A device and a control method for expanding a four-pipe multi-split system with hot water function

Abstract

The present application relates to air conditioning technical field, specifically, it relates to a kind of four-pipe multi-connected system device and control method of hot water function expansion, the present application is realized by the setting of one-way valve group, the orientation of refrigerant is realized when refrigerant in refrigeration, refrigeration+hot water, heating, heating+hot water, make the whole machine while guaranteeing basic function as much as possible the flow direction of refrigerant to hot water generating device, improve the utilization of waste heat, at the same time, the flow direction of refrigerant is realized by one-way valve mechanical control, avoid the control and signal transmission problem that the component such as electronic valve can produce, it is more convenient in the realization of function, more stable in control.And provide a kind of multi-connected system control method, according to indoor side load variation and domestic hot water demand, adjust outdoor side heat exchanger capacity and refrigerant distribution, guarantee user experience while utilizing waste heat.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air conditioning technology, in particular to a device and a control method of a four-pipe multi-split system with hot water function. BACKGROUND

[0002] The four-pipe multi-split system is often used in buildings with large indoor areas, high air conditioning use standards, and high investment allowances. During the whole year operation, the system has the function of frequent alternating conversion or simultaneous use of cooling and heating conditions. The current multi-split system uses refrigerant to absorb heat from a low-temperature heat source and release heat to a high-temperature heat source to achieve the purpose of refrigeration and heating. When refrigerating, the heat in the room is taken out by the refrigerant and released to the outdoor environment by the fan, which causes waste of residual heat. At the same time, there is a multi-split heat recovery system on the market that can achieve the purpose of simultaneous refrigeration and heating, but it needs to be matched with a specific mode conversion device. The device is expensive and the system is complex, which is very inconvenient. The present application expands the hot water function of the four-pipe multi-split system. By adding a hot water generating device to recover residual heat, and by cooperating with a one-way valve group to complete the guidance of the refrigerant, the system adjusts the outdoor heat exchange capacity and the refrigerant distribution according to the indoor load change and the hot water demand, ensures the user experience, and utilizes the residual heat. SUMMARY

[0003] The problem solved by the present application is that the refrigerant guidance control effect of the multi-split system with hot water function is not good.

[0004] To solve the above problems, the present application adopts the following technical scheme: a four-pipe multi-split system with hot water function, comprising: at least one group of indoor units, at least one group of hot water generating devices and an outdoor unit; the outdoor unit comprises: a condenser, a refrigerant cooling device, a refrigerant guiding valve group, and a supercooling device; the refrigerant guiding valve group comprises a first electronic expansion valve, a first pipeline, a second pipeline, a first one-way valve, a second one-way valve, a third one-way valve and a fourth one-way valve; the first pipeline, the second pipeline and the refrigerant cooling device are connected in parallel, the first one-way valve and the third one-way valve are arranged in the first pipeline, the second one-way valve and the fourth one-way valve are arranged in the second pipeline, the inlets of the first one-way valve, the second one-way valve, the third one-way valve and the fourth one-way valve are connected to the outlet of the refrigerant cooling device, the supercooling device is connected between the second one-way valve and the fourth one-way valve, one end of the first electronic expansion valve is connected between the first one-way valve and the third one-way valve, and the other end of the first electronic expansion valve is connected to the condenser; the hot water generating device is connected to the refrigerant cooling device; and the supercooling device is connected to the indoor unit.

[0005] Compared with the prior art, the technical effects achieved by the technical scheme are: through the setting of the one-way valve group, when refrigeration + hot water is generated, the refrigerant on the hot water generating device side passes through the second electronic expansion valve to control the flow, and before the system main refrigerant is guided back to the refrigerant cooling device through the liquid pipe, the system main refrigerant passes through the condenser, passes through the first electronic expansion valve to control the refrigerant flow, and is combined with the hot water side refrigerant through the third one-way valve; when heating + hot water is generated, the indoor unit side refrigerant flows to the refrigerant cooling device through the fourth one-way valve and is combined with the hot water side refrigerant, and then flows through the first one-way valve into the outdoor unit heat exchanger to exchange heat. The system realizes the guidance of the refrigerant when refrigeration, refrigeration + hot water, heating, and heating + hot water are generated, so that the whole machine can have as much refrigerant as possible to flow to the hot water generating device while ensuring the basic functions, the utilization of waste heat is improved, the flow of the refrigerant is mechanically controlled by using the one-way valve, the control and signal transmission problems caused by the use of multiple electronic expansion valves and other components are avoided, the realization of the hot water function is more convenient, and the control is more stable.

[0006] Further, the hot water generating device comprises a second electronic expansion valve and a hot water generator, and the second electronic expansion valve is arranged on the water outlet side of the hot water generator.

[0007] Compared with the prior art, the technical effects achieved by the technical scheme are: the flow of the refrigerant at the hot water generator is accurately controlled through the setting of the second electronic expansion valve.

[0008] Further, the outdoor unit further comprises a compressor and a high-pressure gas pipe; the outlet of the compressor is connected to the inlet of the hot water generating device through the high-pressure gas pipe; and the outlet of the hot water generating device is connected to the refrigerant cooling device through a liquid pipe.

[0009] Compared with the prior art, the technical effects achieved by the technical scheme are: part of the refrigerant is guided to the hot water generating device through the high-pressure gas pipe, and the heat-exchanged refrigerant is guided back through the liquid pipe.

[0010] The outdoor unit further comprises a four-way valve, the first port of the four-way valve is connected to the outlet of the compressor, the second port of the four-way valve is connected to the inlet of the condenser, the third port of the four-way valve is connected to the inlet of the compressor, and the fourth port of the four-way valve is connected to the inlet of the indoor unit through a gas pipe.

[0011] Compared with the prior art, the technical effects achieved by the technical scheme are: the four-way valve ensures the switching of the system to switch the refrigeration and heating functions and the realization of the refrigeration and heating functions.

[0012] The outlet of the compressor is provided with an oil separator, and the oil separator is connected to the first port of the four-way valve through the high-pressure gas pipe.

[0013] Compared with the prior art, the technical effects reached by adopting the technical scheme are that the oil separator separates the lubricating oil in the high-pressure high-temperature refrigerant discharged by the refrigeration compressor, ensures the precision of the supercooling degree of the refrigerant during guiding, and ensures that the device is safely and efficiently operated.

[0014] The gas-liquid separator is connected with the third port of the four-way valve.

[0015] Compared with the prior art, the technical effects reached by adopting the technical scheme are that the gas-liquid separator ensures the gas-liquid separation of the refrigerant, ensures the precision of the temperature and pressure of the refrigerant, and ensures the stability of the whole system.

[0016] Another purpose of the present application is to provide a control method of a four-pipe multi-split system to solve the problem of poor guiding control effect of the refrigerant of the multi-split system that can provide hot water function. The control method of the four-pipe multi-split system comprises: obtaining the ambient temperature of the outdoor unit; obtaining the refrigerant temperature at the outlet side of the hot water generating device; obtaining the whole machine calculated capacity, which is divided into three intervals a1, a2 and a3, wherein a3 is greater than a2, and a2 is greater than a1; adjusting the opening degrees of the first and second electronic expansion valves according to the whole machine calculated capacity, the outdoor ring working condition of the outdoor unit and the refrigerant temperature at the outlet side of the hot water generating device to ensure the stability of the multi-split system in providing hot water function.

[0017] The calculation formula of the whole machine calculated capacity is:

[0018] Wherein, Ac is the percentage of refrigeration indoor unit demand, which is related to the indoor and outdoor unit ambient temperature;

[0019] The opening indoor unit capacity; The outdoor whole machine capacity.

[0020] Compared with the prior art, the technical effects reached by adopting the technical scheme are that the control method of the four-pipe multi-split system provided by the present application can accurately adjust the refrigerant flow direction and capacity according to the outdoor unit ambient temperature, the refrigerant temperature at the outlet side of the hot water generating device and the whole machine calculated capacity, ensure the accurate and stable operation of the system, and fully utilize the waste heat.

[0021] Further, according to the whole machine calculation capacity, the outdoor unit environment temperature and the hot water generating device outlet side refrigerant temperature, the first electronic expansion valve opening degree and the second electronic expansion valve opening degree are adjusted, comprising: judging whether the outdoor unit environment temperature is lower than the first temperature threshold value and whether the hot water generating device outlet side refrigerant temperature is higher than the rated temperature, if yes, the second electronic expansion valve preset valve step value is 30-100 pls, and when the whole machine calculation capacity is a1, the first electronic expansion valve preset valve step value is 70-180 pls, when the whole machine calculation capacity is a2, the first electronic expansion valve preset valve step value is 250-380 pls, and when the whole machine calculation capacity is a3, the first electronic expansion valve preset valve step value is the maximum value.

[0022] Compared with the prior art, the technical effects achieved by adopting the technical scheme are: first, according to the demand of the whole machine calculation capacity, the problem of low middle pipe temperature triggering freeze protection is avoided. Second, the full utilization of waste heat is realized while avoiding the problem of refrigerant accumulation.

[0023] Further, whether the outdoor unit environment temperature is higher than the first temperature threshold value and whether it is lower than the second temperature threshold value are judged, if yes, whether the hot water generating device outlet side refrigerant temperature is lower than the rated temperature is judged, if yes, the first electronic expansion valve preset valve step value is 120-180 pls;

[0024] The second electronic expansion valve is controlled according to the water module target supercooling degree, and the water module target supercooling degree is divided into b1, b2 and b3, and b4 three intervals, wherein, b4 is greater than b3, b3 is greater than b2, and b2 is greater than b1; when the whole machine calculation capacity is a1, the water module target supercooling degree is b1; when the whole machine calculation capacity is a2, the water module target supercooling degree is b2; when the whole machine calculation capacity is a3, the water module target supercooling degree is b3. Wherein, the water module target supercooling degree = system high pressure temperature - hot water generator plate exchange air side outlet temperature.

[0025] Compared with the prior art, the technical effects achieved by adopting the technical scheme are: first, the four-pipe multi-split system pipeline is complex and long, and the refrigerant also has a certain temperature drop in the pipeline flow. The hot water generator target supercooling degree control is to control the second electronic expansion valve step number to be opened or closed according to the difference between the current supercooling degree of the hot water generator and the target supercooling degree fed back by the system. Adjusting the second electronic expansion valve according to the target supercooling degree of the water module can ensure the full heat exchange of the hot water generating device and the accurate control of the hot water generating device side. Second, the first electromagnetic expansion valve step number is fixed, which ensures the flow and can bear the waste heat that cannot be consumed by the water side and prevent the accumulation of refrigerant.

[0026] Further, it is judged whether the environment temperature of the outdoor unit is higher than the second temperature threshold value, if yes, it is judged whether the refrigerant temperature at the outlet side of the hot water generating device is lower than the rated temperature, if yes, the preset valve step value of the first electronic expansion valve is 30-100 pls, and the preset valve step value of the second electronic expansion valve is the maximum value; if no, the water module target supercooling degree is b4, and when the whole machine calculated capacity is a1, the preset valve step value of the first electronic expansion valve is 70-150 pls; when the whole machine calculated capacity is a2, the preset valve step value of the first electronic expansion valve is 150-250 pls; when the whole machine calculated capacity is a3, the preset valve step value of the first electronic expansion valve is 250-380 pls.

[0027] Compared with the prior art, the technical effects achieved by adopting the technical scheme are: the refrigerant flow is adjusted in real time according to the environment temperature of the outdoor unit, and the heat exchange capacity of the outdoor unit side and the hot water side and the stable operation of the system are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0028] Fig. 1 A structure schematic diagram of a four-pipe multi-split system refrigeration + hot water heating mode provided by the embodiment of the application;

[0029] Fig. 2 A structure schematic diagram of a four-pipe multi-split system heating + hot water heating mode provided by the embodiment of the application;

[0030] Fig. 3 A flow chart of a control method of a four-pipe multi-split system provided by the embodiment of the application.

[0031] BRIEF DESCRIPTION OF DRAWINGS

[0032] 10-compressor, 11-gas-liquid separator, 12-condenser, 13-first electromagnetic expansion valve, 14-supercooling device, 15-oil separator, 16-four-way valve, 17-second electromagnetic expansion valve, 18-hot water generator, 19-hot water generating device, 20-refrigerant cooling device, 21-first check valve, 22-second check valve, 23-third check valve, 24-fourth check valve, 26-high pressure gas pipe, 27-liquid pipe one, 28-liquid pipe two, 29a-indoor unit one, 29b-indoor unit two. DETAILED DESCRIPTION

[0033] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application but not all of the embodiments. In the following description, specific details such as specific configurations and components are provided only to help a comprehensive understanding of the embodiments of the present application. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, descriptions of known functions and structures are omitted in the embodiments for clarity and conciseness.

[0034] The present application aims to provide a control method, device, and storage medium of a four-pipe multi-split system with expanded hot water function, and a four-pipe system. The multi-split system provided by the present application makes full use of energy without the need for a specific mode conversion device, thereby reducing costs, and through the arrangement of a one-way valve group, the direction of refrigerant is completed, and the outdoor heat exchange capacity and refrigerant distribution are adjusted according to the indoor load change and hot water demand, thereby ensuring user experience and fully utilizing waste heat.

[0035] Reference will be made to the drawings below Figs. 1-3 The technical solutions of some embodiments of the present application are described.

[0036] As shown in Fig. 1 The present embodiment provides a four-pipe multi-split system with expanded hot water function, which comprises at least one group of indoor units, at least one group of hot water generating devices, and an outdoor unit. The outdoor unit comprises a condenser 12, a refrigerant cooling device 20, a refrigerant guiding valve group, and a supercooling device 14. The refrigerant guiding valve group comprises a first electronic expansion valve 13, a first pipeline, a second pipeline, a first one-way valve 21, a second one-way valve 22, a third one-way valve 23, and a fourth one-way valve 24. The first pipeline, the second pipeline, and the refrigerant cooling device 20 are connected in parallel. The first one-way valve 21 and the third one-way valve 23 are arranged on the first pipeline, the second one-way valve 22 and the fourth one-way valve 24 are arranged on the second pipeline, the inlets of the first one-way valve 24, the second one-way valve 22, the third one-way valve 23, and the fourth one-way valve 24 are connected to the outlet of the refrigerant cooling device 20, the supercooling device 14 is connected between the second one-way valve 22 and the fourth one-way valve 24, one end of the first electronic expansion valve 13 is connected between the first one-way valve 21 and the third one-way valve 23, and the other end of the first electronic expansion valve 13 is connected to the condenser 12. The hot water generating device 18 is connected to the refrigerant cooling device 20. The supercooling device 14 is connected to indoor unit one 29a and indoor unit two 29b.

[0037] The conventional four-way control multi-connected system needs to set multiple four-way valves to complete the guiding of refrigerant, or connect external devices to maintain the stability of the overall system, or match with specific mode conversion devices, which are expensive and cause system complexity. The four-way control multi-connected system provided in the embodiment sets the position of the check valve group. When refrigeration + hot water is required, the refrigerant on the hot water generating device side passes through the second electronic expansion valve to control the flow, and before being guided back to the refrigerant cooling device through the liquid pipe, the main refrigerant of the system passes through the condenser, passes through the first electronic expansion valve to control the flow of the refrigerant, and is combined with the hot water side refrigerant through the third check valve; when heating + hot water is required, the indoor unit side refrigerant flows to the refrigerant cooling device through the fourth check valve and is combined with the hot water side refrigerant, and then flows into the outdoor heat exchanger through the first check valve to exchange heat. The system realizes the guiding of the refrigerant in refrigeration, refrigeration + hot water, heating, heating + hot water, and hot water, so that as much refrigerant as possible flows to the hot water generating device while ensuring the basic functions of refrigeration and heating, thereby improving the utilization of waste heat. At the same time, the flow direction of the refrigerant is mechanically controlled by using the check valve, avoiding the control and signal transmission problems caused by the use of electronic valves and other components, and being more convenient in function realization and more stable in control. The use of multiple electronic expansion valves and other components avoids the control and signal transmission problems, and ensures that sufficient refrigerant flows through the refrigerant cooling device, thereby ensuring the stability of the system.

[0038] At the same time, the number of indoor units and hot water generating devices can be set according to actual needs.

[0039] In addition, the hot water generating device 19 includes a second electronic expansion valve 17 and a hot water generator 18, and the second electronic expansion valve 17 is arranged on the water outlet side of the hot water generator 18. The purpose of arranging the second electronic expansion valve here is to detect the temperature of the refrigerant at this position and control the flow of the refrigerant at this position. At the same time, the hot water generator 18 has an electric heating function, which can also meet the hot water demand of the user when the demand of the indoor unit is large.

[0040] The outdoor unit further includes a compressor 10 and a high-pressure gas pipe 26. The outlet of the compressor 10 is connected with the inlet of the hot water generating device 19 through the high-pressure gas pipe 26. The outlet of the hot water generating device 19 is connected with the refrigerant cooling device 20 through a liquid pipe 27. The high-pressure gas pipe 26 can meet the demand of guiding the high-temperature and high-pressure gas of the compressor 10. A high-pressure gas pipe 26 is led out again through the position of the four-way valve 16 to guide the refrigerant to the hot water generating device 19, complete the utilization of waste heat, and guide the refrigerant back to be combined with other refrigerants in front of the refrigerant cooling device 20 through the liquid pipe 27.

[0041] Meanwhile, the first port c of the four-way valve 16 is connected to the outlet of the compressor 10, the second port d of the four-way valve 16 is connected to the inlet of the condenser 12, the third port e of the four-way valve 16 is connected to the inlet of the compressor 10, and the fourth port f of the four-way valve 16 is connected to the inlets of the indoor units 29a and 29b through the air pipes.

[0042] The four-way valve 16 ensures the switching of the system switching refrigeration and heating functions and the realization of the basic functions of refrigeration and heating.

[0043] The outlet of the compressor 10 is provided with an oil separator 15, and the oil separator 15 is connected to the first port c of the four-way valve 16 through the high-pressure air pipe 26. The inlet of the compressor 10 is provided with an air-liquid separator 11, and the air-liquid separator 11 is connected to the third port e of the four-way valve 16.

[0044] The oil separator 15 separates the lubricating oil in the high-pressure and high-temperature refrigerant discharged by the compressor 10 during refrigeration, and the air-liquid separator 11 ensures the air-liquid separation of the refrigerant, ensures the accuracy of the refrigerant temperature and pressure, ensures the accuracy of the supercooling degree of the refrigerant during the guidance of the refrigerant, and ensures the safe and efficient operation of the entire system.

[0045] Another object of the present application is to provide a control method of a four-pipe multi-split system to solve the problem of poor refrigerant guidance control effect of a multi-split system that can provide hot water function, as shown in Figs. 1-3 as shown, comprising:

[0046] The ambient temperature of the outdoor unit is obtained, the refrigerant temperature at the outlet side of the hot water generating device is obtained, the whole machine calculation capacity is obtained, the whole machine calculation capacity is divided into three intervals a1, a2 and a3, wherein a3 is greater than a2, and a2 is greater than a1; the first electronic expansion valve opening degree and the second electronic expansion valve opening degree are adjusted according to the whole machine calculation capacity, the outdoor ring working condition of the outdoor unit and the refrigerant temperature at the outlet side of the hot water generating device, so as to ensure the stability of the multi-split system in the hot water supply function.

[0047] The calculation formula of the whole machine calculation capacity is:

[0048] Among them, Ac——Refrigeration indoor unit demand percentage, related to indoor and outdoor unit ambient temperature;

[0049] The opening indoor unit capacity; The outdoor unit whole machine capacity.

[0050] Specifically, it includes:

[0051] If the ambient temperature of the outdoor unit is lower than the first temperature threshold and the refrigerant temperature at the outlet side of the hot water generating device is higher than the rated temperature, the preset valve step value of the second electronic expansion valve is 30-100 pls, and when the calculated capacity of the whole machine is a1, the preset valve step value of the first electronic expansion valve is 70-180 pls, when the calculated capacity of the whole machine is a2, the preset valve step value of the first electronic expansion valve is 250-380 pls, and when the calculated capacity of the whole machine is a3, the preset valve step value of the first electronic expansion valve is the maximum value.

[0052] Preferably, a1 is less than 30%, a2 is preferably 30%-70%, and a3 is greater than 70%. The first temperature threshold is preferably 25°C, the second temperature threshold is preferably 42°C, and the rated temperature is preferably 48°C.

[0053] By adjusting according to the different calculated capacity requirements of the whole machine, the problem of low temperature of the indoor unit and easy triggering of the freeze protection is avoided. The second electronic expansion valve maintaining a certain standby step number can prevent the accumulation of refrigerant.

[0054] At the same time, if the ambient temperature of the outdoor unit is higher than the first temperature threshold and lower than the second temperature threshold, it is determined whether the refrigerant temperature at the outlet side of the hot water generating device is lower than the rated temperature, and if so, the preset valve step value of the first electronic expansion valve is 120-180 pls; the second electronic expansion valve is controlled according to the water module target supercooling degree, which is divided into b1, b2, and b3, b4 three intervals, wherein b4 is greater than b3, b3 is greater than b2, and b2 is greater than b1; when the calculated capacity of the whole machine is a1, the water module target supercooling degree is b1; when the calculated capacity of the whole machine is a2, the water module target supercooling degree is b2; when the calculated capacity of the whole machine is a3, the water module target supercooling degree is b3.

[0055] The water module target supercooling degree = system high pressure temperature - hot water generator plate exchange air side outlet temperature. b1 is preferably 8-10°C, b2 is preferably 10-12°C, b3 is preferably 12-14°C, and b4 is preferably 14-18°C.

[0056] The advantages of such setting are: first, the piping of the four-pipe multi-split system is complex and relatively long, and the refrigerant also has a certain temperature drop in the flow of the piping. The hot water generator target supercooling degree control is to control the second electronic expansion valve step number to be opened or closed according to the difference between the current supercooling degree and the target supercooling degree of the hot water generator fed back by the system, and the adjustment of the second electronic expansion valve according to the target supercooling degree of the water module can ensure sufficient heat exchange of the hot water generating device and accurate control of the side of the hot water generating device. Second, the first electromagnetic expansion valve step number is fixed, which ensures the flow and can bear the excess heat that cannot be consumed by the water side and prevent the accumulation of refrigerant.

[0057] Further, it is judged whether the environment temperature of the outdoor unit is higher than the second temperature threshold value, if yes, it is judged whether the refrigerant temperature at the outlet side of the hot water generating device is lower than the rated temperature, if yes, the preset valve step value of the first electronic expansion valve is 30-100 pls, and the preset valve step maximum value of the second electronic expansion valve; if no, the water module target supercooling degree is b4, and when the whole machine calculated capacity is a1, the preset valve step value of the first electronic expansion valve is 70-150 pls; when the whole machine calculated capacity is a2, the preset valve step value of the first electronic expansion valve is 150-250 pls; when the whole machine calculated capacity is a3, the preset valve step value of the first electronic expansion valve is 250-380 pls.

[0058] When the environment temperature of the outdoor unit is higher than the second temperature threshold value, and the refrigerant temperature at the outlet side of the hot water generating device is lower than the rated temperature, the heat exchange capacity of the outdoor unit side and the heat exchange capacity of the hot water side are similar, and meanwhile, when the system pipeline is long, there is a certain temperature drop in the flow of the refrigerant in the pipeline, and a reasonable target supercooling degree needs to be set to accurately control the second electronic expansion valve and make the hot water side fully exchange heat. When the refrigerant temperature at the outlet side of the hot water generating device is higher than the rated temperature, the refrigerant flow is controlled to be reasonable to make the heat exchange capacity of the two sides suitable, and ensure the heat exchange efficiency.

[0059] The embodiment also provides an air conditioning system, a computer readable storage medium storing a computer program, and a processor, and when the computer program is read and run by the processor, the above multi-split system control method is realized.

[0060] The embodiment also provides a computer readable storage medium storing a computer program, and when the computer program is read and run by the processor, the above multi-split system control method is realized. The computer readable storage medium has all the advantages of the above multi-split system control method, and will not be repeated here.

[0061] Although the present application is disclosed as above, the present application is not limited to this. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and therefore the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. A four-pipe multi-split system with extended hot water function, characterized in that, The system comprises: at least one set of indoor units, at least one set of hot water generating devices and an outdoor unit; the outdoor unit comprises a condenser, a refrigerant cooling device, a refrigerant guide valve group and a supercooling device; the refrigerant guide valve group comprises a first electronic expansion valve, a first pipeline, a second pipeline, a first one-way valve, a second one-way valve, a third one-way valve and a fourth one-way valve; the first pipeline, the second pipeline and the refrigerant cooling device are connected in parallel, the first one-way valve and the third one-way valve are arranged on the first pipeline, the second one-way valve and the fourth one-way valve are arranged on the second pipeline, the inlets of the first one-way valve, the second one-way valve, the third one-way valve and the fourth one-way valve are connected to the outlet of the refrigerant cooling device, the supercooling device is connected between the second one-way valve and the fourth one-way valve, one end of the first electronic expansion valve is connected between the first one-way valve and the third one-way valve, and the other end of the first electronic expansion valve is connected to the condenser; the hot water generating device is connected to the refrigerant cooling device; and the supercooling device is connected to the indoor unit.

2. The four-pipe multi-split system with hot water function according to claim 1, wherein the hot water generating device comprises a second electronic expansion valve and a hot water generator, and the second electronic expansion valve is arranged on the water outlet side of the hot water generator.

3. The four-pipe multi-split system with hot water function according to claim 1, wherein the outdoor unit further comprises a compressor and a high-pressure gas pipeline; the outlet of the compressor is connected to the inlet of the hot water generating device through the high-pressure gas pipeline; and the outlet of the hot water generating device is connected to the refrigerant cooling device through a liquid pipeline.

4. The four-pipe multi-split system with hot water function according to claim 3, wherein the outdoor unit further comprises a four-way valve; the first port of the four-way valve is connected to the outlet of the compressor; the second port of the four-way valve is connected to the inlet of the condenser; the third port of the four-way valve is connected to the inlet of the compressor; and the fourth port of the four-way valve is connected to the inlet of the indoor unit through a gas pipeline.

5. The four-pipe multi-split system with hot water function according to claim 4, wherein the outlet of the compressor is provided with an oil separator, and the oil separator is connected to the first port of the four-way valve through the high-pressure gas pipeline.

6. The four-pipe multi-split system with hot water function according to claim 4, wherein the inlet of the compressor is provided with a gas-liquid separator, and the gas-liquid separator is connected to the third port of the four-way valve.

7. A control method of a four-pipe multi-split system, which is implemented by the four-pipe multi-split system with hot water function according to any one of claims 1 to 6, and comprises the following steps: obtaining the ambient temperature of the outdoor unit; obtaining the refrigerant temperature on the outlet side of the hot water generating device; obtaining the total calculated capacity, which is divided into three intervals a1, a2 and a3, wherein a3>a2, and a2>a1. ​ ​ ​ ​ ​ According to the whole machine calculated capacity, the outdoor unit environment temperature and the hot water generating device outlet side refrigerant temperature, the first electronic expansion valve opening degree and the second electronic expansion valve opening degree are adjusted to ensure the stability of the hot water supply function of the multi-split system.

8. The control method of the four- tandem multi-up system according to claim 7, wherein, According to the whole machine calculated capacity, the outdoor unit environment temperature and the hot water generating device outlet side refrigerant temperature, the first electronic expansion valve opening degree and the second electronic expansion valve opening degree are adjusted, including: judging whether the outdoor unit environment temperature is lower than a first temperature threshold and whether the hot water generating device outlet side refrigerant temperature is higher than a rated temperature, if yes, the second electronic expansion valve preset valve step value is 30-100 pls, and when the whole machine calculated capacity is a1, the first electronic expansion valve preset valve step value is 70-180 pls; when the whole machine calculated capacity is a2, the first electronic expansion valve preset valve step value is 250-380 pls; when the whole machine calculated capacity is a3, the first electronic expansion valve preset valve step value is the maximum value.

9. The control method of a four- train package system according to claim 7, wherein, According to the whole machine calculated capacity, the outdoor unit environment temperature and the hot water generating device outlet side refrigerant temperature, the first electronic expansion valve opening degree and the second electronic expansion valve opening degree are adjusted, including: judging whether the outdoor unit environment temperature is higher than a first temperature threshold and whether it is lower than a second temperature threshold, if yes, judging whether the hot water generating device outlet side refrigerant temperature is lower than a rated temperature, if yes, the first electronic expansion valve preset valve step value is 120-180 pls; The second electronic expansion valve is controlled according to the water module target supercooling degree, which is divided into b1, b2 and b3, and b4 four intervals, wherein b4>b3, b3>b2, b2>b1; when the whole machine calculated capacity is a1, the water module target supercooling degree is b1; when the whole machine calculated capacity is a2, the water module target supercooling degree is b2; when the whole machine calculated capacity is a3, the water module target supercooling degree is b3.

10. The control method of a four- train package system according to claim 9, wherein, According to the whole machine calculated capacity, the outdoor unit environment temperature and the hot water generating device outlet side refrigerant temperature, the first electronic expansion valve opening degree and the second electronic expansion valve opening degree are adjusted, including: judging whether the outdoor unit environment temperature is higher than a second temperature threshold, if yes, judging whether the hot water generating device outlet side refrigerant temperature is lower than a rated temperature, if yes, the first electronic expansion valve preset valve step value is 30-100 pls, and the second electronic expansion valve preset valve step value is the maximum value; if not, the water module target supercooling degree is b4, and the second electronic expansion valve is adjusted according to the water module target supercooling degree, and when the whole machine calculated capacity is a1, the first electronic expansion valve preset valve step value is 70-150 pls; when the whole machine calculated capacity is a2, the first electronic expansion valve preset valve step value is 150-250 pls; when the whole machine calculated capacity is a3, the first electronic expansion valve preset valve step value is 250-380 pls.

Images