Heat recovery multi-split air conditioning system and control method thereof

Abstract

The present invention provides a heat recovery multi-split air conditioning system and a control method thereof, wherein a heat recovery multi-split air conditioning system comprises a heat recovery outdoor unit refrigerant system, an indoor water circulation pretreatment system and a plurality of indoor water circulation heat exchange systems, wherein the plurality of indoor water circulation heat exchange systems respectively form heat exchange with the heat recovery outdoor unit refrigerant system through their respective first heat exchangers, the indoor water circulation pretreatment system forms heat exchange with the heat recovery outdoor unit refrigerant system through a second heat exchanger, and the indoor water circulation pretreatment system forms heat exchange with the indoor water circulation heat exchange system through a third heat exchanger. According to the present invention, the indoor water circulation pretreatment system can be controlled to pre-treat the water entering the indoor heat exchanger for heating or cooling, thereby enabling the indoor water circulation heat exchange system to quickly heat or cool, and shortening the temperature regulation response speed of the indoor water circulation heat exchange system.

Description

Technical Field

[0001] The present invention belongs to the technical field of air conditioning, and in particular relates to a heat recovery multi-split air conditioning system and a control method thereof. Background Art

[0002] Since all outdoor and indoor pipes of a multi-split air conditioning system are interconnected, once a refrigerant leak occurs indoors, all the refrigerant in the system will leak into one room, causing the refrigerant concentration in the room to be too high, posing a safety hazard. In response to the aforementioned problems, the prior art mostly uses a heat recovery multi-split air conditioning system, in which only water flows through the indoor unit without circulating refrigerant, completely avoiding the risk of refrigerant leaking into the room. However, this type of air conditioning system regulates the indoor temperature based on water as a heat exchange medium, which means that the water needs to be heated (cooled), and the specific heat capacity of water is relatively high, so the heat exchange process will take longer than air, thus prolonging the time it takes to produce a comfort effect. Summary of the invention

[0003] Therefore, the technical problem to be solved by the present invention is to provide a heat recovery multi-split air-conditioning system and a control method thereof, wherein the indoor water circulation pretreatment system can be controlled to pre-heat or cool the water entering the indoor heat exchanger, thereby enabling the indoor water circulation heat exchange system to quickly heat or cool and shorten the temperature regulation response speed of the indoor water circulation heat exchange system.

[0004] In order to solve the above problems, the present invention provides a heat recovery multi-split air-conditioning system, including a heat recovery outdoor refrigerant system, an indoor water circulation pretreatment system and a plurality of indoor water circulation heat exchange systems, the plurality of indoor water circulation heat exchange systems respectively form heat exchange with the heat recovery outdoor refrigerant system through their respective corresponding first heat exchangers, the indoor water circulation pretreatment system forms heat exchange with the heat recovery outdoor refrigerant system through a second heat exchanger, and the indoor water circulation pretreatment system forms heat exchange with the indoor water circulation heat exchange system through a third heat exchanger.

[0005] Preferably, the second heat exchanger includes a first preheating heat exchanger and a first precooling heat exchanger, the third heat exchanger includes a second preheating heat exchanger and a second precooling heat exchanger, a water circulation is formed between the first preheating heat exchanger and the second preheating heat exchanger, and a water circulation is formed between the first precooling heat exchanger and the second precooling heat exchanger.

[0006] Preferably, the indoor water circulation heat exchange system comprises a water tank, the water tank has a first water branch tank and a second water branch tank which are independent of each other, the second preheating heat exchanger is located in the first water branch tank, and the second precooling heat exchanger is located in the second water branch tank.

[0007] Preferably, the indoor water circulation heat exchange system also includes an indoor heat exchanger, which is connected to the first port of the first heat exchanger, and the indoor heat exchanger can be selectively connected to one of the first water distribution tank and the second water distribution tank through a first reversing valve, and the second port of the first heat exchanger can be selectively connected to one of the first water distribution tank and the second water distribution tank through a second reversing valve.

[0008] Preferably, the first water distribution tank has a first water outlet pipe, the second water distribution tank has a second water outlet pipe, and a first electromagnetic stop valve is further provided between the first water outlet pipe and the second water outlet pipe.

[0009] Preferably, the first water outlet pipe is provided with a water outlet of a first water pump connected to the first port of the second reversing valve, and the second water outlet pipe is provided with a water outlet of a second water pump connected to the second port of the second reversing valve.

[0010] Preferably, a second electromagnetic stop valve is provided between the second reversing valve and the second port of the first heat exchanger.

[0011] The present invention also provides a control method for a heat recovery multi-split air conditioning system, which is used to control the heat recovery multi-split air conditioning system, comprising the following steps:

[0012] Acquire the operation mode of a first indoor water circulation heat exchange system among the multiple indoor water circulation heat exchange systems of the heat recovery multi-split air conditioning system, the water temperature of the first indoor water circulation heat exchange system, and the indoor environment temperature corresponding to the first indoor water circulation heat exchange system;

[0013] Compare the obtained water temperature with the indoor ambient temperature;

[0014] According to the acquired operation mode and size relationship, the refrigerant passage on the refrigerant side of the second heat exchanger, the refrigerant passage on the refrigerant side of the first heat exchanger corresponding to the first indoor water circulation heat exchange system, and the first reversing valve and the second reversing valve corresponding to the first indoor water circulation heat exchange system are controlled and switched. The first indoor water circulation heat exchange system is any one of the multiple indoor water circulation heat exchange systems.

[0015] Preferably, when the operation mode of the first indoor water circulation heat exchange system is the cooling mode and the water temperature is ≥ the indoor ambient temperature, the throttling element corresponding to the first pre-cooling heat exchanger in the second heat exchanger is controlled to open, the low-pressure electromagnetic stop valve is controlled to open, and the high-pressure electromagnetic stop valve is controlled to close; the throttling element corresponding to the first heat exchanger corresponding to the first indoor water circulation heat exchange system is controlled to open, the low-pressure electromagnetic stop valve is controlled to open, and the high-pressure electromagnetic stop valve is controlled to close; the first reversing valve and the second reversing valve corresponding to the first indoor water circulation heat exchange system are controlled to be connected to the second water distribution tank respectively.

[0016] Preferably, after controlling the throttling element corresponding to the first pre-cooling heat exchanger in the second heat exchanger to open, the low-pressure electromagnetic stop valve to open, and the high-pressure electromagnetic stop valve to close for a first preset time, the user-set temperature is obtained, and when the indoor ambient temperature is ≤ the user-set temperature + △Tl, the refrigerant in the first pre-cooling heat exchanger is controlled to be cut off, △Tl is the cooling preset temperature threshold, △Tl>0℃.

[0017] Preferably, when the operation mode of the first indoor water circulation heat exchange system is the heating mode and the water temperature is ≤ the indoor ambient temperature, the throttling element corresponding to the first preheating heat exchanger in the second heat exchanger is controlled to open, the high-pressure electromagnetic stop valve is controlled to open, and the low-pressure electromagnetic stop valve is controlled to close; the throttling element corresponding to the first heat exchanger corresponding to the first indoor water circulation heat exchange system is controlled to open, the high-pressure electromagnetic stop valve is controlled to open, and the low-pressure electromagnetic stop valve is controlled to close; the first reversing valve and the second reversing valve corresponding to the first indoor water circulation heat exchange system are controlled to be connected to the first water distribution tank respectively.

[0018] Preferably, after controlling the throttling element corresponding to the first preheating heat exchanger in the second heat exchanger to open, the high-pressure electromagnetic stop valve to open, and the low-pressure electromagnetic stop valve to close for a first preset time, the user-set temperature is obtained, and when the indoor ambient temperature is ≥ the user-set temperature - △Tr, the refrigerant in the first preheating heat exchanger is controlled to be cut off, △Tr is the heating preset temperature threshold, △Tr>0℃.

[0019] Preferably, when the operation mode of all indoor water circulation heat exchange systems is cooling mode and the water temperature is ≥ indoor ambient temperature, the throttling elements corresponding to the first precooling heat exchanger and the first preheating heat exchanger in the second heat exchanger are controlled to open, the low-pressure electromagnetic stop valve is opened, and the high-pressure electromagnetic stop valve is closed; the throttling elements corresponding to the first heat exchanger corresponding to each indoor water circulation heat exchange system are controlled to open, the low-pressure electromagnetic stop valve is opened, and the high-pressure electromagnetic stop valve is closed; the first reversing valve and the second reversing valve corresponding to each indoor water circulation heat exchange system are controlled to be connected with the second water distribution tank respectively, and the first water distribution tank is controlled to be connected with the second water distribution tank.

[0020] Preferably, when the operation mode of all indoor water circulation heat exchange systems is the heating mode and the water temperature is ≤ the indoor ambient temperature, the throttling elements corresponding to the first precooling heat exchanger and the first preheating heat exchanger in the second heat exchanger are controlled to open, the high-pressure electromagnetic stop valve is controlled to open, and the low-pressure electromagnetic stop valve is controlled to close; the throttling elements corresponding to the first heat exchanger corresponding to each indoor water circulation heat exchange system are controlled to open, the high-pressure electromagnetic stop valve is controlled to open, and the low-pressure electromagnetic stop valve is controlled to close; the first reversing valve and the second reversing valve corresponding to each indoor water circulation heat exchange system are controlled to be connected with the first water distribution tank respectively, and the first water distribution tank is controlled to be connected with the second water distribution tank.

[0021] The present invention provides a heat recovery multi-split air-conditioning system and a control method thereof. Since the indoor water circulation pretreatment system forms heat exchange with the heat recovery machine refrigerant system through the second heat exchanger and forms heat exchange with the indoor water circulation heat exchange system through the third heat exchanger, the water entering the indoor heat exchanger can be pre-heated or cooled before entering, thereby enabling the indoor water circulation heat exchange system to quickly heat or cool, shortening the temperature regulation response speed of the indoor water circulation heat exchange system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a schematic structural diagram of a heat recovery multi-split air conditioning system according to an embodiment of the present invention.

[0023] The reference numerals are as follows:

[0024] 1. First heat exchanger; 11. Heat recovery outdoor unit; 12. Liquid pipe main; 13. Low-pressure gas pipe main; 14. High-pressure gas pipe main; 15. Throttling element; 16. High-pressure electromagnetic stop valve; 17. Low-pressure electromagnetic stop valve; 2. Second heat exchanger; 21. First preheating heat exchanger; 22. First precooling heat exchanger; 23. Third water pump; 24. Fourth water pump; 3. Third heat exchanger; 31. Second preheating heat exchanger; 32. Second precooling heat exchanger; 33. Water tank; 331. First water distribution tank; 332. Second water distribution tank; 333. First electromagnetic stop valve; 34. Indoor heat exchanger; 35. First reversing valve; 36. Second reversing valve; 371. First water pump; 372. Second water pump; 38. Second electromagnetic stop valve. DETAILED DESCRIPTION

[0025] See also Figure 1As shown, according to an embodiment of the present invention, a heat recovery multi-split air conditioning system is provided, including a heat recovery outdoor unit refrigerant system, an indoor water circulation pretreatment system and a plurality of indoor water circulation heat exchange systems, wherein the heat recovery outdoor unit refrigerant system specifically includes a heat recovery outdoor unit 11 and a liquid pipe main pipe 12, a low-pressure gas pipe main pipe 13 and a high-pressure gas pipe main pipe 14 led out thereof, the liquid pipe main pipe 12, the low-pressure gas pipe main pipe 13 and the high-pressure gas pipe main pipe 14 are respectively connected to the corresponding first heat exchanger 1 or the second heat exchanger 2 through corresponding branch pipes, and a throttling element 15 and a corresponding throttling element 16 are provided on the branch pipe corresponding to the liquid pipe main pipe 12. A low-pressure electromagnetic stop valve 17 is provided on the branch pipe of the low-pressure gas main pipe 13, and a high-pressure electromagnetic stop valve 16 is provided on the branch pipe corresponding to the high-pressure gas main pipe 14, so as to realize the switching of the refrigerant passage on the refrigerant side of the first heat exchanger 1 and the second heat exchanger 2. The multiple indoor water circulation heat exchange systems respectively form heat exchange with the heat recovery outdoor refrigerant system through their corresponding first heat exchangers 1, the indoor water circulation pretreatment system forms heat exchange with the heat recovery outdoor refrigerant system through the second heat exchanger 2, and the indoor water circulation pretreatment system and the indoor water circulation heat exchange system form heat exchange through the third heat exchanger 3. In this technical solution, since the indoor water circulation pretreatment system forms heat exchange with the heat recovery machine refrigerant system through the second heat exchanger 2 and forms heat exchange with the indoor water circulation heat exchange system through the third heat exchanger 3, the water entering the indoor heat exchanger 34 can be pre-heated or cooled before entering, so that the indoor water circulation heat exchange system can be quickly heated or cooled, shortening the temperature regulation response speed of the indoor water circulation heat exchange system.

[0026] Specifically, the second heat exchanger 2 includes a first preheating heat exchanger 21 and a first precooling heat exchanger 22, and the third heat exchanger 3 includes a second preheating heat exchanger 31 and a second precooling heat exchanger 32. A water cycle is formed between the first preheating heat exchanger 21 and the second preheating heat exchanger 31, and a water cycle is formed between the first precooling heat exchanger 22 and the second precooling heat exchanger 32. The indoor water circulation heat exchange system includes a water tank 33, and the water tank 33 has a first water branch tank 331 and a second water branch tank 332 that are independent of each other. The second preheating heat exchanger 31 is located in the first water branch tank 331, and the second precooling heat exchanger 32 is located in the second water branch tank 332. The first water branch tank 331 and the second water branch tank 332 are separately arranged to adapt to the random selectivity of cooling or heating of multiple indoor water circulation heat exchange systems, so that the rapid heating or cooling in the dual mode of cooling and heating of the air conditioning system can be used.

[0027] Furthermore, the indoor water circulation heat exchange system also includes an indoor heat exchanger 34, which is connected to the first port of the first heat exchanger 1. The indoor heat exchanger 34 can be selectively connected to one of the first water distribution tank 331 and the second water distribution tank 332 through a first reversing valve 35, and the second port of the first heat exchanger 1 can be selectively connected to one of the first water distribution tank 331 and the second water distribution tank 332 through a second reversing valve 36, so that the indoor water circulation heat exchange system can have a dual-mode selection that is compatible with the cooling and heating modes of the heat recovery outdoor unit refrigerant system.

[0028] The first water distribution tank 331 has a first water outlet pipe, the second water distribution tank 332 has a second water outlet pipe, and a first electromagnetic stop valve 333 is also provided between the first water outlet pipe and the second water outlet pipe, so that when the multiple indoor water circulation pretreatment systems are all in heating mode or cooling mode, the first water distribution tank 331 and the second water distribution tank 332 can be combined to improve the pretreatment capacity of the indoor water circulation heat exchange system. It can be understood that when the multiple indoor water circulation pretreatment systems are all in heating mode, the refrigerant flow path in the first precooling heat exchanger 22 is also controlled as a heating flow path, so that the first precooling heat exchanger 22 and the second precooling heat exchanger 32 can objectively play a cooling role.

[0029] The first water outlet pipe is provided with a water outlet of a first water pump 371 which is communicated with the first port of the second reversing valve 36, and the second water outlet pipe is provided with a water outlet of a second water pump 372 which is communicated with the second port of the second reversing valve 36, so as to ensure that the water in the indoor water circulation heat exchange system is first heated or cooled by the corresponding heat exchanger in the water tank 33 before flowing into the corresponding indoor heat exchanger 34. Furthermore, a second electromagnetic stop valve 38 is provided between the second reversing valve 36 and the second port of the first heat exchanger 1, so as to control the second electromagnetic stop valve 38 to close so as to close the corresponding indoor water circulation heat exchange system.

[0030] Furthermore, the indoor water circulation pretreatment system has a third water pump 23 and a fourth water pump 24. The third water pump 23 is located in the pipeline between the first precooling heat exchanger 22 and the second precooling heat exchanger 32, and the fourth water pump 24 is located in the pipeline between the first preheating heat exchanger 21 and the second preheating heat exchanger 31, so as to realize the rapid operation of its water circulation.

[0031] According to an embodiment of the present invention, a control method for a heat recovery multi-split air conditioning system is also provided, which is used to control the above-mentioned heat recovery multi-split air conditioning system, comprising the following steps:

[0032] Acquire the operation mode of a first indoor water circulation heat exchange system among the multiple indoor water circulation heat exchange systems of the heat recovery multi-split air conditioning system, the water temperature of the first indoor water circulation heat exchange system, and the indoor environment temperature corresponding to the first indoor water circulation heat exchange system;

[0033] Compare the obtained water temperature with the indoor ambient temperature;

[0034] According to the acquired operation mode and size relationship, the refrigerant passage on the refrigerant side of the second heat exchanger 2, the refrigerant passage on the refrigerant side of the first heat exchanger 1 corresponding to the first indoor water circulation heat exchange system, and the first reversing valve 35 and the second reversing valve 36 corresponding to the first indoor water circulation heat exchange system are controlled and switched. The first indoor water circulation heat exchange system is any one of the multiple indoor water circulation heat exchange systems.

[0035] In this technical solution, by acquiring the operating mode of each indoor water circulation heat exchange system, the refrigerant operating state (cooling or heating) on ​​the refrigerant side of the corresponding first heat exchanger 1 can be controlled to meet the mode selection requirements on the indoor side. When there is a difference between the indoor water temperature and the indoor ambient temperature, the corresponding indoor water circulation pretreatment system is started to pretreat the water in the corresponding indoor water circulation heat exchange system, thereby achieving rapid heating or cooling.

[0036] In some embodiments, when the operation mode of the first indoor water circulation heat exchange system is the cooling mode and the water temperature is ≥ the indoor ambient temperature, the throttling element 15 corresponding to the first pre-cooling heat exchanger 22 in the second heat exchanger 2 is controlled to be opened, the low-pressure electromagnetic stop valve 17 is controlled to be opened, and the high-pressure electromagnetic stop valve 16 is controlled to be closed; the throttling element 15 corresponding to the first heat exchanger 1 corresponding to the first indoor water circulation heat exchange system is controlled to be opened, the low-pressure electromagnetic stop valve 17 is controlled to be opened, and the high-pressure electromagnetic stop valve 16 is controlled to be closed; the first reversing valve 35 and the second reversing valve 36 corresponding to the first indoor water circulation heat exchange system are controlled to be connected with the second water distribution tank 332 respectively. It can be understood that at this time, the first water pump 371, the second water pump 372, the third water pump 23, and the fourth water pump 24 are also controlled to operate simultaneously to ensure the water circulation power in the corresponding system.

[0037] After the throttling element 15 corresponding to the first precooling heat exchanger 22 in the second heat exchanger 2 is controlled to open, the low-pressure electromagnetic stop valve 17 is opened, and the high-pressure electromagnetic stop valve 16 is closed to execute the first preset time, the user set temperature is obtained, and when the indoor ambient temperature is ≤ the user set temperature + △Tl, the refrigerant in the first precooling heat exchanger 22 is controlled to be cut off, △Tl is the cooling preset temperature threshold, △Tl>0℃, for example, △Tl=3℃. In this way, the indoor water circulation pretreatment system can be shut down in advance in the cooling mode to achieve energy saving. At the same time, the third water pump 23 and the fourth water pump 24 are also controlled to be shut down at the same time.

[0038] In some embodiments, when the operation mode of the first indoor water circulation heat exchange system is the heating mode and the water temperature is ≤ the indoor ambient temperature, the throttling element 15 corresponding to the first preheating heat exchanger 21 in the second heat exchanger 2 is controlled to be opened, the high-pressure electromagnetic stop valve 16 is controlled to be opened, and the low-pressure electromagnetic stop valve 17 is controlled to be closed; the throttling element 15 corresponding to the first heat exchanger 1 corresponding to the first indoor water circulation heat exchange system is controlled to be opened, the high-pressure electromagnetic stop valve 16 is controlled to be opened, and the low-pressure electromagnetic stop valve 17 is controlled to be closed, and the first reversing valve 35 and the second reversing valve 36 corresponding to the first indoor water circulation heat exchange system are controlled to be connected to the first water distribution tank 331 respectively. It can be understood that at this time, the first water pump 371, the second water pump 372, the third water pump 23, and the fourth water pump 24 are also controlled to operate at the same time to ensure the water circulation power in the corresponding system.

[0039] After the throttling element 15 corresponding to the first preheating heat exchanger 21 in the second heat exchanger 2 is controlled to open, the high-pressure electromagnetic stop valve 16 is opened, and the low-pressure electromagnetic stop valve 17 is closed for the first preset time, the user set temperature is obtained, and when the indoor ambient temperature is ≥ the user set temperature-△Tr, the refrigerant in the first preheating heat exchanger 21 is controlled to be cut off, and △Tr is the preset temperature threshold for heating, △Tr>0℃, for example, △Tr=3℃. In this way, the indoor water circulation pretreatment system can be shut down in advance in the cooling mode to achieve energy saving. At the same time, the third water pump 23 and the fourth water pump 24 are also controlled to be shut down at the same time.

[0040] In some embodiments, when the operation mode of all indoor water circulation heat exchange systems is cooling mode and the water temperature is ≥ indoor ambient temperature, the throttling elements 15 corresponding to the first precooling heat exchanger 22 and the first preheating heat exchanger 21 in the second heat exchanger 2 are controlled to be opened, the low-pressure electromagnetic stop valve 17 is opened, and the high-pressure electromagnetic stop valve 16 is closed; the throttling element 15 corresponding to the first heat exchanger 1 corresponding to each indoor water circulation heat exchange system is controlled to be opened, the low-pressure electromagnetic stop valve 17 is opened, and the high-pressure electromagnetic stop valve 16 is closed, and the first reversing valve 35 and the second reversing valve 36 corresponding to each indoor water circulation heat exchange system are controlled to be connected to the second water distribution tank 332 respectively, and the first water distribution tank 331 and the second water distribution tank 332 are controlled to be connected. connected; or, when the operation mode of all indoor water circulation heat exchange systems is heating mode and the water temperature is ≤ indoor ambient temperature, the throttling elements 15 corresponding to the first precooling heat exchanger 22 and the first preheating heat exchanger 21 in the second heat exchanger 2 are controlled to be opened, the high-pressure electromagnetic stop valve 16 is opened, and the low-pressure electromagnetic stop valve 17 is closed; the throttling element 15 corresponding to the first heat exchanger 1 corresponding to each indoor water circulation heat exchange system is controlled to be opened, the high-pressure electromagnetic stop valve 16 is opened, and the low-pressure electromagnetic stop valve 17 is closed, the first reversing valve 35 and the second reversing valve 36 corresponding to each indoor water circulation heat exchange system are controlled to be connected to the first water distribution tank 331 respectively, and the first water distribution tank 331 is controlled to be connected to the second water distribution tank 332.

[0041] It is understandable that when the heat recovery multi-split air-conditioning system is selected to be shut down, the corresponding water pump, electromagnetic stop valve, and switching valve will all be shut down and stop running.

[0042] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0043] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention, and these improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A control method for a heat recovery multi-split air conditioning system, characterized in that: Used to control a heat recovery multi-split air conditioning system, the heat recovery multi-split air conditioning system comprises a heat recovery outdoor refrigerant system, an indoor water circulation pretreatment system and a plurality of indoor water circulation heat exchange systems, the plurality of indoor water circulation heat exchange systems respectively form heat exchange with the heat recovery outdoor refrigerant system through their respective first heat exchangers (1), the indoor water circulation pretreatment system forms heat exchange with the heat recovery outdoor refrigerant system through a second heat exchanger (2), and the indoor water circulation pretreatment system forms heat exchange with the indoor water circulation heat exchange system through a third heat exchanger (3); the second heat exchanger (2) comprises a first preheating heat exchanger (21) and a first precooling heat exchanger (22), the third heat exchanger (3) comprises a second preheating heat exchanger (31) and a second precooling heat exchanger (32), a water circulation is formed between the first preheating heat exchanger (21) and the second preheating heat exchanger (31), the first precooling heat exchanger (22) and the first precooling heat exchanger (22) form a water circulation, and the first precooling heat exchanger (22) and the second preheating heat exchanger (32) form a water circulation. A water cycle is formed between the two precooling heat exchangers (32); the indoor water circulation heat exchange system comprises a water tank (33), the water tank (33) comprises a first water branch tank (331) and a second water branch tank (332) which are independent of each other, the second preheating heat exchanger (31) is located in the first water branch tank (331), and the second precooling heat exchanger (32) is located in the second water branch tank (332); the indoor water circulation heat exchange system further comprises an indoor heat exchanger (34), the indoor heat exchanger (34) is communicated with a first port of the first heat exchanger (1), the indoor heat exchanger (34) can be selectively communicated with one of the first water branch tank (331) and the second water branch tank (332) through a first reversing valve (35), and the second port of the first heat exchanger (1) can be selectively communicated with one of the first water branch tank (331) and the second water branch tank (332) through a second reversing valve (36); the control method comprises the following steps: Acquire the operation mode of a first indoor water circulation heat exchange system among the multiple indoor water circulation heat exchange systems of the heat recovery multi-split air conditioning system, the water temperature of the first indoor water circulation heat exchange system, and the indoor environment temperature corresponding to the first indoor water circulation heat exchange system; Compare the obtained water temperature with the indoor ambient temperature; According to the acquired operation mode and size relationship, the refrigerant passage on the refrigerant side of the second heat exchanger (2), the refrigerant passage on the refrigerant side of the first heat exchanger (1) corresponding to the first indoor water circulation heat exchange system, and the first reversing valve (35) and the second reversing valve (36) corresponding to the first indoor water circulation heat exchange system are controlled and switched. The first indoor water circulation heat exchange system is any one of the multiple indoor water circulation heat exchange systems.

2. The control method of the heat recovery multi-split air conditioning system according to claim 1, characterized in that: When the operation mode of the first indoor water circulation heat exchange system is the cooling mode and the water temperature is greater than or equal to the indoor ambient temperature, the throttling element (15) corresponding to the first precooling heat exchanger (22) in the second heat exchanger (2) is controlled to be opened, the low-pressure electromagnetic stop valve (17) is controlled to be opened, and the high-pressure electromagnetic stop valve (16) is controlled to be closed; the throttling element (15) corresponding to the first heat exchanger (1) corresponding to the first indoor water circulation heat exchange system is controlled to be opened, the low-pressure electromagnetic stop valve (17) is controlled to be opened, and the high-pressure electromagnetic stop valve (16) is controlled to be closed; and the first reversing valve (35) and the second reversing valve (36) corresponding to the first indoor water circulation heat exchange system are controlled to be connected to the second water distribution tank (332) respectively.

3. The control method of the heat recovery multi-split air conditioning system according to claim 2, characterized in that: After controlling the throttling element (15) corresponding to the first precooling heat exchanger (22) in the second heat exchanger (2) to open, the low-pressure electromagnetic stop valve (17) to open, and the high-pressure electromagnetic stop valve (16) to close for a first preset time, the user set temperature is obtained. When the indoor ambient temperature is ≤ the user set temperature + △Tl, the refrigerant in the first precooling heat exchanger (22) is controlled to be cut off, △Tl is the cooling preset temperature threshold, △Tl>0°C.

4. The control method of the heat recovery multi-split air conditioning system according to claim 1, characterized in that: When the operation mode of the first indoor water circulation heat exchange system is the heating mode and the water temperature is ≤ the indoor ambient temperature, the throttling element (15) corresponding to the first preheating heat exchanger (21) in the second heat exchanger (2) is controlled to be opened, the high-pressure electromagnetic stop valve (16) is controlled to be opened, and the low-pressure electromagnetic stop valve (17) is controlled to be closed; the throttling element (15) corresponding to the first heat exchanger (1) corresponding to the first indoor water circulation heat exchange system is controlled to be opened, the high-pressure electromagnetic stop valve (16) is controlled to be opened, and the low-pressure electromagnetic stop valve (17) is controlled to be closed; and the first reversing valve (35) and the second reversing valve (36) corresponding to the first indoor water circulation heat exchange system are controlled to be connected to the first water distribution tank (331) respectively.

5. The control method of the heat recovery multi-split air conditioning system according to claim 4, characterized in that: After controlling the throttling element (15) corresponding to the first preheating heat exchanger (21) in the second heat exchanger (2) to open, the high-pressure electromagnetic stop valve (16) to open, and the low-pressure electromagnetic stop valve (17) to close for a first preset time, the user set temperature is obtained, and when the indoor ambient temperature is ≥ the user set temperature - △Tr, the refrigerant in the first preheating heat exchanger (21) is controlled to be cut off, △Tr is the heating preset temperature threshold, △Tr>0°C.

6. The control method of the heat recovery multi-split air conditioning system according to claim 1, characterized in that: When the operation mode of all indoor water circulation heat exchange systems is cooling mode and the water temperature is greater than or equal to the indoor ambient temperature, the throttling elements (15) corresponding to the first precooling heat exchanger (22) and the first preheating heat exchanger (21) in the second heat exchanger (2) are controlled to be opened, the low-pressure electromagnetic stop valve (17) is controlled to be opened, and the high-pressure electromagnetic stop valve (16) is controlled to be closed; the throttling elements (15) corresponding to the first heat exchanger (1) corresponding to each indoor water circulation heat exchange system are controlled to be opened, the low-pressure electromagnetic stop valve (17) is controlled to be opened, and the high-pressure electromagnetic stop valve (16) is controlled to be closed; the first reversing valve (35) and the second reversing valve (36) corresponding to each indoor water circulation heat exchange system are controlled to be connected to the second water distribution tank (332) respectively, and the first water distribution tank (331) is controlled to be connected to the second water distribution tank (332).

7. The control method of the heat recovery multi-split air conditioning system according to claim 1, characterized in that: When the operation mode of all indoor water circulation heat exchange systems is the heating mode and the water temperature is ≤ the indoor ambient temperature, the throttling elements (15) corresponding to the first precooling heat exchanger (22) and the first preheating heat exchanger (21) in the second heat exchanger (2) are controlled to be opened, the high-pressure electromagnetic stop valve (16) is controlled to be opened, and the low-pressure electromagnetic stop valve (17) is controlled to be closed; the throttling elements (15) corresponding to the first heat exchanger (1) corresponding to each indoor water circulation heat exchange system are controlled to be opened, the high-pressure electromagnetic stop valve (16) is controlled to be opened, and the low-pressure electromagnetic stop valve (17) is controlled to be closed; the first reversing valve (35) and the second reversing valve (36) corresponding to each indoor water circulation heat exchange system are controlled to be connected to the first water distribution tank (331) respectively, and the first water distribution tank (331) is controlled to be connected to the second water distribution tank (332).

8. The control method of the heat recovery multi-split air conditioning system according to claim 1, characterized in that: The first water distribution tank (331) has a first water outlet pipe, the second water distribution tank (332) has a second water outlet pipe, and a first electromagnetic stop valve (333) is provided between the first water outlet pipe and the second water outlet pipe.

9. The control method of the heat recovery multi-split air conditioning system according to claim 8, characterized in that: The first water outlet pipe is provided with a water outlet of a first water pump (371) which is in communication with the first port of the second reversing valve (36); the second water outlet pipe is provided with a water outlet of a second water pump (372) which is in communication with the second port of the second reversing valve (36).

10. The control method of the heat recovery multi-split air conditioning system according to claim 1, characterized in that: A second electromagnetic stop valve (38) is provided between the second reversing valve (36) and the second port of the first heat exchanger (1).

Images