Container type battery pack multi-stage fire fighting structure and fire fighting system

Abstract

The invention discloses a container type battery pack multi-stage fire-fighting structure and a fire-fighting system.The container type battery pack multi-stage fire-fighting structure comprises a box body, a battery module, a liquid cooling unit, a dehumidifier, a confluence cabinet, a fire-fighting unit, front-section detection equipment and a smoke exhaust unit are arranged in the box body, and the fire-fighting unit comprises a fire extinguishing agent tank and a water storage tank; the fire extinguishing agent tank and the water storage tank are connected with a spraying pipeline arranged in the box body through valves, the front-section detection equipment comprises gas detection, temperature detection and smoke alarm, and the front-section detection equipment is connected with a fire fighting unit through a control host. The structure design is reasonable and ingenious, the environment in the box body is detected through the front-section detection equipment, temperature, gas and smoke concentration are subjected to multi-stage early warning, and when early warning is triggered, the control host controls the fire fighting unit to open the fire extinguishing agent tank or the water storage tank according to logic judgment and spray the battery module in the box body for multiple times, so that the fire extinguishing effect is improved. Fire reburning is avoided, and complete fire extinguishing is achieved.

Description

Technical Field

[0001] The present invention relates to a fire fighting structure and a fire fighting system, in particular to a container-type battery pack multi-level fire fighting structure and a fire fighting system. Background Art

[0002] The status of energy storage systems in power systems is becoming increasingly prominent. With the continuous expansion of battery energy storage, battery packs are an important safety line of defense for energy storage power stations. During the thermal runaway of energy storage power stations, chemical reactions are still taking place inside the batteries, which may lead to a domino effect and cause major fire hazards. When the energy storage system is working, especially when charging or discharging at high currents, some battery cells may thermally run away and cause fires, which in turn cause battery pack fires. If the fire is not discovered and extinguished in time, it will further expand to a fire in the battery cluster or even the entire energy storage compartment. Therefore, it is necessary to design a fire protection system for battery packs of energy storage systems to improve the safety and response capabilities of battery packs in the event of a fire.

[0003] In the field of energy storage fire fighting technology, two forms of fire fighting are generally used: gas fire fighting and liquid fire fighting. The mainstream uses gas fire fighting. The fire fighting device is placed inside the PACK box, and the fire fighting is carried out from the inside. When the detector detects an abnormal signal: ① When the particles or lithium dendrites inside the battery cell cause an internal short circuit between the positive and negative pole pieces, if the internal short circuit is not severe, the temperature gradually rises after the heat accumulates. When the temperature rises to 130-150°C, the entire diaphragm carbonizes into an insulating layer, reducing the probability of large-area positive and negative contact short circuits. At this time, generally only thermal failure will occur, that is, the gas volatilized and expanded by the electrolyte breaks through the safety valve of the battery cell, relieves the internal pressure of the battery cell, and is manifested as smoke on the outside, but thermal runaway generally does not occur after the heat drops, that is, there is no fire or explosion. For this degree of thermal failure, a single eruption fire fighting strategy initiated by the internal temperature and smoke sensing system of the energy storage system can achieve the effect of cooling and extinguishing the fire. ② If the internal short circuit is very severe, the temperature rises rapidly to above 200℃ after heat accumulation, the entire diaphragm is melted, the positive and negative plates are in contact with a large area, forming a forced short circuit, and the high-pressure gas of the volatilized and expanded electrolyte instantly breaks through the safety valve of the battery cell, and quickly catches fire after contacting oxygen. If the pressure is higher, there may even be an explosion, accompanied by heat diffusion, and contact heat conduction causes thermal runaway in adjacent batteries, and then the same thermal runaway phenomenon repeats in adjacent batteries. For this kind of thermal runaway accompanied by heat diffusion, the ordinary one-time fire-fighting system is obviously powerless, and the probability of re-ignition is very high. At the same time, the fire-fighting trigger may be delayed or not triggered, and only part of the fire-fighting agent can be sprayed into the PACK box, and the fire-fighting effect is not good. After the fire-fighting is started, the fire-fighting agent is sprayed in an open and scattered manner, and the fire-fighting effect is not good, which brings great difficulties to the handling of lithium battery fires.

[0004] The Chinese patent with the publication number of CN118267662 discloses a fire protection system for battery packs of energy storage systems. The invention application proposes a graded fire extinguishing of the pack, namely, the first-level fire extinguishing: when the battery pack has an abnormal working state, such as overheating, overcharging or abnormal current and voltage, but the composite detector does not detect obvious abnormal signals, such as no sharp rise in temperature or smoke, in this case, the system will perform the first-level fire extinguishing. The first-level fire extinguishing may usually be fast and low-level, spraying only a small amount of coolant or turning on only a local cooling fan, aiming to suppress the fire source early and reduce the temperature. Second-level fire extinguishing: If the working state of the battery pack and the signal of the composite detector are abnormal at the same time, it indicates that the fire may be serious, and the battery pack may have a fault or the safety hazard is increasing. In this case, the system will execute the second-level fire extinguishing level, which may include a higher flow coolant injection, or fully initiate fire isolation measures to prevent the spread of the fire, and may seek external supervision and professional intervention. The fire extinguishing levels of the first-level fire extinguishing and the second-level fire extinguishing are determined by the injection pressure and injection range. Through the graded injection strategy, the system can adjust the fire extinguishing effect according to different levels of fire; although the second-level fire extinguishing will spray a higher flow of fire extinguishing agent, in fact, the fire extinguishing agent is only sprayed once. If the fire source is more intense, it will still re-ignite. Summary of the invention

[0005] In order to overcome the above-mentioned shortcomings, the present invention provides a container-type battery pack multi-level fire protection structure and fire protection system, which can perform multi-level fire protection monitoring, take fire protection measures in time, quickly extinguish the fire and prevent re-ignition, thereby achieving the purpose of complete fire extinguishing.

[0006] To achieve this purpose, the method adopted by the present invention is: a container-type battery pack multi-stage fire protection structure, including a box body, in which a battery module, a high-voltage box, a liquid cooling unit, a dehumidifier, a junction cabinet, a fire-fighting unit, a front-end detection device and a smoke exhaust unit are arranged, and a spray pipe is arranged between the top of the box body and the battery module. The spray pipe is connected to the fire-fighting unit through a valve, and the front-end detection device transmits signals with the fire-fighting unit and the smoke exhaust unit through the control host.

[0007] The fire fighting unit comprises a fire extinguishing agent tank and a water storage tank.

[0008] The front-end detection equipment includes H2 gas detector, temperature detector, CO gas detector and smoke detector.

[0009] The dehumidifier is connected to the water storage tank through a pipeline.

[0010] The smoke exhaust unit comprises a smoke exhaust machine and electric shutters.

[0011] The fire protection system based on the multi-level fire protection structure of the containerized battery pack has the following steps:

[0012] (1) The front-end detection equipment detects the gas and temperature inside and outside the box through H2 gas detectors, temperature detectors, CO gas detectors and smoke detectors, and transmits the signals to the control host in real time;

[0013] (2) If a single detector in any area enters the fire alarm state, i.e. the first-level warning, the buzzer alarm and the sound and light alarm are triggered. If the gas detector is triggered, the control host will link the smoke exhaust unit to exhaust the smoke;

[0014] (3) Multiple detectors in any area alarm at the same time or the detector detection index exceeds the set value, that is, a secondary fire alarm, triggering a buzzer alarm and an audible and visual alarm;

[0015] (4) When the second-level fire alarm lasts longer than the set time, it will be upgraded to a third-level alarm;

[0016] (5) When personnel or the control host discovers a fire, the fire extinguishing agent or water spray is automatically or manually started and the application power is turned off;

[0017] (6) The control host calculates and determines whether it is a battery thermal failure or thermal runaway based on the received detector position and the information from the detector;

[0018] (7) If it is judged as a thermal failure, only one precise spraying of the fire extinguishing agent is required;

[0019] (8) If it is judged to be thermal runaway, multiple spraying is required, and the first precise spraying of fire extinguishing agent is carried out first;

[0020] (9) After the first spraying, wait 2 to 5 minutes before spraying for the second time;

[0021] (10) After the second spraying, spray for the third time 2 to 5 minutes later to prevent re-ignition.

[0022] The beneficial effects are as follows: the structural design of the present invention is reasonable and ingenious. The environment inside the box is detected by the front-end detection equipment, and the temperature, gas and smoke concentrations are divided into multi-level warnings. When the warning is triggered, the control host controls the fire-fighting unit to open the fire extinguishing agent tank or water storage tank according to logical judgment, and sprays the battery module in the box multiple times to avoid the re-ignition of the fire and achieve complete fire extinguishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0024] Figure 1 It is a front structural diagram of the present invention;

[0025] Figure 2 It is a rear view structural diagram of the present invention. DETAILED DESCRIPTION

[0026] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0027] In the description of the invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0028] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components; the fixed connection can be welding or gluing. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] like Figure 1 , Figure 2 The container-type battery pack multi-stage fire protection structure shown includes a box body 1, in which a battery module 2, a high-voltage box 3, a liquid cooling unit 4, a dehumidifier 5, a junction cabinet 10, a fire-fighting unit 9, a front-end detection device 7 and a smoke exhaust unit 8 are arranged. The battery module 2 includes a plurality of battery compartments divided by the front end of the box body, and a battery pack is arranged in each battery compartment. A high-voltage box 3 is arranged at the bottom of the battery module 2, and a liquid cooling unit 4 and a dehumidifier 5 are arranged at the rear end of the box body 1. The liquid cooling unit 4 cools the space of the battery module 2, and the dehumidifier 5 keeps the box dry. A junction cabinet 10 and a fire-fighting unit 9 are arranged on the back of the battery module 2. A spray pipe 6 is arranged between the top of the box body 1 and the battery module 2. The spray pipe 6 is connected to the fire-fighting unit 9 through a valve, and the front-end detection device 7 transmits signals with the fire-fighting unit 9 and the smoke exhaust unit 8 through the control host.

[0030] The fire fighting unit 9 includes a fire extinguishing agent tank 91 and a water storage tank 92. The fire extinguishing agent can be perfluorohexanone, aerosol, heptafluoropropane, etc. The battery compartment and the battery pack can be protected by full flooding of the space and the battery pack. Sprinklers are arranged on the top of the battery compartment and around the battery pack. The water storage tank is connected to the external water inlet pipe through a pipeline.

[0031] The front-end detection equipment 7 includes an H2 gas detector, a temperature detector, a CO gas detector and a smoke detector.

[0032] The dehumidifier 5 is connected to the water storage tank 92 through a pipeline.

[0033] The smoke exhaust unit 8 includes a smoke exhaust fan and electric shutters, which are arranged on the side wall of the box body 1. When the gas concentration exceeds the standard, the linkage control logic of the control host is activated to exhaust the combustible gas and the toxic gas.

[0034] The fire protection system based on the multi-level fire protection structure of the containerized battery pack has the following steps:

[0035] (1) The front-end detection equipment detects the gas and temperature inside and outside the box through H2 gas detectors, temperature detectors, CO gas detectors and smoke detectors, and transmits the signals to the control host in real time;

[0036] (2) If a single detector in any area enters the fire alarm state, i.e. the first-level warning, the buzzer alarm and the sound and light alarm are triggered. If the gas detector is triggered, the control host will link the smoke exhaust unit to exhaust the smoke;

[0037] (3) Multiple detectors in any area alarm at the same time or the detector detection index exceeds the set value, that is, a secondary fire alarm, triggering a buzzer alarm and an audible and visual alarm;

[0038] (4) When the second-level fire alarm lasts longer than the set time, it will be upgraded to a third-level alarm;

[0039] (5) When personnel or the control host discovers a fire, the fire extinguishing agent or water spray is automatically or manually started and the application power is turned off;

[0040] (6) The control host calculates and determines whether it is a battery thermal failure or thermal runaway based on the received detector position and the information from the detector;

[0041] (7) If it is judged as a thermal failure, only one precise spraying of the fire extinguishing agent is required;

[0042] (8) If it is judged to be thermal runaway, multiple spraying is required, and the first precise spraying of fire extinguishing agent is carried out first;

[0043] (9) After the first spraying, wait 2 to 5 minutes before spraying for the second time;

[0044] (10) After the second spraying, spray for the third time 2 to 5 minutes later to prevent re-ignition.

[0045] Thermal failure: Particles or lithium dendrites inside the battery cell cause an internal short circuit between the positive and negative pole pieces. If the internal short circuit is not severe, the temperature gradually rises after heat accumulation. When the temperature rises to 130-150°C, the thermal shutdown function of the positive and negative electrode diaphragms takes effect, and the entire diaphragm carbonizes into an insulating layer, reducing the probability of large-area positive and negative contact short circuits. At this time, generally only thermal failure will occur, that is, the gas volatilized and expanded by the electrolyte breaks through the safety valve of the battery cell, relieves the internal pressure of the battery cell, and smoke is externally manifested, but thermal runaway generally does not occur after the heat drops, that is, there is no fire or explosion. For this degree of thermal failure, a single eruption firefighting strategy activated by the internal temperature and smoke sensing systems of the energy storage system can achieve the effect of cooling and extinguishing the fire.

[0046] Thermal runaway: manifested as fire or explosion. Particles or lithium dendrites inside the battery cell cause an internal short circuit between the positive and negative electrodes. If the internal short circuit is very severe, the temperature rises rapidly to above 200°C after heat accumulation. At this time, the thermal shutdown function of the separator between the positive and negative electrodes does not have time to work, and the entire separator is melted. The positive and negative electrodes are in large-area contact, forming a forced short circuit. The high-pressure gas volatilized and expanded by the electrolyte instantly breaks through the safety valve of the battery cell, and quickly catches fire after contacting oxygen. If the pressure is higher, there may even be an explosion. At the same time, accompanied by heat diffusion, contact heat conduction causes the separator inside the adjacent battery cell to melt rapidly, and the positive and negative electrodes are in large-area contact, forming a forced short circuit, and the battery cell has thermal runaway. Then the adjacent battery cells repeat the same thermal runaway phenomenon. For this kind of thermal runaway accompanied by heat diffusion, the ordinary one-time eruption fire-fighting system is obviously powerless, and the probability of re-ignition is very high, which requires multiple eruptions to solve.

[0047] When the external wiring harness of the box is on fire and is detected by the detector and the alarm is confirmed, the prefabricated control logic can be used to control only the top nozzle of the battery compartment to open, and the gas in the entire battery compartment space is fully flooded to extinguish the fire. When the fire extinguishing agent is used for full annihilation extinguishing, the concentration must be not less than 8%. The calculation formula for the amount of fire extinguishing agent is as follows: According to T / CECS10171-2022, there is the following formula

[0048]

[0049] Where:

[0050] m--fire extinguishing agent dosage, in kilograms (kg);

[0051] c--fire extinguishing concentration, %;

[0052] V--Net volume of the protection area, in cubic meters (m 3 );

[0053] S--Specific volume of superheated vapor of fire extinguishing agent at 101kPa atmospheric pressure and the lowest ambient temperature of the protection area, in cubic meters per kilogram (m 3 / kg).

[0054] S=0.0664+0.000274·T

[0055] Where:

[0056] T--Minimum ambient temperature of the protection area, in degrees Celsius (℃), the cabin temperature is calculated as 0℃;

[0057] The structural design of the present invention is reasonable and ingenious. The environment inside the box is detected by the front-end detection equipment, and the temperature, gas and smoke concentrations are divided into multi-level warnings. When the warning is triggered, the control host controls the fire-fighting unit to open the fire extinguishing agent tank or the water storage tank according to logical judgment, and sprays the battery module in the box multiple times to avoid the re-ignition of the fire and achieve complete fire extinguishing.

[0058] The above is based on the present invention as an inspiration. Through the above description, relevant staff can make various changes and modifications without departing from the technical idea of ​​this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A container-type battery pack multi-stage fire protection structure, comprising a box body (1), characterized in that: A battery module (2), a high-voltage box (3), a liquid cooling unit (4), a dehumidifier (5), a junction box (10), a fire-fighting unit (9), a front-end detection device (7) and a smoke exhaust unit (8) are arranged in the box body (1). A spray pipe (6) is arranged between the top of the box body (1) and the battery module. The spray pipe (6) is connected to the fire-fighting unit (9) through a valve. The front-end detection device (7) transmits signals to the fire-fighting unit (9) and the smoke exhaust unit (8) through a control host.

2. The multi-level fire protection structure of containerized battery pack according to claim 1 is characterized in that: The fire fighting unit (9) comprises a fire extinguishing agent tank (91) and a water storage tank (92).

3. The multi-level fire protection structure of containerized battery pack according to claim 1 is characterized in that: The front-end detection equipment (7) comprises an H2 gas detector, a temperature detector, a CO gas detector and a smoke detector.

4. The multi-level fire protection structure of containerized battery pack according to claim 2 is characterized in that: The dehumidifier (4) is connected to the water storage tank (92) via a pipeline.

5. The multi-level fire protection structure of containerized battery pack according to claim 1 is characterized in that: The smoke exhaust unit (8) comprises a smoke exhaust machine and an electric shutter.

6. A fire protection system based on the multi-level fire protection structure of a containerized battery pack according to any one of claims 1 to 4, characterized in that: Here are the steps: The fire protection system based on the multi-level fire protection structure of the containerized battery pack has the following steps: (1) The front-end detection equipment detects the gas and temperature inside and outside the box through H2 gas detectors, temperature detectors, CO gas detectors and smoke detectors, and transmits the signals to the control host in real time; (2) If a single detector in any area enters the fire alarm state, i.e. the first-level warning, the buzzer alarm and the sound and light alarm are triggered. If the gas detector is triggered, the control host will link the smoke exhaust unit to exhaust the smoke; (3) Multiple detectors in any area alarm at the same time or the detector detection index exceeds the set value, that is, a secondary fire alarm, triggering a buzzer alarm and an audible and visual alarm; (4) When the second-level fire alarm lasts longer than the set time, it will be upgraded to a third-level alarm; (5) When personnel or the control host discovers a fire, the fire extinguishing agent or water spray is automatically or manually started and the application power is turned off; (6) The control host calculates and determines whether it is a battery thermal failure or thermal runaway based on the received detector position and the information from the detector; (7) If it is judged as a thermal failure, only one precise spraying of the fire extinguishing agent is required; (8) If it is judged to be thermal runaway, multiple spraying is required, and the first precise spraying of fire extinguishing agent is carried out first; (9) After the first spraying, wait 2 to 5 minutes before spraying for the second time; (10) After the second spraying, spray for the third time 2 to 5 minutes later to prevent re-ignition.

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