CN114678581A - Lithium battery fireproof heat insulation structure and early warning system - Google Patents
Lithium battery fireproof heat insulation structure and early warning system Download PDFInfo
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- H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
- H01M50/233—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders characterised by physical properties of casings or racks, e.g. dimensions
- H01M50/24—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders characterised by physical properties of casings or racks, e.g. dimensions adapted for protecting batteries from their environment, e.g. from corrosion
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Abstract
The invention discloses a lithium battery fireproof heat insulation structure, which comprises a protection device, wherein the protection device comprises a U-shaped protection outer frame, a side protection buffer mechanism, a top protection buffer mechanism and a linkage buffer mechanism, the side protection buffer mechanism is slidably arranged on the inner peripheral side surface of the U-shaped protection outer frame, the top protection buffer mechanism is arranged on the inner top part of the U-shaped protection outer frame, the linkage buffer mechanism is respectively in sliding fit with the side protection buffer mechanism and the top protection buffer mechanism on the adjacent surfaces, the lithium battery can achieve the fireproof heat insulation effect, meanwhile, the impact force generated when the lithium battery is subjected to fire explosion can be relieved, the area range influenced by the explosion of the lithium battery is reduced, the time length of the lithium battery from the current dimension stable state to the thermal runaway state is estimated through an early warning system of the lithium battery fireproof heat insulation structure, the reliability prediction of the time length of the lithium battery when the thermal runaway state occurs is realized, the time length of the lithium battery is close to the thermal runaway state from the dimension stable state to the thermal runaway state actually, and reliable early warning prompt before the lithium battery is out of control is achieved.
Description
Technical Field
The invention belongs to the technical field of lithium batteries, and relates to a lithium battery fireproof heat insulation structure and an early warning system.
Background
With the development of power batteries, lithium batteries have the advantages of no pollution, long service life and the like, so that pure electric vehicles become the mainstream of new energy vehicle development, however, in recent years, fire caused by electric vehicles has caused huge life and property loss, the safety of electric vehicles is questioned, people worry about potential safety hazards of electric vehicles, in the frequency of fire of electric vehicles, thermal runaway of a power lithium battery system is the leading cause of fire of electric vehicles, the lithium batteries have the characteristics of high combustion speed, large quantity of toxic gases generation and the like after thermal runaway, and the lithium batteries are prone to explosion.
In the prior art, a lithium battery structure with fire prevention and heat insulation cannot be effectively designed, and particularly, explosion reduction relieving treatment cannot be carried out on the lithium battery, so that the problems that the impact force generated after explosion of the lithium battery is too large and the influence range is large are caused; meanwhile, whether the existing lithium battery is cooled or not can not be judged according to the temperature in the lithium battery in the using process, so that once the temperature in the lithium battery is too high, the time for the lithium battery to reach thermal runaway is accelerated, the time for the lithium battery to reach the thermal runaway can not be effectively relieved, and the reliable early warning prompt before the lithium battery is out of control can not be realized, so that personnel can not be evacuated in time, and the personnel and property loss are great.
Disclosure of Invention
The invention aims to provide a lithium battery fireproof heat insulation structure and an early warning system, which solve the problems in the prior art.
The purpose of the invention can be realized by the following technical scheme:
a lithium battery fireproof heat insulation structure comprises a protection device, wherein the protection device is involved in the use process of a lithium battery and comprises a U-shaped protection outer frame, a side protection buffer mechanism and a top protection buffer mechanism, the side protection buffer mechanism is slidably mounted on the inner peripheral side surface of the U-shaped protection outer frame, and the top protection buffer mechanism is mounted at the inner top of the U-shaped protection outer frame;
a cover plate is fixed on the upper end surface of the U-shaped protective outer frame through bolts;
the side protection buffer mechanism comprises a side protection flame-retardant plate, the outer side surface of the side protection flame-retardant plate is connected with the side surface of the U-shaped protection outer frame through a first telescopic rod, a first buffer spring is sleeved on the outer side of the first telescopic rod, a first rotary movable groove is formed in the upper end surface of the side protection flame-retardant plate, and first buffer limiting grooves are symmetrically formed in two sides of the first rotary movable groove;
the top protection buffer mechanism comprises a top protection flame-retardant plate, the upper end face of the top protection flame-retardant plate is connected with the top of the U-shaped protection outer frame through a second telescopic rod, a second buffer spring is sleeved on the outer side of the second telescopic rod, second rotating movable grooves are formed in two sides of the top protection flame-retardant plate, and second buffer limiting grooves are formed in two sides of the first rotating movable grooves symmetrically.
The linkage buffer mechanism is respectively in sliding fit with the side protection buffer mechanism and the top protection buffer mechanism of the adjacent surface;
the linkage buffer mechanism comprises a first linkage plate and a second linkage plate which are hinged with each other, the first linkage plate is hinged with a first rotating column, one end of the first rotating column is fixedly provided with a first limiting sliding plate, the first limiting sliding plates at two ends of the first rotating column are in sliding fit with a second buffering limiting groove, the second linkage plate is hinged with a second rotating column, one end of the second rotating column is fixedly provided with a second limiting sliding plate, the second limiting sliding plates at two ends of the second rotating column are in sliding fit with the first buffering limiting groove, and the second linkage plate is fixedly connected with the inner side face of the U-shaped protection outer frame through a telescopic push rod.
Furthermore, the top protection flame-retardant plate, the first linkage plate and the second linkage plate are all made of flame-retardant materials.
An early warning system of a lithium battery fireproof heat insulation structure comprises a battery parameter acquisition module, an internal and external temperature difference preprocessing module, a parameter dynamic analysis module, an electric quantity storage analysis module, an out-of-control trigger pre-judging module, a control and regulation and stabilization module, an out-of-control spread prediction module and an early warning prompt module;
the battery parameter acquisition module is used for detecting the pressure and temperature values of the surface of the lithium battery in real time;
the internal and external temperature difference preprocessing module is used for extracting the temperature inside the lithium battery and the temperature value of each point to be detected on the outer surface of the lithium battery, screening the temperature of each point to be detected on the outer surface of the lithium battery and calculating the average value to obtain the average temperature of the outer surface of the lithium battery, comparing the internal temperature of the lithium battery with the average temperature of the outer surface to obtain the internal and external temperature difference, comparing the internal and external temperature difference with the internal and external temperature difference value range corresponding to each set temperature difference grade, determining the temperature difference grade corresponding to the current internal and external temperature difference of the lithium battery, and screening the relative temperature difference danger coefficient corresponding to the temperature difference grade;
the parameter dynamic analysis module is used for detecting a load voltage corresponding to a known resistor R1 in a closed loop formed by the lithium battery, an open-circuit voltage of the closed loop formed by the lithium battery and the known resistor and a current flowing through the known resistor, and analyzing a current internal resistance value of the lithium battery according to the load voltage, the open-circuit voltage and the current flowing through the known resistor
Sending the analyzed current internal resistance of the lithium battery to an electric quantity storage analysis module;
the electric quantity storage analysis module is used for receiving the current internal resistance of the lithium battery sent by the basic parameter analysis module, extracting the rated capacity, the rated internal resistance and the internal resistance in the battery retirement state of the lithium battery, analyzing the current health state of the lithium battery according to the current internal resistance, the rated internal resistance and the internal resistance in the battery retirement state of the lithium battery, and reversely deducing the residual electric quantity of the current lithium battery by adopting the analyzed current health state of the lithium battery and combining the rated capacity of the lithium battery;
the runaway trigger pre-judging module is used for extracting the temperature in the lithium battery acquired in the battery parameter acquisition module, comparing the temperature in the lithium battery with the thermal runaway pre-control temperature of the lithium battery, and sending lithium battery pre-runaway trigger information to the droop control and regulation module if the temperature reaches the thermal runaway pre-control temperature of the lithium battery;
the temperature reduction and regulation module is used for receiving the lithium battery pre-out-of-control trigger information, starting lithium battery cooling liquid to carry out cooling treatment on the lithium battery according to the received lithium battery pre-out-of-control trigger information, meanwhile, extracting the temperature inside the lithium battery in real time, and carrying out speed reduction analysis on the temperature inside the lithium battery after cooling treatment in a fixed time period to obtain the temperature reduction acceleration inside the lithium battery in the fixed time period;
the out-of-control spreading prediction module is used for acquiring the temperature reduction acceleration inside the lithium battery in real time in the cooling process of the lithium battery, extracting the pressure value of the surface of the lithium battery and the temperature grade corresponding to the temperature difference inside and outside the lithium battery under the condition that the temperature reduction acceleration inside the lithium battery is in a stable state, screening out the danger coefficient of the relative temperature difference according to the temperature grade, and counting the time consumed for the lithium battery to reach the stable state inside the lithium battery in the cooling process
The method comprises the steps of extracting real-time residual electric quantity of the lithium battery from the thermal runaway pre-control temperature to the process that the temperature drop acceleration in the lithium battery is in a stable maintenance state, carrying out comprehensive analysis on data information of the interference lithium battery by adopting an out-of-control spreading prediction model, analyzing the predicted spreading time of the lithium battery when the lithium battery is spread to the thermal runaway state in the current state, and sending the predicted spreading time to an early warning prompt module.
The early warning prompting module is used for receiving the predicted extension time of the lithium battery which is transmitted by the uncontrolled extension predicting module and extends to the thermal uncontrolled state in the current state, and early warning prompting is carried out.
Further, battery parameter acquisition module includes pressure sensor and a plurality of temperature sensor, and pressure sensor installs in the lithium cell outside for the pressure numerical value that real-time detection lithium cell surface received, temperature sensor distributes and waits to detect the some department at lithium cell inside and lithium cell surface week side, is used for the temperature numerical value of each point of awaiting measuring of real-time detection lithium cell inside and surface week side.
Furthermore, a lithium battery closed loop adopted for detecting the internal resistance of the lithium battery consists of the lithium battery, a relay, a known resistor, a voltage sensor and a current sensor, when the internal resistance of the lithium battery needs to be detected, the relay in the closed loop formed by the lithium battery is controlled to be switched on and off so as to detect the load voltage corresponding to the known resistor and the open-circuit voltage of the closed loop, and the current flowing through the known resistor is R;
the current internal resistance calculation formula of the lithium battery is
，
For a load voltage corresponding to a known resistance of the loop formed by the lithium battery,
the open circuit voltage corresponding to the loop where the lithium battery is located,
is the current flowing through a known resistance.
Further, the electric quantity storage analysis module analyzes the current health state of the lithium battery through the current internal resistance of the lithium battery, the rated internal resistance of the lithium battery and the internal resistance in the decommissioning state of the battery;
the formula adopted by the current state of health (SOH) of the lithium battery is as follows:
；
the formula of the residual capacity of the lithium battery is as follows:
；
wherein the content of the first and second substances,
is the current internal resistance of the lithium battery,
is the rated internal resistance of the lithium battery,
is the internal resistance of the battery in the retired state,
is the rated capacity of the lithium battery.
Further, the lithium battery thermal runaway pre-management temperature =
*T2，
And the value is 0.568, and T2 is the thermal runaway initiation temperature of the lithium battery.
Further, the runaway propagation prediction model:
and e is a natural number,
，
the real-time residual electric quantity of the lithium battery is measured in the process that the lithium battery is in a stable state from the temperature of thermal runaway pre-control,
the average value of the residual electric quantity of the lithium battery in the process from the thermal runaway pre-control temperature to the stable maintaining state of the lithium battery is obtained,
the unit of the time consumed by the lithium battery when the lithium battery reaches the stable state is second, the residual electric quantity of the lithium battery is analyzed in turn for 10 seconds in the process of temperature reduction treatment,
is the rated capacity of the lithium battery,
the pressure value of the surface of the lithium battery in a stable state is shown,
the value of the pressure on the surface of the lithium battery when the lithium battery reaches thermal runaway is shown, and y is a relative temperature difference danger coefficient mapped by a temperature grade corresponding to the internal and external temperature difference of the lithium battery in a stable state.
The invention has the beneficial effects that:
according to the fireproof and heat-insulating structure of the lithium battery, provided by the invention, through the fireproof and heat-insulating structural design of the lithium battery, the fireproof and heat-insulating effect of the lithium battery can be achieved, meanwhile, the impact force generated when the lithium battery is subjected to fire explosion can be relieved, and the area range influenced by the explosion of the lithium battery is reduced.
According to the invention, the collected internal temperature of the lithium battery is compared with the thermal runaway pre-control temperature of the lithium battery, whether battery pre-runaway trigger information is sent to the drop-control and stabilization module is judged, the drop-control and stabilization module carries out cooling treatment on the lithium battery according to the battery pre-runaway trigger information so as to reduce the temperature rise speed of the internal temperature of the lithium battery, so that the temperature early warning judgment of the lithium battery is triggered in advance, the lithium battery reaching the thermal runaway pre-control temperature of the lithium battery can be subjected to emergency cooling control treatment, the internal temperature of the lithium battery can be prevented from continuously rising and accelerating to the initiation temperature to the greatest extent, and the time for the lithium battery reaching the thermal runaway state can be delayed.
According to the invention, through comprehensive analysis on the temperature, the pressure, the residual capacity of the battery and the like which influence the performance of the lithium battery, the time length of the lithium battery from the current maintenance state to the thermal runaway state is estimated, the reliability prediction of the time length of the lithium battery in the thermal runaway state is realized, the time length of the lithium battery from the maintenance state to the thermal runaway state is maximally approached, and the reliable early warning prompt before the lithium battery is out of control is reached, so that managers can be informed to carry out protection treatment in time within the estimated extension time length, personnel are evacuated to the maximum degree, casualties are reduced, and the effect of early warning prompt is reached.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a sectional view of a lithium battery fireproof and heat-insulating structure according to the present invention;
FIG. 2 is an enlarged view of A of the present invention;
fig. 3 is a structural view of a side shield fire retardant panel in accordance with the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example one
Referring to fig. 1-3, a lithium battery fireproof heat insulation structure comprises a protection device related to a lithium battery in use, the protection device comprises a U-shaped protection frame 1, a side protection buffer mechanism 2, a top protection buffer mechanism 3 and a linkage buffer mechanism 4, the side protection buffer mechanism 2 is installed on the inner peripheral side surface of the U-shaped protection frame 1 in a sliding mode, the top protection buffer mechanism 3 is installed on the inner top of the U-shaped protection frame, and the linkage buffer mechanism 4 is in sliding fit with the side protection buffer mechanism 2 and the top protection buffer mechanism 3 of adjacent surfaces respectively.
The upper end surface of the U-shaped protective outer frame 1 is fixed with a cover plate through bolts.
Side protection buffer gear 2 is including the fire-retardant board 21 of side protection, and the terminal surface is fixed with slider 22 with spout 11 matched with under the fire-retardant board 21 of side protection, and the fire-retardant board 21 lateral surface of side protection is connected with U type protection frame 1 side through first telescopic link 23, and first telescopic link 23 outside cover has first buffer spring 24, and the fire-retardant board 21 up end of side protection is opened has first rotation activity groove 25, and first rotation activity groove 25 both sides symmetry is opened has first buffering spacing groove 26.
The top protection buffer mechanism 3 comprises a top protection flame-retardant plate 21, the upper end face of the top protection flame-retardant plate 21 is connected with the top of the U-shaped protection outer frame 1 through a second telescopic rod 32, a second buffer spring 33 is sleeved on the outer side of the second telescopic rod 32, two sides of the top protection flame-retardant plate 21 are provided with second rotating movable grooves 34, and two sides of each first rotating movable groove 25 are symmetrically provided with second buffer limiting grooves 35.
The linkage buffer mechanism 4 comprises a first linkage plate 41 and a second linkage plate 42 which are hinged to each other, the first linkage plate 41 is hinged to the first rotating column 412, a first limiting sliding plate 411 is fixed at one end of the first rotating column 412, the first limiting sliding plates 411 at two ends of the first rotating column 412 are in sliding fit with the second buffer limiting groove 35, the second linkage plate 42 is hinged to the second rotating column 422, a second limiting sliding plate 421 is fixed at one end of the second rotating column 422, the second limiting sliding plates 421 at two ends of the second rotating column 422 are in sliding fit with the first buffer limiting groove 26, and the second linkage plate 42 is fixedly connected with the inner side face of the U-shaped protective outer frame 1 through a telescopic push rod 44.
The top protection flame-retardant plate 21, the top protection flame-retardant plate 31, the first linkage plate 41 and the second linkage plate 42 are all made of flame-retardant materials.
When the lithium battery is used, the lithium battery is fixed at the bottom of the U-shaped protective outer frame 1 through bolts, and a temperature sensor and a pressure sensor are fixed on the outer surface of the lithium battery.
Design through this structure can make the lithium cell play the thermal-insulated effect of fire prevention in the use, simultaneously, in case when the inside temperature of lithium cell conflagration or explosion takes place, impact force when side protection buffer gear, top protection buffer gear and the linkage buffer gear who connects top and lateral part can explode the lithium cell is cushioned, reduces the regional scope that the lithium cell explosion influences.
Example two
The early warning system of the fireproof and heat-insulating structure of the lithium battery comprises a battery parameter acquisition module, an internal and external temperature difference preprocessing module, a parameter dynamic analysis module, an electric quantity storage analysis module, an out-of-control triggering pre-judgment module, a reduction control and regulation stability module, an out-of-control spreading prediction module and an early warning prompt module.
The battery parameter acquisition module is used for the pressure on real-time detection lithium cell surface, temperature value, wherein, battery parameter acquisition module includes pressure sensor and a plurality of temperature sensor, and pressure sensor installs in the lithium cell outside for the pressure value that real-time detection lithium cell surface received, and temperature sensor distributes and waits to detect the punishment department in lithium cell inside and lithium cell surface week side, is used for the temperature value of each punishment department of awaiting measuring of real-time detection lithium cell inside and surface week side.
The internal and external temperature difference preprocessing module is used for extracting the temperature inside the lithium battery and the temperature value of each point to be detected on the outer surface of the lithium battery, screening the temperature of each point to be detected on the outer surface of the lithium battery and calculating the average value to obtain the average temperature of the outer surface of the lithium battery, comparing the internal temperature of the lithium battery with the average temperature of the outer surface to obtain the internal and external temperature difference, comparing the internal and external temperature difference with the internal and external temperature difference value range corresponding to each set temperature difference grade, determining the temperature difference grade corresponding to the current internal and external temperature difference of the lithium battery, and screening the relative temperature difference danger coefficient corresponding to the temperature difference grade.
The temperature difference grades are marked as 1 grade, 2 grade, 3 grade, 4 grade and 5 grade, and the temperature ranges corresponding to the temperature difference grades are respectively as follows: 1-5 ℃, 5-22 ℃, 22-83 ℃, 83-118 ℃ and 118-.
The relative temperature difference risk coefficients corresponding to the temperature levels are respectively
The determination of the relative temperature difference danger coefficient corresponding to each temperature grade is an average value of time for counting the time for continuously increasing the temperature difference between the inside and the outside of the lithium battery to a fixed temperature value (2 ℃) when the lithium battery is at the upper limit temperature and the lower limit temperature of the current temperature difference and the lithium battery is not subjected to cooling treatment such as liquid cooling, air cooling and the like.
Namely, detect the lithium batteryThe external temperature difference is respectively at 1 ℃, 5 ℃, 22 ℃, 83 ℃, 118 ℃ and 520 ℃, the time t1, t2, t3, t4, t5 and t6 required by the internal temperature difference and the external temperature difference of the lithium battery to continuously rise to fixed temperature values are sequentially obtained, the average value of the time t1 and t2, the average value of the time t2 and t3, the average value of the time t3 and t4, the average value of the time t4 and t5 and the average value of the time t5 and t6 are sequentially obtained, and the time t1, the time t2, the average value of the time t2 and the average value of the time t5 and the time t6 are obtained to obtain the time
，
，
，
，
And will time
The time and the time adopted for the temperature difference between the inside and the outside of the lithium battery to continuously rise to a fixed temperature value under the grade 1 temperature level
The time and the time adopted for the temperature difference between the inside and the outside of the lithium battery to continuously rise to a fixed temperature value under the 2-level temperature level
The time is used as the time for the temperature difference between the inside and the outside of the lithium battery to continuously rise to a fixed temperature value under the grade 3 temperature grade
The time is taken as the time for the temperature difference between the inside and the outside of the lithium battery to continuously rise to a fixed temperature value under the 4-level temperature grade, and the time is calculated
And the time for the temperature difference between the inside and the outside of the lithium battery to continuously rise to a fixed temperature value under the 5-level temperature grade is adopted.
When the internal and external temperature difference of the lithium battery is more than 118 ℃ and less than 520 ℃, the relative temperature difference danger coefficient of the corresponding temperature difference grade is 1 ((
) Relative temperature difference hazard coefficient corresponding to 4 th temperature difference grade
Relative temperature difference hazard coefficient corresponding to the 3 rd temperature difference grade
Relative temperature difference hazard coefficient corresponding to 2 nd temperature difference grade
Relative temperature difference hazard coefficient corresponding to 1 st temperature difference grade
。
The parameter dynamic analysis module is used for detecting a load voltage corresponding to a known resistor R1 in a closed loop formed by the lithium battery, an open-circuit voltage of the closed loop formed by the lithium battery and the known resistor and a current flowing through the known resistor, and analyzing a current internal resistance value of the lithium battery according to the load voltage, the open-circuit voltage and the current flowing through the known resistor
And sending the analyzed current internal resistance of the lithium battery to an electric quantity storage analysis module, wherein the current internal resistance calculation formula of the lithium battery is
，
For a load voltage corresponding to a known resistance of the loop formed by the lithium battery,
the open circuit voltage corresponding to the loop where the lithium battery is located,
is the current flowing through a known resistance.
With the changes of the service life, the charging and discharging times, the environmental temperature and the like of the lithium battery, the internal resistance of the lithium battery also changes along with the changes, but is not fixed and unchanged.
The lithium battery closed loop adopted by the lithium battery internal resistance detection is composed of a lithium battery, a relay, a known resistor, a voltage sensor and a current sensor, when the internal resistance of the lithium battery needs to be detected, the relay in the closed loop formed by the lithium battery is controlled to be switched on and off, so that the load voltage corresponding to the known resistor and the open-circuit voltage of the closed loop are detected, and the current flowing through the known resistor is R.
The electric quantity storage analysis module is used for receiving the current internal resistance of the lithium battery sent by the basic parameter analysis module, extracting the rated capacity, the rated internal resistance and the internal resistance in the battery retirement state of the lithium battery, analyzing the current health state of the lithium battery according to the current internal resistance, the rated internal resistance and the internal resistance in the battery retirement state of the lithium battery, and reversely deducing the residual electric quantity of the current lithium battery by adopting the analyzed current health state of the lithium battery and combining the rated capacity of the lithium battery.
Analyzing the current health state of the lithium battery through the current internal resistance of the lithium battery, the rated internal resistance of the lithium battery and the internal resistance in the state of retirement of the lithium battery, wherein the formula adopted by the current health state SOH of the lithium battery is as follows:
；
the formula of the residual capacity of the lithium battery is as follows:
；
wherein the content of the first and second substances,
is the current internal resistance of the lithium battery,
is the rated internal resistance of the lithium battery,
is the internal resistance of the battery in the retired state,
the rated capacity of the lithium battery.
The out-of-control triggering pre-judging module is used for extracting the temperature in the lithium battery collected in the battery parameter collecting module, comparing the temperature in the lithium battery with the thermal out-of-control pre-control temperature of the lithium battery, and sending pre-out-of-control triggering information of the lithium battery to the drop control stabilizing module if the temperature reaches the thermal out-of-control pre-control temperature of the lithium battery, wherein the thermal out-of-control pre-management temperature of the lithium battery is =
*T2，
And the value is 0.568, and T2 is the thermal runaway initiation temperature of the lithium battery.
When the battery is out of control due to heat, the lithium battery undergoes self-discharge of the battery in sequence along with the rise of the temperature of the battery, a solid electrolyte membrane of a negative electrode is decomposed, a negative electrode material reacts with an electrolyte, a diaphragm melts, a positive electrode material is decomposed, an electrolyte solution is decomposed, the negative electrode material reacts with a binder, electrolysis is also combusted, and further, when the battery is out of control due to heat, the battery still needs to undergo a period of time until combustion occurs.
The cooling control and stability regulation module is used for receiving lithium battery pre-out-of-control trigger information, starting lithium battery cooling liquid to cool a lithium battery according to the received lithium battery pre-out-of-control trigger information, meanwhile, extracting the temperature inside the lithium battery in real time, carrying out speed reduction analysis on the temperature inside the lithium battery after cooling treatment in a fixed time period, and obtaining the temperature reduction acceleration inside the lithium battery in the fixed time period, wherein the temperature reduction acceleration inside the lithium battery is equal to the ratio of the temperature value reduced after cooling treatment of the cooling liquid in the fixed time period to the fixed time period.
Through contrasting the internal temperature of the lithium battery with the thermal runaway pre-control temperature of the lithium battery to trigger the temperature early warning judgment of the lithium battery in advance, the emergency cooling management and control treatment can be carried out on the lithium battery reaching the thermal runaway pre-control temperature of the lithium battery, the internal temperature of the lithium battery can be prevented from continuously rising to the initiation temperature to the greatest extent, and the time for delaying the lithium battery to reach the thermal runaway state can be reached.
The out-of-control spreading prediction module is used for acquiring the temperature reduction acceleration inside the lithium battery in real time in the cooling process of the lithium battery, extracting the pressure value of the surface of the lithium battery and the temperature grade corresponding to the temperature difference inside and outside the lithium battery under the condition that the temperature reduction acceleration inside the lithium battery is in a stable maintenance state (the value of the internal temperature reduction acceleration is equal to 0), screening out the danger coefficient of the relative temperature difference according to the temperature grade, and counting the time consumed for the lithium battery to reach the stable maintenance state inside the lithium battery in the cooling process
The method comprises the steps of extracting real-time residual electric quantity of the lithium battery from the thermal runaway pre-control temperature to the process that the temperature drop acceleration in the lithium battery is in a stable maintenance state, carrying out comprehensive analysis on data information of the interference lithium battery by adopting an out-of-control spreading prediction model, analyzing the predicted spreading time of the lithium battery when the lithium battery is spread to the thermal runaway state in the current state, and sending the predicted spreading time to an early warning prompt module.
An uncontrolled propagation prediction model:
and e is a natural number,
，
the real-time residual capacity of the lithium battery is measured in the process that the lithium battery is in a stable state from the temperature of thermal runaway pre-control,
the average value of the residual electric quantity of the lithium battery in the process from the thermal runaway pre-control temperature to the stable maintaining state of the lithium battery is obtained,
the unit of the time consumed by the lithium battery when the lithium battery reaches the stable state is second, the residual electric quantity of the lithium battery is analyzed in turn for 10 seconds in the process of temperature reduction treatment,
is the rated capacity of the lithium battery,
the pressure value of the surface of the lithium battery in a stable state is shown,
the value of the pressure on the surface of the lithium battery when the lithium battery reaches thermal runaway is shown, and y is a relative temperature difference danger coefficient mapped by a temperature grade corresponding to the internal and external temperature difference of the lithium battery in a stable state.
When the temperature-dropping acceleration in the lithium battery is in a stability maintaining state, due to the characteristics of materials in the lithium battery, the lithium battery still evolves into a thermal runaway state, only the time length evolving to the thermal runaway state is extended, the estimated extension time length of the lithium battery extending to the thermal runaway state in the current state can be roughly estimated through analyzing main interference factors influencing the thermal runaway of the lithium battery and the time length consumed by the temperature-dropping acceleration in the lithium battery reaching the stability maintaining state, and combining an out-of-control extension prediction model, but not the time length of the lithium battery actually reaching the thermal runaway state, due to the comprehensive interference of chemical reaction in the lithium battery and external environment and dynamic change, the time length of the lithium battery extending to the thermal runaway state from the current state cannot be accurately predicted, only the actual time length can be maximally approached, so that a manager can be informed of timely protection treatment within the estimated extension time length, evacuation is carried out as early as possible, people are evacuated to the maximum degree, casualties are reduced, and the effect of early warning and reminding is achieved.
The early warning prompting module is used for receiving the predicted extension time of the lithium battery extending to the thermal runaway state under the current state sent by the runaway extension predicting module, and carrying out early warning reminding so that managers can know the time of the lithium battery reaching the thermal runaway state as early as possible, and corresponding measures are adopted to protect personnel and equipment, and property loss is reduced.
The foregoing is merely exemplary and illustrative of the principles of the present invention and various modifications, additions and substitutions of the specific embodiments described herein may be made by those skilled in the art without departing from the principles of the present invention or exceeding the scope of the claims set forth herein.
Claims (9)
1. The utility model provides a lithium cell fire prevention heat-proof structure which characterized in that: the protective device comprises a U-shaped protective outer frame (1), a side protective buffer mechanism (2) and a top protective buffer mechanism (3), wherein the side protective buffer mechanism (2) is slidably mounted on the inner peripheral side surface of the U-shaped protective outer frame (1), and the top protective buffer mechanism (3) is mounted at the inner top part;
a cover plate is fixed on the upper end surface of the U-shaped protective outer frame (1) through bolts;
the side protection buffer mechanism (2) comprises a side protection flame-retardant plate (21), the outer side surface of the side protection flame-retardant plate (21) is connected with the side surface of the U-shaped protection outer frame (1) through a first telescopic rod (23), a first buffer spring (24) is sleeved on the outer side of the first telescopic rod (23), a first rotating movable groove (25) is formed in the upper end surface of the side protection flame-retardant plate (21), and first buffer limiting grooves (26) are symmetrically formed in two sides of the first rotating movable groove (25);
the top protection buffer mechanism (3) comprises a top protection flame-retardant plate (21), the upper end face of the top protection flame-retardant plate (21) is connected with the top of the U-shaped protection outer frame (1) through a second telescopic rod (32), a second buffer spring (33) is sleeved on the outer side of the second telescopic rod (32), two sides of the top protection flame-retardant plate (21) are provided with second rotating movable grooves (34), and two sides of each first rotating movable groove (25) are symmetrically provided with second buffer limiting grooves (35).
2. The lithium battery fireproof and heat-insulating structure of claim 1, wherein: the device also comprises a linkage buffer mechanism (4), wherein the linkage buffer mechanism (4) is respectively in sliding fit with the side protection buffer mechanism (2) and the top protection buffer mechanism (3) of the adjacent surface;
the linkage buffer mechanism (4) comprises a first linkage plate (41) and a second linkage plate (42) which are hinged to each other, the first linkage plate (41) is hinged to a first rotating column (412), a first limiting sliding plate (411) is fixed to one end of the first rotating column (412), the first limiting sliding plates (411) at two ends of the first rotating column (412) are in sliding fit with a second buffering limiting groove (35), the second linkage plate (42) is hinged to a second rotating column (422), a second limiting sliding plate (421) is fixed to one end of the second rotating column (422), the second limiting sliding plates (421) at two ends of the second rotating column (422) are in sliding fit with a first buffering limiting groove (26), and the second linkage plate (42) is fixedly connected with the inner side face of the U-shaped protective outer frame (1) through a telescopic push rod (44).
3. The lithium battery fireproof and heat-insulating structure of claim 2, wherein: the top protection flame-retardant plate (21), the top protection flame-retardant plate (31), the first linkage plate (41) and the second linkage plate (42) are all made of flame-retardant materials.
4. The early warning system of the fireproof and heat-insulation structure of the lithium battery as claimed in any one of claims 1 to 3, wherein: the system comprises a battery parameter acquisition module, an internal and external temperature difference preprocessing module, a parameter dynamic analysis module, an electric quantity storage analysis module, an out-of-control trigger pre-judgment module, a control reduction and regulation and stabilization module, an out-of-control spread prediction module and an early warning prompt module;
the battery parameter acquisition module is used for detecting the pressure and temperature values of the surface of the lithium battery in real time;
the internal and external temperature difference preprocessing module is used for extracting the temperature inside the lithium battery and the temperature value of each point to be detected on the outer surface of the lithium battery, screening the temperature of each point to be detected on the outer surface of the lithium battery, averaging the temperature to obtain the average temperature of the outer surface of the lithium battery, comparing the internal temperature of the lithium battery with the average temperature of the outer surface to obtain the internal and external temperature difference, comparing the internal and external temperature difference with the internal and external temperature difference value range corresponding to each set temperature difference grade, determining the temperature difference grade corresponding to the current internal and external temperature difference of the lithium battery, and screening the relative temperature difference risk coefficient corresponding to the temperature difference grade;
the parameter dynamic analysis module is used for detecting a load voltage corresponding to a known resistor R1 in a closed loop formed by the lithium battery, an open-circuit voltage of the closed loop formed by the lithium battery and the known resistor and a current flowing through the known resistor, and analyzing a current internal resistance value of the lithium battery according to the load voltage, the open-circuit voltage and the current flowing through the known resistor
Sending the analyzed current internal resistance of the lithium battery to an electric quantity storage analysis module;
the electric quantity storage analysis module is used for receiving the current internal resistance of the lithium battery sent by the basic parameter analysis module, extracting the rated capacity, the rated internal resistance and the internal resistance in the battery retirement state of the lithium battery, analyzing the current health state of the lithium battery according to the current internal resistance, the rated internal resistance and the internal resistance in the battery retirement state of the lithium battery, and reversely deducing the residual electric quantity of the current lithium battery by adopting the analyzed current health state of the lithium battery and combining the rated capacity of the lithium battery;
the out-of-control triggering pre-judging module is used for extracting the temperature in the lithium battery collected in the battery parameter collecting module, comparing the temperature in the lithium battery with the thermal out-of-control pre-control temperature of the lithium battery, and sending pre-out-of-control triggering information of the lithium battery to the drop control stabilizing module if the temperature reaches the thermal out-of-control pre-control temperature of the lithium battery;
the temperature reduction and regulation module is used for receiving the lithium battery pre-out-of-control trigger information, starting lithium battery cooling liquid to carry out cooling treatment on the lithium battery according to the received lithium battery pre-out-of-control trigger information, meanwhile, extracting the temperature inside the lithium battery in real time, and carrying out speed reduction analysis on the temperature inside the lithium battery after cooling treatment in a fixed time period to obtain the temperature reduction acceleration inside the lithium battery in the fixed time period;
the out-of-control spreading prediction module is used for acquiring the temperature reduction acceleration inside the lithium battery in real time in the process of carrying out cooling treatment on the lithium battery, extracting the pressure value of the surface of the lithium battery with the temperature reduction acceleration inside the lithium battery in a maintenance state and the temperature grade corresponding to the temperature difference inside and outside the lithium battery, screening out the danger coefficient of the relative temperature difference according to the temperature grade, and counting the time consumed by the lithium battery to reach the maintenance state in the process of carrying out cooling treatment on the lithium battery
Extracting real-time residual electric quantity of the lithium battery from the thermal runaway pre-control temperature to the process that the temperature reduction acceleration in the lithium battery is in a stability maintenance state, comprehensively analyzing data information of the interference lithium battery by adopting an out-of-control extension prediction model, analyzing the estimated extension time of the lithium battery when the lithium battery extends to the thermal runaway state in the current state, and simultaneously sending the estimated extension time to an early warning prompt module;
the early warning prompting module is used for receiving the predicted extension time of the lithium battery which is transmitted by the uncontrolled extension predicting module and extends to the thermal uncontrolled state in the current state, and early warning prompting is carried out.
5. The early warning system of the fireproof and heat-insulation structure of the lithium battery as claimed in claim 4, wherein: the battery parameter acquisition module comprises a pressure sensor and a plurality of temperature sensors, the pressure sensor is installed outside the lithium battery and used for detecting the pressure value received by the surface of the lithium battery in real time, and the temperature sensors are distributed at the positions to be detected of the inner part of the lithium battery and the peripheral side of the outer surface of the lithium battery and used for detecting the temperature values of the positions to be detected of the inner part of the lithium battery and the peripheral side of the outer surface in real time.
6. The early warning system of the fireproof and heat-insulation structure of the lithium battery as claimed in claim 5, wherein: when the internal resistance of the lithium battery needs to be detected, the on-off of the relay in the closed loop formed by the lithium battery is controlled to detect the load voltage corresponding to the known resistance and the open-circuit voltage of the closed loop, so that the current flowing through the known resistance is R;
the current internal resistance calculation formula of the lithium battery is
，
For a load voltage corresponding to a known resistance of the loop formed by the lithium battery,
the open circuit voltage corresponding to the loop where the lithium battery is located,
is the current flowing through a known resistance.
7. The early warning system of the fireproof and heat-insulation structure of the lithium battery as claimed in claim 6, wherein: the electric quantity storage analysis module analyzes the current health state of the lithium battery according to the current internal resistance of the lithium battery, the rated internal resistance of the lithium battery and the internal resistance in the decommissioning state of the battery;
the formula adopted by the current state of health (SOH) of the lithium battery is as follows:
；
residual capacity of lithium batteryThe quantity formula is:
；
wherein the content of the first and second substances,
is the current internal resistance of the lithium battery,
is the rated internal resistance of the lithium battery,
is the internal resistance of the battery in the retired state,
the rated capacity of the lithium battery.
8. The early warning system of the fireproof and heat-insulation structure of the lithium battery as claimed in claim 7, wherein: thermal runaway pre-management temperature of lithium battery =
*T2，
And taking the value of 0.568, wherein T2 is the thermal runaway initiation temperature of the lithium battery.
9. The early warning system of the fireproof and heat-insulation structure of the lithium battery as claimed in claim 8, wherein: the runaway propagation prediction model comprises the following steps:
and e is a natural number,
，
the real-time residual electric quantity of the lithium battery is measured in the process that the lithium battery is in a stable state from the temperature of thermal runaway pre-control,
the average value of the residual electric quantity of the lithium battery in the process from the thermal runaway pre-control temperature to the stable maintaining state of the lithium battery is obtained,
the unit of the time consumed by the lithium battery when the lithium battery reaches the stable state is second, the residual electric quantity of the lithium battery is analyzed in turn for 10 seconds in the process of temperature reduction treatment,
is the rated capacity of the lithium battery,
the pressure value of the surface of the lithium battery in a stable state is shown,
the value of the pressure on the surface of the lithium battery when the lithium battery reaches thermal runaway is shown, and y is a relative temperature difference danger coefficient mapped by a temperature grade corresponding to the internal and external temperature difference of the lithium battery in a stable state.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115332702A (en) * | 2022-10-13 | 2022-11-11 | 惠州市纬世新能源有限公司 | High-safety battery cell structure |
| CN116859249A (en) * | 2023-05-31 | 2023-10-10 | 长兴太湖能谷科技有限公司 | Lithium battery monitoring management system based on big data |
| CN117420452A (en) * | 2023-12-18 | 2024-01-19 | 深圳市海雷新能源有限公司 | Monitoring and early warning system for lithium battery energy storage |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115332702A (en) * | 2022-10-13 | 2022-11-11 | 惠州市纬世新能源有限公司 | High-safety battery cell structure |
| CN115332702B (en) * | 2022-10-13 | 2023-02-03 | 惠州市纬世新能源有限公司 | High-safety battery cell structure |
| CN116859249A (en) * | 2023-05-31 | 2023-10-10 | 长兴太湖能谷科技有限公司 | Lithium battery monitoring management system based on big data |
| CN116859249B (en) * | 2023-05-31 | 2024-05-10 | 长兴太湖能谷科技有限公司 | Lithium battery monitoring management system based on big data |
| CN117420452A (en) * | 2023-12-18 | 2024-01-19 | 深圳市海雷新能源有限公司 | Monitoring and early warning system for lithium battery energy storage |
| CN117420452B (en) * | 2023-12-18 | 2024-03-12 | 深圳市海雷新能源有限公司 | Monitoring and early warning system for lithium battery energy storage |
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