Compressor assembly, air conditioning system, control method of air conditioning system and air conditioner

Abstract

The invention provides a compressor assembly, an air conditioning system, a control method of the air conditioning system and an air conditioner, the compressor assembly comprises a compressor and an oil separator, the compressor is provided with a machine shell, a first compression cylinder and a second compression cylinder, the first compression cylinder is arranged in the machine shell, the upper portion of the machine shell is provided with a first exhaust port, and the bottom of the machine shell is provided with an oil pool; an exhaust port of the first compression cylinder is located in the machine shell. The oil separator is located outside the machine shell, an exhaust port of the second compression cylinder is communicated with a refrigerant inlet of the oil separator, an oil return port of the oil separator is communicated with the oil pool and located above the oil pool, and the oil separator is provided with a gas outlet. The first exhaust port communicates with the gas outlet through a one-way valve. The one-way valve is configured to prevent gas of the gas outlet from flowing towards the first exhaust port. According to the technical scheme, when the exhaust pressure of the first exhaust port is larger than the exhaust pressure of the gas outlet, the efficiency that lubricating oil at the bottom of the oil separator returns to the oil pool can be improved.

Description

Technical Field

[0001] This invention belongs to the field of air conditioning technology, specifically relating to a compressor assembly, an air conditioning system and its control method, and an air conditioner. Background Technology

[0002] Air conditioners are used for cooling and dehumidifying in summer and for heating in winter. For example... Figure 1 As shown, a prior art air conditioning system includes a refrigerant circulation loop formed by connecting a compressor, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger. There are two outdoor heat exchangers, designated as a first outdoor heat exchanger 32 and a second outdoor heat exchanger 31. There are also two indoor heat exchangers, designated as a first indoor heat exchanger 52 and a second indoor heat exchanger 51. The compressor is a dual-intake, dual-exhaust compressor, comprising a housing 1, a first compression cylinder 151, and a second compression cylinder 152. The first compression cylinder 151 is disposed within the housing 1. The upper part of the housing 1 has a first exhaust port 12, and the bottom of the housing 1 has an oil sump 153 for containing lubricating oil. The exhaust port of the first compression cylinder 151 is located inside the housing 1, communicating with the first exhaust port 12 through the interior of the housing 1. The oil separator 13 is located outside the casing 1. The exhaust port of the second compression cylinder 152 is connected to the refrigerant inlet of the oil separator 13. The oil return port 131 of the oil separator 13 is connected to the oil sump 153, and the oil return port 131 of the oil separator 13 is located above the oil sump 153. The first exhaust port 12 is connected to one end of the first outdoor heat exchanger 32, the gas outlet 12' is connected to one end of the second outdoor heat exchanger 31, the intake port 11 of the first compression cylinder is connected to one end of the second indoor heat exchanger 51, and the intake port 11' of the second compression cylinder is connected to one end of the first indoor heat exchanger 52. One end of both the first outdoor heat exchanger 32 and the second outdoor heat exchanger 31 is connected to one end of both the first indoor heat exchanger 52 and the second indoor heat exchanger 51 through a throttling device.

[0003] The first compression cylinder 151 and the second compression cylinder 152 are independent compression cylinders. During the compression of the refrigerant, lubricating oil is carried out. The exhaust gas from the first compression cylinder 151 is filtered by the motor and other components inside the compressor housing, resulting in a low oil discharge rate. The exhaust gas from the second compression cylinder 152 is separated from the lubricating oil by an oil separator 13. The lubricating oil separated at the bottom of the oil separator 13 returns to the oil sump 153 at the bottom of the compressor. The oil sump 153 at the bottom of the compressor is connected to the first exhaust port 12, ensuring that the pressure in the oil sump 153 is the same as the pressure at the first exhaust port 12. Under certain operating conditions, the exhaust pressure at the first exhaust port 12 may be greater than the exhaust pressure at the gas outlet 12', causing the pressure in the oil sump 153 to be greater than the pressure at the oil return port 131 of the oil separator. This affects the return of lubricating oil from the oil return port 131 to the oil sump 153, thus requiring a solution. Summary of the Invention

[0004] Therefore, the present invention provides a compressor assembly, an air conditioning system and its control method, and an air conditioner. The main technical problem to be solved is: how to improve the efficiency of oil return from the oil separator to the oil sump when the exhaust pressure of the first exhaust port is greater than the exhaust pressure of the gas outlet.

[0005] To address the aforementioned problems, the present invention provides a compressor assembly comprising a compressor and an oil separator. The compressor has a housing, a first compression cylinder, and a second compression cylinder. The first compression cylinder is disposed within the housing, and the upper part of the housing has a first exhaust port. The bottom of the housing has an oil sump. The exhaust port of the first compression cylinder is located inside the housing and communicates with the first exhaust port through the interior of the housing. The oil separator is located outside the housing. The exhaust port of the second compression cylinder communicates with the refrigerant inlet of the oil separator. The oil return port of the oil separator communicates with the oil sump and is located above the oil sump. The oil separator has a second exhaust port. The first exhaust port is connected to the gas outlet via a one-way valve, which is configured to prevent gas from the gas outlet from flowing to the first exhaust port.

[0006] The present invention also provides an air conditioning system, which may include the compressor assembly described above.

[0007] In some embodiments, the air conditioning system further includes a first indoor heat exchanger, a second indoor heat exchanger, a first outdoor heat exchanger, and a second outdoor heat exchanger; the second outdoor heat exchanger has a heat exchange channel, the gas outlet is selectively connected to one end of the first outdoor heat exchanger or one end of the first indoor heat exchanger, the first exhaust port is selectively connected to one end of the heat exchange channel or one end of the second indoor heat exchanger, the other ends of the first outdoor heat exchanger and the heat exchange channel are connected to the other ends of the first indoor heat exchanger and the second indoor heat exchanger through a throttling device, the intake port of the first compression cylinder is selectively connected to one end of the second indoor heat exchanger or one end of the heat exchange channel, and the intake port of the second compression cylinder is selectively connected to one end of the first indoor heat exchanger or one end of the first outdoor heat exchanger.

[0008] In some embodiments, the first exhaust port is selectively connected to one end of the heat exchange channel or one end of the second indoor heat exchanger via a first four-way reversing valve, and the intake port of the first compression cylinder is also selectively connected to one end of the second indoor heat exchanger or one end of the heat exchange channel via the first four-way reversing valve; wherein, the first four-way reversing valve has a first D port, a first E port, a first S port and a first C port, the first four-way reversing valve is connected to the first exhaust port via the first D port, to one end of the second indoor heat exchanger via the first E port, to the intake port of the first compression cylinder via the first S port, and to one end of the heat exchange channel via the first C port.

[0009] In some embodiments, the air conditioning system further includes a first switching valve, one end of which is connected to the first E port, and the other end of which is connected to the intake port of the second compression cylinder.

[0010] In some embodiments, the gas outlet is selectively connected to one end of the first outdoor heat exchanger or one end of the first indoor heat exchanger via a second four-way reversing valve, and the intake port of the second compression cylinder is also selectively connected to one end of the first indoor heat exchanger or one end of the first outdoor heat exchanger via the second four-way reversing valve; wherein, the second four-way reversing valve has a second D port, a second E port, a second S port, and a second C port, the second four-way reversing valve is connected to the gas outlet via the second D port, to one end of the first indoor heat exchanger via the second E port, to the intake port of the second compression cylinder via the second S port, and to one end of the first outdoor heat exchanger via the second C port.

[0011] In some embodiments, the second outdoor heat exchanger further has a first channel capable of exchanging heat with the heat exchange channel, the first channel being connected to an external water line for exchanging heat with water within the water line.

[0012] In some embodiments, the water path includes a hot water pipe disposed upstream of the first channel.

[0013] In some embodiments, the first indoor heat exchanger and the second indoor heat exchanger are both disposed in the same air duct, and the second indoor heat exchanger is located upstream of the first indoor heat exchanger in the air duct.

[0014] In some embodiments, the displacement of the first compression cylinder is V1, the displacement of the second compression cylinder is V2, and V1 / V2 = 0.6~1.3.

[0015] The present invention also provides an air conditioner comprising the compressor assembly described above, or an air conditioning system comprising any one of the above-described embodiments.

[0016] In some embodiments, the air conditioning system further includes a first indoor heat exchanger, a second indoor heat exchanger, a first outdoor heat exchanger, and a second outdoor heat exchanger; the second outdoor heat exchanger has a heat exchange channel; the gas outlet is selectively connected to one end of the first outdoor heat exchanger or one end of the first indoor heat exchanger; the first exhaust port is selectively connected to one end of the heat exchange channel or one end of the second indoor heat exchanger; the other ends of both the first outdoor heat exchanger and the heat exchange channel are connected to the other ends of both the first indoor heat exchanger and the second indoor heat exchanger via a throttling device; the intake port of the first compression cylinder is selectively connected to one end of the second indoor heat exchanger or one end of the heat exchange channel; and the intake port of the second compression cylinder is selectively connected to one end of the first indoor heat exchanger or one end of the first outdoor heat exchanger. The air conditioner has an exhaust duct, a fresh air duct, and an outlet air duct. The fresh air duct and the exhaust duct exchange heat and moisture through a total heat exchanger. The second outdoor heat exchanger is located in the exhaust duct and downstream of the total heat exchanger. The fresh air duct discharges air through the outlet air duct. Both the first indoor heat exchanger and the second indoor heat exchanger are located in the outlet air duct.

[0017] In some embodiments, when the air conditioning system is operating in cooling mode, and the second heat exchanger further has a first channel capable of exchanging heat with the heat exchange channel, the first channel being connected to an external water circuit for heat exchange with water within the water circuit, the outlet water temperature of the first channel is defined as T_w, T_w_set is a first preset temperature, and ΔT is a second preset temperature; wherein, When |T_w-T_w_set|≤ΔT, maintain the current water flow rate of the first channel; when T_w-T_w_set<-ΔT, decrease the current water flow rate of the first channel; when T_w-T_w_set>ΔT, increase the water flow rate of the first channel. And / or, when the throttling device includes a first throttling device disposed on the flow path of the second outdoor heat exchanger, and the first throttling device is a throttling valve, if |T_w-T_w_set|≤ΔT, maintain the current opening degree of the first throttling device; if T_w-T_w_set<-ΔT, increase the opening degree of the first throttling device; if T_w-T_w_set>ΔT, decrease the opening degree of the first throttling device; when hot water is not required, close the first throttling device.

[0018] The compressor assembly, air conditioning system, control method, and air conditioner provided by this invention have the following beneficial effects: 1. Since the first exhaust port is connected to the gas outlet through a one-way valve, and the one-way valve is configured to prevent gas from the gas outlet from flowing to the first exhaust port, when the exhaust pressure of the first exhaust port is greater than the exhaust pressure of the gas outlet, the one-way valve opens, connecting the first exhaust port to the gas outlet. This balances the exhaust pressure of the first exhaust port and the gas outlet, making the exhaust pressure of the first exhaust port and the exhaust pressure of the gas outlet more consistent. This also makes the pressure at the bottom of the oil separator more consistent with the pressure in the oil sump. At the same time, since the oil return port of the oil separator is located above the oil sump, the lubricating oil in the oil separator can return to the oil sump under the action of gravity. Thus, the combination of the one-way valve and gravity can improve the efficiency of the oil return port of the oil separator to return to the oil sump when the exhaust pressure of the first exhaust port is greater than the exhaust pressure of the gas outlet, thereby ensuring the performance and reliability of the system.

[0019] 2. This invention features two different evaporation temperatures during cooling operation. The air being processed flows sequentially through two heat exchangers with high and low evaporation temperatures, thereby achieving stepped cooling and dehumidification of the air and reducing irreversible losses in the heat exchange process. Furthermore, it features two different condensation temperatures during heating operation, further reducing irreversible losses in the heat exchange process.

[0020] 3. The present invention has two different evaporation temperatures during heating operation. It can utilize the second outdoor heat exchanger to absorb heat from hot water pipes, such as the outlet pipe of a solar water heater or the drain pipe of indoor domestic hot water, thereby slowing down the frosting speed of the second outdoor heat exchanger in heating mode. Attached Figure Description

[0021] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0022] Figure 1 This is a structural diagram of an existing air conditioning system; Figure 2 This is a schematic diagram of the compressor assembly of the present invention; Figure 3 This is a schematic diagram of an air conditioning system in cooling mode according to an embodiment of the present invention; Figure 4 yes Figure 3 A schematic diagram of a central air conditioning system in heating mode; Figure 5 This is a schematic diagram of an air conditioning system in cooling mode according to another embodiment of the present invention; Figure 6 yes Figure 5 A schematic diagram of a central air conditioning system in heating mode; Figure 7 yes Figure 5 A schematic diagram of a central air conditioning system in reheat and dehumidification mode; Figure 8 This is the trend of the improvement of APF relative to conventional air conditioning systems when the ratio of the heat exchange area of ​​the evaporator on the windward side to the evaporator on the leeward side of the air conditioning system of the present invention is 2:1, corresponding to different displacement ratios of the compressor components. Figure 9 This paper describes the trend of the improvement in APF (Average Power Circulation) relative to conventional air conditioning systems when the ratio of the heat exchange area of ​​the evaporator on the windward side to the evaporator on the leeward side of the air conditioning system of the present invention is 1:2, corresponding to different displacement ratios of the compressor components.

[0023] The attached diagram is labeled as follows: 1. Housing; 2. Fresh air duct; 3. Exhaust air duct; 4. Outlet air duct; 6. Total heat exchanger; 7. Fresh air filter; 8. First switching valve; 10. Return air valve; 11. Fresh air valve; 11'. Inlet of the first compression cylinder; 11'. Inlet of the second compression cylinder; 12. First exhaust port; 12'. Gas outlet; 13. Oil separator; 14. Second switching valve; 21. First four-way reversing valve; 22. Second four-way reversing valve; 31. Second outdoor heat exchanger; 32. First outdoor heat exchanger; 51. 52. Second indoor heat exchanger; 41. Second throttling device; 42. First throttling device; 43. Third throttling device; 81. Check valve; 131. Oil return port; 151. First compression cylinder; 152. Second compression cylinder; 153. Oil sump; 311. Heat exchange passage; 312. First passage; 211. First D port; 212. First E port; 213. First S port; 214. First C port; 221. Second D port; 222. Second E port; 223. Second S port; 224. Second C port. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0026] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0027] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0028] See also Figure 2 As shown, according to an embodiment of the present invention, a compressor assembly is provided, comprising a compressor and an oil separator 13. The compressor has a housing 1, a first compression cylinder 151, and a second compression cylinder 152. The first compression cylinder 151 is disposed inside the housing 1, with a first exhaust port 12 at the upper part of the housing 1 and an oil sump 153 at the bottom of the housing 1. The exhaust port of the first compression cylinder 151 is located inside the housing 1 and communicates with the first exhaust port 12 through the interior of the housing 1. The oil separator 13 is located outside the housing 1, and the exhaust port of the second compression cylinder 152 communicates with the refrigerant inlet of the oil separator 13. The oil return port 131 of the oil separator 13 communicates with the oil sump 153 and is located above the oil sump 153. The oil separator 13 has a gas outlet 12'. The first exhaust port 12 is connected to the gas outlet 12' via a one-way valve 81, which is configured to prevent gas from the gas outlet 12' from flowing to the first exhaust port 12.

[0029] In the above example, when the compressor assembly is applied in an air conditioning system, the compressor assembly is connected to different flow paths within the air conditioning system via the first exhaust port 12 and the gas outlet 12' to achieve refrigerant circulation within the air conditioning system. Specifically, since the first exhaust port 12 is connected to the gas outlet 12' via a one-way valve 81, and the one-way valve 81 is configured to prevent gas from the gas outlet 12' from flowing to the first exhaust port 12, when the exhaust pressure of the first exhaust port 12 is greater than the exhaust pressure of the gas outlet 12', the one-way valve 81 opens, connecting the first exhaust port 12 to the gas outlet 12'. This balances the exhaust pressures of the first exhaust port 12 and the gas outlet 12', helping to bring the exhaust pressures of the first exhaust port 12 and the gas outlet 12' closer together. This ensures that the pressure at the bottom of the oil separator 13 is consistent with the pressure in the oil sump 153. Simultaneously, since the return port 131 of the oil separator 13 is located above the oil sump 153, the lubricating oil in the oil separator 13 can return to the oil sump 153 under the influence of gravity. Thus, the combination of the one-way valve 81 and gravity improves the efficiency of oil return from the oil separator's return port 131 to the oil sump 153 when the exhaust pressure of the first exhaust port 12 is greater than the exhaust pressure of the gas outlet 12', thereby ensuring the performance and reliability of the system.

[0030] The one-way valve 81 ensures that the refrigerant pressure at the gas outlet 12' is always not lower than the pressure at the first exhaust port 12 during the operation of the air conditioning system, and ensures that the lubricating oil in the oil separator 13 can return to the oil sump 153 through pressure difference or gravity.

[0031] In some implementations, such as Figure 2 As shown, the aforementioned compressor assembly also includes a crankshaft. A first roller and a second roller are sequentially mounted axially on the crankshaft. The first roller is located inside a first compression cylinder 151, and the second roller is located inside a second compression cylinder 152. When the crankshaft is driven to rotate, it drives the first roller to rotate within the first compression cylinder 151 and the second roller to rotate within the second compression cylinder 152. The rotation of the first roller compresses the gas inside the first compression cylinder 151, and the rotation of the second roller compresses the gas inside the second compression cylinder 152.

[0032] The aforementioned compressor assembly also includes a motor assembly, which is disposed within the housing 1 and is used to drive the crankshaft to rotate.

[0033] In some implementations, such as Figure 3-4 As shown, the present invention also provides an air conditioning system, which includes the compressor assembly described above.

[0034] The aforementioned air conditioning system further includes a first indoor heat exchanger 52, a second indoor heat exchanger 51, a first outdoor heat exchanger 32, and a second outdoor heat exchanger 31. The second outdoor heat exchanger 31 has a heat exchange channel 311, and its gas outlet 12' is selectively connected to one end of the first outdoor heat exchanger 32 or one end of the first indoor heat exchanger 52. The first exhaust port 12 is selectively connected to one end of the heat exchange channel 311 or one end of the second indoor heat exchanger 51. The other ends of both the first outdoor heat exchanger 32 and the heat exchange channel 311 are connected to the other ends of both the first indoor heat exchanger 52 and the second indoor heat exchanger 51 via a throttling device. The intake port 11 of the first compressor cylinder is selectively connected to one end of the second indoor heat exchanger 51 or one end of the heat exchange channel 311. The intake port 11' of the second compressor cylinder is selectively connected to one end of the first indoor heat exchanger 52 or one end of the first outdoor heat exchanger 32.

[0035] In the example above, the air conditioning system can switch between cooling and heating modes by changing the connections between its various components. Specifically, when the air conditioning system is in cooling mode, such as... Figure 3 As shown, gas outlet 12' is connected to one end of the first outdoor heat exchanger 32. First exhaust port 12 is connected to one end of the heat exchange channel 311. Inlet 11 of the first compressor cylinder is connected to one end of the second indoor heat exchanger 51. Inlet 11' of the second compressor cylinder is connected to one end of the first indoor heat exchanger 52. When the air conditioning system is in heating mode, as... Figure 4 As shown, gas outlet 12' is connected to one end of the first indoor heat exchanger 52. First exhaust port 12 is connected to one end of the second indoor heat exchanger 51. Intake port 11 of the first compression cylinder is connected to one end of the heat exchange channel 311. Intake port 11' of the second compression cylinder is connected to one end of the first outdoor heat exchanger 32.

[0036] Because the compressor assembly has two independent intake and exhaust ports, different intake and exhaust pressures can be achieved in a single air conditioning system.

[0037] To achieve the function that the first exhaust port 12 can be selectively connected to one end of the heat exchange channel 311 or one end of the second indoor heat exchanger 51, and the intake port 11 of the first compression cylinder can be selectively connected to one end of the second indoor heat exchanger 51 or one end of the heat exchange channel 311, in some embodiments, such as Figure 3-4As shown, the aforementioned first exhaust port 12 is selectively connected to one end of the heat exchange channel 311 or one end of the second indoor heat exchanger 51 via the first four-way reversing valve 21, and the intake port 11 of the first compression cylinder is also selectively connected to one end of the second indoor heat exchanger 51 or one end of the heat exchange channel 311 via the first four-way reversing valve 21. The first four-way reversing valve 21 has a first D port 211, a first E port 212, a first S port 213, and a first C port 214. The first four-way reversing valve 21 is connected to the first exhaust port 12 via the first D port 211, to one end of the second indoor heat exchanger 51 via the first E port 212, to the intake port 11 of the first compression cylinder via the first S port 213, and to one end of the heat exchange channel 311 via the first C port 214.

[0038] Furthermore, such as Figure 5-7 As shown, the aforementioned air conditioning system also includes a first switching valve 8, one end of which is connected to the aforementioned first E port 212, and the other end of which is connected to the intake port 11' of the second compression cylinder. The first switching valve 8 can be a solenoid valve, etc.

[0039] In the example above, the air conditioning system can be put into reheat and dehumidification mode by setting the first switching valve 8.

[0040] To achieve the aforementioned function that the gas outlet 12' can be selectively connected to one end of the first outdoor heat exchanger 32 or one end of the first indoor heat exchanger 52, and the air intake 11' of the second compression cylinder can be selectively connected to one end of the first indoor heat exchanger 52 or one end of the first outdoor heat exchanger 32, in some embodiments, such as Figure 3-4 As shown, the aforementioned gas outlet 12' can be selectively connected to one end of the first outdoor heat exchanger 32 or one end of the first indoor heat exchanger 52 via the second four-way reversing valve 22, and the intake port 11' of the second compression cylinder can also be selectively connected to one end of the first indoor heat exchanger 52 or one end of the first outdoor heat exchanger 32 via the second four-way reversing valve 22; wherein, the second four-way reversing valve 22 has a second D port 221, a second E port 222, a second S port 223, and a second C port 224. The second four-way reversing valve 22 is connected to the gas outlet 12' via the second D port 221, connected to one end of the first indoor heat exchanger 52 via the second E port 222, connected to the intake port 11' of the second compression cylinder via the second S port 223, and connected to one end of the first outdoor heat exchanger 32 via the second C port 224.

[0041] In some implementations, such as Figure 3-4As shown, the aforementioned second outdoor heat exchanger 31 also has a first channel 312 capable of exchanging heat with the heat exchange channel 311. The first channel 312 is used to connect to an external water line for heat exchange with the water in the water line. In this embodiment, the second outdoor heat exchanger 31 can be a shell-and-tube heat exchanger.

[0042] In the example above, when the air conditioning system is cooling, the air conditioning system can use the second outdoor heat exchanger 31 to heat the water in the water circuit, thereby providing domestic hot water to the user.

[0043] In some embodiments, the aforementioned water path may include a hot water pipe located upstream of the first channel 312. This hot water pipe can be the outlet pipe of a solar water heater or the drainage pipe for indoor domestic hot water. Thus, when the air conditioning system is heating, it can absorb heat from the hot water pipe through the second heat exchanger, slowing down the frosting rate of the first outdoor heat exchanger 32. Additionally, it can increase the evaporation temperature of the second outdoor heat exchanger 31 and the suction saturation temperature of the first compressor cylinder 151, thereby improving system energy efficiency.

[0044] In some implementations, such as Figure 3-4 As shown, the aforementioned first indoor heat exchanger 52 and second indoor heat exchanger 51 can be installed in the same air duct, and the second indoor heat exchanger 51 is located upstream of the first indoor heat exchanger 52 in the air duct. In this way, when the air conditioning system is in cooling mode, the air flows through the second indoor heat exchanger 51 and the first indoor heat exchanger 52 in sequence, thereby achieving stepped cooling and dehumidification of the treated air and reducing irreversible losses in the heat exchange process.

[0045] In the above example, when the air conditioning system is cooling, the first indoor heat exchanger 52 and the second indoor heat exchanger 51 are respectively connected to two different air intake ports of the compressor, so that they have two different evaporation temperatures during cooling operation. The air being processed flows through the second indoor heat exchanger 51 and the first indoor heat exchanger 52 in sequence, so that the second indoor heat exchanger 51 is a high-temperature evaporator and the first indoor heat exchanger 52 is a low-temperature evaporator. The high-temperature evaporator is mainly responsible for the sensible heat load, and the low-temperature evaporator is mainly responsible for the latent heat load. The return air is cooled and dehumidified by the high-temperature and low-temperature evaporators in a stepped manner.

[0046] In some implementations, such as Figure 3-4As shown, the aforementioned throttling device includes a first throttling device 42, a second throttling device 41, and a third throttling device 43. The first throttling device 42 is disposed in the flow path of the second outdoor heat exchanger 31, the second throttling device 41 is disposed in the flow path of the first outdoor heat exchanger 32, and the third throttling device 43 is disposed in the flow path of the first indoor heat exchanger 52. The first throttling device 42, the second throttling device 41, and the third throttling device 43 can all be throttling valves, such as electronic expansion valves. Preferably, the aforementioned second throttling device 41 can be a valve-closing, flow-free electronic expansion valve.

[0047] In some implementations, such as Figure 3-4 As shown, a second switching valve 14 is also provided on the pipeline between the oil return port 131 of the aforementioned oil separator 13 and the oil sump 153.

[0048] In some embodiments, the displacement of the first compression cylinder 151 is V1, and the displacement of the second compression cylinder 152 is V2, wherein V1 / V2 = 0.6~1.3.

[0049] In the above examples, the heat exchangers used in the air conditioning system of this invention typically have two or three rows. When the ratio of the heat exchanger area corresponding to the intake port 11 of the first compressor cylinder and the intake port 11' of the second compressor cylinder is constant, different compressor displacement ratios will affect the annual improvement in APF (Average Power Factor) compared to conventional air conditioning systems. Taking a three-row heat exchanger as an example, when the ratio of the evaporator area on the windward side to the evaporator area on the leeward side is 2:1, the trend of the improvement in APF compared to conventional air conditioning systems for different displacement ratios is as follows: Figure 8 As shown in the figure. When the ratio of the evaporator area on the windward side to the evaporator area on the leeward side is 1:2, the trend of the improvement in APF relative to conventional air conditioning systems for different displacement ratios is as follows. Figure 9 As shown. In this case, the compressor in a conventional air conditioning system is a single-suction, single-discharge compressor, meaning the compressor has a single suction port and a single discharge port. (Summary) Figure 8 and Figure 9 In order to maintain a better annual energy efficiency APF improvement in the air conditioning system of the present invention, the range of V1 / V2 is designed to be between 0.6 and 1.3.

[0050] In some embodiments, the present invention also provides an air conditioner that may include the compressor assembly described above, or an air conditioning system that includes any of the above-described components.

[0051] In some implementations, such as Figure 5-7As shown, the air conditioning system also includes an oil separator 13, a first indoor heat exchanger 52, a second indoor heat exchanger 51, a first outdoor heat exchanger 32, and a second outdoor heat exchanger 31; the second outdoor heat exchanger 31 has a heat exchange channel 311, and a gas outlet 12' is selectively connected to one end of the first outdoor heat exchanger 32 or one end of the first indoor heat exchanger 52, and a first exhaust port 12 is selectively connected to one end of the heat exchange channel 311 or one end of the second indoor heat exchanger 51; the other ends of the first outdoor heat exchanger 32 and the heat exchange channel 311 are connected to the first indoor heat exchanger 52 and the second outdoor heat exchanger 51 through a throttling device. The other ends of the second indoor heat exchanger 51 are connected. The air intake 11 of the first compressor cylinder can be selectively connected to one end of the second indoor heat exchanger 51 or one end of the heat exchange channel 311. When the air intake 11' of the second compressor cylinder can be selectively connected to one end of the first indoor heat exchanger 52 or one end of the first outdoor heat exchanger 32, the air conditioner has an exhaust duct 3, a fresh air duct 2, and an outlet air duct 4. The fresh air duct 2 and the exhaust air duct 3 exchange heat through a total heat exchanger 6, thus enabling heat and moisture exchange between the fresh air and the exhaust air, thereby recovering the energy of the exhaust air and reducing the waste of exhaust air energy. Furthermore, the total heat exchanger 6 is also used to dehumidify the fresh air in the fresh air duct 2.

[0052] The second outdoor heat exchanger 31 can be installed inside the exhaust duct 3, downstream of the total heat exchanger 6. This allows the air conditioning system to recover energy from the exhaust air using the second outdoor heat exchanger 31, reducing energy waste and irreversible losses in the heat exchange process, thus improving the system's energy efficiency ratio. An exhaust fan can be installed at the second outdoor heat exchanger 31. The first on / off valve 8 is in the closed state in this mode.

[0053] The aforementioned fresh air duct 2 exits through the air outlet duct 4, which may be equipped with a blower. Both the first indoor heat exchanger 52 and the second indoor heat exchanger 51 are located in the air outlet duct 4, allowing the fresh air to exchange heat with the first indoor heat exchanger 52 and the second indoor heat exchanger 51 before entering the room, thereby reducing the temperature difference between the fresh air and the room temperature.

[0054] In some embodiments, the inlet of the aforementioned fresh air duct 2 may be equipped with a fresh air filter 7, and a fresh air valve 11 may be installed in the fresh air duct 2. The aforementioned air conditioner also has a return air duct, in which a return air valve 10 is installed. By controlling the fresh air valve 11 and the return air valve 10, 100% fresh air and partial fresh air functions can be achieved. In this scenario, the second outdoor heat exchanger 31 can be an air-refrigerant heat exchanger such as a finned tube heat exchanger or a microchannel heat exchanger.

[0055] In some embodiments, the present invention also provides a control method for any of the above-mentioned air conditioning systems. When the air conditioning system is in cooling operation, and the second heat exchanger also has a first channel 312 capable of exchanging heat with the heat exchange channel 311, the first channel 312 being connected to a water path for heat exchange with water in the water path, the outlet water temperature of the first channel 312 is defined as T_w, T_w_set is a first preset temperature, and ΔT is a second preset temperature. When |T_w - T_w_set| ≤ ΔT, it indicates that the water temperature is within the preset range, so the current water flow rate of the first channel 312 is maintained. When T_w - T_w_set < -ΔT, it indicates that the water temperature is too low, and the current water flow rate of the first channel 312 needs to be reduced to allow less water to absorb heat and increase the water temperature. When T_w - T_w_set > ΔT, it indicates that the water temperature is too high, and the water flow rate of the first channel 312 needs to be increased to allow more water to absorb heat and decrease the water temperature.

[0056] In some embodiments, when the aforementioned throttling device includes a first throttling device 42 disposed in the flow path of the second outdoor heat exchanger 31, and the first throttling device 42 is a throttling valve, if |T_w - T_w_set| ≤ ΔT, it indicates that the water temperature is within a preset range, so the current opening of the first throttling device 42 is maintained. When T_w - T_w_set < -ΔT, it indicates that the water temperature is too low, so the opening of the first throttling device 42 is increased to increase the refrigerant flow rate in the flow path of the second outdoor heat exchanger 31, increasing heat dissipation and raising the water temperature. When T_w - T_w_set > ΔT, it indicates that the water temperature is too high, so the opening of the first throttling device 42 is decreased to decrease the refrigerant flow rate in the flow path of the second outdoor heat exchanger 31, reducing heat dissipation and lowering the water temperature. When hot water is not needed, the first throttling device 42 is closed. At this time, the first exhaust port 12 on the compressor assembly mixes with the high-temperature refrigerant gas at the gas outlet 12' through the one-way valve 81 and enters the second D port 221 of the second four-way reversing valve 22.

[0057] For ease of understanding, the overall structure of the present invention will be described below, and its working principle will be explained.

[0058] When the air conditioning system is running in cooling mode, both the first four-way reversing valve 21 and the second four-way reversing valve 22 are in the first open state, such as... Figure 5As shown. The first four-way valve directional valve has its first D port 211 connected to its first C port 214, and its first S port 213 connected to its first E port 212. The second four-way valve directional valve has its second D port 221 connected to its second C port 224, and its second S port 223 connected to its second E port 222. The high-temperature, high-pressure refrigerant gas discharged from the compressor assembly enters the first outdoor heat exchanger 32 and the second outdoor heat exchanger 31 via the first four-way reversing valve 21 and the second four-way reversing valve 22, respectively. There, it releases heat and condenses into high-pressure liquid refrigerant. The high-pressure liquid refrigerant then undergoes throttling and pressure reduction via the first throttling device 42 and the second throttling device 41, resulting in two separate paths: one path evaporates and absorbs heat in the second indoor heat exchanger 51 on the windward side, then enters the suction port 11 of the first compression cylinder via the first E port 212 and the first S port 213 of the first four-way reversing valve 21; the other path further throttles and reduces pressure via the third throttling device 43, then enters the second indoor heat exchanger 51 on the leeward side. In the second indoor heat exchanger 51, it evaporates and absorbs heat, then enters the suction port of the second compression cylinder 152 via the second E port 222 and the second S port 223 of the second four-way reversing valve 22. The refrigerant entering the compressor assembly is compressed within its respective compression cylinder and discharged through its corresponding exhaust port, thus completing the entire refrigeration cycle. The first switching valve 8 is closed in this mode.

[0059] In cooling mode, the first indoor heat exchanger 52 on the windward side and the second indoor heat exchanger 51 on the leeward side serve as a high-temperature evaporator and a low-temperature evaporator, respectively. The return air is cooled and dehumidified by the high and low temperature evaporators in stages, reducing irreversible losses in the heat exchange process and improving the system's energy efficiency ratio.

[0060] When the air conditioning system is running in heating mode, both the first four-way reversing valve 21 and the second four-way reversing valve 22 are in the second open state, such as... Figure 6As shown. The first four-way valve directional valve has its first D port 211 connected to its first E port 212, and its first S port 213 connected to its first C port 214. The second four-way valve directional valve has its second D port 221 connected to its second E port 222, and its second S port 223 connected to its second C port 224. The high-temperature, high-pressure gaseous refrigerant discharged from the first exhaust port 12 of the compressor assembly enters the first indoor heat exchanger 52 on the windward side of the room through the first D port 211 and the first E port 212 of the first four-way reversing valve 21, where it condenses and releases heat to become liquid. The high-temperature, high-pressure gaseous refrigerant discharged from the gas outlet 12' of the compressor assembly enters the second indoor heat exchanger 51 on the leeward side of the room through the second D port 221 and the second E port 222 of the second four-way reversing valve 22, where it condenses and releases heat to become liquid. Subsequently, it is initially throttled and depressurized by the third throttling device 43 and mixes with the refrigerant liquid from the second indoor heat exchanger 51. After being throttled and depressurized by the first throttling device 42 and the second throttling device 41 respectively, it enters the first outdoor heat exchanger 32 and the second outdoor heat exchanger 31, where it evaporates and absorbs heat to become low-pressure gas. Gaseous refrigerant flowing from the second outdoor heat exchanger enters the suction port 11 of the first compressor cylinder via the first C port 214 and the first S port 213 of the first four-way reversing valve 21; gaseous refrigerant flowing from the second outdoor heat exchanger 31 enters the suction port 11' of the second compressor cylinder via the second C port 224 and the second S port 223 of the second four-way reversing valve 22. The refrigerant entering the compressor assembly is compressed in its respective compressor cylinder and then discharged through its corresponding exhaust port, thus completing the entire heating cycle. The first switching valve 8 is in the closed state in this mode.

[0061] When operating in heating mode, there are two evaporation pressures. The evaporator in the air outlet duct 4 can recover the heat carried away by the indoor exhaust air, reducing the system's energy consumption.

[0062] When the air conditioning system is running in constant temperature and dehumidification mode, such as Figure 7 As shown, the second four-way directional valve 22 is in the second open state, and the first four-way directional valve 21 is in the first open state, as follows. Figure 7As shown. The first D port 211 of the first four-way directional valve 21 is connected to the first C port 214, and the first E port 212 is connected to the first S port 213. The second D port 221 of the second four-way directional valve 22 is connected to the second E port 222, and the second S port 223 is connected to the second C port 224. The high-temperature, high-pressure gaseous refrigerant discharged from the first discharge port 12 of the compressor assembly enters the second outdoor heat exchanger through the first D port 211 and the first C port 214 of the first four-way reversing valve 21, condenses and releases heat to become liquid refrigerant, and then is throttled and depressurized by the first throttling device 42; the high-temperature, high-pressure gaseous refrigerant discharged from the gas outlet 12' of the compressor assembly enters the first indoor heat exchanger 52 on the leeward side of the room through the second D and second E ports 222 of the second four-way reversing valve 22, condenses and releases heat to become liquid refrigerant, and then is throttled and depressurized by the third throttling device 43, and mixes with the refrigerant that has been throttled and depressurized by the first throttling device 42. The mixed refrigerant enters the second indoor heat exchanger 51 on the windward side of the room, evaporates and absorbs heat to become gaseous. The gaseous refrigerant enters the suction port 11 of the first compression cylinder and the suction port 11' of the second compression cylinder through two separate paths. One path directly enters the suction port 152 of the second compression cylinder via the first switching valve 8, while the other path is drawn into the suction port 11 of the first compression cylinder via the first E port 212 and the first S port 213 of the first four-way reversing valve 21. After entering the compressor assembly, the refrigerant is compressed in its respective compression cylinder and discharged through the corresponding exhaust port, thus completing the entire reheat dehumidification cycle.

[0063] In the constant temperature dehumidification mode, the second throttling device 41 can be fully closed, the first outdoor heat exchanger 32 is in a short-circuit state and does not participate in the system circulation, and the other end of the first outdoor heat exchanger 32 is connected to the second C port 224 and the second S port 223 of the second four-way reversing valve 22, and is in a low-pressure state, so there is no refrigerant migration problem. The second indoor heat exchanger 51 acts as an evaporator to cool and dehumidify the indoor air, and the first indoor heat exchanger 52 acts as a low-temperature condenser to reheat the cooled and dehumidified air, so that the low-temperature and low-humidity air after passing through the dehumidification evaporator is sent into the room at a temperature close to the return air temperature, thereby improving the comfort of the indoor environment.

[0064] The one-way valve 81 in this invention is an automatic valve that allows fluid to flow in only one direction while preventing reverse flow. Its core principle is to achieve automatic opening and closing using the fluid's own pressure difference. Along the flow direction of the one-way valve 81: it opens when the pressure at the inlet is higher than the pressure at the outlet; it closes when the pressure at the inlet is lower than the pressure at the outlet. This invention, through the one-way valve 81, ensures that the refrigerant pressure at the gas outlet 12' is not lower than the refrigerant pressure at the first exhaust port 12 under different operating conditions, thus guaranteeing the system's performance and reliability. Specifically, when the air conditioning system is operating in cooling mode, and the second heat exchanger also has a first channel 312 capable of exchanging heat with the heat exchange channel 311 (the first channel 312 is connected to the water circuit for heat exchange with the water), the second outdoor heat exchanger 31 uses refrigerant to release heat to the water to produce hot water, and the first outdoor heat exchanger 32 releases heat to the outdoor air. When the water temperature is low or the water flow rate is high, because the heat transfer coefficient of water is higher than that of air, the refrigerant saturation temperature in the second outdoor heat exchanger 31 is lower than that in the first outdoor heat exchanger 32. At this time, the exhaust pressure of gas outlet 12' is higher than that of the first exhaust port 12. The one-way valve 81 is in a shut-off state, which can achieve dual condensation temperature to improve system efficiency. Simultaneously, it ensures that the lubricating oil in the oil separator 13 returns to the oil sump 153 at the bottom of the compressor through the pressure difference between gas outlet 12' and the first exhaust port 12. When the water temperature rises to a certain level, or the water flow rate is low, or hot water is not turned on, the refrigerant condensation temperature in the second outdoor heat exchanger 31 increases, exceeding the refrigerant saturation temperature in the first outdoor heat exchanger 32. If there is no one-way valve 81, the pressure at the first exhaust port 12 is higher than the pressure at gas outlet 12', and the lubricating oil in the oil separator 13 cannot return to the compressor oil sump 153, resulting in a lack of oil in the compressor. With the addition of the check valve 81, the pressure at the first exhaust port 12 is higher than the pressure at the gas outlet 12', causing the check valve 81 to open. At this time, dual condensation temperature cannot be achieved, but it can ensure that the lubricating oil in the compressor oil separator 13 can return to the compressor oil sump 153 by gravity, thus ensuring the reliability of compressor operation.

[0065] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A compressor assembly characterized by: The compressor assembly comprises a compressor and an oil separator (13), the compressor has a casing (1), a first compression cylinder (151) and a second compression cylinder (152), the first compression cylinder (151) is arranged in the casing (1), the upper part of the casing (1) is provided with a first exhaust port (12), the bottom of the casing (1) has an oil pool (153); the exhaust port of the first compression cylinder (151) is located inside the casing (1) to communicate with the first exhaust port (12) through the inside of the casing (1); the oil separator (13) is located outside the casing (1), the exhaust port of the second compression cylinder (152) communicates with the refrigerant inlet of the oil separator (13), the oil return port (131) of the oil separator (13) communicates with the oil pool (153), and the oil return port (131) of the oil separator (13) is located above the oil pool (153), and the oil separator (13) has a gas outlet (12'); The first exhaust port (12) communicates with the gas outlet (12') through a one-way valve (81), and the one-way valve (81) is configured to prevent gas in the gas outlet (12') from flowing to the first exhaust port (12).

2. An air conditioning system characterized by: The compressor assembly of claim 1 is also included.

3. The air conditioning system of claim 2, wherein: The first indoor heat exchanger (52), the second indoor heat exchanger (51), the first outdoor heat exchanger (32) and the second outdoor heat exchanger (31) are also included; the second outdoor heat exchanger (31) has a heat exchange channel (311), the gas outlet (12') selectively communicates with one end of the first outdoor heat exchanger (32) or one end of the first indoor heat exchanger (52), the first exhaust port (12) selectively communicates with one end of the heat exchange channel (311) or one end of the second indoor heat exchanger (51), the other end of the first outdoor heat exchanger (32) and the heat exchange channel (311) both communicate with the other end of the first indoor heat exchanger (52) and the second indoor heat exchanger (51) through a throttling device, the suction port (11) of the first compression cylinder selectively communicates with one end of the second indoor heat exchanger (51) or one end of the heat exchange channel (311), and the suction port (11') of the second compression cylinder selectively communicates with one end of the first indoor heat exchanger (52) or one end of the first outdoor heat exchanger (32).

4. The air conditioning system of claim 3, wherein: The first exhaust port (12) is selectively communicated with one end of the heat exchange passage (311) or one end of the second indoor heat exchanger (51) through a first four-way reversing valve (21), and the suction port (11) of the first compression cylinder is also selectively communicated with one end of the second indoor heat exchanger (51) or one end of the heat exchange passage (311) through the first four-way reversing valve (21); wherein the first four-way reversing valve (21) has a first D port (211), a first E port (212), a first S port (213) and a first C port (214), the first four-way reversing valve (21) is communicated with the first exhaust port (12) through the first D port (211), and is communicated with one end of the second indoor heat exchanger (51) through the first E port (212), and is communicated with the suction port (11) of the first compression cylinder through the first S port (213), and is communicated with one end of the heat exchange passage (311) through the first C port (214).

5. The air conditioning system of claim 4, wherein: A first switch valve (8) is further included, one end of the first switch valve (8) is communicated with the first E port (212), and the other end of the first switch valve (8) is communicated with the suction port (11') of the second compression cylinder.

6. The air conditioning system according to any one of claims 3-5, wherein: The gas outlet (12') is selectively communicated with one end of the first outdoor heat exchanger (32) or one end of the first indoor heat exchanger (52) through a second four-way reversing valve (22), and the suction port (11') of the second compression cylinder is also selectively communicated with one end of the first indoor heat exchanger (52) or one end of the first outdoor heat exchanger (32) through the second four-way reversing valve (22); wherein the second four-way reversing valve (22) has a second D port (221), a second E port (222), a second S port (223) and a second C port (224), the second four-way reversing valve (22) is communicated with the gas outlet (12') through the second D port (221), and is communicated with one end of the first indoor heat exchanger (52) through the second E port (222), and is communicated with the suction port (11') of the second compression cylinder through the second S port (223), and is communicated with one end of the first outdoor heat exchanger (32) through the second C port (224).

7. The air conditioning system according to any one of claims 2-5, wherein: The second outdoor heat exchanger (31) further has a first passage (312) capable of exchanging heat with the heat exchange passage (311), and the first passage (312) is used to be connected to an external water circuit to exchange heat with water in the water circuit.

8. The air conditioning system of claim 7, wherein: The water circuit includes a hot water pipeline arranged on the upstream side of the first passage (312).

9. The air conditioning system according to any one of claims 3-5, 8, wherein: The first indoor heat exchanger (52) and the second indoor heat exchanger (51) are both arranged in the same air duct, and the second indoor heat exchanger (51) is located upstream of the first indoor heat exchanger (52) in the air duct.

10. The air conditioning system according to any one of claims 3-5 and 8, characterized in that: The displacement of the first compression cylinder (151) is V1, and the displacement of the second compression cylinder (152) is V2, with V1 / V2 = 0.6~1.

3.

11. An air conditioner characterized by comprising: It includes the compressor assembly as described in claim 1, or the air conditioning system as described in any one of claims 2-10.

12. The air conditioner of claim 11, wherein: When the air conditioning system further includes a first indoor heat exchanger (52), a second indoor heat exchanger (51), a first outdoor heat exchanger (32), and a second outdoor heat exchanger (31); the second outdoor heat exchanger (31) has a heat exchange channel (311), the gas outlet (12') is selectively connected to one end of the first outdoor heat exchanger (32) or one end of the first indoor heat exchanger (52), and the first exhaust port (12) is selectively connected to one end of the heat exchange channel (311) or one end of the second indoor heat exchanger (51), the... The other ends of the first outdoor heat exchanger (32) and the heat exchange channel (311) are connected to the other ends of the first indoor heat exchanger (52) and the second indoor heat exchanger (51) through a throttling device. The suction port (11) of the first compression cylinder can be selectively connected to one end of the second indoor heat exchanger (51) or one end of the heat exchange channel (311). The suction port (11') of the second compression cylinder can be selectively connected to one end of the first indoor heat exchanger (52) or one end of the first outdoor heat exchanger (32). The air conditioner has an exhaust duct (3), a fresh air duct (2), and an outlet air duct (4). The fresh air duct (2) and the exhaust duct (3) exchange heat through a total heat exchanger (6). The second outdoor heat exchanger (31) is located in the exhaust duct (3) and downstream of the total heat exchanger (6). The fresh air duct (2) discharges air through the outlet air duct (4). The first indoor heat exchanger (52) and the second indoor heat exchanger (51) are both located in the outlet air duct (4).

13. A control method of the air conditioning system according to any one of claims 3 to 10, characterized by: When the air conditioning system is in cooling operation, and the second outdoor heat exchanger (31) also has a first channel (312) capable of exchanging heat with the heat exchange channel (311), the first channel (312) is used to connect to an external water circuit for heat exchange with the water in the water circuit. The outlet water temperature of the first channel (312) is defined as T_w, T_w_set is a first preset temperature, and ΔT is a second preset temperature; where... When |T_w-T_w_set|≤ΔT, the water flow of the current first channel (312) is maintained; when T_w-T_w_set<-ΔT, the water flow of the current first channel (312) is reduced; when T_w-T_w_set>ΔT, the water flow of the first channel (312) is increased; When the throttling device comprises a first throttling device (42) arranged on the flow path of the second outdoor heat exchanger (31), and the first throttling device (42) is a throttle valve, if |T_w-T_w_set|≤ΔT, the opening of the current first throttling device (42) is maintained; when T_w-T_w_set<-ΔT, the opening of the first throttling device (42) is increased; when T_w-T_w_set>ΔT, the opening of the first throttling device (42) is decreased; when hot water is not needed, the first throttling device (42) is closed.

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