Battery pack fault monitoring system and battery pack fault monitoring and processing system

Abstract

The utility model discloses a battery pack fault monitoring system and a battery pack fault monitoring and processing system. The monitoring system comprises a first monitoring device and a second monitoring device. The first monitoring device is arranged in the battery pack and is used for monitoring a first gas signal generated in the battery pack so as to preliminarily judge whether liquid leakage or thermal runaway occurs in the battery pack; and the second monitoring device is used for monitoring a second gas signal generated by the battery pack so as to accurately judge liquid leakage or thermal runaway of the battery pack. According to the utility model, two faults of liquid leakage or thermal runaway possibly occur in a single battery in the operation process of the battery pack, whether the battery pack has a fault can be accurately judged through the first monitoring device, and the fault type can be accurately judged by using the second monitoring device, so that effective support is provided for subsequent fault processing means, and the working efficiency of the battery pack is improved. And misoperation during troubleshooting is avoided.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, and particularly relates to a battery pack fault monitoring system and a battery pack fault monitoring and processing system. Background Art

[0002] Lithium-ion batteries are widely used in various fields, covering multiple fields such as electronic products, electric vehicles, energy storage systems, aerospace, etc.

[0003] Due to the principle and structural characteristics of lithium-ion batteries, faults will occur during repeated use.

[0004] Generally, there are two types of faults. One is that the battery leaks liquid, and the other is that the battery undergoes thermal runaway during use.

[0005] In order to meet the demand for large-capacity use, lithium-ion batteries are generally assembled into battery packs for use. How to accurately monitor whether the battery pack has a fault and the type of the fault are currently technical problems urgently to be solved in this field. Content of the Utility Model

[0006] In order to accurately monitor whether the battery pack has a fault and the type of the fault, the first aspect of the utility model provides a battery pack fault monitoring system.

[0007] The monitoring system includes a first monitoring device and a second monitoring device;

[0008] The first monitoring device is arranged in the battery pack to monitor the first gas signal generated in the battery pack, and then make a preliminary determination on whether the battery pack has liquid leakage or thermal runaway;

[0009] The second monitoring device is used to monitor the second gas signal generated in the battery pack, and then make an accurate determination on whether the battery pack has liquid leakage or thermal runaway.

[0010] Furthermore, the above-mentioned first monitoring device is a TVOC detection device or a first air pressure sensor arranged in the battery pack; the second monitoring device is an air flow sensor or a second air pressure sensor.

[0011] The second aspect of the utility model provides a battery pack fault monitoring and processing system, including a fault monitoring part and a fault processing part;

[0012] The fault monitoring part includes a first monitoring device and a second monitoring device;

[0013] The first monitoring device is arranged in the battery pack to monitor the first gas signal generated in the battery pack, and then make a preliminary determination on whether the battery pack has liquid leakage or thermal runaway;

[0014] The second monitoring device is used to monitor the second gas signal generated inside the battery pack, and then accurately determine whether the battery pack has liquid leakage or thermal runaway.

[0015] The fault handling part includes a fire extinguishing medium storage tank, a liquid inlet pipeline assembly, a liquid return pipeline assembly, and a fire extinguishing medium flow passage provided on the battery pack;

[0016] The fire extinguishing medium storage tank, the liquid inlet pipeline assembly, the fire extinguishing medium flow passage, and the liquid return pipeline assembly are connected in sequence to form a fire extinguishing medium circulation path;

[0017] The fire extinguishing medium flow passage is used to inject the fire extinguishing medium into the battery pack to suppress thermal runaway.

[0018] Further, the above-mentioned fire extinguishing medium flow passage includes a horizontal passage and a vertical passage. The horizontal passage is located above the explosion relief membranes of each single battery in the battery pack, and vertical passages are provided between the horizontal passage and each single battery explosion relief membrane.

[0019] Further, the above-mentioned first monitoring device is a TVOC detection device or a first air pressure sensor provided inside the battery pack; the second monitoring device is an air flow sensor or a second air pressure sensor.

[0020] Further, the above-mentioned second monitoring device is installed in the fire extinguishing medium flow passage or the liquid return pipeline assembly. Description of the Drawings

[0021] Figure 1 It is a flowchart of the monitoring method in Embodiment 1;

[0022] Figure 2 It is a flowchart of the monitoring and processing method in Embodiment 2;

[0023] Figure 3 It is a principle block diagram of the monitoring and processing system in Embodiment 2.

[0024] The reference numerals are as follows:

[0025] 1 - First monitoring device, 2 - Second monitoring device, 3 - Fire extinguishing medium storage tank, 4 - Liquid inlet pipeline assembly, 41 - Liquid inlet pipe, 42 - Liquid inlet pump, 43 - Liquid inlet switch, 5 - Liquid return pipeline assembly, 51 - Liquid return pipe, 52 - Liquid return pump, 6 - Fire extinguishing medium flow passage, 61 - Horizontal passage, 62 - Vertical passage. Detailed Embodiment

[0026] The technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments, rather than all the embodiments. Based on the following embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0027] Meanwhile, it should be noted that the orientation or positional relationship indicated by terms such as "upper, lower, inner and outer" in the text is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of simplified description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the technical solution. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0028] Unless otherwise clearly defined and limited in the present utility model, the terms "installation, connection and connection" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection: it may also be a mechanical connection, an electrical connection or a direct connection, and may also be indirectly connected through an intermediate medium, or may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0029] The battery pack mainly includes a box body and a plurality of single cells; the single cells can be connected in series, in parallel, or in a mixed series-parallel connection of two, and can be adjusted at any time according to actual needs.

[0030] During the operation of the single cells of the battery pack, faults such as liquid leakage or thermal runaway may occur:

[0031] After the single cell leaks liquid, the capacity of the single cell will rapidly decrease, which will affect the cycle life of the entire battery pack. In severe cases, it may even cause a short circuit of the entire battery pack.

[0032] When a single cell undergoes thermal runaway, the chemical substances inside it may decompose, gasify or evaporate, generating gas, which causes the temperature inside the battery to rise rapidly. The high temperature may cause the melting, deformation or rupture of the battery components, further exacerbating the degree of thermal runaway, and even posing risks of fire and explosion.

[0033] Currently, to determine whether a single battery in a battery pack leaks, a detection resistor is usually used. For example, in the Chinese patent "A Battery Leakage Detection Device, Battery and Battery Pack" with the application number 2022110453290, the device includes: a leakage detection tape, which includes a conductive material and an insulating layer provided between the conductive material and the battery case. The leakage detection tape is configured to enable the conductive material to contact the battery case through the electrolyte leaked from the battery cell group; a leakage detection unit, the first acquisition end of the leakage detection unit is connected to the battery case, and the second acquisition end of the leakage detection unit is connected to the conductive material of the leakage detection tape. The leakage detection unit is used to detect whether the battery has a leakage failure according to the resistance collected between the battery case and the leakage detection tape.

[0034] Currently, the technical means for determining thermal runaway of a single battery in a battery pack mainly rely on the temperature and / or air pressure of the single battery to determine whether the single battery has thermal runaway. However, since the temperature threshold and air pressure threshold for thermal runaway of a single battery are a range of values, if the triggering temperature or air pressure value of the fire protection device is set too low, it may cause misoperation. If the triggering temperature or air pressure value of the fire protection device is set too low, it may cause the lag of the fire protection device, resulting in the inability to suppress thermal runaway in a timely and effective manner.

[0035] In addition, when the existing battery pack judges leakage and thermal runaway faults, usually two sets of independent judgment criteria and judgment systems are required, resulting in a more complex system and higher cost of the battery pack.

[0036] The present utility model provides a method for monitoring battery pack faults. Its basic principle is: skillfully using the gas released by the single battery in the battery pack as an indicator for judging both leakage and thermal runaway faults, it can accurately determine whether there is a leakage or thermal runaway fault in the single battery in the battery pack, and at the same time, it can also accurately distinguish which one of the leakage or thermal runaway faults the single battery has occurred. Compared with the prior art, by using different indicators and systems to judge the leakage and thermal runaway faults of the battery pack, the judgment method is simpler, the judgment system is more concise, and the judgment accuracy is higher.

[0037] Embodiment 1

[0038] As Figure 1 shown, this embodiment provides a method for monitoring battery pack faults, and its specific steps are as follows:

[0039] If a first gas signal is detected in the battery pack, it is determined that there is a leakage or thermal runaway in the single battery in the battery pack;

[0040] Since volatile gases are generated when a single battery leaks and thermal runaway smoke is generated when a single battery has thermal runaway, by monitoring the first gas signal, it is possible to accurately determine that there is a leakage or thermal runaway fault in the battery pack;

[0041] If a second gas signal is detected from the battery pack, it is determined that a thermal runaway has occurred in the single cells within the battery pack; otherwise, it is determined that only leakage has occurred in the single cells within the battery pack.

[0042] Since the components, air pressure, and air flow of the volatile gases generated by leakage are all different from those of the thermal runaway flue gas generated by thermal runaway, it is possible to accurately determine whether leakage or thermal runaway has occurred in the battery pack by monitoring the second gas signal detected from the battery pack.

[0043] Based on the above monitoring method, this embodiment also provides a battery pack fault monitoring system, which includes a first monitoring device and a second monitoring device;

[0044] The first gas signal may originate from the volatile gases generated after leakage of the single cells, or it may also originate from the thermal runaway flue gas generated after thermal runaway. The first gas signal is monitored by the first monitoring device;

[0045] The first monitoring device may be a TVOC detection device for detecting gas components, or a first pressure sensor for detecting the air pressure signal of volatile gases may be used;

[0046] The second gas signal originates from the thermal runaway flue gas generated after thermal runaway of the single cells. Since the air flow and air pressure of the thermal runaway flue gas are relatively large, the second gas signal is monitored by the second monitoring device;

[0047] The second monitoring device may be an air flow sensor for detecting the air flow signal of the thermal runaway flue gas, or a second pressure sensor for detecting the pressure signal of the thermal runaway flue gas;

[0048] It should be noted that: since the air pressure of the volatile gases generated during leakage is relatively small and the flue gas pressure of the thermal runaway flue gas is relatively large, that is to say, the air pressure of the first gas signal is less than that of the second gas signal. Therefore, when the first pressure sensor is used as the first monitoring device and the second pressure sensor is used as the second monitoring device, the first pressure sensor and the second pressure sensor need to satisfy the following relationship:

[0049] The minimum air pressure measurement value of the first pressure sensor can satisfy the monitoring of the air pressure of the volatile gases, and the minimum air pressure measurement value of the second pressure sensor should be greater than the maximum air pressure measurement value of the first pressure sensor.

[0050] Since the TVOC detection device has a higher monitoring sensitivity to volatile gases than the first pressure sensor, it is preferred to use the TVOC detection device as the first monitoring device.

[0051] Embodiment 2

[0052] AsFigure 2 As shown in the figure, this embodiment provides a method for monitoring and processing battery pack failures, and its specific steps are as follows:

[0053] Fault monitoring;

[0054] If a first gas signal is detected in the battery pack, it is determined that the single cells in the battery pack have leaked or experienced thermal runaway.

[0055] When a single cell leaks, volatile gases are generated, and when a single cell experiences thermal runaway, thermal runaway smoke is generated. Therefore, by monitoring the first gas signal, it is possible to accurately determine that the battery pack has experienced a leakage or thermal runaway fault.

[0056] If a second gas signal is detected in the battery pack, it is determined that the single cells in the battery pack have experienced thermal runaway, and conversely, it is determined that only leakage has occurred in the single cells in the battery pack.

[0057] Since the components, air pressure, and air flow of the volatile gases generated by leakage are different from those of the thermal runaway smoke generated by thermal runaway, by monitoring the second gas signal generated by the battery pack, it is possible to accurately determine whether the battery pack has experienced a leakage or thermal runaway fault.

[0058] Fault handling;

[0059] If only the first gas signal is detected, the battery pack is controlled to stop operating, and the leaking battery in the battery pack is repaired.

[0060] Specifically, after the battery pack management system only receives the first gas signal, it controls the battery pack to stop operating. Then, the operator screens the leaking single cells and replaces the single cells that have experienced thermal runaway.

[0061] If the second gas signal is detected, the fire protection device is controlled to start working to handle the thermal runaway event.

[0062] Specifically, the fire protection device can act on the battery pack experiencing thermal runaway using a fire protection medium, or it can exhaust the thermal runaway smoke from the battery pack and process the thermal runaway smoke.

[0063] Based on the description of the above method, as Figure 3 shown in the figure, this embodiment also provides a fault monitoring and processing system for a battery pack, and this system includes a fault monitoring part and a fault handling part;

[0064] The fault monitoring part includes a first monitoring device 1 and a second monitoring device 2;

[0065] The first gas signal may originate from the volatile gas generated after the leakage of the single cell, or may also originate from the thermal runaway flue gas generated after thermal runaway. The first gas signal is monitored by the first monitoring device 1;

[0066] The first monitoring device 1 can be a TVOC detection device for detecting gas components, or can adopt a first pressure sensor for detecting the air pressure signal of volatile gases;

[0067] The second gas signal originates from the thermal runaway flue gas generated after the thermal runaway of the single cell. Due to the relatively large air flow and air pressure of the thermal runaway flue gas, the second gas signal is monitored by the second monitoring device 2;

[0068] The second monitoring device 2 can be an air flow sensor for detecting the air flow signal of the thermal runaway flue gas, or can be a second pressure sensor for detecting the pressure signal of the thermal runaway flue gas;

[0069] It should be noted that: since the air pressure of the volatile gas generated during leakage is small, and the flue gas pressure of the thermal runaway flue gas is large, that is to say, the air pressure of the first gas signal is less than the air pressure of the second gas signal. Therefore, when the first pressure sensor is used as the first monitoring device and the second pressure sensor is used as the second monitoring device, the first pressure sensor and the second pressure sensor need to satisfy the following relationship:

[0070] The minimum air pressure measurement value of the first pressure sensor can satisfy the monitoring of the air pressure of the volatile gas, and the minimum air pressure measurement value of the second pressure sensor should be greater than the maximum air pressure measurement value of the first pressure sensor.

[0071] Since the TVOC detection device has a higher monitoring sensitivity to volatile gases than the first pressure sensor, it is preferred to use the TVOC detection device as the first monitoring device.

[0072] The fault handling part includes a fire protection device; the fire protection device includes a fire protection medium storage tank 3, a liquid inlet pipeline assembly 4, a liquid return pipeline assembly 5, and a fire protection medium circulation channel 6 provided on the battery pack; the fire protection medium storage tank 3, the liquid inlet pipeline assembly 4, the fire protection medium circulation channel 6, and the liquid return pipeline assembly 5 are connected in sequence to form a fire protection medium circulation path; the fire protection medium circulation channel 6 is used to inject the fire protection medium into the battery pack to suppress thermal runaway;

[0073] Preferably, in order to accurately extinguish the single cell that has undergone thermal runaway, in this embodiment, the fire protection medium circulation channel 6 of the battery pack includes a horizontal channel 61 and a vertical channel 62. The horizontal channel 61 is located above the explosion relief membranes of the single cells of the battery pack (for the convenience of processing and manufacturing, the horizontal channel can be integrally formed on the battery pack box body), and a vertical channel 62 is provided between the horizontal channel 61 and each single cell explosion relief membrane.

[0074] The liquid inlet pipeline assembly 4 includes a liquid inlet pipe 41, a liquid inlet pump 42, and a liquid inlet switch 43 provided on the liquid inlet pipe 41; the liquid return pipeline assembly 5 includes a liquid return pipe 51 and a liquid return pump 52 provided on the liquid return pipe 51;

[0075] When thermal runaway occurs in a certain single battery, when the second monitoring device detects the thermal runaway flue gas, the liquid inlet switch 43 is opened, and the liquid inlet pump 42 and the liquid return pump 52 start to work. The fire extinguishing medium in the fire extinguishing medium storage tank 3 sequentially passes through the liquid inlet pipeline assembly 4, the horizontal channel 61, and the vertical channel 62 and directly acts on the inner cavity of the single battery.

[0076] In this embodiment, the first monitoring device 1 is arranged inside the box body of the battery pack, and the second monitoring device 2 is arranged in the horizontal channel 61 or the liquid return pipeline assembly 5;

[0077] In some embodiments, the fire extinguishing medium circulation channel on the battery pack is the inner cavity of the battery pack. That is to say, when suppressing thermal runaway, the fire extinguishing medium is directly injected into the battery pack, and the fire extinguishing medium acts on each single battery, realizing the suppression of thermal runaway.

Claims

1. A battery pack fault monitoring system, characterized in that: comprising a first monitoring device and a second monitoring device; The first monitoring device is disposed in the battery pack to monitor a first gas signal generated in the battery pack, and then preliminarily determines whether the battery pack has leakage or thermal runaway; The second monitoring device is used to monitor the second gas signal generated by the battery pack, and then accurately determine whether the battery pack has leakage or thermal runaway.

2. A battery pack fault monitoring system according to claim 1, characterized in that: The first monitoring device is a TVOC detection device or a first air pressure sensor arranged in the battery pack; the second monitoring device is an air flow sensor or a second air pressure sensor.

3. A battery pack fault monitoring and processing system, characterized in that: Including fault monitoring part and fault handling part; The fault monitoring part includes a first monitoring device and a second monitoring device; The first monitoring device is disposed in the battery pack to monitor a first gas signal generated in the battery pack, and then preliminarily determines whether the battery pack has leakage or thermal runaway; The second monitoring device is used to monitor the second gas signal generated in the battery pack, and then accurately determine whether the battery pack has leakage or thermal runaway; The fault monitoring part includes a fire medium storage box, a liquid inlet pipeline assembly, a liquid return pipeline assembly, and a fire medium circulation channel arranged on the battery pack; The fire-fighting medium storage box, the liquid inlet pipeline assembly, the fire-fighting medium circulation channel, and the liquid return pipeline assembly are connected in sequence to form a fire-fighting medium circulation passage; The fire-fighting medium circulation channel is used to inject the fire-fighting medium into the battery pack to suppress thermal runaway.

4. A battery pack fault monitoring and processing system according to claim 3, characterized in that: The fire-fighting medium circulation channel includes a horizontal channel and a vertical channel. The horizontal channel is located above the explosion-proof membranes of each single battery of the battery pack, and a vertical channel is arranged between the horizontal channel and the explosion-proof membranes of each single battery.

5. A battery pack fault monitoring and processing system according to claim 4, characterized in that: The first monitoring device is a TVOC detection device or a first air pressure sensor arranged in the battery pack; the second monitoring device is an air flow sensor or a second air pressure sensor.

6. A battery pack fault monitoring and processing system according to claim 5, characterized in that: The second monitoring device is installed in the fire-fighting medium circulation channel or the liquid return pipeline component.

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