阅读说明：本技术 一种空调系统及其控制方法 (Air conditioning system and control method thereof ) 是由 邵英 于 2021-07-26 设计创作，主要内容包括：本公开提供一种空调系统及其控制方法,空调系统包括：压缩机、室内换热器、节流装置、第一室外换热器、第一蓄热体、第一支路和第二支路,第一蓄热体与第一室外换热器串联并设置在第一支路上,第一支路包括第一管段和第二管段,第一室外换热器设置于第一管段上,第一蓄热体设置于第二管段上,第二支路并联设置在第二管段上,第二支路上设置有第一阀,第二管段上设置有第二阀,第一蓄热体能够从冷媒管路的外部吸收热量以对第一室外换热器进行化霜。根据本公开有效利用空调系统外部的热量储蓄在第一蓄热体内部以在第一室外换热器需要化霜时来对第一室外换热器进行化霜,有效地解决空调系统分段除霜过程中室内侧供热量降低的问题。(The present disclosure provides an air conditioning system and a control method thereof, the air conditioning system including: the compressor, indoor heat exchanger, throttling arrangement, first outdoor heat exchanger, first heat accumulator, first branch road and second branch road, first heat accumulator and first outdoor heat exchanger series connection are set up on first branch road, first branch road includes first pipeline section and second pipeline section, first outdoor heat exchanger sets up on first pipeline section, first heat accumulator sets up on the second pipeline section, the second branch road parallel connection sets up on the second pipeline section, be provided with first valve on the second branch road, be provided with the second valve on the second pipeline section, first heat accumulator can follow the outside absorption heat of refrigerant pipeline in order to change the frost to first outdoor heat exchanger. According to the outdoor defrosting method, the heat outside the air conditioning system is effectively stored in the first heat accumulator to defrost the first outdoor heat exchanger when the first outdoor heat exchanger needs defrosting, and the problem that the indoor side heat supply amount is reduced in the segmented defrosting process of the air conditioning system is effectively solved.)

1. An air conditioning system characterized by: the method comprises the following steps:

a compressor (1), an indoor heat exchanger (3), a throttling device (4), a first outdoor heat exchanger (71), a first heat accumulator (91), a first branch (101) and a second branch (102), the first heat accumulator (91) is connected in series with the first outdoor heat exchanger (71) and is arranged on the first branch (101), the first branch (101) comprises a first pipe section (201) and a second pipe section (202), the first outdoor heat exchanger (71) is disposed on the first tube section (201), the first heat accumulator (91) is arranged on the second tube section (202), the second branch (102) is arranged on the second tube section (202) in parallel, a first valve (611) is arranged on the second branch (102), a second valve (612) is arranged on the second pipe section (202), the first heat accumulator (91) can absorb heat from the outside of a refrigerant pipe to defrost the first outdoor heat exchanger (71).

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

also comprises a second outdoor heat exchanger (72), a second heat accumulator (92), a third branch (103) and a fourth branch (104), the second heat accumulator (92) is connected in series with the second outdoor heat exchanger (72) and is arranged on a third branch (103), the third branch (103) being in parallel with the first branch (101), the third branch (103) comprising a third tube section (203) and a fourth tube section (204), the second outdoor heat exchanger (72) is disposed on the third tube section (203), the second heat accumulator (92) is arranged on the fourth tube section (204), the fourth branch (104) is arranged on the fourth tube section (204) in parallel, a third valve (621) is arranged on the fourth pipe section (204), a fourth valve (622) is arranged on the fourth branch (104), the second heat accumulator (92) can absorb heat from the outside of the refrigerant pipe to defrost the second outdoor heat exchanger (72).

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

the first heat accumulator (91) is disposed at a position between the first outdoor heat exchanger (71) and the throttling device (4), and the second heat accumulator (92) is disposed at a position between the second outdoor heat exchanger (72) and the throttling device (4).

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

first heat accumulator (91) includes first thermal-collecting tube (301) and first phase change thermal storage material (302), first phase change thermal storage material (302) set up in the inside of first thermal-collecting tube (301), first thermal-collecting tube (301) can absorb the heat through electric heating or solar energy's mode, second tube segment (202) wear to establish the entering the inside of first thermal-collecting tube (301).

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

work as when first thermal-collecting tube (301) can absorb the heat through the electrical heating, air conditioning system still includes first electric heating part (303), entering is worn to establish in first electric heating part (303) the inside of first thermal-collecting tube (301), the power of first electric heating part (303) is at least one of commercial power, photovoltaic electricity, wind-powered electricity and water and electricity.

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

the second heat accumulator (92) comprises a second heat collecting tube and a second phase change heat storage material, the second phase change heat storage material is arranged inside the second heat collecting tube, the second heat collecting tube can absorb heat in an electric heating or solar energy mode, and the fourth tube section (204) penetrates into the second heat collecting tube.

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

work as when the second thermal-collecting tube can absorb the heat through electric heating, air conditioning system still includes second electric heating part, second electric heating part wears to establish the entering the inside of second thermal-collecting tube, the power of second electric heating part is at least one in commercial power, photovoltaic electricity, wind-powered electricity and the water and electricity.

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

the first valve (611) and the second valve (612) are both solenoid valves; the third valve (621) and the fourth valve (622) are both solenoid valves.

9. The air conditioning system according to any one of claims 1 to 8, characterized in that:

the outdoor temperature sensor also comprises a first temperature sensor (5) capable of detecting the temperature of the outdoor pipe and a second temperature sensor (8) capable of detecting the temperature of the outdoor environment; and/or, also include the four-way valve (2).

10. A control method of an air conditioning system according to any one of claims 1 to 9, characterized in that:

when a first outdoor heat exchanger (71), a second outdoor heat exchanger (72), a first valve (611), a second valve (612), a third valve (621), and a fourth valve (622) are included at the same time, the control method includes:

a detection step of detecting an operation mode of the air conditioning system;

a control step of controlling the second valve (612) and the third valve (621) to be closed, controlling the first valve (611) and the fourth valve (622) to be opened, and controlling the suction of the compressor (1) to be communicated with the indoor heat exchanger (3) when the air conditioning system needs to operate in a cooling mode; when the air conditioning system needs to operate in a heating mode, controlling the second valve (612) and the third valve (621) to be closed, controlling the first valve (611) and the fourth valve (622) to be opened, and controlling the exhaust gas of the compressor (1) to be communicated with the indoor heat exchanger (3);

when the first outdoor heat exchanger (71) needs defrosting, controlling the first valve (611) to be closed, controlling the second valve (612) to be opened, controlling the third valve (621) to be closed, and controlling the fourth valve (622) to be opened; when the second outdoor heat exchanger (72) needs defrosting, controlling the first valve (611) to be opened, controlling the second valve (612) to be closed, controlling the third valve (621) to be opened, and controlling the fourth valve (622) to be closed;

when the air conditioning system needs to operate in a reverse cycle defrosting mode, the second valve (612) and the third valve (621) are controlled to be closed, the first valve (611) and the fourth valve (622) are controlled to be opened, and suction air of the compressor (1) is controlled to be communicated with the indoor heat exchanger (3).

11. The control method according to claim 10, characterized in that:

the detecting step can also detect the outdoor environment temperature T_{Ring (C)}And outdoor pipe temperature T_Pipe；

A judgment step of judging T_{Ring (C)}And the relationship between T1 and T2, and judging T_PipeRelationships with T3, T4, and T5, wherein T1 is a first preset temperature, T2 is a second preset temperature, T3 is a third preset temperature, T4 is a fourth preset temperature, T5 is a fifth preset temperature, T1 > T2, T3 > T4 > T5;

the control step is also when T_{Ring (C)}Not less than T1, and T_PipeControlling the first outdoor heat exchanger (71) and the second outdoor heat exchanger (72) to defrost in sections and alternatively when the temperature is less than or equal to T3; also when T2 < T_{Ring (C)}< T1, and T_PipeControlling the first outdoor heat exchanger (71) and the second outdoor heat exchanger (72) to defrost in sections and alternately and reversely circulate when the temperature is less than or equal to T4; also when T_{Ring (C)}< T2, and T_PipeAnd when the temperature is less than T5, controlling the first outdoor heat exchanger (71) and the second outdoor heat exchanger (72) to reversely circulate and defrost.

12. The control method according to claim 11, characterized in that:

the detecting step may be further configured to detect the T_{Ring (C)}And said T_PipePreviously, detecting the heating operation time t1 of the air conditioning system and the accumulative operation time t2 of the air conditioning system;

the judging step judges the relationship between t1 and t01 and judges the relationship between t2 and t 02;

the control step is that when T1 is more than or equal to T01 or T2 is more than or equal to T02, the T detection is started_{Ring (C)}And said T_PipeWherein t01 is a first predetermined time, and t02 is a second predetermined time.

13. The control method according to claim 12, characterized in that:

in the control step, when T is_{Ring (C)}Not less than T1 and T_PipeAt T3, controlling the first outdoor heat exchanger (71) and the second outdoor heat exchanger (72) to alternately defrost, namely controlling the first valve (611) to close, controlling the second valve (612) to open, controlling the third valve (621) to close, controlling the fourth valve (622) to open, controlling the first valve (611) to open after a time T03, controlling the second valve (612) to close, controlling the third valve (621) to open, controlling the fourth valve (622) to close, controlling the air conditioning system to switch to a heating mode after T03, wherein T03 is a third preset time.

14. The control method according to claim 12, characterized in that:

in the control step, when T6 is less than or equal to T_{Ring (C)}< T1 and T_PipeAt ≦ T4, where T2 < T6 < T1, controlling the first outdoor heat exchanger (71) and the second outdoor heat exchanger (72) to alternately defrost, i.e., controlling the first valve (611) to close, controlling the second valve (612) to open, controlling the third valve (621) to close, controlling the fourth valve (622) to open, controlling the first valve (611) to open, controlling the second valve (612) to close, controlling the third valve (621) to open, controlling the fourth valve (622) to close, and also controlling the air conditioning system to turn to a heating mode after a third preset time T03;

when T1 is not less than T04 or T2 is not less than T05, and when T_PipeAt ≦ T7, where T04 > T01, T05 > T02, T5 < T7 < T4, the control system enters the reverse cycle defrost mode and operates for a sixth preset time T06, and then controls the air conditioning system to go to the heating mode, i.e., controls both the second valve (612) and the third valve (621) to be closed, controls both the first valve (611) and the fourth valve (622) to be open, and controls the discharge air of the compressor (1) to communicate with the indoor heat exchanger (3).

15. The control method according to claim 12, characterized in that:

in the control step, when T2 is less than or equal to T_{Ring (C)}< T6 and T_PipeAt ≦ T7, where T2 < T6 < T1, T5 < T7 < T4, controlling the first outdoor heat exchanger (71) and the second outdoor heat exchanger (72) to alternately defrost, i.e., controlling the first valve (611) to close, controlling the second valve (612) to open, controlling the third valve (621) to close, controlling the fourth valve (622) to open, controlling the first valve (611) to open, controlling the second valve (612) to close, controlling the third valve (621) to open, controlling the fourth valve (622) to close, also for a seventh preset time T07, controlling the air conditioning system to go to a heating mode;

when T1 is not less than T04 or T2 is not less than T05, and when T_PipeT2, wherein T04 > T01, T05 > T02, the control system enters a reverse cycle defrost mode and operates for a sixth preset time T06, and then controls the air conditioning system to go to a heating mode, i.e., controls the second valve (612) and the third valve (621) to be closed, controls the first valve (611) and the fourth valve (622) to be opened, and controls the discharge air of the compressor (1) to be communicated with the indoor heat exchanger (3), wherein T07>t06。

16. The control method according to claim 12, characterized in that:

when T is_{Ring (C)}T2 and T are not more than_PipeAnd when the time is less than or equal to T5 and when the time T1 is more than or equal to the eighth preset time T08 or the time T2 is more than or equal to the ninth preset time T09, the control system enters the reverse cycle defrosting mode and operates for a tenth preset time T10.

Technical Field

The disclosure relates to the technical field of air conditioners, in particular to an air conditioning system and a control method thereof.

Background

In the heating operation process of the air conditioner, because the outdoor heat exchanger can frost, the defrosting cycle needs to be carried out irregularly, the air conditioner generally adopts reverse cycle defrosting, namely, the air conditioner operates in a refrigeration mode, and in the defrosting process, hot air is not output from the indoor side, so that the indoor heat supply is discontinuous, and the comfort is reduced.

In order to improve the comfort level of the heating operation of the air conditioner and realize the indoor continuous heat supply, a sectional defrosting method is provided, namely, an outdoor heat exchanger is divided into two parts, when defrosting is needed in the heating process, one part is in normal heating operation, and the other part is in defrosting operation. The sectional defrosting generally adopts a hot gas bypass mode, the heat for defrosting comes from the exhaust of the compressor, the total heat supply of the system is reduced, and the heat supply is obviously reduced although continuous heat supply is realized at the indoor side.

Because the air conditioner in the prior art can reduce the total heat supply of the system in the reverse cycle defrosting or sectional defrosting mode, the indoor heat supply is obviously reduced, and the like, the air conditioner system and the control method thereof are researched and designed.

BRIEF SUMMARY OF THE PRESENT DISCLOSURE

Therefore, the technical problem to be solved by the present disclosure is to overcome the defect that the air conditioner in the prior art reduces the total heat supply of the system in the reverse cycle defrosting or the sectional defrosting mode, which results in a significant reduction of the heat supply in the room, thereby providing an air conditioning system and a control method thereof.

In order to solve the above problems, the present disclosure provides an air conditioning system, comprising:

the first outdoor heat exchanger is arranged on the first pipe section, the first heat accumulator is arranged on the second pipe section, the second branch is arranged on the second pipe section in parallel, a first valve is arranged on the second branch, a second valve is arranged on the second pipe section, and the first heat accumulator can absorb heat from the outside of a refrigerant pipeline to defrost the first outdoor heat exchanger.

In some embodiments, the heat pump system further comprises a second outdoor heat exchanger, a second heat accumulator, a third branch and a fourth branch, the second heat accumulator is connected in series with the second outdoor heat exchanger and is arranged on the third branch, the third branch is connected in parallel with the first branch, the third branch comprises a third pipe section and a fourth pipe section, the second outdoor heat exchanger is arranged on the third pipe section, the second heat accumulator is arranged on the fourth pipe section, the fourth branch is connected in parallel on the fourth pipe section, a third valve is arranged on the fourth pipe section, and a fourth valve is arranged on the fourth branch, and the second heat accumulator can absorb heat from the outside of the refrigerant pipeline to defrost the second outdoor heat exchanger.

In some embodiments, the first heat accumulator is disposed at a position between the first outdoor heat exchanger and the throttling device, and the second heat accumulator is disposed at a position between the second outdoor heat exchanger and the throttling device.

In some embodiments, the first heat storage body includes a first heat collecting tube and a first phase change heat storage material, the first phase change heat storage material is disposed inside the first heat collecting tube, the first heat collecting tube can absorb heat by electric heating or solar energy, and the second tube section penetrates into the first heat collecting tube.

In some embodiments, when first thermal-collecting tube can absorb the heat through electric heating, air conditioning system still includes first electric heating part, first electric heating part wears to establish the entering the inside of first thermal-collecting tube, the power of first electric heating part is at least one in commercial power, photovoltaic electricity, wind-powered electricity and the water and electricity.

In some embodiments, the second heat storage body includes a second heat collecting tube and a second phase change heat storage material, the second phase change heat storage material is disposed inside the second heat collecting tube, the second heat collecting tube can absorb heat by electric heating or solar energy, and the fourth tube segment penetrates into the inside of the second heat collecting tube.

In some embodiments, when the second thermal-collecting tube can absorb the heat through electric heating, air conditioning system still includes second electric heating part, the second electric heating part wears to establish the entering the inside of second thermal-collecting tube, the power of second electric heating part is at least one in commercial power, photovoltaic electricity, wind-powered electricity and the water and electricity.

In some embodiments, the first valve and the second valve are both solenoid valves; the third valve and the fourth valve are both solenoid valves.

In some embodiments, the system further comprises a first temperature sensor capable of detecting the temperature of the outdoor pipe, and a second temperature sensor capable of detecting the temperature of the outdoor environment; and/or, also include the four-way valve.

The present disclosure also provides a control method of an air conditioning system as set forth in any of the preceding claims, wherein:

when the first outdoor heat exchanger, the second outdoor heat exchanger, the first valve, the second valve, the third valve and the fourth valve are included at the same time, the control method includes:

a detection step of detecting an operation mode of the air conditioning system;

controlling the second valve and the third valve to be closed, controlling the first valve and the fourth valve to be opened, and controlling suction air of the compressor to be communicated with the indoor heat exchanger when the air conditioning system needs to operate in a cooling mode; when the air conditioning system needs to operate in a heating mode, controlling the second valve and the third valve to be closed, controlling the first valve and the fourth valve to be opened, and controlling the exhaust of the compressor to be communicated with the indoor heat exchanger;

when the first outdoor heat exchanger needs defrosting, controlling the first valve to be closed, controlling the second valve to be opened, controlling the third valve to be closed, and controlling the fourth valve to be opened; when the second outdoor heat exchanger needs defrosting, controlling the first valve to be opened, controlling the second valve to be closed, controlling the third valve to be opened, and controlling the fourth valve to be closed;

and when the air conditioning system needs to operate in a reverse-cycle defrosting mode, controlling the second valve and the third valve to be closed, controlling the first valve and the fourth valve to be opened, and controlling the air suction of the compressor to be communicated with the indoor heat exchanger.

In some embodiments, the detecting step can also detect the outdoor ambient temperature T_{Ring (C)}And outdoor pipe temperature T_Pipe；

A judgment step of judging T_{Ring (C)}And the relationship between T1 and T2, and judging T_PipeRelationships to T3, T4, and T5, wherein T1 is a first preset temperature, T2 is a second preset temperature, T3 is a third preset temperature, T4 is a fourth preset temperature, T5 is a fifth preset temperature, T1 > T2, T3 > T4 > T5;

the control step is also when T_{Ring (C)}Not less than T1, and T_PipeWhen the temperature is less than or equal to T3, controlling the first outdoor heat exchanger and the second outdoor heat exchanger to defrost in sections and alternately; also when T2 < T_{Ring (C)}< T1, and T_PipeWhen the temperature is less than or equal to T4, controlling the first outdoor heat exchanger and the second outdoor heat exchanger to defrost in sections and alternately defrost and reverse circulation defrost; also when T_{Ring (C)}< T2, and T_PipeAnd when the temperature is less than T5, controlling the first outdoor heat exchanger and the second outdoor heat exchanger to reversely circulate and defrost.

In some embodiments, the detecting step can be further performed on detecting the T_{Ring (C)}And said T_PipePreviously, detecting the heating operation time t1 of the air conditioning system and the accumulative operation time t2 of the air conditioning system;

the judging step judges the relationship between t1 and t01 and judges the relationship between t2 and t 02;

the control step is that when T1 is more than or equal to T01 or T2 is more than or equal to T02, the T detection is started_{Ring (C)}And said T_PipeWherein t01 is a first predetermined time, and t02 is a second predetermined time.

In some embodiments, the controlling step is performed when T is_{Ring (C)}Not less than T1 and T_PipeControlling the first outdoor heat exchanger and the second outdoor heat exchanger to alternatively defrost when the temperature is less than or equal to T3, namely controlling the first valve to be closed, controlling the second valve to be opened, controlling the third valve to be closed, controlling the fourth valve to be opened, and controlling the first valve to be opened after the time duration of T03,controlling the second valve to be closed, controlling the third valve to be opened, controlling the fourth valve to be closed, and controlling the air conditioning system to be switched to a heating mode after the time t03, wherein the time t03 is a third preset time.

In some embodiments, the controlling step is performed when T6 ≦ T_{Ring (C)}< T1 and T_PipeAt T4 or less, wherein T2 < T6 < T1, controlling the first outdoor heat exchanger and the second outdoor heat exchanger to alternately defrost, namely controlling the first valve to close, controlling the second valve to open, controlling the third valve to close, controlling the fourth valve to open, controlling the first valve to open, controlling the second valve to close, controlling the third valve to open, controlling the fourth valve to close after a third preset time T03, and controlling the air conditioning system to be switched to a heating mode after the third preset time T03;

when T1 is not less than T04 or T2 is not less than T05, and when T_PipeAt ≦ T7, where T04 > T01, T05 > T02, T5 < T7 < T4, the control system enters the reverse cycle defrost mode and operates for a sixth preset time T06, and then controls the air conditioning system to go to the heating mode, i.e., controls the second valve and the third valve to both close, controls the first valve and the fourth valve to both open, and controls the suction of the compressor to communicate with the indoor heat exchanger.

In some embodiments, the controlling step is performed when T2 ≦ T_{Ring (C)}< T6 and T_PipeAt ≦ T7, where T2 < T6 < T1, T5 < T7 < T4, controlling the first outdoor heat exchanger and the second outdoor heat exchanger to alternately defrost, i.e., controlling the first valve to close, controlling the second valve to open, controlling the third valve to close, controlling the fourth valve to open for a seventh preset time T07, controlling the first valve to open, controlling the second valve to close, controlling the third valve to open, controlling the fourth valve to close, and also for the third preset time T03, and then controlling the air conditioning system to turn to heating mode;

when T1 is not less than T04 or T2 is not less than T05, and when T_PipeWhen the temperature is less than or equal to T2, wherein T04 is more than T01, T05 is more than T02, controlThe system enters a reverse circulation defrosting mode and operates for a sixth preset time t06, and then the air conditioning system is controlled to be switched to a heating mode, namely the second valve and the third valve are controlled to be closed, the first valve and the fourth valve are controlled to be opened, and the exhaust of the compressor is controlled to be communicated with the indoor heat exchanger, wherein t07>t06。

In some embodiments, when T_{Ring (C)}T2 and T are not more than_PipeAnd when the time is less than or equal to T5 and when the time T1 is more than or equal to the eighth preset time T08 or the time T2 is more than or equal to the ninth preset time T09, the control system enters the reverse cycle defrosting mode and operates for a tenth preset time T10.

The air conditioning system and the control method thereof have the following beneficial effects:

according to the defrosting method, the first heat accumulator connected with the first outdoor heat exchanger in series is arranged on a refrigerant pipeline of the air-conditioning system, the first heat accumulator can absorb heat from the outside of the refrigerant pipeline, the heat outside the air-conditioning system can be effectively stored in the first heat accumulator so as to defrost the first outdoor heat exchanger when the first outdoor heat exchanger needs defrosting, the second branch is connected with the second pipe section where the first heat accumulator is located in parallel, and the second branch and the second pipe section are respectively provided with the first valve and the second valve, so that the connection and the disconnection of the first heat accumulator can be controlled, and the problem of heat supply reduction in the indoor side in the segmented defrosting process of the air-conditioning system is effectively solved; the second heat accumulator which is connected with the second outdoor heat exchanger in series is arranged on a refrigerant pipeline of the air-conditioning system, the second heat accumulator can absorb heat from the outside of the refrigerant pipeline, the heat outside the air-conditioning system can be effectively utilized to be stored in the second heat accumulator so as to defrost the second outdoor heat exchanger when the second outdoor heat exchanger needs defrosting, the fourth branch is connected with the fourth pipe section where the second heat accumulator is arranged in parallel, and the fourth branch and the fourth pipe section are respectively provided with the fourth valve and the third valve, so that whether the second heat accumulator is connected or not can be controlled, the problem that the heat supply quantity inside the room is reduced in the sectional defrosting process of the air-conditioning system is effectively utilized, the heat outside the air-conditioning system is not used any more, and the heat discharged by the compressor can be effectively increased in the sectional defrosting process, the comfort level in the room is improved.

Drawings

FIG. 1 is a system diagram of a thermal storage section defrost of an air conditioning system of the present disclosure;

fig. 2 is a structural view of the first heat storage body in fig. 1.

The reference numerals are represented as:

1. a compressor; 2. a four-way valve; 3. an indoor heat exchanger; 4. a throttling device; 5. a first temperature sensor; 611. a first valve; 612. a second valve; 621. a third valve; 622. a fourth valve; 71. a first outdoor heat exchanger; 72. a second outdoor heat exchanger; 8. a second temperature sensor; 91. a first heat storage body; 92. a second heat storage body; 101. a first branch; 201. a first tube section; 202. a second tube section; 102. a second branch; 103. a third branch; 203. a third tube section; 204. a fourth tube section; 104. a fourth branch; 105. refrigerant lines (i.e., heat exchange coil pipes); 301. a first heat collecting tube; 302. a first phase change heat storage material; 303. a first electric heating member; 304. a power source.

Detailed Description

As shown in fig. 1-2, the present disclosure provides an air conditioning system comprising:

the first heat accumulator 91 is connected with the first outdoor heat exchanger 71 in series and arranged on the first branch 101, the first branch 101 comprises a first pipe section 201 and a second pipe section 202, the first outdoor heat exchanger 71 is arranged on the first pipe section 201, the first heat accumulator 91 is arranged on the second pipe section 202, the second branch 102 is arranged on the second pipe section 202 in parallel, the second branch 102 is provided with a first valve 611, the second pipe section 202 is provided with a second valve 612, and the first heat accumulator 91 can absorb heat from the outside of a refrigerant pipeline 105 to defrost the first outdoor heat exchanger 71.

This is disclosed through set up the first heat accumulator of establishing ties with first outdoor heat exchanger on air conditioning system's refrigerant pipeline, and first heat accumulator can follow the outside absorption heat of refrigerant pipeline, can utilize the outside heat deposit of air conditioning system inside in order to change the frost to first outdoor heat exchanger when first outdoor heat exchanger needs to change the frost effectively, the second branch road is parallelly connected with the second pipeline section at first heat accumulator place, and set up first valve and second valve on second branch road and the second pipeline section respectively, can control the switch-on of first heat accumulator and whether, solve the problem that the indoor side heat supply volume reduces in the air conditioning system segmentation defrosting process effectively.

In some embodiments, the heat exchanger further includes a second outdoor heat exchanger 72, a second heat accumulator 92, a third branch 103, and a fourth branch 104, the second heat accumulator 92 is connected in series with the second outdoor heat exchanger 72 and disposed on the third branch 103, the third branch 103 is connected in parallel with the first branch 101, the third branch 103 includes a third pipe segment 203 and a fourth pipe segment 204, the second outdoor heat exchanger 72 is disposed on the third pipe segment 203, the second heat accumulator 92 is disposed on the fourth pipe segment 204, the fourth branch 104 is connected in parallel with the fourth pipe segment 204, the fourth pipe segment 204 is disposed with a third valve 621, the fourth branch 104 is disposed with a fourth valve 622, and the second heat accumulator 92 can absorb heat from outside of the refrigerant pipeline to defrost the second outdoor heat exchanger 72.

The second heat accumulator which is connected with the second outdoor heat exchanger in series is arranged on a refrigerant pipeline of the air-conditioning system, the second heat accumulator can absorb heat from the outside of the refrigerant pipeline, the heat outside the air-conditioning system can be effectively utilized to be stored in the second heat accumulator so as to defrost the second outdoor heat exchanger when the second outdoor heat exchanger needs defrosting, the fourth branch is connected with the fourth pipe section where the second heat accumulator is arranged in parallel, and the fourth branch and the fourth pipe section are respectively provided with the fourth valve and the third valve, so that whether the second heat accumulator is connected or not can be controlled, the problem that the heat supply quantity inside the room is reduced in the sectional defrosting process of the air-conditioning system is effectively solved, the heat outside the air-conditioning system is effectively utilized, the heat discharged by a compressor is not used, and the heat supply quantity inside the room can be effectively increased in the sectional defrosting process, the comfort level in the room is improved.

In some embodiments, the first heat accumulator 91 is disposed at a position between the first outdoor heat exchanger 71 and the throttle device 4, and the second heat accumulator 92 is disposed at a position between the second outdoor heat exchanger 72 and the throttle device 4. According to the outdoor heat exchanger, the first heat accumulator is arranged between the first outdoor heat exchanger and the throttling device, so that when indoor heating is performed, a refrigerant flows through the throttling device for throttling and depressurizing firstly, and then reaches the first heat accumulator to be heated, and the heat can be used for heating the first outdoor heat exchanger to defrost the first outdoor heat exchanger; the second heat accumulator is arranged between the second outdoor heat exchanger and the throttling device, so that when indoor heating is conducted, the refrigerant flows through the throttling device for throttling and depressurizing firstly, and then reaches the second heat accumulator to be heated, and the heat can be used for heating the second outdoor heat exchanger to defrost the second outdoor heat exchanger.

In some embodiments, the first heat storage body 91 includes a first heat collecting tube 301 and a first phase change heat storage material 302, the first phase change heat storage material 302 is disposed inside the first heat collecting tube 301, the first heat collecting tube 301 can absorb heat by electric heating or solar energy, and the second tube segment 202 penetrates into the inside of the first heat collecting tube 301. The first heat accumulator is preferably in a structural form, namely, the first phase-change heat storage material can absorb heat in an electric heating or solar energy mode, the first heat collecting tube is used for collecting heat and transferring the heat to a refrigerant in the second tube section through connection between the second tube section and the first heat collecting tube, the heat of the refrigerant is improved, defrosting of the first outdoor heat exchanger is further performed, the first phase-change heat storage material can absorb heat to generate phase change so as to store more heat, and the heat storage capacity is improved.

In some embodiments, when first thermal-collecting tube 301 can absorb heat through electrical heating, air conditioning system still includes first electric heating component 303, first electric heating component 303 wears to establish the entering the inside of first thermal-collecting tube 301, the power 304 of first electric heating component 303 is at least one of commercial power, photovoltaic electricity, wind-powered electricity and water and electricity. This is this is the further preferred structural style of this disclosed first thermal-collecting tube, wears to establish through first heater block and gets into that first thermal-collecting tube is inside in order to heat first phase change material, and the power of first electric heater block derives from one in commercial power, photovoltaic electricity, wind-powered electricity and the water and electricity, can provide different multiple modes for the heat collection of the electrical heating of first thermal-collecting tube, avoids using the carminative heat of compressor to come the defrosting, effectively guarantees indoor heating capacity.

In some embodiments, the second heat storage body 92 includes a second heat collecting tube (not shown) and a second phase change heat storage material (not shown), the second phase change heat storage material (not shown) is disposed inside the second heat collecting tube (not shown), the second heat collecting tube (not shown) can absorb heat through electric heating or solar energy, and the fourth tube segment 204 is inserted into the inside of the second heat collecting tube (not shown). The second phase change heat storage material can absorb heat in an electric heating or solar energy mode, the second heat collection pipe is used for collecting heat, the heat is transferred to a refrigerant in the fourth pipe section through connection between the fourth pipe section and the second heat collection pipe, the heat of the refrigerant is improved, defrosting of the second outdoor heat exchanger is further performed, and the second phase change heat storage material can absorb heat to perform phase change so as to store more heat, and the heat storage capacity is improved.

In some embodiments, when the second heat collecting tube (not shown) can absorb heat through electric heating, the air conditioning system further includes a second electric heating part (not shown), the second electric heating part (not shown) penetrates into the inside of the second heat collecting tube (not shown), and a power supply of the second electric heating part is at least one of commercial power, photovoltaic power, wind power and water power. This is this is the further preferred structural style of this disclosed second thermal-collecting tube, wears to establish through the second heater block and gets into that the second thermal-collecting tube is inside in order to heat second phase change heat storage material, and the power of second electric heater block derives from one in commercial power, photovoltaic electricity, wind-powered electricity and the water and electricity, can provide different multiple modes for the heat collection of the electrical heating of second thermal-collecting tube, avoids using the carminative heat of compressor to come the defrosting, effectively guarantees indoor heating capacity.

In some embodiments, the first valve 611 and the second valve 612 are both solenoid valves; the third valve 621 and the fourth valve 622 are both solenoid valves. This is a preferred form of construction for the first, second, third and fourth valves of the present disclosure, enabling precise control of the respective circuits.

In some embodiments, a first temperature sensor 5 capable of detecting the temperature of the outdoor pipe, and a second temperature sensor 8 capable of detecting the temperature of the outdoor environment; and/or, also includes four-way valve 2. The temperature control device has the advantages that the temperature of the outdoor pipe can be detected through the first temperature sensor, and the outdoor environment temperature can be detected through the second temperature sensor so as to provide conditions for control; the four-way valve 2 comprises four ends D \ E \ S \ C.

The present disclosure also provides a control method of an air conditioning system as set forth in any of the preceding claims, wherein:

when the first outdoor heat exchanger 71, the second outdoor heat exchanger 72, the first valve 611, the second valve 612, the third valve 621, and the fourth valve 622 are included at the same time, the control method includes:

a detection step of detecting an operation mode of the air conditioning system;

a control step of controlling both the second valve 612 and the third valve 621 to be closed, controlling both the first valve 611 and the fourth valve 622 to be opened, and controlling suction air of the compressor 1 to communicate with the indoor heat exchanger 3 when the air conditioning system needs to operate in a cooling mode; when the air conditioning system needs to operate in a heating mode, controlling both the second valve 612 and the third valve 621 to be closed, controlling both the first valve 611 and the fourth valve 622 to be opened, and controlling the discharge air of the compressor 1 to communicate with the indoor heat exchanger 3;

when the first outdoor heat exchanger 71 needs defrosting, controlling the first valve 611 to be closed, controlling the second valve 612 to be opened, controlling the third valve 621 to be closed, and controlling the fourth valve 622 to be opened; when the second outdoor heat exchanger 72 needs defrosting, the first valve 611 is controlled to be opened, the second valve 612 is controlled to be closed, the third valve 621 is controlled to be opened, and the fourth valve 622 is controlled to be closed;

when the air conditioning system needs to operate in the reverse cycle defrost mode, the second valve 612 and the third valve 621 are controlled to be closed, the first valve 611 and the fourth valve 622 are controlled to be opened, and the suction air of the compressor 1 is controlled to communicate with the indoor heat exchanger 3.

The air conditioning system can judge and carry out different control modes according to different situations according to different control forms under different modes, and refrigeration, heating, segmented defrosting and reverse circulation defrosting are achieved. The second valve and the third valve are controlled to be closed in a refrigerating and heating mode, only the first valve and the fourth valve are opened, and therefore it is guaranteed that a refrigerant cannot flow through the first heat accumulator and the second heat accumulator, and the two heat accumulators do not work;

when the first outdoor heat exchanger needs defrosting, sectional defrosting is adopted, the second outdoor heat exchanger evaporates and absorbs heat to provide heat for the indoor heat exchanger, the second valve is opened to ensure that the refrigerant passes through the first heat accumulator, the third valve is closed to ensure that the refrigerant does not pass through the second heat accumulator, therefore, the refrigerant reaches the first outdoor heat exchanger after being heated by the first heat accumulator to be heated and defrosted, the refrigerant simultaneously passes through the fourth valve and enters the second outdoor heat exchanger, and the second outdoor heat exchanger normally evaporates and absorbs heat, so that the sectional defrosting effect is realized, external energy absorbed by the first heat accumulator is utilized for defrosting, the energy of the air conditioning system cannot be weakened, and the heat at the indoor side is improved;

when the second outdoor heat exchanger needs defrosting, sectional defrosting is adopted, the first outdoor heat exchanger evaporates and absorbs heat to provide heat for the indoor heat exchanger, the third valve is opened to ensure that the refrigerant passes through the second heat accumulator, and the second valve is closed to ensure that the refrigerant does not pass through the first heat accumulator, so that the refrigerant reaches the second outdoor heat exchanger after being heated by the second heat accumulator to be heated and defrosted, the refrigerant simultaneously passes through the first valve and enters the first outdoor heat exchanger, and the first outdoor heat exchanger normally evaporates and absorbs heat, so that the sectional defrosting effect is realized, external energy absorbed by the second heat accumulator is utilized for defrosting, the energy of the air conditioning system cannot be weakened, and the heat at the indoor side is improved;

under the condition that the outdoor environment temperature and the outdoor pipe temperature are low, defrosting cannot be effectively performed through sectional defrosting, a reverse circulation defrosting mode needs to be started, namely heat is absorbed from the indoor space, and the compressor reversely circulates to provide heat for the two outdoor heat exchangers so as to defrost.

The air conditioning device comprises a compressor 1, a four-way valve 2, an outdoor heat exchanger, a first heat accumulator 91, a second heat accumulator 92, a throttling device 4, an indoor heat exchanger 3 and a plurality of electromagnetic valves. The outdoor heat exchanger comprises two parts: and the first outdoor heat exchanger 71 and the second outdoor heat exchanger 72 are arranged in parallel, and a heat accumulator is arranged between each part and the throttling device.

1. In the cooling operation, the first valve 611 and the fourth valve 622 are kept open, the second valve 612 and the third valve 621 are kept closed, and the refrigerant flow direction is:

2. in heating operation, the first valve 611 and the fourth valve 622 are kept open, the second valve 612 and the third valve 621 are kept closed, and the refrigerant flow direction is:

3. when the defrosting is carried out in a segmented mode, the two parts of the outdoor heat exchanger are sequentially defrosted. When the first outdoor heat exchanger 71 is defrosted and the second outdoor heat exchanger 72 is operated for heating, the first valve 611 and the third valve 621 are kept closed, and the second valve 612 and the fourth valve 622 are kept open.

The flow direction of the refrigerant is as follows:

when the first outdoor heat exchanger 71 is in heating operation and the second outdoor heat exchanger 72 is defrosted, the first valve 611 and the third valve 621 are kept open, the second valve 612 and the fourth valve 622 are kept closed, and the refrigerant flow direction is as follows:

4. during reverse cycle defrosting, the second valve 612 and the third valve 621 are closed, the first valve 611 and the fourth valve 622 are opened, and the four-way valve is powered off, wherein the flow direction of the refrigerant is as follows:

compressor 1-four-way valve 2--throttling means 4-indoor heat exchanger 3-four-way valve 2-compressor 1.

In some embodiments, the detecting step can also detect the outdoor ambient temperature T_{Ring (C)}And outdoor pipe temperature T_Pipe；

A judgment step of judging T_{Ring (C)}And the relationship between T1 and T2, and judging T_PipeRelationships to T3, T4, and T5, wherein T1 is a first preset temperature, T2 is a second preset temperature, T3 is a third preset temperature, T4 is a fourth preset temperature, T5 is a fifth preset temperature, T1 > T2, T3 > T4 > T5;

the control step is also when T_{Ring (C)}Not less than T1, and T_PipeControlling the first outdoor heat exchanger 71 and the second outdoor heat exchanger 72 to defrost in sections and alternatively when the temperature is less than or equal to T3; also when T2 < T_{Ring (C)}< T1, and T_PipeWhen the temperature is less than or equal to T4, controlling the first outdoor heat exchanger 71 and the second outdoor heat exchanger 72 to defrost in sections and alternately defrost and reverse circulation defrost; also when T_{Ring (C)}< T2, and T_PipeIf the temperature is less than T5, the first outdoor heat exchanger 71 and the second outdoor heat exchanger 72 are controlled to reversely circulate for defrosting.

T1 is preferably 0 ℃, T2 is preferably-10 ℃, T3 is preferably-2 ℃, T4 is preferably-6 ℃ and T5 is preferably-14 ℃.

This is a further preferred control of the present disclosure, based on the outdoor ambient temperature T_{Ring (C)}And outdoor pipe temperature T_PipeJudging whether two outdoor heat exchangers should be subjected to sectional defrosting or reverse circulation defrosting, and when T is higher than the preset threshold value, judging whether two outdoor heat exchangers should be subjected to sectional defrosting or not_{Ring (C)}Not less than T1, and T_PipeWhen the defrosting effect is less than or equal to T3, the condition indicates that the frost is not too thick, and the two outdoor heat exchangers are controlled to defrost in sections and alternately at the moment, so that the effective defrosting effect of the two outdoor heat exchangers can be ensured; when T2 < T_{Ring (C)}< T1, and T_PipeWhen the defrosting effect is less than or equal to T4, the frosting is thicker at the moment, a frost layer cannot be effectively removed through sectional defrosting, and the two outdoor heat exchangers are defrosted through sectional defrosting and then combined with reverse circulation defrosting, so that the effective defrosting effect can be ensured; when T is_{Ring (C)}< T2, and T_PipeT5 indicates that frosting is very thick this moment, has failed effective defrosting through sectional type defrosting, and this disclosure can guarantee the effective defrosting effect to two outdoor heat exchangers through reverse circulation defrosting this moment.

In some embodiments, the detecting step can be further performed on detecting the T_{Ring (C)}And said T_PipePreviously, detecting the heating operation time t1 of the air conditioning system and the accumulative operation time t2 of the air conditioning system;

the judging step judges the relationship between t1 and t01 and judges the relationship between t2 and t 02;

the control step is that when T1 is more than or equal to T01 or T2 is more than or equal to T02, the T detection is started_{Ring (C)}And said T_PipeWherein t01 is a first predetermined time, and t02 is a second predetermined time. t01 is preferably 30 minutes, t02 is preferably 60 minutes.

The control method is a precondition judgment control means before the defrosting is detected and judged, namely t1 is not less than t01 or t2 is not less than t02, the system can be preliminarily judged to enter the stable running state, at the moment, whether defrosting and defrosting are needed is further judged, and the defrosting detection and defrosting control precision can be improved.

After the heating operation of the system reaches continuous 30 minutes or cumulative operation for 60 minutes, entering a sectional defrosting mode if the following conditions are met:

in some embodiments, when T is in the control step_{Ring (C)}Not less than T1 and T_PipeAt T3, the first outdoor heat exchanger 71 and the second outdoor heat exchanger 72 are controlled to alternately defrost, that is, the previous operation steps are to control the first valve 611 to close, control the second valve 612 to open, control the third valve 621 to close, control the fourth valve 622 to open, control the first valve 611 to open after a time T03, control the second valve 612 to close, control the third valve 621 to open, control the fourth valve 622 to close, and also control the air conditioning system to switch to the heating mode after the time T03, wherein T03 is a third preset time. t01 is preferably 30 minutes, t02 is preferably 60 minutes, and t03 is preferably 2 minutes.

This is the sectional defrosting judgment and control method of the present disclosure, T_{Ring (C)}Not less than T1 and T_PipeJudge that the frost layer is not too thick when T3 is less than or equal to, through control two outdoor heat exchanger segmentation defrosting and change the frost in turn, can guarantee the effective defrosting effect to two outdoor heat exchangers, change the heat exchanger of defrosting behind T03, belong to regularly the defrosting, namely the defrosting T03 minute to second outdoor heat exchanger 72 again behind first outdoor heat exchanger 71 defrosting T03 minute, can realize the effect of changing the frost in turn.

The preferred mode in this case is T_{Ring (C)}≥0，T_PipeLess than or equal to-2; the second valve 612 is opened, the first valve 611 is closed, after 2 minutes of operation, the first valve 611 and the third valve 621 are opened, the second valve 612 and the fourth valve 622 are closed, and after 2 minutes of operation, the system goes to normal heating mode.

② in some embodiments, in the controlling step, when T6 ≦ T_{Ring (C)}< T1 and T_PipeT4, wherein T2 < T6 < T1, and T6 is preferably-5 ℃, controlling the first outdoor heat exchanger 71 and the second outdoor heat exchanger 72 to alternately defrost, i.e., controlling the first valve 611 to close, the second valve 612 to open, the third valve 621 to close, and the fourth valve 622 to open during a period of timeAfter a third preset time t03, controlling the first valve 611 to open, the second valve 612 to close, the third valve 621 to open, the fourth valve 622 to close, and the third preset time t03, and then controlling the air conditioning system to switch to a heating mode;

when T1 is not less than T04 or T2 is not less than T05, and when T_PipeT7 is preferably-10 ℃ at ≦ T7, where T04 > T01, T05 > T02, T5 < T7 < T4, the control system enters the reverse cycle defrost mode and operates for a sixth predetermined time T06, and then controls the air conditioning system to go to the heating mode, i.e., controls the second valve 612 and the third valve 621 to both be closed, controls the first valve 611 and the fourth valve 622 to both be open, and controls the discharge of the compressor 1 to communicate with the indoor heat exchanger 3.

The method for judging and controlling sectional defrosting and reverse circulation defrosting is disclosed, and T is more than or equal to T6_{Ring (C)}< T1 and T_PipeJudging that the frost layer is a bit thick when the temperature is less than or equal to T4, and controlling the modes of sectional defrosting, alternate defrosting and reverse circulation defrosting of the two outdoor heat exchangers to ensure the effective defrosting effect of the two outdoor heat exchangers, when the temperature is more than or equal to T04 when T1 or more than or equal to T2 or more than or equal to T05, and when the temperature is more than or equal to T2_PipeT7 is less than or equal to the frost, and the single sectional defrosting can not be removed completely, so that the reverse cycle defrosting is needed to ensure the defrosting is clean.

The preferred modes in this case are: -5. ltoreq. T_{Ring (C)}＜0，T_PipeLess than or equal to-6; the second valve 612 is opened, the first valve 611 is closed, after 2 minutes of operation, the first valve 611 and the third valve 621 are opened, the second valve 612 and the fourth valve 622 are closed, and after 2 minutes of operation, the system is switched to a normal heating mode; when the system is continuously operated for 2 hours or the cumulative operation reaches 4 hours and T_PipeAnd (3) the four-way valve is powered off, the system is switched to a reverse circulation defrosting mode for 4 minutes, and then the system is switched to a normal heating mode.

③ in some embodiments, in the step of controlling, when T2 is less than or equal to T_{Ring (C)}< T6 and T_PipeAt ≦ T7, wherein T2 < T6 < T1, T5 < T7 < T4, controlling the alternating defrosting of the first outdoor heat exchanger 71 and the second outdoor heat exchanger 72, i.e. controlling the first valve during the previous period of time611 is closed, the second valve 612 is controlled to be opened, the third valve 621 is controlled to be closed, the fourth valve 622 is controlled to be opened, after a seventh preset time t07, the first valve 611 is controlled to be opened, the second valve 612 is controlled to be closed, the third valve 621 is controlled to be opened, the fourth valve 622 is controlled to be closed, the third preset time t03 is also continued, and then the air-conditioning system is controlled to be switched to a heating mode;

when T1 is not less than T04 or T2 is not less than T05, and when T_PipeT2, wherein T04 > T01, T05 > T02, the control system enters a reverse cycle defrost mode and operates for a sixth preset time T06, and then controls the air conditioning system to go to a heating mode, i.e., controls the second valve 612 and the third valve 621 to both be closed, controls the first valve 611 and the fourth valve 622 to both be open, and controls the discharge air of the compressor 1 to communicate with the indoor heat exchanger 3, wherein T07>t06。

The method for judging and controlling sectional defrosting and reverse circulation defrosting is disclosed, and T is more than or equal to T2_{Ring (C)}< T6 and T_PipeJudging that the frost layer is thicker than the second condition when the frost layer is less than or equal to T7, and controlling the modes of sectional defrosting, alternate defrosting and reverse circulation defrosting of the two outdoor heat exchangers to ensure the effective defrosting effect of the two outdoor heat exchangers, when T1 is more than or equal to T04 or T2 is more than or equal to T05, and when T1 is more than or equal to T04 or T2 is more than or equal to T05_PipeWhen the defrosting time is less than or equal to T2, frost is thicker, and the single sectional defrosting can not be completely removed, so that reverse cycle defrosting is needed to ensure that the defrosting is clean, and the sectional defrosting time T07 is longer than the sectional defrosting time T06 under the second condition, so that the sectional defrosting time is prolonged, and the defrosting effect is enhanced.

The preferred conditions for this are: -10. ltoreq. T_{Ring (C)}＜-5，T_PipeLess than or equal to-10; the second valve 612 is opened, the first valve 611 is closed, after 3 minutes of operation, the first valve 611 and the third valve 621 are opened, the second valve 612 and the fourth valve 622 are closed, and after 3 minutes of operation, the system is switched to a normal heating mode; when the system is continuously operated for 2 hours or the cumulative operation reaches 4 hours and T_PipeThe four-way valve is powered off at most-10, the system is switched to a reverse circulation defrosting mode for 4 minutes, and then the system is switched to a normal heating mode;

because frost build-up is thick, longer defrosting times are required. The frost is relatively thick, and the single sectional defrosting can not be completely removed, so that reverse cycle defrosting is needed to ensure that the defrosting is clean. The reverse circulation defrosting is used for ensuring the defrosting effect when the sectional defrosting is insufficient.

(iv) in some embodiments, when T is_{Ring (C)}T2 and T are not more than_PipeWhen the time is less than or equal to T5, and when the time T1 is more than or equal to the eighth preset time T08 or the time T2 is more than or equal to the ninth preset time T09, the time T08 is preferably 45 minutes, and the time T09 is preferably 60 minutes, the control system enters a reverse cycle defrosting mode and operates for a tenth preset time T10. t10 is preferably 6 minutes. It is therefore preferred that this case is T_{Ring (C)}＜-10，T_PipeThe system continuously runs for 45 minutes or runs for 60 minutes cumulatively, and the system switches to a reverse circulation defrosting mode for 6 minutes;

when T is_{Ring (C)}< T2, and T_PipeT5 indicates that frosting is very thick this moment, has failed effective defrosting through sectional type defrosting, and this disclosure can guarantee the effective defrosting effect to two outdoor heat exchangers through reverse circulation defrosting this moment. If the frosting condition reaches the degree, the frosting condition is very bad, even the frosting condition is possibly frozen, and the sectional defrosting can not be carried out, so the reverse circulation defrosting is directly used to ensure the defrosting effect of the two outdoor heat exchangers.

The above description is only exemplary of the present disclosure and should not be taken as limiting the disclosure, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure. The foregoing is only a preferred embodiment of the present disclosure, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present disclosure, and these modifications and variations should also be regarded as the protection scope of the present disclosure.