CN219779039U - Energy storage unit and energy storage system - Google Patents

Abstract

The utility model relates to the technical field of energy storage equipment, and discloses an energy storage unit and an energy storage system, wherein the energy storage unit comprises: a plurality of batteries; the battery boxes are provided with accommodating grooves, at least one battery is placed in each accommodating groove, and overflow holes are also formed in the battery boxes and located above the batteries; the overflow pipeline is communicated with the accommodating groove through the overflow hole; the water inlet pipeline comprises a main pipeline and a plurality of water inlet pipes, the main pipeline is used for communicating a fire water source, each battery box corresponds to at least one water inlet pipe, one end of each water inlet pipe is communicated with the main pipeline, and the other end of each water inlet pipe extends to the bottom of the corresponding accommodating groove. The energy storage unit provided by the utility model can solve the problems of multiple fires and re-fires caused by chemical reactions in the battery of the lithium ion battery system, and can also avoid scrapping of the whole set of energy storage system during fire extinguishment.

Description

Energy storage unit and energy storage system

Technical Field

The utility model relates to the technical field of energy storage equipment, in particular to an energy storage unit and an energy storage system.

Background

Along with the continuous increase of energy storage market demands, more and more enterprises join in the super runway, however, the technical level of each enterprise in the energy storage field is uneven, so that the energy storage system product has great potential safety hazard. Because the energy storage system continuously generates accidents such as spontaneous combustion, explosion, fire and the like, and immeasurable loss is caused, the energy storage system not only makes the quality of the product, but also is a set of efficient and reliable fire control device.

The lithium ion battery energy storage system is ignited and burnt, and is often not restrained in time when a certain single battery in the battery energy storage system is in thermal runaway at first, so that a heat source is diffused to an adjacent battery until the whole battery stack, and finally, the whole battery energy storage system is ignited and even exploded.

In the traditional energy storage system, a whole set of energy storage system is often provided with a set of gas fire-extinguishing fire-control device or a spray fire-extinguishing control device or the combination of the gas fire-extinguishing control device and the spray fire-extinguishing control device, in order to pursue high capacity and high cost performance, a mode of a whole cabin one-system is adopted, and when a fire occurs in a certain place in a battery system, the fire-extinguishing control device performs fire-extinguishing action on the whole battery system, so that certain defects exist in the gas fire-extinguishing control device and the spray fire-extinguishing control device: the gas fire control device can not thoroughly solve the problems of multiple fires and re-fires of the lithium ion battery system caused by chemical reactions in the battery; once the spraying fire control device is started, the whole set of energy storage system is scrapped, and the loss is serious.

Disclosure of Invention

The utility model provides an energy storage unit and an energy storage system, which can solve the problems of multiple fires and re-fires caused by chemical reactions in a battery of a lithium ion battery system and avoid scrapping of the whole set of energy storage system during fire extinguishment.

In a first aspect, an embodiment of the present utility model provides an energy storage unit, including:

a plurality of batteries;

the battery boxes are provided with accommodating grooves, at least one battery is placed in each accommodating groove, and overflow holes are also formed in the battery boxes and located above the batteries;

the overflow pipeline is communicated with the accommodating groove through the overflow hole; a kind of electronic device with high-pressure air-conditioning system

The water inlet pipeline comprises a main pipeline and a plurality of water inlet pipes, the main pipeline is used for communicating a fire water source, each battery box corresponds to at least one water inlet pipe, one end of the water inlet pipe is communicated with the main pipeline, and the other end of the water inlet pipe extends to the bottom of the accommodating groove.

In some embodiments, the energy storage unit further comprises a fire control device, the fire control device comprises a control host and a plurality of control valves, the control valves are electrically connected with the control host, the plurality of control valves are arranged in one-to-one correspondence with the water inlet pipes, and the control valves are used for controlling the connection and disconnection between the water inlet pipes and the main pipeline.

In some embodiments, the fire control device further comprises a detection component electrically connected with the control host, wherein the detection component is used for detecting at least one of temperature, smoke concentration and combustible gas concentration in the battery box.

In some embodiments, the detection assembly includes at least one of a temperature sensor for detecting the temperature within the battery box, a smoke sensor for detecting the smoke concentration within the battery box, and a combustible gas detector for detecting the combustible gas concentration within the battery box.

In some embodiments, the fire control device further comprises a fire alarm electrically connected to the control host.

In some embodiments, the fire control device further comprises a camera for acquiring video images of the battery box.

In some embodiments, a plurality of the battery boxes are arranged at intervals; the overflow pipeline comprises a drain pipe, the length direction of the drain pipe is parallel to the arrangement direction of the plurality of battery boxes, and the drain pipe is communicated with the accommodating groove through the overflow hole.

In some of these embodiments, the drain pipe is provided with an opening that communicates an interior space of the drain pipe with an interior space of the drain pipe; the overflow pipeline further comprises a connecting pipe, one end of the connecting pipe is communicated with the overflow hole, and the other end of the connecting pipe stretches into the opening.

In some embodiments, the energy storage unit further includes a drain tank disposed below the battery case, the drain tank being in communication with the overflow line.

In a second aspect, embodiments of the present utility model provide an energy storage system comprising an energy storage unit according to the first aspect.

The energy storage unit provided by the embodiment of the utility model has the beneficial effects that: because the battery box is provided with the accommodation groove and the overflow hole, at least one battery is placed in each accommodation groove, the overflow hole is positioned above the battery, the overflow pipeline is communicated with the accommodation groove through the overflow hole, and the water inlet pipeline comprises a main pipeline and a plurality of water inlet pipes, the main pipeline is used for communicating a fire-fighting water source, each battery box corresponds to at least one water inlet pipe, one end of the water inlet pipe is communicated with the main pipeline, and the other end of the water inlet pipe extends to the bottom of the accommodation groove, so when the battery in a certain battery box needs to extinguish a fire, the water inlet pipe can be used for leading the fire-fighting water flowing to the bottom of the accommodation groove to flow to other batteries which do not need to extinguish the fire, the scrappage of the whole set of energy storage system is avoided when the fire is avoided, and the fire-fighting water inside the accommodation groove can flow out from the overflow hole to the overflow pipeline after the battery is completely immersed, the fire-fighting water is in a fluidness, the battery can be kept to be cooled continuously, and the problems of multiple times of fire and after chemical reactions in the battery are solved.

Compared with the prior art, the energy storage system provided by the utility model has similar beneficial effects as compared with the energy storage unit provided by the utility model, and the description is omitted here.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of an energy storage system according to one embodiment of the present utility model;

FIG. 2 is a schematic diagram of the internal structure of the energy storage system shown in FIG. 1;

FIG. 3 is a schematic diagram of a partial structure of an energy storage unit in the energy storage system shown in FIG. 1;

fig. 4 is a partial enlarged view of a portion a of the energy storage unit shown in fig. 3;

fig. 5 is an exploded structural view of the energy storage unit shown in fig. 3;

FIG. 6 is a top view of the energy storage system shown in FIG. 1;

FIG. 7 is a schematic diagram of a fire control device alarm in the energy storage system of FIG. 1;

fig. 8 is a control logic diagram of the fire control device in the energy storage system shown in fig. 1.

The meaning of the labels in the figures is:

100. an energy storage system;

101. a battery;

10. a battery box; 11. a receiving groove; 12. an overflow hole;

20. a water overflow pipeline; 21. a drain pipe; 211. opening holes; 22. a connecting pipe;

30. a water inlet pipeline; 31. a main pipeline; 32. a water inlet pipe; 311. a water inlet;

40. a control host;

50. a control valve;

60. a detection assembly; 61. a temperature sensor; 62. a smoke sensor; 63. a combustible gas detector;

70. a fire alarm;

80. a camera;

90. a container; 91. a drainage channel; 92. and a water outlet.

Detailed Description

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Reference in the specification to "one embodiment," "some embodiments," or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the utility model. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In order to describe the technical scheme of the utility model, the following description is made with reference to specific drawings and embodiments.

Referring to fig. 1 and 2, in one aspect, an embodiment of the present utility model provides an energy storage unit for an energy storage system 100, where the energy storage unit includes a plurality of batteries 101 and a plurality of battery boxes 10, and the energy storage unit further includes a water overflow pipeline 20 and a water inlet pipeline 30.

Referring to fig. 3, 4 and 5, the battery box 10 is provided with accommodating grooves 11, at least one battery 101 is placed in each accommodating groove 11, the battery box 10 is further provided with overflow holes 12, and the overflow holes 12 are located above the batteries 101.

It will be appreciated that one or more batteries 101 may be disposed in each of the receiving slots 11, and one or more overflow holes 12 may be provided. Since the overflow hole 12 is located above the battery 101, when fire water is introduced into the accommodating groove 11, the fire water flows out of the overflow hole 12 after completely immersing the battery 101, so that the problems of multiple fires and re-fires caused by chemical reactions inside the battery 101 can be avoided.

The water overflow pipeline 20 is communicated with the accommodating groove 11 through the water overflow hole 12. The water inlet pipeline 30 comprises a main pipeline 31 and a plurality of water inlet pipes 32, the main pipeline 31 is used for communicating a fire water source, each battery box 10 corresponds to at least one water inlet pipe 32, one end of each water inlet pipe 32 is communicated with the main pipeline 31, and the other end of each water inlet pipe 32 extends to the bottom of the corresponding accommodating groove 11.

It can be appreciated that since the end of the water inlet pipe 32 far away from the main pipe 31 extends to the bottom of the accommodating groove 11, when flowing fire water is introduced into the bottom of the accommodating groove 11 through the water inlet pipe 32, the fire water will not splash onto other batteries 101 which do not need to be extinguished, so that the whole set of energy storage system 100 is prevented from being scrapped during fire extinguishment, and the batteries 101 can be cooled rapidly and continuously.

According to the energy storage unit provided by the embodiment of the utility model, as the battery box 10 is provided with the accommodating grooves 11 and the overflow holes 12, at least one battery 101 is placed in each accommodating groove 11, the overflow holes 12 are positioned above the batteries 101, the overflow water pipeline 20 is communicated with the accommodating grooves 11 through the overflow holes 12, the water inlet pipeline 30 comprises a main pipeline 31 and a plurality of water inlet pipelines 32, the main pipeline 31 is used for communicating with a fire-fighting water source, each battery box 10 corresponds to at least one water inlet pipeline 32, one end of each water inlet pipeline 32 is communicated with the main pipeline 31, and the other end of each water inlet pipeline 32 extends to the bottom of the corresponding accommodating groove 11, so that when a battery 101 in a certain battery box 10 needs to be extinguished, the flowing fire-fighting water can flow to the bottom of the accommodating groove 11 through the water inlet pipeline 32 and can not splash to other batteries 101 which do not need to be extinguished, the scrapping of the whole set of the energy storage system 100 is avoided when the battery 101 is completely immersed in the fire, the fire-fighting water in the bottom of the accommodating grooves 11 flows out from the overflow pipeline 20 after the battery 101 is completely immersed, the problem that the chemical reaction inside the battery 101 and the fire is repeatedly ignited is solved.

According to the energy storage unit provided by the embodiment of the utility model, the structural design of the independent battery box 10 is adopted, and when a certain battery 101 has a fire, the water inlet pipeline 30 performs water injection action, because the independent battery box 10 is adopted to isolate the battery 101, point-to-point fire protection can be achieved, the fault range is reduced, the loss is reduced, only a small number of faulty batteries 101 need to be replaced in the later stage, and the whole energy storage system 100 does not need to be scrapped.

Optionally, the main conduit 31 is provided with a water inlet 311, and a fire water source may be in communication with the main conduit 31 via the water inlet 311.

Referring to fig. 2, 3, 4 and 5, in some embodiments, a plurality of battery boxes 10 are spaced apart; the water overflow pipe 20 includes a water drain pipe 21, the length direction of the water drain pipe 21 is parallel to the arrangement direction of the plurality of battery boxes 10, and the water drain pipe 21 communicates with the accommodating groove 11 through the water overflow hole 12.

By adopting the scheme, fire water in the accommodating groove 11 of the battery box 10 can be orderly discharged into the drain pipe 21, so that the fire water is prevented from affecting other batteries 101 which do not need to extinguish fire.

Alternatively, the drain pipe 21 is provided with an opening 211, the opening 211 communicating the inner space of the drain pipe 21 with the inner space of the drain pipe 21; the water overflow pipe 20 further includes a connection pipe 22, one end of the connection pipe 22 is connected to the water overflow hole 12, and the other end of the connection pipe 22 extends into the opening 211. So arranged, the drain pipe 21 is conveniently communicated with the accommodating groove 11 through the overflow hole 12.

Referring to fig. 1 and 2 together, the energy storage unit may further include a drain tank 91 disposed below the battery case 10, and the drain tank 91 is in communication with the overflow pipe 20. So configured, the fire water discharged from the water overflow pipe 20 can be collected through the water discharge groove 91, avoiding the free flow of the fire water.

Wherein, the bottom of the water discharge groove 91 may be provided with a water discharge opening 92, and fire water in the water discharge groove 91 may be discharged through the water discharge opening 92.

In this embodiment, the energy storage unit further includes a container 90, and the battery case 10, the overflow pipe 20 and the water inlet pipe 30 are all disposed in the container 90, and the drainage tank 91 is disposed at the bottom of the container 90.

Referring to fig. 1 to 6, in some embodiments, the energy storage unit further includes a fire control device, the fire control device includes a control host 40 and a plurality of control valves 50, the control valves 50 are electrically connected to the control host 40, the plurality of water inlet pipes 32 of the plurality of control valves 50 are disposed in a one-to-one correspondence, and the control valves 50 are used for controlling the connection and disconnection between the water inlet pipes 32 and the main pipeline 31.

By adopting the above scheme, when the battery 101 in a certain battery box 10 needs to extinguish fire, the control host 40 is used for controlling the control valve 50, so that the corresponding water inlet pipe 32 is controlled to be communicated with the main pipeline 31, fire water is introduced into the accommodating groove 11 of the battery box 10 needing to extinguish fire, and the fire water is not introduced into the accommodating groove 11 of the battery box 10 not needing to extinguish fire.

It will be appreciated that the control host 40 may be a single-chip microcomputer or a programmable controller, etc., and that the control valve 50 is opened when it receives a start signal from the control host 40, so that fire water starts to be injected into the battery box 10 through the water inlet pipe 32.

It will be further appreciated that when it is desired to fill the fire-extinguishing battery box 10 with water, the control valve 50 at the outlet of the water inlet pipe 32 of the battery box 10 is opened (and remains open at all times in the event of a power failure), while the control valves 50 associated with the other battery boxes 10 are not actuated.

In order to ensure sufficient water injection time for the system, the fire control device also includes an independent fire power source to ensure that the fire control device continues to operate properly after all power sources of the energy storage system 100 are turned off.

Optionally, the fire control device further includes a detecting component 60, where the detecting component 60 is electrically connected to the control host 40, and the detecting component 60 is used for detecting at least one of a temperature, a smoke concentration and a combustible gas concentration in the battery box 10. So set up, can use the detection component 60 to detect at least one of temperature, smog concentration and flammable gas concentration in the battery case 10 to with the signal transmission that catches fire that detects to control host computer 40, the condition that whether the battery 101 in the battery case 10 that is convenient for control host computer 40 according to the detection component 60 obtained catches fire lets in fire water in the storage tank 11 of the battery case 10 that needs to put out a fire.

It will be appreciated that when at least one of the temperature, smoke concentration and combustible gas concentration within the battery compartment 10 exceeds a threshold, the detection assembly 60 will send a corresponding signal to the control host 40.

In this embodiment, the detecting unit 60 is used for detecting the temperature, smoke concentration and combustible gas concentration in the battery box 10. By such arrangement, the three parameters of temperature, smoke concentration and combustible gas concentration in the battery box 10 can be used to comprehensively judge whether the battery 101 in the battery box 10 catches fire or not, so that false alarm is avoided.

The detection assembly 60 includes at least one of a temperature sensor 61, a smoke sensor 62, and a flammable gas detector 63. In other embodiments, the detection assembly 60 may also include other components that can detect the temperature, smoke concentration, and combustible gas concentration within the battery compartment 10.

It will be appreciated that the temperature sensor 61 is used to detect the temperature within the battery box 10, the smoke sensor 62 is used to detect the smoke concentration within the battery box 10, and the flammable gas detector 63 is used to detect the flammable gas concentration within the battery box 10.

It will be appreciated that the temperature sensor 61 may comprise a thermistor, thermocouple, infrared sensor, thermopile, or the like, the smoke sensor 62 may comprise a photoelectric sensor, ion sensor, or the like, and the combustible gas detector 63 may comprise an electrochemical sensor, infrared sensor, semiconductor sensor, or the like.

Optionally, the fire control device further includes a fire alarm 70, where the fire alarm 70 is electrically connected to the control host 40, and the fire alarm 70 may be an audible and visual alarm or an audible and visual alarm, and in this embodiment, the fire alarm 70 is an audible and visual alarm. So configured, when the control host 40 acquires a fire signal, the control host 40 is used to transmit a signal to the fire alarm 70, and the fire alarm 70 is used to remind related personnel.

In this embodiment, the fire control device further includes a camera 80, and the camera 80 is used to obtain a video image of the battery box 10. By means of the arrangement, fire conditions in the battery box 10 can be confirmed manually through the camera 80, whether the fire-fighting water source water inlet valve outside the container 90 is opened or not can be judged, and once water injection is confirmed, the water inlet valve outside the container 90 is opened.

Optionally, the container 90 includes a battery compartment and an equipment compartment, the control host 40 of the fire control device is disposed in the equipment compartment, the fire alarm 70 is disposed on the outer surface of the equipment compartment, the battery 101, the battery box 10, the overflow pipe 20 and the water inlet pipe 30 are all disposed in the battery compartment, and the detection assembly 60 is disposed on the ceiling of the top of the battery compartment. In the battery compartment, the batteries 101 are arranged on both sides of the container 90, a maintenance channel is reserved in the middle, and a water inlet pipeline 30 is arranged between the batteries 101 and the side wall of the container 90.

In another aspect, an embodiment of the present utility model provides an energy storage system 100, where the energy storage system 100 includes the energy storage unit described above.

Optionally, the energy storage system 100 further includes a BMS (Battery Management System ) electrically connected to the control host 40, and the BMS can determine whether the battery 101 in the battery box 10 with a certain number is overheated.

Referring to fig. 7 and 8 together, the control logic of the fire control device of the energy storage system 100 provided in the above embodiment is divided into a first-level alarm and a second-level alarm, when the control host 40 receives any one of the single alarm signals of the temperature sensor 61, the smoke sensor 62, the flammable gas detector 63, the manual alarm (inspection and discovery of personnel), and the overtemperature of the battery 101, the alarm signals are transmitted to the control host 40 through communication, and the control host 40 only starts the audible and visual alarm outside the container 90, and does not perform water injection, which is the first-level alarm of the fire control device.

When the fire control device gives a primary alarm, an external fire water source is connected with the water inlet 311 to prepare for water injection, temperature reduction and fire extinguishment of the battery compartment, and the primary alarm does not carry out water injection.

When one of the following combined signals appears in the detection assembly 60, the fire control device reports a secondary alarm, and the combined signals are: 1. manual alarm & temperature reaches a threshold (temperature sensor 61) & battery 101 overtemperature (BMS); 2. manual alarm & smoke signal (smoke sensor 62) & battery 101 overtemperature (BMS); 3. smoke signal (smoke sensor 62) & temperature reaching threshold (temperature sensor 61) & battery 101 overtemperature (BMS); 4. the concentration of the combustible gas reaches a threshold value (a combustible gas detector 63) & the temperature reaches a threshold value (a temperature sensor 61) & the battery 101 overtemperature (BMS); 5. the combustible gas concentration reaches a threshold (combustible gas detector 63) & smoke signal (smoke sensor 62) & temperature reaches a threshold (temperature sensor 61) & battery 101 over temperature (BMS).

The secondary alarm is a combined signal, and the BMS reports the overtemperature signal of the battery 101, locks the numbers of the thermal runaway battery 101 and the corresponding battery box 10, and transmits the signal to the control host 40, so as to judge the control valve 50 of the water inlet pipe 32 of the corresponding battery box 10 to be started.

After the secondary alarm occurs, the fire condition in the battery compartment is confirmed by a person through the camera 80 to judge whether to open the fire-fighting water inlet valve outside the compartment, and once water injection is confirmed, the fire-fighting water is injected into the water inlet 311 by opening the water inlet valve outside the compartment.

The control host 40 receiving the secondary alert signal may do the following: 1. starting an audible and visual alarm to prompt an operator on duty; 2. cutting off the signal of the external connection power supply and the internal auxiliary power supply lamp; 3. actuating the control valve 50 of the corresponding battery box 10; 4. and receiving the fire extinguishing feedback signal, sending a water injection signal to a local monitoring system, and informing of water injection.

The energy storage unit provided by the embodiment of the utility model adopts a plurality of detection early warning and accurate limited control methods, so that the problem of misjudgment caused by simple control logic and single detection points of the traditional fire control device is avoided.

The above embodiments are only for illustrating the technical solution of the present utility model, and are not limiting; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present utility model, and are intended to be included in the scope of the present utility model.

Claims (10)

1. An energy storage unit, comprising:

a plurality of batteries;

the battery boxes are provided with accommodating grooves, at least one battery is placed in each accommodating groove, and overflow holes are also formed in the battery boxes and located above the batteries;

the overflow pipeline is communicated with the accommodating groove through the overflow hole; a kind of electronic device with high-pressure air-conditioning system

The water inlet pipeline comprises a main pipeline and a plurality of water inlet pipes, the main pipeline is used for communicating a fire water source, each battery box corresponds to at least one water inlet pipe, one end of the water inlet pipe is communicated with the main pipeline, and the other end of the water inlet pipe extends to the bottom of the accommodating groove.

2. The energy storage unit according to claim 1, further comprising a fire control device, wherein the fire control device comprises a control host and a plurality of control valves, the control valves are electrically connected with the control host, the plurality of control valves are arranged in a one-to-one correspondence with the plurality of water inlet pipes, and the control valves are used for controlling the connection and disconnection between the water inlet pipes and the main pipeline.

3. The energy storage unit of claim 2, wherein the fire control device further comprises a detection assembly electrically connected to the control host, the detection assembly configured to detect at least one of a temperature, a smoke concentration, and a combustible gas concentration within the battery box.

4. The energy storage unit of claim 3, wherein the detection assembly comprises at least one of a temperature sensor for detecting the temperature within the battery compartment, a smoke sensor for detecting the smoke concentration within the battery compartment, and a combustible gas detector for detecting the combustible gas concentration within the battery compartment.

5. The energy storage unit of claim 3, wherein the fire control device further comprises a fire alarm electrically connected to the control host.

6. The energy storage unit of claim 2, wherein the fire control device further comprises a camera for acquiring video images of the battery box.

7. The energy storage unit according to any one of claims 1 to 6, wherein a plurality of the battery boxes are arranged at intervals; the overflow pipeline comprises a drain pipe, the length direction of the drain pipe is parallel to the arrangement direction of the plurality of battery boxes, and the drain pipe is communicated with the accommodating groove through the overflow hole.

8. The energy storage unit according to claim 7, wherein the drain pipe is provided with an opening communicating an inner space of the drain pipe with an inner space of the drain pipe; the overflow pipeline further comprises a connecting pipe, one end of the connecting pipe is communicated with the overflow hole, and the other end of the connecting pipe stretches into the opening.

9. The energy storage unit according to any one of claims 1 to 6, further comprising a drainage channel provided below the battery box, the drainage channel being in communication with the overflow line.

10. An energy storage system, characterized in that the energy storage system comprises an energy storage unit according to any one of claims 1 to 9.