A method and system for inhibiting thermal runaway of lithium battery in energy storage system

Abstract

The present invention relates to the field of lithium battery technology, and provides a method and system for inhibiting thermal runaway of a lithium battery in an energy storage system, the method comprising: dividing the lithium battery of the energy storage system into a plurality of battery cells, and setting a heat conducting plate and a heat insulating layer between different battery cells; starting the cooling system and determining the corresponding power; determining the initial coolant flow rate to be released according to the coolant inlet temperature and the coolant outlet temperature; determining the volume of the fire extinguishing agent to be released according to the current temperature and critical temperature of the first battery cell, and releasing the corresponding coolant and fire extinguishing agent in combination with the initial coolant flow rate, and performing a cooling operation on the first battery cell; in the cooling operation, determining the adjusted coolant flow rate according to the temperature threshold, the real-time temperature difference inside the first battery cell, and the initial coolant flow rate; and continuing to perform a cooling operation on the first battery cell according to the volume of the fire extinguishing agent and the adjusted coolant flow rate. The present invention can improve the inhibition effect of thermal runaway of lithium batteries.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a method, system and electronic equipment for suppressing thermal runaway of a lithium battery in an energy storage system. Background Art

[0002] Nowadays, with the widespread application of power batteries and energy storage batteries, lithium battery fire and explosion accidents occur frequently, and safety performance has attracted much attention. Most accidents are caused by thermal runaway of lithium batteries under abuse conditions such as overcharging, over-discharging, extrusion, high temperature, short circuit, etc. Currently, physical cooling is mainly carried out by external cooling system or setting fire extinguishing agent in lithium battery pack to suppress thermal runaway.

[0003] However, the above cooling methods are mainly used to reduce the current hazards after thermal runaway occurs, such as inhibiting the expansion of thermal runaway and reducing the risk of fire and explosion, and the continuous cooling effect on thermal runaway lithium batteries is poor. Summary of the invention

[0004] The present invention aims to solve the technical problems existing in the prior art and provides a method, system and electronic equipment for suppressing thermal runaway of a lithium battery in an energy storage system, which can improve the suppression effect of thermal runaway of the lithium battery.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] The present invention provides a method for inhibiting thermal runaway of a lithium battery in an energy storage system, the method comprising:

[0007] Divide the lithium battery of the energy storage system into a plurality of battery cells, and arrange heat conducting plates and heat insulating layers between different battery cells; wherein each of the battery cells is arranged in a honeycomb structure;

[0008] Acquire the current temperature of each of the battery cells in real time, and when there is a first battery cell whose current temperature is greater than a temperature threshold, start the cooling system and determine the corresponding power;

[0009] Determine the initial coolant flow rate to be released according to the coolant inlet temperature and the coolant outlet temperature;

[0010] Determine the volume of the fire extinguishing agent to be released according to the current temperature and critical temperature of the first battery unit, and release the corresponding coolant and fire extinguishing agent in combination with the initial coolant flow rate to cool the first battery unit;

[0011] In a cooling operation, determining an adjusted coolant flow rate according to the temperature threshold, the real-time temperature difference inside the first battery unit, and the initial coolant flow rate;

[0012] The first battery cell continues to be cooled according to the volume of the fire extinguishing agent and the adjusted coolant flow rate, so as to suppress thermal runaway of the first battery cell.

[0013] Optionally, before arranging the heat conducting plates between different battery cells, the method further includes:

[0014] Obtain multiple candidate heat conducting plates;

[0015] Determine a first amount of heat transferred per unit time by each of the candidate heat conducting plates;

[0016] A candidate heat conducting plate whose first heat quantity satisfies the heat threshold is determined as the heat conducting plate to be set.

[0017] Optionally, the first heat is expressed as:

[0018]

[0019] Wherein, q is the first heat, k is the thermal conductivity, A is the area of ​​the heat conducting plate, dT is the temperature difference, dx is the distance in the thickness direction of the heat conducting plate, β is the second correction coefficient, and L is the length of the heat conducting path.

[0020] Optionally, when there is a first battery cell whose current temperature is greater than a temperature threshold, starting the cooling system and determining the corresponding power includes:

[0021] obtaining a first constant for adjusting the efficiency of the cooling system;

[0022] calculating a first difference between a current temperature of the first battery cell and the temperature threshold, and a first quotient of the current temperature and the temperature threshold;

[0023] The power of the cooling system is determined according to the first constant, the first difference and the first quotient.

[0024] Optionally, the power of the cooling system is expressed as:

[0025]

[0026] Among them, P cool is the power of the cooling system, i is the number of the battery cell, T i is the current temperature of the ith battery cell, T max is the temperature threshold, k cool is the first constant of the cooling system, and γ is the exponential coefficient.

[0027] Optionally, the initial coolant flow rate is expressed as:

[0028]

[0029] Where Q is the initial coolant flow rate, T in is the coolant inlet temperature, T out is the coolant outlet temperature, ΔT is the coolant inlet and outlet temperature difference, Δt is the time interval, m is the coolant mass, c p is the specific heat capacity of the coolant, and α is the first correction coefficient.

[0030] Optionally, the volume of the fire extinguishing agent is expressed as:

[0031]

[0032] Among them, V release is the volume of extinguishing agent released, k release is the release coefficient, T i is the current temperature of the ith battery cell, T critical is the critical temperature, and γ is the exponential coefficient.

[0033] Optionally, the adjusted coolant flow rate is expressed as:

[0034]

[0035] Among them, Q adjusted is the adjusted coolant flow rate, Q initial is the initial coolant flow rate, ΔT real-time is the real-time temperature difference, and τ is the third correction coefficient.

[0036] Optionally, the method further includes:

[0037] Acquiring material data, temperature data, and environmental data of the first battery cell;

[0038] constructing a heat conduction model based on the material data, the temperature data and the environment data;

[0039] Optimizing the initial coolant flow rate and the power of the cooling system based on the temperature gradient output by the heat conduction model;

[0040] The temperature gradient output by the heat conduction model is expressed as:

[0041]

[0042] in, is the temperature gradient output by the temperature conduction model, a is the thermal diffusion coefficient, β is the second correction coefficient, T is the temperature, t is the time, is the Laplace operator of temperature.

[0043] The present invention also provides a thermal runaway suppression system for a lithium battery in an energy storage system, the system comprising:

[0044] A structural division module, used to divide the lithium battery of the energy storage system into a plurality of battery cells, and to arrange a heat conducting plate and a heat insulating layer between different battery cells; wherein each of the battery cells is arranged in a honeycomb structure;

[0045] A cooling start module, used for obtaining the current temperature of each of the battery cells in real time, and when there is a first battery cell whose current temperature is greater than a temperature threshold, starting the cooling system and determining the corresponding power;

[0046] A first coolant module, used to determine an initial coolant flow rate to be released according to a coolant inlet temperature and a coolant outlet temperature;

[0047] a first cooling module, configured to determine the volume of the fire extinguishing agent to be released according to the current temperature and the critical temperature of the first battery unit, and release the corresponding coolant and the fire extinguishing agent in combination with the initial coolant flow rate to cool the first battery unit;

[0048] a second coolant module, used to determine an adjusted coolant flow rate according to the temperature threshold, the real-time temperature difference inside the first battery unit, and the initial coolant flow rate during a cooling operation;

[0049] The second cooling module is used to continue cooling the first battery cell according to the volume of the fire extinguishing agent and the adjusted coolant flow rate, so as to suppress thermal runaway of the first battery cell.

[0050] In addition, to achieve the above-mentioned purpose, the present invention also proposes an electronic device, comprising: a memory for storing a computer software program; a processor for reading and executing the computer software program, thereby implementing a method for suppressing thermal runaway of a lithium battery in an energy storage system as described above.

[0051] The beneficial effects of the present invention are:

[0052] (1) The present invention can effectively prevent the risk of thermal runaway of lithium batteries under abuse conditions such as overcharging, over-discharging, extrusion, high temperature, short circuit, etc. by dynamically adjusting the coolant flow rate, releasing fire extinguishing agents, etc., thereby greatly improving the safety of the battery system.

[0053] (2) The present invention uses a nonlinear heat conduction model and real-time temperature monitoring to more accurately predict and control the temperature distribution of the battery system, thereby improving the stability of the system and reducing the instability caused by temperature fluctuations.

[0054] (3) The present invention dynamically adjusts the coolant flow rate so that the cooling system can adaptively adjust the working state according to the real-time temperature conditions. This not only improves the continuous cooling effect of the cooling system on the lithium battery, but also reduces unnecessary energy consumption and improves the energy efficiency of the system.

[0055] (4) The present invention effectively controls the temperature of the battery system, avoids damage to the battery caused by long-term high temperature, prolongs the service life of the battery, and reduces maintenance costs.

[0056] (5) The present invention has designed a set of multi-level safety measures and temperature control solutions by comprehensively considering the safety and performance requirements under various working conditions, thereby improving the reliability of the battery system, reducing the occurrence of emergencies, and ensuring the stable operation of the system.

[0057] In summary, the present invention can enhance the inhibitory effect on thermal runaway of lithium batteries, improve the safety, stability and reliability of lithium battery systems, while also optimizing energy efficiency and extending battery life, providing strong support for the development of the battery energy storage field. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 A scene diagram of a method for suppressing thermal runaway of a lithium battery in an energy storage system provided by the present invention;

[0059] Figure 2 A flow chart of a method for suppressing thermal runaway of a lithium battery in an energy storage system provided by the present invention;

[0060] Figure 3 A schematic diagram of the structure of a thermal runaway suppression system for a lithium battery in an energy storage system provided by the present invention;

[0061] Figure 4 A schematic diagram of the hardware structure of a possible electronic device provided by the present invention. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0063] See also Figure 1 , Figure 1 This is a scene diagram of a method for suppressing thermal runaway of a lithium battery in an energy storage system provided by the present invention. Figure 1As shown, the terminal and the server are connected via a network, such as a wired or wireless network connection. The terminal may include but is not limited to portable terminals such as mobile phones and tablets installed with various network platform applications, as well as fixed terminals such as computers, query machines, and advertising machines. The server provides users with various business services, including service push servers, user recommendation servers, etc.

[0064] It should be noted that Figure 1 The scenario diagram of a method for suppressing thermal runaway of a lithium battery in an energy storage system shown is only an example. The terminal, server, and application scenario described in the embodiment of the present invention are intended to more clearly illustrate the technical solution of the embodiment of the present invention, and do not generate any limitation on the technical solution provided by the embodiment of the present invention. A person of ordinary skill in the art can know that with the evolution of the system and the emergence of new business scenarios, the technical solution provided by the embodiment of the present invention is also applicable to similar technical problems.

[0065] Among them, the terminal can be used for:

[0066] Divide the lithium battery of the energy storage system into a plurality of battery cells, and arrange heat conducting plates and heat insulating layers between different battery cells; wherein each of the battery cells is arranged in a honeycomb structure;

[0067] Acquire the current temperature of each of the battery cells in real time, and when there is a first battery cell whose current temperature is greater than a temperature threshold, start the cooling system and determine the corresponding power;

[0068] Determine the initial coolant flow rate to be released according to the coolant inlet temperature and the coolant outlet temperature;

[0069] Determine the volume of the fire extinguishing agent to be released according to the current temperature and critical temperature of the first battery unit, and release the corresponding coolant and fire extinguishing agent in combination with the initial coolant flow rate to cool the first battery unit;

[0070] In a cooling operation, determining an adjusted coolant flow rate according to the temperature threshold, the real-time temperature difference inside the first battery unit, and the initial coolant flow rate;

[0071] The first battery cell continues to be cooled according to the volume of the fire extinguishing agent and the adjusted coolant flow rate, so as to suppress thermal runaway of the first battery cell.

[0072] See also Figure 2 , provides a flow chart of a method for suppressing thermal runaway of a lithium battery in an energy storage system of the present invention, comprising the following steps:

[0073] Step 201: Divide the lithium battery of the energy storage system into a plurality of battery cells, and set a heat conducting plate and a heat insulating layer between different battery cells.

[0074] Among them, each battery cell is arranged in a honeycomb structure.

[0075] In some embodiments, the energy storage system lithium battery can be divided into multiple battery cells to better manage temperature. Each battery cell can have its own temperature monitoring and control system to ensure uniform temperature distribution. At the same time, the setting of the heat conducting plate can help heat transfer evenly between battery cells, effectively reduce temperature gradients, and improve the thermal management efficiency of the system.

[0076] In some embodiments, by providing a heat insulation layer between different battery cells, the heat transfer of a single battery cell can be effectively isolated to prevent thermal runaway from spreading to the entire system. This design can limit potential thermal runaway events and improve the safety of the system.

[0077] In some embodiments, the battery cells can be arranged in a honeycomb structure to improve the structural stability of the system. This arrangement can maximize the use of space and leave enough gaps between the battery cells to facilitate the installation of heat conduction plates and insulation layers. It can also effectively arrange cooling fans or other accessories to further optimize the heat dissipation effect of the system.

[0078] In some embodiments, the lithium battery of the energy storage system can be divided into multiple battery cells, making the maintenance of a single battery cell easier. If a battery cell needs to be replaced or repaired, the cell can be operated separately without affecting the entire system, thereby improving the maintainability and operability of the system.

[0079] In summary, the present invention divides the lithium battery of the energy storage system into multiple battery cells, and arranges heat conduction plates and insulation layers between different cells, and adopts a honeycomb structure arrangement, which can effectively optimize thermal management, reduce the risk of thermal runaway, enhance structural stability and improve the maintainability of the system.

[0080] In some embodiments, before step 201, the present invention further includes:

[0081] Obtain multiple candidate heat conducting plates;

[0082] Determine a first amount of heat transferred per unit time by each of the candidate heat conducting plates;

[0083] A candidate heat conducting plate whose first heat quantity satisfies the heat threshold is determined as the heat conducting plate to be set.

[0084] In some embodiments, the first heat is expressed as:

[0085]

[0086] Wherein, q is the first heat, k is the thermal conductivity, A is the area of ​​the heat conducting plate, dT is the temperature difference, dx is the distance in the thickness direction of the heat conducting plate, β is the second correction coefficient, and L is the length of the heat conducting path.

[0087] In a specific implementation, q is the first heat, in watts (W), which represents the heat transferred through the heat conducting plate;

[0088] k is the thermal conductivity, measured in watts per meter per Kelvin (W / (m·K)), which indicates the ability of a material to conduct heat;

[0089] A is the area of ​​the heat conducting plate, in square meters (m 2 ), which represents the cross-sectional area where heat conduction occurs;

[0090] dT is the temperature difference in Kelvin (K), which indicates the temperature difference on both sides of the heat conducting plate;

[0091] dx is the distance in the thickness direction of the heat conducting plate, in meters (m), indicating the distance of heat conduction;

[0092] β is the second correction coefficient, which has no fixed unit and is used to adjust the impact of the nonlinear correction term in the formula;

[0093] L is the heat conduction path length, in meters (m), which indicates the length of the heat conduction path.

[0094] In the specific implementation, this formula contains a nonlinear correction term To more accurately describe complex heat conduction phenomena, is the product of the correction factor β and the ratio of area to path length, which is used to adjust the nonlinear part of the heat flow. It is the second derivative of temperature, which indicates the quadratic rate of change of temperature along the thickness direction, taking into account more complex temperature changes.

[0095] It can be understood that in the standard heat conduction part Describes the linear process of heat conduction from the high temperature side to the low temperature side, reflecting the basic characteristics of thermal conductive materials. A more complex description of the temperature gradient variation is introduced to adjust the standard linear model to make it closer to reality.

[0096] In the present invention, by considering that lithium batteries will produce complex temperature changes under abuse conditions such as overcharge, over discharge, extrusion, high temperature and short circuit, the standard linear heat conduction equation may not be sufficient to accurately describe the actual heat conduction process. By introducing nonlinear correction terms, the formula can better predict and control the heat transfer inside the battery, thereby effectively suppressing thermal runaway and improving the safety performance of the battery.

[0097] In some embodiments, the thermal conductivity k, the area A of the heat conducting plate, the length L of the heat conducting path, and the correction coefficient β can be obtained first. Then the temperature difference dT on both sides of the heat conducting plate and the distance dx in the thickness direction of the heat conducting plate are measured to calculate the temperature gradient Then, based on the temperature distribution, calculate the second-order derivative of the temperature gradient Finally, the above data are substituted into the formula to calculate the heat flow q.

[0098] Through the above methods, the present invention can accurately evaluate the heat conduction of the heat conducting plate under various working conditions, ensuring that the battery system can effectively suppress thermal runaway in actual use and improve safety and reliability.

[0099] Step 202: Acquire the current temperature of each of the battery cells in real time. When there is a first battery cell whose current temperature is greater than a temperature threshold, start the cooling system and determine the corresponding power.

[0100] In some embodiments, step 202 may include:

[0101] obtaining a first constant for adjusting the efficiency of the cooling system;

[0102] calculating a first difference between a current temperature of the first battery cell and the temperature threshold, and a first quotient of the current temperature and the temperature threshold;

[0103] The power of the cooling system is determined according to the first constant, the first difference and the first quotient.

[0104] In some embodiments, the power of the cooling system is expressed as:

[0105]

[0106] Among them, P cool is the power of the cooling system, i is the number of the battery cell, T i is the current temperature of the ith battery cell, T max is the temperature threshold, k cool is the first constant of the cooling system, and γ is the exponential coefficient.

[0107] In the specific implementation, P cool is the power of the cooling system, in watts (W), representing the power consumption of the cooling system on the i-th battery unit;

[0108] i is the number value of the battery cell, which is used to identify a specific battery cell;

[0109] T i is the current temperature of the i-th battery cell, in Kelvin (K), indicating the actual temperature of the battery cell at a certain moment;

[0110] T max is the temperature threshold, in Kelvin (K), which indicates the maximum operating temperature that the battery system can safely withstand;

[0111] k cool It is the first constant of the cooling system, with the unit of watt per Kelvin square (W / K2), which represents the efficiency coefficient of the cooling system;

[0112] γ is the exponential coefficient, which has no fixed unit and is used to adjust the impact of the exponential part;

[0113] In the specific implementation, the formula is used to describe the relationship between the power consumption of the cooling system and the temperature of the battery cell. It includes two parts: the secondary temperature difference term (T i -T max ) 2 Indicates the current temperature T i and temperature threshold T max When the temperature difference is large, the value of this item will increase rapidly, indicating that the cooling system needs to consume more power to reduce the temperature.

[0114] Index term Indicates temperature T i Relative to the threshold temperature T max exponential relationship. When T i Close to or exceeding T max , the exponential term increases significantly, reflecting the need for more cooling power at high temperatures.

[0115] It can be understood that the overall formula combines the quadratic temperature difference term with the exponential term to calculate the power consumption of the cooling system on a specific battery cell. The first constant is used to adjust the efficiency of the cooling system. The specific value depends on the design and performance parameters of the cooling system. The exponential coefficient is used to adjust the influence of the exponential term so that the formula can more accurately describe the changes in cooling demand under high temperature conditions. In lithium battery energy storage systems, battery cells may increase in temperature due to overcharging, over-discharging, extrusion, high temperature, short circuit and other conditions, reaching or even exceeding the safety temperature threshold. This formula ensures that the cooling system can work efficiently under different temperature conditions and avoid thermal runaway by calculating the cooling power requirements of each battery cell in real time.

[0116] In some embodiments, the current temperature T of each battery cell may be obtained first. i Then, according to the system design, determine the safe temperature threshold T max . Then determine the cooling system constant k cool and exponential coefficient γ, these parameters are usually determined by experimental data and system design. i , T max , kcool Substitute γ into the formula to calculate the cooling power P of each battery cell cool .

[0117] By calculating the real-time cooling power requirements of each battery cell in the above manner, the cooling system can dynamically adjust its operating power to ensure that the battery system avoids overheating and thermal runaway when working efficiently, thereby improving the safety and reliability of the battery system. It can provide precise temperature control measures, which is especially suitable for complex and high-risk lithium battery application scenarios.

[0118] Step 203: Determine the initial coolant flow rate to be released according to the coolant inlet temperature and the coolant outlet temperature.

[0119] In some embodiments, the initial coolant flow rate is expressed as:

[0120]

[0121] Where Q is the initial coolant flow rate, T in is the coolant inlet temperature, T out is the coolant outlet temperature, ΔT is the coolant inlet and outlet temperature difference, Δt is the time interval, m is the coolant mass, c p is the specific heat capacity of the coolant, and α is the first correction coefficient.

[0122] In the specific implementation, Q is the initial coolant flow rate in cubic meters per second (m 3 / s), which indicates the total flow rate of the coolant in the time interval;

[0123] T in is the coolant inlet temperature, in Kelvin (K), indicating the temperature of the coolant entering the cooling system;

[0124] T out is the coolant outlet temperature, in Kelvin (K), which indicates the temperature of the coolant leaving the cooling system;

[0125] ΔT is the temperature difference between the inlet and outlet of the coolant, in Kelvin (K), which indicates the temperature change of the coolant in the system. ΔT = T out -T in ;

[0126] Δt is the time interval in seconds (s), which indicates the time interval of coolant flow;

[0127] m is the mass of the coolant in kilograms (kg), indicating the total mass of the coolant;

[0128] c pis the specific heat capacity of the coolant, measured in joules per kilogram per Kelvin (J / (kg·K)), which indicates the ability of the coolant to absorb or release heat;

[0129] α is the first correction coefficient, which has no fixed unit and is used to adjust the nonlinear correction term in the formula.

[0130] In the specific implementation, the formula includes a nonlinear correction term To more accurately describe the complex heat transfer phenomena in the cooling process. It is the ratio of the temperature difference to the inlet temperature, reflecting the nonlinear effect of the coolant when the inlet and outlet temperature difference is large. It is the natural logarithm of the ratio of the coolant inlet and outlet temperatures, and represents the logarithmic relationship of the coolant during temperature changes.

[0131] It can be understood that this formula should be used to design and optimize the cooling system of lithium batteries to ensure that the cooling system can efficiently remove heat from the battery under different working conditions to prevent thermal runaway. Accurate calculation of coolant flow is essential to keep the battery temperature stable.

[0132] In some embodiments, the inlet temperature and outlet temperature of the coolant can be obtained first, and then the inlet and outlet temperature difference can be calculated. Then the coolant mass, specific heat capacity, time interval and correction factor can be determined. The above parameters are substituted into the formula to calculate the initial coolant flow rate.

[0133] In summary, the present invention provides a more accurate coolant flow calculation method by considering the temperature difference and the nonlinear effect in the coolant flow process. In this way, the cooling system can dynamically adjust the coolant flow to ensure that the lithium battery system is maintained within a safe temperature range when working efficiently, thereby improving the safety and reliability of the system.

[0134] Step 204: determine the volume of the fire extinguishing agent to be released according to the current temperature and critical temperature of the first battery unit, and release the corresponding coolant and fire extinguishing agent in combination with the initial coolant flow rate to cool the first battery unit.

[0135] In some embodiments, the volume of fire extinguishing agent is expressed as:

[0136]

[0137] Among them, V release is the volume of extinguishing agent released, k release is the release coefficient, T i is the current temperature of the ith battery cell, T critical is the critical temperature, and γ is the exponential coefficient.

[0138] In the specific implementation, V releaseis the volume of the extinguishing agent released, in cubic meters (m 3 ), which indicates the total amount of extinguishing agent that needs to be released under specific conditions;

[0139] k release is the release coefficient, in cubic meters per square Kelvin (m 3 / K 2 ), which represents the efficiency coefficient of the fire extinguishing agent release;

[0140] T i is the current temperature of the ith battery cell, in Kelvin (K), indicating the actual temperature of the ith battery cell at a certain moment;

[0141] T critical is the critical temperature, in Kelvin (K), which indicates the temperature threshold that the battery system can safely withstand;

[0142] γ is the exponential coefficient, which has no fixed unit and is used to adjust the impact of the exponential part;

[0143] In the specific implementation, (T i -T critical 2 This means that when the temperature difference is large, the value of this item will increase rapidly, indicating that more extinguishing agent needs to be released to deal with the high temperature situation. Indicates that when T i Close to or exceeding T critical The exponential term increases significantly when the temperature reaches or exceeds the critical temperature, reflecting the need to rapidly increase the amount of extinguishing agent released under high temperature conditions. In this way, the formula describes the volume of extinguishing agent that needs to be released to suppress battery thermal runaway when the temperature reaches or exceeds the critical temperature.

[0144] It is understood that in lithium battery energy storage systems, when the battery temperature rises to or above the critical temperature due to overcharging, over-discharging, extrusion, high temperature or short circuit, in order to prevent thermal runaway, the fire extinguishing agent must be quickly released to cool down and suppress the risk of fire. This formula determines the volume of fire extinguishing agent that needs to be released by calculating the relationship between the actual temperature of each battery cell and the critical temperature.

[0145] In some embodiments, the current temperature of each battery cell can be obtained first, and then the safety critical temperature can be determined according to the battery system design. Then the release coefficient and exponential coefficient can be determined, and then the fire extinguishing agent release coefficient and exponential coefficient can be determined. Then the above determined values ​​can be substituted into the formula to calculate the volume of fire extinguishing agent that needs to be released.

[0146] In summary, the present invention provides an accurate method for calculating the amount of fire extinguishing agent released by considering the difference between the current temperature and the critical temperature and their exponential relationship. When the battery temperature rises to a dangerous level, the cooling system can release an appropriate amount of fire extinguishing agent in time to ensure that the battery system is maintained within a safe temperature range when working efficiently, thereby improving the safety and reliability of the system.

[0147] Step 205: During the cooling operation, determine the adjusted coolant flow rate according to the temperature threshold, the real-time temperature difference inside the first battery unit, and the initial coolant flow rate.

[0148] In some embodiments, the adjusted coolant flow rate is expressed as:

[0149]

[0150] Among them, Q adjusted is the adjusted coolant flow rate, Q initial is the initial coolant flow rate, ΔT real-time is the real-time temperature difference, and τ is the third correction coefficient.

[0151] In the specific implementation, Q adjusted is the adjusted coolant flow rate in cubic meters per second (m 3 / s), which indicates the coolant flow rate adjusted in real time;

[0152] Q initial is the initial coolant flow rate in cubic meters per second (m 3 / s), represents the unadjusted initial coolant flow rate;

[0153] ΔT real-time is the real-time temperature difference, in Kelvin (K), indicating the real-time temperature difference between the inlet and outlet of the coolant;

[0154] τ is the third correction coefficient, which has no fixed unit and is used to adjust the impact of the exponential part;

[0155] In the specific implementation, Indicates the real-time temperature difference ΔT real-time With temperature threshold T max The ratio of +1. When the real-time temperature difference is large, the value of this item will increase, resulting in an increase in the adjusted coolant flow rate. It represents the exponent of the ratio of the real-time temperature difference to the temperature threshold multiplied by the correction coefficient τ. When the real-time temperature difference is large relative to the temperature threshold, the value of this item will increase rapidly, resulting in a significant increase in the adjusted coolant flow rate.

[0156] In summary, this formula describes the amount of coolant flow to be adjusted according to the size of the real-time temperature difference. By considering the linear and exponential relationship of the temperature difference, the coolant flow can be adjusted more accurately to ensure that the battery system can still remain within a safe temperature range under high temperature conditions.

[0157] It is understandable that in lithium battery energy storage systems, the temperature fluctuates greatly, especially under abnormal conditions, the temperature may rise rapidly. Adjusting the coolant flow rate can reduce the temperature in time to prevent the battery from overheating and causing thermal runaway. This formula can dynamically adjust the coolant flow rate according to the real-time temperature difference to ensure the safe operation of the battery system under different conditions.

[0158] In some embodiments, the inlet temperature and outlet temperature of the coolant can be obtained, and the real-time temperature difference can be calculated. Then the temperature threshold is determined according to the system design. Then the initial coolant flow rate is determined according to the system design. Then the correction coefficient ττ is determined. Finally, the above parameters are substituted into the formula to calculate the adjusted coolant flow rate.

[0159] In summary, the present invention provides a method for dynamically adjusting the coolant flow rate by considering the size of the real-time temperature difference and the exponential relationship. In this way, the cooling system can adaptively adjust the coolant flow rate according to the real-time temperature conditions, ensuring that the battery system remains within a safe temperature range under different operating conditions, thereby improving the safety and reliability of the system.

[0160] Step 206: Continue to cool the first battery cell according to the volume of the fire extinguishing agent and the adjusted coolant flow rate to suppress thermal runaway of the first battery cell.

[0161] In some embodiments, the volume of fire extinguishing agent required for release may be determined based on a calculated fire extinguishing agent volume formula, where the volume is calculated based on factors such as the current temperature of the battery cell and the critical temperature.

[0162] In some embodiments, the method and device for releasing the fire extinguishing agent can be determined to ensure that the fire extinguishing agent can effectively cover the entire battery cell and quickly reduce the temperature.

[0163] In some embodiments, the adjusted coolant flow rate can be determined according to the adjusted coolant flow rate formula. This flow rate is calculated based on parameters such as the real-time temperature difference and the temperature threshold, and can more effectively reduce the temperature of the battery unit.

[0164] In some embodiments, the operating state and parameter settings of the cooling system can be determined to ensure that the adjusted coolant flow rate can reach and cover the entire surface of the battery unit in a timely manner to achieve an effective cooling effect.

[0165] In some embodiments, after the volume of the fire extinguishing agent and the adjusted coolant flow rate are determined, the first battery unit may be cooled by releasing the fire extinguishing agent and circulating the coolant.

[0166] It can be understood that the release of the fire extinguishing agent can quickly reduce the temperature of the battery cell and effectively suppress the development trend of thermal runaway. At the same time, the adjusted coolant flow can continuously take away the heat and keep the temperature of the battery cell within a safe range.

[0167] In some embodiments, the temperature change of the first battery cell can be continuously monitored during the cooling operation to ensure that the temperature is stable within a safe range. The release amount of the fire extinguishing agent and the flow rate of the coolant can be adjusted according to actual conditions to achieve the best cooling effect and avoid new problems caused by too low or too high temperature.

[0168] In summary, the present invention can effectively suppress thermal runaway of the first battery unit and ensure safe operation of the system under high temperature conditions by comprehensively utilizing fire extinguishing agent and coolant to perform cooling operations.

[0169] In some embodiments, the method of the present invention further comprises:

[0170] Acquiring material data, temperature data, and environmental data of the first battery cell;

[0171] constructing a heat conduction model based on the material data, the temperature data and the environment data;

[0172] Optimizing the initial coolant flow rate and the power of the cooling system based on the temperature gradient output by the heat conduction model;

[0173] Among them, the temperature gradient output by the heat conduction model is expressed as:

[0174]

[0175] in, is the temperature gradient output by the temperature conduction model, a is the thermal diffusion coefficient, β is the second correction coefficient, T is the temperature, t is the time, is the Laplace operator of temperature.

[0176] In the specific implementation, is the temperature gradient output by the temperature conduction model, which represents the first-order derivative of temperature in the x direction, indicating the rate of change of temperature with time. The unit is Kelvin per second (K / s), indicating the rate of change of temperature in time t;

[0177] a is the thermal diffusion coefficient, in square meters per second (m 2 / s), which indicates the ability of heat to diffuse in the material;

[0178] β is the second correction coefficient, which has no fixed unit and is used to adjust the effect of nonlinear term on temperature change;

[0179] T is temperature, the unit is Kelvin (K), which indicates the temperature of the material;

[0180] t is time, the unit is second (s), indicating the time variable;

[0181] is the Laplace operator of temperature in Kelvin per square meter (K / m 2 ), which represents the second-order rate of change of temperature in space.

[0182] In practice, this formula is an extended heat conduction equation that describes how the temperature changes over time inside a material. The formula takes into account the effects of heat diffusion and nonlinear heat conduction. It represents the second derivative of temperature in space, also known as the Laplace operator of temperature. It reflects the uniform diffusion of temperature in all spatial directions. a is the thermal diffusion coefficient, which represents the rate at which heat diffuses in the material. This term describes the thermal diffusion process inside the material, similar to the form of Fourier's law.

[0183] middle, It represents the first derivative of temperature in the x direction, that is, the temperature gradient. It is the square of the temperature gradient, reflecting the nonlinear effect of the temperature gradient. In the equation, the correction factor β is divided by the temperature T to adjust the effect of the nonlinear term on the overall temperature change. The nonlinear term describes the effect of the change in temperature gradient in space on the temperature diffusion. When the temperature gradient is large, the effect of this term increases, reflecting the difference in the thermal conductivity characteristics of the material at different temperatures.

[0184] It is understandable that in lithium battery energy storage systems, the temperature distribution of batteries will become very complex under abuse conditions such as overcharging, over-discharging, extrusion, high temperature and short circuit. Simple linear heat conduction equations may not be sufficient to accurately describe this complex heat conduction behavior. Therefore, by introducing nonlinear correction terms, the formula can better describe and predict the temperature changes inside the battery, ensuring that the cooling system can be adjusted in time to prevent thermal runaway.

[0185] In some embodiments, the initial temperature distribution and boundary conditions of the battery system can be determined first. Then, based on the initial conditions and boundary conditions, the spatial gradient of the temperature can be calculated. and the Laplacian operator Then substitute the thermal diffusion coefficient a, the second correction coefficient β, temperature T, time t and its derivative into the formula to calculate the rate of change of temperature over time: Finally, the variation of temperature field with time is solved iteratively through numerical method to obtain the temperature distribution of each time step.

[0186] In summary, the present invention provides a more comprehensive method for describing temperature changes by considering the nonlinear effect of temperature gradient. This can more accurately predict the temperature distribution of the battery system under different working conditions, optimize the design and control of the cooling system, ensure that the lithium battery system is maintained within a safe temperature range when working efficiently, and improve the safety and reliability of the system.

[0187] See also Figure 3 , Figure 3 A schematic structural diagram of a thermal runaway suppression system for a lithium battery in an energy storage system provided by the present invention.

[0188] like Figure 3 As shown, a thermal runaway suppression system for a lithium battery in an energy storage system proposed in an embodiment of the present invention includes:

[0189] The structural division module 301 is used to divide the lithium battery of the energy storage system into a plurality of battery cells, and to set a heat conducting plate and a heat insulating layer between different battery cells; wherein each of the battery cells is arranged in a honeycomb structure;

[0190] A cooling start module 302 is used to obtain the current temperature of each of the battery cells in real time, and when there is a first battery cell whose current temperature is greater than a temperature threshold, start the cooling system and determine the corresponding power;

[0191] The first coolant module 303 is used to determine the initial coolant flow rate to be released according to the coolant inlet temperature and the coolant outlet temperature;

[0192] A first cooling module 304 is used to determine the volume of the fire extinguishing agent to be released according to the current temperature and critical temperature of the first battery unit, and release the corresponding coolant and fire extinguishing agent in combination with the initial coolant flow rate to cool the first battery unit;

[0193] A second coolant module 305 is used to determine an adjusted coolant flow rate according to the temperature threshold, the real-time temperature difference inside the first battery unit, and the initial coolant flow rate during a cooling operation;

[0194] The second cooling module 306 is used to continue cooling the first battery unit according to the volume of the fire extinguishing agent and the adjusted coolant flow rate, so as to suppress thermal runaway of the first battery unit.

[0195] See also Figure 4 , Figure 4 Schematic diagram of an electronic device provided by an embodiment of the present invention. Figure 4As shown, an embodiment of the present invention provides an electronic device 400, including a memory 410, a processor 420, and a computer program 411 stored in the memory 410 and executable on the processor 420. When the processor 420 executes the computer program 411, the following steps are implemented:

[0196] Divide the lithium battery of the energy storage system into a plurality of battery cells, and arrange heat conducting plates and heat insulating layers between different battery cells; wherein each of the battery cells is arranged in a honeycomb structure;

[0197] Acquire the current temperature of each of the battery cells in real time, and when there is a first battery cell whose current temperature is greater than a temperature threshold, start the cooling system and determine the corresponding power;

[0198] Determine the initial coolant flow rate to be released according to the coolant inlet temperature and the coolant outlet temperature;

[0199] Determine the volume of the fire extinguishing agent to be released according to the current temperature and critical temperature of the first battery unit, and release the corresponding coolant and fire extinguishing agent in combination with the initial coolant flow rate to cool the first battery unit;

[0200] In a cooling operation, determining an adjusted coolant flow rate according to the temperature threshold, the real-time temperature difference inside the first battery unit, and the initial coolant flow rate;

[0201] The first battery cell continues to be cooled according to the volume of the fire extinguishing agent and the adjusted coolant flow rate, so as to suppress thermal runaway of the first battery cell.

[0202] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0203] Those skilled in the art will appreciate that embodiments of the present invention may provide methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects.

Claims

1. A method for suppressing thermal runaway of a lithium battery in an energy storage system, characterized in that: The method comprises: Divide the lithium battery of the energy storage system into a plurality of battery cells, and arrange heat conducting plates and heat insulating layers between different battery cells; wherein each of the battery cells is arranged in a honeycomb structure; The current temperature of each battery cell is obtained in real time. When there is a first battery cell whose current temperature is greater than a temperature threshold, the cooling system is turned on and the corresponding power is determined, including: obtaining a first constant for adjusting the efficiency of the cooling system; calculating a first difference between the current temperature of the first battery cell and the temperature threshold, and a first quotient between the current temperature and the temperature threshold; determining the power of the cooling system according to the first constant, the first difference and the first quotient; the power of the cooling system is expressed as: Among them, P cool is the power of the cooling system, i is the number of the battery cell, T i is the current temperature of the ith battery cell, T max is the temperature threshold, k cool is the first constant of the cooling system, γ is the exponential coefficient; According to the coolant inlet temperature and the coolant outlet temperature, the initial coolant flow rate to be released is determined; the initial coolant flow rate is expressed as: Where Q is the initial coolant flow rate, T in is the coolant inlet temperature, T out is the coolant outlet temperature, ΔT is the coolant inlet and outlet temperature difference, Δt is the time interval, m is the coolant mass, c p is the specific heat capacity of the coolant, α is the first correction coefficient; Determine the volume of the fire extinguishing agent to be released according to the current temperature and critical temperature of the first battery unit, and release the corresponding coolant and fire extinguishing agent in combination with the initial coolant flow rate to cool the first battery unit; In the cooling operation, the adjusted coolant flow rate is determined according to the temperature threshold, the real-time temperature difference inside the first battery unit, and the initial coolant flow rate; the adjusted coolant flow rate is expressed as: Among them, Q adjusted is the adjusted coolant flow rate, Q initial is the initial coolant flow rate, ΔT real-time is the real-time temperature difference, τ is the third correction coefficient; The first battery cell continues to be cooled according to the volume of the fire extinguishing agent and the adjusted coolant flow rate, so as to suppress thermal runaway of the first battery cell.

2. The method for suppressing thermal runaway of a lithium battery in an energy storage system according to claim 1, characterized in that: Before the heat conducting plates are arranged between different battery cells, the method further comprises: Obtain multiple candidate heat conducting plates; Determine a first amount of heat transferred per unit time by each of the candidate heat conducting plates; A candidate heat conducting plate whose first heat quantity satisfies the heat threshold is determined as the heat conducting plate to be set.

3. The method for suppressing thermal runaway of a lithium battery in an energy storage system according to claim 2, characterized in that: The first heat is expressed as: Wherein, q is the first heat, k is the thermal conductivity, A is the area of ​​the heat conducting plate, dT is the temperature difference, dx is the distance in the thickness direction of the heat conducting plate, β is the second correction coefficient, and L is the length of the heat conducting path.

4. The method for suppressing thermal runaway of a lithium battery in an energy storage system according to claim 1, characterized in that: The volume of the fire extinguishing agent is expressed as: Among them, V release is the volume of extinguishing agent released, k release is the release coefficient, T i is the current temperature of the ith battery cell, T critical is the critical temperature, and γ is the exponential coefficient.

5. The method for suppressing thermal runaway of a lithium battery in an energy storage system according to any one of claims 1 to 4, characterized in that: The method further comprises: Acquiring material data, temperature data, and environmental data of the first battery cell; constructing a heat conduction model based on the material data, the temperature data and the environment data; Optimizing the initial coolant flow rate and the power of the cooling system based on the temperature gradient output by the heat conduction model; The temperature gradient output by the heat conduction model is expressed as: in, is the temperature gradient output by the temperature conduction model, a is the thermal diffusion coefficient, β is the second correction coefficient, T is the temperature, t is the time, is the Laplace operator of temperature.

6. A thermal runaway suppression system for a lithium battery in an energy storage system, used to execute the thermal runaway suppression method for a lithium battery in an energy storage system as described in any one of claims 1 to 5, characterized in that: The system comprises: A structural division module, used to divide the lithium battery of the energy storage system into a plurality of battery cells, and to arrange a heat conducting plate and a heat insulating layer between different battery cells; wherein each of the battery cells is arranged in a honeycomb structure; A cooling start module, used for obtaining the current temperature of each of the battery cells in real time, and when there is a first battery cell whose current temperature is greater than a temperature threshold, starting the cooling system and determining the corresponding power; A first coolant module, used to determine an initial coolant flow rate to be released according to a coolant inlet temperature and a coolant outlet temperature; a first cooling module, configured to determine the volume of the fire extinguishing agent to be released according to the current temperature and the critical temperature of the first battery unit, and release the corresponding coolant and the fire extinguishing agent in combination with the initial coolant flow rate to cool the first battery unit; a second coolant module, used to determine an adjusted coolant flow rate according to the temperature threshold, the real-time temperature difference inside the first battery unit, and the initial coolant flow rate during a cooling operation; The second cooling module is used to continue cooling the first battery cell according to the volume of the fire extinguishing agent and the adjusted coolant flow rate, so as to suppress thermal runaway of the first battery cell.

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