Air conditioning system and control method thereof, and energy storage battery unit

Abstract

The application provides an air conditioning system and a control method thereof and an energy storage battery unit, wherein the air conditioning system comprises a first compressor with a first suction port and a first exhaust port, an intermediate cooler with a first inlet, a first outlet, a second inlet and a second outlet, a heat exchanger with a first heat exchange flow channel, an evaporator with a second heat exchange flow channel and a third heat exchange flow channel capable of heat exchange, the first exhaust port, the first inlet, the first outlet, the second heat exchange flow channel and the first suction port are sequentially connected, the second outlet is connected to one end of the first heat exchange flow channel, the other end of the first heat exchange flow channel is connected to the second inlet through a one-way valve, the heat exchanger is connected to a target device for heat exchange, and a circulating pump, the third heat exchange flow channel and a fourth heat exchange flow channel in the target device form a liquid cooling circulation loop. According to the application, the air conditioning system can perform liquid cooling and refrigeration cooling on the energy storage battery cabinet, so that the cooling effect of the energy storage battery cabinet is better.

Description

Technical Field

[0001] This invention belongs to the field of battery cabinet technology, specifically relating to an air conditioning system and its control method, and an energy storage battery unit. Background Technology

[0002] Conventional energy storage battery cabinets are typically equipped with liquid cooling systems to lower their own temperature. When an energy storage battery cabinet with a liquid cooling system is fitted with a liquid cooling system, it forms an energy storage battery unit. The energy storage battery unit has a cabinet-like outer casing, within which both the battery cabinet and the liquid cooling system are housed. Because the cabinet-like casing is usually semi-enclosed with limited airflow, heat tends to accumulate quickly, making it difficult for a liquid cooling system alone to effectively cool the battery cabinet. Summary of the Invention

[0003] Therefore, the present invention provides an air conditioning system that can solve the technical problem that the liquid cooling system equipped with the existing energy storage battery cabinet is difficult to effectively cool the energy storage battery cabinet.

[0004] To address the aforementioned problems, this invention provides an air conditioning system comprising: a first compressor, an intercooler, a heat exchanger, an evaporator, a circulating pump, and a one-way valve. The first compressor has a first suction port and a first discharge port. The intercooler has a first inlet, a first outlet, a second inlet, and a second outlet. The heat exchanger has a first heat exchange channel. The evaporator has a second heat exchange channel and a third heat exchange channel capable of heat exchange. The first discharge port is connected to the first inlet. The first outlet is connected to one end of the second heat exchange channel. The other end of the second heat exchange channel is connected to the first suction port. The second outlet is connected to one end of the first heat exchange channel. The other end of the first heat exchange channel is connected to the second inlet via the one-way valve. The one-way valve is used to guide the flow from the first heat exchange channel to the intercooler. The heat exchanger is heat-exchange connected to a target device. A fourth heat exchange channel is formed within the target device. The circulating pump, the third heat exchange channel, and the fourth heat exchange channel constitute a liquid-cooled circulating loop.

[0005] In some embodiments, the air conditioning system further includes a three-way valve having a first valve port, a second valve port, and a third valve port, and the heat exchanger further has a fifth heat exchange channel, the first valve port being connected to the first exhaust port, the second valve port being connected to the first inlet, the third valve port being connected to one end of the fifth heat exchange channel, and the other end of the fifth heat exchange channel being connected to a flow path between the first outlet and the second heat exchange channel.

[0006] In some embodiments, a fan is provided on the outside of the heat exchanger, and the heat exchanger is located between the fan and the target device.

[0007] In some implementations, the second outlet is connected to one end of the first heat exchange channel via a control valve.

[0008] In some embodiments, an electric heater is provided on the liquid cooling circulation loop, which can heat the coolant flowing in the liquid cooling circulation loop.

[0009] In some embodiments, the air conditioning system further includes a second compressor and a condenser, the second compressor having a second intake port and a second exhaust port, the condenser having a third inlet and a third outlet, the intercooler also having a fourth inlet and a fourth outlet, the second exhaust port being connected to the third inlet, the third outlet being connected to the fourth inlet, and the fourth outlet being connected to the second intake port.

[0010] The present invention also provides a control method for controlling the operation of the aforementioned air conditioning system, the control method comprising:

[0011] The ambient temperature T;

[0012] When T < T1, the air conditioning system is controlled to operate in heating mode;

[0013] When T1≤T<T2, the air conditioning system is controlled to operate in the first cooling mode;

[0014] When T≥T2, the air conditioning system is controlled to operate in the second cooling mode;

[0015] Where T1 is the first preset temperature, T2 is the second preset temperature, and T2 > T1.

[0016] In some embodiments, when the air conditioning system includes a three-way valve, a fan, and a control valve, the first cooling mode includes: controlling the first compressor to start, controlling the first valve port of the three-way valve to connect with the second valve port, controlling the control valve to open, controlling the fan to run, and controlling the circulation pump to start.

[0017] In some embodiments, when the air conditioning system includes a three-way valve, a fan, and a control valve, the second cooling mode includes: controlling the first compressor to start, controlling the first valve port of the three-way valve to connect with the second valve port, controlling the control valve to close, controlling the fan to run, and controlling the circulation pump to start.

[0018] In some implementations, when the air conditioning system further includes a second compressor, the second compressor is controlled to start.

[0019] In some embodiments, when the air conditioning system includes a three-way valve, a fan, and an electric heater, the heating mode includes: controlling the first compressor to start, controlling the first valve port of the three-way valve to connect with the third valve port, controlling the fan to run, controlling the circulating pump to start, and controlling the electric heater to be energized.

[0020] The present invention also provides an energy storage battery unit, including the aforementioned air conditioning system and energy storage battery cabinet, wherein the energy storage battery cabinet is the target device.

[0021] The air conditioning system and its control method, as well as the energy storage battery unit provided by this invention, have the following beneficial effects:

[0022] The air conditioning system of this application is applied to an energy storage battery unit. The target equipment is an energy storage battery cabinet. When the battery cabinet needs cooling, the high-temperature and high-pressure refrigerant discharged from the first compressor enters the intercooler and becomes a gas-liquid two-phase refrigerant. The liquid refrigerant flows out in two paths. One path of liquid refrigerant flows out from the first outlet of the intercooler, then flows into the second heat exchange channel of the evaporator for evaporation and heat absorption, and finally returns to the first compressor to form a cycle. At the same time, the circulation pump is turned on, and the coolant circulates in the circulation loop. During the process of the refrigerant flowing through the second heat exchange channel, it exchanges heat with the coolant flowing through the third heat exchange channel, thereby cooling the coolant in the circulation loop. The cooled coolant then liquid-cools the energy storage battery cabinet. The other path of liquid refrigerant flows out from the second outlet of the intercooler, then flows into the first heat exchange channel of the heat exchanger for evaporation and heat absorption. Since the heat exchanger is heat-exchange connected to the energy storage battery cabinet, it can absorb the heat generated by the energy storage battery cabinet and cool it down. Finally, the refrigerant in the first heat exchange channel returns to the intercooler to form a cycle. In other words, the air conditioning system of this application can both liquid cool and refrigerate the energy storage battery cabinet, thus achieving a better cooling effect on the energy storage battery cabinet. Attached Figure Description

[0023] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of an energy storage battery unit according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the refrigerant and coolant flow direction when the air conditioning system of the energy storage battery unit is operating in the first cooling mode according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the refrigerant and coolant flow direction when the air conditioning system of the energy storage battery unit is operating in the second cooling mode according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the refrigerant and coolant flow direction of the air conditioning system of the energy storage battery unit in the heating mode according to an embodiment of the present invention;

[0028] Figure 5 This is a control flowchart of the air conditioning system of the energy storage battery unit according to an embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of an existing energy storage battery unit.

[0030] The reference numerals in the attached figures are as follows:

[0031] 1. First compressor; 2. Intercooler; 3. Heat exchanger; 4. Evaporator; 5. Circulating pump; 6. Check valve; 7. First valve port; 8. Second valve port; 9. Third valve port; 10. Control valve; 11. Electric heater; 12. Second compressor; 13. Condenser; 14. Energy storage battery cabinet; 15. First throttling element; 16. Second throttling element. Detailed Implementation

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] See also Figures 1 to 5 As shown, according to an embodiment of the present invention, an air conditioning system is provided, comprising: a first compressor 1, an intercooler 2, a heat exchanger 3, an evaporator 4, a circulating pump 5, and a one-way valve 6. The first compressor 1 has a first suction port and a first discharge port. The intercooler 2 has a first inlet, a first outlet, a second inlet, and a second outlet. The heat exchanger 3 has a first heat exchange channel. The evaporator 4 has a second heat exchange channel and a third heat exchange channel capable of heat exchange. The first discharge port is connected to the first inlet, the first outlet is connected to one end of the second heat exchange channel, the other end of the second heat exchange channel is connected to the first suction port, the second outlet is connected to one end of the first heat exchange channel, and the other end of the first heat exchange channel is connected to the second inlet via the one-way valve 6. The one-way valve 6 is used to guide the flow from the first heat exchange channel to the intercooler 2. The heat exchanger 3 is heat-exchange connected to a target device, and a fourth heat exchange channel is formed within the target device. The circulating pump 5, the third heat exchange channel, and the fourth heat exchange channel constitute a liquid-cooled circulating loop.

[0037] In this technical solution, the air conditioning system of this application is applied to the energy storage battery unit, the target equipment is the energy storage battery cabinet, and when the battery cabinet needs to be cooled, the high temperature and high pressure refrigerant discharged by the first compressor 1 enters the intercooler 2 and becomes a gas-liquid two-phase refrigerant, in which the liquid refrigerant flows out in two separate streams. One stream of liquid refrigerant flows out from the first outlet of the intercooler 2, then flows into the second heat exchange channel of the evaporator 4 for evaporation and heat absorption, and finally returns to the first compressor 1 to form a cycle. At the same time, the circulation pump 5 is turned on, and the coolant circulates in the circulation loop. As the refrigerant flows through the second heat exchange channel, it exchanges heat with the coolant flowing through the third heat exchange channel, which cools the coolant in the circulation loop. The cooled coolant then liquid-cools the energy storage battery cabinet 14. Another stream of liquid refrigerant flows out from the second outlet of the intercooler 2, then flows into the first heat exchange channel of the heat exchanger 3 for evaporation and heat absorption. Since the heat exchanger 3 is heat-exchange connected to the energy storage battery cabinet 14, the heat exchanger 3 can absorb the heat generated by the energy storage battery cabinet 14 and cool it down. Finally, the refrigerant in the first heat exchange channel returns to the intercooler 2 to form a cycle. That is, the air conditioning system of this application can both liquid cool the energy storage battery cabinet 14 and refrigerate the energy storage battery cabinet 14, thus achieving a better cooling effect on the energy storage battery cabinet 14.

[0038] See Figure 4 As shown, the air conditioning system also includes a three-way valve, which has a first valve port 7, a second valve port 8 and a third valve port 9. The heat exchanger 3 also has a fifth heat exchange flow channel. The first valve port 7 is connected to the first exhaust port, the second valve port 8 is connected to the first inlet, and the third valve port 9 is connected to one end of the fifth heat exchange flow channel. The other end of the fifth heat exchange flow channel is connected to the flow path between the first outlet and the second heat exchange flow channel.

[0039] In this embodiment, when the outside temperature is low and the energy storage battery cabinet 14 needs to be kept warm, the first valve port 7 and the third valve port 9 of the three-way valve are connected. The high-temperature, high-pressure refrigerant discharged from the first compressor 1 then enters the fifth heat exchange channel of the heat exchanger 3 for condensation. During condensation, the heat exchanger 3 releases heat to keep the energy storage battery cabinet 14 warm. The condensed refrigerant flows through the second heat exchange channel of the evaporator 4 for evaporation and heat absorption, and finally returns to the first compressor 1, thus forming a cycle. When the energy storage battery cabinet 14 needs to be cooled, simply connect the first valve port 7 and the second valve port 8 of the three-way valve to start the first compressor 1 and the circulating pump 5. A connection node is formed at the other end of the fifth heat exchange channel, connecting it to the flow path between the first outlet and the second heat exchange channel. A first throttling element 15 is provided on the flow path between the connection node and the evaporator 4. The first throttling element 15 is used to throttle the refrigerant flowing out of the fifth heat exchange channel of the intercooler 2 or the heat exchanger 3.

[0040] It should be noted that in existing technologies, liquid cooling systems can only cool the energy storage battery cabinet 14, while the air conditioning system of this application can not only effectively cool the energy storage battery cabinet 14, but also keep it warm when the outside temperature is low. Furthermore, while a typical air conditioning system requires a four-way valve to achieve both cooling and heating, the air conditioning system of this application only needs a three-way valve to achieve both. It is understood that cooling or keeping the energy storage battery cabinet 14 warm primarily refers to cooling or keeping the batteries inside the cabinet 14 warm.

[0041] See Figure 4 As shown, an electric heater 11 is installed on the liquid cooling circulation loop, which can heat the coolant flowing in the liquid cooling circulation loop. That is, when the outside temperature is low and the energy storage battery cabinet 14 needs to be kept warm, the electric heater 11 can also heat the coolant in the liquid cooling circulation loop, so that the heated coolant can also keep the energy storage battery cabinet 14 warm. The coolant can be water.

[0042] In one specific implementation, a fan is installed on the outside of the heat exchanger 3, and the heat exchanger 3 is located between the fan and the target equipment. When the fan is running, the airflow generated by the fan can quickly carry the cold or heat generated by the heat exchanger 3 into the energy storage battery cabinet 14, thereby improving the cooling or insulation effect of the energy storage battery cabinet 14 and enhancing the uniformity of cooling or insulation. Because the heat exchanger 3 acts as both an evaporator and a condenser, and the heat exchanger 3 is also equipped with a fan, the heat exchanger 3 of this application can be called an air-cooled evaporative condenser, and the fan of this application can be called an air-cooled evaporative condenser fan.

[0043] See Figure 3As shown, the second outlet is connected to one end of the first heat exchange channel via control valve 10. Control valve 10 can be an existing solenoid valve or an electric valve. When the energy storage battery cabinet 14 needs to be cooled, the first valve port 7 and the second valve port 8 of the three-way valve can be connected, control valve 10 can be closed, the first compressor 1 and the circulating pump 5 can be started, and the fan can be operated. The high-temperature and high-pressure refrigerant discharged from the first compressor 1 then enters the intercooler 2 and becomes a gas-liquid two-phase refrigerant. Since control valve 10 is closed, the liquid refrigerant in it only flows out from the first outlet of the intercooler 2, and then flows into the second heat exchange channel of the evaporator 4 for evaporation and heat absorption, and finally returns to the first compressor 1. During the process of the refrigerant flowing through the second heat exchange channel, it exchanges heat with the coolant flowing through the third heat exchange channel, thereby cooling the coolant in the circulation loop. The cooled coolant then liquid cools the energy storage battery cabinet 14. Since heat exchanger 3 does not participate in cooling the energy storage battery cabinet 14, but the fan operation does provide air cooling for the energy storage battery cabinet 14, the operating mode of the air conditioning system in this state can be called the maximum liquid supply cooling plus air cooling mode. In this mode, especially when the ambient temperature is high, the energy storage battery cabinet 14 can be cooled more effectively.

[0044] See also Figures 2 to 4 As shown, the air conditioning system also includes a second compressor 12 and a condenser 13. The second compressor 12 has a second suction port and a second discharge port, the condenser 13 has a third inlet and a third outlet, and the intercooler 2 also has a fourth inlet and a fourth outlet. The second discharge port is connected to the third inlet, the third outlet is connected to the fourth inlet, and the fourth outlet is connected to the second suction port. A condenser fan is correspondingly provided on the condenser 13.

[0045] In this embodiment, when the ambient temperature is high, existing liquid cooling systems often suffer from high exhaust temperatures and high heat loads on the condenser 13, which can easily lead to system shutdown and significantly impact the stable operation of the energy storage battery unit. The air conditioning system of this application, by adding a second compressor 12, becomes a two-stage compressor. The first compressor 1 can be referred to as the low-pressure stage compressor, and the second compressor 12 as the high-pressure stage compressor. When the energy storage battery cabinet 14 needs cooling, the first valve port 7 and the second valve port 8 of the three-way valve are connected. The high-temperature, high-pressure refrigerant discharged from the first compressor 1 enters the intercooler 2 as a two-phase gas-liquid refrigerant. The second compressor 12 draws in and compresses the gaseous refrigerant from the intercooler 2. Since the gaseous refrigerant has already been compressed once by the first compressor 1 and has a certain initial pressure, a smaller pressure ratio is needed for the refrigerant to reach the predetermined pressure after being drawn in by the second compressor 12. This smaller pressure ratio also ensures that the temperature of the refrigerant discharged from the second compressor 12 is not too high, thus preventing excessive heat load and exhaust temperature on the condenser 13 and avoiding system shutdown. In other words, compared to conventional single-stage compression liquid cooling systems, two-stage compression has a smaller condensation load, which is beneficial to the stability of the system when operating at high temperatures.

[0046] It should also be noted that a second throttling element 16 is provided in the flow path between the third outlet of the condenser 13 and the fourth inlet of the intercooler 2. After the second compressor 12 draws in and compresses the gaseous refrigerant in the intercooler 2, the discharged refrigerant flows into the condenser 13 for condensation, and then returns to the intercooler 2 after being throttled by the second throttling element 16. Since the refrigerant temperature is lower after being throttled by the second throttling element 16, when the throttled refrigerant flows into the intercooler 2, it will cool the high-temperature and high-pressure gaseous refrigerant discharged by the first compressor 1, thereby turning the high-temperature and high-pressure gaseous refrigerant into a gas-liquid two-phase refrigerant. This method enables the intercooler 2 to have an automatic cooling function.

[0047] The present invention also provides a control method for controlling the operation of the aforementioned air conditioning system, the control method comprising:

[0048] Obtain the ambient temperature T;

[0049] When T < T1, control the air conditioning system to operate in heating mode;

[0050] When T1≤T<T2, control the air conditioning system to operate in the first cooling mode;

[0051] When T≥T2, control the air conditioning system to operate in the second cooling mode;

[0052] Where T1 is the first preset temperature, T2 is the second preset temperature, and T2 > T1.

[0053] In this technical solution, T1 is 5℃ and T2 is 35℃. When the outside temperature is less than 5℃, it indicates that the outside temperature is low, so the air conditioning system needs to be controlled to operate in heating mode to keep the energy storage battery cabinet 14 warm. When the outside temperature is greater than or equal to 5℃ but less than 35℃, it indicates that the outside temperature is moderate, but the energy storage battery cabinet 14 will generate heat during operation, so the air conditioning system needs to be controlled to operate in first cooling mode to cool the energy storage battery cabinet 14. When the outside temperature is greater than 35℃, it indicates that the outside temperature is high, and the energy storage battery cabinet 14 will generate heat during operation, so the air conditioning system needs to be controlled to operate in second cooling mode to cool the energy storage battery cabinet 14.

[0054] In one specific implementation, when the air conditioning system includes components such as a first compressor 1, an intercooler 2, a heat exchanger 3, an evaporator 4, a circulation pump 5, a one-way valve 6, a first throttling element 15, a three-way valve, a fan, and a control valve 10, the first cooling mode includes: controlling the first compressor 1 to start, controlling the first valve port 7 and the second valve port 8 of the three-way valve to connect, controlling the control valve 10 to open, controlling the fan to run, and controlling the circulation pump 5 to start. The high-temperature, high-pressure refrigerant discharged from the first compressor 1 then enters the intercooler 2 after being diverted by the three-way valve, becoming a two-phase refrigerant. The liquid refrigerant flows out in two paths. One path of liquid refrigerant flows out from the first outlet of the intercooler 2, passes through the first throttling element 15, and flows into the second heat exchange channel of the evaporator 4 for evaporation and heat absorption, finally returning to the first compressor 1 to form a cycle. Simultaneously, the circulating pump 5 starts, and the coolant circulates within the circulation loop. As the refrigerant flows through the second heat exchange channel, it exchanges heat with the coolant flowing through the third heat exchange channel, cooling the coolant within the circulation loop. This cooled coolant then provides liquid cooling for the energy storage battery cabinet 14. Another stream of liquid refrigerant flows out from the second outlet of the intercooler 2 and then into the first heat exchange channel of the heat exchanger 3 for evaporation and heat absorption. Since the fan is also running, it blows cold air into the energy storage battery cabinet 14 to cool it. Finally, the refrigerant in the first heat exchange channel returns to the intercooler 2, forming a cycle. In other words, in the first cooling mode, the air conditioning system can both provide liquid cooling and general cooling for the energy storage battery cabinet 14.

[0055] Furthermore, when the air conditioning system includes components such as a first compressor 1, an intercooler 2, a heat exchanger 3, an evaporator 4, a circulation pump 5, a one-way valve 6, a first throttling element 15, a three-way valve, a fan, and a control valve 10, the second cooling mode includes: controlling the first compressor 1 to start, controlling the first valve port 7 and the second valve port 8 of the three-way valve to connect, controlling the control valve 10 to close, controlling the fan to run, and controlling the circulation pump 5 to start. The high-temperature, high-pressure refrigerant discharged from the first compressor 1 enters the intercooler 2 and becomes a two-phase refrigerant. Because the control valve 10 is closed, the liquid refrigerant flows out only from the first outlet of the intercooler 2, passes through the first throttling element 15, and flows into the second heat exchange channel of the evaporator 4 for evaporation and heat absorption, finally returning to the first compressor 1. During the flow of the refrigerant through the second heat exchange channel, it exchanges heat with the coolant flowing through the third heat exchange channel, causing the coolant in the circulation loop to cool down. The cooled coolant then provides liquid cooling for the energy storage battery cabinet 14. Since heat exchanger 3 does not participate in cooling the energy storage battery cabinet 14, but the fan operation does provide air cooling for the energy storage battery cabinet 14, the second cooling mode can be called the maximum liquid supply cooling plus air cooling mode. When the ambient temperature is greater than or equal to 35℃, the maximum liquid supply cooling plus air cooling can better cool the energy storage battery cabinet 14.

[0056] Furthermore, when the air conditioning system is operating in either the first or second cooling mode, if the system also includes a second compressor 12, a condenser 13, and a second throttling element 16, the second compressor 12 needs to be started. The second compressor 12 draws in and compresses the gaseous refrigerant from the intercooler 2. Since this gaseous refrigerant has already been compressed once by the first compressor 1 and has a certain initial pressure, a smaller pressure ratio is needed after the second compressor 12 draws it in to reach the predetermined pressure. This smaller pressure ratio also ensures that the temperature of the refrigerant discharged from the second compressor 12 is not too high, thus preventing the heat load and exhaust temperature of the condenser 13 from becoming too high and avoiding system shutdown. In other words, the two-stage compression results in a lower condensing load, which is beneficial for system stability during high-temperature operation. After the second compressor 12 draws in and compresses the gaseous refrigerant from the intercooler 2, the discharged refrigerant flows into the condenser 13 for condensation, and then returns to the intercooler 2 after being throttled by the second throttling element 16. Because the refrigerant temperature is lower after being throttled by the second throttling element 16, when the throttled refrigerant flows into the intercooler 2, it cools the high-temperature, high-pressure gaseous refrigerant discharged from the first compressor 1, thus turning the high-temperature, high-pressure gaseous refrigerant into a gas-liquid two-phase refrigerant. This method gives the intercooler 2 an automatic cooling function. Specifically, when the complete air conditioning system is operating in the first cooling mode, the flow direction of the refrigerant and coolant is as follows: Figure 2 As shown; when the complete air conditioning system is operating in the second cooling mode, the flow direction of refrigerant and coolant is as follows. Figure 3 As shown.

[0057] As a specific implementation method, the heating mode includes: controlling the start of the first compressor 1, controlling the connection between the first valve port 7 and the third valve port 9 of the three-way valve, controlling the operation of the fan, controlling the start of the circulation pump 5, and controlling the energization of the electric heater 11. The high-temperature, high-pressure refrigerant discharged from the first compressor 1 enters the fifth heat exchange channel of the heat exchanger 3 for condensation. During condensation, the heat exchanger 3 releases heat and the fan also runs, thus the fan can blow hot air into the energy storage battery cabinet 14 for insulation. The condensed refrigerant flows into the second heat exchange channel of the evaporator 4 after being throttled by the first throttling element 15, where it evaporates and absorbs heat, and finally returns to the first compressor 1, thus forming a cycle. Simultaneously, the electric heater 11 is energized, heating the coolant flowing in the liquid-cooled circulation loop, so that the heated coolant also insulates the energy storage battery cabinet 14. Specifically, when the complete air conditioning system operates in heating mode, the flow direction of the refrigerant and coolant is as follows: Figure 4 As shown.

[0058] Figure 5 The diagram shown is a control flowchart of an air conditioning system according to an embodiment of the present invention. Figure 5 In this system, Mode 1 is the first cooling mode, Mode 2 is the second cooling mode, and Mode 3 is the heating mode. In the first cooling mode, the water temperature (i.e., coolant temperature) can be controlled by adjusting the frequency of the high-pressure stage compressor, and the speed of the air-cooled evaporative condenser fan can be adjusted according to the internal temperature of the battery storage cabinet 14 to moderately cool the battery storage cabinet 14. In the second cooling mode, the air-cooled evaporative condenser fan can be controlled to run at full speed to provide a larger airflow for cooling the battery storage cabinet 14 per unit time, and the water temperature can be controlled by adjusting the frequency of the high-pressure stage compressor, thus effectively cooling the battery storage cabinet 14. In the heating mode, the air-cooled evaporative condenser fan can be controlled to run at low speed, and the supply air temperature can be controlled by adjusting the frequency of the low-pressure stage compressor to moderately insulate the battery storage cabinet 14.

[0059] The present invention also provides an energy storage battery unit, including the aforementioned air conditioning system and energy storage battery cabinet 14, wherein the energy storage battery cabinet 14 is the aforementioned target device. The energy storage battery unit has a cabinet-type outer casing, and both the air conditioning system and the energy storage battery cabinet 14 are located within the cabinet-type outer casing. It is understood that the air conditioning system of this application can also be applied to other devices with high heat generation, besides the battery cabinet.

[0060] Figure 6 The diagram shown is a schematic of an energy storage battery unit in the prior art. Figure 6In this system, the second compressor 12, condenser 13, second throttling element 16, and evaporator 4 form a refrigerant circulation loop, while the circulation pump 5, evaporator 4, and energy storage battery cabinet 14 form a liquid cooling circulation loop. The refrigerant discharged from the second compressor 12 flows into the condenser 13 for condensation and heat release, then flows through the second throttling element 16 for throttling. The throttled refrigerant then flows into one heat exchange channel of the evaporator 4 for evaporation and heat absorption, finally returning to the second compressor 12, thus forming a refrigerant circulation. Simultaneously, the circulation pump 5 drives the coolant to circulate within the liquid cooling circulation loop. During the flow of the coolant through the other heat exchange channel of the evaporator 4, it exchanges heat with the refrigerant and cools down. The cooled coolant then liquid cools the energy storage battery cabinet 14. Therefore, this liquid cooling system can only liquid cool the energy storage battery cabinet 14, and it suffers from poor cooling effect, inability to insulate the energy storage battery cabinet 14, and high exhaust temperature. This application overcomes these shortcomings of the prior art.

[0061] 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.

[0062] 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 should be included within the protection scope of the present invention. The above are merely preferred embodiments 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. An air conditioning system, characterized by, The air conditioning system comprises a first compressor (1), an intermediate cooler (2), a heat exchanger (3), an evaporator (4), a circulating pump (5) and a one-way valve (6), the first compressor (1) has a first suction port and a first discharge port, the intermediate cooler (2) has a first inlet, a first outlet, a second inlet and a second outlet, the heat exchanger (3) has a first heat exchange flow channel, the evaporator (4) has a second heat exchange flow channel and a third heat exchange flow channel capable of heat exchange, the first discharge port is connected to the first inlet, one end of the second heat exchange flow channel is connected to the first outlet, the other end of the second heat exchange flow channel is connected to the first suction port, the second outlet is connected to one end of the first heat exchange flow channel, the other end of the first heat exchange flow channel is connected to the second inlet through the one-way valve (6), the one-way valve (6) is used for guiding the flow in the direction from the first heat exchange flow channel to the intermediate cooler (2), the heat exchanger (3) is in heat exchange connection with a target device, the target device is formed with a fourth heat exchange flow channel, the circulating pump (5), the third heat exchange flow channel and the fourth heat exchange flow channel form a liquid cooling circulation loop. The air conditioning system further comprises a three-way valve, the three-way valve has a first valve port (7), a second valve port (8) and a third valve port (9), the heat exchanger (3) further has a fifth heat exchange flow channel, the first valve port (7) is connected to the first discharge port, the second valve port (8) is connected to the first inlet, the third valve port (9) is connected to one end of the fifth heat exchange flow channel, and the other end of the fifth heat exchange flow channel is connected to a flow path between the first outlet and the second heat exchange flow channel.

2. The air conditioning system of claim 1, wherein, A fan is arranged outside the heat exchanger (3), and the heat exchanger (3) is between the fan and the target device.

3. The air conditioning system of claim 1, wherein, The second outlet is connected to one end of the first heat exchange flow channel through a control valve (10).

4. The air conditioning system of claim 1, wherein, An electric heater (11) is arranged on the liquid cooling circulation loop, and the electric heater can heat the cooling liquid flowing in the liquid cooling circulation loop.

5. The air conditioning system according to any one of claims 1 to 4, wherein The air conditioning system further comprises a second compressor (12) and a condenser (13), the second compressor (12) has a second suction port and a second discharge port, the condenser (13) has a third inlet and a third outlet, the intermediate cooler (2) further has a fourth inlet and a fourth outlet, the second discharge port is connected to the third inlet, the third outlet is connected to the fourth inlet, and the fourth outlet is connected to the second suction port.

6. A control method of an air conditioning system, characterized by, The control method comprises the following steps: obtaining the temperature T of the outside world; when T < T1, controlling the air conditioning system to run in a heating mode; when T1 ≤ T < T2, controlling the air conditioning system to run in a first refrigeration mode; when T ≥ T2, controlling the air conditioning system to run in a second refrigeration mode; wherein T1 is a first preset temperature, T2 is a second preset temperature, and T2 > T1.

7. The control method according to claim 6, characterized by The heat exchanger (3) is provided with a fan outside, the heat exchanger (3) is between the fan and the target device, the second outlet is connected to one end of the first heat exchange flow channel through a control valve (10), the first refrigeration mode comprises: controlling the first compressor (1) to start, controlling the first valve port (7) of the three-way valve to communicate with the second valve port (8), controlling the control valve (10) to open, controlling the fan to run, and controlling the circulating pump (5) to start.

8. The control method according to claim 6, characterized by, The heat exchanger (3) is provided with a fan outside, the heat exchanger (3) is between the fan and the target device, the second outlet is connected to one end of the first heat exchange flow channel through a control valve (10), the first refrigeration mode comprises: controlling the first compressor (1) to start, controlling the first valve port (7) of the three-way valve to communicate with the second valve port (8), controlling the control valve (10) to open, controlling the fan to run, and controlling the circulating pump (5) to start.

9. The control method according to claim 7 or 8, characterized by, The air conditioning system further comprises a second compressor (12) and a condenser (13), the second compressor (12) has a second suction port and a second discharge port, the condenser (13) has a third inlet and a third outlet, the intermediate cooler (2) further has a fourth inlet and a fourth outlet, the second discharge port is connected to the third inlet, the third outlet is connected to the fourth inlet, and the fourth outlet is connected to the second suction port, and the second compressor (12) is controlled to start.

10. The control method according to claim 7, characterized by, The liquid cooling circulation circuit is provided with an electric heater (11), the electric heater can heat the cooling liquid circulating in the liquid cooling circulation circuit, and the heating mode comprises: controlling the first compressor (1) to start, controlling the first valve port (7) of the three-way valve to communicate with the third valve port (9), controlling the fan to run, controlling the circulating pump (5) to start, and controlling the electric heater (11) to be powered on.

11. An energy storage battery pack, characterized by, The air conditioning system comprises the air conditioning system and an energy storage battery cabinet (14), and the energy storage battery cabinet (14) is the target device.

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