Battery water cooling unit system and control method thereof

Abstract

The invention provides a battery water cooling unit system which is characterized in that the system comprises a refrigerant system, a battery side water path and a heat dissipation water tank side water path, the battery side water path is connected to one side of the refrigerant system, and the heat dissipation water tank side water path is connected to the other side of the refrigerant system; the battery side water path and the heat dissipation water tank side water path are connected in a selectable mode. An air cooling heat exchanger, a condenser and a fan in a traditional battery water cooling unit can be omitted, the requirements for large occupied space and special installation positions are met, heat of a battery is transferred into a vehicle ATS through a refrigerant system, and the high failure rate of the air cooling heat exchanger, the condenser and the fan is solved; according to the battery heat management unit disclosed by the invention, four modes are switched by controlling the compressor, the PTC heater and the proportional control valve, so that the requirements of various modes of a battery can be met, and an energy-saving effect can also be achieved.

Description

Technical Field

[0001] This invention relates to the technical field of power battery cooling technology, specifically to a battery water-cooled unit system and its control method. Background Technology

[0002] With the rapid popularization of new energy vehicles, the electrification of mining trucks and excavators used in mines has gradually become widespread. As a core energy component, the operating temperature of the power battery directly determines the charging and discharging efficiency, cycle life, and safety performance. It is known that the optimal operating range of the power battery is 25-40℃. When the temperature is below 0℃, the discharge rate decreases by more than 30%, and when it is above 50℃, thermal runaway is likely to occur. Therefore, efficient temperature control of the power battery has become a critical requirement.

[0003] In current conventional battery water-cooled units, the air-cooled heat exchanger and condenser are typically integrated with the fan as a single unit, resulting in a large size and high cost. Furthermore, the inclusion of the air-cooled heat exchanger, condenser, and fan in the unit imposes specific requirements on its installation location within the vehicle. Additionally, mining trucks and excavators, being off-road vehicles, operate in poor conditions with high vibration and dust levels, leading to a high failure rate for the air-cooled heat exchanger, condenser, and fan.

[0004] Therefore, there is an urgent need to provide a new solution to address the aforementioned technical defects and shortcomings. Summary of the Invention

[0005] To address the shortcomings and deficiencies in existing technologies, this invention provides a battery water-cooled unit system and its control method.

[0006] To address the shortcomings and deficiencies in existing technologies, the present invention provides the following specific solution: A battery water-cooled unit system, characterized in that: the system includes a refrigerant system, a battery-side water circuit, and a heat dissipation tank-side water circuit; the battery-side water circuit is connected to one side of the refrigerant system, and the heat dissipation tank-side water circuit is connected to the other side of the refrigerant system; the battery-side water circuit and the heat dissipation tank-side water circuit are connected in an optional manner; wherein... The refrigerant system includes a compressor, the compressor outlet of which is connected to the refrigerant-side inlet of the condenser heat exchange plate, the refrigerant-side outlet of the condenser heat exchange plate is connected to the inlet of an electronic expansion valve, the outlet of the electronic expansion valve is connected to the refrigerant inlet of the evaporator heat exchange plate, and the refrigerant outlet of the evaporator heat exchange plate is connected to the compressor inlet via a gas-liquid separator; a high-pressure sensor is connected between the compressor outlet and the refrigerant-side inlet of the condenser heat exchange plate, and a temperature and pressure sensor is connected between the refrigerant outlet of the evaporator heat exchange plate and the inlet of the gas-liquid separator; The battery-side water circuit includes a second water pump. The outlet of the second water pump is connected to the coolant inlet of the evaporator heat exchange plate. The coolant outlet of the evaporator heat exchange plate is connected to the inlet of the PTC heater via a proportional control valve. The outlet of the PTC heater is connected to the coolant inlet of the power battery. The coolant outlet of the power battery is connected to the inlet of the second water pump. A battery inlet water temperature sensor is connected between the outlet of the PTC heater and the coolant inlet of the power battery. A battery outlet water temperature sensor is connected between the outlet of the second water pump and the coolant inlet of the evaporator heat exchange plate. The water circuit on the side of the heat exchange tank includes a first water pump. The outlet of the first water pump is connected to the coolant inlet of the condenser heat exchange plate via a proportional control valve. The coolant outlet of the condenser heat exchange plate is connected to the inlet of the drive system heat exchanger. The outlet of the drive system heat exchanger is connected to the inlet of the heat exchange tank. A cooling fan is provided on one side of the heat exchange tank. The outlet of the heat exchange tank is connected to the inlet of the first water pump. An external circulating water temperature sensor is also connected between the proportional control valve and the coolant inlet of the condenser heat exchange plate. Heat exchange can be achieved between the refrigerant flow path formed between the refrigerant inlet and refrigerant outlet of the evaporator heat exchange plate and the coolant flow path formed between the coolant inlet and coolant outlet of the evaporator heat exchange plate. Heat exchange can be achieved between the refrigerant flow path formed between the refrigerant inlet and refrigerant outlet of the condenser heat exchange plate and the coolant flow path formed between the coolant inlet and coolant outlet of the condenser heat exchange plate. The proportional control valve can control the connection or disconnection between the battery-side water circuit and the radiator-side water circuit, and can adjust the ratio of the cross-flow area between the two when they are connected. The system receives requests from the power battery and controls the compressor, PTC heater, and proportional control valve to switch between four operating modes: battery self-circulation, heating, refrigerant cooling, and natural air cooling.

[0007] As a further preferred embodiment of the present invention When the power battery sends a self-circulation request, the system enters the battery self-circulation working mode; When the power battery sends a heating request, the system enters the heating working mode; When the power battery sends a cooling request, the system compares the real-time detection result T4 of the external circulation water temperature sensor with the target water temperature T of the battery to determine whether the system enters the refrigerant cooling mode or the natural air cooling mode.

[0008] As a further preferred embodiment of the present invention When the power battery sends a cooling request: If the comparison between the real-time detection result T4 of the external circulating water temperature sensor and the target water temperature T of the battery satisfies T4≤T-5℃, then the system is determined to enter the natural air cooling mode; otherwise, the system is determined to enter the refrigerant cooling mode.

[0009] As a further preferred embodiment of the present invention, the system is capable of switching between a natural air cooling mode and a refrigerant cooling mode in the following manner: When the system is operating in natural air cooling mode, if the comparison result of the real-time detection result T4 of the external circulation water temperature sensor and the target water temperature T of the battery satisfies T4≤T-5℃, the system will switch from natural air cooling mode to refrigerant cooling mode; otherwise, the system will continue to operate in the current natural air cooling mode. When the system is operating in refrigerant cooling mode, if the comparison result of the real-time detection result T4 of the external circulating water temperature sensor and the target water temperature T of the battery satisfies T4≤T-10℃, the system will switch from refrigerant cooling mode to natural air cooling mode; otherwise, the system will continue to operate in the current refrigerant cooling mode.

[0010] As a further preferred embodiment of the present invention When the system is operating in battery self-circulation mode, the proportional control valve disconnects the water circuit on the battery side from the water circuit on the radiator side. At this time, the second water pump is started, the PTC heater remains off, the compressor remains off, and the electronic expansion valve remains at its default opening.

[0011] As a further preferred embodiment of the present invention When the system is in heating mode, the proportional control valve disconnects the water circuit on the battery side from the water circuit on the cooling tank side. At this time, the second water pump is started, the PTC heater outputs according to the preset heating power, the compressor remains off, and the electronic expansion valve remains open at the default position. The heating power P of the PTC heater satisfies: ; in, This is the difference between the battery inlet water temperature T3 detected by the battery inlet water temperature sensor and the target battery water temperature T when the system is operating in heating mode; that is... .

[0012] As a further preferred embodiment of the present invention When the system is operating in refrigerant refrigeration mode, the proportional control valve controls the disconnection between the battery-side water circuit and the radiator-side water circuit. At this time, the second water pump is started, the PTC heater remains off, the compressor is started, and the opening of the electronic expansion valve is adjusted. The compressor speed N satisfies: ; in, This is the difference between the battery inlet water temperature T3 detected by the battery inlet water temperature sensor and the target battery water temperature T when the system is operating in refrigerant cooling mode. p is the proportional control coefficient; K is the integral control coefficient; and both satisfy 1500RPM≤N≤8000RPM. The opening degree K of the electronic expansion valve satisfies: ; in, Temperature measured by temperature and pressure sensor The pressure measured by the temperature and pressure sensor is converted into the refrigerant temperature in the two-phase region at that pressure. for and The difference; and simultaneously satisfy 66 steps ≤ K ≤ 500 steps.

[0013] As a further preferred embodiment of the present invention When the system is operating in natural air cooling mode, the proportional control valve controls the connection between the battery-side water circuit and the radiator-side water circuit. At this time, the second water pump is started, the PTC heater is kept off, the compressor is kept off, and the electronic expansion valve is kept at the default opening. At this time, the power battery is cooled only by the radiator and the cooling fan.

[0014] As a further preferred embodiment of the present invention When the system is operating in natural air cooling mode, the water temperature entering the power battery is regulated by adjusting the opening ratio of the proportional control valve. The proportional control valve has the following 5 opening ratio modes: 1) Opening degree 1 indicates that the battery water circuit is completely disconnected from the water circuit on the cooling water tank side; 2) An opening degree of 2 indicates that the battery water circuit is connected in series with the cooling water tank side water circuit by 25%. 3) An opening degree of 3 indicates that the battery water circuit and the cooling water tank side water circuit are connected in series by 50%. 4) An opening degree of 4 indicates that the battery water circuit and the cooling water tank side water circuit are connected in series for 75%; 5) An opening degree of 5 indicates that the battery water circuit and the cooling water tank side water circuit are connected in series by 100%; 25%, 50%, 75%, and 100% represent the proportion of the water flow area after the waterways on both sides are connected in series. When the battery inlet water temperature T3 measured by the battery inlet water temperature sensor satisfies T3 < T-5℃, the proportional control valve will decrease its opening by 1 degree accordingly. When the battery inlet water temperature T3 measured by the battery inlet water temperature sensor satisfies T3 > T, the proportional control valve will increase its opening by 1 degree accordingly. After each action is completed, hold for 60 seconds before proceeding to the next judgment process.

[0015] Furthermore, the present invention also provides a control method for a battery water-cooled unit system, characterized by comprising the following steps: S1: The system receives a working mode request from the power battery; S2: Based on the request received from the power battery, the system switches between four operating modes—battery self-circulation, heating, refrigerant cooling, and natural air cooling—by controlling the compressor, PTC heater, and proportional control valve. S21: When the power battery sends a self-circulation request, the system enters the battery self-circulation working mode; at this time, the proportional control valve controls the disconnection between the battery side water circuit and the radiator side water circuit, the second water pump is started, the PTC heater is kept off, the compressor is kept off, and the electronic expansion valve is kept at the default opening. S22: When the power battery sends a heating request, the system enters the heating working mode; at this time, the proportional control valve controls the disconnection between the battery side water circuit and the radiator side water circuit, the second water pump is started, the PTC heater outputs according to the preset heating power, the compressor remains off, and the electronic expansion valve remains at the default opening. S23: When the power battery sends a cooling request, the system compares the real-time detection result T4 of the external circulation water temperature sensor with the target water temperature T of the battery to determine whether the system enters the refrigerant cooling mode or the natural air cooling mode.

[0016] S231: If the comparison between the real-time detection result T4 of the external circulation water temperature sensor and the target water temperature T of the battery satisfies T4≤T-5℃, then the system is judged to enter the natural air cooling working mode; at this time, the proportional control valve controls the connection between the water circuit on the battery side and the water circuit on the radiator side, the second water pump is started, the PTC heater is kept off, the compressor is kept off, and the electronic expansion valve is kept at the default opening; at this time, the power battery is cooled only by the radiator and the cooling fan, and the water temperature entering the power battery is regulated by adjusting the opening ratio of the proportional control valve. S232: If the comparison between the real-time detection result T4 of the external circulation water temperature sensor and the target water temperature T of the battery does not satisfy T4≤T-5℃, then the system is judged to enter the refrigerant cooling working mode; at this time, the proportional control valve controls the disconnection between the water circuit on the battery side and the water circuit on the radiator side, the second water pump is started, the PTC heater is kept off, the compressor is started, and the opening of the electronic expansion valve is adjusted.

[0017] Compared with existing technologies, the technical effects that this invention can achieve include: 1) This invention provides a battery water-cooled unit system and its control method, which can eliminate the air-cooled heat exchanger, condenser and fan in the traditional battery water-cooled unit, solve the requirements of large space occupation and special installation position, and transfer the heat of the battery to the vehicle ATS through the refrigerant system, thus solving the high failure rate of the air-cooled heat exchanger, condenser and fan.

[0018] 2) This invention provides a battery water-cooled unit system and its control method. The battery thermal management unit of this invention achieves four modes of switching by controlling the compressor, PTC heater and proportional control valve, which can not only meet the needs of various battery modes, but also achieve energy saving effect. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the battery water-cooled unit system of the present invention.

[0020] Figure 2 This is a schematic diagram of the self-circulation and heating operation mode of the battery water-cooled unit system of the present invention.

[0021] Figure 3 This is a schematic diagram of the refrigerant cooling working mode of the battery water-cooled unit system of the present invention.

[0022] Figure 4 This is a schematic diagram of the natural air cooling working mode of the battery water cooling unit system of the present invention.

[0023] Figure 5 This is a schematic diagram of the cooling mode switching of the battery water-cooled unit system of the present invention.

[0024] The attached diagrams specify the following components: 1-compressor, 2-high pressure sensor, 3-condenser heat exchange plate, 4-electronic expansion valve, 5-evaporator heat exchange plate, 6-temperature and pressure sensor, 7-gas-liquid separator, 8-drive system heat exchanger, 9-cooling water tank, 10-cooling fan, 11-first water pump, 12-proportional control valve, 13-external circulation water temperature sensor, 14-PTC heater, 15-battery inlet water temperature sensor, 16-power battery, 17-second water pump, 18-battery outlet water temperature sensor. Detailed Implementation

[0025] 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. 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.

[0026] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] [First Embodiment] like Figure 1 The diagram shows a battery water-cooled unit system according to a first embodiment of the present invention. The system includes a refrigerant system, a battery-side water circuit, and a heat sink-side water circuit. The battery-side water circuit is connected to one side of the refrigerant system, and the heat sink-side water circuit is connected to the other side of the refrigerant system. The battery-side water circuit and the heat sink-side water circuit are connected in an optional manner. The refrigerant system includes a compressor 1. The outlet of compressor 1 is connected to the refrigerant inlet of the condenser heat exchange plate 3. The refrigerant outlet of the condenser heat exchange plate 3 is connected to the inlet of the electronic expansion valve 4. The outlet of the electronic expansion valve 4 is connected to the refrigerant inlet of the evaporator heat exchange plate 5. The refrigerant outlet of the evaporator heat exchange plate 5 is connected to the inlet of compressor 1 via a gas-liquid separator 7. A high-pressure sensor 2 is connected between the outlet of compressor 1 and the refrigerant inlet of the condenser heat exchange plate 3. The high-pressure sensor 2 measures in real time whether the discharge pressure of compressor 1 exceeds a threshold to protect the compressor. The refrigerant outlet of the evaporator heat exchange plate 5 is connected to the gas-liquid separator 7. A temperature and pressure sensor 6 is connected between the inlet and outlet of the gas-liquid separator 7. The temperature and pressure sensor 6 can detect the temperature and pressure between the refrigerant outlet of the evaporator heat exchange plate 5 and the inlet of the gas-liquid separator 7, so as to provide a basis for adjusting the opening of the electronic expansion valve 4. The refrigerant in the refrigerant system is compressed into a high temperature and high pressure gaseous state by the compressor 1. It flows through the condenser heat exchange plate 3 and releases heat to the water circuit on the heat sink side, becoming a medium temperature and high pressure liquid. It expands into a low temperature and low pressure gas-liquid two-phase system through the electronic expansion valve 4. Then, it absorbs heat from the battery side water circuit through the evaporator heat exchange plate 5 to complete vaporization. Finally, it returns to the compressor 1 after passing through the gas-liquid separator 7. The battery-side water circuit includes a second water pump 17, which drives the coolant in the battery-side water circuit to flow in a preset direction. The outlet of the second water pump 17 is connected to the coolant inlet of the evaporator heat exchange plate 5. The coolant outlet of the evaporator heat exchange plate 5 is connected to the inlet of the PTC heater 14 via a proportional control valve 12. When the system is operating in heating mode, the PTC heater 14 can provide heating power. The outlet of the PTC heater 14 is connected to the coolant inlet of the power battery 16. The coolant outlet of the power battery 16 is connected to the inlet of the second water pump 17. A battery inlet water temperature sensor 15 is connected between the outlet of the PTC heater 14 and the coolant inlet of the power battery 16. A battery outlet water temperature sensor 18 is connected between the outlet of the second water pump 17 and the coolant inlet of the evaporator heat exchange plate 5. The battery inlet water temperature sensor 15 serves as the control target of the TMS system (thermal management system) to ensure that it reaches the required battery temperature. The battery outlet water temperature sensor 18 provides feedback on the battery outlet water temperature after cooling or heating. The coolant circulating in the battery side water circuit is pumped by the second water pump 17 to the evaporator heat exchange plate 5, and then passes through the proportional control valve 12, PTC heater 14 and power battery 17 in sequence before returning to the second water pump 17. The cooling water tank side water circuit includes a first water pump 11, which drives the coolant in the cooling water tank side water circuit to flow in a preset direction. The outlet of the first water pump 11 is connected to the coolant inlet of the condenser heat exchange plate 3 via a proportional control valve 12. The coolant outlet of the condenser heat exchange plate 3 is connected to the inlet of the drive system heat exchanger 8, which dissipates heat for the drive system. The outlet of the drive system heat exchanger 8 is connected to the inlet of the cooling water tank 9. A cooling fan 10 is installed on one side of the cooling water tank 9. When the system operates in natural temperature range... In air-cooled operation mode, the power battery 16 can be cooled by the radiator 9 and the cooling fan 10 alone. The outlet of the radiator 9 is connected to the inlet of the first water pump 11. An external circulating water temperature sensor 13 is also connected between the proportional control valve 12 and the coolant inlet of the condenser heat exchange plate 3. The coolant in the water circuit on the radiator side is pumped from the first water pump 11 to the proportional control valve 12, and then passes through the condenser heat exchange plate 3, the drive system heat exchanger 8 and the radiator 9 in sequence before returning to the first water pump 11. In this embodiment, the first water pump 11 is in a normally open state.

[0029] Heat exchange can be achieved between the refrigerant flow path formed between the refrigerant inlet and refrigerant outlet of the evaporator heat exchange plate 5 and the coolant flow path formed between the coolant inlet and coolant outlet of the evaporator heat exchange plate 5; the evaporator heat exchange plate 5 is shared by the refrigerant system and the battery water circuit, the refrigerant flow path is located inside the refrigerant system, and the coolant flow path is located inside the battery water circuit, and heat exchange can be achieved between the two; Heat exchange can be achieved between the refrigerant flow path formed between the refrigerant inlet and refrigerant outlet of the condenser heat exchange plate 3 and the coolant flow path formed between the coolant inlet and coolant outlet of the condenser heat exchange plate 3; the condenser heat exchange plate 3 is shared by the refrigerant system and the water circuit on the heat dissipation tank side, the refrigerant flow path of the condenser is located inside the refrigerant system, and the coolant flow path of the condenser is located inside the water circuit on the heat dissipation tank side, and heat exchange can be achieved between the two. The proportional control valve 12 can control the connection or disconnection between the battery-side water circuit and the radiator-side water circuit, and can adjust the ratio of the water flow area between the two when they are connected. For example, the ratio of the water flow area can be adjusted to 25%, 50%, 75% and 100% respectively. In this embodiment, the proportional control valve 12 is a four-way proportional water valve. Those skilled in the art can also select other control valve structures that can realize both on-off control function and opening degree adjustment function according to actual needs. The system receives requests from the power battery and controls the compressor 1, PTC heater 14, and proportional control valve 12 to switch between four working modes: battery self-circulation, heating, refrigerant cooling, and natural air cooling.

[0030] In this embodiment, When the power battery 16 sends a self-circulation request, the system enters the battery self-circulation working mode; When the power battery 16 sends a heating request, the system enters the heating working mode; When the power battery 16 sends a cooling request, the system compares the real-time detection result T4 of the external circulation water temperature sensor 13 with the target water temperature T of the battery to determine whether the system enters the refrigerant cooling mode or the natural air cooling mode.

[0031] Specifically, it refers to, such as Figure 5 As shown, when the power battery 16 sends a cooling request: If the comparison result of the real-time detection result T4 of the external circulation water temperature sensor 13 and the target water temperature T of the battery satisfies T4≤T-5℃, then the system is judged to enter the natural air cooling working mode. Otherwise, the system is determined to have entered refrigerant refrigeration mode.

[0032] To achieve a balance between energy saving and performance, the system can switch between natural air cooling and refrigerant cooling modes in the following ways: When the system is operating in natural air cooling mode, if the comparison result of the real-time detection result T4 of the external circulation water temperature sensor 13 and the target water temperature T of the battery satisfies T4≤T-5℃, the system will switch from natural air cooling mode to refrigerant cooling mode; otherwise, the system will continue to operate in the current natural air cooling mode. When the system is operating in refrigerant cooling mode, if the comparison result of the real-time detection result T4 of the external circulating water temperature sensor 13 and the target water temperature T of the battery satisfies T4≤T-10℃, the system will switch from refrigerant cooling mode to natural air cooling mode; otherwise, the system will continue to operate in the current refrigerant cooling mode.

[0033] This control method can reduce compressor energy consumption in low-temperature environments and reduce the frequent switching between natural air cooling and refrigerant cooling, thus ensuring the service life of components.

[0034] When the system operates in battery self-circulation mode, such as Figure 2 As shown, the proportional control valve 12 controls the disconnection between the battery-side water circuit and the radiator-side water circuit. At this time, the evaporator heat exchange plate 5 is connected to the PTC heater 14, and the first water pump 11 is connected to the condenser heat exchange plate 3. At this time, the second water pump 17 is started, the PTC heater 14 is kept off, the compressor 1 is kept off, and the electronic expansion valve 4 is kept at the default opening.

[0035] When the system is operating in heating mode, such as Figure 2 As shown, the proportional control valve 12 controls the disconnection between the battery-side water circuit and the radiator-side water circuit. At this time, the evaporator heat exchange plate 5 is connected to the PTC heater 14, and the first water pump 11 is connected to the condenser heat exchange plate 3. At this time, the second water pump 17 is started, the PTC heater 14 outputs according to the preset heating power, the compressor 1 remains in the off state, and the electronic expansion valve 4 remains at the default opening. The heating power P of PTC heater 14 satisfies: ; in, This is the difference between the battery inlet water temperature T3 detected by the battery inlet water temperature sensor 15 and the target battery water temperature T when the system is operating in heating mode; that is... p is the proportional adjustment coefficient; k is the integral adjustment coefficient.

[0036] When the system operates in refrigerant refrigeration mode, such as Figure 3 As shown, the proportional control valve 12 controls the disconnection between the battery-side water circuit and the radiator-side water circuit. At this time, the evaporator heat exchange plate 5 is connected to the PTC heater 14, and the first water pump 11 is connected to the condenser heat exchange plate 3. At this time, the second water pump 17 is started, the PTC heater 14 is kept closed, the compressor 1 is started, and the opening of the electronic expansion valve 4 is adjusted to adjust the superheat of the compressor 1 suction port. The rotational speed N of compressor 1 satisfies: ; in, This is the difference between the battery inlet water temperature T3 detected by the battery inlet water temperature sensor 15 and the target battery water temperature T when the system is operating in refrigerant cooling mode. Simultaneously satisfying 1500RPM≤N≤8000RPM; The opening degree K of the electronic expansion valve 4 satisfies: ; in, The temperature measured by temperature and pressure sensor 6; The pressure measured by temperature and pressure sensor 6 is converted into the refrigerant temperature in the two-phase region at that pressure. for and The difference; and simultaneously satisfying 66 steps ≤ K ≤ 500 steps; When the system operates in natural air cooling mode, such as Figure 4 As shown, the proportional control valve 12 controls the interconnection between the battery-side water circuit and the radiator-side water circuit. At this time, the second water pump 17 is started, the PTC heater 14 is kept off, the compressor 1 is kept off, and the electronic expansion valve 4 is kept at the default opening. At this time, the power battery 16 is cooled only by the radiator 9 and the cooling fan 10 to achieve energy saving.

[0037] At this time, the water temperature entering the power battery 16 can be controlled by adjusting the opening ratio of the proportional control valve 12. The proportional control valve 12 has the following 5 opening modes: 1) Opening degree 1 indicates that the battery water circuit is completely disconnected from the water circuit on the cooling water tank side; 2) An opening degree of 2 indicates that the battery water circuit is connected in series with the cooling water tank side water circuit by 25%. 3) An opening degree of 3 indicates that the battery water circuit and the cooling water tank side water circuit are connected in series by 50%. 4) An opening degree of 4 indicates that the battery water circuit and the cooling water tank side water circuit are connected in series for 75%; 5) An opening of 5 indicates that the battery water circuit and the cooling water tank side water circuit are connected in series by 100%.

[0038] 25%, 50%, 75%, and 100% represent the proportion of the water flow area after the waterways on both sides are connected.

[0039] Correspondingly, When the battery inlet water temperature T3 measured by the battery inlet water temperature sensor 15 satisfies T3 < T-5℃, the proportional control valve 12 will decrease its opening by 1 degree accordingly. When the battery inlet water temperature T3 measured by the battery inlet water temperature sensor 15 satisfies T3 > T, the proportional control valve 12 will increase its opening by 1 degree accordingly. After each action is completed, hold for 60 seconds before proceeding to the next judgment process.

[0040] [Second Embodiment] The second embodiment of the present invention also provides a control method for a battery water-cooled unit system mentioned in the first embodiment, comprising the following steps: S1: The system receives a working mode request from the power battery 16; S2: Based on the request received from the power battery, the system switches between four operating modes—battery self-circulation, heating, refrigerant cooling, and natural air cooling—by controlling the compressor 1, PTC heater 14, and proportional control valve 12. S21: When the power battery 16 sends a self-circulation request, the system enters the battery self-circulation working mode; at this time, the proportional control valve 12 controls the disconnection between the battery side water circuit and the radiator side water circuit, the second water pump 17 is started, the PTC heater 14 remains in the off state, the compressor 1 remains in the off state, and the electronic expansion valve 4 remains in the default opening state. S22: When the power battery 16 sends a heating request, the system enters the heating working mode; at this time, the proportional control valve 12 controls the disconnection between the battery side water circuit and the radiator side water circuit, the second water pump 17 is started, the PTC heater 14 outputs according to the preset heating power, the compressor 1 remains in the off state, and the electronic expansion valve 4 remains at the default opening. S23: When the power battery 16 sends a cooling request, the system compares the real-time detection result T4 of the external circulation water temperature sensor 13 with the target water temperature T of the battery to determine whether the system enters the refrigerant cooling working mode or the natural air cooling working mode.

[0041] S231: If the comparison result of the real-time detection result T4 of the external circulation water temperature sensor 13 and the target water temperature T of the battery satisfies T4≤T-5℃, then the system is judged to enter the natural air cooling working mode; at this time, the proportional control valve 12 controls the connection between the water circuit on the battery side and the water circuit on the radiator side, the second water pump 17 is started, the PTC heater 14 is kept in the closed state, the compressor 1 is kept in the closed state, and the electronic expansion valve 4 is kept at the default opening degree; at this time, only the radiator 9 and the cooling fan 10 are used to cool the power battery 16, and the water temperature entering the power battery 16 is controlled by adjusting the opening ratio of the proportional control valve 12. S232: If the comparison result of the real-time detection result T4 of the external circulation water temperature sensor 13 and the target water temperature T of the battery does not meet the condition T4≤T-5℃, then the system is judged to enter the refrigerant cooling working mode; at this time, the proportional control valve 12 controls the disconnection between the water circuit on the battery side and the water circuit on the heat sink side, the second water pump 17 is started, the PTC heater 14 is kept closed, the compressor 1 is started, and the opening of the electronic expansion valve 4 is adjusted.

[0042] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A battery water-cooled unit system, characterized in that: The system includes a refrigerant system, a battery-side water circuit, and a radiator-side water circuit. The battery-side water circuit is connected to one side of the refrigerant system, and the radiator-side water circuit is connected to the other side of the refrigerant system. The battery-side water circuit and the radiator-side water circuit are connected in an optional manner. The refrigerant system includes a compressor (1), the outlet of which is connected to the refrigerant side inlet of the condenser heat exchange plate (3), the refrigerant side outlet of the condenser heat exchange plate (3) is connected to the inlet of the electronic expansion valve (4), the outlet of the electronic expansion valve (4) is connected to the refrigerant inlet of the evaporator heat exchange plate (5), and the refrigerant outlet of the evaporator heat exchange plate (5) is connected to the inlet of the compressor (1) via a gas-liquid separator (7); a high-pressure sensor (2) is connected between the outlet of the compressor (1) and the refrigerant side inlet of the condenser heat exchange plate (3), and a temperature and pressure sensor (6) is connected between the refrigerant outlet of the evaporator heat exchange plate (5) and the inlet of the gas-liquid separator (7); The battery-side water circuit includes a second water pump (17). The outlet of the second water pump (17) is connected to the coolant inlet of the evaporator heat exchange plate (5). The coolant outlet of the evaporator heat exchange plate (5) is connected to the inlet of the PTC heater (14) via a proportional control valve (12). The outlet of the PTC heater (14) is connected to the coolant inlet of the power battery (16). The coolant outlet of the power battery (16) is connected to the inlet of the second water pump (17). A battery inlet water temperature sensor (15) is connected between the outlet of the PTC heater (14) and the coolant inlet of the power battery (16). A battery outlet water temperature sensor (18) is connected between the outlet of the second water pump (17) and the coolant inlet of the evaporator heat exchange plate (5). The side water circuit of the heat dissipation tank includes a first water pump (11). The outlet of the first water pump (11) is connected to the coolant inlet of the condenser heat exchange plate (3) via a proportional control valve (12). The coolant outlet of the condenser heat exchange plate (3) is connected to the inlet of the drive system heat exchanger (8). The outlet of the drive system heat exchanger (8) is connected to the inlet of the heat dissipation tank (9). A cooling fan (10) is provided on one side of the heat dissipation tank (9). The outlet of the heat dissipation tank (9) is connected to the inlet of the first water pump (11). An external circulating water temperature sensor (13) is also connected between the proportional control valve (12) and the coolant inlet of the condenser heat exchange plate (3). Heat exchange can be achieved between the refrigerant flow path formed between the refrigerant inlet and refrigerant outlet of the evaporator heat exchange plate (5) and the coolant flow path formed between the coolant inlet and coolant outlet of the evaporator heat exchange plate (5). Heat exchange can be achieved between the refrigerant flow path formed between the refrigerant inlet and refrigerant outlet of the condenser heat exchange plate (3) and the coolant flow path formed between the coolant inlet and coolant outlet of the condenser heat exchange plate (3). The proportional control valve (12) can control the connection or disconnection between the battery-side water circuit and the heat dissipation tank-side water circuit, and can adjust the ratio of the cross-flow area between the two when they are connected. The system receives requests from the power battery and controls the compressor (1), PTC heater (14), and proportional control valve (12) to switch between four working modes: battery self-circulation, heating, refrigerant cooling, and natural air cooling.

2. The battery water-cooled unit system according to claim 1, characterized in that: When the power battery (16) sends a self-circulation request, the system enters the battery self-circulation working mode; When the power battery (16) sends a heating request, the system enters the heating working mode; When the power battery (16) sends a cooling request, the system compares the real-time detection result T4 of the external circulation water temperature sensor (13) with the target water temperature T of the battery to determine whether the system enters the refrigerant cooling working mode or the natural air cooling working mode.

3. The battery water-cooled unit system according to claim 2, characterized in that: When the power battery (16) sends a cooling request: If the comparison between the real-time detection result T4 of the external circulating water temperature sensor (13) and the target water temperature T of the battery satisfies T4≤T-5℃, then the system is judged to enter the natural air cooling working mode; otherwise, the system is judged to enter the refrigerant cooling working mode.

4. The battery water-cooled unit system according to claim 3, characterized in that: The system can switch between natural air cooling mode and refrigerant cooling mode in the following manner: When the system is operating in natural air cooling mode, if the comparison result of the real-time detection result T4 of the external circulating water temperature sensor (13) and the target water temperature T of the battery satisfies T4≤T-5℃, the system will switch from natural air cooling mode to refrigerant cooling mode; otherwise, the system will continue to operate in the current natural air cooling mode. When the system is operating in refrigerant cooling mode, if the comparison result of the real-time detection result T4 of the external circulating water temperature sensor (13) and the target water temperature T of the battery satisfies T4≤T-10℃, the system will switch from refrigerant cooling mode to natural air cooling mode; otherwise, the system will continue to operate in the current refrigerant cooling mode.

5. A battery water-cooled unit system according to claim 1, characterized in that: When the system is in battery self-circulation mode, the proportional control valve (12) controls the disconnection between the battery side water circuit and the radiator side water circuit. At this time, the second water pump (17) is started, the PTC heater (14) is kept off, the compressor (1) is kept off, and the electronic expansion valve (4) is kept at the default opening.

6. The battery water-cooled unit system according to claim 1, characterized in that: When the system is in heating mode, the proportional control valve (12) controls the disconnection between the battery side water circuit and the heat dissipation tank side water circuit. At this time, the second water pump (17) is started, the PTC heater (14) outputs according to the preset heating power, the compressor (1) remains closed, and the electronic expansion valve (4) remains open by default. The heating power P of the PTC heater (14) satisfies: ; in, The difference between the battery inlet water temperature T3 detected by the battery inlet water temperature sensor (15) and the battery target water temperature T when the system is operating in heating mode; that is... .

7. A battery water-cooled unit system according to claim 1, characterized in that: When the system is working in refrigerant refrigeration mode, the proportional control valve (12) controls the disconnection between the battery side water circuit and the heat dissipation tank side water circuit. At this time, the second water pump (17) is started, the PTC heater (14) is kept closed, the compressor (1) is started, and the opening of the electronic expansion valve (4) is adjusted. The rotational speed N of the compressor (1) satisfies: ; in, The difference between the battery inlet water temperature T3 detected by the battery inlet water temperature sensor (15) and the battery target water temperature T when the system is operating in refrigerant cooling mode is denoted as T3. p is the proportional control coefficient; k is the integral control coefficient; and both satisfy 1500RPM≤N≤8000RPM. The opening degree K of the electronic expansion valve (4) satisfies: ; in, The temperature is measured by the temperature and pressure sensor (6); The pressure measured by the temperature and pressure sensor (6) is converted into the refrigerant temperature in the two-phase region under that pressure; for and The difference; and simultaneously satisfy 66 steps ≤ K ≤ 500 steps.

8. A battery water-cooled unit system according to claim 1, characterized in that: When the system is in natural air cooling mode, the proportional control valve (12) controls the connection between the battery side water circuit and the radiator side water circuit. At this time, the second water pump (17) is started, the PTC heater (14) is kept off, the compressor (1) is kept off, and the electronic expansion valve (4) is kept at the default opening. At this time, the power battery (16) is cooled only by the radiator (9) and the cooling fan (10).

9. A battery water-cooled unit system according to claim 7, characterized in that: When the system is operating in natural air cooling mode, the water temperature entering the power battery (16) is controlled by adjusting the opening ratio of the proportional control valve (12). The proportional control valve (12) has the following five opening modes: 1) Opening degree 1 indicates that the battery water circuit is completely disconnected from the water circuit on the cooling water tank side; 2) An opening degree of 2 indicates that the battery water circuit is connected in series with the cooling water tank side water circuit by 25%. 3) An opening degree of 3 indicates that the battery water circuit and the cooling water tank side water circuit are connected in series by 50%. 4) An opening degree of 4 indicates that the battery water circuit and the cooling water tank side water circuit are connected in series for 75%; 5) An opening degree of 5 indicates that the battery water circuit and the cooling water tank side water circuit are connected in series by 100%; 25%, 50%, 75%, and 100% represent the proportion of the water flow area after the waterways on both sides are connected in series. When the battery inlet water temperature T3 measured by the battery inlet water temperature sensor (15) satisfies T3 < T-5℃, the proportional control valve (12) will decrease its opening by 1 degree accordingly. When the battery inlet water temperature T3 measured by the battery inlet water temperature sensor (15) satisfies T3>T, the proportional control valve (12) will increase its opening by 1 degree accordingly. After each action is completed, hold for 60 seconds before proceeding to the next judgment process.

10. A control method for a battery water-cooled unit system according to any one of claims 1-9, characterized in that: Includes the following steps: S1: The system receives a working mode request from the power battery (16); S2: Based on the request received from the power battery, the system switches between four working modes—battery self-circulation, heating, refrigerant cooling, and natural air cooling—by controlling the compressor (1), PTC heater (14), and proportional control valve (12). S21: When the power battery (16) sends a self-circulation request, the system enters the battery self-circulation working mode; at this time, the proportional control valve (12) controls the disconnection between the battery side water circuit and the radiator side water circuit, and the second water pump (17) is started, the PTC heater (14) is kept off, the compressor (1) is kept off, and the electronic expansion valve (4) is kept at the default opening. S22: When the power battery (16) sends a heating request, the system enters the heating working mode; at this time, the proportional control valve (12) controls the disconnection between the battery side water circuit and the heat sink side water circuit. At this time, the second water pump (17) is started, the PTC heater (14) outputs according to the preset heating power, the compressor (1) remains closed, and the electronic expansion valve (4) remains open by default. S23: When the power battery (16) sends a cooling request, the system compares the real-time detection result T4 of the external circulation water temperature sensor (13) with the target water temperature T of the battery to determine whether the system enters the refrigerant cooling working mode or the natural air cooling working mode. S231: If the comparison result of the real-time detection result T4 of the external circulation water temperature sensor (13) and the target water temperature T of the battery satisfies T4≤T-5℃, then the system is judged to enter the natural air cooling working mode; at this time, the proportional control valve (12) controls the connection between the water circuit on the battery side and the water circuit on the heat sink side. At this time, the second water pump (17) is started, the PTC heater (14) is kept closed, the compressor (1) is kept closed, and the electronic expansion valve (4) is kept at the default opening. At this time, the power battery (16) is cooled only by the heat sink (9) and the cooling fan (10). The water temperature of the power battery (16) is controlled by adjusting the opening ratio of the proportional control valve (12). S232: If the real-time detection result T4 of the external circulation water temperature sensor (13) does not meet the comparison result of the battery target water temperature T, the system is judged to enter the refrigerant cooling working mode. At this time, the proportional control valve (12) controls the disconnection between the battery side water circuit and the heat dissipation tank side water circuit. At this time, the second water pump (17) is started, the PTC heater (14) is kept closed, the compressor (1) is started, and the opening of the electronic expansion valve (4) is adjusted.

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