Air conditioning system and control method thereof

Abstract

The present invention provides an air-conditioning system and a control method thereof, wherein the air-conditioning system includes a water tank having a heat exchange structure, a control valve having four ports, the exhaust port of the compressor is connected to the first port, the intake port is connected to the second port, the indoor heat exchanger, the outdoor heat exchanger and the first throttling element are all arranged on the first flow path, the first end of the first flow path is connected to the third port, and the second end is connected to the fourth port, the heat exchange structure and the second throttling element are both arranged on the second flow path, and both ends of the second flow path are connected to the first flow path. According to the present invention, by connecting the water tank and the outdoor heat exchanger in parallel, the high-temperature and high-pressure refrigerant discharged by the compressor will be divided into two parts, one part of which flows through the relevant components of the air-conditioning system in sequence to ensure normal cooling of the air conditioner. The other part of the high-temperature and high-pressure refrigerant flows through the heat exchange structure of the water tank and heats the water in the water tank by heat exchange, so that the air-conditioning system has the functions of both cooling and heating water.

Description

Technical Field

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

[0002] During summer nights, users need to use air conditioning for cooling and hot water for bathing, so there is a demand for air conditioning cooling + water heater, but current air conditioners do not have the function of cooling and heating water at the same time. Summary of the Invention

[0003] Therefore, the present invention provides an air conditioning system that can overcome the deficiency of existing air conditioners that do not have the functions of cooling and heating water at the same time.

[0004] In order to solve the above problems, the present invention provides an air-conditioning system, comprising: a compressor, a control valve, an indoor heat exchanger, an outdoor heat exchanger, a first throttling element, a second throttling element and a water tank, the water tank having a heat exchange structure, the control valve having a first port, a second port, a third port and a fourth port, the exhaust port of the compressor is connected to the first port, the intake port of the compressor is connected to the second port, the indoor heat exchanger, the outdoor heat exchanger and the first throttling element are all arranged on a first flow path, the first end of the first flow path is connected to the third port, the second end of the first flow path is connected to the fourth port, the heat exchange structure and the second throttling element are both arranged on a second flow path, both ends of the second flow path are connected to the first flow path, and the first end of the second flow path is between the first end of the first flow path and the outdoor heat exchanger, and the second end of the second flow path is between the first throttling element and the indoor heat exchanger.

[0005] In some embodiments, the control valve is a four-way valve having a first state. When the four-way valve is in the first state, the first port and the third port are connected in the four-way valve, and the second port and the fourth port are connected in the four-way valve.

[0006] In some embodiments, a first three-way valve and a second three-way valve are further provided on the second flow path, the first three-way valve being located between the heat exchange structure and the first end of the second flow path, the first three-way valve having a fifth port, a sixth port and a seventh port, the fifth port and the sixth port being both connected to the second flow path, and further comprising a third flow path, the first end of the third flow path being connected to the seventh port, the second end of the third flow path being connected to the first flow path, and the second end of the third flow path being located between the indoor heat exchanger and the second end of the first flow path; the second three-way valve being located between the second throttling element and the second end of the second flow path, the second three-way valve having an eighth port, a ninth port and a tenth port, the eighth port and the ninth port being both connected to the second flow path, and further comprising a fourth flow path, the first end of the fourth flow path being connected to the tenth port, the second end of the fourth flow path being connected to the first flow path, and the second end of the fourth flow path being located between the outdoor heat exchanger and the first throttling element.

[0007] In some embodiments, relative to the fifth port, the sixth port is close to the first end of the second flow path, and the first three-way valve has a second state. When the first three-way valve is in the second state, the fifth port and the seventh port are connected within the first three-way valve; relative to the eighth port, the ninth port is close to the second end of the second flow path, and the second three-way valve has a third state. When the second three-way valve is in the third state, the eighth port and the tenth port are connected within the second three-way valve.

[0008] In some embodiments, the first three-way valve further has a fifth state. When the first three-way valve is in the fifth state, the fifth port and the sixth port are connected in the first three-way valve; the second three-way valve further has a sixth state. When the second three-way valve is in the sixth state, the eighth port and the ninth port are connected in the second three-way valve.

[0009] In some embodiments, the four-way valve further has a fourth state. When the four-way valve is in the fourth state, the first port and the fourth port are in communication within the four-way valve, and the second port and the third port are in communication within the four-way valve.

[0010] The present invention also provides a control method for an air-conditioning system, which is used to control the operation of the above-mentioned air-conditioning system. The control method includes: obtaining the operating mode of the air-conditioning system and obtaining the water temperature T1 in the water tank; according to the operating mode and the size of T1, controlling the switching of the four-way valve between the first state and the fourth state, controlling the switching of the first three-way valve between the second state and the fifth state, controlling the switching of the second three-way valve between the third state and the sixth state, controlling the first throttling element to open or close, and controlling the second throttling element to open or close.

[0011] In some embodiments, when the air-conditioning system operates in heat storage + cooling mode, Ta-T1≥Tb, and T1≤Tc, the four-way valve is controlled to be in the first state, the first three-way valve is controlled to be in the fifth state, the second three-way valve is controlled to be in the sixth state, the first throttling element is controlled to be closed, and the second throttling element is controlled to be open, wherein Ta is a first preset value, Tb is a second preset value, and Tc is a third preset value.

[0012] In some embodiments, when Ta-T1<Tb, or T1>Tc, the first throttling element is controlled to open.

[0013] In some embodiments, when Ta-T1≤Td, the second throttling element is controlled to be closed, wherein Td is a fourth preset value.

[0014] In some embodiments, the outdoor temperature T2 is obtained. When the air-conditioning system operates in the cold storage + cooling mode, T2 < Te, and T1 > Tf, the four-way valve is controlled to be in the first state, the first three-way valve is controlled to be in the second state, the second three-way valve is controlled to be in the third state, the first throttling element is controlled to be open, and the second throttling element is controlled to be open, wherein Te is the fifth preset value and Tf is the sixth preset value.

[0015] In some embodiments, when T1 ≤ Tf, the second throttling element is controlled to be closed.

[0016] In some embodiments, the outdoor temperature T2 is obtained. When the air-conditioning system operates in the heat absorption + cooling mode and T2>Tg>T1, the four-way valve is controlled to be in the first state, the first three-way valve is controlled to be in the fifth state, the second three-way valve is controlled to be in the sixth state, the first throttling element is controlled to be open, and the second throttling element is controlled to be open, wherein Tg is the seventh preset value.

[0017] In some embodiments, when T1 ≥ Tg, the second throttling element is controlled to be closed.

[0018] In some embodiments, the outdoor temperature T2 is obtained. When the air-conditioning system operates in the heat absorption + heating mode, T2 ≥ Th, and T1 < Ti, the four-way valve is controlled to be in the fourth state, the first three-way valve is controlled to be in the second state, the second three-way valve is controlled to be in the third state, the first throttling element is controlled to be open, and the second throttling element is controlled to be open, wherein Th is the eighth preset value and Ti is the ninth preset value.

[0019] In some embodiments, when T1 ≥ Ti, the second throttling element is controlled to be closed.

[0020] In some embodiments, the outdoor temperature T2 is obtained. When the air-conditioning system operates in the heat release + heating mode, T2≤Tj, and T2<T1, the four-way valve is controlled to be in the fourth state, the first three-way valve is controlled to be in the fifth state, the second three-way valve is controlled to be in the sixth state, the first throttling element is controlled to be open, and the second throttling element is controlled to be open, wherein Tj is the tenth preset value.

[0021] In some embodiments, when T2 ≥ T1, the second throttling element is controlled to be closed.

[0022] The present invention provides an air conditioning system and control method thereof. By connecting a water tank in parallel with an outdoor heat exchanger, the high-temperature, high-pressure refrigerant discharged from the compressor is divided into two parts. One part flows sequentially through the outdoor heat exchanger, a first throttling element, and the indoor heat exchanger before returning to the compressor, ensuring normal cooling of the air conditioning system. The other part of the high-temperature, high-pressure refrigerant flows through the heat exchange structure of the water tank, heating the water in the water tank through heat exchange. This allows the air conditioning system to simultaneously cool and heat water, meeting the needs of air conditioning and hot water bathing in summer. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of an air-conditioning system according to an embodiment of the present invention operating in a heat storage + cooling mode;

[0024] Figure 2 This is a schematic diagram of an air-conditioning system according to an embodiment of the present invention operating in a cold storage + cooling mode;

[0025] Figure 3 This is a schematic diagram of an air-conditioning system according to an embodiment of the present invention operating in a heat absorption + heating mode;

[0026] Figure 4 This is a schematic diagram of an air-conditioning system according to an embodiment of the present invention operating in a heat release + heating mode.

[0027] The reference numerals indicate:

[0028] 1. Compressor; 2. Four-way valve; 3. Indoor heat exchanger; 4. Outdoor heat exchanger; 5. First throttling element; 6. Second throttling element; 7. Water tank; 8. First flow path; 9. Second flow path; 10. First three-way valve; 11. Second three-way valve; 12. Third flow path; 13. Fourth flow path; 14. Gas-liquid separator. DETAILED DESCRIPTION

[0029] See also Figures 1 to 4 As shown, according to an embodiment of the present invention, an air-conditioning system is provided, including: a compressor 1, a control valve, an indoor heat exchanger 3, an outdoor heat exchanger 4, a first throttling element 5, a second throttling element 6 and a water tank 7, the water tank 7 having a heat exchange structure, the control valve having a first port, a second port, a third port and a fourth port, the exhaust port of the compressor 1 is connected to the first port, the intake port of the compressor 1 is connected to the second port, the indoor heat exchanger 3, the outdoor heat exchanger 4 and the first throttling element 5 are all arranged on the first flow path 8, the first end of the first flow path 8 is connected to the third port, and the second end of the first flow path 8 is connected to the fourth port, the heat exchange structure and the second throttling element 6 are both arranged on the second flow path 9, both ends of the second flow path 9 are connected to the first flow path 8, and the first end of the second flow path 9 is between the first end of the first flow path 8 and the outdoor heat exchanger 4, and the second end of the second flow path 9 is between the first throttling element 5 and the indoor heat exchanger 3. In this technical solution, by connecting water tank 7 in parallel with outdoor heat exchanger 4, the high-temperature, high-pressure refrigerant discharged from compressor 1 is divided into two parts. One part flows sequentially through outdoor heat exchanger 4, first throttling element 5, and indoor heat exchanger 3, and finally returns to compressor 1, ensuring normal cooling of the air conditioning system. The other part of the high-temperature, high-pressure refrigerant flows through the heat exchange structure of water tank 7, heating the water in water tank 7 through heat exchange, allowing the air conditioning system to simultaneously cool and heat water, meeting the needs of air conditioning and hot water bathing in summer.

[0030] See also Figure 1As shown, the control valve is a four-way valve 2 having a valve core, which controls the connectivity of each port. The four-way valve 2 has a first state. In the first state, the first port and the third port are connected within the four-way valve 2, and the second port and the fourth port are connected within the four-way valve 2. At this time, the high-temperature, high-pressure refrigerant discharged from the exhaust port of the compressor 1 enters the first port of the four-way valve 2, then flows out of the third port of the four-way valve 2 and into the first flow path 8. When the refrigerant reaches the first intersection of the first flow path 8 and the second flow path 9, it splits into two parallel paths. The first refrigerant flows through the outdoor heat exchanger 4 and then enters the first throttling element 5 for throttling. The second refrigerant flows through the heat exchange structure of the water tank 7, heating the water in the water tank 7. After heat exchange, the refrigerant flows into the second throttling element 6 for throttling. The two refrigerant paths then converge at the second intersection of the first flow path 8 and the second flow path 9. The collected refrigerant flows through the indoor heat exchanger 3 to realize cooling of the air-conditioning system. Next, the refrigerant flows into the fourth port of the four-way valve 2, then flows out from the second port of the four-way valve 2, and finally returns to the compressor 1 to complete the refrigerant cycle.

[0031] Specifically, when the air conditioning system is cooling, if the outdoor temperature is high, the outdoor heat exchange temperature difference becomes smaller, and the outdoor heat exchange capacity decreases, resulting in a poor heat exchange effect. In order to improve this situation, a first three-way valve 10 and a second three-way valve 11 are also provided on the second flow path 9. The first three-way valve 10 is located between the heat exchange structure and the first end of the second flow path 9. The first three-way valve 10 has a fifth port, a sixth port and a seventh port. The fifth port and the sixth port are both connected to the second flow path 9. The air-conditioning system also includes a third flow path 12. The first end of the third flow path 12 is connected to the seventh port, the second end of the third flow path 12 is connected to the first flow path 8, and the second end of the third flow path 12 is between the indoor heat exchanger 3 and the second end of the first flow path 8; the second three-way valve 11 is located between the second throttling element 6 and the second end of the second flow path 9. The second three-way valve 11 has an eighth port, a ninth port and a tenth port. The eighth port and the ninth port are both connected to the second flow path 9. The air-conditioning system also includes a fourth flow path 13. The first end of the fourth flow path 13 is connected to the tenth port, the second end of the fourth flow path 13 is connected to the first flow path 8, and the second end of the fourth flow path 13 is between the outdoor heat exchanger 4 and the first throttling element 5. The addition of the first three-way valve 10, the second three-way valve 11, the third flow path 12 and the fourth flow path 13 can guide the flow direction of the refrigerant and improve this situation. Specifically, when the outdoor temperature is low at night, the heat exchange structure of the water tank 7 works in parallel with the indoor heat exchanger 3, and the indoor heat exchanger 3 is cooled. At the same time, a part of the low-temperature refrigerant flows into the heat exchange structure of the water tank 7, and the water in the water tank 7 is cooled by heat exchange; when the outdoor temperature is high during the day, while the air-conditioning system is kept cooling, the heat exchange structure of the water tank 7 is made to work in parallel with the outdoor heat exchanger 4. A part of the high-temperature and high-pressure refrigerant discharged from the exhaust port of the compressor 1 flows through the outdoor heat exchanger 4, and the other part flows through the heat exchange structure of the water tank 7. Because the water temperature in the water tank 7 is low at this time and the heat exchange temperature difference is large, the heat exchange effect is good, which can increase the high-temperature cooling capacity.

[0032] See also Figure 2As shown, relative to the fifth port, the sixth port is near the first end of the second flow path 9, and the first three-way valve 10 is in the second state. When the first three-way valve 10 is in the second state, the fifth port and the seventh port are connected within the first three-way valve 10. Relative to the eighth port, the ninth port is near the second end of the second flow path 9, and the second three-way valve 11 is in the third state. When the second three-way valve 11 is in the third state, the eighth port and the tenth port are connected within the second three-way valve 11. When the four-way valve 2 is in the first state, the first three-way valve 10 is in the second state, and the second three-way valve 11 is in the third state, the high-temperature and high-pressure refrigerant discharged from the exhaust port of the compressor 1 enters through the first port of the four-way valve 2, then flows out through the third port of the four-way valve 2 and enters the first flow path 8, then flows through the outdoor heat exchanger 4. When the refrigerant reaches the intersection of the first flow path 8 and the fourth flow path 13, it splits into two parallel paths. The first path of refrigerant enters the first throttling element 5 for throttling, then flows through the outdoor heat exchanger 4, achieving cooling for the air conditioning system. The second refrigerant enters the fourth flow path 13, then flows into the tenth port of the second three-way valve 11, then flows out from the eighth port of the second three-way valve 11 and enters the second throttling element 6 for throttling. When the throttled low-temperature refrigerant flows through the heat exchange structure of the water tank 7, the water in the water tank 7 is cooled by heat exchange. The refrigerant after heat exchange then flows into the fifth port of the first three-way valve 10, then flows out from the seventh port of the first three-way valve 10 and enters the third flow path 12. Next, the two refrigerants are combined at the intersection of the first flow path 8 and the third flow path 12. The combined refrigerant flows into the fourth port of the four-way valve 2, then flows out from the second port of the four-way valve 2, and finally returns to the compressor 1, thereby achieving cooling of the water in the water tank while the air-conditioning system is cooling at night.

[0033] In this embodiment, the first three-way valve 10 also has a fifth state. When the first three-way valve 10 is in the fifth state, the fifth port and the sixth port are connected within the first three-way valve 10. The second three-way valve 11 also has a sixth state. When the second three-way valve 11 is in the sixth state, the eighth port and the ninth port are connected within the second three-way valve 11. After cooling the water in the water tank 7 at night, when the outdoor temperature is higher during the day, the water tank 7 is used as a condenser, and the lower temperature water absorbs heat, significantly lowering the condensing temperature, improving heat exchange capacity, and achieving the purpose of increasing high-temperature cooling capacity. Specifically, when the four-way valve 2 is in the first state, the first three-way valve 10 is in the fifth state, and the second three-way valve 11 is in the sixth state, the high-temperature and high-pressure refrigerant discharged from the exhaust port of the compressor 1 enters the first port of the four-way valve 2, then flows out of the third port of the four-way valve 2 and enters the first flow path 8. When the refrigerant reaches the first intersection of the first flow path 8 and the second flow path 9, it splits into two parallel paths. Among them, the first refrigerant flows through the outdoor heat exchanger 4, and then enters the first throttling element 5 for throttling. The second refrigerant flows through the heat exchange structure of the water tank 7. The low-temperature water in the water tank 7 condenses the high-temperature and high-pressure refrigerant to increase the high-temperature cooling capacity. The refrigerant after heat exchange flows into the second throttling element 6 for throttling. The throttled refrigerant flows into the eighth port of the second three-way valve 11, and then flows out from the ninth port of the second three-way valve 11. Next, the two refrigerants converge at the second intersection of the first flow path 8 and the second flow path 9. The converged refrigerant flows through the indoor heat exchanger 3 to realize the cooling of the air-conditioning system. The refrigerant then flows into the fourth port of the four-way valve 2, and then flows out from the second port of the four-way valve 2, and finally returns to the compressor 1 to complete the refrigerant cycle, thereby achieving when the outdoor temperature is high during the day, while the air-conditioning system is cooling, the low-temperature water in the water tank is used to absorb heat to increase the high-temperature cooling capacity. The flow direction of the refrigerant in this process is the same as the flow direction of the refrigerant when the air-conditioning system cools and heats the water in the water tank. Please refer to Figure 1 .

[0034] As a specific embodiment, the four-way valve 2 also has a fourth state. When the four-way valve 2 is in the fourth state, the first port and the fourth port are connected within the four-way valve 2, and the second port and the third port are connected within the four-way valve 2. When the air conditioning system is heating, the outdoor heat exchanger 4 evaporates and absorbs heat. When the outdoor temperature is low, the heat transfer temperature difference is small, and the heating effect is poor. Therefore, when the outdoor temperature is high during the day, the water tank is heated and stored. When the temperature drops at night, heat is absorbed from the water tank to increase the low-temperature heating capacity. Specifically, when the four-way valve 2 is in the fourth state, the first three-way valve 10 is in the second state, and the second three-way valve 11 is in the third state, the high-temperature and high-pressure refrigerant discharged from the exhaust port of the compressor 1 enters the first port of the four-way valve 2, then flows out of the fourth port of the four-way valve 2 and enters the first flow path 8. When the refrigerant reaches the intersection of the first flow path 8 and the third flow path 12, it splits into two parallel paths. Among them, the first refrigerant flows through the indoor heat exchanger 3 to achieve air conditioning heating, and then enters the first throttling element 5 for throttling. The second refrigerant enters the third flow path 12, then flows into the seventh port of the first three-way valve 10, and then flows out from the fifth port of the first three-way valve 10 and enters the second flow path 9, and then flows through the heat exchange structure of the water tank 7, heating the water in the water tank 7 through heat exchange, and then enters the second throttling element 6 for throttling. The throttled low-temperature refrigerant flows into the eighth port of the second three-way valve 11, and then flows out from the tenth port of the second three-way valve 11 and enters the fourth flow path 13. Next, the two refrigerants are combined at the intersection of the first flow path 8 and the fourth flow path 13. The combined refrigerant flows through the outdoor heat exchanger 4, then enters the third port of the four-way valve 2, and then flows out from the second port of the four-way valve 2, and finally returns to the compressor 1, thereby achieving heating and energy storage of the water tank while the air conditioning system is heating when the outdoor temperature is high during the day. Figure 3As shown. When the four-way valve 2 is in the fourth state, the first three-way valve 10 is in the fifth state, and the second three-way valve 11 is in the sixth state, the high-temperature and high-pressure refrigerant discharged from the exhaust port of the compressor 1 will enter from the first port of the four-way valve 2, then flow out from the fourth port of the four-way valve 2 and enter the first flow path 8, and then flow through the indoor heat exchanger 3 to achieve air conditioning heating. When the refrigerant reaches the second intersection of the first flow path 8 and the second flow path 9, it will be divided into two parallel paths. Among them, the first path of refrigerant enters the first throttling element 5 for throttling, and then flows through the outdoor heat exchanger 4. The second path enters the second flow path 9, then flows into the ninth port of the second three-way valve 11, and then flows out from the eighth port of the second three-way valve 11 and enters the second throttling element 6 for throttling. The throttled low-temperature refrigerant flows through the heat exchange structure of the water tank 7, absorbs heat from the hot water in the water tank 7 through heat exchange, and increases the low-temperature heating capacity. The refrigerant after heat exchange flows into the fifth port of the first three-way valve 10 and then flows out from the sixth port of the first three-way valve 10. Next, the two refrigerants are combined at the first intersection of the first flow path 8 and the second flow path 9. The combined refrigerant enters the third port of the four-way valve 2, then flows out from the second port of the four-way valve 2, and finally returns to the compressor 1, completing the refrigerant cycle. This allows the air conditioning system to absorb heat from the water tank while heating the air at night, thereby increasing the low-temperature heating capacity.

[0035] Furthermore, a gas-liquid separator 14 is provided between the air intake of the compressor 1 and the second port of the four-way valve 2. The gas-liquid separator 14 has an inlet and an outlet. The inlet of the gas-liquid separator 14 is connected to the second port of the four-way valve 2, and the outlet of the gas-liquid separator 14 is connected to the air intake of the compressor 1. The gas-liquid separator 14 can separate gas and liquid to prevent the compressor 1 from inhaling liquid.

[0036] Preferably, the heat exchange structure on the water tank 7 is a heat exchange coil, which has a longer flow path and can improve the heat exchange effect of the refrigerant in the water tank 7.

[0037] The present invention also provides a control method for an air conditioning system, for controlling the operation of the aforementioned air conditioning system. The control method comprises: obtaining the operating mode of the air conditioning system and obtaining the water temperature T1 within the water tank 7; and, based on the operating mode and the value of T1, controlling the switching of the four-way valve 2 between the first and fourth states, controlling the switching of the first three-way valve 10 between the second and fifth states, controlling the switching of the second three-way valve 11 between the third and sixth states, controlling the opening or closing of the first throttling element 5, and controlling the opening or closing of the second throttling element 6. When the air conditioning system operates in different modes and the water temperature within the water tank 7 is within different temperature ranges, depending on the specific circumstances, the air conditioning system can be controlled to heat the water within the water tank 7, cool the water within the water tank 7, or absorb heat from the water within the water tank 7 when cooling; and can be controlled to absorb heat and store energy within the water within the water tank 7, or release heat within the water within the water tank 7 when heating. To achieve the above functions, it is necessary to control the four-way valve 2, the first three-way valve 10 and the second three-way valve 11 to be in corresponding states, and control the first throttling element 5 and the second throttling element 6 to open or close under corresponding conditions, so that the refrigerant can circulate correctly in the corresponding mode.

[0038] When the air conditioning system operates in thermal storage + cooling mode, and Ta - T1 ≥ Tb and T1 ≤ Tc, the four-way valve 2 is controlled to the first state, the first three-way valve 10 is controlled to the fifth state, and the second three-way valve 11 is controlled to the sixth state. The first throttle element 5 is closed, and the second throttle element 6 is opened. Ta is the preset water temperature of the air conditioning system, which ranges from 35 to 55°C, Tb is 3°C, and Tc is 45 to 55°C. In thermal storage + cooling mode, the air conditioning system simultaneously cools and heats the water in the water tank 7. The refrigerant flow in this mode can be seen in the discussion above regarding the cooling and water tank heating mode. In this mode, when Ta - T1 ≥ Tb and T1 ≤ Tc, the water temperature in the water tank 7 is low, and the first throttle element 5 needs to be closed, reducing the refrigerant flow to the outdoor heat exchanger 4. Compressor 1 then discharges the high-temperature, high-pressure refrigerant directly into the heat exchange structure of the water tank 7, rapidly heating the water in the water tank 7 to meet demand. In this case, the water tank 7 acts as a condenser.

[0039] When Ta-T1<Tb, or T1>Tc, it indicates that the water temperature in the water tank 7 is approaching the preset water temperature, and as the water temperature rises, the condensation effect becomes worse. In order to ensure the cooling effect, the first throttling element 5 needs to be opened to allow the outdoor heat exchanger 4 to lower the condensation temperature and increase the cooling capacity.

[0040] Specifically, Td is -1°C. When Ta-T1≤Td, it indicates that the water temperature in the water tank 7 has reached the set water temperature, and the second throttling element 6 is controlled to be closed. The water tank 7 does not participate in the system condensation, and there is no need to heat the water tank 7 anymore.

[0041] In this embodiment, the outdoor temperature T2 is obtained. When the air conditioning system operates in cold storage + cooling mode, and T2 < Te, and T1 > Tf, the four-way valve 2 is controlled to the first state, the first three-way valve 10 is controlled to the second state, the second three-way valve 11 is controlled to the third state, the first throttle element 5 is controlled to open, and the second throttle element 6 is controlled to open. Where Te is 20 to 30°C and Tf is 5°C, the cold storage + cooling mode allows the air conditioning system to cool the water in the water tank 7 while also cooling it. The refrigerant flow direction in this mode can be referred to above regarding the air conditioning system cooling and cooling the water tank. In this mode, when T2 < Te and T1 > Tf, it indicates that although the outdoor temperature has dropped at night, the water in the water tank 7 can be further cooled. Therefore, the heat exchange structure of the water tank 7 needs to operate in parallel with the indoor heat exchanger 3, allowing the air conditioning system to cool while simultaneously cooling the water in the water tank 7.

[0042] When T1≤Tf, it indicates that the water temperature in the water tank 7 has dropped to the target temperature, and the second throttling element 6 is controlled to be closed. The water tank 7 does not participate in heat exchange and there is no need to cool the water tank 7 anymore.

[0043] In this embodiment, when the air conditioning system operates in heat absorption + cooling mode and T2 > Tg > T1, the four-way valve 2 is controlled to the first state, the first three-way valve 10 is controlled to the fifth state, the second three-way valve 11 is controlled to the sixth state, the first throttle element 5 is controlled to open, and the second throttle element 6 is controlled to open. Where Tg is between 35 and 45°C, in heat absorption + cooling mode, the air conditioning system is cooling while the low-temperature water in the water tank 7 also condenses the high-temperature, high-pressure refrigerant. The refrigerant flow in this mode can be referred to the above discussion regarding the air conditioning system cooling and the water tank 7 condensing the high-temperature, high-pressure refrigerant. In this mode, when T2 > Tg > T1, indicating that the outdoor temperature is high during the day, but the water temperature in the water tank 7 is low, the water tank 7 can be used as a condenser. The heat exchange structure of the water tank 7 needs to operate in parallel with the outdoor heat exchanger 4. A portion of the high-temperature, high-pressure gas discharged from the compressor 1 enters the heat exchange structure of the water tank 7. At this time, the water temperature in the water tank is low, the heat exchange temperature difference is large, and the heat exchange effect is good, which helps to increase the high-temperature cooling capacity.

[0044] When T1 ≥ Tg, it indicates that the water temperature in the water tank 7 is too high and the condensation effect becomes poor, so the second throttling element 6 is controlled to be closed and the water tank 7 does not participate in heat exchange.

[0045] In this embodiment, when the air conditioning system operates in heat absorption + heating mode, and T2 ≥ Th, and T1 < Ti, the four-way valve 2 is controlled to the fourth state, the first three-way valve 10 is controlled to the second state, the second three-way valve 11 is controlled to the third state, the first throttle element 5 is controlled to open, and the second throttle element 6 is controlled to open. Where Th is between 10 and 20°C, and Ti is between 45 and 55°C, the heat absorption + heating mode allows the air conditioning system to heat the water in the water tank 7 while also heating it. The refrigerant flow direction in this mode can be referred to the above discussion regarding the air conditioning system heating and heating the water tank 7. In this mode, when T2 ≥ Th, and T1 < Ti, it indicates that the outdoor temperature is high during the day, the outdoor heat exchanger 4 has good heat exchange performance and sufficient capacity, but the water temperature in the water tank 7 is low, requiring the heat exchange structure of the water tank 7 to operate in parallel with the outdoor heat exchanger 4 to heat the water tank and store excess heat.

[0046] When T1≥Ti, it indicates that the water temperature in the water tank 7 has reached the target temperature, and the second throttling element 6 is controlled to be closed. The water tank 7 does not participate in heat exchange and does not need to be heated anymore.

[0047] In this embodiment, when the air conditioning system operates in the heat release + heating mode, T2 ≤ Tj, and T2 < T1, the four-way valve 2 is controlled to the fourth state, the first three-way valve 10 is controlled to the fifth state, the second three-way valve 11 is controlled to the sixth state, the first throttling element 5 is controlled to open, and the second throttling element 6 is controlled to open. Where Tj is 2°C, the heat release + heating mode allows the air conditioning system to heat while also absorbing heat from the water in the water tank 7. The refrigerant flow direction in this mode can refer to the above discussion regarding the air conditioning system heating and absorbing heat from the water tank 7. In this mode, when T2 ≤ Tj, and T2 < T1, it indicates that the outdoor temperature is low at night, the heat transfer temperature difference is small, and the heating effect is poor. Therefore, the heat exchange structure of the outdoor heat exchanger 4 and the water tank 7 needs to operate in parallel to absorb heat from the water tank 7 and increase the low-temperature heating capacity.

[0048] When T2≥T1, it indicates that the water temperature in the water tank 7 is lower than the outside temperature and can no longer absorb heat from the water tank 7. The second throttling element 6 is controlled to be closed and the water tank 7 does not participate in heat exchange.

[0049] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. An air conditioning system, characterized in that: The invention comprises a compressor (1), a control valve, an indoor heat exchanger (3), an outdoor heat exchanger (4), a first throttling element (5), a second throttling element (6) and a water tank (7); the water tank (7) has a heat exchange structure; the control valve has a first port, a second port, a third port and a fourth port; the exhaust port of the compressor (1) is connected to the first port; the intake port of the compressor (1) is connected to the second port; the indoor heat exchanger (3), the outdoor heat exchanger (4) and the first throttling element (5) are all arranged on a first flow path (8) , the first end of the first flow path (8) is in communication with the third port, the second end of the first flow path (8) is in communication with the fourth port, the heat exchange structure and the second throttling element (6) are both arranged on the second flow path (9), both ends of the second flow path (9) are in communication with the first flow path (8), and the first end of the second flow path (9) is between the first end of the first flow path (8) and the outdoor heat exchanger (4), and the second end of the second flow path (9) is between the first throttling element (5) and the indoor heat exchanger (3); The second flow path (9) is further provided with a first three-way valve (10) and a second three-way valve (11), wherein the first three-way valve (10) is located between the heat exchange structure and the first end of the second flow path (9), and the first three-way valve (10) has a fifth port, a sixth port and a seventh port, wherein the fifth port and the sixth port are both in communication with the second flow path (9), and further comprises a third flow path (12), wherein the first end of the third flow path (12) is in communication with the seventh port, the second end of the third flow path (12) is in communication with the first flow path (8), and the second end of the third flow path (12) is located in the indoor heat exchanger (3). and the second end of the first flow path (8); the second three-way valve (11) is located between the second throttling element (6) and the second end of the second flow path (9), the second three-way valve (11) has an eighth port, a ninth port and a tenth port, the eighth port and the ninth port are both connected to the second flow path (9), and also includes a fourth flow path (13), the first end of the fourth flow path (13) is connected to the tenth port, the second end of the fourth flow path (13) is connected to the first flow path (8), and the second end of the fourth flow path (13) is located between the outdoor heat exchanger (4) and the first throttling element (5).

2. The air conditioning system according to claim 1, characterized in that The control valve is a four-way valve (2), and the four-way valve (2) has a first state. When the four-way valve (2) is in the first state, the first port and the third port are communicated in the four-way valve (2), and the second port and the fourth port are communicated in the four-way valve (2).

3. The air conditioning system according to claim 2, characterized in that Relative to the fifth port, the sixth port is close to the first end of the second flow path (9), and the first three-way valve (10) has a second state. When the first three-way valve (10) is in the second state, the fifth port and the seventh port are communicated in the first three-way valve (10); relative to the eighth port, the ninth port is close to the second end of the second flow path (9), and the second three-way valve (11) has a third state. When the second three-way valve (11) is in the third state, the eighth port and the tenth port are communicated in the second three-way valve (11).

4. The air conditioning system according to claim 3, characterized in that The first three-way valve (10) further has a fifth state. When the first three-way valve (10) is in the fifth state, the fifth port and the sixth port are communicated in the first three-way valve (10). The second three-way valve (11) further has a sixth state. When the second three-way valve (11) is in the sixth state, the eighth port and the ninth port are communicated in the second three-way valve (11).

5. The air conditioning system according to claim 4, characterized in that The four-way valve (2) also has a fourth state. When the four-way valve (2) is in the fourth state, the first port and the fourth port are communicated in the four-way valve (2), and the second port and the third port are communicated in the four-way valve (2).

6. A method for controlling an air conditioning system, characterized in that: For controlling the operation of the air conditioning system according to claim 5, the control method comprises: Obtaining the operating mode of the air-conditioning system and the water temperature T1 in the water tank (7); According to the operating mode and the size of T1, the four-way valve (2) is controlled to switch between the first state and the fourth state, the first three-way valve (10) is controlled to switch between the second state and the fifth state, the second three-way valve (11) is controlled to switch between the third state and the sixth state, the first throttling element (5) is controlled to open or close, and the second throttling element (6) is controlled to open or close.

7. The control method according to claim 6, characterized in that: When the air-conditioning system operates in a heat storage + cooling mode, Ta-T1≥Tb, and T1≤Tc, the four-way valve (2) is controlled to be in the first state, the first three-way valve (10) is controlled to be in the fifth state, the second three-way valve (11) is controlled to be in the sixth state, the first throttling element (5) is controlled to be closed, and the second throttling element (6) is controlled to be open, wherein Ta is a first preset value, Tb is a second preset value, and Tc is a third preset value.

8. The control method according to claim 7, characterized in that: When Ta-T1<Tb, or T1>Tc, the first throttling element (5) is controlled to open.

9. The control method according to claim 7, characterized in that: When Ta-T1≤Td, the second throttling element (6) is controlled to be closed, wherein Td is a fourth preset value.

10. The control method according to claim 6, characterized in that: Obtaining the outdoor temperature T2, when the air-conditioning system operates in a cold storage + cooling mode, T2 < Te, and T1 > Tf, controlling the four-way valve (2) to be in the first state, controlling the first three-way valve (10) to be in the second state, controlling the second three-way valve (11) to be in the third state, controlling the first throttling element (5) to be opened, and controlling the second throttling element (6) to be opened, wherein Te is a fifth preset value, and Tf is a sixth preset value.

11. The control method according to claim 10, characterized in that: When T1≤Tf, the second throttling element (6) is controlled to be closed.

12. The control method according to claim 6, characterized in that: Obtaining the outdoor temperature T2, when the air-conditioning system operates in the heat absorption + cooling mode, and T2>Tg>T1, controlling the four-way valve (2) to be in the first state, controlling the first three-way valve (10) to be in the fifth state, controlling the second three-way valve (11) to be in the sixth state, controlling the first throttling element (5) to be opened, and controlling the second throttling element (6) to be opened, wherein Tg is a seventh preset value.

13. The control method according to claim 12, characterized in that: When T1≥Tg, the second throttling element (6) is controlled to be closed.

14. The control method according to claim 6, characterized in that: Obtaining the outdoor temperature T2, when the air-conditioning system operates in the heat absorption + heating mode, T2 ≥ Th, and T1 < Ti, controlling the four-way valve (2) to be in the fourth state, controlling the first three-way valve (10) to be in the second state, controlling the second three-way valve (11) to be in the third state, controlling the first throttling element (5) to be opened, and controlling the second throttling element (6) to be opened, wherein Th is the eighth preset value, and Ti is the ninth preset value.

15. The control method according to claim 14, characterized in that: When T1≥Ti, the second throttling element (6) is controlled to be closed.

16. The control method according to claim 6, characterized in that: Obtaining the outdoor temperature T2, when the air-conditioning system operates in the heat release + heating mode, T2≤Tj, and T2<T1, controlling the four-way valve (2) to be in the fourth state, controlling the first three-way valve (10) to be in the fifth state, controlling the second three-way valve (11) to be in the sixth state, controlling the first throttling element (5) to be open, and controlling the second throttling element (6) to be open, wherein Tj is the tenth preset value.

17. The control method according to claim 16, characterized in that: When T2≥T1, the second throttling element (6) is controlled to be closed.

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