Immersed battery thermal management system and control method

Abstract

The invention provides an immersed battery thermal management system and a control method. The system comprises a battery, a circulating system and a temperature control system, wherein the battery comprises a battery box body as well as a battery module and a cooling medium which are positioned in the battery box body; the battery module is immersed in the cooling medium and comprises a plurality of battery cells; the circulating system comprises a circulating pump and a storage tank used for storing a cooling medium, the battery, the circulating pump and the storage tank are connected through a first pipeline to form a first circulating loop, and the circulating pump is arranged on the first pipeline; the temperature control system comprises a controller and a temperature sensor for acquiring the temperature of each battery cell, and the controller is connected with the temperature sensor and the circulating pump; the controller is configured to obtain the temperature value of each battery cell, and obtain the maximum temperature value Tmax and the temperature difference value Tdiff; and according to the maximum temperature value Tmax and the temperature difference value Tdiff, the working state of the circulating pump is controlled. Balanced and efficient heat dissipation of the battery module can be achieved, and the energy-saving requirement of the system can be met.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of energy storage, and in particular to an immersed battery thermal management system and a control method. BACKGROUND

[0002] At present, lithium ion batteries are widely used in electrical equipment (for example, vehicles or energy storage power stations) due to their high energy density, long cycle life and other advantages. However, the performance, life and safety of lithium ion batteries need to rely on the working temperature.

[0003] In related technologies, a liquid cooling plate is usually arranged at the bottom of the battery module to exchange heat with the battery module, but the above heat exchange mode has an uneven heat exchange capacity, which leads to uneven temperature at the top and bottom of the battery module, affecting the performance of the battery module. Therefore, the immersed liquid cooling technology emerges as the times require, that is, the battery module is directly immersed in the liquid coolant to realize all-around heat exchange of the battery module.

[0004] However, the current immersed liquid cooling mode is difficult to balance the demand for efficient heat dissipation and energy saving. SUMMARY

[0005] In view of the above problems, embodiments of the present application provide an immersed battery thermal management system and a control method, which can balance the demand for efficient heat dissipation and energy saving.

[0006] In order to achieve the above purpose, embodiments of the present application provide the following technical solutions:

[0007] In a first aspect, the present application provides an immersed battery thermal management system, which comprises:

[0008] a battery, comprising a battery box, a battery module and a cooling medium in the battery box; wherein the battery module is immersed in the cooling medium and comprises a plurality of battery cells;

[0009] a circulation system, comprising a circulating pump and a storage tank for storing the cooling medium, the battery, the circulating pump and the storage tank being connected by a first pipeline to form a first circulation loop, the circulating pump being arranged on the first pipeline and being used to drive the circulation of the cooling medium;

[0010] a temperature control system, comprising a controller and a temperature sensor for acquiring the temperature of each battery cell, the controller being connected with the temperature sensor and the circulating pump;

[0011] The controller is configured to:

[0012] acquire the temperature value of each battery cell and obtain the maximum temperature value T max and the temperature difference value Tdiff ;

[0013] according to the maximum temperature value T max and the temperature difference value T diff , control the working state of the circulating pump, the working state including the start-stop state of the circulating pump and the gear adjustment of the circulating pump.

[0014] In a possible implementation, further comprising a control valve and a condenser, the battery, the condenser and the storage tank are connected through a second pipeline to form a second circulation loop, the control valve is arranged on the second pipeline and connected with the controller, and the controller is further configured to:

[0015] according to the maximum temperature value T max and a preset threshold, control the working state of the control valve to start or close the second circulation loop.

[0016] In a possible implementation, further comprising a first heat exchanger, the first heat exchanger is arranged on the first circulation loop and used for heat exchange with the cooling medium in the first pipeline;

[0017] and / or, further comprising a second heat exchanger, the second heat exchanger is connected with the storage tank and used for heat exchange with the cooling medium in the storage tank.

[0018] In a possible implementation, the cooling medium comprises a mixture of a base liquid and nanoparticles, and the nanoparticles comprise at least one of aluminum oxide and boron nitride.

[0019] In a possible implementation, the controller is further configured to:

[0020] according to the maximum temperature value T max satisfying a first condition and the temperature difference value T diff satisfying a second condition, control the circulating pump to be in a stop state; or,

[0021] according to the maximum temperature T max satisfying a first condition and the temperature difference value T diff not satisfying a second condition, control the circulating pump to be in a start state and at a first gear.

[0022] In a possible implementation, the controller is further configured to:

[0023] according to the maximum temperature value T max satisfying a third condition and the temperature difference value T diff satisfying a second condition, control the circulating pump to be in a start state and at a first gear; or,

[0024] According to the maximum temperature value T max satisfies a third condition, and the temperature difference value T diff does not satisfy the second condition, the circulating pump is controlled to be in an open state and in a second gear;

[0025] Among the third condition, the maximum temperature T max is greater than the maximum value T max in the first condition, and the second gear is greater than the first gear.

[0026] In a possible implementation, the controller is further configured to:

[0027] According to the maximum temperature value T max satisfies a fourth condition, and the temperature difference value T diff satisfies the second condition, the circulating pump is controlled to be in an open state and in a second gear; or,

[0028] According to the maximum temperature value T max satisfies a fourth condition, and the temperature difference value T diff does not satisfy the second condition, the circulating pump is controlled to be in an open state and in a third gear;

[0029] Among the fourth condition, the maximum temperature T max is greater than the maximum value T max in the third condition, and the third gear is greater than the second gear.

[0030] In a possible implementation, the controller is further configured to:

[0031] According to the maximum temperature value T max satisfies a fifth condition, the battery module is controlled to stop power supply, and the fifth condition is a preset threshold.

[0032] In a second aspect, the embodiments of the present application provide a control method for a submerged thermal management system, including the following steps:

[0033] Obtaining temperature values of each cell to obtain a plurality of temperature values;

[0034] According to the plurality of temperature values, a maximum temperature value T max and a temperature difference value T diff are determined.

[0035] According to the maximum temperature value T max and the temperature difference value T diff , the working state of the circulating pump of the submerged battery thermal management system is controlled, and the working state includes the start-stop state of the circulating pump and the gear adjustment of the circulating pump.

[0036] In a possible implementation, the method further includes:

[0037] According to the maximum temperature value T max satisfies a first condition, and the temperature difference value T diff satisfies a second condition, controlling the circulating pump to be in a stop state; or,

[0038] According to the maximum temperature T max satisfies a first condition, and the temperature difference value T diff does not satisfy a second condition, controlling the circulating pump to be in an open state and at a first gear.

[0039] In a possible implementation, the method further includes:

[0040] According to the maximum temperature value T max satisfies a third condition, and the temperature difference value T diff satisfies a second condition, controlling the circulating pump to be in an open state and at a first gear; or,

[0041] According to the maximum temperature value T max satisfies a third condition, and the temperature difference value T diff does not satisfy a second condition, controlling the circulating pump to be in an open state and at a second gear.

[0042] In the third condition, the maximum temperature T max is greater than the maximum value T max in the first condition, and the second gear is greater than the first gear.

[0043] In a possible implementation, the method further includes:

[0044] According to the maximum temperature value T max satisfies a fourth condition, and the temperature difference value T diff satisfies a second condition, controlling the circulating pump to be in an open state and at a second gear; or,

[0045] According to the maximum temperature value T max satisfies a fourth condition, and the temperature difference value T diff does not satisfy a second condition, controlling the circulating pump to be in an open state and at a third gear.

[0046] In the fourth condition, the maximum temperature T max is greater than the maximum value T max in the third condition, and the third gear is greater than the second gear.

[0047] In a possible implementation, the method further includes:

[0048] According to the maximum temperature value T max The fifth condition is met, the battery module is controlled to stop power supply, and the control valve of the immersion battery thermal management system is controlled to open to start the second circulating loop.

[0049] The immersion battery thermal management system and the control method provided by the embodiments of the present application can improve the temperature uniformity of the battery module by immersing the battery module in the cooling medium, thereby improving the performance of the battery and prolonging the service life of the battery.

[0050] In addition, the controller controls the working state of the circulating pump according to the maximum temperature value T max and the temperature difference T diff , including the start-stop state of the circulating pump and the gear adjustment of the circulating pump. In this way, according to the real-time temperature of the battery module, it can be determined when the circulating pump is started, and in the started state, the gear of the circulating pump is adjusted, so that when the temperature of the battery module is low and does not need to be cooled, the circulating pump can be in a stopped state, reducing unnecessary energy consumption; when the temperature rises to the point where cooling is needed, the circulating pump is started in time for cooling. And in the started state, according to the maximum temperature value T max and the temperature difference T diff , the gear of the circulating pump is adjusted according to the double judgment conditions, which can effectively reduce the overall energy consumption of the system and improve the energy utilization efficiency, so as to ensure that the immersion battery management system can balance the high-efficiency cooling efficiency and energy-saving demand.

[0051] In addition to the technical problems solved by the embodiments of the present application, the technical features constituting the technical solutions and the beneficial effects brought by these technical features, the other technical problems solved by the immersion battery thermal management system and the control method provided by the embodiments of the present application, the other technical features included in the technical solutions and the beneficial effects brought by these technical features will be further described in detail in the specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0053] Figure 1 The schematic diagram of the immersion battery thermal management system provided by the embodiments of the present application;

[0054] Figure 2 A schematic diagram of a battery provided for an embodiment of the present application;

[0055] Figure 3 A flowchart of a control method of an immersion battery thermal management system provided for an embodiment of the present application;

[0056] Figure 4 A control logic diagram of a control method of an immersion battery thermal management system provided for an embodiment of the present application.

[0057] Explanation of reference signs:

[0058] 100: battery; 110: battery box; 111: box; 112: box cover; 113: sealing element; 120: battery module;

[0059] 200: circulation system; 210: circulation pump; 220: storage tank; 230: first pipeline; 240: control valve; 250: condenser; 260: second pipeline; 270: three-way valve; 280: first heat exchanger; 290: second heat exchanger;

[0060] 300: temperature control system; 310: controller; 320: temperature sensor; 330: data acquisition instrument. DETAILED DESCRIPTION

[0061] In the related art, in order to improve the temperature uniformity of the battery module, the immersion liquid cooling technology is usually used to cool the battery module. However, the control logic of the current immersion liquid cooling technology is unreasonable, which leads to the inability to simultaneously balance the efficient heat dissipation and energy saving requirements.

[0062] In view of the above technical problems, the embodiments of the present application provide an immersion battery thermal management system and a control method. By immersing the battery module in the cooling medium, each surface of the battery module can contact the cooling medium, thereby improving the temperature uniformity of the battery module, and further improving the performance of the battery and prolonging the service life of the battery.

[0063] In addition, the controller controls the working state of the circulation pump according to the maximum temperature value T max and the temperature difference value T diff , the working state including the start-stop state of the circulation pump and the gear adjustment of the circulation pump. According to the real-time temperature of the battery module, it is adjusted when the circulation pump is started, and in the started state, the gear of the circulation pump is adjusted. In this way, when the temperature of the battery module is low and no heat dissipation is needed, the circulation pump can be in a stopped state, reducing unnecessary energy consumption; when the temperature rises to the need for heat dissipation, the circulation pump is started in time for cooling. And in the started state, according to the maximum temperature value T max and the temperature difference value Tdiff The double judgment condition reasonably adjusts the gear of the circulating pump, which can effectively reduce the overall energy consumption of the system, improve the energy utilization efficiency, so as to ensure that the immersed battery management system can balance the high heat dissipation efficiency and energy saving demand.

[0064] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more apparent, clear and easy to understand, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0065] The embodiments of the present application provide an immersed battery thermal management system for cooling the battery so that the battery is in a suitable temperature range.

[0066] Please refer to Figure 1 and Figure 2 The immersed battery thermal management system includes a battery 100, and the battery 100 includes a battery box body 110, which is used as a bearing component of the battery 100 and provides a mounting carrier for a battery module 120 and a cooling medium (not shown in the figure).

[0067] The battery box body 110 includes a box body 111 with an opening and a box cover 112, and the box cover 112 is connected with the box body 111 and covers the opening of the box body 111. It should be noted that a sealing element 113 is arranged between the box body 111 and the box cover 112, which can realize the sealing of the battery box body 110 by using the sealing element 113, so as to avoid the overflow of the cooling medium.

[0068] Please continue to refer to Figure 2 The battery 100 further includes the battery module 120 and a heat exchange medium, and the battery module 120 is arranged in the battery box body 110, and the heat exchange medium is filled in the battery box body 110, so as to ensure that the battery module 120 is immersed in the heat exchange medium. In this way, each surface of the battery module 120 can contact the cooling medium, which improves the temperature balance of the battery module, effectively avoids the inconsistent problem of battery performance caused by local high or low temperature, and further improves the performance of the battery and prolongs the service life of the battery.

[0069] Please continue to refer to Figure 1 The immersed battery thermal management system further includes a circulating system 200, and the circulating system 200 includes a circulating pump 210 and a storage tank 220, wherein the storage tank 220 is used to store the cooling medium, so as to ensure that the battery box body 110 always has cooling medium with suitable temperature.

[0070] The circulating pump 210, the storage tank 220 and the battery 100 can be connected through the first pipeline 230 to form a first circulation loop, and the circulating pump 210 is arranged on the first pipeline 230 and is used to drive the circulation of the cooling medium, so that the circulation of the cooling medium in the storage tank 220 and the cooling medium in the battery box 110 can be ensured, and the cooling medium in the battery box 110 can be ensured to be always in a suitable temperature range.

[0071] Please refer to Figure 1 The battery box 110 has a first liquid inlet and a first liquid outlet, and the first pipeline 230 is used to connect the first liquid inlet and the second liquid outlet of the storage tank 220 and connect the first liquid outlet and the second liquid inlet of the storage tank 220, so as to realize the connection between the battery box 110 and the storage tank 220.

[0072] The immersion type battery thermal management system further comprises a temperature control system 300, and the temperature control system 300 comprises a controller 310 and a plurality of temperature sensors 320. The temperature sensors 320 are used to obtain the temperature of each battery cell, so as to obtain the temperature of each battery cell in real time. It should be noted that the temperature sensors 320 can be arranged on the end surface of the battery cell in the length direction.

[0073] The controller 310 is connected with the temperature sensors 320 and the circulating pump 210, so that the controller 310 can also control the working state of the circulating pump 210 according to the temperature sensors 320.

[0074] Exemplarily, the controller 310 is configured to:

[0075] obtain the temperature value of each battery cell and obtain the maximum temperature value T max and the temperature difference value T diff .

[0076] According to the maximum temperature value T max and the temperature difference value T diff , the working state of the circulating pump 210 is controlled, and the working state includes the start-stop state of the circulating pump 210 and the gear adjustment of the circulating pump 210.

[0077] It should be noted that the transmission of the temperature value of each battery cell can be directly realized by the temperature sensor 320, or other implementation manners can also be used. Exemplarily, the temperature control system further comprises a data acquisition instrument 330 connected with the controller 310 and the temperature sensor 320. The data acquisition instrument 330 has powerful data receiving, integration and transmission functions, and can simultaneously receive temperature signals from multiple temperature sensors 320. After receiving these signals, the data acquisition instrument 330 will preprocess the data, such as filtering, amplifying and the like, to eliminate noise interference and improve the accuracy and reliability of the data. After preprocessing, the data acquisition instrument 330 will package and arrange the data according to the format and protocol recognizable by the controller 310, and then transmit the arranged temperature data to the controller 310 quickly and accurately through wired or wireless communication.

[0078] The controller according to the maximum temperature value T max and the temperature difference value T diff controls the working state of the circulating pump, and the working state includes the start-stop state of the circulating pump and the gear adjustment of the circulating pump. According to the real-time temperature of the battery module, it is adjusted when the circulating pump is started, and in the state of starting, the gear of the circulating pump is adjusted.

[0079] In this way, when the temperature of the battery module is low and no heat dissipation is needed, the circulating pump can be in a stopped state, reducing unnecessary energy consumption; when the temperature rises to the need for heat dissipation, the circulating pump is started in time for cooling. In addition, in the state of starting, the controller adjusts the gear of the circulating pump according to parameters such as the maximum temperature value T max and the temperature difference value T diff , which can effectively reduce the overall energy consumption of the system and improve the energy utilization efficiency, so as to ensure that the immersed battery management system can balance the high-efficiency heat dissipation efficiency and energy-saving demand.

[0080] At the same time, taking the maximum temperature value T max and the temperature difference value T diff as double judgment standards, the controller 310 can comprehensively consider the overall temperature level and internal temperature uniformity of the battery module, avoiding the one-sidedness that may be caused by single index judgment, so as to realize more accurate and comprehensive control of the battery thermal management system.

[0081] In one possible implementation, the immersed battery thermal management system further comprises a control valve 240 and a condenser 250, the battery 100, the condenser 250 and the storage tank 220 are connected through a second pipeline 260 to form a second circulation loop, and the control valve 240 is arranged on the second pipeline 260 and connected with the controller 310.

[0082] It should be noted that the start or stop of the second circulation loop needs to be determined according to the maximum temperature value T max The controller 310 is further configured to determine, for example, that the maximum temperature value T

[0083] According to the maximum temperature value T max and a preset threshold value, the working state of the control valve 240 of the immersed battery thermal management system is controlled to start or stop the second circulation loop. The preset threshold value is the maximum safe value that the battery cell can withstand. If the temperature exceeds this value, the battery cell is at risk of thermal runaway.

[0084] In some embodiments, when the maximum temperature value T max is greater than the preset threshold value, the controller 310 controls the control valve 240 of the immersed battery thermal management system to be in a start state, at which time the second circulation loop is started. Since the temperature of the battery cell is high, it is easy to cause some of the cooling medium located in the battery box 110 to vaporize. At this time, the condenser 250 is used to convert the vaporized cooling medium into low-temperature liquid cooling medium, so as to ensure the temperature of the cooling medium. It should be noted that, in this step, in order to ensure the safety of the battery 100, the controller 310 can control the battery module 120 to be powered off at this stage.

[0085] In other embodiments, when the maximum temperature value T max is less than the preset threshold value, the controller 310 controls the control valve 240 of the immersed battery thermal management system to be in a stop state, at which time the second circulation loop is not started, and the first circulation loop is still used to cool the battery module 120.

[0086] It should be understood that the first pipeline 230 and the second pipeline 260 can partially overlap, and a three-way valve 270 is arranged at the intersection of the first pipeline 230 and the second pipeline 260, so that the start or stop of the first circulation loop and the second circulation loop can be freely controlled.

[0087] In one possible implementation, the immersed battery thermal management system further comprises a first heat exchanger 280, which is arranged on the first circulation loop and is used to exchange heat with the cooling medium in the first pipeline 230 to reduce the temperature of the cooling medium, thereby improving the heat exchange efficiency between the cooling medium and the battery module 120 and improving the service life and safety of the battery module 120.

[0088] And / or, the immersed battery thermal management system further comprises a second heat exchanger 290, which is connected with the storage tank 220 and is used to exchange heat with the cooling medium in the storage tank 220 to reduce the temperature of the cooling medium in the storage tank 220.

[0089] The second heat exchanger 290 can be connected to the storage tank 220 in various ways. For example, the second heat exchanger 290 is arranged at one side of the storage tank 220 and connected to the storage tank 220 through a pipeline. For another example, the second heat exchanger 290 is arranged in the storage tank 220, or the second heat exchanger 290 is a condensing coil, so as to reduce the temperature of the cooling medium in the storage tank 220 to the greatest extent.

[0090] In a possible implementation, the cooling medium includes a mixture of a base liquid and nanoparticles, and the nanoparticles include at least one of aluminum oxide and boron nitride. In some embodiments, the base liquid can be a conventional fluorocarbon liquid, and when the nanoparticles include aluminum oxide or boron nitride, the content of aluminum oxide or boron nitride accounts for 20%-50%. In some embodiments, when the nanoparticles include a mixture of aluminum oxide and boron nitride, the respective contents of aluminum oxide and boron nitride can be freely set as long as the content of the nanoparticles is ensured to be 20%-50%.

[0091] The base liquid is modified by the nanoparticles, the thermal conductivity of the cooling medium is improved, the heat dissipation efficiency of the cooling medium is further enhanced, the cooling efficiency of the system is improved, the efficient heat dissipation of the battery module is achieved, and a foundation is laid for high-rate fast charging of the battery.

[0092] In addition, in the embodiment, the battery module 120 is directly immersed in the cooling medium, compared with the technical solution of the liquid cooling plate in the related art, the complex cooling channel, the liquid cooling plate, and the structural design of the liquid cooling plate and the battery are omitted, the lightweight design of the system structure is achieved, and in addition, the cooling liquid directly contacts the battery pack, so that the system is more compact, and the volume and weight of the system are reduced.

[0093] The concentration of the nanoparticles in the cooling medium can be different in a direction perpendicular to the bottom wall of the box body 111, for example, the concentration of the nanoparticles in the bottom layer is greater than the concentration of the nanoparticles in the top layer, so that a thermal conductivity gradient is formed, and the heat dissipation efficiency of the cooling medium is improved.

[0094] In a possible implementation, the controller 310 is further configured to:

[0095] According to the maximum temperature value T max satisfies the first condition, and the temperature difference value T diff satisfies the second condition, the circulating pump is in a stopped state. The temperature difference value T diff = T max -T min .

[0096] In the embodiment, the first condition is that T max is less than 35℃, and the second condition is that the temperature difference value T diffless than 6°C. When the maximum temperature value T max less than 35°C, and the temperature difference value T diff less than 6°C, which indicates that the temperature of the battery module 120 meets the actual requirement. At this time, the circulating pump 210 can be turned off, so that the cooling medium in the tank 111 is in a static state. This effectively avoids the unnecessary continuous operation of the circulating pump 210, greatly saves the energy consumed by the operation of the circulating pump 210, and reduces the operation cost of the immersion battery thermal management system.

[0097] Alternatively, when the maximum temperature value T max less than 35°C, and the temperature difference value T diff greater than 6°C, which indicates that the temperatures of the battery cells are not balanced, and some battery cells can have a temperature that is too high. Accordingly, the circulating pump 210 is controlled to be in an open state and located at a first gear. The first gear can be the lowest gear of the circulating pump 210. In this way, the cooling medium in the battery tank 110 can be circulated at a small flow rate, which can preliminarily adjust the temperature imbalance and promote the uniform distribution of heat, and can also avoid unnecessary energy waste caused by too large a flow rate.

[0098] It should be noted that when the maximum temperature value T max less than 35°C, and the temperature difference value T diff greater than 6°C, the circulating pump 210 can be turned on at all times or can be maintained for a first running duration and then turned off when the temperature difference value T diff less than 6°C. The first running duration can be freely set according to the actual cooling condition.

[0099] In one possible implementation, the controller 310 is further configured to:

[0100] when the maximum temperature value T max satisfies a third condition, and the temperature difference value T diff satisfies a second condition, control the circulating pump to be in an open state and located at a first gear; or

[0101] when the maximum temperature value T max satisfies the third condition, and the temperature difference value T diff does not satisfy the second condition, control the circulating pump to be in an open state and located at a second gear.

[0102] The third condition is that the maximum temperature T max is greater than the maximum value T max in the first condition, and the second gear is greater than the first gear. For example, the third condition is that the maximum temperature T max is greater than 35°C and less than 50°C.

[0103] It should be noted that the rotation speed of the second gear of the circulating pump 210 is greater than the rotation speed of the first gear of the circulating pump 210. In this way, when the maximum temperature value T max When the third condition is met, it can be determined again whether the temperature difference T diff satisfies the second condition, and the gear of the circulating pump 210 is reasonably set. For example, when the temperature difference T diff satisfies the second condition, the circulating pump is controlled to be in an open state and located at the first gear; or, when the temperature difference T diff does not satisfy the second condition, the circulating pump is controlled to be in an open state and located at the second gear. In this way, by reasonably setting the rotation speed of the circulating pump 210, it can be avoided that the flow is too large or too small, and thus unnecessary energy waste or insufficient cooling capacity is prevented.

[0104] It should be noted that when the circulating pump 210 is in the second gear, it can be always turned on, or it can be maintained for a second running duration, and then when the temperature difference T diff is less than 6℃, the circulating pump 210 can stop running, wherein the second running duration can be freely set according to the actual cooling situation, and the second running duration can be equal to the first running duration.

[0105] In one possible implementation, the controller is further configured to:

[0106] According to the fourth condition that the maximum temperature value T max satisfies, and the second condition that the temperature difference T diff satisfies, the circulating pump is controlled to be in an open state and located at the second gear; or,

[0107] According to the fourth condition that the maximum temperature value T max satisfies, and the second condition that the temperature difference T diff does not satisfy, the circulating pump is controlled to be in an open state and located at the third gear;

[0108] Wherein, the maximum temperature T max in the fourth condition is greater than the maximum value T max in the third condition, and the third gear is greater than the second gear.

[0109] For example, the fourth condition is that the maximum temperature T max is greater than 50℃ and less than 65℃. The rotation speed of the third gear of the circulating pump 210 is greater than the rotation speed of the second gear of the circulating pump 210. In this way, when the maximum temperature value T max satisfies the fourth condition, it can be determined again whether the temperature difference T diff satisfies the second condition, and the gear of the circulating pump 210 is reasonably set. For example, when the temperature difference T diff satisfies the second condition, the circulating pump is controlled to be in an open state and located at the second gear; or, when the temperature difference Tdiff If the second condition is not met, the circulating pump is controlled to be in the open state and be located at the third gear. In this way, by reasonably setting the rotating speed of the circulating pump 210, it is possible to avoid excessive or insufficient flow, thereby preventing unnecessary energy waste or insufficient cooling capacity.

[0110] It should be noted that when the circulating pump 210 is in the second gear, it can be kept on, or it can be kept running for the third running time and then wait for the temperature difference T diff When the temperature is less than 6° C., the circulation pump 210 may stop running, wherein the third running time may be freely set according to the actual cooling situation, and the third running time may be equal to the first running time and the second running time.

[0111] In a possible implementation, the controller is further configured to:

[0112] According to the maximum temperature T max When the fifth condition is met, the battery module is controlled to stop supplying power.

[0113] In this embodiment, the fifth condition is the maximum temperature value T max Greater than 65°C, where the fifth condition is a preset threshold. At this time, the heat generation of the battery module 120 is the maximum, and the current cooling strategy is no longer able to cool the battery module 120. If it continues to operate, it will cause thermal failure of the battery module. Therefore, this embodiment also controls the battery module to stop powering through the controller to improve the safety of the battery use process.

[0114] It should be noted that when the maximum temperature T max When the temperature is greater than 65°C, the circulation pump can be turned on or off while starting the second circulation loop and disconnecting the power to the battery module 120. Figure 4 , when the circulation pump is on, it can be in the third gear.

[0115] Please refer to Figure 3 An embodiment of the present application provides a control method for an immersion battery thermal management system, which is used to control the immersion battery thermal management system described in any of the above embodiments.

[0116] Exemplarily, the control method of the submerged battery thermal management system includes the following steps:

[0117] Step S100: Acquire the temperature value of each battery cell to obtain multiple temperature values.

[0118] The temperature value of each battery cell is obtained by a temperature sensor provided on the corresponding battery cell. In some embodiments, the temperature sensor 320 can be provided on a large surface of the battery cell to improve the test accuracy of the temperature sensor 320.

[0119] Step S200: determining a maximum temperature value T max and a temperature difference value T diff , according to the plurality of temperature values. Wherein the temperature difference value T diff = T max - T min .

[0120] Step S300: controlling a working state of the circulating pump of the immersed battery thermal management system, including start-stop state of the circulating pump and gear adjustment of the circulating pump, according to the maximum temperature value T max and the temperature difference value T diff .

[0121] In this way, according to the real-time temperature of the battery module, it can be determined when to start the circulating pump, and in the started state, the gear of the circulating pump can be adjusted, so that when the temperature of the battery module is low and no heat dissipation is needed, the circulating pump can be in a stopped state, reducing unnecessary energy consumption; when the temperature rises to the need of heat dissipation, the circulating pump is started in time for cooling. And in the started state, according to the maximum temperature value T max and the temperature difference value T diff , the gear of the circulating pump is reasonably adjusted under the double judgment conditions, which can effectively reduce the overall energy consumption of the system and improve the energy utilization efficiency, so as to ensure that the immersed battery management system can balance the high-efficiency heat dissipation efficiency and energy-saving demand.

[0122] Please refer to Figure 4 , in a possible implementation manner, the control method of the immersed battery management system further comprises:

[0123] controlling the circulating pump to be in a stopped state, according to the maximum temperature value T max satisfying a first condition and the temperature difference value T diff satisfying a second condition. In the embodiment, the first condition is that T max is less than 35℃, and the second condition is that the temperature difference value T diff is less than 6℃. When the maximum temperature value T max is less than 35℃ and the temperature difference value T diff is less than 6℃, it indicates that the temperature of the battery module 120 meets the actual demand, at this time, the circulating pump 210 can be closed, so that the cooling medium in the box 111 is in a static state, effectively avoiding the unnecessary continuous running of the circulating pump 210, greatly saving the energy consumed by the running of the circulating pump 210, and reducing the operation cost of the immersed battery thermal management system.

[0124] Further, when the maximum temperature value T max satisfies the first condition, it is also needed to continue to judge the temperature difference value T diffIn relation to the second condition, if yes, the temperature difference T diff If the second condition is not met, the circulating pump is controlled to be in an on state and at a first gear. By having the circulating pump 210 at the lowest gear and running for the first time duration, a preliminary adjustment is made for the temperature imbalance issue.

[0125] In one possible implementation, the control method of the immersion battery thermal management system further includes:

[0126] According to the maximum temperature value T max If the third condition is met, and the temperature difference T diff If the second condition is met, the circulating pump is controlled to be in an on state and at a first gear. The maximum temperature T max is greater than the maximum value T max of the first condition, and the second gear is greater than the first gear. Exemplarily, the third condition is that the maximum temperature T max is greater than 35℃ and less than 50℃.

[0127] Alternatively, according to the maximum temperature value T max If the third condition is met, and the temperature difference T diff If the second condition is not met, the circulating pump is controlled to be in an on state and at a second gear; wherein the maximum temperature T max of the third condition is greater than the maximum value T max of the first condition, and the second gear is greater than the first gear.

[0128] In this way, when the maximum temperature value T max meets the third condition, it can be determined again whether the temperature difference T diff meets the second condition, and the gear of the circulating pump 210 is set more reasonably. Exemplarily, when the temperature difference T diff meets the second condition, the circulating pump is controlled to be in an on state and at a first gear; or, when the temperature difference T diff does not meet the second condition, the circulating pump is controlled to be in an on state and at a second gear. In this way, by reasonably setting the rotating speed of the circulating pump 210, it can be avoided that the flow is too large or too small, and thus it can be prevented that unwanted energy waste or insufficient cooling capacity is caused.

[0129] In one possible implementation, the control method of the immersion battery thermal management system further includes:

[0130] According to the maximum temperature value T max If the fourth condition is met, and the temperature difference T diff If the second condition is met, the circulating pump is controlled to be in an on state and at a second gear; or,

[0131] According to the maximum temperature value T max If the fourth condition is met, and the temperature difference Tdiff If the second condition is not met, the circulating pump is controlled to be in an open state and in the third gear;

[0132] The maximum temperature T max is greater than the maximum value T max , and the third gear is greater than the second gear.

[0133] The maximum temperature value T max is greater than the maximum temperature value T diff , the second condition is met, and the circulating pump is controlled to be in the second gear.

[0134] In a possible implementation, the control method of the immersion battery thermal management system further includes: according to the maximum temperature value T max If the fifth condition is met, the battery module is controlled to stop power supply, and the control valve of the immersion battery thermal management system is controlled to be open to start the second circulating loop.

[0135] In this embodiment, the fifth condition is that the maximum temperature value T max is greater than 65℃, wherein the fifth condition is a preset threshold value, at this time, the battery module 120 generates the maximum heat, and the current cooling strategy cannot cool the battery module 120, and if the battery module 120 continues to run, thermal failure of the battery module 120 will occur, therefore, the controller is further used to control the battery module to stop power supply and start the second circulating loop, so as to improve the safety of the battery in use.

[0136] It should be noted that when the maximum temperature value T max is greater than 65℃, the circulating pump can be in an open state or a closed state when the second circulating loop is started and the battery module 120 is powered off. For example, please refer to Figure 4 When the circulating pump is in an open state, the circulating pump can be in the third gear.

[0137] In this specification, each embodiment or implementation is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the embodiments can be mutually referred to.

[0138] It should be noted that, as the specification mentions "one embodiment", "an embodiment", "the exemplary embodiment", "some embodiments", and the like, it is meant that a described embodiment can include a particular feature, structure, or characteristic, but every embodiment can not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, where a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of those skilled in the art to effect such feature, structure, or characteristic in connection with an alternative embodiment whether or not the alternative embodiment is expressly described or implied.

[0139] Finally, it should be noted that the above-described embodiments are merely intended for describing and illustrating, but not limiting, the technical solutions of the present application; even though the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some or all of the technical features; and such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An immersion battery thermal management system, characterized in that: include: A battery comprising a battery case, a battery module and a cooling medium located within the battery case; wherein the battery module is immersed in the cooling medium and comprises a plurality of battery cells; a circulation system comprising a circulation pump and a storage tank for storing a cooling medium, wherein the battery, the circulation pump, and the storage tank are connected via a first pipeline to form a first circulation loop, and the circulation pump is disposed on the first pipeline to drive the circulation of the cooling medium; A temperature control system, comprising a controller and a temperature sensor for obtaining the temperature of each of the battery cells, wherein the controller is connected to the temperature sensor and the circulation pump; The controller is configured to: Get the temperature value of each cell and get the maximum temperature value T max And the temperature difference T diff ; According to the maximum temperature value T max and the temperature difference T diff , control the working state of the circulation pump, the working state includes the start and stop state of the circulation pump, and the gear adjustment of the circulation pump.

2. The submerged battery thermal management system according to claim 1, characterized in that: The battery, the condenser, and the storage tank are connected via a second pipeline to form a second circulation loop. The control valve is provided on the second pipeline and is connected to the controller. The controller is further configured as follows: According to the maximum temperature value T max and a preset threshold value to control the working state of the control valve to start or close the second circulation loop.

3. The submerged battery thermal management system according to claim 2, characterized in that: The system further comprises a first heat exchanger, which is disposed on the first circulation loop and is used to exchange heat with the cooling medium in the first pipeline; And / or, it further includes a second heat exchanger, which is connected to the storage tank and is used to exchange heat with the cooling medium in the storage tank.

4. The submerged battery thermal management system according to any one of claims 1 to 3, characterized in that: The cooling medium includes a mixture of a base fluid and nanoparticles, and the nanoparticles include at least one of aluminum oxide and boron nitride.

5. The submerged battery thermal management system according to any one of claims 1 to 3, characterized in that: The controller is further configured to: According to the maximum temperature value T max The first condition is met, and the temperature difference T diff If the second condition is met, the circulating pump is controlled to be in a stopped state; or, According to the maximum temperature T max The first condition is met, and the temperature difference T diff If the second condition is not met, the circulating pump is controlled to be in the on state and located at the first gear.

6. The submerged battery thermal management system according to claim 5, characterized in that: The controller is further configured to: According to the maximum temperature value T max The third condition is met, and the temperature difference T diff If the second condition is met, the circulating pump is controlled to be in an on state and in a first gear position; or, According to the maximum temperature value T max The third condition is met, and the temperature difference T diff If the second condition is not met, the circulating pump is controlled to be in an on state and located at the second gear position; Among them, the maximum temperature T in the third condition max Greater than the maximum value T in the first condition max , the second gear is greater than the first gear.

7. The submerged battery thermal management system according to claim 6, characterized in that: The controller is further configured to: According to the maximum temperature value T max The fourth condition is met, and the temperature difference T diff If the second condition is met, the circulating pump is controlled to be in the on state and in the second gear position; or According to the maximum temperature value T max The fourth condition is met, and the temperature difference T diff If the second condition is not met, the circulating pump is controlled to be in an on state and located at the third gear; Among them, the maximum temperature T in the fourth condition max Greater than the maximum value T in the third condition max , the third gear is greater than the second gear.

8. The submerged battery thermal management system according to claim 7, characterized in that: The controller is further configured to: According to the maximum temperature value T max When a fifth condition is met, the battery module is controlled to stop supplying power, and the fifth condition is a preset threshold.

9. A control method for an immersion battery thermal management system according to any one of claims 1 to 8, characterized in that: The control method includes: Get the temperature value of each battery cell and obtain multiple temperature values; According to the multiple temperature values, the maximum temperature value T is determined. max and the temperature difference T diff ; According to the maximum temperature value T max and the temperature difference T diff , controlling the working state of the circulation pump of the submerged battery thermal management system, wherein the working state includes the start and stop state of the circulation pump, and the gear adjustment of the circulation pump.

10. The control method of the submerged battery thermal management system according to claim 9, characterized in that: The method further comprises: According to the maximum temperature value T max The first condition is met, and the temperature difference T diff If the second condition is met, the circulating pump is controlled to be in a stopped state; or, According to the maximum temperature T max The first condition is met, and the temperature difference T diff If the second condition is not met, the circulating pump is controlled to be in the on state and located at the first gear.

11. The control method of the submerged battery thermal management system according to claim 10, characterized in that: The method further comprises: According to the maximum temperature value T max The third condition is met, and the temperature difference T diff If the second condition is met, the circulating pump is controlled to be in the on state and in the first gear position; or According to the maximum temperature value T max The third condition is met, and the temperature difference T diff If the second condition is not met, the circulating pump is controlled to be in an on state and located at the second gear position; Among them, the maximum temperature T in the third condition max Greater than the maximum value T in the first condition max , the second gear is greater than the first gear.

12. The control method of the submerged battery thermal management system according to claim 11, characterized in that: The method further comprises: According to the maximum temperature value T max The fourth condition is met, and the temperature difference T diff If the second condition is met, the circulating pump is controlled to be in the on state and in the second gear position; or According to the maximum temperature value T max The fourth condition is met, and the temperature difference T diff If the second condition is not met, the circulating pump is controlled to be in an on state and located at the third gear; Among them, the maximum temperature T in the fourth condition max Greater than the maximum value T in the third condition max , the third gear is greater than the second gear.

13. The control method of the submerged battery thermal management system according to claim 12, characterized in that: The method further comprises: According to the maximum temperature value T max If the fifth condition is met, the battery module is controlled to stop supplying power, and the control valve of the submerged battery thermal management system is controlled to open to start the second circulation loop.

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