Battery pack direct cooling system and method and vehicle

Abstract

The invention discloses a battery pack direct cooling system and method and a vehicle. The system comprises a controller, a refrigerant storage tank, a vacuumizing device, a battery pack direct cooling plate, a flow adjusting pump, a control valve and a first temperature detector. The vacuumizing device and the first temperature detector are both connected with the refrigerant storage tank, the output end of the refrigerant storage tank is connected with the input end of the flow adjusting pump through the control valve, and the output end of the flow adjusting pump is connected with the input end of the battery pack direct cooling plate through a pipeline. The controller is used for determining the target temperature required by the refrigerant gas according to the operation condition of the battery pack; and the first temperature detected by the first temperature detector is obtained, whether the first temperature is smaller than or equal to the target temperature or not is judged, and if not, the control valve is closed, the vacuumizing device is started, and the refrigerant gas in the refrigerant storage tank is cooled till the first temperature is smaller than or equal to the target temperature. The system can realize high-efficiency cooling of the battery pack.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery thermal management, and particularly relates to a battery pack direct cooling system, method and vehicle. BACKGROUND

[0002] At present, with the continuous improvement of new energy technology and the continuous control of vehicle production enterprises on vehicle research and development cost, the new energy battery develops direct cooling technology on the basis of traditional liquid cooling, and the advantages are as follows: 1. Cooling efficiency is improved: the direct cooling technology establishes a temperature control system inside the battery pack, directly absorbs the heat of the battery cell, and the cooling efficiency is extremely high, which can be more than 3 times of the liquid cooling. This efficient cooling method helps to prolong the service life of the battery and improve the performance and charging and discharging capacity of the battery; 2. Lighter weight: the direct cooling system can save the water system of the battery circuit, simplify the system structure, reduce the controllable components such as water pump, thereby saving space and weight. This is of great significance to reduce the weight of the vehicle and improve the energy efficiency of the vehicle; 3. Space saving and low cost: since the water system and related components are saved, the direct cooling system is more space-saving in space layout, and may bring potential cost reduction.

[0003] However, the existing technology still has many problems such as poor cooling effect, low cooling efficiency and inability to cool specifically when using direct cooling method. SUMMARY

[0004] The embodiments of the present application provide a battery pack direct cooling system, method and vehicle, which can adjust the temperature of the refrigerant gas according to the operating condition of the battery pack, realize efficient cooling of the battery pack, and has better cooling effect.

[0005] In a first aspect, an embodiment of the present application provides the following technical scheme: A battery pack direct cooling system, comprising: a controller, a refrigerant storage tank, a vacuumizing device, a battery pack direct cooling plate, a flow regulating pump, a control valve and a first temperature detector, the controller is electrically connected with the vacuumizing device, the flow regulating pump, the control valve and the first temperature detector respectively; the vacuumizing device and the first temperature detector are connected with the refrigerant storage tank, an output end of the refrigerant storage tank is connected with an input end of the flow regulating pump through the control valve, and an output end of the flow regulating pump is connected with an input end of the battery pack direct cooling plate through a pipeline; the controller is used for determining a target temperature required by the refrigerant gas according to an operating condition of the battery pack, acquiring a first temperature detected by the first temperature detector, judging whether the first temperature is less than or equal to the target temperature, and if not, closing the control valve and opening the vacuumizing device, so that the vacuumizing device cools the refrigerant gas in the refrigerant storage tank until the first temperature is less than or equal to the target temperature.

[0006] Preferably, the system further comprises a plurality of second temperature detectors, each of which is electrically connected to the controller and is arranged on the battery cell of the battery pack to detect the temperature of the different battery cell; the controller is further configured to obtain a second temperature set detected by the second temperature detectors; and if the maximum temperature difference in the second temperature set is less than or equal to the temperature difference limit, the flow rate of the refrigerant gas is adjusted to the target flow rate by the flow regulating pump, wherein the maximum temperature difference is the difference between the maximum temperature and the minimum temperature.

[0007] Preferably, the second temperature detector is arranged between every 3-6 battery cells in the battery pack.

[0008] Preferably, the system further comprises a flow detector electrically connected to the controller, wherein the flow detector is arranged at the input end of the battery pack direct cooling plate; the flow detector is configured to detect the flow of the refrigerant gas flowing into the battery pack direct cooling plate; and the controller is further configured to adjust the rotating speed of the flow regulating pump according to the flow.

[0009] Preferably, the material of the flow channel of the battery pack direct cooling plate is a nano material.

[0010] In a second aspect, the present application provides the following technical solutions through an embodiment of the present application. A control method of a battery pack direct cooling system, applied to a controller of the battery pack direct cooling system as described in any of the preceding first aspect, the method comprising: when the battery pack is started, determining a target temperature required by the refrigerant gas according to the operating condition of the battery pack; obtaining a first temperature detected by a first temperature detector; determining whether the first temperature is less than or equal to the target temperature, and if not, closing the control valve, starting the vacuumizing device, and cooling the refrigerant gas in the refrigerant storage tank until the first temperature is less than or equal to the target temperature.

[0011] Preferably, the system comprises a plurality of second temperature detectors, the controller is electrically connected with the plurality of second temperature detectors respectively, the plurality of second temperature detectors are arranged on the battery cells of the battery pack at intervals, and are used to detect the temperatures of different battery cells; after the battery pack is started, the system further comprises: determining a target flow rate of the refrigerant gas and a heat generation amount of the battery pack according to an operating condition of the battery pack; after determining that the first temperature is less than or equal to the target temperature, the system further comprises: closing the vacuumizing device, opening the control valve and the flow regulating valve; obtaining a second temperature set detected by the second temperature detectors; if a maximum temperature difference value in the second temperature set is less than or equal to a temperature difference limit value, adjusting the flow rate of the refrigerant gas to the target flow rate by the flow regulating pump, wherein the maximum temperature difference value is a difference value between a maximum temperature and a minimum temperature.

[0012] Preferably, the system further comprises: if the maximum temperature difference value is greater than the temperature difference limit value, dynamically adjusting the flow rate of the refrigerant gas by the flow regulating pump until the maximum temperature difference value is less than or equal to the temperature difference limit value; when the maximum temperature difference value is less than or equal to the temperature difference limit value, adjusting the flow rate of the refrigerant gas to the target flow rate by the flow regulating pump, and adjusting the temperature of the refrigerant gas to the target temperature by the vacuumizing device.

[0013] Preferably, the dynamically adjusting the flow rate of the refrigerant gas by the flow regulating pump comprises: reducing the flow rate of the refrigerant gas by the flow regulating pump according to a preset flow rate step every unit time length.

[0014] In a third aspect, an embodiment of the present application provides the following technical solution. A vehicle comprising a vehicle body and the battery pack direct cooling system according to any one of the preceding first aspect.

[0015] The one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: The battery pack direct cooling system provided by the embodiment of the present application, the controller can determine the target temperature required by the refrigerant gas according to the operating condition of the battery pack, acquire the first temperature detected by the first temperature detector, judge whether the first temperature is less than or equal to the target temperature, if not, close the control valve, start the vacuumizing device, and cool the refrigerant gas in the refrigerant storage tank until it is judged that the first temperature is less than or equal to the target temperature. The controller can dynamically calculate the target temperature of the refrigerant according to the real-time operating condition of the battery pack, and perform closed-loop regulation through the actual temperature fed back by the first temperature detector. When it is detected that the temperature of the refrigerant is higher than the target value, the system immediately closes the control valve and starts the vacuumizing device to cool the refrigerant gas, avoiding the invalid circulation of the refrigerant in the pipeline, ensuring that the battery pack is always in a better working temperature range, avoiding the risk of capacity attenuation or thermal runaway caused by overheating, and improving the temperature uniformity. Moreover, the vacuumizing device is started only when the temperature of the refrigerant is out of limit, avoiding the energy waste caused by the continuous operation of the traditional compressor, and having the characteristics of higher efficiency, lower energy consumption and better cooling effect. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0017] Figure 1 The structure diagram of the battery pack direct cooling system in the embodiment of the present application is shown. Figure 2 The control flow diagram of the direct cooling system in the embodiment of the present application is shown. Figure 3 The flow diagram of the control method of the battery pack direct cooling system in the embodiment of the present application is shown. Figure 4 The structure diagram of the vehicle in the embodiment of the present application is shown.

[0018] Reference signs: 10-first temperature detector; 20-vacuumizing device; 30-control valve; 40-pipeline; 50-second temperature detector; 60-cell; 70-battery pack direct cooling plate; 80-flow detector; 90-inlet of the direct cooling plate; 100-flow regulating pump; 110-refrigerant storage tank. DETAILED DESCRIPTION

[0019] The embodiment of the present application provides a battery pack direct cooling system, method and vehicle. The system can adjust the temperature of the refrigerant gas according to the operating condition of the battery pack, realize efficient cooling of the battery pack, and has better cooling effect.

[0020] The technical scheme of the embodiments of the present application is to solve the above technical problem, and the general idea is as follows: A battery pack direct cooling system, comprising: a controller, a refrigerant storage tank, a vacuumizing device, a battery pack direct cooling plate, a flow regulating pump, a control valve and a first temperature detector, the controller is electrically connected with the vacuumizing device, the flow regulating pump, the control valve and the first temperature detector respectively; the vacuumizing device and the first temperature detector are connected with the refrigerant storage tank, the output end of the refrigerant storage tank is connected with the input end of the flow regulating pump through the control valve, and the output end of the flow regulating pump is connected with the input end of the battery pack direct cooling plate through a pipeline; the controller is used for determining a target temperature required by refrigerant gas according to the operating condition of the battery pack; a first temperature detected by the first temperature detector is acquired, and it is judged whether the first temperature is less than or equal to the target temperature, if not, the control valve is closed, the vacuumizing device is started, and the refrigerant gas in the refrigerant storage tank is cooled until the first temperature is less than or equal to the target temperature.

[0021] In order to better understand the above technical scheme, the above technical scheme will be described in detail in combination with the drawings of the specification and the specific embodiments.

[0022] In the first aspect, the battery pack direct cooling system provided by the embodiments of the present application is specifically as shown in Figure 1 The controller (not shown in the figure), the refrigerant storage tank 110, the vacuumizing device 20, the battery pack direct cooling plate 70, the flow regulating pump 100, the control valve 30 and the first temperature detector 10, the controller is electrically connected with the vacuumizing device 20, the flow regulating pump 100, the control valve 30 and the first temperature detector 10 respectively. The vacuumizing device 20 and the first temperature detector 10 are connected with the refrigerant storage tank 110, the output end of the refrigerant storage tank 110 is connected with the input end of the flow regulating pump 100 through the control valve 30, and the output end of the flow regulating pump 100 is connected with the input end of the battery pack direct cooling plate 70 through the pipeline 40, and the flow regulating pump 100 is used for adjusting the flow rate of the refrigerant gas flowing out of the refrigerant storage tank 110 when the control valve 30 is opened.

[0023] Among them, the controller can be a single-chip microcomputer, which can be integrated in a battery management system (BMS). The control valve 30 can be an electronic butterfly valve, a stop valve or a check valve, etc.

[0024] The first temperature detector 10 can be a temperature sensor, a thermal resistance thermometer or a thermocouple thermometer, etc., and the flow regulating pump 100 can be a gas flow regulating pump.

[0025] In specific embodiments, the refrigerant storage tank 110 is used to store refrigerant gas, the vacuumizing device 20 and the first temperature detector 10 can be installed at an upper position of the refrigerant storage tank 110, the vacuumizing device 20 reduces the temperature of the refrigerant through a vacuum environment to reduce the temperature of the refrigerant gas at different depths (or different degrees), and the first temperature detector 10 is used to detect the temperature of the refrigerant gas in the refrigerant storage tank 110. The control valve 30 is installed on the pipeline 40 between the refrigerant storage tank 110 and the flow regulating pump 100, and is used to control the refrigerant flow state; the flow regulating pump 100 is used to regulate the flow rate of the refrigerant gas, so that the refrigerant gas enters the battery pack direct cooling plate 70 at different flow rates.

[0026] Among them, the vacuumizing device 20 can be a vacuum pump, a refrigeration machine or an ion pump, etc., for example, in one application scenario, the vacuumizing device 20 adopts a vacuum pump. In this application, the refrigerant storage tank 110 and the control valve 30, the control valve 30 and the flow regulating pump 100, and the flow regulating pump 100 and the battery pack cooling plate are connected by the pipeline 40.

[0027] When the refrigerant storage tank 110 is cooled, or the battery pack does not need to be cooled, the control valve 30 is closed. When the control valve 30 is in the closed state, the refrigerant gas cannot enter the battery pack direct cooling plate 70, the refrigerant storage tank 110 is isolated from the main circulation loop to form an independent cooling unit, and the pressure fluctuation under abnormal working conditions is prevented from affecting the entire system. The vacuum pump is used to reduce the pressure in the refrigerant storage tank 110, so that the boiling point of the refrigerant is lowered and the heat is quickly absorbed and cooled.

[0028] For example, the refrigerant temperature can be accurately controlled within ±1℃, ensuring that the battery pack is always in the best working interval of 20-35℃, avoiding the risk of capacity attenuation or thermal runaway caused by overheating. For example, under the high-rate discharge working condition of the battery pack, the maximum temperature of the battery module using the direct cooling technology can be reduced from 40.37℃ to 27.05℃, and the temperature difference is compressed from 11.4℃ to 4.65℃, significantly improving the cooling efficiency.

[0029] It should be noted that the battery pack direct cooling technology mainly uses the latent heat of phase change of the refrigerant to absorb or release heat. Since the refrigerant changes from liquid to gas while flowing through the evaporator (direct cooling plate), it absorbs the heat generated by the battery, and then is compressed into high-temperature and high-pressure gas by the compressor, enters the condenser to be cooled into liquid, and then enters the evaporator through the throttling device to complete a cycle. There will be refrigerant in liquid and gas forms in the battery pack direct cooling plate for a long time, and the cooling plate flow channel is made of metal, which causes rust on the inner wall of the direct cooling plate.

[0030] Further, in order to reduce the corrosion of the battery pack direct cooling plate 70 and improve the heat conduction efficiency, the flow channel of the battery pack direct cooling plate 70 can adopt a nano material, which can effectively support heat exchange while avoiding rust in the flow channel of the battery pack direct cooling plate 70. For example, the nano material can be an organic nano material, an inorganic non-metallic material, etc., as long as it can meet the requirement of high thermal conductivity, and the specific nano material used is not limited in the present application.

[0031] For example, in a certain new energy vehicle battery pack, the direct cooling plate flow channel adopts a nano ceramic coating material with a thickness of 50-100 μm, which improves corrosion resistance while reducing thermal resistance.

[0032] Further, in order to realize more precise regulation and control of the flow regulating pump 100, the system can further include a flow detector 80 electrically connected to the controller, the flow detector 80 being arranged at the input end of the battery pack direct cooling plate 70 (i.e. the inlet 90 of the direct cooling plate), the flow detector 80 being configured to detect the flow rate of the refrigerant gas entering the battery pack direct cooling plate 70, and the controller being further configured to adjust the rotational speed of the flow regulating pump 100 according to the flow rate.

[0033] For example, the flow detector 80 can be a gas flow sensor, an electromagnetic flowmeter or a turbine flowmeter, etc., and the present application is not limited thereto.

[0034] In specific embodiments, the inlet 90 and the outlet of the battery direct cooling plate are each provided with a gas flow sensor for detecting the flow rate of the gas flowing out of the battery pack direct cooling plate 70.

[0035] The controller is configured to determine a target temperature required by the refrigerant gas according to the operating condition of the battery pack, obtain the first temperature detected by the first temperature detector 10, and determine whether the first temperature is less than or equal to the target temperature. If not, the control valve 30 is closed and the vacuum pump is opened to cool the refrigerant gas in the refrigerant storage tank 110 until it is determined that the first temperature is less than or equal to the target temperature.

[0036] For example, the operating condition of the battery pack can include fast charging condition, slow charging condition, high-speed running condition, small current running condition, etc.

[0037] In specific embodiments, according to the operating condition of the battery pack, the target temperature required by the refrigerant gas can include: determining the heat generation of the battery pack according to the operating condition of the battery pack; and determining the target temperature required by the refrigerant gas according to the heat generation and the normal operating temperature of the battery pack, wherein the normal operating temperature is a relatively optimal temperature range required by the battery pack during operation. The temperature range can be set as required, and the present application is not limited thereto.

[0038] Further, in order to avoid the problem of uneven cooling effect caused by the excessive or insufficient gas flow in the battery pack direct cooling plate 70, which makes the temperature distribution inside the battery pack uneven, and the maximum temperature difference between the battery cells 60 is high, the system can further include a plurality of second temperature detectors 50, and the controller is electrically connected with the plurality of second temperature detectors 50. The plurality of second temperature detectors 50 are arranged on the battery cells 60 of the battery pack at intervals, and are used to detect the temperatures of different battery cells 60 in the battery pack.

[0039] The second temperature detector 50 can be a temperature sensor, a thermal resistance thermometer, or a thermocouple thermometer, etc.

[0040] In specific embodiments, the second temperature detector 50 is arranged between every 3-6 battery cells in the battery pack. For example, the second temperature sensor is arranged in groups of every 4 battery cells, and is used to collect the temperature of the battery cell 60 in real time.

[0041] By arranging the first temperature detector 10 on the refrigerant storage tank 110, and arranging the plurality of second temperature detectors 50 on the plurality of battery cells 60 respectively, the temperature of the refrigerant gas and the temperature of the battery cell are monitored respectively.

[0042] After the battery pack is started, the controller is further configured to determine a target flow rate of the refrigerant gas according to the operating condition of the battery pack; after determining that the first temperature is less than or equal to the target temperature, the controller is configured to close the vacuum pump 20, and open the control valve 30 and the flow regulating valve; the controller is configured to obtain a second temperature set detected by the second temperature detector 50; if the maximum temperature difference value in the second temperature set is less than or equal to the temperature difference limit value, the controller is configured to adjust the flow rate of the refrigerant gas to the target flow rate by the flow regulating pump 100, wherein the maximum temperature difference value is between the maximum temperature and the minimum temperature.

[0043] It should be noted that the temperature difference limit value can also be determined according to the operating condition of the battery pack, and the corresponding temperature difference limit values under different operating conditions are different. Of course, as other optional embodiments, the temperature difference limit value can also be a set value.

[0044] In specific embodiments, determining the target flow rate required by the refrigerant gas according to the operating condition of the battery pack can include: determining the heat generation of the battery pack according to the operating condition of the battery pack; and determining the target flow rate required by the refrigerant gas according to the heat generation and a preset corresponding relationship, wherein the preset corresponding relationship includes a corresponding relationship between the heat generation of the battery cell 60 and the target flow rate which is calibrated in advance.

[0045] The preset corresponding relationship can be obtained by pre-controlling the thermal management of different new energy vehicles, inputting the thermal management demand information of different batteries under different conditions, and adjusting and controlling under different operating conditions and flow rates of the battery pack.

[0046] For example, when the vehicle is in fast charging condition, the host computer inputs the thermal management requirement as follows: the target temperature of the refrigerant gas is -10℃, the target flow rate is 0.8 m / s, and the temperature difference limit is 3℃. After the controller is started, if the initial temperature of the refrigerant gas is 5℃, the control valve 30 is closed, and the vacuum pump is started. The vacuum environment is formed in the refrigerant storage tank 110, and the refrigerant gas is cooled to -10℃. Then, the vacuum pump is stopped, the control valve 30 and the flow regulating pump 100 are started, and the initial flow rate is set to 0.5 m / s.

[0047] In actual operation, the method further includes: if the maximum temperature difference value is greater than the temperature difference limit, the flow rate of the refrigerant gas is dynamically adjusted by the flow regulating pump 100, and / or the temperature of the refrigerant gas is dynamically adjusted by the vacuum pumping device 20, until the maximum temperature difference value is less than or equal to the temperature difference limit; when the maximum temperature difference value is less than or equal to the temperature difference limit, the flow rate of the refrigerant gas is adjusted to the target flow rate by the flow regulating pump 100, and the temperature of the refrigerant gas is adjusted to the target temperature by the vacuum pumping device 20.

[0048] As an embodiment, dynamically adjusting the flow rate of the refrigerant gas by the flow regulating pump 100 can include: every unit time, the flow regulating pump 100 reduces the flow rate of the refrigerant gas by a preset flow rate step. In specific embodiments, dynamically adjusting the temperature of the refrigerant gas by the vacuum pumping device 20 can include: every unit time, the vacuum pumping device 20 increases the temperature of the refrigerant gas by a preset temperature step.

[0049] For example: the unit time can be 1-5 seconds, the preset flow rate step can be 0.1-0.5 m / s, and the preset temperature step can be 0.5-1℃.

[0050] For example, in the battery pack operation, if the maximum temperature difference of the battery cell 60 is 4℃ (exceeding the temperature difference limit), the controller reduces the flow rate by 0.1 m / s every 5 seconds until the temperature difference is reduced to less than 3℃, and then adjusts the flow rate to the target flow rate (such as 0.8 m / s) to maintain stable operation.

[0051] By the above method, the battery pack can be uniformly cooled under different conditions, the corrosion rate of the direct cooling plate is reduced by more than 90%, and the service life of the battery cell 60 is extended by 15%-20%.

[0052] For example, Figure 2As shown, the control process of the battery pack direct cooling system shown in the present application is as follows: first, control input battery different operating condition thermal management demand information, decompose target temperature, target flow and temperature difference limit, then monitor the temperature of the refrigerant gas in the refrigerant storage tank, judge whether the temperature of the refrigerant gas needs to be reduced; if it needs to be reduced, close the control valve, start the vacuum pump, and stop when the target temperature is reached; if it does not need to be reduced, the process enters the next step. Control the flow regulating pump to adjust the refrigerant flow to the target flow, then judge whether the refrigerant gas flow meets the refrigerant flow demand, if it meets, send the refrigerant gas to the battery pack direct cooling plate; if it does not meet, open the control valve and the flow regulating pump, and adjust again; judge whether the maximum temperature difference of the battery cell is less than or equal to the temperature difference limit, if it meets, the process is ended; if it does not meet, return to the step of controlling the flow regulating pump to adjust the refrigerant flow to the target flow, and adjust again until the temperature difference requirement is met and the process is ended.

[0053] When using the system, first, according to different operating conditions of the battery pack, the flow rate demand (target flow rate) of the refrigerant gas corresponding to the heat generation of the battery cell under different operating conditions, the refrigerant temperature for cooling (target temperature), and the maximum temperature difference limit between the battery cells are decomposed. After decomposing these demand targets, when the battery pack operates under different operating conditions, according to the current temperature demand of the refrigerant, it is judged whether the refrigerant needs to be further cooled. If it needs to be further cooled to a certain temperature, the electronic butterfly valve is closed, the vacuum pump is opened, and the refrigerant is cooled by using the vacuum environment.

[0054] The present application monitors the maximum temperature difference between the battery cells. When the maximum temperature difference limit is less than or equal to the temperature difference limit, the target flow rate and the target temperature corresponding to the heat generation of the battery cell are fixedly adjusted. At this time, uniform cooling of the battery pack can be realized. When the maximum temperature difference exceeds the temperature difference limit, it means that the flow rate in the direct cooling plate is not uniform. Therefore, the flow rate demand of the refrigerant and the refrigerant temperature for cooling are dynamically adjusted. The flow rate and / or the refrigerant temperature are adjusted (for example, the flow rate is slowed down or the refrigerant temperature is increased), until the maximum temperature difference between the battery cells is less than or equal to the temperature difference limit. Then, the target flow rate and the target temperature corresponding to the heat generation of the battery cell are fixedly adjusted.

[0055] The present application dynamically adjusts the flow rate demand of the refrigerant and the refrigerant temperature for cooling based on the feedback of the maximum temperature difference between the battery cells. The law of dynamic adjustment is step-by-step adjustment, until the maximum temperature difference limit between the battery cells is less than or equal to the temperature difference limit. In addition, the vacuum pump directionally cools the refrigerant in the storage tank. The vacuum pump is started only when the refrigerant temperature exceeds the limit, avoiding the energy waste caused by the continuous operation of the traditional compressor.

[0056] In summary, the battery pack direct cooling system provided by the embodiment of the present application can avoid uneven cooling effect: the heat management requirements of the battery pack under different working conditions are decomposed by the control unit to obtain appropriate gas flow, so as to avoid too large or too small gas flow in the battery pack direct cooling plate, avoid uneven temperature distribution in the battery pack, and control the temperature difference between the battery cells within a small range; avoid rust in the direct cooling plate: the flow channel of the battery pack direct cooling plate is made of nanometer material, which not only solves the problem of rust in the flow channel of the direct cooling plate, but also better exchanges heat, so that the heat dissipation performance of the battery pack is better.

[0057] In a second aspect, based on the same inventive concept, the embodiment provides a control method of a battery pack direct cooling system, as shown in the method, the method comprises the following steps S101 to S103: Figure 3 Step S101, when the battery pack is started, the target temperature required by the refrigerant gas is determined according to the operating condition of the battery pack; Step S102, obtaining the first temperature detected by the first temperature detector; Step S103, judging whether the first temperature is less than or equal to the target temperature, if not, closing the control valve, starting the vacuumizing device, and cooling the refrigerant gas in the refrigerant storage tank until it is judged that the first temperature is less than or equal to the target temperature.

[0058] As an optional embodiment, after determining the target temperature of the refrigerant gas according to the operating condition of the battery pack, it further comprises: determining the target flow rate of the refrigerant gas according to the operating condition of the battery pack; after judging that the first temperature is less than or equal to the target temperature, it further comprises: closing the vacuumizing device, opening the control valve and the flow regulating valve; obtaining a second temperature set detected by a second temperature detector; if the maximum temperature difference value in the second temperature set is less than or equal to the temperature difference limit value, the flow rate of the refrigerant gas is adjusted to the target flow rate by the flow regulating pump, wherein the maximum temperature difference value is the difference between the maximum temperature and the minimum temperature.

[0059] As an optional embodiment, the method further comprises: if the maximum temperature difference value is greater than the temperature difference limit value, the flow rate of the refrigerant gas is dynamically adjusted by the flow regulating pump, and / or the temperature of the refrigerant gas is dynamically adjusted by the vacuumizing device, until the maximum temperature difference value is less than or equal to the temperature difference limit value; when the maximum temperature difference value is less than or equal to the temperature difference limit value, the flow rate of the refrigerant gas is adjusted to the target flow rate by the flow regulating pump, and the temperature of the refrigerant gas is adjusted to the target temperature by the vacuumizing device.

[0060] ​As an optional embodiment, the dynamic adjustment of the flow rate of the refrigerant gas by the flow regulating pump comprises: every other unit time, the flow regulating pump reduces the flow rate of the refrigerant gas by a preset flow rate step; the dynamic adjustment of the temperature of the refrigerant gas by the vacuumizing device comprises: every other unit time, the vacuumizing device increases the temperature of the refrigerant gas by a preset temperature step.

[0061] The control method of the battery pack direct cooling system provided by the embodiment of the present application has the same implementation principle and technical effects as the system embodiment, and for brief description, the part not mentioned in the method embodiment can refer to the corresponding content in the system embodiment.

[0062] In a third aspect, based on the same inventive concept, the embodiment provides a vehicle 500, as shown, comprising a vehicle body 502 and the battery pack direct cooling system 501 according to any one of the preceding first aspect. Figure 4

[0063] Since the battery pack direct cooling system included in the vehicle according to the embodiment of the present application has been described in the foregoing, the specific structure and effect principle of the vehicle can be understood by those skilled in the art based on the battery pack direct cooling system according to the embodiment of the present application, which will not be described here. Any vehicle including the battery pack direct cooling system according to the embodiment of the present application belongs to the scope of the present application.

[0064] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0065] The present application is described with reference to flowcharts and / or block diagrams of the method, device (system), and computer program product according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one flow or multiple flows and / or blocks Figure 1 The modules that implement the functions specified in one flow or multiple flows and / or blocks.

[0066] ​These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0067] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that are executed on the computer or other programmable apparatus provide steps for implementing the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0068] While the preferred embodiments of the application have been described, additional variations and modifications can be made to the embodiments by those skilled in the art once they learn of the basic inventive concepts. Therefore, the appended claims are intended to cover all such additional variations and modifications as fall within the scope of the application.

[0069] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A battery pack direct cooling system, characterized by, The system comprises: a controller, a refrigerant storage tank, a vacuumizing device, a battery pack direct cooling plate, a flow regulating pump, a control valve and a first temperature detector, the controller is electrically connected with the vacuumizing device, the flow regulating pump, the control valve and the first temperature detector respectively; the vacuumizing device and the first temperature detector are connected with the refrigerant storage tank, the output end of the refrigerant storage tank is connected with the input end of the flow regulating pump through the control valve, and the output end of the flow regulating pump is connected with the input end of the battery pack direct cooling plate through a pipeline; the controller is used for determining a target temperature required by refrigerant gas according to the operating condition of the battery pack, acquiring a first temperature detected by the first temperature detector, judging whether the first temperature is less than or equal to the target temperature, and if not, closing the control valve, opening the vacuumizing device, and cooling the refrigerant gas in the refrigerant storage tank until the first temperature is less than or equal to the target temperature.

2. A battery pack direct cooling system as claimed in claim 1, wherein, The system further comprises a plurality of second temperature detectors, the controller is electrically connected with the plurality of second temperature detectors respectively, the plurality of second temperature detectors are arranged on the battery pack in intervals and are used for detecting the temperatures of different battery cells; the controller is further used for acquiring a second temperature set detected by the second temperature detectors, and if the maximum temperature difference value in the second temperature set is less than or equal to a temperature difference limit value, adjusting the flow rate of the refrigerant gas to a target flow rate through the flow regulating pump, wherein the maximum temperature difference value is the difference between the maximum temperature and the minimum temperature.

3. A battery pack direct cooling system as claimed in claim 2, wherein, The second temperature detectors are arranged between every 3-6 battery cells in the battery pack.

4. A battery pack direct cooling system as claimed in claim 1, wherein, The system further comprises: a flow detector which is electrically connected with the controller, and is arranged at the input end of the battery pack direct cooling plate, the flow detector is used for detecting the flow rate of the refrigerant gas flowing into the battery pack direct cooling plate, and the controller is further used for adjusting the rotating speed of the flow regulating pump according to the flow rate of the refrigerant gas.

5. A battery pack direct cooling system as claimed in claim 1, wherein, The material of the flow channel of the battery pack direct cooling plate is a nano material.

6. A control method of a battery pack direct cooling system, characterized by, The method is applied to the controller of the battery pack direct cooling system as claimed in any one of claims 1-5, and the method comprises: when the battery pack is started, determining a target temperature required by the refrigerant gas according to the operating condition of the battery pack; acquiring a first temperature detected by a first temperature detector; judging whether the first temperature is less than or equal to the target temperature, and if not, closing the control valve, opening the vacuumizing device, and cooling the refrigerant gas in the refrigerant storage tank until the first temperature is less than or equal to the target temperature.

7. The method of claim 6, wherein the battery pack direct cooling system is controlled by a controller. The system comprises a plurality of second temperature detectors, the controller is electrically connected with the plurality of second temperature detectors respectively, the plurality of second temperature detectors are arranged on the battery pack in intervals and are used for detecting the temperatures of different battery cells, and after the battery pack is started, the method further comprises: determining a target flow rate of the refrigerant gas according to the operating condition of the battery pack; after it is judged that the first temperature is less than or equal to the target temperature, the method further comprises: closing the vacuumizing device, opening the control valve and the flow regulating valve; acquiring a second temperature set detected by a second temperature detector; if a maximum temperature difference value in the second temperature set is less than or equal to a temperature difference limit value, adjusting the flow rate of the refrigerant gas to a target flow rate by the flow rate adjusting pump, wherein the maximum temperature difference value is a difference between a maximum temperature and a minimum temperature.

8. The method of claim 7, wherein the battery pack direct cooling system is controlled by a controller. Further comprising: if the maximum temperature difference value is greater than the temperature difference limit value, dynamically adjusting the flow rate of the refrigerant gas by the flow rate adjusting pump until the maximum temperature difference value is less than or equal to the temperature difference limit value; when the maximum temperature difference value is less than or equal to the temperature difference limit value, adjusting the flow rate of the refrigerant gas to the target flow rate by the flow rate adjusting pump and adjusting the temperature of the refrigerant gas to a target temperature by the vacuumizing device.

9. The control method of the battery pack direct cooling system according to claim 8, wherein, The dynamically adjusting the flow rate of the refrigerant gas by the flow rate adjusting pump comprises: every other unit of time, adjusting the flow rate adjusting pump to reduce the flow rate of the refrigerant gas by a preset flow rate step.

10. A vehicle characterized by comprising: The vehicle body and the battery pack direct cooling system according to any one of claims 1-5.

Images