A multi-connection system and control method thereof

Abstract

The present invention discloses a multi-split system and a control method thereof. The multi-split system comprises: a hot water heat exchanger and a constant temperature water tank; the hot water heat exchanger is connected between an outdoor heat exchanger and an indoor heat exchanger via a first pipe; the hot water heat exchanger is further connected between a main water inlet and the water inlet of the constant temperature water tank via a second pipe; the hot water heat exchanger is used to exchange heat between the refrigerant in the first pipe and the water in the second pipe. The present invention realizes the use of condensation waste heat to produce hot water, fully and effectively recycles and utilizes condensation waste heat, improves energy utilization, and improves the energy-saving effect and economic benefits of the unit. Furthermore, the production of hot water does not affect the efficiency of cooling or heating, and can achieve long-term continuous hot water production, thus solving the problem that the multi-split system cannot effectively utilize condensation waste heat.

Description

Technical Field

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

[0002] When the multi-split system is cooling, it will discharge the condensation heat into the air through the outdoor condenser. This heat is not utilized, resulting in energy waste.

[0003] The air-conditioning water heater is equipped with a water tank. During cooling, the refrigerant discharged from the compressor first enters the water tank to make hot water, and then enters the outdoor heat exchanger to achieve heat recovery. However, this solution has poor water heating efficiency. In order to avoid excessively high water temperature affecting the cooling efficiency, it is impossible to achieve long-term continuous hot water production, and this solution cannot be applied to multi-split systems.

[0004] With regard to the problem that the multi-split system in the existing technology cannot effectively utilize the waste heat of condensation, no effective solution has been proposed so far. Summary of the Invention

[0005] The embodiments of the present invention provide a multi-split system and a control method thereof, so as to at least solve the problem in the prior art that the multi-split system cannot effectively utilize the waste heat of condensation.

[0006] To solve the above technical problems, an embodiment of the present invention provides a multi-split system, comprising: a hot water heat exchanger and a constant temperature water tank;

[0007] The hot water heat exchanger is connected between the outdoor heat exchanger and the indoor heat exchanger through a first pipeline;

[0008] The hot water heat exchanger is also connected between the main water inlet and the water inlet of the constant temperature water tank through a second pipeline;

[0009] The hot water heat exchanger is used to exchange heat between the refrigerant in the first pipeline and the water in the second pipeline.

[0010] Optionally, the multi-connected system includes: a high-pressure air pipe, a low-pressure air pipe and a liquid pipe; a third pipeline is arranged in the constant temperature water tank, the first end of the third pipeline is connected to the high-pressure air pipe, and the second end of the third pipeline is connected to the liquid pipe.

[0011] Optionally, a first valve is provided at the first end of the third pipeline, and a second valve is provided at the second end of the third pipeline.

[0012] Optionally, a flow regulating valve is provided at the first end of the third pipeline.

[0013] Optionally, the multi-connected system further comprises: a first four-way valve and a second four-way valve;

[0014] The first port of the first four-way valve is connected to the exhaust port of the compressor, the second port of the first four-way valve is connected to the outdoor heat exchanger, the third port of the first four-way valve is connected to the suction port of the compressor, and the fourth port of the first four-way valve is connected to the low-pressure gas pipe;

[0015] The first port of the second four-way valve is connected to the exhaust port of the compressor, the second port of the second four-way valve is connected to the outdoor heat exchanger through the third valve, the third port of the second four-way valve is connected to the low-pressure gas pipe, and the fourth port of the second four-way valve is connected to the high-pressure gas pipe.

[0016] Optionally, the multi-split system also includes: a fourth pipeline, which is arranged on the chassis of the outdoor unit of the multi-split system, the inlet of the fourth pipeline is connected to the water outlet of the constant temperature water tank, and the outlet of the fourth pipeline is connected to the domestic water pipeline or the water inlet of the constant temperature water tank.

[0017] Optionally, a fourth valve is provided at the inlet of the fourth pipeline.

[0018] Optionally, the fourth pipeline is also provided on the outdoor heat exchanger.

[0019] Optionally, the hot water heat exchanger includes at least one heat exchanger. When the hot water heat exchanger includes at least two heat exchangers, the at least two heat exchangers are connected in parallel.

[0020] Optionally, the constant temperature water tank includes a first-stage water tank or a two-stage water tank; when the constant temperature water tank includes a two-stage water tank, the second pipeline is connected to the water inlet of the first-stage water tank, and the first-stage water tank and the second-stage water tank are connected in series; a third pipeline is arranged in the second-stage water tank, the first end of the third pipeline is connected to the high-pressure air pipe, and the second end of the third pipeline is connected to the liquid pipe; the water outlet of the second-stage water tank is connected to the fourth pipeline.

[0021] An embodiment of the present invention further provides a control method for a multi-split system, which is applied to the multi-split system described in an embodiment of the present invention. The method includes:

[0022] Detecting water supply temperature requirements or defrost requirements;

[0023] According to the current working mode of the multi-split system, the first four-way valve and the second four-way valve are controlled to produce hot water;

[0024] The first port of the first four-way valve is connected to the exhaust port of the compressor, the second port of the first four-way valve is connected to the outdoor heat exchanger, the third port of the first four-way valve is connected to the suction port of the compressor, and the fourth port of the first four-way valve is connected to the low-pressure gas pipe.

[0025] The first port of the second four-way valve is connected to the exhaust port of the compressor, the second port of the second four-way valve is connected to the outdoor heat exchanger through the third valve, the third port of the second four-way valve is connected to the low-pressure gas pipe, and the fourth port of the second four-way valve is connected to the high-pressure gas pipe.

[0026] Optionally, according to the current working mode of the multi-split system, controlling the first four-way valve and the second four-way valve to produce hot water includes:

[0027] If the current working mode is the cooling mode, the main water inlet is opened, the first port of the first four-way valve is controlled to be connected to the second port and the third port of the first four-way valve is controlled to be connected to the fourth port, the first port of the second four-way valve is controlled to be connected to the fourth port and the second port of the second four-way valve is controlled to be connected to the third port, and the third valve is controlled to be closed, so as to enter the cooling and hot water making mode;

[0028] If the current working mode is the heating mode, the main water inlet is opened, the first port of the first four-way valve is controlled to be connected to the fourth port and the second port of the first four-way valve is controlled to be connected to the third port, the first port of the second four-way valve is controlled to be connected to the fourth port and the second port of the second four-way valve is controlled to be connected to the third port, and the third valve is controlled to be closed to enter the heating and hot water making mode.

[0029] Optionally, hot water is produced, including: producing hot water according to the outlet water temperature of the hot water heat exchanger and the water temperature in the constant temperature water tank.

[0030] Optionally, hot water is produced based on the outlet water temperature of the hot water heat exchanger and the water temperature in the constant temperature water tank, including:

[0031] monitoring the outlet water temperature of the hot water heat exchanger;

[0032] When the outlet water temperature of the hot water heat exchanger is lower than the first preset temperature, controlling the constant temperature water tank to enter a heating mode;

[0033] When the outlet water temperature of the hot water heat exchanger is greater than or equal to the first preset temperature, the water temperature in the constant temperature water tank is monitored; when the water temperature in the constant temperature water tank is less than the second preset temperature, the monitoring of the outlet water temperature of the hot water heat exchanger is continued; when the water temperature in the constant temperature water tank is greater than or equal to the second preset temperature, the constant temperature water tank is controlled to supply hot water.

[0034] Optionally, controlling the constant temperature water tank to enter a heating mode includes:

[0035] Opening the first valve and the second valve, and controlling the opening of the flow regulating valve according to the difference between the water temperature in the constant temperature water tank and the second preset temperature;

[0036] In which, a third pipeline is set in the constant temperature water tank, the first end of the third pipeline is connected to the high-pressure gas pipe, and the second end of the third pipeline is connected to the liquid pipe; the first valve and the flow regulating valve are set at the first end of the third pipeline, and the second valve is set at the second end of the third pipeline.

[0037] Optionally, when a defrost demand is detected, the constant temperature water tank is controlled to supply hot water, including: opening the fourth valve; wherein the fourth valve is arranged at the inlet of the fourth pipeline, the fourth pipeline is arranged at least on the chassis of the outdoor unit of the multi-split system, the inlet of the fourth pipeline is connected to the water outlet of the constant temperature water tank, and the outlet of the fourth pipeline is connected to the domestic water pipeline or the water inlet of the constant temperature water tank.

[0038] An embodiment of the present invention further provides a multi-connection system, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in the embodiment of the present invention when executing the computer program.

[0039] An embodiment of the present invention further provides a non-volatile computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method described in the embodiment of the present invention are implemented.

[0040] By applying the technical solution of the present invention, a multi-connected system is provided with a hot water heat exchanger and a constant temperature water tank, which realizes the use of waste heat from condensation to make hot water, fully and effectively recycles and utilizes waste heat from condensation, improves energy utilization, improves the energy-saving effect and economic benefits of the unit, and the hot water production will not affect the efficiency of cooling or heating, and can achieve long-term continuous hot water production. The water entering the water circulation system can be heated once in the hot water heat exchanger, or it can be heated twice in the constant temperature water tank using a refrigerant according to demand. Through this graded heating, different hot water temperature requirements can be met, and hot water of different temperatures can be provided for different environments. The produced hot water can be used to solve the problem of easy frost and ice formation at the bottom of the outdoor heat exchanger, and the produced hot water can also be used directly for defrosting, so that continuous heating can still be achieved during defrosting without affecting user comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of a multi-connection system provided by the first embodiment of the present invention. Figure 1 ;

[0042] Figure 2 This is a schematic diagram of a multi-connection system provided by the first embodiment of the present invention. Figure 2 ;

[0043] Figure 3 is a schematic diagram of the fourth pipeline provided in Example 1 of the present invention;

[0044] Figure 4 is a schematic diagram of a hot water heat exchanger provided in Example 1 of the present invention;

[0045] Figure 5 is a schematic diagram of a two-stage water tank provided in Example 1 of the present invention;

[0046] Figure 6 Schematic diagram of the refrigerant flow direction of the multi-split system in cooling mode provided by the first embodiment of the present invention;

[0047] Figure 7 Schematic diagram of refrigerant flow in the multi-split system in heating mode provided by the first embodiment of the present invention;

[0048] Figure 8 Schematic diagram of the refrigerant flow direction of the multi-split system in cooling and hot water production mode provided by the first embodiment of the present invention;

[0049] Figure 9 Schematic diagram of the refrigerant flow direction of the multi-split system in heating and hot water production mode provided by the first embodiment of the present invention;

[0050] Figure 10 is a flow chart of a control method for a multi-connected system provided in the second embodiment of the present invention;

[0051] Figure 11 This is a flow chart of a multi-split system for hot water production provided by the second embodiment of the present invention;

[0052] Description of reference numerals:

[0053] Hot water heat exchanger 10, first pipeline 11, second pipeline 12, constant temperature water tank 20, third pipeline 21, first valve 22, second valve 23, flow regulating valve 24, one-way valve 25, fourth pipeline 26, domestic water pipeline 27, fourth valve 28, outdoor heat exchanger 30, high-pressure gas pipe 31, low-pressure gas pipe 32, liquid pipe 33, indoor heat exchanger 40, first four-way valve 51, second four-way valve 52, third valve 53, compressor 60, oil separator 61, gas-liquid separator 62, main water inlet A, first-stage water tank 201, second-stage water tank 202, fifth valve 203. DETAILED DESCRIPTION

[0054] To make the objectives, technical solutions, and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings. It is apparent that the embodiments described are only some, not all, of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0055] Example 1

[0056] This embodiment provides a multi-split system, which includes a water circulation system and a refrigerant circulation system. Figure 1 As shown, the multi-split system includes: a hot water heat exchanger 10 and a constant temperature water tank 20.

[0057] The hot water heat exchanger 10 is connected to the outdoor heat exchanger 30 and the indoor heat exchanger 40 via a first pipe 11. The first pipe 11 is used to circulate refrigerant and serves as a refrigerant pipeline. Specifically, one end of the first pipe 11 is connected to the outdoor heat exchanger 30, and the other end is connected to the indoor heat exchanger 40 via a liquid pipe.

[0058] The hot water heat exchanger 10 is also connected via a second pipe 12 between a main water inlet A and the water inlet of the thermostatic water tank 20. Second pipe 12 is used to circulate water and serves as a water pipeline. Main water inlet A is the main water inlet for the entire water circulation system and is used to supply water to the water circulation system. A water pump can be located at main water inlet A to provide power for the water circulation. For example, when main water inlet A and the water pump are turned on, room-temperature tap water enters the water circulation system.

[0059] The hot water heat exchanger 10 is used to exchange heat between the refrigerant in the first pipeline 11 and the water in the second pipeline 12. During cooling, the refrigerant discharged from the compressor first enters the outdoor heat exchanger 30 and then enters the hot water heat exchanger 10. During heating, the refrigerant discharged from the compressor first enters the indoor heat exchanger 40 and then enters the hot water heat exchanger 10. Whether cooling or heating, the hot water heat exchanger 10 can use the waste heat of condensation to produce hot water.

[0060] The hot water heat exchanger 10 acts as a heat exchanger in the water circulation system, making full use of the waste heat of condensation to produce hot water. At the same time, the hot water heat exchanger 10 acts as a throttling component in the refrigerant circulation system, controlling the refrigerant flow and reducing the refrigerant pressure.

[0061] The multi-split system of this embodiment is provided with a hot water heat exchanger 10 and a constant temperature water tank 20, which realizes the use of waste heat from condensation to produce hot water, fully and effectively recovers and utilizes waste heat from condensation, improves energy utilization, and improves the energy-saving effect and economic benefits of the unit. In addition, the production of hot water does not affect the efficiency of cooling or heating, and long-term continuous hot water production can be achieved.

[0062] like Figure 2As shown, the multi-split system includes a high-pressure air pipe 31, a low-pressure air pipe 32, and a liquid pipe 33. A third pipe 21 is disposed within the thermostatic water tank 20. The first end of the third pipe 21 is connected to the high-pressure air pipe 31, and the second end of the third pipe 21 is connected to the liquid pipe 33. In other words, the thermostatic water tank 20 is connected between the high-pressure air pipe 31 and the liquid pipe 33 via the third pipe 21. The third pipe 21 is used to circulate refrigerant and serves as a refrigerant pipe. The first end of the third pipe 21 corresponds to the refrigerant inlet of the thermostatic water tank 20, and the second end of the third pipe 21 corresponds to the refrigerant outlet of the thermostatic water tank 20.

[0063] A third pipe 21 is provided in the thermostatic water tank 20. The refrigerant flowing through the third pipe 21 can be used to reheat the water in the thermostatic water tank 20, ensuring that the water in the tank meets the set temperature. In other words, water entering the water circulation system can be heated primarily in the hot water heat exchanger 10 and then, as needed, reheated in the thermostatic water tank 20. This staged heating process can meet different hot water temperature requirements and provide hot water at different temperatures for different environments.

[0064] Specifically, a first valve 22 is provided at the first end of the third pipe 21, and a second valve 23 is provided at the second end of the third pipe 21. By controlling the opening and closing of the first valve 22 and the second valve 23, it is possible to control whether the refrigerant enters the thermostatic water tank 20 through the third pipe 21 for secondary heating and flows out of the thermostatic water tank 20. When secondary heating is not required, the first valve 22 and the second valve 23 can be closed to prevent the refrigerant from entering the thermostatic water tank 20.

[0065] A flow control valve 24 is also provided at the first end of the third pipeline 21. The flow control valve 24 is used to control the flow of refrigerant entering the thermostatic water tank 20, thereby controlling the water temperature within the tank. The flow control valve 24 can be an adjustable valve such as an electronic expansion valve.

[0066] A one-way valve 25 may also be provided at the first end of the third pipeline 21 to control the flow direction of the refrigerant and ensure that the refrigerant flows from the high-pressure gas pipe 31 to the constant temperature water tank 20 .

[0067] A water temperature sensor can be installed in the thermostatic water tank 20 to monitor the water temperature therein. A refrigerant inlet pipe temperature sensor can be installed at the refrigerant inlet of the thermostatic water tank 20 to obtain the refrigerant inlet pipe temperature. A refrigerant outlet pipe temperature sensor can be installed at the refrigerant outlet of the thermostatic water tank 20 to obtain the refrigerant outlet pipe temperature.

[0068] A water inlet temperature sensor is provided at the water inlet of the hot water heat exchanger 10 to monitor the water inlet temperature of the hot water heat exchanger 10 , and a water outlet temperature sensor can be provided at the water outlet of the hot water heat exchanger 10 to monitor the water outlet temperature of the hot water heat exchanger 10 .

[0069] like Figure 2As shown, the multi-connected system further includes: a first four-way valve 51 and a second four-way valve 52 .

[0070] The first port (i.e., port D) of the first four-way valve 51 is connected to the exhaust port of the compressor 60, the second port (i.e., port C) of the first four-way valve 51 is connected to the outdoor heat exchanger 30, the third port (i.e., port S) of the first four-way valve 51 is connected to the intake port of the compressor 60, and the fourth port (i.e., port E) of the first four-way valve 51 is connected to the low-pressure air pipe 32.

[0071] The first port (i.e., port D) of the second four-way valve 52 is connected to the exhaust port of the compressor 60, the second port (i.e., port C) of the second four-way valve 52 is connected to the outdoor heat exchanger 30 through the third valve 53, the third port (i.e., port S) of the second four-way valve 52 is connected to the low-pressure gas pipe 32, and the fourth port (i.e., port E) of the second four-way valve 52 is connected to the high-pressure gas pipe 31.

[0072] Through the coordinated control of the first four-way valve 51 and the second four-way valve 52, the mode switching of the multi-split system can be achieved. For example, the working modes of the multi-split system include: cooling mode, heating mode, cooling and hot water mode, and heating and hot water mode.

[0073] During winter heating, when the surface temperature of the outdoor unit's evaporator coil falls below the dew point of the air being cooled, water vapor in the air accumulates as a loose layer of ice crystals on the surface of the outdoor heat exchanger, forming a frost layer. During defrosting, water droplets accumulate at the bottom of the heat exchanger, causing ice to form. This reduces heat exchange and heating efficiency, and in severe cases, can damage the compressor. Furthermore, during heating operation in low-temperature, high-humidity conditions, the system frequently defrosts, and heating cannot be continuously provided during defrost periods, affecting user comfort.

[0074] In view of the above problems, the multi-split system of this embodiment may further include: a fourth pipeline 26, which is arranged on the chassis of the outdoor unit of the multi-split system, such as Figure 3 Reference Figure 2 The inlet of fourth pipe 26 is connected to the outlet of thermostatic water tank 20. Thermostatic water tank 20 supplies hot water, and the outlet of thermostatic water tank 20 can be connected to fourth pipe 26 and / or domestic water pipe 27. The outlet of fourth pipe 26 is connected to domestic water pipe 27 or the inlet of thermostatic water tank 20. This means that defrosted water can be directly discharged from domestic water pipe 27 for daily use, or returned to thermostatic water tank 20 for reheating and recycling. A hose can be used for fourth pipe 26.

[0075] Hot water is supplied to the chassis of the outdoor unit through the fourth pipe 26. The produced hot water can be used to solve the problem of frost and ice easily forming on the bottom of the outdoor heat exchanger. The produced hot water can also be used directly for defrosting, so that heating can continue during defrosting without affecting user comfort.

[0076] A fourth valve 28 is provided at the inlet of the fourth pipeline 26 for controlling the on-off of the fourth pipeline 26 .

[0077] The fourth pipeline 26 is also provided on the outdoor heat exchanger 30. That is, the fourth pipeline 26 can also be provided on the outdoor heat exchanger 30, thereby utilizing the prepared hot water to make defrosting more thorough.

[0078] The hot water heat exchanger 10 includes at least one heat exchanger. When the hot water heat exchanger 10 includes at least two heat exchangers, the at least two heat exchangers are connected in parallel to achieve better heat exchange effect and heat exchange efficiency. Figure 4 As shown, taking a plate heat exchanger as an example, each plate heat exchanger is connected in parallel, the pipe on the left circulates refrigerant (i.e., refrigerant), and the pipe on the right circulates water, and hot water is produced by heat exchange between water and refrigerant.

[0079] The constant temperature water tank 20 includes a first-stage water tank or a two-stage water tank. Figure 5 As shown, when the constant temperature water tank 20 includes two-stage water tanks, the second pipeline 12 is connected to the water inlet of the first-stage water tank 201, and the first-stage water tank 201 and the second-stage water tank 202 are connected in series; a third pipeline 21 is set in the second-stage water tank 202, and the first end of the third pipeline 21 is connected to the high-pressure air pipe 31, and the second end of the third pipeline 21 is connected to the liquid pipe 33; the water outlet of the second-stage water tank 202 is connected to the fourth pipeline 26.

[0080] The first-stage water tank 201 is used for water storage, and the second-stage water tank 202 is used for heating and defrosting. A fifth valve 203 is provided on the pipeline connecting the first-stage water tank 201 and the second-stage water tank 202 in series. When the fifth valve 203 is opened, water can be transported from the first-stage water tank 201 to the second-stage water tank 202. The first-stage water tank 201 and the second-stage water tank 202 each store water at different temperatures for use in different scenarios. Both the first-stage water tank 201 and the second-stage water tank 202 can be connected to the domestic water pipeline to meet domestic water needs at different temperatures. By providing two-stage water tanks, different water needs can be better met.

[0081] The following describes the various modes of the multi-split system with reference to the accompanying drawings. In the following figure, the arrows indicate the direction of refrigerant flow.

[0082] like Figure 6Figure 2 shows the refrigerant flow in the VRF system in cooling mode. In cooling mode, the first four-way valve 51 is de-energized, meaning its D port is connected to its C port, and its S port is connected to its E port. The second four-way valve 52 is de-energized, meaning its D port is connected to its C port, and its S port is connected to its E port. The third valve 53 is open. The water circulation system is inoperative. Specifically, the water circulation system's main water inlet A, first valve 22, second valve 23, flow control valve 24, and fourth valve 28 are all closed.

[0083] In the cooling mode, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 60 passes through the oil separator 61, the D port and the C port of the first four-way valve 51 in sequence, enters the outdoor heat exchanger 30 for condensation, and then enters the indoor heat exchanger 40 through the hot water heat exchanger 10 and the liquid pipe 33. The refrigerant flowing out of the indoor heat exchanger 40 is divided into two paths. One path of refrigerant passes through the low-pressure gas pipe 32, the E port and the S port of the first four-way valve 51, and the gas-liquid separator 62 in sequence, and then returns to the compressor 60. The other path of refrigerant passes through the high-pressure gas pipe 31, the E port and the S port of the second four-way valve 52, the E port and the S port of the first four-way valve 51, and the gas-liquid separator 62 in sequence, and then returns to the compressor 60, completing a refrigeration cycle.

[0084] like Figure 7 Figure 2 shows the refrigerant flow in the VRF system in heating mode. In heating mode, the first four-way valve 51 is energized, connecting port D to port E and port S to port C. The second four-way valve 52 is de-energized, connecting port D to port C and port S to port E. The third valve 53 is closed. The water circulation system is inoperative. Specifically, the water circulation system's main water inlet A, first valve 22, second valve 23, flow control valve 24, and fourth valve 28 are all closed.

[0085] In heating mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 60 passes through the oil separator 61, the D port, and the E port of the first four-way valve 51. The refrigerant flowing out of the E port of the first four-way valve 51 is split into two paths. One path passes through the low-pressure gas pipe 32 and enters the indoor heat exchanger 40 for condensation. The other path passes through the S port and the E port of the second four-way valve 52, the high-pressure gas pipe 31, and enters the indoor heat exchanger 40 for condensation. The refrigerant flowing out of the indoor heat exchanger 40 passes through the liquid pipe 33, the hot water generator 10, the outdoor heat exchanger 30, the C port and the S port of the first four-way valve 51, and the gas-liquid separator 62, before returning to the compressor 60, completing a heating cycle.

[0086] like Figure 8Figure 2 shows the refrigerant flow in a VRF system operating in both cooling and hot water production mode. In this mode, the first four-way valve 51 is de-energized, meaning its D port is connected to its C port and its S port is connected to its E port. The second four-way valve 52 is energized, meaning its D port is connected to its E port and its S port is connected to its C port. The third valve 53 is closed. The main water inlet A of the water circulation system is open.

[0087] In the cooling and hot water making mode, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 60 passes through the oil separator 61 and is divided into two paths. One path of refrigerant enters the outdoor heat exchanger 30 through the D port and C port of the first four-way valve 51 and is condensed into a high-temperature and high-pressure liquid refrigerant. The other path of refrigerant flows to the constant temperature water tank 20 through the D port and E port of the second four-way valve 52 and the high-pressure air pipe 31 to perform secondary heating on the water in the constant temperature water tank 20.

[0088] The refrigerant flowing out of outdoor heat exchanger 30 enters hot water heat exchanger 10, where it exchanges heat with water entering the water circulation system through main water inlet A. After the water is heated to a certain temperature, it enters constant-temperature water tank 20. Hot water heat exchanger 10 acts as a heat exchanger in the water circulation system, fully utilizing the waste heat from condensation. It also serves as a throttling component in the refrigerant circulation system, controlling the refrigerant flow and reducing the refrigerant pressure.

[0089] The throttled refrigerant flowing out of the hot water heat exchanger 10 enters the indoor heat exchanger 40 through the liquid pipe 33. The refrigerant is evaporated into a low-temperature and low-pressure gaseous refrigerant in the indoor heat exchanger 40, and then returns to the compressor 60 through the low-pressure gas pipe 32, the E port and the S port of the first four-way valve 51, and the gas-liquid separator 62 in sequence, completing a refrigeration cycle.

[0090] like Figure 9 Figure 2 shows the refrigerant flow in a VRF system operating in both heating and hot water production mode. In this mode, the first four-way valve 51 is energized, connecting port D to port E and port S to port C. The second four-way valve 52 is energized, connecting port D to port E and port S to port C. The third valve 53 is closed. The main water inlet A of the water circulation system is open.

[0091] In the heating and hot water making mode, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 60 passes through the oil separator 61 and is divided into two paths. One path of refrigerant enters the indoor heat exchanger 40 for condensation through the D port and E port of the first four-way valve 51 and the low-pressure air pipe 32, and the other path of refrigerant flows to the constant temperature water tank 20 and the indoor heat exchanger 40 through the D port and E port of the second four-way valve 52 and the high-pressure air pipe 31 to perform secondary heating on the water in the constant temperature water tank 20.

[0092] The refrigerant flowing out of indoor heat exchanger 40 enters hot water heat exchanger 10 through liquid pipe 33. There, the refrigerant exchanges heat with water entering the water circulation system through main water inlet A. After the water is heated to a certain temperature, it enters constant-temperature water tank 20. Hot water heat exchanger 10 serves as a heat exchanger in the water circulation system, fully utilizing the waste heat from condensation. It also acts as a throttling component in the refrigerant circulation system, controlling the refrigerant flow and reducing the refrigerant pressure.

[0093] The throttled refrigerant flowing out of the hot water heat exchanger 10 enters the outdoor heat exchanger 30 for evaporation, and then returns to the compressor 60 through the C port and S port of the first four-way valve 51 and the gas-liquid separator 62 in sequence, completing a heating cycle.

[0094] In the cooling and hot water making mode or in the heating and hot water making mode, if the outlet water temperature of the hot water heat exchanger 10 does not reach the first preset temperature, the water in the thermostatic water tank 20 needs to be heated again. Specifically, the first valve 22 is opened to allow the refrigerant to enter the thermostatic water tank 20, and the second valve 23 is opened at the same time to allow the refrigerant to flow out of the thermostatic water tank 20 and continue to participate in the circulation. The opening of the flow regulating valve 24 is controlled according to the difference between the water temperature in the thermostatic water tank 20 and the second preset temperature (i.e., the set water temperature), and the flow of refrigerant entering the thermostatic water tank 20 is adjusted to achieve control of the water temperature in the water tank and achieve heating or heat preservation. For example, if the water temperature in the thermostatic water tank 20 is less than the second preset temperature, the opening of the flow regulating valve 24 is increased; if the water temperature in the thermostatic water tank 20 is greater than or equal to the second preset temperature, the opening of the flow regulating valve 24 is reduced.

[0095] During heating, the outdoor heat exchanger 30 acts as an evaporator, and water vapor easily forms a frost layer on the coil surface. After defrosting, frost easily accumulates at the bottom of the outdoor heat exchanger 30 to form ice. During the defrosting process of the outdoor heat exchanger 30, the fourth valve 28 can be opened to allow the hot water produced in the constant temperature water tank 20 to pass through the fourth pipe 26 to the outdoor unit to melt the ice layer, thereby avoiding the influence of ice on the heat exchange performance.

[0096] Example 2

[0097] This embodiment provides a control method for a multi-split system, which is applied to the multi-split system described in the above embodiment. Explanations of terms that are the same or corresponding to those in the above embodiment will not be repeated in this embodiment.

[0098] Figure 10 This is a flow chart of a control method for a multi-connected system provided in the second embodiment of the present invention. Figure 10 As shown, the method includes the following steps:

[0099] S1001, detecting water supply temperature requirement or defrost requirement.

[0100] S1002, according to the current working mode of the multi-split system, controlling the first four-way valve 51 and the second four-way valve 52 to produce hot water.

[0101] The user sets the set temperature of the thermostatic water tank 20, indicating a water supply temperature requirement. Meeting the defrost conditions indicates a defrost requirement. The VLSI system's operating modes include: cooling mode, heating mode, cooling and hot water mode, and heating and hot water mode.

[0102] When the water supply temperature requirement or the defrost requirement is detected in this embodiment, the first four-way valve 51 and the second four-way valve 52 are controlled according to the current working mode of the multi-split system to realize mode switching, switching to a mode capable of producing hot water to produce hot water and meet the water supply temperature requirement or the defrost requirement.

[0103] In one embodiment, according to the current working mode of the multi-split system, controlling the first four-way valve 51 and the second four-way valve 52 to produce hot water includes:

[0104] If the current working mode is cooling mode, the main water inlet A is opened, the first port of the first four-way valve 51 is controlled to be connected to the second port and the third port of the first four-way valve 51 is controlled to be connected to the fourth port, the first port of the second four-way valve 52 is controlled to be connected to the fourth port and the second port of the second four-way valve 52 is controlled to be connected to the third port, and the third valve 53 is controlled to be closed, so as to enter the cooling and hot water production mode;

[0105] If the current working mode is heating mode, the main water inlet is opened, the first port of the first four-way valve 51 is controlled to be connected to the fourth port and the second port of the first four-way valve 51 is controlled to be connected to the third port, the first port of the second four-way valve 52 is controlled to be connected to the fourth port and the second port of the second four-way valve 52 is controlled to be connected to the third port, and the third valve 53 is controlled to be closed to enter the heating and hot water making mode.

[0106] Through the above control, it is possible to smoothly and reliably enter the mode capable of producing hot water, utilize the hot water heat exchanger 10 to exchange heat between the refrigerant and water, and utilize the waste heat of condensation to produce hot water.

[0107] In one embodiment, producing hot water includes producing hot water according to the outlet water temperature of the hot water heat exchanger 10 and the water temperature in the constant temperature water tank 20. This embodiment can effectively control the water temperature and obtain the required hot water.

[0108] Specifically, hot water is produced according to the outlet water temperature of the hot water heat exchanger 10 and the water temperature in the constant temperature water tank 20, including:

[0109] Monitor the outlet water temperature of the hot water heat exchanger 10;

[0110] When the outlet water temperature of the hot water heat exchanger 10 is lower than the first preset temperature, the constant temperature water tank 20 is controlled to enter the heating mode;

[0111] When the outlet water temperature of the hot water heat exchanger 10 is greater than or equal to the first preset temperature, the water temperature in the constant temperature water tank 20 is monitored; when the water temperature in the constant temperature water tank 20 is less than the second preset temperature, the flow returns to continue monitoring the outlet water temperature of the hot water heat exchanger 10; when the water temperature in the constant temperature water tank 20 is greater than or equal to the second preset temperature, the constant temperature water tank 20 is controlled to supply hot water.

[0112] The first preset temperature is pre-set according to actual conditions, and the second preset temperature is the target water temperature of the water tank set by the user, that is, the set water temperature.

[0113] The outlet water temperature of the hot water heat exchanger 10 is greater than or equal to the first preset temperature, indicating that the produced hot water temperature is sufficient to meet the requirements and can enter the constant temperature water tank 10 for insulation for use. At this time, specific water temperature control can be performed by monitoring the water temperature in the constant temperature water tank 20.

[0114] If the outlet water temperature of the hot water heat exchanger 10 is lower than the first preset temperature, the water needs to be heated again in the constant temperature water tank 20 so that the water temperature reaches the required set water temperature.

[0115] This embodiment can achieve precise control of the water temperature in the constant temperature water tank 20 .

[0116] Furthermore, controlling the thermostatic water tank 20 to enter heating mode includes: opening the first valve 22 and the second valve 23, and controlling the opening of the flow control valve 24 based on the difference between the water temperature in the thermostatic water tank 20 and a second preset temperature; wherein a third pipeline 21 is provided in the thermostatic water tank 20, a first end of the third pipeline 21 being connected to the high-pressure gas pipe 31, and a second end of the third pipeline 21 being connected to the liquid pipe 33; the first valve 22 and the flow control valve 24 being provided at the first end of the third pipeline 21, and the second valve 23 being provided at the second end of the third pipeline 21. When the water temperature in the thermostatic water tank 20 is greater than or equal to the second preset temperature, the opening of the flow control valve 24 can be reduced according to actual conditions to maintain heat.

[0117] In this embodiment, the first valve 22 is opened to allow the refrigerant to enter the constant temperature water tank 20, and the second valve 23 is opened at the same time to allow the refrigerant to flow out of the constant temperature water tank 20 and continue to participate in the circulation. Controlling the opening of the flow regulating valve 24 can adjust the flow of refrigerant entering the constant temperature water tank 20 to achieve control of the water temperature in the water tank and realize heating or insulation.

[0118] When a defrost demand is detected, the thermostatic water tank 20 is controlled to supply hot water, including opening a fourth valve 28. The fourth valve 28 is disposed at the inlet of a fourth pipe 26, which is disposed on at least the chassis of the outdoor unit of the multi-split system. The inlet of the fourth pipe 26 is connected to the water outlet of the thermostatic water tank 20, and the outlet of the fourth pipe 26 is connected to the domestic water pipe 27 or the water inlet of the thermostatic water tank 20. By supplying hot water to the chassis of the outdoor unit through the fourth pipe 26, the generated hot water can be used to address the problem of frost and ice formation on the bottom of the outdoor heat exchanger. The generated hot water can also be used directly for defrosting, thereby maintaining continuous heating during defrosting without affecting user comfort.

[0119] like Figure 11 The figure shows a flow chart of a multi-split system for hot water production, which includes the following steps:

[0120] S1101, detecting the water supply temperature requirement.

[0121] S1102: Detecting the need for defrosting the outdoor unit.

[0122] S1103, sending a hot water making instruction.

[0123] S1104 , monitoring the outlet water temperature of the hot water heat exchanger 10 .

[0124] S1105, determine whether the outlet water temperature of the hot water heat exchanger 10 is greater than or equal to T1 (ie, the first preset temperature), if so, proceed to S1106, if not, proceed to S1109.

[0125] S1106, monitoring the water temperature in the constant temperature water tank 20.

[0126] S1107, determine whether the water temperature in the constant temperature water tank 20 is greater than or equal to T2 (ie, the second preset temperature), if so, enter S1108, if not, return to S1105.

[0127] S1108, supply hot water.

[0128] S1109, the constant temperature water tank 20 enters the heating mode.

[0129] In this embodiment, when the water supply temperature requirement or the outdoor unit defrosting requirement is detected, the water is heated to a certain temperature through the hot water heat exchanger 10, and the heated water enters the constant temperature water tank 20 for heat preservation or secondary heating to obtain hot water that can be used for domestic water and / or defrosting and melting ice.

[0130] This embodiment provides a multifunctional multi-split system that can produce hot water for a long time and has a defrosting function. It has working modes such as cooling, heating, cooling + hot water production, and heating + hot water production. It can effectively use the waste heat of condensation to produce hot water, improve energy utilization, and improve energy saving effects and economic benefits; the hot water temperature is controlled by the hot water heat exchanger 10 and the constant temperature water tank 20, and the water flowing into the water circulation system is heated in stages to provide hot water of different temperatures for different environments; the hot water produced for heating can be used to solve the problem of easy frost and ice formation at the bottom of the outdoor heat exchanger, and the produced hot water can also be used directly for defrosting, so as to achieve continuous heating without stopping the machine and ensure user comfort.

[0131] Example 3

[0132] This embodiment provides a multi-connection system, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method described in the embodiment of the present invention are implemented.

[0133] Example 4

[0134] This embodiment provides a non-volatile computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method described in the embodiment of the present invention are implemented.

[0135] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A multi-connection system, characterized in that: include: Hot water heat exchanger and constant temperature water tank; The hot water heat exchanger is connected between the outdoor heat exchanger and the indoor heat exchanger through a first pipeline; The hot water heat exchanger is also connected between the main water inlet and the water inlet of the constant temperature water tank through a second pipeline; The hot water heat exchanger is used to exchange heat between the refrigerant in the first pipeline and the water in the second pipeline; The multi-split system includes: a high-pressure air pipe, a low-pressure air pipe and a liquid pipe; the constant temperature water tank includes a two-stage water tank, the second pipe is connected to the water inlet of the first-stage water tank, and the first-stage water tank and the second-stage water tank are connected in series; a third pipe is arranged in the second-stage water tank, the first end of the third pipe is connected to the high-pressure air pipe, and the second end of the third pipe is connected to the liquid pipe; the water outlet of the second-stage water tank is connected to the fourth pipe.

2. The multi-connection system according to claim 1, characterized in that: A first valve is provided at the first end of the third pipeline, and a second valve is provided at the second end of the third pipeline.

3. The multi-connection system according to claim 1, characterized in that: A flow regulating valve is provided at the first end of the third pipeline.

4. The multi-connection system according to claim 1, characterized in that: Also includes: a first four-way valve and a second four-way valve; The first port of the first four-way valve is connected to the exhaust port of the compressor, the second port of the first four-way valve is connected to the outdoor heat exchanger, the third port of the first four-way valve is connected to the suction port of the compressor, and the fourth port of the first four-way valve is connected to the low-pressure gas pipe; The first port of the second four-way valve is connected to the exhaust port of the compressor, the second port of the second four-way valve is connected to the outdoor heat exchanger through the third valve, the third port of the second four-way valve is connected to the low-pressure gas pipe, and the fourth port of the second four-way valve is connected to the high-pressure gas pipe.

5. The multi-connection system according to claim 1, characterized in that: The fourth pipeline is arranged on the chassis of the outdoor unit of the multi-split system, the inlet of the fourth pipeline is connected to the water outlet of the second-stage water tank, and the outlet of the fourth pipeline is connected to the domestic water pipeline or the water inlet of the first-stage water tank.

6. The multi-connection system according to claim 5, characterized in that: A fourth valve is provided at the inlet of the fourth pipeline.

7. The multi-connection system according to claim 5, characterized in that: The fourth pipeline is also arranged on the outdoor heat exchanger.

8. The multi-connection system according to any one of claims 1 to 7, characterized in that: The hot water heat exchanger includes at least one heat exchanger. When the hot water heat exchanger includes at least two heat exchangers, the at least two heat exchangers are connected in parallel.

9. A control method for a multi-connected system, characterized in that: Applied to the multi-connected system according to any one of claims 1 to 8, the method comprises: Detection of water supply temperature requirements or defrost requirements; According to the current working mode of the multi-split system, the first four-way valve and the second four-way valve are controlled to produce hot water; The first port of the first four-way valve is connected to the exhaust port of the compressor, the second port of the first four-way valve is connected to the outdoor heat exchanger, the third port of the first four-way valve is connected to the suction port of the compressor, and the fourth port of the first four-way valve is connected to the low-pressure gas pipe. The first port of the second four-way valve is connected to the exhaust port of the compressor, the second port of the second four-way valve is connected to the outdoor heat exchanger through the third valve, the third port of the second four-way valve is connected to the low-pressure gas pipe, and the fourth port of the second four-way valve is connected to the high-pressure gas pipe.

10. The method according to claim 9, characterized in that According to the current working mode of the multi-split system, controlling the first four-way valve and the second four-way valve to produce hot water includes: If the current working mode is the cooling mode, the main water inlet is opened, the first port of the first four-way valve is controlled to be connected to the second port and the third port of the first four-way valve is controlled to be connected to the fourth port, the first port of the second four-way valve is controlled to be connected to the fourth port and the second port of the second four-way valve is controlled to be connected to the third port, and the third valve is controlled to be closed, so as to enter the cooling and hot water making mode; If the current working mode is the heating mode, the main water inlet is opened, the first port of the first four-way valve is controlled to be connected to the fourth port and the second port of the first four-way valve is controlled to be connected to the third port, the first port of the second four-way valve is controlled to be connected to the fourth port and the second port of the second four-way valve is controlled to be connected to the third port, and the third valve is controlled to be closed to enter the heating and hot water making mode.

11. The method according to claim 9, characterized in that Producing hot water, including: Hot water is produced according to the outlet water temperature of the hot water heat exchanger and the water temperature in the constant temperature water tank.

12. The method according to claim 11, characterized in that According to the outlet water temperature of the hot water heat exchanger and the water temperature in the constant temperature water tank, hot water is produced, including: monitoring the outlet water temperature of the hot water heat exchanger; When the outlet water temperature of the hot water heat exchanger is lower than a first preset temperature, controlling the constant temperature water tank to enter a heating mode; When the outlet water temperature of the hot water heat exchanger is greater than or equal to the first preset temperature, the water temperature in the constant temperature water tank is monitored; when the water temperature in the constant temperature water tank is less than the second preset temperature, the monitoring of the outlet water temperature of the hot water heat exchanger is continued; when the water temperature in the constant temperature water tank is greater than or equal to the second preset temperature, the constant temperature water tank is controlled to supply hot water.

13. The method according to claim 12, characterized in that Controlling the constant temperature water tank to enter a heating mode includes: Opening the first valve and the second valve, and controlling the opening of the flow regulating valve according to the difference between the water temperature in the constant temperature water tank and the second preset temperature; In which, a third pipeline is set in the constant temperature water tank, the first end of the third pipeline is connected to the high-pressure gas pipe, and the second end of the third pipeline is connected to the liquid pipe; the first valve and the flow regulating valve are set at the first end of the third pipeline, and the second valve is set at the second end of the third pipeline.

14. The method according to claim 12, characterized in that When a defrosting demand is detected, controlling the constant temperature water tank to supply hot water includes: Open the fourth valve; In which, the fourth valve is arranged at the inlet of the fourth pipeline, the fourth pipeline is arranged at least on the chassis of the outdoor unit of the multi-split system, the inlet of the fourth pipeline is connected to the water outlet of the constant temperature water tank, and the outlet of the fourth pipeline is connected to the domestic water pipeline or the water inlet of the constant temperature water tank.

15. A multi-connection system comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method according to any one of claims 9 to 14 when executing the computer program.

16. A non-volatile computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 9 to 14 are implemented.

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