CN207515270U

CN207515270U - Heat pump system

Info

Publication number: CN207515270U
Application number: CN201721208771.5U
Authority: CN
Inventors: 彭光前; 吴俊鸿; 于博; 车雯; 陈英强; 廖敏; 连彩云; 田雅颂; 翟振坤
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2017-09-20
Filing date: 2017-09-20
Publication date: 2018-06-19
Anticipated expiration: 2027-09-20

Abstract

The utility model discloses a heat pump system. The heat pump system comprises a compressor, an outdoor heat exchanger, an indoor heat exchanger and a throttling device, and further comprises an indoor auxiliary heating device and a bypass branch, wherein the indoor auxiliary heating device is used for carrying out auxiliary heating in a defrosting mode of operation of the heat pump system, the indoor auxiliary heating device is operated to heat in the defrosting mode of operation of the heat pump system, and the bypass branch, the compressor and the outdoor heat exchanger form a defrosting loop, so that refrigerant discharged by the compressor does not flow through the indoor heat exchanger and enters the outdoor heat exchanger to defrost. The utility model provides a heat pump system is because the refrigerant is not flowing through indoor heat exchanger under the mode of changing frost, consequently can open indoor auxiliary heating device and heat the indoor environment when changing frost, guarantees the travelling comfort of indoor environment under the mode of changing frost, can maintain the frost effect of changing of preferred simultaneously.

Description

Heat pump system

Technical Field

The utility model relates to an air conditioner defrosting technical field, especially a heat pump system.

Background

The defrosting mode of the existing heat pump air conditioning system mainly comprises a refrigeration cycle defrosting mode and a hot gas defrosting mode. The defrosting of the refrigeration cycle is to switch the system from the heating cycle to the refrigeration cycle through a four-way reversing valve, and the defrosting of the hot gas is to increase the flow of an expansion valve under the heating cycle to make a high-temperature refrigerant enter an outdoor heat exchanger for defrosting. In the defrosting process of the two modes, heat supply to the indoor space cannot be performed, the temperature of the room is reduced, and the comfort of the room is affected. Especially in the refrigeration cycle defrosting mode, the indoor heat exchanger is used as an evaporator during defrosting, and indoor heat can be absorbed.

An indoor unit of an existing heat pump air conditioning system is provided with an auxiliary heating device, the auxiliary heating device is turned on under the conditions that the external environment temperature is low and the heat supply capacity is insufficient, but the auxiliary heating device needs to be turned off in consideration of electrical safety and defrosting reliability during the defrosting of a refrigeration cycle of the heat pump system. The reason is that when the refrigeration cycle defrosting is carried out, the indoor heat exchanger is used as an evaporator, condensation water can be generated on the surface of the indoor heat exchanger, and if the auxiliary heating device and the inner fan are started, the condensation water on the surface of the indoor heat exchanger is blown down onto the auxiliary heating device by the inner fan, so that potential safety hazards exist; and when carrying out the steam defrosting, though indoor heat exchanger does not do the evaporimeter, auxiliary heating device and interior fan open and do not have the potential safety hazard, but interior fan operation time can be through the evaporimeter with the heat in the system insufflate indoor, reduce the heat that is used for the defrosting, and it is long when the extension changes the frost, reduce the reliability of changing the frost.

SUMMERY OF THE UTILITY MODEL

In view of this, one of the objectives of the present invention is to provide a heat pump system that can ensure both the comfort of the indoor temperature and the electrical safety during defrosting.

In order to achieve the above purpose, on the one hand, the utility model adopts the following technical scheme:

the heat pump system is characterized in that a compressor, an outdoor heat exchanger, an indoor heat exchanger and a throttling device are arranged on a refrigerant flow path of the heat pump system, the heat pump system further comprises an indoor auxiliary heating device and a bypass branch, the indoor auxiliary heating device and the bypass branch are arranged, when the heat pump system operates in a defrosting mode, the indoor auxiliary heating device operates to heat, the bypass branch, the compressor and the outdoor heat exchanger form a defrosting loop, and refrigerant discharged by the compressor does not flow through the indoor heat exchanger and enters the outdoor heat exchanger to be defrosted.

Preferably, the heat pump system further includes a four-way valve, one end of the bypass branch is located between the outdoor heat exchanger and the indoor heat exchanger, and the other end of the bypass branch is located between the compressor and the four-way valve or between the four-way valve and the indoor heat exchanger.

Preferably, the heat pump system further comprises a four-way valve, and the four-way valve is reversed when the heat pump system is switched from a heating mode to a defrosting mode;

the bypass branch can communicate a suction pipeline of the compressor in a refrigeration mode with a refrigerant outlet pipeline of the outdoor heat exchanger in the refrigeration mode.

Preferably, the refrigeration system further comprises a first switching device, and the first switching device is used for switching and communicating the suction pipeline of the compressor in the refrigeration mode between the bypass branch and the refrigerant inlet pipeline of the indoor heat exchanger in the refrigeration mode.

Preferably, the first switching means comprises a first three-way valve; or,

the first switching device comprises a first two-way valve and a second two-way valve which are respectively arranged on the bypass branch and a refrigerant inlet pipeline of the indoor heat exchanger in the refrigeration mode.

Preferably, the throttling device is arranged between the outdoor heat exchanger and a connection position of the bypass branch and a refrigerant outlet pipeline of the outdoor heat exchanger in a refrigeration mode; or,

the throttling device is arranged between the connection position of the bypass branch and a refrigerant outlet pipeline of the outdoor heat exchanger in a refrigeration mode and the indoor heat exchanger, and the bypass branch is provided with a defrosting throttling element.

Preferably, the bypass branch may communicate a discharge line of the compressor with a refrigerant inlet line of the outdoor heat exchanger in the heating mode.

Preferably, the heat pump system further comprises a four-way valve, and the four-way valve does not reverse when the heat pump system is switched from a heating mode to a defrosting mode;

the bypass branch can communicate the exhaust pipeline of the compressor in the heating mode with the refrigerant inlet pipeline of the outdoor heat exchanger in the heating mode.

Preferably, the heat pump system further includes a throttling branch, a defrosting throttling element is disposed on the throttling branch, and the throttling branch can communicate a refrigerant outlet pipeline of the outdoor heat exchanger in the heating mode with a suction port of the compressor, so as to throttle the refrigerant flowing out of the outdoor heat exchanger when defrosting the outdoor heat exchanger.

Preferably, the refrigeration system further comprises a second switching device, and the second switching device is used for switching and communicating the refrigerant outlet pipeline of the outdoor heat exchanger in the heating mode between the suction pipeline of the compressor in the heating mode and the throttling branch.

Preferably, the second switching device comprises a second three-way valve; or,

the second switching device comprises a suction pipeline arranged in the heating mode of the compressor and a third two-way valve and a fourth two-way valve arranged on the throttling branch.

Preferably, the heat exchanger further comprises a third switching device, and the third switching device is used for switching and communicating the exhaust pipeline of the compressor in the heating mode between the bypass branch and the refrigerant inlet pipeline of the indoor heat exchanger in the heating mode.

Preferably, the third switching device includes a third three-way valve; or,

the third switching device comprises a refrigerant inlet pipeline which is arranged in the heating mode of the indoor heat exchanger and a fifth two-way valve and a sixth two-way valve which are arranged on the bypass branch.

On the other hand, the utility model adopts the following technical scheme:

a compressor, an outdoor heat exchanger, an indoor heat exchanger and a throttling device are arranged on a refrigerant flow path of the heat pump system, the heat pump system further comprises a bypass branch, and the bypass branch can form a defrosting loop with the compressor, the outdoor heat exchanger and the throttling device, so that refrigerant discharged by the compressor does not flow through the indoor heat exchanger and enters the outdoor heat exchanger for defrosting.

On the other hand, the utility model adopts the following technical scheme:

a compressor, an outdoor heat exchanger, an indoor heat exchanger and a throttling device are arranged on a refrigerant flow path of the heat pump system, the heat pump system further comprises a bypass branch, the bypass branch can form a defrosting loop with the compressor and the outdoor heat exchanger, so that refrigerant discharged by the compressor does not flow through the indoor heat exchanger and enters the outdoor heat exchanger for defrosting, and a defrosting throttling element is further arranged on the defrosting loop.

The utility model provides a be provided with the bypass branch road among the heat pump system, the bypass branch road can form with compressor and outdoor heat exchanger and change the frost return circuit, thus, when the heat pump system operation changes the frost mode, can make compressor exhaust refrigerant not flow through indoor heat exchanger and get into outdoor heat exchanger and change the frost, thereby can effectively improve outdoor heat exchanger's heat exchange efficiency, because the refrigerant does not flow through indoor heat exchanger under changing the frost mode, consequently can open indoor auxiliary heating device and heat the indoor environment when changing the frost, guarantee to change the travelling comfort of indoor environment under the frost mode, can maintain the change frost effect of preferred simultaneously.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

fig. 1 is a schematic view illustrating a refrigerant flow direction of one of the air conditioning system structures in the cooling mode according to an embodiment of the present invention;

fig. 2 is a schematic view illustrating a refrigerant flow direction in a heating mode of one of the air conditioning system structures according to an embodiment of the present invention;

fig. 3 is a schematic view illustrating a refrigerant flow direction of one of the air conditioning system structures in a defrosting mode according to an embodiment of the present invention;

fig. 4 is a schematic view illustrating a refrigerant flow direction of a second air conditioning system structure in a defrosting mode according to an embodiment of the present invention;

fig. 5 is a schematic view illustrating a refrigerant flow direction of a third air conditioning system structure in a cooling mode according to an embodiment of the present invention;

fig. 6 is a schematic view illustrating a refrigerant flow direction of the third air conditioning system structure in the heating mode according to the embodiment of the present invention;

fig. 7 is a schematic view illustrating a refrigerant flow direction of the third air conditioning system structure in a defrosting mode according to an embodiment of the present invention;

fig. 8 is a schematic view illustrating the flow direction of the refrigerant in the defrosting mode of the air conditioning system according to the embodiment of the present invention;

fig. 9 is a schematic view illustrating the flow direction of refrigerant in the cooling mode of the fifth air conditioning system structure according to the embodiment of the present invention;

fig. 10 is a schematic view illustrating the flow direction of refrigerant in the fifth heating mode of the air conditioning system structure according to the embodiment of the present invention;

fig. 11 is a schematic view illustrating a refrigerant flow direction of the fifth air conditioning system structure in the defrosting mode according to an embodiment of the present invention;

fig. 12 is a schematic view illustrating a flow direction of refrigerant in a defrosting mode according to a sixth embodiment of the present invention;

fig. 13 is a schematic view illustrating a flow direction of refrigerant in the seventh cooling mode of the air conditioning system structure according to the embodiment of the present invention;

fig. 14 is a schematic view illustrating a refrigerant flow direction in a seventh heating mode of the air conditioning system structure according to an embodiment of the present invention;

fig. 15 is a schematic view illustrating a refrigerant flow direction of a seventh air conditioning system structure in a defrosting mode according to an embodiment of the present invention;

fig. 16 is a schematic view illustrating a refrigerant flow direction of an air conditioning system according to an embodiment of the present invention in a defrosting mode;

fig. 17 is a schematic view illustrating a flow direction of refrigerant in a cooling mode of an air conditioning system according to an embodiment of the present invention;

fig. 18 is a schematic view illustrating a flow direction of refrigerant in the heating mode of the air conditioning system according to the embodiment of the present invention;

fig. 19 is a schematic view illustrating a refrigerant flow direction of the air conditioning system structure in the defrosting thermal mode according to an embodiment of the present invention;

fig. 20 is a schematic view illustrating a refrigerant flow direction of the air conditioning system according to the embodiment of the present invention in the defrosting thermal mode.

In the figure, 1, a compressor; 2. a four-way valve; 3. a stop valve; 4. an indoor heat exchanger; 5. an indoor auxiliary heating device; 6. a stop valve; 7. a first electronic expansion valve; 8. an outdoor heat exchanger; 9. a first three-way valve; 10. a bypass branch; 11. a second electronic expansion valve; 12. a first two-way valve; 13. a second two-way valve; 14. a second three-way valve; 15. a throttling branch; 16. a third electronic expansion valve; 17. a third two-way valve; 18. a fourth two-way valve; 19. a third three-way valve; 20. a fifth two-way valve; 21. a sixth two-way valve.

Detailed Description

The present invention will be described below based on examples, but the present invention is not limited to only these examples. In the following detailed description of the present invention, certain specific details are set forth in detail. It will be apparent to those skilled in the art that the present invention may be practiced without these specific details. Well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.

Further, those of ordinary skill in the art will appreciate that the drawings provided herein are for illustrative purposes and are not necessarily drawn to scale.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, what is meant is "including, but not limited to".

In the description of the present invention, it is to be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

The utility model provides a heat pump system will use air conditioning system to describe the various embodiments of its structure as the example below, of course, can understand, it also can be applied to in other needs carry out the plant equipment of defrosting to outdoor heat exchanger, for example heat pump water heater etc..

As shown in fig. 1, the air conditioning system comprises a compressor 1, a four-way valve 2, an outdoor heat exchanger 8, an indoor heat exchanger 4 and a throttling device, so that the compressor 1, the four-way valve 2, the outdoor heat exchanger 8, the indoor heat exchanger 4 and the throttling device can form a refrigerant circulation loop of the air conditioning system, and heating and cooling of the air conditioning system are realized through the four-way valve 2. The air conditioning system further comprises an indoor auxiliary heating device 5 and a bypass branch 10, wherein the indoor auxiliary heating device 5 is used for performing auxiliary heating when the air conditioning system operates in a defrosting mode, and of course, it can be understood that when the air conditioning system operates in a heating mode and the heat supply to the indoor environment cannot meet the requirement, the indoor auxiliary heating device 5 can be turned on to perform auxiliary heating. Bypass branch 10 can form the return circuit of defrosting with compressor 1 and outdoor heat exchanger 8, so, when air conditioning system operation defrosting mode, can make compressor 1 exhaust refrigerant not flow through indoor heat exchanger 4 and get into outdoor heat exchanger 8 and defrost, thereby can effectively improve outdoor heat exchanger 8's defrosting efficiency, in addition, because the refrigerant does not flow through indoor heat exchanger 4 under the defrosting mode, can not form the condensation water on indoor heat exchanger 4's surface, consequently can open indoor auxiliary heating device 5 and heat indoor environment when defrosting, guarantee the travelling comfort of indoor environment under the defrosting mode, in addition, electrical safety has also been guaranteed.

The throttling device may be any structure capable of throttling the refrigerant, for example, the first electronic expansion valve 7 shown in fig. 1, or other throttling elements such as a capillary tube, a short tube, and an orifice plate.

One end of the bypass branch is positioned between the outdoor heat exchanger and the indoor heat exchanger, and the other end of the bypass branch is positioned between the compressor and the four-way valve or between the four-way valve and the indoor heat exchanger, so that the bypass branch, the compressor and the outdoor heat exchanger can conveniently form a defrosting loop. When the air conditioning system is switched from the heating mode to the defrosting mode, the four-way valve 2 can be switched or not, and the requirements can be met by reasonably setting the connection position of the bypass branch 10. When the air conditioning system is switched from the heating mode to the defrosting mode, if the four-way valve 2 needs to be reversed, the bypass branch is connected with the air suction pipeline of the compressor, and if the reversing is not needed, the bypass branch is connected with the exhaust pipeline of the compressor.

For example, in the embodiments shown in fig. 1 to 8, the four-way valve 2 needs to be reversed when the air conditioning system is switched from the heating mode to the defrosting mode, whereas in the embodiments shown in fig. 9 to 20, the reversing is not needed.

Various embodiments of an air conditioning system are described below in conjunction with fig. 1-20.

When the four-way valve 2 is required to be reversed during mode switching, the bypass branch 10 can communicate the suction pipeline of the compressor 1 in the cooling mode with the refrigerant outlet pipeline of the outdoor heat exchanger 8 in the cooling mode. Specifically, one end of the bypass branch 10 may be connected to a pipeline between the four-way valve 2 and the indoor heat exchanger 4 as shown in fig. 1, and in other embodiments, may be connected to a pipeline between a suction port of the compressor 1 and the four-way valve 2. The other end of the bypass branch 10 may be connected between the first electronic expansion valve 7 and the outdoor heat exchanger 8 as shown in fig. 1, so that the first electronic expansion valve 7 is located between the connection position of the bypass branch 10 and the refrigerant outlet pipeline of the outdoor heat exchanger 8 in the cooling mode and the indoor heat exchanger 4, or may be connected between the first electronic expansion valve 7 and the indoor heat exchanger 4 as shown in fig. 5, so that the first electronic expansion valve 7 is located between the connection position of the bypass branch 10 and the refrigerant outlet pipeline of the outdoor heat exchanger 8 in the cooling mode and the outdoor heat exchanger 8.

Preferably, when the other end of the bypass branch 10 is connected between the first electronic expansion valve 7 and the outdoor heat exchanger 8 as shown in fig. 1, a defrosting throttling element is disposed on the bypass branch 10, so as to ensure that, in a defrosting mode, the refrigerant flowing out of the outdoor heat exchanger 8 can be throttled and then return to the compressor 1, ensure the suction superheat degree of the compressor 1, and avoid the compressor 1 from generating a suction liquid-carrying phenomenon to affect the normal operation of the system. The defrosting throttle element may be any structure capable of throttling the refrigerant, and may be, for example, the second electronic expansion valve 11 shown in fig. 1, or other throttle elements such as a capillary tube, a short tube, and an orifice plate.

Further, the air conditioner further comprises a first switching device, which is used for switching and communicating the air suction pipeline of the compressor 1 in the cooling mode between the bypass branch 10 and the refrigerant inlet pipeline of the indoor heat exchanger 4 in the cooling mode, so as to realize switching between the heating mode and the defrosting mode. The first switching device can be a three-way valve, and the switching communication between the pipelines can also be realized through the combination of two-way valves.

Fig. 1 to 3 show a specific embodiment of an air conditioning system in which an indoor heat exchanger 4 and an indoor auxiliary heating device 5 are located in an indoor unit in which an indoor fan (not shown) is further provided. The outdoor heat exchanger 8, the four-way valve 2, the compressor 1, the first electronic expansion valve 7 and the bypass branch 10 are located in the outdoor unit, and two stop valves 3 and 6 are respectively arranged on two connecting pipelines of the indoor unit and the outdoor unit so as to facilitate the installation of the indoor unit and the outdoor unit.

A first three-way valve 9 is arranged among one end of the bypass branch 10, the four-way valve 2 and the indoor heat exchanger 4, a first port of the first three-way valve 9 is connected with the indoor heat exchanger 4, a second port is connected with the four-way valve 2, and a third port is connected with one end of the bypass branch 10. The other end of the bypass branch 10 is connected to a pipe between the outdoor heat exchanger 8 and the first electronic expansion valve 7. The bypass branch 10 is provided with a second electronic expansion valve 11. When the air conditioning system operates in a heating and cooling mode, the four-way valve 2 is communicated with the indoor heat exchanger 4 through the first three-way valve 9, and when the air conditioning system operates in a defrosting mode, the four-way valve 2 is communicated with the bypass branch 10 through the first three-way valve 9.

As shown in fig. 1, when the air conditioning system operates in the cooling mode, the refrigerant flow path is:

compressor 1 → four-way valve 2 → outdoor heat exchanger 8 → first electronic expansion valve 7 → indoor heat exchanger 4 → first three-way valve 9 → four-way valve 2 → compressor 1

As shown in fig. 2, when the air conditioning system is switched from the cooling mode to the heating mode, the four-way valve 2 is switched, and the flow path of the refrigerant is:

compressor 1 → four-way valve 2 → first three-way valve 9 → indoor heat exchanger 4 → first electronic expansion valve 7 → outdoor heat exchanger 8 → four-way valve 2 → compressor 1

As shown in fig. 3, when the air conditioning system needs defrosting, the four-way valve 2 is reversed, after the reversing, after the compressor 1 is started to operate for a predetermined time (for example, 0 to 60s), the first three-way valve 9 switches the communication position, so that the four-way valve 2 is communicated with the bypass branch 10, and at the same time, the indoor auxiliary heating device 5 is controlled to be turned on, and the indoor fan is controlled to operate at a predetermined rotation speed (normally, the indoor fan operates at a speed lower than a normal rotation speed, for example, the speed lower than 1000rpm, and a specific rotation speed can be determined according to the outlet air temperature), where the flow path of the:

compressor 1 → four-way valve 2 → outdoor heat exchanger 8 → bypass branch 10 (second electronic expansion valve 11) → first three-way valve 9 → four-way valve 2 → compressor 1

Thus, in the defrosting mode, the high-temperature and high-pressure refrigerant directly enters the outdoor heat exchanger 8 without flowing through the indoor heat exchanger 4 to be defrosted, and the indoor environment temperature is ensured by the indoor auxiliary heating device 5. When the tube temperature of the outdoor heat exchanger 8 reaches a predetermined value, for example, 25 to 45 ℃, the defrosting state is exited, and the indoor auxiliary heating device 5 and the indoor fan are restored to normal operation.

Fig. 4 shows another embodiment of the air conditioning system, in which the purpose of switching the pipe connection positions can also be achieved by using two-way valves instead of the first three-way valve 9 in the embodiment shown in fig. 1 to 3, i.e., a first two-way valve 12 disposed on the bypass branch 10 and a second two-way valve 13 disposed on the refrigerant inlet pipe of the indoor heat exchanger 4 in the cooling mode, for example, in the embodiment shown in fig. 4, the second two-way valve 13 is disposed between the four-way valve 2 and the indoor heat exchanger 4. When the air conditioning system operates in the heating and cooling mode, the first two-way valve 12 is closed, the second two-way valve 13 is opened, and when the air conditioning system operates in the defrosting mode, the first two-way valve 12 is opened, the second two-way valve 13 is closed, and the flow path of the refrigerant is similar to that of the embodiment shown in fig. 1 to 3, and is not described again here.

Fig. 5 to 7 show an embodiment of an air conditioning system, which is different from the embodiment shown in fig. 1 to 3 in that the other end of the bypass branch 10 is connected between the first electronic expansion valve 7 and the indoor heat exchanger 4, so that the first electronic expansion valve 7 can be shared by the defrosting circuit and the refrigerant circulation circuit, the second electronic expansion valve 11 is omitted, and the structure is simpler.

As shown in fig. 5, when the air conditioning system operates in the cooling mode, the refrigerant flow path is:

As shown in fig. 6, when the air conditioning system is switched from the cooling mode to the heating mode, the four-way valve is switched, and the flow path of the refrigerant is:

As shown in fig. 7, when the air conditioning system needs defrosting, the four-way valve 2 is reversed, after the reversing, and after the compressor 1 is started to operate for a predetermined time (for example, 0 to 60s), the first three-way valve 9 switches the communication position, so that the four-way valve 2 is communicated with the bypass branch 10, the indoor auxiliary heating device 5 is controlled to be turned on, and the indoor fan is controlled to operate at a predetermined rotation speed, and at this time, the flow path of the refrigerant is:

compressor 1 → four-way valve 2 → outdoor heat exchanger 8 → first electronic expansion valve 7 → bypass branch 10 → first three-way valve 9 → four-way valve 2 → compressor 1

Fig. 8 shows another embodiment of the air conditioning system, in which the purpose of switching the pipe connection positions can also be achieved by using two-way valves instead of the first three-way valve 9 in the embodiment shown in fig. 5 to 7, i.e., the two-way valves are respectively the first two-way valve 9 disposed on the bypass branch 10 and the second two-way valve 13 disposed on the refrigerant inlet pipe of the indoor heat exchanger 4 in the cooling mode, for example, in the embodiment shown in fig. 8, the second two-way valve 13 is disposed between the four-way valve 2 and the indoor heat exchanger 4. When the air conditioning system operates in the heating and cooling mode, the first two-way valve 12 is closed, the second two-way valve 13 is opened, and when the air conditioning system operates in the defrosting mode, the first two-way valve 12 is opened, the second two-way valve 13 is closed, and the flow path of the refrigerant is similar to that of the embodiment shown in fig. 5 to 7, and is not described again here.

In the case where the four-way valve 2 is not required to be reversed at the time of mode switching (of course, it is understood that the embodiments described below may also be applied to a single heating pump system without the four-way valve 2), the bypass branch 10 may communicate the discharge line of the compressor 1 with the refrigerant inlet line of the outdoor heat exchanger 8 in the heating mode, for example, the bypass branch 10 may communicate the discharge line of the compressor 1 in the heating mode with the refrigerant inlet line of the outdoor heat exchanger 8 in the heating mode. Specifically, one end of the bypass branch 10 may be connected to a pipeline between the compressor 1 and the four-way valve 2 as shown in fig. 9, or may be connected to a pipeline between the four-way valve 2 and the indoor heat exchanger 4, and the other end of the bypass branch 10 is connected between the first electronic expansion valve 7 and the outdoor heat exchanger 8. Under the condition that the four-way valve 2 is not required to be reversed, the compressor 1 is not required to be stopped, the defrosting of the air-conditioning system can be further facilitated, and the stability and the reliability of the system are ensured.

In the defrosting mode of the heat pump system, the throttling device may be disposed on the upstream side of the outdoor heat exchanger 8 as shown in fig. 15, 16, 19 and 20, or may be disposed on the downstream side of the outdoor heat exchanger 8 as shown in fig. 11 and 12, and when disposed on the downstream side, a throttling branch (described in detail later) needs to be disposed.

As shown in fig. 13 to 20, when the throttling means is disposed at the upstream side of the outdoor heat exchanger 8 in the defrosting mode, one end of the bypass branch 10 is connected to the discharge line of the compressor 1 in the heating mode, for example, it may be connected between the compressor 1 and the four-way valve 2, or between the four-way valve 2 and the indoor heat exchanger 4, the other end of the bypass branch 10 may be connected between the first electronic expansion valve 7 and the outdoor heat exchanger 8 as shown in fig. 13, the first electronic expansion valve 7 is located between the connection position of the bypass branch 10 and the refrigerant outlet pipeline of the outdoor heat exchanger 8 in the cooling mode and the indoor heat exchanger 4, or may be connected between the first electronic expansion valve 7 and the indoor heat exchanger 4 as shown in fig. 17, so that the first electronic expansion valve 7 is located between the connection position of the bypass branch 10 and the refrigerant outlet pipeline of the outdoor heat exchanger 8 in the cooling mode and the outdoor heat exchanger 8. The suction superheat degree of the compressor 1 is ensured, and the phenomenon that the compressor 1 sucks air and takes liquid to influence the normal operation of the system is avoided. The defrosting throttle element may have any structure capable of throttling the refrigerant, and may be, for example, the second electronic expansion valve 11 shown in fig. 13, or other throttle elements such as a capillary tube, a short tube, and an orifice plate.

Further, the air conditioner further comprises a third switching device, which is used for switching and communicating an exhaust pipeline of the compressor 1 in the heating mode between the bypass branch 10 and a refrigerant inlet pipeline of the indoor heat exchanger 4 in the heating mode to realize switching between the heating mode and the defrosting mode, wherein the third switching device can be a three-way valve, and can also realize switching and communicating between the pipelines through combination of two-way valves.

Fig. 13 to 15 show an embodiment of an air conditioning system, in which a third three-way valve 19 is disposed between one end of the bypass 10, the four-way valve 2, and the compressor 1, a first port of the third three-way valve 19 is connected to one end of the bypass 10, a second port is connected to the four-way valve 2, and a third port is connected to an exhaust port of the compressor 1. The other end of the bypass branch 10 is connected to a pipe between the outdoor heat exchanger 8 and the first electronic expansion valve 7. The bypass branch 10 is provided with a second electronic expansion valve 11. The third three-way valve 19 communicates the compressor 1 with the four-way valve 2 when the air conditioning system operates in heating and cooling modes, and the third three-way valve 19 communicates the compressor 1 with the bypass branch 10 when the air conditioning system operates in defrosting mode.

As shown in fig. 13, when the air conditioning system operates in the cooling mode, the refrigerant flow path is:

compressor 1 → third three-way valve 19 → four-way valve 2 → outdoor heat exchanger 8 → first electronic expansion valve 7 → indoor heat exchanger 4 → four-way valve 2 → compressor 1

As shown in fig. 14, when the air conditioning system is switched from the cooling mode to the heating mode, the four-way valve 2 is switched, and the refrigerant flow path is:

compressor 1 → third three-way valve 19 → four-way valve 2 → indoor heat exchanger 4 → first electronic expansion valve 7 → outdoor heat exchanger 8 → four-way valve 2 → compressor 1

As shown in fig. 15, when the air conditioning system needs defrosting, the four-way valve 2 is not reversed, the third three-way valve 19 switches the communication position, so that the compressor 1 is communicated with the bypass branch 10, the indoor auxiliary heating device 5 is controlled to be turned on, and the indoor fan is controlled to operate at a predetermined rotation speed, and at this time, the flow path of the refrigerant is:

compressor 1 → third three-way valve 19 → bypass branch 10 (second electronic expansion valve 11) → outdoor heat exchanger 8 → four-way valve 2 → compressor 1

Fig. 16 shows another embodiment of the air conditioning system, in which the purpose of switching the pipe connection positions is also achieved by using two-way valves, namely, a fifth two-way valve 20 disposed on the refrigerant inlet pipe of the indoor heat exchanger 4 in the heating mode and a sixth two-way valve 21 disposed on the bypass branch 10, instead of the third three-way valve 19 in the embodiment shown in fig. 13 to 15, for example, in the embodiment shown in fig. 16, the fifth two-way valve 20 is disposed between the four-way valve 2 and the indoor heat exchanger 4. When the air conditioning system operates in the heating and cooling mode, the fifth two-way valve 20 is opened, the sixth two-way valve 21 is closed, when the air conditioning system operates in the defrosting mode, the fifth two-way valve 20 is closed, the sixth two-way valve 21 is opened, and a flow path of a refrigerant is similar to that in the embodiment shown in fig. 13 to 15, and is not described again here.

Fig. 17 to 19 illustrate an embodiment of an air conditioning system, which is different from the embodiment illustrated in fig. 13 to 15 in that the other end of the bypass branch 10 is connected between the first electronic expansion valve 7 and the indoor heat exchanger 4, so that the first electronic expansion valve 7 can be shared by the defrosting circuit and the refrigerant circulation circuit, the second electronic expansion valve 11 is omitted, and the structure is simpler.

As shown in fig. 17, when the air conditioning system operates in the cooling mode, the refrigerant flow path is:

As shown in fig. 18, when the air conditioning system is switched from the cooling mode to the heating mode, the four-way valve 2 is switched, and the refrigerant flow path is:

As shown in fig. 19, when the air conditioning system needs defrosting, the four-way valve 2 is not reversed, the third three-way valve 19 switches the communication position, so that the compressor 1 is communicated with the bypass branch 10, the indoor auxiliary heating device 5 is controlled to be turned on, and the indoor fan is controlled to operate at a predetermined rotation speed, and at this time, the flow path of the refrigerant is:

compressor 1 → third three-way valve 19 → bypass branch 10 → first electronic expansion valve 7 → outdoor heat exchanger 8 → four-way valve 2 → compressor 1

Fig. 20 shows another embodiment of an air conditioning system, in which the purpose of switching the pipe connection positions is also achieved by using two-way valves instead of the third three-way valve in the embodiment shown in fig. 17 to 19, that is, a fifth two-way valve 20 disposed on the refrigerant inlet pipe of the indoor heat exchanger 4 in the heating mode and a sixth two-way valve 21 disposed on the bypass branch 10, for example, in the embodiment shown in fig. 16, the fifth two-way valve 20 is disposed between the four-way valve 2 and the indoor heat exchanger 4. When the air conditioning system operates in the heating and cooling mode, the fifth two-way valve 20 is opened, the sixth two-way valve 21 is closed, and when the air conditioning system operates in the defrosting mode, the fifth two-way valve 20 is closed, the sixth two-way valve 21 is opened, and a flow path of a refrigerant is similar to that in the embodiment shown in fig. 17 to 19, and is not described again here.

As shown in fig. 9 to 12, when the throttling device is disposed on the downstream side of the outdoor heat exchanger 8 in the defrosting mode, preferably, the heat pump system further includes a throttling branch 15, a defrosting throttling element is disposed on the throttling branch 15, and the throttling branch 15 can communicate a refrigerant outlet pipeline of the outdoor heat exchanger 8 in the heating mode with a suction port of the compressor 1, so that the refrigerant flowing out of the outdoor heat exchanger 8 can be throttled when the outdoor heat exchanger 8 is defrosted, thereby ensuring a suction superheat degree of the compressor 1 and avoiding the compressor 1 from generating a suction liquid carrying phenomenon to affect the normal operation of the system. The defrosting throttle element may have any structure capable of throttling the refrigerant, and may be, for example, the third electronic expansion valve 16 shown in fig. 9, or may be another throttle element such as a capillary tube, a short tube, or an orifice plate.

Further, the air conditioner further comprises a second switching device, wherein the second switching device is used for switching and communicating the refrigerant outlet pipeline of the outdoor heat exchanger 8 in the heating mode between the suction pipeline and the throttling branch 15 of the compressor 1 in the heating mode, so that the heating mode and the defrosting mode are switched. The second switching device can be a three-way valve, and the switching communication between the pipelines can also be realized through the combination of two-way valves.

Fig. 9 to 11 show a specific embodiment of an air conditioning system in which an indoor heat exchanger 4 and an indoor auxiliary heating apparatus 5 are located in an indoor unit in which an indoor fan is further provided. The outdoor heat exchanger 8, the four-way valve 2, the compressor 1, the first electronic expansion valve 7, the bypass branch 10 and the throttling branch 15 are positioned in the outdoor unit, and two stop valves 3 and 6 are respectively arranged on two connecting pipelines of the indoor unit and the outdoor unit so as to facilitate the installation of the indoor unit and the outdoor unit.

A third three-way valve 19 is arranged among one end of the bypass branch 10, the four-way valve 2 and the exhaust port of the compressor 1, a first port of the third three-way valve 19 is connected with the four-way valve 2, a second port is connected with the exhaust port of the compressor 1, and a third port is connected with one end of the bypass branch 10. The other end of the bypass branch 10 is connected to a pipe between the outdoor heat exchanger 8 and the first electronic expansion valve 7. A second three-way valve 14 is arranged among the outdoor heat exchanger 8, the four-way valve 2 and one end of the throttling branch 15, a first port of the second three-way valve 14 is connected with the outdoor heat exchanger 8, a second port is connected with the four-way valve 2, a third port is connected with one end of the throttling branch 15, and the other end of the throttling branch 15 is connected with an air suction port of the compressor 1. A third electronic expansion valve 16 is arranged on the throttle branch 15.

As shown in fig. 9, when the air conditioning system operates in the cooling mode, the refrigerant flow path is:

compressor 1 → third three-way valve 19 → four-way valve 2 → second three-way valve 14 → outdoor heat exchanger 8 → first electronic expansion valve 7 → indoor heat exchanger 4 → four-way valve 2 → compressor 1

As shown in fig. 10, when the air conditioning system is switched from the cooling mode to the heating mode, the four-way valve is switched, and the flow path of the refrigerant is:

compressor 1 → third three-way valve 19 → four-way valve 2 → indoor heat exchanger 4 → first electronic expansion valve 7 → outdoor heat exchanger 8 → second three-way valve 14 → four-way valve 2 → compressor 1

As shown in fig. 11, when the air conditioning system needs defrosting, the four-way valve 2 is not reversed, the compressor 1 is not stopped, the third three-way valve 19 and the second three-way valve 14 switch the communication position, so that the exhaust port of the compressor 1 is communicated with the outdoor heat exchanger 8, the air inlet of the compressor 1 is communicated with the throttling branch 15, the indoor auxiliary heating device 5 is controlled to be turned on, and the indoor fan is controlled to operate at a predetermined rotation speed, and at this time, the flow path of the refrigerant is:

compressor 1 → third three-way valve 19 → outdoor heat exchanger 8 → second three-way valve 14 → throttle branch 15 (third electronic expansion valve 16) → compressor 1

Fig. 12 shows another embodiment of the air conditioning system, in which the third three-way valve 19 in the embodiment of fig. 9 to 11 is replaced by two-way valves, and the second three-way valve 14 in the embodiment of fig. 9 to 11 is replaced by two-way valves, and the purpose of switching the pipe connection position can also be achieved by providing a sixth two-way valve 21 in the bypass branch 10, a fifth two-way valve 20 in the pipe between the four-way valve 2 and the indoor heat exchanger 4, and a third two-way valve 17 in the suction pipe of the compressor 1 in the heating mode, for example, in the embodiment of fig. 12, the third two-way valve 17 is provided in the pipe between the four-way valve 2 and the outdoor heat exchanger 8, and the fourth two-way valve 18 is provided in the throttle branch 15. When the air conditioning system operates in the heating and cooling modes, the sixth two-way valve 21 and the fourth two-way valve 18 are closed, and the fifth two-way valve 20 and the third two-way valve 17 are opened, whereas when the air conditioning system operates in the defrosting mode, the sixth two-way valve 21 and the fourth two-way valve 18 are opened, and the fifth two-way valve 20 and the third two-way valve 17 are closed.

Those skilled in the art will readily appreciate that the above-described preferred embodiments may be freely combined, superimposed, without conflict.

It will be understood that the above-described embodiments are illustrative only and not restrictive, and that various obvious and equivalent modifications and substitutions may be made in the details described herein by those skilled in the art without departing from the basic principles of the invention.

Claims

1. The heat pump system is characterized in that a compressor, an outdoor heat exchanger, an indoor heat exchanger and a throttling device are arranged on a refrigerant flow path of the heat pump system, the heat pump system further comprises an indoor auxiliary heating device and a bypass branch, the indoor auxiliary heating device and the bypass branch are arranged, when the heat pump system operates in a defrosting mode, the indoor auxiliary heating device operates to heat, the bypass branch, the compressor and the outdoor heat exchanger form a defrosting loop, and refrigerant discharged by the compressor does not flow through the indoor heat exchanger and enters the outdoor heat exchanger to be defrosted.

2. The heat pump system of claim 1, further comprising a four-way valve, wherein one end of the bypass path is located between the outdoor heat exchanger and the indoor heat exchanger, and the other end of the bypass path is located between the compressor and the four-way valve or between the four-way valve and the indoor heat exchanger.

3. The heat pump system of claim 1, further comprising a four-way valve that reverses direction when the heat pump system switches from a heating mode to a defrosting mode;

4. The heat pump system as claimed in claim 3, further comprising a first switching device for switching communication between the suction line of the compressor in the cooling mode and the refrigerant inlet line of the indoor heat exchanger in the cooling mode.

5. The heat pump system of claim 4, wherein the first switching device comprises a first three-way valve; or,

6. The heat pump system according to any one of claims 3 to 5, wherein the throttling device is disposed between a connection position of the bypass branch and the refrigerant outlet pipeline of the outdoor heat exchanger in the cooling mode and the outdoor heat exchanger; or,

7. The heat pump system of claim 1, wherein the bypass branch is configured to communicate a discharge line of the compressor with a refrigerant inlet line of the outdoor heat exchanger in the heating mode.

8. The heat pump system of claim 7, further comprising a four-way valve that does not reverse when the heat pump system switches from a heating mode to a defrosting mode;

9. The heat pump system according to claim 8, wherein the throttling device is disposed between a connection position of the bypass branch and the refrigerant outlet pipeline of the outdoor heat exchanger in the cooling mode and the outdoor heat exchanger; or,

10. The heat pump system according to claim 7, further comprising a throttling branch, wherein a defrosting throttling element is disposed on the throttling branch, and the throttling branch is capable of communicating a refrigerant outlet pipeline of the outdoor heat exchanger in the heating mode with a suction port of the compressor, so as to throttle refrigerant flowing out of the outdoor heat exchanger when defrosting the outdoor heat exchanger.

11. The heat pump system as claimed in claim 10, further comprising a second switching device for switching communication of the refrigerant outlet line of the outdoor heat exchanger in the heating mode between the suction line of the compressor in the heating mode and the throttle branch.

12. The heat pump system of claim 11, wherein the second switching device comprises a second three-way valve; or,

13. The heat pump system according to any one of claims 7 to 12, further comprising a third switching device for switching communication of a discharge line of the compressor in the heating mode between the bypass branch and a refrigerant inlet line of the indoor heat exchanger in the heating mode.

14. The heat pump system of claim 13, wherein the third switching device comprises a third three-way valve; or,

15. The heat pump system is characterized in that a compressor, an outdoor heat exchanger, an indoor heat exchanger and a throttling device are arranged on a refrigerant flow path of the heat pump system, and the heat pump system further comprises a bypass branch which can form a defrosting loop with the compressor, the outdoor heat exchanger and the throttling device, so that refrigerant discharged by the compressor does not flow through the indoor heat exchanger and enters the outdoor heat exchanger for defrosting.

16. The heat pump system is characterized in that a compressor, an outdoor heat exchanger, an indoor heat exchanger and a throttling device are arranged on a refrigerant flow path of the heat pump system, the heat pump system further comprises a bypass branch, the bypass branch can form a defrosting loop with the compressor and the outdoor heat exchanger, so that refrigerant discharged by the compressor does not flow through the indoor heat exchanger and enters the outdoor heat exchanger for defrosting, and a defrosting throttling element is further arranged on the defrosting loop.