CN109718490B - Method for screening dosage of fire extinguishing agent for extinguishing lithium ion battery fire - Google Patents
Method for screening dosage of fire extinguishing agent for extinguishing lithium ion battery fire Download PDFInfo
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Abstract
The invention relates to a method for screening the using amount of a fire extinguishing agent for extinguishing a lithium ion battery fire, which comprises a method for determining the using amount of the fire extinguishing agent for the battery fire and a method for estimating the using amount of the fire extinguishing agent for a protection area. The method for determining the using amount of the fire extinguishing agent for the battery fire is to obtain the amount of the fire extinguishing agent required in a unit volume space for extinguishing the battery fire and enabling the surface temperature of the battery to reach the expected temperature after the fire is extinguished through experiments. The method for estimating the using amount of the fire extinguishing agent in the protection area extrapolates the using amount of the fire extinguishing agent in the whole protection area through the using amount of the fire extinguishing agent in the battery. The method for determining the amount of the battery fire extinguishing agent comprises the steps of single battery fire extinguishing experiment, data fitting, determination of the expected amount of the extinguishing agent, determination of the theoretical amount of the single battery fire extinguishing agent and the like. The invention can screen out the fire extinguishing agent dosage required for extinguishing the battery fire in a certain space volume and enabling the surface temperature of the battery to reach the expected value through experiments, thereby providing reference for the fire fighting design of new energy vehicles and electrochemical energy storage power stations using lithium ion battery energy storage systems.
Description
Technical Field
The invention belongs to the technical field of safety, relates to a fire-fighting system, and particularly relates to a method for screening the using amount of a fire extinguishing agent for extinguishing a lithium ion battery fire.
Background
In recent years, with the appearance and the increasing severity of environmental problems such as greenhouse effect and haze, novel energy storage devices such as lithium ion batteries and all-solid-state batteries are increasingly applied to new energy automobiles, smart power grids and the like. Among a plurality of novel energy storage devices, the technology of the lithium ion battery is mature, and the lithium ion battery becomes a mainstream product in the novel energy storage device by virtue of excellent characteristics of high energy density, long cycle life and the like. However, there is still much room for improvement in terms of unit cost, cycle life, and safety performance of lithium ion batteries. Among them, the safety problem of the lithium ion battery is particularly troublesome. Due to the special properties of the lithium ion battery, when the lithium ion battery is under an abuse condition, a chain reaction occurs inside the battery, the temperature inside the battery rises rapidly, and the lithium ion battery is easy to generate thermal runaway, so that serious fire explosion accidents are developed. Aiming at the characteristic that the lithium ion battery is easy to cause fire due to thermal runaway, a plurality of organizations have developed systematic research on the lithium ion battery fire extinguishing technology. The existing research shows that part of solid, liquid and gas fire extinguishing agents can effectively inhibit the lithium ion battery. The solid fire extinguishing agent mainly comprises dry powder, superfine dry powder, aerosol and the like; the liquid fire extinguishing agent mainly comprises water (containing additives), foam extinguishing agent, novel alkyl halide, water film-forming fire extinguishing agent and the like; the gaseous extinguishing agent mainly comprises carbon dioxide, heptafluoropropane and the like. The invention mainly aims at the gas fire extinguishing agent and the novel alkyl halide fire extinguishing agent because the novel alkyl halide and the gas fire extinguishing agent are easy to clean, have low environmental effect and are convenient to carry, and the gas fire extinguishing agent is increasingly emphasized in the lithium ion battery fire extinguishing.
At present, a unified fire extinguishing scheme and a fire extinguishing agent dosage screening method are not formed in the industry for extinguishing lithium ion battery fires. The existing lithium ion battery fire extinguishing technology still has great defects and shortcomings: (1) the amount of fire extinguishing agent required for extinguishing a single lithium ion battery fire in a certain space volume cannot be estimated. (2) The problem of after-combustion of the lithium ion battery after fire extinguishment is difficult to solve. (3) A scientific and reasonable fire extinguishing agent screening method is lacked, and the dosage of the fire extinguishing agent of a large-scale lithium ion battery energy storage system cannot be extrapolated according to a small-scale lithium ion battery fire extinguishing experiment. (4) Most of the existing fire extinguishing agent screening methods only aim at certain batteries or certain types of fire extinguishing agents and do not have universality.
The invention provides a screening method for the amount of a fire extinguishing agent for extinguishing a lithium ion battery fire. The method can determine the fire extinguishing agent dosage required by the protected lithium ion battery energy storage system according to the lithium ion battery material system and the space volume where the lithium ion battery material system is located, so as to provide reference for the design of a fire extinguishing system of the lithium ion battery energy storage equipment and protect the lithium ion battery energy storage equipment more efficiently.
Disclosure of Invention
The invention aims to select the appropriate amount of the fire extinguishing agent according to the number of the lithium ion batteries, a material system and the total energy of the battery pack, provide reference and reference for the installation of the fire extinguishing agent in the energy storage equipment and protect the lithium ion battery energy storage equipment more efficiently.
The invention also aims to provide a method for screening the using amount of the fire extinguishing agent for extinguishing the lithium ion battery fire, which provides reference for the fire fighting design of the lithium ion battery energy storage equipment and ensures the safe operation of the lithium ion battery energy storage equipment. Through multiple experiments and data fitting, the recommended fire extinguishing agent consumption of a specific battery is found, the fire extinguishing agent consumption of the whole lithium ion battery system is obtained through external pushing, reference is provided for fire protection design of the lithium ion battery energy storage equipment, and the fire protection system can protect the lithium ion battery energy storage equipment more efficiently.
The technical scheme adopted by the invention is as follows: a method for screening the dosage of a fire extinguishing agent for extinguishing a lithium ion battery fire comprises the following steps:
step one, a method for determining the using amount of a battery fire extinguishing agent comprises the following steps:
the method for determining the amount of the fire extinguishing agent for the battery fire comprises the step of obtaining the amount of the fire extinguishing agent required for extinguishing the battery fire and enabling the surface temperature of the battery to reach a desired value through experiments. The method for determining the usage amount of the battery fire extinguishing agent comprises a single battery fire extinguishing experiment, data fitting, determination of the expected usage amount of the extinguishing agent, determination of the theoretical usage amount of the single battery fire extinguishing agent, a battery pack fire extinguishing experiment, calculation of the compensation coefficient of the usage amount of the battery fire extinguishing agent and calculation of the usage amount of the battery fire extinguishing agent in unit volume; data fitting the data used were battery peak temperature and fire suppressant dose; the expected amount of fire extinguishing agent can be determined according to a data fitting curve; the theoretical dosage of the single battery fire extinguishing agent is determined according to the expected dosage of the fire extinguishing agent on the surfaces of the batteries; the compensation coefficient of the using amount of the battery pack fire extinguishing agent can be obtained by comparing and calculating a battery pack fire extinguishing experiment and a single battery fire extinguishing experiment;
step two, a prediction method of the amount of the fire extinguishing agent in the protected area:
the method for estimating the amount of the fire extinguishing agent in the protection area calculates the total amount of the fire extinguishing agent to be used in the protection area by extrapolating the amount of the fire extinguishing agent in the battery and the space volume of the protection area.
The screening method mainly comprises a battery fire extinguishing agent usage determining method and a protection area extinguishing agent usage estimating method. The method for determining the usage of the battery fire extinguishing agent comprises a single battery fire extinguishing experiment, data fitting, the expected usage of the extinguishing agent, the theoretical usage of the single battery fire extinguishing agent, a battery pack fire extinguishing experiment, calculation of a compensation coefficient of the usage of the battery fire extinguishing agent and calculation of the usage of the battery fire extinguishing agent in unit volume. The method for estimating the amount of the fire extinguishing agent in the protection area calculates the total amount of the fire extinguishing agent to be used in the protection area by extrapolating the amount of the fire extinguishing agent in the battery and the space volume of the protection area.
The experimental device adopted in the single battery and battery pack fire extinguishing experiment mainly comprises an experimental module cavity, a thermal runaway trigger device, a temperature acquisition device, a thermocouple and a fire extinguishing device.
Wherein, the actual size preparation of the battery module of experiment module cavity according to the quantity of needs screening 1: 1, manufacturing; in order to enhance the strength of the cavity, the cavity is made of steel with the thickness of 6 mm; the side wall of the cavity is provided with a line opening hole and a fire detection pipe fixing long hole, the distance between the fire detection pipe and the battery can be adjusted according to experiment requirements, and the adjustable distance is 4-10 cm; an observation window is arranged on the long side wall of the cavity of the experiment module and used for observing whether the battery reburning occurs in the experiment; the upper part of the experiment module cavity is provided with a pressure relief round hole with the radius of 12.5, so that the overhigh pressure in the experiment module cavity is prevented.
Wherein, the thermal runaway of the battery in the experiment can be triggered by heating or overcharging. When thermal runaway is triggered in a heating mode, a high-power sheet heater with the same size as a battery is used; when the thermal runaway is triggered in an overcharging mode, the used charging current is the maximum charging current of the tested battery.
Furthermore, in order to leave a certain safety margin for the screening result, the battery adopted in the experimental stage is the battery with the highest danger of the state of charge of 100% after thermal runaway.
Further, in the experiment, in order to make the batteries closer to the close arrangement state in the actual situation, the steel clamping plate is used for clamping the batteries and the heating plate.
Wherein, the temperature measurement is preferably performed by a K-type thermocouple with the diameter of 0.5mm-1.0 mm; the data acquisition equipment can continuously monitor and record the parameters of the test process, and the sampling period is not more than 1 s.
The fire extinguishing device mainly comprises a fire extinguishing agent storage tank, a fire extinguishing medium, an electromagnetic valve, a fire detection pipe, a control box and the like. The fire extinguishing device can be automatically triggered and also can be manually started.
Further, the fire extinguishing storage tank is made of steel, and the pressure resistance of the fire extinguishing storage tank is 10 MPa; the fire extinguishing medium is gas or liquid fire extinguishing medium, such as heptafluoropropane, perfluorohexanone, water and the like; the fire detection pipe is connected with the electromagnetic valve, the electromagnetic valve is kept in a normally open state during automatic release, and the electromagnetic valve is manually controlled to be opened during manual release; and a programmable control device, an alternating current contactor, an electromagnetic relay and the like are integrated in the control box.
Further, the driving gas of the fire extinguishing medium is nitrogen or argon; the pressure filled in the fire extinguishing storage tank can be changed according to the application scene and the type of the fire extinguishing medium.
Further, the melting and cracking temperature of the fire-detecting pipe is 120-180 ℃.
Furthermore, the mass gradient of the fire extinguishing agent is preferably 0.2-0.5kg, and the smaller the mass gradient is, the more accurate the experimental result is.
Furthermore, for the accuracy of the experimental result, each working condition experiment should be repeated for 1-3 times.
Wherein, the data fitting refers to performing second-order or third-order polynomial fitting by using the battery temperature data and the fire extinguishing agent dosage.
Furthermore, the battery temperature data is generally selected as the peak temperature that can be reached by the long surface and the bottom surface of the battery after the fire extinguishing agent is released. However, the temperature data is not limited to the long surface and the bottom surface, and if the other surfaces have temperature requirements, the peak temperature can be collected and analyzed at the same time.
Furthermore, for novel halogenated hydrocarbons, such as fire extinguishing media of heptafluoropropane and perfluorohexanone, a third-order polynomial fitting can be adopted; a second order polynomial fit may be used for fire extinguishing media such as water.
Wherein the expected amount of the fire extinguishing agent is determined by selecting the corresponding amount of the fire extinguishing agent (x-axis value) from the ideal battery peak temperature (y-axis value) on a curve fitted by peak temperature-amount of the fire extinguishing agent for a plurality of surfaces. In the process, the desired amount of extinguishing agent is designated Rexp。
The theoretical dosage of the single battery fire extinguishing agent is determined by selecting the maximum value of the expected dosages of the fire extinguishing agents on the surfaces of the batteries and determining the theoretical dosage of the single battery fire extinguishing agent of the current battery. In the method, the theoretical dosage of the single battery fire extinguishing agent is recorded as Rsin。
Because the amount of the fire extinguishing agent of the battery pack is possibly different from the amount of the fire extinguishing agent of the single battery, a fire extinguishing agent compensation coefficient is set in the calculation of the part and is marked as delta, and the delta is obtained by comparing and calculating the result of the fire extinguishing experiment of the battery pack with the result of the fire extinguishing experiment of the single battery.
Wherein, the initial dosage of the fire extinguishing agent used in the battery pack fire extinguishing experiment is larger, and 1.5-2.0kg is recommended.
In the battery pack fire extinguishing experiment, except the number of the batteries, all other external conditions are consistent with the single battery fire extinguishing experiment.
Wherein, if the battery temperature obtained by the battery pack fire extinguishing experiment is higher than any point on the fitting curve, the using amount of the fire extinguishing agent is increased (the using amount of the fire extinguishing agent is recommended to be increased by taking 0.5kg as a gradient), and the experiment is carried out again.
Among them, in order to save cost, the battery pack used herein is a small-sized battery pack composed of 2 to 3 batteries. Experiments can also be performed using standard modules, which results are closer to reality.
The method for estimating the using amount of the fire extinguishing agent in the protection area extrapolates the using amount of the fire extinguishing agent in the whole protection area through the using amount of the fire extinguishing agent in the battery and the space volume of the protection area.
Wherein, the extrapolation calculation means: the amount of fire extinguishing agent required per unit volume of battery fire, which is obtained by the method of determining the amount of the battery fire extinguishing agent, is denoted as R in the method, as shown in the following formula (1)ef. Further, according to the stored energyThe total volume of the space in which the battery system of the apparatus is located can be extrapolated to the total amount of fire suppressant required by the entire battery system, which is denoted as D in this screening method.
D＝Ref×V(1)
D: extrapolating the total amount (kg) of the fire extinguishing agent required by the lithium ion battery energy storage system;
Ref: the amount of fire extinguishing agent (kg/m) required to extinguish a unit volume battery fire3)；
V: total volume (m) of space in which lithium ion battery system is located in protection zone3)；
The invention has the advantages that: 1. the screening method introduces the concept of quantification into the selection of the using amount of the battery fire extinguishing agent for the first time, can determine the using amount of a fire extinguishing medium according to the total volume of the space where the battery system is located, and can protect the energy storage equipment of the lithium ion battery more efficiently. 2. The screening method is suitable for lithium ion batteries of different systems. 3. The screening method screens the using amount of the fire extinguishing agent in a mode of combining experiments with data analysis, the process is simple, and the screening result is more accurate. 4. The screening method is suitable for various gas and liquid fire extinguishing mediums, such as water (containing additives), heptafluoropropane, perfluorohexanone and the like. 5. The method still has universality for batteries with different systems and sizes, and the screening method has the possibility of large-scale popularization and application in the industry. 6. The method considers the compensation coefficient of the fire extinguishing agent consumption between the single battery and the battery pack for fire extinguishing, and the screening result is more accurate.
Drawings
Fig. 1 is a schematic diagram of an experimental module cavity for fire extinguishing experiments, wherein 1 is a lithium ion battery cell, 2 is a high-power slice heater, 3 is a heat insulation plate, 4 is a constraint splint, 5 is a fire detection pipe, 6 is an observation window, 7 is a long hole for fixing the fire detection pipe, 8 is a wire hole, and 9 is an experimental battery module cavity.
Fig. 2 is a schematic diagram of an experimental apparatus for fire extinguishing experiments, in which 1 is a lithium ion battery cell, 5 is a fire detection tube, 7 is a long fixing hole of the fire detection tube, 8 is a wire hole, 9 is an experimental battery module cavity, 10 is a balance, 11 is a support, 12 is an electromagnetic valve, 13 is a fire extinguishing agent storage tank, 14 is a fire detection tube plug, 15 is a communication line, 16 is an electric cabinet, and 17 is an operation touch screen.
Fig. 3 is a diagram of arrangement of thermocouples in a fire extinguishing test of a single battery under a heating condition, wherein fig. 3(a) is a top view and fig. 3(b) is a cross-sectional view. Wherein 18 is a thermocouple, T1 is a thermocouple measurement point one, T2 is a thermocouple measurement point two, T3 is a thermocouple measurement point three, T4 is a thermocouple measurement point four, and T5 is a thermocouple measurement point five. Wherein, 1 is a lithium ion single battery, 2 is a high-power thin sheet heater, 3 is a heat insulation material plate, and 4 is a constraint splint.
FIG. 4 is a diagram of thermocouple arrangement in a battery pack fire extinguishing test under a heating condition, wherein T1 is a thermocouple measurement point one, and T2 is a thermocouple measurement point two. Wherein, 1 and 1 'are lithium ion single batteries, 1' is a high-power thin heater, 3 is a heat insulation material plate, and 4 is a restraint splint, wherein the battery 2 for obtaining the battery temperature and calculating the compensation coefficient of the fire extinguishing agent consumption is a high-power thin heater.
FIG. 5 is a flow chart of the experimental screening and calculation extrapolation process.
Detailed Description
The invention is further described below with reference to the accompanying drawings and the detailed description.
The method for screening the using amount of the fire extinguishing agent for extinguishing the lithium ion battery fire mainly comprises the following steps: a method for determining the using amount of a fire extinguishing agent for a battery fire and a method for estimating the using amount of the fire extinguishing agent for a protection area. The method for determining the usage amount of the battery fire extinguishing agent comprises the steps of single battery fire extinguishing experiment, data fitting, determination of the expected usage amount of the extinguishing agent, determination of the theoretical usage amount of the single battery fire extinguishing agent, battery pack fire extinguishing experiment, calculation of the compensation coefficient of the usage amount of the battery fire extinguishing agent in the battery pack, calculation of the usage amount of the battery fire extinguishing agent in unit volume and the like.
The experimental device that fire extinguishing experiment adopted mainly includes experiment module cavity, thermal runaway trigger device, temperature acquisition device, thermocouple, extinguishing device. Wherein, in order to increase the reliability and the practicality of experiment, experiment module cavity and battery module etc. compare the preparation, and it mainly includes thermal-insulated material board 3, retrains splint 4, observation window 6, and the fixed slot hole of firewire pipe 7, line hole 8 etc.. The thermal runaway trigger device mainly comprises a high-power sheet heater 2 and a charge-discharge cycle instrument, wherein in order to ensure that the trigger condition is more real, when the thermal runaway is triggered by heating, the peak temperature of a high-power heating sheet is not less than the thermal runaway peak temperature +/-50 ℃ of the tested battery; when thermal runaway is induced by overcharge, the charging current should be the maximum charging current of the battery under test. The fire extinguishing device can be triggered manually or triggered automatically to release a fire extinguishing agent, and mainly comprises a fire detection pipe 5, an electromagnetic valve 12, a fire extinguishing agent storage tank 13, a communication line 15, an electric cabinet 16, an operation touch screen 17 and the like.
The main implementation process of the invention is as follows:
before the single battery fire extinguishing experiment, temperature measuring points are arranged according to the mode of a graph 3, wherein three measuring points are arranged on the long surface of the lithium ion single battery 1 by using thermocouples 18, namely a thermocouple measuring point two T2, a thermocouple measuring point three T3 and a thermocouple measuring point four T4, and one measuring point is arranged on the bottom surface of the lithium ion single battery 1, namely a thermocouple measuring point five T5. The lithium ion single battery 1 is tightly attached to the high-power sheet heater 2, and a measuring point is arranged on the surface of the high-power sheet heater 2 to monitor the temperature change of the high-power sheet heater, namely a thermocouple measuring point T1. In the experiment, in order to simulate the situation that the cells are closely arranged in the cell module, the cells are clamped with the heating sheets by using the constraint clamping plates 4, wherein in order to reduce the influence of the heat transfer of the constraint clamping plates on the experiment, the heat insulation material plates 3 are arranged between the cells and the constraints. The structure after will pressing from both sides tightly is put into for the experiment battery module cavity 9, before the experiment, can change the fire detection pipe apart from battery temperature in the fixed slot hole 7 department of fire detection pipe to change fire extinguishing agent release mouth apart from battery temperature, and then satisfy the demand of different application scenes. After the experiment started, the heating plate was opened and the temperature recording was started.
After the lithium ion single battery 1 is out of control due to heat, the safety valve is opened, the emergent flame and high-temperature gas are released from the interior of the battery 1, at the moment, the fire probe pipe 5 is heated, melted and broken, and the fire extinguishing agent pre-filled in the fire extinguishing agent storage tank 13 is released from the broken opening under the action of the high-pressure inert gas. Under the condition that the heating method is out of control by touch heating, in order to reduce the influence of the heat of the heater on the experimental result, the heater is closed when the battery safety valve is opened. After the experiment is finished, temperature data of a thermocouple measuring point I T1-a thermocouple measuring point five T5 can be obtained, wherein the thermocouple measuring point I T1 is arranged to ensure that the heating plate has normal heat input, the average value of the temperatures of a thermocouple measuring point II T2-a thermocouple measuring point IV T4 is taken as the surface temperature of the battery, and the thermocouple measuring point five T5 is taken as the temperature of the bottom surface of the battery.
The experiment is repeated by taking 0.1-0.5kg as the mass gradient of the fire extinguishing agent and selecting the fire extinguishing agents with different masses.
The fire extinguishing experiment of the battery pack can be carried out by imitating the fire extinguishing experiment of a single battery, and it is noted that if the cost is considered, a simple module consisting of 3-4 batteries can be used, if the result is more accurate, the standard module of the battery can be used for carrying out the experiment.
As shown in fig. 5, the steps of screening the amount of fire extinguishing agent in the protected area are as follows: (1) and carrying out single battery fire extinguishing experiments of different doses of fire extinguishing agents (according to mass gradient) in the module cavity. (2) Temperature data was extracted for different surfaces of each set of experimental cells. (3) And (4) drawing the change curves of the long surface temperature and the bottom surface temperature of the battery with time before and after the fire extinguishing agent is released. (4) And searching the corresponding surface peak temperature of the battery after the fire extinguishing agent with different mass is released from the curve, and performing data fitting by taking the mass of the fire extinguishing agent and the surface peak temperature of the battery as data points. (5) Finding out the expected dosage R of the fire extinguishing agent on each surface according to the fitting result of the peak temperature data of the surfaces of the batteries and the expected temperature of each surface of the battery after fire extinguishingexp1、Rexp2… … are provided. (6) Comparing expected dosages of different surfaces of the same battery, screening out the maximum value, determining the maximum value as the theoretical dosage of the single battery fire extinguishing agent, and recording the maximum value as Rsin. (7) The fire extinguishing experiment of the battery pack is carried out by using a certain mass of fire extinguishing agent. (8) Temperature data was extracted for each surface of the cell adjacent to the heat patch during the experiment. (9) And (4) drawing the change curves of the long surface temperature and the bottom surface temperature of the battery with time before and after the fire extinguishing agent is released. (10) Finding the peak temperature T of the long surface and the bottom surface of the batterymod1、Tmod2It is brought into the fitted curve in step (4) and the long surface temperature (T) is obtainedmod1) The corresponding theoretical dosage of the fitted extinguishing agent is recorded as Rmod1And bottom surface temperature (T)mod2) The corresponding theoretical dosage of the fitted extinguishing agent is recorded as Rmod2. (12) According to electricityActual dosage R of fire extinguishing agent used in fire extinguishing experiment of battery packmodAnd the theoretical dosage R obtained from the fitted curvemod1、Rmod2Respectively calculating the compensation coefficient delta of the fire extinguishing agent dosage on each surface in the fire extinguishing of the battery pack1，δ2… … (13) in order to keep a certain safety margin, the maximum value is selected from all compensation coefficients to be used as the compensation coefficient of the using amount of the fire extinguishing agent of the battery pack, and is recorded as delta. (14) Calculating the fire extinguishing agent dosage R required by the battery in unit volume according to the theoretical dosage of the single battery fire extinguishing agent, the volume of the chamber where the battery fire extinguishing experiment is positioned and the compensation coefficient of the battery pack fire extinguishing agent dosageef. (15) And extrapolating and calculating the total amount of the fire extinguishing agent required by the lithium ion battery system in the protection area according to the total volume of the space where the lithium ion battery system is located.
The first embodiment is as follows:
this example was only qualitatively analyzed for the convenience of the reader and no quantitative calculations were made.
Fire extinguishing experiments with different fire extinguishing agents were carried out with a mass gradient of 0.5kg of fire extinguishing agent, and each experiment was repeated once. After the experiment is finished, the peak temperatures of the long surface and the bottom surface of the battery are respectively fitted with the using amount of the fire extinguishing agent to obtain a battery long surface peak temperature-fire extinguishing agent using amount fitting curve and a battery bottom surface peak temperature-fire extinguishing agent using amount fitting curve.
The expected dosage of the fire extinguishing agent on the long surface of the single battery and the expected dosage of the fire extinguishing agent on the bottom surface of the single battery are respectively found on a battery long surface peak temperature-fire extinguishing agent dosage fitting curve and a battery bottom surface peak temperature-fire extinguishing agent dosage fitting curve through the expected temperature values of the long surface and the bottom surface of the battery after the fire extinguishing agent is released, and are respectively marked as Rexp1And Rexp2。
As shown in the following formula (2), in order to ensure that the temperature of each surface meets the expected requirement, a larger amount of the fire extinguishing agent is selected from the two, and the larger amount is used as the theoretical amount of the single battery fire extinguishing agent and is recorded as Rsin。
Rsin＝{Rexp1,Rexp2}max(2)
Rsin: theoretical dosage (kg) of the single battery fire extinguishing agent;
Rexp1: the expected amount (kg) of long surface extinguishing agent;
Rexp2: the expected amount (kg) of the bottom surface fire extinguishing agent;
{}max: selecting a maximum function;
in order to make the screening result have practical significance and have no accuracy loss in the extrapolation process, the method introduces the compensation coefficient of the using amount of the fire extinguishing agent of the battery pack. The fire extinguishing experiment of the lithium ion battery pack is carried out by using the fire extinguishing agent with certain mass, and the temperature data of different surfaces of the battery 1' close to the heating sheet in the experiment are extracted. Finding the peak temperature of the long surface and the bottom surface of the battery at the moment, and respectively recording the peak temperature as Tmod1、Tmod2. Will Tmod1、Tmod2Respectively carrying the temperature of the long surface peak value obtained by the single battery fire extinguishing experiment and the fire extinguishing agent dosage fitting curve and the battery bottom surface peak value temperature-fire extinguishing agent dosage fitting curve to obtain the temperature (T) of the long surface peak value in the fitting curvemod1) Lower corresponding theoretical dosage (R) of battery pack extinguishing agentmod1) And bottom surface temperature (T)mod2) Lower corresponding theoretical dosage (R) of battery pack extinguishing agentmod2)。
Subsequently, as shown in the following formula (3), the actual amount R of the fire extinguishing agent used in extinguishing the fire of the battery pack is setmodAnd the theoretical dosage R obtained from the fitted curvemod1、Rmod2And respectively calculating the ratio to obtain the compensation coefficient of the dosage of each surface fire extinguishing agent. In order to leave a safety margin, the maximum value is selected as a compensation factor for the amount of the fire extinguishing agent used in the battery pack, as shown in the following formula (4).
δn＝Rmod/Rmodn(3)
δn: compensation factors for different surface battery pack fire suppressant dosages, wherein n is 1,2 … …; wherein, when n is 1, it represents the long surface, and when n is 2, it represents the bottom surface.
Rmod: actual dosage (kg) of the fire extinguishing agent in the battery pack fire extinguishing experiment;
Rmodn: the theoretical dosage of the battery pack for fire extinguishing is obtained from a fitting curve of a single battery fire extinguishing experiment, wherein n is equal to1,2 … …; wherein, when n is 1, it represents the long surface, and when n is 2, it represents the bottom surface.
δ＝{δ1,δ2……δn}max(4)
δ: and the compensation coefficient of the using amount of the fire extinguishing agent of the battery pack.
δ1: the compensation coefficient of the fire extinguishing agent consumption of the battery pack is based on the result of long-surface operation.
δ2: and the battery pack fire extinguishing agent consumption compensation coefficient is based on the result of the bottom surface operation.
δn: the battery pack fire extinguishing agent consumption compensation coefficient is based on the calculation results of other surfaces. The screening results of the long surface and the bottom surface are only generally obtained in the part.
{}max: selecting a maximum function;
the theoretical dosage R of the extinguishing agent is expressed by the following formula (5)sinVolume V of chamber where battery fire extinguishing experiment is locatedtestAnd the compensation coefficient delta of the fire extinguishing agent dosage of the battery pack can be calculated to obtain the amount R of the fire extinguishing agent required by extinguishing the battery fire in unit volumeef。
Ref＝δ×Rsin/Vtest(5)
Ref: the amount of fire extinguishing agent (kg/m) required to extinguish a unit volume battery fire3)；
Rsin: theoretical dosage (kg) of the single battery fire extinguishing agent;
δ: the compensation coefficient of the using amount of the fire extinguishing agent of the battery pack;
Vtest: volume (m) of chamber in which battery fire extinguishing experiment is located3)；
Finally, the total amount of fire-extinguishing agent required is further extrapolated from the total volume of the protective area of the lithium-ion battery system, as shown in equation (1) below.
D＝Ref×V(1)
D: extrapolating the total amount (kg) of the fire extinguishing agent required by the lithium ion battery energy storage system;
Ref: fire station for extinguishing battery fire per unit volumeThe amount of fire extinguishing agent required (kg/m)3)；
V: total volume (m) of space in which lithium ion battery system is located in protection zone3)；
The present embodiments are illustrative only, and do not limit the scope of the invention, and modifications and variations that may be made by those skilled in the art without departing from the principles of the invention are to be considered as within the scope of the invention.
Claims (7)
1. A method for screening the dosage of a fire extinguishing agent for extinguishing a lithium ion battery fire is characterized by comprising the following steps: the method comprises the following steps:
step one, a method for determining the using amount of a battery fire extinguishing agent comprises the following steps:
the method for determining the amount of the fire extinguishing agent for the battery fire comprises the steps of obtaining the amount of the fire extinguishing agent required for extinguishing the battery fire and enabling the surface temperature of the battery to reach a desired value through experiments; the method for determining the using amount of the battery fire extinguishing agent comprises a single battery fire extinguishing experiment, data fitting, determination of the expected using amount of the extinguishing agent, determination of the theoretical using amount of the single battery fire extinguishing agent, a battery pack fire extinguishing experiment, calculation of the compensating coefficient of the using amount of the battery fire extinguishing agent and calculation of the using amount of the battery fire extinguishing agent in unit volume; data fitting the data used were battery peak temperature and fire suppressant dose; the expected dosage of the fire extinguishing agent is determined according to a data fitting curve; the theoretical dosage of the fire extinguishing agent of the single battery is determined according to the expected dosage of the fire extinguishing agent on the surfaces of the batteries; the compensation coefficient of the using amount of the fire extinguishing agent of the battery pack is obtained by comparing and calculating a fire extinguishing experiment of the battery pack with a fire extinguishing experiment of a single battery;
step two, a prediction method of the amount of the fire extinguishing agent in the protected area:
the method for estimating the usage amount of the fire extinguishing agent in the protection area calculates the total amount of the fire extinguishing agent to be used in the protection area by extrapolating the usage amount of the fire extinguishing agent for the battery fire and the space volume of the protection area, wherein the expected usage amount of a larger fire extinguishing agent is selected as the theoretical usage amount of the single battery fire extinguishing agent in the screening process, and the maximum value of the compensation coefficients of the usage amounts of the fire extinguishing agents on the long surface and the bottom surface is selected as the compensation coefficient of the usage amount of the fire extinguishing agent for the battery pack fire, so that the effect of.
2. The screening method of the amount of the fire extinguishing agent for extinguishing a lithium ion battery fire according to claim 1, characterized in that: the experimental device adopted by the fire extinguishing experiment of the single battery mainly comprises an experimental module cavity, a thermal runaway trigger device, a data acquisition device, a thermocouple and a fire extinguishing device; the actual size of the battery module of experiment module cavity according to the quantity of needs screening is according to 1: 1, manufacturing; the thermal runaway trigger device is a high-power sheet heater with the same size as the battery; the fire extinguishing device can release the fire extinguishing agent manually or automatically.
3. The screening method of the amount of the fire extinguishing agent for extinguishing a lithium ion battery fire according to claim 1, characterized in that: the adopted experimental device highly simulates the real working condition of the lithium battery; in order to keep the environment similar to that in the battery pack, the cavity of the experimental module is kept relatively closed in the test, and a certain observation window is reserved except for the wire holes so as to observe whether the battery open fire is extinguished by the extinguishing agent in the extinguishing process; the glass of the observation window is made of high-strength corrosion-resistant toughened glass, so that the experimental equipment is prevented from being damaged by shock waves generated by thermal runaway of the battery.
4. The screening method of the amount of the fire extinguishing agent for extinguishing a lithium ion battery fire according to claim 1, characterized in that: when a fire extinguishing experiment is carried out, in order to enable the thermal runaway triggering condition to be closer to the actual condition, a high-power sheet heater with the same size as a battery is used for triggering the thermal runaway of the battery; in the experiment, in order to ensure that the triggering condition is more real, the peak temperature of the high-power heating plate should be within +/-50% of the thermal runaway peak temperature of the tested batteryoAnd C is in the range.
5. The screening method of the amount of the fire extinguishing agent for extinguishing a lithium ion battery fire according to claim 1, characterized in that: the battery temperature data of gathering in the experiment of putting out a fire is the temperature on the different surfaces of battery, and to square lithium ion battery, the temperature acquisition position is bottom surface, long side and the short side on battery surface, and to soft packet of lithium ion battery, the temperature acquisition position is long side.
6. The screening method of the amount of the fire extinguishing agent for extinguishing a lithium ion battery fire according to claim 1, characterized in that: the peak temperature of the battery surface is directly related to the thermal runaway propagation of the adjacent battery, and the peak temperature of the battery can directly reflect the suppression effect of the fire extinguishing agent, so that the data used in data fitting is the peak temperature of the battery surface and the dosage of the fire extinguishing agent in the current experiment.
7. The screening method of the amount of the fire extinguishing agent for extinguishing a lithium ion battery fire according to claim 1, characterized in that: in the method, temperature data used for data fitting are derived from different characteristic surfaces of the battery, such as the bottom surface and the long side surface of a hard-shell battery and the long side surface of a soft package battery; the method comprises the steps of obtaining data fitting curves of a plurality of battery surfaces through data fitting, finding expected dosage of the fire extinguishing agent on each surface in the fitting curves of the battery surfaces according to different requirements, and determining the theoretical dosage of the fire extinguishing agent of a certain type of battery through further comparison.
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| CN110420415A (en) * | 2019-08-27 | 2019-11-08 | 应急管理部天津消防研究所 | A method of it spurting extinguishing chemical twice and inhibits ternary lithium-ion electric Pool fire |
| CN112310533B (en) | 2019-11-15 | 2022-03-01 | 宁德时代新能源科技股份有限公司 | Battery box and device |
| CN114053628B (en) * | 2020-07-30 | 2023-06-27 | 哲弗智能系统（上海）有限公司 | Method, device, computer equipment and medium for determining injection quantity of gas inhibitor |
| TW202218713A (en) * | 2020-10-29 | 2022-05-16 | 美商科慕Ｆｃ有限責任公司 | Thermal protection of lithium ion batteries |
| CN112909421A (en) * | 2021-01-29 | 2021-06-04 | 北京电子工程总体研究所 | Method for preventing thermal runaway diffusion of lithium ion battery or battery pack |
| TW202239047A (en) * | 2021-03-19 | 2022-10-01 | 美商科慕Ｆｃ有限責任公司 | Thermal protection of lithium ion batteries |
| TW202239046A (en) * | 2021-03-19 | 2022-10-01 | 美商科慕Ｆｃ有限責任公司 | Thermal protection of lithium ion batteries |
| CN114569918B (en) * | 2022-03-08 | 2022-11-22 | 中国电力科学研究院有限公司 | Method and device for controlling charging amount and effective amount of fire extinguishing agent of lithium battery fire extinguishing system |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104001297A (en) * | 2014-05-21 | 2014-08-27 | 中国南方电网有限责任公司调峰调频发电公司 | Lithium ion battery fire test cabinet with self-assembled automatic alarm and fire extinguishment system |
| US20190046822A1 (en) * | 2016-07-12 | 2019-02-14 | Mitsui Chemicals Industrial Products Ltd. | Automatic fire extinguisher |
-
2018
- 2018-12-19 CN CN201811557894.9A patent/CN109718490B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104001297A (en) * | 2014-05-21 | 2014-08-27 | 中国南方电网有限责任公司调峰调频发电公司 | Lithium ion battery fire test cabinet with self-assembled automatic alarm and fire extinguishment system |
| US20190046822A1 (en) * | 2016-07-12 | 2019-02-14 | Mitsui Chemicals Industrial Products Ltd. | Automatic fire extinguisher |
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