Multi-split system, control method thereof and air conditioner

Abstract

The invention provides a multi-split system, a control method of the multi-split system and an air conditioner. The multi-split system comprises an outdoor unit, an indoor unit, a water tank, a first electromagnetic valve, a second electromagnetic valve, a first expansion valve, a second expansion valve and a plurality of refrigerant pipelines connected among the outdoor unit, the indoor unit and the water tank. The indoor unit and the water tank form a parallel branch; the first electromagnetic valve, the indoor unit and the first expansion valve form a series branch, and the first electromagnetic valve and the first expansion valve are arranged at the two ends of the indoor unit correspondingly; the second electromagnetic valve, the water tank and the second expansion valve form a series branch, and the second electromagnetic valve and the second expansion valve are arranged at the two ends of the water tank respectively. The first electromagnetic valve and the first expansion valve are arranged at the two ends of the indoor unit respectively, and the second electromagnetic valve and the second expansion valve are arranged at the two ends of the water tank respectively, so that multiple functions of the air conditioner are achieved, excess energy generated by the air conditioner is fully utilized, recycled heat is used for preparing hot water, the hot water preparation cost is saved, and the heat exchange efficiency of the air conditioner is greatly improved.

Description

Technical Field

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

[0002] A multi-connected heat recovery air conditioner system is a multi-connected air conditioner system with waste heat recovery added to a common multi-connected air conditioner system. This system mainly adds a four-way valve to the common multi-connected air conditioner system to switch the high-temperature refrigerant to a hot water tank, and stores the waste heat in the tank to achieve the purpose of heat recovery; this system switches the refrigerant to the tank on the common multi-connected air conditioner system to achieve the effect of making hot water.

[0003] In existing multi-connected air conditioners, due to the limitation of the operating range of the compressor, the water temperature is usually lower than the required temperature, and thus cannot meet the higher requirements for the water temperature of domestic hot water. As the functions of air conditioners become more diverse in the market, users' demands for air conditioners that can simultaneously meet the needs of refrigeration, heating, and domestic hot water are becoming more and more intense; and during the refrigeration process, a large amount of heat is discharged from the outdoor unit, resulting in a large amount of energy loss. Therefore, how to provide a system to recover the excess heat for making hot water, and at the same time improve the heat exchange efficiency of the refrigeration system while recovering heat for making hot water is an urgent problem to be solved at present. Summary of the Invention

[0004] The present invention aims to provide a multi-connected air conditioner system, a control method thereof, and an air conditioner. An electromagnetic valve is added to the existing multi-connected air conditioner system. By controlling the electromagnetic valve, the air conditioner system is divided into an air conditioner system module and a hot water production system module. The hot water production heat recovery module is externally connected to a water tank to realize the hot water production function and function upgrade.

[0005] To achieve the above object, the present invention provides a multi-connected air conditioner system, including: an outdoor unit, an indoor unit, a water tank, a first electromagnetic valve, a second electromagnetic valve, a first expansion valve, a second expansion valve, and multiple refrigerant pipes connecting the outdoor unit, the indoor unit, and the water tank; the indoor unit and the water tank form a parallel branch; the first electromagnetic valve, the indoor unit, and the first expansion valve form a series branch, and the first electromagnetic valve and the first expansion valve are respectively arranged at both ends of the indoor unit; the second electromagnetic valve, the water tank, and the second expansion valve form a series branch, and the second electromagnetic valve and the second expansion valve are respectively arranged at both ends of the water tank.

[0006] In the present invention, the first solenoid valve and the first expansion valve are respectively arranged at both ends of the indoor unit, and the second solenoid valve and the second expansion valve are respectively arranged at both ends of the water tank, so as to ensure that the multi-connected air-conditioning system selects the corresponding operation mode according to the user's needs. While realizing the multi-function of the air conditioner, the redundant energy generated by the air conditioner can be fully utilized, and the recovered heat is used to prepare hot water, which not only saves the cost of making hot water, but also greatly improves the heat exchange efficiency of the air conditioner. Specifically, the indoor unit and the water tank form a parallel branch, the first solenoid valve, the indoor unit and the first expansion valve form a series branch, and the second solenoid valve, the water tank and the second expansion valve form a series branch, so as to divide the multi-connected air-conditioning system into an air-conditioning system and a hot water system. Further, the multi-connected air-conditioning system has three modes: refrigeration and hot water production mode, heating mode, and hot water production mode. The hot water production module is externally connected to the water tank, and the hot water production function is realized through heat recovery, so as to realize the upgrade of the function.

[0007] In any of the above technical solutions, the indoor unit includes an evaporator, and the first solenoid valve and the first expansion valve are respectively arranged at both ends of the evaporator; the outdoor unit includes a condenser and a compressor, the first expansion valve and the second expansion valve are respectively communicated with one end of the condenser, and the first solenoid valve and the second solenoid valve are respectively communicated with the outlet of the compressor.

[0008] By setting the evaporator, it is ensured that the transported refrigerant is converted into steam and absorbs heat, so as to achieve the purpose of refrigeration; the first solenoid valve and the first expansion valve are respectively arranged at both ends of the evaporator. The purpose of the first expansion valve is to throttle the high-temperature and high-pressure refrigerant through it to convert it into low-temperature and low-pressure steam, and further enter the evaporator to absorb the heat from the outside. In addition, the first expansion valve can control the superheat degree of the evaporator within a certain range to avoid the occurrence of abnormal overheating; the first solenoid valve is communicated with the evaporator, and its purpose is to control the flow direction of the refrigerant to regulate the operation state of the air conditioner.

[0009] By setting the condenser, it is ensured that the high-temperature and high-pressure steam transported from the indoor unit exchanges heat with the air outdoors, and then is converted into liquid refrigerant to achieve the purpose of refrigeration. The first expansion valve and the second expansion valve are respectively communicated with one end of the condenser. The first expansion valve can steam-treat the liquid refrigerant transported from the condenser to the evaporator through control, so as to ensure the absorption of heat from the outside and achieve the purpose of refrigeration; the refrigerant transported from the water tank to the evaporator first passes through the second expansion valve and then through the first expansion valve. The first expansion valve and the second expansion valve steam-treat the liquid refrigerant in the water tank through control and enter the evaporator, so as to achieve the purpose of refrigeration.

[0010] In any of the above technical solutions, a check valve is arranged at one end of the indoor unit, and the check valve and the first solenoid valve form a parallel branch.

[0011] By setting a check valve at one end of the indoor unit and forming a parallel branch with the first solenoid valve, it is ensured that the forward and reverse flow of the refrigerant can be controlled, so that the refrigerant can only flow in a certain specified direction. After the refrigerant exchanges heat with the condenser and the water tank, it then passes through the throttle and enters the evaporator for heat exchange to achieve the purpose of air-conditioning refrigeration. Further, the liquid refrigerant formed after absorbing heat in the evaporator is transported back to the compressor through the check valve and the first solenoid valve, and continuously circulates to achieve the purpose of air-conditioning refrigeration and heat recovery for making hot water.

[0012] In any of the above technical solutions, an exhaust solenoid valve and a check solenoid valve are provided between the compressor and the second solenoid valve, and the exhaust solenoid valve and the check solenoid valve form a parallel branch.

[0013] By setting an exhaust solenoid valve between the compressor and the second solenoid valve, it is ensured that the high-pressure gas formed by the compressor can be adjusted through the exhaust solenoid valve, thereby controlling the flow, blocking or changing the flow direction of the compressed gas in the refrigerant pipeline, and further realizing multiple modes of the multi-connected air-conditioning system. By further setting a check solenoid valve between the compressor and the second solenoid valve, the check solenoid valve can open or close the valve depending on the flow of the liquid refrigerant in the pipeline, so as to avoid the reverse flow of the refrigerant; when the outlet pressure is greater than the inlet, the refrigerant will not flow back; the main purpose of the check solenoid valve is to control the one-way flow of the refrigerant medium.

[0014] In any of the above technical solutions, stop valves are provided at both ends of the water tank and the indoor unit.

[0015] Setting stop valves at both ends of the water tank or the indoor unit can achieve functions such as refrigerant delivery, cut-off, and adjustment, and has sealing performance and reliability; the stop valve has a small opening height during the opening and closing process, is easy to adjust the flow rate, is convenient for manufacturing and maintenance, and has a wide pressure application range. Preferably, on the series pipeline of the indoor unit, one stop valve is set between the first expansion valve and one end of the evaporator, and then the other stop valve is set between the first solenoid valve and the other end of the evaporator, so as to ensure that the flow of the refrigerant medium in the indoor unit pipeline can be effectively opened or blocked; on the series pipeline of the water tank, one stop valve is set between the second expansion valve and one end of the water tank, and then the other stop valve is set between the second solenoid valve and the other end of the water tank, so as to ensure that the flow of the refrigerant medium in the water tank pipeline can be effectively opened or blocked.

[0016] In any of the above technical solutions, temperature sensors are provided around the condenser, compressor, evaporator, and water tank.

[0017] By arranging temperature sensors around the condenser, the outdoor ambient temperature can be obtained; by arranging a temperature sensor at the outlet of the compressor, the exhaust temperature at the outlet can be obtained; by arranging temperature sensors around the evaporator, the indoor ambient temperature can be obtained; by arranging temperature sensors around the water tank, the actual water temperature of the water tank can be obtained. Comparing the obtained outdoor ambient temperature and indoor ambient temperature with the set temperature of the air conditioner, and comparing the obtained actual water temperature with the set temperature of the water tank, so as to achieve the purpose of air-conditioning refrigeration and heat recovery for making hot water. Detecting the exhaust temperature of the compressor to achieve the purpose of controlling and protecting the compressor.

[0018] In any of the above technical solutions, the multi-connected air-conditioning system includes at least two indoor units, and parallel branches are formed between the indoor units.

[0019] The parallel branches can enable the communication between multiple indoor units to be connected in parallel, and the outdoor unit equally receives the communication signals of each indoor unit. The multi-connected air-conditioning system only uses one outdoor unit, which is convenient and beautiful to install, and flexible and convenient to control. The multi-connected air-conditioning system can achieve centralized management of each indoor unit and adopt network control. One indoor unit can be operated alone, or multiple indoor units can be operated simultaneously, making the control more flexible and energy-saving.

[0020] The present invention also provides a control method for a multi-connected air-conditioning system. A four-way valve, an exhaust solenoid valve and a check solenoid valve are arranged on the refrigerant pipeline, and the method includes the following steps: collecting the ambient temperatures of the outdoor unit, the indoor units and the water tank, and judging whether the operation mode of the multi-connected air-conditioning system is the target operation mode according to the magnitude relationship between the ambient temperature and the set temperature; if so, controlling the opening and closing of the first solenoid valve, the second solenoid valve, the exhaust solenoid valve, the check solenoid valve and the four-way valve; calculating the target frequency of the compressor, the target opening of the first expansion valve and the target opening of the second expansion valve according to the ambient temperature, and performing control.

[0021] The present invention collects the ambient temperatures of the outdoor unit, the indoor units and the water tank through temperature sensors, and compares the ambient temperature of the indoor unit with the set temperature of the air conditioner, and also compares the ambient temperature of the water tank, that is, the actual water temperature, with the set water temperature, so as to judge whether the current operation mode of the multi-connected air-conditioning system is the target operation mode; if so, the control of the air-conditioning refrigeration and heat recovery for making hot water mode takes effect, and the opening and closing of the solenoid valves are controlled. The solenoid valves include the first solenoid valve, the second solenoid valve, the exhaust solenoid valve, the check solenoid valve and the four-way valve. If not, only the air-conditioning refrigeration mode is operated and heat recovery is not involved. When entering the heat recovery mode, the target frequency of the compressor, the target opening of the first expansion valve and the target opening of the second expansion valve need to be calculated according to the ambient temperature of the outdoor unit and the actual temperature of the water tank, and real-time control is performed.

[0022] In any of the above technical solutions, when the multi-connected unit system is in the air-conditioning cooling and hot water modes, the control devices of the first expansion valve and the second expansion valve are opened and the target opening degrees are controlled, the first solenoid valve, the second solenoid valve, and the exhaust solenoid valve are opened, the check solenoid valve is closed, the compressor is started and the target frequency is controlled, and the four-way valve is not powered on; and / or when the multi-connected unit system is in the air-conditioning heating mode, the control device of the first expansion valve is opened and the target opening degree is controlled, the control device of the second expansion valve is closed, the first solenoid valve is opened, the second solenoid valve, the exhaust solenoid valve, and the check solenoid valve are closed, the compressor is started and the target frequency is controlled, and the four-way valve is powered on for commutation; and / or when the multi-connected unit system is in the hot water mode, the control device of the first expansion valve is closed, the control device of the second expansion valve is opened and the target opening degree is controlled, the first solenoid valve and the exhaust solenoid valve are closed, the second solenoid valve and the check solenoid valve are opened, the compressor is started and the target frequency is controlled, and the four-way valve is powered on for commutation.

[0023] When the multi-connected unit system is in the air-conditioning cooling and hot water modes, the outlet of the compressor is connected to one end of the condenser through the four-way valve, and the other end of the condenser is connected to one end of the evaporator through the first expansion valve; the outlet of the compressor is connected to one end of the water tank through the exhaust solenoid valve and the second solenoid valve, and the other end of the water tank is connected to one end of the evaporator through the first expansion valve; the other end of the evaporator is connected to the outlet of the compressor through the check valve and the first solenoid valve; the refrigerant flows out from the outlet of the compressor, passes through the first path and the second path simultaneously, and then passes through the first expansion valve, the evaporator, the check valve, and the first solenoid valve together, and finally returns to the outlet of the compressor; wherein, the first path passes through the four-way valve and the condenser in sequence, and the second path passes through the exhaust solenoid valve, the second solenoid valve, the water tank, and the second expansion valve in sequence; the check valve and the first solenoid valve form a parallel branch, and the exhaust solenoid valve is arranged between the compressor and the second solenoid valve.

[0024] When the multi-connected unit system is in the air-conditioning heating mode, the outlet of the compressor is connected to one end of the evaporator through the four-way valve and the first solenoid valve, the other end of the evaporator is connected to one end of the condenser through the first expansion valve, and the other end of the condenser is connected to the outlet of the compressor through the four-way valve; the high-temperature and high-pressure refrigerant flows out from the outlet of the compressor, passes through the four-way valve, the first solenoid valve, the evaporator, the first expansion valve, and the condenser in sequence, and finally returns to the outlet of the compressor.

[0025] When the multi-connected unit system is in the hot water mode, the outlet of the compressor is connected to one end of the water tank through the four-way valve and the second solenoid valve, the other end of the water tank is connected to one end of the condenser through the second expansion valve, and the other end of the condenser is connected to the outlet of the compressor through the four-way valve; the high-temperature and high-pressure refrigerant flows out from the outlet of the compressor, passes through the four-way valve, the second solenoid valve, the water tank, the second expansion valve, and the condenser in sequence, and finally returns to the outlet of the compressor.

[0026] The present invention also provides an air conditioner, which adopts the above-mentioned multi-connected unit system. The air conditioner has the same beneficial effects as the multi-connected unit system, so they will not be elaborated here.

[0027] After adopting the technical solution of the present invention, the following technical effects can be achieved:

[0028] In the present invention, the first solenoid valve and the first expansion valve are respectively arranged at both ends of the indoor unit, and the second solenoid valve and the second expansion valve are respectively arranged at both ends of the water tank, so as to ensure that the multi-connected unit system selects the corresponding operation mode according to the user's needs. While realizing the multi-function of the air conditioner, the redundant energy generated by the air conditioner can be fully utilized, and the recovered heat is used to prepare hot water, which not only saves the cost of preparing hot water, but also greatly improves the heat exchange efficiency of the air conditioner. The indoor unit and the water tank form a parallel branch, the first solenoid valve, the indoor unit and the first expansion valve form a series branch, and the second solenoid valve, the water tank and the second expansion valve form a series branch, so as to divide the multi-connected unit system into an air conditioning system and a hot water system. Further, the multi-connected unit system has three modes: refrigeration and hot water production mode, heating mode, and hot water production mode. The hot water production module is externally connected to the water tank, and the hot water production function is realized by means of heat recovery, realizing the upgrade of the function. Description of the Drawings

[0029] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0030] Figure 1 is a schematic structural diagram of a multi-connected unit system provided by an embodiment of the present invention;

[0031] Figure 2 is a schematic flow diagram of a control method for a multi-connected unit system provided by an embodiment of the present invention;

[0032] Figure 3 is a schematic flow diagram of a control method for a multi-connected unit system provided by an embodiment of the present invention;

[0033] Figure 4 is a schematic flow diagram of a control method for a multi-connected unit system provided by an embodiment of the present invention.

[0034] Description of the Reference Numerals:

[0035] 100 - Outdoor unit; 110 - Condenser; 120 - Compressor; 130 - Four-way valve; 200 - Indoor unit; 210 - Evaporator; 300 - Water tank; 410 - First solenoid valve; 420 - Second solenoid valve; 510 - First expansion valve; 520 - Second expansion valve; 610 - Exhaust solenoid valve; 620 - Check valve; 630 - Check solenoid valve; 640 - Stop valve; 650 - Temperature sensor; 710 - Low-pressure pressure switch; 720 - Suction sensor; 730 - Defrost sensor; 740 - Filter; 750 - Fine tube sensor; 760 - Thick tube sensor; 770 - Middle sensor. Detailed implementation manner

[0036] To make the above objects, features, and advantages of the present invention more apparent and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] An embodiment of the present invention provides a multi-connected air conditioner system, including: an outdoor unit 100, an indoor unit 200, a water tank 300, a first solenoid valve 410, a second solenoid valve 420, a first expansion valve 510, a second expansion valve 520, and multiple refrigerant pipes connecting the outdoor unit 100, the indoor unit 200, and the water tank 300; the indoor unit 200 and the water tank 300 form a parallel branch; the first solenoid valve 410, the indoor unit 200, and the first expansion valve 510 form a series branch, and the first solenoid valve 410 and the first expansion valve 510 are respectively arranged at both ends of the indoor unit 200; the second solenoid valve 420, the water tank 300, and the second expansion valve 520 form a series branch, and the second solenoid valve 420 and the second expansion valve 520 are respectively arranged at both ends of the water tank 300.

[0038] As Figure 1As shown in the figure, in the embodiment of the present invention, the first solenoid valve 410 and the first expansion valve 510 are respectively arranged at both ends of the indoor unit 200, and the second solenoid valve 420 and the second expansion valve 520 are respectively arranged at both ends of the water tank 300, so as to ensure that the multi-connected air-conditioning system selects the corresponding operation mode according to the user's needs. While realizing the multi-function of the air conditioner, the redundant energy generated by the air conditioner can be fully utilized, and the recovered heat is used to prepare hot water, which not only saves the cost of making hot water, but also greatly improves the heat exchange efficiency of the air conditioner. Specifically, the indoor unit 200 and the water tank 300 form a parallel branch, the first solenoid valve 410, the indoor unit 200 and the first expansion valve 510 form a series branch, and the second solenoid valve 420, the water tank 300 and the second expansion valve 520 form a series branch, so as to divide the multi-connected air-conditioning system into an air-conditioning system and a hot water system. Further, the multi-connected air-conditioning system has three modes: refrigeration and hot water production mode, heating mode, and hot water production mode. The hot water production module is externally connected to the water tank 300, and the hot water production function is realized by means of heat recovery, so as to realize the upgrade of the function.

[0039] It should be noted that the series branch formed by the first solenoid valve 410, the indoor unit 200 and the first expansion valve 510 is used as the first branch, and the series branch formed by the second solenoid valve 420, the water tank 300 and the second expansion valve 520 is used as the second branch. The first branch and the second branch form a parallel branch with each other, so as to ensure the separate operation of the air-conditioning system and the hot water system. Preferably, a four-way valve 130 is arranged at the outlet of the compressor 120, which can change and control the flow direction of the refrigerant, and thus realize the multi-function mode of the multi-connected air-conditioning system.

[0040] In some embodiments of the present application, the indoor unit 200 includes an evaporator 210, and the first solenoid valve 410 and the first expansion valve 510 are respectively arranged at both ends of the evaporator 210; the outdoor unit 100 includes a condenser 110 and a compressor 120, and the first expansion valve 510 and the second expansion valve 520 are respectively communicated with one end of the condenser 110, and the first solenoid valve 410 and the second solenoid valve 420 are respectively communicated with the outlet of the compressor 120.

[0041] As Figure 1 shown, by setting the evaporator 210, it is ensured that the transported refrigerant is converted into steam and absorbs heat, so as to achieve the purpose of refrigeration; the first solenoid valve 410 and the first expansion valve 510 are respectively arranged at both ends of the evaporator 210. The purpose of the first expansion valve 510 is to throttle the high-temperature and high-pressure refrigerant into low-temperature and low-pressure steam through it, and further enter the evaporator 210 to absorb the heat from the outside. In addition, the first expansion valve 510 can control the superheat of the evaporator 210 within a certain range to avoid the occurrence of abnormal overheating; the first solenoid valve 410 is communicated with the evaporator 210, and its purpose is to control the flow direction of the refrigerant to regulate the operation state of the air conditioner.

[0042] By setting the condenser 110 to ensure that the high-temperature and high-pressure steam of the indoor unit 200 to be conveyed exchanges heat with the air outdoors, and then is converted into a liquid refrigerant to achieve the purpose of refrigeration. The first expansion valve 510 and the second expansion valve 520 are respectively communicated with one end of the condenser 110. The first expansion valve 510 can perform steam treatment on the liquid refrigerant conveyed from the condenser 110 to the evaporator 210 through control, so as to ensure absorbing the heat from the outside and achieving the purpose of refrigeration; the refrigerant conveyed from the water tank 300 to the evaporator 210 first passes through the second expansion valve 520 and then through the first expansion valve 510. Among them, the first expansion valve 510 and the second expansion valve 520 perform steam treatment on the liquid refrigerant in the water tank 300 through control and enter the evaporator 210, so as to achieve the purpose of refrigeration.

[0043] Preferably, a liquid storage tank is provided at the suction port of the compressor 120, and a low-pressure pressure switch 710 can be provided at one end of the liquid storage tank far from the connection with the compressor 120 to protect the pressure of the liquid storage tank; a suction sensor 720 is provided on the pipeline near the low-pressure pressure switch 710 to ensure that the state of the refrigerant absorbed by the compressor 120 can be monitored in real time; a defrosting sensor 730 is provided at one end of the condenser 110 close to the first expansion valve 510. When the condenser 110 is frosted, the flow direction of the refrigerant is switched through the four-way valve 130 to increase the temperature on the condenser 110, so as to defrost in a short time.

[0044] In addition, a filter 740 is provided on the connection pipeline between the condenser 110 and the first expansion valve 510 or the second expansion valve 520 for primary filtration; a filter 740 is provided on the connection pipeline between the evaporator 210 and the first expansion valve 510, and a filter 740 is provided on the connection pipeline between the water tank 300 and the second expansion valve 520. The filter 740 can further effectively filter the gas to protect the evaporator 210 and the water tank 300.

[0045] In the air-conditioning system, a thin-tube sensor 750 is provided between the first expansion valve 510 and the filter 740, a thick-tube sensor 760 is provided between the first solenoid valve 410 and the evaporator 210, and a middle sensor 770 is provided on the evaporator 210 to ensure detecting the thin-tube temperature, thick-tube temperature, and middle temperature of the indoor unit 200; in the hot water system, a thin-tube sensor 750 is provided between the second expansion valve 520 and the filter 740, and a thick-tube sensor 760 is provided between the second solenoid valve 420 and the water tank 300 to ensure detecting the thin-tube temperature and thick-tube temperature of the water tank 300.

[0046] In some embodiments of the present application, a check valve 620 is provided at one end of the indoor unit 200, and the check valve 620 and the first solenoid valve 410 form a parallel branch.

[0047] As Figure 1 shown, by providing a check valve 620 at one end of the indoor unit 200 and forming a parallel branch with the first solenoid valve 410, it is ensured that the forward and reverse flow rates of the refrigerant can be controlled, so that the refrigerant can only flow in a certain specified direction. After the refrigerant exchanges heat with the condenser 110 and the water tank 300, it then passes through throttling and enters the evaporator 210 for heat exchange to achieve the purpose of air-conditioning refrigeration. Further, the liquid refrigerant formed after absorbing heat in the evaporator 210 is transported back into the compressor 120 through the check valve 620 and the first solenoid valve 410, and continuously circulates to achieve the purpose of air-conditioning refrigeration and heat recovery for making hot water.

[0048] In some embodiments of the present application, an exhaust solenoid valve 610 and a check solenoid valve 630 are provided between the compressor 120 and the second solenoid valve 420, and the exhaust solenoid valve 610 and the check solenoid valve 630 form a parallel branch.

[0049] As Figure 1 shown, by providing an exhaust solenoid valve 610 between the compressor 120 and the second solenoid valve 420, it is ensured that the high-pressure gas formed by the compressor 120 can be adjusted through the exhaust solenoid valve 610, thereby controlling the flow, blocking or changing the flow direction of the compressed gas in the refrigerant pipeline, and further realizing various modes of the multi-connected air-conditioning system. By further providing a check solenoid valve 630 between the compressor 120 and the second solenoid valve 420, the check solenoid valve 630 can open or close the valve depending on the flow of the liquid refrigerant in the pipeline, thereby avoiding the reverse flow of the refrigerant; when the outlet pressure is greater than the inlet, the refrigerant will not flow back; the main purpose of the check solenoid valve 630 is to control the one-way flow of the refrigerant medium.

[0050] In some embodiments of the present application, stop valves 640 are provided at both ends of the water tank 300 and the indoor unit 200.

[0051] As Figure 1As shown in the figure, stop valves 640 are provided at both ends of the water tank 300 or the indoor unit 200, which can realize functions such as refrigerant transportation, cut-off, and regulation, and have good sealing performance and reliability. During the opening and closing process of the stop valve 640, the opening height is small, which is easy to adjust the flow rate, convenient for manufacturing and maintenance, and has a wide pressure application range. Preferably, on the series pipeline of the indoor unit 200, one stop valve 640 is arranged between one end of the first expansion valve 510 and the evaporator 210, and then another stop valve 640 is arranged between one end of the first solenoid valve 410 and the other end of the evaporator 210, so as to ensure that the refrigerant medium can be effectively opened or blocked in the pipeline of the indoor unit 200; on the series pipeline of the water tank 300, one stop valve 640 is arranged between one end of the second expansion valve 520 and the water tank 300, and then another stop valve 640 is arranged between one end of the second solenoid valve 420 and the other end of the water tank 300, so as to ensure that the refrigerant medium can be effectively opened or blocked in the pipeline of the water tank 300.

[0052] In some embodiments of the present application, temperature sensors 650 are arranged around the condenser 110, the compressor 120, the evaporator 210, and the water tank 300.

[0053] As Figure 1 shown in the figure, by arranging the temperature sensor 650 around the condenser 110, the outdoor ambient temperature can be obtained; by arranging the temperature sensor 650 at the outlet of the compressor 120, the exhaust temperature at the outlet can be obtained; by arranging the temperature sensor 650 around the evaporator 210, the indoor ambient temperature can be obtained; by arranging the temperature sensor 650 around the water tank 300, the actual water temperature of the water tank 300 can be obtained. Comparing the obtained outdoor ambient temperature and indoor ambient temperature with the set temperature of the air conditioner, and comparing the obtained actual water temperature with the set temperature of the water tank 300, so as to achieve the purpose of air-conditioning refrigeration and heat recovery for making hot water. Detecting the exhaust temperature of the compressor 120 to achieve the purpose of controlling and protecting the compressor 120.

[0054] In some embodiments of the present application, the multi-connected air-conditioning system includes at least two indoor units 200, and parallel branches are formed between the indoor units 200.

[0055] As Figure 1 shown in the figure, the parallel branches can make the communication between multiple indoor units 200 be connected in parallel, and the outdoor unit 100 equally receives the communication signals of each indoor unit 200. Specifically, the multi-connected air-conditioning system only uses one outdoor unit 100, which is convenient and beautiful to install, and flexible and convenient to control. The multi-connected air-conditioning system can realize the centralized management of each indoor unit 200 and adopt network control. One indoor unit 200 can be operated alone, or multiple indoor units 200 can be operated simultaneously, making the control more flexible and energy-saving.

[0056] An embodiment of the present invention further provides a control method for a multi-connected air conditioner system. A four-way valve, an exhaust solenoid valve, and a check solenoid valve are provided on the refrigerant pipeline. The method includes the following steps: collecting the ambient temperatures of the outdoor unit, the indoor units, and the water tank, and judging whether the operating mode of the multi-connected air conditioner system is the target operating mode according to the relationship between the ambient temperature and the set temperature; if so, controlling the opening and closing of the first solenoid valve, the second solenoid valve, the exhaust solenoid valve, the check solenoid valve, and the four-way valve; calculating the target frequency of the compressor, the target opening of the first expansion valve, and the target opening of the second expansion valve according to the ambient temperature, and performing control.

[0057] As Figures 2 to 4 shown, in this embodiment, temperature sensors are used to collect the ambient temperatures of the outdoor unit, the indoor units, and the water tank, and compare the ambient temperature of the indoor unit with the set temperature of the air conditioner, and compare the ambient temperature of the water tank, that is, the actual water temperature, with the set water temperature, so as to judge whether the current operating mode of the multi-connected air conditioner system is the target operating mode; if so, the control of the air-conditioning refrigeration and heat recovery hot water supply mode takes effect, and the opening and closing of the solenoid valve are controlled. The solenoid valve includes the first solenoid valve, the second solenoid valve, the exhaust solenoid valve, the check solenoid valve, and the four-way valve. If not, only the air-conditioning refrigeration mode is operated, and heat recovery is not involved. When entering the heat recovery mode, it is necessary to calculate the target frequency of the compressor, the target opening of the first expansion valve, and the target opening of the second expansion valve according to the ambient temperature of the outdoor unit and the actual temperature of the water tank, and perform real-time control.

[0058] The specific implementation steps of the multi-connected air conditioner system for heat recovery hot water supply are as follows:

[0059] S10: Communicate between the host and the indoor units;

[0060] S20: Control the current working state of the entire system. If the multi-connected air conditioner system is in the operating state of air-conditioning refrigeration and heat recovery hot water supply, then the control of the air-conditioning refrigeration and heat recovery hot water supply mode takes effect;

[0061] S30: Collect the ambient temperature T ao of the outdoor unit, the ambient temperature T ai of the indoor units, the set temperature T 设定 of the air conditioner, the actual water temperature T 实际水温 of the water tank, the set water temperature T 设定水温 of the water tank and other sensor temperatures;

[0062] S40: The multi-connected air conditioner system judges the relationship between the ambient temperature T ai of the indoor units and the set temperature T 设定 of the air conditioner;

[0063] S41: If T 设定 > T aiWhen the temperature is -1°C, the unit is required to be shut down and standby.

[0064] S50: If T 设定 ≤ T ai When the temperature is -1°C, the air-conditioning cooling demand is turned on.

[0065] S60: Determine the actual water temperature T of the water tank 实际水温 ≥ 55°C;

[0066] S61: If T 实际水温 < 55°C, do not intervene in heat recovery and only operate the air-conditioning cooling mode;

[0067] S70: If T 实际水温 ≥ 55°C, control the solenoid valves to act in place: the first solenoid valve, the second solenoid valve, and the exhaust solenoid valve are opened, and the check solenoid valve is closed;

[0068] S71: Calculate the initial frequency F of the compressor 初始 , calculated according to the ambient temperature T of the outdoor unit ao Calculate,

[0069] F 初始 =(A 开空调内机台数 × 2500W × F 最大频率 × B 制冷外环修正系数 ) / nominal capacity;

[0070] When 43°C < T ao , B = 0.8; when 30°C < T ao ≤ 43°C, B = 1.0; when 24°C < T ao ≤ 30°C, B = 0.8; when 18°C < T ao ≤ 24°C, B = 0.6; when T ao < 18°C, B = 0.4;

[0071] S72: Calculate the target evaporation temperature. After running at the initial frequency for 5 minutes, switch to closed-loop control of the target evaporation temperature. The target middle temperature T 目标中部传感器温度 is distinguished according to the ambient temperature T of the outdoor unit as follows ao ,

[0072] When T ao < 29°C, T 目标中部传感器温度 = 12°C; when T ao ≥ 29°C, T 目标中部传感器温度 = 8°C;

[0073] S73: Calculate the middle temperature difference △T 中部温差 , △T 中部温差 = T 目标中部传感器温度 - T 实际蒸发 ;

[0074] S74: Retrieve the target correction value ΔF.

[0075]

[0076] S75: Calculate the compressor frequency F. Calculate the target frequency = the previous calculated target frequency + the current target frequency × ΔF. The frequency calculation period is 20 s, and complete the frequency control.

[0077] S80: Initial valve step control P of the air conditioner 空调初始阀步 , maintain for 3 min.

[0078] Single - open: The initial valve step of the single - open air conditioner P = 150 p. Multi - open: The initial valve step of the multi - open air conditioner P = 110 p.

[0079] S81: Calculate the superheat degree TSH of the closed - loop control of the first expansion valve.

[0080] TSH = T 室内机粗管温度 - T 室内机细管温度 - SHS;

[0081] The superheat correction value SHS is selected according to the exhaust temperature.

[0082] T 排气 ≥95°C, SHS = a 1 ; 80°C ≤ T 排气 <95°C, SHS = a 2 ; 60°C ≤ T 排气 <80

[0083] °C, SHS = a 3 ; T 排气 <60°C, SHS = a 4 ;

[0084] S82: Calculate the regulating valve step ΔP of the closed - loop control of the first expansion valve.

[0085] When TSH ≤ - 5°C, ΔP = - 7; when - 3 ≤ TSH < - 5°C, ΔP = - 5; when - 1 ≤ TSH < - 3°C, ΔP = - 2; when - 1 ≤ TSH < 1°C, ΔP = 0; when 1 ≤ TSH < 3°C, ΔP = 2; when 3 ≤ TSH < 5°C, ΔP = 5; when 5 ≤ TSH, ΔP = 7.

[0086] S83: Calculate the target opening P of the closed - loop control of the first expansion valve 目标开度 ,

[0087] Calculate according to the general principle, P 目标开度 = P 当前开度 +ΔP, the valve - regulating period is 20 S.

[0088] Complete the closed - loop control of the first expansion valve.

[0089] S90: Initial valve step control P of water tank 水箱初始阀步 , maintain for 3 min,

[0090] P 水箱初始阀步 = 90p;

[0091] S91: In the heat recovery mode, calculate the heat recovery superheat WTSH of the closed-loop control of the second expansion valve, WTSH = T 水箱细管温度 - T 除霜温度 - WSHS

[0092] The water tank superheat correction value WSHS is selected according to the water temperature,

[0093] T 水温 ≥48 °C, WSHS = b 1 ; 35 °C ≤ T 水温 <48 °C, WSHS = b 2 ; 25 °C ≤ T 水温

[0094] <35 °C, WSHS = b 3 ; T 水温 <25 °C, WSHS = b 4 ;

[0095] S92: In the heat recovery mode, calculate the regulating valve step △P of the closed-loop control of the second expansion valve 水箱 ,

[0096] When WTSH ≤ -5 °C, △P 水箱 = -6; when -3 ≤ WTSH < -5 °C, △P 水箱 = -4; when -1 ≤ WTSH

[0097] < -3 °C, △P 水箱 = -2; when -1 ≤ WTSH < 1 °C, △P 水箱 = 0; when 1 ≤ WTSH < 3 °C, △P 水箱 = 2; when 3 ≤ WTSH < 5 °C, △P 水箱 = 4; when 5 ≤ TSH, △P 水箱 = 6;

[0098] S93: In the heat recovery mode, calculate P of the closed-loop control of the second expansion valve 水箱目标开度 ,

[0099] Calculate according to the general principle, P 水箱目标开度 = P 水箱当前开度 + ΔP 水箱 , the valve adjustment period is 20S,

[0100] Complete the closed-loop control of the second expansion valve in the heat recovery mode;

[0101] S94: The multi-connected air-conditioning system performs hot water production control with heat recovery.

[0102] In some embodiments of the present application, when the multi-connected air-conditioning system is in the air-conditioning cooling and hot water modes, the control devices of the first expansion valve and the second expansion valve are opened and the target opening degrees are controlled, the first solenoid valve, the second solenoid valve, and the exhaust solenoid valve are opened, the check solenoid valve is closed, the compressor is started and the target frequency is controlled, and the four-way valve is not powered on; and / or when the multi-connected air-conditioning system is in the air-conditioning heating mode, the control device of the first expansion valve is opened and the target opening degree is controlled, the control device of the second expansion valve is closed, the first solenoid valve is opened, the second solenoid valve, the exhaust solenoid valve, and the check solenoid valve are closed, the compressor is started and the target frequency is controlled, and the four-way valve is powered on for commutation; and / or when the multi-connected air-conditioning system is in the hot water mode, the control device of the first expansion valve is closed, the control device of the second expansion valve is opened and the target opening degree is controlled, the first solenoid valve and the exhaust solenoid valve are closed, the second solenoid valve and the check solenoid valve are opened, the compressor is started and the target frequency is controlled, and the four-way valve is powered on for commutation.

[0103] As Figures 1 to 4 shown, when the multi-connected air-conditioning system is in the air-conditioning cooling and hot water modes, the outlet of the compressor is connected to one end of the condenser through the four-way valve, and the other end of the condenser is connected to one end of the evaporator through the first expansion valve; the outlet of the compressor is connected to one end of the water tank through the exhaust solenoid valve and the second solenoid valve, and the other end of the water tank is connected to one end of the evaporator through the first expansion valve; the other end of the evaporator is connected to the outlet of the compressor through the check valve and the first solenoid valve; the refrigerant flows out of the outlet of the compressor, passes through the first path and the second path simultaneously, and then passes through the first expansion valve, the evaporator, the check valve, and the first solenoid valve together, and finally returns to the outlet of the compressor; wherein, the first path passes through the four-way valve and the condenser in sequence, and the second path passes through the exhaust solenoid valve, the second solenoid valve, the water tank, and the second expansion valve in sequence; the check valve and the first solenoid valve form a parallel branch, and the exhaust solenoid valve is arranged between the compressor and the second solenoid valve.

[0104] When the multi-connected air-conditioning system is in the air-conditioning heating mode, the outlet of the compressor is connected to one end of the evaporator through the four-way valve and the first solenoid valve, the other end of the evaporator is connected to one end of the condenser through the first expansion valve, and the other end of the condenser is connected to the outlet of the compressor through the four-way valve; the high-temperature and high-pressure refrigerant flows out of the outlet of the compressor, passes through the four-way valve, the first solenoid valve, the evaporator, the first expansion valve, and the condenser in sequence, and finally returns to the outlet of the compressor.

[0105] When the multi-connected air-conditioning system is in the hot water mode, the outlet of the compressor is communicated with one end of the water tank through a four-way valve and a second solenoid valve. The other end of the water tank is communicated with one end of the condenser through a second expansion valve. The other end of the condenser is communicated with the outlet of the compressor through the four-way valve. The high-temperature and high-pressure refrigerant flows out from the outlet of the compressor, successively passes through the four-way valve, the second solenoid valve, the water tank, the second expansion valve, and the condenser, and finally returns to the outlet of the compressor.

[0106] An embodiment of the present invention further provides an air conditioner, and the air conditioner adopts the above multi-connected air-conditioning system.

[0107] 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 them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-connected air conditioner system, characterized in that, it includes: an outdoor unit (100), an indoor unit (200), a water tank (300), a first solenoid valve (410), a second solenoid valve (420), a first expansion valve (510), a second expansion valve (520), and multiple refrigerant pipes connected between the outdoor unit (100), the indoor unit (200), and the water tank (300); the indoor unit (200) and the water tank (300) form a parallel branch; the first solenoid valve (410), the indoor unit (200), and the first expansion valve (510) form a series branch, and the first solenoid valve (410) and the first expansion valve (510) are respectively arranged at both ends of the indoor unit (200); the second solenoid valve (420), the water tank (300), and the second expansion valve (520) form a series branch, and the second solenoid valve (420) and the second expansion valve (520) are respectively arranged at both ends of the water tank (300).

2. The multi-connected air conditioner system according to claim 1, characterized in that, the indoor unit (200) includes an evaporator (210), and the first solenoid valve (410) and the first expansion valve (510) are respectively arranged at both ends of the evaporator (210); the outdoor unit (100) includes a condenser (110) and a compressor (120), the first expansion valve (510) and the second expansion valve (520) are respectively communicated with one end of the condenser (110), and the first solenoid valve (410) and the second solenoid valve (420) are respectively communicated with the outlet of the compressor (120).

3. The multi-connected air conditioner system according to claim 1, characterized in that, a check valve (620) is arranged at one end of the indoor unit (200), and the check valve (620) and the first solenoid valve (410) form a parallel branch.

4. The multi-connected air conditioner system according to claim 2, characterized in that, an exhaust solenoid valve (610) and a check solenoid valve (630) are arranged between the compressor (120) and the second solenoid valve (420), and the exhaust solenoid valve (610) and the check solenoid valve (630) form a parallel branch.

5. The multi-connected air conditioner system according to claim 1, characterized in that, stop valves (640) are arranged at both ends of the water tank (300) and the indoor unit (200).

6. The multi-connected air conditioner system according to claim 2, characterized in that, temperature sensors (650) are arranged around the condenser (110), the compressor (120), the evaporator (210), and the water tank (300).

7. The multi-connected air conditioner system according to claim 1, characterized in that, the multi-connected air conditioner system includes at least two indoor units (200), and parallel branches are formed between the indoor units (200).

8. A control method for a multi-connected air-conditioning system, the control method being used for the multi-connected air-conditioning system according to any one of claims 1 to 7, wherein a four-way valve, an exhaust solenoid valve, and a check solenoid valve are provided on the refrigerant pipeline. Characterized in that, It includes the following steps: Collect the ambient temperatures of the outdoor unit, the indoor units, and the water tank, and judge whether the operating mode of the multi-connected air-conditioning system is the target operating mode according to the magnitude relationship between the ambient temperature and the set temperature; If so, control the opening and closing of the first solenoid valve, the second solenoid valve, the exhaust solenoid valve, the check solenoid valve, and the four-way valve; Calculate the target frequency of the compressor, the target opening degree of the first expansion valve, and the target opening degree of the second expansion valve according to the ambient temperature, and perform control.

9. According to the control method described in claim 8, Characterized in that, When the multi-connected air-conditioning system is in the air-conditioning cooling and hot water modes, turn on the control devices of the first expansion valve and the second expansion valve and control the target opening degrees, turn on the first solenoid valve, the second solenoid valve, and the exhaust solenoid valve, turn off the check solenoid valve, turn on the compressor and control the target frequency, and the four-way valve is not powered on; and / or When the multi-connected air-conditioning system is in the air-conditioning heating mode, turn on the control device of the first expansion valve and control the target opening degree, turn off the control device of the second expansion valve, turn on the first solenoid valve, turn off the second solenoid valve, the exhaust solenoid valve, and the check solenoid valve, turn on the compressor and control the target frequency, and the four-way valve is powered on for commutation; and / or When the multi-connected air-conditioning system is in the hot water mode, turn off the control device of the first expansion valve, turn on the control device of the second expansion valve and control the target opening degree, turn off the first solenoid valve and the exhaust solenoid valve, turn on the second solenoid valve and the check solenoid valve, turn on the compressor and control the target frequency, and the four-way valve is powered on for commutation.

10. An air conditioner, the air conditioner adopting the multi-connected air-conditioning system according to any one of claims 1 to 7.

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