Energy storage equipment

Abstract

The utility model discloses an energy storage device. The energy storage equipment comprises a battery pack group, a fault processing device and a fault monitoring device, each battery pack group comprises at least one battery pack, and a fire-fighting medium circulation channel is arranged on the battery pack; the fault monitoring device comprises a first monitoring device and a second monitoring device; when a battery pack of the energy storage equipment is in operation, a single battery may have two faults of liquid leakage or thermal runaway, whether the battery pack has a fault can be accurately judged by monitoring the first gas signal through the first monitoring device, and the fault type can be accurately judged by using the second gas signal; therefore, effective support is provided for subsequent fault processing means, and misoperation during fault removal is avoided. Meanwhile, fire-fighting media directly act on the battery pack with thermal runaway through the fault processing device, and spreading of thermal runaway can be effectively restrained.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, and specifically relates to an energy storage device. Background Art

[0002] The application areas of lithium-ion batteries are very wide, covering many fields from electronic products to electric vehicles, energy storage systems, aerospace and so on.

[0003] Due to the principles and structural characteristics of lithium-ion batteries, failures may occur during repeated use.

[0004] There are generally two types of faults: one is battery leakage, and the other is thermal runaway of the battery during use.

[0005] In order to meet the demand for large-capacity use, multiple lithium-ion batteries are generally used in a battery pack. Especially in energy storage equipment, multiple battery packs are generally installed in an energy storage cabinet for use. However, during use, the single cells in the battery pack may leak or have thermal runaway failures. How to accurately monitor the type of failure and handle different failures in a timely and effective manner is a technical problem that urgently needs to be solved in this field. Utility Model Content

[0006] In order to accurately monitor whether a battery pack in an energy storage device has a fault and the type of fault, and to effectively handle the fault, the utility model provides an energy storage device.

[0007] The energy storage device includes a battery pack, a fault handling device and a fault monitoring device;

[0008] The number of battery pack groups is N, N≥1, each battery pack group includes at least one battery pack, and a fire-fighting medium circulation channel is provided on the battery pack;

[0009] The fault handling device includes a fire-fighting medium storage box, a liquid inlet pipeline assembly and a liquid return pipeline assembly; the fire-fighting medium storage box, the liquid inlet pipeline assembly, the fire-fighting medium circulation channel and the liquid return pipeline assembly constitute a fire-fighting medium circulation system;

[0010] The fault monitoring device includes a first monitoring device and a second monitoring device;

[0011] Each battery pack is provided with a first monitoring device for monitoring the first gas signal generated in the battery pack; the second monitoring device is arranged on the liquid return pipeline for monitoring the second gas signal generated by the battery pack, and the second gas signal is used to trigger the fault handling device to suppress the thermal runaway of the battery pack.

[0012] During the operation of the battery pack of the energy storage device, the single cell may have two faults, namely, leakage or thermal runaway. The utility model can accurately determine whether the battery pack has a fault by monitoring the first gas signal through the first monitoring device, and accurately determine the type of fault by using the second gas signal, thereby providing effective support for the subsequent fault handling means to avoid misoperation during troubleshooting;

[0013] At the same time, the utility model can effectively suppress the spread of thermal runaway by directly applying the fire-fighting medium to the battery pack that has thermal runaway through the fault handling device.

[0014] Furthermore, there are at least two battery packs; the liquid inlet pipeline assembly includes a liquid inlet main pipeline and a liquid return branch pipeline matching the number of battery packs; the liquid return pipeline assembly includes a liquid return main pipeline and a liquid return branch pipeline matching the number of battery packs;

[0015] The liquid inlet main line is equipped with a liquid inlet pump and a liquid inlet main switch in sequence along the flow direction of the fire-fighting medium;

[0016] The return liquid main line is provided with a return liquid main switch and a return liquid pump in sequence along the flow direction of the fire fighting medium;

[0017] Each battery pack is connected in parallel between the liquid inlet main line and the liquid return main line through its corresponding liquid inlet branch line and liquid return branch line, and each liquid inlet branch line is provided with a first switch, and each liquid return branch line is provided with a second monitoring device and a second switch in sequence along the flow direction of the fire-fighting medium.

[0018] When the energy storage device has more than two battery pack groups, a liquid inlet main line, a liquid return main line, and liquid inlet branch lines and liquid return branch lines that match the number of battery pack groups can be used to implement a fire-fighting medium storage box to simultaneously carry out fire-fighting for each battery pack group. In addition, by controlling the first switch on each liquid inlet branch line and the second switch on each liquid return branch line, when thermal runaway is suppressed for a battery pack group that has thermal runaway, the fire-fighting medium can be prevented from entering the remaining battery pack groups, which not only improves the thermal runaway suppression efficiency, but also saves the storage capacity of the fire-fighting medium in the fire-fighting medium storage box.

[0019] Furthermore, the above-mentioned battery pack group has M battery packs, M≥2; the fire medium flow channels of each battery pack in the battery pack group are connected in series, and the fire medium flow channel inlet of the first battery pack is connected to the outlet through a liquid inlet branch pipeline and a liquid inlet main pipeline, and the fire medium flow channel outlet of the Mth battery pack is connected to the inlet of the fire medium storage box through a liquid return branch pipeline and a liquid return main pipeline.

[0020] Furthermore, in order to improve the sensitivity and accuracy of monitoring thermal runaway faults and leakage faults, the first monitoring device is a TCOV 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 arranged in the liquid return branch pipeline.

[0021] Furthermore, the fault monitoring device also includes a temperature sensor provided on each single cell. The temperature of each single cell is monitored in real time by the temperature sensor. When the temperature of a single cell rises above a certain threshold but does not reach thermal runaway, the energy storage device is controlled to start alarming and stop running, thereby improving the safety of the energy storage device.

[0022] Furthermore, the fault monitoring device also includes a third air pressure sensor disposed on the liquid return main line. The application of the third air pressure sensor can monitor the thermal runaway of the battery pack through the third air pressure sensor of the liquid return main line, ensuring that when the second monitoring device fails, the fault handling device can still suppress the thermal runaway.

[0023] Furthermore, the fault monitoring device further includes a liquid level sensor arranged in the fire-fighting medium storage box. The liquid level sensor can monitor the liquid level of the fire-fighting medium in the fire-fighting medium storage box in real time. When the fire-fighting medium in the fire-fighting medium storage box evaporates and causes insufficient storage of the fire-fighting medium, the fire-fighting medium can be replenished in time to avoid the problem that insufficient storage of the fire-fighting medium affects the fire-fighting effect in the later stage.

[0024] Furthermore, the above-mentioned liquid return main line and liquid inlet main line are both provided with adsorption and filtration units. Since there are some flammable gases and harmful gases in the thermal runaway flue gas, the fire fighting medium returning to the fire fighting medium storage tank will carry impurities. In order to adsorb the flammable gases and harmful gases in the liquid return main line and prevent the fire fighting medium returning to the fire fighting medium storage tank from clogging the liquid return main line, an adsorption and filtration unit is provided on the liquid return main line.

[0025] At the same time, some of the thermal runaway smoke may spread to the liquid inlet main line. In order to adsorb the combustible gas and harmful gas in the liquid inlet main line, an adsorption filtration unit is also arranged on the liquid inlet main line.

[0026] Furthermore, the battery pack comprises a box body and a plurality of single cells arranged in the box body and insulated from the box body;

[0027] The box body includes an upper cover assembly, a lower cover assembly and a cylinder;

[0028] A fire-fighting medium circulation channel is provided in the upper cover assembly; an explosion-relief channel is provided between the explosion-relief membrane of each single cell top cover and the fire-fighting medium circulation channel, and after the single cell thermal runaway breaks through the explosion-relief membrane, the fire-fighting medium is directly injected into the inner cavity of the single cell thermal runaway through the fire-fighting medium circulation channel and the explosion-relief channel;

[0029] A heat exchange medium circulation channel is provided in the lower cover assembly, and the temperature of each single battery is controlled by the heat exchange medium flowing in the heat exchange medium circulation channel;

[0030] A first monitoring device is arranged in the box.

[0031] The utility model ingeniously designs the box body of the battery pack, uses the upper cover assembly constituting the box body as the fire-fighting medium circulation channel of the battery pack, and uses the lower cover assembly constituting the box body as the heat exchange medium circulation channel of the battery pack, so that the battery pack can use the heat exchange medium to control the temperature of each single battery in the battery pack during operation without almost increasing the volume, thereby reducing the probability of thermal runaway. At the same time, when thermal runaway occurs in a single battery, the fire-fighting medium circulation channel and the connecting channel can be used to inject the fire-fighting medium into the single battery where thermal runaway occurs, and the fire-fighting medium can absorb and cool the thermal runaway smoke released by the single battery, thereby reducing the danger of thermal runaway and improving the safety of the battery pack.

[0032] Furthermore, the energy storage device further comprises a temperature control device; the temperature control device comprises a liquid cooler, a liquid cooling medium outflow pipeline and a liquid cooling medium return pipeline;

[0033] One end of the liquid cooling medium outflow pipeline is connected to the outlet of the liquid cooling machine, and the other end of the liquid cooling medium outflow pipeline is connected to the inlet of the heat exchange medium circulation channel of each battery pack; one end of the liquid cooling medium return pipeline is connected to the inlet of the liquid cooling machine, and the other end of the liquid cooling medium return pipeline is connected to the outlet of the heat exchange medium circulation channel of each battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a three-dimensional schematic diagram of an energy storage device;

[0035] Figure 2 It is the main view of the energy storage device;

[0036] Figure 3 It is a schematic diagram of a fault monitoring device and a fault handling device in an energy storage device;

[0037] Figure 4 is a schematic diagram of the three-dimensional structure of a battery pack;

[0038] Figure 5 A schematic diagram of the structure of the battery pack after removing the upper cover assembly and the end cover;

[0039] Figure 6 A cross-sectional view of the battery pack from the first perspective;

[0040] Figure 7 is a structural schematic diagram of a first plate;

[0041] Figure 8 for Figure 7 A cross-sectional view of

[0042] Fig. 9 is a schematic structural diagram of a second plate;

[0043] Fig.10 for Fig. 9 A cross-sectional view of

[0044] Fig.11 is a cross-sectional view of the battery pack from a second viewing angle;

[0045] Fig.12 for Fig.11 A partial enlarged view of

[0046] Fig.13 It is a schematic diagram of the structure of the insulating top cover from the first perspective;

[0047] Fig.14 It is a schematic diagram of the structure of the insulating top cover from a second perspective;

[0048] Fig.15 It is a structural schematic diagram of an insulating fixing frame;

[0049] Fig.16 This is the schematic diagram of the temperature control device.

[0050] The reference numerals are as follows:

[0051] 100-Energy storage equipment, 101-Energy storage cabinet, 102-Battery pack, 103-Fault handling device, 1031-Fire protection medium storage box, 10311-Liquid level sensor, 1032-Liquid inlet pipeline assembly, 10321-Liquid inlet main pipeline, 10322-Liquid inlet branch pipeline, 1033-Liquid return pipeline assembly, 10331-Liquid return main pipeline, 10332-Liquid return branch pipeline, 1034-Liquid inlet pump, 1035-Liquid inlet main switch Off, 1036- liquid return main switch, 1037- liquid return pump, 1038- first switch, 1039- second switch, 104- fault monitoring device, 1041- first monitoring device, 1042- second monitoring device, 1043- third air pressure sensor, 105- battery pack, 106- adsorption filtration unit, 107- temperature control device, 1071- liquid cooler, 1072- liquid cooling medium outflow pipeline, 1073- liquid cooling medium return pipeline;

[0052] 1-box, 2-end cover, 3-upper cover assembly, 4-lower cover assembly, 5-single battery, 6-fire medium circulation channel, 7-explosion relief channel, 8-first plate, 9-first quick plug connector, 10-first horizontal plate, 11-first vertical plate, 12-heat exchange medium circulation channel, 13-second plate, 14-second quick plug connector, 15-second horizontal plate, 16-second vertical plate, 17-weight reduction groove, 18-accommodation cavity, 19-main control circuit board, 20-signal output terminal, 21-insulating top cover, 22-pole avoidance hole, 23-insulating fixing frame, 24-first connecting pipe, 25-second connecting pipe, 26-annular sealing ring, 27-through hole. DETAILED DESCRIPTION

[0053] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments, not all of the embodiments. Based on the following embodiments, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this utility model.

[0054] At the same time, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" in the text are based on the directions or positional relationships shown in the drawings, and are only for the convenience of simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the technical solution. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0055] In this utility model, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0056] Energy storage equipment is generally divided into household energy storage equipment, industrial and commercial energy storage equipment, and large-scale energy storage equipment on the power generation side of power plants according to usage scenarios and capacity.

[0057] The energy storage device mainly includes an energy storage cabinet and at least one battery pack arranged in the energy storage cabinet;

[0058] The battery pack mainly includes a box and multiple single cells; the single cells can be connected in series or in parallel, or in a mixed connection of two series and parallel connections, which can be adjusted at any time according to actual needs.

[0059] The battery pack's single cells may leak or experience thermal runaway during operation:

[0060] When a single cell leaks, the capacity of the single cell will drop rapidly, thus affecting the cycle life of the entire battery pack. In severe cases, it may even cause a short circuit in the entire battery pack.

[0061] When a single battery cell experiences thermal runaway, the chemical substances inside it may decompose, vaporize or evaporate, generating gases, which will cause the temperature inside the battery to rise rapidly. High temperature may cause the battery components to melt, deform or rupture, further aggravating the degree of thermal runaway and even posing the risk of fire and explosion.

[0062] Existing methods for detecting leakage of single cells in a battery pack usually use a detection resistor to determine whether leakage has occurred. For example, Chinese patent application number 2022110453290 discloses a battery leakage detection device, a battery, and a battery pack. The device includes: a leakage detection belt, the leakage detection includes a conductive material and an insulating layer arranged between the conductive material and the battery shell, and the leakage detection belt is configured to enable the conductive material to contact the battery shell through the electrolyte leaked from the battery cell group; a leakage detection unit, the first collection end of the leakage detection unit is connected to the battery shell, and the second collection end of the leakage detection unit is connected to the conductive material of the leakage detection belt. The leakage detection unit is used to detect whether the battery has a leakage failure based on the resistance between the battery shell and the leakage detection belt.

[0063] Existing technical means for detecting thermal runaway of single cells in a battery pack mainly rely on the temperature and / or air pressure of the single cell to determine whether thermal runaway has occurred in the single cell. However, since the temperature threshold and air pressure threshold of thermal runaway of the single cell are a range of values, if the trigger temperature or air pressure value of the fault handling device is set to a low value, it may cause misoperation. If the trigger temperature or air pressure value of the fault handling device is set to a low value, it may cause a lag in the fault handling device, resulting in the inability to suppress thermal runaway in a timely and effective manner.

[0064] In addition, existing battery packs usually require two independent sets of judgment standards and judgment systems when judging leakage and thermal runaway faults, which makes the battery pack system more complex and costly.

[0065] like Figures 1 to 3 As shown, this embodiment provides an energy storage device 100, including an energy storage cabinet 101, a battery pack 102, a fault handling device 103 and a fault monitoring device 104;

[0066] The number of battery pack groups 102 is N, N≥1, each battery pack group 102 includes at least one battery pack 105, and a firefighting medium circulation channel is provided on the battery pack 105;

[0067] The fault handling device 103 includes a fire-fighting medium storage box 1031, a liquid inlet pipeline assembly 1032, and a liquid return pipeline assembly 1033; the fire-fighting medium storage box 1031, the liquid inlet pipeline assembly 1032, the fire-fighting medium circulation channel, and the liquid return pipeline assembly 1033 constitute a fire-fighting medium circulation system;

[0068] The fault monitoring device 104 includes a first monitoring device 1041 and a second monitoring device 1042;

[0069] Each battery pack 105 is provided with a first monitoring device 1041 for monitoring the first gas signal generated in the battery pack; the second monitoring device 1042 is arranged on the liquid return pipeline assembly 1033 for monitoring the second gas signal generated by the battery pack, and the second gas signal is used to trigger the release of the fire-fighting medium of the fault handling device, thereby suppressing the thermal runaway of the battery pack.

[0070] The first gas signal may come from volatile gas generated after leakage of a single cell, or may also come from thermal runaway smoke generated after thermal runaway. The first monitoring device 1041 may be a TVOC detection device for detecting gas components, or may be a first air pressure sensor for detecting volatile gas pressure signals;

[0071] The second gas signal comes from the thermal runaway smoke generated after the single battery is thermally runaway. Since the airflow and air pressure of the thermal runaway smoke are relatively large, the second monitoring device 1042 may be an airflow sensor for detecting the flow signal of the thermal runaway smoke, or may be a second air pressure sensor for detecting the pressure signal of the thermal runaway smoke.

[0072] It should be noted that: since the pressure of the volatile gas generated during the leakage is relatively small, the flue gas pressure of the thermal runaway flue gas is relatively large, that is, the pressure of the first gas signal is smaller than the pressure of the second gas signal. Therefore, when the first air pressure sensor is used as the first monitoring device 1041 and the second air pressure sensor is used as the second monitoring device 1042, the first air pressure sensor and the second air pressure sensor need to satisfy the following relationship:

[0073] The minimum air pressure measurement value of the first air pressure sensor can meet the air pressure of the volatile gas to be monitored, and the minimum air pressure measurement value of the second air pressure sensor is greater than the maximum air pressure measurement value of the first air pressure sensor.

[0074] Since the TVOC detection device has a higher sensitivity to volatile gas monitoring than the first air pressure sensor, the TVOC detection device is preferably used as the first monitoring device in this embodiment.

[0075] In order to improve the safety of the energy storage device, the fault monitoring device in this embodiment also includes a temperature sensor provided on each single cell, which monitors the temperature of each single cell in real time. When the temperature of a single cell rises above a certain threshold but does not reach thermal runaway, the energy storage device is controlled to start an alarm and stop running, thereby improving the safety of the energy storage device.

[0076] In order to prevent the fault handling device from being triggered when the second monitoring device fails, the present embodiment also includes a third air pressure sensor 1043 arranged on the return liquid main line. When the second monitoring device 1042 fails, the third air pressure sensor senses the pressure of the thermal runaway flue gas in the return main liquid pipeline, and then triggers the fault handling device to suppress the thermal runaway.

[0077] like Figure 3 As shown, in this embodiment, N battery packs 102 are arranged from top to bottom in the energy storage cabinet 101, N ≥ 2, the liquid inlet pipeline assembly 1032 includes a liquid inlet main pipeline 10321 and liquid inlet branch pipelines 10322 matching the number of battery packs, and the liquid return pipeline assembly 1033 includes a liquid return main pipeline 10331 and liquid return branch pipelines 10332 matching the number of battery packs;

[0078] The main liquid inlet line 10321 is provided with a liquid inlet pump 1034 and a liquid inlet master switch 1035 in sequence along the flow direction of the fire fighting medium; the main liquid return line 10331 is provided with a liquid return master switch 1036 and a liquid return pump 1037 in sequence along the flow direction of the fire fighting medium;

[0079] Each battery pack 102 is connected in parallel between the liquid inlet main line 10321 and the liquid return main line 10331 through its corresponding liquid inlet branch line 10322 and liquid return branch line 10332, and each liquid inlet branch line 10322 is provided with a first switch 1038, and each liquid return branch line 10332 is provided with a second monitoring device and a second switch 1039 in sequence along the flow direction of the fire-fighting medium.

[0080] In this embodiment, each battery pack group 102 has M battery packs 105, M≥2, the fire medium flow channels of each battery pack in the battery pack group are connected in series, and the fire medium flow channel inlet of the first battery pack is connected to the fire medium storage box outlet through the liquid inlet branch pipeline 10322 and the liquid inlet main pipeline 10321, and the fire medium flow channel outlet of the Mth battery pack is connected to the fire medium storage box 1031 inlet through the liquid return branch pipeline 10332 and the liquid return main pipeline 10331.

[0081] There are some flammable and harmful gases in the thermal runaway flue gas, and the fire fighting medium flowing back to the fire fighting medium storage box will carry impurities. In order to adsorb the flammable and harmful gases in the return liquid main line and prevent the fire fighting medium flowing back to the fire fighting medium storage box from clogging the return liquid main line, an adsorption filter unit 106 is provided on the return liquid main line 10331 in this embodiment. Figure 1 As shown, the adsorption filter unit 106 of the liquid return main line 10331 is installed between the fire protection medium flow channel and the liquid return main switch;

[0082] At the same time, some of the thermal runaway smoke may spread to the liquid inlet main line. In order to adsorb the combustible gas and harmful gas in the liquid inlet main line, an adsorption and filtration unit is also provided on the liquid inlet main line 10321 in this embodiment. Figure 1 As shown, the adsorption and filtration unit 106 of the liquid inlet main line 10321 is installed between the fire-fighting medium flow channel and the liquid inlet main switch.

[0083] The fire-fighting medium stored in the fire-fighting medium storage box is water, or a mixed solution of ethylene glycol and water. The fire-fighting medium will evaporate when left for a long time. Therefore, in this embodiment, the fire-fighting medium storage box 1031 is also provided with a liquid level sensor 10311, which can monitor the liquid level of the fire-fighting medium in the fire-fighting medium storage box 1031 in real time. When the fire-fighting medium in the fire-fighting medium storage box 1031 evaporates and the storage amount of the fire-fighting medium is insufficient, the fire-fighting medium can be replenished in time to avoid the problem of insufficient storage amount of the fire-fighting medium, which affects the subsequent fire-fighting effect.

[0084] In this embodiment, the structure of the battery pack is as follows: Figures 4 to 6 As shown:

[0085] The battery pack 1 includes a box body 1 and a plurality of single cells 5 arranged in the box body and insulated from the box body;

[0086] The box body 1 includes an upper cover assembly 3, a lower cover assembly 4 and two end covers 2;

[0087] In this embodiment, a fire-fighting medium circulation channel 6 is provided in the upper cover assembly 3; an explosion-relief channel 7 is provided between the explosion-relief membrane of the top cover of each single cell 5 and the fire-fighting medium circulation channel 6. After the single cell breaks through the explosion-relief membrane due to thermal runaway, the fire-fighting medium is directly injected into the inner cavity of the single cell having thermal runaway through the fire-fighting medium circulation channel and the explosion-relief channel;

[0088] Specifically, if Figure 7 As shown, in this embodiment, the upper cover assembly 3 includes a first plate 8 and a first quick-connect connector 9; in order to ensure the strength and temperature resistance of the first plate 8, the first plate 8 is made of metal material. Considering the cost and weight, the first plate 8 is made of aluminum material in this embodiment;

[0089] like Figure 7 as well as Figure 8 As shown, the first plate 8 includes an integrally formed first horizontal plate 10 and two first vertical plates 11, and a fire-fighting medium circulation channel 6 is integrally formed in the first horizontal plate 10 (usually integrally formed by extrusion or casting process, in order to form a closed fire-fighting medium circulation channel 6, a blocking plate needs to be welded at each end of the extruded or cast first horizontal plate), and a plurality of through holes 27 for connecting the explosion-relief channel 7 and the fire-fighting medium circulation channel 6 are opened on the first horizontal plate 10; the two first vertical plates 11 are used to be spliced ​​with the lower cover assembly 4 to form two side walls of the box body 1; the first quick-plug connector 9 is installed on the first horizontal plate 10 and is used as a connecting piece for connecting the fire-fighting medium circulation channel 6 with the liquid inlet pipeline assembly and the liquid return pipeline assembly.

[0090] like Fig. 9 as well as Fig.10 As shown, a heat exchange medium flow channel 12 is provided in the lower cover assembly 4, and the temperature of each single battery 5 is controlled by the heat exchange medium flowing in the heat exchange medium flow channel 12. There are many options for the heat exchange medium, which can be air, liquid or phase change material. The temperature control effect of air is poorer than that of liquid and phase change material. When used here, the phase change material has a higher cost than liquid, and the temperature control effect is not stable enough. Therefore, the preferred heat exchange medium in this embodiment is liquid, which can be any one of water, mineral oil and ethylene glycol.

[0091] In this embodiment, the specific structure of the lower cover assembly 4 is basically similar to that of the upper cover assembly 3, including a second plate 13 and a second quick-plug connector 14; the second plate 13 includes an integrally formed second horizontal plate 15 and two second vertical plates 16, and a heat exchange medium flow channel 12 is integrally formed in the second horizontal plate 15 (usually integrally formed by extrusion or casting process, in order to form a closed thermal runaway flue gas emission channel, a blocking plate needs to be welded at both ends of the extruded or cast second horizontal plate); the two second vertical plates 16 are used to be spliced ​​with the upper cover assembly 3 to form two side walls of the box body 1; there are two second quick-plug connectors 14, and both are installed on the second horizontal plate 15, respectively used as the inlet and outlet of the heat exchange medium flow channel 12.

[0092] It should also be noted that: in this embodiment, the integrally formed heat exchange medium flow channel 12 is S-shaped, which can improve the heat exchange effect. At the same time, in this embodiment, the first vertical plate 11 and the second vertical plate 16 are connected up and down to form the side wall of the box body 1 by means of concave-convex matching combined with screw fastening, which is more convenient for assembly, and a weight reduction groove 17 can also be provided in the first vertical plate 11 and / or the second vertical plate 16 to reduce the weight of the battery module.

[0093] In some other embodiments, the first plate 8 of the upper cover assembly 3 and the second plate 13 of the lower cover assembly 4 may also be constructed by welding multiple sheet metal parts. However, the manufacturing process of this method is relatively complicated, and the processing efficiency and performance of the parts are difficult to guarantee.

[0094] In this embodiment, Figure 4 and Figure 5 As shown, there are two end caps 2, and both are fixedly connected to the upper cover assembly 3 and the lower cover assembly 4 by screw connection. In order to ensure good sealing and insulation, a sealing insulating pad is arranged between the end cap 2 and the upper cover assembly 3 and the lower cover assembly 4; and there is an accommodating cavity 18 between one of the two end caps 2 and the single battery 5, and a signal output terminal 20 is arranged on the main control circuit board 19, and at least part of the signal output terminal 20 extends out of the end cap 2. The main control circuit board 19 is arranged in the end cap 2, which not only improves the integration of the battery module, but also reduces the influence of the external environment on the circuit part of the battery module.

[0095] In addition, if Figure 6 , Fig.12 , Fig.13 , Fig.14 as well as Fig.15 As shown, in the utility model, an insulating top cover 21 is buckled and installed on the top of each single cell 5, and the single cell is insulated from the upper cover assembly 3 through the insulating top cover 21. The insulating top cover 21 is made of non-metallic insulating material, such as ABS material or nylon; the insulating top cover 21 includes a square plate and side walls extending downward along the four sides of the square plate; in order to avoid the poles on the single cell, the insulating top cover 21 is provided with pole avoidance holes 22 for the poles of the single cell 5 to extend out; the use of the insulating top cover 21 not only keeps the single cell 5 insulated from the upper cover assembly 3, but also insulates the single cells 5 located on both sides of the box body 1 from the side walls of the box body, and two adjacent single cells 5 connected in series can also be insulated from each other.

[0096] The bottom of each single cell 5 is fixedly mounted on the lower cover assembly 4 through an insulating fixing frame 23, and the bottom of each single cell 5 is insulated from the lower cover assembly 4. The insulating fixing frame 23 includes a rectangular frame adapted to the shape of the single cell 5, and two ears for connecting with the lower cover assembly are arranged on the side wall of the rectangular frame. The bottom of the single cell 5 and the lower cover assembly 4 can be insulated by adding a thin insulating pad or coating an insulating layer on the lower cover assembly.

[0097] In order to further reduce the manufacturing cost and assembly times of the insulating top cover 21 and the insulating fixing frame 23, the present embodiment optimizes the structure, and multiple single cells 5 can also share an insulating top cover 21 and an insulating fixing frame 23. In the present embodiment, two single cells connected in series and located in the same straight line share an insulating top cover and an insulating fixing frame.

[0098] In some other embodiments, partitions and insulating sealants may be added to the box body to achieve positioning and insulation of the single cells. However, this method requires the installation of partitions on the upper cover assembly 3 or the lower cover assembly 4, as well as a process of injecting insulating sealants, which makes the production of the entire battery module more cumbersome and the structure more complicated.

[0099] like Fig.12 As shown, in this embodiment, the explosion relief channel 7 is divided into two parts, including a first connecting tube 24 and a second connecting tube 25; the first connecting tube 24 is sealed and fixed on the upper cover assembly 3 by welding, and the orthographic projection of the first connecting tube 24 on the upper cover assembly 3 needs to cover the through hole 27 opened on the first horizontal plate 10, the second connecting tube 25 is integrally formed on the insulating top cover 21, and the orthographic projection of the second connecting tube 25 on the single battery top cover needs to cover the area of ​​the explosion relief membrane, the first connecting tube 24 is inserted into the second connecting tube 25, and the gap between the first connecting tube 24 and the second connecting tube 25 is kept sealed from the outside.

[0100] The plug-in connection method of the first connecting pipe 24 and the second connecting pipe 25 makes it easy to complete the assembly of the explosion relief channel 7 and the connection with the fire medium flow channel 6 during the box assembly process. The assembly process is simple, and the second connecting pipe 25 is integrally formed on the insulating top cover 21, which means that the second connecting pipe 25 also has good insulation performance;

[0101] In some other embodiments, a pipe may be used, and its two ends may be welded to the upper cover assembly and the top cover of the single cell to form a connecting channel, but this method is relatively difficult to process.

[0102] In this embodiment, Fig.12 As shown, an annular sealing ring 26 is provided on the upper surface of the top cover of the single cell 5, and the upper surface of the annular sealing ring 26 is used to closely contact the end of the first connecting tube 24 inside the second connecting tube 25 (or the contact surface can be designed as a labyrinth seal structure similar to a concave-convex fit), which can prevent the thermal runaway smoke from overflowing and ensure the airtightness of the explosion venting channel 7. In some other embodiments, a sealing ring can also be added at the gap position between the first connecting tube 24 and the second connecting tube 25, but this setting will make the plugging process of the two not smooth enough.

[0103] In this embodiment, in order to make the first connecting tube 24 and the second connecting tube 25 plug-fit more smoothly, the portion of the first connecting tube 24 located inside the second connecting tube 25 is at least partially tapered.

[0104] In some other embodiments, the entire inner cavity of the battery pack box serves as a fire-fighting medium circulation channel. However, compared with the solution of using the upper cover assembly as the fire-fighting medium circulation channel, this method greatly increases the amount of fire-fighting medium used, and the fire-fighting medium cannot act on the inner cavity of the single battery in time, resulting in a relatively poor fire-fighting effect.

[0105] like Fig.16 As shown, the energy storage device in this embodiment also includes a temperature control device 107, which includes a liquid cooler 1071, a liquid cooling medium outflow pipeline 1072 and a liquid cooling medium return pipeline 1073; one end of the liquid cooling medium outflow pipeline 1072 is connected to the outlet of the liquid cooler 1071, and the other end of the liquid cooling medium outflow pipeline 1072 is connected to the inlet of the heat exchange medium circulation channel of each battery pack; one end of the liquid cooling medium return pipeline 1073 is connected to the inlet of the liquid cooler 1071, and the other end of the liquid cooling medium return pipeline 1073 is connected to the outlet of the heat exchange medium circulation channel 12 of each battery pack.

[0106] Based on the above description of the structure of the battery pack and the fault handling device in the energy storage device, the fault monitoring and handling method of the energy storage device is now introduced:

[0107] Fault monitoring

[0108] If the first monitoring device 1041 in any battery pack 102 detects that a first gas signal is generated in the battery pack, it is determined that at least one single battery in the battery pack 102 has leakage or thermal runaway;

[0109] If the second monitoring device 1042 corresponding to the battery pack 102 detects the second gas signal released by the battery pack, it is determined that thermal runaway has occurred in the single battery in the battery pack; otherwise, it is determined that only liquid leakage has occurred in the single battery in the battery pack;

[0110] Troubleshooting

[0111] If the fault is determined to be a leakage of a single battery, the energy storage device is controlled to stop running and undergo maintenance;

[0112] If the fault is determined to be thermal runaway of a single battery, then:

[0113] The liquid inlet pump 1034, the liquid inlet main switch 1035, and the liquid return main switch 1036 are turned on, and at the same time, the first switch 1038 and the second switch 1039 corresponding to the battery pack having thermal runaway are controlled to be turned on, and the first switches 1038 and the second switches 1039 corresponding to the other battery packs are turned off;

[0114] The fire-fighting medium storage box 1031 enters the inner cavity of the single battery where thermal runaway occurs through the liquid inlet main line 10321, the liquid inlet branch line 10322, the fire-fighting medium flow channel 6, and the explosion relief channel 7 in sequence to suppress the thermal runaway. After that, the fire-fighting medium carries part of the thermal runaway substances through the liquid return branch line 10332 and the liquid return main line 10331 and returns to the fire-fighting medium storage box 1031.

[0115] Since each liquid inlet branch pipeline 10322 and each liquid return branch pipeline 10332 in the fault handling device is provided with a first switch 1038 and a second switch 1039, by controlling the first switch 1038 and the second switch 1039 corresponding to each battery pack group, the fire-fighting medium can be accurately controlled to act on the battery pack that has thermal runaway, thereby preventing the fire-fighting medium from entering the battery pack that has not experienced thermal runaway.

[0116] It should be noted that, in this embodiment, the first switch 1038 is a normally closed switch, and the second switch 1039 is a normally open switch.

Claims

1. An energy storage device, characterized in that: It includes a battery pack, a fault handling device and a fault monitoring device; The number of battery pack groups is N, N≥1, each battery pack group includes at least one battery pack, and a fire-fighting medium circulation channel is provided on the battery pack; The fault handling device includes a fire-fighting medium storage box, a liquid inlet pipeline assembly and a liquid return pipeline assembly; the fire-fighting medium storage box, the liquid inlet pipeline assembly, the fire-fighting medium circulation channel and the liquid return pipeline assembly constitute a fire-fighting medium circulation system; The fault monitoring device includes a first monitoring device and a second monitoring device; Each battery pack is provided with a first monitoring device for monitoring the first gas signal generated in the battery pack; the second monitoring device is arranged on the liquid return pipeline for monitoring the second gas signal generated by the battery pack, and the second gas signal is used to trigger the release of the fire-fighting medium of the fault handling device, thereby suppressing the thermal runaway of the battery pack.

2. An energy storage device according to claim 1, characterized in that: There are at least two battery packs; the liquid inlet pipeline assembly includes a liquid inlet main pipeline and liquid inlet branch pipelines matching the number of battery packs; the liquid return pipeline assembly includes a liquid return main pipeline and liquid return branch pipelines matching the number of battery packs; The liquid inlet main line is equipped with a liquid inlet pump and a liquid inlet main switch in sequence along the flow direction of the fire-fighting medium; The return liquid main line is provided with a return liquid main switch and a return liquid pump in sequence along the flow direction of the fire fighting medium; Each battery pack is connected in parallel between the liquid inlet main line and the liquid return main line through its corresponding liquid inlet branch line and liquid return branch line, and each liquid inlet branch line is provided with a first switch, and each liquid return branch line is provided with a second monitoring device and a second switch in sequence along the flow direction of the fire-fighting medium.

3. An energy storage device according to claim 2, characterized in that: The battery pack group has M battery packs, M≥2; the fire medium flow channels of each battery pack in the battery pack group are connected in series, and the fire medium flow channel inlet of the first battery pack is connected to the fire medium storage box outlet through a liquid inlet branch pipeline and a liquid inlet main pipeline, and the fire medium flow channel outlet of the Mth battery pack is connected to the fire medium storage box inlet through a liquid return branch pipeline and a liquid return main pipeline.

4. An energy storage device according to claim 3, characterized in that: The first monitoring device is a TCOV 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 arranged in the liquid return branch pipeline.

5. An energy storage device according to claim 4, characterized in that: The fault monitoring device further comprises a temperature sensor arranged on each single battery.

6. An energy storage device according to claim 5, characterized in that: The fault monitoring device also includes a third air pressure sensor arranged on the liquid return main line.

7. An energy storage device according to claim 6, characterized in that: The fault monitoring device also includes a liquid level sensor arranged in the fire-fighting medium storage tank.

8. An energy storage device according to claim 7, characterized in that: The main liquid inlet line and the main liquid return line are both provided with adsorption and filtration units.

9. An energy storage device according to any one of claims 1 to 8, characterized in that: The battery pack includes a box body and a plurality of single cells arranged in the box body and insulated from the box body; The box body includes an upper cover assembly, a lower cover assembly and two end covers; A fire-fighting medium circulation channel is provided in the upper cover assembly; an explosion-relief channel is provided between the explosion-relief membrane of each single cell top cover and the fire-fighting medium circulation channel, and after the single cell thermal runaway breaks through the explosion-relief membrane, the fire-fighting medium is directly injected into the inner cavity of the single cell thermal runaway through the fire-fighting medium circulation channel and the explosion-relief channel; A heat exchange medium circulation channel is provided in the lower cover assembly, and the temperature of each single battery is controlled by the heat exchange medium flowing in the heat exchange medium circulation channel; A first monitoring device is arranged in the box.

10. An energy storage device according to claim 9, characterized in that: It also includes a temperature control device; the temperature control device includes a liquid cooler, a liquid cooling medium outflow pipeline, and a liquid cooling medium return pipeline; One end of the liquid cooling medium outflow pipeline is connected to the outlet of the liquid cooling machine, and the other end of the liquid cooling medium outflow pipeline is connected to the inlet of the heat exchange medium circulation channel of each battery pack; one end of the liquid cooling medium return pipeline is connected to the inlet of the liquid cooling machine, and the other end of the liquid cooling medium return pipeline is connected to the outlet of the heat exchange medium circulation channel of each battery module.

Images