CN117847707A

CN117847707A - Defrosting control method for air conditioner

Info

Publication number: CN117847707A
Application number: CN202211214209.9A
Authority: CN
Inventors: 王江南; 张恒; 董辰; 刘心怡
Original assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Current assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Priority date: 2022-09-30
Filing date: 2022-09-30
Publication date: 2024-04-09

Abstract

The invention discloses a defrosting control method of an air conditioner, which relates to the technical field of air conditioners and can improve the comfort of users at least to a certain extent. An indoor unit having an indoor heat exchanger; an outdoor unit including an outdoor heat exchanger including a first portion and a second portion; the indoor heat exchanger is connected with the outdoor heat exchanger through a gas side piping and a liquid side piping; judging whether the air conditioner meets a defrosting condition or not when the air conditioner operates in a heating mode; if yes, controlling the air conditioner to operate in a first defrosting mode or a second defrosting mode, wherein the first defrosting mode is refrigerant sensible heat defrosting, the second defrosting mode is refrigerant waste heat defrosting, and the first defrosting mode and the second defrosting mode are not performed simultaneously.

Description

Defrosting control method for air conditioner

Technical Field

The invention relates to the technical field of air conditioners, in particular to a defrosting control method of an air conditioner.

Background

When the air conditioner performs heating operation, the outdoor heat exchanger component can frost after the temperature and the humidity of the external environment reach certain conditions. In the related art, an air conditioner defrost an outdoor heat exchanger assembly in a reverse defrosting mode, and a refrigerant discharged from a compressor is supplied to the outdoor heat exchanger assembly by flowing the refrigerant in heating in a reverse direction, so that the outdoor heat exchanger assembly is defrosted by using heat of the compressor. When in reverse defrosting, the air conditioner stops heating the room, and the indoor heat exchanger is required to absorb a part of heat from the room, so that the indoor temperature is reduced, the indoor thermal comfort is seriously affected, and the use experience of a user is reduced.

Disclosure of Invention

The embodiment of the invention provides a defrosting control method for an air conditioner, which can improve the comfort of a user at least to a certain extent.

In order to achieve the above purpose, the embodiment of the present invention adopts the following technical scheme:

the embodiment of the application provides a defrosting control method of an air conditioner,

the air conditioner includes: an indoor unit having an indoor heat exchanger;

an outdoor unit including an outdoor heat exchanger including a first portion and a second portion;

the indoor heat exchanger is connected with the outdoor heat exchanger through a gas side piping and a liquid side piping;

judging whether the air conditioner meets a defrosting condition or not when the air conditioner operates in a heating mode;

if yes, controlling the air conditioner to operate in a first defrosting mode or a second defrosting mode, wherein the first defrosting mode is refrigerant sensible heat defrosting, the second defrosting mode is refrigerant waste heat defrosting, and the first defrosting mode and the second defrosting mode are not performed simultaneously.

Drawings

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

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

Fig. 3 is a schematic diagram of a cooling mode of an air conditioner according to a first embodiment of the present application;

fig. 4 is a schematic diagram of a refrigeration mode of an air conditioner according to a second embodiment of the present application;

fig. 5 is a schematic diagram of an air conditioner heating mode according to a first embodiment of the present application;

fig. 6 is a schematic diagram of an air conditioner heating mode according to a second embodiment of the present application;

fig. 7 is a schematic view of an air conditioner according to a first embodiment of the present application defrosting a first portion;

fig. 8 is a schematic diagram of a defrosting of a first portion of an air conditioner according to a second embodiment of the present disclosure;

fig. 9 is a schematic diagram of an air conditioner according to a first embodiment of the present application defrosting a second portion;

fig. 10 is a schematic diagram of an air conditioner according to a second embodiment of the present application defrosting a second portion;

fig. 11 is a flowchart of a first defrosting control method of an air conditioner according to an embodiment of the present application;

fig. 12 is a flowchart of a second defrosting control method for an air conditioner according to an embodiment of the present application.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate description of the present invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

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 or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In order to solve the technical problem, the application is improved from the aspect of still keeping the use state of the indoor heat exchanger as a condenser when defrosting the outdoor heat exchanger assembly. Specifically, the outdoor heat exchanger assembly comprises the first part and the second part which are arranged in parallel, when the air conditioner defrost the first part, a defrosting branch is utilized to bypass a part of refrigerant at the exhaust port of the compressor to the first part for defrosting, and at the moment, the second part can serve as an evaporator to continuously ensure the heating cycle of the air conditioner. When the air conditioner is used for defrosting the second part, the second part can be defrosted by utilizing the latent heat of the high-pressure medium-temperature refrigerant flowing out of the indoor heat exchanger, and at the moment, the first part can be used as an evaporator to continuously ensure the heating cycle of the air conditioner. Therefore, the defrosting of the first part and the second part in turn can be realized, the indoor heating state of the indoor heat exchanger is still ensured, the influence on the indoor temperature in the defrosting process of the air conditioner can be avoided, the indoor temperature can be kept in a high-temperature state, and the comfort of a user is improved. And the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port of the compressor is utilized to defrost the first part, so that the defrosting effect is obvious. And the second part is defrosted by utilizing the high-pressure medium-temperature refrigerant flowing out of the indoor heat exchanger, so that the defrosting effect is obvious. Therefore, by means of a defrosting mode combining low-pressure sensible heat and high-pressure waste heat, the advantages of waste heat defrosting and sensible heat defrosting can be utilized, meanwhile, the problems of serious waste of waste heat defrosting capacity, poor sensible heat defrosting reliability and narrow applicable working conditions can be avoided, and the defrosting speed and reliability of the air conditioner can be improved to a certain extent.

The air conditioner according to the embodiment of the present application will be described below.

Referring to fig. 1 and 2, fig. 1 is a schematic diagram of an air conditioner according to a first embodiment of the present application, and fig. 2 is a schematic diagram of an air conditioner according to a second embodiment of the present application. The embodiment of the application provides an air conditioner 100, including: a compressor 1, a reversing assembly 2, an indoor heat exchanger 3, an outdoor heat exchanger assembly 4, a defrost branch 5 and a bypass branch 6.

Specifically, the indoor machine is provided with an indoor heat exchanger 3, the outdoor machine comprises an outdoor heat exchanger assembly 4, the outdoor heat exchanger assembly 4 comprises a first part 41 and a second part 42, the indoor heat exchanger 3 and the outdoor heat exchanger assembly 4 are connected through an air side piping and a liquid side piping, and when the air conditioner operates in a heating mode, whether the air conditioner meets a defrosting condition is judged; if yes, controlling the air conditioner to operate in a first defrosting mode or a second defrosting mode, wherein the first defrosting mode is refrigerant sensible heat defrosting, the second defrosting mode is refrigerant waste heat defrosting, and the first defrosting mode and the second defrosting mode are not performed simultaneously.

During sensible heat defrosting of the refrigerant, the refrigerant is discharged from the compressor 1 and directly enters the first portion 41, and the sensible heat of the high-temperature high-pressure gaseous refrigerant is utilized to defrost; the refrigerant waste heat defrosting is to make the refrigerant insufficiently exchange heat by stopping the fan or the breeze operation of the fan by utilizing the refrigerant flowing through the indoor heat exchanger, so that the refrigerant insufficiently exchanged heat flows through the second part to defrost the second part.

Specifically, in order to realize switching of the above two defrosting modes, when the first portion uses sensible heat of the refrigerant to defrost, the first portion 41 and the second portion 42 are controlled to be connected in parallel. When the second portion 42 is defrosted using the residual heat of the refrigerant, the first portion 41 and the second portion 42 are connected in series.

Specifically, in order to realize the effect of heating without cooling during defrosting, the device further comprises: an outdoor fan disposed at one side of the outdoor heat exchanger; when the first portion 41 uses sensible heat of the refrigerant to defrost, the outdoor fan is controlled to operate so as to improve the evaporation capacity of the first portion 41.

And, further comprising: an indoor fan provided at one side of the indoor heat exchanger 3; when the second portion 42 uses the residual heat of the refrigerant to defrost, the indoor fan is controlled to stop, and the residual heat of the refrigerant defrost is sensible heat and latent heat defrost; or controlling the indoor fan to operate at the speed not lower than the upper limit rotation speed, and defrosting the residual heat of the refrigerant to be sensible heat defrosting.

Wherein the indoor fan is operated at not lower than the upper limit rotation speed, and can be operated by breeze. The supercooling degree of the liquid refrigerant after the refrigerant passes through the indoor unit can be controlled by controlling the fan, when the fan operates with breeze, the refrigerant is supercooled liquid refrigerant, the residual heat defrosting of the refrigerant is sensible heat defrosting,

In another embodiment, the second portion 42 is configured to defrost by utilizing the residual heat of the refrigerant, and the indoor unit is stopped, and the residual heat of the refrigerant may be used for sensible heat defrosting, or the residual heat of the refrigerant may be used for sensible heat and latent heat defrosting when the indoor fan is not lower than the upper limit rotation speed.

With continued reference to fig. 1, the compressor 1 has an intake 11 and an exhaust 12. Specifically, the suction port 11 of the compressor 1 is used for sucking air, the refrigerant enters the compression chamber of the compressor 1 through the suction port 11 to be compressed, a high-temperature and high-pressure refrigerant is formed, and the high-temperature and high-pressure refrigerant gas is discharged from the discharge port 12 of the compressor 1 to the compressor 1, and then enters the air conditioner 100 to circulate the refrigerant.

By way of example, the compressor 1 may be a scroll compressor, a rotor compressor, a screw compressor or other type of compressor.

With continued reference to fig. 1, the reversing assembly 2 has a first port 21, a second port 22, a third port 23, and a fourth port 24. The first valve port 21 is connected to the exhaust port 12. The fourth port 24 is connected to the suction port 11. The first valve port 21 may be in reverse communication with one of the second valve port 22 and the third valve port 23, and the fourth valve port 24 may be in reverse communication with the other of the second valve port 22 and the third valve port 23. That is, when the first valve port 21 is in conduction with the second valve port 22, the third valve port 23 is in conduction with the fourth valve port 24; when the first port 21 is in communication with the third port 23, the second port 22 is in communication with the fourth port 24.

Illustratively, the reversing assembly 2 may be a four-way reversing valve. The four-way reversing valve can have two states of opening and closing, when the four-way reversing valve is powered on, the four-way reversing valve is opened, the first valve port 21 is communicated with the second valve port 22, and the third valve port 23 is communicated with the fourth valve port 24; when the four-way reversing valve is powered off, the four-way reversing valve is closed, the first valve port 21 is communicated with the third valve port 23, and the second valve port 22 is communicated with the fourth valve port 24. Of course, it will be appreciated that in other examples, when the four-way reversing valve is de-energized, the first port 21 is in communication with the second port 22, and the third port 23 is in communication with the fourth port 24; when the four-way reversing valve is electrified, the first valve port 21 is communicated with the third valve port 23, and the second valve port 22 is communicated with the fourth valve port 24.

With continued reference to fig. 1, the first end of the indoor heat exchanger 3 is connected to the second valve port 22.

With continued reference to fig. 1, the outdoor heat exchanger assembly 4 includes a first portion 41 and a second portion 42. The first end of the first portion 41 is connected to the third valve opening 23. The first end of the second portion 42 is connected to the third valve port 23 with a first on-off valve 45 connected in series therebetween. The first on-off valve 45 may be used to control the on-off between the first end of the second portion 42 and the third valve port 23.

Therefore, the first end of the first portion 41 may be in communication with the third valve opening 23, and the on-off between the second portion 42 and the third valve opening 23 may be controlled by the first on-off valve 45, which is beneficial to improving the reliability of the air conditioner 100.

With continued reference to fig. 1, a first throttle valve 43 is connected between the second end of the first portion 41 and the second end of the indoor heat exchanger 3. The first throttle valve 43 may serve to throttle and depressurize the refrigerant flowing therethrough. The first throttle valve 43 may also function to control the on-off between the second end of the first portion 41 and the second end of the indoor heat exchanger 3. That is, the opening degree of the first throttle valve 43 is adjustable. The first throttle valve 43 may have a full open state (opening degree is 100%), a full closed state (opening degree is 0), and a throttle state (opening degree is between 0 to 100%). In the fully closed state of the first throttle valve 43, the second end of the first portion 41 is not in communication with the second end of the indoor heat exchanger 3. In the fully opened state and the throttled state of the first throttle valve 43, the second end of the first portion 41 is in communication with the second end of the indoor heat exchanger 3, and in the throttled state, the first throttle valve 43 can throttle and depressurize the refrigerant flowing therethrough.

A second throttle valve 44 is connected between the second end of the second portion 42 and the second end of the indoor heat exchanger 3. The second throttle valve 44 may serve to throttle and depressurize the refrigerant flowing therethrough. The second throttle valve 44 may also function to control the on-off between the second end of the second portion 42 and the second end of the indoor heat exchanger 3. That is, the opening degree of the second throttle valve 44 is adjustable. The second throttle valve 44 may have a full open state (opening degree is 100%), a full closed state (opening degree is 0), and a throttle state (opening degree is between 0 to 100%). In the fully closed state of the second throttle valve 44, the second end of the second portion 42 is not in communication with the second end of the indoor heat exchanger 3. In the fully opened state and the throttled state of the first portion 41, the second end of the second portion 42 is in communication with the second end of the indoor heat exchanger 3, and in the throttled state, the second throttle valve 44 may throttle and depressurize the refrigerant flowing therethrough.

Thus, the opening/closing of the first throttle valve 43 can be controlled to open/close the second end of the first portion 41 and the second end of the indoor heat exchanger 3, and the refrigerant flowing through the first throttle valve 43 can be throttled and depressurized by controlling the opening/closing of the first throttle valve 43. The opening and closing of the second throttle valve 44 can be controlled to control the on-off between the second end of the second portion 42 and the second end of the indoor heat exchanger 3, and the refrigerant flowing through the first throttle valve 43 can be throttled and depressurized by controlling the opening degree of the first throttle valve 43. Thereby contributing to the improvement of stability and reliability of the air conditioner 100.

With continued reference to fig. 1, the first end of the defrost branch 5 is connected to the exhaust port 12. A second end of the defrost branch 5 is connected to a line between the first throttle valve 43 and the second end of the first portion 41. The defrosting branch 5 is connected with a second on-off valve 51 in series. The second on-off valve 51 can control the on-off of the defrost branch 5. It will be appreciated that the second end of the defrost branch 5 is located between the first throttle valve 43 and the second end of the first portion 41, and the refrigerant in the defrost branch 5 can avoid the first throttle valve 43 to directly enter the first portion 41, so that the first throttle valve 43 can be prevented from affecting the state of the refrigerant on the defrost branch 5, and thus the state of the refrigerant on the defrost branch 5 at high temperature and high pressure can be ensured. In addition, when frost is present on the first portion 41, the second switching valve 51 may be controlled to be opened so that the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 may enter the first portion 41 along the defrost branch 5, thereby defrosting the first portion 41 using sensible heat of the discharge of the compressor 1. Meanwhile, when the first part 41 is not required to defrost, the second on-off valve 51 can be controlled to be closed, so that the high-temperature and high-pressure gaseous refrigerant discharged from the air outlet 12 can be prevented from flowing to the defrosting branch 5, thereby influencing the normal operation of the air conditioner 100 and being beneficial to improving the operation reliability of the air conditioner 100.

With continued reference to fig. 1, the first end of the bypass branch 6 is connected to the first end of the second portion 42. The second end of the bypass branch 6 is connected to the line between the first throttle 43 and the second end of the first part 41. A third throttle 61 is connected in series to the bypass branch 6. The third throttle valve 61 may function to throttle and depressurize the refrigerant flowing therethrough. The third throttle 61 may also function to control the on-off between the first end of the second portion 42 and the second end of the first portion 41. That is, the opening degree of the third throttle valve 61 is adjustable. The third throttle valve 61 may have a full open state (opening degree is 100%), a full closed state (opening degree is 0), and a throttle state (opening degree is between 0 to 100%). In the fully closed state of the third throttle 61, there is no conduction between the first end of the second portion 42 and the second end of the first portion 41. In the fully opened state and the throttled state of the first portion 41, the first end of the second portion 42 is in communication with the second end of the first portion 41, and in the throttled state, the third throttle valve 61 may throttle and depressurize the refrigerant flowing therethrough.

The air conditioner 100 according to the embodiment of the present application has a cooling mode, a heating mode, and a defrosting mode. The control process and the flow direction of the refrigerant in the cooling mode, the heating mode and the defrosting mode according to the embodiment of the present application are described in detail below.

Refrigeration mode

Referring to fig. 3 and fig. 4, fig. 3 is a schematic diagram of a cooling mode of an air conditioner according to a first embodiment of the present application, and fig. 4 is a schematic diagram of a cooling mode of an air conditioner according to a second embodiment of the present application. When the air conditioner 100 is in the cooling mode, the first valve port 21 of the reversing assembly 2 is communicated with the third valve port 23, the second valve port 22 is communicated with the fourth valve port 24, the first on-off valve 45 is opened, the second on-off valve 51 is disconnected, the first throttle valve 43 is throttled, the second throttle valve 44 is throttled, and the third throttle valve 61 is fully closed.

The flow direction of the refrigerant is as follows: the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the reversing assembly 2 through the first valve port 21, and flows out of the reversing assembly 2 through the third valve port 23. The refrigerant flowing out of the third valve 23 flows into the first portion 41 and the second portion 42, respectively, and is sufficiently heat-exchanged in the first portion 41 and the second portion 42 to become a high-pressure supercooled liquid refrigerant. Then, the refrigerant flowing out of the first portion 41 flows through the first throttle valve 43 to be throttled down, and the refrigerant flowing out of the second portion 42 flows through the second throttle valve 44 to be throttled down. The refrigerant throttled and depressurized by the first throttle valve 43 and the refrigerant throttled and depressurized by the second throttle valve 44 flow into the indoor heat exchanger 3, and are changed into low-temperature and low-pressure overheated gaseous refrigerant after heat exchange by the indoor heat exchanger 3, and finally flow back to the air suction port 11 of the compressor 1 through the second valve port 22 and the fourth valve port 24 in sequence, so that the refrigeration cycle of the air conditioner 100 is completed.

Heating mode

Referring to fig. 5 and 6, fig. 5 is a schematic diagram of an air conditioner heating mode according to a first embodiment of the present application, and fig. 6 is a schematic diagram of an air conditioner heating mode according to a second embodiment of the present application. When the air conditioner 100 is in the heating mode, the first valve port 21 and the second valve port 22 of the control reversing assembly 2 are communicated, the third valve port 23 and the fourth valve port 24 are communicated, the first on-off valve 45 is opened, the second on-off valve 51 is disconnected, the first throttle valve 43 is throttled, the second throttle valve 44 is throttled, and the third throttle valve 61 is fully closed.

The flow direction of the refrigerant is as follows: the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the reversing assembly 2 through the first valve port 21, and flows out of the reversing assembly 2 through the second valve port 22. The refrigerant flowing out of the second valve port 22 flows into the indoor heat exchanger 3, is changed into a high-temperature high-pressure liquid refrigerant after heat exchange in the indoor heat exchanger 3, then flows out of the indoor heat exchanger 3 and flows into the first throttle valve 43 and the second throttle valve 44 respectively, and the refrigerant throttled and depressurized by the first throttle valve 43 flows into the first portion 41 and is evaporated into a low-temperature low-pressure superheated gaseous refrigerant in the first portion 41. The refrigerant throttled and depressurized by the second throttle valve 44 flows into the second portion 42, evaporates into a low-temperature low-pressure superheated gaseous refrigerant in the second portion 42, and finally flows out of the first portion 41 and the second portion 42 to flow back to the suction port 11 of the compressor 1 through the third valve port 23 and the fourth valve port 24 in sequence, thereby completing the heating cycle of the air conditioner 100.

Defrosting mode

Referring to fig. 7 and 8, fig. 7 is a schematic diagram of an air conditioner for defrosting a first portion according to a first embodiment of the present application, and fig. 8 is a schematic diagram of an air conditioner for defrosting a first portion according to a second embodiment of the present application. When defrosting the first part 41, the first valve port 21 and the second valve port 22 of the reversing assembly 2 are controlled to be communicated, the third valve port 23 and the fourth valve port 24 are controlled to be communicated, the first throttle valve 43 is controlled to be fully closed, the second throttle valve 44 is controlled to be throttled, the first on-off valve 45 is opened, the second on-off valve 51 is opened, and the third throttle valve 61 is controlled to be fully closed.

The flow direction of the refrigerant is as follows: the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows to the reversing assembly 2 and the defrost branch 5, respectively. The refrigerant flowing toward the reversing assembly 2 flows into the reversing assembly 2 through the first valve port 21 and flows out of the reversing assembly 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows into the indoor heat exchanger 3. The high-temperature and high-pressure gaseous refrigerant flowing to the indoor heat exchanger 3 is condensed into a high-temperature and high-pressure supercooled liquid refrigerant after fully exchanging heat in the indoor heat exchanger 3, then flows out of the indoor heat exchanger 3 and flows to the second throttle valve 44, becomes a low-temperature and low-pressure two-phase refrigerant after being throttled by the second throttle valve 44, then flows to the second portion 42, and becomes a low-temperature and low-pressure superheated gaseous refrigerant under the evaporation of the second portion 42. The high-temperature and high-pressure gaseous refrigerant flowing to the defrost branch 5 flows into the first portion 41, and frost of the first portion 41 is removed by sensible heat of the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1. The refrigerant flowing out of the first portion 41 and the refrigerant flowing out of the second portion 42 flow back to the suction port 11 of the compressor 1 through the third port 23 and the fourth port 24 in this order, and the first defrost flow path includes the discharge port 12 of the compressor 1, the first portion 41, the third port 23 and the fourth port 24 of the reversing assembly 2, and the suction port 11 of the compressor 1 which are sequentially connected, so that the defrost refrigerant circulation of the first portion 41 is completed.

Referring to fig. 9 and 10, fig. 9 is a schematic diagram of an air conditioner for defrosting a second portion according to a first embodiment of the present application, and fig. 10 is a schematic diagram of an air conditioner for defrosting a second portion according to a second embodiment of the present application. When defrosting the second part 42, the first valve port 21 and the second valve port 22 of the reversing assembly 2 are controlled to be communicated, the third valve port 23 and the fourth valve port 24 are controlled to be communicated, the first throttle valve 43 is controlled to be fully closed, the second throttle valve 44 is controlled to be fully opened, the first on-off valve 45 is controlled to be fully closed, the second on-off valve 51 is controlled to be closed, and the third throttle valve 61 is controlled to be throttled.

The flow direction of the refrigerant is as follows: the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the reversing assembly 2 through the first valve port 21, and flows out of the reversing assembly 2 through the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3, the high-temperature and high-pressure gaseous refrigerant exchanges heat incompletely in the indoor heat exchanger 3, the high-temperature and high-pressure supercooled liquid refrigerant or two-phase refrigerant with small supercooling degree is changed into the high-temperature and high-pressure supercooled liquid refrigerant after exchanging heat, the high-temperature and high-pressure supercooled liquid refrigerant flows out of the indoor heat exchanger 3 to the second throttle valve 44 after flowing out of the indoor heat exchanger 3, the high-temperature and high-pressure supercooled liquid refrigerant (the residual heat is sensible heat) or the high-temperature and high-pressure two-phase refrigerant (the residual heat is sensible heat and latent heat) flows to the second throttle valve 42, the refrigerant after defrosting in the second portion 42 flows to the bypass branch 6, then flows to the third throttle valve 61 on the bypass branch 6, the low-temperature and low-pressure two-phase refrigerant is changed into the first portion 41 after throttling and reducing pressure in the third throttle valve 61, the low-temperature and low-pressure overheated gaseous refrigerant is evaporated in the first portion 41, finally the refrigerant flowing out of the first portion 41 flows to the second portion 23 and the second valve port 24 sequentially through the third valve port 23, the fourth valve port 24, the second valve port 1, the reversing valve 2, the second valve port 1, the second valve port 2, the reversing valve 2, the second port 2, the reversing valve 2 and the second valve 4, the bypass valve 2, the second port 1, the bypass valve 2, and the bypass valve 4.

Therefore, a part of refrigerant at the exhaust port 12 of the compressor 1 can be bypassed to the first part 41 by the defrosting branch 5 to defrost the second part 42 by the high-pressure medium-temperature refrigerant flowing out of the indoor heat exchanger 3, so that the first part 41 and the second part 42 can be defrosted in turn, and the indoor heating state of the indoor heat exchanger 3 is still ensured. In addition, the reversing assembly 2 is not reversed in the process of switching between heating and defrosting, so that the service life of the reversing assembly 2 can be prolonged.

With continued reference to fig. 9, the first portion 41 may be located directly above the second portion 42. As shown in fig. 10, the first portion 41 may also be located directly below the second portion 42. Therefore, the defrosting branch 5 and the bypass branch 6 can be reasonably arranged, which is beneficial to reducing the cost.

With continued reference to fig. 9, the second end of the bypass branch 6 is connected to the line between the second end of the defrost branch 5 and the second end of the first portion 41. The arrangement can avoid the influence of the defrosting branch 5 on the bypass branch 6, thereby being beneficial to improving the reliability of the air conditioner 100, and can reasonably set the position of the bypass branch 6.

In other embodiments, referring to fig. 10, the second end of the bypass branch 6 is connected to the line between the second end of the defrost branch 5 and the first throttle 43. Thereby, the position of the bypass branch 6 can be set appropriately.

Referring to fig. 9, the first, second and third throttles 43, 44 and 61 may be electronic expansion valves. This arrangement can improve the operation speed and accuracy of the air conditioner 100. In other embodiments, the first, second, and third throttles 43, 44, 61 may also be thermal expansion valves.

In some embodiments, first portion 41 and second portion 42 may be split into two separate heat exchangers. Thus, when the air conditioner 100 is in the cooling or heating mode, it is possible to prevent the air conditioner 100 from being stopped when one of the first and second parts 41 and 42 is damaged, and to improve the stability and reliability of the operation of the air conditioner 100.

In other embodiments, the first portion 41 and the second portion 42 may be divided into two portions of the same heat exchanger. This arrangement facilitates assembly of the air conditioner 100, thereby contributing to an improvement in the assembly efficiency of the air conditioner 100.

In some embodiments, the first on-off valve 45 may be a two-way valve. This arrangement is advantageous in improving the response speed and reliability of the air conditioner 100.

In some embodiments, the second on-off valve 51 may be a solenoid valve. This arrangement is advantageous in improving the response speed and reliability of the air conditioner 100.

In other embodiments, the second on-off valve 51 may also be an electronic expansion valve.

With continued reference to fig. 9, the first throttle valve 43 and the second throttle valve 44 are connected to the second end of the indoor heat exchanger 3 through the same subcooler 47. By providing the supercooler 47, flash gas generated in the throttle process of the air conditioner 100 can be reduced, which is advantageous for improving the refrigerating capacity of the air conditioner 100, and also for improving the stability of the operation of the compressor 1, thereby being advantageous for improving the stability and reliability of the air conditioner 100.

With continued reference to fig. 1, a first end of the indoor heat exchanger 3 is connected to a first stop valve 31, and a second end of the indoor heat exchanger 3 is connected to a second stop valve 32. Thus, by providing the first and second shut-off valves 31 and 32, maintenance and repair of the air conditioner 100 are facilitated. Specifically, when the indoor heat exchanger 3 needs to be repaired or replaced, the first stop valve 31 and the second stop valve 32 can be closed, so that the indoor heat exchanger 3 can be more conveniently repaired without discharging the refrigerant of the whole air conditioner 100.

For example, the air conditioner 100 may be a multi-split system. The air conditioner 100 includes a plurality of indoor units. An indoor heat exchanger 3 is arranged in each indoor unit. The indoor units are connected in parallel. The first ends of the indoor heat exchangers 3 of the plurality of indoor units may be connected to the first shut-off valve 31. The second ends of the indoor heat exchangers 3 of the plurality of indoor units may be connected to the second shut-off valve 32. It will be understood, of course, that in other examples, the air conditioner 100 may include only one indoor unit.

With continued reference to fig. 1, in some embodiments, the air conditioner 100 further includes a gas-liquid separator 7. A gas-liquid separator 7 is arranged between the compressor 1 and the reversing assembly 2. The gas-liquid separator 7 has a liquid inlet 71 and a gas outlet 72. The liquid inlet 71 is connected to the fourth valve port 24. The gas outlet 72 is connected to the suction port 11. By arranging the gas-liquid separator, the gas-liquid separation effect can be carried out on the refrigerant entering the compressor 1, so that the problem of liquid impact on the compressor 1 is avoided, and the compressor 1 is protected.

With continued reference to fig. 1, in some embodiments, the air conditioner 100 further includes an oil separator 8. The oil separator 8 is disposed between the compressor 1 and the reversing assembly 2. The gas-oil separator 8 has an inlet 81, a gas discharge port 82, and an oil outlet 84. Inlet 81 is connected to exhaust port 12. The gas discharge port 82 is connected to the first valve port 21. The oil outlet 84 is connected to the suction port 11. By providing the oil separator 8, the protection effect on the compressor 1 can be improved, thereby contributing to the improvement of the stability and reliability of the air conditioner 100.

With continued reference to fig. 1, in some embodiments, the air conditioner 100 further includes an oil return capillary tube 83. The oil return capillary 83 is located between the compressor 1 and the oil outlet 84 of the oil separator 8. The oil return capillary 83 may return the liquid separated in the oil separator 8 to the suction port 11 of the compressor 1.

With continued reference to fig. 1, in some embodiments, one side of the outdoor heat exchanger assembly may be provided with an outdoor fan 46. This arrangement can improve the heat exchange efficiency of the outdoor heat exchanger assembly 4.

Based on the above-described structure of the air conditioner 100, there are two defrosting methods of the air conditioner 100 according to the embodiment of the present application. Next, a defrosting control method of the air conditioner 100 according to the first embodiment of the present application will be described.

Referring to fig. 11, fig. 11 is a flowchart of a first defrosting control method of an air conditioner according to an embodiment of the present application. The defrosting control method of the air conditioner 100 includes the steps of:

s1: when the air conditioner 100 operates in the heating mode, it is determined whether the air conditioner 100 satisfies a defrosting condition. When the air conditioner 100 is in the heating mode, the first valve port 21 and the second valve port 22 of the reversing assembly 2 are communicated, the third valve port 23 and the fourth valve port 24 are communicated, the first on-off valve 45 is opened, the second on-off valve 51 is disconnected, the first throttle valve 43 is throttled, the second throttle valve 44 is throttled, and the third throttle valve 61 is fully closed.

S2: if the air conditioner 100 satisfies the defrosting condition, the first throttle valve 43 is controlled to be fully closed, and the second on-off valve 51 is opened, so that the air conditioner 100 operates in the first defrosting mode to defrost the first portion 41.

Thus, in the first defrost mode, the first port 21 and the second port 22 of the reversing assembly 2 are maintained in conduction, the third port 23 and the fourth port 24 are in conduction, the first throttle 43 is fully closed, the second throttle 44 is throttled, the first on-off valve 45 is opened, the second on-off valve 51 is opened, and the third throttle 61 is fully closed. At this time, the flow direction of the refrigerant in the first defrost mode may be: the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows to the reversing assembly 2 and the defrost branch 5, respectively. The refrigerant flowing toward the reversing assembly 2 flows into the reversing assembly 2 through the first valve port 21 and flows out of the reversing assembly 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows into the indoor heat exchanger 3. The high-temperature and high-pressure gaseous refrigerant flowing to the indoor heat exchanger 3 is condensed into a high-temperature and high-pressure supercooled liquid refrigerant after fully exchanging heat in the indoor heat exchanger 3, then flows out of the indoor heat exchanger 3 and flows to the second throttle valve 44, becomes a low-temperature and low-pressure two-phase refrigerant after being throttled by the second throttle valve 44, then flows to the second portion 42, and becomes a low-temperature and low-pressure superheated gaseous refrigerant under the evaporation of the second portion 42. The high-temperature and high-pressure gaseous refrigerant flowing to the defrost branch 5 flows into the first portion 41, and frost of the first portion 41 is removed by sensible heat of the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1. The refrigerant flowing out of the first portion 41 and the refrigerant flowing out of the second portion 42 flow back to the suction port 11 of the compressor 1 through the third port 23 and the fourth port 24 in this order. The first defrost flow path includes the discharge port 12 of the compressor 1, the first portion 41, the third port 23, the fourth port 24 of the reversing assembly 2, and the suction port 11 of the compressor 1, which are sequentially connected.

S3: judging whether the air conditioner 100 satisfies a first defrosting mode end condition;

s4: if the air conditioner satisfies the first defrosting mode end condition, the second throttle valve 44 is controlled to be fully opened, the first on-off valve 45 is closed, the second on-off valve 51 is closed, and the third throttle valve 61 throttles to control the air conditioner 100 to exit the first defrosting mode, operate the second defrosting mode, and defrost the second portion 42 in the second defrosting mode.

Thus, in the second defrost mode, the first port 21 and the second port 22 of the reversing assembly 2 are kept in conduction, the third port 23 and the fourth port 24 are in conduction, the first throttle valve 43 is fully closed, the second throttle valve 44 is fully opened, the first on-off valve 45 is closed, the second on-off valve 51 is closed, and the third throttle valve 61 is throttled. At this time, the flow direction of the refrigerant in the second defrost mode may be: the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the reversing assembly 2 through the first valve port 21, and flows out of the reversing assembly 2 through the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3, the high-temperature and high-pressure gaseous refrigerant exchanges heat incompletely in the indoor heat exchanger 3, the high-temperature and high-pressure supercooled liquid refrigerant or two-phase refrigerant with small supercooling degree is changed into the high-temperature and high-pressure supercooled liquid refrigerant after exchanging heat, the high-temperature and high-pressure supercooled liquid refrigerant flows out of the indoor heat exchanger 3 to the second throttle valve 44 after flowing out of the indoor heat exchanger 3, the high-temperature and high-pressure supercooled liquid refrigerant (the residual heat is sensible heat) or the high-temperature and high-pressure two-phase refrigerant (the residual heat is sensible heat plus latent heat) flows out of the indoor heat exchanger 3 to the second portion 42, the refrigerant after defrosting in the second portion 42 flows to the bypass branch 6, then flows to the third throttle valve 61 on the bypass branch 6, the low-temperature and low-pressure two-phase refrigerant is changed into the low-temperature and low-pressure two-phase refrigerant after throttling and reducing pressure by the third throttle valve 61, the refrigerant flows into the first portion 41 and is evaporated into the low-temperature and low-pressure superheated gaseous refrigerant in the first portion 41, and finally the refrigerant flowing out of the first portion 41 flows back to the air suction port 11 of the compressor 1 through the third valve port 23 and the fourth valve port 24 in turn. The second defrost flow path includes the discharge port 12 of the compressor 1, the first valve port 21 of the reversing assembly 2, the second valve port 22, the indoor heat exchanger 3, the second throttle valve 44, the second portion 42, the bypass branch 6, the third throttle valve 61, the first portion 41, the third valve port 23 of the reversing assembly 2, the fourth valve port 24, and the suction port 11 of the compressor 1, which are sequentially connected.

S5: it is determined whether the air conditioner 100 satisfies the second defrost mode end condition.

S6: if the second defrosting mode end condition is satisfied, the first throttle valve 43 is controlled to throttle, the second throttle valve 44 is controlled to throttle, the first on-off valve 45 is opened, the second on-off valve 51 is closed, and the third throttle valve 61 is closed to exit the second defrosting mode and operate the heating mode.

Therefore, when the heating mode is switched to the first defrosting mode and the second defrosting mode for defrosting the first portion 41 and the second portion 42, the reversing assembly 2 is not reversed all the time, so that the power consumption of the air conditioner 100 can be reduced, the air conditioner 100 can realize uninterrupted heating, the indoor can be kept in a high-temperature state all the time, and the comfort of a user can be improved. Meanwhile, the first defrosting mode utilizes the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 to defrost the first part 41, and the defrosting effect is obvious. The second defrosting mode utilizes the high-pressure medium-temperature refrigerant flowing out of the indoor heat exchanger 3 to defrost the second part 42, and not only can the advantages of waste heat defrosting and sensible heat defrosting be utilized by a defrosting mode combining low-pressure sensible heat and high-pressure waste heat, but also the problems of serious waste of waste heat defrosting capacity, poor reliability of sensible heat defrosting and narrow applicable working condition can be avoided, thereby being beneficial to improving the reliability and stability of the operation of the air conditioner 100.

In some embodiments, first portion 41 is positioned directly above second portion 42, and in a first defrost mode, first portion 41 is defrosted and in a second defrost mode, second portion 42 is defrosted. Therefore, when the first portion 41 is located directly above the second portion 42, during the defrosting of the outdoor heat exchanger assembly 4, by defrosting the first portion 41 first, and then defrosting the second portion 42 after the defrosting of the first portion 41 is completed, the defrosting effect of the outdoor heat exchanger assembly 4 is ensured, and the problem that the defrosting effect of the second portion 42 is deteriorated due to the defrosting of the second portion 42 first and then the defrosting of the first portion 41 is prevented, when the defrosted water of the first portion 41 drops onto the second portion 42 as an evaporator, the second portion 42 is frozen is solved.

In some embodiments, to increase the evaporation capacity of the first portion 41, the outdoor fan 46 is disposed on a side of the first portion 41 away from the second portion 42, and if the air conditioner satisfies the first defrosting mode end condition, the outdoor fan 46 is controlled to be turned on so that air can be supplied to the first portion 41 in step S4. Thus, after the defrosting of the first portion 41 is completed, the outdoor fan 46 is turned on to improve the evaporation capacity of the first portion 41, and further to improve the suction pressure of the compressor 1, so that the indoor side can be quickly discharged after the defrosting of the air conditioner 100 is completed, which is beneficial to improving the use experience of users.

In some embodiments, the outdoor ambient temperature Ta, the temperature Te1 of the second end of the first portion 41, and the temperature Te2 of the second end of the second portion 42 are acquired before the air conditioner 100 is judged to satisfy the defrosting condition. If Ta is less than or equal to a and Te1/Te2 is less than or equal to b, and the continuous operation time of the air conditioner 100 in the heating mode reaches the first set duration, the conditioning system is judged to meet the defrosting condition. Thus, the air conditioner 100 can accurately judge whether to defrost, which is beneficial to improving the sensitivity and reliability of the air conditioner 100 in defrosting.

Illustratively, in the embodiment illustrated in fig. 10, the outdoor temperature sensor 9 may be disposed at the outside of the air conditioner 100 for acquiring the outdoor ambient temperature Ta, the first portion Te temperature sensor 411 may be disposed at the second end of the first portion 41 for acquiring the temperature Te1 of the second end of the first portion 41, and the second portion Te temperature sensor 421 may be disposed at the second end of the second portion 42 for acquiring the temperature Te2 of the second end of the second portion 42.

In some embodiments, -7 ℃ < a < 7 ℃. For example, the threshold value a of the outdoor ambient temperature Ta may be-6 ℃, -5 ℃, -4 ℃, -3 ℃, -2 ℃, -1 ℃, 0 ℃, 1 ℃, 2 ℃, 3 ℃, 4 ℃, 5 ℃, 6 ℃ or the like.

In some embodiments, b is-5 ℃ to 0 ℃. For example, the ratio Te1/Te2 may be-5 ℃, -4 ℃, -3 ℃, -2 ℃, -1 ℃ or 0 ℃ or the like.

In some embodiments, the first set period of time is greater than or equal to 10 minutes. For example, the value of the first set period of time may be 10min, 11min, 12min, 13min, or 14 min.

In some embodiments, the first defrost mode end condition is: the temperature Te1 at the second end of the first portion 41 is equal to or greater than f for a first preset time. Therefore, when the first defrosting mode end condition is met, the first defrosting mode can be timely exited, so that the intelligent degree and reliability of the air conditioner 100 can be improved.

In some embodiments, the second defrost mode end condition is: the temperature Te2 at the second end of the second portion 42 is greater than or equal to f for a first predetermined time. Therefore, the second defrosting mode can be timely exited when the second defrosting mode ending condition is met, so that the intelligent degree and the reliability of the air conditioner 100 are improved.

In some embodiments, 10.ltoreq.f.ltoreq.25℃. For example, the temperature f at the second end of the second portion 42 may have a value of 10 ℃, 11 ℃, 12 ℃, 13 ℃, 14 ℃, 15 ℃, 16 ℃, 17 ℃, 18 ℃, 19 ℃, 20 ℃, 21 ℃, 22 ℃, 23 ℃, 24 ℃, 25 ℃, or the like.

In some embodiments, 5 seconds or less the first preset time or less than 30 seconds. For example, the first preset time may take a value of 5 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds, 30 seconds, or the like.

In some embodiments, the second throttle valve 44 is adjustable in opening. When defrosting the first portion 41, the opening degree of the second throttle valve 44 is adjusted to satisfy the first preset condition. The first preset condition is: the suction superheat degree of the compressor 1 satisfies: tsh is more than or equal to d, and the exhaust superheat degree of the compressor 1 meets the following conditions: tdsh is greater than or equal to e; where tssh=tg 2-tc_ps, tg2 being the temperature of the first end of the second portion 42, tc_ps being the saturation temperature corresponding to the suction pressure Ps at the suction port 11. This arrangement can improve the accuracy of the opening degree control of the second throttle valve 44, thereby contributing to an improvement in the reliability of the air conditioner 100. Note that tdsh=td—tc_pd, td is the temperature of the discharge port 12 of the compressor 1, and tc_pd is the saturation temperature corresponding to the discharge pressure Pd at the discharge port 12.

Illustratively, in the embodiment illustrated in fig. 10, a second portion temperature sensor 422 may be disposed at the first end of the second portion 42 for obtaining the temperature Tg2 of the first end of the second portion 42, an intake pressure sensor 111 may be disposed at the intake port 11 of the compressor 1 for detecting the intake pressure Ps, and an exhaust pressure sensor 121 may be disposed at the exhaust port 12 of the compressor 1 for detecting the exhaust pressure Pd. A discharge temperature sensor 122 may be provided at the discharge port 12 of the compressor 1 for detecting the discharge temperature Td.

In some embodiments, the opening of the third throttle valve 61 is adjustable, and the opening of the third throttle valve 61 is adjusted to meet the second preset condition when defrosting the second portion 42. The second preset condition is: the suction superheat degree of the compressor 1 satisfies: tsh is more than or equal to d, and the exhaust superheat degree of the compressor 1 meets the following conditions: tdsh.gtsh.gtoreq.e. Where tssh=tg 1-tc_ps, tg1 is the temperature of the first end of the first portion 41, tc_ps is the saturation temperature corresponding to the suction pressure Ps at the suction port 11.

For example, in the embodiment illustrated in fig. 10, a first portion temperature sensor 412 may be provided at the first end of the first portion 41 for acquiring the temperature Tg1 of the first end of the first portion 41.

In some embodiments, 0.ltoreq.d.ltoreq.10℃. For example, d may be 0 ℃, 1 ℃,2 ℃, 3 ℃, 4 ℃, 5 ℃, 6 ℃, 7 ℃, 8 ℃, 9 ℃, or 10 ℃.

In some embodiments, 20.ltoreq.e.ltoreq.40℃. For example, e may be 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, or the like.

In some embodiments, the indoor fan of the air conditioner 100 is controlled to cease operation or operate with a minimum damper while defrosting the second portion 42. This arrangement ensures that the refrigerant flowing into the second portion 42 has waste heat in the second defrost mode, thereby ensuring the defrost efficiency of the second portion 42.

Next, a defrosting control method of the air conditioner 100 according to the second embodiment of the present application will be described.

Referring to fig. 12, fig. 12 is a flowchart of a second defrosting control method for an air conditioner according to an embodiment of the present application. The defrosting control method of the air conditioner 100 includes the steps of:

S2: if the air conditioner 100 satisfies the defrosting condition, the first throttle valve 43 is controlled to be fully closed, the second throttle valve 44 is controlled to be fully opened, the first on-off valve 45 is closed, and the third throttle valve 61 is throttled, so that the air conditioner 100 operates in the first defrosting mode to defrost the second portion 42.

Thus, in the first defrost mode, the first port 21 and the second port 22 of the reversing assembly 2 are kept in conduction, the third port 23 and the fourth port 24 are in conduction, the first throttle valve 43 is fully closed, the second throttle valve 44 is fully opened, the first on-off valve 45 is fully closed, the second on-off valve 51 is closed, and the third throttle valve 61 is throttled. At this time, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the reversing assembly 2 through the first valve port 21, and flows out of the reversing assembly 2 through the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3, the high-temperature and high-pressure gaseous refrigerant exchanges heat incompletely in the indoor heat exchanger 3, the high-temperature and high-pressure supercooled liquid refrigerant or two-phase refrigerant with small supercooling degree is changed into the high-temperature and high-pressure supercooled liquid refrigerant after exchanging heat, the high-temperature and high-pressure supercooled liquid refrigerant flows out of the indoor heat exchanger 3 to the second throttle valve 44 after flowing out of the indoor heat exchanger 3, the high-temperature and high-pressure supercooled liquid refrigerant (the residual heat is sensible heat) or the high-temperature and high-pressure two-phase refrigerant (the residual heat is sensible heat plus latent heat) flows out of the indoor heat exchanger 3 to the second portion 42, the refrigerant after defrosting in the second portion 42 flows to the bypass branch 6, then flows to the third throttle valve 61 on the bypass branch 6, the low-temperature and low-pressure two-phase refrigerant is changed into the low-temperature and low-pressure two-phase refrigerant after throttling and reducing pressure by the third throttle valve 61, the refrigerant flows into the first portion 41 and is evaporated into the low-temperature and low-pressure superheated gaseous refrigerant in the first portion 41, and finally the refrigerant flowing out of the first portion 41 flows back to the air suction port 11 of the valve port of the compressor 1 through the third valve port 23 and the fourth valve port 24 sequentially. The second defrost flow path includes the discharge port 12 of the compressor 1, the first valve port 21 of the reversing assembly 2, the second valve port 22, the indoor heat exchanger 3, the second throttle valve 44, the second portion 42, the bypass branch 6, the third throttle valve 61, the first portion 41, the third valve port 23 of the reversing assembly 2, the fourth valve port 24, and the suction port 11 of the compressor 1, which are sequentially connected.

S3: it is determined whether the air conditioner 100 satisfies the first defrost mode end condition.

S4: if the air conditioner satisfies the first defrosting mode end condition, the second throttle valve 44 is controlled to throttle, the first on-off valve 45 is opened, the second on-off valve 51 is opened, and the third throttle valve 61 is fully closed to control the air conditioner 100 to exit the first defrosting mode, operate the second defrosting mode, and defrost the first portion 41 in the second defrosting mode.

Thus, in the second defrost mode, the first port 21 and the second port 22 of the reversing assembly 2 are maintained in conduction, the third port 23 and the fourth port 24 are in conduction, the first throttle valve 43 is fully closed, the second throttle valve 44 is throttled, the first on-off valve 45 is opened, the second on-off valve 51 is opened, and the third throttle valve 61 is fully closed. At this time, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows to the reversing module 2 and the defrost branch 5, respectively. The refrigerant flowing toward the reversing assembly 2 flows into the reversing assembly 2 through the first valve port 21 and flows out of the reversing assembly 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows into the indoor heat exchanger 3. The high-temperature and high-pressure gaseous refrigerant flowing to the indoor heat exchanger 3 is condensed into a high-temperature and high-pressure supercooled liquid refrigerant after fully exchanging heat in the indoor heat exchanger 3, then flows out of the indoor heat exchanger 3 and flows to the second throttle valve 44, becomes a low-temperature and low-pressure two-phase refrigerant after being throttled by the second throttle valve 44, then flows to the second portion 42, and becomes a low-temperature and low-pressure superheated gaseous refrigerant under the evaporation of the second portion 42. The high-temperature and high-pressure gaseous refrigerant flowing to the defrost branch 5 flows into the first portion 41, and frost of the first portion 41 is removed by sensible heat of the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1. The refrigerant flowing out of the first portion 41 and the refrigerant flowing out of the second portion 42 flow back to the suction port 11 of the compressor 1 through the third port 23 and the fourth port 24 in this order. The first defrost flow path includes the discharge port 12 of the compressor 1, the first portion 41, the third port 23, the fourth port 24 of the reversing assembly 2, and the suction port 11 of the compressor 1, which are sequentially connected.

Therefore, when the heating mode is switched to the first defrosting mode and the second defrosting mode for defrosting the first portion 41 and the second portion 42, the reversing assembly 2 is not reversed all the time, so that the power consumption of the air conditioner 100 can be reduced, the air conditioner 100 can realize uninterrupted heating, the indoor can be kept in a high-temperature state all the time, and the comfort of a user can be improved. Meanwhile, the second defrosting mode utilizes the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 to defrost the first part 41, and the defrosting effect is remarkable. The first defrosting mode utilizes the high-pressure medium-temperature refrigerant flowing out of the indoor heat exchanger 3 to defrost the second part 42, and not only can the advantages of waste heat defrosting and sensible heat defrosting be utilized by a defrosting mode combining low-pressure sensible heat and high-pressure waste heat, but also the problems of serious waste of waste heat defrosting capacity, poor reliability of sensible heat defrosting and narrow applicable working condition can be avoided, thereby being beneficial to improving the reliability and stability of the operation of the air conditioner 100.

In some embodiments, the second portion 42 is located directly above the first portion 41, and in the first defrost mode, the second portion 42 is defrosted and in the second defrost mode, the first portion 41 is defrosted. Therefore, when the second portion 42 is located directly above the first portion 41, during the defrosting of the outdoor heat exchanger assembly 4, by defrosting the second portion 42 first, and defrosting the first portion 41 after the defrosting of the second portion 42 is completed, it is beneficial to ensure the defrosting effect of the outdoor heat exchanger assembly 4, and the problem that the defrosting effect of the first portion 41 is deteriorated because the defrosting of the first portion 41 is performed first and then the defrosting of the second portion 42 is performed is prevented, and when the defrosted water of the second portion 42 drops onto the first portion 41 as an evaporator, the first portion 41 is frozen.

In some embodiments, to increase the evaporation capacity of the second portion 42, the outdoor fan 46 is disposed on a side of the second portion 42 away from the first portion 41, and if the air conditioner satisfies the first defrosting mode end condition, the outdoor fan 46 is controlled to be turned on so that air can be supplied to the second portion 42 in step S4. Thus, after the defrosting of the second portion 42 is completed, the outdoor fan 46 is turned on to improve the evaporation capacity of the second portion 42, and further to improve the suction pressure of the compressor 1, so that the indoor side can be quickly discharged after the defrosting of the air conditioner 100 is completed, which is beneficial to improving the use experience of users.

In some embodiments, the outdoor ambient temperature Ta, the temperature Te1 of the second end of the first portion 41, and the temperature Te2 of the second end of the second portion 42 are acquired before the air conditioner 100 is judged to satisfy the defrosting condition. If Ta is less than or equal to a and Te1/Te2 is less than or equal to b, and the continuous operation time of the air conditioner 100 in the heating mode reaches the first set duration, the conditioning system is judged to meet the defrosting condition. Thus, the air conditioner 100 can prepare for judging whether to defrost, which is advantageous in improving the sensitivity and reliability of the defrosting of the air conditioner 100.

In some embodiments, the first defrost mode end condition is: the temperature Te2 at the second end of the second portion 42 is greater than or equal to f for a first predetermined time. Therefore, when the first defrosting mode end condition is met, the first defrosting mode can be timely exited, so that the intelligent degree and reliability of the air conditioner 100 can be improved.

In some embodiments, the second defrost mode end condition is: the temperature Te1 at the second end of the first portion 41 is equal to or greater than f for a first preset time. Therefore, the second defrosting mode can be timely exited when the second defrosting mode ending condition is met, so that the intelligent degree and the reliability of the air conditioner 100 are improved.

Illustratively, in the embodiment illustrated in fig. 10, a second portion temperature sensor 422 may be provided at the first end of the second portion 42 for obtaining the temperature Tg2 of the first end of the second portion 42, an intake pressure sensor 111 may be provided at the intake port 11 of the compressor 1 for detecting the intake pressure Ps, and an exhaust pressure sensor 121 and an exhaust temperature sensor 122 may be provided at the exhaust port 12 of the compressor 1 for detecting the exhaust pressure Pd and the exhaust temperature Td.

From the foregoing description of the embodiments, it will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of functional modules is illustrated, and in practical application, the above-described functional allocation may be implemented by different functional modules according to needs, i.e. the internal structure of the apparatus is divided into different functional modules to implement all or part of the functions described above.

In the description of the present specification, a particular feature, structure, material, or characteristic may be combined in any suitable manner in one or more embodiments or examples.

The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A defrosting control method of an air conditioner, the air conditioner comprising: an indoor unit having an indoor heat exchanger;

2. A control method as set forth in claim 1 wherein said first portion and said second portion are controlled in parallel when said first defrost mode is operating.

3. A control method as set forth in claim 1 wherein said first portion and said second portion are controlled in series when said second defrost mode is operating.

4. The control method according to claim 1, characterized by further comprising:

an outdoor fan disposed at one side of the outdoor heat exchanger;

an indoor fan arranged at one side of the indoor heat exchanger;

when the first defrosting mode is operated, controlling the outdoor fan to operate so as to improve the evaporation capacity of the first part;

And when the second defrosting mode is operated, controlling the indoor fan to stop or controlling the indoor fan not to operate below the upper limit rotating speed.

5. The control method according to claim 1, characterized in that the air conditioner includes:

a first defrost flow path and a second defrost flow path;

the first defrosting flow path comprises an exhaust port of the compressor, a defrosting branch, a first part of the outdoor heat exchanger and an air suction port of the compressor which are connected in sequence;

the defrosting branch is connected with a second on-off valve in series;

the second defrosting flow path comprises an exhaust port, an indoor heat exchanger, a second throttle valve, a second part of an outdoor heat exchanger, a bypass branch, a first part and an air suction port of the compressor which are sequentially connected, and a third throttle valve is connected in series on the bypass branch;

the method comprises the following steps:

if yes, controlling the air conditioner to operate a first defrosting mode, and defrosting one of the first part and the second part in the first defrosting mode;

judging whether the air conditioner meets a first defrosting mode ending condition;

If yes, controlling the air conditioner to exit the first defrosting mode;

when defrosting the first part, the second throttle valve is throttled, the second on-off valve is opened, and the third throttle valve is fully closed;

and when defrosting the second part, the second throttle valve is fully opened, the second on-off valve is closed, and the third throttle valve is throttled.

6. The defrosting control method of an air conditioner as set forth in claim 5, wherein if a first defrosting mode end condition is satisfied, controlling the air conditioner to exit a first defrosting mode, operating a second defrosting mode in which the other one of the first portion and the second portion is defrosted;

judging whether the air conditioner meets a second defrosting mode ending condition;

and if yes, controlling the air conditioner to exit the second defrosting mode, and operating the heating mode.

7. The defrosting control method of an air conditioner as set forth in claim 6, wherein an outdoor ambient temperature Ta, a temperature Te1 of a second end of the first portion, and a temperature Te2 of a second end of the second portion are acquired before the air conditioner is judged to satisfy the defrosting condition;

If Ta is less than or equal to a and Te1/Te2 is less than or equal to b, and the continuous operation time of the air conditioner in the heating mode reaches a first set duration, judging that the conditioning system meets the defrosting condition;

preferentially, -7 ℃ is less than 7 ℃, b is less than or equal to-5 ℃ and less than or equal to 0 ℃, and the first set time period is more than or equal to 10 min.

8. The defrosting control method of an air conditioner as claimed in claim 1, wherein in the first defrosting mode, the first portion is defrosted, and in the second defrosting mode, the second portion is defrosted;

wherein, the first defrosting mode end condition is: the temperature Te1 of the second end of the first part is more than or equal to f and lasts for a first preset time; and/or, the second defrosting mode end condition is: the temperature Te2 of the second end of the second part is more than or equal to f and lasts for a first preset time.

9. The defrosting control method of an air conditioner as claimed in claim 1, wherein in the first defrosting mode, the second portion is defrosted, and in the second defrosting mode, the first portion is defrosted;

wherein, the first defrosting mode end condition is: the temperature Te2 of the second end of the second part is more than or equal to f and lasts for a first preset time; and/or, the second defrosting mode end condition is: the temperature Te1 of the second end of the first part is more than or equal to f and lasts for a first preset time.

10. The defrosting control method for an air conditioner as claimed in claim 8 or 9, wherein f is 10 ℃ to 25 ℃ and/or 5 seconds to 30 seconds.