Battery pack liquid cooling system and its blockage detection and maintenance method

Abstract

The application provides a battery pack liquid cooling system and a clogging detection and maintenance method thereof, and relates to the technical field of batteries.The shunt joint is detachably connected to the box, so that the circulation of the cooling liquid in the battery pack is realized, the clogged shunt joint can be cleaned or maintained conveniently, and the battery management system can realize real-time monitoring of the temperature of each position in the battery pack through multiple temperature detection modules and multiple sampling points.In this way, the liquid cooling system failure caused by the clogging of the shunt joint can be effectively captured, the cooling liquid flow is blocked, and the temperature of the local area is abnormal.Based on the real-time temperature data, the battery management unit can accurately analyze the specific position of the clogging, the shunt joint at the corresponding position can be cleaned or replaced after the clogging position is determined, the clogging detection efficiency and maintenance efficiency of the liquid cooling system are improved, the maintenance cost is reduced, and the reliability of the liquid cooling system is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery liquid cooling, in particular to a battery pack liquid cooling system and a clogging detection and maintenance method thereof. BACKGROUND

[0002] With the wide application of new energy vehicles, energy storage systems and other high-power electronic devices, the temperature management of battery packs has become one of the key technologies to ensure the safety of devices, improve efficiency and prolong service life. As an efficient thermal management solution, the liquid cooling system has been widely used in the heat dissipation system of battery packs. The liquid cooling system absorbs the heat inside the battery pack through the circulating cooling liquid, and releases it through the heat dissipation device, thereby effectively controlling the temperature of the battery. However, with the use of the liquid cooling system, especially under long-term operating conditions, clogging may occur inside the liquid cooling system, thereby affecting the heat dissipation efficiency of the system, and even causing the battery to overheat, which may cause safety problems in severe cases.

[0003] At present, the existing battery pack liquid cooling system does not provide effective detection means for the clogging problem that may occur inside the liquid cooling system during design and maintenance. Most liquid cooling systems lack real-time monitoring and fault warning functions, and cannot detect in time when clogging occurs. Once clogging occurs, it is often only possible to find the problem through indirect methods such as comprehensive inspection or flow detection, which not only increases the difficulty of maintenance, but also cannot repair in time.

[0004] In addition, the liquid cooling plate design in the prior art is usually a whole module, which cannot detect or repair the clogging problem inside the liquid cooling plate. When the liquid cooling plate is clogged, the prior art can only replace the entire liquid cooling plate to solve the problem. This approach not only increases the maintenance cost, but also wastes a lot of available resources, which is not conducive to environmental protection and sustainable development. SUMMARY

[0005] Therefore, the present application provides a battery pack liquid cooling system and a clogging detection and maintenance method thereof, which can effectively detect the clogging inside the battery pack liquid cooling system and facilitate maintenance, thereby improving the maintenance efficiency of the system, reducing the cost and improving the reliability of the system.

[0006] The technical scheme of the present application is as follows:

[0007] In a first aspect, the present application provides a battery pack liquid cooling system, comprising:

[0008] The box body has a liquid passage cavity in the inner side wall of the length direction of both sides, and a liquid passage opening is arranged at the end of the box body and connected with the liquid passage cavity. The liquid passage opening is used for the inlet and outlet of the cooling liquid.

[0009] The liquid cooling plate is provided with a plurality of liquid cooling plates which are fixed vertically and at equal intervals along the length direction of the box body inside the box body, and the two ends of the liquid cooling plate are respectively provided with threaded interfaces;

[0010] The battery cell is arranged between the two adjacent liquid cooling plates.

[0011] The shunt connector is detachably arranged on the side wall of the box body, and the shunt connector comprises a connecting rod and a locking portion which are connected with each other. The outer peripheral surface of the end of the connecting rod away from the locking portion is provided with external threads. The connecting rod passes through the liquid passage from the outer side wall of the box body and is connected with the threaded interface through the external threads. The locking portion is sealingly abutted on the outer side wall of the box body. The shunt hole which is in communication with the liquid passage is formed in the connecting rod. The shunt channel which is in communication with the shunt hole is formed in the end of the connecting rod away from the locking portion.

[0012] The battery management system comprises a battery cell management unit and a battery management unit. The battery cell management unit comprises a plurality of temperature detection modules. A plurality of detection areas are arranged along the length direction of the box body inside the box body. A plurality of sampling points are arranged along the width direction of the box body in each detection area. The temperature detection modules are located at the sampling points and are used to collect the temperature data of the battery cells at the sampling points. The battery management unit is used to receive and process the temperature detection data transmitted by the battery cell management unit. Whether the temperature abnormity caused by the blockage of the shunt connector exists in the box body is analyzed and judged based on the temperature data, so as to determine the detection area in which the blockage occurs, and the shunt connector in the blocked detection area is maintained or replaced.

[0013] On the basis of the above technical scheme, preferably, the battery management unit comprises a processing unit and a collection module. The collection module is used to collect typical data under the charging working condition of the battery pack. The typical data at least comprises the ambient temperature, the water inlet temperature, the busbar current, the initial minimum temperature of the battery cell and the initial maximum temperature of the battery cell. The processing unit is used to receive the typical data transmitted by the collection module. The current data collected under the real-time working condition is compared with the typical data stored in the basic database by the processing unit, so as to judge whether the blockage occurs.

[0014] On the basis of the above technical scheme, preferably, the box body comprises a bottom plate, two horizontal edge frames and two longitudinal edge frames. The two horizontal edge frames are fixedly arranged at the two ends of the length direction of the bottom plate. The two longitudinal edge frames are fixedly arranged at the two ends of the width direction of the bottom plate. The horizontal edge frame, the longitudinal edge frame and the bottom plate enclose an installation cavity. The liquid cooling plate is vertically arranged in the installation cavity. The two ends of the liquid cooling plate are connected with the longitudinal edge frame through the fixing bolts. The liquid passage is arranged inside the longitudinal edge frame in the length direction. The liquid inlet is located at one end of the longitudinal edge frame in the length direction. The connecting rod passes through the liquid passage from the outer side wall of the longitudinal edge frame and is connected with the threaded interface through the external threads. The locking portion is sealingly abutted on the outer side wall of the longitudinal edge frame.

[0015] On the basis of the above technical scheme, preferably, the liquid cooling plate comprises a heat exchange plate and a current collector fixedly arranged at both ends of the heat exchange plate, the heat exchange plate has a plurality of flow channels inside, and a threaded interface is arranged at an end of the current collector away from the heat exchange plate and is in communication with the flow channels.

[0016] On the basis of the above technical scheme, preferably, the inner wall and the outer wall of the longitudinal frame are respectively provided with a first connecting hole and a second connecting hole in communication with the liquid passage hole, the connecting rod passes through the second connecting hole, the liquid passage cavity and the first connecting hole and is connected with the threaded interface, a first sealing member is arranged between the threaded interface and the first connecting hole, and a second sealing member is arranged between the locking portion and the second connecting hole.

[0017] On the basis of the above technical scheme, preferably, the connecting rod comprises a first rod portion and a second rod portion which are integrally connected, the diameter of the first rod portion is greater than that of the second rod portion, the first rod portion is located in the liquid passage cavity, the diameter of the first connecting hole is greater than that of the second rod portion and smaller than that of the first rod portion, the end face of the first rod portion is sealingly connected with the inner wall of the side of the liquid passage cavity facing the first connecting hole through a third sealing member, the second rod portion is located in the threaded interface, and external threads are arranged on the second rod portion, and a fourth sealing member is arranged between the outer peripheral surface of the second rod portion and the inner wall of the threaded interface.

[0018] In a second aspect, the application discloses a method for detecting and repairing blockage of a battery pack liquid cooling system, comprising the following steps:

[0019] S1. After the use equipment is shipped, typical data of the battery pack is collected and stored as a basic database;

[0020] S2. Under a real-time charging condition, the typical database in the basic database is continuously collected and updated, and the data under the current condition is compared with the basic database;

[0021] S3. When the real-time collected data is inconsistent with the data in the basic database, the related data in the basic database is updated;

[0022] S4. When a group of data collected under the real-time condition is completely consistent with a group of data in the database, the group of data under the current condition and the group of data in the database are continuously compared, according to the difference between the real-time data and the typical data, the current difference, the temperature rise rate difference and the temperature difference comparison indexes are used to judge whether the liquid cooling system has a blockage fault, and the sampling point number in the detection area which does not meet the set condition is recorded;

[0023] S5. The abnormal detection area is located and a fault report is output;

[0024] S6. The shunt joint on the located abnormal detection area is disassembled and cleaned or replaced.

[0025] On the basis of the above technical solutions, preferably, step S4 further comprises the following steps:

[0026] S41, compare the current working condition group data with the same group of data in the database at the same time bus current difference, when the current difference is less than the set value, continue to compare, when the current difference is greater than the set value, end the continuous comparison;

[0027] S42, when the continuous comparison is ended, compare the current working condition group data with the temperature difference and the temperature difference of the same time period corresponding to all sampling points in the same group data in the database, when the temperature difference and the temperature difference are less than 0.1℃ / min, replace the current working condition group data with the comparison data in the database, when the temperature difference and the temperature difference are greater than 0.1℃ / min, record the sampling point number in the detection area that does not meet the set condition.

[0028] On the basis of the above technical solutions, preferably, step S5 comprises the following steps:

[0029] S51, when the number of abnormal temperatures of the detection points in the detection area is greater than or equal to N-1, output the number of the abnormal detection area, when it is less than N-1, define it as a false positive, N is the number of detection points in the detection area, and N≥3;

[0030] S52, when the abnormal output is the sampling column number at both ends of the length direction of the box body, report the liquid cooling system blockage fault and the detection area corresponding to the sampling column number, and the detection area corresponding to the shunt joint number and the liquid cooling plate number;

[0031] S53, when the abnormal output is the sampling column number in the middle of the box body, output the numbers of the two sampling columns adjacent to the abnormal sampling column, compare the temperature difference of the current working condition group data with the temperature difference of all sampling points in the same time period corresponding to the same group data in the database, when the temperature difference is less than 0.05℃ / min, output the numbers of the detection areas corresponding to both sides of the abnormal sampling column, report the liquid cooling system blockage fault and the shunt joint number and the liquid cooling plate number corresponding to the detection area; when the temperature difference is greater than 0.05℃ / min, output the number of the detection area corresponding to the side of the abnormal sampling column, report the liquid cooling system blockage fault and the shunt joint number and the liquid cooling plate number corresponding to the detection area.

[0032] On the basis of the above technical solutions, preferably, step S6 further comprises the following steps:

[0033] S61, read the number of the detection area where the blockage occurs, remove the shunt joints on both sides of the box body corresponding to the detection area, and clean or replace the shunt joints;

[0034] S62, a standard fast charging process is carried out, the fault is read through the diagnostic instrument, when there is no fault report, the maintenance is completed, when there is a blockage fault, the detection area number where the blockage occurs is read, and it is determined whether it is the same as the detection area of the replaced shunt connector;

[0035] S63, when the number of the blocked area is different from the detection area of the replaced shunt connector, step S61 is performed again, when the number of the blocked area is the same as the detection area of the replaced shunt connector, the liquid cooling plate corresponding to the detection area is replaced.

[0036] The present application has the following beneficial effects relative to the prior art:

[0037] (1) By detachably connecting the shunt connector on the box, the circulation of the cooling liquid in the battery pack is realized, the shunt connector can be quickly detached from the box, thereby facilitating the cleaning or maintenance of the blocked shunt connector. The battery management system can realize real-time monitoring of the temperature at each position inside the battery pack through multiple temperature detection modules and multiple sampling points. In this way, the liquid cooling system failure caused by the blockage of the shunt connector can be effectively captured, which causes the cooling liquid to flow to be blocked, thereby causing the temperature of the local area to be abnormal. Based on these real-time temperature data, the battery management unit can accurately analyze the specific position of the blockage, avoiding the delay or missed detection caused by manual inspection or inaccurate detection in the traditional method. After determining the blockage position, the shunt connector at the corresponding position can be cleaned or replaced, thereby improving the blockage detection efficiency and maintenance efficiency of the liquid cooling system, reducing the maintenance cost while improving the reliability of the liquid cooling system.

[0038] (2) By combining real-time data acquisition, typical data storage data comparison and analysis, efficient monitoring and fault diagnosis of the battery pack liquid cooling system can be realized. By comparing the typical data collected under charging conditions with the real-time working condition data, the battery management unit can timely determine whether there is a blockage, and based on the temperature detection data of each sampling point in the detection area, whether there is a temperature anomaly caused by the blockage of the shunt connector in the box is analyzed and determined based on the temperature data to determine the detection area where the blockage occurs, thereby facilitating the maintenance or replacement of the shunt connector in the blocked detection area.

[0039] (3) By providing the shunt connector and the multiple sealing elements, the structure is tightened and sealed while ensuring the normal flow of the cooling liquid inside the battery pack. At the same time, the shunt connector is convenient to disassemble when the blockage occurs subsequently, has high maintenance efficiency and low cost. In addition, the arrangement of the shunt connector and the multiple sealing elements also effectively solves the problem of cooling liquid leakage that may be caused by vibration and long-term use, further improving the safety and reliability of the battery pack.

[0040] (4) The disclosed clogging detection and maintenance method can effectively identify and locate the clogging problem by real-time data collection and comparison with the basic database, combined with multiple indicators such as current and temperature to monitor the liquid cooling system. Each step from data collection, real-time comparison, to difference analysis, fault location, and maintenance operation has a clear process and technical means, ensuring the efficient and stable operation of the liquid cooling system. This method not only improves the accuracy of fault diagnosis, but also reduces maintenance time and cost, helping to improve the overall reliability and maintenance efficiency of the battery pack liquid cooling system.

[0041] (5) The fluctuation of bus current is used to determine whether to end the current continuous comparison, improving the efficiency of comparison; by comparing the temperature rise rate difference and temperature difference, the cooling effect of the liquid cooling system is accurately judged, and the database is updated in time and the fault area is recorded, ensuring the efficiency of fault location and the pertinence of subsequent maintenance. This series of measures effectively optimizes the monitoring capability of the system, making the fault detection more precise and efficient.(6) By refining the abnormal judgment, dynamically comparing the temperature rise rate difference, and accurately locating the fault area, the intelligence and precision of the battery pack liquid cooling system clogging detection and maintenance method are improved, which can effectively reduce misjudgment and improve the efficiency of fault location, and provide accurate guidance information for maintenance. This scheme optimizes the monitoring and maintenance process of the liquid cooling system, has significant technical advantages, especially in the accuracy of fault diagnosis, maintenance efficiency and system reliability. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0043] Figure 1 is a schematic diagram of the three-dimensional structure of the battery pack liquid cooling system disclosed by the present application;

[0044] Figure 2 is an exploded view of the battery pack liquid cooling system disclosed by the present application;

[0045] Figure 3 is a schematic diagram of the structure of the liquid cooling plate disclosed by the present application;

[0046] Figure 4 is a schematic diagram of the three-dimensional structure of the shunt joint disclosed by the present application;

[0047] Figure 5 is a top view of the battery pack liquid cooling system disclosed by the present application;

[0048] Figure 6 As Figure 5 A-A is a schematic view of a plane in the middle;

[0049] Figure 7 As Figure 6 B is a local enlarged view in the middle;

[0050] Figure 8 As a schematic view of the arrangement position of the sampling points in the box body disclosed by the application;

[0051] Figure 9 As a schematic view of the arrangement of the internal detection area of the box body disclosed by the application;

[0052] Figure 10 As a flow chart of the blockage detection method of the battery pack liquid cooling system disclosed by the application;

[0053] Figure 11 As a flow chart of the blockage repair method of the battery pack liquid cooling system disclosed by the application;

[0054] Reference signs:

[0055] 1, box body; 11, bottom plate; 12, horizontal frame; 13, vertical frame; 131, liquid passage cavity; 132, liquid passage; 133, first connecting hole; 134, second connecting hole; 2, liquid cooling plate; 21, heat exchange plate; 22, current collector; 211, flow channel; 221, threaded interface; 3, battery cell; W, fixing bolt; 4, shunt connector; 41, connecting rod; 42, locking part; 411, external thread; 412, shunt hole; 413, shunt passage; M1, first sealing element; M2, second sealing element; M3, third sealing element; M4, fourth sealing element; 41a, first rod part; 41b, second rod part; Q, detection area; P, sampling point. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the application will be clearly and completely described below in conjunction with the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0057] As Figure 1 shown, in combination Figures 2-7 , the application discloses a battery pack liquid cooling system, which comprises a box body 1, a liquid cooling plate 2, a battery cell 3, a shunt connector 4 and a battery management system.

[0058] Among them, the box body 1 serves as the outer shell of the battery pack, which is used to carry the internal battery cells 3 and provide an installation base for the liquid cooling system. In this embodiment, a liquid cavity 131 is opened inside the two side walls of the box body 1 in the longitudinal direction, and the coolant can flow through this cavity. A liquid port 132 connected to the liquid cavity 131 is opened at the end of the box body 1, and the liquid port 132 is used for the coolant to enter and exit. In this embodiment, liquid cavities 131 are respectively set inside the two opposite side walls of the box body 1, so that liquid can enter one liquid cavity 131 and discharge the other liquid cavity 131.

[0059] There are multiple liquid cooling plates 2, which are vertically fixed inside the box body 1 at equal intervals along the length direction of the box body 1. The liquid cooling plates 2 are vertically fixed inside the box body 1. On the one hand, the structural strength of the entire battery pack box body 1 is improved. On the other hand, it is convenient to install the battery cell 3 in the space formed by two adjacent liquid cooling plates 2 and the box body 1, so as to realize the contact heat exchange between the liquid cooling plate 2 and the side wall of the battery cell 3. Threaded interfaces 221 are respectively provided at both ends of the liquid cooling plate 2. The threaded interfaces 221 facilitate the establishment of a quick and detachable connection with the shunt joint 4, thereby improving the maintainability of the system and facilitating the introduction of the cooling liquid in the liquid cavity 131 into or out of the liquid cooling plate 2 through the shunt joint 4, so as to realize the circulation of the cooling liquid inside the battery pack.

[0060] The diverter joint 4 is detachably arranged on the side wall of the box body 1. The detachable structure allows the liquid cooling system to be accurately repaired and replaced when blockage occurs. In the liquid cooling system, the blockage locations are mostly concentrated at the diverter joint 4. By removing the diverter joint 4, the diverter joint 4 can be quickly cleaned or replaced without replacing the liquid cooling plate 2.

[0061] In this embodiment, the diverter joint 4 includes a connecting rod 41 and a locking portion 42 that are interconnected. The outer peripheral surface of the end of the connecting rod 41 away from the locking portion 42 has an external thread 411. The connecting rod 41 passes through the liquid cavity 131 from the outer wall of the box body 1 and is connected to the threaded interface 221 through the external thread 411. The locking portion 42 is sealed against the outer wall of the box body 1. A diverter hole 412 connected to the liquid cavity 131 is provided on the connecting rod 41. A diverter channel 413 connected to the diverter hole 412 is provided on the end of the connecting rod 41 away from the locking portion 42.

[0062] Through the arrangement of the shunt joint 4, the connecting rod 41 can be screwed through the liquid passage 131 by the external thread 411 and the threaded interface 221 on the liquid cooling plate 2, while the locking part 42 abuts against the outer sidewall of the box 1, so as to realize the fixed connection of the liquid cooling plate 2 and the inner sidewall of the box 1 in the horizontal direction. The shunt hole 412 and the shunt passage 413 arranged on the shunt joint 4 enable the cooling liquid in the liquid passage 131 to flow through these holes, so as to form a flow channel for the cooling liquid inside the liquid cooling plate 2 and the box 1. This structural arrangement effectively realizes the circulating flow of the cooling liquid in the battery pack, and improves the heat dissipation effect of the liquid cooling system. At the same time, when the shunt joint 4 is blocked, the shunt joint 4 can be quickly disassembled from the box 1, so as to facilitate the cleaning or repair of the blocked shunt joint 4.

[0063] In order to determine the blocked position, the battery management system is further arranged in the embodiment, which includes a battery cell management unit and a battery management unit. The battery cell management unit includes a plurality of temperature detection modules. A plurality of detection areas Q are arranged along the length direction of the box 1 inside the box 1. Each detection area Q is provided with a plurality of sampling points P along the width direction of the box 1. The temperature detection modules are located at the sampling points P and are used to collect the temperature data of the battery cells at the sampling points P. The battery management unit is used to receive and process the temperature detection data transmitted by the battery cell management unit, to analyze and determine whether there is a temperature anomaly caused by the blockage of the shunt joint 4 inside the box 1, to determine the detection area Q where the blockage occurs, and to facilitate the repair or replacement of the shunt joint 4 in the blocked detection area Q.

[0064] The battery management system can realize real-time monitoring of the temperature at each position inside the battery pack through the plurality of temperature detection modules and the plurality of sampling points P. In this way, the liquid cooling system failure caused by the blockage of the shunt joint 4 can be effectively captured, which causes the cooling liquid flow to be blocked and the temperature of the local area to be abnormal. Based on these real-time temperature data, the battery management unit can accurately analyze the specific position where the blockage occurs, avoiding the delay or missed detection caused by manual inspection or inaccurate detection in the traditional method. After the blocked position is determined, the shunt joint 4 at the corresponding position can be cleaned or replaced, thereby improving the blockage detection efficiency and repair efficiency of the liquid cooling system, reducing the maintenance cost, and improving the reliability of the liquid cooling system.

[0065] In order to determine whether the liquid cooling system is blocked, the embodiment further discloses the following scheme: the battery management unit of the embodiment includes a processing unit and a collection module. The collection module is used to collect typical data under the charging working condition of the battery pack. The typical data at least includes the ambient temperature, the inlet temperature, the bus current, the initial minimum temperature of the battery cell, and the initial maximum temperature of the battery cell 3. The processing unit is used to receive the typical data transmitted by the collection module. Under the real-time working condition, the processing unit compares the current data collected under the real-time working condition with the typical data stored in the basic database, to determine whether the blockage occurs.

[0066] Among the above typical data, the ambient temperature helps to evaluate the influence of external conditions on the liquid cooling system, the inlet temperature reflects the temperature condition of the coolant, the bus current is the charging current of the battery pack, and the initial minimum temperature and the initial maximum temperature of the battery cell help to monitor the temperature condition of different battery cells in the battery pack. It is worth noting that the initial minimum temperature and the initial maximum temperature of the battery cell are obtained by the temperature detection module.

[0067] The basic database contains the above typical data collected under the charging condition of the battery pack, which represents the typical performance and expected state of the system under normal working conditions. The basic database serves as a reference for comparison of real-time data, which will be used as a standard data set to determine whether the system is running normally.

[0068] The core function of the processing unit is to compare the real-time working condition data with the typical data stored in the basic database. The purpose of this comparison is to determine whether the current working condition matches the typical data and to ensure the normal operation of the liquid cooling system. If there is a deviation between the real-time data and the typical data, it may indicate that an abnormality has occurred in the liquid cooling system (such as blockage of the liquid cooling pipeline, poor flow of the coolant, etc.), which requires further inspection of the system failure. At this time, it is necessary to determine whether there is a temperature anomaly in the box 1 due to the blockage of the shunt joint 4 based on temperature data analysis, to determine the detection area Q where the blockage occurs, and to facilitate the repair or replacement of the shunt joint 4 in the blocked detection area Q.

[0069] By combining real-time data acquisition, typical data storage, and data comparison analysis, efficient monitoring and fault diagnosis of the battery pack liquid cooling system can be achieved. By comparing the typical data collected under the charging condition with the real-time working condition data, the battery management unit can timely determine whether there is a blockage, and in combination with the temperature detection data of each sampling point P in the detection area Q, it can determine whether there is a temperature anomaly in the box 1 due to the blockage of the shunt joint 4 based on temperature data analysis, to determine the detection area Q where the blockage occurs, and to facilitate the repair or replacement of the shunt joint 4 in the blocked detection area Q.

[0070] The box 1 disclosed in the embodiment comprises a bottom plate 11, two horizontal frames 12 and two vertical frames 13, the two horizontal frames 12 are respectively fixedly arranged at the two ends of the bottom plate 11 in the length direction, the two vertical frames 13 are respectively fixedly arranged at the two ends of the bottom plate 11 in the width direction, the horizontal frame 12, the vertical frame 13 and the bottom plate 11 form an installation cavity, the liquid cooling plate 2 is vertically arranged in the installation cavity, the two ends of the liquid cooling plate 2 are connected with the vertical frame 13 through the fixing bolt W, the liquid passage 131 is arranged inside the vertical frame 13 in the length direction, the liquid inlet 132 is located at one end of the vertical frame 13 in the length direction, the connecting rod 41 passes through the liquid passage 131 from the outer wall of the vertical frame 13 and is connected with the threaded interface 221 through the external thread 411, and the locking part 42 is sealed and abuts against the outer wall of the vertical frame 13.

[0071] In the embodiment, the shunt joint 4 horizontally passes through the vertical frame 13 and is threadedly and tightly connected with the liquid cooling plate 2, on the one hand, the firm connection between the two is realized, the sealing effect of the connection is improved, on the other hand, it is ensured that the cooling liquid enters the inside of the liquid cooling plate 2 in the liquid passage 131. At the same time, the vertical frame 13 and the liquid cooling plate 2 are connected through the fixing bolt W, which further ensures the fixation of the liquid cooling plate 2 in the box 1, avoids loosening of the liquid cooling plate 2 due to vibration or external force during operation, and ensures the sealing effect of the connection between the liquid cooling plate 2 and the vertical frame 13.

[0072] In the above embodiment, the locking part 42 is preferably a bolt cap, which is convenient for rotating by a wrench, realizes quick connection of the vertical frame 13 and the liquid cooling plate 2 by the shunt joint 4, and realizes the flow passage formed by the liquid passage 131, the shunt joint 4 and the liquid cooling plate 2.

[0073] As some preferable embodiments, the liquid cooling plate 2 comprises a heat exchange plate 21 and a current collector 22 fixedly arranged at the two ends of the heat exchange plate 21, the heat exchange plate 21 has a plurality of flow channels 211 inside, the threaded interface 221 is arranged at one end of the current collector 22 away from the heat exchange plate 21 and is in communication with the flow channel 211. By dividing the liquid cooling plate 2 into the heat exchange plate 21 and the current collector 22, the processing of the flow channel 211 inside the heat exchange plate 21 is facilitated, and the current collector 22 is convenient for connection through the threaded interface 221 and the shunt interface. In the embodiment, the liquid cooling plate 2 and the current collector 22 are connected through a welding process.

[0074] In order to realize the connection of the vertical frame 13 and the liquid cooling plate 2 by the shunt joint 4, the first connecting hole 133 and the second connecting hole 134 in communication with the liquid passage are respectively arranged on the inner wall and the outer wall of the vertical frame 13 in the embodiment, the connecting rod 41 passes through the second connecting hole 134, the liquid passage 131 and the first connecting hole 133 and is connected with the threaded interface 221, the first sealing element M1 is arranged between the threaded interface 221 and the first connecting hole 133, and the second sealing element M2 is arranged between the locking part 42 and the second connecting hole 134.

[0075] Specifically, the first sealing member M1 is located between the threaded interface 221 and the inner wall of the longitudinal frame 13. After the liquid cooling plate 2 and the inner wall of the box body 1 are tightly connected through the first sealing member M1, the first sealing member M1 can effectively seal the first connecting hole 133 on the threaded interface 221 and the inner wall of the box body 1. Even if the liquid cooling plate 2 and the box body 1 are slightly displaced due to long-term work or vibration, the first sealing member M1 can prevent the cooling liquid from leaking from the connection between the threaded interface 221 and the inner wall of the box body 1, avoid the cooling liquid from leaking into the box body 1, and reduce the damage risk of the cooling liquid to the battery cell 3.

[0076] As some preferred embodiments, the connecting rod 41 comprises a first rod portion 41a and a second rod portion 41b which are integrally connected. The diameter of the first rod portion 41a is greater than that of the second rod portion 41b. The first rod portion 41a is located in the liquid passage 131. The diameter of the first connecting hole 133 is greater than that of the second rod portion 41b and smaller than that of the first rod portion 41a. The end surface of the first rod portion 41a is sealed and connected with the inner wall of the liquid passage 131 on the side facing the first connecting hole 133 through the third sealing member M3. The second rod portion 41b is located in the threaded interface 221, and the external thread 411 is arranged on the second rod portion 41b. The fourth sealing member M4 is arranged between the outer peripheral surface of the second rod portion 41b and the inner wall of the threaded interface 221.

[0077] By segmenting the connecting rod 41, when the entire flow divider 4 passes through the longitudinal frame 13, the second rod portion 41b is effectively threadedly connected with the threaded interface 221 on the liquid cooling plate 2 through the external thread 411. The first rod portion 41a is located in the liquid passage 131 and will not pass through the liquid passage 131. The diameter of the first rod portion 41a is greater than that of the second rod portion 41b, so that the end surface of the first rod portion 41a is sealed and connected with the inner wall of the liquid passage 131 through the third sealing member M3, avoiding the cooling liquid in the liquid passage 131 from leaking to the inside of the battery pack through the connection between the first rod portion 41a and the first connecting hole 133, and improving the liquid cooling sealing reliability.

[0078] Through the arrangement of the fourth sealing member M4, the contact surface between the second rod portion 41b and the threaded interface 221 is fully sealed, avoiding the leakage of the cooling liquid from the connection between the second rod portion 41b and the threaded interface 221, ensuring that the cooling liquid will not leak from the connection gap between the second rod portion 41b and the threaded interface 221 to the first sealing member M1, thereby avoiding or reducing the risk of the cooling liquid leaking from the connection between the liquid cooling plate 2 and the inner wall of the longitudinal frame 13 to the inside of the box body 1.

[0079] The battery pack liquid cooling system disclosed in the above embodiment, through the setting of the shunt joint 4 and the multiple sealing pieces, ensures the normal flow of the cooling liquid inside the battery pack, improves the fastening and sealing capacity of the structure, and facilitates the disassembly when the subsequent blockage occurs, has high maintenance efficiency and low cost. In addition, the setting of the shunt joint 4 and the multiple sealing pieces also effectively solves the problem of cooling liquid leakage that may be caused by vibration and long-term use, further improves the safety and reliability of the battery pack.

[0080] The application further provides a blockage detection and maintenance method for the battery pack liquid cooling system, referring to the accompanying drawings Figures 8-11 as shown, comprising the following steps:

[0081] S1, after the use of the electrical equipment, the typical data of the battery pack is collected and stored as a basic database;

[0082] The key of this step is to preliminarily collect the performance of the battery pack liquid cooling system under typical working conditions to form a "typical data" set. The working conditions mainly involve charging conditions, and the data includes environmental temperature, inlet temperature, bus current, initial minimum temperature of the battery cell, and initial maximum temperature of the battery cell, and other key parameters. The database storing these typical data will be used as a reference value for the normal operation of the battery pack liquid cooling system, and will be used for comparison with the data under actual working conditions during subsequent real-time monitoring.

[0083] S2, under the real-time charging condition, the typical database in the basic database is continuously collected and updated, and the data under the current working condition is compared with the basic database;

[0084] Under the charging condition of the battery pack, the typical data is collected in real time through the collection module, and the real-time collected data is continuously stored and updated in the basic database. This step ensures that the data in the database can be dynamically adjusted with the change of the working condition of the battery pack, so that it is more close to the actual situation. With the passage of time, the battery pack liquid cooling system will experience different loads and environmental conditions, and continuous updating of the database can better adapt to various working conditions.

[0085] S3, when the real-time collected data is inconsistent with the data in the basic database, update the related data in the basic database; when a certain typical data collected does not match the data in the database, it means that there is new typical data, then the related data in the database is automatically updated, and the update of the database ensures that the system can adapt to these changes and improve the monitoring accuracy.

[0086] S4, when a certain set of data collected in real-time working condition and the same set of data in the database are completely consistent, then extract the set of data in the current working condition and the same set of data in the database for continuous comparison, according to the difference between real-time data and typical data, using current difference, temperature rise rate difference and temperature difference comparison index to judge whether the liquid cooling system has a blockage fault, and record the sampling point number in the detection area that does not meet the set condition;

[0087] If a certain set of data collected in real-time working condition and the same set of data in the database are completely consistent, it means that this set of data meets the expectation under normal operating conditions. At this time, the system starts to deeply compare the differences between real-time data and database data, focusing on current difference, temperature rise rate difference and temperature difference. These indicators can help determine whether the liquid cooling system has a blockage.

[0088] S5, positioning the abnormal detection area and outputting a fault report;

[0089] S6, disassembling the shunt joint on the positioned abnormal detection area and cleaning or replacing it.

[0090] This method monitors the liquid cooling system by comparing real-time data collection with the basic database, combining multiple indicators such as current and temperature, which can effectively identify and locate the blockage problem. Each step from data collection, real-time comparison, to difference analysis, fault location, and maintenance operation has a clear process and technical means, ensuring efficient and stable operation of the liquid cooling system. This method not only improves the accuracy of fault diagnosis, but also reduces maintenance time and cost, helping to improve the overall reliability and maintenance efficiency of the battery pack liquid cooling system.

[0091] In the above embodiment, step S4 further comprises the following steps:

[0092] S41, compare the bus current difference of the set of data in the current working condition with the same set of data in the database at the same time, when the current difference is less than the set value, continue to compare, when the current difference is greater than the set value, end the continuous comparison.

[0093] Since the bus current reflects the energy transmission during charging, its fluctuation is very sensitive to identifying working condition differences, and can more accurately reflect changes in system status than other typical parameters (such as water inlet, etc.). When the bus current difference is greater than the set value, it means that the charging process has an abnormality or significant change, at which point the comparison has lost its significance, and continuing to compare will waste time and computing resources. Therefore, setting the current difference threshold as the end of comparison is an efficient strategy.

[0094] For example, when the battery difference is less than 5A, the comparison is continued when the current difference is less than the set value, ensuring that the comparison process is not terminated prematurely due to a too small current fluctuation. When the current difference is greater than the set value, it indicates that the liquid cooling system has a significant abnormality, at which point the comparison can be stopped and further fault localization can be performed.

[0095] S42, when the continuous comparison is ended, the temperature rise rate difference and temperature difference of the same time period corresponding to all sampling points in the same group of data in the database under the current working condition are compared, when the temperature rise rate difference and temperature difference are both less than 0.1℃ / min, the current working condition group data is replaced with the comparison data in the database, when the temperature rise rate difference and temperature difference are both greater than 0.1℃ / min, the sampling point number in the detection area that does not meet the set condition is recorded.

[0096] When the liquid cooling system is working, any blockage or flow obstruction will cause the heat transfer efficiency to decrease, which in turn affects the temperature rise rate and temperature distribution. By comparing the temperature rise rate difference and temperature difference under the current working condition, it can help further diagnose whether there is blockage. When the temperature rise rate difference and temperature difference are both less than 0.1℃ / min, it indicates that the performance of the liquid cooling system under the current working condition is good, and the group data can be updated to the database as new typical data reference, ensuring the accuracy and real-time of the basic database. When the temperature rise rate difference and temperature difference are both greater than 0.1℃ / min, it indicates that the liquid cooling system may have blockage or other performance problems. At this time, the system will record the sampling point number where the abnormal data is located, which is convenient for subsequent positioning of the detection area where the sampling point is located.

[0097] The fluctuation of the bus current is used to determine whether to end the current continuous comparison, improving the efficiency of the comparison. By comparing the temperature rise rate difference and temperature difference, it can accurately judge whether the cooling effect of the liquid cooling system is abnormal, update the database in time and record the fault area, ensuring the efficiency of fault positioning and the pertinence of subsequent maintenance. This series of measures effectively optimizes the monitoring ability of the system, making the fault detection more precise and efficient.

[0098] In order to further determine the blockage of the detection area in the box, the embodiment discloses the following technical scheme.

[0099] Specifically, step S5 further includes the following steps:

[0100] S51, when the number of abnormal detection points in the detection area is greater than or equal to N-1, output the number of the abnormal detection area, when it is less than N-1, it is defined as a false positive, N is the number of sampling points in the detection area, and N≥3.

[0101] By setting the threshold value N-1, that is, only when the number of abnormal temperature points is close to the total number of the entire detection area, it is determined that the area has a problem. In this way, false positives caused by occasional or small-scale abnormalities can be reduced, and accidental temperature fluctuations can be avoided. For example, in the present embodiment, the box is divided into 4 vertical detection areas from left to right, which are X-1, X-2, X-3 and X-4. Each vertical detection area has four small areas from top to bottom. The leftmost vertical detection area X-1 is divided into 1-1, 2-1, 3-1 and 4-1 from top to bottom. The middle two vertical areas are numbered 1-2, 2-2, 3-2 and 4-2, and 1-3, 2-3, 3-3 and 4-3. The rightmost vertical area is numbered 1-4, 2-4, 3-4 and 4-4. The four detection areas correspond to five sampling columns, which are NTCX-1, NTCX-2, NTCX-3, NTCX-4 and NTCX-5. Each sampling column has four NTC sampling points from top to bottom. The topmost is NTC1-1~NTC1-5(corresponding to the first row of battery cells), the middle is NTC2-1~NTC2-5(corresponding to the second row of battery cells) and NTC3-1~NTC3-5(corresponding to the third row of battery cells), and the bottommost is NTC4-1~NTC4-5(corresponding to the fourth row of battery cells). Among them, there is a vertical detection area between two sampling columns, for example, the vertical detection area X-1 between the box NTCX-1 and NTCX-2.

[0102] When there are at least 3 abnormal sampling points in one sampling column in a vertical detection area, it is considered that the area has a problem, which effectively avoids unnecessary alarms and overreaction, and improves the accuracy of detection and the stability of the system.

[0103] In practical applications, the liquid cooling system may cause temporary fluctuations in some temperature points due to changes in external environment or other non-systematic reasons. By setting such an abnormal number threshold, the system can make a judgment based on the overall performance of most detection points, reduce false positives caused by local or occasional problems, and ensure the reliability of the final diagnosis result.

[0104] S52, when the abnormal output is the sampling column number at both ends of the box length direction, report the liquid cooling system blockage fault and the detection area corresponding to the sampling column number, and the shunt joint number and the liquid cooling plate number corresponding to the detection area.

[0105] Specifically, when the abnormal sampling column number is on the left and right sides of the box, the abnormal detection area number output is X-1 or X-5, which means that there is a single-sided cell in the detection area corresponding to the single-sided cell. The determination of this detection area is unique, and when reporting the fault information, not only the abnormal area is indicated, but also the specific hardware component number (such as the shunt joint number and the liquid cooling plate number) is reported together, which can greatly improve the maintenance efficiency and accuracy, and reduce the positioning time and workload of maintenance personnel.

[0106] Specifically, in the first leftmost column sampling column NTCX-1, at least three sampling points are abnormal, which means that the detection area is X-1. In the last column sampling column NTCX-5 on the right, at least three sampling points are abnormal, which means that the detection area is X-5. Because these sampling columns only have a single-sided area with a cell, the detection area can be uniquely determined.

[0107] Step S53, when the abnormal output is the sampling column number in the middle of the box, output the two sampling column numbers adjacent to the abnormal sampling column number, compare the temperature rise rate difference of the same time period corresponding to all sampling points in the same group of data in the current working condition and the database, when the temperature rise rate difference is less than 0.05℃ / min, output the detection area number corresponding to the two sides of the abnormal sampling column number, report the liquid cooling system blockage fault and the shunt joint number and the liquid cooling plate number corresponding to the detection area; when the temperature rise rate difference is greater than 0.05℃ / min, output the detection area number corresponding to the side of the abnormal sampling column number, report the liquid cooling system blockage fault and the shunt joint number and the liquid cooling plate number corresponding to the detection area.

[0108] For example, when the output abnormal sampling column number is NTCX-2, determine the sampling column numbers NTCX-1 and NTCX-2 to see which detection area corresponding to the shunt joint is blocked. Then compare the temperature rise rate difference of the same time period corresponding to all sampling points in the same group of data in the current working condition and the database, when the temperature rise rate difference is less than 0.05℃ / min, if the sampling column numbers NTCX-1 and NTCX-2 are both abnormal, the abnormal results are consistent, which means that the detection area with the number X-1 between NTCX-2 and NTCX-1 and the detection area with the number X-2 between NTCX-2 and NTCX-1 are blocked, and if only one side is abnormal, for example, only NTCX-1 is abnormal, it means that the detection area with the number X-1 between NTCX-2 and NTCX-1 is blocked.

[0109] By refining the abnormality judgment, dynamically comparing the temperature rise rate difference, and accurately locating the fault area, the intelligence and accuracy of the battery pack liquid cooling system blockage detection and maintenance method are improved, which can effectively reduce misjudgment and improve the efficiency of fault location, and provide accurate guidance information for maintenance. This scheme optimizes the monitoring and maintenance process of the liquid cooling system, has significant technical advantages, especially in the accuracy of fault diagnosis, maintenance efficiency and system reliability.

[0110] In order to realize the maintenance of the blockage, the step S6 of the present application further comprises the following steps:

[0111] S61, read the detection area number where the blockage occurs, remove the shunt joint on both sides of the box corresponding to the detection area, and clean or replace the shunt joint.

[0112] This step first locates the blocked detection area, and by reading the specific area number, it can accurately find the shunt joint that may be blocked. The shunt joint is one of the key components of the liquid cooling system, responsible for guiding the flow of cooling liquid to different areas, and once blocked, it will affect the liquid cooling effect. Therefore, cleaning or replacing the shunt joint can effectively solve the fluid blockage problem and restore the system to normal operation.

[0113] S62, perform a standard fast charging process, read the fault through the diagnostic instrument, and if there is no fault reported, the maintenance is completed, and if there is a blockage fault, read the detection area number where the blockage occurs, and determine whether it is the same as the detection area where the shunt joint has been replaced.

[0114] By implementing the standard fast charging process, the system can simulate the load under actual working conditions, thereby quickly verifying the working condition of the liquid cooling system. If the fault disappears after maintenance, no fault is reported, which means that the shunt joint problem has been solved and the system has returned to normal operation. This verification process provides immediate feedback on the effectiveness of the maintenance, ensuring the effectiveness of the maintenance operation.

[0115] S63, when the number of the blocked area is different from the detection area where the shunt joint has been replaced, perform step S61 again, and when the number of the blocked area is the same as the detection area where the shunt joint has been replaced, replace the liquid cooling plate corresponding to the detection area.

[0116] The liquid cooling plate is one of the core components of the battery pack liquid cooling system, responsible for heat exchange with the cooling liquid. If the liquid cooling plate is blocked, it may cause the cooling liquid to fail to circulate effectively, thereby affecting the heat dissipation effect of the battery. This step compares whether the fault location has been solved and the corresponding area of the shunt joint, and if the blockage still exists and the shunt joint replacement area is ineffective, the liquid cooling plate needs to be removed for maintenance.

[0117] The above merely provides the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery pack liquid cooling system, characterized by, The application relates to a battery pack, which comprises a box (1), a liquid cooling plate (2) and a battery cell (3). The box (1) is internally provided with liquid passing cavities (131) on both sides in the length direction, and is internally provided with liquid passing openings (132) at the ends and in communication with the liquid passing cavities (131); the liquid passing openings (132) are used for feeding and discharging cooling liquid. The liquid cooling plate (2) is vertically fixed in the box (1) at equal intervals in the length direction of the box (1) and is provided with threaded interfaces (221) at both ends. The battery cell (3) is arranged between two adjacent liquid cooling plates (2). The shunt connector (4) is detachably arranged on the side wall of the box (1) and comprises a connecting rod (41) and a locking part (42) which are connected with each other; the outer periphery of one end of the connecting rod (41) away from the locking part (42) is provided with an external thread (411); the connecting rod (41) passes through the liquid passing cavity (131) from the outer side wall of the box (1) and is connected with the threaded interface (221) through the external thread (411); the locking part (42) is sealed and abuts on the outer side wall of the box (1); the connecting rod (41) is provided with a shunt hole (412) in communication with the liquid passing cavity (131); and the connecting rod (41) is provided with a shunt channel (413) in communication with the shunt hole (412) at the end away from the locking part (42). The battery management system comprises a battery cell management unit and a battery management unit; the battery cell management unit comprises a plurality of temperature detection modules; a plurality of detection areas (Q) are arranged in the box along the length direction of the box; a plurality of sampling points (P) are arranged in each detection area (Q) along the width direction of the box (1); the temperature detection modules are arranged at the sampling points (P) and are used for collecting the battery cell temperature data at the sampling points (P); the battery management unit is used for receiving and processing the temperature detection data transmitted by the battery cell management unit, judging whether the temperature abnormity caused by the blockage of the shunt connector (4) exists in the box (1) based on the temperature data, determining the detection area (Q) where the blockage occurs, and facilitating the maintenance or replacement of the shunt connector (4) in the blocked detection area (Q). The battery management unit comprises a processing unit and a collection module; the collection module is used for collecting typical data under the battery pack charging working condition; the typical data at least comprises an environment temperature, an inlet temperature, a bus current, a battery cell initial minimum temperature and a battery cell initial maximum temperature; the processing unit is used for receiving the typical data transmitted by the collection module; under the real-time working condition, the processing unit compares the current data collected under the real-time working condition with the typical data stored in the basic database to judge whether the blockage occurs. When a certain group of data collected under the real-time working condition is completely consistent with the same group of data in the database, the current data under the working condition and the same group of data in the database are continuously compared; according to the difference between the real-time data and the typical data, the current difference, the temperature rise rate difference and the temperature difference comparison indexes are used to judge whether the liquid cooling system is blocked and to record the sampling point number in the detection area which does not satisfy the set condition.

2. The battery pack liquid cooling system of claim 1, wherein: The box (1) comprises a bottom plate (11), two horizontal frames (12) and two vertical frames (13), the two horizontal frames (12) are fixedly arranged at the two ends of the bottom plate (11) in the length direction, the two vertical frames (13) are fixedly arranged at the two ends of the bottom plate (11) in the width direction, the horizontal frame (12), the vertical frame (13) and the bottom plate (11) form an installation cavity, the liquid cooling plate (2) is vertically arranged in the installation cavity, the two ends of the liquid cooling plate (2) are connected with the vertical frame (13) through the fixing bolt (W), the liquid passage (131) is arranged inside the vertical frame (13) in the length direction, the liquid inlet (132) is located at one end of the vertical frame (13) in the length direction, the connecting rod (41) passes through the liquid passage (131) from the outer wall of the vertical frame (13) and is connected with the threaded interface (221) through the external thread (411), and the locking part (42) is sealed and abuts against the outer wall of the vertical frame (13).

3. The battery pack liquid cooling system of claim 2, wherein: The liquid cooling plate (2) comprises a heat exchange plate (21) and a current collector (22) fixedly arranged at the two ends of the heat exchange plate (21), the heat exchange plate (21) has a plurality of flow channels (211) inside, the threaded interface (221) is arranged at one end of the current collector (22) away from the heat exchange plate (21) and is in communication with the flow channel (211).

4. The battery pack liquid cooling system of claim 2, wherein: The inner wall and the outer wall of the vertical frame (13) are respectively provided with a first connecting hole (133) and a second connecting hole (134) in communication with the liquid passage, the connecting rod (41) passes through the second connecting hole (134), the liquid passage (131) and the first connecting hole (133) and is connected with the threaded interface (221), the first sealing element (M1) is arranged between the threaded interface (221) and the first connecting hole (133), and the second sealing element (M2) is arranged between the locking part (42) and the second connecting hole (134).

5. The battery pack liquid cooling system of claim 4, wherein: The connecting rod (41) comprises a first rod part (41a) and a second rod part (41b) connected integrally, the diameter of the first rod part (41a) is greater than that of the second rod part (41b), the first rod part (41a) is located in the liquid passage (131), the diameter of the first connecting hole (133) is greater than that of the second rod part (41b) and smaller than that of the first rod part (41a), the end surface of the first rod part (41a) is sealingly connected with the inner wall of the liquid passage (131) on the side facing the first connecting hole (133) through the third sealing element (M3), the second rod part (41b) is located in the threaded interface (221), and the external thread (411) is arranged on the second rod part (41b), and the fourth sealing element (M4) is arranged between the outer peripheral surface of the second rod part (41b) and the inner wall of the threaded interface (221).

6. A method of clogging detection and maintenance of a battery pack liquid cooling system according to any one of claims 1 to 5, characterized in that The method comprises the following steps: S1, after the use of the electrical equipment, the typical data of the battery pack is collected and stored as a basic database; S2, in the real-time charging condition, the typical database in the basic database is continuously collected and updated, and the data in the current condition is compared with the basic database; S3, when the real-time collected data is inconsistent with the data in the basic database, the related data in the basic database is updated; S4, when a certain group of data collected in real time and the same group of data in the database are completely consistent, then the group of data in the current working condition and the same group of data in the database are extracted for continuous comparison, according to the difference between the real-time data and the typical data, the current difference, the temperature rise rate difference and the temperature difference comparison index are used to judge whether the liquid cooling system has a blockage fault, and the sampling point number in the detection area that does not meet the set condition is recorded; S5, positioning the abnormal detection area and outputting the fault report; S6, disassembling the shunt joint on the positioned abnormal detection area and cleaning or replacing it.

7. The method of claim 6, wherein the method further comprises: determining whether the liquid cooling system is blocked based on the measured temperature of the battery pack. Step S4 further includes the following steps: S41, compare the bus current difference of the group data in the current working condition and the same group data in the database at the same time, when the current difference is less than the set value, continue to compare, when the current difference is greater than the set value, end the continuous comparison; S42, when the continuous comparison is ended, compare the temperature rise rate difference and the temperature difference of the group data in the current working condition and the same group data in the database corresponding to the same time period of all sampling points, when the temperature rise rate difference and the temperature difference are both less than 0.1℃ / min, replace the group of comparison data in the database with the group of data in the current working condition, when the temperature rise rate difference and the temperature difference are both greater than 0.1℃ / min, record the sampling point number in the detection area that does not meet the set condition.

8. The method of claim 7, wherein the method further comprises: Step S5 specifically includes the following steps: S51, when the number of abnormal temperature detection points in the detection area is greater than or equal to N-1, output the number of abnormal detection areas, when it is less than N-1, it is defined as a false positive, N is the number of sampling points in the detection area, and N≥3; S52, when the abnormal output is the sampling column number at both ends of the length direction of the box body, report the liquid cooling system blockage fault and the detection area corresponding to the sampling column number, and the detection area corresponding to the shunt joint number and the liquid cooling plate number; S53, when the abnormal output is the sampling column number in the middle of the box body, output the numbers of the two sampling columns adjacent to the abnormal sampling column, compare the temperature rise rate difference of the group data in the current working condition and the same group data in the database corresponding to the same time period of all sampling points, when the temperature rise rate difference is less than 0.05℃ / min, output the numbers of the detection areas corresponding to both sides of the abnormal sampling column, report the liquid cooling system blockage fault and the detection area corresponding to the shunt joint number and the liquid cooling plate number; when the temperature rise rate difference is greater than 0.05℃ / min, output the number of the detection area corresponding to the side of the abnormal sampling column, report the liquid cooling system blockage fault and the detection area corresponding to the shunt joint number and the liquid cooling plate number.

9. The method of claim 6, wherein the method further comprises: determining whether the battery pack liquid cooling system is blocked based on the temperature of the battery pack liquid cooling system. Step S6 further includes the following steps: S61, read the detection area number where the blockage occurs, remove the shunt joints on both sides of the box body corresponding to the detection area, and clean or replace the shunt joints; S62, perform a standard fast charging process, read the fault through the diagnostic instrument, if there is no fault report, the repair is completed, if there is a blockage fault, read the detection area number where the blockage occurs, and determine whether it is the same as the detection area where the shunt joint has been replaced. S63, when the number of the blocked area and the detection area of the replaced shunt joint are different, proceed with step S61, and when the number of the blocked area and the detection area of the replaced shunt joint are the same, replace the liquid cooling plate corresponding to the detection area.

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