water through heat exchange, the refrigerant is condensed into a high-temperature and high-pressure liquid, which is throttled by the main expansion valve XV1 to form a gas-liquid two-phase refrigerant, and then passes through the fifth reverse check valve CV5, The seventh reverse check valve CV7 and the ninth reverse check valve CV9 respectively flow into the corresponding three gas-liquid separators, and the gas-liquid separation process of each gas-liquid separator is processed into liquid refrigerant and gaseous refrigerant. Among them, the liquid refrigerant flows into the upper circuit of the second heat exchanger corresponding to each gas-liquid separator and exchanges heat with the external environment, absorbs heat and evaporates to form a gaseous refrigerant; at the same time, the gaseous refrigerant flows through the first A one-way valve CV1, a second one-way valve CV2, and a third one-way valve CV3 enter the lower circuit corresponding to the second heat exchanger, and finally flow through the four-way valve 4DCV and be sucked into the compressor CP. The air-conditioning system continuously circulates to produce hot water and absorb heat from the air.

Under heating conditions, when the ambient temperature is low, the second heat exchanger will be frosted. The air conditioning system can defrost the three second heat exchangers one by one.

When defrosting the front second heat exchanger EH2f, turn off the fan of the front second heat exchanger EH2f, close the second defrost switch valve SV2 and the third defrost switch valve SV3, and open the first defrost switch valve SV1 and bypass expansion valve XV2, the high-pressure side of the compressor CP is connected to the first three-way valve 3DCV1, and the first three-way valve 3DCV1 is controlled to make the front second heat exchanger EH2f communicate with the high-pressure side of the compressor CP. The gaseous refrigerant enters the front second heat exchanger EH2f to start defrosting. After the refrigerant is condensed in the upper and lower circuits of the front second heat exchanger EH2f1, it flows through the first gas-liquid separator GLS1 and the fourth positive The one-way valve CV4 enters the main pipeline after being throttled by the bypass expansion valve XV2, mixed with the refrigerant after being throttled by the main expansion valve XV1, and then enters the other central second heat exchanger EH2m working in the heating state And the second heat exchanger EH2b at the rear for evaporation.

When defrosting the middle second heat exchanger EH2m, turn off the fan of the middle second heat exchanger EH2m, close the first defrost switch valve SV1, the third defrost switch valve SV3, and the refrigeration switch valve SV4, and turn on the second defrost switch EH2m. Frost switch valve SV2 and bypass expansion valve XV2, the high-pressure side of the compressor CP is connected to the second three-way valve 3DCV2, and the second three-way valve 3DCV2 is controlled to make the middle second heat exchanger EH2m communicate with the high-pressure side of the compressor CP . The high-pressure gas refrigerant enters the middle second heat exchanger EH2m to start defrosting. The refrigerant condenses in the upper and lower circuits of the middle second heat exchanger EH2m, and then flows through the second gas-liquid separator GLS2 and the sixth forward direction. The check valve CV6, after throttling by the bypass main expansion valve XV2, enters the main pipeline, mixes with the refrigerant after throttling by the main expansion valve XV1, and enters the second heat exchange at the front of the other working in the heating state EH2f and the second heat exchanger EH2b in the rear are evaporated.

When defrosting the rear second heat exchanger EH2b, turn off the fan of the rear second heat exchanger EH2b, close the first defrost switch valve SV1, the second defrost switch valve SV2, and the refrigeration switch valve SV4, and turn on the first defrost switch valve SV1. The three-way defrost switch valve SV3 and the bypass main circuit expansion valve XV12, the high-pressure side of the compressor CP is connected to the third three-way valve 3DCV3, and the third three-way valve 3DCV3 is controlled to make the second heat exchanger EH2b at the rear and the compressor The high-pressure side of the CP is connected. The high-pressure gas refrigerant enters the rear second heat exchanger EH2b to start defrosting. The refrigerant condenses in the upper and lower circuits of the rear second heat exchanger EH2b, and then flows through the third gas-liquid separator GLS3 and the eighth The positive one-way valve CV8, after throttling by the bypass expansion valve XV2, enters the main pipeline, mixes with the refrigerant after throttling by the main expansion valve XV1, and enters the second heat exchange at the front of the other working in the heating state EH2f and the second heat exchanger EH2m in the middle for evaporation.

It can be seen that this air conditioning system only defrosts one second heat exchanger, and then defrosts other second heat exchangers after the defrosting of the second heat exchanger is completed. Therefore, during the defrosting process, the air-conditioning system still maintains a heating cycle, and will not absorb heat from the first heat exchanger EH1 for defrosting, so that the user's water temperature fluctuations during the entire defrosting process are small and the comfort is guaranteed.

In addition, when the second heat exchanger is defrosted one by one, the pressure in the second heat exchanger in the defrosting state gradually increases from low to high, and a bypass expansion valve XV2 is set and connected to the throttling of the main expansion valve XV1 In the low-pressure pipeline behind. Through the control of the bypass expansion valve XV2, the refrigerant in the second heat exchanger in defrosting can be discharged smoothly, and the flow can be controlled, so that the temperature of the second heat exchanger rises faster, and the rapid defrosting is achieved. Effect.

Of course, the fourth positive one-way valve CV4, the sixth positive one-way valve CV6 and the eighth positive one-way valve CV8 of the air conditioning system can also be directly connected to the high-pressure pipeline of the main circuit expansion valve XV1. With this arrangement, the second heat exchanger in the defrosting state completely relies on the pressure self-balance of the air conditioning system to discharge liquid, but the liquid discharge speed is relatively slow and the defrosting time is longer.

It should be noted that the air-cooled heat pump air conditioning system in this embodiment includes three second heat exchangers, and it can be understood that the number of second heat exchangers is not limited to three. According to actual needs, the air-cooled heat pump air-conditioning system can adopt two or more heat exchangers, and each second heat exchanger is arranged in parallel. Among them, multiple refers to an integer greater than or equal to 3, such as 3, 4, 5, 6, 7, and so on. In addition, when the air-cooled heat pump air conditioning system includes two or multiple second heat exchangers other than 3, the connection relationship between each second heat exchanger and other devices is similar to that of the aforementioned two second heat exchangers. Those skilled in the art can achieve this without any doubt based on the above description, so this article will not repeat them here.

In the air conditioning system provided by the present invention in the above four embodiments, under heating conditions, the gas-liquid two-phase refrigerant formed by the main circuit expansion valve throttling is separated into gaseous refrigerant and liquid refrigerant in the gas-liquid separator And then flow into the independent upper and lower circuits of the second heat exchanger to participate in heat exchange, ensuring that the upper circuit is basically pure liquid refrigerant, and the lower circuit is basically pure gaseous refrigerant. Because the flow of the upper circuit is greater than that of the lower circuit, the liquid refrigerant can more fully exchange heat and thus be more thoroughly evaporated, thereby improving the heating capacity of the air conditioning system under various working conditions.

Furthermore, due to the short flow of the lower loop of the second heat exchanger, the one-way valve is closed under refrigeration conditions, and the liquid refrigerant flows through the gas-liquid separator and the main expansion valve in turn after being throttled by the capillary tube, and then enters the first heat exchanger. In the heater, this can limit the flow of refrigerant from the lower loop to the gas-liquid separator, so as to prevent a large amount of uncondensed gaseous refrigerant from entering the gas-liquid separator due to excessive refrigerant flow. At the same time, the refrigerant flows into the lower circuit from the gas-liquid separator through the one-way valve bypass under the heating condition, which ensures the smooth flow of the refrigerant under the heating condition, thereby ensuring the normal progress of the entire refrigeration condition. .

It should be noted that the air-cooled heat pump air-conditioning system provided by the above three or four embodiments not only solves the problem of refrigerant distribution in the second heat exchanger under heating conditions, but also has the following features, namely:

First, under the same heat exchange rate, the difference between the saturated evaporation temperature and the air heat exchange temperature is reduced, the frosting temperature of the unit is reduced, the defrosting cycle is prolonged, and the operating range of the unit is expanded.

Second, under heating conditions, the lower loop of the second heat exchanger is gaseous refrigerant, the heat exchange is smaller, the temperature is higher than the upper loop, and the amount of frosting is smaller.

Third, under defrosting conditions, the temperature of the lower circuit of the second heat exchanger is also higher than that of the upper circuit, so that the frost layer melts quickly, so that the defrosting drainage is smoother, thereby improving the defrosting drainage effect.

Fourth, under refrigeration conditions, the lower loop of the second heat exchanger can also be used for condensation heat exchange, so that the heat exchange area of the second heat exchanger can be fully utilized.

So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

An air-cooled heat pump air-conditioning system with high-efficiency heating, comprising a compressor, a first heat exchanger, a second heat exchanger, a directional control valve, and a main expansion valve, characterized in that the air-conditioning system also includes a gas-liquid separation Device

The second heat exchanger is divided into an upper circuit and a lower circuit that are independent of each other. The upper circuit is in communication with the liquid phase port of the gas-liquid separator, and the lower circuit is in communication with the gas-phase port of the gas-liquid separator. , The main circuit expansion valve is connected to the gas-liquid mixing port of the first heat exchanger and the gas-liquid separator, and the flow of the upper loop is greater than that of the lower loop;

Under refrigeration conditions, the directional control valve is located in the first working position to control the high-pressure side of the compressor to communicate with both the upper circuit and the lower circuit, and the low-pressure side of the compressor is connected to the lower circuit. The first heat exchanger is connected;

Under heating conditions, the directional control valve is located in the second working position to control the high-pressure side of the compressor to communicate with the first heat exchanger, and the low-pressure side of the compressor and the upper circuit and The two lower circuits are in communication.
The high-efficiency heating air-cooled heat pump air-conditioning system according to claim 1, wherein the lower circuit and the gas-liquid separator are connected by a flow control device, and the flow control device is used for cooling under cooling conditions. Throttling the refrigerant flowing into the gas-liquid separator from the lower circuit, and directly conducts the refrigerant flowing from the gas-liquid separator into the lower circuit under heating conditions.
The air-cooled heat pump air-conditioning system for efficient heating according to claim 2, wherein the flow control device is a parallel assembly of a one-way valve and a capillary tube, and the capillary tube is used for throttling the flow rate under cooling conditions. The lower circuit flows into the refrigerant of the gas-liquid separator, and the one-way valve is used to directly conduct the refrigerant flowing from the gas-liquid separator into the lower circuit under heating conditions.
The air-cooled heat pump air-conditioning system for efficient heating according to any one of claims 1 to 3, wherein the number of the second heat exchanger is two or more, and two or more The second heat exchanger is arranged in parallel.
The air-cooled heat pump air-conditioning system with high-efficiency heating according to claim 1, wherein the number of the second heat exchangers is two or more, and the air-conditioning system further includes a connection with each of the second heat exchangers. A three-way valve, a defrost switch valve and the gas-liquid separator corresponding to the heat exchanger;

The three-way valve is arranged between the high-pressure side of the compressor, the directional control valve and the corresponding second heat exchanger, and is used to control the second heat exchanger to be selectively connected to the second heat exchanger. Communicating with the high-pressure side of the compressor or communicating with the directional control valve;

The defrost switch valve is arranged between the high-pressure side of the compressor and the three-way valve, and is used to control the shutoff or conduction of the high-pressure side of the compressor and the three-way valve.
The air-cooled heat pump air-conditioning system for efficient heating according to claim 5, wherein the inlet of each gas-liquid separator and the main expansion valve pass through a positive one-way valve and a reverse one-way valve. Valves are connected in parallel components; wherein, a positive check valve allows refrigerant to flow from the corresponding gas-liquid separator to the main expansion valve, and a reverse check valve allows refrigerant to flow from the main expansion valve to The corresponding gas-liquid separator.
The high-efficiency heating air-cooled heat pump air-conditioning system according to claim 6, wherein the air-conditioning system further comprises a refrigeration switch valve and a bypass expansion valve assembly arranged in parallel, and the refrigeration switch valve and bypass expansion valve assembly arranged in parallel are arranged in parallel. The circuit expansion valve assembly is used to connect each of the positive one-way valve and the main circuit expansion valve in series;

When each of the second heat exchangers is in a cooling condition, the cooling on-off valve is opened, and the second expansion valve is closed;

When each of the second heat exchangers is in heating mode, the cooling switch valve is closed, and the second expansion valve is closed

When at least one of the second heat exchangers is in the defrosting state, the refrigeration switch valve is closed, and the second expansion valve is activated.
The air-cooled heat pump air-conditioning system for high-efficiency heating according to any one of claims 5 to 7, wherein each of the lower loops and the corresponding gas-liquid separator are connected by a flow control device, and the flow The control device is used for throttling the refrigerant flowing from the lower circuit into the gas-liquid separator under refrigerating conditions, and directly conducts the refrigerant flowing from the gas-liquid separator into the lower circuit under heating conditions The refrigerant.
The high-efficiency heating air-cooled heat pump air conditioning system according to claim 8, wherein the flow control device is a parallel assembly of a one-way valve and a capillary tube, and the capillary tube is used for throttling the flow under refrigeration conditions. The lower circuit flows into the refrigerant of the gas-liquid separator, and the one-way valve is used to directly conduct the refrigerant flowing from the gas-liquid separator into the lower circuit under heating conditions.
The air-cooled heat pump air-conditioning system for high-efficiency heating according to any one of claims 1 to 3 or 5 to 7, wherein the liquid phase port of the gas-liquid separator is arranged at its bottom, and the gas-liquid The gas-phase port of the separator is arranged at the top thereof, and the gas-liquid mixing port of the gas-liquid separator is arranged at the middle part.